Harmful emissions are a global issue and cause trouble for human health and for the environment. There is a wide variety of pollutants and one pollutant is hydrogen sulfide, H2S, that is a member of the group Volatile Sulfur Compounds. H2S is a compound that is known for its smell of rotten eggs and is detectable by the human nose at very low concentrations. At higher concentrations, H2S is highly toxic and even deadly for humans. It is also a corrosive gas, and can, therefore, cause problems for materials that are being exposed to it. This can be an issue when H2S is present in biogas since it can damage engines or pipes. It can also poison catalysts that are used for methane upgrading. There are different methods of removing H2S from air and common ones are to use adsorption media or catalytic oxidation for gas-solid reactions. The catalytic oxidation is oxidizing the H2S and converts it into elemental sulfur. A problem with these techniques is that they need replacement after some time when they have been saturated. The aim and objectives for this project are to find appropriate materials to test in a test rig that was finalized at the beginning of the project, to compare their lifetime. This was done to find the most cost effective material for H2S removal. The effect of humidity in the air was also examined. Eight different samples were tested. Two of these were activated carbonwithout impregnations and the other six were partial catalytic materials (impregnated carbons or metal oxide based materials). The partial catalytic materials were significantly better than the activated carbons. The lifetimes varied among the partial catalytic materials as well, andare believed to be due to different active compounds on the surfacesand the structure. When running the experiments with 70 % relative humidity, the lifetimes were significantly longer than when the same materials were run for 30 %. A lower concentration of H2S in low relative humidity showed lower or the same loading capacity than higher concentrations. Regeneration was tested for one of the metal based materials with a satisfactory result. / Skadliga utsläpp i luften är en global diskussion och orsakar problem för människors hälsa och för miljön. Det finns en mängd olika föroreningar och en av dessa är vätesulfid, H2S, som är en flyktig svavelförening. H2S är en förorening som är känd för att lukta ruttna ägg och detekteras av en människas luktsinne redan vid mycket låga koncentrationer. Vid högre koncentrationer är H2S mycket giftig och till och med dödligt. Det är också en frätande gas och kan därför orsaka problem för material. Detta kan vara ett problem med H2S i biogas eftersom det kan skada motorer eller röranslutningar. Ett annat problem är att föreningen kan förgifta katalysatorer som används för uppgradering av metan vid biogasproduktion. Det finns olika metoder för att avlägsna H2S från luft och några avde vanligaste är att använda adsorptionsmedia eller katalytisk oxidation. Den katalytiska oxidationen oxiderar H2S och omvandlar det till elementärt svavel. Ett problem med dessa tekniker är att materialet behöver bytas ut efter en tid då de mättas. Syftet och målen för detta projekt är att hitta lämpliga material att testa i en provrigg som byggdes färdigt i början av projektet, för att jämföra deras livstid och hur livslängden kan relateras till deras kostnad. Detta gjordes för att hitta det mest kostnadseffektiva materialet för borttagning av H2S från luft. Effekten av luftfuktighet undersöktes också. Åtta olika material testades. Två av dessa var aktivt kol utan impregneringar och de andra sex var impregnerade kol och metalloxidbaserade material. De impregnerade aktiva kolen och de metallbaserade materialen var signifikant bättre än de aktiva kolmaterialen. Livslängden var även olika för de impregnerade aktiva kolmaterialen, och antas bero på hur impregneringarna genomfördes och materialens struktur. När experimenten kördes med 70% relativ luftfuktighet var livstiden signifikant längre än när samma material kördes med 30% relativ luftfuktighet. En lägre koncentration av H2S i låg relativ fuktighet resulterade i lägre eller samma kapacitet att ta upp än H2S vid högre koncentrationer av H2S. Renegenerering testades för ett av de metallbaserade materialenmed tillfredsställande resultat.

