The Aerodynamic Loads On A Flat Plate Between Parallel Walls Due To Rotational Flow Disturbances

In the thesis the effects of rotational flow disturbances on a body placed in an inviscid, incompressible fluid stream and in particular the case of a flat plate situated midway between two parallel planes were studied. A single vortex approaching the flat plate was first considered and then expanded to simulate the effects of pseudo-turbulence on the flat plate.;The finite-element and finite-difference numerical methods were evaluated in the thesis and arguments were made in support of using the finite-difference approach rather than the finite-element approach. The fact that the finite-difference technique was used for the particular flow problems studied in the thesis does not detract from the usefulness of finite-element methods for other flow problems particularly when further research has been made on variational methods applied to the non-linear fluid flow equations.;Theory for a Rotational Channel Vortex was developed and used to provide the upstream boundary conditions to the solution for the unsteady flow over a semi-infinite and then a finite flat plate. Also, new techniques were introduced in the thesis to predict the internal and external boundary conditions. It was found during the study that several methods were available to predict the boundary conditions on the flat plate but it was shown to be most important to select the appropriate method to formulate the correct boundary conditions on a body immersed in an unsteady rotational flow. The use of pseudo-turbulence models to simulate the approaching flow was also considered and it was shown that the loading on the plate could be determined using this approach. For instance the results showed that it was possible to predict the instantaneous unsteady loads on the flat plate from a particular approaching pseudo-turbulence with a particular power spectral density of the velocity fluctuations

CARDIOPROTECTIVE EFFECT OF DATE PALM AGAINST DOXORUBICIN-INDUCED CARDIOTOXICITY

Objective: Doxorubicin (Dox), an anthracycline antibiotic, has been widely used to treat cancer, principally hematological malignancies, and solid tumors. The administration of Dox is a topic of concern in the medical community, as it frequently related to dose-dependent cardiotoxicity. Therefore, the present study was designed to investigate the protective potential of date palm fruit extract on Dox-induced cardiotoxicity.Methods: A total of 40 female albino rats were used in this study and classified into four groups including control, date palm fruit extract, Dox, and treated date palm fruit extract groups.Results: Dox produced a significant increase in creatine kinase-MB and lactate dehydrogenase activities. It also decreased the activities of cardiac glutathione peroxidase and superoxide dismutase but increase levels of cardiac malondialdehyde and also of urinary 8-hydroxy-2-deoxyguanosine. Myocardial toxicity of Dox also appeared in the elevation of serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels, while level of high-density lipoprotein cholesterol decreased. Histopathological studies revealed alteration of cardiac tissue structure by Dox. Treatment with date palm fruit extract restored the aforementioned parameters.Conclusion: Date palm fruit exhibits a cardioprotective influence on the heart tissue against toxicity induced by Dox

Modulatory and Toxicological Perspectives on the Effects of the Small Molecule Kinetin

Plant hormones are small regulatory molecules that exert pharmacological actions in mammalian cells such as anti-oxidative and pro-metabolic effects. Kinetin belongs to the group of plant hormones cytokinin and has been associated with modulatory functions in mammalian cells. The mammalian adenosine receptor (A2a-R) is known to modulate multiple physiological responses in animal cells. Here, we describe that kinetin binds to the adenosine receptor (A2a-R) through the Asn253 residue in an adenosine dependent manner. To harness the beneficial effects of kinetin for future human use, we assess its acute toxicity by analyzing different biochemical and histological markers in rats. Kinetin at a dose below 1 mg/kg had no adverse effects on the serum level of glucose or on the activity of serum alanine transaminase (ALT) or aspartate aminotransferase (AST) enzymes in the kinetin treated rats. Whereas, creatinine levels increased after a kinetin treatment at a dose of 0.5 mg/kg. Furthermore, 5 mg/kg treated kinetin rats showed normal renal corpuscles, but a mild degeneration was observed in the renal glomeruli and renal tubules, as well as few degenerated hepatocytes were also observed in the liver. Kinetin doses below 5 mg/kg did not show any localized toxicity in the liver and kidney tissues. In addition to unraveling the binding interaction between kinetin and A2a-R, our findings suggest safe dose limits for the future use of kinetin as a therapeutic and modulatory agent against various pathophysiological conditions

Analytical Design Procedure for Forward Wave Couplers in RGW Technology Based on Hybrid PEC/PMC Waveguide Model

In this paper, a systematic design methodology of a 0dB and a 3dB forward couplers based on the ridge gap waveguide (RGW) technology is presented. This methodology is based on exact theoretical formulations rather than any approximate or empirical equations. The procedure of the proposed design methodology is mainly to build a virtual equivalent waveguide model. This waveguide has two horizontal upper and lower perfect electric conductor (PEC) walls, while the left and the right walls are made of perfect magnetic conductors (PMC). A detailed analysis for this hybrid PEC/PMC waveguide, a common waveguide for coupling, is introduced as the starting phase for designing the RGW couplers. The equivalent RGW coupler that assures the same operation of the hybrid PEC/PMC waveguide at a specific frequency range is deduced based on detailed theoretical aspects. Moreover, a simple analyzing of transitional bends and phase shifters with accurate calculations is presented in this paper, which are the fundamental building blocks of several mmW components such as the six-port junction and the butler matrix. The possibility of tuning the coupler center frequency is introduced without the need of using any nonlinear elements. The resulting RGW couplers are implemented through well-known full wave simulator (Ansoft HFSS), with verification through prototype measurements in order to confirm the validity of the proposed methodology. A good agreement is achieved between measurement and simulation results

