Dissertations / Theses on the topic 'Total number of actions'

The field of microfluidics has recently been gathering a lot of attention due to the enormous demand for devices that work in the micro scale. The problem facing many researchers and designers is the uncertainty in using macro scaled theory, as it seems in some situations they are incorrect. The general idea of this work was to decide whether or not the flow through micro diffusers and nozzles follow the same trends seen in macro scale theory. Four testing wafers were fabricated using PDMS soft lithography including 38 diffuser/nozzle channels a piece. Each nozzle and diffuser consisted of a throat dimension of 100μm x 50μm, leg lengths of 142μm, and half angles varying from 0o – 90o in increments of 5o. The flow speeds tested included throat Reynolds numbers of 8.9 – 89 in increments of 8.9 using distilled water as the fluid. The static pressure difference was measured from the entrance to the exit of both the diffusers and the nozzles and the collected data was plotted against a fully attached macro theory as well as Idelchik's approximations. Data for diffusers and nozzles up to HA = 50o hints at the idea that the flow is neither separating nor creating a vena contracta. In this region, static pressure recovery within diffuser flow is observed as less than macro theory would predict and the losses that occur within a nozzle are also less than macro theory would predict. Approaching a 50o HA and beyond shows evidence of unstable separation and vena contracta formation. In general, it appears that there is a micro scaled phenomenon happening in which flow gains available energy when the flow area is increased and looses available energy when the flow area decreases. These new micro scaled phenomenon observations seem to lead to a larger and smaller magnitude of pressure loss respectively.<br>M.S.<br>Department of Mechanical, Materials and Aerospace Engineering<br>Engineering and Computer Science<br>Mechanical Engineering MSME

The experiments which are required to directly assess the operational stability of thermostable biocatalysts can be time-consuming, troublesome, and, in the context of industry, expensive. In the present work, we develop and validate two methods for quickly estimating the total turnover number (a useful indicator of lifetime productivity) of a biocatalyst for any desired operating temperature. The first method is a heuristic approach, built upon a complete mathematical derivation from first principles, in which the total turnover number can be calculated from two simple biochemical measurements. The second method relies on a single non-isothermal, continuous-mode experiment in conjunction with mathematical modeling to determine the intrinsic deactivation parameters of the biocatalyst. Both methods provide estimates of the total turnover number which are well within one order of magnitude of the values measured directly via isothermal aging tests and therefore are extremely valuable tools in terms of the amount of experimental time eliminated.

This thesis presents a new DC/AC inverter circuit which is based on a switched-capacitor circuit topology with reduced components (power switch and capacitor) count for low power applications. The proposed circuit has distinct features of both voltage boost-up and near sinusoidal (multi-level/staircase) AC output voltage. The main idea is to utilise a simple circuit technique called resonant-based Double Switch Single Capacitor Switched-Capacitor (DSSC SCC) with variable duty cycle Pulse Width Modulation (PWM) control technique in such a way that multi-level voltage can be realised across a capacitor. In order to show the superiority of the applied technique, comparisons with other techniques/circuits configurations are presented. The circuit technique can significantly reduce the number of multiple stages of switched-capacitor circuit cells of the recent switched-capacitor multi-level inverter topology. The proposed inverter (with integrated DSSC SCC technique) can generate a line-frequency with 13-levels near sinusoidal AC output voltage with low total harmonics distortion. The output voltage can be achieved with the least number of components use and only a single DC source is used as an input. The proposed inverter topology is also reviewed against other inverter-based switched-capacitor circuit topology and the well-known multi-level inverter topology. The proposed inverter has shown a tremendous reduction in the total harmonics distortion and circuit component count in comparison with the recent Switched-Capacitor Boost multi-level inverter and the classical Cascaded H-Bridge multi-level inverter. Mathematical analysis shows the design of the proposed inverter and PSPICE simulation result to verify the design is also presented. The practical experiment implementation of the proposed system is presented and proves the correct operation of the proposed inverter topology by showing consistency between simulation results and practical results.

The measurement of submicrometre (< 1.0 m) and ultrafine particles (diameter < 0.1 m) number concentration have attracted attention since the last decade because the potential health impacts associated with exposure to these particles can be more significant than those due to exposure to larger particles. At present, ultrafine particles are not regularly monitored and they are yet to be incorporated into air quality monitoring programs. As a result, very few studies have analysed their long-term and spatial variations in ultrafine particle concentration, and none have been in Australia. To address this gap in scientific knowledge, the aim of this research was to investigate the long-term trends and seasonal variations in particle number concentrations in Brisbane, Australia. Data collected over a five-year period were analysed using weighted regression models. Monthly mean concentrations in the morning (6:00-10:00) and the afternoon (16:00-19:00) were plotted against time in months, using the monthly variance as the weights. During the five-year period, submicrometre and ultrafine particle concentrations increased in the morning by 105.7% and 81.5% respectively whereas in the afternoon there was no significant trend. The morning concentrations were associated with fresh traffic emissions and the afternoon concentrations with the background. The statistical tests applied to the seasonal models, on the other hand, indicated that there was no seasonal component. The spatial variation in size distribution in a large urban area was investigated using particle number size distribution data collected at nine different locations during different campaigns. The size distributions were represented by the modal structures and cumulative size distributions. Particle number peaked at around 30 nm, except at an isolated site dominated by diesel trucks, where the particle number peaked at around 60 nm. It was found that ultrafine particles contributed to 82%-90% of the total particle number. At the sites dominated by petrol vehicles, nanoparticles (< 50 nm) contributed 60%-70% of the total particle number, and at the site dominated by diesel trucks they contributed 50%. Although the sampling campaigns took place during different seasons and were of varying duration these variations did not have an effect on the particle size distributions. The results suggested that the distributions were rather affected by differences in traffic composition and distance to the road. To investigate the occurrence of nucleation events, that is, secondary particle formation from gaseous precursors, particle size distribution data collected over a 13 month period during 5 different campaigns were analysed. The study area was a complex urban environment influenced by anthropogenic and natural sources. The study introduced a new application of time series differencing for the identification of nucleation events. To evaluate the conditions favourable to nucleation, the meteorological conditions and gaseous concentrations prior to and during nucleation events were recorded. Gaseous concentrations did not exhibit a clear pattern of change in concentration. It was also found that nucleation was associated with sea breeze and long-range transport. The implications of this finding are that whilst vehicles are the most important source of ultrafine particles, sea breeze and aged gaseous emissions play a more important role in secondary particle formation in the study area.

The measurement of submicrometre (< 1.0 m) and ultrafine particles (diameter < 0.1 m) number concentration have attracted attention since the last decade because the potential health impacts associated with exposure to these particles can be more significant than those due to exposure to larger particles. At present, ultrafine particles are not regularly monitored and they are yet to be incorporated into air quality monitoring programs. As a result, very few studies have analysed their long-term and spatial variations in ultrafine particle concentration, and none have been in Australia. To address this gap in scientific knowledge, the aim of this research was to investigate the long-term trends and seasonal variations in particle number concentrations in Brisbane, Australia. Data collected over a five-year period were analysed using weighted regression models. Monthly mean concentrations in the morning (6:00-10:00) and the afternoon (16:00-19:00) were plotted against time in months, using the monthly variance as the weights. During the five-year period, submicrometre and ultrafine particle concentrations increased in the morning by 105.7% and 81.5% respectively whereas in the afternoon there was no significant trend. The morning concentrations were associated with fresh traffic emissions and the afternoon concentrations with the background. The statistical tests applied to the seasonal models, on the other hand, indicated that there was no seasonal component. The spatial variation in size distribution in a large urban area was investigated using particle number size distribution data collected at nine different locations during different campaigns. The size distributions were represented by the modal structures and cumulative size distributions. Particle number peaked at around 30 nm, except at an isolated site dominated by diesel trucks, where the particle number peaked at around 60 nm. It was found that ultrafine particles contributed to 82%-90% of the total particle number. At the sites dominated by petrol vehicles, nanoparticles (< 50 nm) contributed 60%-70% of the total particle number, and at the site dominated by diesel trucks they contributed 50%. Although the sampling campaigns took place during different seasons and were of varying duration these variations did not have an effect on the particle size distributions. The results suggested that the distributions were rather affected by differences in traffic composition and distance to the road. To investigate the occurrence of nucleation events, that is, secondary particle formation from gaseous precursors, particle size distribution data collected over a 13 month period during 5 different campaigns were analysed. The study area was a complex urban environment influenced by anthropogenic and natural sources. The study introduced a new application of time series differencing for the identification of nucleation events. To evaluate the conditions favourable to nucleation, the meteorological conditions and gaseous concentrations prior to and during nucleation events were recorded. Gaseous concentrations did not exhibit a clear pattern of change in concentration. It was also found that nucleation was associated with sea breeze and long-range transport. The implications of this finding are that whilst vehicles are the most important source of ultrafine particles, sea breeze and aged gaseous emissions play a more important role in secondary particle formation in the study area.

Different techniques were studied to evaluate the presence of different microorganisms that played important roles in decay processes of historic stones. In that scope, limestones and sandstones from Nemrut Mount Monument, and marbles and andesites from Temple of Augustus were studied. For measurement of enzymatic activity, fluorescein diacetate (FDA) hydrolysis method previously applied to assess soil microbial activity was carried out. Total microflora method based on countings of colony number was conducted for determination of the level of bacterial and fungal activity of stones. ATP bioluminescence method, developed for the field of hygiene monitoring, was carried out in order to detect global metabolic activity degree in historic stones. Most probable number (MPN) method was carried out to detect the number of microbial cells, namely nitrifying and sulphur oxidising bacteria which could take part in the decay processes. Moreover, fungi identification was done for determining occurance of detrimental species. Presence of lichenic and algal zones existed on stones of Nemrut Mount Monument and the presence of black discolorations on stones of Temple of Augustus was common. Results have shown that the bacterial and fungal activity was low, however considerable quantity of FDA hydrolyses has shown the importance of algal population in the stones of two studied historical sites. This study has proved that FDA hydrolyses, total microflora and MPN method were efficient for the evaluation of biodeterioration in historic stones.

