bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transforming chromium containing collagen wastes into flexible composite sheets using cellulose derivatives: Structural, thermal, and mechanical investigations
Authors: Ashokkumar Meiyazhagan , Thanikaivelan Palanisamy , Krishnaraj Kaliappa , Chandrasekaran Bangaru 
Published: May 2011

AbstractLeather, footwear, and clothing industries produce significant quantity of chromium containing proteinaceous wastes. One of the major uses of these wastes is to convert them into sheets or boards. However, the previous methods could not provide flexible sheets with desired strength. Here, we describe a simple and efficient method for the preparation of flexible composite sheets using chromium containing collagenous wastes (CS) with the use of cellulose derivatives. The leather wastes have been partially hydrolyzed and converted into composite sheets under microwaves with the addition of 2‐hydroxyethyl cellulose (HEC) in varying concentrations from 2.5 to 20 wt%. A comprehensive strength as high as 3.14 ± 0.45 MPa with a softness of 3.8 ± 0.2 mm is achieved with the addition of 20 wt% HEC in the CS/HEC composite sheets. Scanning electron microscopic and mercury intrusion porosimetric analysis demonstrate the reduction in pores, especially micro pores (<50 μm), when the concentration of HEC is higher thereby showing improved interfacial adhesion of HEC onto CS. Infrared spectroscopy result indicates the presence of distinctive bands associated with both CS and HEC. There is also a reasonable increase in the thermal stability of the CS/HEC sheets as the content of HEC increases. Hence, the developed CS/HEC composite sheets were found to be flexible and have improved thermo‐mechanical properties, which are suitable for applications in leather product and allied industries. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Non‐isothermal crystallization of poly(ethylene oxide)/silver nanoplate composites
Authors: Rahmansyah Nandho , Lo Chieh‐Tsung , Syu Ciou‐Mei , Lee Chien‐Liang 
Published: May 2011

AbstractThe non‐isothermal crystallization of poly(ethylene oxide) (PEO)/silver nanoplate composites was studied using differential scanning calorimetry. The non‐isothermal crystallization was analyzed by combining the Avrami and Ozawa equations. It was found that the Avrami exponent for neat PEO ranges from 2.51 to 2.53, whereas it ranges from 2.54 to 3.16 for its composites, indicating that the spherical crystal morphology does not change with the addition of nanoplates. However, the rate determination of crystal growth transfers from diffusion to nucleation. The crystallization half‐time showed an increase with the addition of silver nanoplates in PEO, indicating that the overall crystallization rate of PEO decreases with the addition of nanoplates. However, the nucleation activity is larger than unity in the composites and the value increases with an increase in the nanoplate content. This behavior implies that the nanoplates act as anti‐nucleating agents to hinder nucleation. Copyright © 2011 Society of Chemical Industry
Preparation and characterization of electrospun ultrafine polyamide‐6 nanofibers
Authors: Nirmala Rajkumar , Navamathavan Rangaswamy , El‐Newehy Mohamed Hassan , Kim Hak Yong 
Published: May 2011

AbstractWe report on the preparation and characterization of ultrafine polyamide‐6 nanofibers by the electrospinning technique. The effect of electrospinning on the formation of ultrafine polyamide‐6 nanofiber structure was examined. The morphological and structural characterizations and thermal properties of the ultrafine polyamide‐6 nanofibers were investigated in comparison with bulk polyamide‐6 pellets. In order to accurately characterize the ultrafine polyamide‐6 nanofiber structure by direct identification of mass resolved components, we performed matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. Field emission scanning electron microscopy images revealed the presence of ultrafine polyamide‐6 nanofibers bound between the main fibers. The diameter of the polyamide‐6 nanofibers was observed to be in the range 75–110 nm, whereas the ultrafine structures consisted of regularly distributed very fine nanofibers with diameters of about 9–28 nm. The MALDI‐TOF spectra showed the presence of protonated and sodiated ions that were assigned to polyamide‐6 chains. Copyright © 2011 Society of Chemical Industry
Banded spherulites of electrospun poly(trimethylene terephthalate)/carbon nanotube composite mats
Authors: Wu Defeng , Yang Tao , Sun Yurong , Shi Tiejun , Zhou Weidong , Zhang Ming 
Published: May 2011

