bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Synchrotron Radiation Techniques for Model Validation of Advanced Structural Materials
Authors: Froideval Annick , Samaras Maria , Iglesias Roberto , Pouchon Manuel A. , Chen Jiachao , Grolimund Daniel , Raabe Joerg , Schuppler Stefan , Victoria Maximo , Hoffelner Wolfgang 
Published: June 2009

AbstractSynchrotron radiation techniques represent powerful tools to characterize materials down to the nanometer level. This paper presents a survey of the state‐of‐the‐art synchrotron‐based techniques which are particularly well‐suited for investigating materials properties. Complementary X‐ray absorption techniques such as extended X‐ray absorption fine structure (EXAFS), X‐ray magnetic circular dichroism (XMCD), photoemission electron microscopy (PEEM) are used to address the individual local atomic structure and magnetic moments in Fe–Cr model systems. The formation of atomic clusters/precipitates in such systems is also investigated by means of scanning transmission X‐ray microscopy (STXM). Such advanced analytical techniques can not only offer valuable structural and magnetic information on such systems, they can also serve for validating computational calculations performed at different time and length scales which can help improve materials lifetime predictions.
Principles of Highly Resolved Determination of Texture and Microstructure using High‐Energy Synchrotron Radiation
Authors: Klein Helmut 
Published: June 2009

AbstractDiffraction imaging with hard X‐rays (high‐energy synchrotron radiation) using the detector sweeping techniques allows measurement of the texture and microstructure of polycrystalline materials with high orientation‐ and location‐resolution. These techniques provide continuous two‐dimensional images of different sections and projections of the six‐dimensional “orientation‐location” space. For the high orientation resolution case, it is possible to measure the orientation and location coordinates of up to 105 individual grains simultaneously. From these parameters, the grain size and shape can also be obtained, yielding the complete orientation stereology of the polycrystalline aggregate, which is required for its complete characterization. For the high location resolution case, the intensity at any point of the diagrams corresponds to a pole density as a function of the orientation‐location space.
Producing Supramolecular Functional Materials Based on Fiber Network Reconstruction
Authors: Tang Shaokun , Liu Xiang Yang , Strom Christina S. 
Published: June 2009

AbstractHere, the creation of new supramolecular functional materials based on the reconstruction of three‐dimensional interconnecting self‐organized nanofiber networks by a surfactant is reported. The system under investigation is N‐lauroyl‐L‐glutamic acid di‐n‐butylamide in propylene glycol. The architecture of networks is implemented in terms of surfactants, e.g. sorbitan monolaurate. The elastic performance of the soft functional material is either weakened or strengthened (up to 300% for the current system) by reconstructing the topology of a fiber network. A topology transition of gel fiber network from spherulite‐like to comb‐like to spherulite‐like is performed with the introduction of this surfactant. The Span 20 molecules are selectively adsorbed on the side surfaces of the crystalline fibers and promote the nucleation of side branches, giving rise to the transformation of the network architecture from spherulite‐like topology to comb‐like topology. At high surfactant concentrations, the occurrence of micelles may provide an increasing number of nucleation centers for spherulitic growth, leading to the reformation of spherulite‐like topology. An analysis on fiber network topology supports and verifies a perfect agreement between the topological behavior and the rheological behavior of the functional materials. The approach identified in this study opens up a completely new avenue in designing and producing self‐supporting supramolecular functional materials with designated macroscopic properties.
Evolution of Electrical, Chemical, and Structural Properties of Transparent and Conducting Chemically Derived Graphene Thin Films
Authors: Mattevi Cecilia , Eda Goki , Agnoli Stefano , Miller Steve , Mkhoyan K. Andre , Celik Ozgur , Mastrogiovanni Daniel , Granozzi Gaetano , Garfunkel Eric , Chhowalla Manish 
Published: June 2009