Analysis of intersection crashes is a significant area in traffic safety research. This study contributes to the area by identifying traffic-geometric characteristics and driver demographics that affect different types of crashes at signalized intersections. A simple methodology to estimate crash frequency at intersections based on the size of the intersection is also developed herein. First phase of this thesis used the crash frequency data from 1,335 signalized intersections obtained from six jurisdictions in Florida, namely, Brevard, Seminole, Dade, Orange, and Hillsborough Counties and the City of Orlando. Using these data a simple methodology has been developed to identify the expected number of crashes by type and severity at signalized intersections. Intersection size, based on the total number of lanes, was used as a factor that was simple to identify and a representative of many geometric and traffic characteristics of an intersection. The results from the analysis showed that crash frequency generally increased with the increased size of intersections but the rates of increase differed for different intersection types (i.e., Four-legged intersection with both streets two-way, Four-legged intersection with at least one street one-way, and T-intersections). The results also showed that the dominant type of crashes differed at these intersection types and severity of crashes was higher at the intersections with more conflict points and larger differential in speed limits between major and minor roads. The analysis may potentially be useful for traffic engineers for evaluating safety at signalized intersections in a simple and efficient manner. The findings in this analysis provide strong evidence that the patterns of crashes by type and severity vary with the size and type of intersections. Thus, in future analysis of crashes at intersections, the size and type of intersections should be considered to account for the effects of intersection characteristics on crash frequency. In the second phase, data (crash and intersection characteristics) obtained from individual jurisdictions are linked to the Department of Highway Safety and Motor Vehicles (DHSMV) database to include characteristics of the at-fault drivers involved in crashes. These crashes are analyzed using contingency tables and binary logistic regression models. This study categorizes crashes into three major types based on relative initial movement direction of the involved vehicles. These crash types are, 1) Initial movement in same direction (IMSD) crashes. This crash type includes rear end and sideswipe crashes because the involved vehicles for these crashes would be traveling in the same direction prior to the crash. 2) Initial movement in opposite direction (IMOD) crashes comprising left-turn and head on crashes. 3) Initial movement in perpendicular direction (IMPD) crashes, which include angle and right-turn crashes. Vehicles involved in these crashes would be traveling on different roadways that constitute the intersection. Using the crash, intersection, and at-fault driver characteristics for all crashes as inputs, three logistic regression models are developed. In the logistic regression analyses total number of through lanes at an intersection is used as a surrogate measure to AADT per lane and also intersection type is introduced as a 'predictor' of crash type. The binary logistic regression analyses indicated, among other results, that at intersections with one-way roads, adverse weather conditions, older drivers and/or female drivers increase the likelihood of being at-fault at IMOD crashes. Similar factors associated with other groups of crashes (i.e., IMSD and IMPD) are also identified. These findings from the study may be used to develop specialized training programs by zooming in onto problematic intersections/maneuvers.<br>M.S.<br>Department of Civil and Environmental Engineering<br>Engineering and Computer Science<br>Civil Engineering

Com o aumento do processamento de petróleos mais pesados, torna-se interessante realizar um estudo dos possíveis mecanismos de deterioração que poderão ocorrer em função do aumento do Índice de Acidez Total (IAT). Dessa forma, o presente trabalho teve como objetivo principal avaliar as linhas e equipamentos que compõe a bateria de pré-aquecimento da carga de uma unidade de Hidrotratamento (HDT) de diesel. Esse trecho teoricamente está susceptível a ocorrência de corrosão por ácidos naftênicos devido a dois principais fatores: a presença desses ácidos com teores de neutralização superiores a 0,5 mg KOH/g na composição química da carga e a temperatura de processamento, que se encontra em um intervalo de 200 a 400ºC, adequado para existência de tal mecanismo de deterioração. Os dados obtidos em campo referentes à taxa de corrosão das linhas e dos equipamentos foram parametrizados em suas variáveis operacionais e através de uma análise comparativa com dados encontrados na literatura foram obtidas informações importantes para avaliar a ocorrência de corrosão naftênica.<br>With the increased processing of heavier oils, it is interesting a study of possible mechanisms of deterioration that may occur due to the increase of the Total Acid Number (TAN). Thus, this study aims to evaluate the main lines and equipment that comprise the battery of preheating of the load of a unit of Hydrotreating (HDT) of diesel. This excerpt is theoretically likely to occur from corrosion by naphthenic acids due to two main factors: the presence of these acids with levels of neutralizing more than 0.5 mg KOH/g in the chemical composition of the load and the temperature of processing, which is in a range from 200 º C to 400 º C, suitable for the existence of such a deterioration mechanism. Data from field concerning to the rate of corrosion of the lines and equipment were parameterized in their operational variables and through a comparative analysis with data found in literature were obtained important information to evaluate the occurrence of naphthenic corrosion.

The deterioration of air quality is a significant issue in large and growing cities. This work investigates particulate emissions from transport, the largest source of air pollution in cities today. Emitters such as busy roads and diesel trains are investigated, with specific reference to the evolution of particles over time and distance. Diesel trains are investigated as an alternative to road traffic in investigating evolutionary processes. Higher emissions and solitary sources mean that the emitted plume can be observed over time in a single location. These results represent the first investigation of the evolution of fine and ultrafine aerosol particles from this type of source. Aerosols near a busy road are investigated, with the result that a dependence of total number concentration on distance from the road is shown to be related to the fragmentation of nanoparticle clusters. Local meteorological conditions are also monitored and humidity is shown to vary with distance from the road in a nonmonotonic way. Particles from a busy road were also examined using a scanning electron microscope, with the intention of understanding the make up of the emitted aerosol plume. It was determined that due to significant surface behaviour post-deposition, this method of analysis could not directly classify airborne pollutants. Some interesting results were obtained however, particularly in terms of composite particles and the analysis of deposited patterns. This thesis introduces new work in terms of the analysis of diesel train particulate emissions, as well as adding further evidence towards the fragmentation process of aerosol evolution in both background concentrations and emitted aerosol plumes.

Requirements of high performing engine oil are today necessary since the development of new machinery with modern standardsis a cutting edge technology demanding highly optimized components. One way of increasing the lubricating properties of engineoil is through the addition of antioxidants. Antioxidants included in lubricants have a number of functions, one being buffering theinorganic acids sulphuric acid and nitric acid.A novel method expected to lower the hydrogen ion concentration in acidified engine oil was evaluated in this thesis. Thecapability of four different types of cation exchangers to serve as complements for buffering additives in heavy vehicle engineswas assessed. Two cation exchangers were weak and two were strong. The analysis techniques used to evaluate what effect thecation exchangers have on engine oil were standard test method ASTM D4739, for measurements of the total base number (TBN),and inductively coupled plasma – atomic emission spectroscopy (ICP-AES). With ASTM D4739 it was found that weak cationexchangers give positive results with respect to the ability to decrease the hydrogen ion concentration in acidified engine oil.However, after begin subjected to strong cation exchangers, ASTM D4739 indicated that the hydrogen ion concentration in theacidified engine oil remains the same or increases.With additional literature studies of a variety of cation exchangers currently on the market, further optimization of the cationexchanging material could likely be achieved. In addition, the preparation method used during the evaluation of the cationexchangers should be optimized to give more reliable results.

Chemical components in wood contain multiple anionic groups, including carboxyl groups and hydroxyl groups. During kraft cooking and bleaching, such structures are also formed, degraded or modified by the action of reactions both deliberate and unwanted. It has previously been found by Laine that anionic groups with pKa values of 3.3 and 5.5 can explain the observed anionic charge on chemical fibres, corresponding to carboxylic acids on hemicelluloses as well as oxidized lignin structures, respectively. It has further been found that most of the fibre charge can be accounted for through the contribution from methylglucuronic acids as well as hexenuronic acids. This study aimed to provide additional information regarding the charge component unaffiliated with either of the aforementioned uronic acids by studying kraft pulps procured from an industrial kraft mill corresponding to unit operations through a fibreline using the ODHot(EOP)D1D2 bleaching sequence. Each sample had its total charge determined by means of conductometric titration, its content of methylglucuronic acid determined by means of methanolysis followed by GC, and its content of hexenuronic acids determined by means of the HUT-method for the determination of hexenuronic acids, followed by either UV absorbance measurements or calculations based on the reduction in kappa number during the selective acid hydrolysis. The lignin content was determined by means of kappa number analysis as well as by calculations based on the kappa number after selective acid hydrolysis, which was assumed to be characteristic of the kappa number addition from the lignin content of the samples. The hexenuronic acid content was successfully determined according to the HUT-method. A difference in content was observed when results for the unbleached and oxygen delignified samples that was obtained from UV measurements were compared with the observed difference in kappa number prior and after selective acid hydrolysis for said samples. In both cases, the results based on the difference in kappa number was higher. No correlation between remaining charge and lignin content could be made. It was instead observed that individual bleaching steps had binary effects on each of the analysed components of the fibre charge. A significant increase in charge unaffiliated with methylglucuronic acid or hexenuronic acid was observed during the EOP step, indicating an oxidation of chemical structures in the pulp: this effect could not be correlated to lignin content.<br>Kemisk massa kan ses som ett kompositmaterial bestående av cellulosa, hemicellulosa och lignin. Dessa beståndsdelar, liksom separata lågmolekylära föreningar, innehåller anjoniska kemiska grupper som bidrar till att ge träfibrer en anjonisk laddning. Ytterligare sådana grupper kan bildas under reaktioner vid kokning och blekning, tillika kan sådana grupper modifieras eller brytas ner. Laine har tidigare visat att fiberladdningen kan förklaras genom två skilda kategorier av kemiska grupper med pKa värden på 3,3 samt 5,5, vilka kan kopplas till karboxylsyragrupper på hemicellulosor respektive till lignin. Man har därtill funnit att stora delar av fiberladdningen kan förklaras genom tillskott från de två uronsyrorna metylglukuronsyra och hexenuronsyra. Denna studie syftar till att undersöka det laddningstillskott som inte kan länkas till någon av dessa två uronsyror. Detta har gjorts genom att studera kemiska massor från industrin, tagna från de olika stegen i en bleksekvens av typen ODHot(EOP)D1D2. Massornas totalladdning mättes medelst konduktometrisk titrering, emedan metylglukuronsyrahalten mättes via methanolysis följt av GC och hexenuronsyrahalten mättes via selektiv syrahydrolys per HUT-metoden följt av UV-karakterisering respektive beräkningar baserade på differensen i kappa tal före och efter sagda hydrolys. Ligninhalten i samtliga prov mättes via kappatalsmätningar samt genom beräkningar baserade på kappatalet efter selektiv syrahydrolys, vilket anses vara kappatalsbidraget från ligninföreningarna. Hexenuronsyrahalterna uppmätta medelst UV-karakterisering respektive kappatalsdifferens jämfördes mot varandra och fanns ge olika resultat för de oblekta och syrgasdelignifierade massorna. I bägge fallen gav mätningen baserade på kappatalsdifferens högre utslag. Ingen korrelation mellan kvarvarande laddning - totalladdning minus tillskottet från uronsyrorna - och ligninhalt kunde observeras. Istället observerades binära effekter för varje uppmätt komponent under vardera blekningssteg. Under EOP-steget observerades ett tillskott till den kvarvarande laddningen, vilket skulle kunna förklaras genom oxidation av trästrukturer. Dock kan ej heller detta relateras till ligninhalten i proverna.

