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  • 1.
    Abarkan, Myriam
    et al.
    Univ Bordeaux, France.
    Pirog, Antoine
    Univ Bordeaux, France.
    Mafilaza, Donnie
    Univ Bordeaux, France.
    Pathak, Gaurav
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. MOC, France.
    NKaoua, Gilles
    Univ Bordeaux, France.
    Puginier, Emilie
    Univ Bordeaux, France.
    OConnor, Rodney
    MOC, France.
    Raoux, Matthieu
    Univ Bordeaux, France.
    Donahue, Mary
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. MOC, France.
    Renaud, Sylvie
    Univ Bordeaux, France.
    Lang, Jochen
    Univ Bordeaux, France.
    Vertical Organic Electrochemical Transistors and Electronics for Low Amplitude Micro-Organ Signals2022In: Advanced Science, E-ISSN 2198-3844, Vol. 9, no 8, article id 2105211Article in journal (Refereed)
    Abstract [en]

    Electrical signals are fundamental to key biological events such as brain activity, heartbeat, or vital hormone secretion. Their capture and analysis provide insight into cell or organ physiology and a number of bioelectronic medical devices aim to improve signal acquisition. Organic electrochemical transistors (OECT) have proven their capacity to capture neuronal and cardiac signals with high fidelity and amplification. Vertical PEDOT:PSS-based OECTs (vOECTs) further enhance signal amplification and device density but have not been characterized in biological applications. An electronic board with individually tuneable transistor biases overcomes fabrication induced heterogeneity in device metrics and allows quantitative biological experiments. Careful exploration of vOECT electric parameters defines voltage biases compatible with reliable transistor function in biological experiments and provides useful maximal transconductance values without influencing cellular signal generation or propagation. This permits successful application in monitoring micro-organs of prime importance in diabetes, the endocrine pancreatic islets, which are known for their far smaller signal amplitudes as compared to neurons or heart cells. Moreover, vOECTs capture their single-cell action potentials and multicellular slow potentials reflecting micro-organ organizations as well as their modulation by the physiological stimulator glucose. This opens the possibility to use OECTs in new biomedical fields well beyond their classical applications.

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  • 2.
    Abdullaeva, Oliya
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Sahalianov, Ihor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Silverå Ejneby, Malin
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jakesova, Marie
    Brno Univ Technol, Czech Republic.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Liin, Sara
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Glowacki, Eric
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Brno Univ Technol, Czech Republic.
    Faradaic Pixels for Precise Hydrogen Peroxide Delivery to Control M-Type Voltage-Gated Potassium Channels2022In: Advanced Science, E-ISSN 2198-3844, Vol. 9, no 3, article id 2103132Article in journal (Refereed)
    Abstract [en]

    H2O2 plays a significant role in a range of physiological processes where it performs vital tasks in redox signaling. The sensitivity of many biological pathways to H2O2 opens up a unique direction in the development of bioelectronics devices to control levels of reactive-oxygen species (ROS). Here a microfabricated ROS modulation device that relies on controlled faradaic reactions is presented. A concentric pixel arrangement of a peroxide-evolving cathode surrounded by an anode ring which decomposes the peroxide, resulting in localized peroxide delivery is reported. The conducting polymer (poly(3,4-ethylenedioxythiophene) (PEDOT), is exploited as the cathode. PEDOT selectively catalyzes the oxygen reduction reaction resulting in the production of hydrogen peroxide (H2O2). Using electrochemical and optical assays, combined with modeling, the performance of the devices is benchmarked. The concentric pixels generate tunable gradients of peroxide and oxygen concentrations. The faradaic devices are prototyped by modulating human H2O2-sensitive Kv7.2/7.3 (M-type) channels expressed in a single-cell model (Xenopus laevis oocytes). The Kv7 ion channel family is responsible for regulating neuronal excitability in the heart, brain, and smooth muscles, making it an ideal platform for faradaic ROS stimulation. The results demonstrate the potential of PEDOT to act as an H2O2 delivery system, paving the way to ROS-based organic bioelectronics.

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  • 3.
    Abolhasani, Hasanali
    et al.
    Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran.
    Farzi, Gholamali
    Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran.
    Davoodi, Ali
    Materials and Metallurgical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad 917751111, Iran.
    Vakili-Azghandi, Mojtaba
    Department of Materials Engineering, Faculty of Engineering, University of Gonabad, Gonabad, 96919-57678, Iran.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Neisiany, Rasoul Esmaeely
    Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran.
    Development of self-healable acrylic water-based environmental-friendly coating as an alternative to chromates coatings2023In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 176, article id 107402Article in journal (Refereed)
    Abstract [en]

    In this study, different coating systems, including solvent-based epoxy and water-based acrylic resins, were evaluated for their potential as an alternative to chromate coatings in order to avoid Cr(VI) toxic hazards. The resins were used as either pigment-free coatings or were formulated with 20-wt% zinc/aluminum pigments. The coatings were subsequently applied on galvanized ST12 steel plates and their corrosion resistance was investigated by electrochemical impedance spectroscopy (EIS) evaluations. The effect of the binder and pigment type on the impact resistance of two different polymeric coatings was also evaluated. The results of impact tests revealed completely peeled film from the substrate for epoxy coatings. However, under the same experimental conditions, very few small cracks were created in water-based acrylic coatings for both pigmented and pigment-free cases. In addition, some other parameters such as drying time and coating cost were taken into account to select a good alternative to chromate coatings. The results of this work can facilitate the introduction of an inexpensive environmentally friendly acrylic coating as a promising self-healing alternative to chromate coating.

  • 4.
    Acevedo Gomez, Yasna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    On Gas Contaminants, and Bipolar Plates in Proton Exchange Membrane Fuel Cells2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The proton exchange membrane (PEM) fuel cell is an electrochemical device that converts chemical energy into electrical energy through two electrocatalytic reactions. The most common catalyst used is platinum on carbon (Pt/C), which has shown the best performance in the fuel cell until now. However, the drawback of this catalyst is that it does not tolerate impurities, and both hydrogen and oxygen may carry small amounts of impurities depending on the production sources. The purpose of this thesis is to understand the effect of two impurities that are less investigated, i.e., ammonia, which may accompany the hydrogen rich reformates from renewable sources, and nitrogen dioxide, which may come from air pollution. The mechanism of contamination and an adequate recovery method for the respective contaminant are studied. Additionally, electroplated bipolar plates with Ni-Mo and Ni-Mo-P coatings were tested as alternatives to stainless steel and carbon materials.

    The results show that ammonia not only provokes changes in the polymer membrane but also in the oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR) and catalyst ionomer in both electrodes. The extent of performance recovery after the contamination depends on the concentration used and the exposure time. In contrast, nitrogen dioxide affects the catalyst in the electrode directly; the contamination is related to side reactions that are produced on the catalyst’s surface. However, NO2 is not attached strongly to the catalyst and it is possible to restore the performance by using clean air. The time the recovery process takes depends on the potential applied and the air flow.

    Finally, the evaluation of electroplated Ni-Mo and Ni-Mo-P on stainless steel by ex situ and in situ studies shows that these coatings reduce the internal contact resistance (ICR) and the corrosion rate of the stainless steel considerably. However, the in situ experiments show that phosphorus addition to the coating does not improve the fuel cell performance; thus, the Ni-Mo alloy is found to be a promising choice for electroplating stainless steel bipolar plates.

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  • 5.
    Acevedo Gomez, Yasna
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Effect of nitrogen dioxide impurities on PEM fuel cell performanceManuscript (preprint) (Other academic)
    Abstract [en]

    Air is the most practical and economical oxidant to feed to the cathode in a proton exchange membrane fuel cell (PEMFC). However, the air is accompanied by small amounts of impurities that affect the performance of the fuel cell. Among these, nitrogen dioxide is the impurity that has been least investigated, and its effect is not fully understood. In this study, a possible mechanism is proposed based on the contamination of the fuel cell at different concentrations and adsorption potentials, and by employing stripping cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The results at different concentrations showed that the catalyst sites are blocked by the adsorption of NO2, and that there is a non-linear relationship between the concentration and degradation. The degradation is suggested to be related to the formation of intermediate species, as also shown by the pseudo-inductive impedance at the concentration of 100 and 200 ppm. Furthermore, the cyclic voltammetry showed that there is an oxidation to NO3- at 1.05 V, followed by the reduction of this specie to NO2- at 0.68 V, and a subsequent reduction of NO2- to N2O and/or NH2OH.

  • 6.
    Acevedo Gomez, Yasna
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Performance recovery after contamination with nitrogen dioxide in a PEM fuel cellManuscript (preprint) (Other academic)
    Abstract [en]

    While the market of fuel cell vehicles is increasing, these vehicles will still coexist with combustion engine vehicles on the roads and will be exposed to an environment with significant amounts of contaminants that will decrease the durability of the fuel cell. In order to investigate different recovery methods, a PEM fuel cell is in this study contaminated with 100 ppm of NO2 at the cathode side. The possibility to recover the cell performance is studied by using different airflow rates, different current densities, and by subjecting the cell to successive polarization curves. The results show that the successive polarization curves are the best choice for recovery; it took 35 min to reach full recovery of cell performance, compared to 4.5 hours of recovery with pure air at 0.5 A cm-2 and 110 ml min-1. However, the performance recovery at a current density of 0.2 A cm-2 and air flow 275 ml min-1 was done in 66 min, which is also a possible alternative. Additionally, two operation techniques are suggested and compared during 7 h of operation; air recovery and air depletion. The air recovery technique shows to be a better choice than the air depletion technique.

