bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of ultrahigh‐molecular‐weight polyethylene membranes via a thermally induced phase‐separation method
Authors: Ding Huaiyu , Tian Ye , Wang Lihua , Liu Biqian 
Published: May 2007

AbstractPorous, flat membranes of ultrahigh‐molecular‐weight polyethylene were prepared as thermally resistant and solvent‐resistant membranes by the thermally induced phase‐separation method. Diphenyl ether and decalin were chosen as the diluents. The phase diagrams were drawn with the cloud‐point temperatures and the crystallization temperatures. According to the phase diagrams, scanning electron microscopy images, and porosities of the samples, the influential factors, including the polymer concentration, cooling rate, and viscosity, were investigated. Porous ultrahigh‐molecular‐weight polyethylene membranes with thermal and solvent resistance could be prepared with suitable diluents and cooling rates by the thermally induced phase‐separation method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Synthesis and characterization of functionalized triblock polymer: The prepared polymer is cholesteryl terminated and chain‐extended PCL
Authors: Guo Jinbao , Sun Jie , Cao Hui , Zhao Dongyu , Yang Huai 
Published: May 2007

AbstractThe functionalized triblock polymer for the preparation of self‐assembly biomaterials, Chol‐(CL)n‐Chol, was synthesized through ring‐opening polymerization of ε‐caprolactone (ε‐CL) following by chain‐extension reaction. The chemical structure of functionalized triblock polymer was confirmed by Fourier transform infrared and 1H‐NMR. The molecular weight of the functionalized polymer increased with decreasing feed ratio of the initiator cholesterol (Chol) to the monomer ε‐CL. Liquid crystalline properties and the self‐assembly behavior of the functionalized polymer were validated by Wide angle X‐ray diffraction, differential scanning calorimetry, and polarizing light microscope. The results showed that Chol‐(CL)n‐Chol (n ≤ 40) exhibited liquid crystallinity in particular temperature ranges because of the incorporation of the cholesteryl moiety. In addition, the functionalized triblock polymer can be homogeneously blended with high molecular weight poly(ε‐caprolactone) (PCL), which offers the possibility to modify the properties of biomaterials based on PCL. Mixing a small amount of a Chol‐(CL)n‐Chol functionalized polymer with PCL, or coating a thin layer of the functionalized polymer on the surface of a PCL‐based implant may modify cell response. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Application of similarity aggregation techniques to a population of paraplegic patients
Authors: Parisot Pierre 
Published: May 2007

AbstractWe studied a population of paraplegic patients in order to give prominence to a possible relationship between the topography of their spinal lesion and the occurrence of special articular diseases (P.O.A.).According to the motor and sensory state of their spinal cord, we first tried to obtain a classification of these lesions (the usual one schematically separates ‘flaccid’ and ‘rigid’ paraplegics).We mainly put the emphasis on this clustering step of the study:
— choice and meaning of the data and their coding;
— explanation and justification of the method used: the similarity aggregation;
— interpretation of results and discussion.
Estimation for incomplete manpower data
Authors: McClean S. I. , Gribbin J. O. 
Published: May 2007

AbstractMuch attention has been paid to both non‐parametric and parametric estimation for survival data with right censoring, particularly in the medical literature. In manpower planning the completed length of service until leaving is of great interest, and here also the data are right censored since people are still in service when data collection ends. However, it often occurs that the data are also left truncated since people are already in service at the beginning of data collection. These people have often been neglected both in estimation of the empirical distribution function and also in fitting particular parametric distributions. However, it is important to include them so as to use all the data, particularly when data are only present for a short period.The methods developed were applied to data for the completed length of service of both skilled and unskilled workers where the data were collected over a period of years. Using modified Kaplan‐Meier estimation, applied to these data sets, empirical distribution functions were obtained. A number of parametric distributions were also fitted. The goodness of fit of these distributions as predictors of leavers and stayers over a given period was then tested using a chi‐squared test.
On the control of queueing systems with failures and repairs
Authors: Menaldi José‐Luis , Robin Maurice 
Published: May 2007