In-situ and ex-situ studies of barnacle proteinaceous cements settled at earlier time points using μ-Raman spectroscopy and synchrotron based X-ray microprobe fluorescence techniques

Among the different biofouling species, barnacles resemble a specific threat as they are difficult to remove, able to damage fouling release coatings and increase the drag force of ships. Additionally, barnacles are a good model system for research on permanent underwater adhesion strategies. This study aims to understand and compare the spatial organization and the chemistry of the adhesive secreted by two different species (Balanus amphitrite and Balanus improvisus) of cyprid larvae and juvenile barnacles for settlement. Raman spectromicroscopy and synchrotron based X-ray microprobe fluorescence analysis have been applied for the in-situ and ex-situ investigation of juvenile barnacle cement chemistry. Confocal Raman spectromicroscopy revealed the chemical heterogeneity of the barnacle baseplate and allowed to distinguish three regions of various chemical compositions. The adhesive of cyprids was different from the one of larvae and analyzed in detail from the metamorphosis to the age of fourteen days. The results of these studies provided information on the chemical composition and morphological structure of both barnacle species at different life stages

Primary versus deferred ureteroscopy for management of calculus anuria in children: Review article

Background: The incidence of urolithiasis in the pediatric population is on the rise. Urolithiasis in the pediatric age group, although occurring less in adults, causes considerable morbidity. The role of ureteroscopy (URS) in the management of calculus anuria could be primary or deferred. The deferred URS after initial ureteral stenting or percutaneous drainage is the standard one. However, the remarkable progress in the manufacturing of ureteroscopes and lithotripters favored the primary URS.Objective: This study aimed to evaluate the results of primary versus deferred URS for management of obstructive calculus anuria (OCA) in children in previous literatures.Methods: We have searched literature in the American National Center for Biotechnology Information (NCBI), PubMed, Google scholar, Egyptian bank of knowledge, and science direct.Conclusion: Primary URS is a definitive stone management technique and an appropriate option that can reduce hospital stay, prevent multiple anesthesia, and alleviate the costs in children with OCA when performed by skilled endourologists. However the deferred URS is a favored procedure for management of calculus anuria in pediatric patients compared to primary URS

Wideband Printed Ridge Gap Rat-Race Coupler for Differential Feeding Antenna

In this paper, a wideband 3 dB hybrid 180° rat-race coupler is introduced in the printed ridge gap waveguide technology. It has simultaneous wide matching and isolation bandwidth with low output amplitude imbalance. It operates in the millimeter wave band from 25.8 to 34.2 GHz (27.96%) with 15 dB return loss and isolation, and ±0.5 dB output amplitude imbalance. The proposed design employing an open stub at the middle of the 3λ/4 branch line and quarter wavelength lines at all the ports of the coupler. The objective of the added open stub is to separate the output ports amplitudes around the -3 dB level by certain values depending on the required amplitude imbalance. The analytical derivation for the role of the added open stub is presented along with a parametric study on its effect on amplitude imbalance, matching, and isolation. This results in having two intersection points for the output ports instead of one of the conventional coupler and hence the amplitude imbalance bandwidth increases. The objective of the added quarter wavelength lines is to improve the matching and isolation bandwidths. First, the conventional rat-race coupler is presented and a bandwidth of 14.25% at 30 GHz is achieved. After that the rat-race with the added quarter wavelength lines is presented to illustrate the objective of the added quarter wavelength lines and a bandwidth of 19.44% is achieved. Finally, the rat-race with the quarter wavelength lines and the added stub is presented and a prototype is fabricated and measured. The s-parameters measurements are in a good agreement with the simulated ones

EVALUATION OF CYCLIC ADENOSINE MONOPHOSPHATE AND NEUROTRANSMITTERS IN EXPERIMENTAL OBESITY: IMPACT OF BLACK PEPPER AND COFFEE AQUEOUS EXTRACTS

ABSTRACTObjective: This study aims to evaluate the effect of black pepper and coffee extracts on chronic and acute experimental-induced obesity and energyhomeostasis.Methods: Rats were divided into 10 groups including control, high-fat diet (HFD), triton, HFD+triton, black pepper+HFD, black pepper+HFD+triton,coffee+HFD, coffee+HFD+triton, mixture+HFD, and mixture+HFD+triton groups. Blood glucose, serum insulin, and insulin resistance were estimated.Body mass index, food efficiency intake, and body weight gain were calculated. Lipid profile, liver and kidney functions were measured, serum and braincyclic adenosine monophosphate (cAMP) was estimated, and brain neurotransmitters were measured by high-performance liquid chromatography.Furthermore, histopathology of liver was performed.Results: Findings showed that blood glucose, insulin resistance, lipid profile, kidney and liver functions as well as brain cAMP and neurotransmitterswere significantly increased, concomitant with a significant decrease in insulin resistance and serum cAMP in both HFD and triton-induced obesitygroups compared to control.Conclusion: Supplementation with black pepper extract, coffee extract, and a mixture of both significantly improved these findings. In conclusion,black pepper and coffee extracts are overlooked as promising weight reduction and antihyperlipidemic agents.Keywords: Energy homeostasis, Obesity, Black pepper extract, Coffee extract, Cyclic adenosine monophosphate, Neurotransmitters

CLOSED-LOOP CONVEYOR SYSTEMS WITH MULTIPLE POISSON INPUT AND MULTIPLE SERVERS.

Dept. of Industrial and Manufacturing Systems Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1976 .S38. Source: Dissertation Abstracts International, Volume: 37-10, Section: B, page: 5279. Thesis (Ph.D.)--University of Windsor (Canada), 1976