bluuebunny/crossref_metadata_2025_split huggingface dataset:
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Neutron Imaging
Authors: Lehmann E. H. , Kaestner A. P. 
Published: September 2009

Abstract
This article describes the present status of neutron tomography (NT) as a valuable tool for scientific studies and for industry‐related investigations. Similar to X‐ray tomography, the determination of the volume data is based on a sequence of single projections of the object under investigation while it rotates around its vertical (or horizontal) axis. The reason why NT differs from X‐ray techniques in the interaction probability with matter, which causes alternative contrast variations, is outlined in detail.
On the basis of the presentation of principles, the description of existing facilities, tools for image postprocessing, and some examples of prominent application ranges are given. The article concludes with the outlook for further improvements and methodical development in NT.
The testing effect: The role of feedback and collaboration in a tertiary classroom setting
Authors: Vojdanoska Marija , Cranney Jacquelyn , Newell Ben R. 
Published: September 2009

AbstractSuccessful retrieval on a test compared to just re‐studying material improves long‐term retention—a phenomenon called the ‘testing effect’. This study investigated the role of feedback and collaborative testing on the retention of course material in a tertiary educational setting. Tested material was better retained relative to non‐tested material (testing effect), and feedback facilitated correction of errors. Group testing produced higher performance on the initial, but not final test performance, compared to individual testing. This set of findings suggests that to encourage long‐term retention, educators should utilise individual formative testing with feedback; theoretical implications are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Supporting remote collaborative problem‐solving
Authors: Hansen Miriam , Spada Hans 
Published: September 2009

AbstractWe propose a framework of individual problem‐solving and communicative demands (IproCo) that bridges the gap between models from cognitive psychology and communication pragmatics. Furthermore, we present two experiments conducted to identify factors influencing the demands and to test possibilities for support. The experiments employed a remote collaborative picture‐sorting task with concrete and abstract pictures and applied non‐interactive conditions compared to interactive conditions. In a first experiment, the influence of the postulated demands on collaboration process and outcome was analysed, and the impact of shared applications was tested. In a second experiment, we evaluated instructional support measures consisting of model collaboration and a collaboration script. The collaboration process showed benefits of the support but the outcome did not. However, the support measures fostered the collaboration process even in the particularly difficult conditions with non‐interactive communication. We discuss the impact of the IproCo framework and apply it to other tasks. Copyright © 2009 John Wiley & Sons, Ltd.
Neural‐network‐based finite‐time H∞ control for extended Markov jump nonlinear systems
Authors: Luan Xiaoli , Liu Fei , Shi Peng 
Published: September 2009

AbstractThis paper presents a neural‐network‐based finite‐time H∞ control design technique for a class of extended Markov jump nonlinear systems. The considered stochastic character is described by a Markov process, but with only partially known transition jump rates. The sufficient conditions for the existence of the desired controller are derived in terms of linear matrix inequalities such that the closed‐loop system trajectory stays within a prescribed bound in a fixed time interval and has a guaranteed H∞ noise attenuation performance for all admissible uncertainties and approximation errors of the neural networks. A numerical example is used to illustrate the effectiveness of the developed theoretic results. Copyright © 2009 John Wiley & Sons, Ltd.
Recent Progress in Exploring Magnetocaloric Materials
Authors: Shen B. G. , Sun J. R. , Hu F. X. , Zhang H. W. , Cheng Z. H. 
Published: September 2009

AbstractThe magnetic refrigeration technique based on the magnetocaloric effect (MCE) has attracted increasing interest because of its high efficiency and environment friendliness. In this article, our recent progress in exploring effective MCE materials is reviewed with emphasis on the MCE in the LaFe13−xSixbased alloys discovered by us. These alloys show large entropy changes over a wide temperature range near room temperature. The effects of magnetic rare‐earth doping, interstitial atoms and high pressure on the MCE have been systematically studied. Special issues, such as appropriate approaches to determining the MCE associated with the first‐order magnetic transition, the depression of magnetic and thermal hysteresis, and the key factors determining the magnetic exchange in alloys of this kind, are discussed. The applicability of giant MCE materials to magnetic refrigeration near ambient temperature is evaluated. A brief review of other materials with significant MCE is also presented.
Highly Surface‐roughened “Flower‐like” Silver Nanoparticles for Extremely Sensitive Substrates of Surface‐enhanced Raman Scattering
Authors: Liang Hongyan , Li Zhipeng , Wang Wenzhong , Wu Youshi , Xu Hongxing 
Published: September 2009