Wastewater treatment plants (WWTP) are often the cause of malodor. The compounds which are the main causes of the odor is hydrogen sulfide (H2S), ammonia(NH3), mercaptans (RSH) and volatile organic compounds (V OC) [1]. The odorous air can be analyzed to determine the concentration of the odorants. The odorous can also be analyzed by measuring the odor. The odor is measured, a test panel of people smells the odorous air and determines how many times greater the concentration of the odorants is compared to the odor threshold which is the concentration at which a compound or a mixture is detectable by smell [3]. Measurements were done at three systems for air purication at three different locations, the Vimmerby WWTP, the Alvim WWTP and Renova's biological waste treatment facility in Gothenburg. The odor was measured at the inlet and the outlet and the concentration of H2S and ozone (O3) were measured at all the sampling points of the systems. The system at Vimmerby consisted of three CIFs followed by an UV-reactor and an AC-reactor. In Alvim there were two system which used UV and AC. The system at Renova consisted of a barrier filter followed by UV and AC. The system at the Vimmerby WWTP had a conversion rate between 87-97% of H2.S The CIFs had conversions between 50-64% of the H2S. H2S was not detected at any of the other systems. O3 was only detected at Renova where ground level O3 was present at the inlet, 0.16 ppm. The concentration increased to 0.20 ppm after the UV-reactor. The activated carbon could adsorb all the incoming O3. The odor at the Vimmerby WWTP was determined to 27500 Ou/m3 at the inlet and 19071 Ou/m3 at the outlet. The odor conversion over the system was 31%. The odor conversion at the Alvim WWTP was 99.8%. With an odor of 5490 Ou/m3 atthe inlet and 11 Ou/m3 at the outlet. The ingoing air at the system at Renova had an odor of 434 Ou/m3 and was reduced to 36 Ou/m3 at outlet. The odor conversion at Renova was 92%. To increase the accuracy of the measurements the time between the sampling and measurements should have been minimized. The test panels should also have been larger and the panelists should have been screened in advance, so results from panelists which were over and under sensitive to odors were not included in the final results. / Vattenreningsverk är ofta en källa till dåligt lukt. De kemiska föreningar som är den huvudsakliga orsaken till dålig lukt är svavelväte (H2S) ammoniak (NH3),merkaptaner (RSH) och lättflyktiga organiska föreningar (V OC) [1]. Det går att mäta lukt genom att mäta koncentrationen av föreningarna som orsakar den dåliga lukten. Det går även att avgöra hur stark lukt är genom att en testpanel får lukta på utspädda luktprover. På så vis går det att bestämma hur många gånger luften måste spädas ut för att nå lukttröskeln. Lukttröskeln definieras som den koncentration som ett ämne eller en blandning går att detektera med hjälp av lukt [3]. Matningar gjordes vid system för luftrening vid tre anläggningar, två vattenreningsverk, Vimmerby och Alvim, och Renovas behandlingsanläggning för biologåkt avfall i Göteborg. Lukten mättes vid inloppet och utloppet av sytemen. H2S och O3 mättes vid alla av systemens mätpunkter. Systemet i Vimmerby bestodav tre katalytiska järnfilter i serie följt av en UV-reaktor och aktivt kol. I Alvim fanns det två system med UV följt av aktivt kol. Hos Renova bestod systemet av ett partikelfilter följt av UV och aktivt kol. Systemet vid Vimmerbys vattenreningsverk hade en omsättning mellan 87-97% av HSS Omsättningen av H2S  över de katalytiska järnfilterna var mellan 50-64%. H2S detekterades inte vid några av de andra systemen. O3 detekterades endast vid Renovas anläggning där marknära O3 fanns i det ingående flödet, 0.16 ppm. Koncentrationen ökade till 0.20 ppm efter UV -reaktorn. Det aktiva kolet klarade avatt adsobera allt det inkommande. Lukten vid systemet vid Vimmerby mättes till 27500 Ou/m3 vid inloppet och vid utloppet till 19071 Ou/m3. Omsättningen av lukten bestämdes till 31% över systemet. Omsättningen av lukten vid Alvim bestämdes till 99.8%. Lukten vidinloppet var 5490 Ou/m3 och 11 Ou/m3 vid utloppet. Luften vid inloppet vidsystemet hos Renova var 434 Ou/m3 och 36 Ou/m3. Omsättningen av lukten hos Renova var 92%. Exaktheten för mätningar kunde ha förbättrats om tiden mellan provtagningen och analysen av provet hade minimerats. Testpanelen skulle också haft flera deltagare som skulle varit gallrade i förväg så att resultat från paneldeltagare som var över- och okänsliga för lukt inte fanns med i det slutgiltiga resultatet.

