bluuebunny/crossref_metadata_2025_split huggingface dataset:
Curing Behavior of Epoxy Resin Using Controllable Curing Agents Based on Nickel Complexes
Authors: Omrani Abdollah , Ghaemy Mousa , Rostami Abbas A. 
Published: February 2006

AbstractSummary: The curing reaction kinetics and mechanism of the diglycidyl ether of bisphenol A (DGEBA) with three complexes of Ni(II) with diethylentriamine (Dien), Pyrazole (Pz) and Pyridine (Py) as ligands have been studied using differential scanning calorimetry (DSC). The curing reaction was characterized by high cure onset and peak maximum temperatures. The kinetics of the curing reaction were evaluated using the Ozawa method. The average values of activation energy for the three nickel complexes increased in the order: Dien‐based curing agent > Pz‐based curing agent > Py‐based curing agent. Three main curing mechanisms (catalytic, complex cation and free ligand polymerization path) have been proposed depending on the cure temperature. It was also shown that the cure kinetics of DGEBA with Dien‐ and Py‐based complexes could be described by the Sestak‐Berggren equation. The water absorption, chemical resistance and thermal stability of the thermosets were also studied. The results showed that the thermoset obtained with the Py‐based complex was more thermally stable than those obtained with the other two curing agents.Activation energy versus conversion plots for the epoxy systems studied.imageActivation energy versus conversion plots for the epoxy systems studied.
Adult‐onset primary lower limb dystonia
Authors: Schneider Susanne A. , Edwards Mark J. , Grill Stephen E. , Goldstein Suzanne , Kanchana Su , Quinn Niall P. , Bhatia Kailash P. , Hallett Mark , Reich Stephen G. 
Published: February 2006

AbstractThe lower extremity is affected infrequently in adult‐onset primary dystonia in contrast to childhood‐onset dystonia, which typically begins in the foot. When dystonia affects the foot in an adult, it is usually on a secondary basis. We present findings on 17 patients (11 women, 6 men; average age of onset 48.4 years; average time to diagnosis 2.7 years) with adult‐onset primary foot dystonia. Prior to diagnosis, most patients underwent extensive testing and treatment, including unnecessary surgeries. Only the left lower extremity was involved in 8 patients, only the right in 7, and both in 2. The most common patterns were plantar flexion of all toes and inversion of the foot, typically activated with standing or walking. Only 2 patients had dystonia elsewhere. There was a family history of possible dystonia in 2 patients. One of five tested for DYT1 was positive, in the absence of a family history. One of eight patients treated with levodopa experienced mild improvement. Six of eight treated with botulinum toxin improved. No patient has been observed to have a secondary cause of dystonia. The prognosis, with regard to progression or spread to other body parts, has been favorable. Although uncommon, foot dystonia on a primary basis, not due to DYT1, can begin in adulthood. In this series of patients, the diagnosis was often not recognized, leading to extensive and unnecessary testing and treatment and emphasizing the need for wider recognition. © 2006 Movement Disorder Society
The numerical modelling of advective transport in the presence of fluid pressure transients
Authors: Selvadurai A. P. S. , Dong W. 
Published: February 2006

AbstractConventional modelling of transport problems for porous media usually assumes that the Darcy flow velocities are steady. In certain practical situations, the flow velocity can exhibit time‐dependency, either due to the transient character of the flow process or time dependency in the boundary conditions associated with potential flow. In this paper, we consider certain one‐ and three‐dimensional problems of the advective transport of a chemical species in a fluid‐saturated porous region. In particular, the advective flow velocity is governed by the piezo‐conduction equation that takes into account the compressibilities of the pore fluid and the porous skeleton. Time‐ and/or mesh‐refining adaptive schemes used in the computational modelling are developed on the basis of a Fourier analysis, which can lead to accurate and optimal solutions for the advective transport problem with time‐ and space‐dependent advective flow velocity distributions. Copyright © 2006 John Wiley & Sons, Ltd.
Minimizing the makespan in open‐shop scheduling problems with a convex resource consumption function
Authors: Shabtay Dvir , Kaspi Moshe 
Published: February 2006

