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436 Uppsatser om Biomass losses - Sida 23 av 30
Risken för spridning av röta vid förröjning i granskog i södra Sverige :
Root rot causes large economical losses for Swedish forestry. The spread of root rot can partly be prevented by treating the spruce stumps in thinnings. Late pre-commercial thinning (PCT) is one of the forestry measures where stump treatment is not used. Late PCT can be defined as: The act of cleaning the stand with the aim of improving accessibility and sight within the stand, and so to increase the mean stem´s volume during the first conventional thinning.
The aim of this study was to examine how late PCT is performed, its spatial extent and if it aids the spreading of root rot. The study was limited to encompass late PCT before first conventional thinnings in spruce stands in southern Sweden.
Samples of spruce stumps were taken from four stands where late PTC had been carried out.
Askans inverkan på beläggningstendensen i ett biobränsleeldat kraftvärmeverk och växtplatsens påverkan på askegenskaperna :
This report was written by Sofia Ericson and describes the degree thesis with the title: ?Connections between the growing site of bio fuel, the chemical composition of bio fuel ash and the deposit growth in a bio fuel fired boiler.? The purpose of this degree thesis was to avoid melted deposit growth in the bio fuel fired boiler at ENA Kraft in Enköping.
Potassium and sodium are known to lower the melting point of bio fuel ashes and are therefore not wanted in the trees in higher amounts than necessary for the growth. Silicon is also known to be important for the deposit growth but it is not possible to say in general if higher or lower contents of silicon is better. The relation between silicon and other chemical substances is more important than the total amount of silicon.
Inga miljövinster med ekologisk produktion? : Lägesrapport över den svenska jordbruksdebatten
Organic agriculture is financially promoted in Sweden by special environmental support and as consumers we are all encouraged to buy organic food. At the same time scholars at the Swedish University of Agricultural Sciences claim that organic farming does not provide any environmental benefits. The main criticism is that organic farming has lower yields than conventional, which means that more land is needed to produce the same amount of food as in conventional farming, leading to deforestation and loss of biodiversity. As for climate change, the critics claim that the significantly higher productivity in conventional crop production compared to organic, releases surplus land, which could be used for bio-fuel production and thereby replace the fossil fuels. The critics also claim that organic farming causes higher nutrient leaching than conventional.
Solenergi och värmelagring i kvarteret Lagern
Humanity stands before a huge challenge to lower its emissions of carbon dioxide and its use of energy at the same time as the global population is rising and the developing countries are being industrialized. A lot of newly built buildings are due to this challenge, designed to be more energy efficient but also use renewable energy resources instead of pollutant fossil fuels .Solar energy is one of the purest forms of energy that exists in abundant amounts, which is why it is most likely that it could come to play a major part in the future energy market. The main purpose of this report is to investigate the possibility to implement a sustainable energy system with solar thermal heat and heat storage as main sources of energy in the neighborhood ?kvarteret Lagern?, which is the area where the old football stadium ?Rasunda Stadion? was located. New developments within different heat storage techniques have opened up new approaches to enable buildings an all year round heat supply from solar energy. This report will focus on heat storage in boreholes. At the present here is only a preliminary plan of how the neighborhood is supposed to be designed.
Direct-EGR tillämpat på HCCI
The Homogeneous Charge Compression Ignition (HCCI) engine is promising in terms of lowNOx, low particulates and high efficiency. Due to its homogeneous charge, where thecombustion starts almost simultaneously from a number of points in the combustion chamber,only lean mixtures are possible to burn because of the resulting rapid combustion, which is muchfaster than the combustion in an SI-engine or a diesel engine. When richer mixtures are used thecombustion will start earlier and also be more violent.To phase the combustion later and lower the combustion speed, external cooled EGR can beused. The EGR-system used in this thesis uses a divided exhaust channel where one channel andits corresponding valve are used only for transporting EGR back to the intake system.Consequently the EGR-valve is connected to the intake pressure. This system is called Direct-EGR (D-EGR).Engine tests verified that the CA50 indeed is phased later when cooled EGR is used.
