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592 Uppsatser om Sampling simulation - Sida 35 av 40

Methane production from dairy cows : relations between enteric production and production from faeces and urine

Methane (CH4) is a greenhouse gas (GHG) that contributes to the global warming. One of the largest sources of methane is livestock, preferably ruminants which alone counted for 30% of the total agricultural anthropogenic methane emissions in the year of 2000. The reason to why ruminants are such large contributors of methane are that the gas is produced in the rumen by enteric formation and leaves the animals by belching, exhaling or by the excreta.Diets high in concentrates can result in a lower emission of methane. Also diets with a high content of starch, such as alfalfa-grass, have a methane-decreasing. It is profitable to reduce enteric methane formation since that form of methane is unavoidably lost.

Undersökning av egenskaper hos vibrationsdämpare

På Käppalaverket i Stockholm står luftningen av de biologiska bassängerna för omkring en femtedel av verkets totala elenergiförbrukning. I ett försök att minska energikostnaden utvärderades under hösten 2010 nya metoder för luftflödesreglering på verket. Grundtanken var att styra luftflödet efter medelvärdet på utgående ammoniumkoncentration under en längre tid, istället för som idag efter momentana värden.Ett vanligt sätt att styra luftflöden på reningsverk idag är att använda återkoppling från utgående ammoniumkoncentration, vilket syftar till att alltid hålla den utgående koncentrationen vid ett valt börvärde. Lagstiftade gränsvärden på ammonium avser dock normalt medelvärden över en längre tid, såsom kvartal eller år. Istället för att anpassa luftflödet efter den inkommande belastningen är det därför möjligt att hålla luftflödet relativt konstant medan istället den utgående koncentrationen tillåts variera.I denna studie visades en energibesparing kunna erhållas om luftflödets variation reduceras.

Influence of prescribed burning and/or mechanical site preparation on stand stem density and growth of Scots pine stands above the Arctic Circle : results 9-19 years after stand establishment

Prescribed burning was commonly used for site preparation in Sweden to establish new forests until the 1960?s, when mechanical scarification was introduced. During recent decades the interest in prescribed burnings has increased again, mainly due to certifications of forestry stating that 5% of the regeneration areas should be burned on dry and mesic soils. The objective of the study was to evaluate actual influence of prescribed burning compared to other site preparation on stand stem density, growth parameters and tree damages for Scots pine (Pinus sylvestris L.) after direct seeding and planting. The study also attempts to simulate growth until first thinning.

The French market and customers? perceptions of Nordic softwood offerings

The study of the French market for softwood has been done in collaboration with VIDA AB. The aim of the study was to investigate important product quality and service quality dimensions, the customers? perception of the offering and generally describe the French market and present actors. The market for softwood around the world changes over time and new markets can mean opportunities for the sawmilling industry. The French market is the second biggest European market for softwood, has had presence of actors with sourcing of raw material from the Nordic countries for decades and there is a growing interest for building with wood. Theory being used is about the different dimensions that make up the total quality of softwood, together with intangible dimensions making up the total offering that helps the sawmilling industry to create positive perceived value for the customers. Methodological approach in the study was a case study research design, aimed at providing knowledge about one specific subject in one context. The general description was mostly carried out by literature studies and data from various statistics sources.

Utvärdering av fjädrande statorfötter : Nytt koncept i vattenkraftgeneratorer

This thesis is an evaluation of a new design concept for statorfeets in Gallejaur hydro power plant. Founder of the work is Vattenfall AB Vattenkraft. During the 70- and 80´s nuclear power began to be phased in to the Swedish grid, which meant that hydropower became an important source of rules. The generators began running in so called intermittent operations instead of basic operations, which meant 300-600 start/stop per year instead of one-ten numbers start/stop per year. In order to deal with the thermal forces that arise at every start and stop suppliers began to mount so called sliding joints, which is to take advantage of these forces and maintain the stator shape.

Musik i samband med venprovtagning för att lindra stress och smärta hos patienten : En interventionsstudie

Bakgrund: En av sjuksko?terskans grundla?ggande uppgifter a?r att lindra patientens lidande i samband med va?rd. Lugn musik har visat sig vara ett effektivt verktyg fo?r att minska patienters upplevelser av stress och sma?rta vid flera procedurer inom sjukva?rden. Parametrar som hja?rtfrekvens och blodtryck kan pa?verkas av musiken.

Korrelation mellan hållfasthet i kalkcementpelare och oförstärkt lera : En studie av sonderingar utförda på projekt BanaVäg i Väst

A today common soil reinforcement method is the installation of lime-cement columns. Lime-cement columns have been used since the 1970?s and have been a useful method for stabilizing soil at great depths. It is mostly used for stabilizing road and railway embankments because the method is economically viable and the columns are easy to install. The total costs for the installation of the lime-cement columns is dependent on the numbers of installed columns, what percentage of lime and cement that has been used and the pattern in which the columns has been installed.

Friluftsliv i gymnasiet: Elevers engagemang, motivation och erfarenheter : En kvalitativ intervjustudie om gymnasieelevers upplevelser av friluftsundervisning

The purpose of this study is to examine how outdoor education (friluftsliv) in upper secondary school is perceived by both students and teachers, and to identify the conditions that influence their motivation and commitment to participate in outdoor education activities. The study also aims to analyze the significance of students previous experiences on their perceptions of outdoor education in school. The following research questions were investigated: ? ? ? ?Which factors do students and teachers believe promote or hinder students engagement in outdoor education in upper secondary school? ? ? ? ?How do students and teachers explain the ways in which previous experiences of outdoor activities affect students engagement and motivation in outdoor education? ? ? ? ?How do students and teachers perceive that organizational conditions and teaching design influence the possibilities of creating meaningful outdoor education? The study is theoretically based on Self-Determination Theory (SDT) (Deci & Ryan, 2000) and Sense of Coherence (SOC) (Antonovsky, 1991). SDT was used to understand how autonomy, competence, and solidarity influence student?s motivation, while SOC highlights how comprehensibility, manageability, and meaningfulness shape student?s experiences of outdoor education.

