bluuebunny/crossref_metadata_2025 huggingface dataset:
The positive influence of maternal identification on body image, eating attitudes, and self‐esteem of Hispanic and Anglo girls
Authors: Hahn‐Smith Anne Madeleine , Smith Jane Ellen
Published: August 2002

Objective

The role of maternal identification in the development of girls' body image, eating attitudes, and self‐esteem was examined.

Method

Hispanic and Anglo girls (n = 410) ages 8–13 were surveyed using the Body Esteem Scale (BES), the Children's Eating Attitudes Test, the Piers‐Harris Children's Self‐Concept Scale, and the Child Figure Drawing task. From this sample, normal‐weight girls with high or low scores on the BES were selected for the main study. Ninety‐two mother‐daughter pairs participated in this second phase in which mothers completed similar questionnaires and girls performed a Q‐sort task measuring maternal identification.

Results

Maternal identification was positively correlated with girls' self‐esteem and negatively correlated with eating problems and body dissatisfaction. Also, mothers with high self‐esteem tended to have daughters with high self‐esteem. The mothers of girls with low BES scores found a significantly greater discrepancy than the mothers of girls with high BES scores when contrasting their daughters' current shape with either the ideal figure for their daughter or the figure they believed boys would find attractive.

Discussion

Girls who aspired to be like their mothers in terms of personality traits felt better about themselves and their bodies compared with girls with low maternal identification. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 429–440, 2001.
Estimating angle of arrival with non‐uniformly spaced array
Authors: Nakazawa Toshiyuki , Takahashi Masaharu , Abe Minoru
Published: August 2002

The present direction‐finding equipment has insufficient accuracy and resolution, so that accurate evaluation of the direction of arrival and the position cannot be carried out. Although each radar signal has a narrow bandwidth, the entire bandwidth for various radars used exceeds four octaves. In order to search all of these, equipment for each bandwidth is used at present so that the entire frequency range is covered. However, it is more effective from the standpoint of equipment size and cost to cover the entire spectrum with a single kind of equipment. It is desirable to realize high‐accuracy high‐resolution direction finding over a broad bandwidth. In realization, broadband antennas are used, and high‐gain antennas are also needed in a low‐S/N environment. Since the dimensions of high‐gain and broadband antennas are large, an array configuration with a half‐wave spacing may not physically be possible. Thus, the array spacing becomes more than a half‐wavelength. If the range of direction estimation is −90 to +90°, the phase difference exceeds 360° so that ambiguity occurs. As a method to resolve this ambiguity problem, a nonuniformly spaced array is effective. In this paper, the array conditions for a nonuniformly spaced array are determined in the case of one arriving wave. Next, the case of several arriving waves is discussed and the array conditions for several arriving waves are derived. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(3): 1–8, 2002
Detecting Each Position of Residual Reflections Using a Radiation Pattern Measurement Method for Eliminating Reflections by Distance Changing Technique
Authors: Nishizawa Kazushi , Konishi Yoshihiko , Makino Shigeru , Katagi Takashi
Published: August 2002

In order to carry out high‐precision measurement of the radiation characteristics of antennas and to evaluate the reflection characteristics of microwave anechoic chamber used for antenna measurement, it is important to recognize the location and intensity of the unwanted reflection sources caused by the ambient environment. In this paper, the radiation pattern measurement proposed by the authors is applied for estimating the location of the reflection sources and their effects on the radiation pattern. In the proposed radiation pattern measurement method, the reflected waves are eliminated by the Fourier transform of the measured reflected electric field data obtained on varying the measurement distance. First, a method for estimating the locations of the reflected wave sources and their effects is theoretically shown from the radiation pattern of the reflected wave. This pattern is obtained after the direct radiation pattern obtained from the radiation pattern with the reflected wave suppressed is eliminated from the measured radiation pattern. From a verification experiment using a standard L‐band horn, the effectiveness of the method is verified. Second, a window function is applied to the measurement distance range so that the sidelobes of the Fourier transform spectrum are reduced. From the radiation pattern of the reflected wave obtained by applying a gating process to this Fourier spectrum at each angle, the effect of several reflection sources is estimated individually. From the results of computer simulation, the effectiveness of the proposed method is verified. Further, the range of applicability of the method is discussed. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(4): 33–43, 2002
An Approximate Method for Minimizing Communications Cost and Time for Replication Update of Distributed Databases
Authors: Wakahara Yasushi
Published: August 2002

In distributed databases, oriented toward general business software such as groupware, the asynchronous update method is widely used in order to align the databases. In this method, each database has replicas of the other databases, and the replicas are updated at the same time according to a predetermined replica routing schedule. This paper discusses an approximate method for minimizing the communication cost and time needed for updating the replicas in such a distributed database. More precisely, the case in which the communication cost is proportional to the amount of transferred data is considered, and an optimization problem is formulated in which the replication routing schedule minimizing the time for the replica update is to be determined from those minimizing the communication cost for the replica update. An approximate solution for the formulated problem is presented. Then the result of evaluation of the approximate replication routing schedule obtained as the approximate solution is discussed, and it is shown that the communication cost for replica update is minimized and that the time for the replica update is at most 1.2 times the minimum value if the number of distributed databases is at most 7. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(4): 61–70, 2002
Analysis of door seal structure of microwave oven with consideration of higher modes by the FDTD method
Authors: Kusama Yuusuke , Hashimoto Osamu , Makida Minoru
Published: August 2002

