High-fidelity chemical kinetic models for low-temperature combustion processes require high-fidelity data from fundamental experiments conducted in idealized transient reactors, such as shock tubes and rapid compression machines (RCM). Non-intrusive laser absorption diagnostics, in particular quantum cascade lasers (QCL) in the mid-infrared wavelength region, provide a unique opportunity to obtain quantitative, time-resolved species concentration and temperature from these reactive systems. In this work, three novel laser absorption diagnostics in the mid-infrared wavelength region are presented for three different experimental applications. The first diagnostic was developed for measuring CO2 concentration using an external cavity QCL centered in the ν3 fundamental vibrational band of CO2. Absorption cross-sections were measured in a shock tube, at a fixed wavelength for the R(32) line centered at 2371.42 cm-1 (4.217 µm) over 700 – 2900 K and nominal pressures of 1, 5 and 10 bar. The diagnostic was used to measure rate coefficients for the reaction between carbon monoxide and hydroxyl radical over 700 – 1230 K and 1.2 – 9.8 bar using highly dilute mixtures. The second diagnostic was developed for measuring CO concentration using a pulsed QCL centered at 2046.28 cm-1 (4.887 µm) and an off-axis cavity implemented on the RCM. The duty cycle and pulse repetition rate of the laser were optimized for increased tuning range, high chirp rate and increased line-width to achieve effective laser-cavity coupling. A gain factor of 133 and time resolution of 10 μs were demonstrated. CO concentration-time profiles during the oxidation of highly dilute n-heptane/air mixtures were recorded and compared with chemical kinetic models. This represents the first application of a cavity-enhanced absorption diagnostic in an RCM. Finally, a calibration-free temperature diagnostic based on a pair of pulsed QCLs centered at 2196.66 cm-1 and 2046.28 cm-1 was implemented on the RCM. The down-chirp phenomenon resulted in large spectral tuning (∆v ~ 2.8 cm-1) within a single pulse of each laser at a high pulse repetition frequency (100 kHz). The diagnostic for was used to measure the temperature rise during first-stage ignition of n-pentane at nominal pressures of 10 and 15 bar for the first time.

O propósito deste trabalho é a modelagem experimental e estudo do controle do processo de hidroconformação de tubos. Assim, o trabalho visa o projeto e a construção de um dispositivo servo-controlado de hidroconformação de tubos com um sistema de controle digital. O trabalho compreende o projeto e a construção de um dispositivo a ser acoplado em uma prensa hidráulica, a instrumentação dos equipamentos usados e a implantação do sistema de controle automático do processo através de um computador PC e de placas de interface A/D e D/A. Os aplicativos de controle foram desenvolvidos em linguagem de alto nível no sistema operacional Windows. No projeto do aplicativo, inicialmente foram realizadas rotinas para testes do sistema em malha aberta. As demais rotinas são aquelas associadas às funções matemáticas do modelo fenomenológico do sistema de hidroconformação, aquelas destinadas ao controlador de malha fechada. O tipo de estratégia de controle a ser utilizada foi definida no decorrer do projeto e foi baseada em um modelo de processo não linear, linearizado em torno de cada ponto de operação. Para fins de obtenção do modelo nominal para o controlador, os atuadores e sensores tiveram suas dinâmicas desprezadas face a dinâmica do processo e suas curvas de processo foram levantadas experimentalmente. / This works aims is the experimental modeling of a tube hydroforming (THF) “T" branch, and de THF process automatic control study. Thus, the design and the construction of a servo-controlled hydraulic device for THF, with a automatic digital control system, is embedded in our objectives. Design and construction of device to append on a hydraulic press, implantation of the measurement equipment and implementation of the control system algorithms through a PC with I/O interface boards is necessary. Control algorithms were developed in Hi-level language for windows operating system. The application design was based on experimental initial tests performed with no feed-backing controlling mode. Routes related to phenomenological mathematical model of the THF process were validate against the literature database, and were devoted to the feed-backing controller mode. Control strategy to employ in final application was defined during the process calibration, based on the non-linear characteristics of the “T" branch THF. To obtain the final load path model sensors and cylinders had their dynamics neglected because the THF dynamic is very much higher, and had their behavior curves experimentally raised.

