bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limb amputations in fixed dystonia: A form of body integrity identity disorder?
Authors: Edwards Mark J. , Alonso‐Canovas Araceli , Schrag Arnette , Bloem Bastiaan R. , Thompson Philip D. , Bhatia Kailash 
Published: April 2011

AbstractFixed dystonia is a disabling disorder mainly affecting young women who develop fixed abnormal limb postures and pain after apparently minor peripheral injury. There is continued debate regarding its pathophysiology and management. We report 5 cases of fixed dystonia in patients who sought amputation of the affected limb. We place these cases in the context of previous reports of patients with healthy limbs and patients with chronic regional pain syndrome who have sought amputation. Our cases, combined with recent data regarding disorders of mental rotation in patients with fixed dystonia, as well as previous data regarding body integrity identity disorder and amputations sought by patients with chronic regional pain syndrome, raise the possibility that patients with fixed dystonia might have a deficit in body schema that predisposes them to developing fixed dystonia and drives some to seek amputation. The outcome of amputation in fixed dystonia is invariably unfavorable. © 2011 Movement Disorder Society
Creep analysis of bamboo high‐density polyethylene composites: Effect of interfacial treatment and fiber loading level
Authors: Xu Yanjun , Lee Sun‐Young , Wu Qinglin 
Published: April 2011

AbstractThe effect of chemical treatment at fiber–plastic interface and fiber loading level on creep property of bamboo fiber high‐density polyethylene (BF/HDPE) composites was investigated. For single modifier systems, the use of maleic anhydride grafted polyethylene (PE‐g‐MA) as a coupling agent helped reduce the creep and achieved the optimum effect at the 5.7% loading level. The addition of either a semicrystalline or an amorphous MA grafted ethylene propylene rubber (sEPR‐g‐MA or aEPR‐g‐MA) as an impact modifier increased the creep. For the combined modifiers, the use of PE‐g‐MA in EPR‐g‐MA modified composites gradually improved creep performance. Four‐element Burgers model was shown to fit measured creep data well only within the specified test period. However, both partially stretched Burgers (PSB) model and fully stretched Burgers (FSB) model could be applied for characterization and prediction when the stretching exponent was fixed at certain given values. The FSB model offered a better long‐term prediction based on the short‐term creep data. Time‐temperature superposition technique produced smooth master creep curves through horizontal shifts, but it slightly over‐predicted the long‐term creep for most composite systems. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Polythiophene/borax conducting composite II: Electrorheology and industrial applications
Authors: Gumus O. Yunus , Erol Ozlem , Unal H. Ibrahim 
Published: April 2011

AbstractIn this study, polythiophene (PT) and polythiophene/ borax conducting composite (PT/borax) were in‐situ synthesized using FeCl3 as oxidizing agent containing 89.2% PT and 10.8% borax. The electrorheological (ER), creep‐recovery, and vibration damping characteristics of the PT/borax composite were investigated. A volume fraction series (φ = 5–25%) of the PT/borax/silicone oil dispersions were prepared and sedimentation stabilities were determined. An ER activity was observed from the samples, when subjected to external electric field strength thus, they were classified as smart materials. Some parameters affecting the ER properties of the dispersions such as volume fraction, shear rate, electric field strength, frequency and temperature were investigated. Creep tests were applied to the suspensions to investigate the viscoelastic behaviors and recoverable viscoelastic deformations observed. Finally, real time vibration damping experiment was carried out on a modified automobile shock absorber and a 68% vibration damping capacity determined for borax/SO suspension system under E = 0.3kV/mm condition. POLYM. COMPOS., 2011.© 2011 Society of Plastics Engineers
Carbon nanofibers for strain and impact damage sensing in glass fiber reinforced composites based on an unsaturated polyester resin
Authors: Monti Marco , Natali Maurizio , Petrucci Roberto , Kenny José M. , Torre Luigi 
Published: April 2011

