bluuebunny/crossref_metadata_2025_split huggingface dataset:
An acoustic emission study on the fracture behavior of continuous glass fiber/polypropylene composites based on commingled yarn
Authors: Wang Yantao , Dong Qingzhi , Zhang Degang , Xu Yongjun 
Published: February 2008

AbstractThe fracture behavior of continuous glass fiber reinforced polypropylene composites made of commingled yarn in the form of biaxial (±±45°) noncrimp warp‐knitted fabric, twill woven fabric, and swirl mat, respectively, was investigated by virtue of single edge notched tensile (SEN‐T) specimens. These composite laminates were manufactured by compression molding and cooled at two different rates (1°C/min and 10°C/min) during the last processing phase of the laminates. The failure mechanisms were studied by acoustic emission (AE) analysis. AE amplitude ranges corresponding to the individual failure modes have been identified. For biaxial noncrimp fabric reinforced materials, the failure mechanisms involved in the fracture procedure are governed by the interface related failure events. Higher cooling rate, which is accompanied by better fiber/matrix adhesion, results in not only the increase in the relative proportion of high‐amplitude failure events, but also the occurrence of a large quantity of fiber fracture events. For woven fabric and mat reinforced composites, fiber‐dominated failure mechanisms result in the higher fracture toughness when compared with biaxial noncrimp fabric composites. Under this circumstance, the change in cooling rate only results in the difference in the relative frequency of the individual failure modes. In addition, it is found out that the initiation fracture toughness of SEN‐T specimens can be easily assessed by marking the load value which corresponds to the first point of AE signals emitted stably in AE events‐displacement curves. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Effects of polymer molecular weight and filler particle size on flow behavior of wood polymer composites
Authors: Hristov Velichko , Vlachopoulos John 
Published: February 2008

AbstractThe influence of polymer matrix molecular weight and filler particle size on rheological properties and extrudate distortions of metallocene polyethylene (mPE)/wood flour (WF) composites has been investigated by rotational and capillary rheometers. It was found that at low shear rates smaller filler particles provide higher shear viscosity than the larger sized filler. At high shear rates and WF loadings above 30 wt%, the effect of particle size on the melt flow properties becomes negligible. The relative increase of the storage modulus with decreasing particle size is more pronounced in the case of low molecular weight polymer matrix than that in higher molecular weight polyethylene based composites. The wood filled polyethylenes exhibit extrudate surface defects, which are complex function of the shear rate, polymer matrix molecular weight, and filler particle size. Increasing the shear rate results in pressure oscillations and spurt‐flow. It was also observed that the evolution of the extrudate surface tearing is strongly dependent on the pressure during a single pressure oscillation cycle in the spurt flow regime. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Microencapsulation of ammonium polyphosphate: Preparation, characterization, and its flame retardance in polypropylene
Authors: Wu Kun , Wang Zhengzhou , Liang Haojun 
Published: February 2008

AbstractMicroencapsulated ammonium polyphosphate (MCAPP) with a melamine–formaldehyde (MF) resin coating layer was prepared by in situ polymerization. MCAPP was characterized by Fourier transform infrared, X‐ray photoelectron spectroscopy, and so on. The results show that the microencapsulation with MF resin leads to a decrease in the particles' size and water absorption. The flame retardant action and mechanism of MCAPP and ammonium polyphosphate (APP) in polypropylene are studied using limiting oxygen index (LOI) and UL 94 test, and their thermal stability is evaluated by thermogravimetric analysis. The LOI value of the PP/MCAPP composite at 30 wt% loading is 30.5%, whereas the corresponding value of the PP/APP composite is only 20%. Moreover, the LOI values of the PP/MCAPP/PER composites are higher than the ones of the PP/APP/PER composites. In the UL 94 test, the PP/MCAPP/PER composites with suitable ratios of MCAPP to PER can reach the V‐0 rating, and the best rating of the PP/APP/PER composites is V‐1. V‐1. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Synthesis and characterization of polyimide/multi‐walled carbon nanotube nanocomposites
Authors: Mo Te‐Cheng , Wang Hong‐Wen , Chen San‐Yan , Yeh Yun‐Chieh 
Published: February 2008

