bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flame retardancy of whisker silicon oxide/rigid polyurethane foam composites with expandable graphite
Authors: Bian Xiang‐Cheng , Tang Jian‐Hua , Li Zhong‐Ming 
Published: September 2008

AbstractRigid polyurethane foam (RPUF) composites filled with various expandable graphite (EG) or/and whisker silicon (WSi) loadings were prepared with the same density (0.08 g/cm3). When the WSi content reached 10 wt %, the composite had the best mechanical properties, the values of compressive strength and modulus reached 0.74 and 21.0 MPa, respectively. Compared with only EG filled RPUF, the addition of 10 wt % WSi to EG/RPUF would also bring out improvement on their flame retardant and mechanical properties. Maintaining EG 20 wt %, the compressive strength increased from 0.17 (EG/RPUF) to 0.39 MPa (WSi/EG/RPUF), the compressive modulus increased from 9.32 (EG/RPUF) to 10.11 MPa (WSi/EG/RPUF), and the limiting oxygen index value increased from 28 vol % (EG/RPUF) to 32.5 vol % (WSi/EG/RPUF). The thermogravimetric analysis showed that the addition of EG and WSi particles improved the thermal stability of the composites. The dynamical mechanical analysis (DMA) showed that EG and WSi particles led to up‐shift of the glass transition temperature. Moreover, 10 wt % EG and 10 wt % WSi filled RPUF had the highest storage modulus, as the EG and WSi exhibited a desirable synergetic effect on flame retardant properties and dynamic mechanical properties of RPUF composites. The morphologies of the composites were analyzed with scanning electron microscopy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Formaldehyde‐free aminoresin wood adhesives based on dimethoxyethanal
Authors: Despres A. , Pizzi A. , Vu C. , Pasch H. 
Published: September 2008

AbstractAminoresin precursors prepared by the addition of a new, colorless, nonvolatile and nontoxic aldehyde, dimethoxyethanal (DME), to melamine or urea gave resins for boards that were able to harden, however they were underperforming because of the lower reactivity of DME in relation to formaldehyde. Melamine and urea reacts with one and two (melamine up to three) molecules of DME to form M‐DME and U‐DME (called DU), but the subsequent cross‐linking reaction to form bridges does not occur unless the reaction is catalyzed during resin preparation by the addition of glyoxylic acid. Such bridges between two melamine molecules form only up to the formation of dimers and no more. The use of glyoxylic acid during the reaction has allowed the formation of different oligomers formed by both aldol condensation and condensation of melamine and glyoxylic acid with two molecules of melamine to form dimers. These were observed by 13C NMR and MALDI‐TOF (matrix‐assisted laser desorption/ionization mass spectroscopy). However, the addition of 20% isocyanate (pMDI) was necessary to satisfy the relevant mechanical strength standards of panels prepared with these resins. pMDI contributed to cross‐linking of M‐DME and DU by its reaction to form urethane bridges according to reactions already described. The adhesive resins so formed had excellent performance and were colorless, and they produced boards that well satisfied the requirements of the relevant standards for interior panels. Formaldehyde emission was down to what would be expected obtained by just heating the wood chips in absence of adhesives. The panels emission was sufficiently low to even satisfy the most severe relevant F**** JIS A 5908 Japanese standard. These adhesives are colorless as MUF and UF resins. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of polymerization method on structure and properties of cationic polyacrylamide
Authors: Shen Yinghua , Zhang Aiqin , Wu Genzhuang 
Published: September 2008