This paper focuses on the choke structure, which is generally used in suppressing the leakage wave from the door gap of microwave ovens. A choke structure which simulates the interdigital periodic choke structure for mass‐produced microwave ovens is considered, and the shielding effect is examined by the FDTD method for leaky waves (hybrid waves) including the higher modes, as a situation very close to practice. As an application of such an analysis to the optimal design of the choke groove, the shielding effect is examined as a function of the angle of the metal plates composing the choke groove. It is shown that the proposed method of analysis is effective for such a complex structure. © 2002 Scripta Technica, Electron Comm Jpn Pt 2, 85(3): 50–57, 2002
The quantum‐classical correspondence for the degree of freedom in 2D irregular sound fields
Authors: Fujisaka Yoh‐ichi , Tohyama Mikio , Sugimura Akira
Published: August 2002

In the area of research on quantum chaos, the correspondence between the quantum and classical theories on the chaos is a problem. In the billiard problem of a stadium type in a classical system (to be replaced with the acoustic line tracing the acoustics), it is known that the acoustic line locus exhibits a chaotic behavior. However, no chaos exists in the wave phenomena in a quantum system as a linear wave field. Where in the linear wave field a chaotic behavior exists and how the linear wave field is related to the chaotic nature of the classical system have been research topics. The objective of the present research is to search the correspondence between the classical and quantum theories on the chaos from the point of view of indoor acoustics. The authors define semistadium boundaries with higher‐order curves of more than second order and calculate the degrees of freedom in the wave system and classical system. From the point of view of degrees of freedom in the system, the correspondence is analyzed on the chaos between the wave and classical theories. It is found that the correspondence between the chaotic nature of the acoustic line propagation and the wave nature depends on the degrees of freedom of the system. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(3): 61–68, 2002
Performance of M‐ary/SSMA using soft decision Viterbi decoding
Authors: Ito Katsuyuki , Hamamura Masanori , Tachikawa Shin'ichi
Published: August 2002

In this paper, we discuss the performance of M‐ary/SSMA and M‐ary/SSMA systems using convolutional code and co‐channel interference (CCI) cancellation techniques. First, we show a proposed system model and describe a soft decision method of M‐ary/SS which can operate soft decision Viterbi decoding. Next, we evaluate the system performance in an AWGN environment and a Rayleigh fading environment by computer simulations. As a result, spectral efficiency of the system using convolutional code is improved in both environments, though its effects depend on the coding rate. Finally, we discuss the systems using CCI cancellation and convolutional code. As a result, when the spreading factor becomes large, its performance becomes inferior to that of the system which applies no convolutional code in an AWGN environment. However, under a Rayleigh fading environment, a considerable improvement of the performance can be obtained. © 2002 Scripta Technica, Electron Comm Jpn Pt 3, 85(6): 11–20, 2002
Growth of thick and low‐doped 4H‐SiC epitaxial layers in a vertical radiant‐heating VPE reactor
Authors: Tsuchida Hidekazu , Kamata Isaho , Jikimoto Tamotsu , Izumi Kunikazu
Published: August 2002

A new vertical radiant‐heating reactor has been designed and constructed for thick SiC vapor‐phase epitaxy (VPE). Growth of 4H‐SiC epitaxial layers is performed under a reduced pressure as low as 6.7 × 103 Pa. A high growth rate exceeding 16 µm/h has been achieved in the reactor. Smooth surface is obtained by controlling the input C/Si ratio of source gases, and we have demonstrated growth of very thick layers over 160 µm with a mirrorlike morphology. Low‐background doping in the 1013 cm−3 range (n‐type) and intentional n‐type doping in a range from low 1015 to low 1019 cm−3 have also been demonstrated. We have performed photoluminescence spectroscopy and deep level transient spectroscopy to check impurities and intrinsic defects in the epitaxial layers, and the spectra show that the layers have a good purity and quality. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 18–25, 2002; DOI 10.1002/eej.1134
Novel development of an inductively coupled thermal plasma with pulse amplitude modulation of electromagnetic field
Authors: Sakuta Tadahiro , Tanaka Yasunori , Hashimoto Yoshifumi , Katsuki Makoto
Published: August 2002

