bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analysis of optimal reclosing for enhancement of transient stability
Authors: Yagami Masaki , Murata Toshiaki , Tamura Junji 
Published: March 2004

AbstractThis paper presents a new method of determining an optimal reclosing time (ORCT) of circuit breakers by using the kinetic energy of synchronous generators. The significance of the proposed method is that it uses the kinetic energy of each generator, which can be obtained easily. Consequently, this technique may be implemented for on‐line application. The proposed method is verified by simulation study using EMTP/ATP. 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 32–39, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10261
The closest load flow limit in electrical power systems by Monte Carlo simulation
Authors: Sato Hiroyuki 
Published: March 2004

AbstractThis paper describes a method of obtaining a point in voltage vector space for the shortest distance between normal operation and a critical point of load flow in electrical power systems by means of Monte Carlo simulation. It also presents the characteristics of the power distance, voltage distance, and inner products of eigenvectors and voltage differences with respect to the point on the trajectory of minimum search. The critical point is characterized by the zero determinant of the Jacobian matrix. The point is known as the saddle node bifurcation. We propose a method of calculating the critical point under the bus constraints of the load flow equation. A new set of voltages is given by a random generator for a step of the Monte Carlo simulation. We calculate the power distance and draw a trajectory for the closest bifurcation by a random process. The result shows that the right eigenvector is parallel to the normal line to the tangential planes at the closest bifurcation. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 40–48, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10268
A multi‐objective optimization model for determining urban energy systems under integrated energy service in a specific area
Authors: Sugihara Hideharu , Komoto Jun , Tsuji Kiichiro 
Published: March 2004

AbstractThe integrated energy service system for a specific area is supposed to deliver electric and thermal energy in an integrated manner for the purpose of reducing cost, primary energy consumption, and CO2 emission. Under an assumption of the service system, this paper develops a multi‐objective optimization model for determining urban energy systems. Considering the various energy system alternatives, such as photovoltaic generations for residential houses and fuel‐cell cogenerations for business and commercial customers, the model determines the share of the energy system alternatives in order to minimize the above three indices. As numerical examples, this paper illustrates trade‐off analyses in the case when the proposed model is applied to a 2 km × 2 km square area in Osaka. Finally, this paper illustrates the role of various energy system alternatives from CO2 reduction and fossil energy reduction points of view. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 20–31, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10275
A practical design of multiloop robust PID control systems
Authors: Katayama Masaru , Yamamoto Toru , Mada Yasuhiro 
Published: March 2004

AbstractIn this paper, a new design scheme of multiloop predictive self‐tuning PID controllers is proposed for multivariable systems. The proposed scheme first uses a static precompensator as an approximately decoupling device in order to roughly reduce the interaction terms of the controlled object. The static matrix precompensator is adjusted by an on‐line estimator. Furthermore, by regarding the approximately decoupled system as a series of single‐input single‐output subsystems, a single‐input single‐output PID controller is designed for each subsystem. The PID parameters are calculated on‐line based on the relationship between the PID control and the generalized predictive control laws. The proposed scheme is numerically evaluated on a simulation example. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 63–71, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10284
Characteristics of a hybrid‐type switched reluctance motor with salient pole stator
Authors: Oyama Jun , Higuchi Tsuyoshi , Abe Takashi , Koga Takahiro 
Published: March 2004

AbstractIn this paper, we propose a new hybrid‐type switched reluctance motor (SRM) with salient pole stator, which has a pair of permanent magnets attached symmetrically between the iron poles of the rotor. We describe experimental results not only on the basic characteristics of the hybrid SRM, but also characteristics with a current control loop under optimized advanced firing angle and cutoff angle control. Considerable improvement of machine performance, especially in the efficiency and power factor, for the hybrid SRM over the conventional VR‐type SRM is confirmed. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 72–79, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10285
Analysis of diffraction from a uniaxial chiral slab with a two‐dimensional array of patches
Authors: Asai Masamitsu , Yamakita Jiro , Wakabayashi Hideaki 
Published: March 2004

