Modelling of combustion and sorbent reactions in three-dimensional flow environment of a circulating fluidized bed furnace

This thesis presents a three-dimensional, semi-empirical, steady state model for simulating the combustion, gasification, and formation of emissions in circulating fluidized bed (CFB) processes. In a large-scale CFB furnace, the local feeding of fuel, air, and other input materials, as well as the limited mixing rate of different reactants produce inhomogeneous process conditions. To simulate the real conditions, the furnace should be modelled three-dimensionally or the three-dimensional effects should be taken into account. The only available methods for simulating the large CFB furnaces three-dimensionally are semi-empirical models, which apply a relatively coarse calculation mesh and a combination of fundamental conservation equations, theoretical models and empirical correlations. The number of such models is extremely small. The main objective of this work was to achieve a model which can be applied to calculating industrial scale CFB boilers and which can simulate all the essential sub-phenomena: fluid dynamics, reactions, the attrition of particles, and heat transfer. The core of the work was to develop the model frame and the required sub-models for determining the combustion and sorbent reactions. The objective was reached, and the developed model was successfully used for studying various industrial scale CFB boilers combusting different types of fuel. The model for sorbent reactions, which includes the main reactions for calcitic limestones, was applied for studying the new possible phenomena occurring in the oxygen-fired combustion. The presented combustion and sorbent models and principles can be utilized in other model approaches as well, including other empirical and semi-empirical model approaches, and CFD based simulations. The main achievement is the overall model frame which can be utilized for the further development and testing of new sub-models and theories, and for concentrating the knowledge gathered from the experimental work carried out at bench scale, pilot scale and industrial scale apparatus, and from the computational work performed by other modelling methods.

Epälineaaristen regressiomenetelmien vertaaminen robottikäden otemallinnuksessa

Tässä työssä verrattiin monikerrosperseptronin, radiaalikantafunktioverkon, tukivektoriregression ja relevanssivektoriregression soveltuvuutta robottikäden otemallinnukseen. Menetelmille ohjelmoitiin koeympäristö Matlabiin, jossa mallit koestettiin kolmiulotteisella kappaledatalla. Koejärjestely sisälsi kaksi vaihetta. Kokeiden ensimmäisessä vaiheessa menetelmille haettiin sopivat parametrit ja toisessa vaiheessa menetelmät koestettiin. Kokeilla kerättiin dataa menetelmien keskinäiseen vertailuun. Vertailussa huomioitiin laskentanopeus, koulutusaika ja tarkkuus. Tukivektoriregressio löydettiin potentiaaliseksi vaihtoehdoksi mallintamiseen. Tukivektoriregression koetuloksia analysoitiin muita menetelmiä enemmän hyvien koetulosten takia.

NATURAL DURABILITY OF Eucalyptus dunnii Maiden, Eucalyptus robusta Sm., Eucalyptus tereticornis Sm. AND Hovenia dulcis Thunb. WOOD IN FIELD AND FOREST ENVIRONMENT

AB STRACT This study aimed at evaluating the natural durability of Eucalyptus dunnii, Eucalyptus robusta, Eucalyptus tereticornis and Hovenia dulcis woods submitted to a deterioration test in two environments, field and forest. The test samples were buried until half of their length (150 mm). Evaluations were carried out each 45 days, totalizing a 405-day period, with three-repetition withdrawal of each species for environment, totalizing nine samples from each environment, making up 24 test samples for evaluation. After percentage calculations of mass loss and resistance degree classification, the deterioration index was adopted for decomposition evaluation and fungal decay potential determination of test samples. The study has been carried out in completely randomized design (CRD), evaluated through analysis of variance (ANOVA) with subsequent comparison of means by Turkey' s test, in a 5%-level of probability of error, along with regression analysis. Eucalyptus tereticornis wood presented lesser mass loss in both environments. Hovenia dulcis presented lesser deterioration probability in both environments. Forest environment test samples presented greater mass loss percentages and lesser deterioration index.

Test Campaign Parameter Editor for a Graphical TTCN-3 Development Environment

This paper presents the design for a graphical parameter editor for Testing and Test Control Notation 3 (TTCN-3) test suites. This work was done in the context of OpenTTCN IDE, a TTCN-3 development environment built on top of the Eclipse platform. The design presented relies on an additional parameter editing tab added to the launch configurations for test campaigns. This parameter editing tab shows the list of editable parameters and allows opening editing components for the different parameters. Each TTCN-3 primitive type will have a specific editing component providing tools to ease modification of values of that type.

