Free wake analysis of hover performance using a new influence coefficient method

A new approach to the prediction of helicopter rotor performance using a free wake analysis was developed. This new method uses a relaxation process that does not suffer from the convergence problems associated with previous time marching simulations. This wake relaxation procedure was coupled to a vortex-lattice, lifting surface loads analysis to produce a novel, self contained performance prediction code: EHPIC (Evaluation of Helicopter Performance using Influence Coefficients). The major technical features of the EHPIC code are described and a substantial amount of background information on the capabilities and proper operation of the code is supplied. Sample problems were undertaken to demonstrate the robustness and flexibility of the basic approach. Also, a performance correlation study was carried out to establish the breadth of applicability of the code, with very favorable results

Organometallic compounds in drug discovery: Past, present and future

International audienceIn this review, we present an overview of some of the medicinally-relevant organometallic drugs that have been used in the past or that are currently in clinical trials as well as an example of compounds that are currently in the initial stage of drug development. Three main classes of organometallic complexes have been chosen for discussion: antimicrobial organoarsenicals, antimalarial and anticancer ferrocene-containing compounds and anticancer catalytic organometallic complexes. The purpose of this review is to provide readers with a focus on the significant progress that has been made for each of these respective fields of medicine

Creating E-Business Value And Firm Performance From Supply Chain Perspective

After e-commerce (electronic commerce) bubbled in the new millennium, the trend of information technology thus moved forward e-business (electronic business) manifestly. This is because e-business integrated and valued greater than e-commerce both in the physical and virtual networks. Also, it apparently shows that businesses are planning to achieve digitally tightened integration with suppliers, customers, and employees from the development of information technology in recent years. It means that e-business technologies are widely used by businesses. However, not all businesses are successfully using e-business technologies. Some of them face the failure of e-business technologies use to yield satisfactory value and firm performance due to the much more important lack of significant knowledge or capability to use e-business technologies. Therefore, such researches of e-business have been paid much attention by academia and practitioners. This study would initially investigate the relevant references of e-business technologies use and IT integration capability in order to identify the involved relationships. Furthermore, intrafirm integration and interfirm integration are regarded as two significant mediators and then try to verify the influence of above-mentioned variables on e-business value and firm performance so as to propose the research model. The results and findings in this study support the hypotheses we presented in the light of 248 respondents gathered from Taiwan top 1000 enterprises. Expect that there is a guideline to follow and the research model would contribute to enhance the success of e-business value and firm performance for businesses as using e-business technologies. Moreover, the results and findings of this study could be as the reference for academia and practitioners as conducting related researches

Aerobiology, image analysis and allergenicity of pollen and spores in Singapore

Ph.DDOCTOR OF PHILOSOPH

Effect Of Inulin On Oral Bioavailability Of Minerals And Drugs

The present study was conducted to evaluate the potential and effect of different doses of inulin in enhancing the oral absorption of zinc and magnesium. The effect of different doses of inulin in the oral bioavailability of the 2 model drugs, acyclovir and atenolol, was also assessed. Prior to the study, two simple, rapid and sensitive flame atomic absorption spectrophotometer methods were successfully developed for the determination of zinc and magnesium in rat plasma, respectively. The accuracy values were between 91 – 107% for zinc and 92 – 105% for magnesium, while the coefficient of variation values were all less than 12.5% for both zinc and magnesium

Modelling and simulation of drying process for ceramic membrane fabrication

For ages, ceramic properties and structure is known for its brittleness and its failure such as cracking and warping. This weakness also relates to the high sensitivity of ceramic to any thermal gradient effects. Therefore, processing steps of green body of ceramic is crucial especially in membrane fabrication that has a multilayer structure to ensure the efficiency of its applications. Thus, every step of ceramic membrane preparation and fabrication needs careful control and monitoring to fulfil these aims. Drying is one of the main problems that is always associated with the cracks and leakages of the ceramic membrane. In fact, the drying process is one of the longest steps corresponding to various evolutions of parameters during the evaporation process. Due to the limitation in experimental or empirical ability to determine the changes of dynamic critical variables during drying, modelling and simulation seems to be the right option to determine and investigate these nonlinear and dynamic variables and will be the focus of this study. This two-dimensional mathematical modelling approach is able to predict the changes of variables in heat and mass transfer during the drying process. The governing system of fully coupled non-linear partial differential equations of the model was derived from a mechanistic approach where the mass and energy conservation laws are defined for a particular phase into which Darcy’s law and Fick’s law are substituted. A fully implicit algorithm has been employed for numerical solution using the finite element method in which the Galerkin weighted residual method is used in the spatial discretization and a backward finite difference time-stepping scheme is employed for time integration. The ability of this improved model is not restricted to a single homogenous layer of hygroscopic and nonhygroscopic material, but on the novelty to incorporate multilayer heterogeneous material properties as a membrane structure. A good agreement obtained by respective validation works suggested that the model development and implementation are satisfactory. Subsequently, case studies involving single layer and multilayer have produced reasonable accuracy at all times. The application of the model at various case studies involves a convective and enhanced intermittent drying mode which demonstrates the robustness and trustworthiness in predicting and optimising the drying process

Characterization of Aquatic Fulvic Acids by Chromatographic Methods

Several chromatographic and spectroscopic techniques were applied to Suwanne River reference fulvic acids (FA) and their permethylated derivatives. Retention mechanisms, structural characteristics, and thermal stabilities of FA and its derivatives and fractions were evaluated