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Numrering	Referens	Omslagsbild	Hitta
1.	Proceedings of the 2010 Winter Simulation Conference 2010 Samlingsverk (redaktörskap) (refereegranskat)
2.	Ekman, Jonas, et al. (författare) Projekt: Rymdforskarskolan 2015 Annan publikation (populärvet., debatt m.m.)abstract The Graduate School of Space Technology
3.	Eivazihollagh, Alireza, et al. (författare) On chelating surfactants : Molecular perspectives and application prospects 2019 Ingår i: Journal of Molecular Liquids. - : Elsevier BV. - 0167-7322 .- 1873-3166. ; 278, s. 688-705 Tidskriftsartikel (refereegranskat)abstract Chelating agents, molecules that very strongly coordinates certain metal ions, are used industrially as well as in consumer products to minimize disturbances and increase performance of reactions and applications. The widely used sequestering agents, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) belong to this branch of readily water-soluble compounds. When these chemical structures also have hydrophobic parts, they are prone to adsorb at air-water interfaces and to self-assemble. Such bifunctional molecules can be called chelating surfactants and will have more extended utilization prospects than common chelating agents or ordinary ionic surfactants. The present review attempts to highlight the fundamental behavior of chelating surfactants in solution and at interfaces, and their very specific interactions with metal ions. Methods to recover chelating surfactants from metal chelates are also described. Moreover, utilization of chelating surfactants in applications for metal removal in environmental engineering and mineral processing, as well as for metal control in the fields of biology, chemistry and physics, is exemplified and discussed.
4.	Moldenhauer, Patrick, 1983, et al. (författare) Chemical-looping combustion with heavy liquid fuels in a 10 kW pilot plant 2017 Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820. ; 156, s. 124-137 Tidskriftsartikel (refereegranskat)abstract In this study, chemical-looping combustion was performed with highly viscous vacuum residue. A fuel reactor with a fuel-injection system for liquid fuels was designed and built for a chemical-looping reactor with the nominal fuel input of 10 kWth. The gas velocities in the riser section and at the gas-distribution nozzles of this unit are comparable to those of industrial circulating fluidized-bed boilers. Reference experiments were performed with an ilmenite oxygen carrier and two different fuel blends that contained 40 wt.% and respectively 80 wt.% of vacuum residue in fuel oil 1. Fuel conversion was in line with that of experiments from an earlier campaign, where fuel oil 1 was used as fuel. The fuel contained a significant fraction of sulfur, but no SO2 was detected in the flue gas of the air reactor. More experiments were performed using an oxygen carrier based on calcium manganite. The oxygen carrier was exposed to fluidization at hot conditions (more than 600°C) for about 95 h, out of which fuel was injected during a total of 9.6 h. Undiluted vacuum residue, fuel oil 1 as well as different blends of these two were used as fuel. Furthermore, the parameters fuel flow, fuel-reactor temperature and air flow in the air reactor were varied to observe trends in fuel conversion. The experiments were carried out with a fuel flow corresponding to 4.0-6.2 kWth and an oxygen carrier-to-fuel ratio of about 1300-2000 kg/MWth (fuel-reactor bed mass per thermal fuel-power). With undiluted vacuum residue as fuel and a fuel-reactor temperature of 1000°C, up to 93% of all carbon leaving the fuel reactor was in the form of CO2. Carbon leakage from fuel reactor to air reactor was usually below 1% for all fuel types tested, but no SO2 was detected in the off-gas from the air reactor. The reactivity of the calcium manganite-based material decreased over the course of the experiments, which is likely due to sulfur poisoning. No defluidization or agglomeration problems were experienced over the course of the experimental campaign.
5.	Grolig, Jan Gustav, 1986 (författare) Coated Ferritic Stainless Steels as Interconnects in Solid Oxide Fuel Cells - Material Development and Electrical Properties 2015 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Solid oxide fuel cells (SOFCs) are attracting increasing interest as devices with potentialuses in decentralized and clean electricity and heat production. Several challengeswith respect to materials have to be overcome to achieve efficiencies and life-spansthat are sufficient for long-term applications.An important element of an SOFC stack is the interconnect component, which connectstwo adjacent fuel cell elements. Interconnects, which are commonly composedof ferritic stainless steels, have to be corrosion-resistant, mechanically stable and costoptimized.This work aimed to investigate economic solutions for interconnect materials and tounderstand the underlying mechanisms of degradation and electrical conduction ofthese materials. Mainly two substrates, a commercially available steel (AISI 441) anda ferritic stainless steel that was optimized for an SOFC application (Sandvik SanergyHT) were combined with different barrier coatings and exposed to a cathode-sideatmosphere. A method was developed that allows for the electrical characterizationof promising material systems and model alloys, thereby facilitating a fundamentalunderstanding of the dominant electrical conduction processes linked to the oxidescales that grow on interconnects. The AISI 441 steel coated with reactive elementsand cobalt showed good corrosion and chromium evaporation profiles, while AISI 441coated with cerium and cobalt also had promising electrical properties. The SanergyHT steel was examined with coatings of copper and iron and copper and manganese,respectively. The corrosion and chromium evaporation profiles of Sanergy HT wereimproved by coating with copper and iron. The copper and iron-coated Sanergy HTshowed lower area specific resistance values than cobalt-coated Sanergy HT. Chromia,which is the main constituent of oxide scales, was synthesized using differentmethods. The electrical properties of chromia were found to be sensitive to not onlyimpurities, but also heat treatment. Finally the electrical properties of cobalt- andcobalt cerium-coated Sanergy HT steels were investigated. It was revealed that theaddition of cerium improved the conductivity of the interconnect by both slowingdown chromia growth and preventing the outward diffusion of iron into the spinel.
6.	Chen, Zhe, et al. (författare) Nano-scale characterization of white layer in broached Inconel 718 2017 Ingår i: Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing. - Amsterdam : Elsevier BV. - 0921-5093 .- 1873-4936. ; 684, s. 373-384 Tidskriftsartikel (refereegranskat)abstract The formation mechanism of white layers during broaching and their mechanical properties are not well investigated and understood to date. In the present study, multiple advanced characterization techniques with nano-scale resolution, including transmission electron microscopy (TEM), transmission Kikuchi diffraction (TKD), atom probe tomography (APT) as well as nano-indentation, have been used to systematically examine the microstructural evolution and corresponding mechanical properties of a surface white layer formed when broaching the nickel-based superalloy Inconel 718.TEM observations showed that the broached white layer consists of nano-sized grains, mostly in the range of 20–50 nm. The crystallographic texture detected by TKD further revealed that the refined microstructure is primarily caused by strong shear deformation. Co-located Al-rich and Nb-rich fine clusters have been identified by APT, which are most likely to be γ′ and γ′′ clusters in a form of co-precipitates, where the clusters showed elongated and aligned appearance associated with the severe shearing history. The microstructural characteristics and crystallography of the broached white layer suggest that it was essentially formed by adiabatic shear localization in which the dominant metallurgical process is rotational dynamic recrystallization based on mechanically-driven subgrain rotations. The grain refinement within the white layer led to an increase of the surface nano-hardness by 14% and a reduction in elastic modulus by nearly 10% compared to that of the bulk material. This is primarily due to the greatly increased volume fraction of grain boundaries, when the grain size was reduced down to the nanoscale.
7.	Hosseini, Seyedehsan, 1994 (författare) Additive-Driven Improvements in Interfacial Properties and Processing of TMP-Polymer Composites 2023 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Efforts to address environmental concerns have resulted in new regulations designed to plan the reduction of plastic and synthetic polymer usage, necessitating the search for sustainable natural alternatives with comparable cost-effectiveness and mechanical performance. Thermomechanical pulp (TMP) fibres are one of the most affordable natural fibres that have no chemical refining in production, production have a high yield of 90-98% and TMP fibres have been demonstrated to improve the mechanical characteristics (strength, stiffness and toughness) of wood-polymer composites (WPCs) compared to the pure polymer. The integration of TMP fibres with non-polar synthetic polymers remains a challenge due to surface polarity differences. This PhD thesis aims to ease the processing of TMP fibre composites through the incorporation of additives. The hypothesis posits that incorporating magnesium stearate (MgSt), molybdenum disulfide (MoS2) and alkyl ketene dimer (AKD) as additives in TMP composites will enhance interfacial properties, resulting in improved processability and flow behaviour at high temperatures. MoS2 is known for its interaction with lignin, which exists in TMP and MgSt is recognised for its ability to improve flow in pharmaceutical processing when combined with cellulose, also a component of TMP. AKD modifies the hydrophilic properties of lignocellulosic surfaces. The experimental work explores the effect of these additives on the properties of TMP composites of ethylene acrylic acid copolymer (EAA) and polypropylene (PP) matrices. The dynamic mechanical analysis (DMA) and mechanical analysis results reveal that MoS2 exhibits superior interaction with TMP fibres, yielding enhanced interfacial properties compared to MgSt in between EAA and TMP fibres. Rheological studies elucidate the transition from a fluid-like state to a network-like structure upon the incorporation of TMP into the PP matrix. The incorporation of AKD with C18 reduces the viscosity of TMP-PP composites and PP itself, and, as determined through theoretical Hansen solubility parameter (HSP) calculations, increases compatibility between cellulose in TMP fibres and PP. The addition of AKD influences both the colour (lighter) and shape (smoother surface) of the extrudate filaments in the TMP-PP composites, indicative of improved processing. In addition, frictional analysis demonstrates the reduction of the coefficient of friction (COF) between metal and TMP fibre by MgSt and AKD treatments.
