bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Implementation of MAC Grid-Based IIM-Stokes Solver for Incompressible Two-Phase Flows
Authors: Tan Zhijun , Lim K. M. , Khoo B. C. 
Published: September 2011

AbstractIn this paper, a novel implementation of immersed interface method combined with Stokes solver on a MAC staggered grid for solving the steady two-fluid Stokes equations with interfaces. The velocity components along the interface are introduced as two augmented variables and the resulting augmented equation is then solved by the GMRES method. The augmented variables and /or the forces are related to the jumps in pressure and the jumps in the derivatives of both pressure and velocity, and are interpolated using cubic splines and are then applied to the fluid through the jump conditions. The Stokes equations are discretized on a staggered Cartesian grid via a second order finite difference method and solved by the conjugate gradient Uzawa-type method. The numerical results show that the overall scheme is second order accurate. The major advantages of the present IIM-Stokes solver are the efficiency and flexibility in terms of types of fluid flow and different boundary conditions. The proposed method avoids solution of the pressure Poisson equation, and comparisons are made to show the advantages of time savings by the present method. The generalized two-phase Stokes solver with correction terms has also been applied to incompressible two-phase Navier-Stokes flow.
Labor Market Returns to Higher Education in Vietnam
Authors: Doan Tinh , Stevens Philip 
Published: September 2011

Abstract
This paper employs the Ordinary Least Squares, Instrumental Variables and Treatment Effect models to a new dataset from the Vietnam Household Living Standards Survey (VHLSS) to estimate return to four-year university education in 2008. Our estimates reveal that income premium of four-year university education is about 97 percent above that of high school education, and robust to the various estimators.
Association of Cogan-Reese Syndrome, Exfoliation Syndrome, and Secondary Open-Angle Glaucoma
Authors: Holló Gábor , Kóthy Péter , Konstas Anastasios G.P. 
Published: September 2011

Purpose To present a case with co-existence of Cogan-Reese syndrome and exfoliation syndrome. Case report A 72-year-old Caucasian woman presented for consultation due to uncontrolled intraocular pressure (IOP) of the right eye. Clinical examination revealed the presence of Cogan-Reese syndrome and exfoliation syndrome OD. This eye exhibited elevated IOP, open anterior chamber angle, advanced glaucomatous optic nerve head damage, and severe glaucomatous visual field loss. The left eye was completely normal without IOP elevation or visual field damage. To our knowledge this is the first case report demonstrating the coexistence of the Cogan-Reese syndrome, exfoliation syndrome, and secondary open-angle glaucoma. Since both syndromes frequently lead to secondary open-angle glaucoma, it is not feasible to determine with certainty which condition was the cause of secondary open-angle glaucoma in our case. It is conceivable that both conditions contributed to glaucoma development. Conclusions Cogan-Reese syndrome, exfoliation syndrome and secondary open-angle glaucoma may present on the same eye.
Trends in stroke hospitalizations and associated risk factors among children and young adults, 1995–2008
Authors: George Mary G. , Tong Xin , Kuklina Elena V. , Labarthe Darwin R. 
Published: September 2011

AbstractObjective:The aim of this study was to determine acute stroke hospitalization rates for children and young adults and the prevalence of stroke risk factors among children and young adults hospitalized for acute stroke.Methods:The study population consisted of 1995–2008 hospitalizations from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project. Subarachnoid hemorrhage, intracerebral hemorrhage, and ischemic stroke hospitalizations were identified by the primary International Classification of Diseases, 9th ed, Clinical Modification (ICD‐9‐CM) code. Seven consecutive 2‐year time intervals were selected. Three age groups were utilized: 5 to 14 years, 15 to 34 years, and 35 to 44 years. Stroke risk factors and comorbidities among those hospitalized with acute stroke were identified by secondary ICD‐9‐CM codes.Results:During the period of study, the prevalence of hospitalizations of acute ischemic stroke increased among all age and gender groups except females aged 5 to 14 years. Females aged 15 to 34 years and males and females aged 35 to 44 years showed a decrease in the prevalence of hospitalizations for subarachnoid hemorrhage, whereas females aged 5 to 14 years showed increases for subarachnoid hemorrhage. Hypertension, diabetes, obesity, lipid disorders, and tobacco use were among the most common coexisting conditions, and their prevalence increased from 1995 to 2008 among adolescents and young adults (aged 15–44 years) hospitalized with acute ischemic stroke.Interpretation:Increases in the prevalence of ischemic stroke hospitalizations and coexisting traditional stroke risk factors and health risk behaviors were identified among acute ischemic stroke hospitalizations in young adults. Our results from national surveillance data accentuate the need for public health initiatives to reduce risk factors for stroke among adolescents and young adults. ANN NEUROL 2011;
Dihydropyridine calcium channel blockers and the progression of parkinsonism
Authors: Marras Connie , Gruneir Andrea , Rochon Paula , Wang Xuesong , Anderson Geoff , Brotchie Jonathan , Bell Chaim M. , Fox Susan , Austin Peter C. 
Published: September 2011