  • 7.
    Acevedo Gomez, Yasna
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Performance Recovery after Contamination with Nitrogen Dioxide in a PEM Fuel Cell2020In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 25, no 5, article id 1115Article in journal (Refereed)
    Abstract [en]

    While the market for fuel cell vehicles is increasing, these vehicles will still coexist with combustion engine vehicles on the roads and will be exposed to an environment with significant amounts of contaminants that will decrease the durability of the fuel cell. To investigate different recovery methods, in this study, a PEM fuel cell was contaminated with 100 ppm of NO2 at the cathode side. The possibility to recover the cell performance was studied by using different airflow rates, different current densities, and by subjecting the cell to successive polarization curves. The results show that the successive polarization curves are the best choice for recovery; it took 35 min to reach full recovery of cell performance, compared to 4.5 h of recovery with pure air at 0.5 A cm(-2) and 110 mL min(-1). However, the performance recovery at a current density of 0.2 A cm(-2) and air flow 275 mL min(-1) was done in 66 min, which is also a possible alternative. Additionally, two operation techniques were suggested and compared during 7 h of operation: air recovery and air depletion. The air recovery technique was shown to be a better choice than the air depletion technique.

  • 8.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Group of Forest Products2018In: Presented at Symposium "Perspectives in Renewables", 4-5 June 2018, BOKU Vienna, Austria, 2018Conference paper (Other academic)
  • 9.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Utilisation of renewable biomass and waste materials in furniture and construction composites2018Conference paper (Other academic)
  • 10.
    Adler, Anneli
    et al.
    Swedish University of Agricultural Sciences.
    Kumaniaev, Ivan
    Stockholm University.
    Karacic, Almir
    Swedish University of Agricultural Sciences.
    Baddigam, Kiran Reddy
    Stockholm University.
    Hanes, Rebecca J.
    Strategic Energy Analysis Center, USA; Center for Bioenergy Innovation, USA.
    Subbotina, Elena
    Stockholm University.
    Bartling, Andrew W.
    Center for Bioenergy Innovation, USA; Catalytic Carbon Transformation and Scale-up Center, USA.
    Huertas-Alonso, Alberto J.
    Stockholm University; University of Castilla-La Mancha, Spain.
    Moreno, Andres
    University of Castilla-La Mancha, Spain.
    Håkansson, Helena
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Mathew, Aji P.
    Stockholm University.
    Beckham, Gregg T.
    Center for Bioenergy Innovation, USA; Renewable Resources and Enabling Sciences Center; USA.
    Samec, Joseph S.M.
    Stockholm University; Chulalongkorn University, Thailand .
    Lignin-first biorefining of Nordic poplar to produce cellulose fibers could displace cotton production on agricultural lands2022In: Joule, E-ISSN 2542-4351, Vol. 6, no 8, p. 1845-1858Article in journal (Refereed)
    Abstract [en]

    Here, we show that lignin-first biorefining of poplar can enable the production of dissolving cellulose pulp that can produce regenerated cellulose, which could substitute cotton. These results in turn indicate that agricultural land dedicated to cotton could be reclaimed for food production by extending poplar plantations to produce textile fibers. Based on climate-adapted poplar clones capable of growth on marginal lands in the Nordic region, we estimate an environmentally sustainable annual biomass production of ∼11 tonnes/ha. At scale, lignin-first biorefining of this poplar could annually generate 2.4 tonnes/ha of dissolving pulp for textiles and 1.1 m3 biofuels. Life cycle assessment indicates that, relative to cotton production, this approach could substantially reduce water consumption and identifies certain areas for further improvement. Overall, this work highlights a new value chain to reduce the environmental footprint of textiles, chemicals, and biofuels while enabling land reclamation and water savings from cotton back to food production.

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  • 11.
    Ahlgren, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry.
    Remediation of diclofenac in a non-sterile bioreactor using the white rot fungus Trametes versicolor2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    From an environmental perspective, it is interesting to assess new methods for efficient removal of drugs from wastewater. The purpose of this project was to assess the possibility of using the white rot fungus Trametes versicolor  to degrade diclofenac in a lab scale bioreactor. Two methods for quantitative analysis of diclofenac were developed, using GC-MS and UHPLC-Q-TOF (C18-column). Both methods were partly validated, with regard to sensitivity, linearity, accuracy and precision, which highlighted the superiority of UHPLC-Q-TOF over GC-MS. Two HILIC columns were also assessed, but proved unsuitable for quantitative analysis of diclofenac under the used conditions. The fungal mycelia were immobilized on plastic carriers in a nutrient solution. In initial E-flask experiments, 10 mg/L diclofenac was added to an active culture and a heat-killed control of T. versicolor . Samples were analyzed, and the results from the active culture indicated a 98% removal of diclofenac after 48 hours. The lab scale bioreactor was used in a semi-continuous mode with the influent containing 10 mg/L diclofenac. Samples were collected from the effluent to monitor the concentration over 7 days. The results showed a decline in concentration to a stable level of approximately 2 mg/L. The initial experiments showed that most of the removal (85%) was due to sorption of diclofenac, but a clear difference was seen between the active and heat-killed culture. It was impossible to conclude from the bioreactor experiment if the observed removal was due to sorption or to a combination of sorption and enzymatic remediation.

  • 12.
    Ahlström, Peter
    et al.
    University of Borås, School of Engineering.
    Aim, Karel
    Dohrn, Ralf
    Elliott, J Richard
    Jackson, George
    Jaubert, Jean Noël
    Rebello de A. Macedo, Maria Eugénia
    Pokki, Juha-Pekka
    Reczey, Kati
    Victorov, Alexey
    Fele Zilnik, Ljudmila
    Economou, Ioannis
    A Survey of the Role of Thermodynamics and Transport Properties in ChE University Education in Europe and the USA2010In: Chemical Engineering Education, ISSN 0009-2479, Vol. 44, no 1, p. 35-43Article in journal (Refereed)
    Abstract [en]

    Thermodynamics and Transport Properties (TTP) is a central subject in the majority of chemical engineering curricula worldwide and it is thus of interest to know how it is taught today in various countries if chemical engineering education is to be improved. A survey of graduate thermodynamics education in the USA was performed a few years ago by Visco et al. [1] but as far as we know no systematic study of the undergraduate thermodynamics education has been performed, at least in recent years. In the present study, a survey about TTP education in Europe and the USA is presented. Results were obtained from nearly twenty different European countries and the USA and in total answers from about 150 universities were used for this study. The study is performed under the auspices of the Working Party of Thermodynamics and Transport Properties of the European Federation of Chemical Engineering. The survey was performed using a web based surveying system for which invitations were sent out to the universities by local representatives who were responsible for one or more countries each. Of the universities that answered more than 70 % offer BSc education 65 % offer MSc education and 55 % offer PhD education. Most universities offer at least two courses of thermodynamics. The following discussion is mainly based on the first two (undergraduate) courses reported. Half of these are taught to chemical engineers exclusively whereas the rest are taught with other branches of engineering, mainly mechanical and / or process engineering. In general two sets of course lengths were observed, corresponding either to a full semester of full time studies or to quarter of a semester. Most courses are centered around lectures and exercise classes with little or no laboratory work whereas home assignments are given in the vast majority (70-80 %) of the courses. The first course is mainly centered around the first and second law of thermodynamics whereas the second course is frequently more concentrated on phase equilibria. Both of these courses are mainly comprising of classical thermodynamics whereas the molecular interpretation often is touched upon. An analysis of the differences between thermodynamics education in Europe and the USA in presently being undertaken and results from this will also be presented. An investigation of the use of thermodynamics within industry is also on-going within the Working Party and results will be reported in the near future. [1] S.K.Dube, D.P. Visco, Chem. Eng. Ed., 2005, 258-263.

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  • 13.
    Ahlström, Peter
    et al.
    University of Borås, School of Engineering.
    Moodley, Suren
    University of Borås, School of Engineering.
    Bolton, Kim
    University of Borås, School of Engineering.
    Ramjugernath, D.
    University of Borås, School of Engineering.
    Computer Simulations of Vapor-Liquid-Liquid Equilibria Involving Hydrocarbons and Water2008In: Proceedings of the 100th Annual Meeting of the American Institute for Chemical Engineering, 2008, CHPC National Meeting, Durban, South Africa, December 9-10, 2008, AlChe Annual Meeting, Philadelphia, November 15-21, 2008, 2008Conference paper (Other academic)
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  • 14.
    Ahlén Norberg, Evelina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Influence of current harmonics on the degradation of the catalyst coated membrane in PEMFC2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The marine shipping industry is dominated by fossil fuel driven propulsion. Electrification of marine vessels is one of the main strategies to enable emission-free propulsion. Hydrogen is an excellent energy carrier to meet the power demand of a marine vessel. Proton exchange membrane fuel cells (PEMFC) is a commercially available alternative for converting hydrogen into electricity. However, durability issues of the PEMFC is a constraint with the technology which limits technical lifetime. Research around ripple currents impact on degradation of PEMFC is scarce and the reported results are ambiguous and lack clear correlation between the effects of the ripple current on the lifetime of a PEMFC.

    This master thesis evaluates the impact on degradation of a single cell PEMFC by imposing a sinusoidal (70 Hz, 50 % amplitude) AC ripple to a dynamic load cycle. The dynamic load cycle is designed to simulate typical operating conditions of a marine vessel. Constant load cycling at 0.4 A/cm2 with the same ripple characteristics was also conducted to verify the dynamic load cycling impact on the performance losses of the PEMFC.

    The in-situ characterization showed performance losses both during the dynamic and constant load cycling, for the ripple current and reference tests. To conclude, no significant effects on degradation by the sinusoidal ripple current of 70 Hz and 50% amplitude is found when applied to a single cell PEMFC despite of performance losses for all cases.

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  • 15.
    Ahmad, Waqar
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Sultan Qaboos Univ, Oman.
    Vakilinejad, Ali
    Sultan Qaboos Univ, Oman;Univ Tehran, Iran.
    Aman, Zachary M.
    Univ Western Australia, Australia.
    Vakili-Nezhaad, G. Reza
    Sultan Qaboos Univ, Oman.
    Thermophysical Study of Binary Systems of tert-Amyl Methyl Ether with n-Hexane and m-Xylene2019In: Journal of Chemical and Engineering Data, ISSN 0021-9568, E-ISSN 1520-5134, Vol. 64, no 2, p. 459-470Article in journal (Refereed)
    Abstract [en]

    This work presents the experimentally determined density (rho), viscosity (eta), speed of sound (u), and surface tension (sigma) data for tert-amyl methyl ether (TAME) + n-hexane and TAME + m-xylene systems at several temperatures (298.15, 308.15, 318.15, 323.15, and 328.15 K). These experimentally determined thermophysical data are utilized to compute various excess/deviation parameters such as molar volume (V-E), isentropic compressibility (K-s(E)), speed of sound (u(E)), deviation in viscosity (Delta In eta), isobaric thermal expansion coefficient (alpha(E)(P)), and surface tension (sigma(E)). The inspection of parameters response may interpret the existing specific molecular interactions as well as the mixing behavior of solutions. The critical analysis of observed parametric behavior have unveiled the strong and weak molecular interactions in TAME with m-xylene and TAME with n-hexane systems, respectively.