AbstractSurface‐enhanced Raman scattering (SERS) is a new optical spectroscopic analysis technique with potential for highly sensitive detection of molecules. Recently, many efforts have been made to find SERS substrates with high sensitivity and reproducibility. In this Research News article, we provide a focused review on the synthesis of monodispersed silver particles with a novel, highly roughened, “flower‐like” morphology by reducing silver nitrate with ascorbic acid in aqueous solutions. The nanometer‐scale surface roughness of the particles can provide several hot spots on a single particle, which significantly increases SERS enhancement. The incident polarization‐dependent SERS of individual particles is also studied. Although the different “hot spots” on a single particle can have a strong polarization dependency, the total Raman signals from an individual particle usually have no obvious polarization dependency. Moreover, these flower‐like silver particles can be measured by SERS with high enhancement several times, which indicates the high stability of the hot spots. Hence, the flower‐like silver particles here can serve as highly sensitive and reproducible SERS substrates.
Integrated multi‐echelon supply chain design with inventories under uncertainty: MINLP models, computational strategies
Authors: You Fengqi , Grossmann Ignacio E. 
Published: September 2009

AbstractWe address in this article a problem that is of significance to the chemical industry, namely, the optimal design of a multi‐echelon supply chain and the associated inventory systems in the presence of uncertain customer demands. By using the guaranteed service approach to model the multi‐echelon stochastic inventory system, we develop an optimization model to simultaneously determine the transportation, inventory, and network structure of a multi‐echelon supply chain. The model is an MINLP with a nonconvex objective function including bilinear, trilinear, and square root terms. By exploiting the properties of the basic model, we reformulate this problem as a separable concave minimization program. A spatial decomposition algorithm based on the integration of Lagrangean relaxation and piecewise linear approximation is proposed to obtain near global optimal solutions with reasonable computational expense. Examples for specialty chemicals and industrial gas supply chains with up to 15 plants, 100 potential distribution centers, and 200 markets are presented. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Phenolic foams from wood tar resols
Authors: Dos‐Santos Cláudio G. , Costa Marcelo A. , De Morais Willy A. , Pasa Vânya M. D. 
Published: September 2009

AbstractThis article investigates resole‐type phenolic foams, in which 40% phenol was substituted with distilled oily fractions from wood tar. Different proportions of blowing agent, hexamethylenetetramine, and stabilizer, a sodium alkyl sulfate surface active agent, were used to produce a series of rigid foams, which were characterized by curing index, density and hardness. The average curing index was about 90% and densities ranged from 480 to 960 kg.m−3. A fractal dimension (Df) approach was used to assess the homogeneity of pores within the foams and an average (dimensionless) value of 2.6 was found, indicating a non uniform structure. Compressive strength tests of the foams gave values above 1.0 MPa, which is higher than those for typical phenolic foams. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of polymeric flame retardants containing phosphorus‐nitrogen‐bromide and their application in acrylonitrile‐butadiene‐styrene
Authors: Yan Li , Zheng Yubin , Liu Jianping , Shang Hongzhou 
Published: September 2009

AbstractA series of polymeric flame retardants (PFRs) containing phosphorus‐nitrogen‐bromide were synthesized from spirocyclic pentaerythritol bisphosphorate disphosphoryl chloride (SPDPC), 2‐methoxyl‐4,6‐dichloro‐1,3,5‐triazine (MDCT), and tetrabromobisphenol A (TBBPA). The influence of monomer ratio on their thermal stability was investigated by adjusting the proportion of SPDPC/MDCT (mol/mol) from 80/20 to 20/80. The flammability properties of the PFRs blended with ABS were evaluated using LOI and UL‐94 vertical test. The structures of the flame retardants were characterized by means of Fourier transform infrared spectra (FTIR) and proton nuclear magnetic resonance spectroscopy (1H‐NMR). The results show that the initial temperature of decomposition is 274°C and with 35% charring residue at 500°C when the ratio of SPDPC/MDCT is 50/50. V‐0 ratings in the UL‐94 vertical test were achieved at 20–30% loading of PFRs, when LOI values reached at least 26.9%. The flame retardancy is strongly dependent on the ratio of P, N, and Br. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Stable poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) microspheres via precipitation polymerization
Authors: Jiang Xuhong , Tu Weiping 
Published: September 2009