Orientador: Olivio Novaski<br>Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica<br>Made available in DSpace on 2018-08-05T23:28:35Z (GMT). No. of bitstreams: 1 Rosa_MauricioAmstaldenSanta_M.pdf: 22360101 bytes, checksum: bce3557b6395f41ecfa23d132ffc75c8 (MD5) Previous issue date: 2005<br>Resumo: O objetivo deste trabalho é avaliar a ISO 9001:2000 como catalisadora de programas de melhoria. Mantendo o detalhamento sobre a gestão do processo da versão 94, a versão 2000 enfatiza o conceito de melhoria contínua, propondo um novo desafio aos que buscam implementá-la. Para tal, algumas adequações se fazem necessárias a fim de contemplar os quesitos da nova versão, e os programas de melhoria iniciados na unidade alvo têm este intuito, sendo os resultados destes refletidos diretamente sobre os indicadores utilizados. Este reflexo poderá ser avaliado ao se comparar os dados históricos relativos aos indicadores de processo (rejeição, desperdício, confiabilidade de entrega, produtividade e projetos de melhoria) e de satisfação de clientes (reclamações de qualidade relativas à produção e satisfação de clientes internos) adotados para a versão 94 e os números obtidos após o início das ações de transformação, executadas visando à adequação à nova versão. Especificamente a respeito das normas, será feita uma revisão de literatura, abrangendo a comparação entre as duas versões, ressaltando o que a mais recente ¿ centrada na melhoria contínua ¿ traz de diferencial em relação à versão anterior. Também se fará uma explanação sobre o conceito de melhoria contínua ¿ foco da versão 2000 ¿ nas visões da norma e de teóricos da qualidade, e sobre o uso e a importância dos indicadores. Com isto, será possível avaliar o potencial da ISO 9001:2000 como instrumento de canalização de esforços para a melhoria<br>Abstract: The aim of this research paper is to evaluate ISO 9001:2000 version as a catalyst for improvement programs. Keeping the detailed data on process management brought up by the 94 version, ISO 9001:2000 emphasizes the concept of continuous improvement, presenting a new challenge to those who try to implement it. For such an effort, some settlements are needed in order to meet all the new version requirements, and the improvement programs started in the target-unit have such goal, and their results have directly reflected upon the unit performance indicators. This effect on the indicators will be more clearly evaluated by comparing historical data related to process (rejection, waste, serviceability, productivity and improvement programs) and to customer satisfaction (customer complaints related to manufacturing process and internal customer satisfaction) established considering 94 version and the numbers achieved after the actions focused on the new ISO version took place. Particularly concerning to norms, a literature review will be done, embracing a comparison between the two versions, paying special attention to what the 2000 version ¿ focused on continuous improvement ¿ brings as differential over the previous one. A brief explanation on the concept of continuous improvement ¿ core of the 2000 version ¿ will also be part of this paper considering the norm and experts contributions, and on the use and relevance of indicators. Based on that, it will be possible to evaluate the potential of ISO 9001:2000 as a tool to canalize improvement efforts<br>Mestrado<br>Gestão da Qualidade Total<br>Mestre em Engenharia Mecânica

The aims of the dissertation thesis are to provide the comprehensive economic-statistical viewpoint on the issue of estimating labour productivity and total factor productivity; to evaluate the quality of the available data sources and to test the usage of new inputs to the production function in the Czech Republic. The first chapter provides a theoretical basis for subsequent estimates of labour productivity and total factor productivity. The second and third chapters concentrate on a detailed definition of data sources and definitions of input and output indicators in the production function. Moreover, the second chapter introduces new approaches to the estimation of the input indicators to the production function (labour services, capital services). The fourth chapter deals with estimates of labour productivity. Specifically, the relationship of labour productivity and educational structures are examined as well as estimates for regions of the Czech Republic and estimates for non-market industry that do not allow the use of the traditional approach. The fifth chapter focuses on possible particularization and improvement of the estimation of total factor productivity using new input variables. The same chapter further compares the index number approach and econometric approach including the test of constant returns to scale. The estimation of total factor productivity in individual Czech regions is also part of the chapter.

This thesis examines the domination number of the semi-strong product of two graphs G and H where both G and H are simple and connected graphs. The product has an edge set that is the union of the edge set of the direct product of G and H together with the cardinality of V(H), copies of G. Unlike the other more common products (Cartesian, direct and strong), the semi-strong product is neither commutative nor associative. The semi-strong product is not supermultiplicative, so it does not satisfy a Vizing like conjecture. It is also not submultiplicative so it shares these two properties with the direct product. After giving the basic definitions related with graphs, domination in graphs and basic properties of the semi-strong product, this paper includes a general upper bound for the domination of the semi-strong product of any two graphs G and H as less than or equal to twice the domination numbers of each graph individually. Similar general results for the semi-strong product perfect-paired domination numbers of any two graphs G and H, as well as semi-strong products of some specific types of cycle graphs are also addressed.

Orientador: Fernanda da Cruz Landim-Alvarenga<br>Resumo: As tecnologias de reprodução assistida, tais como a fertilização in vitro (FIV), transferência de embriões, transgenia e clonagem, ainda não tem o impacto comercial desejado devido a baixa produção embrionária. Apenas 30 a 40% dos blastocistos desenvolvidos são obtidos de oócitos após a MIV, fertilização e cultivo dos embriões, embora 80% dos oócitos maturados in vitro sejam fertilizados com sucesso. O soro fetal bovino (SFB) é o suplemento mais utilizado no cultivo de embriões in vitro, uma vez que melhora o desenvolvimento dos blastocistos. Apesar disso, sua presença está relacionada a alterações do metabolismo embrionário, perda de qualidade e indução de modificações na expressão de vários genes embrionários. Na tentativa de minimizar os efeitos deletérios do SFB, várias citocinas e fatores de crescimento têm sido acrescentados aos meios de cultivo embrionários in vitro, com a intenção de mimetizar as condições de cultivo in vivo. O presente experimento tem como objetivo avaliar e comparar os efeitos da adição do SFB e de meio condicionado por células mesenquimais estromais (MSCs) durante o cultivo embrionário. Os parâmetros analisados foram a viabilidade embrionária, apoptose e o perfil transcricional de genes relacionados à qualidade dos embriões. Não foi observado uma diferença (P≥0,05) na clivagem dos blastocistos, porém observou-se que a taxa de produção de embriões utilizando SFB no CIV foi maior (P≤0,05) quando comparada com MC, mas não diferiu (P≥0,05) do grupo pro... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Endometrial mesenchymal stromal cell (eMSCs) secretes bioactive molecules such as cytokines and growth factors which are released as soluble factors or through extracellular vesicles (EVs). Conditioned medium (CM) of the MSCs maintains the immunomodulation and regenerative potential properties of the cells that produced it. This study investigated the use of CM by eMSC plus BSA as alternative to FBS in embryo culture medium. The developmental ability and quality of bovine embryos were determined by assessing their cell number and gene expression. The percentage of embryos that underwent cleavage was similar (P>0.05) among the groups but blastocyst formation was higher (P<0.05) in FBS group. The total cell number was higher in CM group, but not statistically different from the others (P>0.05). The relative mRNA expression of ELOVL6 was higher in the CM group, CASP3 in the BSA group, ACSL3 and VEGF in the FBS group. Taken together, these data suggest that CM can be used as an alternative supplement to FBS. We observed a different gene expression profile, suggesting the CM inhibited an increase in the relative mRNA levels for CASP3. Moreover, the CM favored the total number cells, inhibited the percentage of cells in apoptosis and produces better quality embryo.<br>Mestre

Made available in DSpace on 2014-06-11T19:23:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-30Bitstream added on 2014-06-13T18:10:03Z : No. of bitstreams: 1 coelho_wr_dr_ilha_prot.pdf: 3240058 bytes, checksum: f2c138a1a2cb98ce4eb9f9618ea59484 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Cavitação em bombas centrífugas é a formação de bolhas de vapor do fluido bombeado na região de sucção do equipamento. As bolhas de vapor formadas em algum local do escoamento, em geral na região de sucção da bomba, entrarão posteriormente em colapso. Este fenômeno é importante cientificamente, tecnicamente e economicamente. Cientificamente é interessante, pois envolve o escoamento de um fluido em estado líquido, simultaneamente ocorre a formação de bolhas de vapor, que também escoam juntamente ao fluido líquido. O processo de vaporização e condensação de um fluido é complexo, pois envolve mudança de fase, um fenômeno térmico não linear. Tecnicamente, é importante porque quando o escoamento se dá com cavitação os parâmetros hidrodinâmicos do escoamento bem como da bomba, em geral, são fortemente alterados na direção termodinâmica de maior produção de irreversibilidades. Economicamente, é custoso porque a cavitação, em geral, leva a perda de eficiência termodinâmica dos processos e em conseqüência haverá maior custo na produção de um dado bem, diminuindo a eficiência econômica e a competitividade da empresa. O escoamento com cavitação na sucção de bombas apresenta três aspectos danosos principais: cavitação pulsante com baixa vazão; cavitação não pulsante com baixa altura útil; e erosão cavitacional. A cavitação pulsante é caracterizada por grande formação de bolhas de forma transitória com baixa freqüência e grande amplitude, gerando forças vibratórias importantes no sistema de bombeamento. A cavitação pulsante também causa colapso do fluxo de massa do fluido bombeado com valores que vão do fluxo normal da instalação até valores quase nulos, transitoriamente. Na cavitação pulsante a erosão cavitacional e a queda na altura útil são pequenas...<br>Cavitation in centrifugal pumps is the development of vapor bubbles from the pumped liquid into equipment suction region. Vapor bubbles developed somewhere in the flow, generally in the pump suction, will afterwards along the flow to collapse. This phenomenon is scientifically, technically and economically important. Scientifically, it is interesting because involves the flow of a fluid on liquid state, and simultaneously happens vapor bubbles development that also flow together the liquid fluid. Fluid vaporization and condensation processes are complex because involves phase change, a non-linear thermal phenomenon. Technically, it is important because when the flow happens with cavitation the flow and pump hydrodynamic parameters, generally, are strongly modified toward bigger thermodynamic irreversibility production. Economically, it is expensive because cavitation, generally, leads to thermodynamic process efficiency loss, and consequently it will have bigger costs for production of a given good, then decreasing economic efficiency and company competitiveness. Flow with cavitation in the pump suction presents three main devastating aspects: surging cavitation with low flow rate; steady cavitation with low total head; and cavitational erosion. Surging cavitation is characterized by unsteady, low frequency and high amplitude, intense bubbles development, producing strong vibration forces into the pumping system. Surging cavitation also causes the collapse of pumped fluid mass flow rate with values that goes from the normal flow to values that almost reach the zero flow, unsteadily. In surging cavitation, the cavitational erosion and the breakdown in total head are small. In steady cavitation the mass flow rate, and even the flow rate... (Complete abstract click electronic access below)

