Sök:

Sökresultat:

95 Uppsatser om Soxhlet extraction - Sida 6 av 7

Kvalitet och ekonomi i utförandet av förstagallring baserat på olika gallrings- och underväxtröjningsprogram :

Stora Enso Skog has a long term contract regarding felling rights and silvicultural activities on forest owned by Bergvik Skog. In the autumn 2006, Bergvik Skog proposed a new thinning program, ?Bergvikgallring?. The new program implied an increased focus on extraction of smaller trees compared to the present thinning program, Stora Enso Skog?s ?Kvalitetsgallring?.

En miljo?ja?mfo?relse av traditionellt stambyte kontra relining av tappvattenro?r : Med hja?lp av livscykelanalys

This study was a final thesis, for the bachelor program in civil engineering at theUniversity of Uppsala, which was made on behalf of Riksbyggen in Uppsala. Acomparative study of two stain renovation methods; tradition pipe replacement andrelining was done with an environmental perspective. A simplified life cycleassessment (LCA) was done according to the International Organization ofStandardization (ISO) with the LCA tool Eco-indicator 99, in order to be estimate theimpact on the environment. LCA is a method that follows a product or a system?from the cradle to the grave?, which means that all the environmental impact over alifetime is considered.The work was executed by using a stairway with nine apartments in a house called?Uppsala Hus 9? as a reference object, which was provided by Riksbyggen.

The legacy of the mill : a metal polluted forest soil in Gusum

Soils in a metal contaminated site on Stångberget in Gusum in southeastSweden were investigated and compared to relatively unaffected soils a fewkilometres away. Pollution came from historical release of untreated flue gasesfrom a brass mill. The objective was to find information on how high the metalconcentrations are, if metals from the polluted soil affect the surroundings andif the metal contamination affects the microbial community. The soil wasinvestigated using several different methods, such as field XRF measurements,chemical analysis of metal, carbon and nitrogen content, pH, acid neutralizingcapacity, texture, soil depth, field leach tests, sequential extraction and microbialfunctional profiles. The study showed that copper and zinc concentrationswere above Swedish Environmental Protection Agency guidelines for lesssensitive land use on the entire investigated area.

Retention av tungmetaller i en anlagd våtmark : studier av Vattenparken i Enköpings kommun

The aim of this study was to examine the amounts of heavy metals in the sediment of a wetland constructed for stormwater treatment. The wetland is called Vattenparken and is located in the city of Enköping. The heavy metals which were analysed were Pb, Cd, Ni, Zn, Cu, Cr and Hg. The total metal concentrations were determined using HNO3 chemical extraction. From 8 sampling sites 5 sediment cores were taken.

Förnybar energi ur ett kvinnligt och manligt perspektiv : En attitydundersökning med avseende på att kartlägga hur synen på fönybar energi påverkas av om individen är kvinna eller man

Abstract The extraction and usage of energy give rise to immense environmental problems which helps to accelerate climate change. Energy is an important resource for the community and there are a variety of different types of energy sources available, that are either classified as renewable or non-renewable energy sources. The usage of renewable energy sources cause less environmental impact than the usage of non-renewable energy, which in turn means that the energy?s strain on the environment is strongly affected by the type of energy source used.The aim of the study is to describe to what extent attitudes towards renewable energy are affected by whether the individual is male or female, by examining the hypothesis regarding how women have a closer connection to nature and to a larger extent shows on an pro-environmentally friendly behavior than men, and if it also can be detected on issues related to renewable energy and thus imply that women have a friendlier approach towards renewable energy than men. A number of ecofeminist believe that women have a stronger bond with the nature through her embodiment as a woman and by her maternal role, which according to previous research also leads to the fact that women shows on a more extensive environmental behavior.Through a qualitative research method in the form of semi-structured interviews has three female and three male respondents been asked questions with regards to the environment, individual responsibility and energy.

Kina i Afrika : En studie av Kinas afrikapolicy

Since the beginning of the new millennium, China has opened itself to the outside world and in an enormous pace increased its contacts and relationships with other countries. The trigger to these dramatic changes of economic and foreign policies is the insight that China can no longer sustain its rapid economic growth, largely based on industrial production, on energy and raw materials from China alone.Good relations with African countries have been of highest priority in China?s strategy of ?Going global?. The new African policy is based on the two principles of mutual benefit and non-interference in internal affairs ? as opposite to the West?s strategy of structural adjustment programmes (SAP), which include massive interference in internal affairs.

Kemisk kommunikation hos häst

Feromoner är substanser som används vid kemisk kommunikation mellan individer av samma art. Hos häst har ännu inga feromoner identifierats men studier gjorda i Litauen tyder på att kresoler, ämnen som bildas i tarmen vid nedbrytning av bland annat aminosyror och som utsöndras via urin och avföring, kan ha feromon effekt hos häst.Syftet med detta examensarbete var att undersöka förekomsten av kresoler och andra substanser i urin och brunstsekret från ston i östrus med hänsyn till variation mellan dagar i brunst och mellan provmaterial.Prover samlades in från 8 ston under 10 brunster och vid tre tillfällen från ston i diöstrus. Uppsamling av flyktiga substanser från urin- och sekretproverna gjordes med ?Solid Phase Micro Extraction? (SPME). För separering och identifiering av substanserna användes gaskromatografi och masspektrometri.