AbstractWe consider open‐shop scheduling problems where operation‐processing times are a convex decreasing function of a common limited nonrenewable resource. The scheduler's objective is to determine the optimal job sequence on each machine and the optimal resource allocation for each operation in order to minimize the makespan. We prove that this problem is NP‐hard, but for the special case of the two‐machine problem we provide an efficient optimization algorithm. We also provide a fully polynomial approximation scheme for solving the preemptive case. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
An accurate multigrid solver for computing singular solutions of elliptic problems
Authors: Köstler H. , Rüde U. 
Published: February 2006

AbstractIn this article we present a method to solve partial differential equations (PDE) containing generalized functions as source terms. Typical applications are point sources and sinks in porous media flow that are described by Dirac δ‐functions or point loads and dipoles as source terms for electrostatic potentials.For analysing the accuracy of such computations, standard techniques cannot be used, since they rely on global smoothness. This is true for both Sobolev space arguments for finite element based methods, and for continuity and differentiability arguments in finite difference analysis. At the singularity, the solution and its derivatives tend to infinity and therefore standard error norms will not even converge.We will demonstrate that these difficulties can be overcome by using a mesh‐dependent representation of the singular sources constructed by appropriate smoothing and by using other metrics to measure accuracy and convergence of the numerical solution. In the standard case our technique is equivalent to representing singular distributions by properly scaled finite element basis functions. Only minor modifications to the discretization and solver are necessary to obtain the same asymptotic accuracy and efficiency as for regular and smooth solutions. Copyright © 2006 John Wiley & Sons, Ltd.
A multilevel adaptive solver based on second‐generation wavelet thresholding techniques
Authors: Limon Alfonso , Morris Hedley 
Published: February 2006

AbstractIn this manuscript, we introduce a second‐generation wavelet thresholding technique used to construct a numerically stable non‐dyadic sparse grid representation. The resulting second‐generation wavelet projectors, when coupled to a multigrid solver, provide an elegant method for integrating the numerical solution. The combined method is then utilized in the solution of a singular perturbation problem that arises when modelling an n‐MOS gate exhibiting quantum tunnelling. The resulting solution is compared with the full Schrödinger–Poisson system, and the two solutions are shown to be in good agreement. Copyright © 2006 John Wiley & Sons, Ltd.
Remission of aplastic anemia induced by treatment for Graves disease in a pediatric patient
Authors: Das Prabodh Kumar , Wherrett Diane , Dror Yigal 
Published: February 2006

AbstractAplastic anemia (AA) is mediated by T‐cell autoimmunity in the majority of cases; it is rare and mostly idiopathic in children. We describe a child, who developed AA following Graves' disease which could not be attributed to antithyroid drugs. We hypothesized that both diseases were caused by similar autoimmune process. We monitored the blood counts and did not administer any conventional treatment for AA assuming that the existing anti‐ hematopoietic stem cell humoral and cellular immunity might subside with induction of remission of Grave's disease. The child went into complete remission with the treatment of the Graves' disease. Pediatr Blood Cancer 2007;49:210–212. © 2007 Wiley‐Liss, Inc.
Outcome for children <4 years of age with malignant central nervous system tumors treated with high‐dose chemotherapy and autologous stem cell rescue
Authors: Thorarinsdottir Halldora K. , Rood Brian , Kamani Naynesh , Lafond Debbie , Perez‐Albuerne Evelio , Loechelt Brett , Packer Roger J. , MacDonald Tobey J. 
Published: February 2006