Students often use the web as a source of help for problems that they encounter on programming assignments.In this work, we seek to understand how students use the web to search for help on their assignments.We used a mixed methods approach with 344 students who complete a survey and 41 students who participate in a focus group meetings and helped in recording data about their search habits.The survey reveals data about student reported search habits while the focus group uses a web browser plug-in to record actual search patterns.We examine the results collectively and as broken down by class year.Survey results show that at least 2/3 of the students from each class year rely on search engines to locate resources for help with their programming bugs in at least half of their assignments;search habits vary by class year;and the value of different types of resources such as tutorials and forums varies by class year.Focus group results exposes the high frequency web sites used by the students in solving their programming assignments.

Knie- und Hüftgelenkersatz zählt weltweit zu den erfolgreichsten und häufigsten Operationen, wenngleich 3-24% der Patienten unzufrieden sind. Der OECD-Ländervergleich ergab 2014 für Deutschland die höchste Durchführungsrate an Hüft-TEP und die zweithöchste an Knie-TEP. Erhebungen der Patientenzufriedenheit und Rückkehrbereitschaft können zur Prozessoptimierung und Qualitätsverbesserung genutzt werden und zugleich eine Steigerung der Zufriedenheit und Kundenbindung fördern. Mit der erstmaligen Aufnahme eines P4P-Ansatzes im KHSG, sind zukünftig qualitätsbezogene Zuschlagszahlungen an ein Krankenhaus unter Berücksichtigung der Patientenzufriedenheit denkbar. Damit gewinnen Erwartungen der Patienten an ein Krankenhaus zunehmend an Bedeutung, da deren Erfüllung Einfluss auf die Erlösrechnung haben kann. Parallel kann eine Anpassung der Versorgungsstruktur dazu führen, dass verstärkt Behandlungszentren entstehen und operative Eingriffe bei geringer Fallzahl in abgeschiedenen, ländlichen Regionen nicht mehr erbracht werden. Diese Studie befasste sich mit medizinischen und servicebezogenen Parametern sowie Krankenhausdaten, die signifikant mit der Zufriedenheit bei Patienten nach Knie- und Hüft-TEP assoziiert waren und die Bereitschaft in dasselbe Krankenhaus zurückzukehren beeinflussen. Neben der Frage, ob unterschiedliche Parameter Einfluss auf die Gesamtzufriedenheit und Rückkehrbereitschaft haben, wurde untersucht, inwiefern potentielle Einflussgrößen zwischen Knie- und Hüft-TEP-Patienten variieren. Zudem wurde die Relevanz verschiedener Kriterien erhoben, die aus Patientensicht Einfluss auf die Wahl eines zukünftigen Krankenhausaufenthalts haben kann. Die Daten der Studie wurden über eine schriftliche Befragung von Knie- und Hüft-TEP-Patienten gewonnen, die zwischen 2010 und 2011 in sächsischen Krankenhäusern in den Direktionsbezirken Dresden und Chemnitz behandelt wurden. Zufriedenheit und Rückkehrbereitschaft waren jeweils abhängige Variablen in mehreren logistischen Regressionsanalysen. Gemeinsam mit den unabhängigen Variablen wurden diese über einen validierten, mehrdimensionalen Fragebogen anhand 6-stufiger Skalen abgefragt und zusammen mit Routinedaten der Krankenhäuser bivariat und multivariat ausgewertet. Die Krankenhausdaten wurden den strukturierten Qualitätsberichten der Krankenhäuser entnommen. In die Analyse wurden 856 Fragebögen von Knie-TEP-Patienten und 810 Fragebögen von Hüft-TEP-Patienten eingeschlossen, was einer Rücklaufquote von 12,04% bzw. 11,89% entsprach. Bei beiden Behandlungsgruppen war im Ergebnis der multivariaten Analyse das subjektive Behandlungsergebnis sowohl mit der Gesamtzufriedenheit als auch mit der Rückkehrbereitschaft assoziiert. Postoperative Komplikationen waren jeweils nur mit der Rückkehrbereitschaft verknüpft. Einfluss auf die Rückkehrbereitschaft hatte bei Knie-TEP-Patienten zudem die Freundlichkeit des Pflegepersonals, die Organisation und der Ablauf von Untersuchungen sowie die Zimmerausstattung. Letztere wies zusammen mit der Qualität des Essens einen Zusammenhang zur Gesamtzufriedenheit bei dieser Patientengruppe auf. Bei den Hüft-TEP-Patienten war die Einschätzung der Aufenthaltsdauer, die verständliche Beantwortung von Patientenfragen durch Ärzte, die Sauberkeit und die verständliche Aufklärung über die Operation sowie die Wahrung der Privatsphäre bei Untersuchungen auch mit der Rückkehrbereitschaft assoziiert. Ein weiterer Zusammenhang zur Gesamtzufriedenheit zeigte sich dagegen bei der Einschätzung der ärztlichen Betreuung und der Einschätzung der Aufenthaltsdauer für Hüft-TEP-Patienten. Den Krankenhausparametern Behandlungsfallzahl, postoperative Beweglichkeit und Reoperation lag kein Zusammenhang gegenüber den abhängigen Variablen zugrunde. Die Befragten beider Behandlungsgruppen gaben gleichermaßen an, dass die Qualität der Behandlung bei der zukünftigen Wahl eines Krankenhauses am wichtigsten ist. Demgegenüber waren die Entfernung der Klinik zum Wohnort sowie die Größe des Krankenhauses im unteren Bereich der Bewertung angesiedelt. Es konnten verschiedene Interventionsmaßnahmen aufgezeigt werden, die auf der Makro-, Meso- und Mikroebene einzuordnen waren und in ihren Auswirkungen den einzelnen Patienten ebenso wie Entscheidungsträger im Gesundheitswesen ansprechen. Die relevanten Einflussfaktoren aus Patientensicht zeigten, dass Zufriedenheit und Rückkehrbereitschaft differenziert bewertet werden und auch zwischen Knie- und Hüft-TEP-Patienten variieren. Die Ergebnisse liefern krankenhausübergreifend wertvolle Informationen und unterstützen das medizinische Fachpersonal, Erwartungen von Knie- und Hüft-TEP-Patienten gerecht zu werden, die sich unter anderem auf die Bereiche Personalentwicklung, Patientenaufklärung und Catering erstreckten. Patientenzufriedenheit kann sich auf die Compliance auswirken, womit ein verbessertes Behandlungsergebnis erreicht werden kann. Infolge einer gezielten Steigerung der Patientenzufriedenheit sind Einsparungen durch eine kürzere Krankenhausverweildauer oder seltenere Komplikationen denkbar. Somit konnte die Präsenz der Patientenzufriedenheit im Rahmen aktueller DRG-Abrechnungsverfahren und zukünftig unter Berücksichtigung des P4P-Ansatzes aufgezeigt werden, die neben einer Erlössteigerung für das einzelne Krankenhaus zugleich Einsparungen auf der Gesundheitssystemebene bewirken kann. In Betracht an den im Aufbau befindlichen P4P-Ansatz, können die Ergebnisse als Grundlage dienen, um die Wirksamkeit der Patientenzufriedenheit als einem von vier möglichen Leistungszielen statistisch auf deren Wirksamkeit zu überprüfen. Die Bewertung verschiedener Parameter bei der zukünftigen Wahl eines Krankenhauses deutet darauf hin, dass sich weitere Anfahrtswege infolge der im Wandel befindlichen Versorgungsstruktur aus Patientensicht nicht nachteilig auswirken werden<br>Knee and hip joint replacements are among the most successful and frequent operations conducted worldwide, with 3-24% of all patients being dissatisfied. In 2014, an OECD country comparison showed that Germany had the highest implementation rate for total hip replacement and the second highest for total knee replacement. Surveys of patient satisfaction and willingness to return can be used to optimize processes and improve quality while at the same time encouraging an increase in satisfaction and customer loyalty. With the first-time inclusion of a P4P approach in the German Hospital Structures Act (Krankenhausstrukturgesetz (KHSG)), quality-related supplementary payments to a hospital may be feasible in the future, taking patient satisfaction into account. In this way, patients' expectations of a hospital increasingly gain in importance, since their fulfilment can have an impact on the revenue calculation. At the same time, an adjustment of the care structure may lead to the increasing emergence of treatment centers and that surgical intervention will no longer be provided in isolated, rural regions with a sparse number of cases. This study looked at medical and services-related parameters as well as hospital data significantly associated with satisfaction in patients after total knee and hip endoprosthesis and affecting their willingness to return to the same hospital. In addition to the question whether different parameters have an influence on the overall satisfaction and willingness to return, the extent was examined to which potential influencing variables vary between the total knee and hip endoprosthesis patients. In addition, the relevance of different criteria was assessed, which from the view of a patient may have an influence on the choice of a future hospital stay. The data of the study were obtained through a written survey of total knee and hip endoprosthesis patients treated between 2010 and 2011 in Saxon hospitals of the directorate districts of Dresden and Chemnitz. In several logistic regression analyses, the dependent variables were satisfaction and returnability, respectively. These were obtained together with the independent variables on the basis of 6-step scales by way of a validated, multidimensional questionnaire and were evaluated in bivariate and multivariate manner together with the routine data of the hospitals. The hospital data were retrieved from the structured quality reports of the hospitals. The analysis included 856 questionnaires of total knee endoprosthesis patients and 810 questionnaires of total hip endoprosthesis patients, which corresponded to a return rate of 12.04% and 11.89%, respectively. In the result of the multivariate analysis, the subjective outcomes of the treatment for both treatment groups were associated with overall satisfaction as well as with the readiness to return. Postoperative complications were in each case only associated with the willingness to return. In the case of total knee endoprosthesis patients, the friendliness of the nurses, the organization, and the course of examinations as well as the room equipment had an influence on the willingness to return. The latter, together with the quality of the food, was related to the overall satisfaction in this patient group. In the total hip endoprosthesis patients, the readiness to return was also associated with assessing the duration of stay, the clarity of the doctors’ answers to patients, the cleanliness, and clear information provided of the operation as well as the maintenance of privacy during examinations. A further link to the overall satisfaction of total hip endoprosthesis patients was found, however, in the assessment of medical care and the assessment of the duration of stay. The hospital parameters of the number of patients treated, postoperative mobility, and reoperation were not related to the dependent variables. Respondents of both treatment groups also stated in equal measure that the quality of treatment is most important in their future choice of a hospital. On the other hand, the distance from the hospital to the place of residence, as well as the size of the hospital, was located in the lower segment of the evaluation. Various interventions could be identified, which could be categorized on the macro, meso, and micro level and of which their impacts are addressed to the individual patient as well as the decision makers in the healthcare system. The relevant influencing factors from the patient's view showed that satisfaction and the willingness to return are assessed differently and also vary between the knee and the hip endoprosthesis patients. The results provide valuable comprehensive information for hospitals and help medical professionals meet the expectations of knee and hip endoprosthesis patients, including personnel development, patient education, and catering. Patient satisfaction can affect compliance, resulting in an improved treatment outcome. As a result of a targeted increase in patient satisfaction, savings are possible due to a shorter hospital stay or more infrequent complications. Thus, the presence of patient satisfaction could be demonstrated within current DRG billing procedures and, in the future, taking into account the P4P approach, which in addition to an increase in revenue for the individual hospital at the same time can bring about savings on the health care system level. Considering the ongoing P4P approach, the results can serve as a basis to statistically assess the efficacy of patient satisfaction as one of four possible performance targets. The assessment of various parameters in the future choice of a hospital suggests that further access routes will not be disadvantageous from the patient's perspective due to the changing care structure

