bluuebunny/crossref_metadata_2025_split huggingface dataset:
The efficacy of protective effects of tannic acid, gallic acid, ellagic acid, and propyl gallate against hydrogen peroxide‐induced oxidative stress and DNA damages in IMR‐90 cells
Authors: Chen Ching‐Hsein , Liu Tsan‐Zon , Chen Chin‐Hui , Wong Chung Hang , Chen Chi‐Hung , Lu Fung‐Jou , Chen Ssu Ching 
Published: July 2007

AbstractThere is increasing evidence that reactive oxygen species (ROS) are intimately involved in the oxidative damage of tissues for a wide variety of pulmonary diseases. Thus, it is desirable to search for chemopreventive agents that can counteract ROS‐mediated injury to the pulmonary tissues. Using a human lung fibroblast IMR‐90 cells as the experimental model, we first demonstrated that nearly 90% of intracellular ROS could be removed when H2O2‐treated cells (200 μM) simultaneously incubated with 10 μg/mL of tannic acid (TA), gallic acid (GA), ellagic acid (EA), and propyl gallate (PA). Using C11‐BODIPY581/591 as a lipid peroxidation probe, we also attested that all these compounds examined (10 μg/mL) could alleviate H2O2‐evoked lipid peroxidation phenomena. Next, we examined the protective effects of these compounds on the depletion of intracellular glutathione (iGSH) in H2O2‐treated cells using CMF‐DA probe. Interestingly, PA was demonstrated to be the only compound that could effectively protect the integrity of iGSH from being depleted by this system. Finally, the protective effects of these compounds against oxidative DNA damage were evaluated using 8‐oxoguanine formation as a marker. Our data indicated that all four compounds suppressed the formation of 8‐oxoguanine effectively. Taken together, our data suggested that TA, GA, EA, and PA can protect cells from oxidative stress.
Comparison of the relative recovery of polyphenolics in two fruit extracts from a model of degradation during digestion and metabolism
Authors: Stevenson David E. , Cooney Janine M. , Jensen Dwayne J. , Zhang Jingli , Wibisono Reginald 
Published: July 2007

AbstractTo simulate the effects of digestion and metabolism on the survival of different polyphenolic compounds, extracts of blueberry and apple were deglycosylated by acid hydrolysis, followed by enzymic glucuronidation under neutral conditions, yielding ∼︁5% overall recovery of polyphenolics. The major polyphenolics before and after the treatment were compared, to estimate which species are likely to be present in the intestinal lumen, undegraded and available for absorption, after consumption of the fruit. Whereas blueberry extract consisted predominantly of anthocyanins, epicatechin and caffeoyl quinate esters, the major components of the treated extract were quercetin glucuronides and (unglucuronidated) caffeoyl quinates, with only traces of anthocyanidin derivatives. In apple extract, compositional changes were less marked, but caffeoyl quinates, procyanidins and quercetin were enriched at the expense of caffeic acid, epicatechin and catechin. Hydrophobic compounds like phloretin and quercetin were extensively glucuronidated, whereas caffeic acid and caffeoyl quinate were not. These results suggest that the major polyphenolic components of a fruit are not necessarily the most important contributors to any health benefits because the polyphenolic composition in the intestinal lumen and consequently, in the circulation, may be considerably different.
Biphasic modulation of cell proliferation by sulforaphane at physiologically relevant exposure times in a human colon cancer cell line
Authors: Pappa Gerlinde , Bartsch Helmut , Gerhäuser Clarissa 
Published: July 2007

AbstractSulforaphane (SFN), a cancer chemopreventive compound derived from broccoli, is able to induce cell cycle arrest and apoptosis in various tumor cell lines. Here we show that cell growth inhibition by SFN follows a biphasic pattern: Transient exposure of 40‐16 human colon carcinoma cells for up to 6 h resulted in reversible G2/M cell cycle arrest and cytostatic growth inhibition even at elevated concentrations, whereas a minimum continuous exposure time of 12 h was necessary for SFN to irreversibly arrest cells in G2/M phase and subsequently induce apoptosis. IC50 values after 12 h of exposure followed by drug‐free recovery up to 72 h (6.4–8.1 μM) were indistinguishable from those of chronic exposure for 24 to 72 h (5.4–6.6 μM). Low concentrations of SFN caused a transient decrease in glutathione (GSH) levels followed by GSH induction, which may be related to reversible G2/M arrest and cytostatic effects. Depletion of GSH does not seem to play a role in SFN‐mediated apoptosis induction. Our data clearly contribute to a better understanding of the kinetics of antiproliferative activity of SFN.
Multijoint reflexes of the stroke arm: Neural coupling of the elbow and shoulder
Authors: Sangani Samir G. , Starsky Andrew J. , Mcguire John R. , Schmit Brian D. 
Published: July 2007

