Effect of Hydrogen on Pristine Amorphous V2O5 Thin Film

Sequentially deposited layer by layer up to five vanadium oxide film is deposited on glass and silica substrates at 300 k by vacuum thermal evaporation technique. The deposited samples subjected to reduction process in the preparation situe by hydrogen gas at 473k for 10 minutes and 573 k for 10, 20 minutes. The XRD investigation of the samples demonstrates that the pristine sample is amorphous while those reduced are crystalline. The existed phases in virgin samples are educated by Raman spectroscopy which indicates the single V2O5 phase. The different phases in the reduced sample are identified by analyzing their XRD patterns. The electrical resistance of the reduced samples is measured as a function of temperature during heating and cooling cycles. The transition temperature from semiconducting to metal state is defined by the derivative of dR/d

A Packet Scheduling Scheme for Improving Real-time Applications Performance in Downlink LTE–advanced

Quality of Service based packet scheduling is a key-feature of LTE-A mandating selection and transmission of individual user packets based on their priority. HARQ Aware Scheduling, Retransmission Aware Proportional Fair, Chase Combining Based Max C/I Scheduling and Maximum- Largest Weighted First (M-LWDF) are popular Packet Scheduling Algorithms (PSAs) developed to meet QoS requirements. In highly erroneous LTE-A cannel, M-LWDF is considered to be one of best PSA. To validate the performance of M-LWDF for the LTE-A channel, Mean User Throughout, and Fairness performance measures were evaluated for 3 different PSAs designed based on M-LWDF algorithm in this paper. A C++ based simulation results indicate the superiority of the PSA3 algorithm within the threshold of the performance measures against benchmarks. It has shown more efficiency and the performance of RTA traffic was enhanced. Results show that PSA3 is superior to its benchmark PSA2 by 12% in Mean User Throughput and 11% in Fairness. PSA2 performed the worst because it prioritizes new users and it allocated all available RBs to the scheduled user leaving the rest to wait in the buffer. PSA3 maintians good Mean User Throughput and fairnessdue to scheduling each user on its RB which leads to multi-user diversity

Maximum-largest weighted delay first algorithm for heterogeneous traffic in 4G networks

Real time applications with strict QoS like delay sensitive applications require an advanced technology to adopt them. This is where Long Term Evolution-Advanced (LTE-A) fulfills this requirement. With this ever evolving technology the need for improvements is required. Packet scheduling is one of the important key features of LTE-A, where it dictates user selection and transmission of those user’s packets based on the priority of the users to reach the receiver correctly. Packet scheduling is one mean to achieve those QoS requirements that real-time applications require. Such algorithms are HARQ Aware Scheduling Algorithm (HAS), Retransmission Aware Proportional Fair Algorithm (RAPF), Chase Combining Based Max C/I Scheduling and Maximum- Largest WeightedDealy First algorithm (M-LWDF). In this paper, M-LWDF is one of the best algorithms in LTE-A which was chosen for further investigated to support QoS in high mobility environment. Packet Loss Ratio (PLR), and Mean User Throughput performance measures were used to validate the performance of M-LWDF algorithm against other algorithms using similar mobile environment. Simulation results indicate the capability of M-LWDF algorithm within the threshold of the performance measures against other benchmarks where it has demonstrated more efficiency to support and improve the performance of real-time multimedia traffic

Synthesis of carbon-supported PdIrNi catalysts and their performance towards ethanol electrooxidation

Direct ethanol fuel cells (DEFCs) have shown a high potential to supply energy and contribute to saving the climate due to their bioethanol sustainability and carbon neutrality. Nonetheless, there is a consistent need to develop new catalyst electrodes that are active for the ethanol oxidation reaction (EOR). In this work, two C-supported PdIrNi catalysts, that have been reported only once, are prepared via a facile NaBH4 co-reduction route. Their physiochemical characterization (X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS)) results show alloyed PdIrNi nanoparticles that are well dispersed (< 3 nm) and exist in metallic state that is air-stable apart from Ni and, slightly, Pd. Their electrocatalytic activity towards EOR was evaluated by means of cyclic voltammetry (CV) and chronoamperometry (CA). Even though the physiochemical characterization of PdIrNi/C and Pd4Ir2Ni1/C is promising, their EOR performance has proven them less active than their Pd/C counterpart. Although the oxidation current peak of Pd/C is 1.8 A/mgPd, it is only 0.48 A/mgPd for Pd4Ir2Ni1/C and 0.52 A/mgPd for PdIrNi/C. These results were obtained three times and are reproducible, but since they do not add up with the sound PdIrNi microstructure, more advanced and in situ EOR studies are necessary to better understand the poor EOR performance

Seismic Imaging of Mantle Transition Zone Discontinuities beneath the Northern Red Sea and Adjacent Areas

The dramatic asymmetry in terms of surface elevation, Cenozoic volcanisms and earthquake activity across the Red Sea is an enigmatic issue in global tectonics, partially due to the unavailability of broad-band seismic data on the African Plate adjacent to the Red Sea. Here, we report the first comprehensive image of the mantle transition zone (MTZ) discontinuities using data from the Egyptian National Seismic Network, and compare the resulting depths of the 410 and 660-km discontinuities with those observed on the Arabian side. Our results show that when a standard earth model is used for time-to-depth conversion, the resulting depth of the discontinuities increases systematically towards the axis of the Afro-Arabian Dome (AAD) from both the west and east. Relative to the westernmost area, the maximum depression of the 410-km discontinuity is about 30 km, and that of the 660-km discontinuity is about 45 km. The observed systematic variations can best be explained by a model involving a hydrated MTZ and an upper-mantle low-velocity zone beneath the AAD. Models invoking one or more mantle plumes originated from the MTZ or the lower-mantle beneath the study area are not consistent with the observations

Differential regulation of the Drosophila sleep homeostat by circadian and arousal inputs.