8.	Hosseini, Seyedehsan, 1994, et al. (författare) Alkyl ketene dimer modification of thermomechanical pulp promotes processability with polypropylene 2024 Ingår i: Polymer Composites. - 1548-0569 .- 0272-8397. ; 45:1, s. 825-835 Tidskriftsartikel (refereegranskat)abstract Alkyl ketene dimers (AKDs) are known to efficiently react with cellulose with a dual polarity in their structure: a polar component and a nonpolar component. AKD of three different carbon chain lengths, 4, 10, and 16 carbons have been synthesized, and thermomechanical pulp (TMP) fibers were modified by them. The modification of TMP fibers with AKD resulted in an increased water contact angle, showing the presence of the AKDs on the TMP fibers and a new carbonyl peak in the IR spectra, suggesting modification of the TMP fibers with AKD groups. Calculating the Hansen solubility parameters of AKD and AKD conjugated to TMP in polypropylene (PP) indicates improved compatibility, especially of longer chain AKD and TMP AKD. The rheological studies of the composites showed that the AKD with the longest carbon chain decreases the melt viscosity of the PP-TMP-AKD composite, which combined with the shape and the color of the extruded composite filaments indicates improved flow properties and reduced stress build up during processing. The research findings demonstrate the ability of AKD to enhance the dispersibility and compatibility of natural fibers with PP.
9.	Brandin, Jan, 1958-, et al. (författare) Multi-function catalysts for glycerol upgrading 2010 Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract During the last three years Biofuel-Solution, a privately held Swedish entity, has developed an IP-portfolio around gas-phase glycerol conversion into medium-value chemicals. The targeted chemicals have large to very large markets, to allow for use by more than a fraction of the glycerol available today without impacting the cost of the product. The reason behind is that glycerol is a by-product from the biofuel industry, including biodiesel and bioethanol. This indicates large production volumes, even though the glycerol is a fraction of the fuel produced. A by-product from any fuel process will be vast and therefore any chemical produced from this side-product will have to have a large market to offset it to. In order to avoid changing the fundamental market behavior, similar to what the biodiesel industry has done to the glycerol market. In the course of this work, several end-products have been targeted. These include plastic monomers, mono-alcohols and energy gases; using acrolein as a common starting point. To produce chemicals with high purity and efficiency, selective and active catalysts are required. For instance, a process for producing propionaldehyde and n-propanol has been developed to the point of demonstration and commercialization building on the gas-phase platform. By developing multi-function catalysts which perform more than one task simultaneously, synergies can be reached that cannot be achieved with traditional catalysts. For instance, by combining catalyst functionalities, reactions that are both endothermic and exothermic can be performed simultaneously. This mean lower inlet reactor temperatures (in this particular case) and a more even temperature distribution. By performing the dehydration of glycerol to acrolein in combination with another, exothermal reaction by-products can be suppressed and yields increased. It also means that new reaction pathways can be achieved, allowing for new ways to produce chemicals and fuels from glycerol. As in the case of ethane production from acrolein, where a catalyst surface has been devised where acrolein is first adsorbed. The actual mechanism is unknown but in speculation, the adsorbed acrolein is decarbonyled into ethylene and carbon monoxide on a first reaction site. The formed carbon monoxide diffuses to another active site, where it reacts with water through the so called water-gas shift reaction to carbon dioxide and hydrogen. Said carbon dioxide leaves as an end-product, and the hydrogen diffuses to another active site where it reacts with ethylene to form ethane. This gives a way of producing energy gases from glycerol in a very compact reactor set-up, effectively reducing footprint and capital cost and increasing productivity of an installation.
10.	Eriksson, Gunnar, et al. (författare) Combustion and fuel characterisation of wheat distillers dried grain with solubles (DDGS) and possible combustion applications 2012 Ingår i: Fuel. - : Elsevier. - 0016-2361 .- 1873-7153. ; 102, s. 208-220 Tidskriftsartikel (refereegranskat)abstract The present transition to a sustainable global energy system requires that biomass is increasingly combusted for heat and power production. Agricultural fuels considered include alkali-rich fuels with high phosphorus content. One such fuel is wheat distiller’s dried grain with solubles (wheat DDGS) from wheat-based ethanol production. Further increases in ethanol production may saturate the current market for wheat DDGS as livestock feed, and fuel uses are therefore considered. Fuel properties of wheat DDGS have been determined. The ash content (5.4 ± 1.6 %wt d.s.) is similar to many agricultural fuels. In comparison to most other biomass fuels the sulphur content is high (0.538 ± 0.232 %wt d.s.), and so are the contents of nitrogen (5.1 ± 0.6 %wt d.s.), phosphorus (0.960. ± 0.073 %wt d.s.) and potassium (1.30 ± 0.35 %wt d.s.). To determine fuel-specific combustion properties, wheat DDGS and mixes between wheat DDGS and logging residues (LR 60 %wt d.s. and DDGS 40 %wt d.s.), and wheat straw (wheat straw 50 %wt d.s., DDGS 50 %wt d.s.) were pelletized and combusted in a bubbling fluidised bed combustor (5 kW) and in a pellets burner combustor (20 kW). Pure wheat DDGS powder was also combusted in a powder burner (150 kW). Wheat DDGS had a high bed agglomeration and slagging tendency compared to other biomass fuels, although these tendencies were significantly lower for the mixture with the Ca-rich LR, probably reflecting the higher first melting temperatures of K–Ca/Mg-phosphates compared to K-phosphates. Combustion and co-combustion of wheat DDGS resulted in relatively large emissions of fine particles (<1 μm) for all combustion appliances. For powder combustion PMtot was sixteen times higher than from softwood stem wood. While the Cl concentrations of the fine particles from the the mixture of LR and wheat DDGS in fluidised bed combustion were lower than from combustion of pure LR, the Cl- and P-concentrations were considerably higher from the wheat DDGS mixtures combusted in the other appliances at higher fuel particle temperature. The particles from powder combustion of wheat DDGS contained mainly K, P, Cl, Na and S, and as KPO3 (i.e. the main phase identified with XRD) is known to have a low melting temperature, this suggests that powder combustion of wheat DDGS should be used with caution. The high slagging and bed agglomeration tendency of wheat DDGS, and the high emissions of fine particles rich in K, P and Cl from combustion at high temperature, mean that it is best used mixed with other fuels, preferably with high Ca and Mg contents, and in equipment where fuel particle temperatures during combustion are moderate, i.e. fluidised beds and possibly grate combustors rather than powder combustors.
11.	Larsson, Ann-Charlotte, et al. (författare) Targeting by Comparison with Laboratory Experiments the SCR Catalyst Deactivation Process by Potassium and Zinc Salts in a Large-Scale Biomass Combustion Boiler 2006 Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 20:4, s. 1398-1405 Tidskriftsartikel (refereegranskat)abstract The deactivation of a commercial selective catalytic reduction (SCR) catalyst of type V2O5−WO3/TiO2 has been studied in this work through comparisons of results from a full-scale biomass combustion plant with those from laboratory experiments. In the latter, the catalyst was exposed to KCl, K2SO4, and ZnCl2 by both wet impregnation with diluted salt solutions and deposition of generated submicrometer aerosol particles by means of an electrostatic field. The reactivity of freshly prepared and deactivated catalyst samples was examined in the SCR reaction, for which the influence of the different salts and the method of exposure were explored. Chemical and physical characterizations of the catalyst samples were carried out focusing on surface area, pore volume, pore size, chemical composition, and the penetration profiles of potassium and zinc. Particle-deposition deactivation as well as commercially exposed catalyst samples were shown to impact surface area and catalyst activity similarly and to have penetration profiles with pronounced peaks. Salt impregnation influenced pore sizes and catalyst activity more strongly and showed flat penetration profiles. Deposition of submicrometer-sized particles on the monolithic SCR catalyst has been shown to induce deactivation of the catalyst with characteristics resembling those obtained in a commercial biomass combustion plant; the laboratory process can be used to further assess the deactivation mechanism by biomass combustion.
12.	Zhou, Ming, et al. (författare) Oligoamine ionic liquids supported on mesoporous microspheres for CO2 separation with good sorption kinetics and low cost 2020 Ingår i: Journal of CO2 Utilization. - : Elsevier. - 2212-9820 .- 2212-9839. ; 39 Tidskriftsartikel (refereegranskat)abstract Ionic liquids display good CO2 absorption capacity but poor absorption kinetics and high costs. In the present work, we show that these problems can be solved by impregnating the new low cost ionic liquid pentaethylenehexammonium chloride [PEHA][Cl] and the corresponding amine precursor on a low cost mesoporous microsphere support. Nitrogen adsorption/ desorption, high-resolution SEM and thermogravimetric analysis were employed to analyze the structural and thermal properties of the prepared sorbents. The CO2 adsorption and desorption performance was studied by column experiments and mathematical models were fitted to the data. The results showed that sorbents displayed excellent sorption kinetics and capacity, comparable to the best reports in the literature. In addition, the sorbents could be regenerated and displayed high thermal stability. Finally, the costs of the sorbents developed in the present work is much lower than previously reported sorbents. Therefore this novel supported IL system could be promising for industrial CO2 removal and recovery applications.