A novel system of an inductively coupled thermal plasma with a fundamental frequency of 450 kHz has been developed. This system has a capability of modulating the amplitude of the coil current periodically with a cycle on the order of 10 ms, including an inverter power supply rated with a power of 50 kW, an induction plasma torch with a 10‐turn coil, and vacuum chamber. The controlled modulation of the coil current can lead the plasma to be under various transient states intentionally. A pulse‐modulated inductively coupled plasma of Ar‐H2 plasma was successfully generated at a plasma power of 30 kW under the atmospheric pressure condition. The on‐time and off‐time of the pulsation were set to 10 and 5 ms, respectively, for a stable pulse‐modulated plasma establishment, and the ratio of minimum to maximum of the amplitude of the coil current can be set down to 61.7%. In order to investigate the transient behavior of the plasma dynamics in such a pulsing mode, spectroscopic observations of an argon atomic spectral line at a wavelength of 751 nm were made. It was found that the pulse‐modulated plasma has a characteristic time on the order of 2 to 5 ms to rise or to decrease. The excitation temperature of the Ar atom was estimated from the spectroscopic measurement by the Boltzmann plot method, and it was found to change periodically from 5000 to 10,000 K with the pulse modulation of the amplitude of the coil current. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 26–33, 2002; DOI 10.1002/eej.1135
Characteristic performance of radio‐frequency (RF) plasma heating using inverter RF power supplies
Authors: Imai Takahiro , Sawada Hiroyuki , Hattori Norifumi , Uesugi Yoshihiko , Takamura Shuichi
Published: August 2002

High‐heat‐flux plasmas are produced by high‐power (∼14 kW) ICRF heating using inverter power supplies in the linear diverter simulator NAGDIS‐II. The power flow of radiated RF power is investigated by a calorimetric method. From conventional power calculation using antenna voltage and current, about 70% of the RF power is radiated into the plasma. But the increase of the plasma heat load along the magnetic field by RF heating is about 10% of the RF power. Through this experiment, we find that about half of the RF power is lost at the antenna surface through the formation of RF‐induced sheath, and about 30% of the power is lost into the wall of the vacuum vessel through the charge exchange and elastic collision of ions with neutrals. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 34–41, 2002; DOI 10.1002/eej.1136
Genetic toxicology testing of the antimalarial drugs chloroquine and a new analog, AQ‐13
Authors: Riccio Edward S. , Lee Pamela S. , Winegar Richard A. , Krogstad Donald J. , De Dibyendu , Mirsalis Jon C.
Published: August 2002

AQ‐13 ([N1‐(7‐chloro‐quinolin‐4yl)‐3‐(N3,N3‐diethylamino)propylamine] dihydrochloride trihydrate) is an aminoquinoline antimalarial drug that is effective against chloroquine‐resistant strains of Plasmodium falciparum. It is structurally similar to the widely used chloroquine diphosphate (CQ). We evaluated these drugs in the three assays currently recommended by the International Conference on Harmonization (ICH): bacterial mutagenesis in Salmonella typhimurium and Escherichia coli, mammalian cell mutagenesis in L5178Y mouse lymphoma cells, and micronucleus induction in rat bone marrow. A small but statistically significant increase in revertant colonies was produced by CQ with Salmonella tester strain TA98 without metabolic activation (MA) and by AQ‐13 with strain TA1537 both with and without MA. In L5178Y cells, testing of CQ and AQ‐13 up to cytotoxic concentrations with and without MA produced no increase in mutant colonies and no increase in the numbers of small colonies. Slight decreases in the ratio of polychromatic erythrocytes (PCE) to red blood cells (RBC) were observed in male and female rats treated with CQ and in females only treated with AQ‐13; however, none of these changes was statistically significant. No increases in the frequency of micronucleated PCE were observed at any dose level of CQ or AQ‐13. Although both CQ and AQ‐13 showed weak bacterial mutagenicity, this mutagenic effect was not confirmed in either the mouse lymphoma mutagenesis assay or the micronucleus assay. These results indicate that CQ and AQ‐13 should pose minimal risk of genotoxic damage in human populations being administered these drugs. Environ. Mol. Mutagen. 38:69–79, 2001 © 2001 Wiley‐Liss, Inc.
Tangential‐projection algorithm for manifold representation in unidentifiable model updating problems
Authors: Katafygiotis Lambros S. , Lam Heung‐Fai
Published: August 2002

The problem of updating a structural model and its associated uncertainties by utilizing structural response data is addressed. In an identifiable case, the posterior probability density function (PDF) of the uncertain model parameters for given measured data can be approximated by a weighted sum of Gaussian distributions centered at a number of discrete optimal values of the parameters at which some positive measure‐of‐fit function is minimized. The present paper focuses on the problem of model updating in the general unidentifiable case for which certain simplifying assumptions available for identifiable cases are not valid. In this case, the PDF is distributed in the neighbourhood of an extended and usually highly complex manifold of the parameter space that cannot be calculated explicitly. The computational difficulties associated with calculating the highly complex posterior PDF are discussed and a new adaptive algorithm, referred to as the tangential‐projection (TP) algorithm, allowing for an efficient approximate representation of the above manifold and the posterior PDF is presented. Using this approximation, expressions for calculating the uncertain predictive response are established. A numerical example involving noisy data is presented to demonstrate the proposed method. Copyright © 2002 John Wiley & Sons, Ltd.
Inelastic deformation response of SDOF systems subjected to earthquakes
Authors: Riddell Rafael , Garcia Jaime E. , Garces Eugenio
Published: August 2002