AbstractThe crystallization of poly(trimethylene terephthalate) (PTT) composites containing carbon nanotubes (CNTs) were studied in this work. The electrospinning technology was employed successfully to fabricate thin film samples with well‐embedded CNTs for spherulite observations using atom force microscopy. The results show that the composites present a higher overall crystallization rate than that of the neat PTT due to the nucleation effect of the CNTs. Banded spherulites can be observed on both the neat PTT and the composites. The presence of CNTs does not change the twisting mode of PTT crystal, but reduces band spacing and twist period. This is attributed to the enhanced fold staggering level of lamellae caused by the narrowed lamellae size and accelerated spherulite growth, which is further confirmed by analysis through secondary nucleation theory. Copyright © 2011 Society of Chemical Industry
Biomedical applications of biodegradable polymers
Authors: Ulery Bret D. , Nair Lakshmi S. , Laurencin Cato T. 
Published: May 2011

AbstractUtilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. Specifically, polymeric biomaterials that are biodegradable provide the significant advantage of being able to be broken down and removed after they have served their function. Applications are wide ranging with degradable polymers being used clinically as surgical sutures and implants. To fit functional demand, materials with desired physical, chemical, biological, biomechanical, and degradation properties must be selected. Fortunately, a wide range of natural and synthetic degradable polymers has been investigated for biomedical applications with novel materials constantly being developed to meet new challenges. This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
A coarse‐grained molecular model of strain‐hardening for polymers in the marginally glassy state
Authors: Nayak Kapileswar , Read Daniel J. , McLeish Tom C. B. , Hine Peter J. , Tassieri Manlio 
Published: May 2011

AbstractWe have developed a simple bead‐spring model, intended to mimic the internal dynamics of individual polymer chains in the region of the glass transition temperature. Entanglement constraints on the chains are approximated by “sliplinks.” We model the chain dynamics using a dynamic Monte Carlo scheme, with a hop acceptance criterion based on the traversal of high energy barriers. We use this to address the recent experiments of Hine et al., which investigated the effects of melt processing on stress‐strain behavior. Polystyrene samples were stretched, annealed at constant length for various times, then either subjected to shrinkage tests or further stress‐strain tests. Our model reproduces, at a qualitative level, the observations of Hine et al. It indicates that whilst the initial (weak) strain hardening involves deformation of chain subunits smaller than the entanglement length, the transition to stronger strain hardening involves the “pulling tight” of a small fraction of chain strands trapped in between entanglements. The insights gained suggest a route towards development of molecular‐based constitutive models for strain hardening in the glassy state, and specifically the effect of melt processing. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Caregiving styles and attachment orientations in couples facing advanced cancer
Authors: Braun Michal , Hales Sarah , Gilad Lior , Mikulicer Mario , Rydall Anne , Rodin Gary 
Published: May 2011

AbstractObjectiveThis study examines associations between caregiving styles and caregivers' and patients' attachment orientations among couples facing advanced cancer. Four caregiving styles were examined: proximate, sensitive, controlling, and compulsive.MethodA total of 110 patients with advanced gastrointestinal or lung cancer and their spouse caregivers were recruited. Measures included: the Experiences in Close Relationships Inventory, the Caregiving Questionnaire, and the Demand Subscale from the Caregiving Burden Scale.ResultsCaregivers reported high levels of proximate and sensitive caregiving and moderate levels of controlling and compulsive caregiving. Hierarchical regressions were conducted to examine the contribution of caregivers' and patients' attachment orientations to each caregiving style while controlling for caregiving demands. Both caregiving proximity and sensitive caregiving were negatively associated with caregivers' avoidant attachment. Controlling caregiving was positively related to caregivers' avoidant and anxious attachment orientations. Compulsive caregiving was positively associated with caregiving demand and caregivers' attachment anxiety. In addition, compulsive caregiving was positively associated with patients' attachment avoidance and negatively associated with patients' attachment anxiety.ConclusionsThe study demonstrated two clusters of ways to provide care: other–oriented and self‐oriented. The study revealed that both patients' and caregivers' attachment orientations contributed to caregivers' patterns of caregiving. Insecure attachment orientations and resulting couple interaction patterns of ‘demand‐withdrawal’ and ‘avoidance‐pursuit’ are potential sources of distress that may benefit from exploration in psychotherapeutic interventions for couples facing advanced cancer. Copyright © 2011 John Wiley & Sons, Ltd.
Obstacles and opportunities in deploying model‐based GUI testing of mobile software: a survey
Authors: Janicki Marek , Katara Mika , Pääkkönen Tuula 
Published: May 2011

