Electrical transport across Au/Nb:SrTiO3 Schottky interface with different Nb doping

We have investigated electron transport in Nb doped SrTiO$_3$ single crystals for two doping densities. We find that the resistivity and mobility are temperature dependent in both whereas the carrier concentration is almost temperature invariant. We rationalize this using the hydrogenic theory for shallow donors. Further, we probe electrical transport across Schottky interfaces of Au on TiO$_2$ terminated n-type SrTiO$_3$. Quantitative analysis of macroscopic I-V measurements reveal thermionic emission dominated transport for the low doped substrate whereas it deviates from such behavior for the high doped substrate. This work is relevant for designing devices to study electronic transport using oxide-semiconductors.Comment: 10 Pages, 3 Figure

Fluctuation relations for heat engines in time-periodic steady states

A fluctuation relation for heat engines (FRHE) has been derived recently. In the beginning, the system is in contact with the cooler bath. The system is then coupled to the hotter bath and external parameters are changed cyclically, eventually bringing the system back to its initial state, once the coupling with the hot bath is switched off. In this work, we lift the condition of initial thermal equilibrium and derive a new fluctuation relation for the central system (heat engine) being in a time-periodic steady state (TPSS). Carnot's inequality for classical thermodynamics follows as a direct consequence of this fluctuation theorem even in TPSS. For the special cases of the absence of hot bath and no extraction of work, we obtain the integral fluctuation theorem for total entropy and the generalized exchange fluctuation theorem, respectively. Recently microsized heat engines have been realized experimentally in the TPSS. We numerically simulate the same model and verify our proposed theorems.Comment: 9 page

The R-Process Alliance: A Comprehensive Abundance Analysis of HD 222925, a Metal-Poor Star with an Extreme R-Process Enhancement of [Eu/H] = -0.14

We present a detailed abundance analysis of the bright (V = 9.02), metal-poor ([Fe/H] = -1.47 +/- 0.08) field red horizontal-branch star HD 222925, which was observed as part of an ongoing survey by the R-Process Alliance. We calculate stellar parameters and derive abundances for 46 elements based on 901 lines examined in a high-resolution optical spectrum obtained using the Magellan Inamori Kyocera Echelle spectrograph. We detect 28 elements with 38 <= Z <= 90; their abundance pattern is a close match to the Solar r-process component. The distinguishing characteristic of HD 222925 is an extreme enhancement of r-process elements ([Eu/Fe] = +1.33 +/- 0.08, [Ba/Eu] = -0.78 +/- 0.10) in a moderately metal-poor star, so the abundance of r-process elements is the highest ([Eu/H] = -0.14 +/- 0.09) in any known r-process-enhanced star. The abundance ratios among lighter (Z <= 30) elements are typical for metal-poor stars, indicating that production of these elements was dominated by normal Type II supernovae, with no discernible contributions from Type Ia supernovae or asymptotic giant branch stars. The chemical and kinematic properties of HD 222925 suggest it formed in a low-mass dwarf galaxy, which was enriched by a high-yield r-process event before being disrupted by interaction with the Milky Way.Comment: Accepted for publication in the Astrophysical Journal (17 pages, 4 figures, 3 tables

Structured hydrological analysis for targeting fallow evaporation to improve water productivity at the irrigation system level

International audienceThis paper provides results of an application of a holistic systematic approach of water accounting using remote sensing and GIS coupled with ground water modeling to evaluate water saving options by tracking non-beneficial evaporation in the Liuyuankou Irrigation System (LIS) of China. Groundwater rise is a major issue in the LIS, where groundwater levels have risen alarmingly close to the ground surface (within 1 m) near the Yellow River. The lumped water balance analysis showed high fallow evaporation losses and which need to be reduced for improving water productivity. The seasonal actual evapotranspiration (ETs) was estimated by applying the SEBAL algorithm for eighteen NOAA AVHRR-12 images over the year of 1990?1991. This analysis was aided by the unsupervised land use classification applied to two Landsat 5 TM images of the study area. SEBAL results confirmed that a significant amount (116.7 MCM) of water can be saved by reducing ETs from fallow land which will result in improved water productivity at the irrigation system. The water accounting indicator (for the analysis period) shows that the process fraction per unit of depleted water (PFdepleted) is 0.52 for LIS, meaning that 52% of the depleted water is consumed by agricultural crops and 48% is lost through non-process depletion. Finally, the groundwater modeling was applied to simulate three land use and water management interventions to assess their effectiveness for both water savings and impact on the groundwater in LIS. MODFLOW's Zone Budget code calculates the groundwater budget of user-specified subregions, the exchange of flows between subregions and also calculates a volumetric water budget for the entire model at the end of each time step. The simulation results showed that fallow evaporation could be reduced between 14.2% (25.51 MCM) and 45.3% (81.36 MCM) by interventions such as canal lining and ground water pumping. The reduction in non-beneficial ETs volumes would mean that more water would be available for other uses and it would allow the introduction of more surface water supplies in the area through improved water management strategies. This will ultimately lead to improved water productivity of the LIS system

