Orientador: Jaime Aparecido Cury / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-25T22:05:28Z (GMT). No. of bitstreams: 1 Queiroz_CelsoSilva_M.pdf: 4148499 bytes, checksum: a250fc32bc9b3c95e74bc4505b1ca920 (MD5) Previous issue date: 1999 / Resumo: O objetivo do trabalho foi avaliar a relação entre o estresse e a concentração dos compostos sulfurados voláteis (CSV) no hálito bucal. Para tanto, foram avaliadas duas condições estressantes: Estudo I - prova; Estudo II - tensão pré-menstrual (TPM). O Estudo I foi composto de 2 grupos: A e B. O grupo A (34 voluntários), foi subdividido em 18 voluntários com estresse e 16 voluntários sem estresse. As concentrações dos CSV e foram medidas 1 semana antes da prova, no dia e 1 semana após, através do monitor de sulfetos (Halimeter) e o fluxo salivar também foi mensurado. No grupo B (37 voluntários), além dessas análises foram mensurados o pH, "capacidade tampão", cálcio, fósforo e proteína na saliva. O Estudo II foi composto por 50 voluntárias: 27 mulheres sem TPM (controle) e 23 mulheres com TPM. As mensurações dos CSV e do fluxo salivar foram realizadas nos períodos não-menstrual, pré-menstrual e de menstruação. A análise estatística mostrou que tanto no Grupo A (n=34) quanto no Grupo B (n=37) a concentração dos CSV no dia da prova foi maior (p<0,05) enquanto que a taxa de fluxo salivar foi menor (p<0,05). Os voluntários com estresse (n=18) e sem estresse (n=16) também apresentaram maiores concentrações de CSV no dia da prova (p<0,05), enquanto o fluxo salivar foi menor somente nos voluntários não estressados (p<0,05). A análise bioquímica da saliva do Grupo B revelou - que o pH foi menor no dia da prova (p<0,05), e as demais análises não foram diferentes (p>0,05). No Estudo II, as voluntárias sem TPM (n=26) apresentaram maior concentração dos CSV no período menstrual (p<0,05). Enquanto nas voluntárias com TPM (n=23) a concentração dos CSV foi maior (p<0,05) nos períodos menstrual e pré-menstrual. Já o fluxo salivar não mostrou diferenças (p>0,05). Os resultados sugerem que o estresse é um fator pré-disponente da halitose, cujo mecanismo não pode ser explicado somente pela diminuição do fluxo salivar / Abstract:The aim of study was to evaluate the relationship between stress and volatile sulfur compounds (VSC) present in mouth air. Thus, two stressfull conditions were evaluated: Study 1- examination; Study II - premenstrual syndrome (PMS). Study I was composed of 2 groups: A and B. Group A (34 volunteers), was divided in 18 volunteers with stress and 16 volunteers without stress. VSC concentrations were measured a week before, on day and a week after the exam using a sulfide monitor (Halimeter) and the salivary flow was measured. In group B (37 volunteers), others analyisis as pH, "buffer capacity", proteins, calcium and phosphorus, in saliva were performed. In study II, fifty women were selected: 27 women without PMS symptoms (control group) and 23 women with PMS symptoms. The measurements were performed during non-menstrual, PMS and menstrual periods. The statistical results showed in both groups A and B an increase of VSC concentration on the exam day (p<0.05) and the salivary flow was lower (p<0.05). Volunteers with stress (n=18) and without stress (n=16), presented higher VSC concentration on the exam (p<0.05), but there was statistical diferences in the salivary flow rate only in the volunteers without stress (p<0.05). The biochemistry analisys of the saliva in group B showed that pH was lower on the exam day (p<0.05), and others analisys were not statistical differences (p>0.05). In study II, the volunteers without PMS symptoms (n=26) presented higher VSC concentration in the menstrual period (p<0.05). Volunteers with PMS (h=23) showed a greater VSC concentration in both menstrual and PMS periods (p<0.05). Salivary flow rate was not statistically different (p>0.05). The results suggest that stressful conditions can be a predisposing factor for bad breath, and the mechanism cannot be explained only by the decrease of the salivary flow / Mestrado / Fisiologia Oral / Mestre em Odontologia

