I Sverige finns idag en vedertagen metod för att bestämma dimensionerande flöde för dammanläggningar. De teoretiska beräkningarna av dimensionerande flöde för dammanläggningar tillhörande flödesdimensioneringsklass I baseras på HBV-modellen, en begreppsmässig hydrologisk beräkningsmodell som beskriver samspelet mellan de meteorologiska och hydrologiska förhållanden som råder inom ett avrinningsområde. Begreppsmässiga hydrologiska modeller baseras på vattenbalansen och används för att bestämma tillrinning till vattendrag, sjöar eller andra vattenförekomster. Vid hydrologisk modellering med begreppsmässiga modeller tas ingen explicit hänsyn till vattendragets geometri. Trånga sektioner i naturliga vattendrag kan hindra vattnets framfart och orsaka dämning uppströms den trånga sektionen.

In early January 2010 the authors participated in a meeting with the chief engineer for a company in which a central part is manufacturing of printed circuit boards (PCB). At this meeting it emerged that the machinery and production methods have changed substantially since the early 1990's. The spreadsheet for preliminary production time calculations by the company is today based on conditions from almost 20 years ago. The company has over the years been trying to adjust the spreadsheet template. The result of these adjustments has filled it with historical residue, something which makes the template difficult and time consuming when the primary user tries to handle it.The purpose of this study was to help the company increase its accuracy in the representation of the production times for the different PCB-based products by developing a new costing model based on an already existing but inadequate spreadsheet template. The company also expressed the wish that the new costing model would be less time consuming to work with.The methods used to achieve the goal are interviewing, participatory observations and meetings with relevant persons. The data obtained were analyzed using the theory on PCB production and visualization of data.

Latent heat storage is a way to store thermal energy when a phase change material undergoes a phase change. The advantage of latent heat storage is the capability to store more energy per mass unit than other heat storage methods. The most commonly used phase change in latent heat storage is the transition between solid and liquid. Phase change materials can be divided into organics, inorganics and eutectics.In the Nordic electricity market the price of electricity is set every hour by Nordpool spot, which leads to price fluctuations because of changes in demand. The main goal of this report is to create a latent heat storage system in a single-family home and investigate the possibility to save money by charging the latent heat storage system when the price of electricity is low, and discharge when the price is high.The thermodynamic model consisted of a ?tube-in-tube? heat exchanger with phase change material in the outer tube and water as the heat transfer fluid in the inner tube.

Samtidigt som debatten kring jordens klimatförändring är i full gång har intresset för att miljöcertifiera byggnader vuxit oerhört. För fastighetsägare är det en möjlighet att bevisa för sina hyresgäster och köpare att byggnaden är hållbar. Är en byggnad miljöcertifierad har en oberoende part intygat att den uppfyller en nivå av hållbarhet som bestäms utifrån standardiserade kriterier. Fastighetsägaren kan alltså använda certifikatet i marknadsföringssyfte.Den här studien undersökte om en byggnad som är byggnadsminnesförklarad kan miljöcertifieras med Miljöbyggnad. Målet var att hitta kostnadseffektiva lösningar för att uppfylla de miljöcertifieringskriterier som eventuellt inte uppfylls idag.

To understand the motives, and perhaps more importantly the barriers, for farmers to convert from conventional to organic farming is of great interest for policy makers as well as for academics. In Sweden and in other EU countries, proposed targets of the area in organic farmland have failed to be reached in spite of different kinds of policy measures. Most studies agree that the average profitability seems to be comparable to or better in organic than in conventional farming. This would indicate that there must be other factors of importance which can explain the low particiapation rate. A higher perceived risk in organic farming with respect to yield and price is frequently brought up as a potential explanation within a qualitative framework.

The public transport network in Täby commune consists currently of two types of bus line of whichboth belong to the category of feeder lines. The first type terminates at Danderyds sjukhus and feedsto the subway whereas the second type terminates at Täby centrum and feeds to Roslagsbanan, asuburban narrow-gauge railway system in northern Stockholm. The trunk bus line that connectsgreater parts of the commune with Danderyd is the ring line 604 and goes both clockwise (604H) andcounterclockwise (604V). The main negative aspect of this structure is the complicity in incorporatingit timetable-wise with other bus lines that share the same route, such as through Enebyberg.The goal of this project is to investigate the possibilities of splitting ring line 604 and connecting theends to two different bus routes that terminate at Täby centrum today. Apart from easing thecoordination with other bus lines through Enebyberg, the extension also creates new directconnections from various areas in Täby to Danderyds sjukhus.