Performance‐based seismic design requires reliable methods to predict earthquake demands on structures, and particularly inelastic deformations, to ensure that specific damage‐based criteria are met. Several methods based on the response of equivalent linear single‐degree‐of‐freedom (SDOF) systems have been proposed to estimate the response of multi‐degree‐of‐freedom structures. These methods do not offer advantages over the traditional Veletsos–Newmark–Hall (VNH) procedure, indeed, they have been shown to be inaccurate. In this study, the VNH method is revised, considering the inelastic response of elastoplastic, bilinear, and stiffness‐degrading systems with 5% damping subjected to two sets of earthquake ground motions. One is an ensemble of 51 earthquake records in the Circumpacific Belt, and the other is a group of 44 records in California. A statistical analysis of the response data provides factors for constructing VNH inelastic spectra. Such factors show that the ‘equal‐displacement’ and ‘equal‐energy’ rules to relate elastic and inelastic responses are unconservative for high ductilities in the acceleration‐ and velocity‐sensitive regions of the spectrum. It is also shown that, on average, the effect of the type of force–deformation relationship of non‐linear systems is not significant, and responses can be conservatively predicted using the simple elastoplastic model. Copyright © 2001 John Wiley & Sons, Ltd.
Duration of strong ground motion during Mexican earthquakes in terms of magnitude, distance to the rupture area and dominant site period
Authors: Reinoso Eduardo , Ordaz Mario
Published: August 2002

A study of the duration of strong ground motion using accelerometric data of subduction and normal‐faulting Mexican earthquakes is presented. Duration is obtained based on the time between 2.5 and 97.5 per cent of the Arias intensity. An expression to predict this duration in terms of the magnitude, distance to the rupture area and site period is proposed and compared with predictions available in the literature. The effect of large duration for very distant sites and the contribution of soft soils to the duration of strong ground motion are widely discussed. We have found that large magnitude not only yields long duration at the source, but also proportionally longer duration with distance and with dominant site period compared to small magnitude. The duration obtained from the regression is used as a parameter to obtain input and hysteretic energy and on the use of damage models available in the literature. Finally, duration is used together with the random vibration theory to predict response spectra. Copyright © 2001 John Wiley & Sons, Ltd.
Optimal control of linear buildings under seismic excitations
Authors: Aldemir U. , Bakioglu M. , Akhiev S. S.
Published: August 2002

Considerable effort has been devoted to develop optimal control methods for reducing structural response under seismic forces. In this study analytical solution of the linear regulator problem applied widely to the control of earthquake‐excited structures is obtained by using the sufficient conditions of optimality even though almost all of the optimal controls proposed previously for structural control are based on the necessary conditions of optimality. Since the resulting optimal closed–open‐loop control cannot be implemented for civil structures exposed to earthquake forces, the solution of the optimal closed–open‐loop control is carried out approximately based on the prediction of the seismic acceleration values in the near future. Upon obtaining the relation between the exact optimal solution and future values of seismic accelerations, it is shown numerically that the solution of the optimal closed–open‐loop control problem can be performed approximately by using only the first few predicted seismic acceleration values if a given norm criteria is satisfied. Calculated performance measures indicate that the suggested approximate solution is better than the closed‐loop control and as we predict the future values of the excitation more accurately, it will approach the optimal solution. Copyright © 2001 John Wiley & Sons, Ltd.
Hysteretic energy spectrum and damage control
Authors: Riddell Rafael , Garcia Jaime E.
Published: August 2002

The inelastic response of single‐degree‐of‐freedom (SDOF) systems subjected to earthquake motions is studied and a method to derive hysteretic energy dissipation spectra is proposed. The amount of energy dissipated through inelastic deformation combined with other response parameters allow the estimation of the required deformation capacity to avoid collapse for a given design earthquake. In the first part of the study, a detailed analysis of correlation between energy and ground motion intensity indices is carried out to identify the indices to be used as scaling parameters and base line of the energy dissipation spectrum. The response of elastoplastic, bilinear, and stiffness degrading systems with 5 per cent damping, subjected to a world‐wide ensemble of 52 earthquake records is considered. The statistical analysis of the response data provides the factors for constructing the energy dissipation spectrum as well as the Newmark–Hall inelastic spectra. The combination of these spectra allows the estimation of the ultimate deformation capacity required to survive the design earthquake, capacity that can also be presented in spectral form as an example shows. Copyright © 2001 John Wiley & Sons, Ltd.
Computational fluid dynamics modelling of boundary roughness in gravel‐bed rivers: an investigation of the effects of random variability in bed elevation
Authors: Nicholas A.P.
Published: August 2002