AbstractThe reflex torque responses of the elbow and shoulder to constant velocity angular extensions of the full comfortable range of the spastic elbow were measured in 16 people with unilateral stroke and 6 neurologically intact controls in order to identify the interjoint reflex coupling that occurs after stroke. The resulting responses showed a substantial reflex torque at the elbow and shoulder in subjects with stroke, with 12 of the 16 subjects producing adduction of the shoulder in response to passive extension of the elbow. The presence of simultaneous shoulder flexion torque with elbow flexion torque and with an identical waveform indicated an active role of biarticular elbow/shoulder flexors, such as the biceps. As the biceps muscle produces a shoulder abduction moment, shoulder adduction produced during elbow extension was thought to be associated with neural rather than biomechanical coupling. These results suggest that spasticity in people with stroke is more complex than its traditional perception as a hyperexcitable stretch reflex, and includes potent heteronymous reflex pathways. The reflex coupling observed between the shoulder and elbow should be considered in the diagnosis and clinical management of spasticity. The potential impact of this reflex on the coordination of volitional arm movements will be examined in future studies. Muscle Nerve, 2007
APPN—An Introduction
Authors: Nilausen Jesper 
Published: July 2007

AbstractThis first article in a series on managing APPN Networks briefly introduces a relatively new networking architecture.Both traditional hierarchical SNA Networks and modern distributed Client/Server environments highly benefit from utilizing APPN functionality in their network configurations. APPN actually grew up in an environment which combines these two worlds: The IBM midrange computer environment based on AS/400 machines.APPN is part of IBM SNA (Systems Network Architecture) and many abbreviations in this series of articles actually are commonly used SNA terms.
Development of a new heterojunction structure (ACJ ‐HIT) and its application to polycrystalline silicon solar cells
Authors: Tanaka Makoto , Taguchi Mikio , Takahama Tsuysohi , Sawada Toru , Kuroda Shigeru , Matsuyama Takao , Tsuda Shinya , Takeoka Akio , Nakano Shoichi , Hanafusa Hiroshi , Kuwano Yukinori 
Published: July 2007

AbstractA new solar cell structure named HIT (Heterojunction with Intrinsic Thin layer) has been developed based on new artificially constructed junction (ACJ) technology. In this structure a non‐doped a‐Si thin layer was inserted between the p(a‐Si)/n(c‐Si) heterojunction, improving the output characteristics and achieving a conversion efficiency of 18.1%. This structure was applied to cast polycrystalline silicon solar cells of a practical size. A high conversion efficeincy of 13.6% was obtained with a cell size of 10 cm × 10 cm using various technologies, including hydrogen plasma passivation.
Parameter estimation and screening of solar cells
Authors: Appelbaum J. , Chait A. , Thompson D. 
Published: July 2007

AbstractThe aggregation (sorting) of the individual solar cells into an array is commonly based on a single operating point on the current‐voltage (I‐V) characteristic curve. an alternative approach for cell performance prediction and cell screening is provided by modelling the cell using an equivalent electrical circuit, in which the parameters involved are related to the physical phenomena in the device. These analytical models may be represented by a double exponential I‐V characteristic with seven parameters, by a double exponential model with five parameters or by a single exponential equation with four or five parameters. In this article we address issues concerning methodologies for the determination of solar cell parameters based on measured data points of the I‐V characteristic, and introduce a procedure for screening solar cells for arrays. We show that common curve‐fitting techniques, e.g. least‐squares, may produce many combinations of parameter values while maintaining a good fit between the fitted and measured I‐V characteristics of the cell. Therefore, techniques relying on curve‐fitting criteria alone cannot be used directly for cell parameterization. We propose a consistent procedure that takes into account the entire set of parameter values for a batch of cells. This procedure is based on a definition of a mean cell representing the batch, and takes into account the relative contribution of each parameter to the overall goodness of fit. the procedure is demonstrated on a batch of 50 silicon cells for Space Station Freedom.
Measuring the costs of photovoltaics in an electric utility planning framework
Authors: Awerbuch Shimon 
Published: July 2007

