bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reducing dimensionality in topology optimization using adaptive design variable fields
Authors: Guest James K. , Smith Genut Lindsey C. 
Published: August 2009

AbstractTopology optimization methodologies typically use the same discretization for the design variable and analysis meshes. Analysis accuracy and expense are thus directly tied to design dimensionality and optimization expense. This paper proposes leveraging properties of the Heaviside projection method (HPM) to separate the design variable field from the analysis mesh in continuum topology optimization. HPM projects independent design variables onto element space over a prescribed length scale. A single design variable therefore influences several elements, creating a redundancy within the design that can be exploited to reduce the number of independent design variables without significantly restricting the design space. The algorithm begins with sparse design variable fields and adapts these fields as the optimization progresses. The technique is demonstrated on minimum compliance (maximum stiffness) problems solved using continuous optimization and genetic algorithms. For the former, the proposed algorithm typically identifies solutions having objective functions within 1% of those found using full design variable fields. Computational savings are minor to moderate for the minimum compliance formulation with a single constraint, and are substantial for formulations having many local constraints. When using genetic algorithms, solutions are consistently obtained on mesh resolutions that were previously considered intractable. Copyright © 2009 John Wiley & Sons, Ltd.
Viscoplasticity using peridynamics
Authors: Foster J. T. , Silling S. A. , Chen W. W. 
Published: August 2009

AbstractPeridynamics is a continuum reformulation of the standard theory of solid mechanics. Unlike the partial differential equations of the standard theory, the basic equations of peridynamics are applicable even when cracks and other singularities appear in the deformation field. The assumptions in the original peridynamic theory resulted in severe restrictions on the types of material response that could be modeled, including a limitation on the Poisson ratio. Recent theoretical developments have shown promise for overcoming these limitations, but have not previously incorporated rate dependence and have not been demonstrated in realistic applications. In this paper, a new method for implementing a rate‐dependent plastic material within a peridynamic numerical model is proposed and demonstrated. The resulting material model implementation is fitted to rate‐dependent test data on 6061‐T6 aluminum alloy. It is shown that with this material model, the peridynamic method accurately reproduces the experimental results for Taylor impact tests over a wide range of impact velocities. The resulting model retains the advantages of the peridynamic formulation regarding discontinuities while allowing greater generality in material response than was previously possible. Copyright © 2009 John Wiley & Sons, Ltd.
Identifying indicators of well‐being for caregivers of children with disabilities
Authors: Larson Elizabeth 
Published: August 2009

AbstractThis study identified key indicators of well‐being for caregivers of children with disabilities, Thirty‐nine caregivers completed life satisfaction and psychological well‐being (WB) measures, and qualitative interviews. Data analysis included descriptive statistics of WB measures and categorical analysis of qualitative data. Data triangulation was achieved by importing theoretically derived codes for initial qualitative coding and quantitizing qualitative categories. Core indicators focused on positive family functioning and a reasonable family lifestyle, caregiver's personal growth and capacity to manage life demands, and the importance of daily balance. Study limitations included no standardized assessments of the child with disabilities' functioning, and the inclusion of caregivers with a range of years of experience. Findings suggest therapists need to attend to how interventions foster or impede positive family functioning and assist caregivers in balancing daily occupations to support capacity to caregiving. Future research should examine how well‐being varies over time as caregivers adapt from initial and later caregiving. Copyright © 2009 John Wiley & Sons, Ltd.
Low‐dose oral midazolam reduces fear and distress during needle procedures in children with cancer
Authors: Hedén Lena , von Essen Louise , Frykholm Peter , Ljungman Gustaf 
Published: August 2009

