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993 Uppsatser om Forest fuels - Sida 50 av 67
Strömningen i och över en skog : utvärdering av en 'mixing-layer' hypotes
A new theory for predicting the windprofile over a canopy has been evaluated. The theory was first presented by Harman and Finnigan (2007). The theory relies on the forming of a mixing-layer above the canopy, due to different mean wind in and above the canopy. Characteristics from both mixing-layer and Monin Obukhov similarity theory have been used to develop the governingequations that give the wind profile. The theory has been used to calculate wind profiles for sixdifferent atmospheric stabilities.
Den ekonomiska lönsamheten för solvärme i Sverige
The sun is an endless energy source and the heat it produces can be used to heatup our homes. This technology is relatively old and was introduced in the late70-s. There are two kinds of solar collectors that are most frequently used todayand these are plain solar collectors and vacuum solar collectors. The plain solarcollectors are the once that are used the most but the vacuum solar collectorshave increased more as a percentage the last couple of years.The biggest question asked regarding an investment in solar heating is if theplant is economically profitable. This question has no direct answer because itis dependent on a couple of prerequisites.
Det energiproducerande huset
We are heading towards a huge switch of how energy is produced with fossil fuels being replaced by renewable energy sources. It is not difficult to replace the energy you use in the house and there is no need for futuristic technology. There are already many established products on the market such as high efficiency vacuum solar collectors, heat pumps & small wind power stations that can supply the energy being used in a house. The company Sol & Energiteknik SE AB in Huskvarna has many different products which can reduce the need for an outside energy distributor. An average house in Sweden uses 15 000 kWh for heating, 5000 kWh for tap water and 5000 kWh for electricity.
Förutsättningar och Avsättningar för Biogas för Gröna Vessigebro : Version 1.0
The community Vessigebro, in Falkenberg and its surrounding areas housing one percent of all dairy cattle and two percent of all pigs in Sweden. This means that there is a large amount of manure as a basis for producing biogas in the area. A number of farmers have therefore formed a cooperative named Vessigebro biogas and started the project Green Vessigebro, with the goal of creating the conditions for a more profitable and more sustainable agriculture production.The study deals with the conditions and sale opportunities of the feasibility study Green Vessigebro. The study has looked at the work that was previously carried out for the biogas that could be produced on the farms in Vessigebro, The main pipeline for natural gas on the Swedish west coast and its operators, the Swedish Competition Act , Electricity Act , Natural Gas Act, the District Heating Act , Sustainability Act , previously proposed measures, municipality interest in biogas from Vessigebro , possible collaborations, possible sale opportunities and perform calculations with data from the municipality Ljungby for a suggested transportation of biogas between Vessigebro and Ljungby.The study shows that there are several interesting sale opportunities for biogas from Vessigebro. The production and use of biogas in Sweden is increasing and the trend seems set to continue.
Hur kan mångfalden gynnas på SCA:s naturvårdsareal? : natur- och kulturvärden i Peltovaara mångfaldspark
Områden med skyddad skog i norra Fennoskandia, som tidigare beskrivits som orörd urskog, har på senare tid visat sig vara påverkade av långvarigt mänskligt resursutnyttjande. Historiska analyser av ekosystem, där även antropogena störningar beaktas, har därför börjat lyftas fram som en viktig del i naturvårdsarbete (Foster m.fl. 2003). De hjälper oss att förstå hur strukturer och störningsdynamik har förändrats över tiden, vilket kan vara till stor hjälp vid skötselplanering och restaurering.
Det övergripande syftet med den här studien var att kvantifiera kulturspår och analysera förekomsterna av kulturvärden i relation till framförallt naturvärden, men även sociala värden, i ett skyddsvärt borealt barrskogsområde. Min avsikt var att försöka exemplifiera hur skogshistoria kan användas för att skapa underlag för skötselplanering i områden med naturvårdsanpassad skogsskötsel.
Kunskapsläge och attityder till vildsvin (Sus scrofa) och dess förvaltning i Sverige
The wild boar (Sus scrofa) is since its recent establishment and increasing density a controversial species in Sweden. But the attitudes towards the wild boar are poorly documented so far. To improve this knowledge, a questionnaire was sent out to chosen people (n=400) connected to the management and/or land use activities.
The study got 162 replies (reply frequency 40,5%) and the results show varying attitude trends among organizations and individuals, with some aspects coherent within groups and some not. Farmers and their organization showed the most negative attitudes towards wild boars, which was expected due to the practical and economic problems they suffer from this species. People involved with forestry were more positive to wild boars, probably because the species does not affect forest growth etc severely, and may even promote plant establishment by the rooting.