13.	Sefidari, Hamid, et al. (författare) The effect of disintegrated iron-ore pellet dust on deposit formation in a pilot-scale pulverized coal combustion furnace. Part II : Thermochemical equilibrium calculations and viscosity estimations 2018 Ingår i: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 180, s. 189-206 Tidskriftsartikel (refereegranskat)abstract Fly ash particles from the combustion of solid-fuels together with disintegrated particles arising from iron-ore pellets result in accumulation of deposits on the refractory linings of the grate-kiln induration machine during the iron-ore pelletizing process. The deposits amass in the high-temperature regions of the induration furnace thus disturbing the flow of gas and pellets. Therefore, to tackle the above-mentioned issues, an understanding of deposit formation mechanism is of crucial importance. This study was conducted with the objective of addressing the effect of disintegrated iron-ore pellet dust on deposit formation and the mechanisms behind deposition (slagging) in the grate-kiln process. A comprehensive set of experiments was conducted in a 0.4 MW pilot-scale pulverized-coal- fired furnace where three different scenarios were considered as follows; Case 1 (reference case): Coal was combusted without the presence of pellet dust. Case 2: Natural gas was combusted together with simultaneous addition of pellet dust to the gas stream. Case 3: Coal was combusted together with the addition of pellet dust simulating the situation in the large-scale setup. Fly ash particles and short-term deposits were characterized and deposition was addressed in Part I of this study. In light of the experimental observations (Part I) and the thermochemical equilibrium calculations (Part II), a scheme of ash transformation during the iron-ore pelletizing process was proposed. The dissolution of hematite particles into the Ca-rich-aluminosilicate melt (from the coal-ash constituents) decreased the viscosity and resulted in the formation of stronger (heavily sintered) deposits. Overall, this pilot-scale work forms part of a wider study which aims at deepening the understanding of ash transformation phenomena during the large-scale pelletizing process.
14.	Yu, Xiaowen, et al. (författare) Hydrogen Evolution Linked to Selective Oxidation of Glycerol over CoMoO4—A Theoretically Predicted Catalyst 2022 Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6832 .- 1614-6840. ; 12:14 Tidskriftsartikel (refereegranskat)abstract Electrochemical valorization of biomass waste (e.g., glycerol) for production of value-added products (such as formic acid) in parallel with hydrogen production holds great potential for developing renewable and clean energy sources. Here, a synergistic effort between theoretical calculations at the atomic level and experiments to predict and validate a promising oxide catalyst for the glycerol oxidation reaction (GOR) are reported, providing a good example of designing novel, cost-effective, and highly efficient electrocatalysts for producing value-added products at the anode and high-purity hydrogen at the cathode. The predicted CoMoO4 catalyst is experimentally validated as a suitable catalyst for GOR and found to perform best among the investigated metal (Mn, Co, Ni) molybdate counterparts. The potential required to reach 10 mA cm−2 is 1.105 V at 60 °C in an electrolyte of 1.0 ᴍ KOH with 0.1 ᴍ glycerol, which is 314 mV lower than for oxygen evolution. The GOR reaction pathway and mechanism based on this CoMoO4 catalyst are revealed by high-performance liquid chromatography and in situ Raman analysis. The coupled quantitative analysis indicates that the CoMoO4 catalyst is highly active toward C—C cleavage, thus presenting a high selectivity (92%) and Faradaic efficiency (90%) for formate production.
15.	Akhtar, Farid, et al. (författare) Preparation of graded silicalite-1 substrates for all-zeolite membranes with excellent CO2/H-2 separation performance 2015 Ingår i: Journal of Membrane Science. - : Elsevier BV. - 0376-7388 .- 1873-3123. ; 493, s. 206-211 Tidskriftsartikel (refereegranskat)abstract Graded silicalite-1 substrates with a high gas permeability and low surface roughness have been produced by pulsed current processing of a thin coating of a submicron silicalite-1 powder onto a powder body of coarser silicalite-1 crystals. Thin zeolite films have been hydrothermally grown onto the graded silicalite-1 support and the all-zeolite membranes display an excellent CO2/H-2 separation factor of 12 at 0 degrees C and a CO2 permeance of 21.3 x 10(-7) mol m(-2) s(-1) Pa-1 for an equimolar CO2/H-2 feed at 505 kPa and 101 kPa helium sweep gas. Thermal cracking estimates based on calculated surface energies and measured thermal expansion coefficients suggest that all-zeolite membranes with a minimal thermal expansion mismatch between the graded substrate and the zeolite film should remain crack-free during thermal cycling and the critical calcination step.
16.	Heshmati, Mohsen, 1987, et al. (författare) Dependency of cohesive laws of a structural adhesive in Mode-I and Mode-II loading on moisture, freeze-thaw cycling, and their synergy 2017 Ingår i: Materials and Design. - : Elsevier BV. - 1873-4197 .- 0264-1275. ; 122, s. 433-447 Tidskriftsartikel (refereegranskat)abstract In recent years, adhesive bonding has found its way to construction applications such as bridges. Given the harsh conditions that such structures are usually exposed to, it is necessary to account for environmental factors, particularly moisture and temperature, in the design phase. Cohesive zone modelling has attracted much attention in the last decade as a promising method to design adhesive joints. Despite this interest, the effects of moisture and thermal cycles on cohesive laws have not been investigated to the knowledge of the authors. In this paper, we present a method to directly measure the environmental-dependent cohesive laws of a structural adhesive loaded in pure Mode-I and Mode-II. Special consideration is given to overcome issues such as the time-consuming nature of moisture ingression and specimen dimensions, which could be problematic due to the size-limitations of conditioning equipment. The accuracy of this method was verified through simulation of the experiments using the finite element analysis. The effects of exposure to 95% relative humidity, immersion in saltwater and distilled water, and freeze-thaw cycles in the presence or absence of moisture were investigated. The results indicate the damaging effects of combined saltwater and freeze-thaw cycles which were clearly reflected on the shape of the cohesive laws.
17.	Andersson, Viktor, 1983, et al. (författare) Alkali-wall interactions in a laboratory-scale reactor for chemical looping combustion studies 2021 Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 217 Tidskriftsartikel (refereegranskat)abstract Alkali metal-containing compounds are readily released during thermal conversion of solid fuels, and may have both detrimental and beneficial effects on chemical looping combustion. Here, we characterize alkali interactions with the inner walls of a laboratory-scale reactor under oxidizing, reducing and inert conditions at temperatures up to 900 °C. KCl aerosol particles are continuously introduced to the stainless steel reactor and the alkali concentration is measured on-line with a surface ionization detector. Aerosol particles evaporate at temperatures above 500 °C and KCl molecules rapidly diffuse to the reactor wall. Up to 92% of the alkali reaching the wall below 700 °C remains adsorbed, while re-evaporation is important at higher temperatures, where up to 74% remains adsorbed. Transient changes in alkali concentration are observed during repeated redox cycles, which are associated with changes in chemical composition of the wall material. Metal oxides on the reactor wall are partially depleted under reducing conditions, which allow for the formation of a new potassium-rich phase that is stable in a reducing atmosphere, but not under inert conditions. The observed wall effects are concluded to be extensive and include major transient effects depending on gas composition, and the implications for laboratory studies and improved experimental methodology are discussed.
18.	Zacharias, Savannah C., et al. (författare) Exploring Supramolecular Gels in Flow-Type Chemistry-Design and Preparation of Stationary Phases 2021 Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 60:28, s. 10056-10063 Tidskriftsartikel (refereegranskat)abstract Two major challenges facing chemical synthesis are product isolation and catalyst recovery. One method to overcome these challenges is to perform the synthesis in a flow system with a catalytic stationary phase. However, the polymeric catalytic materials used in flow systems are often laborious to produce. In this study, we investigate a novel supramolecular gel as a catalytic stationary phase material. The gel is based on a modular, easy to synthesize, oxotriphenylhexanoate (OTHO) gelator comprised of a catalytic unit designed to catalyze the Knoevenagel reaction. The catalytic organogel enhances the rate of product formation and can be reused five times. Use of the OTHO to construct catalytic gels is a flexible technique that can be utilized to improve product isolation and reduce wastage of the catalyst.
19.	Mocholí Montañés, Rubén, 1990, et al. (författare) Dynamic Process Model Validation and Control of the Amine Plant at CO2 Technology Centre Mongstad 2017 Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 10, s. 1527- Tidskriftsartikel (refereegranskat)abstract This paper presents a set of steady-state and transient data for dynamic process model validation of the chemical absorption process with monoethanolamine (MEA) for post-combustion CO2 capture of exhaust gas from a natural gas-fired power plant. The data selection includes a wide range of steady-state operating conditions and transient tests. A dynamic process model developed in the open physical modeling language Modelica is validated. The model is utilized to evaluate the open-loop transient performance at different loads of the plant, showing that pilot plant main process variables respond more slowly at lower operating loads of the plant, to step changes in main process inputs and disturbances. The performance of four decentralized control structures is evaluated, for fast load change transient events. Manipulation of reboiler duty to control CO2 capture ratio at the absorber's inlet and rich solvent flow rate to control the stripper bottom solvent temperature showed the best performance.