Species diversity and geographical distribution of Fusarium species on winter wheat in two regions in Sweden
Various Fusarium species causes some of the most common cereal diseases worldwide. Besides the yield losses that can be a result of these diseases, strains from several Fusarium species can produce mycotoxins, some very toxic. The aim of this study was to investigate which Fusarium species and how many that occurred in winter wheat grains from Mälardalen and Kalmar län, if there was any difference in the distribution of Fusarium fungi between the regions and the potential within species to produce mycotoxins belonging to the group trichothecenes. Winter wheat grains collected in 2009 from ten fields (unsprayed plots) in the two regions were analysed for Fusarium species. PCR was used to amplify the TEF region where after the samples were sequenced.
Sortimentsinriktad avverkning
Forest enterprises have always searched for ways to improve efficiency. For the past few
years there has been an emphasis on stock-keeping levels. Increased demand for fresh
round timber and the need to decrease the amount of tied-up capital has made the forest
industry reduce its inventory levels. This has brought on a higher demand on the timber
supply from the forest management districts concerning both delivery in time and
assortment output. As a result, the flow of timber has fluctuated a lot with serious
consequence for the timber supply during 1994.
Beräkning av koldioxidutsläppet från bostadssektorn i Stockholms län
During the last decades the housing sector has increased continuously, and housings and services accounted for 40 % of the energy usage in Sweden during 2011. The expansion in number of buildings in society has resulted in an increase in both energy usage and emissions of greenhouse gases. It is crucial to enable a sustainable development of society and as a result, the demand to reduce the emissions of carbon dioxide is a current question. In this study, the carbon dioxide emitted from the housing sector in Stockholm is estimated. The housing sector can be divided into different types of houses such as apartment blocks, single-family houses and holiday houses. By collecting information of the energy purchased in respective households, a computational model is generated that calculates the total emission of carbon dioxide.
Fördröjning och bortfall av nätverkskorrektioner : osäkerhetskällor för nätverks-RTK
Network RTK is a real-time technique for accurate positioning with Global Navigation Satellite Systems (GNSS). The technology means the use of correction data from a network of GNSS receivers with known positions (reference stations) to reduce the uncertainty in position for the user´s GNSS receiver (rover). However, this requires that the correction data can be transferred seamlessly to the user in real time. Commonly the corrections are transferred via mobile phones. The Swedish National Land Survey operates a nationwide Network RTK service, where users can receive correction data via GSM or mobile Internet (GPRS).
Överlevnad, tillväxt och skador i planteringar av sitkagran (Picea sitchensis) efter stormen Gudrun
Sitka spruce (Picea sitchensis (Bong.) Carr) is just like Norway spruce (Picea abies) a species in thegenus picea. The natural range of Sitka spruce is a narrow strip along the west coast of North America. Itis the most coastal of all picea species, and very dependent on the mild and humid climate along thepacific coast.Sitka spruce has been grown a long time in the countries around the North Sea, particularly in GreatBritain where it currently is the most important species in British forestry. Sitka spruce has not beenplanted in Swedish forests to any large extent before the storm Gudrun in 2005. Several studies indicatethat the production of wood biomass is higher for Sitka spruce compared to Norway spruce.
Produktivitet vid stubblyftning :
Stump wood was used between 1850 and 1950 for production of tar and as firewood. In the 1950s the use decreased because of the introduction of the cheap fossil oil. In the 1970s stump wood became an interesting issue again as a raw material for the pulp industry. Stump lifting has today become a possible source for bioenergy. The objectives with this study were to investigate the productivity of stump lifting and stump extraction, and to analyse the economy.
Anaerob psykrofil behandling av hushållsavloppsvatten i UASB : Utvärdering av kapaciteten hos en två-stegs UASB-reaktor för behandling av hushållsavloppsvatten
Hammarby Sjöstad is a new district in southern Stockholm. A main objective with the Sjöstad project was to halve the environmental impact compared to other construction work. The environmental goals involve a halved water consumption rate, a local treatment of storm water and trials aiming to extract nutrients from the waste water. Sjöstadsverket is an experimental treatment plant used for testing new treatment processes for domestic waste water from Hammarby Sjöstad. The results are to be compared with the conventional process used at Henrikdals treatment plant today.
