Feasibility Study on IPMC Actuated Contractile Water Jet Thruster Body Contraction

This research was conducted to investigate the feasibility of Ionic Polymer Metal Composite (IPMC) as the actuator for Contractile Water Jet Thruster (CWJT). The thrust that generated from the accelerated volume of ejected fluid depends on the IPMC actuator contraction performance. During this investigation, the variation of contraction frequency and nozzle aperture influence on the body deformation was carried out. The results of the experiments exhibit that the body contraction decreased tremendously from 0.05 Hz to 0.15 Hz. The body contraction has no apparent decrement for more than 0.15 Hz of contraction frequency. Besides, larger nozzle aperture has relatively more body contraction than smaller nozzle aperture. These results show that the fixed actuation force and the contraction frequency have a significant influence on the CWJT body contraction

Electronic and optical properties of Bi2Se3 topological insulator: a promising absorbing layer for broadband photodetector

Bismuth selenide (Bi2Se3) is a van der Waals compound which has been excellently reported as thermoelectric material. Linear dispersion near Fermi energy level is an exciting feature to consider, a promising candidate for photonic device within broadband wavelengths. For this application, detailed knowledge of its structural, electronic and optical properties is very essential. The electronic properties were determined by density functional theory (DFT) calculations implemented in Quantum-Espresso simulation package which uses plane wave basis and pseudopotential for the core electrons. Optical properties are computed by solving Bethe-Salpeter equation of many-body perturbation theory (MBPT) as implemented in Yambo code. The band structure results show the semiconducting behaviour of Bi2Se3. Taken into account the effects of electron-hole interaction by solving Bethe-Salpeter equation, the calculated optical properties are in better agreement with available experimental results. The exciton energy shows that the title material can absorb light within infrared region

Diffusion tensor imaging within the healthy cervical spinal cord: Within-participants reliability and measurement error

This is the final version. Available on open access from Elsevier via the DOI in this record Background Diffusion tensor imaging (DTI) is a promising technique for the visualization of the cervical spinal cord (CSC) in vivo. It provides information about the tissue structure of axonal white matter, and it is thought to be more sensitive than other MR imaging techniques for the evaluation of damage to tracts in the spinal cord. Aim The purpose of this study was to determine the within-participants reliability and error magnitude of measurements of DTI metrics in healthy human CSC. Methods A total of twenty healthy controls (10 male, mean age: 33.9 ± 3.5 years, 10 females, mean age: 47.5 ± 14.4 years), with no family history of any neurological disorders or a contraindication to MRI scanning were recruited over a period of two months. Each participant was scanned twice with an MRI 3 T scanner using standard DTI sequences. Spinal Cord Toolbox (SCT) software was used for image post-processing. Data were first corrected for motion artefact, then segmented, registered to a template, and then the DTI metrics were computed. The within-participants coefficients of variation (CV%), the single and average within-participants intraclass correlation coefficients (ICC) and Bland-Altman plots for WM, VC, DC and LC fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were determined for the cervical spinal cord (between the 2nd and 5th cervical vertebrae). Results DTI metrics showed poor to excellent within-participants reliability for both single and average ICC and moderate to high reproducibility for CV%, all variation dependent on the location of the ROI. The BA plots showed good within-participants agreement between the scan-rescan values. Conclusion Results from this reliability study demonstrate that clinical trials using the DTI technique are feasible and that DTI, in particular regions of the cord is suitable for use for the monitoring of degenerative WM changes.Najran University, Kingdom of Saudi Arabi

Synthesis and characterization of polyvinyl alcohol /polyaniline/functionalized multiwalled carbon nanotube compositeby gamma radiation method

The composite of functionalized multiwalled carbon nanotube (f-MWCNT), polyvinylalcohol (PVA) and polyaniline (PANI) were in-situ synthesized by gamma irradiation method. In order to make the free standing composite films, the mixture was cast onto a glass plate and dried before being exposed to irradiation. The formation and incorporation of PANI onto the surface of f-MWCNT were confirmed by field emission scanning electron microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and UV-Visible (UV-Vis) Spectrophotometer. It was found that in-situ polymerized PANI was coated onto the surface of f-MWCNT due to the increase of f-MWCNT diameter after irradiation and it is supported by the XRD spectra in which it shows that the intensity of main peak in PANI decreases upon irradiation. The increasing of absorption spectra intensity in the FTIR spectra indicates the polymerization of PANI is occurred. In addition, it was found that quinoid unit in composite film is richer as compared to unirradiated sample. This is supported by UV-Vis analysis that shows the benzenoid ring is excited in which the pi-pi* transition peak is shifted to the high wavenumber after irradiation. The calculated value for optical energy band gap decreases after irradiated at 50kGy by gammarays suggested that the resultant composite is more conductive as compared to unirradiated samples

Employees contentment in an organization

In an attempt to stay competitive in the ever growing challenging education world, higher institutions are often trying to develop creative and innovative ways in which to improve their organizations performance. One way to attain this is, by looking into their employees’ job contentment level. It is believed that job contentment level has a direct association with employees’ achievement and organizations success. Hence, by having a better understanding of their perceived job contentment level, an institution should be able to increase its work quality and productivity. This paper will present the findings of the study which aims to determine the main facet affecting employees’ job contentment level based on Job Satisfaction Index [1] such as pay, promotion, supervision, benefit, contingent reward, operating condition, co-workers, nature of work and communication. It is also aimed to determine whether gender could influence job contentment level in a higher learning institution

Characterization of Mixed xWO3(1-x)Y2O3 Nanoparticle Thick Film for Gas Sensing Application