Diploma thesis is focused on chemical characteristics of nine selected sweet cherry varieties in nine parameters. Total and soluble solids were analyzed with these results 13.07–16.58 % for total and 14.67–19.50 °Brix for soluble solids, ash content 0,31–0,39 %, titratable acidity 5.44–9.91 g of malic acid per 1 kg of fresh cherries and formol number 14.45–23.73 ml of 0.1 M NaOH per 100 g of cherries. Then there were analyzed crude proteins content calculated from total nitrogen content determined by Kjeldahl method with results 0.41–0.68 % of crude proteins. Molecular absorption UV/VIS spectrophotometry was used for determination of total phenolic substances 0.30–0.89 g of gallic acid per 1 kg of cherries and total content of anthocyanins 128–848 mg of cyanidine-3-glucoside in 1 kg of cherries. Saccharides were determined by high performance liquid chromatography (HPLC) with ELSD detector. Content of glucose was 45.45–59.49 g/kg and fructose 46.88–60.01 g/kg. All results are compiled using tables and graphs and discussed. Experimental part of the thesis also describes principles and procedures of every analysis, so it can be reproduced. In theoretical part there is described botanical characteristic of cherry tree (Prunus avium L.), active substances contained in its fruits and their use in food industry. At the end of the theoretical part there is described instrumentation of high-performance liquid chromatography.

Os micro-organismos constituem um grande problema em termos econômicos para a indústria petrolífera. Estes são responsáveis pela produção de substâncias corrosivas e a formação de biofilmes, que causam deterioração dos materiais metálicos. Os principais grupos microbianos presentes em amostras ambientais da indústria do petróleo são as bactérias anaeróbias heterotróficas totais (BANHT) e as bactérias redutoras de sulfato (BRS). Atualmente, a quantificação desses grupos microbianos é realizada através da técnica do Número Mais Provável (NMP) que estima o resultado em aproximadamente 28 dias. Neste trabalho foi otimizada uma metodologia para a microscopia de fluorescência de amostras salinas provenientes de tanques de armazenamento de água/óleo. As condições testadas foram o tipo de óleo de imersão, o tipo de diluente, o volume do corante, o volume da amostra corada e a concentração do fixador (glutaraldeído) numa tentativa de correlacionar com resultados de quantificação de BANHT e BRS através da técnica convencional do NMP. Nesse caso, as células totais foram quantificadas por microscopia de fluorescência utilizando o corante fluorescente laranja de acridina (AO). Verificou-se que houve uma correlação entre os resultados da quantificação de células totais por microscopia de fluorescência e os resultados de BANHT pela técnica do NMP, devido a pouca variação de valores expressos em ambas as quantificações. Entretanto, não foi possível correlacionar os resultados da quantificação de células totais com os resultados de BRS por NMP devido à grande variação dos valores de quantificação de BRS. Na microscopia de fluorescência, foi possível, quantificar os micro-organismos em aproximadamente 30 minutos e através das fotografias, verificou-se ainda que as amostras apresentaram-se nítidas e os micro-organismos com uma boa fluorescência<br>Microbial cells constitute a severe problem, from the economic point of view, for the petroleum industry. They are responsible for the production of corrosive metabolites and for the formation of biofilms, causing deterioration in the surface of metallic materials. The main microbial groups present in environmental samples from the petroleum industry include total anaerobic heterothrophic bacteria (TANHB) and sulfate-reducing bacteria (SRB). Nowadays, the quantification of those microbial groups is performed through the use of the most probable number technique (MPN), providing the final quantification after 28 days. In the present work a new methodology, based on fluorescence microscopy, was optimized on saline samples from water/oil storage tanks. The conditions tested were the type of immersion oil, type of diluent, the volume of the dye, the stained sample volume and concentration of fixative (glutaraldehyde) in order to quantify total cells, in an attempt to correlate with TANHB and SRB quantification through MPN. In that case, total cells were quantified with the help of acrydine orange as fluorescent dye. It could be observed a clear correlation between the results obtained for total cells quantification by fluorescence microscopy and the results obtained for TANHB through MPN technique, due to the negligible differences observed in both quantifications. However, when a correlation with SRB cells was tried results of total cells through fluorescence microscopy did not fit entirely. With the use of fluorescence microscopy, it was possible to quantify microbial cells in around 30 minutes and with the help of photographic reports obtained, it could be observed that the samples were clearly observed and the microbial cells indicated a good fluorescence

Orientador: João Batista Aparecido<br>Banca: Jose Luiz Gasche<br>Banca: Paulo Gilberto de Paula Toro<br>Resumo: Cavitação em bombas centrífugas é a formação de bolhas de vapor do fluido bombeado na região de sucção do equipamento. As bolhas de vapor formadas em algum local do escoamento, em geral na região de sucção da bomba, entrarão posteriormente em colapso. Este fenômeno é importante cientificamente, tecnicamente e economicamente. Cientificamente é interessante, pois envolve o escoamento de um fluido em estado líquido, simultaneamente ocorre a formação de bolhas de vapor, que também escoam juntamente ao fluido líquido. O processo de vaporização e condensação de um fluido é complexo, pois envolve mudança de fase, um fenômeno térmico não linear. Tecnicamente, é importante porque quando o escoamento se dá com cavitação os parâmetros hidrodinâmicos do escoamento bem como da bomba, em geral, são fortemente alterados na direção termodinâmica de maior produção de irreversibilidades. Economicamente, é custoso porque a cavitação, em geral, leva a perda de eficiência termodinâmica dos processos e em conseqüência haverá maior custo na produção de um dado bem, diminuindo a eficiência econômica e a competitividade da empresa. O escoamento com cavitação na sucção de bombas apresenta três aspectos danosos principais: cavitação pulsante com baixa vazão; cavitação não pulsante com baixa altura útil; e erosão cavitacional. A cavitação pulsante é caracterizada por grande formação de bolhas de forma transitória com baixa freqüência e grande amplitude, gerando forças vibratórias importantes no sistema de bombeamento. A cavitação pulsante também causa colapso do fluxo de massa do fluido bombeado com valores que vão do fluxo normal da instalação até valores quase nulos, transitoriamente. Na cavitação pulsante a erosão cavitacional e a queda na altura útil são pequenas... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Cavitation in centrifugal pumps is the development of vapor bubbles from the pumped liquid into equipment suction region. Vapor bubbles developed somewhere in the flow, generally in the pump suction, will afterwards along the flow to collapse. This phenomenon is scientifically, technically and economically important. Scientifically, it is interesting because involves the flow of a fluid on liquid state, and simultaneously happens vapor bubbles development that also flow together the liquid fluid. Fluid vaporization and condensation processes are complex because involves phase change, a non-linear thermal phenomenon. Technically, it is important because when the flow happens with cavitation the flow and pump hydrodynamic parameters, generally, are strongly modified toward bigger thermodynamic irreversibility production. Economically, it is expensive because cavitation, generally, leads to thermodynamic process efficiency loss, and consequently it will have bigger costs for production of a given good, then decreasing economic efficiency and company competitiveness. Flow with cavitation in the pump suction presents three main devastating aspects: surging cavitation with low flow rate; steady cavitation with low total head; and cavitational erosion. Surging cavitation is characterized by unsteady, low frequency and high amplitude, intense bubbles development, producing strong vibration forces into the pumping system. Surging cavitation also causes the collapse of pumped fluid mass flow rate with values that goes from the normal flow to values that almost reach the zero flow, unsteadily. In surging cavitation, the cavitational erosion and the breakdown in total head are small. In steady cavitation the mass flow rate, and even the flow rate... (Complete abstract click electronic access below)<br>Mestre

Grease is among the most widely used lubricants in rolling element bearings. Proper understanding of the effect of lubrication due to grease aging can provide a significant increase in the life of the engineering systems. However, at present, there is no sufficient understanding of the grease aging effect in rolling elements bearing. This restricts the optimal usage of the bearing and timely monitoring of the grease. The current research work tries to address this issue with an experimental investigation. This project studies the behavior of 4 types of greases in rolling elements bearings for various operating conditions by recording the temperature and acoustic emission data. The aged samples were prepared to keep in the oven at 150 °C for a series of time duration letting it go through the chemical changes and thermal degradation. Tests were carried out in a test rig with the different levels of oxidized greases for 5 hrs time. And the effects in bearing temperature, acoustic emission were recorded. This is an investigation to analyze the effects of grease composition and aging in rolling elements lubrication by means of acoustic emission and bearing temperature. The IR spectroscopy was carried from the samples collected from the oven in order to understand the change in lubricant composition. The results show that the grease with di-urea thickener and base oil of synthetic ether and polyolester gives the best bearing temperature and acoustic emission behavior compared to the other grease type. The possibility of using the acoustic emission and temperature data to monitor the grease aging is also presented. Along with this, the possibility of using the AE statistical methods, AE count method, and energy plot were also explored to relate with the degree of aging.

