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.

An excessive input of nutrients to lakes and other water bodies has created a problem with eutrophication in Sweden. Untreated, or partially treated, domestic sewage is a major source for discharge of phosphorus (P), which is the nutrient most frequently responsible for eutrophication of most fresh waters and the Baltic Sea. The waste water can be cleaned by Filter materials, which have a high P-retention ability and which after saturation may be used as fertilizers. Four potentially suitable Filter materials were tested in batch- and column experiments in this study. In the batch experiments, the following materials were shaken with waste water in time series ranging from 5 seconds to 60 minutes: coarse (1-4 mm) and fine (0-2 mm) Polonite® (heated bedrock from Poland); Filtralite® (light expanded clay aggregates with limestone added before burning); water cooled blast furnace slag (BF-slag) and BF-slag mixed with 10% burned limestone.

How to create a more effective filter for the dishwashers of tomorrow..

Highly polluted urban storm water from e.g. highways can contain large amounts of heavy metals that may cause harm if they are discharged into recipients. To remove the heavy metals a possible low-cost method that does not require much maintenance, could be the use of reactive filters with Filter materials consisting of industrial residues or other cheap mineral based materials. Dissolved metal ions are removed by reactive filters through the processes of ions binding to active sites on the surface of the Filter materials, or by formation of insoluble precipitates.The ability of CaO-treated granulated blast-furnace slag, iron oxide coated sand, olivine and nepheline to remove seven heavy metals (Cr, Cd, Cu, Ni, Zn, Pb and Hg) from urban storm water was studied. Initially batch experiments were performed where the effect of pH, dissolved organic carbon (DOC) and dissolved ions on the adsorption efficiency was studied.

This paper describes the work done trying to diminish the noise present in the signal from an IR-detector. The project was aiming towards two different kinds of applications; heat protection and presence detection. The hypothesis was that the signal-noise ratio would decrease if a filter and a proper installation were used for the detector. Some experiments were executed to determine what kind of filter were the most suitable for each application and how these could be installed. After executing the experiments and evaluate the results we recommend to use a specific filter for each application.

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.

Normally the operational amplifier is used as a component in active filter design. The goal for future components in filter design is large bandwith and the use of low supply voltages. The use of current-mode instead of voltage-mode circuits gets a step closer to the required performance. A component that use current as the signal conveying part is the current conveyor. In this report a comparative study between two current conveyor structures of second generation (CCII) is performed.

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.

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.

Wastewater contains biodegradable materials, which are often measured as BOD7.Trickling filters are sometimes used as a purification step for BOD-reduction. Atrickling filter is a tower, which is filled with a carrier material. Microorganisms growon the carrier material in the form of a biofilm. This biofilm consists mostly of bacteriathat purify water from BOD.In Älgarås? wastewater treatment plant the water is purified by a trickling filter.However the treatment plant has difficulties reaching the emission requirements forBOD.

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.

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.

Water is our most important provision and its quality is above all dependent on the geological conditions in the area from where it is extracted. Due to geological properties there are certain areas with an elevated risk of high uranium levels in the ground water, which in turn constitutes a risk for human health. Consumption of water that contains a high concentration of uranium implies a health risk due to the chemical characteristics of uranium. Livsmedelsverket (The National Food Administration) and Socialstyrelsen (The National Board of Health and Welfare) therefore recommend that precautionary measures should be taken when the uranium concentration in ground water exceeds 15 micrograms per litre. In particular, drinking water collected from wells in areas with uranium-rich bedrock may have a harmfully high level of uranium. One of the wells of the Ärla water purification plant, located near Eskilstuna, Sweden, contains water that exceeds the guideline of 15 micrograms per litre. One interesting technique for removing uranium from drinking water is adsorption to reactive Filter materials.

The purpose of this report is to examine various roof structures that can operate in a warehouse with large spans. The building that is examined in the report is currently under construction, and the roof construction has already been selected. The selected roof system will therefore be compared with some other structures and materials that have been possible. The report will evaluate three different frame materials, two insulating barriers and two overlaying materials. Another important part in major construction projects is the roof safety.

Wastewater handling of private sewage systems has become an all increasing matter. In Stockholm region the 90 000 private sewage systems contribute with larger phosphorus flows to the Baltic Sea than the two biggest sewage plants in the area, Henriksdal and Käppala, contribute together, even though these two plants purify wastewater from more than one million inhabitants. When summer house areas turn into areas for permanent living ? transition areas ? the load on the existing systems increases, systems that already often are unsatisfying. In those areas it is not clear what the best system choice is; On-site systems for single households; Local collective systems or Connection to central systems.