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One of the most important uses of carbon nanotubes (CNTs) as a nanosensor for variouspolluted gases resulting from the burning of petroleum derivatives containing sulfur compoundsor extracted from the gases associated with petroleum, which are isolated by heat.In this investigation, we tested the adhesion of gas molecules connected with oil: we examinedthe adhesion of gas molecules connected with oil: sulfur dioxide (SO2) and hydrogen sulphide(H2S) on the surface of ((5,0) zigzag and length (100 nm)) CNTs using DFT calculations toexplore the high sensitivity to nanosensor for these molecules, which have gotten awesomeconsideration because of environmental and industrial considerations.From the results obtained in this study geometry optimization (structural properties) fornanosensor for useful assention with trial information. While the electronic properties includedcalculate total energy, HOMO energies, LUMO energies, ionization potential, electron affinity,potential electronic chemical, electronegativity, electrochemical hardness and electronic softness,also, the energy gap of the sensors under study has been calculated and the energy gap varies asstated by the type of gases to be detected. Moreover, we used orbital analysis counting the DOSto finding out the possible orbital hybridization between molecules and CNTs. From theseresults, we can say that the CNTs under study ((5,0) zigzag and the length (100 nm)) has a highsusceptibility to being an effective nanosensor for the gas molecules connected with the oil. Thistype of sensor(CNTs/SO2 or H2S) is standout amongst those a large portion essentialpersonalprotective equipment that is to warn the person of the presence of gases associated with oil,especially in areas of normal gas extraction.

Synthesize of Boron Nitride nanowires were made by utilizing Austenitic hardened steel AISI 316 with a nitriding layer of 15–16 μm thickness. Deposition experiments at deferent substrate temperatures for BN Nanowires productions were carried out with the help of a blended gas stage depositing handle procedure (PVD and CVD). Chemical composition and crystallinity along with the average grain size for BN phases was investigated by using XRD test and FTIR spectrum. The SEM images was used to examine the surface topography. Finally theoretical investigations computations were performed by thickness useful hypothesis (DFT) in Gaussian 09 bundle. According to our results, the impact of the depositing temperature on the chemical composition and the structure should be pointed out as the major effect for the higher deposition rate that leads to thicker and more dense BN surface film, where the more uniform BN Nanostructures wires with a regular diameter of 20 nm and average grain size of ~18nm was compelled through novel materializing crystalline stages causing grain size to rise with increasing deposition temperature to specific level.

Manganese-substituted cobalt nano-ferrites, Co(1−x)Mn(x)Fe2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized using chemical co-precipitation method. Physical properties of Co(1−x)Mn(x)Fe2O4 nano-ferrites were then characterized using thermal gravimetric—differential thermal analysis (TGA/DTA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrometer, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). TGA/DTA study indicates that the thermal stability of the prepared manganese doped cobalt ferrite nanoparticles. X-ray diffraction patterns of all the prepared ferrite samples show good in quality, pure nanosized, single-phased cubical spinel structures, with ferromagnetic behavior. We demonstrated that the expansion of lattice constant (a) and crystallite size (D) induced by manganese substituted of cobalt ferrites exerted remarkable effects on its structural and magnetic properties. The lattice constant (a) and crystallite size (D) increase with increasing manganese substituted cobalt ferrites. Williamson–Hall (W–H) method was used to evaluate the crystallite size and lattice strain of the Co(1−x) Mn(x)Fe2O4 nanoparticles samples by peak broadening. The calculated crystal size of Co(1−x) Mn(x)Fe2O4 nanoparticles on the W–H plots were highly intercorrelated with the HR-TEM and results of Scherrer Deby equation. The other physical parameters, such as X-ray density, hopping length, ionic radius, bond length, tetrahedral edge, octahedral edge, and unshared octahedral edge values were estimated from the highest intensity peak (311) of X-ray diffraction. The Fourier transform infrared (FT-IR) spectrometer of the Co–Mn ferrite nanoparticles systems were recorded in the frequency range of 200–1000 cm−1. FT-IR spectra show the two fundamental absorption bands of interstitial sub-lattice sites (M–O). The high absorption band (ν1) and the low absorption band (ν2) corresponds to the tetrahedral [A] and octahedral (B) sites, respectively, confirming the formation of single cubic spinel ferrite lattice system. The TEM results show that the ferrite nanoparticles have a nearly spherical shape with some agglomerations. From the analysis of VSM, the values of saturation magnetization (Ms) increases from 31.46 to 37.16 emu/g, then decreases with increasing Mn2+ ions substitution in the Co-ferrite system. The coercivity of the Mn2+ ions substituted cobalt ferrites increases up to x = 0.6 followed by a decrease. The optimized magnetic parameters suggest that the material with composition Co0.6Mn0.4Fe2O4 may be suitable for longitudinal magnetic recording media and other various technological applications.

