Critical review of the trailing edge condition in steady and unsteady flow. Blade flutter in compressors and fans: Numerical simulation of the aerodynamic loading

Existing interpretations of the trailing edge condition, addressing both theoretical and experimental works in steady, as well as unsteady flows are critically reviewed. The work of Kutta and Joukowski on the trailing edge condition in steady flow is reviewed. It is shown that for most practical airfoils and blades (as in the case of most turbomachine blades), this condition is violated due to rounded trailing edges and high frequency effects, the flow dynamics in the trailing edge region being dominated by viscous forces; therefore, any meaningful modelling must include viscous effects. The question of to what extent the trailing edge condition affects acoustic radiation from the edge is raised; it is found that violation of the trailing edge condition leads to significant sound diffraction at the tailing edge, which is related to the problem of noise generation. Finally, various trailing edge conditions in unsteady flow are discussed, with emphasis on high reduced frequencies

Simulation of Demographic Change in Palestinian Territories

Mortality, birth rates and retirement play a major role in demographic changes. In most cases, mortality rates decreased in the past century without noticeable decrease in fertility rates, this leads to a significant increase in population growth. In many poor countries like Palestinian territories the number of births has fallen and the life expectancy increased. In this article we concentrate on measuring, analyzing and extrapolating the age structure in Palestine a few decades ago into future. A Fortran program has been designed and used for the simulation and analysis of our statistical data. This study of demographic change in Palestine has shown that Palestinians will have in future problems as the strongest age cohorts are the above-60-year olds. We therefore recommend the increase of both the retirement age and women employment.Comment: For Int. J. Mod. Phys. C 18, issue 11; 9 pages including figures and progra

Gravity observations at Sinai Peninsula and its geophysical and geodetic applications

AbstractSouth Sinai is an interesting region from both tectonic and seismological settings. Tectonically, Sinai Peninsula is strongly dominated by its active boundaries due to its location at the triple junction among the Gulf of Suez rift, the Aqaba–Levant transform fault and the Red Sea Rift. Moreover, reported seismological activities along the three tectonic boundaries indicate its continuous activities.It is thus of great interest to delineate the subsurface geological structure responsible of its tectonic settings and its relation to the seismological activity. Therefore, terrestrial gravity observation has been carried out to figure out the sub-surface structure representing its tectonic settings.On the other hand, the location of Sinai Peninsula between Gulf of Suez, Gulf of Aqepa and Red Sea has made the satellite altimetry data an optimum tool to determine the Gravity sources on the marine regions bounding the Sinai region. Finally, temporal gravity variation of the GRACE satellite mission, launched in 2003 gives the opportunity to monitor its temporal gravity variation on regional scale. Temporal gravity variation from GRACE demonstrates any possible mass redistribution along the pounding tectonic settings and its relation to seismicity.Observed gravity map shows significant gravity anomalies attributed to tectonic and seismicity. Satellite altimetry and gravity data are considered to be a valuable source of data to determine the offshore subsurface structure. Temporal gravity variations from GRACE shows important zones of mass redistribution attributed to its new tectonics and its relation to the seismological activities. Integrating all available data sheds more light on the geodynamic behavior of the selected region and its relation to the seismic activities

Influence of microwave heating on the stability of processed samn

Butter was converted to samn by microwave and conventional heating. The quality of the processed samn by the two methods was followed by determining the acid, peroxide and TBA values over a period of six weeks at 60°C. The fatty acid composition of samn samples was determined by gas-liquid chromatographic technique. The data show that butter conversion to samn by microwave heating was accomplished in about one half of the time that conventional heating requires. Microwave heating obviously increased the development of samn rancidity compared with the conventional heating. The parameters used for measuring lipid rancidity indicated that the main cause of samn rancidity under the present conditions is an oxidation mechanism.Mantequilla fue transformada en samn por calentamiento en microonda y convencional. La calidad del elaborado de samn por los dos métodos fue seguida mediante determinación de los índices de acidez, peróxido y TBA durante un período de seis semanas a 60°C. La composición en ácidos grasos de muestras de samn fue determinada por técnica cromatográfica gas-líquido. Los datos mostraron que la conversión de mantequilla a samn por calentamiento en microonda fue realizada en aproximadamente una vez y media el tiempo que exige el calentamiento convencional. El calentamiento en microonda, evidentemente, aumentó el desarrollo de la rancidez del samn comparado con el calentamiento convencional. Los parámetros usados para la medida de la rancidez lipídica indicaron que la causa principal de la rancidez del samn bajo las condiciones presentes es un mecanismo de oxidación

Influencia del calentamiento en microonda sobre la estabilidad de elaborado de "samn"

Butter was converted to samn by microwave and conventional heating. The quality of the processed samn by the two methods was followed by determining the acid, peroxide and TBA values over a period of six weeks at 60°C. The fatty acid composition of samn samples was determined by gas-liquid chromatographic technique. The data show that butter conversion to samn by microwave heating was accomplished in about one half of the time that conventional heating requires. Microwave heating obviously increased the development of samn rancidity compared with the conventional heating. The parameters used for measuring lipid rancidity indicated that the main cause of samn rancidity under the present conditions is an oxidation mechanism.Mantequilla fue transformada en samn por calentamiento en microonda y convencional. La calidad del elaborado de samn por los dos métodos fue seguida mediante determinación de los índices de acidez, peróxido y TBA durante un período de seis semanas a 60°C. La composición en ácidos grasos de muestras de samn fue determinada por técnica cromatográfica gas-líquido. Los datos mostraron que la conversión de mantequilla a samn por calentamiento en microonda fue realizada en aproximadamente una vez y media el tiempo que exige el calentamiento convencional. El calentamiento en microonda, evidentemente, aumentó el desarrollo de la rancidez del samn comparado con el calentamiento convencional. Los parámetros usados para la medida de la rancidez lipídica indicaron que la causa principal de la rancidez del samn bajo las condiciones presentes es un mecanismo de oxidación