Coatings cover most objects in our daily lives. They can have functional properties such as protecting the coated material or esthetic properties to decorate and provide pleasant appearance. Coatings have historically dried by evaporation of solvents, but now, UV curing coatings are on the uprising. Acrylate functional groups on polymers, oligomers and monomers react through radical chain polymerization initiated by photoinitiators. Photoinitiators are molecules which forms radicals when irradiated with UV light.Coatings are often applied on multiple layers, each layer providing one function for the overall system. To function properly and have desired life time the layers must adhere to each other. The problem of intercoat adhesion has yet to find good techniques for analysis and explanation of what influences it. Many theories have been suggested and most likely many play a part in the overall adhesion.The master thesis project aim to investigate which properties that influences intercoat adhesion and how it can be studied. To relate properties of coatings to the intercoat adhesion one UV curing primer is set to use for all coating systems, and various topcoats have been produced with slight changes in formulation. The study can be divided into two parts; a pre-study and a main study. The pre-study follows up on a previous master thesis conducted at Sherwin-Williams AB. The pre-study has waterbased and waterbased UV-curable topcoats. The main study has UV curable topcoats. Properties which are studied in the main study are chemical backbone of the binder, functionality of monomers, influence of addition of wetting agents, defoamers, fillers and pigment, viscosity, density, pH, curing degree at depth, surface energy, surface tension, surface polarity and monomer to binder ratio.The pull-off method is the best method of analysis of intercoat adhesion today. A dolly is glued to a surface and then lifted, the force of lifting the dolly is measured. The method has one significant drawback; the break must be completely in the interphase of where the adhesion wishes to be analyzed. Throughout this study most interphase failures were between substrate and primer, resulting in no value for intercoat adhesion.No correlation was found between intercoat adhesion and chemical backbone of the binder, functionality of monomers, addition of wetting agents, defoamers, viscosity, pH, surface energy, surface tension or surface polarity. Lower intercoat adhesion was observed for coatings containing talc, calcium carbonate and titanium dioxide. Coating containing titanium dioxide showed insufficient curing above a coating thickness of 40 μm. The insufficient curing could be observed as wrinkles on the surface and liquid coating remaining in the coating interphase. Curing degree in depth of the topcoat is believed to be the main reason to decreased intercoat adhesion for the coating containing titanium dioxide. The insufficient curing could not be confirmed with infrared spectrometry. The reason why talc and calcium carbonate showed decreased intercoat adhesion is not known. Indications suggest that a lower monomer to binder ratio decrease intercoat adhesion, theories to explain this are the high viscosity and the low number of functional groups per volume. A higher number of functional groups per volume could increase the number of crosslinks formed between topcoat and primer. / Färger finns överallt omkring oss. De kan ha funktionella egenskaper så som att skydda det målade materialet eller ge ett önskvärd utseende. Ett bord ska både tåla att få spillt kaffe på sig och se behagligt ut. Ofta appliceras färger i flera lager för att uppnå önskade egenskaper och utseende. Dessa färglager bör sitta bra i varandra för att inte avflagning ska uppstå. Hur bra färgskikten sitter i varandra kallas mellanskiktsvidhäftning. Mellanskiktsvidhäftning har varit en utmaning genom hela färgindustrins historia och ännu har inga entydiga förklaringar på vad som påverkar eller hur man ska mäta det uppkommit.Kommersiella färger har historiskt varit lösningsmedelsbaserade och torkat. Torkning innebär att flyktiga komponenter i färgen avgår genom att evaporera. I och med moderna försök att minska negativa effekter på miljön har vattenbaserade och helt lösningsmedelsfria färger utvecklats. De