Timing and X-ray Spectral Features of Swift J1626.6-5156

In this paper, we extend timing analysis of Baykal et al. (2010) of \src using RXTE-PCA observations between MJD 53724 and MJD 55113 together with a Chandra-ACIS observation on MJD 54897 with a 20 ks exposure. We also present X-ray spectral analysis of these RXTE and Chandra observations. We find that the spin-up rate of the source is correlated with the X-ray flux. Using this correlation, we estimate the distance and surface magnetic field of the source as $\sim 15$kpc and $\sim 9\times 10^{11}$Gauss respectively. From the spectral analysis, we found that power law index increases and Hydrogen column density decreases with decreasing flux.Comment: Revised version; 12 pages, 4 figures, accepted for publication in MNRA

Structural stability studies of graphene in sintered ceramic nanocomposites

The post-sintering structural stability of graphene in alumina nanocomposites synthesised by Spark Plasma Sintering (SPS) and Hot Pressing (HP) was compared. Raman spectroscopy, thermogravimetric analyses and electrical conductivity analyses were conducted to characterise degradation of graphene due to the utilisation of different sintering techniques and conditions. Scanning Electron Microscopy confirmed good dispersion of graphene in SPSed and HPed sample. Graphene in SPSed and HPed nanocomposite samples sintered using longer durations (60 min) were found to possess higher crystallinity, thermal stability and electrical conductivity as compared to SPSed samples sintered using shorter sintering durations (10–20 min). This was attributed to the thermally induced graphitisation caused by longer sintering durations, which was lacking in SPSed samples processed using shorter sintering durations and lower temperature. No additional effect of DC pulsed current on the structural stability of graphene for nanocomposites were observed for samples prepared by SPS

A Case of an Anomalous Right Coronary Artery Arising from the Left Coronary Cusp

An anomalous origin of the right coronary artery is usually asymptomatic. It is mostly found incidentally on an invasive diagnostic angiogram. It does lead to an increased risk of sudden cardiac death, especially in younger patients. We present a case of a 41-year-old who had presented to the hospital with complaints of chest pain. The patient was evaluated by cardiology who performed an angiography that identified an anomalous origin of the right coronary artery arising from the left coronary cusp but no evidence of coronary artery disease. Once identified, these anomalous vessels should be corrected surgically, as these conditions increase the risk of sudden cardiac death arrhythmia and ischemic events

Pulse Profiles of Swift J1626.6+5156

In this paper, we analyzed pulse profiles of Swift J1626.6+5156 using the lightcurves from RXTE-PCA observations between MJD 53724 (just after the outburst) and MJD 55113 and a Chandra-ACIS dataset on MJD 54897 with a 20 ks exposure. We found that pulse profiles show morphological variations and pulsations do not cease even $\sim 1200$ days after the outburst. Despite these variations, we did not find any significant variation in the pulsed fraction with decreasing X-ray flux.Comment: 4 pages, 2 figures, Conference proceeding of "Astrophysics of Neutron Stars 2010 -- a conference in honor of M. Ali Alpar", 2-6 August 2010, Cesme, Izmir, Turke

A semi-quantitative scattering theory of amorphous materials

It is argued that topological disorder in amorphous solids can be described by local strains related to local reference crystals and local rotations. An intuitive localization criterion is formulated from this point of view. The Inverse Participation Ratio and the location of mobility edges in band tails is directly related to the character of the disorder potential in amorphous solid, the coordination number, the transition integral and the nodes of wave functions of the corresponding reference crystal. The dependence of the decay rate of band tails on temperature and static disorder are derived. \textit{Ab initio} simulations on a-Si and experiments on a-Si:H are compared to these predictions.Comment: 4 pages, 2 figures, will be submitted to Phys. Rev. Let

Polycarbonate polymer surface modication by extreme ultraviolet (EUV) radiation

The degree of the biocompatibility of polycarbonate (PC) polymer used as biomaterial can be controlled by surface modification for various biomedical engineering applications. In the past, PC samples were treated by excimer laser for surface reorganization however associated process alteration of bulk properties is reported. Extreme ultraviolet radiation can be employed in order to avoid bulk material alteration due to its limited penetration. In this study, a 10 Hz laser-plasma EUV source based on a double-stream gas-pu_ target irradiated with a 3 ns and 0.8 J Nd:YAG laser pulse was used to irradiate PC samples. The PC samples were irradiated with different number of EUV shots. Pristine and EUV treated samples were investigated by scanning electron microscopy and atomic force microscopy for detailed morphological characterization of micropatterns introduced by the EUV irradiation. Associated chemical modifications were investigated by X-ray photoelectron spectroscopy. Pronounced wall-type micro- and nanostructures appeared on the EUV modified surface resulting in a change of surface roughness and wettability

Determinants of E-Learning Implementation Success In The Iraqi MoHE

The aim of this paper is to investigate the determinants of implementation success of the E-Learning in the Iraqi Ministry of Higher Education (IMoHE) and put a work plan to make the E-Learning widely implemented in the IMoHE. The Technology-Organization- Environment (TOE) framework and the E-Learning literature were used to analyze the factors which may influence this implementation and adoption. A questionnaire which consists of twenty nine questions divided into three parts: Technological factors (Information Systems (IS) infrastructure and IS expertise), Organizational factors (organizational compatibility and organizational benefits), and Environmental factors (competitive pressure and educational partner readiness) were written. The implementation success is characterized by two dimensions Internal Integration and External Diffusion. This questionnaire data gathered from 120 faculty members in the IMoHE were employed to test the relationships between the research models constructs using a structural equation modeling (SEM) approach. The results reveal that IS expertise, and Expected Benefits are key determinants of E-Learning implementation success in terms of Internal Integration and External Diffusion

Core functionalization of semi-crystalline polymeric cylindrical nanoparticles using photo-initiated thiol–ene radical reactions

Sequential ring-opening and reversible addition–fragmentation chain transfer (RAFT) polymerization was used to form a triblock copolymer of tetrahydropyran acrylate (THPA), 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) and L-lactide. Concurrent deprotection of the THPA block and crystallization-driven self-assembly (CDSA) was undertaken and allowed for the formation of cylindrical micelles bearing allyl handles in a short outer core segment. These handles were further functionalized by different thiols using photo-initiated thiol–ene radical reactions to demonstrate that the incorporation of an amorphous PMAC block within the core does not disrupt CDSA and can be used to load the cylindrical nanoparticles with cargo