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336 Uppsatser om Chemical Vapour Deposition - Sida 5 av 23
Recept- och rapporthantering inom blandningsteknik
To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.
Multilateral och unilateral säkerhetspolitisk praktik och strategi för hantering av Syrienkonflikten
This security study attempts to explain the dynamics of international conflict management of an intrastate conflict, through a combination of three theoretical frameworks. The conflict in Syria is shown to be managed mainly through strategies using coercive diplomacy, and some main contributions within the research field relating to strategies of coercion are used for guidance, to important factors which could affect coercive international conflict management, as well as to additional theories which could enhance the study?s explanatory power through a combined theoretical framework. The two added theoretical frameworks are Power Balancing and a Multidimensional concept of Power. With the aid of analytical tools derived from this combined framework the conflict management is analysed within both a multilateral and unilateral setting, offering some explanation as to why international conflict management (practiced by UNSC multilaterally and USA unilaterally) has shown so little progress in regard to the conflict, as well as why one significant, though limited, result could be achieved regarding the destruction of the Syrian regime?s chemical weapons arsenal..
Studier av utseendet på askan i sodapannor med hjälp av bildanalys
To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.
En jämförande studie av fluiddynamiken för olika fluidiseringsmedium i en kallmodell av en 100 kW-anläggning för kemcyklisk förbränning
To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.
Chemical and sensory analyses of juice, cider and vinegar produced from different apple cultivars
The interest for locally produced food is increasing due to consumer concern about the environment, distrust of industrial foods and a demand for high quality products. Apple is the predominant fruit crop in Sweden, and by processing apples into cider and vinegar, these products could significantly contribute to the development of the market of local foods.In this study different yeast types and different bacterial cultures were evaluated for their suitability in cider and vinegar production from cloudy apple juice. Ten apple cultivars (Aroma, Baldwin, Belle de Boskoop, Bramley, Cortland, Gravensteiner, Ingrid-Marie, Jonathan, Rubinola and Spartan) were also evaluated for their suitability for production of juice, cider and vinegar. Chemical analyses including total soluble solids, titratable acidity and total phenols were performed on the products along with sensorial evaluation by taste panels.The yeast strains were shown to have an effect on fermentation rate and the resulting content of total phenols in ciders fermented from cloudy apple juice. Dry commercial starter strains gave a higher appreciated cider compared to cider that was spontaneously fermented, and the ale yeast Safale S-04 was concluded to be the most suited for fermentation of cloudy apple juice.For vinegar production, the bacterial culture had an effect on TSS, but not on any other chemical or taste characteristics.
Energieffektivisering i ett reningsverk för skogsindustriellt avloppsvatten genom förfällning av extraktivämnen
Pulp- and papermills expend vast amounts of water in order to produce pulp, paper and cardboard. Hence, they alsocreate vast amounts of waste water which has to be cleaned before it can be released into the receiving body of water. Insuch a wastewater treatment plant, tremendous amounts of energy are expended by the aeration in the biologicalcleaning process. This aeration is necessary to supply the microorganisms that shall decompose organic material withoxygen, which they need for their metabolism. The transfer of oxygen from the gas phase to the liquid phase isprimarily inhibited by surface-active substances in the waste water like resin acids or fatty acids.
Dominansaggression hos hundar
Sjöfartsektorn är en betydande källa för svavel- och kväveutsläpp. Depositioner av oxiderat svavel, dvs. sulfat, och oxiderat kväve dvs. nitrat, i form av våt och torrdeposition bidrar till försurning och försämrad luftkvalitet. Styrmedel för att minska svavelutsläppen har under de senaste åren bidragit till minskade svavelutsläpp.
Förutsättningar för hantering av kemikalierisker i förskolor : En fallstudie av Haninge kommun
Goods that children come in contact with on a daily basis for example toys, electronics, textiles, household items, have attracted an increased attention in recent years because of a common occurrence of residues of potentially hazardous chemical substances. Some municipalities in Stockholm have developed plans for managing chemical risks and work systematically to phase out products containing hazardous substances. This thesis aims to contribute to an improved knowledge base for any future work with non-toxic nursery schools in Haninge. The study's focus is on the challenges encountered by conditions and problems of preschool personnel to manage chemical risks in early childhood environments. Primary data was collected through a qualitative approach based on semi-structured interviews with both the preschool staff and practitioners working in the central organization of the municipality.
Uppfångning och kvarhållning av 134Cs och 85Sr i olika växtutvecklingsstadier
Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in theevent of rainfall. An increased level of radioactivity in the plants may occur due tointerception and retention of the radionuclides. If the content of the plants is above thethreshold limit value, entire yields may have to be destroyed. In order to preventcontamination or decrease the content countermeasures can be taken. The impact of thebiomass, leaf area index (LAI) and growth stage of the plant on the interception andretention is important to know in order to decide which countermeasures to use.Weather may also be an important factor.In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley andspring oil-seed rape was studied.
