bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Syntheses of Poly(Norbornenyldecaborane) Precursors to Boron Carbide and Boron-Carbide/Silicon-Carbide Ceramics
Authors: Wei Xiaolan , Welna Daniel T. , Bender Jared D. , Sneddon Larry G. , Allcock Harry R. 
Published: April 2011

ABSTRACTPoly(norbornenyldecaborane) (PND) was synthesized via ruthenium catalyzed ring opening metathesis polymerization and was found to be a good single-source polymeric boron carbide precursor. Polymer blends of PND and allylhydridopolycarbosilane (AHPCS) were also found to be excellent precursors to boron-carbide/silicon-carbide composite materials.
Hydrolysis of aluminium metal, synthesis of nano alumina and sol-gel processing of monoliths
Authors: Thiruchitrambalam M. , Palkar V.R. 
Published: April 2011

ABSTRACTHigh purity alumina is usually prepared using various intermediate aluminium compounds such as aluminium nitrate, aluminium alkoxides etc., as precursors. In fact the above mentioned intermediate aluminium compounds themselves are produced from aluminium metal. The present investigation is concerned with examining the feasibility of using aluminium hydroxides prepared by hydrolyzing aluminium metal, for sol gel processing. The study assumes added significance in view of the claims of Alcoa that it is possible to produce high purity aluminium metal in large quantities economically.During the present investigation sols were prepared by using various hydroxides, ie., bayerite, gibbsite and boehmite. Sol gel transition was observed only in the case of boehmite sol and this was gelated by either forced gelation method to prepare powder or controlled gelation method to prepare monoliths.Transparent Xerogels (boehmite) could be prepared by controlled gelation method but the presence of a thin layer of bayerite often resulted in translucency. Crack free monoliths could be prepared by heating the xerogels at a low heating rate(< 1 °C/min). It was found that sol gel processed boehmite transformed to alpha alumina at a relatively lower temperature (∼ 1080 °C ) than the as prepared boehmite which transformed at about 1200 °C.
The thermodynamic stability of three near-degenerate phases of platinum dioxide
Authors: Zhuo Shuping , Sohlberg Karl 
Published: April 2011

ABSTRACTThe thermodynamic stability of the three nearly energy degenerate crystal structures of PtO2 is studied here with first-principles-based calculations of their free energies. For P = 0 the α-(CdI2) structure is the thermodynamically stable phase at low temperature, while the β-(CaCl2) structure is stable at high pressure. The β'-(rutile) structure represents an unstable fixed point on the potential energy surface, or is possibly just barely bound. These results reconcile seemingly contradictory findings and answer longstanding questions about PtO2.
Preparation and Characterization of (C4H9NH3)2MCl4 (M=Mn, Cu)
Authors: Guo Liling , Dai Yadong , Hu Mingjie , Liu Hanxing , Ouyang Shixi 
Published: April 2011

ABSTRACTWith the preparation of organic-inorganic layered perovskite-type compounds (C4H9NH3)2MCl4 (M = Mn, Cu) in solutions, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetry (TG) and differential scanning calorimetry (DSC) have been used to characterize the obtained powders. XRD patterns demonstrate that the two compounds have obvious layered structures and SEM pictures reveal that both (C4H9NH3)2MnCl4 and (C4H9NH3)2CuCl4 take on obvious sheet-like microstructure. TG&DSC curves indicate that (C4H9NH3)2CuCl4 decomposes at much lower temperature than (C4H9NH3)2MnCl4.This is ascribed to weakening interactions between its organic and inorganic components, which is presumably due to the Jahn-Teller distortion of [CuCl6] octahedra.
Pure and Ca-doped LaCoO3 Nanopowders: Sol-Gel Synthesis, Characterization and Magnetic Properties
Authors: Armelao Lidia , Barreca Davide , Bottaro Gregorio , Caneschi Andrea , Sangregorio Claudio , Gasparotto Alberto , Gialanella Stefano , Maragno Cinzia , Tondello Eugenio 
Published: April 2011

ABSTRACTThis work is focused on the sol-gel synthesis of pure and Ca-doped LaCoO3 nanopowders. The samples were prepared starting from methanolic solutions of cobalt (II) acetate (Co(CH3COO)2·4H2O), lanthanum (III) nitrate (La(NO3)3·6H2O) and calcium (II) acetate (Ca(CH3COO)2·H2O). After solvent evaporation, the obtained powders were dried under vacuum and subsequently treated in air up to 1273 K. The system evolution under thermal annealing was studied by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM), while the chemical composition was analyzed by X-ray Photoelectron (XPS) and X-ray Excited Auger electron (XE-AES) spectroscopies. The temperature and field dependence of the magnetic properties of the Ca-doped samples were investigated, and compared to those of the corresponding pure LaCoO3 powders.
Laser Shot Peening of Inconel 600 and Surface Morphology Characterization
Authors: Bugayev A. A. , Gupta M. C. , Orr J. , Levesque S. , Payne R. 
Published: April 2011

