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1194 Uppsatser om Nitrogen flow - Sida 3 av 80
Jordbrukets påverkan på Östersjön : en jämförelse av indikatorer för att beskriva näringsbelastningen
The Baltic Sea, due to its special conditions, is a unique and vulnerable marine environment. There are many pressures that have an impact on the sea and one of the major problems is the extensive flow of nutrients from land. The most visible effect of the supply of nutrients is the annual algal blooms.
One of the main sources of nitrogen and phosphorus supply is agriculture. Nutrient losses
from arable land have been increasing as agricultural production has intensified. At the end of the twentieth century an increased awareness of these problems led to the formation of organizations such as HELCOM and Baltic 21.
Utvärdering av Vissberga lakvattenbehandling
In connection with the admittance of the EC-directive (99/31/EC) in Swedish politic, through the constitution of waste depositing (2001:512) at year 2001, the rules about management the landfills and leachates tightened. At the landfill Vissberga in the municipality of Hallsberg, a leachate treatment plant was constructed just a year thereafter. This treatment plant consisted of an aerated pond with a following land treatment and a willow cultivation to replace the land treatment during the summer. In this case the parameters, which were estimated as the most important to reduce, were iron and nitrogen. The iron would react with the oxygen-rich water in the aerated pond and precipitate to ferric-hydroxide and than settle in a calm zone of the pond.
Utveckling av flödesreaktor : Ett sammarbetesprojekt mellan fakulteten för teknik och naturvetenskap vid Uppsala Universitet och Fagrell produktutveckling AB
This report deals with thecollaborative project between FagrellProdukt Utveckling AB and studentsfrom the Faculty of Science andTechnology at Uppsala University. Theoverall objective of the project wasin addition to developing students'abilities, to help Fagrell withverification and development ofFagrells prototype, Fundamental flowreactor, for flow chemistry. Theuniqueness of Fagrells flow reactor isthat it should be simple andaffordable compared to competing flowreactors in the market.The verification was done bylaboratory and simulation sessions.The verification shows that Fagrellsidea on how to construct a flowreactor is very good.The development included bothtechnology and business. The result ofdevelopments can be helpful for thecommercialization of Fagrell flowreactor..
Miljöpåverkan av äggproduktion : En jämförelse mellan Lilluns ägg och andra svenska äggproducenter
The purpose of this report was to compare Lilluns egg production with other Swedish egg producers based on the flow of nutrients (nitrogen, phosphorus and potassium) in the egg production systems. The main focus in the report was the utilization rate of the forage and the excess of nutrients per kg egg. Additionally, the purpose was to identify the environmental impact from Lilluns egg production and compare the results with other egg producers. The inflow of nutrients associated with forage and poultry was compared with the nutrients that were exported from the production. All of the egg producers in this study had an excess of nutrients.
Kväve i Östra Mälaren : hur kunskap förvaltas och används i tillståndsprocesser
The nitrogen cycle in freshwater bodies is complex and consists of many separate processes affected by a number of important factors for example oxygen concentration in the water, temperature and circulation. Knowledge of the different components of the nitrogen cycle exists; however, a complete and comprehensive picture is difficult conceptually as well as theoretically. The available literature illustrates that the research on nitrogen and the related freshwater processes is still associated with high uncertainty of how much of the supplied nitrogen from the catchment is transported with the water versus and how much is lost due to denitrification, sedimentation or uptake by plants. This report is an interdisciplinary survey of Nitrogen discharge permitting. The research focuses in particular on the decision-making process, the levels of scientific standard and the administrative framework.Application for Nitrogen discharge permits are decided by the Environmental Court with council from their own experts as well as relevant government authorities and organisations.
