5,305 research outputs found

    Generation of a composite grid for turbine flows and consideration of a numerical scheme

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    A composite grid was generated for flows in turbines. It consisted of the C-grid (or O-grid) in the immediate vicinity of the blade and the H-grid in the middle of the blade passage between the C-grids and in the upstream region. This new composite grid provides better smoothness, resolution, and orthogonality than any single grid for a typical turbine blade with a large camber and rounded leading and trailing edges. The C-H (or O-H) composite grid has an unusual grid point that is connected to more than four neighboring nodes in two dimensions (more than six neighboring nodes in three dimensions). A finite-volume lower-upper (LU) implicit scheme to be used on this grid poses no problem and requires no special treatment because each interior cell of this composite grid has only four neighboring cells in two dimensions (six cells in three dimensions). The LU implicit scheme was demonstrated to be efficient and robust for external flows in a broad flow regime and can be easily applied to internal flows and extended from two to three dimensions

    Improperly obtained evidence in the Commonwealth: lessons for England and Wales?

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    English law's traditional approach to the admissibility of improperly obtained evidence is currently being rethought in response to a range of domestic and international pressures. With the position in England and Wales following the House of Lords' decision in A and Others (2005) firmly in mind, this article undertakes a selective review of comparative approaches to the admissibility of improperly obtained evidence in Australia, Canada and New Zealand. Having analysed relevant legislation and case law in each jurisdiction, general principles are derived to guide future developments in English law, in conformity with the European Convention on Human Rights

    Optical properties of microlenses fabricated using hydrophobic effects and polymer-jet-printing technology

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    We describe high-precision microlenses with excellent optical characteristics. The lenses are formed precisely at desired locations on a wafer using a polymer-jet system in which hydrophobic effects define the lens diameter and surface tension creates a high-quality optical surface. To make the lenses, we defined hydrophilic circular regions at desired locations using photolithography to pattern a 0.2-pm thick Teflon (hydrophobic) layer on a quartz substrate, as shown in Figures 1 and 2. Then, using a polymer-microjet printing system (Figure 3), we dispense an exact amount of UV-curable polymer within hydrophilic circles to obtain microlenses having desired optical properties [ 13. Figure 4 shows that adjusting the volume of the UV-curable optical epoxy within a hydrophilic circle of a given diameter changes the curvature of the microlens. The step resolution of the microlens volume is determined by the average droplet size (~25pL) of the polymer-jet print head. This hybrid method enables us to define the locations and diameters of microlenses with a ±1 μm precision as well as to control the curvatures of the microlenses accurately

    Optical switch using frequency-based addressing in a microelectromechanical systems array

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    Embodiments of the present invention provide structures for microelectromechanical systems (MEMS) that can be sensed, activated, controlled or otherwise addressed or made to respond by the application of forcing functions. In particular, an optical shutter structure suitable for use in an optical switch arrangement is disclosed. In one embodiment, an optical shutter or switch can be scaled and/or arranged to form arbitrary switch, multiplexer and/or demultiplexer configurations. In another embodiment of the present invention, an optical switch can include: a shutter; and a flexure coupled to the shutter, whereupon a vibration transmitted to the flexure when in the presence of a resonant frequency causes the shutter to move across an opening for the passage of an optical signal

    Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver

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    In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address

    Susceptibility to renal candidiasis due to immunosuppression induced by breast cancer cell lines

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    Candidiasis is a fungal infection which is prone to occur in people with immunosuppression due to debilitating diseases and nosocomial causes. While few studies have shown evidence of this disease co-existing with malignancy-induced immunosuppression disease, there never were any exclusive animal studies demonstrating this relationship, especially renal candidiasis with breast cancer. This study aims to demonstrate the relationship between renal candidiasis and breast cancer by observing the histopathological changes of the kidneys harvested from female Balb/c mice experimentally induced with breast cancer and inoculated with candida. The mice were randomly assigned to 5 different groups (n=12). Group 1 was injected with phosphate buffer solution (PBS), Group 2 with candida, Group 3 with breast cancer and Groups 4 and 5 having coexistence of candidiasis and breast cancer at 2 different doses of candidiasis respectively. Inoculation of mice with candidiasis spores was done by intravenous injection of Candida albicans via the tail vein. Induction of mice with breast cancer was via injection of 4T1 cancer cells at the right axillary mammary fatpad. Stained slides of Haematoxylin and Eosin (H&E), Periodic Acidic Schiff (PAS) and Gomori Methenamine Silver (GMS) were preapred for histopathology analysis. Grading of primary tumour and identification of metastatic deposits were carried out. Scoring of inflammation and congestion in the kidney was also carried out. Results revealed that group 4 exhibited a highly significant increase in inflammation and congestion (

    Dynamics of axial separation in long rotating drums

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    We propose a continuum description for the axial separation of granular materials in a long rotating drum. The model, operating with two local variables, concentration difference and the dynamic angle of repose, describes both initial transient traveling wave dynamics and long-term segregation of the binary mixture. Segregation proceeds through ultra-slow logarithmic coarsening.Comment: 4 pages, 3 Postscript figures; submitted to PR
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