AbstractDiffraction from a uniaxial chiral slab with a two‐dimensional periodic array of conducting patches is analyzed by the matrix‐based approach. Equatorial anisotropy is assumed for the chirality and permittivity whose optical axis is parallel to the plane of incidence. In the analysis, the total fields are given by the superposition of the current‐dependent scattering fields, which are expanded in terms of the two‐dimensional space harmonics and the incidence fields. The coupled mode equations for the equatorial uniaxial chiral media give the general solutions of fields as superpositions of elliptically polarized eigenmodes. The unknown currents on the patches are determined by applying the method of moments to the boundary conditions of the conducting array. In the numerical computations, the polarization characteristics of diffracted waves are investigated considering the design parameters. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 1–8, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10293
A new approach for completing the phase shifter angle for load flow control in the network with multiple loops
Authors: Sato Masahiro , Hasegawa Tomofumi 
Published: March 2004

AbstractA phase shifter has been used to control line flow. In the network with multiple loops, it is necessary to modify the angle of the phase shifter to reduce the flow on a certain line if it exceeds the limit. A new method to compute the value of the angle that is set to the phase shifter is proposed. The coefficient is computed by using two relations. No one is between the change of the lined flow on a certain line and modification of power injection and two notes. The other is between the change of the flow on a line in the change of the angle of a phase shifter. Then the phase angle is computed by multiplying the coefficient and the amount of flow on the line. The coefficients can be used for finding the locations where phase shifters will be placed in order to correct any overload that may occur at any line in the loops and can be used for computation of available transmission capacity. The validity of this method was shown by numerical examples using an IEEE 30 bus system. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 9–19, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10297
Adsorptive Square‐Wave Voltammetry for the Analysis and Speciation of Complexes of Cd(II)‐Ferron
Authors: Garay Fernando , Solis Velia M. 
Published: March 2004

AbstractThe theory of adsorptive stripping square‐wave voltammetry (SWV) for relatively low ligand concentrations is employed to determine the reduction mechanism of Cd(II)‐ferron complexes accumulated on a static mercury drop electrode at different pH values. The electrochemical behavior of ferron molecules indicated that the adsorptive concentration of Cd(II) is possible in solutions with 3.5<pH<11, providing a wide pH range where the interference of other ligands present in real samples would be not so critical. Cyclic voltammetry experiments were also performed for the purpose of comparison. Fitting between experimental and theoretical square‐wave voltammograms shows that the prevailing species at the reaction layer coincide with the equilibrium bulk distribution. The simulation procedure indicated that the electrochemical rate constants of Cd(II)‐ferron complexes varied from (6±1) s−1 to (0.17±0.01) s−1 for solutions analyzed at pH 3.9 and 10.8, respectively. Changes at the surface concentrations are discussed considering the ligand to complex ratios at the electrode surface and at the solution bulk. From this analysis it is possible to infer that the oxidized metal species are produced in the electrolytic solution instead of on the electrode surface.
Voltammetric Monitoring of Bivalent Iron in Waters and Effluents, Using a Dental Amalgam Sensor Electrode. Some Preliminary Results
Authors: Mikkelsen Øyvind , Schrøder Knut H. 
Published: March 2004

AbstractA very sensitive method for detection of iron(II) in the ng/L range with a deposition time of 180 s by use of differential pulse anodic stripping voltammetry on a novel dental amalgam electrode is introduced and tested in different supporting media. A well‐defined peak for the oxidation of iron metal to ferrous ion was observed around.
Sonoelectroanalysis: Anodic Stripping Voltammetric Determination of Cadmium in Whole Human Blood
Authors: Kruusma Jaanus , Nei Lembit , Hardcastle Joanna L. , Compton Richard G. , Lust Enn , Keis Heldur 
Published: March 2004