Konstruktion av anordning för att undersöka förslitning av syrebärarpartiklar för kemcyklisk förbränning
The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.
Vätskor i indirekt energiöverförande kylsystem och deras potentiella inverkan på miljön
Syftet med studien är att kartlägga innehållet hos vätskorna i de indirekt energiöverförande kylsystemen och att uppskatta deras potentiella miljöpåverkan vid utsläpp. På vätskeprover från system 5 till 8, som är tagna i returledningen på köldbärare 1 i respektive system, har det uppmätts hög syrgashalt, konduktivitet och COD (chemical oxygen demand), vilket ger stor risk för nedbrytning och korrosion. Dessa systemvätskor borde avgasas eller bytas ut. Systemvätskan från system 3, 7 och 8 överskrider gränsvärdena för zink och nickel och de skulle ha toxisk/ - mycket toxisk effekt på vattenlevande djur och växter. Koppar, zink och nickel är nitrifikationshämmande vilket innebär att de påverkar det biologiska reningssteget vid avloppsreningsverket negativt ifall vätskan släpps ut till det kommunala avloppsledningsnätet. Det framgick utifrån den använda värderingsmallen att de sju största miljöaspekterna är relaterade till föroreningsvariablerna: COD (chemical oxygen demand), zink, syrgas, kväve, järn, nickel och pH. Miljöeffekterna uppträder i form av påverkan från metaller och utarmning av naturtyper, biotoper, arter etc.
Sustainable phosphorus management of horse paddocks at Julmyra
Horse keeping is gaining an increasing interest in Sweden. During 2004 to 2010 the number of horses increased
with 10 - 20 %, and was estimated to be 362 700 in 2010. Julmyra Horse Center (JHC), situated in Heby municipality,
is a gated community for people sharing a large interest for horses and a vision of a sustainable horse
management has been formulated. This study evaluates how the horse keeping of today at JHC, and how an
expansion of the horse keeping may affect the risk of enhanced phosphorus load to the nearby lake system
Vansjön ? Nordsjön.
Riskbaserat provtagningsprogram för mikroorganismer i Gäddviks vattentäkt
Risk-based sampling program of microorganisms in the water source in northern SwedenAfter several disease outbreaks caused by parasites in the drinking water during the last years, it is more essential than ever to insure that the water supply companies have enough barriers to counteract the presence of microorganisms in the outgoing water. It is also discussed whether climate changes such as increased precipitation can have a connection to the increased cases of parasites in water sources. The water source at Gäddvik is Luleå municipality?s largest and provides drinking water to 64 500 of Luleå?s 74 000 inhabitants. The investigation of microorganisms in the water source, especially in the Lule River has not been as prioritized as the sampling of chemical parameters.
Avskiljning av uran från dricksvatten med reaktiva filter :
Water is our most important provision and its quality is above all dependent on the
geological conditions in the area from where it is extracted. Due to geological
properties there are certain areas with an elevated risk of high uranium levels in the
ground water, which in turn constitutes a risk for human health. Consumption of water
that contains a high concentration of uranium implies a health risk due to the chemical
characteristics of uranium. Livsmedelsverket (The National Food Administration) and
Socialstyrelsen (The National Board of Health and Welfare) therefore recommend that
precautionary measures should be taken when the uranium concentration in ground
water exceeds 15 micrograms per litre. In particular, drinking water collected from
wells in areas with uranium-rich bedrock may have a harmfully high level of uranium.
One of the wells of the Ärla water purification plant, located near Eskilstuna, Sweden,
contains water that exceeds the guideline of 15 micrograms per litre.
One interesting technique for removing uranium from drinking water is adsorption to
reactive filter materials.
Beräkningsmodell för massbalanser för Slottshagens reningsverk
In the next few years the pollutants loading at the Slottshagen wastewater treatment plant in Norrköping is going to increase due to the reason that one of the waste water treatment plant in the district will be shut down.A survey of how these different pollutants are divided in the treatment process is therefore necessary for mapping out both the loading and treatment efficiency.This can be achieved by studying mass balances.Mass balances were carried out for the water treatment process for the mechanical/chemical,biological and the chemical stage.The mass balance studies show that the treatment efficiency was very good. However in order for the mass balances to be quite consistent and to ensure complete coverage of results and conclusions i.e. more reliable results, sludge samples should be collected and taken at different times per day and the influent rate should be investigated.In this work mass balance has been set up in order to illustrate and identify the factors that should be considered and taken care of for further estimation using mass balances in the future. Furthermore this survey results in a calculating model for the mass balances at thisplant.This calculating model is used as a tool to facilitate future calculations for mass balances for the water treatment process at Slottshagens wastewater treatment plant.Moreover it provides a basis for carrying out further estimation of the treatment process in the near future.In this project the importance of some operating parameters was also taken in consideration.This calculating model can be modified so that calculations of such operating parameters i.e. sludge loading and sludge age can be easily performed.Such information can be used further to evaluate different operation alternative in order to ensure an optimal use of the treatment process with in the plant..