AbstractObjective:A study was undertaken to test the association between dihydropyridine calcium channel blocker use and the time to important milestones of disease progression among patients with parkinsonism.Methods:Data were obtained from Ontario's health care administrative databases. Within a cohort of hypertensive individuals older than 65 years who developed parkinsonism, we examined the effect of the length of exposure to less brain‐penetrant dihydropyridines (amlodipine) and more brain‐penetrant dihydropyridines (eg, nifedipine, felodipine) on parkinsonism milestones as measured by time to requiring drug treatment for parkinsonism, nursing home admission, and death.Results:Among 4,733 hypertensive individuals with parkinsonism, longer treatment with any dihydropyridine was associated with a decreased risk of each of the 3 outcomes. There was no difference, however, between amlodipine (adjusted hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.42–0.50 for initiation of drug treatment; HR, 0.68; 95% CI, 0.63–0.73 for application for nursing home admission; and HR, 0.75; 95% CI, 0.70–0.80 for death) and nonamlodipine dihydropyridines (adjusted HRs [95% CIs], 0.45 [0.39–0.53], 0.74 [0.67–0.81], and 0.74 [0.64–0.85] for the 3 milestones, respectively).Interpretation:We found no specific beneficial effect of treatment with brain‐penetrant dihydropyridines on delaying parkinsonism progression milestones. Dihydropyridine calcium channel blockers are unlikely to have a clinically significant effect on the course of parkinsonism, particularly Parkinson disease, in the doses used to treat hypertension. ANN NEUROL 2012;
Optic radiation tractography and vision in anterior temporal lobe resection
Authors: Winston Gavin P. , Daga Pankaj , Stretton Jason , Modat Marc , Symms Mark R. , McEvoy Andrew W. , Ourselin Sebastien , Duncan John S. 
Published: September 2011

AbstractObjective:Anterior temporal lobe resection (ATLR) is an effective treatment for refractory temporal lobe epilepsy but may result in a contralateral superior visual field deficit (VFD) that precludes driving in the seizure‐free patient. Diffusion tensor imaging (DTI) tractography can delineate the optic radiation preoperatively and stratify risk. It would be advantageous to incorporate display of tracts into interventional magnetic resonance imaging (MRI) to guide surgery.Methods:We studied 20 patients undergoing ATLR. Structural MRI scans, DTI, and visual fields were acquired before and 3 to 12 months following surgery. Tractography of the optic radiation was performed on preoperative images and propagated onto postoperative images. The anteroposterior extent of the damage to Meyer's loop was determined, and visual loss was quantified using Goldmann perimetry.Results:Twelve patients (60%) suffered a VFD (10–92% of upper quadrant; median, 39%). Image registration took <3 minutes and predicted that Meyer's loop was 4.4 to 18.7mm anterior to the resection margin in these patients, but 0.0 to 17.6mm behind the resection margin in the 8 patients without VFD. The extent of damage to Meyer's loop significantly correlated with the degree of VFD and explained 65% of the variance in this measure.Interpretation:The optic radiation can be accurately delineated by tractography and propagated onto postoperative images. The technique is fast enough to propagate accurate preoperative tractography onto intraoperative scans acquired during neurosurgery, with the potential to reduce the risk of VFD. ANN NEUROL 2012;
Thermal stability and pyrolysis kinetics of lignin‐phenol‐formaldehyde resins
Authors: Pérez J. M. , Fernández A. 
Published: September 2011

