Physical,optical and gamma radiation shielding competence of newly boro-tellurite based glasses: TeO2–B2O3–ZnO–Li2O3–Bi2O3

Herein, a traditional melt quenching method was utilized to synthesize glasses with a nominal chemical composition (80-x)TeO₂-xB₂O₃–5ZnO–5Li₂O₃–10Bi₂O₃: 30≤ x ≤ 80 mol%). The produced sample was coded as TBBZL30 to TBBZL80. X-ray diffraction (XRD) has been employed to test the amorphous nature of the synthesized samples. In the range of 200–500 nm wavelength, UV–Vis spectra for the glasses have been performed. Optical energy gaps ($E_{gap}$) have been determined based on the absorption measurements. With the help of ($E_{gap}$), refractive index (n), molar polarizability (α^M), metallization criterion (M^Cri.), molar refractivity (R^M), static dielectric constant (ε^Sta.), optical dielectric constant (ε^Opt.), reflection loss (R^L) and optical transmission (T^Opt.) have been calculated. For the fabricated boro-tellurite glasses, Phy-X/PSD was used to report some shielding factors for several energies between 15 keV and 15 MeV. The maximum attenuation for all samples took place at 15 keV and the mass attenuation coefficient varied between 52.309 and 57.084 cm²/g. The linear attenuation coefficient (LAC) results demonstrated that TBBZL80 has the highest attenuation than the rest of samples which is due to high content of TeO₂ (containing 80 mol% of TeO₂) whereas TBBZL30 has the lowest attenuation. The LAC for the fabricated samples varied between 230.160 and 351.064 cm-¹ at 15 keV. The minimum effective atomic number (EAN) occurred between 0.8 and 4 MeV and varied between 15.16 and 17.35 for TBBZL30 and 25.10–28.33 for TBBZL80. The addition of TeO₂ was found to enhance the EAN and improved shielding properties for the tested TBBZL glass systems.     

The syntactic analysis of arabic by machine

This paper describes a computerized system (PANVS) for the syntactic analysis of Arabic sentences. The system parses both nominal and verbal sentences. It is composed of several components including a lexical analyzer, a morphological analyzer, an automatic spelling error corrector and a parser. The parser is based on Definite Clause Grammar formalism. PANVS has been written in TURBO PROLOG using an IBM PS/2 model 60 microcomputer.Khalid J. Al Daimi (PhD, Cranfield Institute of Technology) was Director of the Computer Center, 1983–92 and is now associate professor of Computer Science at the University of Technology. His research interests include natural language understanding, expert systems and intelligent computer-aided instruction.Maha A. Abdel-Amir has an MSc from the University of Technology. From 1987 to 1990 she worked as a research assistant and is now assistant lecturer. Her main research interest is natural language understanding.     

Experimental study on shear resistance of reactive powder concrete beams without stirrups

Abstract

The tests results of 18 longitudinally reinforced reactive powder concrete (RPC) beams without stirrups and subjected to combined flexural and shear are presented in this paper. The main test variables were the ratio of the shear span-to-effective depth (a/d), the ratio of the longitudinal reinforcement (ρ_w), the percentage of steel fibers volume fractions (V_f) and the percentage of silica fume (SF) powder. The findings of this paper reveal that addition of steel fibers into the RPC mixture does not considerably affect the initial diagonal cracking load but it influences the ultimate load capacity. For all tested fibrous RPC beams, the ratio of the ultimate shear force to diagonal cracking force (V_u∕V_cr) have an average ratio of about 2.5. The shear design equations recommended by the (ACI 318-14) code, (CSA A23.3-04) code, (NZS 3101-06) code and (BS 8110-97) code have been modified to predict the ultimate shear strength of RPC beams without stirrups. The suggested equations gave satisfied predictions for the shear strength of the tested RPC beams with coefficients of variation (COV) ranging from 0.09049 to 0.1817.     

Fatty acid composition and biological activities of volatiles from fruits of two Tunisian olive cultivars

This study investigates volatile compounds, fatty acid composition and antioxidant, antibacterial and antifungal activities of fruits from two olive cultivars (Chemlali and Neb Jmel). Fatty acid profiles varied significantly between cultivars (cvs) where Neb Jmel seem to have higher contents of palmitic and oleic acids (16.4% and 66.4%, respectively) and lower of linoleic acid (9.4%). The volatile profile indicated the apparent difference between cvs. In fact, the main components detected in Chemlali cv. were (E,E)‐2,4‐decadienal (23.0%), (E,Z)‐2,4‐decadienal (14.9%) and nonanal (6.7%), while 3‐ethenylpyridine (15.5%), (E)‐2‐decenal (14.4%) and (E)‐2‐undecenal (7.0%) were the major components in Neb Jmel cv. Furthermore, these volatiles were subjected to screening for their possible antioxidant activities where volatiles from Neb Jmel fruits were found to be better. Results presented here may suggest that the volatiles fraction of two cultivars possess antimicrobial and antifungal activities.     