Mesatorrhalt

AbstractDegree thesis Solid content in Lime Mud By Andre Flodin Process operator program ? Umeå University 17/6 ? 2014 Pages: 21A thesis was made on Billerudkorsnäs production unit in Karlsborg where lime kiln in the causticising department of chemical recovery plant does not meet the required production. Causticising department is the final step in the chemical recycling unit. There, the filtered green liquor is mixed with lime to recover the cooking chemicals used in the pulp factory. The cooking liquid is called white liquor.

Utvärdering av VAV i nybyggt kontorshus

VAV (Variable Air Volume) system has been studied in a newly constructed office-building. The goal for the study has been to evaluate how the ventilations system work in practice, if adjustments can be made to achieve an more energy efficient system and to evaluate if other alternative ventilation systems is to be preferred in the further.The degree project has been executed at Helenius Engineering Firm who is working with the environment, media systems, HVAC and energy in buildings. The building that has been studied is owned and operated by Akademiska hus.Literature studies, visits at site, inventory, review of system documentation, energy analyses, interviews, key figures, LCC, sand energy- and indoor climate simulations has been made to study the building. Where appropriate some tools from Six Sigma have also been used.How to achieve an energy efficient system and a pleasant indoor climate is studied with human health and well-being as base for the indoor climate requirements. Technical support systems such as ventilation systems have to be designed so that an acceptable indoor climate can be achieved.

Utvecklingspotentialer i Björkdals anrikningsprocess: Examensarbete Björkdalsgruvan Hösten 2012

Den här studien utredde utvecklingspotentialer i Björkdals anrikningsprocess med inriktning på flotationsprocesserna, vilka utforskades i syfte att ta reda på i vilken utsträckning de skulle kunna bidra till högre och jämnare guldutbyte genom anpassade parameterval. För att beskriva i vilka flöden guldet fördelades i dagsläget uppställdes en materialbalans. Material provtogs, provbereddes och analyserades med avseende på guldhalten. Provtagningsmetoden grab sampling användes och materialprover från sju provtagningstillfällen under dagen slogs ihop och bildade ett prov. Provstorlekarna baserades på empiri men kontrollerades med Gy´s provtagningsformel.

Sustainable shopping : consumer behavior in purchasing and donating secondhand clothes

Textiles are made in an unsustainable way and there is a need to find alternative ways and material to reduce the negative impacts on the environment, humans and animals. Problems like pollution, excessive water consumption and loss of soil fertility is a result of this lack of diversity. It is a necessity to find innovative alternatives in other fabrics due to the unsustainable use of cotton and polyester fibers. As in many other countries in the Western part of the world, in Sweden there is a rapid turnover and increased selling of clothes that result in increased textile waste. About 15 kilogram of textiles (net inflow) is consumed per person each year.

Förbättrat råvaruutnyttjande vid kvalitets-sortering av timmer : utvärdering av analysprogrammet Stockholmen för automatiserad timmersortering i dimensions- och kvalitetsklasser hos BARO WOOD AB

The aim of this thesis was to analyse BARO WOOD AB:s timber measuring and quality sorting and to evaluate the analyse program Stockholmen. The purpose was to get a better understanding for the quality sorting made at BARO WOOD AB today, analyse differences in center board quality from logs with a good quality and logs with a bad quality, suggest new sorting criterias developed from analyses made with Stockholmen and to evaluate the program Stockholmen. All analyses are based on data gathered in a test sawing made at BARO WOOD AB in June and July 2002. The test sawing was made on four different diameter classes and every diameter class consisted out of A or M-grade logs, with a better quality, and B-grade logs with a lesser quality. The logs where sorted out with BARO WOOD AB:s existing quality criterias.

The major food trees of the Angola black-andwhitecolobus (Colobus angolensis palliatus)in Diani Forest, Kenya

The Angola black-and-white colobus (Colobus angolensis palliatus) is a subspecies of Colobus angolensis inhabiting fragmented forests in coastal Kenya and Tanzania. C. angolensis is regarded as Least Concern in the red list of IUCN because its populations are abundant. However, the populations of C. a.

Förbättring av kvävereduktionsprocessen på avloppsreningsverket Lucerna under WTOS-styrning

Förbättring av kvävereduktionsprocessen på avloppsreningsverket Lucerna under WTOS-styrningJonas WenströmÖvergödning av sjöar och hav är idag ett stort miljöproblem vilket samhället bidrar till genom sitt utsläpp av bland annat kväve. Därför har Sverige genom Baltic Sea Action Plan åtagit sig att minska sin belastning på Östersjön från reningsverk med 3000 ton kväve årligen fram till 2021. Om- och utbyggnader av reningsverk kommer att krävas, men en viss förbättring av reningen kan uppnås genom optimering av befintliga processer.Avloppsreningsverket Lucerna i Västervik hade tidigare problem att uppnå tillräcklig kväverening, men sedan processtyrningssystemet WTOS implementerades 2010 klaras kraven. Efter att WTOS implementerats sker luftningen intermittent i verkets aktivslamsteg, i vilken en biologisk rening sker. För att utreda om kvävereningen ytterligare kunde förbättras utfördes denna studie med huvudmålet att lämna förslag på hur kvävereningen kunde förbättras i verkets aktivslamprocess.

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