Dietary fibre composition and sensory analysis of heat treated wheat and rye bran

When grains of wheat and rye are conventionally milled, large quantities of bran classified as by-products are left and are mainly used for animal feed. Bran is a complex material composed of the aleurone layer, nucellar epidermis, a seed coat, a fruit coat and a small proportion of the germ and endosperm depending on extraction rate. The bran fraction consists of approximately 40-50 % dietary fibre which can contribute to increase the nutritional quality of human cereal food. It would also be valuable for the food industry to convert by-products as bran to products with higher commercial values. The aim of this thesis was to analyse the content and composition of dietary fibre of heat treated wheat and rye bran according to the Uppsala method with some modifications in order to analyse soluble and insoluble dietary fibre separately. Half of the bran samples were precooked, dried and roasted and the other half dried and roasted (uncooked).

Interactions between some plant-parasitic nematodes and Rhizoctonia solani in potato fields

The pathogenic fungus Rhizoctonia solani causes major economic losses for potato producers in Sweden. The producers, as well as advisors, have reported possible increases in severity of R. solani when free-living plant parasitic nematodes are present and active. There are several examples in the literature of interactions between pathogens where one, or both species, support or increase the damage made by the other organism. These complexes are important to investigate and to be able to forecast, since even low incidences of fungi or nematodes may result in an interaction of significance.

Competition for forest fuels in Sweden : exploring the possibilities of modeling forest fuel markets in a regional partial equilibrium framework

This thesis project focuses on the need for better tools for analyzing competition for forest fuels in Sweden, in particular how policy measures may influence the market and involved actors in different regions of Sweden. Raw materials from the forest have for long constituted important inputs in the Swedish forest industry. Today some of these raw materials are increasingly used as inputs also in bioenergy production, largely driven by bioenergy promoting policies, and there are signs of increased competition for forest fuels which may have various and uncertain effects on the industries in question. The thesis project explores the possibilities to adapt previously used forest sector equilibrium models into a new model suitable for analysis of Swedish forest fuel markets, called the Swedish Forest Sector Trade Model (SFSTM). The approach takes into account regional differences in supply and demand for 23 types of products produced and/or used by eight types of producers, plus consumers, in five different regions (four Swedish and one international).

Fältinstruktion för skogsbruksplanering av inhemska skogar i Andinska Patagonien :

The thesis first objective was to develop field instructions for forest planning of native forests in Andean Patagonia, and the second objective was to test the plan on an actual property in the area. The thesis was limited to studies in the province of Rio Negro. Today, there are no official forest management plans for native forests in the Argentinean province of Rio Negro; thus, there is an obvious need for an official forest management plan with clear guidelines. To be granted permission to manage, i.e. through thinning, the native forests on a property it is required to have a forest management plan that is approved by the Forestry Board in the province in question (Thill, B.

Värdering av kvävet i organiska gödselmedel :

Within agriculture it is important to optimize the use of nitrogen, not only from an economic point of view but also to minimize damage to the environment. This can sometimes be difficult, especially within organic farming. Organic farmers are using increasing amounts of waste products from the food industry to cover their nitrogen needs. These different organic fertilizers release nitrogen at different rates and under specific soil conditions. Because of this, it would be beneficial to have a standardized method to measure the amount and rate of nitrogen mineralization from organic fertilizers. This project contributes to this knowledge by investigating whether relatively simple and repeatable laboratory methods can be used to estimate the nitrogen fertilizer value of organic fertilizers.

Methods for Locating Distinct Features in Fingerprint Images

With the advance of the modern information society, the importance of reliable identity authentication has increased dramatically. Using biometrics as a means for verifying the identity of a person increases both the security and the convenience of the systems. By using yourself to verify your identity such risks as lost keys and misplaced passwords are removed and by virtue of this, convenience is also increased. The most mature and well-developed biometric technique is fingerprint recognition. Fingerprints are unique for each individual and they do not change over time, which is very desirable in this application.

Fosforavskiljning och hydraulisk konduktivitet i markbaserade reningssystem ? Kornstorleksfördelningens betydelse

Fosforutsläpp kan leda till övergödning i vattenrecipienten om kritiska nivåer överskrids. De enskilda avloppen står idag för en relativt stor andel av Sveriges fosforutsläpp jämfört med de kommunala avloppen. Detta kan sättas i bakgrund av att staten, alltsedan 1970-talet, har lagt ner stora resurser på att reducera utsläppen hos kommunala avlopp, medan en motsvarande satsning på de enskilda avloppen uteblivit.Merparten av dagens enskilda avlopp utgörs av markbaserade reningssystem, det vill säga avloppslösningar där avloppsvattnet får passera genom markmaterial för att renas. Fosforreningen i markbaserade reningssystem har forskningshistoriskt sett inte varit en prioriterad fråga, vilket har lett till kunskapsbrist inom området. Naturvårdsverket har i och med miljöbalkens införande skärpt sina krav på fosforreningen hos enskilda avlopp.

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.

<- Föregående sida 6 Nästa sida ->