Microstructural, topology, inner morphology, and gas-sensitivity of mixed xWO3(1-x)Y2O3 nanoparticles (x = 1, 0.95, 0.9, 0.85, 0.8) thick-film semiconductor gas sensors were studied. The surface topography and inner morphological properties of the mixed powder and sensing film were characterized with X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Also, gas sensitivity properties of the printed films were evaluated in the presence of methane (CH4) and butane (C4H10) at up to 500 °C operating temperature of the sensor. The results show that the doping agent can modify some structural properties and gas sensitivity of the mixed powder

Histopathological features of peripheral T-cell lymphoma in Sprague Dawley rats induced with N-methyl-N-nitrosourea

This study described the histopathological features of peripheral T-cell lymphoma in male Sprague Dawley rats following intraperitoneal (i.p.) injections of N-methyl-N-nitrosourea (MNU) at a dose of 60 mg/kg body weight per injection, administered twice weekly for 2 consecutive weeks, and followed by a five-month’s observation period. Control rats were injected with normal saline, i.p. All the rats treated with MNU had enlargement of lymph nodes, with 30% had hepatosplenomegaly and 7% had enlarged kidneys at necropsy. Malignant lymphoma was observed in the lymph nodes, spleen, liver, lung, heart, and kidneys. The neoplastic cells were characterised as undifferentiated, and small to large size with bizarre pleomorphic nuclei. The severity was further described as mild, moderate and severe, based on the diffuseness of the lesions. Nonetheless, similar lesions were not observed in the thymus of the rats. Immunohistochemistry staining of the organs was positive for CD3 antibody, which is consistent with T-cell lymphoma

Design and characterization of multiple coupled microring based wavelegnth demultiplexer in silicon-on-insulator (SOI)

We report in this paper, an optimized design and characterization of SOI based single mode, four channels wavelength demultiplexer using microrings. The usage of siliconon- insulator (SOI) allows a wide free spectral range (FSR) for the device that is crucial in developing ultra-compact integrations of planar lightwave circuits (PLCs). The characterizations are done using Finite-Difference Time-Domain (FDTD) mode simulations from RSOFT. Serially cascaded microring arrays up to the third order are presented to study the design trade-off among the FSR, Q-factor and optical losses of the laterally coupled wavelength demultiplexer. The demultiplexer is expected to be working at C-band region of Wavelength Division Multilplexing (WDM) for a wavelength around 1550 nm. Our proposed demultiplexer has low insertion loss (< 0.5 dB) and a crosstalk around 12 ∼ 19 dB

Detection of Bcl-2 gene in leukaemic rats using an EvaGreen real-time RT-PCT assay

Bcl-2 is an anti-apoptotic gene that is involved in the apoptosis process. Suppression of apoptosis by anti- apoptotic gene can contribute to the occurrence of diseases such as leukaemia. The objectives of this study were 2-folds: first, to compare the sensitivity of an EvaGreen quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) with a conventional RT-PCR for the amplification of the Bcl-2 gene; second, to determine the expression of the Bcl-2 gene in N-methyl-N-nitrosourea (MNU)-induced leukaemiain rats using the EvaGreen qRT-PCR assay. A total of 32 male Sprague Dawley rats were assigned into two groups (n=16), namely, control and MNU groups. In particular, MNU was administered intraperitoneally (i.p) at a dose of 60 mg/kg body weight per injection at two times per week for 2 consecutive weeks. The rats were sacrificed after five months and blood samples were collected for RNA extraction and haemogram. The RNAs were converted into cDNA and amplified using both the EvaGreen qPCR and the conventional PCR assays. All the results were normalised with a housekeeper gene, i.e. glyceraldehyde 3-phosphate dehydrogenase (GADPH). The products of amplification were run on gel electrophoresis and all the results were then compared. Based on the relative intensity of the bands, the EvaGreen qRT-PCR assay was highly sensitive compared to the conventional RT-PCR assay as the Bcl-2 gene could not be amplified using the conventional RT-PCR. Interestingly, the results in this study showed that the expression of Bcl-2 was higher in rats with marked lymphocytosis as compared to the leukaemic rats with normal to mildly increase in lymphocyte count. In conclusion, EvaGreen qRT-PCR assay is more sensitive compared to the conventional RT-PCR, and Bcl-2 gene is abundantly expressed in leukaemic rats with marked lymphocytosis compared to the leukaemic rats with normal to mildly increase in lymphocyte number

Electrical transport, microstructure and optical properties of Cr-doped In2O3 thin film prepared by sol–gel method

High transparent In2O3 and Cr-doped In2O3 (In2−xCrxO3) nanocrystalline thin films were prepared using a simple sol–gel method followed by a spin coating technique. The effect of Cr concentration on the structural, microstructure, electrical and optical properties of In2−xCrxO3 were systematically investigated using X-ray diffractometer (XRD), atomic force microscopy (AFM), UV–vis spectroscopy, field emission scanning electron microscopy (FESEM) and Hall effect technique. The films have good crystallization with preferred orientation to (2 2 2) direction. The lattice parameters, a, of In2O3 system increased at lowest dopants (x = 0.025) and decreased as the dopant was further increased. The optical transmittance of films increased up to 98% for x = 0.05 and decreased for further Cr concentrations. From AFM measurement the films nanocrystals morphology was depending on Cr concentrations. The band gap was around 3.76 eV for pure and with x ⩽ 0.075 however it increased. The effect of Cr concentrations on conducting mechanisms of In2O3 film has been investigated from 80 to 300 K using thermal activated conduction band and hopping models. The films, at x = 0.0–0.075, have typical semiconductor behaviour. Three different conducting mechanisms have been estimated. All thermal activation energies and conduction hopping parameters have been determined and analysed in details