AbstractBackgroundChildren with cancer often mention needle procedures as the most frightening, distressing, and sometimes painful aspect of the disease and treatment. The aim was to investigate whether children experience less fear, distress, and/or pain according to parents, nurses, and children ≥7 years of age when they receive oral midazolam versus placebo before a needle is inserted in a subcutaneously implanted intravenous port.ProcedureFifty children 1–18 years of age who were being treated in a pediatric oncology and hematology setting were included consecutively when undergoing routine needle insertion into an intravenous port. All children were subjected to one needle insertion in this randomized, triple‐blind, placebo‐controlled study in which orally administered midazolam (n = 24) 0.3 mg/kg body weight (maximum 10 mg) was compared with placebo (n = 26). Parents, nurses, and children ≥7 years reported the patients' fear, distress, and pain on 0–100 mm Visual Analogue Scales.ResultsFear was lower in the midazolam group according to parents (P = 0.001), nurses (P = 0.001), and children (P = 0.015). Parents and nurses also reported lower distress (P = 0.020 and 0.007, respectively). Post hoc analyses indicated that the effects were more pronounced in younger children (<7 years of age).ConclusionLow‐dose oral midazolam was effective in reducing fear and distress in pediatric oncology patients, especially in younger children, undergoing subcutaneous port needle insertion. Pediatr Blood Cancer 2009; 53:1200–1204. © 2009 Wiley‐Liss, Inc.
Weight patterns in children with higher risk ALL: A report from the Children's Oncology Group (COG) for CCG 1961
Authors: Withycombe Janice S. , Post‐White Janice E. , Meza Jane L. , Hawks Ria G. , Smith Lynette M. , Sacks Nancy , Seibel Nita L. 
Published: August 2009

AbstractBackgroundThis retrospective analysis defined and described patterns and predictors of weight change during treatment in children with acute lymphocytic leukemia (ALL) with high‐risk features who received treatment on Children's Cancer Group protocol CCG 1961.ProcedurePatients (1,638) were enrolled in CCG 1961 from November 1996 to May 2002. Weight was measured as BMI percent (%), specific for age and gender, and defined as 100 × ln(BMI/median BMI).ResultsBy the end of treatment, 23% of children were obese (BMI ≥95%), compared with 14% at diagnosis. Children who received post‐induction intensified therapy (arms C, D, SER with Doxorubicin or Idarubicin) had higher gastrointestinal toxicities and lower BMI% from consolidation through interim maintenance 1. BMI% then increased for all arms between delayed intensification and maintenance 1 or 2. Children who were of Black or Hispanic race, obese at diagnosis, or who had grade 3 or 4 pancreatitis/glucose toxicities during induction had higher BMI% throughout treatment. Children were more likely to be obese at the end of the study if they were aged 5–9 years at diagnosis or female gender. Cranial radiation was not a predictor of obesity.ConclusionsSuccessful treatment of higher risk childhood ALL was associated with obesity, independent of cranial irradiation. The beginning of maintenance therapy may be the best time to intervene with nutritional and behavioral interventions, particularly for children who are obese or aged 5–9 years at diagnosis, female, Black or Hispanic, or those with metabolic toxicities during induction. Pediatr Blood Cancer 2009; 53:1249–1254. © 2009 Wiley‐Liss, Inc.
Biomarkers in the cerebrospinal fluid and neurodegeneration in Langerhans cell histiocytosis
Authors: Gavhed Désirée , Åkefeldt Selma Olsson , Österlundh Gustaf , Laurencikas Evaldas , Hjorth Lars , Blennow Kaj , Rosengren Lars , Henter Jan‐Inge 
Published: August 2009