The optical transmittance, electrical conductivity and morphology of PEDOT:PSS treated with ammonium hydroxide (NH4OH) have been investigated. Transmittance spectra of spun PEDOT:PSS layers were enhanced slightly as a result NH4OH treatment while surface of the films has exhibited variation in the roughness and an increase in the electrical conductivity. Improvement in the physical properties of PEDOT:PSS is shown to be the key factor in enhancing the power conversion effeciency (PCE) with values as high as 4% associated with high fill factor (FF) of 57%, open circuit voltage (VOC) of 0.64 V and larger short circuit current density (JSC) of 11 mA cm−2. Stabiltiy test of the devices has been carried out over a period of 2 months, when a device incorporating PEDOT:PSS with pH ~ 4 as the hole transport layer has shown an improved stability with a degredation in PCE in about 43% whereas JSC has decreased in about 20% compared to a device incorporating pristine PEDOT:PSS with PCE decreased in about 66% and JSC in about 50% over the stated period of test. These effects have been ascribed to the increased acidity of the hole transport layer.

In this research, new titanium metal complexes were designed and prepared for use in biophysical applications, because titanium is biocompatible (non-toxic and accepted by the body). New models of TiMC were designed and prepared by DFT/B3LYP method with SDD base sets and chemical vapor deposition technology, respectively. Structural, electronic transitions, and surface morphology properties were calculated by Gaussian 09 program package, XRD and SEM. The optimized structures for molecules under study have been found in great concurrence with empirical information. The results showed that these complexes have an electronic transition, UV-Vis spectrum, low band gaps, low chemical potential and are softer, can easily interact with enzymes because the enzymes are big soft molecules. The present study is aimed at investigating the effect of TiMC in Biophysics. Moreover, we used an orbital analysis, counting the 3-D electron density and electrostatic potential surfaces to find out the possible orbital hybridization for molecules, thus determining the biological effectiveness of the molecules under study.

In this research, synthetic rubber (polystyrene-butadiene) and natural rubber (polyisoprene) were dissolved in a common solvent (Toluene) to prepare polymeric solutions by using magnetic mixer at temperatures of 35-45°C. It was observed that the degree of solubility for natural rubber was greater than that one for synthetic rubber. There is an increase in the viscosity and torque for both rubbers along with increasing the synthetic and natural rubbers concentration. Laminar behavior is observed for both polymers since Reynolds number is less than 2300. Natural rubber is more suitable to use in pipes with crude oil

This paper presents a sight about the chemical structure deformation of poly (ethylene-co-vinyl acetate) (EVA) samples according to the change ratio of rate constant values. Spectroscopy kinetics fluorescence curves are fitted for two characteristic wavelength domains of fluorescent intensities. The short wavelengths (320-400 nm) domain show spectra overlapping, while at long wavelengths (400-800 nm) domain spectra are arranged in regular for each specific accelerated aging time. The ratio of kinetics rate constant at long wavelengths to kinetics rate constant of short wavelengths is the criterion of the degree chemical structure deformation. Molar extrinsic coefficient relies on the chemical structure change. Through absorbance measurement, EVA samples have been classified into two groups. Presence of Cyasorb additive is the key point of the ranking. The effect of three different accelerated aging of dry (115 oC), damp (85% moisture, 85 oC), and irradiated (UV, 65 oC) aging have been considered for two samples of each group over different aging time. Spectroscopy of absorbance and fluorescent for aged samples have been discussed. In general, Cyasorb adding causes higher chemical structure deformation for the EVA sample. The most effective factor is the damp aging and the less one is the UV irradiation aging, while the biggest chemical structure change of Cyasorb-free sample is produced by damp aging and the less by dry heat.

The present paper analyses and evaluates spoken discourse in the bilingual classroom at Damascus University. It looks at the mechanism of classroom interaction: the use of questions, initiations, repetitions and expansions. Although this paper deals with classroom interaction at Damascus University, it is believed that the results arrived at may be of a more general interest. Video- and audiorecordings of interaction in six EFL classrooms at the ESP Centre, Damascus University are examined in detail. The findings of this research show that classroom language is artificial; this can be exemplified by the teacher's simplified input, his use of display questions that restrict students' responses and his greater number of initiations. This type of discourse is usually described as ‘artificial’, ‘contrived’ and deliberately ‘planned’ for practising the language. It contrasts with other types of language produced in real communicative discourse described as ‘natural’ or ‘authentic’. Given this, EFL learners fin...

Many EFL learners find that they are unable to comprehend natural spoken English delivered at normal speed. The paper reports a study of listening problems encountered in the EFL classroom in the ESP Centre at Damascus University, as reported by the learners themselves. It looks in particular at learner strategies, features of the listening text, characteristics of the speaker, attitudes of the listener, the task to be completed as a result of understanding the text, and the degree of visual or written support for the aural input. The results of the study show that EFL learners experience a range of listening problems. To overcome them, various techniques which help learners to utilise effective strategies to confront problems of listening comprehension are discussed and the pedagogic implications are stated.