AbstractPolyimide/multi‐walled carbon nanotube (PI‐MWNT) nanocomposites were fabricated by an in situ polymerization process. Chemical compatibility between the PI matrix and MWNTs is achieved by pretreatment of the carbon nanotubes in a mixture of sulfuric acid and nitric acid. The dispersion of MWNTs in the PI matrix was found to be enhanced significantly after acid modification. The glass transition (Tg) and decomposition (Td) temperature of PI‐MWNT nanocomposites were improved as the MWNT content increased from 0.5 to 15 wt%. The storage modulus of the PI/MWNT nanocomposites is nine times higher than that of pristine PI at room temperature. The tensile strength of PI doubles when 7 wt% MWNTs is added. The dielectric constant of the PI‐MWNT nanocomposites increased from 3.5 to 80 (1 kHz) as the MWNT content increased to 15 wt%. The present study demonstrates that enhanced mechanical properties can be obtained through a simple in‐situ polymerization process. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Effect of zirconium dioxide on crystallization and melting behavior of flame sprayed polyamide 1010
Authors: Li Yadong , Yan Fufeng , Qiang Kegang , Ma Yizhu , Cao Shaokui , Zhang Zhijun 
Published: February 2008

AbstractThe crystallization and melting behavior of flame sprayed Polyamide 1010 (PA1010) containing zirconium dioxide (ZrO2) were investigated using differential scanning calorimeter (DSC). ZrO2 has a heterogenous nucleation effect on PA1010, leading to a moderate increase in the crystallization temperature and a decrease in the supercooling temperature. A modified Avrami theory could be successfully used to well describe the early stages of non‐isothermal crystallization of PA1010 and its composite coatings. A study of the nucleation activity, which indicated the influence of the filler on the polymer matrix, revealed that the zirconium dioxide nanoparticles had a good nucleation effect on PA1010. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers.
Organic/inorganic hybrid nanospheres coated with palladium/P4VP shells from surface‐initiated atom transfer radical polymerization
Authors: Cheng Zhenping , Zhang Lifen , Zhu Xiulin , Kang E. T. , Neoh K. G. 
Published: February 2008

AbstractCrosslinked poly(4‐vinylbenzyl chloride) (PVBC) nanospheres of about 160 nm were first synthesized by emulsion copolymerization of 4‐vinylbenzyl chloride (VBC) in the presence of a crosslinking agent, p‐divinylbenzene. Subsequent modification of the nanosphere surfaces via surface‐initiated atom transfer radical polymerization of 4‐vinylpyridine, using the VBC units of PVBC on the nanosphere surface as the macroinitiators, produced a well‐defined and covalently tethered poly(4‐vinylpyridine) (P4VP) shells of 24–27 nm in thickness. Activation of the P4VP shells in a PdCl2 solution, followed by reactions with CO or H2S gas, gave rise to the corresponding P4VP composite shells containing densely dispersed palladium metal or palladium sulfide nanoparticles. The chemical composition of the nanosphere surfaces at various stages of surface modification was characterized by X‐ray photoelectron spectroscopy. Field emission scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the organic/inorganic hybrid nanospheres coated with palladium/P4VP shells. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2119–2131, 2008
Preparation of amphiphilic ternary block copolymers with PEO as the middle block and the effect of PEO position on the glass transition temperature (Tg) of copolymers
Authors: Zhang Yi , Pan Mugang , Liu Chao , Huang Junlian 
Published: February 2008