AbstractA detailed description of the electronic properties, chemical state, and structure of uniform single and few‐layered graphene oxide (GO) thin films at different stages of reduction is reported. The residual oxygen content and structure of GO are monitored and these chemical and structural characteristics are correlated to electronic properties of the thin films at various stages of reduction. It is found that the electrical characteristics of reduced GO do not approach those of intrinsic graphene obtained by mechanical cleaving because the material remains significantly oxidized. The residual oxygen forms sp3 bonds with carbon atoms in the basal plane such that the carbon sp2 bonding fraction in fully reduced GO is ∼0.80. The minority sp3 bonds disrupt the transport of carriers delocalized in the sp2 network, limiting the mobility, and conductivity of reduced GO thin films. Extrapolation of electrical conductivity data as a function of oxygen content reveals that complete removal of oxygen should lead to properties that are comparable to graphene.
Microwave regeneration of zeolites in a 1 meter column
Authors: Meier Matthias , Turner Michael , Vallee Steven , Conner William C. , Lee Kyu Ho , Yngvesson Karl S. 
Published: June 2009

AbstractAlthough sorption is a common method of removing volatile organic compounds (VOC's) from processes, the adsorbent must be regenerated to repeat the process. The use of microwaves to regenerate the bed of adsorbent can be more efficient than conventional heating methods. Desorption of methanol from a silicalite zeolite was studied by the use of microwaves in cylindrical column. Temperature probes at five axial and three radial positions monitored the temperature profile in time. A significant amount of microwave energy passed through the dry zeolite bed, whereas a strong attenuation occurs if methanol is adsorbed. The radial temperature distribution conforms to theoretical predictions; however, microwave reflections cause a distortion of the predictions in the axial direction. Irregularities during the saturation of the bed indicated a chemical reaction during the irradiation with microwaves. A fraction of the methanol reacted under microwave irradiation to form dimethylether and water, and to methoxylate the zeolite surface. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Equations to predict precipitation onset and bubblepoint pressures of asphaltenic reservoir fluids
Authors: del Rio J. M. , Ramirez‐Jaramillo E. , Lira‐Galeana C. 
Published: June 2009

AbstractA set of algebraic equations to predict upper onset‐of‐precipitation and bubble‐point pressures of asphaltene‐containing reservoir fluids in wide temperature ranges are proposed. In developing the equations, laboratory data of 11 Mexican and 12 more live oils have been analyzed, and a correlation of these data with temperature has been found. A modified least‐squares regression method has been used to develop two versions of the proposed equations. In one version, a single pressure/temperature data point is required to predict the entire onset/bubble‐point curves at any temperature. For oils with no experimental precipitation data available at all, a second version of the proposed expressions employs standard chromatographic data of the reservoir fluid to provide a reasonable prediction. The average absolute deviations in calculated onset and bubble‐point pressures by the proposed equations are 2.53 and 0.45MPa by the one‐point correlations, respectively, and 3.96 and 1.62 MPa by the compositionally‐based correlations, respectively. The developed expressions are simple and can be used to provide reasonable predictions of upper onset and bubble‐point pressures of asphaltenic live oils in cases where laboratory data are scarce. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Assessment of airborne and dermal exposure to 2‐ethoxyethyl acetate in an occupational environment
Authors: Shih Tung‐Sheng , Kuo Yu‐Chieh , Liang Ro‐Han , Liou Saou‐Hsing , Chang Ho‐Yuan , Chou Tzu‐Chieh 
Published: June 2009

AbstractBackgroundBecause of its chemical–physical properties, 2‐ethoxyethyl acetate (EEAc) can penetrate through the skin. However, no actual occupational environmental studies or empirical dermal exposure measurements have been performed.MethodsTwenty workers from a commercial label silk screening shop were recruited and they completed a questionnaire of demographic information. Environmental monitoring of EEAc exposure via respiratory and dermal routes was performed for five consecutive working days.ResultsAirborne EEAc concentration was over the permissible exposure limit of 5 ppm in 90% of the participants. The dermal EEAc concentration was highest on the palms. The EEAc concentration correlated with skin exposure level (P < 0.001). The dermal EEAc concentrations in individuals who did not wear gloves were higher than in those who wore gloves.ConclusionsEEAc on the skin is strongly associated with airborne EEAc. Wearing impermeable gloves during high‐risk tasks (cleaning process) can reduce EEAc dermal exposure on the palms. Am. J. Ind. Med. 52:654–661, 2009. © 2009 Wiley‐Liss, Inc.
Hartsfield holoprosencephaly–ectrodactyly syndrome in five male patients: Further delineation and review
Authors: Vilain Catheline , Mortier Geert , Van Vliet Guy , Dubourg Christèle , Heinrichs Claudine , de Silva Deephti , Verloes Alain , Baumann Clarisse 
Published: June 2009