20.	Salvador, Christian Mark, 1989, et al. (författare) Indoor ozone/human chemistry and ventilation strategies 2019 Ingår i: Indoor Air. - : Hindawi Limited. - 1600-0668 .- 0905-6947. ; 29:6, s. 913-925 Tidskriftsartikel (refereegranskat)abstract This study aimed to better understand and quantify the influence of ventilation strategies on occupant-related indoor air chemistry. The oxidation of human skin oil constituents was studied in a continuously ventilated climate chamber at two air exchange rates (1 h-1 and 3 h-1 ) and two initial ozone mixing ratios (30 and 60 ppb). Additional measurements were performed to investigate the effect of intermittent ventilation ("off" followed by "on"). Soiled t-shirts were used to simulate the presence of occupants. A time-of-flight-chemical ionization mass spectrometer (ToF-CIMS) in positive mode using protonated water clusters was used to measure the oxygenated reaction products geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO) and 4-oxopentanal (4-OPA). The measurement data were used in a series of mass balance models accounting for formation and removal processes. Reactions of ozone with squalene occurring on the surface of the t-shirts are mass transport limited; ventilation rate has only a small effect on this surface chemistry. Ozone-squalene reactions on the t-shirts produced gas-phase geranyl acetone, which was subsequently removed almost equally by ventilation and further reaction with ozone. About 70% of gas-phase 6-MHO was produced in surface reactions on the t-shirts, the remainder in secondary gas-phase reactions of ozone with geranyl acetone. 6-MHO was primarily removed by ventilation, while further reaction with ozone was responsible for about a third of its removal. 4-OPA was formed primarily on the surfaces of the shirts (~60%); gas-phase reactions of ozone with geranyl acetone and 6-MHO accounted for ~30% and ~10%, respectively. 4-OPA was removed entirely by ventilation. The results from the intermittent ventilation scenarios showed delayed formation of the reaction products and lower product concentrations compared to continuous ventilation.
21.	Öhman, Sebastian, 1991-, et al. (författare) Selective kinetic growth and role of local coordination in forming Al2TiO5-based coatings at lower temperatures 2021 Ingår i: Materials Advances. - : Royal Society of Chemistry. - 2633-5409. ; 2:17, s. 5737-5751 Tidskriftsartikel (refereegranskat)abstract Negative thermal expansion is an elusive property found among certain materials, whose potential applications have remained limited due to the many challenges faced in their synthesis. Herein, we report the successful formation of aluminium titanate-based coatings (Al2TiO5), a material renowned for its low-to-negative thermal expansion, by the co-deposition of aluminium-isopropoxide and titanium-isopropoxide in a hot-wall chemical vapour deposition instrument. While coatings grown at 450 °C were amorphous as-deposited, a short-range order into the Al2TiO5-phase was found and analysed by using Raman spectroscopy. Upon subsequent annealing at 700 °C for 3 hours, crystalline coatings were achieved without forming any binary phases. The selective synthesis of the Al2TiO5 phase is ascribed to the precursors’ inherent chemical similarities, resulting in a kinetic targeting of this phase and a short-range homogeneity, entailing its preferred crystallisation. The role of local coordination is expressed by demonstrating the formation of intergrowth phases ascribed to lower coordinating interstices in the compound. Both the formation and crystallisation temperatures reported herein, as well as the timescales needed for the synthesises, are considerably lower than any conventional adopted solid-state techniques used so far to attain the Al2TiO5 phase.
22.	Decrop, Deborah, et al. (författare) Single-step manufacturing of femtoliter microwell arrays in a novel surface energy mimicking polymer 2015 Ingår i: 18th International Conference on Solid-State Sensors, Actuators and Microsystems (IEEE TRANSDUCER 2015). - : IEEE. Konferensbidrag (refereegranskat)abstract We report a novel polymer material formulation and stamp-molding technique that enable rapid single-step manufacturing of hydrophilic-in-hydrophobic microwell arrays. We developed a modified thiol-ene-epoxy polymer (mOSTE+) formulation that mimics the surface energy of its mold during polymerization. The polymer inherits the surface energy from the mold through molecular self-assembly, in which functional monomers self-assemble at the interface between the liquid prepolymer and the mold surface. Combining this novel mOSTE+ material with a stamp-molding process leads to simultaneous surface energy mimicking and micro-structuring. This method was used to manufacture microwells with hydrophilic bottom and hydrophobic sidewall, depressed in a surrounding hydrophobic surface. The microwell arrays were successfully tested for the self-assembly of 62’000 femtoliter-droplets. Such femtoliter droplet arrays are useful for, e.g., digital ELISA and single cell/molecule analysis applications.
23.	Method and models used in the project Pathways to Sustainable European Energy Systems 2011 Samlingsverk (redaktörskap) (refereegranskat)abstract This book describes the research that has been carried out during the first period (2006-2010) of the Alliance for Global Sustainability (AGS) project "Pathways to Sustainable European Energy Systems". this interdisciplinary project involves more that 40 researchers and addresses various aspects of the challenges faced in transforming the European energy system. Presented in this book are the energy-related methods and models that originate from different scientific disciplines and traditions and that were applied in the Pathways project. Some of the analytical tools are well-known, well-documented, and widely used in academic research. Others have been developed (or refined) during the Pathways project and are therefore unique. The chapters of this book cover around 30 different methods and models used in the Pathways project and presents an overview of the processes through which the research was conducted and the methods and models were co-ordinated.
24.	Bendegard, Saga, 1982-, et al. (författare) ”Förslagsvis kunde en ren översättning av de tyska uttrycken användas”. Fackexperter, språkexperter och terminologiska frågor i Sverige 1941–1983 2019 Ingår i: Svenskans beskrivning 36. Förhandlingar vid trettiosjätte sammankomsten. Uppsala 25–27 oktober 2017. Red. Marco Bianchi, David Håkansson, Björn Melander, Linda Pfister, Maria Westman & Carin Östman. Skrifter utgivna av Institutionen för nordiska språk vid Uppsala universitet 102. - Uppsala : Institutionen för nordiska språk vid Uppsala universitet. - 1102-3619 .- 0083-4661. - 9789151910376 Konferensbidrag (refereegranskat)
25.	Dahlquist, Erik, 1951-, et al. (författare) Experimental and numerical investigation of pellet and black liquor gasification for polygeneration plant 2017 Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 204, s. 1055-1064 Tidskriftsartikel (refereegranskat)abstract It is vital to perform system analysis on integrated biomass gasification in chemical recovery systems in pulp and paper and heat and power plants for polygeneration applications. The proposed integration complements existing pulp and paper and heat and power production systems with production of chemicals such as methane and hydrogen. The potential to introduce gasification-based combined cycles comprising gas turbines and steam turbines to utilize black liquors and wood pellets also merits investigation. To perform such analysis, it is important to first build knowledge on expected synthesis gas composition by gasifying at smaller scale different types of feed stock. In the present paper, the synthesis gas quality from wood pellets gasification has been compared with black liquor gasification by means of numerical simulation as well as through pilot-scale experimental investigations. The experimental results have been correlated into partial least squares models to predict the composition of the synthesis gas produced under different operating conditions. The gas quality prediction models are combined with physical models using a generic open-source modelling language for investigating the dynamic performance of large-scale integrated polygeneration plants. The analysis is further complemented by considering potential gas separation using modern membrane technology for upgrading the synthesis gas with respect to hydrogen content. The experimental data and statistical models presented in this study form an important literature source for future use by the gasification and polygeneration research community on further integrated system analysis.
26.	Järnström, Lars, 1954-, et al. (författare) Ultraviolet-induced aging of flexographic printing plates studied by thermal and structural analysis methods 2009 Ingår i: Journal of Applied Polymer Science. - 0021-8995 .- 1097-4628. ; 112:3, s. 1636-1646 Tidskriftsartikel (refereegranskat)
27.	Pardon, Gaspard, 1983- (författare) From Macro to Nano : Electrokinetic Transport and Surface Control 2014 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Today, the growing and aging population, and the rise of new global threats on human health puts an increasing demand on the healthcare system and calls for preventive actions. To make existing medical treatments more efficient and widely accessible and to prevent the emergence of new threats such as drug-resistant bacteria, improved diagnostic technologies are needed. Potential solutions to address these medical challenges could come from the development of novel lab-on-chip (LoC) for point-of-care (PoC) diagnostics.At the same time, the increasing demand for sustainable energy calls for the development of novel approaches for energy conversion and storage systems (ECS), to which micro- and nanotechnologies could also contribute.This thesis has for objective to contribute to these developments and presents the results of interdisciplinary research at the crossing of three disciplines of physics and engineering: electrokinetic transport in fluids, manufacturing of micro- and nanofluidic systems, and surface control and modification. By combining knowledge from each of these disciplines, novel solutions and functionalities were developed at the macro-, micro- and nanoscale, towards applications in PoC diagnostics and ECS systems.At the macroscale, electrokinetic transport was applied to the development of a novel PoC sampler for the efficient capture of exhaled breath aerosol onto a microfluidic platform.At the microscale, several methods for polymer micromanufacturing and surface modification were developed. Using direct photolithography in off-stoichiometry thiol-ene (OSTE) polymers, a novel manufacturing method for mold-free rapid prototyping of microfluidic devices was developed. An investigation of the photolithography of OSTE polymers revealed that a novel photopatterning mechanism arises from the off-stoichiometric polymer formulation. Using photografting on OSTE surfaces, a novel surface modification method was developed for the photopatterning of the surface energy. Finally, a novel method was developed for single-step microstructuring and micropatterning of surface energy, using a molecular self-alignment process resulting in spontaneous mimicking, in the replica, of the surface energy of the mold.At the nanoscale, several solutions for the study of electrokinetic transport toward selective biofiltration and energy conversion were developed. A novel, comprehensive model was developed for electrostatic gating of the electrokinetic transport in nanofluidics. A novel method for the manufacturing of electrostatically-gated nanofluidic membranes was developed, using atomic layer deposition (ALD) in deep anodic alumina oxide (AAO) nanopores. Finally, a preliminary investigation of the nanopatterning of OSTE polymers was performed for the manufacturing of polymer nanofluidic devices.