Results from a series of numerical simulations of two‐dimensional open‐channel flow, conducted using the computational fluid dynamics (CFD) code FLUENT, are compared with data quantifying the mean and turbulent characteristics of open‐channel flow over two contrasting gravel beds. Boundary roughness effects are represented using both the conventional wall function approach and a random elevation model that simulates the effects of supra‐grid‐scale roughness elements (e.g. particle clusters and small bedforms). Results obtained using the random elevation model are characterized by a peak in turbulent kinetic energy located well above the bed (typically at y/h = 0·1–0·3). This is consistent with the field data and in contrast to the results obtained using the wall function approach for which maximum turbulent kinetic energy levels occur at the bed. Use of the random elevation model to represent supra‐grid‐scale roughness also allows a reduction in the height of the near‐bed mesh cell and therefore offers some potential to overcome problems experienced by the wall function approach in flows characterized by high relative roughness. Despite these benefits, the results of simulations conducted using the random elevation model are sensitive to the horizontal and vertical mesh resolution. Increasing the horizontal mesh resolution results in an increase in the near‐bed velocity gradient and turbulent kinetic energy, effectively roughening the bed. Varying the vertical resolution of the mesh has little effect on simulated mean velocity profiles, but results in substantial changes to the shape of the turbulent kinetic energy profile. These findings have significant implications for the application of CFD within natural gravel‐bed channels, particularly with regard to issues of topographic data collection, roughness parameterization and the derivation of mesh‐independent solutions. Copyright © 2001 John Wiley & Sons, Ltd.
Estimating the mean speed of laminar overland flow using dye injection‐uncertainty on rough surfaces
Authors: Dunkerley David
Published: August 2002

A common method for estimating mean flow speeds in studies of surface runoff is to time the travel of a dye cloud across a measured flow path. Motion of the dye front reflects the surface flow speed, and a correction must be employed to derive a value for the profile mean speed, which is always lower. Whilst laminar flow conditions are widespread in the interrill zone, few data are available with which to establish the relationship linking surface and profile mean speeds, and there are virtually none for the flow range 100 < Re < 500 (Re = Reynolds number) which is studied here. In laboratory experiments on a glued sand board, mean flow speeds were estimated from both dye speeds and the volumetric flow relation
v = Q/
wd with
d measured using a computer‐controlled needle gauge at 64 points. In order to simulate conditions applicable to many dryland soils, the board was also roughened with plant litter and with ceramic tiles (to simulate surface stone cover). Results demonstrate that in the range 100 < Re < 500, there is no consistent relation between surface flow speeds and the profile mean. The mean relationship is
v = 0·56 v
surf, which departs significantly from the theoretical smooth‐surface relation
v = 0·67 v
surf, and exhibits a considerable scatter of values that show a dependence on flow depth. Given the inapplicability of any fixed conversion factor, and the dependence on flow depth, it is suggested that the use of dye timing as a method for estimating
v be abandoned in favour of precision depth measurement and the use of the relation
v = Q/
wd, at least within the laminar flow range tested. Copyright © 2001 John Wiley & Sons, Ltd.
Mapping the geochemistry of the northern Rub' Al Khali using multispectral remote sensing techniques
Authors: White Kevin , Goudie Andrew , Parker Adrian , Al‐Farraj Asma
Published: August 2002

Spatial variations in sand sea geochemistry relate to mixing of different sediment sources and to variations in weathering. Due to problems of accessibility, adequate spatial coverage cannot be achieved using field surveys alone. However, maps of geochemical composition produced from remotely sensed data can be calibrated against limited field data and the results extrapolated over large, inaccessible areas. This technique is applied to part of the Rub' Al Khali in the northern United Arab Emirates. Trend surface analysis of the results suggests that the sand sea at this location can be modelled as an east–west mixing zone of two spectral components: terrestrial reddened quartz sands and marine carbonate sands. Optical dating of these sediments suggests that dune emplacement occurred rapidly around 10 ka BP, when sea level was rising rapidly. The spatial distribution of mineralogical components suggests that this phase of dune emplacement resulted from coastal dune sands being driven inland during marine transgression, thereby becoming mixed with rubified terrestrial sands. Copyright © 2001 John Wiley & Sons, Ltd.
Implications of model uncertainty for the mapping of hillslope‐scale soil erosion predictions
Authors: Brazier Richard E. , Beven Keith J. , Anthony Steven G. , Rowan John S.
Published: August 2002

An integrated modelling approach (MIRSED) which utilizes the process‐based soil erosion model WEPP (Water Erosion Prediction Project) is presented for the assessment of hillslope‐scale soil erosion at five sites throughout England and Wales. The methodology draws upon previous uncertainty analysis of the WEPP hillslope soil erosion model by the authors to qualify model results within an uncertainty framework. A method for incorporating model uncertainty from a range of sources is discussed as a first step towards using and learning from results produced through the GLUE (Generalized Likelihood Uncertainty Estimation) technique. Results are presented and compared to available observed data, which illustrate that levels of uncertainty are significant and must be taken into account if a meaningful understanding of output from models such as WEPP is to be achieved. Furthermore, the collection of quality, observed data is underlined for two reasons: as an essential tool in the development of soil erosion modelling and also to allow further constraint of model uncertainty. Copyright © 2001 John Wiley & Sons, Ltd.
Laboratory simulation of clast abrasion
Authors: Lewin J. , Brewer P. A.
Published: August 2002