Synthesis,Docking and Biological Activities of Novel Hybrids Celecoxib and Anthraquinone Analogs as Potent Cytotoxic Agents

Herein, novel hybrid compounds of celecoxib and 2-aminoanthraquinone derivatives have been synthesized using condensation reactions of celecoxib with 2-aminoanthraquinone derivatives or 2-aminoanthraquinon with celecoxib derivatives. Celecoxib was reacted with different acid chlorides, 2-chloroethylisocyanate and bis (2-chloroethyl) amine hydrochloride. These intermediates were then reacted with 2-aminoanthraquinone. Also the same different acid chlorides and 2-chloroethylisocyanate were reacted with 2-aminoanthraquinone and the resulting intermediates were reacted with celecoxib to give isomers for the previous compounds. The antitumor activities against hepatic carcinoma tumor cell line (HEPG2) have been investigated in vitro, and all these compounds showed promising activities, especially compound 3c, 7, and 12. Flexible docking studies involving AutoDock 4.2 was investigated to identify the potential binding affinities and the mode of interaction of the hybrid compounds into two protein tyrosine kinases namely, SRC (Pp60v-src) and platelet-derived growth factor receptor, PDGFR (c-Kit). The compounds in this study have a preferential affinity for the c-Kit PDGFR PTK over the non-receptor tyrosine kinase SRC (Pp60v-src).     

Solidification/stabilization of Ni(II) by various cement pastes

The immobilization of Ni(II) in various cement matrices was investigated using the solidification/stabilization (S/S) technique. The different cement pastes used in this study were neat Portland cement in absence and presence of water reducing- and water repelling-admixtures as well as blended cement with kaolin. Two ratios of Ni(II) were used (0.5% and 1.0% by weight of the solid binder). The hydration characteristics of the used cement pastes were tested via the determination of the combined water content, phase composition and compressive strength at different time intervals from 1 up to 180 days. The results show that the presence of NiCl₂ caused retardation for the hydration of Portland cement paste in absence and presence of water-reducing agent. But NiCl₂ caused acceleration rather than retardation on the hydration of the mixes containing calcium stearate and/or clay. The degree of immobilization of the added heavy metal ions was very high in the different investigated cement pastes.     

Thermal death of bacterial pathogens in linguiça smoking

Linguiça, a smoked sausage originally from Portugal, is often made in small quantities in California, without inspection. Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serotype Newport, and Yersinia enterocolitica were added individually to batter representing California linguiça. Batter (≤1 mm thick), heated at 50, 55, and 60 °C, showed decimal reduction times ranging from >10 min for most trials at 50 °C to <2 min at 60 °C. Pork casings, stuffed with the batters to a diameter ≤3 cm, length 10 cm, and weight 75–80 g, were hot smoked; sausage centers were at ≥60 °C for ≥90 min. Contaminant levels in the batters (three experiments/pathogen) ranged from 2.3 × 10⁶ to 3.0 × 10¹⁰ CFU/g in various runs; reductions were ≥5 log₁₀ in all cases. These experiments indicate a reasonable margin of safety for products processed in this way.     

Performance evaluation of mobile ad hoc networks under flooding‐based attacks

A mobile ad hoc network (MANET) is an open wireless network that comprises a set of mobile, decentralized, and self‐organized nodes. Its properties render its environment susceptible to different types of attacks, which can paralyze the mobile nodes in MANET. A particularly dangerous type of attack is run primarily under flooding bogus packet mechanisms, such as hello floods, routing table overflows, exploitation of node penalizing schemes, and resource consumption attack (RCA). Flooding‐based attacks impose severe effects because they are intended to consume MANET resources, such as bandwidth, node memory, and battery power. Therefore, identifying such effects facilitates the development of countermeasures against the intrusions. In this paper, we introduce a simulation‐based study on the effects of RCA on MANET. Qual Net v5.0.2 is used to examine the severity of the effects on MANET performance metrics in terms of throughput, end‐to‐end delay, energy consumption, and routing overhead. The effects of RCA are also monitored under two combinations of four factors: we first vary the number of attackers and attackers' positions, and then modify the attackers' radio range and flooding rate. We also examine the effect of flooding mechanism on the energy consumed by resource consumption attackers. Copyright © 2013 John Wiley & Sons, Ltd.