Dual Sources Research Articles

Dual radio frequency plasma source: Understanding via electrical asymmetry effect

On the basis of the global model, the influences of driving voltage and frequency on electron heating in geometrically symmetrical dual capacitively coupled radio frequency plasma have been investigated. Consistent with the experimental and simulation results, non-monotonic behavior of dc self bias and plasma heating with increasing high frequency is observed. In addition to the local maxima of plasma parameters for the integer values of the ratio between the frequencies (ξ), ourstudies also predict local maxima for odd integer values of 2ξ as a consequence of the electrical asymmetry effect produced by dual frequency voltage sources.

Resources as dual sources of advantage: Implications for valuing entrepreneurial‐firm patents

Why and how do resources provide sources of competitive advantage? This study sheds new light on this central question of resource‐based theory by allowing a single resource—entrepreneurial‐firm patents—to play distinctive roles in different competitive arenas. As rights to exclude others, patents serve a well‐known role as legal safeguards in product markets. As quality signals, patents also could improve access and the terms of trade in factor input markets. Based on the financing activities of 370 venture‐backed semiconductor start‐ups, we provide new evidence that patents confer dual advantages in strategic factor markets, improved access and terms of trade, above and beyond their added product‐market protection. The study has important implications for empirical tests of resource‐based theory and the measurement of resource value. Copyright © 2013 John Wiley & Sons, Ltd.

Dual sources of support for dual roles: how mentoring and work–family culture influence work–family conflict and job attitudes

This study examines the influence of mentoring support and perceptions of a supportive work–family culture on the level of work–family conflict (WFC), job satisfaction and affective commitment reported by employees in a Fortune 100 professional services organization. Main effects and interaction effects between mentoring and work–family culture were explored. Results indicate that the presence of a mentor is significantly related to affective commitment while a supportive work–family culture was associated with less WFC – both family interference with work and work interference with family – and greater job satisfaction and affective commitment. For both job satisfaction and affective commitment, there is an interaction effect that suggests a synergy between direct and contextual support. Implications for practice and future research are discussed.

Production of Bacterial Cellulose from Gluconacetobacter persimmonis GH-2 using Dual and Cheaper Carbon Sources

Bacterial cellulose is an exopolysaccharide produced by various species of bacteria such as in the genera Gluconacetobacter, Agrobacterium, Achromobacter, Azotobacter, Rhizobium, Sarcina, Salmonella, Enterobacter, etc. In recent years, bacterial cellulose has been focused for the development of acoustic diaphragms, specialty membranes, biomedical wound care products, scaffold for tissue engineering, etc. In this study, effective culture method to produce bacterial cellulose from cheaper and dual carbon sources by Gluconacetobacter persimmonis was examined. Various fruit juices including pineapple, pomegranate, muskmelon, water melon, tomato, orange, and also molasses, starch hydrolyzate, sugarcane juice, coconut water, coconut milk were used as alternative carbon sources for bacterial cellulose production. Out of which muskmelon gave a highest cellulose yield of 8.08 g/L. Also glucose, fructose, sucrose, maltose, lactose, mannitol, inositol and glycerol were used in combination of two (1:1) as dual carbon sources. Out of these dual carbon sources, the combination of fructose and sucrose (1:1) gave the highest cellulose yield of 8.79 g/L. In this study, an attempt was made to reduce the cost of production medium for cellulose by using natural cheaper carbon sources.

Analysis of Dual Heat Sources in a Partially Open Enclosure

In this study a partially open enclosure with two heat sources is examined to determine the Nusselt number along the hot wall. The first part of the study examines the effect of the Rayleigh number ratio on the Nusselt number. The largest Rayleigh number ratio results in the highest magnitude of the Nusselt number. The second part of the study examines what happens to the Nusselt number along the hot wall as the Rayleigh number ratio for the two blocks is different. This situation can arise when the two blocks have unequal heat source values. The largest Nusselt numbers correspond to the situation when the block along the top wall has a Rayleigh number ratio that is ten times higher than the Rayleigh number ratio for the block along the hot wall. The largest Nusselt number magnitudes can be attributed to the strong vortex in the corner near the hot wall.