AbstractSeveral classes of problems can be modelled as queueing systems with failures where preventative maintenance has to be optimized: relevant examples are computer systems, databases and production lines.This paper studies a simple case of such a situation based on the M/M/1 queue where the state of the server can take two values (on, off); the transition on–off happens either when there is a failure or when one decides to maintain. The characterization and an approximation of an optimal policy are given. Extensions to more general models, including general Markov processes, are examined.
Estimating mean time to absorption for a markov chain with limited information
Authors: Katz Joseph L. , Burford Roger L. 
Published: May 2007

AbstractIn many applications of absorbing Markov chains, solution of the problem at hand involves finding the mean time to absorption. Moreover, in almost all real world applications of Markov chains, accurate estimation of the elements of the probability matrix is a major concern. This paper develops a technique that provides close estimates of the mean number of stages before absorption with only the row sums of the transition matrix of transient states.
A new method for the estimation of variance components directly from the sample covariance matrix
Authors: El‐Shishiny Hisham , Mansour Hussein 
Published: May 2007

AbstractStatistical techniques for the estimation of variance components are usually associated with methodological and computational difficulties.In this paper a new computational method for the estimation of variance components directly from the sample covariance matrix is proposed. A comparison between this method and the maximum likelihood method for variance component estimation, based on their computational performance, is made. Cases for balanced and unbalanced simulated data assuming a two‐way nixed model with correlated errors are considered, and a real‐life application in animal breeding is presented.
On the classification of observations structured into groups
Authors: Bertolino Francesco 
Published: May 2007

AbstractThe paper is concerned with the problem of classifying a specific group into two populations (insect eggs of the same clutch belonging therefore to the same species). Two approaches, one parametric and the other non‐parametric, are described. The classical likelihood ratio procedure is derived. An interpretation and a decomposition of the test criteria is given. A misclassification estimate using the Chernoff–Kullback–Kailath region is provided.
Analysis of patient self‐assessment visual analogue scales
Authors: Solomon P. J. 
Published: May 2007

AbstractThe present paper describes an example of practical analysis of data from an application of visual analogue scales. Potentially useful and simple methods for analysing visual analogue scales are described for effective handling of complex data when the desire is to compare two or more groups of patients. Visual analogue scales were used to assess subjective tolerability in the International Prospective Primary Prevention Study in Hypertension, a large scale clinical trial. The methods are illustrated on the IPPPSH data.
Renewal‐theoretic considerations in evaluation of forecast monitoring schemes
Authors: Sweet Arnold L. , Wilson James R. 
Published: May 2007

AbstractTo evaluate the performance of a scheme for monitoring forecasts that are generated by exponential smoothing, forecasters have traditionally used a simulation‐based estimator of some characteristic of the associated run‐length distribution. The most frequently cited performance measures are the average run length and the probability that the run length does not exceed a user‐specified cut‐off point. However, there is disagreement about the definition of run length that is appropriate in the context of forecasting. In this paper we use fundamental results from renewal theory to establish the precise relationships between conflicting formulations both of the average run length and of the probability density function for the run length. More generally we derive the asymptotic mean and the asymptotic distribution function of the forward recurrence time for both ordinary and delayed renewal processes whose interoccurrence distributions are arithmetic with a given span. We discuss the practical significance of these results in the context of forecasting. Our findings bear directly on the way in which simulation experiments should be designed and executed to compare alternative forecast monitoring schemes.
Analysis of pseudo‐periodic chronological series with irregularly time‐spaced data in view to their prediction. II. Fourier analysis
Authors: Mennessier M. O. , Burki G. , Cordoni J. P. 
Published: May 2007

AbstractThe problem originates from the necessity to predict luminosities of large‐amplitude variable stars that are to be observed by the astronomical satellite HIPPARCOS. The data have a specific character: they are unequally time‐spaced and can be missing during a long time in comparison to the pseudo‐period. So the classical method of time‐series analysis must be adapted and new methods are to be searched.In this paper we present a numerical solution derived from a Fourier analysis.
System availability: Time dependence and statistical inference by (semi) non‐parametric methods
Authors: Gaver D. P. , Jacobs P. A. 
Published: May 2007