AbstractA thermal stability and kinetic study from non‐isothermal experiments of a commercial and a lignin‐novolac resin mixed with two amounts of curing agent has been done employing thermogravimetric analysis technique. Three kinetic models have been tested: a single heating rate method, such as Coats‐Redfern, employing several mechanistic functions and contrasted with Van Krevelen—it is the first time that this method has been employed in polymer degradation. Finally, the Ozawa method allowed the obtaining of the activation energy by the multiple‐heating‐rate without knowing the mechanism. Results show that commercial mixtures of resins lose less weight than lignin‐novolac resins. The calculated kinetic parameters showed that Coats‐Redfern gives similar results to Van Krevelen, which means that these methods are adequate for novolac pyrolysis, and Ozawa shows activation energies in accordance with the last mentioned models. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Recycled‐disposable‐chopstick‐fiber‐reinforced polypropylene green composites
Authors: Shih Yeng‐Fong , Chen Po‐Wei , Wu Chin‐San , Huang Chien‐Ming , Hsieh Chi‐Fa 
Published: September 2011

AbstractThe utilization of disposable chopsticks is very popular in Taiwan, China, and Japan and is one of the major sources of waste in these countries. In this study, recycled disposable chopstick fiber was chemically modified. Subsequently, this modified fiber and polypropylene‐graft‐maleic anhydride were added to polypropylene (PP) to form novel fiber‐reinforced green composites. A heat‐deflection temperature (HDT) test showed an increase of approximately 81% for PP with the addition of 60‐phr fibers, and the HDT of the composite could reach up to 144.8°C. In addition, the tensile strength, Young's modulus, and impact strength were 66, 160.3, and 97.1%, respectively, when the composite material was 40‐phr fibers. Furthermore, this type of reinforced PP would be more environmentally friendly than an artificial‐additive‐reinforced one. It could also effectively reduce and reuse the waste of disposable chopsticks and lower the costs of the materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of a crosslinked system on the morphology and properties of TPVs based on PA/NBR
Authors: Fagundes Enio C. M. , Jacobi Marly A. Maldaner 
Published: September 2011

AbstractThe mechanical properties of thermoplastic vulcanizates (TPVs), depend strongly on their morphologies, which themselves depend on the properties of the primary polymers, the composition of the TPV, and the crosslink system and crosslink process. The morphology is defined during the dynamic vulcanization. This work deals with the study of the influence of crosslink systems on TPVs based on PA/NBR (copolyamide PA6/6‐6 and nitrile rubber) in a 40/60 composition. Dicumyl peroxide, bismaleimide, phenolic resin, a sulfur‐accelerated system, and dicumyl peroxide with two coagents were used as crosslinkers. TPVs were characterized by taking into account their mechanical strength, solvent resistance, compression set, and morphology. The curing system constituted by dicumyl peroxide and sulfur/bismaleimide as coagents resulted in a more defined morphology, and therefore the TPV exhibited the best properties. For these TPVs, a morphology consisting of spherical domains of rubber distributed homogeneously on the polyamide matrix could be observed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigations of the tribological properties of carbon fabric reinforced phenolic polymer composites filled with several nanoparticles
Authors: Wang Qihua , Zhang Xinrui , Pei Xianqiang , Wang Tingmei 
Published: September 2011

AbstractThe carbon fabric composites filled with several nanoparticles were prepared by dip‐coating and hot press molding technique. The friction and wear behavior of the resulting composites were studied systematically using a block‐on‐ring arrangement. Experimental results showed that the optimal content of nanoparticles as fillers contributed to improve the tribological properties of the carbon fabric composites. Moreover, the friction and wear properties of the fabric composites were closely dependent with the sliding conditions. The differences in the transfer film formed on the counterpart surface during the friction process also accounted for the friction and wear behavior of carbon fabric composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
A convenient scheme for synthesizing reduction‐sensitive chitosan‐based amphiphilic copolymers for drug delivery
Authors: Moyuan Cao , Haixia Jin , Weijuan Ye , Peng Liu , Liqun Wang , Hongliang Jiang 
Published: September 2011

AbstractA novel type of reduction‐sensitive graft copolymers, chitosan‐S‐S‐poly(ε‐caprolactone) (CS‐S‐S‐PCL, here ‐S‐S‐ means PCL was conjugated onto chitosan backbone through disulfide linkage), was synthesized through a convenient route using dithiodipropionic anhydride (DTDPA) as a disulfide donor. Reaction of hydroxy‐terminated poly(ε‐caprolactone) (PCL) with DTDPA quantitatively yielded DTDPA functionalized PCL (PCL‐S‐S‐COOH). The disulfide‐containing polyester was regioselectively conjugated onto the hydroxy groups of chitosan under mild and homogeneous conditions, utilizing dodecyl sulfate‐chitosan complexes (SCC) as an intermediate. The self‐assembly and Doxorubicin (Dox) release behavior of the copolymers were investigated. Spherical micelles could be formed through self‐assembly of CS‐S‐S‐PCL in aqueous media. The reduction‐sensitive behavior of CS‐S‐S‐PCL micelles was investigated by using Dithiothreitol (DTT) as a reductive reagent. In the presence of 10 mM DTT, the micelles gradually lost their aggregation stability and were precipitated out after four days. In addition, the Dox release was accelerated when the micelles were treated with DTT. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation of acrylic/acrylate copolymeric surfactants by emulsion polymerization used in pesticide oil‐in‐water emulsions
Authors: Shi Yongli , Zheng Ting , Shang Qing 
Published: September 2011