Plant Growth and Tuber Yield of Several Exotic Potato Genotypes

Potato stolon and tuber number are the most important determinants of yield and these traits are associated with planting time and genotype. This study was conducted to evaluate plant growth, tuber yield contributing traits and tuber yield of potato genotypes in two planting dates. The experiment was done in randomized complete block design with three replications. Results showed that plant growth and traits that contribute to tuber yield of potato were significantly influenced by planting dates and genotypes. Stolon and tuber number as well as tuber weight were periodically investigated. It was observed that the performance of those traits were always higher in 23rd November planting. Different genotypes performed differently on all the studied parameters. Among the genotypes tested, G1 (AC 10069) produced the highest number of stolons, tubers, tuber weight, length and yield of tuber as compared to the check variety. It was observed that 23rd November planted G1 (AC 10069) gave the highest tuber yield (17.79 t.ha-1) which was statistically similar with G3 (AC 10110) (17.00 t.ha-1) when compared to the check variety. It can be concluded that planting time as well as genotype are the critical factors that determine potato yield

Modification of Levenberg-Marquardt Algorithm for Solve Two Dimension Partial Differential Equation

في هذه الدراسة تم تطوير طريقة جديدة تقوم على الشبكة العصبية من أجل حل المعادلات التفاضلية الجزئية البعدين. استخدام الشبكة العصبية المعدلة لتجنب عيوب خوارزمية التدريب لﭭنبرك – ماركوادت. أولا نقترح SVD تحليل القيمة المنفردة إلى J &nbsp;و J-1 &nbsp;إذا كانت المصفوفة J(w) مستطيلة او منفردة . ثانيا نقترح حساب جديد إلى&nbsp; &nbsp;μ بحيث ان &nbsp;. نعتبر ان دالة الهدف الغير خطية&nbsp; E(w) تملك مجموعة غير خالية من الحلول&nbsp; W* &nbsp;ونشير أن ‖ ‖ هو من المعيار 2&nbsp; و E(w): &nbsp;هي مستمرة وقابلة للاشتقاق وتحقق شرط &nbsp;حيث ان L &nbsp;&nbsp;هو ثابت ليبشيتز.In this paper we presented a new way based on neural network has been developed for solutione of two dimension &nbsp;partial differential equations . A modified neural network use to over passing the Disadvantages of LM algorithm, in the beginning we suggest signaler value decompositions of Jacobin matrix (J) and inverse of Jacobin matrix( J-1), if a matrix rectangular or singular &nbsp;Secondly, we suggest new calculation of μk , that ismk=|| E (w)||2 &nbsp; &nbsp;look the nonlinear execution equations E(w) = 0 has not empty solution W* and we refer &nbsp; to the second norm in all cases ,whereE(w): &nbsp;is continuously differentiable and E(x) is Lipeschitz &nbsp;continuous, that is=|| E(w 2)- E(w 1)||£ L|| w&nbsp; 2- w&nbsp; 1|| ,where L&nbsp; is Lipeschitz &nbsp;constant

Geometric discord and Measurement-induced nonlocality for well known bound entangled states

We employ geometric discord and measurement induced nonlocality to quantify non classical correlations of some well-known bipartite bound entangled states, namely the two families of Horodecki's ($2\otimes 4$, $3\otimes 3$ and $4\otimes 4$ dimensional) bound entangled states and that of Bennett etal's in $3\otimes 3$ dimension. In most of the cases our results are analytic and both the measures attain relatively small value. The amount of quantumness in the $4\otimes 4$ bound entangled state of Benatti etal and the $2\otimes 8$ state having the same matrix representation (in computational basis) is same. Coincidently, the $2m\otimes 2m$ Werner and isotropic states also exhibit the same property, when seen as $2\otimes 2m^2$ dimensional states.Comment: V2: Title changed, one more state added; 11 pages (single column), 2 figures, accepted in Quantum Information Processin

Effect of different additives on the physical and chemical CO 2 absorption in polyetherimide hollow fiber membrane contactor system

Porous asymmetric polyetherimide (PEI) hollow fiber membranes were fabricated via a phase-inversion method using ethanol, glycerol and acetone as the additives in the spinning dope. Also, hollow fiber PEI membrane without additives was fabricated. An aqueous solution of 1-methyl-2-pyrrolidone (80 wt.%) was used as bore fluid to prevent forming of an inner dense skin layer. The precipitation rate of the polymer dopes with the different additives was studied using cloud point measurement. The effect of the additives on the resulting membrane structure, surface porosity, pore size, critical water entry pressure, collapsing pressure and physical and chemical CO2 absorption performance by distilled water and NaOH (1 M) solution in a gas–liquid membrane contactor system were investigated and compared. Cloud point diagrams indicated that the precipitation rate of the polymer dopes increased following the trend of ethanol > acetone > glycerol. Results of gas permeation tests showed that ethanol and glycerol as additives provided the membranes with the largest and smallest pore size, respectively. Moreover, all the additives resulted in an increase in the effective surface porosity. The cross-section of the membranes was examined via a scanning electron microscopy. Ethanol in the spinning dope provided the membrane structure with a sublayer with finger-like macrovoids, originating from the inner and outer surfaces of the hollow fiber and extending to the middle section of the hollow fiber wall, which resulted in a larger pore size and higher CO2 absorption rate than the other PEI hollow fiber membranes