28.	Almgren, Karin, et al. (författare) Role of fibre-fibre and fibre-matrix adhesion in stress transfer in composites made from resin-impregnated paper sheets. 2009 Ingår i: International Journal of Adhesion and Adhesives. - : Elsevier BV. - 0143-7496 .- 1879-0127. ; 29:5, s. 551-557 Tidskriftsartikel (refereegranskat)abstract Paper-reinforced plastics are gaining increased interest as packaging materials, where mechanical properties are of great importance. Strength and stress transfer in paper sheets are controlled by fibre-fibre bonds. In paper-reinforced plastics, where the sheet is impregnated with a polymer resin, other stress-transfer mechanisms may be more important. The influence of fibre-fibre bonds on the strength of paper-reinforced plastics was therefore investigated. Paper sheets with different degrees of fibre-fibre bonding were manufactured and used as reinforcement in a polymeric matrix. Image analysis tools were used to verify that the difference in the degree of fibre-fibre bonding had been preserved in the composite materials. Strength and stiffness of the composites were experimentally determined and showed no correlation to the degree of fibre-fibre bonding, in contrast to the behaviour of unimpregnated paper sheets. The degree of fibre-fibre bonding is therefore believed to have little importance in this type of material, where stress is mainly transferred through the fibre-matrix interface.
29.	Ge, Yaxin, et al. (författare) Effects of used bed materials on char gasification : Investigating the role of element migration using online alkali measurements 2022 Ingår i: Fuel processing technology. - : Elsevier. - 0378-3820 .- 1873-7188. ; 238 Tidskriftsartikel (refereegranskat)abstract Online alkali measurements using surface ionization are employed to study alkali release during heating of used industrial fluidized bed materials and gasification of biomass-based char and bed material mixtures. The alkali release from the bed materials starts at 820 °C and increases with temperature, the time a bed material has experienced in an industrial process, and in the presence of CO2. Online alkali measurement during heating of char mixed with used bed material shows significant alkali uptake by the char. Complementary SEM-EDS studies confirm the alkali results and indicate that other important inorganic elements including Si, Mg, and Ca also migrate from the bed material to the char. The migration of elements initially enhances alkali release and char reactivity, but significantly reduces both during the final stage of the gasification. The observed effects on char gasification become more pronounced with increasing amount of bed material and increasing time the material experienced in an industrial process. The ash-layer on the used bed material is concluded to play an important role as a carrier of alkali and other active components. The char and bed material systems are closely connected under operational conditions, and their material exchange has important implications for the thermal conversion.
30.	Pilke, Nina, et al. (författare) Organising Terminology Work in Sweden from the 1940s onwards – Participatory Expert Roles in Networks 2021 Ingår i: Terminology as a Societal Resource. Possibilities and Responsibilities in a Changing World. Special Issue of Terminology International Journal of Theoretical and Applied Issues in Specialized Communication. - : John Benjamins Publishing Company. - 0929-9971 .- 1569-9994. ; 27:1, s. 80-109 Tidskriftsartikel (refereegranskat)abstract The present study deals with organised terminology work in Sweden from the 1940s to the late 2010s. Using archive material, we describe how practical terminology work was carried out in Sweden during the period 1941–2018/ 2019, when the Swedish Centre for Technical Terminology/the Swedish Centre for Terminology (TNC) was the central actor. Thereafter, we discuss models for building a new infrastructure for terminology work after the clo- sure of the TNC in 2018/2019. This discussion is based on interviews and analyses of articles and current reports. The study shows that multifaceted contacts with experts, academia, industry and society have played an essen- tial role for terminology work in Sweden since the 1930s. In the current situ- ation (2019), the activities are being reorganised and responsibility for terminology work is distributed between several actors. A new main actor is the government agency known as the Institute of Language and Folklore (Isof ). Finally, we discuss future visions for terminology work in Sweden.
31.	Albertazzi, S, et al. (författare) The technical feasibility of biomass gasification for hydrogen production 2005 Ingår i: Catalysis Today. - : Elsevier BV. - 0920-5861 .- 1873-4308. ; 106:1-4, s. 297-300 Tidskriftsartikel (refereegranskat)abstract Biomass gasification for energy or hydrogen production is a field in continuous evolution, due to the fact that biomass is a renewable and CO2 neutral source. The ability to produce biomass-derived vehicle fuel on a large scale will help to reduce greenhouse gas and pollution, increase the security of European energy supplies, and enhance the use of renewable energy. The Varnamo, Biomass Gassification Centre in Sweden is a unique plant and an important site for the development of innovative technologies for biomass transformation. At the moment, the Varnamo plant is the heart of the CHRISGAS European project, that aims to convert the produced gas for further upgrading to liquid fuels as dimethyl ether (DME), methanol or Fischer-Tropsch (F-T) derived diesel. The present work is an attempt to highlight the conditions for the reforming unit and the problems related to working with streams having high contents of sulphur and alkali metals.
32.	Cantatore, Valentina, 1986, et al. (författare) Towards multifunctional coating in the boron-doped graphene/copper system 2017 Ingår i: Carbon. - : Elsevier BV. - 0008-6223. ; 115, s. 375-379 Tidskriftsartikel (refereegranskat)abstract A route to achieve multi-functional graphene coating is explored. Chemical bonding between copper substrate and coating results if the graphene is a priori boron doped. After pair-wise binding of boron sites to the Cu(111) surface, co-existence of pseudo-gap property in the graphene subsystem and a metallic density of states in the Cu subsystem at the common Fermi energy emerges. Apparently a paradox is that the two subsystems preserve and even recover their individual integrities upon formation of surface chemical bonds. Sensor capabilities are inferred. Employing pyridine as test molecule, conditioned ability of a nucleophile to offer competitive dative bonding, with the sub-strate, for boron sites is demonstrated. It is shown to occur for the case of half coverage and for adsorption to boron atoms originally bound to the on-top site on Cu(111). The ability of complementary boron sites to compensate for loss of binding between on-top site and boron, resulting from said bonding to the incoming nucleophile, is emphasized. Multifunctional substrate-coating system for catalysis as well as enhanced sensitization is inferred.
33.	Mukesh, Chandrakant, et al. (författare) Production of C-14 Levulinate Ester from Glucose Fermentation Liquors Catalyzed by Acidic Ionic Liquids in a Solvent-Free Self-Biphasic System 2020 Ingår i: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 5:10, s. 4828-4835 Tidskriftsartikel (refereegranskat)abstract Herein, we present the C-14 levulinate ester of 2,3-butanediol as the product of sugar fermentation liquors. The designed Brønsted acidic ionic liquid (BAIL) catalysts enable self-induced phase separation with ester products, and the role of anions has been investigated. Esterification reactions were carried out by 2,3-butanediol (2,3-BDO) and levulinic acid in solvent-free media and low temperatures (60–105 °C). For comparison, sulfuric acid, amberlite IR-120, and sulfonic acid-functionalized pyridinium ionic liquids with different anions were utilized as a catalyst upon esterification reaction. The diester product, namely, butane-2,3-diyl bis(4-oxopentanoate), was formed with a good yield (85%) and selectivity (85%) after complete conversion of 2,3-BDO in 24 h at 80 °C. The low yield (8%) of the monoester was observed. The monoester and diester were separated by a liquid–liquid extraction method. The ester products were characterized by various instrumental techniques such as 1H and 13C NMR, GC–FID, LC–MS, and FT-IR spectroscopy. The Hammett acidity functions of BAILs were determined from UV–vis spectroscopy. The catalyst was successfully recycled and reused in the processes. The spent BAILs were reused in six consecutive cycles with only a ∼7% diminished diester yield and selectivity. The produced levulinate ester will be useful as biofuel additives, solvents, plasticizers, and other applications.
