848 research outputs found

    Numerical solution for the temperature distribution in a cooled guide vane blade of a radial gas turbine

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    A two dimensional finite difference numerical technique is presented to determine the temperature distribution of an internal cooled blade of radial turbine guide vanes. A simple convection cooling is assumed inside the guide vane blade. Such cooling has relatively small cooling effectiveness at the leading edge and at the trailing edge. Heat transfer augmentation in these critical areas may be achieved by using impingement jets and film cooling. A computer program is written in FORTRAN IV for IBM 370/165 computer

    A two-dimensional finite-difference solution for the temperature distribution in a radial gas turbine guide vane blade

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    A two-dimensional finite difference numerical technique is presented to determine the temperature distribution in a solid blade of a radial guide vane. A computer program is written in Fortran IV for IBM 370/165 computer. The computer results obtained from these programs have a similar behavior and trend as those obtained by experimental results

    TF34 engine compression system computer study

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    The stability of the fan and the compressor components was examined individually using linearized and time dependent, one dimensional stability analysis techniques. The stability of the fan core integrated compression system was investigated using a two dimensional compression system model. The analytical equations on which this model was based satisfied the mass, axial momentum, radial momentum, and energy conservation equations for flow through a finite control volume. The results gave an accurate simulation of the flow through the compression system. The speed lines of the components were reproduced; the points of instability were accurately predicted; the locations where the instability was initiated in the fan and the core were indicated; and the variation of the bypass ratio during flow throttling was calculated. The validity of the analytical techniques was then established by comparing these results with test data and with results obtained from the steady state cycle deck

    Aerodynamic stability analysis of NASA J85-13/planar pressure pulse generator installation

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    A digital computer simulation model for the J85-13/Planar Pressure Pulse Generator (P3 G) test installation was developed by modifying an existing General Electric compression system model. This modification included the incorporation of a novel method for describing the unsteady blade lift force. This approach significantly enhanced the capability of the model to handle unsteady flows. In addition, the frequency response characteristics of the J85-13/P3G test installation were analyzed in support of selecting instrumentation locations to avoid standing wave nodes within the test apparatus and thus, low signal levels. The feasibility of employing explicit analytical expression for surge prediction was also studied

    Sustainable Development Between Politics and Policies

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    [abstract not provided]https://fount.aucegypt.edu/faculty_book_chapters/1944/thumbnail.jp

    Controlled Release Ammonio Methacrylate Copolymer-Based Microspheres of Oxypentifylline

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    The objective of this work was to formulate and evaluate a controlled-release Oxypentifylline microspheres that fulfill the requirements for extended release medications using Ammonio Methacrylate Copolymer RS100 as polymeric material. The microsphere were prepared by quasi-emulsion solvent diffusion technique. The effect of process variables such as drug to polymer ratio, stirring rate, and concentration of emulsifier on mean particle size, yield, entrapment efficiency and in vitro release characteristics of microspheres were studied. The prepared microspheres were spherical in shape. The size range varied  from  325.45  to  518.54  µm. The microspheres showed high entrapment efficiency (94.22%) and the release was extended up to 24 hrs. The best microsphere formulation was selected and subjected for in vivo studies which reveal that the bioavailability of the drug increased by more than 3.4 times by formulating it into microspheres. This study  indicated  that  Ammonio Methacrylate Copolymer RS 100 can use successfully to sustain the release of Oxypentifyllin

    Controlled Release Ammonio Methacrylate Copolymer-Based Microspheres of Oxypentifylline

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    The objective of this work was to formulate and evaluate a controlled-release Oxypentifylline microspheres that fulfill the requirements for extended release medications using Ammonio Methacrylate Copolymer RS100 as polymeric material. The microsphere were prepared by quasi-emulsion solvent diffusion technique. The effect of process variables such as drug to polymer ratio, stirring rate, and concentration of emulsifier on mean particle size, yield, entrapment efficiency and in vitro release characteristics of microspheres were studied. The prepared microspheres were spherical in shape. The size range varied  from  325.45  to  518.54  µm. The microspheres showed high entrapment efficiency (94.22%) and the release was extended up to 24 hrs. The best microsphere formulation was selected and subjected for in vivo studies which reveal that the bioavailability of the drug increased by more than 3.4 times by formulating it into microspheres. This study  indicated  that  Ammonio Methacrylate Copolymer RS 100 can use successfully to sustain the release of Oxypentifyllin

    Assessment of Saudi Public Knowledge and Attitudes Toward Mental Health Disorders and Its Demographic Correlation

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    Objectives: To assess Saudi citizen’s level of knowledge, attitude and stigma toward mental disorders and its demographic correlations. Methods: A descriptive cross-sectional study carried out in 15 PHC centers in Hail City, Saudi Arabia; among 403 participants from Jan to May 2020 by using a questionnaire includes the MH Knowledge Scale (MAKS) to assess the levels of MH literacy and the perceived devaluation and discrimination scale (PDD) to evaluate the levels of MH stigma and among the Saudi populations attended the Primary health Care centers. Results: The findings revealed that only 16% of the participants had a high level of knowledge, and only 22 % had low stigma attitude toward MH illnesses. They expressed high familiarity and recognition of schizophrenia and depression. The higher level of MH knowledge was associated with young age, males, students, and those who had experience with mental disorders or had a relationship with MH patients. High stigma attitude was associated with older participants, those with only primary level education, and housewives. In addition, there was a significant positive correlation between high MH knowledge and a positive stigma attitude. Conclusion: working on enhancing community awareness, promoting education, and developing anti-stigma interventions are highly recommended to ameliorate the level of MH knowledge and attitude to improve MH care. Keywords: mental health knowledge, stigma, mental disorders, MAKS, PDD, attitude, PHC, Saudi Arabia. DOI: 10.7176/JHMN/107-01 Publication date: April 30th 202

    Preparation and evaluation of mebeverine hydrochloride as mucoadhesive buccal tablet for local anesthesia

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    Purpose: To formulate and evaluate an antispasmodic drug, mebeverine hydrochloride (Mbv-HCl), as a local anesthetic mucoadhesive buccal tablet.Methods: Mbv-HCl loaded tablets were formulated, using a direct compression technique, with varying polymer concentrations including carbopol 934P alone, carbopol 934P/hydroxypropyl methylcellulose (HPMC) mixture, or carbopol 934P/chitosan mixture. The tablets were evaluated for physicochemical characteristics, in-vitro drug release, bioadhesive strength, swelling, ex-vivo residence time, ex-vivo permeation, drug permeation through the buccal membrane of sheep, and stability.Results: The results indicate that formulation F4, which contains HPMC/carbopol 934P (3:1), showed the best in-vitro drug release profile. The release kinetics for all the formulations fitted well with Hixson- Crowell kinetic model. Bioadhesive strength, surface pH, and swelling index of F4 were 41.52, 6.36, and 231.2 %, respectively. Maximum residence time ex-vivo was exhibited by formulation F4, showing a maximum residence time of about 330 min with 80 % of Mbv-HCl permeated in 6 h ex-vivo. F4 was stable after storage for 60 days at 25 oC/60 % RH and 40 oC/75 % RH, with non-significant change (p < 0.05) in drug content, bioadhesive strength and in vitro release.Conclusion: The optimized mucoadhesive buccal formulation is promising for delivery of Mbv-HCl, and displays high bioadhesion and adequate permeability through sheep buccal membrane to achieve a local anesthetic action.Keywords: Mebeverine hydrochloride, Buccal, Mucoadhesive tablet, Swelling index, Bioadhesive strength, Local anestheti
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