AbstractAcrylamide and 2‐(methacryloyloxy)ethyltrimethylammonium chloride (AM/MADQUAT) copolymers were synthesized by solution and inverse microemulsion polymerization using (NH4)2S2O8/NaHSO3 as redox initiator at the same feed mole ratio, and their microstructure, such as sequence distribution and composition distribution, was calculated from monomer reactivity ratios of different polymerization methods. The results show that charge distribution is more uniform for copolymer prepared in inverse microemulsion than that in solution, and copolymer composition distribution is close to unity, and maintains approximately at the feed ratio. Furthermore, the influence of the two structures of cationic polyacrylamides on kaolinite floc size and effective floc density, reduction of Zeta potential and floc compressive yield stress had been investigated at pH 7. The results show that the kaolinite floc size and effective floc density are strongly dependent upon copolymer microstructure, with greater floc size and lower effective floc density being observed for copolymer prepared in inverse microemulsion than for that in solution. Copolymer microstructure has a marked effect on the Zeta potential, whose reduction in the magnitude was much greater in the presence of copolymer prepared in inverse microemulsion than that in solution. Greater compressive yield stress was achieved for the strong flocs produced by copolymer prepared in inverse microemulsion than for the weak flocs produced by that in solution. The difference in flocs compressive yield stress may be attributed to flocs structure. Therefore, in this article, a correlation between the cationic polyacrylamide structure and flocculation property for kaolinite suspension was established. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Removal of arsenic in water by an ion‐exchange fiber with amino groups
Authors: Zhang Xiaozhuan , Jiang Kai , Tian Zhenbang , Huang Weiqing , Zhao Liang 
Published: September 2008

AbstractA new type of ion‐exchange fiber with amino groups, called RPFA‐I, was prepared. The amino modification and stretching resistance of RPFA‐I were characterized by FTIR spectrum, SEM test, and auto‐tensile test, respectively, and the removal of arsenite and arsenate in solution by RPFA‐I was investigated. The obtained experimental results show that RPFA‐I fibers have fine mechanical properties, and the amino functional groups have grafted to the surface of the matrix material. The adsorption results show that RPFA‐I has a high capacity and good adsorption kinetic property in removal of arsenate and arsenite at the trace level. The removal efficiency was 70% for arsenite and 93% arsenate, respectively, at the concentration of 5 mg/L. The isothermal adsorptions were correspondent to Langmiur/Frundlich adsorption equation, and the adsorption kinetics was fit to the Lagergren pseudosecond order rate equation. The adsorption of the used adsorbent could be efficiently regenerated by 0.1M NaOH in a simple way. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Kinetics study of Ti[O(CH2)4OCHCH2]4 initiated ring‐opening polymerization of ε‐caprolactone by differential scanning calorimetry
Authors: Li Peichun , Zerroukhi Amar , Chen Jianding , Chalamet Yvan , Jeanmaire Thomas , Xia Zhean 
Published: September 2008

AbstractThe ring‐opening polymerization of ε‐caprolactone initiated by Ti[O(CH2)4OCHCH2]4 was investigated by differential scanning calorimetry (DSC). Both isothermal and dynamic experiments have been applied to obtain the kinetic parameters. The apparent polymerization rate constant for different experiments was determined; the activation energy determined is 76–88 KJ/mol by the isothermal method and 75–86 KJ/mol by the dynamic method. Using the obtained kinetic parameters, a model to predict the polymerization process was developed and can well describe the polymerization process, which demonstrates that DSC is a convenient and reliable method to study the kinetics of ring‐opening polymerization. The kinetic results also demonstrate that Ti[O(CH2)4OCHCH2]4 is an efficient initiator in the ring‐opening polymerization of ε‐caprolactone. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of gelatin fiber by gel spinning and its mechanical properties
Authors: Fukae Ryohei , Midorikawa Takehiko 
Published: September 2008

AbstractA gel‐spinning process was used in an attempt to prepare a gelatin fiber with a high level of drawability. A gel fiber prepared by extrusion of 15 wt % gelatin in dimethyl sulfoxide into methanol at −20°C was drawn to sixteen times the original length. After extraction of the dispersion medium, the mechanical strength of the fiber increased markedly with the draw ratio, and the fiber exhibited a tensile strength of 146 MPa and a Young's modulus of 2.3 GPa when drawn to the maximum. A gelatin fiber with greater mechanical strength was obtained when ethylene glycol was used as the spinning solvent. The X‐ray diffraction profile indicated the formation of triple‐helical structures and their lateral association, which is responsible for the mechanical strength of the fiber. Heat‐treatment improved the water‐resistance of the prepared fiber. γ‐Irradiation and treatment with glutaraldehyde improved the mechanical strength of the fiber. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and degradability of poly(lactic acid)–poly(ethylene glycol)–poly(lactic acid)/SiO2 hybrid material
Authors: Wang Hualin , Zhang Yan , Tian Min , Zhai Linfeng , Wei Zheng , Shi Tiejun 
Published: September 2008