  • 16.
    Ahmed, Md Estak
    et al.
    Indian Assoc Cultivat Sci, Sch Chem Sci, Kolkata 700032, India..
    Nayek, Abhijit
    Indian Assoc Cultivat Sci, Sch Chem Sci, Kolkata 700032, India..
    Krizan, Alenka
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Coutard, Nathan
    Univ Grenoble Alpes, Lab Chim & Biol Metaux, IRIG, CEA,CNRS, F-38000 Grenoble, France..
    Morozan, Adina
    Univ Grenoble Alpes, Lab Chim & Biol Metaux, IRIG, CEA,CNRS, F-38000 Grenoble, France..
    Dey, Somdatta Ghosh
    Indian Assoc Cultivat Sci, Sch Chem Sci, Kolkata 700032, India..
    Lomoth, Reiner
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Artero, Vincent
    Univ Grenoble Alpes, Lab Chim & Biol Metaux, IRIG, CEA,CNRS, F-38000 Grenoble, France..
    Dey, Abhishek
    Indian Assoc Cultivat Sci, Sch Chem Sci, Kolkata 700032, India..
    A Bidirectional Bioinspired [FeFe]-Hydrogenase Model2022In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 144, no 8, p. 3614-3625Article in journal (Refereed)
    Abstract [en]

    With the price-competitiveness of solar and wind power, hydrogen technologies may be game changers for a cleaner, defossilized, and sustainable energy future. H-2 can indeed be produced in electrolyzers from water, stored for long periods, and converted back into power, on demand, in fuel cells. The feasibility of the latter process critically depends on the discovery of cheap and efficient catalysts able to replace platinum group metals at the anode and cathode of fuel cells. Bioinspiration can be key for designing such alternative catalysts. Here we show that a novel class of iron-based catalysts inspired from the active site of [FeFe]-hydrogenase behave as unprecedented bidirectional electrocatalysts for interconverting H-2 and protons efficiently under near-neutral aqueous conditions. Such bioinspired catalysts have been implemented at the anode of a functional membrane-less H-2/O-2 fuel cell device.

  • 17.
    Ahmed, Naeem
    et al.
    Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor, Malaysia.
    Shahid, Muhammad
    Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor, Malaysia.
    Siow, Kim S
    Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor, Malaysia.
    Razip Wee, M F Mohd
    Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor, Malaysia.
    Haron, Farah Farhanah
    Pest and Disease Management Programme, Horticulture Research Centre, Malaysian Agricultural Research and Development Institute, Serdang 43400, Selangor, Malaysia.
    Patra, Anuttam
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Fazry, Shazrul
    Department of Food Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor, Malaysia.
    Germination and growth improvement of papaya utilizing oxygen (O2) plasma treatment2022In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 55, no 25, article id 255205Article in journal (Refereed)
    Abstract [en]

    In general, cold plasma treatment improves crop germination and growth. The purpose of this research is to examine the impact of low-pressure O2 plasma treatment on the germination and growth kinetics of papaya seeds. Seeds were treated for 40 s at a discharge power of 80 W using O2 as a monomer. Physical and chemical changes were studied to understand the mechanism of germination and growth improvement. Furthermore, changes in phytohormones and antioxidant activity that were beneficial to germination were also examined. O2 plasma treatment improved wettability, surface etching, and oxidation, and affected other molecular-level changes leading to a 16% germination improvement in papaya.

  • 18.
    Akhand, Victoria
    KTH, School of Chemical Science and Engineering (CHE).
    Mass Balance Model of Impurities for the WoodRoll Process2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The depletion time for fossil fuels calculated from 2009 is 35 years for oil, 37 years for gas

    and 107 years for coal. Hence, it has become essential to reduce the dependence on fossil

    fuels by switching over to renewable resources. This in turn will also help in combating the

    negative effects on the environment like global warming. Thermochemical processes such as

    pyrolysis and gasification of biomass are considered the most efficient technology for

    converting biomass to useful energy carriers. Cortus Energy AB is a Swedish company that

    has developed a patented gasification technology called WoodRoll

    ® for gasification of fuels derived from biomass. However, ash in a thermochemical conversion process can cause

    corrosion, sintering, slag and poisoning of catalysts, which leads to operational problems. In

    addition, heavy metals such as Zn, Pb and Cd are environmentally problematic. These metals

    contribute to environmental pollution by contaminating the soil, which in turn can harm

    humans and the ecosystem via the food chain. The undesired elements should therefore be

    identified to minimize their impact on the overall thermochemical process and to reduce the

    emission of these harmful substances.

    The objective of this master thesis project, on behalf of Cortus Energy AB, was to investigate

    possible key numbers that can be used to describe and predict how the ash behaves in their

    patented WoodRoll® process. The key numbers that have been identified are empirically

    developed based on experience of coal combustion. These key numbers are regularly used for

    fuel derived from biomass by companies specializing in analyzing, although knowledge about

    whether they can actually be used on biomass is limited. In order to ensure that the use of

    these for biomass is correct, they must be experimentally verified in the future. In addition, a

    theoretical investigation is conducted to study which species can form and in what phase this

    occurs. The investigation reveals that there are no clear trends for how the inorganic elements

    behave since contradicting results from different studies have been reported. Formation of

    species and their phase depends on several parameters such as temperature, heating rate,

    particle size, volatility, quantity and interaction between the elements in the biomass. The

    thesis project ends with a mass balance model on selected inorganic elements for wood

    residues, as well as for bark. The model could be a tool for Cortus Energy AB to identify

    approximately how much of each element is present in each stream in the WoodRoll® process.

    The models are verified with analysis results. Inorganic elements that affect the

    overall process and its equipment have been selected for modelling. The volume percent of

    H2, CO, CO2 and CH4 in the models agree well with the values obtained by Cortus Energy

    AB. This shows that the thermodynamic equilibrium calculations performed are reasonable.

  • 19.
    Albaqami, Munirah D.
    et al.
    King Saud Univ, Saudi Arabia.
    Medany, Shymaa S.
    Cairo Univ, Egypt.
    Nafady, Ayman
    King Saud Univ, Saudi Arabia.
    Ibupoto, Mazhar Hussain
    Shah Abdul Latif Univ, Pakistan.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics. Linköping University, Faculty of Science & Engineering.
    Tahira, Aneela
    Univ Sindh, Pakistan.
    Aftab, Umair
    Mehran Univ Engn & Technol, Pakistan.
    Vigolo, Brigitte
    Univ Lorraine, France.
    Ibupoto, Zafar Hussain
    Univ Sindh, Pakistan.
    The fast nucleation/growth of Co3O4 nanowires on cotton silk: the facile development of a potentiometric uric acid biosensor2022In: RSC Advances, E-ISSN 2046-2069, Vol. 12, no 29, p. 18321-18332Article in journal (Refereed)
    Abstract [en]

    In this study, we have used cotton silk as a source of abundant hydroxyl groups for the fast nucleation/growth of cobalt oxide (Co3O4) nanowires via a hydrothermal method. The crystal planes of the Co3O4 nanowires well matched the cubic phase. The as-synthesized Co3O4 nanowires mainly contained cobalt and oxygen elements and were found to be highly sensitive towards uric acid in 0.01 M phosphate buffer solution at pH 7.4. Importantly, the Co3O4 nanowires exhibited a large surface area, which was heavily utilized during the immobilization of the enzyme uricase via a physical adsorption method. The potentiometric response of the uricase-immobilizing Co3O4 nanowires was measured in the presence of uric acid (UA) against a silver/silver chloride (Ag/AgCl) reference electrode. The newly fabricated uric acid biosensor possessed a low limit of detection of 1.0 +/- 0.2 nM with a wide linear range of 5 nM to 10 mM and sensitivity of 30.6 mV dec(-1). Additionally, several related parameters of the developed uric acid biosensor were investigated, such as the repeatability, reproducibility, storage stability, selectivity, and dynamic response time, and these were found to be satisfactory. The good performance of the Co3O4 nanowires was verified based on the fast charge-transfer kinetics, as confirmed via electrochemical impedance spectroscopy. The successful practical use of the uric acid biosensor was demonstrated based on the recovery method. The observed performance of the uricase-immobilizing Co3O4 nanowires revealed that they could be considered as a promising and alternative tool for the detection of uric acid under both in vitro and in vivo conditions. Also, the use of cotton silk as a source of abundant hydroxyl groups may be considered for the remarkably fast nucleation/growth of other metal-oxide nanostructures, thereby facilitating the fabrication of functional electrochemical devices, such as batteries, water-splitting devices, and supercapacitors.

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  • 20. Aldea, Steliana
    et al.
    Snåre, Mathias
    Eränen, Kari
    Grenman, Henrik
    Rautio, Anne-Riika
    Kordás, Krisztian
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Laboratory of Industrial Chemistry and Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, 20500 Åbo-Turku, Finland.
    Salmi, Tapio
    Murzin, Dmitry Y.
    Crystallization of Nano-Calcium Carbonate: The Influence of Process Parameters2016In: Chemie Ingenieur Technik, ISSN 0009-286X, E-ISSN 1522-2640, Vol. 88, no 11, p. 1609-1616Article in journal (Refereed)
    Abstract [en]

    Precipitated calcium carbonate was synthesized by carbonation of calcium hydroxide in the presence and absence of ultrasound (conventional stirring) at atmospheric as well as at elevated pressures and different initial concentrations of Ca(OH)2. Spherical morphology of the formed calcite was favored at high Ca(OH)2 concentrations and low CO2 pressures. The presence of ultrasound did not show any influence on the reaction rate in case of efficient mixing. A small increase of the reaction rate was observed at lower CO2 pressures. Elevated pressures in combination with ultrasound did not lead to notable changes of reaction rate or particle morphology.