AbstractBackgroundProgressive neurodegeneration may result in potentially severe cognitive and motor dysfunctions as a complication of Langerhans cell histiocytosis (LCH), a suggested IL‐17A‐associated inflammatory condition. To detect this complication (CNS‐LCH) early and to evaluate the potential efficacy of therapeutic interventions, biomarkers detecting and measuring ongoing neurodegeneration would be valuable. We evaluated cerebrospinal fluid (CSF) biomarkers of ongoing neurodegeneration in CNS‐LCH patients.ProcedureNine patients with endocrine, neuromotor, cognitive or/and behavioral abnormalities as well as neuroradiological evidence of CNS‐LCH were evaluated 4–12 years after LCH diagnosis for CSF levels of neurofilament protein light chain (NF‐L), glial fibrillary acid protein (GFAp), and total tau protein (TAU). Two patients were analyzed longitudinally. One hundred ten children with newly diagnosed acute lymphoblastic leukemia (ALL) served as controls.ResultsNF‐L, TAU, and GFAp levels were elevated in four, six, and eight of nine patients studied, respectively. NF‐L (P < 0.001) and GFAp (P < 0.001) were higher in patients than in controls (TAU not analyzed in controls). The patient with most severe clinical and neuroradiological CNS‐LCH displayed the highest levels of NF‐L and GFAp whereas three patients without signs of systemic disease had low TAU levels and normal/slightly elevated NF‐L. NF‐L tended to be higher at radiological progression of neurodegeneration than at status quo (P = 0.07). Notably, we experienced frequent lumbar puncture complications in these patients.ConclusionsCSF levels of NF‐L, TAU, and GFAp appear to be elevated in CNS‐LCH. It would be valuable if these markers were validated in order to serve as markers for early CNS‐LCH, to monitor disease progression and to evaluate various treatment attempts for CNS‐LCH. Pediatr Blood Cancer 2009; 53:1264–1270. © 2009 Wiley‐Liss, Inc.
A novel wound dressing composed of nonwoven fabric coated with chitosan and herbal extract membrane for wound healing
Authors: Liu Bai‐Shuan , Huang Tsung‐Bin 
Published: August 2009

AbstractThis study presents a novel design of an easily stripped bilayer composite that consists of an upper layer of soybean protein nonwoven fabric coated with a lower layer, genipin‐crosslinked chitosan and Bletilla striata herbal extract (GCB) film as a wound dressing material (GCB/NWF). Preliminary tests investigated the in vitro characteristics of the genipin‐crosslinked chitosan (GC) film. Experimental results showed that the dark bluish color of the GC film may have resulted from the reaction of genipin with the amino acid group in the chitosan solution. Additionally, adding more wt% genipin caused the bluish color of the GC films to be darker. This new wound dressing material also exhibited good mechanical properties. Genipin and chitosan were released from the soaked GC film. Cytotoxic test revealed that 20 ppm of the genipin in the culture medium could be criteria, over which cytotoxicity to L929 fibroblasts could be produced. However, the chitosan and B. striata herbal extract not only were not toxic but also promoted the viability and growth of L929 fibroblasts. Additionally, the GCB film more effectively supported cell attachment and growth. The in vivo histological assessment results revealed that epithelialization and reconstruction of the wound were achieved by covering the wound with the GCB/NWF wound dressing material, and it would be easily stripped from the wound surface without damaging newly regenerated tissue. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Mechanical behavior of recycled reinforced polyamide railway fasteners
Authors: Casado José Antonio , Carrascal Isidro , Diego Soraya , Polanco Juan Antonio , Gutiérrez‐Solana Federico , García Alberto 
Published: August 2009

AbstractModern railway tracks use short‐fiber glass reinforced polyamide to inject insulating and mechanically resistant fasteners to connect the rails to the sleepers. Some of this material is later withdrawn, due either to defective production or to breakage in service. The recovery of the material for its later re‐use would lead to a great saving, from both an environmental and an economic viewpoint. Mechanical recycling is a simple, economic process that only requires the crushing of the material and its subsequent molding, without the need for any chemical treatments. However, it has some drawbacks; as with any kind of recycling, there is a certain loss of material quality with some degradation of its properties. In this work, the physical and mechanical results for fasteners injected with recycled material are compared to others injected with pure material. The results show that the use of recycled fasteners is limited in‐service by working conditions that increase the thermoplastic material temperature above its critical glass transition temperature, Tg. POLYM. COMPOS., 31:1142–1149, 2010. © 2009 Society of Plastics Engineers
A nonlinear theoretical model for prediction of mechanical behavior of particulate composites and experimental verification of the model predictions
Authors: Ramazani S.A. A. , Najafi C. N. 
Published: August 2009