Effects of thermal environment and supplementation levels on the physiological parameters of moxotó goats in confined and semi-confined rising systems

The objective of this work was to determine the effect of environmental variables and supplementation levels on physiological parameters of Moxotó goats in confined and semi-confined rising systems, in the Brazilian semi-arid region. The semi-confined individuals were kept on a grass based diet during the day and arrested in the end of the afternoon. The confined animals were kept in a management center, receiving two diets composed by forage cactus and maniçoba hay into two different levels (0.5 and 1.5% of the body weight). Inside the management center and in the external environment the environmental comfort parameters were set high during the afternoon period characterizing a situation of thermal discomfort for the animals. During the morning the semi-confined animals presented an average respiratory frequency (69.5 mov min-1) and rectal temperature (39.5 ºC) higher than the confined ones (62.6 mov min-1 and 39.0 ºC, respectively). The confined and semi-confined animals were able to maintain their rectal temperature within normal limits, with increase in the cardiac beatings rate and respiratory frequency. The greater percentage of the used supplementations (1.5%) seemed to increase rectal temperature in the two studied rising systems.

Software Security Vulnerabilities in Mobile Peer-to-peer Environment

Increase of computational power and emergence of new computer technologies led to popularity of local communications between personal trusted devices. By-turn, it led to emergence of security problems related to user data utilized in such communications. One of the main aspects of the data security assurance is security of software operating on mobile devices. The aim of this work was to analyze security threats to PeerHood, software intended for performing personal communications between mobile devices regardless of underlying network technologies. To reach this goal, risk-based software security testing was performed. The results of the testing showed that the project has several security vulnerabilities. So PeerHood cannot be considered as a secure software. The analysis made in the work is the first step towards the further implementation of PeerHood security mechanisms, as well as taking into account security in the development process of this project.

Automation Concept for Electrically Excited LV Synchronous Motor: Implementation into AC500 Programmable Logic Environment

This bachelor’s thesis is a part of the research project realized in the summer 2011 in Lappeenranta University of Technology. The goal of the project was to develop an automation concept for controlling the electrically excited synchronous motor. Thesis concentrates on the implementation of the automation concept into the ABB’s AC500 programmable logic enviroment. The automation program was developed as a state machine with the ABB’s PS501 Control Builder software. For controlling the automation program is developed a fieldbus control and with CodeSys Visualization Tool a local control with control panel. The fieldbus control is done to correspond the ABB drives communication profile and the local control is implemented with a function block which feeds right control words into the statemachine. A field current control of the synchronous motor is realized as a method presented in doctoral thesis of Olli Pyrhönen (Pyrhönen 1998). The Method combines stator flux and torque based openloop control and power factor based feedback control.

Ajuste de parâmetros de transporte de solutos no solo utilizando Matlab 6.5

O sucesso na utilização de modelos matemáticos no estudo do transporte de íons no solo está intimamente ligado à precisão com que os parâmetros de transporte envolvidos neste processo são estabelecidos. De maneira geral, tais parâmetros são determinados mediante a resolução de um problema de otimização não linear em que os dados experimentais, obtidos em ensaios de deslocamento miscível, são ajustados a um modelo teórico. Neste sentido, a utilização de softwares de alta performance no ajuste destes parâmetros mostra-se vantajosa, uma vez que, além da consistência e da disponibilidade de ferramentas numéricas preexistentes, possibilita a incorporação de novas rotinas de acordo com o fenômeno que se queira simular. Sendo assim, este trabalho teve como objetivo desenvolver, em ambiente MATLAB 6.5, uma rotina computacional para a otimização dos seguintes parâmetros de transporte: fator de retardamento (R) e coeficiente de dispersão (D). A rotina desenvolvida foi aplicada a dados experimentais de três ensaios de deslocamento miscível do íon potássio em colunas preenchidas com um Latossolo Vermelho- -Amarelo, fase arenosa. A qualidade dos ajustes obtidos foi avaliada utilizando-se do coeficiente de exatidão. Concluiu-se que a rotina proposta apresentou ótimo desempenho, o que, além de reforçar a consistência do método numérico utilizado, indica que a rotina proposta neste trabalho pode contribuir com o avanço dos estudos teóricos da dinâmica da água e de solutos em meios porosos não saturados.

Image analysis for assessing broiler breeder behavior response to thermal environment

The research proposes a methodology for assessing broiler breeder response to changes in rearing thermal environment. The continuous video recording of a flock analyzed may offer compelling evidences of thermal comfort, as well as other indications of welfare. An algorithm for classifying specific broiler breeder behavior was developed. Videos were recorded over three boxes where 30 breeders were reared. The boxes were mounted inside an environmental chamber were ambient temperature varied from cold to hot. Digital images were processed based on the number of pixels, according to their light intensity variation and binary contrast allowing a sequence of behaviors related to welfare. The system used the default of x, y coordinates, where x represents the horizontal distance from the top left of the work area to the point P, and y is the vertical distance. The video images were observed, and a grid was developed for identifying the area the birds stayed and the time they spent at that place. The sequence was analyzed frame by frame confronting the data with specific adopted thermal neutral rearing standards. The grid mask overlapped the real bird image. The resulting image allows the visualization of clusters, as birds in flock behave in certain patterns. An algorithm indicating the breeder response to thermal environment was developed.

