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1281 Uppsatser om Water purification - Sida 45 av 86

?Det är järnet i blodet som väger? : Elevers uppfattningar om materia en kvalitativ undersökning i årskurs 3

The purpose of this investigation was to find out more about students? spontaneous ideas about properties and transformations of matter. Examples of matter chosen are such which students know about from everyday life and focus is mainly on the questions if students know that all matter has weight and that matter is preserved in transformations.The method used is semi structured qualitative interviews with individual students. Different experiments were carried out together with the students who afterwards were interviewed. However, the students show varying answers and no generalizations can be done.

Modellering av dagvattennät utgående från markhöjder

Enligt Svenskt Vatten ska dagvattensystem vara dimensionerade för att klara ett regnmed en återkomsttid på 10 år. För att utvärdera om ett system är rätt dimensionerat kanen dagvattenmodell upprättas. Det är då viktigt att veta vilka nivåer ledningarna har mendenna information är bristfällig hos många kommuner. Ledningarna borde dock följatopografin i generella drag och borde därför kunna uppskattas därifrån.Syftet med denna studie var därför att utveckla en metod för hur vattenledningarnasnivåer kunde ansättas på ett enkelt sätt utifrån marknivån och hur stor betydelse detskulle ha vid dagvattenmodellering. Ett ytterligare syfte var att även bedöma Lidingöstads dagvattensystem, där information om ledningarnas nivåer saknades, utifrån dennametod.

Vägen till framgång : En studie om festivaler i Stockholm

The purpose of this paper is to examine how events can be successful and stay competitive.Festivals are a big part of the event world and it can be difficult to understand why certainfestivals are successful and others not. In this paper we have conducted a comparison betweentwo major festivals in Stockholm. Both of them reached success, but nevertheless one of themfailed, while the other one is still successful. With this comparison, it appeared that there aremany aspects that help a festival to reach success but also factors that can make a festival afailure. To conduct this study, a number of interviews have been carried through; these havelater been put in relation to different theories about festivals.

Skönhetssömn - sanning eller myt?

Det har aldrig tidigare gjorts några studier som kopplar ihop utseende med sömnbrist. Det är väl känt att sömndeprivation påverkar hälsa. Tanken att attraktivitet också skulle bli negativt påverkat kan baseras på studier som visar att ett friskt utseende och hudkvalitet har effekter på attraktivitet. Förmågan att avgöra om en person är trött utan signaler från beteenden har heller inte tidigare blivit undersökt. I den här studien fotograferades 23 deltagare vid ett baselinetillfälle och efter 36 timmars sömndeprivation.

Fodrets inverkan på resultatet vid undersökning av förekomst av ockult blod i avföringen hos hund :

Hemoplus® (Sarstedt, Nümbrecht, Tyskland) is a guaiac-based fecal occult blood test developed for human medicine. Guaiac-based tests make use of the pseudoperoxidase activity of hemoglobin so the test is not specific for human hemoglobin and can therefore be used in veterinary medicine. Peroxidase-containing foods such as meat (hemoglobin and myoglobin) can cause false-positive results of the test. To ensure that a positive result is not caused by diet, it has been suggested that canine patients should be fed a meatless diet for a few days prior to fecal occult blood testing. The aim of this study was to evaluate the effect of commercial dog food on guaiac-based tests. In this study fecal samples from healthy dogs were analyzed with Hemoplus®.

Prefabricerade väggelement av hampabetong

Lime Hempcrete consists of lime, water and hemp and creates an insulating, sound-absorbing, lightweight and environmentally friendly material that can be used in wall, roof and floor structures (Bevan & Woolley 2008). This construction method is not yet developed in Sweden as there has been a ban on the cultivation of the hemp plant. This ban on the cultivation of hemp was removed in 2003, when the material got a boost. You can use it in many different ways and not just in the construction industry (Ahlsten, 2010).In this study we have investigated the possibility to produce prefabricated wall elements of LHC. We have also studied its mechanical properties and dehydration time.

Rejektvattenbehandlingens inverkan på kvävereduktionen vid Arboga reningsverk

Under 90-talet uppdagades övergödningsproblematiken i Östersjön, varför omgivande länder enades gällande åtgärder för att minska problemen. De svenska reningsverk som genom sina utsläpp av kväve och fosfor påverkade Östersjön tvingades då införa gränsvärden för kväve- och fosforutsläppen. Vid Arboga reningsverk, vars recipient är Arbogaån som mynnar i Galten, Mälaren, har kvävereducering sedan en tid tillbaka varit i drift. Dock krävdes från och med år 2012 att totalkvävehalten i utgående avloppsvatten ej översteg 15 mg tot-N/l. Införandet av detta gränsvärde resulterade i åtgärder för att minska kväveutsläppen.Rejektvattenbehandling är en vanlig metod för att minska halterna totalkväve i utgående avloppsvatten.

