bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dioecy and monoecy in the flora of Sri Lanka and their evolutionary correlations to endemism, growth form, fruit type, seed number and flower size
Authors: Senarath W.T.P.S.K. 
Published: June 2008

The frequency of dioecy and monoecy and the ecological correlates of each sexual system were examined for the flora of Sri Lanka, a tropical continental island. Of the 3,529 species in the total flora, 7.05% are dioecious, 10.25% are monoecious, 1.7% are polygamodioecious, 1.9% are polygamous and 79.1% are hermaphrodites. Study was carried out to test the null hypothesis that the proportionate distribution of dioecious and monoecious taxa in endemism, growth form, fruit type, seed number or flower size was not significantly different from that for the entire flora. Both monoecious and dioecious species in the Sri Lankan flora are significantly associated with the growth form, fruit type, seed number and flower size, whereas only dioecy is associated with endemism. Dioecious species are favored by trees and small flowers, whereas monoecious species are favored by herbs and minute flowers. Both dioecious and monoecious species are, however, associated with fleshy fruits suggesting that animal dispersal of fruits is favored in the Sri Lankan flora. Keywords: Flora, Evolutionary correlations, Dioecy, Monoecy, Sri LankaDOI: 10.3329/bjpt.v15i1.907Bangladesh J. Plant Taxon. 15(1): 13-19, 2008 (June)
New records of phytoplankton for Bangladesh. 5. <i>Euglena, Euglenocapsa</i>
Authors: Khondker Moniruzzaman , Bhuiyan Rauf Ahmed , Yeasmin Jenat , Alam Munirul , Sack R. Bradley , Huq Anwar , Colwell Rita R. 
Published: June 2008

This study presents 20 taxa of the genus Euglena and one species of the rare euglenoid genus Euglenocapsa. All these taxa are reported for the first time from some pond ecosystems of Mathbaria in Pirojpur and Bakerganj of Barisal districts of Bangladesh. Keywords: Phytoplankton, New records, Bangladesh, Euglena, Euglenocapsa, PondsDOI: 10.3329/bjpt.v15i1.910Bangladesh J. Plant Taxon. 15(1): 39-46, 2008 (June)
Neural network‐based adaptive control of piezoelectric actuators with unknown hysteresis
Authors: Xie Wen‐Fang , Fu Jun , Yao Han , Su C.‐Y. 
Published: June 2008

AbstractThis paper proposes a neural network (NN)‐based adaptive control of piezoelectric actuators with unknown hysteresis. Based on the classical Duhem model described by a differential equation, the explicit solution to the equation is explored and a new hysteresis model is constructed as a linear model in series with a piecewise continuous nonlinear function. An NN‐based dynamic pre‐inversion compensator is designed to cancel out the effect of the hysteresis. With the incorporation of the pre‐inversion compensator, an adaptive control scheme is proposed to have the position of the piezoelectric actuator track the desired trajectory. This paper has three distinct features. First, it applies the NN to online approximate complicated piecewise continuous unknown nonlinear functions in the explicit solution to Duhem model. Second, an observer is designed to estimate the output of hysteresis of piezoelectric actuator based on the system input and output. Third, the stability of the controlled piezoelectric actuator with the observer is guaranteed. Simulation results for a practical system validate the effectiveness of the proposed method in this paper. Copyright © 2008 John Wiley & Sons, Ltd.
Adaptive observers for linear stochastic time‐variant systems with disturbances
Authors: Perabò Stefano , Zhang Qinghua 
Published: June 2008

AbstractMotivated by fault detection and isolation problems, we present an approach to the design of state observers for linear time‐variant stochastic systems with unknown parameters and disturbances. The novelties with respect to more conventional techniques are as follows: (a) the joint estimation of state, disturbances and parameters can be carried out; (b) it is a full‐stochastic approach: the unknown parameters and disturbances are random quantities and prior information, in terms of means and covariances, can be easily taken into account; (c) the observer structure is not fixed a priori, rather derived from the optimal one by means of a sliding window approximation; (d) contrary to descriptor system techniques, which estimate the state starting from a restricted set of disturbance‐free equations, our approach is focused on disturbance estimation, from which state estimates are derived straightforwardly. Copyright © 2008 John Wiley & Sons, Ltd.
Adaptive TS‐FNN control for a class of uncertain multi‐time‐delay systems: The exponentially stable sliding mode‐based approach
Authors: Chiang Tung‐Sheng , Chiu Chian‐Song , Liu Peter 
Published: June 2008

