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323 Uppsatser om Nitrogen removal - Sida 21 av 22
Optimalt mottagningsstall för kalvar : en fältstudie
A cattle producer that buys calves that are younger than six months to the herd should have a starter stable to prevent infection spreading in the herd. According to the Swedish animal welfare regulation there has to be a starter stable if more than 50 calves that are younger than four months are bought in yearly to the herd. The aim of the study was to improve the knowledge about bovine buildings and management of starter stables to obtain optimal weight gain and health of the calves. The hypothesis 1) The younger the calves are when purchased, the higher the calf mortality and 2) Purchasing calves from a high number of herds involves a higher risk of calf health problems and calf mortality were tested in the study. The objective of the study was to give advices by way of presenting ideal solutions of how a starter stable should be constructed and managed.
A field study was done during June to September 2008 to collect knowledge and experience from existing starter stables.
Vallbrott med hjälp av grisar :
To investigate the possibilities for effective soil tillage, that could imply lower costs,
lower negative environmental impact and in addition a meaningful occupation for foraging pigs, a field experiment was carried out in Gränna, Småland, during growing season 2006.
The experiment contained two treatments that were repeated three times and were carried
out on a couch grass-infected fallow on a light soil close to Sweden?s second largest lake, Vättern. Ploughing was one treatment and pig rooting followed by ploughing, was the
other. The experiment was conducted according to the guidelines of organic growing and
seedbed preparation was done the same way in the two treatments. The pigs, three groups
of five half-year old Linderödssvin (an old Swedish breed), was encouraged to perform
an even tillage by strip-grazing, i.e.
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.
Förstudie för automatisering av gjutgodsrensning
This thesis work has been performed at the Division of Assembly Technology at Linköping University for a period of ten weeks. The work is part of the project ProFlexA, which is a research project in collaboration between Linköping University, Lund University, and industrial partners such as Combi Wear Parts and Smålands Stålgjuteri AB.The casting process creates random incurred burrs and defects, which must be removed during a cleaning process to make sure that the cast can be sold. Automation has long been sought for the cleaning of castings due to, among other things, poor working conditions for staff, but this has proved difficult to implement with today's technology. Automation has for some time been available for more capital strong companies with large annual volumes, but for smaller companies with small-and medium-sized volumes, automation has not been an option.The goal of ProFlexA is to develop an automated cleaning cell aimed at small-and medium-sized volumes.The goal of the thesis is to do a pre study at ProFlexA?s partners on cleaning of castings, and develop concepts for automated cleaning of castings.By recording the process and cycle times, the cleaning of castings has been documented as it works today, and on this basis, information and statistics has been compiled.
Renare dagvatten från kvarteret Brännugnen
Regnvatten, smältvatten och spolvatten som rinner av från hårdgjorda ytor kallas dagvatten. Dagvatten är ofta förorenat av tungmetaller eller svårnedbrytbara organiska ämnen, som kan göra stor skada om vattnet inte renas innan det når recipienten. I dagsläget finns det inga nationellt fastslagna riktvärden för föroreningshalter i dagvatten. Dagvattengruppen på Vattenfall AB Värme Uppsala har tillsammans med miljökontoret i Uppsala tagit fram riktvärden för föroreningshalter från kvarteret Brännugnen, som området som studerats i detta examensarbete kallas. Vattenfall har idag problem med att klara dessa riktvärden för bland annat metaller i en del av kvarterets dagvattenbrunnar.
Identifiering av fosfatfosfors käll- och flödesfördelning i ett litet jordbruksområde
Eutrophication of lakes and streams are nowadays a well known environmental problem and implies an enrichment of the nutrients phosphorus (P) and nitrogen (N). Phosphorus is considered to be the most important component for the growth of aquatic plants and leads in too large quantities to an intensification of growth. Phosphate (PO4) is the fraction of phosphorus that can easiest be taken up by plants and thus have the greatest impact on eutrophication. Increased plant growth in lakes and unfavorable conditions for aquatic animals are two examples of negative consequences. A significant portion of the increased nutrient supply to nearby water can be derived to phosphate leaching from agricultural areas, where private sewers and agriculture is two main sources.
Effects of biogas residues on respiration and denitrification in arable soil : evaluation of methods, microbial activity and agronomic implications
Agricultural soils constitute the base in human food production and soil content of organic matter and plant nutrients together with soil microbial activity are all important parameters for high crop yield of good quality. These parameters are dependant on proper fertilization.Anaerobic digestion of organic wastes for biogas production generates a liquid residue called biogas residue (BR). It contains organic material and plant nutrients which makes ita potential fertilizer for arable cropping. However, it also contains heavy metals and toxic organic compounds and it is therefore in need of evaluation before usage.Microbial tests were performed aiming to evaluate the agronomic traits of four different BR and to find a viable procedure for evaluating slurry fertilizers. Two experiments where soil respiration and soil potential denitrification activity (PDA) was measured at fertilizer addition were performed.
