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164 Uppsatser om Modelling - Sida 6 av 11

Modellering av oorganiskt kol i boreal jord och vattendrag med hjälp av PHREEQC : Modelling of dissolved inorganic carbon in boreal soils and streams using PHREEQC

Syftet med examensarbetet har varit att studera kol i mindre vattendrag med hjälp av jämviktsmodellering i PHREEQC. Fokus har varit dynamik av löst icke organiskt kol (DIC) samt att förstå hur mycket koldioxid (CO2) som avges från mindre vattendrag och om den mängden har signifikant inverkan på den globala kolbalansen. Med hjälp av provtagen data från Krycklans avrinningsområde år 2003-2007 och 2009 har modellering av DIC och pCO2 utförts med målet att se förändring både över säsong och nedströms i ytvattensystemet. För att utvärdera modellen har tillhandahållen data över uppmätt pCO2 använts. Målet var att jämföra modellerade och tillhandahållna pCO2-värden för att se hur väl modellen kunde beskriva verkligheten och om den fungerade bättre för någon plats eller under vissa delar av året.

Åsktransienter och överspänningar : En spänningsfylld simulering av elkraftsystemet vid Forsmark 3

A power system will inevitably be subjected to transient overvoltages, most often produced by switching operations and lightning strikes. These transient overvoltages may harm sensitive equipment without sufficient protection, but it is not an easy task to predict what transients may occur or how they affect the system. A fault occurred in a low voltage system at Forsmark 2012 and overvoltages from lightning were concluded as the probable cause. The three aims with this thesis are to develop and test a model of the power system at Forsmark 3, analyse the transient behaviour of the system when subjected to lightning surges and identify critical parameters, and lastly to provide a tool for investigating the protection of the system. The Modelling and simulations were performed in the freely available simulation program LT Spice.

Rädda, varna, larma, släck! - En studie om förhållningssätt till varumärke inom den kommunala räddningstjänsten

This study examines how the local rescue services relate to the brand of the rescue service and the concept of brand management. To understand the attitudes against the brand and brand management, empirical data, theoretical Modelling of brand and current laws have been discussed together in a try to get an overview how the rescue services practically works with the brand. The study results are based on a questionnaire survey and qualitative semi-structured interviews. The survey was sent to employees working with the communication of the rescue service. The interviews were held with two employees working with the communication of the rescue service and two fire chiefs.

Undersökning av sambandet mellan strålningstemperatur och NDVI i Sahel

Several studies have analysed the relationship between Normalised DifferenceVegetation Index (NDVI) and radiative surface temperature. A main goal for moststudies have been to find the best method for carrying out land cover classificationsand to study land cover changes, based on a combination between the twoparameters. Since atmospheric components have a significant influence on bothparameters, most applications were based on multi-temporal data. The quality of theindividual values in such a combination is improved, but the biophysical justificationis uncertain. This study presents a different method, based on only the combination ofvalues that have been registered the same day and about the same time of the day.125 daily images of NDVI and 250 images of radiometric temperature were used inorder to analyse the relationship between (1) NDVI and radiative temperature and (2)NDVI and relative temperature difference between early morning and mid-day.Results between NDVI and radiative temperature show a significant negativecorrelation on areas where a distinct growing season develops, and a strong positivcorrelation where vegetation is abscent throghout the season.

Modellstudie av föroreningsretention i Bäckaslövs våtmark : Tillämpning av modellverktygen MIKE SHE WET och MIKE 21

During the nineties, ecological handling of urban storm water became very popular in Sweden. Together with Chalmers University of Technology and two Swedish communities, DHI Water and Environment has been doing research of storm water ponds and constructed wetlands. This thesis work is a part of that research project. The work has been applied at the Bäckaslöv storm water treatment plant in Växjö, Sweden. The plant consists of one storm water pond and a downstream constructed wetland.

Diagnostiksystem i gaffeltruckar

This is a final thesis done at BT, considering one of their forklift truck models called Reflex. The first part of this report is about a preliminary investigation investigating what kind of diagnostic systems BTwants to use, and also which demands there are to meet all expectations on such system. Secondly a diagnostic system, which will show if the drive wheel is worn out, will be presented. In the preliminary investigation, two kinds of diagnostic systems were mentioned. These were Model based diagnosis and Predictive analysis.

Simulation of rattan harvests in Indonesia : different harvesting pressures and the resulting patterns

The objectives of this research were to determine whether the natural rattan resources in Sulawesi, Indonesia can cope with the strongly increased harvesting pressure that has occurred over the last centuries. I was furthermore looking for patterns in the rattan population dynamics that might give a hint on how the harvesting system could be improved to ensure a maximum sustainable yield. To answer these questions, I developed an individual-based model to analyse the dynamics of rattan growth in connection with rattan harvests by locals to identify sustainable levels of rattan harvests around villages in Sulawesi, Indonesia. Scenarios with different harvesting intensities were run to compare the change in harvest amount. For a given harvesting pressure, scenarios with a high number of harvesters and a low harvesting frequency had the same effect as scenarios with high harvesting frequencies and a low number of harvesters.