34.	Du, Chengjun, 1985 (författare) Studies on Diesel sprays under non-reacting and reacting conditions 2017 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Methods for reducing engine-out emissions are urgently needed to mitigate climate change and air pollution. In diesel engines, the quality of fuel-air mixing and the subsequent combustion process strongly affect fuel efficiency and engine-out emissions. However, fuel-air mixing, the subsequent combustion processes, and their dependence on the operating conditions are not yet fully understood. This thesis aims to address this deficiency by analyzing the effects of various orifice geometries and high injection pressures on the characteristics of diesel sprays.The thesis briefly reviews the fundamental physics governing the flow of pressurized fuel through the internal nozzle of a diesel injector, the subsequent formation of the liquid and vapor spray, and the turbulent diffusion combustion processes. The experimental work presented in this thesis can be divided into three main parts. The first focuses on the effects of geometry-induced cavitation on the liquid/vapor phase spray and injection rate evaluation. To this end, a light absorption and scattering technique (LAS) was used to measure the distributions of liquid and vapor sprays formed using nozzles with various geometries. It was found that the vaporization of the diesel spray was controlled by turbulent air mixing. The effects of geometry-induced cavitation on the spray properties were mainly due to differences in the fuel mass flow rate, spray momentum and spreading angle. In addition, the injection rates of cavitating and non-cavitating nozzles were evaluated using the momentum flux measurement method. It was found that failure to account for cavitation caused the injection rate to be overestimated for the cavitating nozzle but not for the non-cavitating nozzle.The second part of the experimental campaign investigates the effect of the injection pressure and nozzle geometry on soot formation and oxidation. A two-dimensional laser extinction method was used to measure time-resolved soot concentrations and soot volume fractions; OH* chemiluminescence imaging was used to measure the lift-off length and measure the distributions of the OH radicals qualitatively; soot luminosity images were used to identify the sooting area in the soot shadowgraph images. It was found that the equivalence ratio in the jet center at the lift-off length (ϕ_cl), which is influenced by the operating conditions, played a critical role in soot formation. Reductions in ϕ_cl thickened the OH zone in the upstream region of the jet, reducing the volume corresponding to the maximum soot volume fraction. The expansion of the OH zone also helped reduce the sooting zone’s width. However, under high sooting conditions (e.g. ϕ_cl>3.5), the sooting zone width in the downstream jet was independent of ϕ_cl. The third part of the thesis investigates combusting and non-combusting sprays formed from different blends of ethanol with diesel fuel. Using 0%-20% ethanol blended with diesel fuels, liquid/vapor phase spray images were captured, the ignition delay was measured, the lift-off length was measured, and natural soot luminosity images were captured. It was found that the differences in the fuels’ composition did not significantly affect the liquid/vapor phase sprays. However, as the ethanol content of the fuel was increased from 0% to 20%, the lift-off length increased and the detectable soot luminescence decreased. This indicates that soot formation declines as the fuel’s ethanol content increases.
35.	Purnomo, Victor, 1992 (författare) Behavior of iron-based oxygen carriers at deep reduction states 2024 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Oxygen carriers have an important role as bed materials in both common circulating fluidized bed combustion unit (also known as oxygen-carrier-aided combustion, OCAC) and in various chemical looping processes. Contrary to conventional bed materials, e.g., sand, oxygen carriers are capable of transferring both oxygen and heat. This makes it possible to produce nitrogen-free product gas streams (in the case of chemical looping processes) and achieve a higher fuel conversion. Having been studied for almost three decades, various oxygen carriers show their own pros and cons depending on the processes for which they are intended to be used. Most of the published studies before this doctoral thesis focused on the reactivity and utilization of oxygen carriers in chemical looping combustion (CLC), where a complete fuel conversion is always desired. Nevertheless, this is not the case in, for example, chemical looping gasification, reforming, and water splitting, where only partial fuel oxidation is necessary, and the produced flue gases are the desired products. In such processes, the oxygen carriers can be exposed to a higher reduction degree than it would be in CLC or OCAC. This warrants further investigations into the deep reduction states of relevant oxygen carriers, which are expected to encounter inevitable performance issues under such a harsh environment. In this thesis, some aspects related to the physical performance and properties of various iron-based oxygen carriers in the occurrence of deep reduction states are examined and presented. The first part of the thesis focuses on the fluidization performance, attrition resistance, and particle size and shape analysis. This part is important mainly for assessing material stability. Iron-based oxygen carriers typically tend to encounter bed defludization at a high degree of reduction. The outward migration of iron into the particle surface, which typically creates a FeO/Fe layer, likely causes defludization. Furthermore, the oxidation state of oxygen carriers does affect the attrition resistance of iron oxygen carriers to varying extents. The results indicate that the presence of Fe-Ti and Fe-Si combinations contribute to a generally stable and low attrition rate, while an Fe-Ca system exhibits a decreasing attrition rate. In addition, the influence of exposure to redox cycles and oxidation degree on the size and shape of oxygen carrier particles seems to be minimal. The oxygen carrier particles generally have a high sphericity but are slightly elongated. Reactivity and fuel conversion are the other focuses of this thesis. These have main implications for engineering design but also for material screening. The apparent kinetic study of oxygen carrier performed in this thesis demonstrates that the changing grain size (CGS) model is applicable to predict the reactivity of three iron oxygen carriers in the presence of CO, H2, and CH4. This applies even at lower oxidation degrees (3 – 5 wt.% reduction), where the reactivity of oxygen carriers has generally decreased. Finally, the gasification rate of pine forest residue char remains at similar levels when using either ilmenite or iron sand as the oxygen carrier.
36.	Lindskog, P, et al. (författare) Optimization as a tool for characterization of advanced constitutive models describing powder compaction 2007 Ingår i: Proceedings of the Euro PM 2007 Congress and Exhibition. - Shrewsbury : European Powder Metallurgy Association. ; , s. 381-386 Konferensbidrag (refereegranskat)abstract The applicability of optimization procedures used in combination with advanced constitutive models, describing dry pressing powder compaction, is investigated by aid of standard finite ele- ment and optimization commercial packages. It is found that, at fairly general conditions, this can be expected to be a very advantageous approach at material characterization
37.	Winikka, Henrik, et al. (författare) Particle formation during pressurized entrained flow gasification of wood powder : Effects of process conditions on chemical composition, nanostructure, and reactivity 2018 Ingår i: Combustion and Flame. - : Elsevier BV. - 0010-2180 .- 1556-2921. ; 189, s. 1339-1351 Tidskriftsartikel (refereegranskat)abstract The influence of operating condition on particle formation during pressurized, oxygen blown gasification of wood powder with an ash content of 0.4 wt% was investigated. The investigation was performed with a pilot scale gasifier operated at 7 bar(a). Two loads, 400 and 600 kW were tested, with the oxygen equivalence ratio (λ) varied between 0.25 and 0.50. Particle concentration and mass size distribution was analyzed with a low pressure cascade impactor and the collected particles were characterized for morphology, elemental composition, nanostructure, and reactivity using scanning electron microscopy/high resolution transmission electron microscopy/energy dispersive spectroscopy, and thermogravimetric analysis. In order to quantify the nanostructure of the particles and identify prevalent sub-structures, a novel image analysis framework was used. It was found that the process temperature, affected both by λ and the load of the gasifier, had a significant influence on the particle formation processes. At low temperature (1060 °C), the formed soot particles seemed to be resistant to the oxidation process; however, when the oxidation process started at 1119 °C, the internal burning of the more reactive particle core began. A further increase in temperature (> 1313 °C) lead to the oxidation of the less reactive particle shell. When the shell finally collapsed due to severe oxidation, the original soot particle shape and nanostructure also disappeared and the resulting particle could not be considered as a soot anymore. Instead, the particle shape and nanostructure at the highest temperatures (> 1430 °C) were a function of the inorganic content and of the inorganic elements the individual particle consisted of. All of these effects together lead to the soot particles in the real gasifier environment having less and less ordered nanostructure and higher and higher reactivity as the temperature increased; i.e., they followed the opposite trend of what is observed during laboratory-scale studies with fuels not containing any ash-forming elements and where the temperature was not controlled by λ.
38.	Finnerman, Oskar, et al. (författare) Reactor modeling assessment for urea-SNCR applications 2017 Ingår i: International Journal of Numerical Methods for Heat and Fluid Flow. - : Emerald Group Publishing Limited. - 0961-5539 .- 1758-6585. ; 27:7, s. 1395-1411 Tidskriftsartikel (refereegranskat)abstract Purpose – The work investigates the effects of neglecting, modeling or partly resolving turbulent fluctuations of velocity, temperature and concentrations on the predicted turbulence-chemistry interaction in urea-SNCR systems.Design/methodology/approach – Numerical predictions of the NO conversion efficiency in an industrial urea-SNCR system are compared to experimental data. Reactor models of varying complexity are assessed, ranging from one-dimensional ideal reactor models to state-of-the-art CFD simulations based on the DES approach. The models employ the same reaction mechanism, but differ in the degree to which they resolve the turbulent fluctuations of the gas phase. A methodology for handling of unknown experimental data with regard to providing adequate boundary conditions is also proposed.Findings – One-dimensional reactor models may be useful for a first quick assessment of urea-SNCR system performance. It is critical to account for heat losses, if present, due to the significant sensitivity of the overall process to temperature. The most comprehensive DES setup evaluated is associated with approximately two orders of magnitude higher computational cost than the conventional RANS-based simulations. For studies that require a large number of simulations (e.g. optimizations or handling of incomplete experimental data), the less costly approaches may be favored with a tolerable loss of accuracy.Originality/value – Novel numerical and experimental results are presented to elucidate the role of turbulent fluctuations on the performance of a complex, turbulent, reacting multiphase flow.
