2,825 research outputs found

    Multiple lump solutions and their interactions for an integrable nonlinear dispersionless PDE in vector fields

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    In this article, lump solutions, lump with I-kink, lump with II- kink, periodic, multiwaves, rogue waves and several other interactions such as lump interaction with II-kink, interaction between lump, lump with I-kink and periodic, interaction between lump, lump with II-kink and periodic are derived for Pavlov equation by using appropriate transformations. Additionally, we also present 3-dimensional, 2-dimensional and contour graphs for our solutions

    Green and facile synthesis of cerium doped Ni3Fe electrocatalyst for efficient oxygen evolution reaction

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    Electrochemical water splitting is the most promising pathway to produce high-purity hydrogen to alleviate global energy crisis. This reaction demands inexpensive, efficient and robust electrocatalyst for its commercial use. Herein, we demonstrate an effective, facile and scalable method for the synthesis of cerium doped Ni3Fe nanostructures as an electrocatalyst for oxygen evolution reaction (OER) by following simple chemical bath deposition route. The different molar ratios (3, 6 and 12 mM) of cerium in the chemical bath were used to study its effect on the structural and the electrochemical properties of the Ni3Fe nanostructured films. Doping of cerium contents induced variations in the morphology of deposited Ni3Fe nanostructures. The optimized electrocatalyst Ni3Fe/Ce-6 yielded high surface area catalyst nanosheets uniformly deposited on three-dimensional conductive scaffold to ensure increase in the exposure of doped Ni3Fe catalytic sites with high electrical conductivity. As a result, this earth-abundant electrocatalyst affords high OER performance with a small overpotential of 310 mV versus reversible hydrogen electrode (RHE) at 10 mA cm-2 and retains good stability up to ~ 10 h in alkaline electrolyte. This scalable strategy has great potential in future advancement of efficient and low-cost electrocatalysts for their large-scale application in energy conversion systems.                     KEY WORDS: Oxygen evolution, Electrocatalyst, Ni3Fe nanostructures, Cerium, Alkaline electrolyte   Bull. Chem. Soc. Ethiop. 2020, 34(2), 353-363 DOI: https://dx.doi.org/10.4314/bcse.v34i2.1

    Obstructive sleep apnea and psychomotor vigilance task performance

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    Background: Obstructive sleep apnea (OSA) is a highly prevalent disorder with considerable morbidity and mortality. Vigilance and attentiveness are often impaired in OSA patients. In occupational medicine settings, subjective reports of sleepiness are notoriously inaccurate, making the identification of objective measures of vigilance potentially important for risk assessments of fitness for duty. In order to evaluate the effects of OSA on attentiveness and vigilance, we conducted a cross-sectional study to examine the association between OSA and psychomotor vigilance task (PVT) performance. Methods: Patients attending sleep clinics for evaluation of possible sleep apnea were recruited. The subjects underwent either a standard overnight laboratory polysomnography or home sleep study. Subjective daytime sleepiness was assessed by Epworth sleepiness scale, and vigilance was tested using a portable device. The participants were asked to respond to the PVT signals using their dominant hand. Each PVT administration lasted 10 minutes, with stimuli signals appearing randomly at variable intervals of 2–10 seconds. Results: Mean age of the participants was 46±15 years, and mean body mass index was 34.3±9.8 kg/m2. Participants with higher Epworth scores had worse PVT performance (P<0.05). In multivariate analyses, age, body mass index, and poor sleep efficiency (measured by Pittsburgh sleep quality index score) were associated with worse PVT performance (P<0.05). In contrast, PVT performance did not differ significantly across categories of apnea hypopnea index severity. Subgroup analysis demonstrated that women had worse performance on all PVT measures (P<0.05). Conclusion: PVT performance can be utilized for risk assessments of sleepiness and may be particularly useful among populations where subjective reports are unreliable

    Managing the Quality of Chromium Sulphate during the Recycling From Tanning Waste Water

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    Quality management is a big issue during recovery and recycling process because if desired quality is not received during chromium recovery or recycling process, we may be faced another problem of recycled materials. This also seen that most important that the production processes is useless without taking specific required quality of chromium., in real way about 60%-70% of chromium salt is used as chemical interaction with the hides but 30%-40% of chemical chromium salt is wasted as the solid and liquid form. Therefore, the quality during the recovery process of the chromium sulphate from chromium wastewater that is most important step for controlling environmental pollution with some economical benefits. Recycling of chromium sulphate is possible by using chemical precipitation method for water treatment, two precipitating agents' magnesium oxide and calcium hydroxide plus alum are used for this purpose. Final findings showed that the optimum pH for efficient recovery with required quality was 8 and the Recycling of chromium sulphate was about 99(%) at pH 8 with good sludge with high settling rate. on the Base of these findings an economical production plant can be designed which are useful for quality improvement