AbstractNarrow‐dispersion or monodisperse with stable and smooth surface polymer microspheres were prepared without a significant coagulum by precipitation polymerization in the absence of any stabilizer. The monomer glycidyl metharylate (GMA) was copolymerized with ethyleneglycol dimethacrylate (EGDMA) as crosslinker by precipitation polymerization technique with 2,2′‐azobisisobutyronitrile as initiator in neat acetonitrile. The effects of the content of EGDMA on the polymerization characteristics and size/uniformity of the microspheres were investigated. The onset of the thermal degradation temperature at higher temperature and the swelling test suggest that the prepared particles were highly crosslinked. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of macroporous silica modified with optically active poly[N‐(oxazolinylphenyl)acrylamide] derivatives for potential application as chiral stationary phases
Authors: Tian Y. , Lu W. , Che Y. , Shen L. B. , Jiang L. M. , Shen Z. Q. 
Published: September 2009

AbstractEnantiopure acrylamide derivatives, (S)‐N‐[o‐(4‐methyl‐4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenyl]acrylamide and (R)‐N‐[o‐(4‐phenyl‐4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenyl]acrylamide, were synthesized through the acylation of chiral 2‐oxazolinylanilines. The radical polymerization of the chiral monomers was carried out with (3‐mercaptopropyl)trimethoxysilane as a chain‐transfer agent to obtain the corresponding optically active prepolymers with a trimethoxysilyl group. By immobilizing the prepolymers on porous silica gel via the grafting‐to method, we prepared a new chiral stationary phase (CSP) and characterized it by elemental analysis, thermogravimetry, and Fourier transform infrared spectroscopy. The enantioseparation capacities of the CSPs were evaluated with high‐performance liquid chromatography toward several racemic compounds, including 1,1′‐bi‐2‐naphthol, benzoin, 2‐amino‐1‐butanol, and loxoprofen sodium under the normal‐phase mode. The results indicate that the CSPs exhibited improved chromatographic performances compared to their brush‐type analogs obtained by the alternative grafting‐from approach. Also, the column packed with poly{(R)‐N‐[o‐(4‐phenyl‐4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenyl]acrylamide}‐bonded silica was found to have an extent of enantioselectivity in the chiral resolution of some unmodified amino acids with reversed‐phase eluents. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Properties and structural characterization of oxidized starch/PVA/α‐zirconium phosphate composites
Authors: Yang Yajuan , Liu Changhua , Chang Peter R. , Chen Yun , Anderson Debbie P. , Stumborg Mark 
Published: September 2009

AbstractTwo series of composites, i.e., polyvinyl alcohol (PVA)/oxidized starch (OST)/exfoliated α‐zirconium phosphate (POST‐ZrPn) and PVA/starch (ST)/exfoliated α‐zirconium phosphate (PST‐ZrPn), were fabricated using a casting and solvent evaporation method. The composites were characterized by Fourier transform infrared spectroscopy (FT‐IR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (XRD), scanning electron microscopy (SEM), tensile testing, and moisture uptake. Compared with PST‐ZrPn, POST‐ZrPn films with the same component ratio showed higher tensile strength (σb), lower elongation at break (εb) and improved water resistance. Additionally, in the POST‐ZrPn series, σb and εb increased with an increase in α‐zirconium phosphate (α‐ZrP) loading; however, higher α‐ZrP loads resulted in the aggregation of α‐ZrP particles. Compared with POST‐ZrP0, the values for σb, εb, and water resistance of POST‐ZrP3, containing 1.5 wt % α‐ZrP, were increased by 128.8%, 51.4%, and 30.2%, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of molecular weight of epoxidized‐natural rubber on viscosity and tack of pressure‐sensitive adhesives
Authors: Poh B. T. , Yong A. T. 
Published: September 2009