39.	Odnevall Wallinder, Inger, et al. (författare) Predictive models of copper runoff from external structures 2004 Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry (RSC). - 1464-0325 .- 1464-0333. ; 6:8, s. 704-712 Tidskriftsartikel (refereegranskat)abstract A general model for annual runoff rate predictions of total copper from naturally patinated copper on buildings at specific urban or rural sites of low chloride influence has been deduced from laboratory and field data. All parameters within the model have a physical meaning and include the average annual rain acidity ( pH), the annual rain quantity and the geometry of a building in terms of surface inclination. In 70% of all reported annual runoff rates, the predicted values are within 30% from the observed values. The individual and interactive effect of rain composition in terms of pH, sulfate, chloride and nitrate concentration was investigated in immersion experiments in artificial rain water representative of urban and rural sites of Europe. The results show pH to have a dominating effect on patina dissolution, nitrate to have a small inhibiting effect, whereas no significant effect was seen for chloride and sulfate. In case pH data are not available, a model has been statistically deduced from field data by considering SO2 as influencing parameter, rather than pH. The predictability with the SO2 model is not as good as with the pH model i.e. the pH model should preferentially be used since it is a better predictor and all parameters within the model can be physically explained.
40.	Dahlin, Sandra, et al. (författare) Chemical aging of Cu-SSZ-13 SCR catalysts for heavy-duty vehicles –Inﬂuence of sulfur dioxide 2018 Ingår i: Catalysis Today. - Amsterdam : Elsevier. - 0920-5861 .- 1873-4308. ; 320, s. 72-83 Tidskriftsartikel (refereegranskat)abstract Selective catalytic reduction of nitrogen oxides is an eﬃcient technique for emission abatement in heavy-dutyvehicles. Cu-SSZ-13 SCR catalysts are more active than vanadium-based catalysts at low temperatures, but aremore sensitive to deactivation by sulfur. Consequently, there is a need to study poisoning by sulfur for thiscatalyst material. This experimental investigation focuses on the eﬀect of sulfur on the low-temperature per-formance of Cu-SSZ-13 SCR catalysts. The eﬀect of sulfur exposure temperature, and the inﬂuence of the NO 2 /NO x ratio, are considered and two diﬀerent regeneration temperatures are compared. In addition, catalystsamples from an engine-aged catalyst are evaluated. The SO 2 exposure temperature is shown to have an im-portant impact on the deactivation of the Cu-SSZ-13 catalyst. The lowest sulfur exposure temperature (220 °C)results in the most severe deactivation, while the highest temperature during sulfur exposure (400 °C) results inthe lowest degree of deactivation. This was found to be related to the amount of sulfur on the catalyst.Additionally, SO 2 exposure was shown to decrease the N 2 O selectivity. The engine-aged catalyst has a decreasedperformance in terms of both decreased activity and increased N 2 O selectivity. For this catalyst, impurities fromfuel and engine-oil can play a role in the deactivation. Diﬀerent deactivation mechanisms are seen for the lab-and engine-aged catalysts.
41.	Shwan, Soran, 1984 (författare) Metal-exchanged zeolites for NH3-SCR applications - Activity and Deactivation studies 2014 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Emissions of nitrogen oxides (NOX) formed during the burning process in internal combustion engines is a major contributor to global air pollutions. One effective way to reduce NOX in lean environments, i.e. oxygen excess is selective catalytic reduction with ammonia (NH3-SCR). Metal-exchanged zeolites have proven to be active as SCR catalysts, where copper and iron are the most common metals. When using metal-exchanged zeolites in exhaust aftertreatment systems, several challenges arise. Resistance towards hydrothermal deactivation and chemisorption of impurities on the active sites of the catalyst are two of the more important challenges. Temperatures between 600-700oC can be seen during regeneration of the particulate filter, which usually is placed upstream close to the SCR catalyst in the exhaust aftertreatment system, and therefore hydrothermal stability of the metal-exchanged zeolite is crucial. Furthermore, high tolerance against catalyst poisons which originate from (bio-) fuels and lubricating oils is desired, where phosphorous and potassium are among the more important poisons. In this thesis thermal and chemical deactivation of iron-exchanged zeolite BEA as SCR catalyst is experimentally studied with special focus paid on the active iron species. Based on the experimental results a kinetic model is developed to predict the decreased activity of the catalyst after deactivation. Several characterization techniques are used to evaluate and correlate structural changes in the catalyst with the decreased activity. Catalysts are prepared and characterized using BET, XPS, XRD, TPD, in-situ FTIR and UV-Vis. The catalytic performance of the samples is measured using a flow-reactor system.It is concluded that the hydrothermal deactivation of Fe-BEA is a result of migration of isolated iron species forming iron cluster inside the zeolite pores and iron particles located on the external surface of the zeolite crystals. Further, it is shown that the growth of iron clusters and particles can be partially reversed by high temperature hydrogen treatment. The chemical deactivation due to phosphorous exposure is the result of formation of metaphosphates replacing hydroxyl groups on the active isolated iron species. Furthermore, the chemical deactivation of Fe-BEA by potassium is concluded to be due to exchange and loss of active isolated iron species in the zeolite forming smaller iron clusters inside the zeolite pores.A kinetic model where different iron species are included was developed based on the hydrothermal deactivation experiments and validated using phosphorous and potassium exposed samples. By fitting and fix the kinetic parameters towards a fresh sample, the decreased SCR activity can be predicted by just decreasing the number of active iron sites, representing loss of active iron species due to hydrothermal treatment and poisoning.The effect of gas atmosphere during solid-state ion-exchange of copper-zeolites was studied as well. It is concluded that copper becomes highly mobile due to formation of copper-ammine complexes in presence of NH3 after reduction of CuII to CuI by adding NO in the exposing gas during the solid-state ion-exchange. Copper-exchanged zeolites could be prepared by exposing physical mixtures of copper-oxides with zeolites to NO and NH3 at as low temperature as 250oC.Finally, the ammonia formation during the rich period of NOX storage and reduction (NSR) cycles was studied using kinetic modeling for the possibility of combining NSR and SCR catalysts in the exhaust aftertreatment system. It is concluded that the formation of ammonia is due to stored NOX and hydrogen from the gas in the first half of the catalyst. However, it was further concluded that the formation of ammonia is delayed due to formation of N2O from stored NOX and formed NH3.
42.	Ström, Henrik, 1981 (författare) Computational optimization of catalyst distributions at the nano-scale 2017 Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 185:Part 2, Special Issue, s. 2224-2231 Tidskriftsartikel (refereegranskat)abstract Catalysis is a key phenomenon in a great number of energy processes, including feedstock conversion, tar cracking, emission abatement and optimizations of energy use. Within heterogeneous, catalytic nano-scale systems, the chemical reactions typically proceed at very high rates at a gas-solid interface. However, the statistical uncertainties characteristic of molecular processes pose efficiency problems for computational optimizations of such nano-scale systems. The present work investigates the performance of a Direct Simulation Monte Carlo (DSMC) code with a stochastic optimization heuristic for evaluations of an optimal catalyst distribution. The DSMC code treats molecular motion with homogeneous and heterogeneous chemical reactions in wall-bounded systems and algorithms have been devised that allow optimization of the distribution of a catalytically active material within a three-dimensional duct (e.g. a pore). The objective function is the outlet concentration of computational molecules that have interacted with the catalytically active surface, and the optimization method used is simulated annealing. The application of a stochastic optimization heuristic is shown to be more efficient within the present DSMC framework than using a macroscopic overlay method. Furthermore, it is shown that the performance of the developed method is superior to that of a gradient search method for the current class of problems. Finally, the advantages and disadvantages of different types of objective functions are discussed.
43.	Farzaneh, Amirfarrokh, et al. (författare) Adsorption of Butanol and Water Vapors in Silicalite‑1 Films with a Low Defect Density 2016 Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 32, s. 11789-11798 Tidskriftsartikel (refereegranskat)abstract Pure silica zeolites are potentially hydrophobic and have therefore been considered to be interesting candidates for separating alcohols, e.g., 1-butanol, from water. Zeolites are traditionally synthesized at high pH, leading to the formation of intracrystalline defects in the form of silanol defects in the framework. These silanol groups introduce polar adsorption sites into the framework, potentially reducing the adsorption selectivity toward alcohols in alcohol/water mixtures. In contrast, zeolites prepared at neutral pH using the fluoride route contain significantly fewer defects. Such crystals should show a much higher butanol/water selectivity than crystals prepared in traditional hydroxide (OH−) media. Moreover, silanol groups are present at the external surface of the zeolite crystals; therefore, minimizing the external surface of the studied adsorbent is important. In this work, we determine adsorption isotherms of 1-butanol and water in silicalite-1 films prepared in a fluoride (F−) medium using in situ attenuated total reflectance−Fourier transform infrared (ATR−FTIR) spectroscopy. This film was composed of well intergrown, plate-shaped b-oriented crystals, resulting in a low external area. Single-component adsorption isotherms of 1-butanol and water were determined in the temperature range of 35− 80 °C. The 1-butanol isotherms were typical for an adsorbate showing a high affinity for a microporous material and a large increase in the amount adsorbed at low partial pressures of 1-butanol. The Langmuir−Freundlich model was successfully fitted to the 1-butanol isotherms, and the heat of adsorption was determined. Water showed a very low affinity for the adsorbent, and the amounts adsorbed were very similar to previous reports for large silicalite-1 crystals prepared in a fluoride medium. The sample also adsorbed much less water than did a reference silicalite-1(OH−) film containing a high density of internal defects.The results show that silicalite-1 films prepared in a F− medium with a low density of defects and external area are very promising for the selective recovery of 1-butanol from aqueous solutions.