Laborationsmätning av vindtäthetens betydelse för en väggs U-värde
To fulfill the climate target that EU and the Swedish government have decided to apply, it becomes increasingly important that the energy efficiency of existing buildings and making new buildings energy efficient as possible. Of Sweden?s total energy consumption in 2011 was 40% used by residential and service. Of the 40% of the energy consumption was 60% used for heating and domestic hot water. A report from year 2012 shows that one reason why the heating volume is so great could be due to underestimating on the energy consumption for the heating in the planning of the building.
Storbankernas kreditprocess efter finansiella kriser : En undersökning av åtgärderna som gjorts i storbankernas kreditprocesser efter en finanskris
Bakgrund och problemdiskussion: Bankkrisen under 1990-talet och den globala krisen mellan 2007 -2009 har kommit som en kalldusch för de svenska storbankerna, Handelsbanken, Nordea, SEB och Swedbank, vilket har lett till betydande kreditförluster. Kreditförluster är den vanligaste orsaken till bankernas ekonomiska problem vid en finansiell kris då återbetalningsförmågan hos kredittagare försämras, samtidigt som det talar för att finansiella kriser är ett återkommande fenomen idag.Syfte: Syftet med detta examensarbete är att se vilka åtgärder i kreditprocessen som gjorts efter finanskriserna i de fyra svenska storbankerna samt även se hur tidigare gjorda åtgärder stod sig under den senaste krisen. Vår ambition med uppsatsen är att de resultat vi får fram ska kunna användas av bankerna i kreditprocessen så att de påverkas mindre vid framtida eventuella kriser.Metod: Uppsatsen grundar sig på en kvalitativ metod med respondenter med gedigen erfarenhet och ansvarspositioner inom storbankernas kreditprocesser och praktisk kunnighet gällande storbankernas påverkan av finansiella kriser.Slutsats: De svenska storbankernas kreditprocesser stod sig bra under den senaste globala krisen i jämförelse med bankkrisen under 1990-talet, orsaken till det är de åtgärder som gjordes i kreditprocessen efter bankkrisen inom banken. Kreditprocessen har under de senaste 20 åren gått från en delvis oprövad och snabb kreditprocess till att idag vara en mer sofistikerad och tungarbetad kreditprocess som ställer högre och strängare krav på kredittagarna. För att få kreditprocessen helt vaccinerad mot finanskriser anser vi att det behövs mer mod och integritet hos kredithandläggare för att på bästa sätt kunna förmedla den rådande situationen på ett korrekt och snabbt sätt..
Bergkyla och bergvärmeutredning för industrilokalen Rödbergsmyran 5 i Umeå, Västerbotten.
Grubbe Ventilation AB is a sheet metal and ventilation company who provides design, installation, service, and repair of ventilation. The company is expanding their business by building a new facility in Umeå, Västerbotten. The property is designed to be used for both office and industrial work.Grubbe Ventelation AB has not yet decided upon wish system which is to be established to provide the building with heating and cooling. The consulting firm Umeå Projekt Team has therefore been asked to investigate the possibilities to invest in geothermal- heating and cooling.If the investigation of a geothermal heating- and cooling system would provide favorable results it would be a very appropriate alternative that provides energy at low costs and are an environmentally friendly option as the energy comes from stored solar energy in the ground is provided by stored solar energy in the ground.The facility ´s heating and cooling consumptions are calculated in the program BV2 and the result indicate a heating demand of 185 000 kWh per year due to thermal transmittance, transmission losses, heating of warm water and a cooling requirement of 5500 kWh.Three different systems of geothermal heating and cooling were tested in the computer program Energy Earth Design. The results show no difference in the dimensioning of the drill hole if merely heating were to be used or both heating and cooling were to be established.