AbstractIn this article, a successful employment of carbon nanofibers (CNFs) as a filler in the unsaturated polyester (UP) matrix of a glass fiber reinforced polymer (GFRP) is reported. Because of the high aspect ratio of carbon nanofibers, very small amount of these particles were sufficient to significantly modify the electrical properties of the obtained glass fiber composites: for this reason, nanocomposite matrices were produced using no more than 1 wt% of these nanoparticles. The goal of this work was to investigate the possibility to correlate the presence of a mechanical stress, or the onset of damage, in the composite produced, with the variation of electrical resistance. Following this goal, the electrical resistance of the samples was constantly measured during their mechanical testing. Two different kinds of load were applied: flexural and impact. It was possible to show that a systematic variation in the electrical resistance of the composite takes place in correspondence of both the growth of a flexural state of stress, and the creation of an impact damage. In the case of the flexural load, the electrical resistance versus strain curves provides information on the growth of damage well before such damage affects the stress–strain curve. In the case of the impact damage, electric resistance measurements were able to monitor the loss of mechanical integrity before the complete failure. SEM pictures of the crack surface have confirmed the role of the carbon nanofibers in the sensing process. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Preparation and characterization of poly (vinyl butyral)‐leather fiber composites
Authors: Ambrósio J.D. , Lucas A.A. , Otaguro H. , Costa L.C. 
Published: April 2011

AbstractThis study reports the preparation and characterization of composites with recycled poly (vinyl butyral) (PVB) and wet blue leather fiber with leather contents of 30, 50, and 70 wt%, using an extruder equipped with a Maillefer single screw operated with a flat extrusion die. The components of the composites were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and Fourier transform infrared spectroscopy (FTIR). After extrusion, the PVB/leather composite plates were compression‐molded to obtain specimens for testing the tensile properties, hardness, abrasion resistance, and tear strength. The morphologies of the composites were analyzed by scanning electron microscopy (SEM). The DMA and FTIR analyses showed that the recycled PVB contained plasticizer remained in the polymer matrix after extrusion. The SEM analysis revealed good interfacial adhesion between the PVB matrix and the leather fibers. Increasing the leather content in the composites led to a significant increase in the tensile modulus and a reduction in the tensile strain at breaks. The Shore hardness of the composites increased with the wt% of leather, whereas the abrasion resistance decreased. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers.
Thermo‐mechanical behavior of polyamide 12—polyamide 66 recycled fiber composites
Authors: Dorigato Andrea , Fambri Luca 
Published: April 2011

AbstractPostconsumed polyamide 66 (PA66) short fibers derived from carpets were utilized as reinforcement in a commercial polyamide (PA12) matrix at different concentrations, ranging from 10 wt% to 30 wt%, in order to evaluate the effect of PA66 content on the mechanical and dynamic behavior of the resulting materials. DSC tests revealed that both melting and crystallization behavior of PA12 matrix was slightly affected by the presence of the fibers, showing a somewhat nucleation effect of PA66. Quasi‐static tensile tests evidenced that the introduction of PA66 fibers provided a slight stiffening effect on the resulting composites, increasing the elastic modulus with the filler content, especially at testing temperatures above Tg. On the other hand, the presence of agglomerated fibers led to an embrittlement of polyamide composites, showing a significant reduction of the tensile properties at break increasing the PA66 fibers content. Tensile dynamic tests confirmed the stiffening effect provided by the recycled fibers, increasing both dynamic moduli (E′ and E″) with PA66 content over the whole range of considered temperatures. Glass transition temperature of PA12 was substantially increased by the presence of the fibers, while the coefficient of linear thermal expansion above Tg was progressively reduced with the filler content. Interestingly, isothermal creep compliance of the material above Tg was substantially reduced by the presence of PA66 fibers. Morphological analysis on the cryofractured surfaces revealed a quite good fiber‐matrix interfacial adhesion, with the presence of some nucleating phenomena on the pulled out surfaces. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Effect of filler content and temperature on steady‐state shear flow of wood/high density polyethylene composites
Authors: Carrino Luigi , Ciliberto Stefano , Giorleo Giuseppe , Prisco Umberto 
Published: April 2011