lösningsmedelfria färgerna torkar inte utan färgfilmen formas genom en kemisk reaktion initierad med hjälp av ultraviolett (UV) ljus. Ett tidigare examensarbete utfört på Sherwin-Williams AB undersökte mellanskiktsvidhäftningen för en UV härdande grund med vattenbaserade topplacker. Detta projekt är menat som en fortsättning på tidigare projekt men fokuserar huvudsakligen på UV härdande topplacker på en låst UV härdande grund. Syftet med studien är att undersöka hur olika egenskaper hos topplacker påverkar mellanskiktsvidhäftningen samt undersöka hur man kan studera mellanskiktsvidhäftning.Den främsta metoden för att undersöka mellanskiktsvidhäftning konstaterades vara dragprovsmätning, då övriga mätmetoder inte ger entydiga resultat. I dragprovningsmetoden limmas en metallknopp på en yta för att sedan dras av vinkelrätt från ytan och kraften som krävs mäts. Nackdelen med metoden är att för att kunna mäta specifikt mellanskiktvidhäftningen måste brottet ske i gränsskiktet mellan färgerna. Brottet uppstod framförallt mellan substrat och grundfärg under studien.Resultaten från studien kunde inte påvisa ett samband mellan den kemiska strukturen av bindemedlet, antalet funktionella grupper på monomer, tillsatser av vätmedel, skumdämpare, viskositet, densitet, pH, ytenergi, ytspänning, ytpolaritet samt krympning av filmen vid härdning. Resultaten indikerar att tillsats av talk, krita eller titandioxid minskar mellanskiktsvidhäftningen. Anledningen till att talk samt krita minskar mellanskiktsvidhäftningen kan ej förklaras. Titandioxiden påverkade uthärdningen av filmen vilket tros vara anledningen till den minskade mellanskiktsvidhäftningen. Det går att se en indikation att minskat förhållande av vikten monomerer mot vikten bindemedel i färgformuleringen minskade mellanskiktsvidhäftnigen. Detta tros bero på en minskad mängd funktionella akrylatgrupper per volym samt ökad viskositet. Förstudien som använde vattenbaserade och vattenbaserade UV härdande topplacker indikerade en försämrad mellanskiktsvidhäftning för rena vattenbaserade system på UV härdande primer.

The invention of plastic has revolutionized people's life style not only by facilitating the storage and transportation of various goods but also by improving mechanical properties of mankind's technological advances. However, plastic is considered to be harmful, as it contains toxic chemical compounds which are accumulated due to its persistence. Therefore, plastic materials represent a threat to the wildlife, since its extensive use and disposal in landfills and natural habitats increased eminently. People's growing concern about the enviromental impact of pastic and its presence in the food chain led to reflections about designing biodegradable materials that potentially may replace a wide range of plastic materials. It has been found that materials made of specific proteins show plastic-like properties. These protein-based materials are both flexible and remarkable strong. Since proteins are available in great abundance and biodegradable, they are a promising source for creating such desired, environmental friendly materials. Although the physicochemical properties of protein-based material are well-established, the quality needs to be improved in order to make them viable for the market. For this purpose, the molecular structure which determines the physicochemical properties has to be analysed. Whey proteins for example form under non-physiological conditions highly ordered structures, called nanofibrils. These nanofibrils form fine-stranded networks which make the resulting material so flexible and remarkably strong. A well-established to determine the molecular structure of these nanofibrils is by means of Solid State Nuclear Magnetic Resonance (NMR) Spectroscopy. For example whey proteins are well known for forming nanofibrils due to their history of being associated with the development of degenerative diseases. For this reason, they may serve as excellent models for analyzing the molecular structure of amyloid fibrils. The aim of this research project is to determine the molecular structure of amyloid fibrils obtained from the whey protein β-lactoglobulin (β-lg). The major challenge hereby is to prepare isotopic laballed β-lg nanofibrils which is for Solid State NMR measurements required.