AbstractUtility planning models evaluate alternative generating options using the revenue requirements method—an engineering‐oriented, discounted cash‐flow (DCF) methodology that has been widely used for over three decades. Discounted cash‐flow techniques were conceived in the context of active expense‐intensive technologies, such as conventional, fuel‐intensive power generation. Photovoltaic (PV) technology, by contrast, is passive and capital intensive—attributes that are similar to those of other new process technolgies, such as computer‐integrated manufacturing. Discounted cash‐flow techniques have a dismal record for correctly valuing new technologies with these attributes, in part because their benefits cannot be easily measured using tradiational accounting concepts.This paper examines how these issues affect cost measurement in both conventional and PV‐based electricity, and presents kWh‐cost estimates for three technologies (coal, gas and PV) using risk‐adjusted approaches, which suggest that PV costs are generally equivalent to the gas/combined cycle and about twice the cost of base‐load coal (environmental externalities are ignored). Finally, the paper evaluates independent power purchases for a typical US utility and finds that in such a setting the cost of PV‐based power is comparable to the firm's published avoided costs.
Emitter design for high‐efficiency silicon solar cells. Part 2: Space cells
Authors: Wang Aihua , Zhao Jianhua , Green M. A. 
Published: July 2007

AbstractOver the last decade there have been substantial improvements in the performance of silicon solar cells. This second part of a two‐part paper examines the implications for use in space. High‐efficiency cells, including cells of above 20% Air Mass 0 efficiency were exposed to 1 MeV of electron irradiation. Although the relative performance loss was higher, the cells gave higher performance than conventional silicon space cells even after 5 × 1015cm−21‐MeV electron radiation damage. However, spectral response measurement shows that the rapid degradation mainly came from damage on the emitter surface. This can be accommodated simply by shallow emitter designs. the efficiency of an optimized silicon space cell is expected to be over 14% after 1 × 1015cm−21 MeV electron radiation.
A general battery model for PV system simulation
Authors: Copetti J. B. , Lorenzo E. , Chenlo F. 
Published: July 2007

AbstractA battery model is proposed as a tool to simulate and optimize photovoltaic (PV) / storage systems. the normalized form of the equations with respect to the battery capacity allows us to generalize its use for any type and size of lead‐acid batteries.The validity of this model to represent the battery voltage evolution during charge, overcharge and discharge processes and to predict the performance of solar systems under different operational conditions is analysed. Moreover, the battery efficiency losses are presented as a function of the upper regulation thresholds of the charge controllers and the size of the array and storage systems in a domestic application in the climate of Madrid.
Solar cell efficiency tables (version 3)
Authors: Green Martin A. , Emery Keith 
Published: July 2007

AbstractTabulations of confirmed efficiencies for a range of photovoltaic cell and module technologies are updated to include recent results (since mid‐1993). Also described are the results of two informal ‘round‐robin’ comparisons of cell and module measurements from a representative sampling of the designated test centres participating in the compilation of these tables.
Fault detection in a photovoltaic plant by time domain reflectometry
Authors: Schirone L. , Califano F. P. , Pastena M. 
Published: July 2007

AbstractA reflectometric technique has been developed for diagnostic monitoring of a photovoltaic plant. Detailed information on the position and type of fault is inferred from the shape of the voltage waveforms resulting when a pulsed voltage excitation is applied to a string consisting of several series‐connected modules. When an open circuit or a short circuit to ground are occurring, direct reading of the results is obtained by means of a software tool performing numerical analysis of the digitized waveforms. Extensions of this approach to the case of parallel‐connected strings, as well as to the cases of a loaded plant and no illumination, are discussed.
Towards high‐eficiency silicon solar cells by rapid thermal processing
Authors: Hartiti B. , Schindler R. , Slaoui A. , Wagner B. , Muller J. C. , Reis I. , Eyer A. , Siffert P. 
Published: July 2007