  • 21.
    Alemrajabi, Mahmood
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Transport Phenomena.
    Recovery of Rare Earth Elements from an Apatite Concentrate2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rare earth elements (REE) are a group of 17 elements including lanthanides, yttrium and scandium; which are found in a variety of classes of minerals worldwide. The criticality of the application, lack of high grade and economically feasible REE resources and a monopolistic supply situation has raised significant attention in recovery of these metals from low grade ores and waste materials. In this thesis, the recovery of REE from an apatite concentrate, containing 0.5 mass% of REE, within the nitrophosphate route of fertilizer production has been investigated. Most of the REE (≥ 95%) content can be recovered into a phosphate precipitate with almost 30 mass% REE. Different processes have been developed to convert the REE phosphate precipitate into a more soluble form to obtain a solution suitable for further REE purification and individual separation. It has been shown that after reprecipitation of the REE phosphate concentrate as REE sodium double sulphate and then transformation into a REE hydroxide concentrate, a solution containing 45g/L REE free of Ca, Fe and P can be obtained. The results suggest that the apatite waste after processing of iron ore have the potential to be a very important source for REE in Europe and that the economy is strongly supported by the simultaneous extraction of phosphorous.

    The potential of using hollow fiber supported liquid membrane (HFSLM) extraction in individual and group separation of REE has been investigated. A hollow fiber supported liquid membrane plant in pilot scale has been operated according to the three main configurations: standard hollow fiber supported liquid membrane technology (HFSLM); hollow fiber renewal liquid membrane technology (HFRSLM) and emulsion pertraction technology (EPT). The standard HFSLM operation is more selective than HFRSLM and EPT, while higher metal transport rate is observed in EPT followed by HFRSLM and HFSLM. The HFRLM configuration helps to maintain the performance of the liquid membrane.

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  • 22.
    Ali Soomro, Razium
    et al.
    University of Bristol, England; University of Sindh, Pakistan.
    Richard Hallam, Keith
    University of Bristol, England.
    Hussain Ibupoto, Zafar
    University of Sindh, Pakistan.
    Tahira, Aneela
    University of Sindh, Pakistan.
    Jawaid, Sana
    University of Sindh, Pakistan.
    Tufail Hussain Sherazi, Syed
    University of Sindh, Pakistan.
    Sirajjuddin,
    Univ Sindh, Natl Ctr Excellence Analyt Chem, Jamshoro 76080, Pakistan.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    A highly selective and sensitive electrochemical determination of melamine based on succinic acid functionalized copper oxide nanostructures2015In: RSC Advances, E-ISSN 2046-2069, Vol. 5, no 127, p. 105090-105097Article in journal (Refereed)
    Abstract [en]

    This study presents the development of a highly selective and sensitive electrochemical sensor for the determination of melamine from aqueous environments. The sensor system is based on functionalised marigold-like CuO nanostructures fabricated using a controlled hydrothermal process, where the utilised succinic acid is considered to play a dual role as a functionalising and growth controlling agent (modifier). The fabricated nanostructures exhibit sharp and well-ordered structural features with dimensions (thickness) in the range of 10-50 nm. The sensor system exhibits strong linearity within the concentration range of 0.1 x 10(-9) to 5.6 x 10(-9) M and demonstrates an excellent limit of detection up to 0.1 x 10(-10) M. The extreme selectivity and sensing capability of the developed sensor is attributed to the synergy of selective interaction between succinic acid and melamine moieties, and the high surface area of marigold-like CuO nanostructures. In addition to this, the developed sensor was also utilised for the determination of melamine from real milk samples collected from different regions of Hyderabad, Pakistan. The obtained excellent recoveries proved the feasibility of the sensor for real life applications. The sensor system offers an operative measure for detecting extremely low melamine content with high selectivity in food contents.

  • 23.
    Alshogran, Forat
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Fabrication of battery separator by coating with sulfonated cellulose nanofibrils on kraft paper and inkjet paper substrates: Tillverkning av batteriseparator genom bestrykning med sulfonerad cellulosananofibriller på kraft papper och bläckstråle papper substrat2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Modified nanocellulose have distinctive qualities and have drawn a lot of interest from a variety of fields. It is a natural, sustainable product that is manufactured from plant-based materials like wood and other renewable resources. It is also biodegradable. It is a possible material for battery separators because of its great mechanical strength, flexibility, and ability to create a stable and consistent membrane. Due to the cost of using it as a membrane, it has been investigated in this work to see if it can be coated onto a substrate and used as battery separator. In this work sulfonated cellulose nanofibrils (SCNF) has been used to be coated on kraft paper and inkjet paper using a rod coater. Parameters like concentration, thickness and substrates have been varied in this experiment. Viscosity was measured using Brookfield instrument to measure the viscosity for 0,5% SCNF and 1,5% SCNF. The coating was carried out using a rod coater and varying between two rods to influence the thickness, the coating used concentrations of 0,5% SCNF and 1,5% SCNF and two different substrates, kraft paper and inkjet paper. Thickness was determined to study the effect of the variation in rod. The mechanical strength was tested on the coated paper substrates and compared the results to the noncoated substrates as reference, the mechanical strength showed an improvement with the coated SCNF substrates. Permeance through the Gurley method was studied in order to understand how the coated substrates behaves compared to the noncoated. Contact angle was determined as well to understand the wettability of the coated substrates and how they would behave as separators in zinc ion batteries. The contact angle decreased with increasing concentration of the SCNF which is a result of the sulfonate groups. Cross sections were analyzed using SEM to study the influence of the coating to the substrates. Ionic conductivity was also tested to evaluate the possibility of the coated substrates as separators.

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  • 24.
    Altaee, Mohammed J.
    et al.
    Environmental Research and Studies Centre, University of Babylon, Hilla, Iraq.
    Altayee, Sarmed A. S.
    Department of Chemical Engineering, College of Engineering, University of Babylon, Hilla 51001, Iraq.
    Kadhim, Majid M. A.
    Department of Civil Engineering, College of Engineering, University of Babylon, Hilla 51001, Iraq.
    Jawdhari, Akram
    Department of Civil Engineering, Queen’s University, Kingston, Canada.
    Majdi, Ali
    Building and Construction Techniques Engineering, Al-Mustaqbal University College, 51001, Babylon, Iraq.
    Chabuk, Ali
    Department of Environment Engineering, College of Engineering, University of Babylon, Hilla 51001, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Evaluation of Existing Bond-Slip Relations for CFRP-Steel Joints and New Model for Linear and Nonlinear Adhesives2022In: Advances in Civil Engineering / Hindawi, ISSN 1687-8086, E-ISSN 1687-8094, Vol. 2022, article id 3673438Article in journal (Refereed)
    Abstract [en]

    Existing bond-slip (τ-s) relations for fibre-reinforced polymer (FRP)-steel joints employ different shapes and mathematical expressions, inferring that their predictions of failure load and mode, and other interface properties, might be inconsistent or inaccurate. In this study, predictions of four widely used τ-s relations are evaluated using a large experimental database of 78 double-lap FRP-steel specimens. To facilitate the evaluation process, a robust finite element (FE) model is developed for each test, implementing data from either of the existing τ-s relations to define the FRP-steel interface. Comparisons between test and FE results indicated that the existing τ-s models were unable of predicting the ultimate load (Pu) and effective bond length (Leff) of FRP-steel joints, or the relation between Pu and bond length and that between Leff and FRP modulus (Ef). A new τ-s model is developed based on an inverse FE simulation, comparison with experimental results, and regression analysis. It considers the effects of Ef, the type of FRP reinforcement (sheet or plate), and applies to both linear and nonlinear adhesives. The model predictions were validated by comparing with results from small bond tests and large FRP-strengthened steel beams tested under bending, yielding excellent results for Pu, failure mode, and all other interfacial properties.

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  • 25.
    Alvarado Ávila, María Isabel
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics. KTH, School of Biotechnology (BIO), Centres, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Toledo-Carrillo, Esteban Alejandro
    KTH, School of Biotechnology (BIO), Centres, Albanova VinnExcellence Center for Protein Technology, ProNova. KTH, School of Engineering Sciences (SCI), Applied Physics.
    Dutta, Joydeep
    KTH, School of Engineering Sciences (SCI), Applied Physics, Materials and Nanophysics. KTH, School of Biotechnology (BIO), Centres, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Improved chlorate production with platinum nanoparticles deposited on fluorinated activated carbon cloth electrodes2020In: Cleaner Engineering and Technology, ISSN 2666-7908, Vol. 1, article id 100016Article in journal (Refereed)
    Abstract [en]

    Sodium chlorate is one of the main oxidizing agents used in the wood industry due to their capability of use as an elemental chlorine-free (CEF) bleaching. A simple way to produce chlorates is by the electrolysis of an aqueous sodium chloride (NaCl) solution. In the present study activated carbon cloth electrodes (ACC) modified with fluorine and platinum nanoparticles (Pt–F/ACC and Pt/ACC) were used as one of the electrodes. Electrofluorination was used for fluorination of the anodes and polyol method was used for the synthesis of platinum nanoparticles. Chlorate production using a typical solution of 100 ​g/l of sodium chloride (NaCl) and 2 ​g/l sodium chromate (Na2Cr2O7) and an applied current of 0.540 ​A was studied. Prior to the electrolysis assays, the microstructural properties of the electrodes were characterized by scanning electron microscopy and surface modifications and bonding using infra-red (FTIR) spectroscopy. Electrochemical properties were determined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Interaction between fluorine (F) and platinum (Pt) on the electrode leads to an improvement of the electrocatalytic properties for chlorine evolution as observed from the increase in the current efficiency from 37.5% at 78.5% after 150 ​min of continuous electrolysis using Pt–F/ACC anodes. The results suggest that modified activated carbon material is an attractive and economical alternative as electrodes for chlorate production. 

