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591 Uppsatser om Wood fuels - Sida 34 av 40
Realisering av returer vid rundvirkestransport med lastbil : hinder, möjligheter, vinster och vinstdelning
Holmen Skog, region Norrköping, is located in an area with good potential for backhauling because a large number of geographically scattered mills. However, despite these factors there are many difficulties preventing the realization of this potential. The purposes of this study were twofold. First, from a hauling contractor perspective, to calculate backhauling profits and suggest a profit sharing scheme. Second, to identify and quantify obstacles and possibilities for realization of backhauls.The study required the use of three different types of methods.
Analys av designalternativ för snabbare dynamik i kolkraftverk med koldioxidavskiljning
Combustion of fossil fuels is today the dominating source of energy. During combustion,carbon dioxide is formed. The carbon dioxide accumulates in the atmosphere,which raises the global average temperature on earth through the so called greenhouseeffect. The only way to reduce the emissions of carbon dioxide from combustionin a coal fired power plant is through carbon capture and storage (CCS).Post-combustion capture is a technology to separate carbon dioxide from the uegas after the combustion for efficient transport and storage. The steady state operationof coal fired power plants with post combustion capture has already beenthoroughly investigated on a pilot scale, however much work remains to investigatethe plants dynamic operation.
"Here comes more drama! #RHOBH" : En undersökning i hur publiken uttrycker känslor på Twitter i relation till realityserien The Real Housewives of Beverly Hills
Denna studie undersöker hur känslor uttrycks på Twitter i relation till reality-serien The Real Housewives of Beverly Hills. För att kunna göra detta har en metod valts som fungerar bra på att undersöka kulturer på internet, Netnografi. 125 tweets har tematiserats efter känslor och operationaliserats med hjälp av det värdeobjekt som känslorna kretsar kring. Tweeten delades först in som positiva, med kärlek och glädje som känslor. De negativa delades in i äckel, avundsjuka, irritation, ilska och hat.
Pre-treatment of grain for ethanol production during storage
Ethanol for automotive purposes is an issue much debated and researchers disagree about the benefits of bioethanol. Converting energy-rich crops into ethanol suitable as motor fuel is a complex process and continuous development and improvements of processes and material used are important steps in the work of developing environmental friendly fuels. Grain is usually preserved by drying which consumes a lot of energy. Alternative storage of high-moisture grain in airtight storage systems reduce the energy required to produce bioethanol and studies have also shown that ethanol yields are increased more than 10% in ethanol fermentations of moist grain compared to dry. Airtight storage is often not perfectly airtight so biocontrol agents are necessary in order to preserve the grain.
Planteringsförbandets betydelse för kvalitetsegenskaper i Contortatall (Pinus contorta var. latifolia)
In Sweden, large scale planting of Lodgepole pine (Pinus contorta var. latifolia) started in the beginning of the 1970?s. At first, the aim was production of pulpwood, but later, also production of timber became considered realistic. Today, Sweden has more than 520 000 ha of Lodgepole pine.
TRUPP - Modell för uppföljning av åkeriernas rundvirkestransporter hos Norra Skogsägarna
Effektiv styrning av ett logistiskt system kräver vanligtvis en uppföljningsprocess som ger feedback. Historiskt har dock utvecklingen inom virkeslogistik fokuserat på modeller och beslutsstöd enbart för destinering och ruttplanering. Målet med denna studie var därför att utveckla en modell för Norra Skogsägarna som på åkerinivå möjliggör effektiv uppföljning av utfört transportarbete under en avgränsad tidsperiod (dygns- till veckonivå).
Den utvecklade modellen ? TRUPP (TRansportUPPföljning) ? baserades på en sorteringsmetodik i Excel. Det första steget består av en sortering av utförda frakter, per åkeri och tidsperiod, i olika kategorier med potentiellt inoptimala frakter.
Studie av Karlskogas fjärrvärmenät för att sänka returtemperaturen
A district heating plant has the advantage that it can take advantage of the waste heat from industries and use of cheap fuels to produce heat. But for the long term is competitive requires that energy is also saved in district heating plants. One way to save energy in a district heating system is to increasing cooling to the return temperature. This leads to less power needed to drive the distribution pumps, and that more energy could be extracted from the same amount of fuel by an improved flue gas condensation.In Karlskoga the return temperature into the district heating plant is high. They would therefore reduce the return temperature in order to extract more energy from the flue gases.
En jämförelse mellan två olika trästomsystem och byggmetoder : Planelement med pelar-balksystem och volymelement med regelsystem
Negativ miljöpåverkan i form av föroreningar och koldioxidutsläpp är enorm idag. Men också de stora kostnader som tillkommer när man ska försöka bygga miljösmart. Framtiden kräver av oss att börja utnyttja förnyelsebara råvaror för en hållbar utveckling. Trä anses vara ett miljövänligt material och bör användas som stommaterial i höga byggnader i större utsträckning än det görs idag. De vanligaste stomsystem som förekommer i träbyggnader är pelar-balksystem, skivsystem av massivträ och regelsystem. Dessa tre stomsystem kan sedan kombineras i tre olika byggmetoder: platsbygge, prefabricerade planelement eller prefabricerade volymer.Det finns flera aspekter som påverkar valet av stomsystem och byggmetod, t.ex.