Modellering av reflektans från ett sockerbetsbestånd med hjälp av en strålningsmodell

The Multispectral Canopy Reflectance Model (MCRM) by Kuusk (1995) has beenused to simulate the reflectance of a sugarbeet canopy. The simulated reflectancevalues show high absorptance in the VIS area, compared to field measurements, andhigh reflectance values in the NIR area. The errors may be due to overestimation ofclorophyll content in the sugarbeet leaves and scattered light during fieldmeasurements. The estimation of the clorophyll content where carried out using thePROSPECT-model by Jacquemoud & Baret (1990).During the vegetation period, the state of the canopy moves towards a closed canopy,with sparse vegetation in spring. The MCRM-model was used to perform a ?spring?simulation, which was compared to the original simulation.

Utveckling av ramverk för editering och simuleringav BPMN

Business Process Modelling Notation (BPMN) is a way to graphically draw a diagram of a business process. A BPMN diagram consists of several so-called flow objects. These are interconnected in the graph through sequence  flows. BPMN models are merely graphical representations of business process and there is a need to simulate these diagrams for different purposes. The simulation that now is available for BPMN is that the model is evaluated by checking if it is correct.

FE-modellering av hjullast på sandwichpanel

This bachelor thesis in mechanical engineering was performed during the spring2015 in collaboration with Composite Consulting Group in Laholm. TheComposites Consulting Group works mainly with design and details of differentcomposite projects, their main area is FE-calculations, 3D-Modelling andmechanical tests with composite materials.The aim of this bachelor thesis was to simplify the calculation process of solidmechanics for sandwich panels by simulation with computer software. The goalwas to decrease the time for the design and calculation process of the constructionand the cost of the practical tests. Our task was to build a static three dimensionalmodel with the computer software Abaqus, where the result should correspondwith the practical pressure tests in laboratory.The project started with collection of material data from Composites ConsultingGroup and by learning the software Abaqus, simultaneously a specification wasdeveloped in corporation with the company. Later on, a static wheel pressuremodel in the software Abaqus was produced which simulated the behavior of thesandwich panel during static wheel-pressure by a pallet truck.

Det är väl bara att sluta dricka?: en litteraturstudie om den bästa vägen ut ur ett alkoholmissbruk

Alkoholberoende och missbruk är ett omfattande problem i såväl Sverige som i övriga delar av världen. Med tanke på de fysiska, psykiska och sociala konsekvenser som missbruket leder till för både missbrukaren, och människor i hans eller hennes omgivning, finns det all anledning att undersöka möjligheter för att åtgärda detta. Syftet med detta examensarbete är att kartlägga olika behandlingsmetoder och att med psykologiska teorier om mänskligt beteende som utgångspunkt komma fram till den behandling en alkoholberoende individ behöver. Resultaten visar på att såväl personlighetsfaktorer som det sociala sammanhang individen befinner sig i har betydelse för om han eller hon missbrukar alkohol eller inte. Den sociala miljön bidrar till stor del till en alkoholberoende individs identitet och beteende.

Kundnyttan av Tekla Structures som verktyg i broprojektering

Byggbranschen är inne i en övergångsfas mellan 2D och 3D. BIM, som arbetsmetod, och 3D-modeller blir allt vanligare. I broprojekt är dock efterfrågan på dessa modeller låg. På WSP i Stockholm används 3D-modelleringprogrammet Tekla Structures i stor utsträckning på flera avdelningar. Önskemål finns om att utöka användningen av programmet även inom broprojektering.

Informationsdesign i hemmets hjärta : Struktur och ordning i kök för personer med neuropsykiatriskt funktionshinder

Business Process Modelling Notation (BPMN) is a way to graphically draw a diagram of a business process. A BPMN diagram consists of several so-called flow objects. These are interconnected in the graph through sequence  flows. BPMN models are merely graphical representations of business process and there is a need to simulate these diagrams for different purposes. The simulation that now is available for BPMN is that the model is evaluated by checking if it is correct.

Modeller för utvärdering av set-up för återvinning av lastlister inom IKEA

Reverse logistics is getting more and more attention both from companies and the public. It is an area with the possibility for companies to do good in the eyes of the public. This work focus on the return system of a one-way handling material called the loading ledge. The loading ledge is developed by IKEA as a substitute for the EUR-pallet in transports from suppliers with a long distance and even flow and in transports from suppliers with short distance and uneven flow. The loading ledge is made out of 100 % recyclable plastic.The purpose of this work is to find the most efficient set-up for recycling of loading ledges within IKEA on a European level from a transport and handling point of view considering aspects like cost, environment, time and, from an administrative point of view, user-friendliness.Who will the participants of the set-up be, where will they be located, which transports are needed and which income and costs does the set-up generate, are questions that will be answered.

Utvärdering av styvhetsegenskaper hos ett nyutvecklat träbjälklag

I samband med att intresset för att bygga högre trähus har ökat så krävs nya lösningar för att t.ex. kunna möta efterfrågan på stora öppna ytor och långa spännvidder. Träbjälklag med lång spännvidd har dock oftast svårigheter med att klara kraven på svikt och vibrationer. Ett nyutvecklat förslag på träbjälklag som förmodas klara dessa krav bättre än traditionella träbjälklag har varit utgångspunkten för detta examensarbete där syftet har varit att undersöka bjälklagets styvhet. Detta gjordes laborativt genom att bygga och testa en prototyp av det föreslagna bjälklaget och genom att en numerisk modell baserad på finita element metoden togs fram och användes för att studera hur olika parametrar påverkar bjälklagets styvhetsegenskaper.Bjälklagets design bygger på fackverksprincipen i primärriktningen och på balkverkan i sekundärriktningen.

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