AbstractThe effect of molecular weight of rubber on viscosity and loop tack of rubber‐adhesives were studied using two grades of epoxidized‐natural rubber, i.e., ENR 25 and ENR 50. Coumarone–indene resin, gum rosin, and petro resin were used as tackifiers. Toluene was used as the solvent throughout the experiment. The adhesive was coated on polyethylene terephthalate (PET) substrate using a SHEEN hand coater. Viscosity was determined by a HAAKE Rotary Viscometer, whereas loop tack was measured by a Llyod Adhesion Tester operating at 10 cm/min. Results show that viscosity increases gradually upto a critical molecular weight of 6.8 × 104 and 3.9 × 104 for ENR 25 and ENR 50, respectively, before a rapid increase in viscosity is observed. Loop tack indicates maximum value at the respective critical molecular weights for the three tackifiers investigated suggesting the culmination of wettability. For both rubbers, loop tack increases with coating thickness due to the concentration effect of adhesive. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Aqueous dispersion polymerization of amphoteric polyacrylamide
Authors: Wu Yumin , Wang Chuanxing , Xu Jun 
Published: September 2009

AbstractThe terpolymer of acrylamide (AM), dimethylaminoethyl methacrylate methyl chloride (DMC), and acrylic acid (AA) was synthesized with their molar ratio of 70 : 15 : 15 through dispersion polymerization in aqueous solution of ammonium sulfate (AS), using poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as stabilizer and 2,2′‐azobis(2‐amidinopropane) dihydrochloride (V‐50) as initiator. The particle size of the terpolymer ranged from 5 to 8 μm and the intrinsic viscosity was from 5.5 to 11.6 dL g−1. The terpolymer had anti‐ polyelectrolyte effect under low AS concentration, but polyelectrolyte effect with the concentration beyond 10%. Polymerization dispersion with low apparent viscosity, uniform particles, good stability, and high molecular weight terpolymer was obtained in single stage. The effects of varying concentrations of salt, stabilizer, and monomers on particle morphology and intrinsic viscosity were investigated. With increasing concentration of AS and PDMC, the intrinsic viscosity of terpolymer increased, then decreased afterward. However, it increased gradually with increase in monomer concentration. The particle size was enlarged with increasing of AS and monomer concentration and decreasing of PDMC concentration. The optimum condition was the concentrations of salt, stabilizer, and monomers 28%, 3.0%, and 8% to 15%, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of polypropylene‐graft‐cardanol by reactive extrusion and its composite material with bamboo powder
Authors: Chen Qinhui , Xue Hanyu , Lin Jinhuo 
Published: September 2009

AbstractThe polypropylene‐graft‐cardanol was prepared by reactive extrusion, which is solvent‐free melt process, continuous processing, and controllable over residence time. The effect of monomer and initiator concentration on grafting ratio, grafting efficiency, and melt flow index (MFI) was also studied. The yield was quantified by UV–vis spectrometer. The chemical structure was investigated by infrared spectroscopy and gel ratio. A possible mechanism was supposed. The particular structure of cardanol can retain the MFI value of matrix resins and prevent polypropylene (PP) from being decomposed. The grafting ratio could be easily obtained from an experimental formula deduced from the linearity relationship between grafting ratio and MFI. The effect of cardanol grafted onto PP on the compatibility of PP and bamboo powder was studied by contact angle measurements, scanning electron microscopy, and tensile properties test. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Correlation between sub‐Tg relaxation processes and mechanical behavior for different hydrothermal ageing conditions in epoxy assemblies
Authors: Chevalier M. , Dantras E. , Tonon C. , Guigue P. , Lacabanne C. , Puig C. , Durin C. 
Published: September 2009

AbstractThe aim of this study is to understand aging phenomena by monitoring physical parameters after real and simulated aging experiments. This study focuses on aluminum‐epoxy assemblies, which are commonly used on spacecraft structures. Different samples are submitted to simulated aging tests. Influence of temperature and moisture is analyzed. Evolution with aging is characterized at two different scales. The macroscopic behavior of the assemblies is studied by single lap shear test. A decrease in the shear rupture stress is observed with increasing temperature and relative humidity. It is demonstrated that temperature has more important influence. The molecular behavior in the adhesive joint is studied by dynamic dielectric spectroscopy measurements. This experiment gives access to molecular mobility in the adhesive. Dipolar entities are identified as evolving with aging conditions. The temperature is more effective than moisture at this scale. An interpretation of the molecular mobility before and after aging shows that water is an important parameter of this study. A link between mechanical and molecular behavior with hydrothermal aging is found. The decrease of mechanical properties occurs while failures become interfacial. In the same time, the interactions between hydroxyether and water increase. The evolution of the macroscopic behavior of the bonded assemblies is due to this combination observed at different scales. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Behavior of absorbed water in elongated polyamide 6
Authors: Sakai Eiichi , Kawagoe Makoto 
Published: September 2009