AbstractBackgroundChildren <4 years of age (yo) with malignant central nervous system (CNS) tumors have a dismal prognosis. In an attempt to delay or obviate radiation therapy (XRT) and improve outcome, our institution has treated children <4 yo with newly diagnosed malignant CNS tumors with high‐dose chemotherapy (HDC) and autologous stem cell rescue (ASCR) followed by selective XRT.ProcedureFifteen children (age 4–38 months) with malignant CNS tumors have completed treatment with HDC/ASCR. All patients received three cycles of induction chemotherapy (cisplatin 3.5 mg/kg‐ day 0, cyclophosphamide 60 mg/kg‐ day 1 and 2, etoposide 2.5 mg/kg‐ day 0–2, vincristine 0.05 mg/kg, day 0, 7, 14) followed by three cycles of HDC (carboplatin 17 mg/kg and thiotepa 6 mg/kg, day 0 and 1) with ASCR. Histology included five medulloblastomas, four primitive neuroectodermal tumors (PNET), five malignant gliomas, and one ependymoma. Outcome and treatment toxicities were evaluated by retrospective chart review.ResultsMedian follow‐up time of the 15 patients is 22 months (range 8–82 months). The 1‐ and 2‐year progression‐free survival (PFS) is 86.1% and 52.2% and overall survival (OS) 91.6% and 72.1%, respectively. Ten patients are alive and disease free 3–77 months (median 18 months) after having completed HDC/ASCR, thereoff five received XRT. Toxicity was primarily myelosuppression. There was no treatment mortality.ConclusionsWe are encouraged by the outcome of 15 children <4 yo with malignant CNS tumors treated with tandem cycles of HDC and ASCR at our institution. The treatment regimen is relatively well tolerated. Pediatr Blood Cancer 2007;48:278–284. © 2006 Wiley‐Liss, Inc.
Spontaneous splenic rupture in a patient with factor XIII deficiency and a novel mutation
Authors: Khalife Hassan , Muwakkit Samar , Al‐Moussawi Hayfa , Dabbous Ibrahim , Khoury Ruby , Peyvandi Flora , Abboud Miguel R. 
Published: February 2006

AbstractWe report a novel mutation in factor XIIIA gene that caused severe congenital factor XIII deficiency in a 6 year and 8 month old male. The mutation is a GA deletion in the core domain leading to a premature stop at codon 502. The child had severe deficiency with two episodes of intracerebral hemorrhage. He also developed spontaneous splenic rupture, an unusual complication of this disorder. Pediatr Blood Cancer 2008;50:113–114. © 2006 Wiley‐Liss, Inc.
Fluorinated and ring‐substituted bisbenzimidazole copper complexes for ethylene/acrylate copolymerization
Authors: Baugh Lisa Saunders , Sissano Joseph A. , Kacker Smita , Berluche Enock , Stibrany Robert T. , Schulz Donald N. , Rucker Steven P. 
Published: February 2006

AbstractBisbenzimidazole copper dichloride complexes (CuBBIMs), when activated with methylaluminoxane, catalyze the random copolymerization of ethylene with acrylates to produce highly linear functional copolymers. To probe the sensitivity of the copolymerization to the catalyst structure, a series of CuBBIM catalysts with various steric, electronic, and geometric ligand characteristics was prepared, including CuBBIMs having benzimidazole ring substituents and ligand backbones of various lengths. Four different acrylates were also evaluated as comonomers (t‐butyl acrylate, methyl acrylate, t‐butyl methacrylate, and methyl methacrylate). Although no obvious ligand‐based influences on copolymerization were identified, the structure of the acrylate comonomer was found to exert significant effects. Copolymers prepared with t‐butyl methacrylate comonomer exhibited the highest ethylene contents (31–63%), whereas those prepared with methyl acrylate contained only minor amounts of ethylene (<15%). Copolymerizations carried out at lowered acrylate feed levels generally had increased ethylene contents but showed smaller yields, lowered molecular weights, and increased branching. Unusual ketoester structures were also observed in the methyl acrylate and methyl methacrylate containing copolymers, suggesting that the acrylate ester group size may be an important controlling factor for copolymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1817–1840, 2006
Novel approach to preparing epoxy/polyhedral oligometric silsesquioxane hybrid materials possessing high mass fractions of polyhedral oligometric silsesquioxane and good homogeneity
Authors: Liu Ying‐Ling , Chang Gung‐Pei 
Published: February 2006

AbstractEpoxy/polyhedral oligometric silsesquioxane (POSS) hybrid materials, containing 50 wt % POSS and exhibiting good homogeneity, were obtained in a two‐step preparation. Monoamine‐functionalized POSS was first reacted with diglycidyl ether of bisphenol A to form an epoxy POSS precursor, which was then cured. Curing agents such as 4,4′‐diaminodiphenylmethane, dicyandiamide (DICY), and diethylphosphite (DEP) were used for the synthesis of the epoxy–POSS hybrid materials. The use of small‐molecule curing agents, such as DICY and DEP, efficiently avoided macrophase separations and enhanced the thermal properties of the hybrid materials. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1869–1876, 2006
Oxygen inhibition in thiol–acrylate photopolymerizations
Authors: O'Brien Allison K. , Cramer Neil B. , Bowman Christopher N. 
Published: February 2006