Produktutveckling och prestandatest av ett vattenvärmedrivet torkskåp : Jämförelse mellan tre utvecklade versioner av ett vattenvärmedrivet torkskåp
AbstractElectricity consumption is a globally increasing problem caused by the high share of electricity produced in coal power plants. These contribute to high carbon emissions when only about 1/3 of the heat generate electricity and the remaining 2/3 of the heat cools off. Combined heat and power plants (CHP) have high efficiency because they use the residual heat for domestic heating. The CHP plant often use fuels from renewable resources, giving them a lower carbon footprint, but are also depending on the heat demand. If electric powered products such as drying cabinets convert to heat powered products more environmentally friendly electricity will be produced by CHP plants, which can supplant electricity, produced from coal power plants and reduce carbon emissions.
Föryngringsplan för en svårt stormskadad fastighet i Kronobergs län :
In January 2005 large forest areas in south Sweden were severely damaged by storm. This final thesis describes the work with creating an ecological and landscape-adapted regeneration plan for a severely storm damaged property in Kronobergs region in south Sweden.
This regeneration plan, in difference to more regular plans, are focusing more on the owner?s use and goal?s for the property and seeing the property from a more comprehensive view in the regeneration process. Beside production and environmental values the plan also take in consideration other values as aesthetic, culture history, landscape picture and recreation values.
Förutsättningar för naturvetenskap i förskolan : En intervjundersökning om förutsättningar för naturvetenskap i förskolan
The purpose of this study is to examine the conditions for pre-school teachers to achieve those goals that are constituted for science education in the Swedish curriculum for the pre-school. The study questions of formulations are: which importance have the conditions for the work with science education in pre-school, which importance have pre-school teachers engagement and knowledge for the work with science education in pre-school and does the pre-school pre-school teachers think that they have enough conditions to achieve those goals that are constituted for science education in the Swedish curriculum for the pre-school. The results are based on an interview survey with ten pre-school teachers from three pre-schools that are connected in a unit. The interviews were recorded and transcribed. The results from the study points out that the pre-school teachers engagement are most important for the work with science education in pre-school to flourish.
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.
Effects of storage time, die channel length and moisture content on pellet quality of lodgepole pine (Pinus contorta Dougl. var. latifolia)
The use of renewable resources is rapidly increasing in Sweden, especially the use of fuel pellets. Through pelletizing the energy content per volume unit is greatly increased and the pellets are more homogeneous with regard to moisture content, particle size and density compared to unrefined fuels like forest residues and chips. For further development of the Swedish pellet industry, the use of different assortments from lodgepole pine (Pinus contorta Dougl. var. latifolia) is of particular interest, mainly because of its high volume production.
Planering : fallstudie av en mjölkgård
The purpose of this paper is to give examples of different ways of economic planning and
calculation within agriculcture. My aim is to use a couple of them as an explanation of a case
from reality. My choice went to budgetsimulation and balanced scorecard since those are best
suited in this specific case.
In the information retrieval I present different instruments of economic planning like theory of
cost, budget and productcalculation. The budgetsimulation describes how to use the different
methods in a long term economic planning. The balanced scorecard is also a model of longand
short-term planning but besides the economy planning it?s also a reminder of your
personal goals.
In the model I have used a dairyfarm as a case.
Varför är Bivarödsånsvatten så brunt?
The river Bivaröd is one of the river Helgeån tributaries which has the highest and the fastest increase in water colour. The reason behind this increase is unclear but several factors have been suggested to affect this pattern. In this work, I studied the role of land use, iron and precipitation for water colour increase in river Bivaröd for the period 1976 -2011. Data from a field study along with data from SRK for river Helgeån were used for the analyses. The results showed that both water colour and iron concentration increase and that there is a strong correlation between these two variables.
Optimerade material för optiska komponenter i koncentrerande solfångare
The energy consumption continues to increase as the use of electronics and energy consuming equipment increases. The use of fossil fuels has to be phased out for this to be sustainable in the long run while the use of renewable energy continues to increase. A renewable energy source is solar energy but the production of heat and electricity are today very expensive compared to other energy sources and an important task for the solar energy market to grow is therefore to minimize the production cost of the solar collectors while increasing its efficiency to produce heat and/or electricity. One way to convert solar energy into heat is by using solar collectors and electricity can be produced by utilizing the produced heat, or by applying solar cells.This thesis aims to recommend a reflective material for the next generation solar collectors from Absolicon and to recommend a commercially available coating for the receiver tube of the solar collector. A market study has been carried out to investigate the cost-related aspects along with the optical and durable aspects for the optical material of the solar collector.
Betydelsen av utfodring under sintiden, sintidens längd och kalvningsintervallet med avseende på kons hälsa under kommande laktation
This essay describes and compares the extensive reindeer management to the more intensive, but grazing based, sheep management system in Sweden. Differences and similarities between the two production systems will be investigated by elucidating the economy, land use and possibilities to influence production and economy through breeding, feeding and product development. The reindeer management area covers the northern part of Sweden whilst the sheep management is dispersed over the country. Both reindeer and sheep are ruminants and have relatively high demands on the quality and digestibility of the feed however reindeers graze on mountain-and forest lands whilst sheep often graze inaccessible areas or cultivated grasslands. Selection intensity is generally lower in the reindeer management compared to the intensity in sheep breeding.