SUMMARYModel‐based testing has not been widely deployed in industry yet. There seem to be both technical and non‐technical reasons for this situation. A survey among mobile software testing professions in Finland was conducted that aimed at investigating possible obstacles and opportunities towards wider deployment of this technology. This paper discusses the results and provides conclusions that indicate that at least in this context, there is much interest among practitioners towards the technology. However, more research is needed to make model creation and maintenance as easy as possible. In addition, metrics should be developed that can be used to report test results in the same manner as using existing testing techniques, enabling comparison between different approaches. Special emphasis should also be placed on enabling quick bug localization. Furthermore, it seems that successful pilot projects are a key to wider industrial adoption. Based on the survey findings, an agenda for the future model‐based testing research is outlined. Copyright © 2011 John Wiley & Sons, Ltd.
Gray‐scale and color Doppler ultrasound characteristics of endometrial cancer in relation to stage, grade and tumor size
Authors: Epstein E. , Van Holsbeke C. , Mascilini F. , MÅsbäck A. , Kannisto P. , Ameye L. , Fischerova D. , Zannoni G. , Vellone V. , Timmerman D. , Testa A. C. 
Published: May 2011

AbstractObjectivesTo describe the gray‐scale and vascular characteristics of endometrial cancer in relation to stage, grade and size using two‐dimensional (2D)/three‐dimensional (3D) transvaginal ultrasound.MethodsThis was a prospective multicenter study including 144 women with endometrial cancer undergoing transvaginal ultrasound before surgery. The sonographic characteristics assessed were echogenicity, endometrial/myometrial border, fibroids, vascular pattern, color score and tumor/uterus anteroposterior (AP) ratio. Histological assessment of tumor stage, grade, type and growth pattern was performed.ResultsHyperechoic or isoechoic tumors were more often seen in Stage IA cancer, whereas mixed or hypoechoic tumors were more often found in cancers of Stage IB or greater (P = 0.003). Hyperechogenicity was more common in Grade 1–2 tumors (i.e. well or moderately differentiated) (P = 0.02) and in tumors with a tumor/uterine AP ratio of < 50% (P = 0.002), whereas a non‐hyperechoic appearance was more commonly found in Grade 3 tumors (i.e. poorly differentiated) and in tumors with a tumor/uterine AP ratio of ≥ 50%. Multiple global vessels were more often seen in tumors of Stage IB or greater than in Stage IA tumors (P = 0.02), in Grade 3 tumors than in Grade 1 and 2 tumors (P = 0.02) and in tumors with a tumor/uterine AP ratio of ≥ 50% (P < 0.001). A moderate/high color score was significantly more common in tumors of higher stage (P = 0.03) and larger size (P = 0.001).ConclusionThe sonographic appearance of endometrial cancer is significantly associated with tumor stage, grade and size. More advanced tumors often have a mixed/hypoechoic echogenicity, a higher color score and multiple globally entering vessels, whereas less advanced tumors are more often hyperechoic and have no or a low color score. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Impact of Doppler sonography on intrauterine management and neonatal outcome in preterm fetuses with intrauterine growth restriction
Authors: Chalubinski K. M. , Repa A. , Stammler‐Safar M. , Ott J. 
Published: May 2011

