Sök:

Sökresultat:

739 Uppsatser om Organic rankine cycle - Sida 38 av 50

Kaliumgödsling på torvmark - effekt på tillväxten hos planterade granar (Picea abies)

Peat  lands  are  a  great  potential  resource  for  increased  forest  growth  in  Sweden, there  are  approximately  6.5  million  hectares  of  peat  lands,  whereof  around  70% produce less wood than one m3sk/ha and year and are therefore classed as forest waste  land.  There  are  over  200  000  hectares  of  peat  land  that  is  already  drained and  wooded,  and  that may  be  suitable  for  fertilization.  Forest  production  on  peat soils  usually  requires  drainage  and  fertilization.  Dewatering  requires  ditching  the area, so that the roots can have access to oxygen. Nitrogen is often abundant in the peat but other nutrients; especially potassium is in short supply. The  purpose  of  this  work  was  to examine  the effects  of  potassium  fertilization  on the  growth  of  spruces  that  were  planted  on  drained  peat  land  and  how  different amount of fertilizers affects the growth. Potassium deficiency is strongly growth inhibiting, since potassium is important for substance  transport  in  the  tree.  Potassium  is  also  important  for  the  carbohydrate formation, and because increasing the sugar content of the cells constitutes a lower freezing temperature does potassium availability in the soil play a major role in the winter  resistance  of  many  species.  Potassium  is  not  found  in  any  organic compounds in the tree, but is present in cell and tissue fluids. A fertilization trial was started in 1978 in Siljansfors Experimental Forest. The plots in the experiment were fertilized with different amounts of potassium and one plot was  left  without  fertilization.  All  plots  that  were  fertilized  with  potassium  grew considerably better than the unfertilized plot. The difference in production between the unfertilized plot and the plot that received the most potassium was 7.2 m3sk/ha and year. The unfertilized plot can still be classified as waste land. The theoretical production capacity was estimated using a Swedish system for site quality  estimation  of  wetlands  after  ditching  (dikningsbonitering).  The  plot  with most  potassium  produced  after  fertilizationaproximately  in  level  with  theoretical estimations.  Key  words:  Peat  land,  Fertilization,  Ditching,  Growth,  site  quality..

En grav är mer än bara en grav... En metodutveckling av tafonomi som redskap att förstå olika anläggningar med djur

This paper deals with a taphonomic study of contexts with osteological material of dog (C. familiaris L.) from the Mesolithic and Neolithic of Sweden and Zealand, Denmark. The general aim is to develop and test a method to try to understand the activity behind and define specific archaeological structures. My questions also regards to wether a taphonomic analysis of the material could be used to identify treatments as wrapping and contraction of the dogs, but also dismembering and other preparations of the body. The study focuses on the relation between the space of decomposition, disarti-culation of the joints, evidence of wall effect, cutmarks, weathering and signs of postdepositional arrangements.The analysis is based on contexts from the materials Hornborgasjön, Vedbæk, Skateholm I and II, Sjöholmen, Ertebølle, Bökeberg, Bredasten, Löddesborg, Bergsvägen and Röekillorna, dating from early Maglemose culture to Neolithic Battle axe culture.The analysis shows that a closer study of taphonomic processes can be used to identify different structures as graves, offerings, religious and non religious contexts or parts of animals, probably put into the ground as waste.

Kvarteret Kajutan - Från lågenergi till plusenergi

Energy and environmental demands regarding buildings have become an increasinglydiscussed topic, both in Sweden and in Europe as a whole. The general trend indicatesthat greater efforts are being put into the energy efficiency of the built environment.There are already numerous examples of houses with a low energy demand, and thenumber of low energy buildings is constantly growing.At the time being, the maximum level for energy demands for housing in Stockholm is110 kWh/m2year, but as soon as next year the limit will be changed to 90. The Swedishagency Energimyndigheten is currently conducting a project to interpret the EU Directiveon the so-called Nearly zero energy buildings, and the preliminary results indicate thatthe level of requirements for purchased energy will end up with about 55 kWh / m2year,which is in line withtoday?s recommendationsfound in FEBY's Kravspecifikation förPassivhus.Starting with a low-energy house in Henriksdalshamnen in Stockholm, we have analyzedvarious energy-efficiency measures and their influence on power and energy needs. Thefinancial aspects associated with the measures have been studied using a model of lifecycle costs.The measures were initially studied individually to give an idea of how much impact theyeach had.