AbstractPoly(lactic acid)–poly(ethylene glycol)–poly(lactic acid) (PLA‐PEG‐PLA)/SiO2 hybrid material is prepared by sol–gel method using tetraethoxysilane (TEOS) and PLA‐PEG‐PLA as raw material. From Fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) spectra, the hydroxyl groups of the silica sol derived from partially hydrolysis of TEOS and the unhydrolyzed ethoxy groups of TEOS can react with PLA‐PEG‐PLA. Differential scanning calorimetry (DSC) curves imply that the glass transition temperature (Tg) of PLA‐PEG‐PLA/SiO2 hybrid material is higher than that of PLA‐PEG‐PLA and increases with the increase of silica content. X‐ray diffraction (XRD) analysis results show that PLA‐PEG‐PLA and PLA‐PEG‐PLA/SiO2 hybrid material are both amorphous. Field scanning electron microscope (FSEM) photographs show that when PLA‐PEG‐PLA/SiO2 hybrid material has been degraded for 12 weeks in normal saline at 37°C, a three‐dimensional porous scaffold is obtained, which is available for cell growth and metabolism. Moreover, the hydroxyl (OH) groups on SiO2 of PLA‐PEG‐PLA/SiO2 hybrid material could buffer the acidity resulted from the degradation of PLA, which is beneficial to proliferation of cell in tissue repairing. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Material morphology and electrical resistivity differences in EPDM rubbers
Authors: Domeier Linda A. , Yang Nancy 
Published: September 2008

AbstractElectrical resistance anomalies noted in EPDM gaskets have been attributed to zinc‐enriched surface sublayers, about 10‐μm thick, in the sulfur cured rubber material. Gasket over‐compression provided the necessary connector pin contact and was also found to cause surprising morphological changes on the gasket surfaces. These included distributions of zinc oxide whiskers in high pressure gasket areas and cone‐shaped features rich in zinc, oxygen, and sulfur primarily in low pressure protruding gasket areas. Such whiskers and cones were only found on the pin side of the gaskets in contact with a molded plastic surface and not on the back side in contact with an aluminum surface. The mechanisms by which such features are formed have not yet been defined. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, physical properties, and crystallization of optically active poly(L‐phenyllactic acid) and poly(L‐phenyllactic acid‐co‐L‐lactic acid)
Authors: Tsuji Hideto , Matsuoka Hiroshi , Itsuno Shinichi 
Published: September 2008

AbstractOptically active poly(L‐phenyllactic acid) (Ph‐PLLA), poly(L‐lactic acid) (PLLA), and poly(L‐phenyllactic acid‐co‐L‐lactic acid) with weight‐average molecular weight exceeding 6 × 103 g mol−1 were successfully synthesized by acid catalyzed direct polycondensation of L‐phenyllactic acid and/or L‐lactic acid in the presence of 2.5–10 wt % of p‐toluenesulfonic acid. Their physical properties and crystallization behavior were investigated by differential scanning calorimetry, thermogravimetry, and polarimetry. The absolute value of specific optical rotation ([α]) for Ph‐PLLA (−38 deg dm−1 g−1 cm3) was much lower than that of [α] for PLLA (−150 deg dm−1 g−1 cm3), suggesting that the helical nature was reduced by incorporation of bulky phenyl group. PLLA was crystallizable during solvent evaporation, heating from room temperature, and cooling from the melt. Incorporation of a very low content of bulky phenyllactyl units even at 4 mol % suppressed the crystallization of L‐lactyl unit sequences during heating and cooling, though the copolymers were crystallizable for L‐phenylactyl units up to 6 mol % during solvent evaporation. The activation energy of thermal degradation (ΔEtd) for Ph‐PLLA (200 kJ mol−1) was higher than that for PLLA (158 kJ mol−1). The ΔEtd for the copolymers increased with an increase in L‐phenyllactyl unit content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Novel divinyl monomer for preparation of unsaturated polymers
Authors: Chen Song , Li Xiao Yu 
Published: September 2008