AbstractThis paper presents an adaptive Takagi–Sugeno fuzzy neural network (TS‐FNN) control for a class of multiple time‐delay uncertain nonlinear systems. First, we develop a sliding surface guaranteed to achieve exponential stability while considering mismatched uncertainty and unknown delays. This exponential stability result based on a novel Lyapunov–Krasovskii method is an improvement when compared with traditional schemes where only asymptotic stability is achieved. The stability analysis is transformed into a linear matrix inequalities problem independent of time delays. Then, a sliding mode control‐based TS‐FNN control scheme is proposed to achieve asymptotic stability for the controlled system. Since the TS‐FNN combines TS fuzzy rules and a neural network structure, fewer numbers of fuzzy rules and tuning parameters are used compared with the traditional pure TS fuzzy approach. Moreover, all the fuzzy membership functions are tuned on‐line even in the presence of input uncertainty. Finally, simulation results show the control performance of the proposed scheme. Copyright © 2008 John Wiley & Sons, Ltd.
Parametric study and estimation in CFD‐based PEM fuel cell models
Authors: Jain Parag , Biegler Lorenz T. , Jhon Myung S. 
Published: June 2008

AbstractWe propose an integrated modeling and optimization framework including detailed computational fluid dynamics based models and polymer electrolyte membrane fuel cell (PEMFC) systems. As an illustration, a multidimensional, multiphysics PEMFC model is constructed that accounts for major transport processes in the gas channels and the membrane electrode assembly. The resulting system of highly nonlinear partial differential‐algebraic equations is fully discretized using a finite volume method, and the resulting large‐scale nonlinear program is linked to a state‐of‐the‐art interior point optimization algorithm. The framework is used for solving challenging parameter estimation problems resulting from incorporation of multiple experimental data points. Also, parametric studies are performed on detailed water transport mechanisms and distribution characteristics, and on overall system performance. Our proposed framework provides a robust and fast solution methodology, and is planned for modeling extensions and addressing other critical issues in PEMFC technology that require large‐scale simulations. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Diameter‐dependent dispersion in cylindrical bead packs
Authors: Vandre Eric , Maier Robert S. , Kroll Daniel M. , McCormick Alon , Davis H. Ted 
Published: June 2008

AbstractIt has recently been argued that longitudinal dispersion in cylindrical packed beds is enhanced due to radial heterogeneities in the porosity and resulting velocity field. In particular, it is predicted that the time scale to attain asymptotic dispersion in a packed bed of radius R is proportional to R2/DT, where DT is the transverse dispersion constant in a homogeneous beadpack, and that the asymptotic longitudinal dispersion constant increases with R/d, where d is the bead diameter. We have measured the asymptotic dispersion rates for packed beds with R/d = 9.5, 12.7, and 25.4 and find good qualitative agreement with the predicted dependence on R/d. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Simple approximate analytical solution for nonisothermal single‐step transformations: Kinetic analysis
Authors: Farjas J. , Roura P. 
Published: June 2008

AbstractWe develop a method for obtaining the approximate solution for the evolution of single‐step transformations under nonisothermal conditions. We have applied it to many reaction models and obtained very simple analytical expressions for the shape of the corresponding transformation rate peaks. These analytical solutions represent a significant simplification of the system's description allowing easy curve fitting to experiment. A remarkable property is that the evolutions of the transformed fraction obtained at different heating rates are identical when time is scaled by a time constant. The accuracy achieved with our method is checked against several reaction models and different temperature dependencies of the transformation rate constant. It is shown that its accuracy is closely related with that of the Kissinger method. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Mechanistic features of the sonochemical degradation of organic pollutants
Authors: Sivasankar Thirugnanasambandam , Moholkar Vijayanand S. 
Published: June 2008