Master of Science / Department of Biological & Agricultural Engineering / Robert E. Wolf / Traditionally, growers spray uniform application of pesticides over the target area regardless of variations in pest infestations. In recent years, variable rate application (VRA) technologies have made it possible to apply pesticides in variable rates across the field. In pesticide application, nozzles play a vital role. In general, pesticides are applied using conventional nozzles. Most conventional nozzles vary flow rates only over a 2:1 range when operated within the recommended pressure range due to a fixed spray orifice. Conventional nozzles vary droplet sizes tremendously when there are speed and application rate changes which results in inefficient application. Conventional nozzles have limitations when used for VRA. A new nozzle called Varitarget nozzle (U.S. Patent No. 5,134,961) was developed and marketed by Bui, (2005) to overcome the limitations with conventional nozzles. Varitarget nozzles have a variable orifice that changes in size in response to pressure changes, allowing varying flow rates with a minimal change in droplet size. Laboratory tests and field tests were conducted to study the performance of Varitarget nozzle. Varitarget black/blue and clear/yellow caps were evaluated in this study. Lab studies were conducted to measure Varitarget characteristics compared to conventional nozzles. The flow rate ratios of Varitarget nozzle black and clear caps were 12:1 and 10:1 while the conventional nozzles produced flow rate ratios ranging from only 3:1 to 4:1. The measured flow rate of Varitarget nozzle black and clear caps was similar to that published by the manufacturer up to 40 psi and varied higher after 40 psi. Both Varitarget black and clear cap nozzle was within the standard VMD requirements until 40 psi and showed increasing trend while the conventional nozzles matched the standard VMD requirements. The VT black and clear cap nozzles showed better coverage at higher pressures when compared to conventional nozzles. CV values for VT black and clear capped nozzles were less than 10% which indicates capability of good uniform distribution. Spray angle of 110 degrees for VT black and clear capped nozzles was consistent over a range of pressures. Field studies were also conducted to compare the Varitarget to conventional nozzles. In the varying speed study, droplet size varied from 498 to 621 microns with a SD of 47.50 for VT black nozzle and 465 to 599 microns with a SD of 54.08 for VT clear cap nozzle as the speed varied from 4 to 12 mph. In the varying application rate study, The droplet size varied from 432 to 510 microns with a SD of 27.84 for VT black nozzle and 355 to 452 microns with a SD of 39.80 as the application rate varied from 4 to 12 GPA. In both studies, the observed pressure range required for spraying was minimum and varied slightly.

[pt] A injeção de água como método de recuperação de petróleo é usualmente utilizada devido à sua eficiência em recuperar óleo que encontra-se recluso no reservatório. Um teste de injetividade consiste basicamente em injetar uma fase (água ou gás) continuamente, por um determinado período de tempo, em um reservatório saturado de óleo. A partir da análise do comportamento da pressão no poço, esse procedimento tem por finalidade estimar, além do volume de óleo recuperável, parâmetros do reservatório, tais como permeabilidade, efeito de película, entre outros. Na atualidade, na literatura são encontrados estudos relativos a um único período de injeção (e um único período de fall-off) em reservatórios multicamadas e estudos relativos a reservatórios de camada única considerando vazão de injeção variável. Em vista disto, este trabalho tem como objetivo propor uma solução analítica aproximada para o comportamento da pressão em um reservatório multicamadas considerando um esquema de múltiplas vazões. A acurácia da solução proposta foi avaliada a partir da comparação com um simulador numérico de diferenças finitas em diferentes cenários. Os resultados exprimem uma considerável consonância entre os dados fornecidos pelo simulador numérico e o modelo proposto. / [en] The water injection is usually used as an oil recovery method due to its efficiency in recovering oil that is trapped in the reservoir. An injectivity test basically consists of continuously injecting a phase (water or gas), for a certain period of time, into an oil-saturated reservoir. From the analysis of the wellbore pressure behavior, this procedure aims to estimate, in addition to the volume of recoverable oil, parameters of the reservoir, such as permeability, film effect, among others. Nowadays, in the literature are found studies referring to a single injection period (and a single fall-off period) in multilayer reservoirs and studies referring to a single layer reservoirs considering variable injection flow-rates. In this context, this work aims to propose an approximate analytical solution for the pressure behavior in a multilayer reservoir considering a scheme of multiple flow-rates. The accuracy of the proposed solution was evaluated by comparison to a commercial finite difference-based flow simulator in different scenarios. The results express a considerable agreement between the data provided by the numerical simulator and the proposed model.