AbstractRapid thermal processing can offer many advantages, such as small overall thermal budget and low power and time consumption, in a strategy focused on cost‐effective techniques for the preparation of solar cells in a continuous way. We show here that this very short duration (a few tens of seconds) of isothermal heating performed in a lamp furnace can be used for many thermal steps of silicon solar cell processing. Rapid thermal processing was applied to form the p‐n junction from a phosphorus‐doped spin‐on silica film deposted on (100) silicon substrates at typical processing temperatures between 800 and 1100°C. the solar cells showed conversion efficiencies as good as those processed in a conventional way.
7000 high‐eficiency cells for a dream
Authors: Verlinden P. J. , Swanson R. M. , Crane R. A. 
Published: July 2007

AbstractThis paper reports on the fabrication of high‐eficiency back‐side contact silicon solar cells in large volume for the '93 World Solar Challenge. the cells were used exclusively on the winning car, the Dream, made by Honda R&D Company, Ltd. the cell efficiencies were between 20% and 22% (AMI.5G, 25°C) (G = global) and the average cell efficiency was greater than 21%. an important program of quality control was necessary to maintain a tight efficiency distribution and a high fabrication yield.
Thin‐film solar cells
Authors: Bloss W. H. , Pfisterer F. , Schubert M. , Walter T. 
Published: July 2007

AbstractThe R&D status of cells and modules based on hydrogenated amorphous silicon (a‐Si:H) and those based on CdTe and CuInSe2is reviewed.The stability of a‐Si:H solar cells is still a major concern. Improvements have been achieved on an empirical basis by application of multijunction structures, optimization of interfaces, etc. Stabilized efficiencies of close to 10% have been reported. In parallel, the introduction of the ‘defect‐pool model’ led to remarkable progress in understanding; it follows that a‐SiGe:H instead of a‐Si:H should be used for the i‐layer (absorber). Improved cell engineering concepts, however, such as enhancement of the built‐in electric field via reduction of the i‐layer thickness and/or folded structures, are believed to be more promising.Polycrystalline thin‐film cells based on CdTe and CuInSe2are not affected by inherent degradation mechanisms. the specific properties of these materials demand heterojunctions, and particular problems arise due to the polycrystallinity of the films and to the lattice mismatch and mismatch of the electronic band structures of the materials involved. These are discussed in conjunction with measures currently applied for optimizing solar cell performance. Both cell types exhibit eficiencies in the range 16‐17%.Estimations of production costs and energy payback times of thin‐film photovoltaic modules are reviewed (even below 1 US$ Wp−1and as low as 4 months, respectively) and environmental concerns, especially for Cd‐containing cells, are summarized.
Coupling of light into mechanically textured silicon solar cells: A ray tracing study
Authors: Brendel R. 
Published: July 2007

AbstractLight coupling into mechanically textured, encapsulated silicon solar cells is studied by three‐dimensional comprehensive ray tracing with our newly developed programme SUNRAYS. We analyse periodic textures with symmetric and non‐symmetric pyramids and grooves. the facet angles of the textures are varied systematically. the study considers the apparent daily motion of the sun and diffuse illumination. SUNRAYS accounts for the dependence of reflection and transmission on the wavelength, the angle of incidence and the polarization of light. As a result of basic interest, we show that the maximum average path length theoretically possible under isotropic illumination is actually achieved by numerous trapping schemes. As a result of practical interest, we demonstrate the outstanding performance of the simple prism groove texture, which yields a large current density while preserving a small surface when compared to all other textures investigated.
Optimum design of integrated tandem‐type a‐Si solar cell submodule
Authors: Nishiwaki Hidenori , Sakai Souichi , Haku Hisao , Ohnishi Michitoshi 
Published: July 2007

