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83 Uppsatser om Particle - Sida 3 av 6
Chewing behaviour of growing cattle
Chewing behaviour includes both eating and ruminating activity. Chewing behaviour is of great importance for the feed intake as through the action of chewing (i.e. eating and ruminating) animals mechanically process the forages in small Particle sizes and prepare the food for digestion. As cattle grow the chewing behaviour changes along with increasing body weight and chewing efficiency is increased. The aim of this thesis was to review the available scientific literature in order to describe chewing behaviour in growing cattle, as well as the factors that affect this behaviour.
Parametriserad 3D-modell av cyklon : Parametrisering av en 3D-modell av ett cyklonfilter i SolidWorks för snabb framtagning av nya konstruktioner till Outotec Skellefteå
This bachelor thesis project has been executed at Outotec Sweden AB in Skellefteå. Outotecs main business focus is selling mineral and metal processing technologies. A rest product from the metal process is Particle-polluted gas and cyclone designs are today the most commonly used abatement device for Particle control. A cyclone provides a simple design with high efficiency Particle percolation by using air streams.The purpose of this work is to reduce the time it takes create new cyclone designs in Outotecs projects. An extensive construction work is needed for every new cyclone order due to new designs.
Sedimentation av lera och fosfor i en anlagd våtmark
The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment Particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.
Konstruktion av anordning för att undersöka förslitning av syrebärarpartiklar för kemcyklisk förbränning
The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier Particles. Those Particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.
Vägval: kortast, snabbasteller hälsosammast : En försöksmodell i GIS för ruttoptimering och beräknad inhalation av luftföroreningar för cykelrutter
Cycling is one of the most sustainable transport modes available and it is widely promoted inmany urban areas. The health benefits from cycling has shown to be substantial, includingdecreased risks of diseases related to overweight and enhancing brain capacity. However, inurban areas cyclists can temporaly be exposed to high levels of air pollution, resulting inhealth risks as opposed to health benefits.The objective of this thesis is to develop a rasterbased test model in GIS that estimates theinhaled dose of air pollution for cyclists based on relative Particle concentration in differenttransportation micro-environments. The method used is a least-cost path approach,calculating three different routes; shortest, fastest and least dose for four different trips withinSödermalm, Stockholm.The results show that the inhaled Particle dose can be greatly reduced, 39% - 58% for three ofthe routes, by choosing the least dose route. One of the most interesting findings is thesubstantial increase of dose when high levels of Particles are combined with uphill cycling.The conclusion for the thesis is that a raster-GIS model can be very useful for estimating doseof different air pollution Particles and chemicals along cycling routes.
Kartläggning av spånprodukter vid Sävar såg
A change towards using more biofuels than fossil fuels is taking place in Sweden, and in many other parts of the world. This makes the use of fuel pellets increasingly popular, causing a greater demand for sawmill sawdust products. There is a trend towards the use of multiple types of shredders, instead of a single type in each sawmill. The purpose of the study was to characterize the different flows of saw Particles that can be found at Sävar såg when cutting thick or thin wood with different cutting techniques. The saw Particles size, shape, moisture content and heat value were analysed by the cutting stations: first cutting fast and slow, second cutting fast and slow, grading fast and slow and planning.
Texturbestämning genom fält-, pipett- och hydrometermetoder :
Texture is an important soil property and accurate Particle size analysis of soil texture is therefore crucial. There are a number of well-established and newly developed methods available for determining soil texture. In order to compare the results of these methods, the differences between them must be determined.
The difficulties, problems and differences regarding texture class determination were examined through a study performed on forest soil samples. The study compared different methods (pipette, hydrometer and field methods) and two types of dispersing agents (sodium pyrophosphate and sodium hexametaphosphate (calgon)) commonly used for Particle size analysis.
Mätning av partikelmassa i avgaser från en dieselmotor
This master thesis was a continuation of a previous study in the diesel exhaust characterization, which is part of the academical work embedded in the EMIR-1 project. The main objective of this thesis work was to finish the installation and make the proper modifications of the particulate mass measuring system located in one of the engine test cells at KTH, in order to be able to measure the mass of the Particles from the exhaust of diesel engines.This experiment requires a diluted flow sample from the exhaust that should be sent to the device that makes possible the measurement of Particle mass, called TEOM. In the first stage of this project, the objective was to study and make the proper modifications in the existing KTH diluter because there were several problems to obtain a constant dilution ratio from it during tests.This modifications were made and it resulted in a great improvement in the maximum inlet and outlet flow that this diluter can handle. Therefore another modification is proposed for controlling the inlet exhaust flow so it will be possible to regulate the dilution ratio and make it constant along a wide range of engine loads and speeds.The second and most important stage was to make particulate mass measurements possible by analyzing the frequency signal from the TEOM device. The idea was to obtain the frequency of oscillation from the tapered element in the TEOM, and therefore with the proper correlations, be able to predict the particulate mass concentration in the exhaust flow from the engine.An electrical problem in the TEOM circuit was detected and corrected, so the signal that carries the frequency from the TEOM can be analyzed properly.