The FGF-21 genetic variants rs838133 and rs838145 are associated with high salt intake in the Emirati population

Food predilection is linked to variants in the hepatokine “Fibroblast Growth Factor-21” gene (FGF21); with rs838133 linked to the sweet tooth in Caucasians. The effect of FGF21 variants on food intake is still unclear in other populations. A cohort of 196 healthy Emirati subjects was investigated [age: 30.34 ± 9.75yrs (44.4% males)]. The FGF21 rs838133 and rs838145 were genotyped. The daily intake was calculated based on a 61-item food frequency questionnaire. Multivariate analysis was performed using in house R script that implements two-way unsupervised hierarchical clustering to detect the association of the studied single-nucleotide polymorphisms (SNPs) and related SNPs in linkage disequilibrium, using data from the 1000 genome project. Both SNPs were in Hardy-Weinberg Equilaribium (HWE). BMI positively correlated with age (p = 0.002), but not with caloric intake. Salt intake was significantly higher in subjects homozygous (A: rs838133) and (G:rs838145),(p = 0.03 and 0.01, respectively). An interaction was observed between both SNPs; significantly associated with high salt intake. Using publicly available data, both SNPs fall within a region transmitted in Iberians which has a profile closely similar to Caucasians, but far from Chinese population. In conclusion, the minor alleles of FGF21 rs838145 and rs838133 are associated with high salt intake in Emiratis and may suggest neuro-metabolic link to dietary preference across different populations

A novel Ph-sensitive liposome to trigger delivery of afatinib to cancer cells: Impact on lung cancer therapy

A novel drug delivery system based on cationic (CL) and pH-sensitive liposomes (PSL) for tyrosine kinase inhibitor afatinib (AFT) were developed to enhance tumor-targetability against NSCLC cells and therapeutic effect. Optimal lipid to drug ratio was selected to prepare AFT-loaded PSL and CL with desirable physiochemical properties based on particle size, drug encapsulation efficiency (EE%), stability and release profiles. Moreover, antitumor activity was performed in vitro on human lung cancer cells (H-1975) using a WST-1 assay and Annexin-V apoptosis assay. The mean particle size of the liposomes was less than 100 nm, and EE% was more than 50% with lipid to drug ratio of 1:0.5. Stability data showed that PSL and CL were physically stable for 1 months at 4 and 25oC. In vitro drug release study demonstrated the sustained release of AFT at pH 7.5; while PSL exhibited fast drug release in pH 5.5. This effect revealed that PSL showed pH-sensitive release behaviors. In addition, the in vitro cytotoxicity study was employed for AFT-loaded PSL due to optimal characterizations. Thus, in vitro anticancer activity revealed that AFT loaded-PSL triggered apoptosis in H-1975 cells. In addition, the inhibitory effect towards H-1975 and HCC-827 was observed, indicating, which indicated high antitumor activity of AFT-loaded PSL. Then, PSL might potentially create practical clinical strategies for better targetability and delivery of AFT for treatment of lung cancer

N-[4-Acetyl-5-(3-methoxy­phen­yl)-4,5-dihydro-1,3,4-thia­diazol-2-yl]acetamide

The title compound, C13H15N3O3S, crystallizes with two mol­ecules in the asymmetric unit. The thia­diazole rings in both the mol­ecules adopt an envelope conformation. The crystal packing is stabilized by inter­molecular N—H⋯O and C—H⋯O inter­actions

Effect of Annealing and Ion Beam Irradiation on AC Electrical Properties for Gold Sputtered PM-355

171-181Deposition of different gold thickness on PM-355 cleaned by ethanol forming thin films using magnetron sputtering. Gold layer with thickness 300, 400, 500, 700, 1000, 1300, and 1500 nm were deposited to prepare Au / PM-355 thin films. Then, ac electrical properties response of thin films for a wide frequency range 20Hz - 5MHz were measured at room temperature. Meanwhile, the measurements of ac conductivity, dielectric constant, and dielectric loss factor were plotted at different frequencies to determine the optimum thickness. Hence, the comparison was done between optimum Au thickness thin films cleaned by two organic solvents and ethanol before annealing at different frequencies. Also, study the effect of annealing and ion beam that extracted radially from conical anode and disc cathode ion source on optimum Au thickness thin film electrical properties. It is found that the annealing increases both dielectric constant, dielectric loss, and ac conductivity of optimum Au thin film at different frequencies. Despite, the nitrogen ion beam effected on these thin films by decreasing the dielectric constant and ac conductivity for all thin films except the chloroform one. Finally, study the comparison between the annealing and followed by ion irradiation thin films. It is noticed the decrease in ac electrical conductivity and dielectric constant at different frequencies