AbstractThe quantitative detection of cadmium in human blood is shown to be possible by anodic stripping voltammetry under conditions of insonation. An immersion horn probe is introduced into a thermostatted conventional three‐electrode cell opposite a Nafion‐coated mercury plated glassy carbon electrode. The enhanced mass transport associated with power ultrasound yields efficient preconcentration of the cadmium before it is detected using anodic differential‐pulse stripping voltammetry. Insonation further offers the crucial benefits of first surface activation and cleaning, helping to prevent electrode fouling by the organic components in blood and second fully equilibrating “free” and “bound” Cd2+ ions in the complex matrix. Acoustic streaming and cavitation promote the mass transport of cadmium to the surface of electrode, facilitating measurements in solutions of low cadmium concentration, where “silent” measurements fail to yield an analytical signal. The system is calibrated using standard micro additions of cadmium to give the total amount of cadmium in blood. The calibration plot, showing the dependence of the cadmium stripping peak height on cadmium concentration in 1 : 50 diluted blood samples, was linear in the range 1×10−10 M to 4×10−9 M Cd2+. The values of cadmium concentration obtained using sonoelectroanalytical methodology were compared with the results obtained by independent atomic absorption spectroscopy (AAS) measurements and good agreement was found.
Design of an Interference‐Free Cholesterol Amperometric Biosensor Based on the Electrosynthesis of Polymeric Films of Diaminonaphthalene Isomers
Authors: García‐Ruiz Esperanza , Vidal Juan Carlos , Aramendía María Teresa , Castillo Juan Ramón 
Published: March 2004

AbstractDifferent cholesterol amperometric biosensors were developed based on entrapment of cholesterol esterase and/or cholesterol oxidase in polymer films of diaminonaphthalene isomers, electrochemically synthesised from aqueous solutions of the monomers and enzymes in phosphate buffer at neutral pH. These conditions permit the growth of films with extraordinary selective properties which allow the preparation of interference‐free biosensors for application in biological media without the response being affected by the presence of either endogenous species (ascorbic and uric acid) or exogenous species like 4‐acetamidophenol. These selective properties were evaluated for the different monolayer and bilayer configurations proposed in function of the film permeation factor. All the steps involved in the preparation of the biosensors and determination of free or total cholesterol were carried out in a flow system. A comparative study was made of the analytical properties of each of the configurations developed and their application to the flow‐injection determination of cholesterol in a synthetic serum.
Critical Comparison of Four Simple Adaptors for Flow Amperometric and Stripping Voltammetry with Mercury Drop Electrodes in Batch Cells
Authors: Cavicchioli Andrea , Daniel Daniela , Gebhardt Ivano , Gutz Rolf 
Published: March 2004

AbstractElectrochemical batch cells with mercury drop electrodes, MDEs, are readily available from a number of producers and widely used in electroanalysis for polarography, voltammetry and stripping voltammetry. To increase sample throughput and reduce reagent and sample consumption, the tendency is to couple the MDE with flow analysis systems (e.g., FIA, SIA or BIA). Many special flow cells for MDEs are described in the literature, but it is easier to convert existing commercial batch cells to flow operation. To assess the performance of such flow adaptors, four models were chosen because they are directly fitted to the glass capillary of any MDE, light enough not to impair the mechanical drop knocker and can be effortlessly built in the laboratory. They were all found adequate for flow amperometry and stripping voltammetry, with differences in sensitivity, flow rate dependence, response time, drop stability, tolerance to bubbles, uncompensated resistance and recontamination of disposed analyte from the electrolytic bath. Two of them, a simple L‐shaped PTFE tube and an upstream nozzle holder made from a disposable pipette tip, gather a larger set of desirable features.
High‐Temperature Electrochemistry: A Review
Authors: Wildgoose Gregory G. , Giovanelli Debora , Lawrence Nathan S. , Compton Richard G. 
Published: March 2004

AbstractHigh‐temperature electrochemistry remains a relatively unexplored field of research, although in recent years significant developments have been made. This report details the main experimental methods and approaches to heating an electrochemical system under both isothermal and non‐isothermal conditions and gives an insight into the experimental and electroanalytical results obtainable under such conditions. It has been shown that the promotion of mass transport at high‐temperatures, through diffusion or convection, often results in increased current signals. This increase benefits electroanalytical measurements by lowering detection limits. High temperatures also usefully enhance the sensitivity of systems with sluggish kinetics.
An original solvent free microwave extraction of essential oils from spices
Authors: Lucchesi Marie Elisabeth , Chemat Farid , Smadja Jacqueline 
Published: March 2004