Energieffektivisering av skolbyggnad från 60-talet : Studie av Hållsta skola i Eskilstuna

In June 2006 the Swedish government decided that the use of energy in buildings should be reduced by 20 percent until 2020, compared to the level of energy used in 1995. To contribute to this goal, the real estate company ?Eskilstuna Kommunfastigheter AB?, set up own goals for their buildings. In 2009, the goal for schools was to have a maximum energy use of 118 kWh/m2year for heating and hot water.The school ?Hållsta skola?, just south of Eskilstuna, exceeds the limit since it used 270 kWh in 2008.

Cash-to-cash-styrning : ett spelteoretiskt angreppssätt

Objective: The objective is to examine if long terms of payment are created because of a perceived zero-sum game in the cash-to-cash cycles between companies. The study will also examine if dependence effects the dependent companies Cash-to-Cash-cycle because of long terms of payment. Scientific method: The study uses a qualitative and a quantitative method, where primary data is collected from semi-structured interviews. Additional primary data is collected from an unstructured interview with an expert in the field of which is examined. Additional data has been collected from the studied companies? annual reports.Theoretical references: The primary theory has been Game theory, where the researchers have used this theory to analyze the behaviors of the companies.

Effektivisering av LCA med hjälp av BIM

This thesis concerns how Sweden relates to life cycle assessment (LCA) in the construction process. LCA means analyzing a products impact and the analysis includes the whole life span of the product. A building has a high complexity and the combination with its unique shape will make the LCA more comprehensive, unlike e.g. aluminum cans. Recently there has been a development of a working procedure in the construction industry.

Analys av gåendes rörelsemönster på Stortorget, Nygatan och Drottninggatan i Gävle

The town square is an important public space and is often described as the city´s living room. By creating a lively city center a sense of security is developed among the citizens which makes them wanting to use the town square regardless the time of the day. One important meeting point in Gävle is the centrally located Stortorget, sited between Drottninggatan and Nygatan. The town square went through an extensive renovation followed by both positive and negative reactions among the City´s inhabitants.  The aim with the study was to investigate the main walking paths and meeting points as a planning support to Gävle Municipality in their work with a new city plan. By studying the pedestrian movement patterns at Stortorget, Nygatan and Drottninggatan, the main walking paths and meeting points during all hours of the day was obtained.

Mot en delad framtid? : Mendeley som exempel på vetenskaplig kommunikation online

The last few years have been characterised by increasing online communication and the emergence of social media, made possible by Web 2.0. In society as well as in research, social media is used for knowledge produc- tion and networking. One example of this is Mendeley, a social reference management tool. With answers from users all over the world, this study investigates the use of Mendeley, if the respondents use other social media and if all of this affects scientific communication. The aim is also to study what the respondents think about the future of scientific communication and if this can be related to current tendencies.The theoretic framework for this study is based on Leah Lievrouws research on the Cycle of Scientific Communication and the relationship between the ?Little Science 2.0?-scenario and the ?Big Science Retrench- ment?-scenario.A qualitative web based survey was conducted (41 answers) and complemented with an interview with a professor in environmental sciences.

Behov av managementverktyg i mjölkproduktionen :

For the company to work well, it is necessary with a good economy, a high qualitative production and a well working system concerning the environment: the whole cycle on the farm needs to be working. At the same time, debaters about the environmental impacts are also requiring higher demands for the dairy farmers and therefore also the management programs. Management programs for feed evaluation calculations have been more developed over the years. Big amounts have been invested in the new feeding system with NorFor, but no one seems to have asked the dairy farmers what they themselves want to spend their money on, and what they need help with. For the dairy farmers it is necessary that the whole company is controlled in the right way, and much more than just feed evaluation is included in this.