AbstractA model for prediction the stress‐strain behavior of particulate composite over wide ranges of filler concentration and composite deformation has been developed through combination of Anderson's and Yilmizer's model. The constitutive equations are extracted from first law of thermodynamic and nonlinear dilatational effects which are produced by filler‐matrix debonding process. In addition to nonlinear behavior that has been resulted by filler‐matrix debonding and was presented by Yilmizer, the formation and growing of void or cavitations has been also introduced in this model, whereas Anderson's model, most important reason for deviation of linear behavior is filler‐matrix debonding and has been indicated by change of modulus. Model predictions for effects of the filler concentration and its particle size and particle size distribution for some matrix‐filler systems are compared with related experimental data from literature and some investigated systems in this work. An excellent agreement even better than prediction of Anderson's model between experimental data and model predictions can be observed in most cases especially for some concentrated systems. POLYM. COMPOS., 31:1150–1155, 2010. © 2009 Society of Plastics Engineers
The role of interface modification on thermal degradation and crystallization behavior of composites from commingled polypropylene fiber and banana fiber
Authors: Paul Sherely Annie , Oommen Charlie , Joseph Kuruvilla , Mathew Gem , Thomas Sabu 
Published: August 2009

AbstractThe thermal degradation behavior of banana fiber and polypropylene/banana fiber composites has been studied by thermogravimetric analysis. Banana fiber was found to be decomposing in two stages, first one around 320°C and the second one around 450°C. For chemically treated banana fiber, the decomposition process has been at a higher temperature, indicating thermal stability for the treated fiber. Activation energies for thermal degradation were estimated using Coats and Redfern method. Calorific value of the banana fiber was measured using a constant volume isothermal bomb calorimeter. Crystallization studies exhibited an increase in the crystallization temperature and crystallinity of polypropylene upon the addition of banana fiber. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Effect of clay modification on the morphological, mechanical, and thermal properties of polyamide 6/polypropylene/montmorillonite nanocomposites
Authors: Kusmono  , Ishak Z.A. Mohd , Chow W.S. , Takeichi T. , Rochmadi  
Published: August 2009

AbstractPolyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic montmorillonite (OMMT) were prepared by melt compounding. The sodium montmorillonite (Na‐MMT) was modified using three different types of alkyl ammonium salts, namely dodecylamine, 12‐aminolauric acid, and stearylamine. The effect of clay modification on the morphological and mechanical properties of PA6/PP nanocomposites was investigated using x‐ray diffraction (XRD), transmission electron microscopy (TEM), tensile, flexural, and impact tests. The thermal properties of PA6/PP nanocomposites were characterized using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and heat distortion temperature (HDT). XRD and TEM results indicated the formation of exfoliated structure for the PA6/PP nanocomposites prepared using stearylamine modified montmorillonite. On the other hand, a mixture of intercalated and exfoliated structures was found for the PA6/PP nanocomposites prepared using 12‐aminolauric acid and dodecylamine modified montmorillonite. Incorporation of OMMT increased the stiffness but decreased the ductility and toughness of PA6/PP blend. The PA6/PP nanocomposite containing stearylamine modified montmorillonite showed the highest tensile, flexural, and thermal properties among all nanocomposites. This could be attributed to better exfoliated structure in the PA6/PP nanocomposite containing stearylamine modified montmorillonite. The storage modulus and HDT of PA6/PP blend were increased significantly with the incorporation of both Na‐MMT and OMMT. The highest value in both storage modulus and HDT was found in the PA6/PP nanocomposite containing stearylamine modified montmorillonite due to its better exfoliated structure. POLYM. COMPOS., 31:1156–1167, 2010. © 2009 Society of Plastics Engineers
Improvement of the mechanical properties of nano‐TiO2/poly(vinyl alcohol) composites by enhanced interaction between nanofiller and matrix
Authors: Lou Yuanhua , Liu Meihong , Miao Xiaowei , Zhang Li , Wang Xinping 
Published: August 2009