No description available.

Both Part I and Part II are included. / The separation of a mixture of glass spheres in water using 2 inch hydrocyclones was studied. <p> Three operating parameters were investigated: feed concentration, volume split and feed flow rate. In addition, three design parameters were cone angle, inlet diameter, and vortex finder length. The performance criterion parameters were the efficiency with which the solids were separated from the liquid, and the energy required per unit mass flowing through the hydrocyclone. </p> <p> First the experimental data were analyzed by three different statistical methods and the results compared in an attempt to determine which statistical method was most suitable for this two criteria system. The three methods were principal component analysis, canonical correlation analysis and multiple regression analysis. The theory behind these methods is briefly outlined. Our conclusion is that using all three methods give much more insight than could be obtained from any individual method. </p> <p> Second, an analysis of the above eight hydrocyclonc parameters of hydrocyclones with cylindrical sections indicated that for the range of parameters covered in this work, feed flow rate and inlet diameter influenced the energy loss most; volume split influenced the separation efficiency the most. Energy loss and separation efficiency are quite independent; this means that it is possible to design and run a hydrocyclone with high separation efficiency and low energy loss. The dilute concentrations used in this work indicate that a hydrocyclone of conventional design can be used in waste water treatment. When the parameters were correlated, a power model gave more consistent interpretation than a linear model. </p> <p> Third, the effect of the three operating parameters on hydrocyclones with three different body shapes suggested that the most efficient cyclone was one with a straight cone and no cylindrical section. The body shape dictated which parameters would significantly affect performance. </p> / Thesis / Master of Engineering (ME)

A frequency response tracer technique was used to study the hydraulic properties of a laboratory flow through reactor with variations in reactor size, flow rate and applied mixing. At any one set of conditions the reactor was studied over a range of input sine wave frequencies. Theoretical models consisting of in-series networks of completely mixed segments, plug flow segments, and dead space allowances were developed to approximate the experimental findings. / Thesis / Master of Engineering (ME)

This study is concerned with digital two-dimensional rivers for games. Specifically the aim is to create a river shape from the basis of a spline curve and make it look like a river with a water flow-rate. This is achieved by developing an artifact capable of river simulations in 2D, with the flow-rate calculated using the necessary hydraulics equations. The scientific process described in Design Science Research Methodology for Information Systems Research is presented and followed. Artifact simulations are demonstrated and evaluated, especially calculations for river mean velocity and discharge are shown to be possible by assuming that the river channel is of trapezoidal shape. Simulations show a type of river not usually seen in games, a river with more accuracy than other game simulations. The artifact river simulations are however limited by a missing smoothness when going between different channel shapes. Also there could be a way of improving the texture used, or possibly use more then one texture in one simulation. The conclusion is that the methods used for river generation by this study could be part of a design tool that targets 2D games.

No description available.

The research presented in this thesis, studies driver gap acceptance behavior for permissive left turn movements at signalized intersections. The thesis attempts to model the gap acceptance behavior using three different approaches, a deterministic statistical approach, a stochastic approach, and a psycho-physical approach. First, the deterministic statistical modeling approach is conducted using logistic regression to characterize the impact of a number of variables on driver gap acceptance behavior. The variables studied are the gap duration, the driver's wait time in search of an acceptable gap, the time required to travel to clear the conflict point, and the rain intensity. Considering stochastic gap acceptance, two stochastic approaches are compared, namely: a Bayesian and a Bootstrap approach. The study develops a procedure to model stochastic gap acceptance behavior while capturing model parameter correlations without the need to store all parameter combinations. The model is then implemented to estimate stochastic opposed saturation flow rates. Finally, the third approach uses a psycho-physical modeling approach. The physical component captures the vehicle constraints on gap acceptance behavior using vehicle dynamics models while the psychological component models the driver deliberation and decision process. In general, the three proposed models capture gap acceptance behavior for different vehicle types, roadway surface conditions, weather effects and types of control which could affect the driver gap acceptance behavior. These findings can be used to develop weather responsive traffic signal timings and can also be integrated into emerging IntelliDrive systems. / Master of Science