    AXL modulates extracellular matrix protein expression and is essential for invasion and metastasis in endometrial cancer

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    The receptor tyrosine kinase AXL promotes migration, invasion, and metastasis. Here, we evaluated the role of AXL in endometrial cancer. High immunohistochemical expression of AXL was found in 76% (63/83) of advanced-stage, and 77% (82/107) of high-grade specimens and correlated with worse survival in uterine serous cancer patients. In vitro, genetic silencing of AXL inhibited migration and invasion but had no effect on proliferation of ARK1 endometrial cancer cells. AXL-deficient cells showed significantly decreased expression of phospho-AKT as well as uPA, MMP-1, MMP-2, MMP-3, and MMP-9. In a xenograft model of human uterine serous carcinoma with AXL-deficient ARK1 cells, there was significantly less tumor burden than xenografts with control ARK1 cells. Together, these findings underscore the therapeutic potentials of AXL as a candidate target for treatment of metastatic endometrial cancer

    Systematic literature review of prediction techniques to identify work skillset

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    A mismatch of skillsets is a main cause to the unemployment in Malaysia. It is a situation where the level and work skillset that are available do not match the market demands and the individual does not know how to identify the skills that they have. To deal with this problem, prediction techniques is used to assist in identifying work-appropriate skills for individual. Thus, a systematic literature review (SLR) on predicting work skillsets using prediction techniques is proposed. The aim of this study is to give an overview on the prediction techniques that have been used to predict work skillset and the accuracy of the techniques. We use SLR to identify 383 prediction techniques studies for identifying skills published from 2014 to 2019. As a result, 9 studies report adequate information and methodology according to our criteria and apply. From the studies, classification techniques are used for predicting work skillset. The algorithms used is Random Forest with precision is 99%. From this study, a future study will be conducted by developing a prediction model to help identifying appropriate work skillsets to meet current needs and identifying the levels of skills they have. The significant of this study is the researchers are able to understand deeply about the prediction techniques used to identify work skillset and the accuracy of the techniques used

    Longitudinal decrease in blood oxygenation level dependent response in cerebral amyloid angiopathy

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    AbstractLower blood oxygenation level dependent (BOLD) signal changes in response to a visual stimulus in functional magnetic resonance imaging (fMRI) have been observed in cross-sectional studies of cerebral amyloid angiopathy (CAA), and are presumed to reflect impaired vascular reactivity. We used fMRI to detect a longitudinal change in BOLD responses to a visual stimulus in CAA, and to determine any correlations between these changes and other established biomarkers of CAA progression. Data were acquired from 22 patients diagnosed with probable CAA (using the Boston Criteria) and 16 healthy controls at baseline and one year. BOLD data were generated from the 200 most active voxels of the primary visual cortex during the fMRI visual stimulus (passively viewing an alternating checkerboard pattern). In general, BOLD amplitudes were lower at one year compared to baseline in patients with CAA (p=0.01) but were unchanged in controls (p=0.18). The longitudinal difference in BOLD amplitudes was significantly lower in CAA compared to controls (p<0.001). White matter hyperintensity (WMH) volumes and number of cerebral microbleeds, both presumed to reflect CAA-mediated vascular injury, increased over time in CAA (p=0.007 and p=0.001, respectively). Longitudinal increases in WMH (rs=0.04, p=0.86) or cerebral microbleeds (rs=−0.18, p=0.45) were not associated with the longitudinal decrease in BOLD amplitudes

    On Supergravity Solutions of Branes in Melvin Universes

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    We study supergravity solutions of type II branes wrapping a Melvin universe. These solutions provide the gravity description of non-commutative field theories with non-constant non-commutative parameter. Typically these theories are non-supersymmetric, though they exhibit some feature of their corresponding supersymmetric theories. An interesting feature of these non-commutative theories is that there is a critical length in the theory in which for distances larger than this length the effects of non-commutativity become important and for smaller distances these effects are negligible. Therefore we would expect to see this kind of non-commutativity in large distances which might be relevant in cosmology. We also study M5-brane wrapping on 11-dimensional Melvin universe and its descendant theories upon compactifying on a circle.Comment: 25 pages, latex file; v2: typos corrected, Refs. adde
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