AbstractA new optimum design, in which the actual daily spectral data under outdoor conditions over a year were considered, was developed for the integrated tandem‐type a‐Si solar cell submodule with a structure of glass/TCO/a‐Si: H(pinpin)/metal. It was found by this design that the optimum cell number connected in series, at which maximum total annual output power was obtained, was small compared with that obtained by the conventional optimum design under standard conditions (AM1.5, 100 mW cm−2). It was also found that when light‐induced degradation was considered, the thickness of the i‐layer for the second pin cell was thinner than that by the conventional optimum design.
Photovoltaic system simulation using a standard electronic circuit simulator
Authors: Castañer Luis , Aloy Raimond , Carles Daniel 
Published: July 2007

AbstractAn approach to photovoltaic (PV) system simulation is presented based on the use of SPICE instead of using a specifically developed software package. SPICE models for PV cells, PV modules, lead‐acid batteries and the rest of the main components of a PV system have been developed. A simulation example of a stand‐alone PV system including measured irradiance data as an input is used to show some of the possibilities inherent in such an approach. Greater flexibility, quick access to all voltages and currents within the system and a simpler way of interfacing with standard electronic components are the main conclusions to be drawn from this work.
Photovoltaic‐powered piston‐type water pump controlled by a linear motor
Authors: Perris Carol , Salameh Ziyad 
Published: July 2007

AbstractThis paper presents a unique technique to control a photovoltaic (PV)‐powered piston‐type water pump. the method uses a linear motor mounted directly onto the piston rod of the pump. This linear motor method replaces the traditional piston‐type water pump, which employs a DC motor with a bulky gear mechanism to convert the rotational motion of the motor to linear motion for the piston.The electric circuit used to control the linear motor employs a four‐quadrant chopper, which uses four fast MOSFETs and a simple logic circuit for the switching.The experimental results show that the PV‐powered linear motor system can be used as an alternative to the PV‐powered DC motor gear system.
The individual effects of total quality management on customers, people and society results and quality performance in SMEs
Authors: Claver Enrique , Tarí Juan José 
Published: July 2007

AbstractThe aim of this paper is to test the individual effects of total quality management (TQM) on customer results, people results, society results and quality performance in a small‐ and medium‐sized enterprise (SME) context. The research is based on information from 85 ISO 9000 certified SMEs in Spain. A number of regression analyses are applied in order to examine the impact of TQM on these four results and identify which factors of TQM have the greatest effect. After analysing the survey data, 10 SMEs were randomly selected for individual visits, in order to check the results. The results show that TQM may improve customer results, people results, society results and quality performance. TQM factors related to training and specialist training are showed to be the most significant predictors of quality outcomes. The contribution of this paper is to study this association in SMEs in Spain. Copyright © 2007 John Wiley & Sons, Ltd.
A simple model matching for the stabilization of an inverted pendulum cart system
Authors: Aguilar‐Ibañez Carlos Fernando , Frias Oscar Octavio Gutiérrez 
Published: July 2007

AbstractWe present a simple model matching controller for the stabilization of the inverted pendulum cart system, assuming that the pendulum is initialized above the horizontal plane. The control strategy consists of forcing the closed‐loop system to behave as another nonlinear target system with some stability properties. To this end, we solve two matching conditions that allow us to shape a suitable target system. Having satisfied both matching conditions, the stabilizing controller is directly obtained from the proposed target system. The obtained close‐loop system is locally asymptotically exponentially stable, with a very large domain of attraction. Copyright © 2007 John Wiley & Sons, Ltd.
Efficient routing of multiple vehicles with no explicit communications
Authors: Arsie Alessandro , Frazzoli Emilio 
Published: July 2007

AbstractIn this paper, we consider a class of dynamic vehicle routing problems, in which a number of mobile agents in the plane must visit target points generated over time by a stochastic process. It is desired to design motion coordination strategies in order to minimize the expected time between the appearance of a target point and the time it is visited by one of the agents. We propose control strategies that, while making minimal or no assumptions on communications between agents, provide the same level of steady‐state performance achieved by the best‐known decentralized strategies. In other words, we demonstrate that inter‐agent communication does not improve the efficiency of such systems, but merely affects the rate of convergence to the steady state. Furthermore, the proposed strategies do not rely on the knowledge of the details of the underlying stochastic process. Copyright © 2007 John Wiley & Sons, Ltd.