Ett träd och dess liv : Förskolebarns uppfattningar om träd

The aim of this study was to investigate preschool children's perceptions of trees in and it was done through qualitative interviews. The children were drawing trees and told me what the tree needs to grow and what happens to the leaves in autumn. In a playful way, they learned more about trees and the purpose was also to examine whether they had acquired new experiences and thoughts on the trees, photosynthesis and decomposition. Then the children were interviewed again to see if their answers were different. The results showed that the children gave different answers at the second interview.

På jakt efter den produkt som flytt - en studie om uppskjuten produktlansering och dess effekter

Many product launches are postponed today, however very little research regarding to customer responses to such events has been carried out. The purpose of this paper is to investigate how people react to a postponed product launch. An experimental study of responses to a postponed launch of a mobile phone, a mineral water and a music album is used to investigate customer reactions. The respondents exposed to the postponed launch showed a higher value of reactance. This reactance affects the attitude, purchase intention and perceived quality of the product in a negative way.

Screens : tävling om strandpromenaden i Helsingborg

The competition for the beach promenade in Helsingborg was announced in 2001 and was arranged by the city of Helsingborg. My contribution to the competition represents the main part of my thesis in the Landscape Architecture Programme. The competition entry is based on the concept of crossing screens of vertical elements which connect the pattern and structure of the city to the beach and the water. The different materials and designs of the screens relate to the various characters of the different parts of the area and they form a sequence and uniting theme along the beach. In addition to the competition entry which was made in 2001, the thesis contains a second part, made in the spring of 2006. It consists of an Introduction with the competition programme and a description of the starting points, a part called Method where the process is described, and the Conclusion with reflections on the competition entry and the process where I also introduce and comment on some other projects which in different ways have are connected to my concept. .

Biobränsleanvändning och Flameless oxidation i degelugnar för glassmältning

Idag värms glasugnar upp med antingen gasol eller olja, detta projekt vill visa på möjligheten att istället använda gas från biobränsleförgasning som förbränns utan synliga flammor. Detta skulle miljömässigt ge fördelarna att biobränslen inte bidrar till växthuseffekten och ge förutsättningar för att minska kväveoxidutsläppen genom bättre teknik än dagens.För att visa att det är möjligt att både behålla produktionen och reducera kväveoxiderna med förgasningsgas konstruerades en modell av ugnen och strömningsbilden studerades i vattenmodell. För att undersöka värmeöverföringen i ugnen behöver en eller flera kalorimetrar konstrueras för att kunna användas vid varma försök. Dimensionsberäkningar gjordes som visade att detta är möjligt med vissa typer av kalorimetrar..

Optimering av informationsinsamlingvid prototyptillverkning

This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.

Fisksamhället i Spexhultasjön, Nässjö

The lake Spexhultasjön is a moderate humic mesotrophic lake that is not acidified. The fish fauna was investigated by using a standard method for sampling freshwater fish with multi mesh gill nets. The fish fauna was diverse with perch, pike, tench, common whitefish, and roach. Perch and roach dominated. There were few pikes.

Utvärdering av avloppsvattenreningen vid Hallsta Pappersbruk : Kartläggning av inkommande avloppsvatten och optimering av driftparametrar

Hallsta paper mill uses large amounts of water during the pulp and paper making processes. The wastewater is treated in two separate activated sludge processes referred to as BIO 1 and BIO 2. The main aim is to reduce the organic substance content, measured as COD (Chemical Oxygen Demand) before the wastewater is released into the environment. Since the effluent produced is very rich in organic substances, the addition of nitrogen (N) and phosphorus (P) are necessary to give satisfactory treatment results. Problems with sludge bulking sometimes occur which lead to increased levels of suspended matter and nutrients in the effluent.

Etanolmarknaden i Brasilien : etanol som fordonsbränsle

According to the EC fuel regulations 2 % bio fuel has to be blended in all fuel by the year 2005, and 5.75 % by the year 2010, which means ethanol for gasoline driven vehicles, so there will be a substantial demand for ethanol. Brazil already has an established industry for producing ethanol and is the leading producer and exporter of fuel ethanol. My purpose with this paper is to investigate why Brazil decided to develop ethanol production on a large-scale operation and to find out today?s situation. Focus will mainly be on ethanol production with sugarcane as a feedstock.

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