  • 26.
    Amin, Muhammad
    et al.
    Interdisciplinary Research Center for Hydrogen Technologies and Carbon Management (IRC-HTCM), King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia.
    Shah, Hamad Hussain
    Department of Engineering, University of Sannio, Benevento, Italy.
    Naveed, Abdul Basit
    Department of Chemistry, University of Louisville, Louisville, KY, United States.
    Iqbal, Amjad
    Faculty of Materials Engineering, Silesian University of Technology, Gliwice, Poland.
    Gamil, Yaser
    Department of Civil Engineering, School of Engineering, Monash University Malaysia, Subang Jaya, Selangor, Malaysia.
    Najeh, Taoufik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Life cycle assessment of iron-biomass supported catalyst for Fischer Tropsch synthesis2024In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 12, article id 1374739Article in journal (Refereed)
    Abstract [en]

    The iron-based biomass-supported catalyst has been used for Fischer-Tropsch synthesis (FTS). However, there is no study regarding the life cycle assessment (LCA) of biomass-supported iron catalysts published in the literature. This study discusses a biomass-supported iron catalyst’s LCA for the conversion of syngas into a liquid fuel product. The waste biomass is one of the source of activated carbon (AC), and it has been used as a support for the catalyst. The FTS reactions are carried out in the fixed-bed reactor at low or high temperatures. The use of promoters in the preparation of catalysts usually enhances C5+ production. In this study, the collection of precise data from on-site laboratory conditions is of utmost importance to ensure the credibility and validity of the study’s outcomes. The environmental impact assessment modeling was carried out using the OpenLCA 1.10.3 software. The LCA results reveals that the synthesis process of iron-based biomass supported catalyst yields a total impact score in terms of global warming potential (GWP) of 1.235E + 01 kg CO2 equivalent. Within this process, the AC stage contributes 52% to the overall GWP, while the preparation stage for the catalyst precursor contributes 48%. The comprehensive evaluation of the iron-based biomass supported catalyst’s impact score in terms of human toxicity reveals a total score of 1.98E−02 kg 1,4-dichlorobenzene (1,4-DB) equivalent.

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  • 27.
    Andersson Krohn, Robert
    KTH, School of Chemical Science and Engineering (CHE).
    Biomethane via Woodroll® - Investigation of Revenues & Profitability Analysis2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Woodroll® is a gasification technology developed by Cortus that produces synthetic gas (syngas) from biomass. Syngas can be used in several different applications. One interesting option is to convert it further into biomethane, which can be used as automotive fuel or replace natural gas in gas grids. The revenues and profitability of biomethane production is heavily dependent on policy instruments and support schemes. These subsidies can be either direct, where the producer receives a feed-in tariff for biomethane production, or indirect, where consumption rather than production is stimulated.

    This work has investigated which revenues that can be expected from biomethane production via Woodrooll® in Sweden, the Netherlands, Germany, the UK, France and Italy, both in terms of amounts and risks. A profitability analysis have also been carried out to preliminary compare the returns in the different countries, where two different scenarios for different revenues have been analyzed for two different feedstock prices.

    The results showed that the Netherlands and Italy provides the potentially highest revenues. However, there are uncertainty factors associated with all cases. Sweden and Germany offers indirect support and negative market trends. The Netherlands and the UK are the only options that provide a feed-in tariff for biomethane production via gasification. In the Netherlands the tariff can be secured before making investment decision but is only disbursed for 12 years. The UK offers a fixed feed-in tariff for 20 years but the tariff is secured first after plant start-up and the tariff may be reduced on a quarterly basis. In fact, the tariff has been reduced with 40 % over the last 24 months, but there are discussions on introducing a separate tariff for gasification. Italy has the support schemes that potentially offer the highest revenues, but gasification is currently not eligible for support. The latter also holds for France, which may be an interesting case in the future.

    If risk is to be minimized, Cortus may either focus on the Netherlands or await the discussions in the UK and France on introducing a gasification tariff. The work on standardization of biomethane use should also be followed since Italy offers the potentially highest return of the investigated countries. It is also recommended to look further for other cases. The best-case scenario for the risk averse is the one that provides a fixed tariff for 20 years and in which the tariff can be secured before an investment decision is taken.

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  • 28.
    Andersson, Mike
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Puglisi, Donatella
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Recent progress in silicon carbide field effect gas sensors2020In: Semiconductor gas sensors / [ed] Raivo Jaaniso and Ooi Kiang Tan, Oxford: Woodhead Publishing Limited, 2020, 2, p. 309-346Chapter in book (Refereed)
    Abstract [en]

    The introduction of silicon carbide as the semiconductor in gas-sensitive field effect devices has disruptively improved this sensor platform extending the operation temperature to more than 600 °C with an increased number of detectable gases. Here, we review recent progress in research and applications, starting with transducer and detection mechanisms, presenting new material combinations as sensing layers for improved selectivity and detection limits down to subparts per billion. We describe how temperature cycled operation combined with advanced data evaluation enables one sensor to act as a sensor array thereby vastly improving selectivity. Field tests require advanced packaging, which is described, and examples of possible applications like selective detection of ammonia for urea injection control in diesel exhausts and toxic volatile organic compounds for indoor air quality monitoring and control are given.

  • 29.
    Andersson, Rassmus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Silicon-based graphite electrodes for Li-ion batteries2018Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The cycling performance of silicon containing graphite electrodes as the anode in lithium-ion batteries has been investigated. Different electrode compositions of silicon, graphite, carbon black, sodium carboxymethylcellulose (CMC-Na), styrene–butadiene rubber (SBR) and using water as the solvent have been prepared and evaluated electrochemically by constant-current-constant-voltage (CCCV) cycling. To understand the impact on the cycling performance of the electrodes, the process parameters in the coating process have been evaluated by rheological measurements of the electrode slurries.

    The highest and most stable capacity was found for the electrode containing 5 wt% silicon (vs. graphite), 3 wt% binder, equal amount of the binders CMC-Na and SBR and 70 wt% solvent in the initial electrode slurry. It showed a stable capacity retention of 360 mAh/g after 315 cycles, before it faded. It was found that the CMC-Na and the solvent have a strong impact on the properties of the electrode slurry and the processing parameters. CMC-Na, the solvent and SBR were also found to be important for the adhesion of the electrode coating on the current collector. The worst cycling performance was obtained for electrodes containing 15 wt% silicon, a solvent amount below 65 wt% and a binder ratio of CMC-Na:SBR below 1:1. Different rheological behaviour for different silicon particles was found to depend on the surface area of the particles.

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    Report - Rassmus Andersson
  • 30.
    Andersson, Rassmus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hernández, Guiomar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Micro versus Nano: Impact of Particle Size on the Flow Characteristics of Silicon Anode Slurries2020In: ENERGY TECHNOLOGY, ISSN 2194-4288, Vol. 8, no 7, article id 2000056Article in journal (Refereed)
    Abstract [en]

    Silicon is interesting for use as a negative electrode material in Li-ion batteries due to its extremely high gravimetric capacity compared with today's state-of-the-art material, graphite. However, during cycling the Si particles suffer from large volume changes, leading to particle cracking, electrolyte decompositions, and electrode disintegration. Although utilizing nm-sized particles can mitigate some of these issues, it would instead be more cost-effective to incorporate mu m-sized silicon particles in the anode. Herein, it is shown that the size of the Si particles not only influences the electrode cycling properties but also has a decisive impact on the processing characteristics during electrode preparation. In water-based slurries and suspensions containing mu m-Si and nm-Si particles, the smaller particles consistently give higher viscosities and more pronounced viscoelastic properties, particularly at low shear rates. This difference is observed even when the Si particles are present as a minor component in blends with graphite. It is found that the viscosity follows the particle volume fraction divided by the particle radius, suggesting that it is dependent on the surface area concentration of the Si particles.

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  • 31.
    Andersson, Sven
    et al.
    SP.
    Bäfver, Linda
    SP.
    Davidsson, Kent
    SP.
    Pettersson, Jens
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Schmidt, Hans
    SP.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Yngvesson, Johan
    SP.
    Skrubberintegrerat vått elfilter, WESP2012Report (Other academic)
  • 32.
    Anukam, Anthony Ike
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nyamukamba, Pardon
    Technology Station: Clothing and Textiles, Cape Peninsula University of Technology, Symphony Way, Bellville, South Africa.
    The Chemistry of Human Excreta Relevant to Biogas Production: A Review2022In: Anaerobic Biodigesters for Human Waste Treatment / [ed] Mukesh Kumar Meghvansi, A. K. Goel, Springer, 2022, p. 29-38Chapter in book (Other academic)
    Abstract [en]

    As obnoxious as it may sound, studies involving human excreta are of great importance to sanitation, one of the most effective ways by which public health can be improved. The composition of human excreta is highly variable and contains all that enters into the toilet including water, urine, anal cleansing materials, lipids, proteins, polysaccharides, chemical elements, and undigested food residues as well as municipal wastes. A great deal of past and present research has focused on efficient utilization of this waste product of the human digestive system, particularly in biological processes, such as anaerobic digestion, where the waste is used as substrate to produce value-added products like biogas. However, there is very limited data on the chemistry of human excreta and its direct impact on anaerobic digestion process efficiency. This review therefore aims to illustrate the significance of the chemistry of human excreta relevant to biogas production and discuss key criteria and values that will help advance research and development of anaerobic digestion systems using human excreta as a treatment technology.

  • 33.
    Arkhipov, Victor P.
    et al.
    Department of Physics, Kazan National Research Technological University, Kazan 420015, Russian Federation.
    Arkhipov, Ruslan
    Institute of Physics, Kazan Federal University, Kazan 420008, Russian Federation.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rhamnolipid Biosurfactant: Use for the Removal of Phenol from Aqueous Solutions by Micellar Solubilization2023In: ACS Omega, E-ISSN 2470-1343, Vol. 8, no 33, p. 30646-30654Article in journal (Refereed)
    Abstract [en]

    Selective measurements of the self-diffusion coefficients of molecules of the biological surfactant rhamnolipid (RL) in individual aqueous solutions and in solutions with phenol as a solubilizate were carried out by nuclear magnetic resonance (NMR) diffusometry. Based on the obtained results, the solubilization characteristics of RLs were calculated. They are the fraction of solubilized phenol molecules, the phenol micelle-water distribution coefficient, the molar solubilization coefficient, the hydrodynamic radii of RL monomers and micelles, the aggregation numbers of micelles, and the solubilization capacity of micelles. Fraction of the solubilized phenol molecules increases and approaches 80-90% with increasing RL concentration. The solubilization capacity of the micelles increases from several units to 102 with an increase in both the concentration of RLs and the concentration of phenol in solution.