Numerical shaper optimization for sputtered optical precision f ilters

A novel optimization procedure for optical precision sputter coaters with respect to the film homogeneity is demonstrated. For a coater concept based on dual cylindrical sputtering sources and a rotating turn-table as sample-holder, the inherent radial decay of the film thickness must be compensated by shaper elements. For that purpose, a simulation model of the particle flux within such a coater is set up and validated against experimental data. Subsequently, the shaper design is optimized according to the modeled metal flux profile. The resulting film thickness deviations are minimized down to ±0.35%.

A Collaborative Reputation System for e-Learning Content

Reputation systems aggregate users' feedback after the completion of a transaction and compute the of products, services, or providers, which can assist other users in decision-making in the future. With the rapid growth of online e-Learning content providing services, a suitable reputation system for more credible e-Learning content delivery has become important and is essential if educational content providers are to remain competitive. Most existing reputation systems focus on generating ratings only for user reputation; they fail to consider the reputations of products or services(item reputation). However, it is essential for B2C e-Learning services to have a reliable reputation rating mechanism for items since they offer guidance for decision-making by presenting the ranks or ratings of e-Learning content items. To overcome this problem, we propose a novel collaborative filtering based reputation rating method. Collaborative filtering, one of the most successful recommendation methods, can be used to improve a reputation system. In this method, dual information sources are formed with groups of co-oriented users and expert users and to adapt it to the reputation rating mechanism. We have evaluated its performance experimentally by comparing various reputation systems.

Driving Saturn's magnetospheric periodicities from the upper atmosphere/ionosphere: Magnetotail response to dual sources

Despite the high degree of axial symmetry of Saturn's internal magnetic field, rotation‐associated periodicities are evident in Saturn's electromagnetic radiation, its magnetic perturbations and its particle populations. Although close to the mean rotation period of the cloud tops, the electromagnetic period drifts slightly over a time scale of years and, at high latitudes, differs for sources in the north and south. The source of the periodicity remains a mystery. The model investigated here places the momentum source in the upper atmosphere/ionosphere, with the wind patterns in the two hemispheres rotating about the spin axis at different rates typical of the 2005–2006 southern summer for which Cassini data have been extensively analyzed. A source at low altitudes would account for the persistence of phase following solar wind disruption of magnetospheric flow patterns but might not produce appropriate magnetospheric responses. However, a magnetohydrodynamic simulation in which vortical winds in the ionosphere drive field‐aligned currents into the magnetosphere shows that the dual sources account nearly quantitatively for many measured magnetospheric responses. This paper focuses on the magnetotail where the model is shown to reproduce many well‐documented results of data analysis including the features that appear distinctly at each of the two periods and those that appear as a carrier signal with amplitude modulation and phase shifts. In particular, the model accounts for current sheet flapping and modulation of the plasma sheet thickness and for the periodic structure of density enhancements at high latitudes at different periods in the north and the south.

The Unpredictable Nature of Internal Tides on Continental Shelves

Abstract Packets of nonlinear internal waves (NLIWs) in a small area of the Mid-Atlantic Bight were 10 times more energetic during a local neap tide than during the preceding spring tide. This counterintuitive result cannot be explained if the waves are generated near the shelf break by the local barotropic tide since changes in shelfbreak stratification explain only a small fraction of the variability in barotropic to baroclinic conversion. Instead, this study suggests that the occurrence of strong NLIWs was caused by the shoaling of distantly generated internal tides with amplitudes that are uncorrelated with the local spring-neap cycle. An extensive set of moored observations show that NLIWs are correlated with the internal tide but uncorrelated with barotropic tide. Using harmonic analysis of a 40-day record, this study associates steady-phase motions at the shelf break with waves generated by the local barotropic tide and variable-phase motions with the shoaling of distantly generated internal tides. The dual sources of internal tide energy (local or remote) mean that shelf internal tides and NLIWs will be predictable with a local model only if the locally generated internal tides are significantly stronger than shoaling internal tides. Since the depth-integrated internal tide energy in the open ocean can greatly exceed that on the shelf, it is likely that shoaling internal tides control the energetics on shelves that are directly exposed to the open ocean.