AbstractWe report on five male subjects with a triad of signs compatible with Hartsfield syndrome: ectrodactyly, holoprosencephaly, and mental retardation. Only six patients with this distinctive association have been reported over the past 20 years, all of them being males. Of the patients described here, some have unreported findings such as vermian hypoplasia in one and prolonged survival into adulthood in two. Two patients developed central diabetes insipidus. All were mentally retarded. No abnormalities were found at the cytogenetic level, including array CGH in two. No known genes for holoprosencephaly or ectrodactyly were found, including GLI2. The cause of Hartsfield syndrome is unknown. An X‐linked defect is possible, although no recurrences have been described to date. Our observations almost double the number of cases. They underscore the usefulness of fetal brain imaging in the differential diagnosis of syndromal clefting diagnosed in utero, particularly when ectrodactyly–ectodermal dysplasia‐clefting syndrome is suspected. © 2009 Wiley‐Liss, Inc.
Reconciliation in captive cotton‐top tamarins (Saguinus oedipus), a cooperative breeding primate
Authors: Peñate Laura , Peláez Fernando , Sánchez Susana 
Published: June 2009

AbstractReconciliation has been demonstrated in all primate species in which the phenomenon has been studied. However, reconciliation has been studied in only two species of callitrichids, and conclusions remain controversial. The first aim of this study has been to find out whether captive cotton‐top tamarins (Saguinus oedipus) reconcile, since this is the first such study on this species. We examined 227 conflicts in three family groups (N=19). Instances in which individuals remained together in t=0 (29; 12.8%) were not analyzed. The cotton‐top tamarins showed heightened affiliation between opponents in the postconflict periods (PC) compared with matched control (MC) periods (39.88±5.12% and 3.18±1.27%, respectively), with a corrected conciliatory tendency of 37.17±5.37%, and a “time window” that included the first 180 sec of the PC period. Former opponents were the most likely recipient of affiliative behaviors during the PC periods: 39.83±4.26% vs. 11.36±5.33% during MC periods. The proportion of attracted pairs (47.13±6.25%) was significantly higher than those of dispersed pairs for male–male conflicts (3.79±1.79), but not for male–female conflicts (27.31±9.32 and 4.82±2.9, respectively). In cooperative‐breeding species, specific sex‐class dyads might differ in how they resolve conflicts. Am. J. Primatol. 71:895–900, 2009. © 2009 Wiley‐Liss, Inc.
Graft copolymerization onto Tamarind Kernel Powder: Ceric(IV)‐initiated graft copolymerization of acrylonitrile
Authors: Goyal Puja , Kumar Vineet , Sharma Pradeep 
Published: June 2009

AbstractTamarind Kernel Powder (TKP) is derived from the seeds of Tamarindus indica Linn., a common and most important tree of India. It is extensively used in cotton sizing, as a wet‐end additive in the paper industry, as a thickening, stabilizing, and gelling agent in the food industry. However, because of its fast biodegradability there is a need to prepare graft copolymers of TKP. The graft copolymerization of acrylonitrile (AN) onto TKP with ceric ammonium nitrate as a redox initiator in an aqueous medium has been studied. The reaction conditions were optimized to afford maximum percent grafting and percentage grafting efficiency of AN onto TKP, which was found to be 86% and 64%, respectively. Fourier Transform Infrared Spectrum of the grafted products showed an additional sharp absorption band at 2244 cm−1 due to CN stretching, thereby confirming the grafting of AN onto TKP. Scanning electron microscopy studies indicated change in contour of the polysaccharide on grafting and the thick polymeric coating of AN on the surface alongwith grafting of AN such that all the gap between polysaccharide particles have been closed. Thermal studies using thermogravimetric and differential gravimetric analyses confirmed that TKP‐g‐AN has overall high thermal stability than pure TKP. Reaction mechanism of grafting of acrylnitrile onto TKP is also proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Photocatalytic properties of silicone polyesters using calcium phosphate/titanium dioxide
Authors: Chu Hawn‐Chung , Lin Li‐Huei , Liu Hsin‐Chi , Chen Ho‐Fu , Liu Hsin‐Jiant , Chen Keng‐Ming 
Published: June 2009