AbstractTo simplify the preparation of unsaturated polymers, a new type of divinyl monomer was designed in this article. The double bonds of the divinyl monomer are different not only in reactivity but also in electron density. Based on quantum chemistry calculation, (z)‐4‐(2‐(acryloyloxy)ethoxy)‐4‐oxobut‐2‐enoic acid (cis‐AEOEA) was selected as the nonelectron‐donating divinyl monomer in which inactive double bond was electron deficient and can be activated by electron‐donating comonomers by forming charge transfer complex (CTC) copolymerization system. So, cis‐AEOEA can be used to simplify the preparation of unsaturated polymers and the content of inactive double bonds left in the polymer is controlled by electron‐donating ability of comonomers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Parameters controlling the swelling of butyl rubber by solvents
Authors: Nohilé Cédrick , Dolez Patricia I. , Vu‐Khanh Toan 
Published: September 2008

AbstractThe method used in the past 30 years for describing the swelling of polymers by solvents is mainly based on the Hansen three‐dimensional solubility parameters. However, the subjectivity of its implementation as well as its limited success for several polymers, and in particular elastomers, which constitute choice materials for protective gloves, has been reported by several authors. In this article, data obtained by Zellers et al. with butyl rubber and a list of 53 solvents are analyzed to identify the parameters controlling the swelling of this elastomer. The absence of a global effect of the Hansen affinity, solvent molar volume and saturation vapor pressure, and Flory–Huggins interaction parameter has been confirmed. It was also shown that one of the main factors controlling the swelling of butyl rubber appears to be the chemical class of the solvents. Within these classes, a linear relationship between butyl rubber swelling and solvent saturation vapor pressure was observed, and the correlation with molar volume is almost as good. On the other side, no correlation can be obtained with the Hansen affinity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Space efficient system for whole‐body exposure of unrestrained rats to 900 MHz electromagnetic fields
Authors: Puranen Lauri , Toivo Tim , Toivonen Tommi , Pitkäaho Risto , Turunen Asko , Sihvonen Ari‐Pekka , Jokela Kari , Heikkinen Päivi , Kumlin Timo , Juutilainen Jukka 
Published: September 2008

AbstractThe aim of this study was to design, implement and analyze a space‐efficient setup for the whole‐body exposure of unrestrained Wistar rats to radiofrequency (RF) electromagnetic fields at 900 MHz. The setup was used for 2 years in a cocarcinogenesis study and part of it for 5 weeks in a central nervous system (CNS) study. Up to 216 rats could be placed in separate cages in nine different exposure chambers on three racks requiring only 9 m2 of floor area (24 rats per m2). Chambers were radial transmission lines (RTL), where the rats could freely move in their cages where food and drinking water was provided ad libitum except during RF exposure periods. Dosimetrical analysis was based on FDTD computations with heterogeneous rat models and was validated with calorimetrical measurements carried out with homogeneous phantoms. The estimated whole‐body average specific absorption rates (SAR) of rats were 0 (sham), 0.4, and 1.3 W/kg in the cocarcinogenesis study and 0 (sham), 0.27, and 2.7 W/kg in the CNS study with an estimated uncertainty of 3 dB (K = 2). The instantaneous and lifetime variations of whole‐body average SAR due to the movement of rats were estimated to be 2.3 and 1.3 dB (K = 1), respectively. Bioelectromagnetics 30:120–128, 2009. © 2008 Wiley‐Liss, Inc.
Teaching local area networking using Samba instead of Windows
Authors: Steffen G. D. , Abu‐Mulaweh H. I. 
Published: September 2008

AbstractThe objective of this article is to demonstrate that the same principal techniques for local area networking can be taught using Linux with Samba instead of Windows NT/2003 at a fraction of the cost. A brief history, availability, and cost of maintaining a Samba based network is presented. The paper also illustrates how existing Windows Server experiments can be modified to use Samba in its place. Important experimental issues such as domain controllers, shares, printing, authentication, and security are also addressed. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 17: 44–51, 2009; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20160
Social and mental health profiles of young male offenders in detention in Greece
Authors: Maniadaki Katerina , Kakouros Efthymios 
Published: September 2008