Yeung Sau-Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 139-172). / Abstracts in English and Chinese. / Title page --- p.i / Acknowledgements --- p.ii / Table of Content --- p.iv / List of Figures --- p.viii / List of Graphs --- p.x / List of Tables --- p.xi / Abbreviations --- p.xiv / Abstract --- p.xv / Chinese Abstract --- p.xvii / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Diabetes Mellitus --- p.2 / Chapter 1.1.1 --- Type 1 diabetes mellitus --- p.3 / Chapter 1.1.2 --- Type 2 diabetes mellitus --- p.5 / Chapter 1.1.3 --- Maturity onset diabetes of the young (MODY) --- p.6 / Chapter 1.1.4 --- Gestational diabetes --- p.7 / Chapter 1.2 --- Effect of Diabetes on Pregnancy --- p.9 / Chapter 1.3 --- Suggested Causes of Diabetic Embryopathy --- p.10 / Chapter 1.3.1 --- Glucose --- p.10 / Chapter 1.3.2 --- Ketone bodies --- p.11 / Chapter 1.3.3 --- Somatomedin inhibitors --- p.12 / Chapter 1.3.4 --- TNF-α --- p.12 / Chapter 1.3.5 --- Oxidative stress --- p.13 / Chapter 1.4 --- Animal Model of Diabetes --- p.15 / Chapter 1.4.1 --- Chemically-induced --- p.15 / Chapter 1.4.2 --- Mutants --- p.17 / Chapter 1.5 --- Gene-teratogen Interaction under Diabetic Pregnancy --- p.19 / Chapter 1.6 --- Strategy of the Thesis --- p.21 / Chapter Chapter 2 --- General Materials and Methods --- p.24 / Chapter 2.1 --- Mouse Maintenance and Mating Method --- p.25 / Chapter 2.2 --- Induction of Diabetes --- p.25 / Chapter 2.3 --- Preparation of All-trans Retinoic Acid --- p.26 / Chapter 2.4 --- Dissection of Embryos --- p.26 / Chapter 2.5 --- DNA Extraction from Yolk Sac for Genotyping --- p.27 / Chapter 2.6 --- Genotyping of Embryos --- p.28 / Chapter 2.7 --- Preparation of RNA Probes for In Situ Hybridization --- p.29 / Chapter 2.7.1 --- Mini-scale preparation of plasmid DNA --- p.29 / Chapter 2.7.2 --- Linearization of plasmid DNA --- p.30 / Chapter 2.7.3 --- In vitro transcription --- p.31 / Chapter 2.8 --- Whole Mount In Situ Hybridization --- p.33 / Chapter 2.8.1 --- Fixation and dehydration of embryos --- p.33 / Chapter 2.8.2 --- Hybridization --- p.33 / Chapter 2.8.3 --- Post-hybridization wash --- p.34 / Chapter 2.8.4 --- Antibody wash and color development --- p.35 / Chapter 2.8.5 --- Embryo powder preparation --- p.36 / Chapter 2.8.6 --- Pre-absorption of antibody --- p.35 / Chapter 2.9 --- Whole Mount TUNEL Staining --- p.36 / Chapter Chapter 3 --- "Maternal Diabetes, Sp2H and RA Interaction" --- p.39 / Chapter 3.1 --- Introduction --- p.40 / Chapter 3.1.1 --- Neural tube defects --- p.41 / Chapter 3.1.2 --- Retinoic acid as environmental factor --- p.41 / Chapter 3.1.3 --- Sp2H as genetic factor --- p.44 / Chapter 3.1.4 --- Experimental design of this chapter --- p.46 / Chapter 3.2 --- Material and Methods --- p.47 / Chapter 3.2.1 --- Sp2H mice --- p.47 / Chapter 3.2.2 --- Mating and RA injection protocol --- p.47 / Chapter 3.2.3 --- Dissection of fetuses and analysis of neural tube development --- p.48 / Chapter 3.3 --- Results --- p.49 / Chapter 3.3.1 --- Maternal diabetes alone --- p.50 / Chapter 3.3.2 --- Sp2H mutation alone --- p.51 / Chapter 3.3.3 --- RA alone --- p.52 / Chapter 3.3.4 --- Maternal diabetes and RA interaction --- p.53 / Chapter 3.3.5 --- Sp2H mutation and RA interaction --- p.55 / Chapter 3.3.6 --- Sp2H mutation and maternal diabetes interaction --- p.57 / Chapter 3.3.7 --- "Maternal diabetes, Sp2H mutation and RA interaction" --- p.59 / Chapter 3.4 --- Discussion --- p.62 / Chapter 3.4.1 --- Maternal diabetes alone does not cause neural tube defects --- p.62 / Chapter 3.4.2 --- RA induces neural tube defects --- p.63 / Chapter 3.4.3 --- Interaction of maternal diabetes with RA in increasing the susceptibility to neural tube defects --- p.64 / Chapter 3.4.4 --- Embryos with Sp2H allele show increased susceptibility to neural tube defects when triggered by maternal diabetes and RA --- p.67 / Chapter Chapter 4 --- Molecular and Cellular Bases of Interaction --- p.71 / Chapter 4.1 --- Introduction --- p.72 / Chapter 4.1.1 --- Mechanism of diabetic embryopathy --- p.72 / Chapter 4.1.2 --- Mechanism of Sp2H mutation in development of neural tube defects --- p.74 / Chapter 4.1.3 --- Mechanism of RA teratogenicity --- p.75 / Chapter 4.1.4 --- "Possible common pathways shared by maternal diabetes, RA and Sp2H mutation" --- p.76 / Chapter 4.1.5 --- Experimental design of this chapter --- p.78 / Chapter 4.2 --- Materials and Methods --- p.80 / Chapter 4.2.1 --- Sample collection for studying Pax3 expression in Sp2H/+ And +/+ embryos in response to maternal diabetes or RA by whole mount in situ hybridization --- p.80 / Chapter 4.2.2 --- "Sample collection for studying the level of apoptosis in response to the interaction of maternal diabetes, Sp2H mutation and RA by whole mount TUNEL staining" --- p.82 / Chapter 4.3 --- Results --- p.86 / Chapter 4.3.1 --- Expression levels of Pax3 mRNA detected by whole mount in situ hybridization / Chapter 4.3.1.1 --- Expression of Pax3 in Sp2H/+/- and +/+ embryos --- p.86 / Chapter 4.3.1.2 --- Effect of maternal diabetes on Pax3 expression in Sp2H/+ and +/+ embryos --- p.87 / Chapter 4.3.1.3 --- Effect of RA on Pax3 expression in Sp2H /+ and +/+ embryos --- p.88 / Chapter 4.3.2 --- Level of apoptosis detected by whole mount TUNEL --- p.89 / Chapter 4.3.2.1 --- Effect of Sp2H allele on apoptosis --- p.94 / Chapter 4.3.2.2 --- Effect of maternal diabetes on apoptosis in Sp2H/+ and +/+ embryos --- p.95 / Chapter 4.3.2.3 --- Effect of RA on apoptosis in Sp2H/+ and +/+ embryos --- p.96 / Chapter 4.3.2.4 --- Effect of maternal diabetes and RA on apoptosis in Sp2H/+ and +/+ embryos --- p.97 / Chapter 4.4 --- Discussion --- p.99 / Chapter 4.4.1 --- Underexpression of Pax3 and increases in apoptosis under maternal diabetes --- p.99 / Chapter 4.4.2 --- "RA does not down regulate Pαx3, but increases apoptosis" --- p.102 / Chapter 4.4.3 --- Interaction of maternal diabetes and RA in increasing apoptosis --- p.104 / Chapter Chapter 5 --- "Maternal Diabetes, NOD and RA Interaction" --- p.108 / Chapter 5.1 --- Introduction --- p.109 / Chapter 5.1.1 --- Diabetic embryopathy in NOD mice --- p.109 / Chapter 5.1.2 --- Experimental design of this chapter --- p.110 / Chapter 5.2 --- Materials and Methods --- p.112 / Chapter 5.2.1 --- NOD mice --- p.112 / Chapter 5.2.2 --- Mating and RA Injection Protocol --- p.112 / Chapter 5.2.3 --- Sample Collection for the Study of Pax3 Expression --- p.113 / Chapter 5.3 --- Results --- p.115 / Chapter 5.3.1 --- Maternal diabetic alone --- p.116 / Chapter 5.3.2 --- NOD mutation alone --- p.117 / Chapter 5.3.3 --- RA alone --- p.118 / Chapter 5.3.4 --- Maternal diabetes and RA interaction --- p.119 / Chapter 5.3.5 --- NOD mutation and RA interaction --- p.121 / Chapter 5.3.6 --- NOD mutation and maternal diabetes interaction --- p.123 / Chapter 5.3.7 --- "Maternal diabetes, NOD mutation and RA interaction" --- p.125 / Chapter 5.3.8 --- Expression of Pax3 in embryos with different copies of NOD alleles --- p.128 / Chapter 5.4 --- Discussion --- p.130 / Chapter 5.4.1 --- Maternal diabetes interacts with NOD mutation to increase susceptibility to neural tube defects --- p.130 / Chapter 5.4.2 --- Interaction of maternal diabetes with NOD mutation is greatly exacerbated when exposed to RA --- p.131 / Chapter 5.4.3 --- Pax3 is not involved in the interaction --- p.133 / Chapter Chapter 6 --- Conclusion and Future Perspectives --- p.134 / References --- p.139 / Figures / Graphs