Climate change is real. Rising world population and increasing energy demands are taking a toll on the planet. Moving towards a greener, cooler and sustainable future, there is a need for cleaner, efficient, and reliable sources of energy, and biomass is one of them. This thesis work performed at KTH Royal Institute of Technology attempts to contribute to this pressing need. High-pressure biomass gasification technology is an important process intensification step. However, it is not well investigated yet. This work attempts to understand the performance and pave the pathway for future studies. Experiments were performed using olivine, magnesite, and silica sand as bed material. Grot and birch were tested as fuel. The experiments were carried out in a 75 KWfuel bubbling fluidized bed gasifier at 20 bar, using Steam/Oxygen as a gasifying agent. Produced gas composition, tar production, and carbon conversion efficiency were examined. Olivine and magnesite showed good resistance against attrition and agglomeration. Stable bed temperature with no signs of defluidization or sintering were observed during the experiments. Silica sand cannot be used as a bed material with grot due to its high ash content. However, mild agglomeration was also observed with the birch feedstock. Carbon dioxide in the produced gas increased with increase in pressure, whereas, carbon monoxide decreased with increase in pressure. Olivine showed excellent reduction properties for tars lighter than naphthalene, whereas, magnesite performed best for overall tar reduction for grot. It was observed that fuel feeding is a big challenge for running operation at high pressure. These tests at 20 bar were an intermediate step to validate BFB biomass gasification at 40 bar. It would be interesting to study the changes in gas composition, tar, and char formation to evaluate the performance related to carbon conversion efficiency, produced gas composition, and tar production for different bed material at 40 bar.

<p>QC 20140428</p>

Studded tyres are used in many countries around the world. Excessive wear of the road is the result when using studded tyres, and thus time of usage is limited or prohibited. A stud consists of a hard metal part enclosed in steel, aluminium, plastic or rubber, which is anchored in the tyre. Both negative and positive impacts have been assessed by several research groups. Positive impacts is the removal of ice and roughening of the pavement, enhancing friction. Negative effects is regarding human health and pavement excessive wear. Studies on how road or equivalent material is worn require scanning electron microscopy (SEM). If in-depth knowledge of what really occurs on the microscale is obtained, this might provide tools for developing road coatings or studs that contribute to the reduction of particle emission and reduced road wear. Different tests were performed in order to obtain information about the wear mechanisms. Sliding with a stud over a granite specimen, using a scratch tester, gave rise to particles in the range of 1 to 100 micrometer. One single sliding contact (20 mm) resulted in transfer of rock material to the stud tip, meaning that the contact is between minerals from the pavement. One passage resulted in cracks along the contact path in the granite plate, while two scratches removed material. Static load with a stud gave rise to cracks in the granite, which indicate that the structure is weakened. Real over-run by car gave information about stud load, but no information about damage could be obtained on granite specimens from the over-run tests.

No description available.

Globalt sett är tunga transporter starkt beroende av fossila bränslen. Under de senaste åren har deras livslängd och miljöpåverkan granskats under nya uppkomna policyn, vilka är inriktade mot en grönare och hållbar framtid. Bland motsvarande lösningar, anses förnybara bränslen som de mest genomförbara med hänsyn till övergångstiden och anpassningsförmågan med den befintliga flottan. Däremot resulterar ökat utblandad biodiesel till bildandet av organiska föreningar som är skadliga för motorns prestanda. Syftet med denna experimentella studie är att studera interaktionen mellan dessa organiska föroreningar (så kallade mjuka partiklar) med bränslefilter. Tidigare analyserades bränslefilter på Scania efter fältförsök som ofta pågick mellan månader till år. För att påskynda analysprocessen flyttades en tidigare designad småskalig testrigg från KTH till Scania. Under examensarbetet har den småskaliga testriggen genomgått ett flertal försök i syfte att utveckla en metod för att studera filterblockering. Hela projektet kan delas upp i två faser. Fas 1 behandlar förståelsen bakom riggens tillvägagångssätt samt bekräfta om det går att erhålla repeterbara resultat. Dessa resultat erhölls genom fortlöpande tester med ett glas-mikrofiber filter och ett testbränsle innehållande natrium- och kalciumföroreningar. Till följd av dessa försök, observerades avlagringar i bränsleledningar samt pumpar, vilket gav upphov till stora tryckfall och flödesskillnader. Som en lösning infördes en specifik rengöringsprocedur för pumparna och testbränslet ersattes med endast föroreningar med kalcium. I fas 2 testades däremot kommersiella filter med olika konfigurationer i flöden. Dessutom genomfördes efteranalyser med hjälp av GC-MS samt