Diploma thesis is focused on the chemical analysis of the juices of black, red and white currant and jostaberry (Ribes a Ribes x culverwellii). The theoretical part is focused to the definition of fruit, fruit importance in human nutrition, description of Ribes and Ribes x culverwellii genuses, active substances in the currants and the jostaberry, description of selected chemical parameters and the determination of some of them. The procedures of determining for the following chemical parameters are described in the experimental section: determination of reducing sugars, determination of total and soluble solids, formol number, pH, titratable acidity, determination of total phenols and anthocyanins and determination of vitamin C in two samples jostaberry, six varieties of black currants, one variety of white currant and two varieties of red currants. Based on the evaluation of the obtained results, the comparison was made with different varieties and the thesis that "overall comparison of the different varieties in the content of phenolic compounds, vitamin C and anthocyanins appears to be the most promising variety of blackcurrant demon. It should however be noted that the highest content of phenolics and anthocyanins were determined in jostaberry„ has been suggested.

Nous cherchons à prouver de nouveaux résultats en théorie des graphes et combinatoire grâce à la vitesse de calcul des ordinateurs, couplée à des algorithmes astucieux. Nous traitons quatre problèmes. Le théorème des quatre couleurs affirme que toute carte d’un monde où les pays sont connexes peut être coloriée avec 4 couleurs sans que deux pays voisins aient la même couleur. Il a été le premier résultat prouvé en utilisant l'ordinateur, en 1989. Nous souhaitions automatiser encore plus cette preuve. Nous expliquons la preuve et fournissons un programme qui permet de la réétablir, ainsi que d'établir d'autres résultats avec la même méthode. Nous donnons des pistes potentielles pour automatiser la recherche de règles de déchargement.Nous étudions également les problèmes de domination dans les grilles. Le plus simple est celui de la domination. Il s'agit de mettre des pierres sur certaines cases d'une grille pour que chaque case ait une pierre, ou ait une voisine qui contienne une pierre. Ce problème a été résolu en 2011 en utilisant l’ordinateur pour prouver une formule donnant le nombre minimum de pierres selon la taille de la grille. Nous adaptons avec succès cette méthode pour la première fois pour des variantes de la domination. Nous résolvons partiellement deux autres problèmes et fournissons des bornes inférieures pour ces problèmes pour les grilles de taille arbitraire.Nous nous sommes aussi penchés sur le dénombrement d’ensembles dominants. Combien y a-t-il d’ensembles dominant une grille donnée ? Nous étudions ce problème de dénombrement pour la domination et trois variantes. Nous prouvons l'existence de taux de croissance asymptotiques pour chacun de ces problèmes. Pour chaque, nous donnons en plus un encadrement de son taux de croissance asymptotique.Nous étudions enfin les polyominos, et leurs façons de paver des rectangles. Il s'agit d'objets généralisant les formes de Tetris : un ensemble de carrés connexe (« en un seul morceau »). Nous avons attaqué un problème posé en 1989 : existe-t-il un polyomino d'ordre impair ? Il s'agit de trouver un polyomino qui peut paver un rectangle avec un nombre impair de copies, mais ne peut paver de rectangle plus petit. Nous n'avons pas résolu ce problème, mais avons créé un programme pour énumérer les polyominos et essayer de trouver leur ordre, en éliminant ceux ne pouvant pas paver de rectangle. Nous établissons aussi une classification, selon leur ordre, des polyominos de taille au plus 18<br>Our goal is to prove new results in graph theory and combinatorics thanks to the speed of computers, used with smart algorithms. We tackle four problems.The four-colour theorem states that any map of a world where all countries are made of one part can be coloured with 4 colours such that no two neighbouring countries have the same colour. It was the first result proved using computers, in 1989. We wished to automatise further this proof. We explain the proof and provide a program which proves it again. It also makes it possible to obtain other results with the same method. We give potential leads to automatise the search for discharging rules.We also study the problems of domination in grids. The simplest one is the one of domination. It consists in putting a stone on some cells of a grid such that every cell has a stone, or has a neighbour which contains a stone. This problem was solved in 2011 using computers, to prove a formula giving the minimum number of stones needed depending on the dimensions of the grid. We successfully adapt this method for the first time for variants of the domination problem. We solve partially two other problems and give for them lower bounds for grids of arbitrary size.We also tackled the counting problem for dominating sets. How many dominating sets are there for a given grid? We study this counting problem for the domination and three variants. We prove the existence of asymptotic growths rates for each of these problems. We also give bounds for each of these growth rates.Finally, we study polyominoes, and the way they can tile rectangles. They are objects which generalise the shapes from Tetris: a connected (of only one part) set of squares. We tried to solve a problem which was set in 1989: is there a polyomino of odd order? It consists in finding a polyomino which can tile a rectangle with an odd number of copies, but cannot tile any smaller rectangle. We did not manage to solve this problem, but we made a program to enumerate polyominoes and try to find their orders, discarding those which cannot tile rectangles. We also give statistics on the orders of polyominoes of size up to 18

碩士<br>國立政治大學<br>應用數學系<br>85<br>A multiple-star representation of a simple graph G assigns each vertex a union of stars in a host tree, such that vertices are adjacent if and only if their assigned sets intersect. The total star number S(G) is the minimum of the total number of stars used in any such representation of G. We obtain the maximum value of S(G) for m-edge connected graphs: m+1, n-vertex graphs: [(n2+1)/4], and n-vertex outerplanar graphs: [3n/2-l].

碩士<br>國立中山大學<br>應用數學系<br>87<br>This thesis discusses the total game chromatic number and the total game coloring number of graphs. We prove that if a graph G is k-degenerate, then its total game coloring number is at most maximum degree of G+3k+2. As a consequence, the total game coloring number of a forest F is at most maximum degree of F+5, and the total game coloring number of a planar graph is at most maximum degree+17. We shall further improve the upper bound of the total game coloring number of a forest (with maximum degree at least 5) to maximum degree+3.

碩士<br>國立交通大學<br>應用數學研究所<br>83<br>In this thesis, we study the total chromatic number of the regular bipartite graphs and some results are obtained when maximum degree of the graps is high.

碩士<br>國立交通大學<br>應用數學研究所<br>83<br>In this thesis, we study the total chromatic number of the eqibipartite graphs and some results are obtained when maximum degree of the graps is n-1.

碩士<br>國立中興大學<br>企業管理學系所<br>102<br>Competitive dynamics has become one of the important issues in strategic management domain, between firm’s competitive analysis is one of the most important issues. However, prior researches in competitive dynamics that explore the firm’s actions and performance are mostly based on the strategic actions and tactical actions, few of them investigated innovative perspectives actions Therefore, this study devoted to combine competitive dynamics and exploration / exploitation, develops exploration actions and exploitation actions, redefines and classifies the actions firms had taken, and further explores the probable influences under the number of competitors’ actions. This study takes chain convenience stores in Taiwan as the objective industry of this study, and takes top 4 chain convenience stores as the samples, which are 7-ELEVEN, FAMILY MART, HI-LIFE and OK. In this study, structured content analysis is adopted and the database of Knowledge Management Winner (KMW) is used. News of the competitive interactions within firms is collected from 2003 to 2012 . Furthermore, we ask for information from managers of the convenience stores and experts in marketing. Ultimately, this study gets 5 exploration actions and 9 exploitation actions. This study focus on the relationship between the exploration actions , exploitation actions and balance actions of the focal firm and performance, considering the number of competitors’ actions as a moderating variable. The empirical results show that: (1) a positive relationship between exploration actions and firm’s long-term performance; (2) a positive relationship between exploitation / balance actions and firm’s short-term performance; (3) the number of competitors’ actions can’t strengthen the positive relationship between exploration actions and firm’s long-term performance; (4) the number of competitors’ actions can strengthen the positive relationship between exploitation / balance actions and firm’s short-term performance.

碩士<br>逢甲大學<br>統計學系統計與精算碩士班<br>103<br>Applications of many assembly situations, assembly can only proceed if all parts for as assembly are available. The completion time is largely determined by the time that the last component is manufactured. In this case, the setup times are included in the job processing time. This is not reasonable to assume that the setup process dominates the overall production process. Such activities are frequently encountered in process manufacturing in which an initial setup is followed by a lengthy uninterrupted production process. Motivated by these observations, this paper studies a multiple-machine order scheduling problem with sum-of- job-processing- times-based learning environment to minimize the number of tardy jobs. First, some dominance rules and a lower bound are first derived and applied in branch-and-bound algorithm for finding the optimal solution. Then genetic algorithm and particle swarm method are demonstrated for finding a near-optimal solution. In addition, the experimental results of all proposed algorithms are also provided.

碩士<br>國立交通大學<br>工業工程與管理系所<br>106<br>Taiwanese economy has always been dominated by small and medium-sized enterprises. The credit of financial institutions can provide sufficient funds for SMEs. When conducting credit, financial institutions need to comply with the Basel Capital Accord III and add 0 to 2.5% of Capital Conservation Buffer. If the amount of Capital Conservation Buffer is not enough, financial institutions cannot resist the fluctuations of the economic cycle. If the amount of Capital Conservation Buffer exceeds the real demand, it will reduce the funds employed available to financial institutions and the loss of investable capital. Therefore, financial institutions need to understand the trend of defaults and the total number of defaults in the future of SME loan cases, in order to be able to prepare appropriate Capital Conservation Buffer. The purpose of this research is to construct a model for predicting whether SME loans will default. This model considers the time characteristics of different SME loan cases and uses two-stage data screening to find the model data that meets the time characteristics of each SME loan case to be predicted. Then use logistic regression to establish their respective prediction models. A set of real data of SME loan cases by a financial organization in Taiwan is used to demonsttrate the reliableness of the propose model. The results show that he default trend predicted by this research method can be close to the actual default, and better than the Cox Proportional Hazards Model. This research method can provide financial institutions with effective and reliable information, help prepare appropriate Capital Conservation Buffer, and increase the flexibility of investable capital.