AbstractAttention is drawn to the development of a new and green alternative technique for the extraction of essential oils from spices. Solvent‐free microwave extraction (SFME) is a combination of dry distillation and microwave heating without added any solvent or water. SFME and hydrodistillation (HD) were compared for the extraction of essential oil from three spices: ajowan (Carum ajowan, Apiaceae), cumin (Cuminum cyminum, Umbelliferae), star anise (Illicium anisatum, Illiciaceae). Better results have been obtained with the proposed method in terms of rapidity (1 h vs. 8 h), efﬁciency and no solvent used. Furthermore, the SFME procedure yielded essential oils that could be analysed directly without any preliminary clean‐up or solvent exchange steps. Copyright © 2004 John Wiley & Sons, Ltd.
Composition of the essential oils of Kaempferia rotunda L. and Kaempferia angustifolia Roscoe rhizomes from Indonesia
Authors: Woerdenbag Herman J. , Windono Tri , Bos Rein , Riswan Sudarsono , Quax Wim J. 
Published: March 2004

AbstractThe volatile constituents of rhizomes (main rhizome, lateral parts) of two medicinally used Indonesian plants of the family Zingiberaceae, Kaempferia rotunda L. and K. angustifolia Roscoe, were investigated by GC and GC–MS (EI) analysis. A total of 75 compounds were identiﬁed. The most abundant constituents were benzyl benzoate (69.7%, 20.2%), n‐pentadecane (22.9%, 53.8%) and camphene (1.0%, 6.2%) in K. rotunda, and n‐pentadecane (17.8%, 5.0%), camphene (9.1%, 12.4%), camphor (6.2%, 5.7%) and bornyl formate (3.7%, 16.3%) in K. angustifolia. Although both species are known in Java under the same local name (kunci pepet) and probably will be interexchanged, there are some marked phytochemical differences. Copyright © 2004 John Wiley & Sons, Ltd.
Chemical composition of the essential oil of nine Eucalyptus species growing in Morocco
Authors: Zrira S. , Bessiere J. M. , Menut C. , Elamrani A. , Benjilali B. 
Published: March 2004

AbstractThe essential oils obtained by steam distillation from the leaves of nine Eucalyptus species (E. cinerea F. Muell., E. baueriana F. Muell., E. smithii R. T. Baker, E. bridgesiana R. T. Baker, E. microtheca F. Muell., E. foecunda Schau., E. pulverulenta Sims, E. propinqua Deane and Maiden, E. erythrocorys F. Muell.) of Moroccan origin have been analysed using GC and GC–MS. A total of 83 constituents were identiﬁed. All the species investigated were found to possess an oil rich in 1,8‐cineole (>68%). In ﬁve species (E. cinerea F. Muell., E. baueriana F. Muell., E. smithii R. T. Baker, E. bridgesiana R. T. Baker and E. microtheca F. Muell.), the 1,8‐cineole content exceeded 80%. Copyright © 2004 John Wiley & Sons, Ltd.
Amino acid‐catalysed retroaldol condensation: the production of natural benzaldehyde and other ﬂavour compounds
Authors: Wolken Wout A. M. , Tramper Johannes , van der Werf Mariët J. 
Published: March 2004

AbstractThe amino acid‐catalysed retroaldol condensation previously described for citral has been extended to other α,β‐unsaturated aldehydes. In the presence of glycine and an elevated pH, six other α,β‐unsaturated aldehydes also underwent retroaldol condensation. Crotonaldehyde, as well as its proposed intermediate, aldol, were converted into acetaldehyde. Hexenal, decenal, methyl crotonaldehyde, farnesal and cinnamaldehyde were also converted into acetaldehyde plus butanal, octanal, acetone, geranyl acetone and benzaldehyde, respectively. Subsequently, the effects of temperature, pH, the buffer and substrate concentration on the conversion rate were studied, using the conversion of cinnamaldehyde into the important ﬂavour compound benzaldehyde as a model. Copyright © 2004 John Wiley & Sons, Ltd.
Pedoarchaeology of Cactus Hill, a sandy Paleoindian site in southeastern Virginia, U.S.A.
Authors: Wagner Daniel P. , McAvoy Joseph M. 
Published: March 2004