44.	Stanicic, Ivana, 1994, et al. (författare) Fate of lead, copper, zinc and antimony during chemical looping gasification of automotive shredder residue 2021 Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 302 Tidskriftsartikel (refereegranskat)abstract Gasification experiments in this study were performed in a 2–4 MW indirect gasifier coupled to a semi-commercial CFB combustor at Chalmers University of Technology. Experiments were carried out during 13 days with automotive shredder residue (ASR), giving a unique opportunity to investigate the bed material under realistic conditions and with long residence times. The metal rich ash was accumulated in the bed, gaining some oxygen carrying capabilities, creating a chemical looping gasification (CLG) process. This study aims to expand the knowledge about the chemistry of zinc, copper, lead and antimony during CLG of ASR. Several experimental methods have been utilized, such as XRD, SEM-EDX and XPS along with detailed thermodynamic calculations to study chemical transformations that can occur in the system. Thermodynamic calculations showed that the reduction potential affect the phase distribution of these elements, where highly reduction conditions result in heavy metals dissolving in the slag phase. Copper and zinc ferrites, lead silicates and antimony oxides were identified at the particle surfaces in the bottom ash. The formation of an iron rich ash layer plays an important role, especially for copper and zinc speciation. The main pathways in the complex CLG system have been discussed in detail.
45.	Annual Transactions of the Nordic Rheology Society - Volume 23 2015 Samlingsverk (redaktörskap) (refereegranskat)
46.	Chalmers Environmental Initiative Progress Report 2001 2001 Samlingsverk (redaktörskap) (refereegranskat)abstract The Board of the Chalmers University of TechnologyFoundation decided in 1999 to invest SEK 100million in a strategic investment in the environmentwith a special focus on environmental systems analysis.This investment was entitled The ChalmersEnvironmental Initiative (CEI). Through thisenvironmental initiative Chalmers has acquired aprominent international position within environmentalsystems analysis.CEI is the result of the active research and educationthat has taken place at Chalmers over the past 10years. A broad base in combination with leadingedge technology presented the opportunity to createa very strong research programme based oninteraction between the various schools at Chalmers.As CEI is integrated into undergraduate anddoctoral programmes at Chalmers, engineers,architects and doctoral students have access, withinthe framework of their studies, to research-basedenvironmental education with a focus on asustainable society. CEI also co-operates with otherparties, such as industry, politicians, various organisationsand the general public, as a further means ofcontributing to sustainable development in society.Within CEI, seven new professors have beenappointed within the following areas:Management for SustainabilityRolf Wolff, 1 June 2000Environmental Systems TechnologyAnne-Marie Tillman, 1 September 2000Sustainable Industrial MetabolismChristian Azar, 1 September 2000Global Environmental MeasurementsDonal Murtagh, 1 November 2000Green ChemistryWilliam J. Frederick Jr, 1 August 2001Sustainable Energy SystemsFilip Johnsson, preliminary 1 October 2001Design for Sustainable Urban DevelopmentVacant: interviews during April 2001The four professors appointed in 2000 are presentedin this report as well as their declaration of intentfor the next few years. At present, the CEI professorsare involved with approximately 40 universities,institutes and industrial partners in the form ofproject co-operation and joint publications. The fourprofessors have the greater proportion of theirenvironmental research funded through externalgrants, compared to CEI. The proportion of facultyfunds and other internal Chalmers funds is at presentvery low. A summary of the financing structureis also included in this report.During 2001, various forms of co-operation wereinitiated between the professors, such as joint projectplans, doctoral students, courses and graduateschools. During autumn 2001, a residential seminaris planned for discussions within CEI as well as anopen presentation of the project and the professors.This major in-house focus on environmental researchhas attracted attention externally and contributedto the opening up of new potential in combinationwith increased expectations. Since May 1, 2000,Chalmers has been a member of the Alliance forGlobal Sustainability (AGS), an association of someof the world’s foremost universities in theenvironmental field. AGS and other platforms formthe basis for international research collaboration.CEI and other environmental activities have led tospin-off effects and contributed to increased interestin Chalmers as an environmental university.Chalmers and Göteborg University were, forexample, jointly awarded the King Carl XVI Gustafvisiting professorship in environmental science for2001-2002 and Margot Wallström received anhonorary doctorate from Chalmers in 2001. A largenumber of well-known environmental researchershave also visited Chalmers to take part inconferences and seminars, including the winners ofthe Volvo Environmental Award for 2000 and thewinner of the City of Göteborg InternationalEnvironmental Award for 2000.
47.	Mouzon, Johanne, et al. (författare) Comparison between slip-casting and uniaxial pressing for the fabrication of translucent yttria ceramics 2008 Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 43:8, s. 2849-2856 Tidskriftsartikel (refereegranskat)abstract Slip casting and uniaxial pressing were compared as first consolidation stages prior to cold isostatic pressing (CIP) to produce translucent yttria ceramics. In the first step, yttria slurries suitable for slip casting were prepared. The viscosity was optimized with respect to the starting agglomeration state, amount of dispersant, milling time, and number of milling balls. Secondly, pellets were prepared either by slip casting or uniaxial pressing and then cold-isostatically pressed. Finally, the pellets were made translucent by a combination of pre-sintering and hot isostatic pressing (HIP). Although slip-cast and pressed samples exhibited similar green-body densities after CIP and pre-sintering, the samples prepared by slip casting were more homogeneous in terms of translucency and microstructure throughout their bodies. This was attributed to the ability of slip casting to minimize density gradients during packing, and to the beneficial effect of ball-milling to remove larger agglomerates before casting. Therefore, slip casting as a first consolidation stage prior to CIP appears to be more suitable than uniaxial pressing in order to prepare homogeneous optical ceramics.
48.	Bendegard, Saga, et al. (författare) Fackexperter, språkexperter och terminologiska frågor i Sverige 1941–1983. Förslag, slutsatser och rekommendationer 2017 Ingår i: Varför svenska? Svenskans beskrivning 36, Uppsala 25-27 oktober 2017. Program. - Uppsala. Konferensbidrag (övrigt vetenskapligt/konstnärligt)
49.	Landqvist, Hans, 1958, et al. (författare) "Gryta bör vara benämning för kärl av kraftigt material ..." Experters bidrag för att skapa terminologiska resurser 2017 Ingår i: Hvem er brukerne av terminologiske ressurser - og hvordan når vi ut til dem? Rapport fra NORDTERM 2017 Kongsberg, Norge, 12.-15. juni 2017 Redaktører: Marianne Aasgaard & Ole Våge. - Oslo : Språkrådet i Norge. - 9788293424079 ; , s. 17-30 Bokkapitel (övrigt vetenskapligt/konstnärligt)
50.	Landqvist, Hans, 1958, et al. (författare) Intresse och engagemang: Kungliga Tekniska högskolans insatser i ett svenskt terminologiskt nätverk 1941–1983 : Interest and involvement: the contributions of the Royal Institute of Technology to a Swedish terminological network 1941–1983 2021 Ingår i: Folkmålsstudier Meddelanden från Föreningen för nordisk filologi. - 0356-1771. ; 59, s. 103-133 Tidskriftsartikel (refereegranskat)abstract In this paper, we study how KTH Royal Institute of Technology (Kungliga Tekniska högskolan – KTH) has participated in and influenced terminology work coordinated by the national terminology centre, the Swedish Centre for Technical Terminology – the TNC, in Sweden during the period 1941–1983. The aim of this paper is to shed light on the development of Swedish (technical) terminology based on networking and experts’ efforts. Based on archive material, we analyze who have been the active KTH experts, in what ways they were involved in the development processes and what effects their efforts had on the term recommendations given by the TNC. The archive material consists of written documents relating to the work process developed by John Wennerberg, who led the TNC between 1941 and 1957. The process was carried out in the form of 373 formal survey letters representing 17 subject fields, with both the TNC and external parties participating. Our results show that the 31 identified KTH experts play a visible role in the processes by 480 received survey letters within 14 subject fields. The response rate, 80 percent, reveal the experts’ involvement in the process and their high esteem of TNC’s work. The analysis of the comprehensive survey letter R198 shows that Wennerberg has considered the experts’ answers regarding terms (selection, linguistic form, acceptance/discourage) and definitions when he has published TNC’s recommendations. Our study shows that networking and experts representing the educational sector and furthermore universities have been an inseparable part of the development of Swedish (technical) terminology during several decades when the national terminology centre in Sweden began to operate and the working methods were established.

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