IIR-filter är överlägsna traditionellt skapade FIR-filter på många punkter. De klarar sig med en klart lägre ordning för att realisera ett filter med samma egenskaper. En nackdel är däremot att filtret är klart känsligare för koefficient kvantisering och förlorar sina egenskaper när koefficienterna ändras, detta inträffar även om förändringen är liten. Genom den speciella struktur som vågdigitala filter använder sig av kommer man runt detta problem. Det betyder bl.a.

The filters used today to purify water are often expensive and the need to find new filter materials is substantial. Studies of pine bark have shown that this is a material that may be used as an alternative to conventional filter materials, such as activated carbon. However, the study of pine bark has shown that a leakage of phenolic compounds may occur when using the material for water purification. Therefore, the purpose of this report is to investigate the release of phenols from pine bark, in order to evaluate the use of pine bark as a filter material. Another assignment is to investigate the amount of metals adsorbed by the filter material.

I detta examensarbete presenteras två olika konstruktionslösningar för ett spegeldämpande filter till en heterodynmottagare för L-bandet. Båda filtren är uppbyggda av distribuerade element i mikrostripsteknik. Filtertyper som behandlas är combline med kapacitansdioder för avstämning samt filter med element av typen commensurate length transmissionsledning. Nödvändig teori om mikrostripteknik och distribuerade element behandlas. Konstruktionen av filtren beskrivs steg för steg från filterkrav till färdig mönsterlayout.

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..

Glulam is a product that was engineered to make use of timber in a more efficient way. Bychoosing timber of similar quality and discarding natural defects during production, thedevelopment of a stronger cross-section is achieved.Carbon fiber is a relatively new material with a high tension capacity. This feature is used toexamine how the bending capacity of the beams improve by adhering carbon fiber laminateson the lower edge of the beamsThe strength of the material is tested with three experiments: carbon fiber on the bottom of thebeam (a), carbon fiber attached to the lower sides of the beam (b) and carbon fiber in thebeam, covered with a layer of wood (c)The results show that the first case, where the carbon fiber is attached to the bottom of thebeam, gave the best result with an increase in capacity of 59 % compared to the nonreinforcedcontrol. The other two cases also show an improvement in capacity, beam-type 3had a capacity increase of 47% and beam-type 4 increased with 25 %Tests were also made with glulam beams reinforced with fiberglass, but these tests were notanalyzed in depth because the purpose was to compare the capacity to carbon fiber. Thisbeam improved its capacity by 40.3%.The tests show that carbon fiber as a reinforcement material for glulam is a good choice whenthere is a requirement for stronger cross-sections in both new production and renovation ofold buildings.

Freshwater ecosystems have long been neglected as an important part of the global carbon cycle. However, research shows that most of the world?s lakes are net-heterotrophic and consequently emitters of greenhouse gases to the atmosphere. In many boreal and north-temperate lakes, most of the yearly emissions usually occur in spring, shortly after ice-thaw. The aim of this study was to quantify the flux of carbon dioxide (CO2) and methane (CH4) in three boreal lakes, during this annual event.

This examination work brings up opportunities to invest in a construction for heating with grain or pellets on farm level. As example we have chosen Fröberga Gård which is a farm located in Östergötland outside of Söderköping. The farm`s residential buildings is to day heated with oil and electricity. The result of our investigation shows that heating with grain is the best alternative, partly because of economical issues but also because you can grow the grain on your own farm and by that you can get better economy in your seed cultivation. To grow 16 tonne of grain as is needed demand gives a insignificant increase of work. Further an advantage is that no investment in machines is needed because all the machines witch is needed already is in use on the farm. In a situation where a new investment is needed as in the case we studied, is it often profitable to invest in a integrated furnace. Because all the components are well adapted to each other, and because that gives a high efficiency. If you already own a well working furnace is it often most profitable to connect a burner to it. It is important to know that heating with grain need more work than heating with pellets, because the high contents of ash in grain. Even if you choose pellets instead of grain the calculation shows good results. Because peat is an excellent but fairly untested raw material for pelletsproduction we have chosen to watch little more on its quality and conductions. We discovered that peat has a high heating value which makes it possible to raise the heat value in pellets through mix up peat and wood. Or you can make pellets with only peat and get a pellet with high heating value. Even the calculation with peatheating shows good results..

