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225 Uppsatser om Nutrient leakage - Sida 8 av 15

Sjöars känslighet för klimatförändringar ? vilka faktorer påverkar?

The Earths climate is changing at a higher rate, i.e between 1861 and 1994 the annual mean temperature in Scandinavia increased with 0,68º C and according to recent climate models the annual mean temperature is likely to rise with another 3º C during this century.A warmer climate in many ways is associated with changing conditions for lake ecosystems. An expected higher water temperature and a stronger summer stratification of the water column increases the risk of anoxic conditions at the lake bottom. Thus anoxic conditions are likely to cause a phosphate leakage from the sediment, i.e. a higher internal loading of phosphate.In this project, the extremely warm summer of 2002 has been used as an example for a possible scenario for a future climate. By comparing levels of phosphorus in the summer of 2002 with a ten-year median value, a phosphorus related sensitivity to climate change has been analyzed for 55 Swedish lakes.

Motor till unikt luftvärmeväxlarsystem

Gtherm is an innovation company who has an unique air heat exchanger underdevelopment. The purpose of this thesis is to provide data of suitable motors for theheat exchanger and to find suitable motor suppliers.A motor specification was designed. It is an important basis for the search of suitablemotors. A compilation was made of nine motor suppliers and the suitable motorsfrom those. The compilation can be used by GTherm in their choice of suppliers andmotors.The compilation of the demands on the motor and analysis of suppliers indicated thatthere were no standard motors available to GTherms air heat exchanger.

Inneluftsventileradekryprumsgrunder : en utvärdering av två tillverkare

This Diploma work investigates internal air ventilated crawl-space in respect to construction and damp. The Diploma work assumes from a general description of crawl-space and general dump problems in ground construction. An internal air ventilated crawl-space is a construction where you take the ventilation air from the building and bring it down to the crawl-space and lets the air circulate before it passes through a retaining aggregate on the way out from the crawl-space. In this matter you get a worm space under the building and a lot less dump problems in form of · Ground damp · Build damp The ground dump reduces through draining around the building, different layer of gravel between the ground and the building and ventilation of the crawl- space. The build dump reduces through ventilation of the crawl-space as fast as possible.

Avena Sativa - En hyperackumulator? : En studie av havres kadmiumupptag

The aim of our research was to investigate if oat is capable of extracting cadmium to such extent that it is usable in decontaminating polluted soils. We grew oat in a hydroponic culture during 28 days in a controlled environment and a total of 30 plants were used. The nutrient solutions were contaminated with cadmium of ten different concentrations after seven days. After harvesting the plants, the roots were separated from the shoots, placed in separate containers and then turned to ashes. The cadmium content was measured three times per sample in an atomic absorption spectrometer.Our results indicate that the ability of oat to extract cadmium from a solution is linearly dependent of the cadmium concentration of the solution.

Utredning av variablerna som påverkar storleken på brytspänningen i lindningskopplare

Brytspänningen är den spänning som uppkommer när överkopplingsmotståndet i lindningskopplaren lämnar sitt föregående läge vid omkoppling. Storleken på brytspänningen i lindningskopplaren beror på hur stor läckinduktansen är. Är den inte känd så kan brytspänningen istället beräknas med hjälp av FEM-programmet ACE (internt ABB-program) i samband med Mathcad. I ACE beräknas först reaktanserna i p.u-enheter mellan lindningarna och hur stora de är beror på lindningslayouten. Det är tidskrävande att använda ACE och Mathcad och uppgiften är att utreda de parametrar som påverkar storleken på brytspänningen samt att ta fram en förenklad beräkning av densamma.Genom simulering i ACE av en mängd olika lindningslayouter visar det sig snart att det är alltför många parametrar som påverkar reaktanserna.

Design of a Direct-conversion Radio Receiver Front-end in CMOS Technology

In this Master's thesis, a direct-conversion receiver front-end has been designed in a 0.18um CMOS technology. Direct-conversion receivers (DCR) have obvious advantages over the heterodyne counterpart. Since the intermediate frequency (IF) is zero, the problem of image is circumvented. As a result, no front-end image reject filter is required and the channel selection requires only a low-pass filter, which makes it easy to integrate directly on chip. However, the DCR also suffers from several drawbacks such as extreme sensitivity to DC offsets, 1/f noise, local oscillator (LO) leakage/radiation, front-end nonlinearity and I/Q mismatch.

Relining ur ett beställarperspektiv

This report is focusing upon relining from a client?s point of view. Potential buyers are given a presentation of the different methods available today together with a general briefing describing the process. An important part of this report are the interviews that took place with already established customers. Property owners, managers, pipe cleaners, and project managers whom all been in contact with relining have answered the questions given along with their own thoughts and have also given recommendations of other persons to talk to.