AbstractThe overall effects of oxygen on thiol–acrylate photopolymerizations were characterized. Specially, the choice of thiol monomer chemistry, functionality, and concentration on the extent of oxygen inhibition were considered. As thiol concentration was increased, the degree of oxygen inhibition was greatly reduced because of chain transfer from the peroxy radical to the thiol. When comparing the copolymerization of 1,6‐hexanediol diacrylate with the alkane‐based thiol (1,6‐hexane dithiol) to the copolymerization with the propionate thiol (glycol dimercaptopropionate), it was found that the propionate system was much more reactive and polymerized to a greater extent in the presence of oxygen. In addition, the functionality was considered where the glycol dimercaptopropionate was compared to a tetrafunctional propionate of similar chemistry (pentaerythritol tetrakis(mercaptopropionate)). Given the same thiol concentration, the higher functionality thiol imparted a faster polymerization rate, due to the increased polymer system viscosity, which limited oxygen diffusion and decreased the extent of overall oxygen inhibition. Thus, preliminary insight is provided into how thiol monomer choice affects the extent of oxygen inhibition in thiol–acrylate photopolymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2007–2014, 2006
Preparation and properties of molecular‐weight‐controlled polyimides derived from 1,4‐bis(4′‐amino‐2′‐trifluoromethylphenoxy)benzene and 4,4′‐oxydiphthalic anhydride
Authors: Wang K. , Yang S. Y. , Fan L. , Zhan M. Sh. , Liu J. G. 
Published: February 2006

AbstractA series of molecular‐weight‐controlled fluorinated aromatic polyimides were synthesized through the polycondensation of a fluorinated aromatic diamine, 1,4‐bis(4′‐amino‐2′‐trifluoromethylphenoxy)benzene, with 4,4′‐oxydiphthalic anhydride in the presence of phthalic anhydride as the molecular‐weight‐controlling and end‐capping agent. Experimental results demonstrated that the resulting polyimides could melt at temperatures of 250–300 °C to give high flowing molten fluids, which were suitable for melt molding to give strong and flexible polyimide sheets. Moreover, the aromatic polyimides also showed good solubility both in polar aprotic solvents and in common solvents. Polyimide solutions with solid concentrations higher than 25 wt % could be prepared with relatively low viscosity and were stable in storage at the ambient temperature. High‐quality polyimide films could be prepared via the casting of the polyimide solutions onto glass plates, followed by baking at a relatively low temperature. The molten behaviors and organosolubility of the molecular‐weight‐controlled aromatic polyimides depended significantly on the polymer molecular weights. Both the melt‐molded polyimide sheets and the solution‐cast polymer films exhibited outstanding combined mechanical and thermal properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1997–2006, 2006
Comparative studies on miscibility and phase behavior of linear and star poly(2‐methyl‐2‐oxazoline) blends with poly(vinylidene fluoride)
Authors: Shen Jia , Zheng Sixun 
Published: February 2006

AbstractThe comparative studies on the miscibility and phase behavior between the blends of linear and star‐shaped poly(2‐methyl‐2‐oxazoline) with poly(vinylidene fluoride) (PVDF) were carried out in this work. The linear poly(2‐methyl‐2‐oxazoline) was synthesized by the ring opening polymerization of 2‐methyl‐2‐oxazoline in the presence of methylp‐toluenesulfonate (MeOTs) whereas the star‐shaped poly(2‐methyl‐2‐oxazoline) was synthesized with octa(3‐iodopropyl) polyhedral oligomeric silsesquioxane [(IC3H6)8Si8O12, OipPOSS] as an octafunctional initiator. The polymers with different topological structures were characterized by means of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. It is found that the star‐shaped poly(2‐methyl‐2‐oxazoline) was miscible with poly(vinylidene fluoride) (PVDF), which was evidenced by single glass‐transition temperature behavior and the equilibrium melting‐point depression. Nonetheless, the blends of linear poly(2‐methyl‐2‐oxazoline) with PVDF were phase‐separated. The difference in miscibility was ascribed to the topological effect of PMOx macromolecules on the miscibility. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 942–952, 2006
Modeling the amorphous phase of comb‐like polymers
Authors: Curcó David , Alemán Carlos 
Published: February 2006

