Electrohydrodynamic Instability of Two Superposed Viscous Dielectric Fluids Flowing down an Inclined Plane with Thermal Conductivity Variation

The linear electrohydrodynamic instability of two superposed viscous dielectric fluids flowing down an inclined plane in the presence of thermal conductivity variation and applied electric fields is investigated. Using long-wavelength approximation, a new instability is presented. It is shown that when there is a variation in thermal conductivity in the fluid even in absence of electric fields or when applied electric fields are present even in absence of thermal conductivity variation, instability can occur under a longitudinal gravitational field. The effects of various parameters as Prandtl number, Reynolds number, electric field, inclination angle, and thermal conductivity variation on the stability of the system are discussed analytically and numerically in detail. The presence of electric field is important to prevent the drop out of the analysis when there is no stratification in thermal conductivity. Key words: Hydrodynamic stability; Viscous fluids; Flows down an inclined plane; Thermal conductivity; Electro-hydrodynamic

Geophysical investigations of a geothermal anomaly at Wadi Ghadir, eastern Egypt

During regional heat flow studies a geothermal anomaly was discovered approximately 2 km from the Red Sea coast at Wadi Ghadir, in the Red Sea Hills of Eastern Egypt. A temperature gradient of 55 C/km was measured in a 150 m drillhole at this location, indicating a heat flow of approximately 175 mw/sqm, approximately four times the regional background heat flow for Egypt. Gravity and magnetic data were collected along Wadi Ghadir, and combined with offshore gravity data, to investigate the source of the thermal anomaly. Magnetic anomalies in the profile do not coincide with the thermal anomaly, but were observed to correlate with outcrops of basic rocks. Other regional heat flow and gravity data indicate that the transition from continental to oceanic type lithosphere occurs close to the Red Sea margin, and that the regional thermal anomaly is possibly related to the formation of the Red Sea

GRIDKIT: Pluggable overlay networks for Grid computing

A `second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication `interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks

Free-Range Rearing Density for Male and Female Milanino Chickens: Growth Performance and Stress Markers

The Milanino is a heavy Italian chicken breed and represents an important genetic resource for alternative production systems. Due to the absence of standard management guidelines for local chicken breeds, this study aims to determine the space requirement to achieve a good equilibrium between growth performance and stress response in Milanino chickens reared according to a separate-sex free-range program. A total of 140 birds (70M:70F) were reared in outdoor pens from 75 to 235 d of life according to the following experimental groups (35 birds/group): (M2) males in 2 m(2)/bird; (F2) females in 2 m(2)/bird; (M10) males in 10 m(2)/bird; (F10) females in 10 m(2)/bird. Growth performance and stress condition were recorded. Bird density affected male body weight, that was higher at the lower density of 10 m2/bird. In contrast, females showed a consistent growth rate irrespective of the bird density suggesting lower space requirements. An overall good adaptability of the breed to the separate-sex free-range system was found, irrespective of both sex and bird density. Moreover, the stress markers values assessed at the end of the growing period suggest the ability of Milanino birds to respond well to environmental stressors. The results provided in this report will be implemented into free-range management guidelines for meat production in the Milanino breed: the separate-sex rearing is recommended during the growing period in outdoor pens and the bird density has to be planned according to the sex

Effect of n-methylacetamide concentration and thawing rate on chicken sperm quality after cryopreservation

In seeking alternative cryoprotectants to glycerol for a reference chicken semen freezing procedure, the aim of the present study was to compare the effect of two concentrations of N-Methylacetamide (MA) and two thawing rates on the quality of frozen-thawed semen. Semen samples were diluted in Lake pre-freezing extender, including 0.1 M trehalose in presence of 6% or 9% MA, loaded into straws, frozen in nitrogen vapors, and stored in liquid nitrogen. The following thawing treatments were used: 5 \ub0C for 100 s and 38 \ub0C for 30 s. Sperm quality (cell membrane integrity, motility and kinetic parameters) was assessed before and after cryopreservation. The decrease of MA concentration from 9 to 6% improved sperm quality after freezing/thawing and this effect was dependent on thawing temperature. Decreasing the MA concentration from 9 to 6% improved the proportion of undamaged membrane, motile, and progressive motile sperm recovered after thawing at 5 \ub0C for 100 s; in contrast, no effect of the MA concentration was observed thawing at 38 \ub0C for 30 s. Therefore, the treatment with 6% MA and thawing at 5 \ub0C for 100 s has given the best cryoprotective action. These results contribute to improve the efficacy of the current chicken semen cryopreservation procedures

A Comparison Study in the Management of Ectopic Pregnancy between State of Qatar and Kingdom of Bahrain

Ectopic pregnancy is of increasing concern to gynecologists since it is a major cause of maternal mortality and morbidity in reproductive age women. It occurs when the conceptus implants in an abnormal position other than the uterus. Although the incidence of ectopic pregnancy during the 20 years studied increased five-folds, the risk of death from ectopic pregnancy declined by 90%. This decline might be related to the increase awareness of this condition that accompanied improved diagnostic technology and thus improved management and care. However, ectopic pregnancy remains the leading cause of maternal mortality in first trimenster. This study was to evaluate the management of ectopic pregnancy in the State of Qatar and the Kingdom of Bahrain in a time period from January I, 2000 to August 31, 2003. Statistical analysis showed high incidence of ectopic pregnancy with increase in age and abortion. Etiological factors including contraceptive usage, infertility treatment and previous ectopic pregnancy were shown to increases ectopic pregnancy rates. In the Kingdom of Bahrain, management of ectopic pregnancy was carried by surgical salpingectomy and Laparoctomy and to a lesser extend medical Methotrexate management was also carried on. While in the State of Qatar it was the opposite as Methotrexate was mainly used rather than the surgical treatment. It is recommended that further investigations are needed to enhance this data and to prove the benefits of medical management over the surgical management.qscienc

Imaging Gold Nanoparticles in Living Cells Environments using Heterodyne Digital Holographic Microscopy

This paper describes an imaging microscopic technique based on heterodyne digital holography where subwavelength-sized gold colloids can be imaged in cell environment. Surface cellular receptors of 3T3 mouse fibroblasts are labeled with 40 nm gold nanoparticles, and the biological specimen is imaged in a total internal reflection configuration with holographic microscopy. Due to a higher scattering efficiency of the gold nanoparticles versus that of cellular structures, accurate localization of a gold marker is obtained within a 3D mapping of the entire sample's scattered field, with a lateral precision of 5 nm and 100 nm in the x,y and in the z directions respectively, demonstrating the ability of holographic microscopy to locate nanoparticles in living cells environments