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The valveless micropump holds great potential for the biomedical community in applications such as drug delivery systems, blood glucose monitoring and many others. It is also a critical component in many a lab-on-a-chip device, which in turn promises to improve our treatment and diagnosis capabilities for diseases such as diabetes, tuberculosis, and HIV/AIDS. The valveless micropump has attracted attention from researchers on the grounds of its simple design, easy manufacturability and sensitive fluid handling characteristics, which are all important in biomedical applications. The pump consists of a pump chamber with a diffuser and nozzle on opposing sides of the pump chamber. The flow into the diffuser and nozzle is induced by an oscillating piezoelectric disc located on top of the pump chamber. The nozzle and diffuser rectify the flow in one direction, due to different pressure loss coefficients. The design process however is complex. In this study, we investigate the characteristics of a diffuser / nozzle based micropump using detailed computational fluid dynamic (CFD) analyses. Significant parameters are derived using the Buckingham-Pi theorem. In part based on this, the respective shapes of the diffuser and of the nozzle of the micropump are selected for numerical investigation. Hence the influence of the selected parameters on the flow rate of the micropump is studied using three-dimensional transient CFD analyses. Velocity profiles from the CFD simulations are also compared to the Jeffery-Hamel solution for flow in a wedge shaped channel. Significant similarities exist between the data and the predicted Jeffery-Hamel velocity profiles near the exit of the diffuser. Three different diffuser geometries were simulated at three frequencies. The flow rate and direction of flow are shown to be highly sensitive to inlet and outlet diffuser shapes, with the absolute flow rate varying by as much as 200% for the geometrical perturbations studied. Entrance losses at both the diffuser inlet and nozzle inlet appear to dominate the flow resistance at extremely laminar flow conditions with the average Reynolds number of Reave ≈ 500. / AFRIKAANSE OPSOMMING: Die kleplosemikropomp hou groot potensiaal in vir die biomediese gemeenskap in toepassings soos medisyne dosering sisteme, bloed glukose monitering en baie ander. Dit is ook ’n kritiese komponent in “lab-on-chip” sisteme, wat beloof om die behandeling en diagnose van siektes soos suikersiekte, tuberkulose enMIV/VIGS te verbeter. Die kleplose mikropomp het tot dusver die aandag van navorsers geniet as gevolg van sy eenvoudige ontwerp, maklike vervaardiging en sensitiewe vloeistof hantering. Hierdie kenmerke is krities inmenige biomediese toepassings. Die pomp bestaan uit ’n pompkamer met ’n diffusor en ’n mondstuk aan teenoorstaande kante van die pompkamer. Vloei in die diffusor en mondstuk in word geinduseer deur ’n ossillerende piëso-elektiese skyf wat bo-op die pompkamer geleë is. Weens verskillende druk verlies koëffisinëte van die diffusor en diemondstuk word die vloei in een rigting gerig. Die ontwerp-proses is egter kompleks. In hierdie studie word die eienskappe van die diffusor /mondstuk ondersoek deur gebruik temaak van gedetailleerde numeriese vloei-dinamiese analises. Belangrike parameters word afgelei deur gebruik te maak van die Buckingham-Pi teorema. Gedeeltelik gebaseer hierop word die onderskeidelike vorms van die diffusor en die mondstuk van die mikropomp geselekteer vir numeriese ondersoek. Gevlolglik word die invloed van die geselekteerde parameters op die vloei tempo van diemikropomp ondersoek deur gebruik temaak van drie-dimensionele tyd afhanklike numeriese vloei-dinamiese analises. Snelheids profiele van hierdie simulasiesword vergelykmet die Jeffrey-Hamel oplossing vir die vloei in ’n wigvormige kanaal. Daar is oorwegende ooreenkomstighede tussen hierdie data en die voorspelde Jeffrey-Hamel snelheids profiele veral by die uitgang van die diffusor. Drie verskillende diffusor vorms is by drie frekwensies gesimuleer. Daar is bewys dat die vloei tempo en vloeirigting baie sensitief is vir inlaat- en uitlaat diffusor vorms en dat die absolute vloei tempo kan varieermet soveel as 200%vir die geometriese versteuringswat ondersoek is. Inlaat verliese by beide die diffusor inlaat en die mondstuk inlaat, blyk om die vloei weerstand te domineer waar die vloei uiters laminêr ismet ’n gemiddelde Reynolds getal van Regem ≈ 500