AbstractIn this work, we apply a methodology recently developed by us to perform atomistic simulations of the amorphous phase of poly(α‐octadecyl β‐aspartate) and poly‐ (octadecyl acrylate). The simulation method, which is denoted SuSi/CB, combines the strength of an algorithm specially designed to generate atomistic models of dense amorphous polymers and the Configurational Bias Monte Carlo procedure. Modeling results reveal that poly(octadecyl acrylate) presents a tendency to adopt backbone helical conformations, while no trace of helicity was detected in the amorphous phase poly(α‐octadecyl β‐aspartate). Regarding the side chain organization, the paraffinic pool formed by the octadecyl side chains is slightly greater for the poly(acrylate) than for the poly(β‐aspartate). According to these features, it can be concluded that the small chemical differences between the two investigated polymers are enough to provide some distinctive structural features. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 953–966, 2006
Computer Simulations for Processing Plasmas
Authors: Bogaerts Annemie , De Bleecker Kathleen , Georgieva Violeta , Kolev Ivan , Madani Myriam , Neyts Erik 
Published: February 2006

AbstractSummary: In this paper, some of our modeling efforts for processing plasmas are presented. We make use of fluid models or particle‐in‐cell–Monte Carlo (PIC‐MC) simulations for the plasma behavior, depending on the application. Fluid models are most suitable to describe the detailed plasma chemistry, like the formation and growth of nanoparticles in so‐called dusty plasmas, and for dielectric barrier discharges (DBDs) at atmospheric pressure. PIC‐MC simulations are the best choice to describe magnetron discharges, operating at low pressure, and for dealing with the plasma dynamics in single‐ and dual‐frequency rf discharges. Finally, we also apply molecular dynamics (MD) simulations for plasma‐surface interaction, more specifically for the plasma deposition of diamond‐like carbon (DLC) films.Calculated potential distribution and electron density profile in the magnetron discharge.imageCalculated potential distribution and electron density profile in the magnetron discharge.
Detection of Biological Molecules from Hard Biological Tissue Using Ion‐Beam‐Induced Desorption and Femtosecond Laser Ablation
Authors: Daskalova Albena , Husinsky Wolfgang 
Published: February 2006

AbstractSummary: In the last 10–15 years laser ablation became very popular for the analysis of solid samples. The study of laser‐matter interaction processes on different time scales – nano, pico, femto, and their application in different fields developed a thorough knowledge of the fundamental laws involved in this process. The intention in the current research was to determine the general features of different ablation processes (ns, fs) and ion beam desorption process. The aim was to perform a complete set of measurements of different target materials by means of mass spectrometry studies. More specifically, the mass spectra of ablated and sputtered particles from organic matter were studied. Time of flight mass spectrometer was used for detection. An investigation of the mechanism of laser ablation of biological tissue is a complicated problem due to the complexity of the examined organic material. In our experiments the main aim was to obtain optimal signal detection without the onset of considerable fragmentation. Comparison will be made between the mass spectra from biological samples obtained with laser ablation, and those obtained under bombardment with 9 keV‐accelerated Xe+ ions. As a general tendency in nanosecond ablation and in SIMS experiments the detection of higher mass molecular species is negligible in correspondence to femtosecond laser ablation mass spectra. This can be due to the process of heating that develops under ion bombardment. This work demonstrates the sensitivity of the TOF technique and the potential of using this method for exploring the dynamics of the laser ablation and ion beam desorption processes.An example of 20 µm holes drilled into vascular transplant‐grafts by 30 fs pulses.imageAn example of 20 µm holes drilled into vascular transplant‐grafts by 30 fs pulses.
Cross Sections and Rate Constants for Charge Transfer into Excited States
Authors: Temelkov Krassimir A. , Vuchkov Nikolay K. , Sabotinov Nikola V. 
Published: February 2006

AbstractSummary: Cross sections and rate constants for charge transfer into excited states in thermal energy collisions are calculated for a gas discharge in He/Cu, Ne/Cu, He/Ag, Ne/Ag, He/Al, Ne/Al, He/Au, He/Hg, He/Cd, and He/Zn mixtures. To our knowledge, the polarizability of the above‐mentioned metal atoms, which determines the ion‐atom interaction and, therefore, the cross section, is calculated for the first time. A cross section for the Ne+Cu impact couple is experimentally obtained.Schematic diagram of the experimental setup.imageSchematic diagram of the experimental setup.