Stabilization of subgrade is an internationally common technique to improve the characteristics of a soft soil. Improving the stiffness and bearing capacity of the subgrade enables the pavement to be designed with reduced depths of subbase and basecourse aggregates. This makes the stabilization technique both economically and environmentally interesting. Both natural and stabilized soils have high inherent property variability that should be considered when the characteristic value is derived. By analyzing the spatial variability in stabilized and natural subgrades it is possible get the parameters needed for reliability?based modeling of soil properties.

This master thesis deals with steel girders subjected to patch loading caused by concentrated moments. There exist no good methods to calculate by hand the ultimate resistance for this load case. In ?tunnplåtshandboken?, (Handbook for sheet metal, which is published by SSAB), one calculation method is presented. It?s however fairly difficult to use, because of many calculation steps and many graphs.

Eutrophication of the Baltic Sea and Swedish lakes remains a major problem despite many years of effort to reduce the emissions of nutrients. One major source is waste water systems, especially private sewage systems. These sewages accounts for a very large share of nutrients per capita in comparison with citizens connected to larger sewage treatment plants. Norrtälje community has the greatest number of private sewage systems in Sweden. Discharges of nutrients, especially phosphorus, to the Baltic Sea from these sewage systems are significant.

I och med Sveriges åtaganden i Baltic Sea Action Plan (BSAP) och de miljökvalitetsnormer (MKN) som beskrivs i ramdirektivet för vatten kommer Käppalaverket sannolikt ställas inför strängare kväve- och fosforreningskrav. Käppala kan då bli tvungna att införa en ny processlösning t.ex. efterdenitrifikation och förfällning. Hur detta kommer att påverka det totala koldioxidavtrycket utreds i denna rapport. Tidigare har stora energiutredningar utförts på verket men aldrig har ett samlat koldioxidavtryck dokumenterats.En kartläggning över Käppalaverkets totala koldioxidavtryck 2011 gjordes för att skapa en referens för framtida modellering.

The goal of this master thesis project was to develop computer models of some plausiblepretreatment techniques and to assess the potential benefits/costs of using pretreatment andanaerobic digestion for waste management of organic waste from a system perspective. Forthis purpose a computer program called ORWARE has been used. ORWARE (organic wasteresearch) is a program for making life cycle assessments of waste management. As the mainpart of the project work the ORWARE system has been provided with three new models ofpretreatment techniques. The additions consist of: One model of pretreatment with ultrasound,one model of thermal hydrolysis and one model of a screw press.

Cumulative effects are seldom treated in Swedish Environmental Impact Assessments (EIA). This report treats these questions and which procedures and methods that can be used when assessing cumulative effects in EIA. This report is a literature study where also a case study is a part. The case study shows how existing methods for cumulative effects can be used in practice. The report is concentrated on biology and treats cumulative effects on premises of biodiversity and roads. Cumulative effects include both direct and indirect effects.

"Food security is a situation that exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life" (FAO Summit, 2003, pp. 28).Food insecurity is of concern regarding the Republic of Mauritius (ROM) since it is defined as a net food importing country. (Farming news, 2008). The impacts of climate change followed by their complexity could potentially have an increased risk effect upon the social and environmental welfare as well as the economic drivers in the ROM (www, UNESCO1, 2009). The primary victims when it comes to the impacts of climate change are the Mauritian agricultural producers since agriculture is highly dependent on climate stability, therefore affecting the yields of the producers.

Löslighet och transport av sällsynta jordartsmetaller i Källfallsfältets gruvsandsmagasinHugo de Campos PereiraSyftet med detta arbete har varit att kartlägga vilka mekanismer som styr lösligheten av sällsynta jordartsmetaller (eng. rare earth elements, REE) i sulfidhaltig anrikningssand vid den föredetta gruvan Källfallsfältet i Västmanland. För syftet har markvatten- och grundvattenprovtagning utförts, tillsammans med laktester och geokemisk modellering med Visual MINTEQ ver. 3.0.Resultaten visade att sulfidvittring är den främsta processen som styr pH i anrikningssanden, och därmed också indirekt REEs löslighet. Däremot är sulfidvittring ingen källa till REE i sig då ämnena inte föreligger sulfidbundna, något som oxiderat tillgänglighetstest NT ENVIR 006 visade.

Bakgrund: I grundskolans läroplan synliggörs tydligt att eleven i matematikundervisningen skall utveckla olika förmågor och att dessa är centrala. En av dessa är kommunikationsförmågan, som är särskilt betydelsefull genom att den sammanlänkas till alla de övriga, såsom de som gäller representation, resonemang och problemlösning. Av denna anledning har kommunikationsförmågan i matematik och medvetenheten kring och utvecklingen av denna hos lärare och elever undersökts i denna studie. En grundförutsättning är att individuell färdighetsträning i lärobok är otillräckligt. Elever bör tidigt få möjlighet till exempelvis arbete i grupp med ett matematiskt problem, då de i tal och skrift kommunicerar matematiska begrepp och metoder.