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  • 34.
    Arkhipov, Victor P.
    et al.
    Department of Physics, Kazan National Research Technological University, Kazan, Russian Federation.
    Arkhipov, Ruslan V.
    Institute of Physics, Kazan Federal University, Kazan, Russian Federation.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    The efficiency of micellar solubilization of naphthalene from aqueous solutions using rhamnolipid as a biological surfactant according to NMR diffusometry2024In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458XArticle in journal (Refereed)
    Abstract [en]

    Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd.The micellar solubilization of naphthalene from its saturated aqueous solutions using the biosurfactant rhamnolipid was studied. Using the NMR diffusion method, selective measurements of the self-diffusion coefficients of molecules of all components of the solution—naphthalene, rhamnolipid, and water—were carried out at various rhamnolipid concentrations from 0.06 to 100 g/L. Based on the results of diffusometry, the distribution of naphthalene molecules between the states free in solution and states bound by micelles was found. With an increase in the concentration of rhamnolipids, the proportion of bound naphthalene molecules increases from 50% at CRL = 2 g/L to 100% at CRL ≥ 50 g/L. The micelle-water partition coefficient Km and the molar solubilization ratio MSR were calculated.

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  • 35.
    Arnberg, Gustav
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Implementation of battery energy storage systems in the Swedish electrical infrastructure2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis investigates the technical and economic feasibility of battery energy storage systems (BESS) in the Swedish electrical infrastructure. The aim is to construct three business cases to represent the technical and economic feasibility of BESS implementation in the Swedish electrical infrastructure in the distribution network on the regional level, 6 kilovolts to 132 kilovolts (kV). The business cases address the technical functions and customers within the infrastructure that is recognized through a literature study to build the most attractive and incentivized business cases from. The literature study investigates the Swedish electrical infrastructure’s structure and its existing and upcoming challenges. It investigates the spectrum of energy storage systems (ESS) to justify the choice of the lithium-ion (Li-ion) BESS. The Li-ion BESS is closer examined, where the systems operational parameters and components are mapped out. Furthermore, the technical functions technical requirements and economic incentives are investigated in a market analysis. Lastly, considerations regarding regulations and permits, the placement of BESS within the infrastructure and its surrounding costs is evaluated. The three business cases that are constructed within the thesis are: 

    1. Combination of frequency related grid support services for a standalone BESS asset operator.
    2. Uninterruptable power supply for a data center.
    3. Peak shaving and a combination of frequency related grid support services for an industrial plant. 

    The, Li-ion BESS is considered to most applicable technology due its fast response time, high power and energy density and scalability to suit the majority of technical functions investigated in the thesis. The business cases economic feasibility is evaluated after two economic indicators, the net present value (NPV) and the payback period. Business case two’s technical function offers no possible revenues and is evaluated as a cost for service where the expenses is divided throughout the project lifetime through linear amortization and the cost per saved kg CO2 is calculated over the lifetime of the BESS. Both business case 1 (NPV= 231.0 MSEK, payback period= 7.8 years) and case 3 (NPV=17.3 MSEK, payback period= 8.8 years) show profitability where business case 2 gives a cost per service between 5.4 and 5.8 MSEK/year and cost per saved kg CO2 between 20.9 and 22.7 SEK/kg CO2

    This thesis focuses on the three largest distribution network operators (DNO) in the distribution network on a regional level: Vattenfall, Eon, and Ellevio. The profitability of the business cases investigated are strongly connected to the location in the network, the voltage connection level, and the type of DNO. Being able to connect to an existing substation on site as for business cases 2 and 3 will lower the capital and operational costs and further improve the profitability. Business case 1 needs a thorough assessment of placement in the electrical infrastructure in Sweden to assure profitability. The NPV and payback period in business cases 1 and 3 could conflict with the interchanging frequency regulation market where prices are rather volatile due to new market initiatives. Therefore, looking forward, building a BESS business case to be implemented comes with lots of uncertainties as the economic incentives shows no guarantee to continuously be profitable. The high price of Li-ion batteries is slowing down the attractiveness of the business cases and need to further decrease to promote profitable business cases. Other ESS technologies as flow batteries and hydrogen storage systems show good applicability to be implemented in the Swedish electrical infrastructure but needs to develop its technical and commercial maturity until it can become competitive with Li-ion BESS. 

    The master thesis is performed in conjunction with Omexom Infratek Sverige AB with the aim to contribute to a broader understanding of the role of BESS in the Swedish electrical infrastructure and to help building BESS technical offers for Omexom Infratek Sverige AB.

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  • 36.
    Arrhenius Håkansson, Isabella
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Separation of low concentration WAF by hollow fiber membrane2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The demand for clean and safe water has increased rapidly with increasing industry and population. Where oil contamination from transport has become an increasing problem and the deteriorating quality of the surface water. Therefore, new techniques to clean and ensure potable water has been emphasized to meet future water demand and to ensure good and safe water quality. One of these new techniques is membranes. This project aims at looking at a specific nanomembrane and its ability to handle hydrocarbons from oil spillage in lake Mälaren. Because of dilution in the lake, the concentration should not exceed 100 μg/L therefore the project only examines low concentration WAF (water accommodated fraction of petroleum-water). 

    The SECA-directive was conducted in northern Europe and North America in 2015, that aims at reducing the environmental- and health risk in the marine environment. One major part of this was reducing the sulphur content in the used fuels. This lead to alternatives fuels called hybrid fuels as MGO (marine gasoil), methanol and LNG (liquefied natural gas). That is a mix of low sulphur content fuel with residual fuels. These hybrid fuels do not work the same way as conventional fuels. Once the fuel is released into the marine environment it is subjected to complex transformations also known as weathering processes. That further complex the composition of the fuel and creates WAF.

    To investigate if the specific membrane could handle WAF an experiment was conducted to see how the membrane behave when operating WAF and if fouling occurs. The experiment was conducted with a bench-top membrane therefore it is only tested on small scale. For this project IR analysis and scent analysis was used to indicate if the samples contained hydrocarbons. But for further works, it may be advantageous to use GC as an analytic method. 

    The permeate flux rapidly decreased, in the beginning, to then become quite constant for all of the concentrations and fuels. This indicates that the fouling of the membrane occurs quite quick in the beginning and using the membrane for an extended time does not lead to more fouling at these concentrations. For low concentrations, the fouling is reversible since it can operate at similar levels before and after the WAF. For these concentrations, operation time and cleaning method the performance of the membrane was not affected. But in the long term use, chemical cleaning can lead to a decrease in the lifespan of the membrane. If no cooling was conducted the permeate flux would increase with the increasing temperature, but would not affect the permeate quality for temperatures below 40 degrees.

    For the analysis result IR could not detect hydrocarbons, this probably has to do with the low concentrations and the separation method. Other studies have shown that it can be hard to determine MGO after 48 hours since it is mostly composed of VOC. The scent analysis could be used to detect if there are hydrocarbons left in the sample. All the WAF for both MGO and RMD80 could be detected. For the retentate, it could differ between no odour and faint odour, which indicates that hydrocarbons tend to attach to the membrane. For the permeate, no odour could be detected except for one sample with RMD80. Which probably was a tainted sample. Since individual hydrocarbons within the TPH could not be identified the chemical composition is unknown. Which limits the understanding of the complex mixtures. 

    The retentate with hydrocarbons needs to be taken care of before being let back into Mälaren. But since there is not a constant flow of hydrocarbons in the retentate a small solution is preferred that can handle small concentrations of hydrocarbons when needed. One example of this is an activated carbon filter that can be regenerated and handle small oil droplets, organic contamination and drug residues.

  • 37.
    Artursson, Madeleine
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Excipients selection in multidrugformulations development: Solution behavior of structurally relatedcalcium channel blockers combined with indapamide2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The increased demand of formulations containing more than one drugrequire improved understanding of the solution evolving from suchsystems and the effect of included excipients on their solubilityand dissolution behaviors.

    In this study, the solution behavior of structurally related drugs(dihydropyridines) combined with indapamide was explored. Inaddition, the origin of solubility differences between the drugswas investigated by determining their solubility and thermalproperties. The concentration of the drugs from supersaturatedsolutions generated by antisolvent addition was measured in bufferand excipients.

    There were distinct differences between the physiochemicalproperties and solubility values of the dihydropyridines, explainedby the additive effect of their hydrophobicity and strength ofcrystal lattice. Indapamide’s solubility was decreased by the sameextent when combined with either of the dihydropyridines. Thedihydropyridines varied in their behavior. Nifedipine maintainedsame supersaturation level until the amount of indapamide addedexceeded 400 mikrogram/ml and then its solubility increased by 2-folds and was maintained. There was no change in the concentrationof felodipine until the amount of added indapamide exceeded itsamorphous solubility, where a decrease was seen in felodipine’ssolubility.

    There was a clear differential solubilization effect of felodipineand indapamide by the excipients. The cyclodextrins was used inindapamide and felodipine combination because the relativesolubility improvement of indapamide.

    The study demonstrates the complexity of the solution behavior ofmultidrug combinations. This doesn’t only involve drugs formulatedtogether in one formulation but could involve medicine formulatedwith various excipients and administrated at the same time.