AbstractSteady state shear flow of wood/high density polyethylene composites is investigated through capillary rheometry to gain better insight into rheology, extrudate distortions, and wall slip phenomena of wood/polymer composite melts. Effects of filler content and temperature on onset and end of stick‐slip transition, in terms of shear rate and shear stress, are also studied. Results show that shear rates at stick‐slip transition decrease while corresponding shear stresses increase with the addition of filler. Furthermore, temperature raises the shear rate and the shear stress at which the transition occurs. It is observed a log‐linear relationship in the plots of wall slip versus the shear stress, in particular, increasing the filler content and decreasing the temperature, these plots are shifted to higher shear stress, as a consequence of viscosity increment. Wall slip and filler content play a fundamental role in surface morphology; specifically, extrudates become smoother with increasing filler content and shear rate, whose increment always results in a rise of the wall slip. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Interface stability behaviors of methanol‐melamine‐formaldehyde shell microPCMs/epoxy matrix composites
Authors: Su Jun‐Feng , Wang Xin‐Yu , Wang Sheng‐Bao , Zhao Yun‐Hui , Zhu Kong‐Ying , Yuan Xiao‐Yan 
Published: April 2011

AbstractMicrocapsules containing phase change materials (microPCMs) have been widely applied in smart temperature‐controlling materials. Interface stability plays a key role in these microPCMs/matrix composites. The aim of this study was to investigate the interface stability behaviors of methanol‐melamine‐formaldehyde (MMF) shell microPCMs containing paraffin/epoxy matrix composites. MMF prepolymer can be applied to fabricated microcapsules with smooth shells. The average diameter of the microPCMs could be controlled in the range of 5–45 μm by stirring speed of 500–6,000 r min−1. From the SEM morphologies of the interphase between the microPCMs and the epoxy‐matrix, it is concluded that the interaction may be enhanced by MMF graft structure due to the increasing of molecular interaction in the interface. During a repeated heat‐transmission process, not only the repeated‐times of thermal absorbing‐releasing process will damage the interface bonding, but also higher thermal conductive speed will make the interface bearing more debonding stress. Large microPCMs in matrix may supply better interface stability. Moreover, the numerical and experimental results are consistent to obtain a clear insight into the rule of interface debonding for microPCMs/matrix composites that the interface perfection can be enhanced by increasing the thickness of interphase. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Octa(aminophenyl) polyhedral oligomeric silsesquioxane/boron‐containing phenol–formaldehyde resin nanocomposites: Synthesis, cured, and thermal properties
Authors: Gao Jungang , Li Xing , Wu Weihong , Lin Haojie 
Published: April 2011

AbstractOcta(aminophenyl) polyhedral oligomeric silsesquioxane (OAP‐POSS) and boron‐containing phenol‐formaldehyde resin (BPFR) were synthesized, respectively. The BPFR nanocomposites with different OAP‐POSS content (wt%) were prepared, and their properties were characterized. The results show that the thermal degradation process of this nanocomposites can be divided into three stages, and they are all following the first order mechanism. The residual ratio and thermal degradation activation energy Ea of 9 wt% OAP‐POSS/BPFR nanocomposites are both better than others and the Ea increase gradually in three stages, which is 93.3, 134.0, and 181.9 kJ mol−1, respectively. Its residual ratio at 900°C is 36.48%. The mechanical loss peak temperature Tp is 228°C for 12 wt% OAP‐POSSS/BPFR nanocomposites, which is higher 48°C than pure BPFR. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Effects of fiber surface chemistry and roughness on interfacial structures of electrospun fiber reinforced epoxy composite films
Authors: Liao Huaqiang , Wu Yiqiong , Wu Meiyu , Liu Haiqing 
Published: April 2011