Experimental abrasion of river‐bed materials has been widely undertaken, producing ‘downstream’ fining rates that generally are believed to be much less than those observed in the field. A conclusion commonly adopted has been that sorting processes are more effective than abrasion processes. A comparative evaluation of results from an abrasion tank and a tumbling barrel are presented, which show that abrasion patterns and rates differ according to the equipment used, clast size and shape, the clast charge (barrel) and water velocity and bed material (tank). Abrasion is a composite process, and the effects achieved appear to be dominated by percussion in the tank and grinding in the barrel. Breakage, crushing and sandblasting are not modelled effectively, nor are effects achieved on clasts when they form part of the bed. Comparisons are made with other equipment used, the very limited amount of direct field abrasion monitoring, and with the probable suite of processes that may occur under field conditions. Also reviewed are the problems that arise when laboratory weight‐loss abrasion coefficients are used or converted into ones of size diminution, as usually derived from field observations of down‐channel trends. It is concluded that field abrasion rates generally have been underestimated, as the processes involved are at best only selectively represented by the experimental equipment so far used, and because the results obtained experimentally are capable of misinterpretation when related to field trends. Copyright © 2002 John Wiley & Sons, Ltd.
Flame retardant properties of EVA‐nanocomposites and improvements by combination of nanofillers with aluminium trihydrate
Authors: Beyer Günter
Published: August 2002

Flame retardant nanocomposites are synthesized by melt‐blending ethylene–vinyl acetate copolymers (EVA) with modified layered silicates (montmorillonites). Thermogravimetric analysis performed under different atmospheres (nitrogen and air) demonstrated a clear increase in the thermal stability of the layered silicate‐based nanocomposites. The use of the cone calorimeter to investigate the fire properties of the materials indicated that the nanocomposites caused a large decrease in heat release. The char‐formation is the main factor important for improvement and its function is outlined. Further improvements of the flame retardancy by combinations of nanofillers and traditional FR‐additives on the basis of metal hydroxides were also studied. Copyright © 2002 John Wiley & Sons, Ltd.
Antibacterial activity of volatile secondary metabolites from Caribbean soft corals of the genus Gorgonia
Authors: Roussis Vassilios , Chinou Ioanna B. , Tsitsimpikou Christina , Vagias Constantinos , Petrakis Panos V.
Published: August 2002

The volatile secondary metabolites of Caribbean corals from three species of the genus Gorgonia were studied. The main constituents of the gorgonian species G. ventalina, G. flabelum and G. mariae were identified and 12 metabolites were isolated and identified. The in vitro antibacterial activity of the volatile constituents was also studied against six Gram‐positive or ‐negative bacteria exhibiting a wide spectrum of antibacterial activities. Furanotriene, dihydro‐α‐santalen‐12‐one and E‐nerolidol showed the most interesting antibacterial action. Copyright © 2001 John Wiley & Sons, Ltd.
Volatile constituents of Vietnamese pummelo, orange, tangerine and lime peel oils
Authors: Minh Tu N. T. , Thanh L. X. , Une A. , Ukeda H. , Sawamura M.
Published: August 2002

The compositions of Vietnamese pummelo (Citrus grandis Osbeck), orange (C. sinensis Osbeck), tangerine (C. reticulata Blanco var. tangerine) and lime (C. limonia Osbeck) peel oil samples have been investigated by GC and GC–MS. The essential oils were extracted by the cold‐pressing method. Hydrocarbons, followed by aldehydes and alcohols, were the most abundant compounds in all four kinds of samples. Their percentages, respectively, were >98.7%, >97.6%, >98.6% and >95.4% in hydrocarbons; >0.3%, 0.4%, >0.3% and 1.1% in total aldehydes; 0.2%, 0.5%, 0.4% and 0.7% in alcohols. In Vietnamese pummelo oil, γ‐terpinene was not detected, while terpinolene was detected in small amounts and nootkatone only at a level of <0.05%. Orange oil composition was comparable to that of other sweet orange oils. δ‐3‐Carene was detected at a level of 0.1%. Tangerine oil is easily distinguished from other citrus oils by its content of various aliphatic aldehydes. Lime oil presented a very different composition from the other oils studied. Its limonene content was substantially lower than that of pummelo, orange and tangerine oils, whereas γ‐terpinene, β‐pinene and α‐pinene occurred in higher proportions, moreover, the sesquiterpene hydrocarbon fraction of this oil is qualitatively more complex and quantitatively more abundant than in the other oils. Copyright © 2002 John Wiley & Sons, Ltd.
Numerical simulation of mold filling in injection molding using a three‐dimensional finite volume approach
Authors: Chang Rong‐yeu , Yang Wen‐hsien
Published: August 2002

This work presents an implicit finite volume approach to simulate the three‐dimensional mold filling problems encountered during the injection molding. The described numerical model deals with the three‐dimensional isothermal flow of incompressible, high‐viscous Newtonian fluids with moving interfaces. The collocated finite volume method and the SIMPLE segregated algorithm are used to discretize and solve the Navier–Stokes equation. In addition, a bounded compressive high‐resolution differencing scheme is adopted to solve the advection equation to capture the interface on a Eulerian framework. This approach effectively solves the flow field in terms of CPU time and memory storage as well as the complicated three‐dimensional melt front topology. Several two‐ and three‐dimensional examples are presented to validate the presented approach and illustrate its capabilities. This method can more accurately predict the critical three‐dimensional phenomena encountered during mold filling than the existing Hele–Shaw analysis model. The presented numerical approach has been proven to be a highly effective and flexible tool for simulating mold filling problems. Copyright © 2001 John Wiley & Sons, Ltd.
High‐order filtering for control volume flow simulation
Authors: De Stefano G. , Denaro F. M. , Riccardi G.
Published: August 2002