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  • 38.
    Ascue Avalos, Katia
    KTH, School of Chemical Science and Engineering (CHE).
    Avfallshanteringens miljöpåverkan - Fem avfallstypers koldioxidutsläpp i SÖRABs återvinningsprocess2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The climate change is one of the biggest environmental problems we face today and is due to the increased greenhouse effect caused by mainly carbon dioxide.  SÖRAB is a waste management company in Sweden who has been getting questions from its customers about the amount of carbon dioxide that is emitted when different types of waste is recycled through their process. This thesis answers this question for five different waste types: gypsum, plastic, textile, concrete and tires. In addition to the emissions from the recycling process in SÖRAB the emissions from another alternative process for each waste is estimated. The alternative process will be either incineration or landfill. With the help of both the alternative process and SÖRABs process an environmental benefit is calculated where a positive environmental benefit means that a saving of carbon dioxide emissions has been made by not sending the waste to incineration or landfill.

     

    The carbon emission from the following parts of the process is included:

    • Transportation of the waste (includes transport by truck and ferry)

      • Transportation within SÖRABs different facilities

      • Transportation from SÖRABs facilities external recycling companies.

    • The energy consumption from ”waste crusher” machine in SÖRAB

    • Fuel consumption from the machines in SÖRAB

    •  The carbon dioxide emissions from the external companies where the waste is recycled. This also includes the transportation in the case a part of the waste is further transported to be incinerated and the emission from the incineration itself.

     

    The results showed that the carbon dioxide emissions for each waste differed very much. The differences were due to each waste recycling process in SÖRAB, which differed in the transported weights, transport lengths, and emission levels in the external company. For plastics, textiles and tires, it was the transportation to the external companies which was the factor that contributed the most to the total carbon dioxide emission. For gypsum and concrete it was the emissions in the external companies that contributed the most, which is due to transport length being shorter for their recycling processes.

     

    The environmental benefit was the highest for the recycling of tires, 611 kg C02/ton plastic is saved by not sending it to incineration and instead recycle it through SÖRABs process.  The result is mainly due to the alternatives process emission from the ferry and incineration.

     

    The environmental benefits were positive for all the waste types except for plastic

     (-9,85)  kg CO2/ton textile) which had a long transportation length in comparison to the alternative process which was to send to incineration. In this report it was nevertheless concluded that this doesn’t mean that it would be a better option to incinerate the plastic since the real environmental benefit of plastic and all the other waste types is in the amount of carbon dioxide that is being saved by not needing to manufacture more of the material that is being regenerated through the recycling process.

     

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  • 39.
    B. Erdal, Nejla
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Adolfsson, Karin H.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Pettersson, Torbjörn
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Green Strategy to Reduced Nanographene Oxide through Microwave Assisted Transformation of Cellulose2018In: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 6, no 1, p. 1245-1255Article in journal (Refereed)
    Abstract [en]

    A green strategy for fabrication of biobased reduced nanographene oxide (r-nGO) was developed. Cellulose derived nanographene oxide (nGO) type carbon nanodots were reduced by microwave assisted hydrothermal treatment with superheated water alone or in the presence of caffeic acid (CA), a green reducing agent. The carbon nanodots, r-nGO and r-nGO-CA, obtained through the two different reaction routes without or with the added reducing agent, were characterized by multiple analytical techniques including FTIR, XPS, Raman, XRD, TGA, TEM, AFM, UV-vis, and DLS to confirm and evaluate the efficiency of the reduction reactions. A significant decrease in oxygen content accompanied by increased number of sp2 hybridized functional groups was confirmed in both cases. The synergistic effect of superheated water and reducing agent resulted in the highest C/O ratio and thermal stability, which also supported a more efficient reduction. Interesting optical properties were detected by fluorescence spectroscopy where nGO, r-nGO, and r-nGO-CA all displayed excitation dependent fluorescence behavior. r-nGO-CA and its precursor nGO were evaluated toward osteoblastic cells MG-63 and exhibited nontoxic behavior up to 200 μg mL-1, which gives promise for utilization in biomedical applications.

  • 40.
    Barrientos, Javier
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Deactivation of cobalt and nickel catalysts in Fischer-Tropsch synthesis and methanation2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

                A potential route for converting different carbon sources (coal, natural gas and biomass) into synthetic fuels is the transformation of these raw materials into synthesis gas (CO and H2), followed by a catalytic step which converts this gas into the desired fuels. The present thesis has focused on two catalytic steps: Fischer-Tropsch synthesis (FTS) and methanation. The Fischer-Tropsch synthesis serves to convert synthesis gas into liquid hydrocarbon-based fuels. Methanation serves instead to produce synthetic natural gas (SNG). Cobalt catalysts have been used in FTS while nickel catalysts have been used in methanation.

                The catalyst lifetime is a parameter of critical importance both in FTS and methanation. The aim of this thesis was to investigate the deactivation causes of the cobalt and nickel catalysts in their respective reactions.

                The resistance to carbonyl-induced sintering of nickel catalysts supported on different carriers (γ-Al2O3, SiO2, TiO2 and α-Al2O3) was studied. TiO2-supported nickel catalysts exhibited lower sintering rates than the other catalysts. The effect of the catalyst pellet size was also evaluated on γ-Al2O3-supported nickel catalysts. The use of large catalyst pellets gave considerably lower sintering rates. The resistance to carbon formation on the above-mentioned supported nickel catalysts was also evaluated. Once again, TiO2-supported nickel catalysts exhibited the lowest carbon formation rates. Finally, the effect of operating conditions on carbon formation and deactivation was studied using Ni/TiO2 catalysts. The use of higher H2/CO ratios and higher pressures reduced the carbon formation rate. Increasing the temperature from 280 °C to 340 °C favored carbon deposition. The addition of steam also reduced the carbon formation rate but accelerated catalyst deactivation.

                The decline in activity of cobalt catalysts with increasing sulfur concentration was also assessed by ex situ poisoning of a cobalt catalyst. A deactivation model was proposed to predict the decline in activity as function of the sulfur coverage and the sulfur-to-cobalt active site ratio. The results also indicate that sulfur decreases the selectivity to long-chain hydrocarbons and olefins.

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    Javier Barrientos - Deactivation of cobalt and nickel catalysts in Fischer-Tropsch synthesis and methanation
  • 41.
    Bastuck, Manuel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Improving the Performance of Gas Sensor Systems with Advanced Data Evaluation, Operation, and Calibration Methods2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In order to facilitate the widespread use of gas sensors, some challenges must still be overcome. Many of those are related to the reliable quantification of ultra-low concentrations of specific compounds in a background of other gases. This thesis focuses on three important items in the measurement chain: sensor material and operating modes, evaluation of the resulting data, and test gas generation for efficient sensor calibration.

    New operating modes and materials for gas-sensitive field-effect transistors have been investigated. Tungsten trioxide as gate oxide can improve the selectivity to hazardous volatile organic compounds like naphthalene even in a strong and variable ethanol background. The influence of gate bias and ultraviolet light has been studied with respect to the transport of oxygen anions on the sensor surface and was used to improve classification and quantification of different gases.

    DAV3E, an internationally recognized MATLAB-based toolbox for the evaluation of cyclic sensor data, has been developed and published as opensource. It provides a user-friendly graphical interface and specially tailored algorithms from multivariate statistics.

    The laboratory tests conducted during this project have been extended with an interlaboratory study and a field test, both yielding valuable insights for future, more complex sensor calibration. A novel, efficient calibration approach has been proposed and evaluated with ten different gas sensor systems. 

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    Improving the Performance of Gas Sensor Systems with Advanced Data Evaluation, Operation, and Calibration Methods
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  • 42.
    Bastuck, Manuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering. Saarland Univ, Germany.
    Baur, T.
    Saarland Univ, Germany.
    Richter, M.
    Bundesanstalt Mat Forsch and Prufung BAM, Germany.
    Mull, B.
    Bundesanstalt Mat Forsch and Prufung BAM, Germany; Fraunhofer Wilhelm Klauditz Inst, Germany.
    Schuetze, A.
    Saarland Univ, Germany.
    Sauerwald, T.
    Saarland Univ, Germany.
    Comparison of ppb-level gas measurements with a metal-oxide semiconductor gas sensor in two independent laboratories2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 273, p. 1037-1046Article in journal (Refereed)
    Abstract [en]

    In this work, we use a gas sensor system consisting of a commercially available gas sensor in temperature cycled operation. It is trained with an extensive gas profile for detection and quantification of hazardous volatile organic compounds (VOC) in the ppb range independent of a varying background of other, less harmful VOCs and inorganic interfering gases like humidity or hydrogen. This training was then validated using a different gas mixture generation apparatus at an independent lab providing analytical methods as reference. While the varying background impedes selective detection of benzene and naphthalene at the low concentrations supplied, both formaldehyde and total VOC can well be quantified, after calibration transfer, by models trained with data from one system and evaluated with data from the other system. The lowest achievable root mean squared errors of prediction were 49 ppb for formaldehyde (in a concentration range of 20-200 ppb) and 150 mu g/m(3) (in a concentration range of 25-450 mu g/m(3)) for total VOC. The latter uncertainty improves to 13 mu g/m(3) with a more confined model range of 220-320 mu g/m(3). The data from the second lab indicate an interfering gas which cannot be detected analytically but strongly influences the sensor signal. This demonstrates the need to take into account all sensor relevant gases, like, e.g., hydrogen and carbon monoxide, in analytical reference measurements.

  • 43.
    Bastuck, Manuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. University of Saarland, Germany.
    Puglisi, Donatella
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering.
    Schuetze, A.
    University of Saarland, Germany.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering.
    Characterizing the Influence of Gate Bias on Electrical and Catalytical Properties of a Porous Platinum Gate on Field Effect Gas Sensors2016In: 2016 IEEE SENSORS, IEEE , 2016Conference paper (Refereed)
    Abstract [en]

    In this work, we exposed an MIS capacitor with porous platinum as gate material to different concentrations of CO and NH3. Its capacitance and typical reaction products (water, CO2 and NO) were monitored at high and low oxygen concentration and different gate bias voltages. We found that the gate bias influences the switch-point of the binary CO response usually seen when either changing the temperature at constant gas concentrations or the CO/O-2 ratio at constant temperature. For NH3, the sensor response as well as product reaction rates increase with bias voltages up to 6 V. A capacitance overshoot is observed when switching on or off either gas at low gate bias, suggesting increasing oxygen surface coverage with decreasing gate bias.