The work describes the development of an adjustment algorithm that will replace today?s manual adjustment of Lead- and Lag-filters at ABB Robotics industrial robots. The adjustment is mainly for the filter parameters in the control system.Three different algorithms have been created to replace the manual adjustment. One of them is based on the criterion from the manual adjustment and another one on optimization of the sensitivity function. The last one is a combination of the two.The report describe the development of the algorithms and how they behave during simulations and tests on real robots.

Sapa Heat Transfer is a company that produces aluminum heat-exchanger strips for the automotive industry. Sapa Heat Transfer wish to chart their emissions of carbon dioxide in order to meet future demands on carbon dioxide reporting. They also would like to examine the meaning of the term ?green electricity? which is marketed as carbon dioxide free, and the sort of electricity that they purchase. This report includes both direct (liquefied petroleum gas and diesel) and indirect (water, process-water, long distance heating, waste) emissions from their company.

The goal with this examination thesis is to investigate the difference in carbon dioxide emissions between a building with a wooden versus concrete carcassing from a life cycle perspective. The huge amounts of carbon dioxide released into air from human activities must be reduced to prevent serious consequences. A way to limit this issue is through performing a comparative study where the result shows which of two products with the same function has the lowest emission of carbon dioxide, whereof the product with the lowest carbon dioxide pollution can be chosen.To be able to perform a study like this an object has been chosen and studies about life cycle analyses have been done. The rental square meter, the thermal conductivity value, the energy requirements and the placement of the building has been set equal in both framework types. There were solely dissimilarities of the two buildings taken into account when this comparison study was performed.The result of the study is that a building constructed with a wooden carcassing has the lowest amount of carbon dioxide emissions.

This reports goal is the give BSR AB more information that's useful towards their customers in marketing of their products.It involves tests of different air filters designed for cars and 3D-modelling of Opti-Flow systems. The three models thats being tested is SAAB (93SS), VAG (1.8T) and Volvo (S60). To every brand there are three different models. A orginal- , sport- and an open cone air filter (Opti-Flow).The results indicate that the open Opti-Flow filter has better performance compared to the other cased filters. The sport filters for SAAB and Volvo has better performance then the original filter.

The main purpose of this study was to determine the impact of bedding material on the faecal microflora of horses. Another objective was to investigate the hygienic and physical qualities of the bedding materials used and how these may change in the course of the trial period. The bedding materials used were sphagnum peat and wood shavings. Six horses had each material as bedding for a three week period in a change?over experiment.

Total organic carbon (TOC) and chemical oxygen demand (COD) are two methods used for measuring organic pollutants in wastewater. Both methods are widely used but the COD method results in production of hazardous wastes, including mercury.The purpose of this study was to validate the method TOC that will replace COD and find a factor to convert TOC to COD. In this study 26 samples were analyzed from four sewage treatment plant in the municipality of Enköping.The results show that the COD method could be replaced by the TOC method.The factor for COD/TOC was between 3.1 - 3.3. Both methods will be used in parallel until 2013 when it will be forbidden to use the COD analysis..

Today, about 15 to 20 percent of Sweden?s total emission of carbon dioxide can be traced to the household sector. By examining apartment blocks in a life cycle perspective, the origin of the carbon dioxide emission has been charted and analyzed. This information has been used to create a computational model that calculates the total emission of carbon dioxide from a specific apartment block. The results from the analyzed apartment blocks indicate that both the use of energy and the emission of carbon dioxide have been reduced since the 1960s. Through the examination of building materials, it is possible to lower the emission of carbon dioxide that origins from the construction phase of an apartment block.

This study was performed in an afforestation experiment established 1982 on an abandoned peat harvesting area, Flakmossen, in the province of Värmland, SW Sweden. The experimen-tal design include planting with Scots pine (Pinus sylvestris), in combination with various drainage intensities (20, 30, and 40 m between ditches), and fertilizer doses 0, 100, and 200 g PK per seedling applied at the date of planting. The aim of this study was to achieve more knowledge about the conditions on afforestation of peat harvesting areas, especially regarding drainage intensity and fertilization requirements, by means of determining the stand growth and yield in the Flakmossen trial. The forest growth did not differ significantly between the drainage intensities tested when the same amount of phosphor and potassium fertilizer was added. Thus, shorter distances between ditches than 40 m can not be recommended. When no fertilization was carried out seedling survival was very low, and the growth of sur-vived seedlings was poor. The largest diameter and height growth were observed in the areas where the highest dose of phosphorus and potassium (200g/seedling) was given.