En jämförelse mellan amplifierad singelmolekylanalys och selektiv agar vid kontroll av hygienisering av avloppsslam
Bringing back the nutrients from the city to the country is becoming increasingly important, as the world?s stores of nutrients get more exhausted. Sewage sludge is an unapplied resource, rich in plant nutrients, which could replace parts of the commercial fertilizers used in Sweden
today. Sewage sludge may contain large amounts of pathogens, such as Campylobacter and Salmonella, why use can cause severe spreading of infections, both to animals and humans. These pathogens have the ability to survive for a long time in soil and water and therefore
some sort of treatment of the sludge is recommended before use.
Böklåda med torv på rastgårdsytan i ekologisk slaktsvinsproduktion : effekter på beteende och emission av kväve (NH3 och N2O)
In organic animal production, synthetic amino acids are not allowed. Therefore, a higher level of crude protein is needed in the diet to pigs, which lead to more nitrogen (N) excreted in the faeces and urine. N can be emitted to the air in the form of e.g. ammonia (NH3), which contributes to eutrophication and acidification and as nitrous oxide (N2O), which is a very potent greenhouse gas. The emission of N can be reduced by e.g.
Torvströ till svenska mjölkkor :
Peat litter is a soft material with high absorbency. About hundred years ago many farmers in Sweden used peat litter to their dairy cows. After the World War II the use of peat litter decreased and the farmers used more straw. Nowadays (year 2007), when it is harder to find straw and sawdust to buy, peat litter is advancing again. The purpose with this study is to investigate peat as a litter to dairy cows.
Tillväxtreaktion på kvarlämnade träd i Hagners "Naturkultur" försök :
The primary goal of this study was to investigate how the radial growth of retained trees responds after thinning-from-above. The National Board of Forestry which initiated this study, was interested in whether there were differences in the growth-response between the tree species Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). Another question of issue was if there were differences in the growth response between trees of different sizes. It is within the framework of the National Board of Forestry?s, Continuous Forests Project that these urgent questions are to be answered.
Restriktioner av växthusgasemissioner : hur påverkas lantbruksföretagens ekonomi och produktionsinriktning?
The agricultural sector accounts for about 13 percent of the total load of greenhouse gas emissions from Sweden (Swedish Environmental Protection Agency, 2007). The Swedish objective to reduce the greenhouse gas emissions with 40 percentage units to the year of 2020, based upon the year of 1990, might imply stricter regulations for Swedish farmers. A regulation or other forms of economic incentives is probably necessary to reduce the emissions originating from the agricultural sector.
This study aims to investigate the economic and managerial impact on two agricultural firms with differing production system given that a constraint on green house gas emissions is introduced. Gases included in this study are carbon dioxide, methane and nitrous oxide.
Gasbedövning av gris inför slakt : koldioxid eller alternativa gasmixturer?
I Sverige är det lagstadgat att djur skall vara bedövade innan de slaktas. Att upprätthålla en god djurvälfärd i slaktsituationen är inte enbart en grundpelare i vår svenska djurskyddslag, utan även en ständigt aktuell fråga som engagerar både livsmedelsproducenter likväl som konsumenter. Bedövning av grisar utförs i stor utsträckning med hjälp av koldioxid. Denna metod är vida omdiskuterad och ofta ifrågasatt ur djurvälfärdsaspekt. Detta då gasen är erkänt aversiv för djurslaget ifråga.
Ett vattendrags väg genom tid och landskap : Höje å
Water is a vital element and also enriches the experience of landscapes. It is naturally in constant movement and change but also exposed to the hands of man. In this paper two stretches of water is described through landscape and time in correlation between development and the experience of the watercourse Höje-å in the rural parts of southern Sweden. The intention is to investigate how Höje-å has changed over time and also how it is experienced in the surrounding landscape. With the help of literary studies the history of Höje-å have been described and through the course of field-studies the experience of two different areas along the watercourse.The biggest changes of Höje-å and its surrounding area have taken part during the last two centuries.
Commercial thinning and its potential for contribution to the timber supply in British Columbia?s Interior forests : a look at Finnish and Swedish forest practices and their applicability in British Columbia?s Interior forests
Thinning is the partial removal of trees in a forest stand prior to final harvest. The term can be divided in pre-commercial thinning where little if any volume is removed from the stand and commercial thinning where removals are intended to provide a positive economic result. From a silvicultural point of view, the goal of thinning is to enhance future crop tree quality by removing low-quality stems and providing sufficient space for the accelerated development of retained ones (Huuskonen & Hynynen, 2006).
The goals of this study was to see if commercial thinning could positively affect the short and medium term timber supply (MTTS) in the Interior regions of British Columbia (BC), and whether or not Scandinavian forestry practices could be adopted in the BC context. The mountain pine beetle (Dendroctonus ponderosae Hopkins) has created significant forest planning problems in BC. The annual allowable cut (AAC) was raised to capture beetle-killed timber while still merchantable.