Navigering, sensorfusion och styrning för autonom markfarkost
The aim of the Master?s Thesis work is to study and develop algorithms for autonomous travel of a UGV (Unmanned Ground Vehicle). A vehicle for the mounting of sensors has been constructed in order to perform the work. Since the UGV is to be used outdoor in urban areas, GPS can be used. To improve precision and robustness, inertial navigation is used in addition to GPS, since GPS reception is likely to be diminished in such areas.
Inverkan av ensilagets partikelstorlek på beteende och beteendestörningar hos mjölkraskvigor :
Modern milk production have come a long way when it comes to accommodating the
nutritional and physiological needs of the animals, but unfortunately the behavioural and
psychological needs of cows and heifers are often left unfulfilled. A long time for eating
is beneficial for the digestion and also gives the cattle something to do and decreases the risks for developing abnormal behaviours. An important factor that influences eating- and ruminating time is the Particle size of the roughage. The aim of the study was to find out if Particle size influences the behaviour of dairy heifers, in particular with regard to eating behaviour and abnormal behaviours.
The study was conducted at Uddetorp farm high school in Skara. Forty-two heifers of the
breeds SR and SF were housed in 8 slatted floor pens.
Från knackningar till blodspår - Analys av Marie Hermansons Mannen under trappan
This essay examines the differences and similarities, weaknesses and strengths of the two Cognitive Semantic theories Conceptual Metaphor Theory and Principled Polysemy Approach to Meaning Analysis. To illustrate the two theories, the Swedish verb-Particle construction "gå upp" is examined and analyzed accordingly. The results showed differences in the number of polysemous meaning found. The methodological evaluation showed that the differences in the underlying ideas concerning meaning-construction behind these two theories make them incompatible..
Kalciums och magnesiums inverkan på arsenikavdrivningen i virvelbäddsugnen : The influence of calcium and magnesium on the expellation of arsenic in the fluidized bed furnace
In the fluidized bed furnace at Rönnskärsverken, Skelleftehamn, sulphur-containing ore concentrates are roasted in order to remove about 50% of the sulphur in the incoming ore concentrate. This occurs in order to reach the goal of a matte containing 55% of copper in the following smelting process. At the same time as the ore concentrate is partially roasted pollutions as arsenic, antimony and bismuth are expelled. Earlier made thermodynamic calculations of equilibrium suggested that calcium and magnesium form stable compounds with arsenic and thereby inhibit expellation of arsenic in the fluidized bed furnace, an element that is undesired. The purpose of this thesis work was to gain knowledge of the mechanisms behind the formation of these stable arsenic compounds.
Transporttidsmodellering vid provpumpning i heterogen jord : spårämnesförsök i en isälvsavlagring
When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.The purpose of this master?s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution.
Dietary fibre composition and sensory analysis of heat treated wheat and rye bran
When grains of wheat and rye are conventionally milled, large quantities of bran classified as by-products are left and are mainly used for animal feed. Bran is a complex material composed of the aleurone layer, nucellar epidermis, a seed coat, a fruit coat and a small proportion of the germ and endosperm depending on extraction rate. The bran fraction consists of approximately 40-50 % dietary fibre which can contribute to increase the nutritional quality of human cereal food. It would also be valuable for the food industry to convert by-products as bran to products with higher commercial values.
The aim of this thesis was to analyse the content and composition of dietary fibre of heat treated wheat and rye bran according to the Uppsala method with some modifications in order to analyse soluble and insoluble dietary fibre separately. Half of the bran samples were precooked, dried and roasted and the other half dried and roasted (uncooked).
Effektiva lösningsmetoder för Schrödingerekvationen : En jämförelse
In this paper the rate of convergence, speed of execution and symplectic properties of the time-integrators Leap-Frog (LF2), fourth order Runge-Kutta(RK4) and Crank-Nicholson (CN2) have been studied. This was done by solving the one-dimensional model for a Particle in a box (Dirichlet-conditions). The results show that RK4 is the fastest in achieving higher tolerances, while CN2 is the fastest in achieving lower tolerances. Fourth order corrections of LF (LF4)and CN (CN4) were also studied, though these showed no improvements overLF2 and CN2. All methods were shown to exhibit symplectic behavior..