Low Frequency VLA Observations of Abell 754: Evidence for a Cluster Radio Halo and Possible Radio Relics

We present 74 MHz and 330 MHz VLA observations of Abell 754. Diffuse, halo-like emission is detected from the center of the cluster at both frequencies. At 330 MHz the resolution of 90'' distinguishes this extended emission from previously known point sources. In addition to the halo and at a much lower level, outlying steep-spectrum emission regions straddle the cluster center and are seen only at 74 MHz. The location, morphology and spectrum of this emission are all highly suggestive of at least one, and possibly two cluster radio relics. Easily obtained higher resolution, higher sensitivity VLA observations at both frequencies are required to confirm the extended nature of the halo-like emission and the 74 MHz relic detections. However, since there is prior evidence that this cluster is or has recently been in the process of a major merger event, the possible discovery of relics in this system is of great interest in light of recent observational and theoretical evidence in favor of a merger-relic connection. We discuss the possible role the merger shock waves, which are seen in the X-ray emission, may have played in the formation of the halo and radio relics in A754.Comment: 15 pages including 4 figures. Accepted for publication by Ap

Language-in-education policy and planning : the case of Lebanon

Recent changes in Lebanon's educational legislation indicate a shift away from using the national language, Arabic, as a medium of instruction in favour of other foreign languages, namely English, French, and German. The latest decree that was passed in 1994 stipulated that these foreign languages can be used as instructional languages in all cycles, including the pre-school and elementary levels. The issue of language-in-education in Lebanon is an old one, dating back to the arrival of foreign missionaries during the second half of the 17th century. Since then several policies and decisions have been made by the colonial powers and the successive Lebanese governments. This paper reviews these policies and decisions in the light of the country's political history with special emphasis on their impact on students and communities at the socioeconomic, educational and political levels. The paper maintains that the policies made by the French during their mandate over Lebanon (1920-1943) favoured the Christian Catholic and Maronite communities. Meanwhile, the policies adopted by the successive Lebanese governments in the era of independence (1943-1975) were largely improvised and more of responses to emotions triggered by independence. Consequently, several socio-economic and educational incentives determined the spread of foreign languages, especially English, in contemporary Lebanon. This widened the gaps among the classes that make up Lebanese society and contributed to the distribution of quality education along sectarian and socioeconomic lines.peer-reviewe

Synthesis and Optical Characterization of Nd3+ Doped TeO2-PbO-Li2O

Glass based on Nd3+-doped TeO2-PbO-Li2O has successfully been made by melt quenching technique and their thermal parameters have been determined using Differential Thermal Analyzer (DTA). The glass is then nucleated and/or growth by controlled heat treatment at slightly below the crystallization temperature. The X-ray diffraction (XRD) technique is used to estimate the nano-crystallite size. Meanwhile, the optical characterization has been determined using the Photoluminescence Spectroscopy. It is found out that the crystallite size is about 20 nm and very much depending on the heat-treatment time. Meanwhile, the intensity of the luminescence spectra is very much depending on the concentration of the dopant.

Regular Solution Theory Model Used To Predict Supercritical CO2 Extraction Of p-chlorophenol Contaminate From Water Stream.

The objective of this paper is the assessments of the feasibility of the extraction process utilizing a near critical carbon dioxide solvent with p-chlorophenol contaminate solute, which would be speeded up if it were possible to predict mutual solubility data

The New Political Economy of EU State Aid Policy

Despite its importance and singularity, the EU’s state aid policy has attracted less scholarly attention than other elements of EU competition policy. Introducing the themes addressed by the special issue, this article briefly reviews the development of EU policy and highlights why the control of state aid matters. The Commission’s response to the current economic crisis notably in banking and the car industry is a key concern, but the interests of the special issue go far beyond. They include: the role of the European Commission in the development of EU policy, the politics of state aid, and a clash between models of capitalism. The special issue also examines the impact of EU policy. It investigates how EU state aid decisions affect not only industrial policy at the national level (and therefore at the EU level), but the welfare state and territorial relations within federal member states, the external implications of EU action and the strategies pursued by the Commission to limit any potential disadvantage to European firms, and the conflict between the EU’s expanding legal order and national

Temperature effects on the strengh properties of microbially stabilized residual soil

Microbially Induced Calcite Precipitation (MICP) is a rather new technology that has shown greater potential in geotechnical engineering applications. The technique utilizes the concept of microbial involvements in carbonate precipitation within the soil matrix that lead to the improvement in strength and stiffness of the soil. This paper evaluated the effects of temperature variations on the performance of microbial calcite precipitations in residual soil. The soil specimens were cured under different temperature conditions; that are atmospheric temperature, 40, 45 and 50° C. Shear strength, pH and amount of calcite precipitated were determined for each curing condition. A bacterial concentration of 1×105 cfu/ml and 0.5 M concentration of the cementation reagents were used for the study. The results indicated a general increase in strength with increase in curing temperature; which is an indication of temperature influence in bacterial activity. The results so far obtained also revealed that the higher the amount of calcite precipitated the more the strength improvement up to 48 hours treatment duration; after which increase in calcite content does not results in the increase in strength

Synthesized and extending the Bidentate Schiff base complexes using multilayer feedforward neural network

Complexes of Pd(II) and Ni(II) have been synthesized with general composition ML2X2 (M =Pd(II), Ni(II); L = benzylsalicylideneimine and X = OCH3, F). All synthesized compoundshave been characterized using elemental analysis, magnetic susceptibility measurements,infrared and NMR spectral studies that led to the conclusion that the ligands act as bidentatemanner to form square planar geometry for all complexes. As an extending work, the modeldevelopment of these complexes using multilayer feedforward neural network wereperformed. NiL1d, PdL1d, NiL1c and PdL1c were fed to the training network as inputs andbacteria as output. Levenberg Marquardt training algorithm was used during the networktraining with 10 nodes in hidden layer. The results of testing network showed that theregression, R is 1, indicating that the developed model is good. This is supported by the small mean square error (MSE) is 1.948x10-28 at epochs 5. The finding in this study is significant, thus contributed to the design of antibacterial agent especially to the bidentate Schiff base complexes.Keywords: Schiff base, palladium(II), nickel(II), antibacterial, regression, neural network

Holographic Screening Length in a Hot Plasma of Two Sphere

We study the screening length of a quark-antiquark pair moving in a hot plasma living in two sphere $S^2$ manifold using AdS/CFT correspondence where the background metric is four dimensional Schwarzschild-AdS black hole. The geodesic solution of the string ends at the boundary is given by a stationary motion in the equatorial plane as such the separation length $L$ of quark-antiquark pair is parallel to the angular velocity $\omega$. The screening length and the bound energy are computed numerically using Mathematica. We find that the plots are bounded from below by some functions related to the momentum transfer $P_c$ of the drag force configuration. We compare the result by computing the screening length in the quark-antiquark reference frame where the gravity dual are "Boost-AdS" and Kerr-AdS black holes. Finding relations of the parameters of both black holes, we argue that the relation between mass parameters $M_{Sch}$ of the Schwarzschild-AdS black hole and $M_{Kerr}$ of the Kerr-AdS black hole in high temperature is given by $M_{Kerr}=M_{Sch}(1-a^2l^2)^{3/2}$, where $a$ is the angular momentum parameter.Comment: Major revision: title changed, adding authors, 13 pages, 8 figures, etc. Accepted for publication in European Physical Journal