This thesis describes the flow of ground water with a free water table, in an isotropic and homogeneous soil overlying a horizontal impermeable layer, from a surface-applied rainfall or irrigation supply to a system of horizontal tube drains. The idealized representation of this situation is in terms of a potential flow towards line sinks. The tube drains (sinks) may be at atmospheric pressure (free flow) or under back-pressure (submerged flow). After describing the flow to systems of drains at uniform depth and equal spacings, the thesis shows the effect of horizontal, vertical and combined misalignments of a single line sink on the free surface, the flow pattern and the rates of flow to each sink. The study was carried out by viscous-flow and electrical analogues, by a numerical method (Relaxation), and by the exact solution of equations based on physical approximations. In theory the extent of the effect of any misalignment is infinite. Experimentally it was found that the vertical misalignment had a significant effect on the free surface, discharge and flow net over the whole range of the experiment, while the horizontal one had a noticeable effect only extending over one spacing on either side of the misaligned drain. An approximate mathematical solution for the horizontal displacement has been obtained. Experiments on the viscous-flow model revealed the importance of the effect on the free surface etc. of the back pressure. The distribution of the effect along the free surface and the correlation between the free surface height and the back pressure are also presented. A new approach was used to elucidate the effect of negative pressure (capillary rise) on the free surface and obtain the surface of atmospheric pressure. An equation, independent of the geometrical scale ratio was derived to relate the various parameters for the unsteady flow to the scaling laws. The introduction of a reference potential at a fixed point in the field provides a method for the correction of the change with time in the position of equipotentials and represents a new technique. The variations of free surface heights with discharge, as observed on the viscous-flow model, were compared with the results of s some recent theories and showed discrepancies between the experiment and theories.

