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Al Fayyum, Egypt

Fayoum University is a public university located in the Egyptian city of Al Fayoum in northern Egypt. From 1976 to 2005, Fayoum University was a public institution within the University of Cairo. In August 2005, it was established as an independent campus with 2,000 faculty members and enrollment of about 25. 000 students. The city of Fayoum is an oasis located approximately 63 miles southwest of Cairo and is noted for its agricultural production and tourism. Wikipedia.

El Sayed A.M.,Fayoum University
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2014

Carboxymethyl cellulose (CMC)/Polyvinyl alcohol (PVA) blend films were prepared by solution casting method. Then, these films were irradiated with γ-rays from a Co-60 source at doses over the range 0-70 kGy to investigate the modifications induced in the optical and dielectric properties. The dielectric constant (ε′) was measured in the temperature range 303-408 K and in the frequency range 10 kHz-1 MHz. The indirect optical band gap was found to increase within the dose range 0-10 kGy, and to decrease at the higher doses. The refractive index values, however, showed a reversed behavior. The highest transmittance percentage was obtained at 10 kGy dose. According to the frequency and temperature dependence of ε′, α- relaxation peaks were observed in all samples and assigned to the micro-Brownian motion of the blend chains. The values of É showed a decrease in the dose range 0-10 kGy and an increase in the dose range 10-70 kGy. The ac conductivity σac (T) showed an Arrhenius type behavior separated into two distinct regions. The results of the present system are compared with those of similar materials. © 2013 Elsevier B.V. All rights reserved. Source

Abdel-Karim M.,Fayoum University
European Journal of Mechanics, A/Solids | Year: 2011

In order to identify different variables that affect ratchetting simulations, variation of elastic modulus during loading and unloading is considered and discussed based on the experimental observations which pointed out by Morestin and Boivin (1996), Ishikawa (1997), Cleveland and Ghosh (2002), Zhou et al. (2005) and recently by Khan et al. (2009a,b,c). Then the effect of such variation on simulations is scrutinized from the theoretical point of view by considering simulations of ratchetting experiments conducted on stainless steel 304L by Hassan et al. (2008) using the well-known Armstrong-Frederick model. It is shown that, using two different values for the elastic modulus during loading and unloading could have a significant effect on simulations of uniaxial ratchetting. On the other hand, such significant effect hardly occurs in the case of simulations of biaxial ratchetting experiments under consideration. The importance of such findings is that the excessive ratchetting over-prediction resulting from any specific kinematic hardening rule is expected to decrease significantly by taking into consideration this effect. In this case, modeling of kinematic hardening rules could necessitate more attention and reconsideration. © 2010 Elsevier Masson SAS. All rights reserved. Source

At room temperature, the contact of Tb3+ ions dissolved in bidistilled water with a polystyrene film incorporating 2-pyridone (PS-Pyr) exhibits terbium-sensitized photoluminescence (PL) when excited at 295 nm. The Tb3+-sensitized emission is attributed to a complex formation as well as a highly efficient and selective energy transfer from 2-pyridone to Tb 3+ ions. This has been utilized as the basis for a selective spectrofluorimetric detection of Tb3+. The association constant and the lifetime of the formed complex were determined; also, the sensing mechanism of the optosensor was proposed. The linear response range covers a concentration range of Tb3+ from 5.0 × 10-9 to 1.0 × 10-6 mol L-1. The LOD and LOQ were 2.9 × 10 -9 and 9.7 × 10-9 mol L-1, respectively. The sensitizer exhibits a unique and a highly selective energy transfer towards Tb3+ ions over a large number of interfering ions. Moreover, the proposed optosensor was easy to prepare, has a relatively fast response time ∼30 s and high stability for at least 42 days. The optosensor has been applied to the determination of terbium ion in synthetic samples with high sensitivity, good reproducibility and accuracy. © 2014 Elsevier B.V. Source

Hassan A.M.S.,Fayoum University
Phytochemical Analysis | Year: 2012

Introduction Bioautographic assays using TLC play an important role in the search for active compounds from plants. A TLC bioautographic assay has previously been established for the detection of acetylcholinesterase inhibitors but not for lipases. Objective Development of a TLC bioautographic method for detecting lipase inhibitors in plant extracts. Methodology After migration of the plant extracts, the TLC plate was sprayed with α-naphtyl acetate and enzyme solutions before incubation at 37°C for 20 min. Finally, the solution of Fast Blue B salt was sprayed onto the TLC plate giving a purple background colouration. Results Lipase inhibitors were visualised as white spots on the TLC plates. Orlistat (a known lipase inhibitor) inhibited lipase down to 0.01 μg. Methanolic extracts of Camellia sinensis (L.) kuntz and Rosmarinus officinalis L after migration on TLC gave enzymatic inhibition when applied in amounts of 82 and 56 μg, respectively. On the other hand the methanolic extract of Morus alba leaves did not exhibit any lipase inhibitory activity. Conclusion The screening test was able to detect lipase inhibition by pure reference substances and by compounds present in complex matrices, such as plant extracts. Copyright © 2011 John Wiley & Sons, Ltd. Source

A novel organo-mineral fertilizer [a 2:10:1 (w/w/w) mixture of calcium sulphate, ground rice bran and humic acid] was used as a soil amendment to study its effect on the growth, fruit yield, leaf nutrient status and antioxidant enzymes activities of tomato (Solanum lycopersicum L.) plants grown in reclaimed saline soil (EC=8.9dSm -1). The organo-mineral fertilizer-treated plants showed increased growth, proline, chlorophyll and nutrient contents. They also revealed increased fruit yield and quality, and increased activity of antioxidant enzymes when compared to the control plants. Therefore, the tested organo-mineral fertilizer may be recommended as a soil amendment for vegetables such as tomato to overcome the adverse effects of salinity stress in newly-reclaimed soils. © 2012 South African Association of Botanists. Source

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