AbstractIn this work, acrylic/acrylate copolymeric surfactants, which can be used in the preparation of pesticide oil‐in‐water emulsions (EW), were synthesized by emulsion polymerization, using potassium persulfate (K2S2O8) as an initiator, dodecyl mercaptan (DDM) as a chain transfer agent at the temperature range of 82–85°C. When the weight ratio of monomers was m(butyl acrylate) : m(methyl methacrylate) : m(acrylic acid) = 4 : 4 : 1.6 and the dosage of DDM was 2% (percentage of monomer mass), the prepared acrylic/acrylate copolymeric surfactants had a number‐average molecular weight of 2.5 × 104 and exhibited good stability for pesticide EW. The carboxylic group distribution studies show that only the surface carboxylic groups make dispersed pesticide oil droplets more stable. The acrylic/acrylate copolymeric surfactants prepared by shot‐monomer had the most surface carboxylic group distribution (46.6%). To obtain greater surface carboxylic group distribution, maleic anhydride (MA) was used to modify the polymer system. Adding 2% MA (percentage of monomer mass) to the polymerization system, the surface carboxylic groups were increased 12% over unmodified acrylic/acrylate copolymeric surfactants. Compared with traditional pesticide EW, the avermectin EW prepared with acrylic/acrylate polymeric surfactant had much better stability. Meanwhile, its pesticide effect was similar to that of a control (1.8% abamectin emulsifiable solution). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Design, Synthesis, and Polymerase‐Catalyzed Incorporation of Click‐Modified Boronic Acid–TTP Analogues
Authors: Cheng Yunfeng , Dai Chaofeng , Peng Hanjing , Zheng Shilong , Jin Shan , Wang Binghe 
Published: September 2011

AbstractDNA molecules are known to be important materials in sensing, aptamer selection, nanocomputing, and construction of unique architectures. The incorporation of modified nucleobases affords unique DNA properties for applications in areas that would otherwise be difficult or not possible. Earlier, we demonstrated that the boronic acid moiety can be introduced into DNA through polymerase‐catalyzed reactions. In order to study whether such incorporation by polymerase is a general phenomenon, we designed and synthesized four boronic acid‐modified thymidine triphosphate (TTP) analogues. The synthesis of certain analogues was through the use of a single dialkyne tether for both the Sonogashira coupling with thymidine and the later Cu‐mediated [3+2] cycloaddition for linking the boronic acid moiety. This approach is much more efficient than the previously described method, and paves the way for the preparation of a large number of boronic acid‐modified TTPs with a diverse set of structural features. All analogues showed very good stability under polymerase chain reaction (PCR) conditions and were recognized as a substrate by DNA polymerase, and thus incorporated into DNA.
Construction of Polymer–Protein Bioconjugates with Varying Chain Topologies: Polymer Molecular Weight and Steric Hindrance Effects
Authors: Wan Xuejuan , Zhang Guoying , Ge Zhishen , Narain Ravin , Liu Shiyong 
Published: September 2011

AbstractWe report on the fabrication of well‐defined polymer–protein bioconjugates with varying chain architectures, including star polymers, star block copolymers, and heteroarm star copolymers through the specific noncovalent interaction between avidin and biotinylated synthetic polymer precursors. Homopolymer and diblock precursors site‐specifically labeled with a single biotin moiety at the chain terminal, chain middle, or diblock junction point were synthesized by a combination of atom‐transfer radical polymerization (ATRP) and click reactions. By taking advantage of molecular recognition between avidin and biotin moieties, supramolecular star polymers, star block copolymers, and heteroarm star copolymers were successfully fabricated. This specific binding process was also assessed by using the diffraction optic technology (DOT) technique. We further investigated the effects of polymer molecular weights, location of biotin functionality within the polymer chain, and polymer chain conformations, that is, steric hindrance effects, on the binding numbers of biotinylated polymer chains per avidin within the polymer–protein bioconjugates, which were determined by the standard avidin/2‐(4‐hydroxyazobenzene)benzoic acid (HABA) assay. The binding numbers vary in the range of 1.9–3.3, depending on the molecular weights, locations of biotin functionality within synthetic polymer precursors, and polymer chain conformations.
Setzungsnachweis für den Lastfall Erdbeben am Beispiel eines Kühlturmes am Arabischen Golf
Authors: Gödecke Jörg‐Henrik , Gödecke Heinz‐Joachim , Viedenz Ulrich 
Published: September 2011