The performance of peristaltic pumps is mainly governed by their tubing or hose materials. Research and development in this area is therefore very important for peristaltic pump manufacturers to keep in front of the competition and to open up new applications to enable further market penetration. Another aspect of this is of course price; performance and cost have to be in balance. As an approach to fabricate a new tube material, the field of negative Poisson's ratio (or: auxetic) materials is explored. The combined deformations of tensile, compression and shear in a peristaltic pump tube may well benefit from the specific characteristics of auxetic materials. Materials can be designed to keep their dimensions constant in directions perpendicular to an applied load. This is referred to as “auxetic balancing”. Finite element modelling shows that lowering the Poisson's ratio will rapidly decrease the maximum stresses in the cross-section of an occluded tube. Optimum values for the Poisson's ratio are found to be between −0.1 and +0.1, preferentially being 0. The re-entrant honeycomb structure is selected for initial trials, but manufacturing of this structure at the desired dimension proved to be too difficult at this time. Instead, electrospun nanofibre membranes are selected as the reinforcement structure. A liquid silicone elastomer is used as the matrix material. Key characteristics for the new material are derived from baseline test results on existing tubing. Laminates are manufactured from electrospun nylon6 nanofibre membranes coated with a liquid silicone rubber. Compression moulding is used to cure the nylon6-silicone rubber laminate, to give two effects: it ensures impregnation of the membrane and the compression deforms the nanofibre structure in such a way that it will become auxetic through-the-thickness. Flat sheet laminates of 2 mm thickness are manufactured with 14 layers of reinforcement. A reinforcing effect and substantial lowering of the through-the-thickness Poisson's ratio is observed for the laminates at low strains. At higher strains (>50%) the effect of the reinforcement diminishes and the Poisson's ratio of the laminate and pure silicone rubber equalises. Finally, tubular laminates are manufactured and the resulting tubes are tested in a peristaltic pump with some promising results (>1 million occlusions before failure). Tube performance is not yet at the required level, but with further optimisation of the laminating process, mould design and (post-)curing large steps forward can be made.