We initiate the study of a new class of semigroup C*-algebras arising from number-theoretic considerations; namely, we generalize the construction of Cuntz, Deninger, and Laca by considering the left regular C*-algebras of ax+b-semigroups from actions of congruence monoids on rings of algebraic integers in number fields. Our motivation for considering actions of congruence monoids comes from class field theory and work on Bost–Connes type systems. We give two presentations and a groupoid model for these algebras, and establish a faithfulness criterion for their representations. We then explicitly compute the primitive ideal space, give a semigroup crossed product description of the boundary quotient, and prove that the construction is functorial in the appropriate sense. These C*-algebras carry canonical time evolutions, so that our construction also produces a new class of C*-dynamical systems. We classify the KMS (equilibrium) states for this canonical time evolution, and show that there are several phase transitions whose complexity depends on properties of a generalized ideal class group. We compute the type of all high temperature KMS states, and consider several related C*-dynamical systems.<br>Graduate

碩士<br>國立臺北教育大學<br>體育學系碩士班<br>107<br>Abstract This experimental study aimed to determine the impact of korfball conditioning games with different number of athletes on the quantity of actions and heart rate. 8 female and 8 male top Taiwanese korfball athletes (age=21.19 ± 1.97) were recruited to play 4 v 4, 4 v 3, 3 v 3, 3 v 2, 2 v 2, and 2 v 1 games in a within-subjects design. The recorded actions consisted of explosive actions without ball (running, veering move, sprinting forward, sprinting backward, sprinting left or right side, vertical jump, moving jump up, horizontal jump, and sharp stop), shot attempts, passes, and boxing out for rebounds. The percentages of maximal heart rate (%HRmax) of the players in the first 30-second game duration were measured. The variables were analyzed by one-way ANOVA with repeated measures. The results indicated that no difference existed in the %HRmax among the various games (p > .05). However, the actions per minute differed in terms of the numbers of players (p < .05). Specifically, 2 v 1 game demonstrated the most frequency of actions (42.825/min). The second most frequency of actions showed in the 2 v 2 game (25.604/min) and 4 v 3 (24.406/min). Last, 3 v 2 game (23.000/min) exhibited higher number of actions than did 3 v 3 game (17.740/min) and 4 v 4 game (17.688/min). Based on the findings of this study about the workload difference of individually total actions in the games as a function of the different numbers of players, three types of korfball conditioning games might be generally distinguished as the references for the design of korfball fitness training. 2 v 1 game could be attributed as the high intensity conditioning, 2 v 2, 3 v 2, and 4 v 3 games could be classified as the moderate-high intensity conditioning, while 3 v 3 and 4 v 4 games could be categorized as the moderate intensity conditioning.

碩士<br>逢甲大學<br>統計與精算所<br>98<br>Deteriorating jobs scheduling has received tremendous attention in the past two decades. However, the group technology has rarely been considered. With the current emphasis on customer service and meeting the promised delivery dates, we consider a single-machine scheduling problem to minimize the total weighted number of late jobs with deteriorating jobs and setup times. A branch-and-bound with several dominance properties and a lower bound is developed to solve this problem. Computational results show that the proposed algorithm can solve instances up to 1,500 jobs. In addition, statistical tests are conducted to investigate the impact of the parameters.

碩士<br>國立臺北大學<br>企業管理學系<br>103<br>This paper explores the influence of number of inventors, patent scope, and activity year of patent upon the corporate performance. The patent data are collected from United States Patent and Trademark Office(USPTO), and financial data are collected from the database of COMPUSTAT. This study uses patent analysis to explore the corporate performance of the American Pharmaceutical industry by use of artificial neural network(ANN). Besides, we find that number of inventors has a positive effect on market value of the American Pharmaceutical Industry, while total patents also have positive effect on it. We find that the RTA has inverse U-shaped influences upon corporate market value. Therefore, we suggest the American pharmaceutical companies should enhance their patent scope in order to increase their profitability.

碩士<br>國立臺灣大學<br>獸醫學研究所<br>96<br>Household dogs in Taiwan have decreased from the total number of estimated 1.6 million in 1999 to approximately 1.3 million in 2007; compared with the survey of the total number of household dogs in Taipei city, both results tended to decrease. On the contrary, when surveying developed countries in the world, we find that dogs in the USA significantly increased since the past decade, from the total number of about fifty million in 1999 to about seventy million in 2007, an increase of twenty million during this period. The tendency of decrease in the total number of household dogs in Taiwan diverges from prosperity of raising household dogs as pets in the developed countries. In this study, a questionnaire investigation was conducted to explore the cause of the phenomena. From samples of nationwide household dog investigation in 2001 and 2003, families with a dog or dogs were sampled, and there were total of 2757 questionnaires that were randomly picked. Based on the phone numbers given in the questionnaires, a follow-up questionnaire study was conducted in turn. It was surveyed if they are still raising a dog or dogs at present or how they raised a dog or dogs in the past. Based on the questionnaire results, it was further analyzed whether the regulations and rules of raising dogs, habitation environment, economic costs, and sense of animal protection are factors that result in creating stress in raising dog or cause unwillingness to raise dog(s). After interview by telephone, there were 1087 successful questionnaires. It was discovered 77% of the interviewees had heard of the Animal Protection Act; up to 80.4% of the interviewees did not feel that the Animal Protection Act generated inconvenience of dog raising; up to 87% of the interviewees did not feel that elevation of the animal welfare generated stress of dog raising; most of the interviewees did not feel that dog raising led to economic burden; for the direct cause for interviewees not to raise a dog or dogs anymore, there were three main causes, namely inconvenience and annoyance, affection and environmental limitation. It is this study’s belief that there is no correlation between economic state of the country and increase/decrease in the number of household dogs. However, it has been found in other studies that a family that is fond of dogs is in general a family with higher income and also with larger number of dogs. The world trend of animal protection does not cause the decline of dog raising trend, since the total number of dogs does not decrease, but grows from year to year in the UK and the USA, in which animal protection is mature and prudent. Most of dog owners in Taiwan do not feel that the Animal Protection Act generate stress for them. According to the supply and demand theory of the economics, annually administered vaccine for dogs is selected as quantification index of animal welfare based on the ratio of import quantity with the total number of dogs of the year and confirmed that the sense of animal welfare in Taiwan is growing daily. Due to elevation of social moral in Taiwan and the elevation of animal welfare, the constraint on dog raising is strengthened. People dare not recklessly raise a dog and are also constrained by the higher moral standard. The study reveals that among the interviewees who do not raise a dog any more, one of the main causes is that they feel inconvenience and annoyance in dog raising, and this is due to aberrant behavior of dogs, in particular dog barking, which is the most frequent aberrant behavior. Another important cause for people not to raise a dog anymore is that the relation-bond between human and dog are deepened. This makes many people feel like they’re losing a family member when they lose their pet. Because the Orientals incline to choose escape as the manner in which they deal with their feelings, they do not raise a dog due to the reason that they are not willing to face the pain of losing a family member again. The government’s long-term education guidance, the birth control policy, limits the source and makes the trend of decrease of household dogs in Taiwan.

碩士<br>國立臺灣大學<br>農藝學研究所<br>106<br>High temperature reduces the fruit set rate of tomato, so does the yield. The total pollen number and the pollen viability were recognized as two major factors involving in the reduction of the fruit set rate. In this study, we measured these two traits of heat-sensitive variety CA4, heat-tolerant variety CLN1621N and their offspring population, 78 F7 recombinant inbred lines (RIL), under 30/25 °C day/night temperature. The results showed these two traits were highly correlated to the light intensity and their broad-sense heritability were from 0.3 to 0.6. In order to understand the genetic architectures of total pollen number and pollen viability under heat stress, we deployed two strategies, genetic mapping and gene expression profiling (ie. transcriptome), using next-generation sequencing technologies. The RNAseq gene profiling data of the RIL population were used to discover single nucleotide polymorphism (SNP) markers. A total of 7,550 SNP markers were identified in this RIL population to construct the high-density genetic map which was consisted of 330 SNP markers with 693.8 cM length. The genetic mapping analyses revealed five quantitative trait loci (QTLs) on chromosome 3, 4, 10 and 11. Each QTL can explain 8.74 % to 34.63% of total variance. In addition, the variation of gene expression of 14 genes in the QTL of the total pollen number on chromosome 4 showed statistically significant association with distinct marker genotypes of this QTL. These 14 genes are the candidate genes to maintain total pollen number under heat stress.