AbstractProbability models are formulated for the availability (probability of being operative, i.e. not failed or down at fixed or random time t) of a variety of simple repairable systems. Single‐exponential approximations of the time‐dependent approach to long‐run availability are presented. Problems of non‐parametric estimation of time‐dependent system availability from data are addressed by way of the empirical Laplace—Stieltjes transform. Uncertainty assessments are made by classical asymptotics (delta method) and by bootstrapping.
An automated front‐end monitor for anthrax surveillance systems based on the rapid detection of airborne endospores
Authors: Yung Pun To , Lester Elizabeth D. , Bearman Greg , Ponce Adrian 
Published: May 2007

AbstractA fully automated anthrax smoke detector (ASD) has been developed and tested. The ASD is intended to serve as a cost effective front‐end monitor for anthrax surveillance systems. The principle of operation is based on measuring airborne endospore concentrations, where a sharp concentration increase signals an anthrax attack. The ASD features an air sampler, a thermal lysis unit, a syringe pump, a time‐gated spectrometer, and endospore detection chemistry comprised of dipicolinic acid (DPA)‐triggered terbium ion (Tb3+) luminescence. Anthrax attacks were simulated using aerosolized Bacillus atrophaeus spores in fumed silica, and corresponding Tb‐DPA intensities were monitored as a function of time and correlated to the number of airborne endospores collected. A concentration dependence of 102–106 spores/mg of fumed silica yielded a dynamic range of 4 orders of magnitude and a limit of detection of 16 spores/L when 250 L of air were sampled. Simulated attacks were detected in less than 15 min. Biotechnol. Bioeng. 2007; 98: 864–871. © 2007 Wiley Periodicals, Inc.
Ultrasound enhanced glucose release from corn in ethanol plants
Authors: Khanal Samir Kumar , Montalbo Melissa , van Leeuwen J. (Hans) , Srinivasan Gowrishankar , Grewell David 
Published: May 2007

AbstractThis work evaluated the use of high power ultrasonic energy to treat corn slurry in dry corn milling ethanol plants to enhance liquefaction and saccharification for ethanol production. Corn slurry samples obtained before and after jet cooking were subjected to ultrasonic pretreatment for 20 and 40 s at amplitudes of vibration ranging from 180 to 299 µmpp (peak to peak amplitude in µm). The resulting samples were then exposed to enzymes (alpha‐amylase and glucoamylase) to convert cornstarch into glucose. A comparison of scanning electron micrographs of raw and sonicated samples showed the development of micropores and the disruption of cell walls in corn mash. The corn particle size declined nearly 20‐fold following ultrasonic treatment at high power settings. The glucose release rate from sonicated samples increased as much as threefold compared to the control group. The efficiency of ultrasound exceeded 100% in terms of energy gain from the sugar released over the ultrasonic energy supplied. Enzymatic activity was enhanced when the corn slurry was sonicated with simultaneous addition of enzymes. This finding suggests that the ultrasonic energy did not degrade or denature the enzymes during the pretreatment. Biotechnol. Bioeng. 2007;98: 978–985. © 2007 Wiley Periodicals, Inc.
Über methylierte Nucleoside und Purine und ihre pharmakologischen Wirkungen, I. Mitteil.: Methylierung von Nucleosiden durch Diazomethan
Authors: Bredereck Hellmut 
Published: May 2007