AbstractThis work considers the mechanistic features of sonochemical degradation of volatile (chlorobenzene) and nonvolatile (phenol) organic pollutants. The sonochemical degradation of pollutant occurs in two pathways: thermal pyrolysis and hydroxylation. By coupling experimental results to bubble dynamics model, we have tried to establish relative contribution of these pathways to degradation of two kinds of pollutants. It is revealed that degradation of volatile pollutants occurs primarily by thermal pyrolysis while hydroxylation is the predominant mechanism of degradation of nonvolatile pollutants. The simulation results also help explain some interesting trends observed in degradation with reaction parameters such as initial pollutant concentration and salt addition to solution. These parameters are found to influence both pathways of degradation that leads to enhancement in degradation. However, the extent of this influence on hydroxylation and pyrolysis pathways is different for phenol and chlorobenzene. This is attributed to different partitioning behavior and solubility of the two pollutants. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Determination of cubic equation of state parameters for pure fluids from first principle solvation calculations
Authors: Hsieh Chieh‐Ming , Lin Shiang‐Tai 
Published: June 2008

AbstractA new method for estimation of parameters in cubic equations of state from ab initio solvation calculations is presented. In this method, the temperature‐dependent interaction parameter a(T) is determined from the attractive component of solvation free energy, whereas the volume parameter b is assumed to be that of solvation cavity. This method requires only element‐specific parameters, i.e., atomic radius and dispersion coefficient, and nine universal parameters for electrostatic and hydrogen‐bonding interactions. The equations of state (EOS) parameters so determined allow the description of the complete fluid phase diagram, including the critical point. We have examined this method using the Peng–Robinson EOS for 392 compounds and achieved an accuracy of 43% in vapor pressure, 17% in liquid density, 5.4% in critical temperature, 11% in critical pressure, and 4% in critical volume. This method is, in principle, applicable to any chemical species and is especially useful for those whose experimental data are not available. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Preparation of magnetic γ‐Al2O3 supported palladium catalyst for hydrogenation of nitrobenzene
Authors: Lang Yuqi , Wang Qiaoqiao , Xing Jianmin , Zhang Bo , Liu Huizhou 
Published: June 2008

AbstractSpherical alumina support with magnetic core of 134 nm in diameter was prepared by the controlled hydrolysis of aluminums iso‐propoxide. The magnetite Fe3O4 nanoparticles were first synthesized by coprecipitation. Later silica film was coated onto the surface of Fe3O4 nano particles with the sodium silicate acidification method. Alumina was supported on Fe3O4/SiO2 film by the controlled hydrolysis of aluminum alkoxide in a dilute solution consisting of cyclohexane and 2‐propanol. Finally, magnetic alumina supported palladium catalysts were prepared by microemulsion method. The surface morphology and crystal structure of the magnetic alumina and catalysts were characterized by XRD, TEM, BET, and VSM, respectively. The results showed that these kinds of composite particle exhibit superparamagnetic behavior with zero coercivity and remanence. The catalysts show high activity for nitrobenzene directly hydrogenating to aniline under mild conditions. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Family‐based association study between NOS‐I and ‐IIA polymorphisms and autism spectrum disorders in Korean trios
Authors: Kim Hyo‐Won , Cho Soo‐Churl , Kim Jae‐Won , Cho In Hee , Kim Soon Ae , Park Mira , Cho Eun Jeong , Yoo Hee‐Jeong 
Published: June 2008

AbstractAutism spectrum disorder (ASD) is a complex neurodevelopmental disorder with a strong genetic component and environmental risk factors. Nitric oxide (NO), which is produced by nitric oxide synthase (NOS), may play a role in the development of ASD. We genotyped nine single nucleotide polymorphisms (SNPs) in the NOS‐I gene and nine SNPs in the NOS‐IIA gene and carried out the transmission disequilibrium test (TDT) and haplotype analysis in 151 Korean ASD trios. We found preferential transmission of the A allele of rs8068149 (P = 0.039) and G allele of rs1060826 (P = 0.035) of NOS‐IIA in ASD and the haplotype analysis revealed that the two haplotypes had significant associations (P = 0.014 and 0.031, respectively). The behavioral subdomain score of failure to use nonverbal behaviors to regulate social interaction in Autism Diagnostic Interview‐Revised (ADI‐R) was significantly higher in subjects with the GG or AG allele in rs1060826 of NOS‐IIA compared to those who had the AA allele (P = 0.027). These results provide significant but weak evidence for an association between NOS‐IIA and ASD in the Korean population. © 2008 Wiley‐Liss, Inc.
The impact of genetic variation in DRD2 and SLC6A3 on smoking cessation in a cohort of participants 1 year after enrollment in a lung cancer screening study
Authors: Styn Mindi A. , Nukui Tomoko , Romkes Marjorie , Perkins Kenneth , Land Stephanie R. , Weissfeld Joel L. 
Published: June 2008