AbstractThis study uses titanium dioxide treated with calcium phosphate to prepare multilayer structure composites. These products are regarded as photocatalysts. Utilizing polyethylene glycol (PEG)–silicone polyester as an adhesive spread on matrix surfaces, this can provide these products with antifouling properties, good weather resistance, and antibacterial property. It has been observed that UV irradiation has caused changes in the film molecular structure of PEG–silicone polyesters, as well as changes in the surface morphology. These changes in molecular structure have been observed by FTIR and Raman analysis. PEG–silicone polyesters contain silicon atoms with both organic and inorganic characteristics. This makes fixation of photocatalysts possible and retards oxidation of organic materials in the polyesters. The results of FTIR and Raman spectrum analyses indicate films made of these polyesters effectively cover calcium phosphate–titanium dioxide photocatalysts, retard surface cracks, and slow down decomposition, caused by UV light. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of dodeca‐tungstophosphric acid on morphology and performance of polyvinyl alcohol membrane for gas separation
Authors: Madaeni S. S. , Rafiee E. , Seyedzadeh Z. , Barzin J. 
Published: June 2009

AbstractIn this article, organic/inorganic membrane was prepared for gas separation by incorporating dodeca‐tungstophosphric acid (PWA) into the base polymer. Flat‐sheet composite membranes were produced via dry‐phase inversion method. In the first stage, the effects of PWA concentration on morphology and performance of polyvinyl alcohol (PVA) membranes were elucidated. For this stage, the preparation of membranes was carried out at constant temperature of 40°C. The porosity of the prepared membrane was slightly increased with addition of PWA. By increasing the PWA concentration up to 6 wt % in the membrane recipe, the permeability of N2, O and air was improved from 50,000 (for no addition of PWA) to around 160,000, 140,000, and 80,000 L m−2 h−1, respectively. For H this was enhanced from 110,000 to 230,000 L m−2 h−1. The ideal selectivity of the membrane was slightly improved for N2/air (from 1 to 1.2). For N2/O2 pair, the initial drop (from 2.5 to 1.5) was followed by a slight increase (1.5–1.9). Moreover, the selectivity was decreased for H2/air (from 2.8 to 1.8) and H2/N2 (from 2.2 to 1.7) by increasing the PWA concentration. The 10 wt % PVA membrane with 6 wt % PWA demonstrated superior performance compared with the other compositions. In summary, the presence of PWA in the casting solution results in lower flux for O2 and higher selectivity for H2/O2 pair. In the second stage, the effects of solvent evaporation temperature (10, 27, 40, and 80°C) on morphology and performance of the membranes were studied. By increasing the temperature, the number and size of voids were increased. The permeation of gases was improved from 100,000 L m−2 h−1 (at 10°C) to 150,000 (O2), 250,000 (air), 380,000 (N2), and 600,000 L m−2 h−1 (H2) by increasing the temperature up to 80°C. This increment resulted in selectivity alteration either increment or diminishment. The selectivity was changed from 1.3 to 3.2 (H2/O2), 0.8–2.5 (N2/O2), 1.2–2.4 (H2/air), 0.6–1.5 (N2/air) and 2.0–1.5 (H2/N2). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Mechanistic study of Sn(Oct)2‐catalyzed ε‐caprolactone polymerization using Sn(Oct)2/BF3 dual catalyst
Authors: Jiang G. , Jones I. A. , Rudd C. D. , Walker G. S. 
Published: June 2009