AbstractThis work reported the effect of surface chemistry and roughness of electrospun fibers on fiber/matrix interfacial structures and the resultant macroscopical properties of composite films. Three types of fibrous mats composed of ultrafine fibers, that is, cellulose acetate (CANM), polyurethane (PUNM), and cellulose acetate/polyurethane composite (CAPUNM) were fabricated through electrospinning. CA fiber surfaces were rough with many hydroxyl groups; PU fiber surfaces were smooth, whereas CAPU composite fibers exhibited cocontiuous structure with rough surfaces. The fiber‐reinforced epoxy composite films were prepared by the solution impregnation method. The fractured surfaces of the composites were analyzed by scanning electron microscopy. Severe interfacial debonding and fiber pullouts were observed for PUNM/epoxy composites, while strong interfacial adhesion was formed for CANM/epoxy and CAPUNM/epoxy composites. The interfacial structure played important roles in the visible light transmittance of the composite films. For example, CANM/epoxy films showed the best optical property, whereas PUNM/epoxy films displayed the poorest light transmitting property and were translucent. The interfacial structure also affected the mechanical properties of the composites. The mechanical strength of fibrous mats followed an increasing order of CANM < CAPUNM < PUNM, but the mechanical strength of the composite films was in a reverse order, that is, CANM/epoxy > CAPUNM/epoxy > PUNM/epoxy. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Thermal and electrical properties of nitrile‐containing polyimide/BaTiO3 composite films
Authors: Hamciuc Elena , Hamciuc Corneliu , Bacosca Irina , Cristea Mariana , Okrasa Lidia 
Published: April 2011

AbstractPolyimide composite films were prepared by mixing the BaTiO3 particles into poly(amic acid) solution followed by film casting and thermal imidization under controlled temperature conditions. The poly(amic acid) was synthesized by solution polycondensation reaction of 4,4′‐oxydiphthalic anhydride with 2,6‐bis(4‐aminophenoxy)benzonitrile, using N‐methyl‐2‐pyrrolidone as solvent. The surface of BaTiO3 particles was modified by treating with an aminosilane coupling agent, 3‐aminopropyltriethoxysilane. Fourier transform infrared spectroscopy, X‐ray diffraction and scanning electron microscopy were used to characterize the structure and properties of the composites. The influence of BaTiO3 content on the composite film properties was evidenced. The films exhibited good thermal stability having the initial decomposition temperature above 520°C. They had stable dielectric properties over large intervals of temperature and frequency. The dielectric constant and the dielectric loss increased with the increase of BaTiO3 content. The dynamic mechanical analysis and dielectric spectroscopy revealed subglass transitions γ and β. At higher temperature an α‐relaxation that corresponds to the glass transition and a conductivity process were evidenced. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Isolated prenatal choroid plexus cysts do not affect child development
Authors: DiPietro Janet A. , Cristofalo Elizabeth A. , Voegtline Kristin M. , Crino Jude 
Published: April 2011

AbstractObjectiveTo examine the effect of isolated prenatal choroid plexus cysts (CPCs) on child cognitive, behavioral, motor, and autonomic development at 18 months of age.MethodsA prospective design was implemented to identify CPC cases and controls in mid‐pregnancy. Cases (n = 25) and controls (n = 45) participated in a follow‐up visit when children were 18 months of age. Child mental and motor development was assessed using standard developmental assessments, socioemotional and behavioral functioning during testing was rated by examiners, and accelerometers provided measures of motor activity and energy expenditure. Cardiac patterns were collected using a three‐lead electrocardiogram (ECG) and quantified as indicators of autonomic control of the heart, including vagal tone.ResultsNo significant differences were found in any outcome measure between children with prenatal CPC detection and those without.ConclusionFindings should provide reassurance to practitioners and parents that isolated CPCs in fetuses with normal karyotypes do not affect child development after birth. Copyright © 2011 John Wiley & Sons, Ltd.
Identification of response bias on apparent pregnancy outcome after second trimester ultrasound
Authors: Kozlowski Peter , Stressig Ruediger , Hammer Ruediger , Siegmann Hans Joerg , Froehlich Susanne , Verde Pablo Emilio , Knippel Alexander Johannes 
Published: April 2011