Våtmarker för näringsretention i Lillån : var bör de ligga och vilken effekt kan vi förvänta
Construction of wetlands in the agricultural landscape may reduce nitrogen and phosphorus
transfer to streams, thereby reducing the eutrophication of lakes and seas. The agriculturalstream Lillån, a tributary to stream Sagån, ends up in Lake Mälaren and is transporting large amounts of these plant nutrients. The aim of this study was to estimate how hypothetical wetlands of different size and location may reduce nitrogen and phosphorus load from stream Lillån. Estimated nutrient retention in several small wetlands was compared to retention in a single large wetland based on existing data from the agricultural stream and from a nearby smaller stream. Retention in the stream was suggested to decrease along with the nutrient concentration in the water.
Möjligheter att minska kväveutlakningen genom att anpassa kvävegödslingen till variationer inom stråsädesfält
Due to excess precipitation that cause runoff, all soils in Sweden naturally leaches nitrogen.High leaching from arable land is an environmental problem when the runoff reacheswaters. In the international agreement, Baltic Sea Action Plan, the aim is to reduce therunoff of nutrients. Sweden has agreed to reduce its load of e.g. nitrogen to the Baltic Sea.One of the proposed measures is an increased use of site-specific N-fertilization, which hasbeen shown to increase nitrogen use efficiency and therefore also reduce the nitrogen runoff.Either yields are increased with the same total amount of nitrogen, or the total quantityof nitrogen is reduced with preserved yield levels, which is profitable for the farmers.The dynamics of nitrogen leaching differs between top dressing applications above orbelow the economical optimum. There is a consensus about a difference in the dynamics,but not about its magnitude.
Fungiciders påverkan på kvävehalten i höstvete : hur påverkar användandet av fungicider utnyttjandet och inlagringen av kväve i höstvete?
A common perception is that fungicide treatments increases yield, but that the nitrogen of the particular grain is diluted so that the overall removal of grain nitrogen from the field remains unchanged. The aim of this paper is to demonstrate that a healthy crop reduces the risk of nutrient loss from agricultural land. The results from genotype and plant protection trials often show constant nitrogen content in the grain, although the yield has been increased. Results from such experiments are therefore processed in order to confirm this and show that it is no statistically significant difference between the protein content (and also nitrogen content) in crops which have undergone fungicide treatment compared to crops which remained untreated. The trials processed have been carried out in the southernmost part of Sweden and are distinguished to concern winter wheat production.The explanation to the results is that a healthy crop is able to maintain the biological functions of the plant in a more efficient way than a crop damaged by a fungal infection.
Effekt av olika kvävegödselmedel på utvecklingen av klumprotsjuka i salladskål (Brassica rapa ssp. pekinensis)
The price trend on rapeseed the latest years has led to an increasing interest to grow the crop among many farmers in Sweden. The price trend has resulted in more than a doubling of the oilseed area since the early 2000s. For many farmers it is an advantage to increase cultivation of rapeseed because of the high proportion of cereals in the crop rotation on many farms, but it is not just benefits. The risk of the fields being infected by clubroot increases within frequent rapeseed cultivation and it often leads to subtantial economic losses. Clubroot is caused by Plasmodiophora brassicae that is a soilborne pathogen in genus Protozoa and its resting spores can be found in the soil for up to 18 years.
Undersökning för generaliteten för lämpligt motståndarantal i Magicka ur ett flowperspektiv
Detta examensarbete undersöker skillnaden i tre olika nybörjargruppers upplevda flow då de spelat Magicka (2011) med motståndarantal som den enda skiljande variabeln. Undersökningen baseras bland annat på Csikszentmihalyis (1990) flowteori och Caillois (2001) teori om att tävlande slutar vara roligt då det urartar i kaos. Syftet med examensarbetet har varit att hitta när mest flow uppstår då nybörjare på Magicka (2011) spelar mot en viss motståndartyp, samt om detta flow bryts när för många motståndare introduceras. Undersökningen har visat att nio motståndare har resulterat i betydligt mer flow än tre, medan skillnaden mellan nio motståndare och 18 har varit obetydlig. Examensarbetet har dock inte lyckats kvantifiera var flow övergår till kaos med den testgrupp och motståndartyp som använts. Framtida forskning skulle exempelvis kunna undersöka på vilket sätt ett varierande motståndarantal skulle påverka flow för en mer erfaren testgrupp som spelar mot andra motståndartyper..