AbstractA novel method was used to investigate the mechanism of Sn(Oct)2‐catalyzed ε‐caprolactone polymerization by using Sn(Oct)2/BF3 dual catalyst. The bulk polymerization was conducted at 110 and 130°C with different Sn(Oct)2/BF3 ratios. The polymerization kinetics was followed using gel permeation chromatography, and the molecular structures of the low‐molecular weight polymers were examined using 1H‐nuclear magnetic resonance (NMR). A polymerization induction period was observed in polymerizations containing the Sn(Oct)2 catalyst, but it was not observed in the system containing only BF3. After the induction period, BF3 and Sn(Oct)2 initiated the polymerization separately. For Sn(Oct)2 catalyst with no purposely added alcohol, the actual initiation species is a tin hydroxide species formed in situ by the reaction of Sn(Oct)2 and adventitious water. For BF3 catalyst, the active species is the protonic acid formed by the reaction of BF3 with the adventitious water. When mixed, the Sn(Oct)2 reacts with the adventitious water faster than the BF3, preventing the BF3 catalyzing any polymerizations during the induction period. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A new method to prepare porous silk fibroin membranes suitable for tissue scaffolding applications
Authors: Nogueira Grínia M. , Weska Raquel F. , Vieira Wellington C. , Polakiewicz Bronislaw , Rodas Andrea C. D. , Higa Olga Z. , Beppu Marisa M. 
Published: June 2009

AbstractA new method to prepare porous silk fibroin (SF) membranes without dialysis is proposed. Silk fibers were degummed to remove sericin and the resultant fibroin was dissolved in a CaCl2‐CH3CH2OH‐H2O ternary solvent. Rather than undergoing dialysis, a fibroin salty solution was diluted in water and then submitted to a mechanical agitation that led to a phase separation through foam formation on the solution surface. This foam was continually collected and then compacted between plates to remove the excess of water. The membranes presented large pores with diameters of greater than 100 μm (as shown by scanning electron microscopy ‐ SEM), porosity of 68% and water content of 91% w/w. X‐ray diffraction (XRD) and infrared spectroscopy (FTIR‐ATR) indicated that the membranes present SF in a β‐sheet structure even before the ethanol treatment. A typical elastic deformation profile and degradation under temperature were observed using calorimetric analysis (DSC), thermal gravimetric analysis (TGA) and mechanical tests. As indicated by the in vitro cytotoxicity tests, these membranes present potential for use as scaffolds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A rationale for the Hirsch‐index rank‐order distribution and a comparison with the impact factor rank‐order distribution
Authors: Egghe Leo 
Published: June 2009

AbstractWe present a rationale for the Hirsch‐index rank‐order distribution and prove that it is a power law (hence a straight line in the log–log scale). This is confirmed by experimental data of Pyykkö and by data produced in this article on 206 mathematics journals. This distribution is of a completely different nature than the impact factor (IF) rank‐order distribution which (as proved in a previous article) is S‐shaped. This is also confirmed by our example. Only in the log–log scale of the h‐index distribution do we notice a concave deviation of the straight line for higher ranks. This phenomenon is discussed.
Der aktuelle Gebrauch der ‘longue durée’ in der Wissenschaftsgeschichte
Authors: Stoff Heiko 
Published: June 2009

AbstractOn the Contemporary Uses of ‘Long Durée’ in the History of Science. In the last years, Fernand Braudel's concept of ‘longue durée’ has been widely used in the German history of science. It thereby served as a historiographical tool for the problem of continuity and discontinuity with regard to the political ruptures of the years 1914, 1918, 1933, and 1945. In the context of historical innovation research, these political events seemed to have discontinued an otherwise ‘longue durée’ of a successful German innovation system, established in the German Empire. Critics of this narrative again stress the continuing functionality of a national innovation system also in the Third Reich. While the first group strengthens the negative impact of political events on a ‘longue durée’ of the German innovation system, thereby constructing a positive and politically charged interpretation of a scientific German ‘Sonderweg’, the latter emphasizes the catalytic role of these events, its function as a reorganizer of research. For this interpretation different methodologies like research ensembles and networks, based on Bruno Latour's non‐structural sociology of practices and interests, proved to be more adequate. Paul Rabinow's use of the term ‘assemblage’ as a contingent, temporal ensemble of practices, actors, structures, routines, value systems and self technologies again places the event at the basis of the historical analysis. While Hans‐Jörg Rheinberger's concept of experimental systems relates to this characterisation of assemblage, it also corresponds to Michel Foucault's reading of Braudel's concept of ‘longue durée’. Foucault fundamentally neglected the separation of event and structure in establishing a connection between series and events based on transformations, thereby avoiding both a totalizing macro history and an individualizing micro history. A future ‘longue durée’‐history, which transgresses the dichotomy of continuity and discontinuity, therefore can be conceptualized as a series of multi‐temporal non‐causal occurrences.