AbstractObjectivesTo test the hypothesis that earlier delivery may be warranted to improve neonatal outcome of fetuses with intrauterine growth restriction (IUGR) with abnormal Doppler parameters.MethodsThis was a retrospective cohort study of 110 fetuses with an antenatal diagnosis of IUGR due to placental insufficiency which had a very low birth weight (< 1500 g), delivered at the Department of Fetomaternal Medicine of the Medical University of Vienna, Austria, between January 1999 and July 2009. Doppler results before delivery were classified as follows: Group 1: abnormal umbilical artery (UA) pulsatility index (PI) more than 2 SD above the mean for normal reference data, or absent UA end‐diastolic flow, both with normal middle cerebral artery (MCA) PI (mean ± 2 SD); Group 2: abnormal UA‐PI > mean + 2 SD, or absent or reversed UA end‐diastolic flow, with abnormal MCA‐PI (< mean − 2 SD) and normal ductus venosus (DV) PI (mean ± 2 SD); Group 3: absent or reversed UA end‐diastolic flow, with abnormal MCA‐PI (< mean − 2 SD) and abnormal DV‐PI (> mean + 2 SD) and/or absent or reversed end‐diastolic DV flow. Pregnancy outcome was analyzed according to Doppler results.ResultsDue to very poor prognosis, 19 fetuses underwent expectant management and died in utero. These were excluded from further analyses. Of the remaining 91 cases, 17 were in Doppler Group 1, 44 in Group 2 and 30 in Group 3. Within 4 weeks after delivery, 0/17 (0%) infants in Group 1 died, 2/44 (4.5%) infants in Group 2 died and 7/30 (23.3%) infants in Group 3 died (P = 0.019). None of the 42 Group 2 cases that delivered at or after 28 completed gestational weeks died within 4 weeks after delivery, in contrast to 4/20 (20.0%) Group 3 cases (P = 0.009). In comparison, among infants delivered before 27 completed gestational weeks, 2/2 (100%) Group 2 cases died and 3/10 (30.0%) Group 3 cases died; P = 0.152).ConclusionsDoppler examinations are highly predictive in assessing the outcome of IUGR fetuses. From 28 completed gestational weeks, early delivery before the onset of fetal cardiac decompensation might be beneficial. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Improvement in the heat resistance of poly(vinyl chloride) profile with styrenic polymers
Authors: Zhang Zhen , Chen Shuangjun , Zhang Jun 
Published: May 2011

AbstractThe styrenic polymers poly(α‐methylstyrene‐acrylonitrile) (α‐MSAN) and poly(acrylonitrile‐butadiene‐styrene) (ABS) and (three types) were used to improve the heat resistance of poly(vinyl chloride) (PVC). The glass transition temperature (Tg) and miscibility were analyzed by dynamic mechanical thermal analysis (DMTA). Effects of composition on heat distortion temperature (HDT) were investigated with the different styrenic polymers. Other physical properties such as mechanical properties and melt flow rate (MFR) were also determined. Morphology was observed by scanning electron microscopy (SEM) in order to support the mechanical property results. The PVC was miscible with α‐MSAN but partially miscible with the ABS series, and α‐MSAN was much more effective in enhancing the Tg and HDT of rigid PVC than the ABS series as for mechanical properties, the addition of α‐MSAN could improve the tensile strength, bending strength, and bending modulus but decrease the impact strength of the materials compared with the addition of the ABS series. Improvement in processability was observed in the MFR results with the addition of the styrenic polymers. On the basis of all the properties, the formulation with an α‐MSAN content of 30 phr (parts per hundred parts of resin) was superior for heat‐resistant PVC profile. The HDT of PVC could be increased from 76.9°C to 85.4°C (measured under the maximum bending stress of 0.45 MPa) and combined with good mechanical properties and processability by the addition of 30 phr of α‐MSAN. Also, a heat‐resistant PVC profile was successfully fabricated. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Influence of acetylation on the tensile properties, water absorption, and thermal stability of (High‐density polyethylene)/(soya powder)/(kenaf core) composites
Authors: Ismail H. , Abdullah A. Hamid , Bakar A. Abu 
Published: May 2011

AbstractComposites comprising high‐density polyethylene (HDPE)/(soya powder)/(kenaf core) were prepared by incorporating different loads of kenaf core powder into HDPE/(soya powder) composites with an internal mixer (Haake PolyLab) for 12 min at 180°C and 50 rpm. The composition of the soya powder used was soluble carbohydrates, 15%; insoluble carbohydrates, 15%; oil, 18%; protein, 38%; and moisture, ash, other, 14%. The effect of kenaf core acetylation on the properties of the HDPE/(soya powder)/(kenaf core) composites was investigated by using a water‐absorption test, a tensile test, thermogravimetric analysis, Fourier‐transform infrared spectroscopy, and field emission scanning electron microscopy (FESEM). The acetylation of the kenaf core caused a significant increase in the water resistance, thermal stability, and tensile properties of the composites. The FESEM results showed that better interaction occurred between acetylated kenaf core and HDPE relative to unmodified kenaf core. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Soil burial degradation of new bio‐based additives. Part I. Rigid poly(vinyl chloride) films
Authors: Lardjane N. , Belhaneche‐Bensemra N. , Massardier V. 
Published: May 2011