ABSTRACTThe results on laser shot peening and its characterization for Inconel 600 are presented. Using an X-ray diffraction technique we show that the residual compressive stresses can be successfully induced in Inconel 600 with parameters of laser peening, which are close to that of 316L stainless steel. The on-line monitoring system involving the acoustic pulse measurements is described for quality control of laser shot peening process. We found that sample scanning during laser processing results in a system of column-like microstructure, which is tilted in direction of scanning. The features of optical properties of tilted microstructure are described. We revealed that the base material injected into the confining water due to laser ablation is transformed to spherical nanoparticles with diameter of 60nm.
Diagnosis and Modelling of Nonlinear Dynamics in Laser Cutting, Welding and Drilling
Authors: Schulz W. 
Published: April 2011

ABSTRACTLaser cutting and welding are well established industrial applications. To maintain productivity and to guarantee product quality the industry tries to introduce monitoring and control systems. The long term goal is the autonomous laser machine. Signal assessment is advancing by monitoring and simulation of the dynamical processes. Applying the advanced results about diagnosis and modelling broadens the potentials to cope with productivity and quality features in drilling, trepanning and fine cutting.As result, in cutting two mechanisms for the formation of adherent dross are revealed theoretically, identified by the monitoring system and can be avoided by modulation of the laser beam power. In welding, the dynamic model predicts the formation of pores sets in or is suspended depending on modulation frequency for the laser power. In drilling the mechanisms governing the maximum depth of the drilled hole – still showing efficient melt removal – are identified experimentally and can be related to the processing parameters theoretically
Thermal and Electric Properties of P(VDF-TrFE) and P(VDF-CTFE) Copolymer Blends
Authors: Li Zhimin , Wang Yuhong , Cheng Z.-Y 
Published: April 2011

ABSTRACTPVDF-based electroactive polymers (EAP) exhibit high electromechanical performance that is attractive for developing high performance actuators and sensors. In an effort to develop very inexpensive electroactive polymers, P(VDF-TrFE)/P(VDF-CTFE) copolymer blends are studied and reported. The structure, morphology, thermal transition and miscibility of the blend system were investigated by DSC and X-ray diffraction. It is found that the phase transition behavior of the blends can be significantly modified using thermal and mechanical treatmentss. The modified film exhibits high polarization response and low remanent polarization. More importantly, a high electrostrictive strain of 5% was observed in the treated blends. Combined with Young's modulus, the results show that the copolymer blends have a electromechanical coupling factor and energy density comparable or even higher than the irradiated P(VDF-TrFE) copolymers.
Epitaxial Phase Transformation between Cylindrical and Double Gyroid Mesophases
Authors: Zhu Lei , Sun Lu , Miao Jianjun , Cui Li , Ge Qing , Quirk Roderic P. , Xue Chenchen , Cheng Stephen Z. D. , Hsiao Benjamin S. , Avila-Orta Carlos A. , Sics Igors , Cantino Marie E. 
Published: April 2011

ABSTRACTComplex phase transformation between the hexagonal cylinder (Hex) and double gyroid (G) phases in a polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer was investigated using two-dimensional (2D) synchrotron small-angle X-ray scattering (SAXS), and transmission electron microscope (TEM). The PS-b-PEO sample contained a small population of another bicontinuous cubic phase having an Im3m symmetry. These two bicontinuous cubic phases (G and Im3m) had the same unit cell dimensions. Under a large-amplitude reciprocating shear, the bicontinuous cubic phases transformed into a “single-crystal”-like Hex phase. When annealed at 150 °C for 40 min, the Hex phase partially transformed into well-oriented twinned structures of the G and Im3m phases without significant loss of orientation in 2D SAXS measurements. Epitaxial phase transformation relationships between the Hex/G and Hex/ Im3m phases were identified. The mechanism of the Hex → G transformation was examined by TEM.
Effects of Chain Extension and Branching on the Properties of Poly (Ethylene-Terephthalate)-Organoclay Nanocomposites
Authors: Keyfoglu Ali Emrah , Yilmazer Ulku 
Published: April 2011

ABSTRACTThe effects of chain extension and branching on the properties of nanocomposites produced from recycled poly (ethylene-terephthalate) and organically modified clay were investigated. As the potential chain extension/branching agent, maleic anhydride (MA) and pyromellitic dianhydride (PMDA) were used. The nanocomposites were prepared by twin-screw extrusion, followed by injection molding. Recycled poly (ethylene-terephthalate) was mixed with 2, 3 or 4 weight % of organically modified montmorillonite. During the second extrusion step, 0.5, 0.75 or 1 weight % of MA or PMDA was added to the products of the first extrusion. The effects of the sequence of addition of the ingredients on the final properties of the nanocomposites were also investigated. X-Ray Diffraction analysis showed that, the interlayer spacing of Cloisite 25A expanded from 19.21 Å to about 28–34 Å after processing with polymer indicating an intercalated structure. PMDA content, MA content and screw speed did not have a significant effect on the expanded interlayer distance. In the first extrusion step, nanocomposites containing 3% organoclay content gave significant increase in Young's modulus and decrease in elongation at break values indicating good interfacial adhesion. After the addition of anhydrides, it was observed that, in general PMDA improved the mechanical properties of the nanocomposite owing to the branching and chain extension effects that increase the molecular weight. However, MA did not significantly improve the properties, since in this case the chain scission seemed to be more dominant.
Dynamics of Nanocomposite Formation and Impact Modification of Polyethyleneterephthalate
Authors: Alyamac Elif , Yilmazer Ulku 
Published: April 2011