Exploring the Stiles–Crawford effect of the first kind with coherent light and dual Maxwellian sources

The visual impact of light obliquely incident on the retina is diminished due to the Stiles-Crawford effect of the first kind. It is normally analyzed by scanning a small Maxwellian source across the eye pupil while making subjective visibility comparisons to a static reference field that enters the eye near the pupil center. Here, we propose an alternative characterization method with two coherent Maxwellian point sources located at opposing sides of the pupil. This produces interference fringes at the retina with an underlying phase gradient. Altering the power ratio of the two point sources makes tuning of the wavefront inclination at the retina feasible. Thus, the Stiles-Crawford effect of the first kind can be examined without scanning the incident light across the pupil. In this paper, a spatial light modulator with holographic phase maps has been used to generate two Maxwellian point sources at the pupil that project a given phase variation onto the retina. We found that the effective obliqueness of light at the retina is determined by the weighted center-of-mass of the field amplitude at the pupil. Alternative techniques to generate the two secondary point sources may improve the accuracy of the method.

Applications of a remote sensing-based two-source energy balance algorithm for mapping surface fluxes without in situ air temperature observations

The two-source energy balance (TSEB) model uses remotely sensed maps of land–surface temperature (LST) along with local air temperature estimates at a nominal blending height to model heat and water fluxes across a landscape, partitioned between dual sources of canopy and soil. For operational implementation of TSEB, however, it is often difficult to obtain representative air temperature data that are compatible with the LST retrievals, which may themselves have residual errors due to atmospheric and emissivity corrections. To address this issue, two different strategies in applying the TSEB model without requiring local air temperature data were tested over a typical Mediterranean agricultural area using a set of high-resolution multispectral airborne remote sensing images. Alleviating the need for accurate local air temperature data as input, these two approaches estimate the surface-to-air temperature gradient that drives the sensible heat flux by directly exploiting the information available in the image. The two approaches include: 1) a scene-based internal calibration (TSEB-IC) procedure that estimates air temperature over a well-watered and fully vegetated pixel in the LST image, and 2) a disaggregation scheme (DisALEXI) that uses air temperature estimates from a time-differential coupled TSEB-atmospheric boundary layer model of atmosphere–land exchange (ALEXI). A comparison of the air temperatures modeled by TSEB-IC and DisALEXI with in situ weather station observations shows good agreement, with average differences on the order of 1K, comparable with the uncertainties in the remotely sensed surface temperature maps. Surface fluxes estimated by each method agree well with micro-meteorological measurements acquired over an olive orchard within the aircraft imaging domain. In comparison with fluxes generated with TSEB using local measurements of air temperature, instantaneous fluxes from these alternative methods show good spatial agreement, with differences of less than 10Wm−2 across the domain. Finally, a sensitivity analysis of the three models, performed by introducing artificial errors into the model inputs, demonstrates that the DisALEXI and TSEB-IC approaches are relatively insensitive to errors in absolute surface temperature calibration, while turbulent fluxes from TSEB applications using local air temperature measurements show sensitivity of approximately 30Wm−2 per degree temperature perturbation. This highlights the value of both internal calibration and time-differential estimation of the surface-to-air temperature gradient within a surface energy balance framework.

Acetylcholine Receptor Gating in a Zebrafish Model for Slow-Channel Syndrome

Slow-channel syndrome (SCS) is an autosomal-dominant disease resulting from mutations in muscle acetylcholine (ACh) receptor subunits. The associated fatigue and muscle degeneration are proposed to result from prolonged synaptic responses that overload intracellular calcium. Single-channel studies on reconstituted receptors bearing human mutations indicate that the prolonged responses result from an increase in receptor open duration and, in some cases, increased sensitivity to ACh. We show that both of these aberrant receptor properties are recapitulated in heterozygotic zebrafish bearing an L258P mutation in the α subunit, thus affording the unique opportunity to compare the single-channel properties of mutant receptors to the synaptic currents in vivo. Whole-cell recordings revealed synaptic currents that decayed along a multiexponential time course, reflecting receptors containing mixtures of wild-type and mutant α subunits. Treatment with quinidine, an open-channel blocker used to treat the human disorder, restored fast synaptic current kinetics and the ability to swim. Quinidine block also revealed that mutant receptors generate a large steady-state current in the absence of ACh. The spontaneous openings reflected a destabilization of the closed state, leading to an apparent increase in the sensitivity of these receptors to ACh. The effective block by quinidine on synaptic currents as well as nonliganded openings points to dual sources for the calcium-dependent myopathy in certain forms of SCS.