AbstractSmoking cessation strategies continue to have disappointing results. By determining the interindividual genetic differences that influence smoking behaviors, we may be able to develop tailored strategies that increase the likelihood of successful cessation. This study attempts to determine genetic influences on the relationship between the dopamine pathway and smoking cessation by examining associations with a variable number tandem repeat variation in SLC6A3 and the DRD2 variants TaqIA (A2 vs. A1), TaqIB (B2 vs. B1), C957T (C vs. T), and −141C Ins/Del (C vs. Del). Baseline smokers in the Pittsburgh Lung Screening Study who provided information on smoking status 1 year later were evaluated. We frequency‐matched those who were not abstinent at 1 year to those who were abstinent at 1 year by gender, decade of age, and time of enrollment (3‐month intervals) in a 3:1 ratio (N = 881). Logistic regression was used to identify the effect of genotype on abstinence at 1 year. In a model containing the matching variables and other genotypes, DRD2 TaqIA was significantly associated with being abstinent at 1 year (P = 0.01). Compared to participants who were homozygous for the TaqIA major allele (A2A2), participants who carried at least one minor allele (A1) were less likely to quit (Odds Ratio: 0.47, 95% CI: 0.24–0.94). The other dopamine receptor genotypes and the SLC6A3 genotype were not associated with smoking status at 1 year. The association between DRD2 TaqIA and smoking cessation supports the hypothesis that genetic variation in the dopamine pathway influences smoking cessation. © 2008 Wiley‐Liss, Inc.
Tensidfreie nichtwässrige Synthese von Metalloxid‐Nanostrukturen
Authors: Pinna Nicola , Niederberger Markus 
Published: June 2008

AbstractTensidfreie nichtwässrige (und/oder nichthydrolytische) Sol‐Gel‐Prozesse repräsentieren eine der vielfältigsten und leistungsfähigsten Synthesemethoden für hoch reine und homogene Metalloxid‐Nanokristalle. Obwohl die verwendeten Reaktionssysteme lediglich aus den Metalloxid‐Vorstufen und organischen Lösungsmitteln bestehen, können auf diesem Weg doch einheitliche Nanokristalle mit vielfältigen Größen und Formen erhalten werden. Durch die geringe Zahl an Ausgangskomponenten gelingt es mit einfachen Mitteln, die Bildungsmechanismen der Metalloxide zu studieren. Nichthydrolytische Wege zu anorganischen Nanomaterialien unter Einsatz von Tensiden wurden kürzlich bereits diskutiert. Der vorliegende Kurzaufsatz ergänzt dieses Thema durch die Behandlung von tensidfreien Prozessen, die mittlerweile eine nützliche Alternative zu Synthesen unter Tensidzusatz sowie zu klassischen Sol‐Gel‐Prozessen in wässrigen Medien darstellen.
Melt mixing of carbon fibers and carbon nanotubes incorporated polyurethanes
Authors: Abdullah Shahrul Azam , Iqbal Azhar , Frormann Lars 
Published: June 2008

AbstractPolyurethane composites filled with carbon fibers (CF) and carbon nanotubes (CNT) were prepared by mixing and injection molding, and its mechanical as well as their thermal properties were investigated. Dynamic mechanical analysis (DMA), thermogravimetry analysis (TGA), and thermal conductivity tests were done, and the properties were evaluated as a function of the filler concentration. The storage modulus of the composites increased with fillers concentration, which also mean the increase of the stiffness, suggest a good adhesion between the polyurethane matrix and the fillers. Addition of more CF and CNT to the composites broadened and lowered the peak of tan δ specifies that the polyurethane composite became more elastic because there is a good adhesion between the fillers and the matrix. The addition of carbon fillers improves the thermal stability of the polyurethane. The inclusions of CNT show a better thermal stability when compared with CF. The addition of carbon fillers also increased the thermal conductivity of the polyurethane composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dehydration of benzene through fluorine containing aromatic polyamide membrane by pervaporation
Authors: Gutch P. K. , Pandey L. K. , Saxena Chhaya 
Published: June 2008