Miljödammars funktion som kväve- och fosforfälla samt som bevattningsdamm i Sölvesborgs kommun

A study was made on four environmental ponds in Sölvesborgs municipality. The reason forthis was to see if the ponds had fulfilled some of the questions that was mentioned in theproject ?Rädda Hanöbukten?. The questions were as following; do the environmental pondsdecrease the leakage of nitrogen and phosphorus into Hanöbukten, do the ponds decrease theuse of groundwater in Sölvesborgs Municipality and are there any restrictions on what thewater in the ponds is allowed to be used for. In order to answer these questions aquestionnaire was made and interviews were held.

Näsnarens framtid i ett näringsstatusperspektiv

Eutrophication has been a problem in aquatic systems for a long time. It is well known that the key nutrient to control the eutrophication process is phosphorus. Lately, it has been possible to reverse the process and recover lakes from eutrophication.During a long time Lake Näsnaren in Katrineholms kommun, Södermanland, has been exposed of a large amount of phosphorus from the city's wastewater. The lake has a great value as a habitat of rare species but also a high recreation value for people living in Katrineholm and Södermanland. Lake Näsnaren is situated in a Natura 2000 area.

Erfarenheter av några utfodringssystem till får :

The evaluation of the function of the feeding of sheep herds is suggested to involve the work effort, the fulfilment of the nutrient needs of the sheep and the feed waste. Mechanisation of the feeding can be very simple or include high degrees of mechanisation. Three different farms, representing different levels of mechanisation are presented. Descriptions and analysis of the feeding systems including mechanisation, work effort and estimations of the feed waste are made on each farm. The herd with the most advanced feed mechanisation included a rolling feed band and mix wagon. The other farms were partly or little mechanised including ad lib feeding from big bales and manual distribution of hay and concentrates. The most mechanised farm was able to feed a large herd of sheep at a low work effort and little feed waste. However, the investment in machinery has to be weighed against the improved efficiency.

Effect of vortex-processed water on tomato (Solanum lycopersicum) plants

This pilot study examined whether treatment with Vortex Process Technology (VPT) of the irrigation water used on tomato (Solanum lycopersicum) plants had any effect on plant growth. In a block experiment, with two blocks comprising 12 vases containing 1 L water and two tomato plantlets, treatment in which, nutrient solution was based on Vortex-treated water was compared with an control using untreated water. All vases were kept in a static aerated culture system in a daylight chamber for four weeks. The results showed that the effect of the two blocks exceeded the effect of vortex treatment in terms of leaf area and weight of fresh and dry matter. Plant height, stem width and internodal length were significantly different in tomato plants grown in Vortex-processed water compared with the untreated control.

Nutritionens betydelse för sårläkning : en litteraturstudie

Syftet med denna litteraturstudie var att via litteraturen beskriva nutritionens betydelse för sårläkning. Studien genomfördes som en deskriptiv litteraturstudie där metoden bestod av att söka vetenskapliga artiklar i databaserna Medline, Cinahl och Academic Search Elite. Sjutton artiklar valdes ut. Resultatet visade att patienter med bensår eller trycksår i många fall inte når upp till de näringsrekommendationer som finns. Det visade sig vara vanligt att dessa patienter ligger vid gränsen för att vara undernärda.

Närsalter och bottenlevande organismer i Mönsteråsviken

The focus of this study was to examine the nutrients and benthic organisms of the bay ?Mönsteråsviken?, which is influenced by eutrophication. The purpose was also to look at an interesting gradient forming in the bay, namely the distance from the river outflow of Lillån. At 18 sampling sites in the bay samples of water, sediments and benthic organisms were collected in late April of 2011. The water was analyzed for nitrate, phosphate and chlorophyll.

Frost hardiness of grapevine cultivars as affected by ground cover under Scandinavian conditions

Cultivation of grapevine is novel under Scandinavian conditions. We studied the impact of ground cover on frost hardiness of grapevine cultivars in Northwestern Scania in a two-factorial trial with four cultivars Solaris, Pinot Gris, Siegerrebe, Ortega and three kinds of ground cover (open soil, plastic cover and gravel). The study was conducted in a grapevine orchard, planted in May 2009, in Broddarp on Bjärepenisula Sweden (N latitude 56°; longitude E 12°). Soil and air temperature were monitored continuously. Frost hardiness measurements were performed every second week from late September to early December 2009. Frost resistance, LT50, was determined by electrolyte leakage measurement of the upper stems after artificial freezing at -15 °C.

Strukturkalkningens möjlighet att hindra fosforutlakning : en litteraturstudie

The purpose of this essay is to find out if liming with Ca(OH2) and CaO can reduce leachingof phosphorus from agricultural land and the problem with eutrophication. This purpose alsoincludes getting knowledge about how to make the phosphorus retained in the soil and beaccessible for the plants. This essay is supposed to show if more research is needed in thissubject. There has not been much research about this subject and therefore the amount ofmaterial to study is limited in this literature review. The research reports that have beenstudied have similar results.

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