AbstractBei der Methylierung von acetylierten Nucleosiden mit Diazomethan in ätherisch‐methylalkoholischer Lösung werden nur die in Nachbarschaft von CO‐Gruppen stehenden NH‐Gruppen methyliert; gleichzeitig erfolgt die Abspaltung der Acetylgruppen. Die Isolierung des 1.3‐Dimethyl‐xanthosins liefert einen zusätzlichen Beweis dafür, daß als Haftstelle der Ribose am Purinring die Stellung 1 und 3 ausscheidet.
Das Kondensationsprinzip, ein einfaches neues Prinzip im Aufbau der aromatischen Kohlenwasserstoffe (Aromatische Kohlenwassertoffe XLII. Mitteilung)
Authors: Clar Erich 
Published: May 2007

AbstractDie neuen Kohlenwasserstoffe Terrylen und Quaterrylen aus der Reihe der Poly‐„rylene”︁, bestehend aus 3 bzw. 4 peri‐Kondensierten Naphthalin‐Systemen werden synthetisiert und beschrieben. Es werden ferner die einfachen Beziehungen (das Kondensationsprinzip) zwischen den Absorptionsspektren der Polyphenyle, der Polyrylene (zusammengesetzt aus peri‐kondensierten Naphthalin‐Systemen) und der Polyanthene (zusammengesetzt aus peri‐kondensierten Anthracen‐Systemen) aufgezeigt.
Über den Sinapinalkohol, den Coniferylalkohol und ihre Dehydrierungspolymerisate
Authors: Freudenberg Karl , Kraft Richard , Heimberger Werner 
Published: May 2007

AbstractZur Synthese des Sinapinalkohols werden Ergänzungen mitgeteilt. Die enzymatische und alkalische Spaltung des Syringins sowie die enzymatische Bildung eines kristallinen dimeren und eines amorphen polymeren Dehydrierungsproduktes des Sinapinalkohols wird beschrieben. Coniferylalkohol läßt sich auch durch eine in Mandeln vorkommende Dehydrogenase in ein ligninartiges Dehydrierungspolymerisat verwandeln.
Pressure Relief of High Pressure Devices
Authors: Luft G. , Broedermann J. , Scheele T. 
Published: May 2007

AbstractPressure relief systems are used to protect pressure vessels and related equipment against situations of excess pressure. In an emergency situation, they should vent sufficient mass to reduce the pressure to a safe level. The effective discharge area of a pressure relief valve is calculated with the theory of flow through convergent‐divergent nozzles taking into account a correction factor. The international standard ISO 4121 and that of the American Petroleum Institute API 520 are recommended for sizing. In order to examine the validity of these methods for sizing valves for use at very high pressures, relief experiments should be performed over a wide range of pressures and temperatures. Because of their industrial importance, high pressures of 150–300 MPa, and large reactor capacities of up to 300,000 t/a, the polymerization of ethylene was selected as an example reaction.
Hydrothermal Biomass Gasification – Effects of Salts, Backmixing and Their Interaction
Authors: Kruse A. , Faquir M. 
Published: May 2007

AbstractGasification in supercritical water at pressures up to 30 MPa and temperatures around 600 °C is a very attractive method to use biomass with a high water content for energy production. Under these conditions hydrogen and carbon dioxide are formed as the main products. The reaction is significantly influenced by biomass ingredients. The effect of alkali salts is of special interest: the addition of alkali salts drastically increases the hydrogen yield, presumably as a consequence of the catalysis of the water‐gas shift reaction. Furthermore, it is observed that in the presence of alkali salts backmixing has a positive effect on the gas yield. A possible explanation is that “active hydrogen” formed by the water‐gas shift reaction inhibits the formation of low reactive species like coke and tarry compounds. The water‐gas shift reaction is a late consecutive reaction, and this effect is evident if prior reaction steps can be influenced by backmixing.
A Supercritical Fluid‐Assisted, Integrated Process for By‐Products from Fat and Lipid Production
Authors: Weber A. , Lee E.‐H. , Shin S.‐K. , Chun B.‐S. 
Published: May 2007