A general methodology is presented in order to obtain a hierarchy of high‐order filter functions, starting from the standard top‐hat filter, naturally linked to control volumes flow simulations. The goal is to have a new filtered variable better represented in its high resolved wavenumber components by using a suitable deconvolution. The proposed formulation is applied to the integral momentum equation, that is the evolution equation for the top‐hat filtered variable, by performing a spatial reconstruction based on the approximate inversion of the averaging operator. A theoretical analysis for the Burgers' model equation is presented, demonstrating that the local de‐averaging is an effective tool to obtain a higher‐order accuracy. It is also shown that the subgrid‐scale term, to be modeled in the deconvolved balance equation, has a smaller absolute importance in the resolved wavenumber range for increasing deconvolution order. A numerical analysis of the procedure is presented, based on high‐order upwind and central fluxes reconstruction, leading to congruent control volume schemes. Finally, the features of the present high‐order conservative formulation are tested in the numerical simulation of a sample turbulent flow: the flow behind a backward‐facing step. Copyright © 2001 John Wiley & Sons, Ltd.
Efficient computation of natural convection in a concentric annulus between an outer square cylinder and an inner circular cylinder
Authors: Shu C. , Zhu Y. D.
Published: August 2002

In this work, the natural convection in a concentric annulus between a cold outer square cylinder and a heated inner circular cylinder is simulated using the differential quadrature (DQ) method. The vorticity‐stream function formulation is used as the governing equation, and the coordinate transformation technique is introduced in the DQ computation. It is shown in this paper that the outer square boundary can be approximated by a super elliptic function. As a result, the coordinate transformation from the physical domain to the computational domain is set up by an analytical expression, and all the geometrical parameters can be computed exactly. Numerical results for Rayleigh numbers range from 104 to 106 and aspect ratios between 1.67 and 5.0 are presented, which are in a good agreement with available data in the literature. It is found that both the aspect ratio and the Rayleigh number are critical to the patterns of flow and thermal fields. The present study suggests that a critical aspect ratio may exist at high Rayleigh number to distinguish the flow and thermal patterns. Copyright © 2002 John Wiley & Sons, Ltd.
Numerical simulation of laminar flow and heat transfer over banks of staggered cylinders
Authors: Roychowdhury D. Ghosh , Das Sarit Kumar , Sundararajan T.
Published: August 2002

A study is conducted to investigate forced convective flow and heat transfer over a bank of staggered cylinders. Using a novel numerical formulation based on a non‐orthogonal collocated grid in a physical plane, the effects of Reynolds number and cylinder spacing on the flow and heat transfer behaviour are systematically studied. It is observed that both the Reynolds number and cylinder spacing influence the recirculatory vortex formation and growth in the region between the cylinders; in turn, the rates of heat transfer between the fluid and the staggered cylinders are affected. As the cylinder spacing decreases, the size and length of eddies reduce. For sufficiently small spacings, eddy formation is completely suppressed even at high Reynolds number. Pressure drop and Nusselt number predictions based on numerical study are in excellent agreement with available correlations. The study provides useful insight on the detailed flow and heat transfer phenomena for the case of a bank of staggered cylinders. Copyright © 2002 John Wiley & Sons, Ltd.
The Demand for Hedging with Futures and Options
Authors: Frechette Darren L.
Published: August 2002

The optimal hedging portfolio is shown to include both futures and options under a variety of circumstances when the marginal cost of hedging is nonzero. Futures and options are treated as substitute goods, and the properties of the resulting hedging demand system are explained. The overall optimal hedge ratio is shown to increase when the marginal cost of trading options is reduced. The overall optimal hedge ratio is shown to decrease when the marginal cost of trading futures is decreased. One implication is that hedging demand can be stimulated by a reduction in the perceived cost of trading options through the education of hedgers about options and the initiation of programs such as the Dairy Options Pilot Program. The demand approach is applied to estimate optimal hedge ratios for dairy producers hedging corn inputs in five regions of Pennsylvania. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:693–712, 2001
Clustering and psychological barriers: the importance of numbers
Authors: Mitchell Jason
Published: August 2002

The contemporary press frequently makes mention of, and identifies significance with, specific numerical values in financial markets. This focus has been suggested to result in clustering. Furthermore, these symbolic numbers are often referred to as psychological barriers. These effects are identified as a widespread phenomenon permeating into the economic decision making and financial market environments. This article outlines various arguments and rationale from the cultural, economic, and behavioral literature why clustering and other effects such as psychological barriers may be expected in financial markets. Evidence across a variety of literatures suggests that financial market clustering derives from a variety of sources. There is evidence from a cultural and conventional basis to suggest that number preference exists and that there is a natural tendency to round that derives from the development of the modern decimal system. The literature also provides valid behavioral and economic reasons as to why these effects may occur. However, no evidence is found to support the notion that clustering or barriers in financial markets would occur as a result of a natural order or as a product of the number progression or simply from the numbers themselves. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:395–428, 2001
Novel ERBB4 juxtamembrane splice variants are frequently expressed in childhood medulloblastoma
Authors: Gilbertson Richard , Hernan Roberto , Pietsch Torsten , Pinto Lais , Scotting Paul , Allibone Richard , Ellison David , Perry Robert , Pearson Andrew , Lunec John
Published: August 2002