One output arm of the sleep homeostat in Drosophila appears to be a group of neurons with projections to the dorsal fan-shaped body (dFB neurons) of the central complex in the brain. However, neurons that regulate the sleep homeostat remain poorly understood. Using neurogenetic approaches combined with Ca2+ imaging, we characterized synaptic connections between dFB neurons and distinct sets of upstream sleep-regulatory neurons. One group of the sleep-promoting upstream neurons is a set of circadian pacemaker neurons that activates dFB neurons via direct glutaminergic excitatory synaptic connections. Opposing this population, a group of arousal-promoting neurons downregulates dFB axonal output with dopamine. Co-activating these two inputs leads to frequent shifts between sleep and wake states. We also show that dFB neurons release the neurotransmitter GABA and inhibit octopaminergic arousal neurons. We propose that dFB neurons integrate synaptic inputs from distinct sets of upstream sleep-promoting circadian clock neurons, and arousal neurons

Extraction, Refining and Characterization of the Fixed Oil of Basil (Ocimumbasilicum L.) Seeds

Basil is considered one of the important medicinal and aromatic plants in Sudan and worldwide. It is very rich sources of phytochemicals which have vital properties affecting human health in reduce risks and diseases. The present study aimed to evaluate the physicochemical characteristics of basil seeds and the oil extracted from them. This included four accessions of basil grown in National Oil Seed Processing Research Institute (NOPRI) farm- University of Gezira- Sudan: (two local accessions of NOPRI and Umteraibat, and two accessions (Egyptian and Maldivian) obtained from Institute for Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany. Themethods used the American Oil Chemists Society (AOCS) official methods. The percentage of moisture content (4-5), oil content (19-28%), crude protein (15-20%), crude fiber (30-36%)and ash (5-8%)for basil seeds. The physical properties of crude oil were specific gravity at room temperature (0.92-0.93) and refractive index (1.4809-1.4823) at 20°C. The Lovibond readings for crude oil color were in the range (0.6-2.5) for the red color and (18-70) for the yellow color, while for the refined oil the red color was (0.2-0.5) and yellow was (2.5-6.2). Chemical properties were: free fatty acids for crude oil (0.2-0.76%) and (0.04-0.06%) for refined oil; peroxide and saponification values and the unsaponifiable matter were (5.7-24.9) ml.eqv.\kg, (195-198) mg KOH/g and (1.6-2.2%) respectively. The fatty acid composition was analyzed using GC-MS, and the percentage of the unsaturated fatty acids oleic, linoleic and linolenic were (0.78-2.13), (22.91-40.39%)and (22.83-39.32%)respectively; the most abundant saturated fatty acids were palmitic and stearic at (14.7-16.67%) and (9.18-11.57%) respectively

Azimuthal Anisotropy beneath North Central Africa from Shear Wave Splitting Analyses

This study represents the first multistation investigation of azimuthal anisotropy beneath the interior of north central Africa, including Libya and adjacent regions, using shear wave splitting (SWS) analysis. Data used in the study include recently available broadband seismic data obtained from 15 stations managed by the Libyan Center for Remote Sensing and Space Science, and those from five other stations at which data are publicly accessible. A total of 583 pairs of high-quality SWS measurements utilizing the PKS, SKKS, and SKS phases demonstrate primarily N-S fast orientations with an average splitting delay time of approximately 1.2 s. An absence of periodic azimuthal variation of the observed splitting parameters indicates the presence of simple anisotropy, and lack of correlation between surficial features and the splitting parameters suggests that the origin of the observed anisotropy is primarily asthenospheric. This conclusion is enhanced by nonperiodic azimuthal variation of the splitting parameters observed at one of the stations located near the boundary of areas with different anisotropic properties. We interpret the observed anisotropy to be the consequence of northward movement of the African plate relative to the asthenosphere toward the Hellenic and Calabrian subduction zones. Local variance in fast orientations may be attributable to flow deflection by the northern edge of the African continental root. The observations provide critical and previously lacking constraints on mantle dynamic models in the vicinity of the convergent boundary between the African and Eurasian plates

Seismic Anisotropy and Mantle Flow beneath the Northern Great Plains of North America

A diverse set of tectonic features and the recent availability of high-quality broadband seismic data from the USArray and other stations on the northern Great Plains of North America provide a distinct opportunity to test different anisotropy-forming mechanisms. A total of 4138 pairs of well-defined splitting parameters observed at 445 stations show systematic spatial variations of anisotropic characteristics. Azimuthally invariant fast orientations subparallel to the absolute plate motion (APM) direction are observed at most of the stations on the Superior Craton and the southern Yavapai province, indicating that a single layer of anisotropy with a horizontal axis of symmetry is sufficient to explain the anisotropic structure. For areas with simple anisotropy, the application of a procedure for estimating the depth of anisotropy using spatial coherency of splitting parameters results in a depth of 200–250 km, suggesting that the observed anisotropy mostly resides in the upper asthenosphere. In the vicinity of the northern boundary of the Yavapai province and the Wyoming Craton, the splitting parameters can be adequately explained by a two-horizontal layer model. The lower layer has an APM-parallel fast orientation, and the upper layer has a fast orientation that is mostly consistent with the regional strike of the boundary. Based on the splitting measurements and previous results from seismic tomography and geodynamic modeling, we propose a model involving deflecting of asthenosphere flow by the bottom of the lithosphere and channeling of flow by a zone of thinned lithosphere approximately along the northern boundary of the Yavapai province