AbstractThe copolymer of polystyrene‐block‐poly(ethylene oxide)‐block‐poly (tert‐butyl acrylate) (PS‐b‐PEO‐b‐PtBA) was prepared, the synthesis process involved ring‐opening polymerization (ROP), nitroxide‐mediated polymerization (NMP), and atom transfer radical polymerization (ATRP), and 4‐hydroxyl‐2,2,6,6‐tetramethylpiperidinyl‐1‐oxy (HTEMPO) was used as parent compound. The PEO precursors with α‐hydroxyl‐ω‐2,2,6,6‐tetramethylpiperidinyl‐1‐oxy end groups(TEMPO‐PEO‐OH) were first obtained by ROP of EO using HTEMPO and diphenylmethylpotassium (DPMK) as the coinitiator. The TEMPO at one end of PEO chain mediated the polymerization of St using benzoyl peroxide as initiator. The resultant PS‐b‐PEO‐OH reacted further with 2‐bromoisobutyryl bromide and then initiated the polymerization of tBA in the presence of CuBr and PMDETA by ATRP. The ternary block copolymers PS‐b‐PEO‐b‐PtBA and intermediates were characterized by gel permeation chromatography, Fourier transform infrared, and nuclear magnetic resonance spectroscopy in detail. Differential scanning calorimetry measurements confirmed that the PS‐b‐PEO‐b‐PtBA with PEO as middle block can weaken the interaction between PS and PtBA blocks, the glass transition temperature (Tg) for two blocks were approximate to their corresponding homopolymers comparing with the PEO‐b‐PS‐b‐PtBA with PEO as the first block. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2624–2631, 2008
Glycopeptide dendrimers, Part III—a review: Use of glycopeptide dendrimers in immunotherapy and diagnosis of cancer and viral diseases
Authors: Niederhafner Petr , Reiniš Milan , Šebestík Jaroslav , Ježek Jan 
Published: February 2008

AbstractGlycopeptide dendrimers containing different types of tumor associated‐carbohydrate antigens (TN, TF, sialyl‐TN, sialyl‐TF, sialyl‐Lex, sialyl‐Lea etc.) were used in diagnosis and therapy of different sorts of cancer. These dendrimeric structures with incorporated T‐cell epitopes and adjuvants can be used as antitumor vaccines. Best results were obtained with multiantigenic vaccines, containing, e.g. five or six different TAAs. The topic of TAAs and their dendrimeric forms at molecular level are reviewed, including structure, syntheses, and biological activities. Use of glycopeptide dendrimers as antiviral vaccines against HIV and influenza is also described. Their syntheses, physico‐chemical properties, and biological activities are given with many examples. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Bacterial selectivity and plausible mode of antibacterial action of designed Pro‐rich short model antimicrobial peptides
Authors: Park Ka Hyon , Park Yoonkyung , Park II‐Seon , Hahm Kyung‐Soo , Shin Song Yub 
Published: February 2008

AbstractTo develop novel Pro‐rich model AMPs with shorter length and higher bacterial selectivity/therapeutic index (TI) than natural AMP, indolicidin, we synthesized a series of undodecapeptides derived from the sequence XXPXXPWXPXX‐NH2 (X indicates Leu or Lys) with different ratios of Lys and Leu residues. Several Pro‐rich model peptides (K7WP3, K6WL1P3, K5WL2P3‐1, K5WL2P3‐2, and K4WL3P3) had approximate 8‐ to 11‐fold higher bacterial selectivity/TI compared to indolicidin. These peptides selectively bind to negatively charged liposomes (EYPG/EYPG; 7:3, w/w) mimicking bacterial membranes. Their high selectivity to negatively charged phospholipids corresponds well with their high bacterial selectivity. Indolicidin showed almost complete depolarization of the cytoplasmic membrane of Staphylococcus aureus and dye‐leakage from negatively charged liposomes at 10 µM, whereas all of Pro‐rich model peptides had very little activity in these assays even at 80 µM, as observed in buforin 2. These results suggest that the ultimate target of our designed Pro‐rich model peptides is probably the intracellular components (e.g. protein, DNA or RNA) rather than the cytoplasmic membranes. Collectively, our designed Pro‐rich short model peptides appear to be excellent candidates for future development as a novel antimicrobial agent. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Deactivation of the boron–oxygen recombination center in silicon by illumination at elevated temperature
Authors: Lim Bianca , Bothe Karsten , Schmidt Jan 
Published: February 2008