We recently reported a significant relationship between tumor cell expression of the ERBB4 receptor, the most recently described member of the epidermal growth factor receptor family, and aggressive tumor phenotype in childhood medulloblastoma. Two alternative juxtamembrane (JM) isoforms of the ERBB4 receptor have been described. Termed JMa and JMb, these variants possess different receptor processing and ligand‐binding characteristics. In the current study, we employed an RT‐PCR and sequencing strategy to determine the pattern of ERBB4 JM isoform expression in a large (n = 78) series of pediatric medulloblastomas. JMa and JMb transcript expression was detected in 53% and 28% of tumor samples, respectively. In addition, two novel ERBB4 JM isoforms, which we have termed JMc and JMd, were isolated from 10% and 36% of tumors, respectively. Sequence analysis revealed the JMc transcript to contain a deletion of the entire JM region. In contrast, JMd includes an extended coding region, retaining both the JMa and JMb sequences. Neither of these novel isoforms was detected in normal human adult cerebellum, but expression of JMd was observed in developing fetal cerebellum, suggesting that this later isoform may represent an ERBB4 transcript restricted to primitive neuroectoderm‐derived tissue. To confirm that the four ERBB4 JM isoforms arise by alternative RNA splicing, we sequenced the intron‐exon junctions of the human ERBB4 gene within the JM region. This demonstrated the four ERBB4 JM variants to be encoded by two short exons containing the JMb and JMa sequences positioned in the order 5′ to 3′ and separated by a 121 bp intron. © 2001 Wiley‐Liss, Inc.
An ins(X;11)(q24;q23) fuses the MLL and the Septin 6/KIAA0128 gene in an infant with AML‐M2
Authors: Borkhardt Arndt , Teigler‐Schlegel Andrea , Fuchs Uta , Keller Claudia , König Margit , Harbott Jochen , Haas Oskar A.
Published: August 2002

The MLL (HRX, ALL‐1 HTRX) gene at chromosome band 11q23 frequently is rearranged in acute lymphoblastic and myeloblastic leukemia. To date, more than 40 different 11q23 abnormalities have been described on the cytogenetic level, and at least 25 of the respective fusion partner genes are cloned. The vast majority of the respective reciprocal translocations generate a chimeric 5′‐MLL/partner‐3′ gene on the derivative 11q23. In this work, we report a unique ins(X;11)(q24;q23) in an infant with acute myeloid leukemia (AML‐M2) that fuses the human KIAA0128 gene at Xq24 with MLL. In contrast to the typical reciprocal MLL translocations, however, we provide evidence that the 5′‐MLL/KIAA0128‐3′ fusion resides on Xq24 rather than on 11q23. The KIAA0128 gene encodes the human Septin 6 protein, which contains an ATP‐GTP binding motif and three nuclear targeting sequences in its carboxy terminus. The maintenance of the reading frame of the 5′‐MLL/KIAA0128‐3′ mRNA fusion allows for the formation of a novel chimeric protein. Septin 6 is the third member of the Septins that is fused to the MLL protein; the other two are hCDCrel at 22q11 and MSF at 17q25. © 2001 Wiley‐Liss, Inc.
SNRPN methylation patterns in germ cell tumors as a reflection of primordial germ cell development
Authors: Bussey Kimberly J. , Lawce Helen J. , Himoe Eleanor , Shu Xiao Ou , Heerema Nyla A. , Perlman Elizabeth J. , Olson Susan B. , Magenis R. Ellen
Published: August 2002

Studies examining altered imprinted gene expression in cancer compare the observed expression pattern to the normal expression pattern for a given tissue of origin, usually the somatic expression pattern for the imprinted gene. Germ cell tumors (GCTs), however, require a developmental stage‐dependent comparison. To explore using methylation as an indicator of germ cell development, we determined the pattern of methylation at the 5′ untranslated region of SNRPN in 89 GCTs from both children and adults. Fifty‐one of 84 tumors (60.7%) (12/30 (40%) of cultured pediatric GCTs, 23/36 (63.9%) of frozen adult GCTs, and 16/23 (69.5%) of frozen pediatric GCTs, with five samples having results from both cultured and uncultured material) demonstrated a nonsomatic methylation pattern after dual digestion with XbaI, NotI, and Southern blot analysis. In contrast, only 2 of 18 (11%) control samples (16 non‐GCTs and 2 normal ovaries) exhibited a nonsomatic pattern. In both cases, the result was shown to be due to copy number differences between maternal and paternal homologs, unlike the GCTs in which there was no evidence of an uneven homolog number. A comparison of the data for only the gonadal GCTs and the control data showed a highly significant difference in the proportion of tumors with methylation alterations at this locus (P = 0.0000539). Since there is no published evidence of the involvement of SNRPN methylation changes in the development of malignancy, the data suggest that the methylation pattern of SNRPN in GCTs reflects that of the primordial germ cell giving rise to the tumor. © 2001 Wiley‐Liss, Inc.