Performance analysis of air-water dual source heat pump water heater with heat recovery

A new air-water dual source heat pump water heater with heat recovery is proposed. The heat pump system can heat water by using a single air source, a single water source, or air-water dual sources. The water is first pre-heated by waste hot water, then heated by the heat pump. Waste heat is recovered by first preheating the cold water and as water source of the heat pump. According to the correlated formulas of the coefficient of performance of air-source heat pump and water-source heat pump, and the gain coefficient of heat recovery-preheater, the formulas for the coefficient of performance of heat pump in six operating modes are obtained by using the dimensionless correspondence analysis method. The system characteristics of heat absorption and release associated with the heat recovery-preheater are analyzed at different working conditions. The developed approaches can provide reference for the optimization of the operating modes and parameters. The results of analysis and experiments show that the coefficient of performance of the device can reach 4–5.5 in winter, twice as much as air source heat pump water heater. The utilization of waste heat in the proposed system is higher than that in the system which only uses waste water to preheating or as heat source. Thus, the effect of energy saving of the new system is obvious. On the other hand, the dimensionless correspondence analysis method is introduced to performance analysis of the heat pump, which also has theoretical significance and practical value.

TEMPERATURE UNIFORMITY ANALYSIS OF A MULTI-WELL VAPOR CHAMBER HEAT SPREADER

In this study, temperature uniformity and heating rate of heat spreader with multi-well are simulated and analyzed by CFD software under natural convection condition. Firstly, multi-well heat spreader made of aluminum, copper, silver and vapor chamber are simulated and compared, when dual and six heat sources are applied at a heating power of 1200W. Secondly, with six heat sources at heating power of 188, 300, 600 and 1200W, the heating rate of heat spreaders are studied. Vapor chamber heat spreader has the better temperature uniformity both in six sources and dual sources mode due to a higher thermal conductivity, followed by silver, copper and aluminum heat spreader. Aluminum and silver heat spreader show the higher heating rate, followed by copper heat spreader, vapor chamber heat spreader due to a larger heat capacity, heat up the slowest.

High-performance LiFePO4/C materials: Effect of carbon source on microstructure and performance

In this work, high-performance LiFePO4/C materials are successfully prepared by a spray drying-carbothermal method. The effect of the carbon source (viz. inorganic, organic and their hybrid) is extensively investigated on the microstructure and electrochemical property of the composite materials. Vulcan XC-72, an inorganic carbon additive, can remarkably improve the electronic conductivity of the composite material; however, the resultant large crystallite size and low specific surface area limit the Li ion diffusion and thereby lower the electrochemical performance. As a typical organic carbon additive, glucose yields mesoporous LiFePO4/C particles with a much higher specific surface area and smaller crystallite size; however, the electronic conductivity of the pyrolyzed carbon is insufficiently high for the real applications. By using the dual hybrid carbon sources, the synthesized LiFePO4/C material features a high electronic conductivity, large specific surface area, small grain size, and the formation of mesopores. In line with these advantages, the composite yields the best electrochemical performance with the discharge capacity of 168.1 mAh g−1 at 0.1 C, which is approximate to the theoretical capacity. This material also performs well at high rates with discharge capacities of 122.0 and 93.0 mAh g−1 at 5.0 and 10.0 C, respectively.

Evaluation of Newly Designed Polygeneration System with CO2 Recycle

A new coal-based polygeneration system with CO2 recycle is proposed in this paper. With the gasified coal gas containing 23 vol % CO2 and the coke oven gas containing 25 vol % CH4 as the dual gas sources, the system mainly produces methanol, dimethyl ether, and electric power. The system adopts CO2/CH4 reforming to modify the C/H ratio of the syngas. Particularly, the CO2, coming from the distillation tower, is recycled separately back to be a reactant during gasification and the resource gas in the reforming unit. As the CO2 concentration in the exhausted gas from the distillation tower is more than 95 wt %, this system does not require a CO2 separation unit. The system avoids the conventional water–gas shift reaction that is used to adjust the ratio of C/H in the syngas, but fully uses the CO2 produced from coal gasification, which solves the problems of CO2 capture and storage. The performance of the whole system’s energy, CO2 emission, and economics are analyzed by Aspen Plus 11.1 and Aspen Icarus 11....