  • 44.
    Bastuck, Manuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering. Saarland University, Lab for Measurement Technology, Germany.
    Puglisi, Donatella
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Schuetze, Andreas
    Saarland University, Saarbrücken, Germany.
    Sauerwald, Tilman
    Saarland University, Saarbrücken, Germany.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    UV-assisted gate bias cycling in gas-sensitive field-effect transistors2018In: Proceedings, ISSN 2504-3900, Vol. 2, no 13, article id 999Article in journal (Refereed)
    Abstract [en]

    Static and dynamic responses of a silicon carbide field-effect transistor gas sensor have been investigated at two different gate biases in several test gases. Especially the dynamic effects are gas dependent and can be used for gas identification. The addition of ultraviolet light reduces internal electrical relaxation effects, but also introduces new, temperature-dependent effects.

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  • 45.
    Bastuck, Manuel
    et al.
    Saarland University, Lab for Measurement Technology, Germany.
    Puglisi, Donatella
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Möller, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Reimringer, Wolfhard
    3S GmbH, Saarbrücken, Germany.
    Schuetze, Andreas
    Saarland University, Germany.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Low-cost chemical gas sensors for selective formaldehyde quantification at ppb-level in field tests2017Conference paper (Refereed)
    Abstract [en]

    Data from a silicon carbide based field-effect transistor were recorded over a period of nine days in a ventilated school room. For enhanced sensitivity and selectivity especially to formaldehyde, porous iridium on pulsed laser deposited tungsten trioxide was used as sensitive layer, in combination with temperature cycled operation and subsequent multivariate data processing techniques. The sensor signal was compared to reference measurements for formaldehyde concentration, CO2 concentration, temperature, and relative humidity. The results show a distinct pattern for the reference formaldehyde concentration, arising from the day/night cycle. Taking this into account, the projections of both principal component analysis and partial least squares regression lead to almost the same result concerning correlation to the reference. The sensor shows cross-sensitivity to an unidentified component of human activity, presumably breath, and, possibly, to other compounds appearing together with formaldehyde in indoor air. Nevertheless, the sensor is able to detect and partially quantify formaldehyde below 40 ppb with a correlation to the reference of 0.48 and negligible interference from ambient temperature or relative humidity.

  • 46.
    Bastuck, Manuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. University of Saarland, Germany.
    Reimringer, W.
    3S GmbH, Germany.
    Conrad, T.
    3S GmbH, Germany.
    Schuetze, A.
    University of Saarland, Germany.
    Dynamic multi-sensor operation and read-out for highly selective gas sensor systems2016In: PROCEEDINGS OF THE 30TH ANNIVERSARY EUROSENSORS CONFERENCE - EUROSENSORS 2016, ELSEVIER SCIENCE BV , 2016, Vol. 168, p. 1685-1688Conference paper (Refereed)
    Abstract [en]

    We describe hardware and algorithms which enable highly selective and sensitive operation of the two gas sensor types used in the SENSIndoor project. The resistance of a metal-oxide semiconductor (MOS) type can rise above 1 G Omega in temperature cycled operation (TCO), which is measured using a logarithmic amplifier. A silicon-carbide based, gas-sensitive field-effect transistor (SiC-FET) driven with a combination of TCO and gate-bias cycled operation (GBCO) is used as second, complimentary sensor. The cyclic sensor signals exhibit distinct shape changes depending on the gas present which is captured by pattern recognition. In this study we use Linear Discriminant Analysis (LDA) for discrimination and Partial Least Squares Regression (PLSR) for quantification of ppb concentrations of target VOCs in changing ppm concentrations of interfering gases for indoor air quality assessment. (C) 2016 The Authors. Published by Elsevier Ltd.

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  • 47. Battista, F.
    et al.
    Picano, Francesco
    KTH, School of Engineering Sciences (SCI).
    Troiani, G.
    Casciola, C. M.
    Turbulence-combustion interaction in H2/CO/air Bunsen flame2020In: ETC 2013 - 14th European Turbulence Conference, Zakon Group LLC , 2020Conference paper (Refereed)
    Abstract [en]

    In last decades, the increasing care to environmental safeguard and costs in the hydrocarbon fuel supplying have prompted in the development of alternative fuels, namely hydrogen based fuels as syngas. Syngas consists in a mixture of hydrogen and carbon monoxide (CO) in different relative concentration, in some cases with small concentration of methane. The aim of this work is to address the dynamics of turbulent hydrogen/carbon-monoxide/air Bunsen flames by means of Direct Numerical Simulation. The main issue is to understand how the thermo-diffusive instabilities occurring in pure hydrogen/air flame [7] are influenced by the presence of the carbon-monoxide. It is well known that the thermo-diffusive instabilities are mainly induced by the high hydrogen diffusivity leading to local quenching and temperature peaks in the flame with consequent increase of pollutant formation (e.g. NOx). The presence of carbon monoxide in the fuel mixture has significant effects in flame dynamics where we observe a damping of the H2/air flame instabilities with less apparent quenching and high temperature peaks. 

  • 48.
    Becker, Sebastian
    KTH, School of Chemical Science and Engineering (CHE).
    Inverkan av olika joner och jonconcentrationer på porstorleksfördelningen i trämassa-fibrer2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The basic ingredient of paper is the individual wood fibers. The property of the fibers depends on a variety of factors e.g., method of pulp production and processing. The final sheet quality depends in part on how the fibers interface between each other and therefore factors that affect the fiber size are of interest.

    The flexibility of the fibers depends in part on the pore water i.e., the fiber swelling. The sheet becomes less flexible at low water content which gives a loss in strength. Thus it becomes desirable to increase the water uptake.

    The experimental investigation described in this report consists of exposing the wood fibers to different ions and ionic strength and then measure the pore size by thermoporosimetry where a DSC (Differential Scanning Calorimeter) is used. DSC measures the freezing point of water in the pores of the wood fibers. As the freezing point varies with the pore size the size distribution can be determined.

    The results show that there are complications with thermoporosimetry measurements at different ion concentrations. The strength of the ionic solutions will contribute to a fictitious pore volume, which makes analysis difficult to interpret.

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  • 49.
    Behi, Hamidreza
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. Research group MOBI – Mobility, Logistics, and Automotive Technology Research Centre, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium b Flanders Make, Heverlee 3001, Belgium.
    Karimi, Danial
    Research group MOBI – Mobility, Logistics, and Automotive Technology Research Centre, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium b Flanders Make, Heverlee 3001, Belgium.
    Behi, Mohammadreza
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. The University of Sydney, School of Chemical and Biomolecular Engineering, NSW 2006, Australia.
    Jaguemont, Joris
    Research group MOBI – Mobility, Logistics, and Automotive Technology Research Centre, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium b Flanders Make, Heverlee 3001, Belgium.
    Ghanbarpour, Morteza
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Behnia, Masud
    Macquarie Business School, Macquarie University, Sydney, Australia.
    Berecibar, Maitane
    Research group MOBI – Mobility, Logistics, and Automotive Technology Research Centre, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium b Flanders Make, Heverlee 3001, Belgium.
    Van Mierlo, Joeri
    Research group MOBI – Mobility, Logistics, and Automotive Technology Research Centre, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium b Flanders Make, Heverlee 3001, Belgium.
    Thermal management analysis using heat pipe in the high current discharging of lithium-ion battery in electric vehicles2020In: Journal of Energy Storage, ISSN 2352-152X, E-ISSN 2352-1538, Vol. 32, article id 101893Article in journal (Refereed)
    Abstract [en]

    Thermal management system (TMS) for commonly used lithium-ion (Li-ion) batteries is an essential requirement in electric vehicle operation due to the excessive heat generation of these batteries during fast charging/discharging. In the current study, a thermal model of lithium-titanate (LTO) cell and three cooling strategies comprising natural air cooling, forced fluid cooling, and a flat heat pipe-assisted method is proposed experimentally. A new thermal analysis of the single battery cell is conducted to identify the most critical zone of the cell in terms of heat generation. This analysis allowed us to maximize heat dissipation with only one heat pipe mounted on the vital region. For further evaluation of the proposed strategies, a computational fluid dynamic (CFD) model is built in COMSOL Multiphysics® and validated with surface temperature profile along the heat pipe and cell. For real applications, a numerical optimization computation is also conducted in the module level to investigate the cooling capacity of the liquid cooling system and liquid cooling system embedded heat pipe (LCHP). The results show that the single heat pipe provided up to 29.1% of the required cooling load in the 8C discharging rate. Moreover, in the module level, the liquid cooling system and LCHP show better performance compared with natural air cooling while reducing the module temperature by 29.9% and 32.6%, respectively.

  • 50.
    Benaya, Mwansa
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry. År.
    Development of an on-line sensor concept for oil change interval prediction: Focus on evaluation and method development of oil quality testing using a sensor and studying how sensor signals map soot and oxidation content in oil samples.2024Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Efficiency, emission, and uptime of vehicles in production and use are three factors that Scania CV AB focuses on to minimise the environmental impact brought about by the automotive industry. Optimising the use of engine oil is valued as a step in obtaining such improvements. This thesis focuses on learning more about how the sensor signals of a Fluid Property Sensor (FPS) detect soot and oxidation in engine oil samples, with comparison to a traditional laboratory analysis with Fourier Transform Infrared Spectroscopy (FTIR). A laboratory test rig was used to conduct measurements of engine oil samples of the grade 5W-20, using the FPS. FTIR was used to determine the oil sample’s soot concentration and oxidation level. Plotting the sensor signals against soot concentration and oxidation levels respectively, revealed that the soot concentration had a strong correlation with the sensor signals and that the oxidation level had a weaker correlation with the sensor signals. An analysis of variance (ANOVA) confirmed that the experiments were different from one another. Principal component analysis (PCA) was performed to study trends and relations between variables in the data and found strong relations between soot, oxidation, dielectric constant, and density. Linear Multivariate Regressions at different temperature intervals demonstrated that density is the sensor parameter with the strongest influence on both soot and oxidation. From Partial Least Squares Regression modelling of the data, it was concluded that the sensor signals had a greater influence on modelling oxidation; however, the soot regression had a better fit to the data points and would perform well on unseen data.

     

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