AbstractSurface‐carboxylated nano‐TiO2 was used to prepare poly (vinyl alcohol) (PVA) nanocomposites to improve the dispersity of nano‐TiO2 particles in PVA and to enhance the interaction between nanofiller and matrix. The effects of the extents of carboxylation and carboxylated nano‐TiO2 loading on mechanical properties of the nanocomposites were investigated. The results show that the tensile strength of the nanocomposites was greatly improved, both by increasing the carboxylated nano‐TiO2 loading and by the extent of carboxylation of the nanoparticles, compared with unmodified nano‐TiO2. The storage modulus within the rubbery state increased and the loss tangent decreased with increasing COOH content on the TiO2 surface and with increasing carboxylated nano‐TiO2 loading. These observations were attributed to a high dispersion of modified nano‐TiO2 in the PVA matrix and to crosslinking between OH groups in PVA chains and COOH moieties on inorganic nanoparticle surfaces. POLYM. COMPOS., 31:1184–1193, 2010. © 2009 Society of Plastics Engineers
Aromatic‐aliphatic poly(butylene adipate‐co‐terephthalate) bionanocomposite: Influence of organic modification on structure and properties
Authors: Mohanty Smita , Nayak Sanjay K. 
Published: August 2009

AbstractBionanocomposite hybrids based on poly(butylene adipate‐co‐terephthalate) (PBAT) and layered silicates were prepared by melt interaction technique using corotating twin screw extruder having a blown film unit. Sodium montmorillonite (Na+MMT) along with three different commercially available nanoclays i.e., Cloisite30B (C30B), Cloisite20A (C20A), Bentonite (B109) have been used as a reinforcing agent. Wide angle X‐ray diffraction (WAXD) studies indicated an increase in d spacing of the nanoclays in the bionanocomposite hybrids revealing formation of intercalated morphology. Morphological studies using transmission electron microscopy also confirmed that nanoclays were finely dispersed in the PBAT matrix and there was presence of partially exfoliated clay galleries along with intercalated structures in the bionanocomposite hybrids. Mechanical tests showed that the bionanocomposite hybrids prepared using B109 nanoclay exhibited higher tensile modulus. Functionalization of PBAT matrix upon grafting with maleic anhydride (MA) resulted in further improvement in mechanical properties. The existence of interfacial bonds in grafted bionanocomposite hybrids are substantiated using fourier transformation infrared spectroscopy. Thermal properties of bionanocomposite hybrids employing DSC, TGA also revealed improved Tg, Tc and thermal stability over the virgin polymer. Dynamic mechanical analysis indicated an increase of storage modulus (E′) of PBAT biopolymer with incorporation of nanofiller. The biodegradability of PBAT bionanocomposite hybrids showed an increase in the rate of biodegradability with addition of Na+MMT due to hydrophilic nature of the nanoclay. POLYM. COMPOS., 31:1194–1204, 2010. © 2009 Society of Plastics Engineers
Proteomic evaluation of wound‐healing processes in potato (Solanum tuberosum L.) tuber tissue
Authors: Chaves Inês , Pinheiro Carla , Paiva Jorge A. P. , Planchon Sébastien , Sergeant Kjell , Renaut Jenny , Graça José A. , Costa Gonçalo , Coelho Ana V. , Ricardo Cândido P. Pinto 
Published: August 2009

AbstractProteins from potato (Solanum tuberosum L.) tuber slices, related to the wound‐healing process, were separated by 2‐DE and identified by an MS analysis in MS and MS/MS mode. Slicing triggered differentiation processes that lead to changes in metabolism, activation of defence and cell‐wall reinforcement. Proteins related to storage, cell growth and division, cell structure, signal transduction, energy production, disease/defence mechanisms and secondary metabolism were detected. Image analysis of the 2‐DE gels revealed a time‐dependent change in the complexity of the polypeptide patterns. By microscopic observation the polyalyphatic domain of suberin was clearly visible by D4, indicating that a closing layer (primary suberisation) was formed by then. A PCA of the six sampling dates revealed two time phases, D0–D2 and D4–D8, with a border position between D2 and D4. Moreover, a PCA of differentially expressed proteins indicated the existence of a succession of proteomic events leading to wound‐periderm reconstruction. Some late‐expressed proteins (D6–D8), including a suberisation‐associated anionic peroxidase, have also been identified in the native periderm. Despite this, protein patterns of D8 slices and native periderm were still different, suggesting that the processes of wound‐periderm formation are extended in time and not fully equivalent. The information presented in this study gives clues for further work on wound healing‐periderm formation processes.