Orientador: José Reinaldo Cerqueira Braz / Resumo: Justificativa: a hiperinsuflação do balonete do tubo traqueal, causada pela rápida difusão do óxido nitroso (N2O), pode determinar lesões traqueais. Objetivos: comparar as pressões de balonetes de tubos traqueais, contendo ou não válvula reguladora de pressão, durante anestesia com N2O e estudar as eventuais lesões da mucosa do segmento traqueal em contato com o balonete do tubo traqueal. Método: dezesseis cães foram submetidos à anestesia venosa com pentobarbital sódico e anestesia inalatória com N2O (1,5 L.min-1) e O2 (1,0 L.min -1). Os cães foram distribuídos aleatoriamente em dois grupos de acordo com o tubo traqueal utilizado: G1 (n=8) tubo traqueal convencional com balonete de baixa pressão (Portex Blue-Line, Inglaterra); G2 (n=8) tubo traqueal dotado de válvula reguladora de pressão de Lanz (Mallincrodt, EUA). Em ambos os grupos, a insuflação do balonete foi feita com ar até a pressão de 30 cm H2O. A medida da pressão do balonete foi realizada através de manômetro (Mallincrodt, EUA), antes e após 60, 120 e 180 minutos do início da... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Background: High endotracheal tube intracuff pressure caused by fast diffusion of nitrous oxide (N2O) may cause mucosal tracheal lesions. Objectives: We have studied the effects of endotracheal tubes intracuff pressures with or without pressure regulating valve on tracheal mucosa during anesthesia with N2O. Methods: Sixteen dogs were submitted to intravenous anesthesia with pentobarbital and inhalational anesthesia with N2O (1.5 L.min-¹) and O2 (1.0 L.min-¹). The dogs were randomly allocated to two groups according to the endotracheal tube: G1 (n=8) conventional endotracheal tube with low-pressure cuff (Portex Blue-line, England); G2 (n=8) endotracheal tube with pressure regulating valve of Lanz from Mallincrodt (USA). In both groups the cuff insufflation was done with air to adjust cuff pressure to 30 cm H2O. Intracuff pressure was measured using a manometer at zero (control) and 60, 120 and 180 minutes after inhation of the N2O. The animals were sacrificed and biopsy specimens from areas of the trachea in contact with the endotracheal cuff were... (Complete abstract, click electronic address below) / Doutor

A thesis on the study of the frequency response of a pneumatic system designed to provide pulsed flow for flow control applications is presented. The system consists of a high pressure air source, a high-frequency solenoid valve, a length of tube and a minor loss. The experiment mimics the pneumatic drive for our Coanda-Assisted Spray Manipulation actuator and applies to many flow control applications involving pulsed flow. Square wave signals of various frequency are fed to the solenoid valve. The flow at the exit of the system is measured with a single hot wire and compared to steady flow through the same geometry. The effect of the inlet pressure, tube length and the size of the minor loss is evaluated. These data are modeled using a Transmission Matrix Model. (60 pages)

Copy of author's previously published article inserted. Bibliography: leaves 127-154. Pollination and fruit development were investigated in relation to abscission and abnormalities, specifically, blanking, semi-blanking, non-splitting and premature splitting of fruit. Pollen germination was assessed in Pistacia vera, P. atlantica and P. terebinthus. The pollen tube pathway in pistachio was documented precisely. Growth periods of normal and abnormal pistachio fruits were investigated.

The prediction of linear viscoelasticity (LVE) of a polymer melts from the knowledge of their structure has received tremendous attention in recent years. Quite accurate quantitative predictions are obtained for linear polymers, including inverse predictions of molecular weight distributions from knowledge of rheological response. The situation for branched polymers is much more complicated for at least two reasons. First, because of the incredible variety of architectures that can be, and are actually, made in the lab or by industry. Second, because branched polymers are characterised by very broad distributions of relaxation times, which are very dependent on details of the architecture. The main objective of this work is to propose a model suitable for predicting LVE of arbitrary mixtures of (a)symmetric stars and linear molecules, where the interrelation of relaxation processes (as reptation, tube length fluctuations or constraint release process) cannot be predicted a priori. We validate it on a large set of experimental data taken from the literature, from our own experiments or from co-workers. Next, we use it to detect long chain branching (LCB) in sparsely branched polycarbonate samples. This characterization technique, based on the analysis of the relaxation moduli, is compared to solution characterization. A similar work is performed for polyethylene samples, on which we compare our method to classical methods based on the measurement of their intrinsic viscosity or on the analysis of their activation energies spectrum. The success of our model in describing the relaxation of an already broad range of polymer structures gives some hope for understanding the dynamics of more complex systems. Indeed, its structure allows us to easily extend it to H or comb polymers and then, to proceed to polymers always closer to the industrial polymers.

H.A. Haus. / "April 5, 1958"--Cover. "Presented at the Symposium on Electronic Waveguides, Polytechnic Institute of Brooklyn, April 8-10, 1958." / Bibliography: p. 131-132. / Army Signal Corps Contract DA36-039-sc-64637. Dept. of the Army Task 3-99-06-108 and Project 3-99-00-100.