AbstractThe boron–oxygen‐related recombination center responsible for the light‐induced degradation of solar cells made on boron‐doped oxygen‐contaminated silicon is deactivated by simultaneously annealing the silicon wafer in the temperature range 135–210 °C and illuminating it with white light. The recombination lifetime after deactivation is found to be stable under illumination at room temperature. The deactivation process is shown to be thermally activated with an activation energy of 0.7 eV. Based on the experimental findings, a defect reaction model is proposed explaining the deactivation of the boron–oxygen center. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mass spectrometry analysis of terpene lactones in Ginkgo biloba
Authors: Ding Shujing , Dudley Ed , Song Qingbao , Plummer Sue , Tang Jiandong , Newton Russell P. , Brenton A. Gareth 
Published: February 2008

AbstractTerpene lactones are a family of compounds with unique chemical structures, first recognised in an extract of Ginkgo biloba. The discovery of terpene lactone derivatives has recently been reported in more and more plant extracts and even food products. In this study, mass spectrometric characteristics of the standard terpene lactones in Ginkgo biloba were comprehensively studied using both an ion trap and a quadrupole time‐of‐flight (QTOF) mass spectrometer. The mass spectral fragmentation data from both techniques was compared to obtain the mass spectrometric fragmentation pathways of the terpene lactones with high confidence. The data obtained will facilitate the analysis and identification of terpene lactones in future plant research via the fragmentation knowledge reported here. Copyright © 2008 John Wiley & Sons, Ltd.
Efficient adaptive designs with mid‐course sample size adjustment in clinical trials
Authors: Bartroff Jay , Lai Tze Leung 
Published: February 2008

AbstractAdaptive designs have been proposed for clinical trials in which the nuisance parameters or alternative of interest are unknown or likely to be misspecified before the trial. Although most previous works on adaptive designs and mid‐course sample size re‐estimation have focused on two‐stage or group‐sequential designs in the normal case, we consider here a new approach that involves at most three stages and is developed in the general framework of multiparameter exponential families. This approach not only maintains the prescribed type I error probability but also provides a simple but asymptotically efficient sequential test whose finite‐sample performance, measured in terms of the expected sample size and power functions, is shown to be comparable to the optimal sequential design, determined by dynamic programming, in the simplified normal mean case with known variance and prespecified alternative, and superior to the existing two‐stage designs and also to adaptive group‐sequential designs when the alternative or nuisance parameters are unknown or misspecified. Copyright © 2008 John Wiley & Sons, Ltd.
The chick embryo as a model for intrauterine ultrasound‐guided heart intervention
Authors: Fechner S. , Busch C. , Oppitz M. , Drews U. , Meyer‐Wittkopf M. 
Published: February 2008

AbstractObjectivesPrenatal minimally invasive therapy represents a challenging option for reducing long‐term complications of pathological fetal heart development. Here, the potential of the chick embryo as a model for ultrasound‐guided intrauterine cardiac intervention is explored.MethodsChick embryos were incubated for 18 days in fenestrated eggs and their hearts were punctured in ovo under ultrasound guidance. Indian ink and Nile blue sulfate were applied to mark the injection channel. After cardiac intervention, embryos were further incubated and subsequently sacrificed for macroscopic and histological evaluation of the heart.ResultsStereomicroscopic analysis revealed that the catheter had successfully penetrated the cardiac ventricular wall in 26/38 embryos. The myocardium was not severely injured. Histological evaluation showed that the myocardium had almost reoccluded after the intervention and that the injection channel was clogged with fibrin. In one case, the embryo was not sacrificed, but was removed from the egg 24 h after the intervention, with no signs of cardiac dysfunction, and was followed up for 6 months.ConclusionsIntrauterine ultrasound‐guided heart intervention in the human fetus can be simulated in the chick embryo. Fenestrated eggs have to be used because the egg shell and shell membrane are impermeable to ultrasound. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Reproductive ecology of the pedunculate barnacleScalpellum stearnsii(Cirripedia: Lepadomorpha: Scalpellidae)
Authors: Ozaki Yuki , Yusa Yoichi , Yamato Shigeyuki , Imaoka Tohru 
Published: February 2008