AbstractAn integrated process for the enzymatic alcoholysis of lipids and the separation of the products by supercritical fluid extraction has been designed and tested with a commercial vegetable oil. The optimization of the reaction conditions and the fractionated separation in a cascade of three separators, which were operable at different temperatures and pressures, have been tested. The fractions were analyzed by HPLC for their content of fatty acid esters and different acylglycerides.
Density Measurements of Fluids and Their Mixtures at High Pressure
Authors: Palavra A. M. F. , Tavares Cardoso M. A. , Coelho J. A. P. , Mourato M. F. B. 
Published: May 2007

AbstractThe principles of the isochoric method are described, as well as the different variants of this method that can be considered according to the technique used to determine the amount of fluid inside the high pressure cell. An automated isochoric apparatus to measure the density of binary mixtures is presented. Accurate isochoric measurements of density of pure fluids, involving molecules like methanol, and mixtures, such as nitrogen plus methane and a multicomponent system with a composition representative of the U.S.A. commercial Gulf Coast natural gas, are analyzed. Moreover, the effect of the thermal degradation of fluids at high temperatures on the accuracy of the density measurements is also discussed.
Structure and Bonding in BAlH5 (B: Be, Ca, Sr) from First‐Principle Calculations.
Authors: Klaveness A. , Vajeeston P. , Ravindran P. , Fjellvaag H. , Kjekshus A. 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis, Structure and Phase Separation of a New 12R‐Type Perovskite‐Related Oxide Ba3NdMn2O9.
Authors: Yang H. , Tang Y. K. , Yao L. D. , Zhang W. , Li Q. A. , Li F. Y. , Jin C. Q. , Yu R. C. 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structures of Dimeric Hydrolysis Products of Thorium.
Authors: Wilson Richard E. , Skanthakumar S. , Sigmon Ginger , Burns Peter C. , Soderholm L. 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structure and Physical Properties of the Polar Oxysulfide CaZnOS.
Authors: Sambrook Timothy , Smura Catherine F. , Clarke Simon J. , Ok Kang Min , Halasyamani P. Shiv 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ternary Zirconium Tin Antimonide ZrSn2‐xSbx (0.2 < x < 0.8), Different from the Parent Binaries ZrSn2 and ZrSb2.
Authors: Tkachuk Andriy V. , Piercey Davin G. , Mar Arthur 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Tetrahedral D Atom Coordination of Nickel and Evidence for Antiisostructural Phase Transition in Orthorhombic Ce2Ni7D≈4.
Authors: Filinchuk Yaroslav E. , Yvon Klaus , Emerich Herman 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Solid State Syntheses and Structure of LaPdCd2 and PrNi0.951(4)Cd2.
Authors: Dogan Ahmet , Rodewald Ute Ch. , Poettgen Rainer 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Functional Anion Concept: Effect of Fluorine Anion on Hydrogen Storage of Sodium Alanate
Authors: Yin Li‐Chang , Wang Ping , Kang Xiang‐Dong , Sun Cheng‐Hua , Cheng Hui‐Ming 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
ZnWO4 Photocatalyst with High Activity for Degradation of Organic Contaminants.
Authors: Huang Guangli , Zhang Chuan , Zhu Yongfa 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stanna‐closo‐dodecaborate: The Crystal Structure of [Li(thf)3]2[SnB11H11], Vibrational Spectroscopy, Thermal Analysis and DFT Calculations.
Authors: Gaedt Torben , Wesemann Lars 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New Family of Heavy‐Fermion Compounds: U4TGa12 (T: Fe, Co, Rh and Pd).
Authors: Jardin R. , Colineau E. , Griveau J.‐C. , Boulet P. , Wastin F. , Rebizant J. 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Organocatalytic Enantioselective Conjugate Addition of Aldehydes to Maleimides.
Authors: Zhao Gui‐Ling , Xu Yongmei , Sunden Henrik , Eriksson Lars , Sayah Mahmoud , Cordova Armando 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Desymmetrization of Prochiral Cyclohexanone Derivatives via the Organocatalytic Direct Aldol Reaction.
Authors: Jiang Jun , He Long , Luo Shi‐Wei , Cun Lin‐Feng , Gong Liu‐Zhu 
Published: May 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.