Dissertação de Mestrado Integrado em Engenharia do Ambiente apresentada à Faculdade de Ciências e Tecnologia<br>O presente trabalho tem como principal objectivo a caracterização de amostras de óleo lubrificante usado com vista à sua regeneração por processos que envolvam tratamentos alcalinos. A regeneração de óleo usado com recurso a pré-tratamentos alcalinos é atualmente utilizada em Portugal. Neste âmbito, foram recolhidas 133 amostras as quais foram submetidas a um teste empírico de coagulação de modo a categoriza-las em quatro classes (A, B1, B2 e C).Adicionalmente, foram avaliadas as seguintes propriedades físico-químicas para todas as amostras: tensão superficial a 30ºC, teor de água, número total de acidez (TAN), índice de saponificação (IS) e viscosidade cinemática a 40ºC. Foram ainda realizadas análises com vista à identificação quantitativa e qualificativa dos elementos químicos presentes nas amostras através da técnica de fluorescência de raios X por dispersão de energia e ainda a identificação de grupos funcionais através da espectroscopia no infravermelho por transformada de Fourier.Os resultados obtidos foram agrupados com base nas quatro classes de coagulação. Foi possível concluir que podem existir diferenças estatisticamente relevantes em algumas propriedades. Designadamente, foi evidente que o TAN da classe B2 é particularmente baixo (cerca de 0.54 mg KOH/g) relativamente ás outras classes. Em relação ao IS, foi a categoria C que apresentou um valor mais elevado (cerca de 32.97 mg KOH/g), o que significa que estas amostras apresentam grande tendência a coagular quando tratadas com KOH. A análise elementar mostrou que o teor de magnésio, fósforo, e enxofre também pode ser discriminatório. Os espectros de FTIR não foram conclusivos para diferenciar as amostras com base na sua classe de coagulação.Globalmente o TAN foi o parâmetro mais determinante para distinguir as diferentes categorias de óleos. Os resultados do TAN sugerem também que os de aditivos empregues na formulação destes lubrificantes, podem estar envolvidos no fenómeno de coagulação observado nas amostras da categoria C. As amostras da categoria C exibem maiores teores de matéria saponificavél pelo que são as mais susceptiveis à ocorrência de reacções de saponificação.<br>This work addresses the characterization of used lubricant oil (ULO) samples aiming to its regeneration through alkaline treatments. Waste oils regeneration via alkaline processes is process implemented in Portugal. Some ULO, when submitted to alkaline conditions experience coagulation, which stands as a hindrance to its regeneration. In this context, 133 samples were obtained and submitted to an empirical coagulation test in order to categorize them into four categories (A, B1,B2 and C) Additionally, the following physiochemical properties were measured in all samples; surface tension at 30ºC, water content, total acid number (TAN), saponification number (SN) and kinematic viscosity at 40ºC. Furthermore, it was also performed elemental analysis aiming to a quantitative and qualitative identification of the chemical elements present in the waste lubricant oil samples through energy dispersive X-ray fluorescence technique and also analysis to exiting functional groups using Fourier transform infrared spectroscopy technique. The results obtained were separated according to the four coagulation categories. It was possible to conclude that some properties display statically relevant differences. Specifically, TAN of category B2 is particularly low (about 0.54 mg KOH/g) comparing to other categories. Regarding SN, category C showed the highest values (about 32,97 mg KOH/g), which means this samples are more likely to experience coagulation when treated with KOH. Elemental analysis, showed that content of magnesium, phosphorus and sulphur can also allow some differentiation. The Fourier transform infrared spectroscopy analysis wasn’t conclusive enough to allow a sample differentiation based on coagulation category.Globally TAN was the most useful property to distinguish the different categories. TAN results also suggest that the additives employed in the oils formulation might be involved in the coagulation phenomena observed in samples from category C. Samples from category C display higher contents of saponifiable matter then the remaining categories, and thus more suitable to experience a saponification reaction.

While studies have indicated the onset of fertility transition in Nigeria as in most Sub- Saharan countries, no systematic attempt has been made to identify the factors responsible for this trend. Existing explanation tends to draw from the demographic transition theory without exploring the value of other key variables. One of these variables is the degree of preference implementation. This study explores the role of fertility preference implementation on the onset of fertility transition in Nigeria. The study estimated the extent to which couples have been able to implement their fertility preferences with a view to better understand the factors that are responsible for the fertility changes in the country. This study was based on the socio-economic and microeconomic frameworks of fertility namely: the Bongaarts et al (1984) version and its Stover’s reformulation (1998) of the proximate determinants of fertility and the Bongaarts (1993) supply-demand framework for the analysis of the determinants of fertility, respectively. The proximate determinant of fertility frameworks holds that all demographic, socioeconomic, cultural, institutional, psychological, health and environmental factors (background variables) operate through the proximate or intermediate variables to affect fertility. The Bongaarts (1993) supply-demand framework posits that fertility (F) as measured by total fertility rate is an outcome of the interaction of supply of births (natural fertility), demand for births (wanted fertility) and degree of fertility preference implementation (an index, which measures the extent to which people have been able to implement their fertility preferences). The degree of preference implementation is in turn dependent on cost of fertility regulation and that of unwanted childbearing. The husbands’ family planning attitude and desired number of children were incorporated into the latter framework to recognize and bring out the crucial roles of the males in eventual fertility outcomes. The 1990, 1999 and 2003 Nigeria Demographic and Health Survey (NDHS) data sets for men, women and couples were used. The methodology of the three NDHS is not too different from each other. They are nationally representative cross-sectional survey of women between the ages of 15 and 49 in 1990, 1999 and 2003 and men between 15 and 64 in 1999 and 15-59 in the 2003 survey. Twenty-four focus group discussions were also conducted among the sexes across the country to gain better insight and understanding into the issues examined. Focus group research is based on facilitating an organized discussion with a group of individuals selected because they were believed to be representative of some class. The discussion is used to bring out insights and understandings in ways, which cannot be captured by questionnaire. The focus group discussions (FGD) are also national in scope. Participants were drawn from the Northern, South Eastern and South Western regions of the country. The study population consisted of 8,781; 8,199 and 7,620 women aged 15-49 interviewed during the 1990, 1999 and 2003 NDHS, respectively. In addition, 2,584 men aged 15-64 and 2,346 men aged 15-59 interviewed during the 1999 and 2003 NDHS, respectively were used. One thousand, one hundred and sixty-eight (1,168) couples’ records derived from the 2003 NDHS and 1,280 (constructed) couples’ records for 1999 were also used. A total of eighty-nine (89) men and eighty-five (85) women participated in the twenty-four (24) focus group discussion sessions. To achieve the research objectives, a wide range of analysis was carried out in the study. In the estimation of all means and medians, the Kaplan Meier survival analysis is used. Some other estimations were done using specific formulations developed for the purpose. Thirty-six binary logistic regression models were also fitted to bring out spousal influences on each other’s attitude to family planning and desired number of children. Lastly, the focus group discussion sessions were analysed by themes to give better understanding into the issues examined. Five hypotheses were tested in the study. There was a general decline in the age specific fertility rates (ASFR) between 1990 and 2003 in all the age groups. This is reflected in the total fertility rate (TFR) for the country as a whole, which declined from 6.32 in 1990 to 5.82 in 2003. The national average masks large variations in the fertility levels between subgroups in the country. The women in the North generally have higher number of children than their Southern counterparts. This is particularly marked in the early childbearing years. Fertility levels are also higher among rural residents compared to those in the urban area. Substantial differences equally exist in the fertility levels of women by their level of education with fertility being negatively associated with level of education. A comparison of the past and current fertility also confirms that fertility has been on the decline in the country. Age at first and last births have been declining and the differentials between the two show that the number of years spent in childbearing is decreasing. Non-marital birth was also found to be increasing over time but at a level below six percent and with no identifiable educational or regional pattern. Teenage motherhood is equally declining both nationally and regionally and is relatively high among teenagers from the rural area and those with less than secondary level of education. The proportion of women that progress from one parity to another decreases as parity increases and no socially imposed optimum number of children is observed (although there is a political four-child policy in existence) among the Nigerian women. Apart from age of mother at the birth of child, which has a positive association with median length of birth interval and the surviving status of preceding child (which is understandably shorter if the preceding child is dead), length of birth interval by other characteristics shows no significant variation across sub groups. Age at first marriage remained between 16 and 17 over the years. This is lower for respondents from the rural, the North and for those with less than secondary level of education. For age at first sexual intercourse, it increased over time in the age groups. Respondents from the North and rural area however initiated sexual intercourse earlier and age at first sexual intercourse increases with level of education. Among the proximate determinant indices, the index of postpartum insusceptibility has the greatest inhibiting effect, followed by that of marriage/sexually active, contraception and then sterility. In the Bongaarts model, the indices reduced total fecundity by 12.46 births in the total sample of married women in 1990; 8.90 births in 1999 and 9.45 births in 2003 while the indices jointly reduced potential fertility by 17.69 births in the total sample of sexually active women in 1990; 16.06 births in 1999 and 16.50 births in 2003 in the Stover’s reformulation. The number of children desired marginally increased over time. This could have been affected by the high proportion of non-response especially in the 1990 survey. The desired number of children is positively related to age and number of surviving children while it is negatively related to education. Number of children desired is found to be lower among urban residents and respondents from the Southern part of the country and highest among currently married women. The focus group discussion sessions also show that people have been revising the number of children they are having downward due to ‘supposed’ economic hardship in the country and the need to give quality education, training and care to the children. However, their desire remain high. The extent, to which fertility preference is achieved, is generally high and increasing over the years in the total sample of married women with some variations in the sub groups. It is higher in the urban compared to the rural; increases with level of education, lowest in the North East and highest in the South West. Surprisingly, the extent to which concordant couples achieve their fertility preferences was lower than that of discordant couples. The fitted logistic models showed no evidence of the husbands having an upper hand in the number of children desired by the wives or on their attitude to family planning and vice versa. While the husbands play greater role in fertility decision-making in households, who has the upper hand between the husbands and the wives in actual fertility outcome was not conclusive in this study. Knowledge about family planning methods and their availability is high. The costs of fertility regulation in terms of its social, economic and in particular health components as well as obstacles to the use of fertility regulation methods were highlighted. The psychological, health, social and more frequently the economic costs of unwanted childbearing were also brought out. The responses to questions on pregnancy wantedness was also validated in this study as people generally acknowledged the circumstance of the birth of additional child(ren) as accidental. Two of the five hypotheses proposed were confirmed. One, the hypothesis that ‘the degree of fertility preference implementation is higher in the south than in the North, higher among urban residents compared to the rural residents and increases as the level of education increases’ is supported by the results of the study. Two, that ‘the degree of fertility preference implementation is increasing and playing an increasing (a more positive) role in fertility changes in Nigeria’ is also supported. The study could not confirm that ‘the indices of marriage/sexual activity, postpartum insusceptibility and contraception (in that order) have the most inhibiting effect on fertility in Nigeria.’ The other two hypotheses could not be proven conclusively either. These were that ‘degree of fertility preference implementation is higher among couples with similar desired number of children than among discordant couples’ and ‘the Husbands have more influence on their wives’ family planning attitude and desired number of children than the wives have over their husbands’. These findings have programme and policy implications. For instance, although the reduction in the number of years spent in child bearing is welcome as a result of decline in the number of older women in active childbearing, the increasing entrance of women under the age of eighteen years is worrisome. This could impact negatively on school enrolment and retention as well as on the health of the women since it is recognised that women under the age of eighteen years is one of the four groups of women with higher risk of morbidity and mortality during pregnancy and childbirth. Despite the pertinent findings of this study, a number of study limitations can be identified. This include not identifying people who have achieved their desired fertility and those who have not and conducting in-depth interview with them to gain greater insight into their fertility decision-making, desire and behaviour. This aspect requires further detailed investigation. A number of programme, policy and research recommendations are made based on the findings of this study.