SEM-EDX. När de två huvudfiltren i parallellt flöde jämfördes samtidigt, indikerades en liknande igensättningstrend och filtreringseffektivitet högre än 99%. Dessutom överensstämde resultatet från inflödet med fältförsöken då alla förfilter påvisade en 90% effektivitet under de två försöken och därmed en signifikant minskning på koncentrationen av mjuka partiklar som går in i huvudfiltret. Slutligen bekräftade SEM-EDX filtreringstypen som observerats i bränslefilter och ytnärvaron av dessa kalciumtvålar. Av de metoder som utvecklats för de två faserna, erhölls repeterbara resultat och därmed föreslås det att dessa metoder används för framtida screening av alternativa bränslefilter. / Heavy-duty transportation across the globe is heavily reliant on fossil fuels. Their longevity and environmental footprint has been scrutinized in recent years with the advent of new policies, directed towards a greener and sustainable future. Among the numerous pathways suggested, renewable fuels are seen as the most feasible in terms of the transition time and adaptability with the existing fleet. However, the increased blending of fuels such as biodiesel results in the formation of organic contaminants that are detrimental to engine performance. The motivation behind this thesis is to study the interaction of these organic contaminants, otherwise known as soft particles, with fuel filters. Prior to this work, fuel filters were analyzed at Scania after on-field trials which often took months to years. In order to accelerate the experiments, a previously designed small-scale test rig was shifted from KTH to Scania. During the course of thesis, the small-scale test rig was operationalized in order to develop a method to study filter blocking. The entire duration of the project can be split into two phases namely, Phase 1 and Phase 2. Phase 1 dealt with understanding the operations of the rig and verifying the possibility of obtaining repeatable results. This was done by performing accelerated tests using a glass-micro fiber filter and test-fuel containing sodium and calcium contaminants. As a consequence of these trials, deposits in fuel lines and pumps were observed, causing massive pressure fluctuations and differences in flow. This was solved by adopting a specific cleaning procedure for the pumps and switching the test-fuel to only calcium contaminants. On the other hand, Phase 2 focused on performance testing of commercial filters in two different flow configurations, and post-test analysis using GC-MS and SEM-EDX. Simultaneous comparison of the two main filters in parallel flow indicated similar clogging trends with filtration efficiencies greater than 99\%. Moreover, the results from inline flow were in agreement with on-field trials as the pre-filters reported an efficiency of 90\% during the two experiments, significantly reducing the concentration of soft particles entering the main-filters. Finally, SEM-EDX further confirmed the  type of filtration observed in fuel filters and the presence of these calcium soaps on the surface.  The methods developed for the two phases provided repeatable results thus proposing their use for screening of filter media alternatives.

The objective of this project was to investigate how organic anthropogenic chemicals (OCs) effect the differentiation of adipocytes in the human body. The objective is also to contribute to novel research in how groups of chemicals in our surrounding affect us. The second objective of the project was to examine the exposure levels of the different compounds in the mixture during and after the differentiation of the stem cells. By setting up a method using GC-MS and spiking samples with a PCB/Pest mixture the retention time and optimal parameters could be determined.  Previous literature studies have resulted in a chemical mixture of the 50 most common OCs analyzed in human blood from the general population and are named the RiskMix chemicals. The RiskMix was prepared in a chemical mixture used to expose the human mesenchymal stem cells (hMSC) during a ten-day long adipogenesis model for the differentiation to adipocytes. The method used is a toxicological assay to determine how and if the hMSCs are affected by this chemical mixture in concentrations of 0.01 – 100 times human relevance.  During the differentiation of the hMSCs the chemical mixture was added in different dilutions and the results showed a significant difference in % adipocytes when exposed to the mixture of 100 times human relevance. However, the number of cells developed, meaning the total number of cells developed both to adipocytes and other cells, showed no significant difference. This means, that the total number of cells developed were not affected by the chemical mixture in the sake of toxicity. The recovery of each compound was calculated between 30-70% showing that the method needs further optimization for the compound with the lower recovery. The relative standard deviation - RSD was calculated to majorly below 20% and shows that the method was stable. The project concludes that chemicals in the RiskMix at 100 times the human relevance has an impact on the development of human adipocytes. However, future studies are required to fully understand which ones of these chemicals contribute to the adipogenic effect and if there is a combined effect of the compounds.