AbstractCommercial sunflower oil was epoxidized, and the epoxidized sunflower oil (ESO) was used as a thermal stabilizer for poly(vinyl chloride) (PVC). Rigid formulations stabilized with ESO as a new stabilizer and epoxidized soybean oil (ESBO) as a commercial stabilizer for comparison were prepared. The aging of the PVC samples was investigated in landfill soil for 24 months. The structure modifications of the polymer were followed by Fourier transform infrared spectroscopy (FTIR). Furthermore, the variations of density and mechanical properties (tensile and Shore D hardness) were considered. The variations of the mass of the samples, the glass transition temperature (Tg), the molar mass distribution, and the weight loss were followed as a function of time of soil burial. The soil burial test showed the loss of additives by migration and biodegradation that led to the modification of density, mechanical properties, molar mass distribution, and weight loss of the PVC samples. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Evaluation and optimization of the mechanical properties of highly filled PVC/(wood flour) composites by using experimental design
Authors: Fasihi Mohammad , Garmabi Hamid 
Published: May 2011

AbstractIn this study, PVC/(wood flour) (WF) composites were prepared by using a counterrotating twin‐screw extruder, and the effects on the mechanical properties of concentration and particle size of the WF, type and amount of coupling agent, K value of PVC, feed rate of extruder, and die temperature were investigated. Optimization of various formulation parameters based on the Taguchi method demonstrated that the wood content and wood particle size were the most important parameters. Flexural modulus increased upon increasing WF loading up to 50 wt%. Also, flexural strength and modulus increased with particle size because of the higher aspect ratio and better quality of mixing. Use of coupling agents had a minor effect that was attributed to the moderately high polarity of PVC causing relatively good compatibility between WF particles and the PVC matrix. The optimum level of WF calculated by considering the contribution factor was 50 wt%. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Vibrational Spectra and Quantum Chemical Calculations of the Pure and Mixed Cluster Anions [SixGe4–x]4– and [GexSn4–x]4– (x = 0–4) in Compounds with Potassium and Cesium
Authors: Ormeci Alim , Aydemir Umut , Somer Mehmet 
Published: May 2011

AbstractThe Raman spectroscopic studies on samples with the starting compositions Cs4[Si2Ge2] and M4[Ge2Sn2] (M = K, Cs) verify unambiguously the presence of phases composed of the mixed cluster moieties [SixGe4–x]4– and [GexSn4–x]4– (x = 1–3) including the pure anions [E4]4– (E = Si, Ge, Sn). The assignment of the vibrational frequencies is supported by normal coordinate analysis (NCA). The results for the mixed cluster anions are discussed in context with their isoelectronic analogs PxAs4–x (x = 1–3) and SbP3. Using the characteristic breathing frequencies, one obtains for the ratio factor of the mixed moieties κ = ν([SixGe4–x]4–) / ν(PxAs4–x) = 0.79, which is in good agreement with the reported value of 0.77 for the pure cluster series [E4]4– (E = Si, Ge, Sn) and X4 (X = P, As, Sb). The experimental average force constants f(Si‐Ge) = 1.01 Ncm–1 and f(Ge‐Sn) = 0.77 Ncm–1 correspond to arithmetic mean of those obtained for the pure anions in the binaries M4E4 (M = K, Rb, Cs; E = Si, Ge, Sn). The phonon frequencies of binary M4E4 (M = K, Cs; E = Si, Ge, Sn) and ternary K4ExE′4–x (E, E′ = Si, Ge or Ge, Sn, E ≠ E′, x = 1, 2, 3) were calculated by using pseudopotential electronic structure method SIESTA. Excellent agreement between the calculated and experimental frequencies was obtained for the pure binaries. The theoretical results compare also well with experimental values for the mixed series [SixGe4–x]4–, whereas for the corresponding mixed Ge‐Sn species the differences between measured and calculated frequencies are greater than 10 %.