Technical and economic analysis of irrigation of asparagus bean in protected environment

This experiment was conducted in Lavras - state of Minas Gerais (MG), Brazil, in a protected environment, and aims to estimate the irrigation depths that maximize productivity and economic returns in the cultivation of asparagus bean and analyze the economic viability of irrigation management. The experimental delineation was randomized blocks with five treatments and four replications. The treatments consisted of five drip irrigation depths: 40, 70, 100, 130 and 160% of water replacement depth up to field capacity. The depths of water that maximize productivity and economic returns were obtained from the regression model adjusted to productivity data, cost of product relations and water cost. The economic viability was achieved on the benefit/cost ratio basis. The depth with the maximum economic return was estimated in 434.4mm, with a productivity of 35,160.6kg ha-1, which is economically viable for the cultivation of asparagus bean, with a expected profitability of R$ 1.70 for every real invested.

Impact of different light sources on broiler rearing environment

Broiler production is highly dependent on the use of artificial light. The light source may affect the effectiveness of housing conditions due to increasing ambient temperature and concentration of noxious gases. This research aimed to evaluate the effects of different bulb types on the thermal, aerial, and acoustic environment of broiler aviaries. The experiment was carried out at a commercial broiler farm in Dourados, Mato Grosso do Sul State, Brazil. Three aviaries were used, and two flocks of male broilers from Cobb® genetic strain were reared from the first day to slaughter. Each aviary was equipped with a different light source, comprising the adopted treatments (A1 - incandescent light bulb, control; A2 - sodium vapor light bulb; A3 - fluorescent light bulb). The aviaries were divided into nine quadrants, and the environmental data (ambient dry bulb temperature and relative humidity), litter surface temperature, CO2 and NH3 concentrations, and bird sound pressure behavior were recorded in each quadrant. The aviary with incandescent light presented higher air and litter temperatures, and concentration of gases than the other tested alternatives. It also presented higher level of sound pressure in the second week of the growing period; however, from this period up to slaughter, there was no effect of the light source on the results of broiler sound pressure level.

Electrically driven fertilizer applicator controlled by fuzzy logic

The present study shows the development, simulation and actual implementation of a closed-loop controller based on fuzzy logic that is able to regulate and standardize the mass flow of a helical fertilizer applicator. The control algorithm was developed using MATLAB's Fuzzy Logic Toolbox. Both open and closed-loop simulations of the controller were performed in MATLAB's Simulink environment. The instantaneous deviation of the mass flow from the set point (SP), its derivative, the equipment´s translation velocity and acceleration were all used as input signals for the controller, whereas the voltage of the applicator's DC electric motor (DCEM) was driven by the controller as output signal. Calibration and validation of the rules and membership functions of the fuzzy logic were accomplished in the computer simulation phase, taking into account the system's response to SP changes. The mass flow variation coefficient, measured in experimental tests, ranged from 6.32 to 13.18%. The steady state error fell between -0.72 and 0.13g s-1 and the recorded average rise time of the system was 0.38 s. The implemented controller was able to both damp the oscillations in mass flow that are characteristic of helical fertilizer applicators, and to effectively respond to SP variations.

Environment in poultry production covered with thermal and aluminum roofing tiles

Brazil is a country of tropical climate, a fact that hinders the poultry production in the aspect of thermal comfort. Thus, we aimed to evaluate the thermal environment in commercial poultry houses with different covers during the months of December 2012 to May 2013, in the municipality of Rio Verde, Goiás. The experimental design was completely randomized in split plots with factorial arrangement of treatments 2x3, being two shed models (thermal and aluminum roof tiles) and three sections within each shed (initial, central and final) for 182 days, having the days as replicates. The thermal environment was assessed through thermal comfort indices: Temperature and Humidity Index, Black Globe Temperature and Humidity Index, Radiant Heat Load and Enthalpy. The data was analyzed by SISVAR 5.1., through the analysis of variance, the Scott Knott test used to compare the means, considering a significance level of 1%. The results showed a significant statistical difference between the sheds and the points assessed (P < 0.05). The thermal shed had the lowest values for the environmental variables (Dbt and Bgt) and thermal indices studied, but larger values for the RH compared to the shed with aluminum covering. The use of thermal covers minimizes the difference in temperature range throughout various times of the day, being at 14:00 o'clock the prominence time to others.