Transformer-less three-port grid-connected power converter for distribution power generation system with dual renewable energy sources

This study proposes a novel transformer-less three-port grid-connected power converter for a distribution power generation system with dual renewable energy sources. The proposed three-port power converter is configured by a three-leg bridge converter, a common-mode circuit and a filter inductor set. The proposed three-port power converter has a high-voltage DC port, a low-voltage DC port and an AC port. The high-voltage and low-voltage DC ports are connected to the dual renewable energy sources, a solar cell array as well as a fuel cell, and the AC port is connected to the utility. The proposed three-port power converter uses the concept of the differential-mode and the common-mode paths of electromagnetic interference filter. Consequently, the three-port power converter is controlled to generate a set of differential-mode currents and a set of common-mode currents. As a result, the differential-mode currents and common-mode currents pass through the differential-mode current path and the common-mode current path to perform the power conversion between the dual renewable energy sources and the utility. A prototype is developed and tested to verify the performance of the proposed three-port power converter. The experimental results show that the proposed three-port power converter achieves the expected performance.

用于大面积薄膜沉积的线形等离子体源研究进展

本文系统介绍了几种线形等离子体源的特点及其应用，根据激励源的不同分别称为直流、射频、甚高频、微波、双频线形等离子体源，有磁场辅助的称为磁场增强线形等离子体源。与传统的大面积等离子体源不同，线形等离子体源仅需在一维方向实现均匀、稳定的等离子体，采用多个线形结构并排，或者与被镀样品在水平/垂直方向以适当速度运动，即可获得大面积均匀的薄膜沉积。近年来，研究人员采用磁场约束技术，减少带电粒子在器壁的复合损失，进一步提高等离子体的密度、均匀度和稳定性。线形等离子体及磁场增强线形等离子体密度 > 1011 cm−3，不均匀度 1 m)，被广泛用于Si3N4、SiO2、光伏电池硅本征层、纳米金刚石等薄膜的大面积沉积，具有很重要的应用价值和科学意义。 The characteristics and application of several kinds of linear plasma sources are introduced. According to the power sources for plasma systems, there are DC, RF, VHF, microwave and dual frequency linear plasma sources, which with a magnet system are called magnetic field enhanced linear plasma sources. Compared with the conventional large scale plasma sources, linear plasma sources take the advantage that they just need to obtain uniform and stable plasma in one dimension. Through the linear plasma array or moving the substrate in horizontal and vertical direction, large scale uniform thin film can be deposited. Recent years, researchers tried to use the magnetic field to confine plasma so as to reduce the recombination loss in plasma and improve the density, uniformity and stability of plasma. The linear plasma sources with the density above1011 cm−3, dis-uniformity below ±5% (L >1 m), have been applied to fabricate large scale Si3N4, SiO2, intrinsic Si and nano-diamond thin film.

GS36 FBG・屈折率センサを用いたFRP積層板の成形モニタリング

In the present study, we propose a system for monitoring cure process of FRP prepregs during hot-press molding using dual light sources, FBG sensors and refractive-index measurement. The optical system is composed of a 1310 nm narrow-band FP-LD light, a 1510nm broad-band SLD light, 1300/1500 WDM couplers, a spectrum recorder and an optical power meter. The FBG sensors have a distal end at which Fresnel's reflection between glass and resin occurs. The reflected 1310nm light form the distal end and the FBG reflection (about 1550nm) were divided into two individual paths by a WDM coupler. The power of 1310nm light was measured by an optical power meter and used for calculating refractive index of matrix resin. Spectra of the FBG light were recorded by a spectrum analyzer. In this study, GFRP prepregs were used for the experiments. From the results in the present paper, it was found that the monitoring system monitor both cure index and strain during molding quantitatively. In addition, it appeared that the system can be used for monitoring existence of air voids.

Regulation of Thalamic Development by Sonic Hedgehog

The thalamus is strategically positioned within the caudal diencephalic area of the forebrain, between the mesencephalon and telencephalon. This location is important for unique aspects of thalamic function, to process and relay sensory and motor information to and from the cerebral cortex. How the thalamus comes to reside within this region of the central nervous system has been the subject of much investigation. Extracellular signals secreted from key locations both extrinsic and intrinsic to the thalamic primordium have recently been identified and shown to play important roles in the growth, regionalization, and specification of thalamic progenitors. One factor in particular, the secreted morphogen Sonic hedgehog (Shh), has been implicated in spatiotemporal and threshold models of thalamic development that differ from other areas of the CNS due, in large part, to its expression within two signaling centers, the basal plate and the zona limitans intrathalamica, a dorsally projecting spike that separates the thalamus from the subthalamic region. Shh signaling from these dual sources exhibit unique and overlapping functions in the control of thalamic progenitor identity and nuclei specification. This review will highlight recent advances in our understanding of Shh function during thalamic development, revealing similarities, and differences that exist between species.