AbstractObjectivesTo investigate whether there is a response bias in outcome studies after prenatal ultrasound and to quantify this potential effect by information source.Materials and methodsAll normal ultrasound scans between week 17 and week 24 and 6 days performed in the years 2004 and 2005 were investigated. A multinomial logistic regression model was applied to investigate the association between responders' outcome (questionnaire, phone interview and inquiry to birth clinic) and the following explanatory variables: maternal age, smoking status, body mass index, congenital anomaly status, low birthweight and preterm deliveries.ResultsFrom the 12 439 women, 7747 (62.3%) sent back the questionnaire, 3032 (24.4%) were interviewed by telephone and in 1660 cases (13.3%) the outcome was obtained from the birth clinic. Maternal age > 34 years [odds ratio (OR) 0.72, confidence interval (CI) 0.61‐0.85/0.35, CI 0.29‐0.42, telephone/birth clinic] and minor anomalies (OR 0.52, CI 0.28‐0.98, birth clinic) were significantly underrepresented in nonresponders. Preterm delivery (OR 1.29, CI 1.11‐1.50/1.30, CI 1.08‐1.57), maternal smoking (OR 1.14, CI 1.07‐1.25/1.31, CI 1.22‐1.40) and stillbirths (OR 2.30, CI 1.09‐4.87, birth clinic) were significantly, major anomalies (OR 1.83, CI 0.94‐3.55/1.80, CI 0.79‐4.10) were considerably overrepresented in these groups.ConclusionSpontaneous responding to prenatal follow‐up questionnaires is significantly biased towards older and nonsmoking mothers with normal pregnancy outcome. Copyright © 2011 John Wiley & Sons, Ltd.
Improvement of melt spinning properties and conductivity of immiscible polypropylene/polystyrene blends containing carbon black by addition of styrene‐ethylene‐butene‐styrene block copolymer
Authors: Strååt Martin , Boldizar Antal , Rigdahl Mikael , Hagström Bengt 
Published: April 2011

AbstractConducting polymeric materials prepared from immiscible blends, such as polypropylene (PP)/polystyrene (PS), together with carbon black (CB), are known to have a relatively high electrical conductivity, because of a selective distribution of CB (double percolation). Melt spinning of immiscible blends containing CB has, however, not been extensively reported on previously. An immiscible 1:1 blend of PP and PS to which 4 wt% CB was added exhibited a very low melt draw‐down ratio at rupture compared wit PP with the same content of CB. By adding 5 wt% SEBS (styrene‐ethylene‐butene‐styrene block copolymer), the ultimate melt draw‐down ratio increased about 10 times, which made the material more suitable for melt spinning. As‐extruded samples of the immiscible blends (with CB) did not have higher electrical conductivities than PP/CB. A heat treatment increased the conductivity of immiscible PP/PS/CB composites, and longer treatment times and higher temperatures promoted the conductivity. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Preparation of polystyrene particles with different morphologies
Authors: Chen Jiafu , Li Yan , Xue Fengfeng , Chen Zhimin , Xu Qun 
Published: April 2011

AbstractMicron‐sized, cross‐linked polystyrene (PS) particles with different morphologies were prepared by the developed dispersion polymerization. By scanning electron microscope (SEM) observation, it was found that these PS particles had interesting shapes such as deformed sphere, hollow hemisphere and spheroid‐like shape when initial monomer concentration, reaction time, and temperature and addition way of the reagent added in the third stage were different. The shape of the PS particles was changed from hollow hemisphere to spheroid‐like shape with prolongation of the reaction time. It was remarkable that the rough surface of hollow‐hemisphere‐like PS particles became smooth and the hollow structure of smooth‐hollow‐hemisphere‐like PS particles grew into solid structure at the same time. The formation mechanism behind these phenomena was discussed. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Kinetic and structural studies of the polymerization of N,N′‐bismaleimide‐4,4′‐diphenylmethane with barbituric acid
Authors: Su Heng‐Lei , Hsu Jung‐Mu , Pan Jing‐Pin , Wang Tsung‐Hsiung , Yu Fu‐En , Chern Chorng‐Shyan 
Published: April 2011

AbstractBoth the isothermal and non‐isothermal polymerizations of N,N′‐bismaleimide‐4,4′‐diphenylmethane (BMI) with barbituric acid (BTA) were investigated by the differential scanning calorimeter. The experimental results showed that the polymerizations of BMI with BTA were governed by the competitive Michael addition reaction and free radical polymerization mechanisms. Furthermore, the contribution of free radical polymerization becomes more important when the mole fraction of BTA decreases. 1H NMR and 13C NMR measurements further support the coexistence of the Michael addition reaction and free radical polymerization mechanisms. A preliminary kinetic model that took into account the competitive Michael addition reaction and free radical polymerization mechanisms was developed. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers