Dynamics of Impurity and Valence Bands in GaMnAs within the Dynamical Mean Field Approximation

We calculate the density-of-states and the spectral function of GaMnAs within the dynamical mean-field approximation. Our model includes the competing effects of the strong spin-orbit coupling on the J=3/2 GaAs hole bands and the exchange interaction between the magnetic ions and the itinerant holes. We study the quasi-particle and impurity bands in the paramagnetic and ferromagnetic phases for different values of impurity-hole coupling at the Mn doping of x=0.05. By analyzing the anisotropic angular distribution of the impurity band carriers at T=0, we conclude that the carrier polarization is optimal when the carriers move along the direction parallel to the average magnetization.Comment: 6 pages, 4 figure

Attenuation of serum laminin concentrations upon treatment of chronic hepatitis

Objectives: The aim of this work was to determine the serum laminin level cutoff point for predicting liver fibrosis highlighting its diagnostic value and determining the effect of treatment on serum laminin concentrations. Methods: Serum laminin concentrations in chronic hepatitis patients (n=62) and controls (n=20) were compared by ELISA and stages of fibrosis were assessed according to the modified Knodell score system. Results: Mean serum laminin concentration in patients (91.9 ± 20.9 ng/ml) was greater than controls (46.2 ± 10.2 ng/ml; p <0.001). Serum concentrations of laminin in all stages of hepatic fibrosis were significantly higher than those of healthy controls (p <0.05). A cutoff point of 52ng laminin/ml of serum was obtained for the discrimination of various stages of liver fibrosis showing a good sensitivity (96.8%) and specificity (80%). After 6 months of treatment, a gradual decrease in serum laminin concentrations were observed, however the level was still higher than that of the healthy group (p<0.05). Conclusions: Our findings suggest that the serum laminin concentration is a useful noninvasive marker of liver fibrosis and shows a strong positive correlation with different stages of the disease

Comparative chemical analysis of volatile compounds of Warionia saharea leaves using hydrodistillation and headspace solid-phase microextraction (HS-SPME)

The objective of this study is to report the comparative chemical analysis of essential oil (EO) obtained by hydrodistillation (HD) and volatile fraction (VF) detected by headspace solid-phase micro-extraction (HS–SPME) isolated from Warionia saharea leaves using Gas Chromatography–Retention Indices (GC-RI) and GC–Mass Spectrometry (GC-MS). 39 volatile compounds identified in hydrodistilled essential oil (HD), representing 92.7% of the total oil, while HS-SPME revealed 25 components constituting 94.1% of the volatile material. The chemical composition of the HS-SPME and HD extract comprised mainly of phenylpropanoids (36.9%) and oxygenated sesquiterpenes (52.8%), respectively. The comparative analysis of two chemoprofiles obtained by two methods shows both qualitative as well as quantitative differences. The current study is the first report involving rapid analysis of volatile components of W. saharea by HS-SPME

Exploiting unknown dynamics in communications amongst coexisting wireless body area networks

© 2015 IEEE. In this paper, we propose a prediction algorithm for dynamic channel allocation amongst coexisting Wireless body area networks (WBANs). Variations in channel assignment due to mobility scenarios within each WBAN as well as the movement of WBANs towards each other is investigated. The proposed scheme is further optimized to allocate the optimum transmission time with synchronous and parallel transmissions such that interference is fully avoided. This reduces the number of interfering nodes and leads to better usage of the scarce limitation of resources in these networks, larger network lifetime, higher energy savings and higher throughput. In fact, the aim of this protocol is to mitigate interference along with maintaining minimum power consumption in order to maximize network lifetime and increase the spatial reuse and throughput of each WBAN. Simulation results show that our approach achieves a much higher spatial reuse using the smart spectrum allocation scheme for interference mitigation in collocated WBANs. We conduct extensive simulations for coexistence prediction in different mobility scenarios using the NS-2 simulator. Consequently, we demonstrate the efficiency of the proposed protocol in providing interference-free channel assignments and higher energy savings

Ammodaucus Leucotrichus Cosson & Durieu fruits essential oil as corrosion inhibitor of tinplate in 0.5M oxalic acid medium and its thermodynamic properties

The anticorrosion proprieties of Ammodaucus leucotrichus Cosson & Durieu essential oil (ALEO) against the corrosion of tinplate in 0.5M oxalic acid medium was studied in the interest to improve the corrosion resistance of cans in interaction with food contains. For this, the gravimetric test, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used. The different corrosion test used show that the ALEO has an anticorrosion effect with an inhibition efficiency of 83.83% at 4g.L-1, this can be pertained to the chemical composition of the studied essential oil. The essential oil behavior at rang temperature (303-373K) show that ALEO exhibits good inhibition even at moderate to high temperatures. The estimation of the corrosion activation parameters reveal that the essential oil shows good inhibitor characteristics with a physisorption mechanism. By using the scanning electron microscopy and energy dispersive X-rays (SEM-EDX), it is clear that the surface is remarkably improved in the presence of ALEO compared with that exposed to the acid medium without essential oil

Deriving optimal operational policies for off-stream man-made reservoir considering conjunctive use of surface- and groundwater at the Bar dam reservoir (Iran)

Study region: The off-stream artificial Bar lake, built in 2015 to store the flood flows of the Bar river for domestic and industrial needs and with the objective to intentionally recharge the aquifer, is situated in the Razavi Khorasan province (Iran). Study focus: We present a methodology, based on the combination of a MODFLOW groundwater flow model for estimating seepage rates, and an optimization model, for the management and operation of an artificial reservoir considering surface/groundwater interactions for satisfying 12 Mm3/year of water demand. We simulated the reliable amount of water that can be supplied from the reservoir, considering reservoir seepage, maximizing water supply yields subject to the water supply reliability requirements, and the additional intentional volume of groundwater recharge. New hydrological insights for the region: Our results demonstrate the reliability of conjunctive use of surface-and ground-water in water scarce areas by exploiting reservoir infrastructures with relevant leakage losses, also for creating additional aquifer storage. In such systems, man-induced changes of lake stages can significantly affect the volume of water that seeps through the lakebed. The aquifer, under managed aquifer recharge operations, may then provide the resource not satisfied by the reservoir release, fulfilling 100 % reliability of water supply. The conjunctive use of surface- and ground-water, by improving water security, may open new sustainability views for leaking reservoirs, even if they were not initially designed for increasing aquifer recharge, in many areas worldwide

Synthesis and Evaluation Antibacterial Activity of Some New Substituted 5-Bromoisatin Containing Five, Six Heterocyclic Ring

This research includes the synthesis of some new different heterocyclic derivatives of 5-Bromoisatin. New sulfonylamide, diazine, oxazole, thiazole and 1,2,3-triazole derivatives of 5-Bromoisatin have been synthesized. The synthesis process started by the reaction of 5-Bromoisatin with different reagents to obtain schiff bases of 5-Bromoisatin intermediate compounds(1, 8, 19) by using glacial acetic acid as a catalyst in three routes. The first route, 5-Bromoisatin reacted with p-aminosulfonylchloride to product compound(1), then converted to sulfonyl amide derivatives(2-7) by the reaction of compound(1) with different substituted primary aromatic amine in absolute ethanol. The second route includes the reaction of 5-Bromoisatin reacted with ethyl glycinate to give 5-bromo-3-(Ethyl imino acetate)-2-oxo indole(8), which undergo react with hydrazine hydrate 80% to obtain hydrazine derivatives(9) that react with different acid anhydrides to obtain diazine derivatives(10-14). Also compound(8) reacts with urea and thiourea to give compounds(15,16) which undergo cyclization with p-bromophenacylbromide in absolute ethanol as a solvent to obtain oxazole (17) and thiazole (18), respectively. The third route included the reaction of 5-Bromoisatin with p-phenylenediamine in ethanol to obtain compound(19) which is converted to new substitutes 1,2,3-triazole derivatives(22,23) by diazotation of compound(19) and treating the resulted salt(20) with sodium azid, then acetylaceton or ethylacetoacetate, respectively. Newly synthesized compounds were identified by spectral methods. (FTIR, 1H-NMR, 13C-NMR) and measurements of some of its physical properties and also some specific reactions. Furthermore the effects of the synthesized compounds were studied on some strains of bacteria

Antifungal activity of Asteriscus graveolens (Forssk.) Less essential oil against Fusarium oxysporum f. sp. albedinis, the causal agent of “Bayoud” disease on date palm

Date palm (Phoenix dactylifera L.) is an important food source and commercial perennial crop in the Sahara and North Africa. “Bayoud”, a vascular wilt disease, incited by the soilborne fungal pathogen Fusarium oxysporum f. sp. albedinis (FOA), has become a serious threat to date production in date palm-growing regions in Morocco. Substantial body of research reported antifungal properties of a wide range of plant extracts. The present work aims to determine chemical composition and anti-FOA activity of Asteriscus graveolens (Forssk.) Less (AG) essential oil. GC/GC-MS analysis revealed the presence of forty-two distinct chemical components in the essential oil samples. The main compounds of the studied essential oils were 6-Oxocyclonerolidol (7.7–73.8%), cis-8-acetoxychrysanthenylacetate (0.6–50.1%) cis-chrysantenyl acetate (0.3–15.4%), 6-hydroxycyclonerolidol (2–13.3%), τ-cadinol (0.4–12.2%) and α-oxobisabolene (0.2–5.5%). Mycelial growth and spore germination of FOA were found to be strongly inhibited by the oil when tested using agar dilution assay. The lowest essential oil (EO) concentration that inhibits 100% of mycelial growth was 3500 ppm for leaves and 4000 ppm for aerial parts EO. These findings contribute significant insight into the potential of using plant extracts for controlling “Bayoud” disease

Anticorrosion properties of Thymus munbyanus Boiss & Reut

  The analysis of essential oil of Thymus munbyanus Boiss & Reut (TM oil) by GC and led to the identification of 32 components accounting for (97.8%) of the total oils were identified. The main compounds of essential oils of Thymus munbyanus were carvacrol (31.7%), g-terpinene (21.9%), p-cymene (14.7%), thymol (7.6%), linalool (4.3%), borneol (3.9%) and α-terpinene (2.1%). The inhibitive effect of TM oil on the corrosion of mild steel in 1M HCl solution has been investigated by weight loss measurement as well as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The corrosion rate calculated by polarization potentiodynamic curves obtained after 30min from immersion in 1M HCl medium. The gravimetric results indicate that TM oil exhibited good inhibition efficiency in 1M HCl solution. The polarization measurements showed that the studied inhibitor is a mixed type with a significant reduction of cathodic and anodic current densities. Electrochemical impedance spectroscopy measurements revealed that the charge transfer resistance increased by increasing the essential oil concentration, which suggests Langmuir isotherm model as a most suitable adsorption mechanism.