AbstractThe state of absorbed water in polyamide 6 elongated to several levels have been investigated in relation to the polymer microstructure. The absorption behavior of distilled water at 20°C was monitored until the saturation. Both the diffusion coefficient and the equilibrium content of water were increased by plastic elongation. The large elongation caused a reduction in the storage modulus and rises in the loss tangents for α‐ and β‐relaxations. The DSC measurements clearly indicated several exothermic peaks showing the presence of freezable bound water in the largely elongated specimen. These results suggest that some microstructural defects like voids are formed by the collapse of crystals by large elongation, and the water molecules are accumulated in such defects under weaker interaction with the surrounding polymer. Supposing the pore as the structural defect, the pore size distribution was obtained from the DSC curve by the method of thermoporosimetry. Assuming the cylindrical pores, they were characterized to have the total volume of about 13.5 × 10−4 mm3 g−1, the surface area of about 1.1 m2 g−1, and the average radius of about 2.5 nm, being appropriately called mesopore. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A Study of the Thermodynamics and Kinetics of Copper Adsorption Using Chemically Modified Rice Husk
Authors: Jaman Hasanur , Chakraborty Debarati , Saha Papita 
Published: September 2009

AbstractThe use of rice husk as a low cost adsorbent for the removal of copper from wastewater has been explored in a laboratory scale experiment. The rice husk used for the study was treated with alkali to increase the sorption properties. The influence of metal ion concentration, weight of biosorbent, stirring rates, temperature and pH were also evaluated, and the results are fitted using adsorption isotherm models. From the experimental results it was observed that almost 90–98% of the copper could be removed using treated rice husk. The Langmuir adsorption isotherm, Freundlich isotherm and Tempkin isotherm models were used to describe the distribution of copper between the liquid and solid phases in batch studies, and it was observed that the Langmuir isotherm better represented the adsorption phenomenon. The experimental rate constant, activation energy, Gibbs free energy, enthalpy and entropy of the reaction were calculated in order to determine the mechanism of the sorption process.
Competitive Sorption of Antimony with Zinc, Nickel, and Aluminum in a Seaweed Based Fixed‐bed Sorption Column
Authors: Bakir Adil , McLoughlin Peter , Tofail Syed A. M. , Fitzgerald Eddy 
Published: September 2009

AbstractThe removal of heavy metals such as Ni(II), Zn(II), Al(III), and Sb(III) from aqueous metal solutions was investigated using novel, cost effective, seaweed derived sorbents. Studies with a laboratory scale fixed‐bed sorption column, using a seaweed waste material (referred to as waste Ascophyllum product (WAP)) from the processing of Ascophyllum nodosum as biosorbent, demonstrated high removal efficiencies (RE) for a variety of heavy metals including Ni(II), Zn(II) and Al(III), with 90, 90 and 74% RE achieved from initial 10 mg/L metal solutions, respectively. The presence of Sb(III) in multi component metal solutions suppressed the removal of Ni(II), Zn(II) and Al(III), reducing the RE to 28, 17 and 24%, respectively. The use of Polysiphonia lanosa as a biosorbent showed a 67% RE for Sb(III), both alone and in combination with other metals. Potentiometric and conductometric titrations, X‐ray photoelectron and mid‐infrared spectroscopic analysis demonstrated that carboxyl, alcohol, sulfonate and ether groups were heavily involved in Sb(III) binding by P. lanosa. Only carboxyl and sulfonate groups were involved in Sb(III) binding by WAP. Furthermore, a greater amount of weak acidic groups (mainly carboxylic functions) were involved in Sb(III) binding by P. lanosa, compared to WAP which involved a greater concentration of strong acidic groups (mainly sulfonates).