AbstractErdbebenerschütterungen können insbesondere bei hochstehendem Grundwasser in sandigen Gründungsböden zur Bodenverflüssigung führen und erhebliche Setzungen verursachen, im ungünstigsten Fall bis zum Grundbruchversagen der gesamten Bauwerksgründung. Nachfolgend wird vom Bau einer setzungsempfindlichen flach gegründeten Kühlturmschale am Arabischen Golf mitsamt dem Setzungsnachweis für die Erdbebeneinwirkung berichtet.Settlement analysis for the load case earthquake using the example of a cooling tower at the Arabian Peninsula. Earthquakes particularly in case of high ground water tables in sandy foundation soils could lead to liquefaction and cause severe settlements, resulting as a worst case scenario in a shear failure of the complete building foundation. In the following about the shallow foundation of a settlement sensitive shell structure of a cooling tower at the Arabian Peninsula will be reported and about the related settlement analysis for the load case earthquake.
Abschätzung der dynamischen Kenngrößen nichtbindiger Böden anhand der Korngrößenverteilungskurve
Authors: Wichtmann Torsten , Triantafyllidis Theodoros 
Published: September 2011

AbstractDie gebräuchlichen empirischen Gleichungen für bodendynamische Kenngrößen wurden für gleichförmige Sande entwickelt und berücksichtigen den Einfluss der Korngrößenverteilungskurve nicht. Ihre Anwendung kann zu einer deutlichen Überschätzung des Schubmoduls ungleichförmiger Böden führen. Zur Erweiterung verschiedener empirischer Gleichungen um den Einfluss der Korngrößenverteilungskurve wurden ca. 650 Resonanzsäulenversuche an 65 speziell gemischten Korngrößenverteilungskurven eines Quarzsandes durchgeführt. Für jede Sandmischung wurden unterschiedliche Anfangslagerungsdichten, Drücke und Scherdehnungsamplituden getestet. In den Versuchen wurde u. a. eine deutliche Abnahme des Schubmoduls Gmax bei kleinen Dehnungsamplituden mit der Ungleichförmigkeitszahl Cu = d60/d10 und mit dem Feinkornanteil gemessen. Der mittlere Korndurchmesser hingegen hat kaum einen Einfluss auf die bodendynamischen Kenngrößen. Es kann gezeigt werden, dass die erweiterten empirischen Gleichungen nicht nur für lineare, sondern auch für abschnittsweise lineare, intermittierend gestufte und S‐förmige Korngrößenverteilungskurven zutreffende Prognosen liefern. Im Vergleich zu den bisher in der Praxis verwendeten Formeln sollten die erweiterten empirischen Gleichungen eine zuverlässigere Abschätzung der dynamischen Kenngrößen ermöglichen.Estimating dynamic properties of granular soils under consideration of the grain size distribution curve. The common empirical formulas for dynamic soil parameters were developed for uniform sands and do not consider the influence of the grain size distribution curve. The application of these formulas can lead to a considerable overestimation of the shear modulus of well‐graded granular soils. 650 resonant column tests on 65 specially mixed grain size distribution curves of a quartz sand have been performed in order to extend various empirical equations by the influence of the grain size distribution curve. For each sand mixture different initial densities, pressures and shear strain amplitudes have been tested. Amongst others, a considerable decrease of the small‐strain shear modulus Gmax with increasing coefficient of uniformity Cu = d60/d10 and increasing fines content was measured. In contrast, mean grain size has nearly no influence on dynamic soil parameters. A good prediction of the extended empirical equations can be demonstrated not only for linear, but also for stepwise linear, gap‐graded and S‐shaped grain size distribution curves. In comparison to the empirical formulas applied so far, the new extended empirical equations should deliver a more reliable estimation of dynamic soil properties.