Flow i fokus : processen att göra ett spel genom research through design
Starting out as a minor form of amusement, the game industry has become one of the most lucrative andsuccessful in the entertainment business competing against giants such as television, movies and music.As the internal competition within the developer community grows companies work hard at discoveringnew ways to attract and keep customers. By having a playcentric approach focusing on user experiencethey hope to achieve that goal. This thesis describes the process of designing a game with focus on theplayer. We apply the concept of flow on game development and investigate through research throughdesign if we are able to create a game that keeps the player in flow.Play tests showed several elements such as control issues and too difficult challenges early in the game,affecting the possibility for players to experience flow while playing. These negative factors came to becalled flowleakers.
?Det är änglakör och hela köret när man väl når det [Flow]? : En kvalitativ studie om ryttares upplevelse av Flow
Syftet med föreliggande studie var att undersöka hur ryttare upplever Flow, och vidare även hur ryttare upplever samspelet inom ekipaget vid Flow. Studien inkluderade 10 kvinnliga informanter (M = 18.7, SD = 1.48) med tävlingserfarenhet som sträcker sig från ingen alls till internationell nivå (Hoppning= 4, Dressyr = 3, Fälttävlan = 2, Ingen tävling = 1). En semi-strukturerad intervjuguide utvecklades utifrån Csikszentmihalyi's holistiska perspektiv på de nio dimensionerna av Flow (Jackson & Csikszentmihalyi, 1999), och data analyserades kvalitativt genom en innehållsanalys. Resultatet visade både att ryttares upplevelse av Flow stämmer väl överens med andra idrottsutövares upplevelse (Swann, Keegan, Piggott och Crust, 2012), och bekräftar tidigare tolkningar av att ridsporten skiljer sig från de flesta andra idrotter genom att utfallet till stor del är beroende av interaktionen och samarbetet mellan häst och ryttare (Beauchamp & Whinton, 2005). Vidare visar resultatet även att samspelet mellan häst och ryttare är en viktig och oersättlig del i upplevelsen av Flow..
Metodundersökning av tre metoder för kvävemätning i en arktisk äng : Jämförelse mellan mätmetoderna extraktion, inkubation och jonbytesmembran (PRS-sond)
The purpose with this report was to compare three commonly occurring methods for measuring plant available nitrogen in soils. The methods extraction, incubation and Plant root simulator (PRS) probe - an ion exchange membrane (Western Ag Innovations, Inc., Saskatoon, Canada) method were used and comparison between these methods were conducted. A full factorial experiment were set up in northern Finland with the treatments excluding herbivores, warming and fertilization to see how the inorganic nitrogen content in the soil was effected by the treatments. Soil cores were taken and from them a subsample was incubated for 18 days and thereafter analyzed for inorganic N in laboratory. PRS- probes were in the ground for 1 month.
Olika typer av täckning och samodling och dess påverkan på antalet skadegörare i en Pak choi odling :
The purpose of this report is to examine the possibilities to decrease the number of insects and other pathogens in a crop of pak choi (Brassica rapa), grown with different types of cover and living mulches. Included in the report is a study of literature where amongst others, a summary on the vegetable pak choi and theories of living mulches and different kind of covers are to be found. To examine the amount of predators in the field, traps were used.
During the autumn 2002 the tests were conducted in Alnarp. The pak choi and the living mulches were planted/sawn at the same time, the different covers were also applied at this time. The total experiment was divided into six different treatments (plus control) of which three were with covers and three were with living mulches.
Once a week the number of leaves, the height and damages were read on ten of the plants from each parcel.
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.