The sexuality of large (non-dwarf) individuals and the characteristics of eggs, larvae and dwarf males were investigated in the pedunculate barnacleScalpellum stearnsii. All 103 large individuals collected in this study were not hermaphrodites but females. The major length axis of the egg was on average 0.50 mm, which was larger than that in most thoracican barnacles with planktotrophic larvae. The larvae hatched as nauplii and metamorphosed into cyprids without feeding (i.e. lecithotrophic development). There was a positive relationship between body weight and egg mass weight in ovigerous females. The number of males attached per female ranged from 0 to 35 (average: 5.9) and there was a positive relationship between the number of males and female body weight. The distribution of dwarf males was skewed significantly towards the lower part of the occludent margin, which is near the fertilization site.
Gametogenic cycle of the smooth clam Callista chione on the south-western coast of Portugal
Authors: Moura P. , Gaspar M.B. , Monteiro C.C. 
Published: February 2008

The gametogenic cycle of the smooth clam Callista chione off the Arrábida region was studied throughout a 17-month period (from January 2004 to May 2005) using standard histological techniques, mean oocyte diameters and a condition index. This species showed a synchronism between sexes both in terms of gametogenic development and spawning. The results indicated that sex-ratio was not significantly different from parity. In January 2004, the gametogenic cycle had already begun and ended in late October 2004. Three spawning peaks were detected: January–March, April–May and August–October. No resting period was observed and a new gametogenic cycle began in early November, immediately after the spawning period. The analysis of the oocyte diameter enabled predicting the main spawning periods, which appear to be largely governed by seawater temperature. The condition index evolved according to the reproductive cycle of the species, with the highest values being observed prior to the main spawning periods. The size at first maturity estimated for C. chione was 50.81 mm.
Gandhi and the Emergence of the Modern Indian Political Canon
Authors: Parel Anthony J. 
Published: February 2008

AbstractThis article explores Mahatma Gandhi's contributions towards the evolution of the modern Indian political canon. Beginning with the Arthasastra, classical India had a political canon of its own. It flourished for over a millennium, but it suffered near extinction with the introduction in the nineteenth century of the Western political canon by the colonial state. Gandhi in the twentieth century intervened and challenged the dominance of the Western canon. He updated the old canon by deleting what was obsolete in it, preserving what was viable, and adding to it what was new and modern.
The “Axial Period”: What Was It and What Does It Signify?
Authors: Black Antony 
Published: February 2008

AbstractKarl Jaspers coined the term the “axial period” to refer to what he saw as the simultaneous development in several different and separate societies—China, India, Iran, Israel, Greece—of “a new departure within mankind.” What he meant has been characterized as “a kind of critical, reflective questioning of the actual and a new vision of what lies beyond.” While it is true that people in each of these separate cultures began to develop new ways of talking about the cosmos, ethics, and community, Jaspers's approach and description of these phenomena were, I shall argue, highly defective. This has led to serious misunderstandings of what was involved.
The Archaeology of Liberty in an American Captial: Excavations in Annapolis
Authors: Leone Mark P. , Armstrong Douglas V. , Marshall Yvonne , Smith Adam T. 
Published: February 2008

Over the last two decades, there has been increasing attention to community archaeology, an archaeology which acknowledges the impact of archaeological research upon the communities among which it is conducted. Doing fieldwork has tangible effects upon the people we work among: archaeologists provide employment, spend money locally, negotiate local power structures, provide exotic connections, and, not least, change the landscape of knowledge by helping local people understand more or different things about their ancestors and about their own historical identity. While this is true worldwide, within American Historical Archaeology this strand of research has converged with a tradition of sophisticated materialist analysis highlighting not only class domination but also resistance and the persistence of alternative practices, ideologies and identities. A key element of this archaeology is public participation in the process of revealing a past of domination, struggle and resistance. The result is an archaeology which aspires not only to revise traditionally endorsed accounts of American history, but also to be an activist archaeology.Mark Leone began this line of activist, participatory historical archaeology many years ago in Annapolis, and many of the scholars currently contributing to this body of work have been trained or inspired by this project. In The Archaeology of Liberty in an American Capital, Leone summarizes twenty-five years of research at Annapolis.The Archaeology of Liberty in an American Capital: Excavations in Annapolis has received the Society for Historical Archaeology's James Deetz Book Award for 2008.