AbstractBackground Among young offenders, mental health problems have been linked both to more serious delinquent acts and to high recidivism rates, but there has been little study of this in Greece.Aims The aims of this study were to describe demographic and family characteristics of young incarcerated male offenders, to determine the prevalence of mental disorders among them and to compare native Greeks with immigrants on these variables.Methods Ninety‐three young males, randomly selected from the three main juvenile detention facilities in Greece, completed the Greek version of the Youth Self Report (YSR); the institutions' social workers completed a questionnaire designed for the study on the youths' demographics and offending.Results Results revealed over‐representation of immigrants, high levels of psychosocial adversity (large family size, low parental educational level, poverty and family offending history) and high prevalence rates not only of externalizing disorders, such as conduct disorder, but also internalizing disorders, including anxiety, depression and somatizing problems.Conclusions and practice implications Young males in Greek correctional institutions need support at many levels, and especially for mental health problems. This will have implications for staff training and juvenile justice system reform. Copyright © 2008 John Wiley & Sons, Ltd.
Psychometric properties of the Beck Depression Inventory‐II with incarcerated male offenders aged 18–21 years
Authors: Palmer Emma J. , Binks Claire 
Published: September 2008

AbstractBackground The Beck Depression Inventory – Second Edition (BDI‐II) is a self‐report measure of depression. Studies have shown it to have good psychometric properties with adult and adolescent clinical and non‐clinical populations. However, this research has mostly been conducted with North American samples.Aims/hypotheses To examine the psychometric characteristics of the BDI‐II with male young adult offenders in the UK.Methods The BDI‐II was administered to 117 incarcerated male young adult offenders aged 18–21 years from the UK.Results The BDI‐II showed good internal consistency and concurrent validity. Factor analysis revealed two factors, relating to cognitive‐affective items and somatic items. The items loading on the two factors were very similar to those found in a North American adolescent (13–17 years) psychiatric inpatient sample.Conclusions and implications for future research The findings suggest that the BDI‐II can be used with confidence in young adult male offenders. It would be useful to confirm its psychometric properties in other offender samples and establish offender population norms. Copyright © 2008 John Wiley & Sons, Ltd.
Prevalence and correlates of traumatic brain injury among delinquent youths
Authors: Perron Brian E. , Howard Matthew O. 
Published: September 2008

AbstractBackground Delinquent youth frequently exhibit high‐risk behaviours that can result in serious injury. However, little is known about traumatic brain injuries (TBIs) and their correlates in this population.Aims To examine the period prevalence and correlates of TBIs in delinquent youths.Method Interviews were conducted with 720 (97.3%) residents of 27 Missouri Division of Youth Services rehabilitation facilities between March 1 and May 31, 2003. Participants [mean age (Mage) = 15.5, standard deviation (SD) = 1.2, 87% male] completed measures assessing TBI, substance use, psychiatric symptoms, and antisocial traits/behaviours. TBI was defined as ever having sustained a head injury causing unconsciousness for more than 20 minutes.Results Nearly one‐in‐five youths (18.3%) reported a lifetime TBI. Youths with TBIs were significantly more likely than youths without to be male, have received a psychiatric diagnosis, report an earlier onset of criminal behaviour/substance use and more lifetime substance use problems and past‐year criminal acts, evidence psychiatric symptoms, report lifetime suicidality, be impulsive, fearless, and external in locus of control and criminally victimized in the year preceding incarceration. Male gender and frequency of own criminal victimization were important predictors of TBI in multivariate analyses. Regression analyses adjusted for demographic factors, indicated that youths with TBIs were at significantly elevated risk for current depressive/anxious symptoms, antisocial behaviour, and substance abuse problems.Conclusions TBI is common among delinquent youth and associated with wide ranging psychiatric dysfunction; however, the causal role of TBIs in the pathogenesis of co‐morbid conditions remains unclear. Copyright © 2008 John Wiley & Sons, Ltd.
Powered partial least squares discriminant analysis
Authors: Liland Kristian Hovde , Indahl Ulf Geir 
Published: September 2008

AbstractFrom the fundamental parts of PLS‐DA, Fisher's canonical discriminant analysis (FCDA) and Powered PLS (PPLS), we develop the concept of powered PLS for classification problems (PPLS‐DA). By taking advantage of a sequence of data reducing linear transformations (consistent with the computation of ordinary PLS‐DA components), PPLS‐DA computes each component from the transformed data by maximization of a parameterized Rayleigh quotient associated with FCDA. Models found by the powered PLS methodology can contribute to reveal the relevance of particular predictors and often requires fewer and simpler components than their ordinary PLS counterparts. From the possibility of imposing restrictions on the powers available for optimization we obtain an explorative approach to predictive modeling not available to the traditional PLS methods. Copyright © 2008 John Wiley & Sons, Ltd.