Kartläggning av ruttplaneringsprocesser för rundvirkestransportörer
Transportation represents 10-15 % of wood supply costs. It is therefore important to improve efficiency in the transport system to decrease these costs. The aim of this study is to map the timber vehicle routing processes used by a sample of timber hauling contractors and to identify possible links between the vehicle routing process and service and economic variables. The study was carried out at Södra Skog in autumn 2008. 15 timber hauling contractors were sampled and interviewed about their work with timber transports.
Effekten av demand-supply chain management : Fallstudie från trävaruindustrin
Enligt Carlsson och Rönnqvist (2005) och Frayret et al. (2007) blir det allt viktigare att arbeta med supply chain management inom trävaruindustrin. En utmaning är att finna ett arbetssätt för att hantera variationen i kundens efterfrågan. Idag hanteras variationen oftast genom onödigt stor lagerhållning (Lee et al., 1997b; So och Zheng, 2003). Syftet med studien är att utreda påverkande faktorer som bidrar till en varierande efterfrågan inom trävaruindustrin samt föreslå hur uppkomsten av dessa kan undvikas. För att svara på syftet har tre frågeställningar tagits fram och en fallstudie genomfördes på ett hyvleri.
Vermicompost for reduction of vegetable waste - and a possible means to produce fish feed in aquaponic systems?
Aquaponics is a food production system consisting of a consecutive cultivation of plants and aquatic animals, fish or shellfish, in recirculating water. The plants feed on the nutritious effluents from the fish tank and bacteria converts ammonia from the fish tank into nitrate that is absorbed by the plants. The plants receive nutrition and the fish gain purified water.
The environmental impact of the production of fish meal and fish oil used in conventional fish feed includes a large consumption of fossil fuels with subsequent carbon dioxide emission.
The aquaponic system can be made environmentally sustainable and self-supporting if supplemented with a vermicompost/vermiculture for the production of worm protein as a fish feed.
Vegetable waste from the hydroponic part of the system can be reused as worm feed in the compost and the protein rich worms can be harvested, dried and grinded and brought back to the aquaculture as fish feed.
As a first step in this direction, I have investigated the effect of recycling of vegetable waste in vermicomposts on the growth and number of earthworms (this was evaluated after harvesting).
The hypotheses were that earthworms can be cultivated in the vegetable waste and that by adding manure to the vermicompost it is possible to obtain a nutrient content adequate to support a continuous worm harvest, in other words create a vermiculture.
Eisenia fetida and Dendrobaena veneta were grown in 20 L bins containing peat mixed with either poultry or cattle manure. The proportions were 70% peat and 30 % manure. Discarded plant parts from lettuce cultivation was added to the vermicomposts (35 g per week) and water was supplied
with 0.8 L per week.
Bois Durci : Ett designprojekt inom 5 mil
Människor förbrukar så mycket resurser att natureninte hinner med att återställa sig och där medförsvinner material allt mera. Det bästa vore om vimänniskor enbart använde oss av material som förbrukadesi samma takt som naturen kan återställa dei.Detta designprojekt fokuserar på Bois Durci, pådess tillverkning och användning. Materialet ärgjort av blod och sågspån och var tillgängligt på1800-1900-talet och försvann när bakeliten kom. Detsägs att materialet är bakelitens fader. I arbetet harjag samarbetat med ett företag från Torsåker i centralaSverige och arbetet utefter deras koncept somgrundar sig i att enbart använda sig av råvaror inomen femmilsradie.Arbetet har utgått från frågeställningen ?Kan BoisDurci tillverkas inom en femmilsradie och hur kanjag som designer ta mig an materialet?? Att användasig av en femmilsradie med utgångspunkten frånTorsåker var inte ett problem, det var enkelt att få tagi både blod och sågspån.
Handelsutvecklingen efter Lettlands självständighet : En studie om ekonomisk transition under perioden åren 1993 fram till 2004
The main purpose of this essay is to investigate if Latvia´s pattern of trade has become more similar to the mature market economies, after Latvia´s independence 1991.Today, the intra-industry trade (IIT) dominates the trade of mature market economies. One of the pioneers of intra-industrial trade is Paul Krugman, who was the first to emphasize the importance "of scale and consumers' desire for variety" in explaining the basis for modern commerce. Customers get more variety and usually cheaper goods when the market gets bigger. I mainly use the modern trade theories to explain the trade pattern in Latvia. To measure how Latvia has developed its intra-industry trade, and thereby is approaching the mature market economies´ trade pattern, I use the Grubel-Lloyd index (GL-index).
Svenska hushålls vedarbete : en fallstudie i Umeåregionen
In Sweden there are 354 000 private individuals owning forest. Of these forest owners there are at least two thirds that are self-employed, which means that about 215 000 forest owners conduct some kind of work in their own forest. Those numbers do not refer to firewood production, but every year 7.3 million piled cubic meters of firewood are used for heating Swedish households. This implies that many households are also producing firewood.
The objective of this study was to assess and analyse the small-scale firewood production in the Umeå-region in terms of persons engaged in the work, equipment used, produced volumes and share of forest-owning households involved in these activities. According to results from a questionnaire, the average firewood producing person is a man between 40-60 years old.
Organizing for value creation : a corporate perspective on urban farming
In the year 1800, about 5 % of the world population lived in cities (World Wide Fund for Nature, 2012, 3). Today that number is about 70 % in Europe and North America, and in 2050 it is expected to be 86 % in the developed world and 67 % in the developing world (www, UN, 2009). In addition, the global population is expected to increase with 2.2 billion people until 2050. As a result of the population increase more food has to be produced which requires more transport from the countryside to the cities. However, this flow of resources faces some difficulties.