Livscykelanalys och optimering av isoleringstjocklek för moderna byggnader : - med fokus på kv Limnologen i Växjö

Syftet med denna rapport är att visa hur en ökning av isolertjockleken i ett hus påverkar kostnader och energiåtgång för isoleringen i ett livscykelperspektiv, samt för husets bruksskede. I studien har en optimering av isoleringen på ett pågående byggprojekt i Växjö, kv Limnologen, utförts. Total energiåtgång för isoleringens livscykel har tagits fram från tidigare utförda livscykelanalyser (LCA). Husets värmebehov har beräknats mha information från ritningar och kontakter med personer i anknytning till kv Limnologen. En ekvation har utformats för att finna ett teoretiskt optimum för isolertjockleken med inriktning mot total energiåtgång, koldioxidutsläpp och ekonomi.

OTEC för Tarawa

Ocean Thermal Energy Conversion, OTEC, a technology using the temperature difference between cold deep seawater and warm surface water, can extract the work in the form of electricity. OTEC gives also synergies of drinkable fresh water. The temperature difference has an impact on the efficiency of the technology, which means that the feasibility of OTEC is geographically limited. The project intends to explore the possibility of replacing the atoll Tarawa?s present electricity generation with an OTEC plant and to explore synergies. In the present situation all of Tarawa?s electricity is generated by fossil fuels.

137Cesium i myrsamhällen i Gävleborgs län 24 årefter Tjernobylolyckan

24 years have passed since the Chernobyl accident when radionuclides were spread over largeareas of Europe, including the Scandinavian countries. Today, measurable activities of 137Csare still observed in many Swedish ecosystems.Ants (belonging to the order Hymenoptera) are social insects which collect organic materialfrom a large area around their nests. This study focuses on the 137Cs activity in ant nests andthe cesium accumulation in these nests. The aims were (1) to estimate the 137Cs fall-out in1986, (2) estimate the radiation exposure of ants and (3) find how 137Cs is distributed in an anthill. Seven ant hills (occupied by the species Formica polyctena) were studied near the villageof Hille, situated north of the city of Gävle in central Sweden.

Drainfill

Ocean Thermal Energy Conversion, OTEC, a technology using the temperature difference between cold deep seawater and warm surface water, can extract the work in the form of electricity. OTEC gives also synergies of drinkable fresh water. The temperature difference has an impact on the efficiency of the technology, which means that the feasibility of OTEC is geographically limited. The project intends to explore the possibility of replacing the atoll Tarawa?s present electricity generation with an OTEC plant and to explore synergies. In the present situation all of Tarawa?s electricity is generated by fossil fuels.

Méthodes et Outils d?Analyse des Incidents

Au sein de la direction informatique RENAULT (DTSI), la plupart des chaînes d?assistance pour les utilisateurs des systèmes d?information, sont modélisées à travers un outil de gestion d?incident (ARS/GII-v2). La majorité des ces incidents est créée par le service des Centres d?Appels, Téléphonie et Visioconférence (DTSI/DSO/CATV). Selon leur complexité ou leur caractéristique, les incidents suivent un cycle de vie qui fait intervenir plusieurs équipes des chaînes d?assistance.

Socialt och emotionellt lärande i grundskolan - hinder och möjligheter vid implementering

Social and emotional learning is getting more and more common to work with in Swedish schools today. That has made it more actual to do studies of how you best can implement a method in health prevention and promotion in schools and how you do for to keep the work sustainable. There are some American studies that describe implementation of methods in schools and a few studies that describe implementation of methods for social and emotional learning in schools. It is important to see implementation as a process and not as an individual event. The process never end but continues as a cycle in three phases; readiness phase, planning phase and implementation phase.The aim of this study was to describe teachers and principals experiences of obstacles and possibilities at implementation of an evidence based program for social an emotional learning in compulsory school as a part of the schools health promotion activities.

<- Föregående sida 38 Nästa sida ->