AbstractCactus Hill is located in the Virginia Coastal Plain on a terrace above the Nottoway River. The site has a record of occupation that spans the Holocene and also offers evidence of humans late in the Pleistocene before Clovis time. Soil investigations identified several deposit types, and demonstrated that multisequal eolian sands forming the site's primary core are arrayed in spatially and temporally discrete horizons. Resting atop an ancient paleosol, the earliest sand stratum (19,540 ± 70 14C yr B.P.) is marked by a conspicuous but culturally sterile buried surface horizon. Eolian sand above this surface supports another sequum in which Clovis and underlying “Blade” artifacts are associated with a fainter surface horizon and pronounced subsoil lamellae. Early Archaic and successively younger artifacts occur above the Clovis level in a more weakly developed uppermost sequum. This soil and cultural stratigraphy, together with considerations of regional topography, demonstrate that the landscape has evolved incrementally since about the last glacial maximum. © 2004 Wiley Periodicals, Inc.
New geochronological and archaeological data for the Sheaman Clovis site, eastern Wyoming, U.S.A.
Authors: Haynes C. Vance , Kornfeld Marcel , Frison George C. 
Published: March 2004

AbstractExcavation of the Sheaman Clovis site in eastern Wyoming by University of Wyoming in the late 1970s produced one radiocarbon age of uncertain relationship to the Clovis level and one age on bone of poor reliability. New excavations in 2000 recovered additional material for radiocarbon dating as well as a Clovis elongated flake multiple use tool at the base of a black, cumulic A horizon. This paper presents evidence of an age of ca. 11,200 ± 50 yr B.P. for the Clovis occupation, and an Allerød‐Younger Dryas age for the paleosol, along with a detailed description of the Clovis tool. © 2004 Wiley Periodicals, Inc.
The formation and sedimentary infilling of the Cave of Hearths and Historic Cave complex, Makapansgat, South Africa
Authors: Latham A.G. , Herries A.I.R. 
Published: March 2004

AbstractThe archaeology of caves is best served by including a study of natural effects prior to and during anthropogenic input. This is especially true for the Cave of Hearths because not only has erosion determined the area of occupation, but also subsequent undermining has caused collapse of some of the rearward parts of the site during Early Stone Age (Acheulian) and later times; and this had a major impact on excavation. The key to understanding the nature of the collapsed layers was the rediscovery of a lower part of the cavern below the whole site. This lower cavern is no longer accessible, but the evidence for it was revealed in a swallow hole by R.J. Mason, and in archived material at the Department of Archaeology, University of Witwatersrand. The creation and dissolution of dolomite fragments in the upper layers has resulted in the formation of thick, carbonate‐cemented breccia that has preserved underlying layers and prevented further collapse. We agree with Mason that further archaeological and hominid finds await excavation under the proximate Historical Cave west entrance. This area has the potential for archaeological and palaeoanthropological material that predates the layers in the Cave of Hearths. © 2004 Wiley Periodicals, Inc.
Effects of bears on rockshelter sediments at Tanay Sur‐les‐Creux, southwestern Switzerland
Authors: Braillard Luc , Guélat Michel , Rentzel Philippe 
Published: March 2004

AbstractSur‐les‐Creux rockshelter is located in the Prealps of southwestern Switzerland. The sequence of deposits in the rockshelter is 80 cm thick and consists of weathered gravels in a phosphate‐rich matrix. A few Middle Palaeolithic artifacts and the bones of cave bear (Ursus spelaeus) were recorded in the fill. We present the results of sedimentological, geochemical, and micromorphological analyses of the rockshelter sediment. All analyses suggest an endokarstic origin of the sediments. The alteration cortices of the gravels imply in situ weathering over a long period. The phosphates are essentially biogenic and have an apatitelike nature. Phosphatization and intense mixing of the sediment are attributed to cave bear (digging of lairs, input of excrements, and carcasses). Only rare carnivore coprolites (lynx) were preserved in the cave deposits. © 2004 Wiley Periodicals, Inc.