AbstractA series of soluble polyamides were synthesized by direct polycondensation of the 5‐tert‐butyl isophthalic acid with different diamines. Solution (20%) of the polymers in suitable solvents was used to cast the membranes. The membranes showed selectivity toward the benzene (Bz) in a mixture of Bz/water (H2O). Water affinity of the membrane was found to be lower than that of Bz. The polyamide incorporating hexafluoro isopropylidene moiety was promising for the dehydaration of Bz and breaking of Bz/H2O azeotrope. The polymers exhibited inherent viscosities, ranging from 0.40 to 0.92 dL/g and 10% weight loss in synthetic air up to 474°C. Glass transition temperature measured by DSC and DMA reached up to 258°C. The membranes were pale yellow in appearance having tensile strength up to 85 MPa, modulus of elasticity up to 2.6 GPa, and elongation at break up to 9.5%, depending upon the exact repeating unit structure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Tin‐coupled star‐shaped block copolymer of styrene and butadiene (I) synthesis and characterization
Authors: Feng Huadong , Zhang Xingying , Zhao Suhe 
Published: June 2008

AbstractA new kind of star‐shaped block copolymer: tin‐coupled polybutadiene‐b‐ploy(styrene‐butadiene) ((SB‐B)4Sn) was synthesized by two‐stage anionic polymerization technology. A novel multifunctional organo‐lithium was used as initiator, and two different types of copolymers were formed, namely, S‐PB‐PSB and S‐PB‐PSB‐PS, depending on the styrene content in loading solution (St%). In copolymerization, the homo‐polybutadiene block was formed in the first reaction stage, and the residual blocks were formed in the second stage with the presence of tetrahydrofuran (THF). S‐PB‐PSB was synthesized when the St% was lower than 34.9%, otherwise S‐PB‐PSB‐PS was generated. Nuclear magnetic resonance (NMR) results showed that the amount of vinyl based upon the butadiene content within poly(butadiene‐styrene) blocks decreased dramatically as the St% was increased. Dynamic mechanical thermal analyzer (DMTA) spectra showed broadened loss peak as the St% was increased. Transmission electron microscopy (TEM) was employed to characterize the copolymer morphology, and the results showed different phase‐separated morphologies as St% increased. Mechanical property testing results indicated that these two copolymers met the requirements of high performance tire tread. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Building ontological relationships: A new approach
Authors: Kayed Ahmad , Hirzallah Nael , Shalabi Luai A. Al , Najjar Mohannad 
Published: June 2008

AbstractOntology plays an essential role in recognizing the meaning of the information in Web documents. It has been shown that extracting concepts is easier than building relationships among them. For a defined set of concepts, many existing algorithms produce all possible relationships for that set. This makes the process of refining the relationships almost impossible. A new algorithm is needed to reduce the number of relationships among a defined set of concepts produced by existing algorithms. This article contributes such an algorithm, which enables a domain‐knowledge expert to refine the relationships linking a set of concepts. In the research reported here, text‐mining tools have been used to extract concepts in the domain of e‐commerce laws. A new algorithm has been proposed to reduce the number of extracted relationships. It groups the concepts according to the number of relationships with other concepts and provides formalization. An experiment and software have been built, proving that reducing the number of relationships will reduce the efforts needed from a human expert.
Next generation of information infrastructure: A comparative case study of Korea versus the United States of America
Authors: Shin Dong‐Hee 
Published: June 2008

AbstractThis study compares the United States of America and Korea's cases of national information infrastructure (NII) development, focusing on the role of the governments in the development of their NIIs and on the realization of the next generation of information infrastructure vision. The important similarities and differences can be seen by comparison on sociotechnical dimensions: government function, histories, visions, policy design, implementation plans, and realities and prospects. Findings show different patterns of NII development, providing insights for the next generation of NIIs. This study provides a prospect towards future information infrastructure needs in the context of dynamic sociotechnical changes.