ABSTRACTThis study was conducted to investigate the effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of poly(ethylene terephthalate), organoclay, and an ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) terpolymer acting as an impact modifier for PET. Among the investigated addition orders, the best sequence of component addition (PI-C i.e. PET, Impact Modifier-Clay) was the one in which poly (ethylene terephthalate) was first compounded with E-MA-GMA. Later, this mixture was compounded with the organoclay in the subsequent run. In X-ray diffraction analysis, extensive layer separation associated with delamination of the original clay structure was observed in PI-C and (CI-P i.e. Clay, Impact Modifier-PET) sequences with both 1 and 3 wt. % clay contents. X-ray diffraction patterns showed that, at these conditions, exfoliated structures were obtained.
Systemic Trends in Disaster Vulnerability: Migrant and Seasonal Farm Workers in North Carolina
Authors: Montz Burrell E , Allen Thomas R , Monitz Gary I 
Published: April 2011

AbstractAlthough researchers from a number of disciplines have long recognized that marginalized groups are at increased risk to the impacts of disasters, it took Hurricane Katrina to bring this to the forefront of policy discussions. An equally insidious problem exists among migrant and seasonal farm workers (MSFWs), yet there is very little work on the nature and range of their vulnerability. In North Carolina, more than ninety per cent of MSFWs are Latino, with the rest being mostly African‐American males. These individuals are particularly vulnerable because of the nature of their work, the poor housing in which they live, and the lack of access to social networks, among other factors. The magnitude of the problem depends on the locations of fields and housing in hazardous areas. Utilizing GIS and Google Earth virtual globe, registered migrant worker camps are mapped using address geocoding with respect to several natural hazards. The results of this work illustrate a compelling need for emergency management to focus on the needs of MSFWs when an event is impending and for policy‐makers to address the factors that put this segment of the population that is so critical to the agricultural economy at such high risk.
Risk Management and Quality Management in Long‐Term Care Organizations: A Collaborative Model
Authors: Guo Kristina L. 
Published: April 2011

AbstractThe U.S. long‐term care system is complex and heavily regulated, yet incidences of risks continue to occur and result in lowered quality of care, and adversely affect patient safety. Risks can be minimized and avoided to safeguard the health and well being of consumers utilizing long‐term care services. The key component to minimizing risks and potential hazards and ensuring high quality in long‐term care facilities is to integrate quality management programs and quality improvement efforts with risk management activities. Currently, risk management and quality management are two distinct functions in long‐term care organizations. Although some activities may be linked, actual coordination and true integration have not taken place. Expansion and integration of risk management and quality improvement functions will result in more effectiveness for both areas. This paper develops a rational model to demonstrate that coordination and integration between risk management and quality management are essential to the delivery of cost effective and quality services in long‐term care organizations.
Restricted Radon Transforms and Projections of Planar Sets
Authors: Oberlin Daniel M. 
Published: April 2011

AbstractWe establish a mixed norm estimate for the Radon transform in ℝ2 when the set of directions has fractional dimension. This estimate is used to prove a result about an exceptional set of directions connected with projections of planar sets. That leads to a conjecture analogous to a well-known conjecture of Furstenberg.
Description–experience Gaps: Assessments in Other Choice Paradigms
Authors: Fantino Edmund , Navarro Anton 
Published: April 2011

ABSTRACTResearchers have become increasingly interested in the description–experience gap or the finding that people respond differently to the same quantitative information depending on whether it is described or experienced. Most studies on the gap have focused on binary choices between a safe option and a risky option and have compared decisions made from description alone versus experience alone. We review studies examining other decision‐related phenomena—probability learning, the sunk‐cost effect, choices in a repeated‐trials prisoner's dilemma, and base‐rate neglect—with an experience‐based approach that often includes conditions combining description and experience. In probability learning, the sunk‐cost effect and a repeated‐trials prisoner's dilemma, participants come closer to behaving optimally when description and experience are simultaneously available than when experience alone is available. In studies of base‐rate neglect, participants respond similarly under conditions of description alone and experience alone. Studies with nonhuman animals strengthen the generality of our conclusions regarding the sunk‐cost effect and suggest a potential cause of base‐rate neglect: a prior experience of having been rewarded for matching like items. Copyright © 2011 John Wiley & Sons, Ltd.
Alkylsulfanylphenyl Derivatives of Cytosine and 7‐Deazaadenine Nucleosides, Nucleotides and Nucleoside Triphosphates: Synthesis, Polymerase Incorporation to DNA and Electrochemical Study
Authors: Macíčková‐Cahová Hana , Pohl Radek , Horáková Petra , Havran Luděk , Špaček Jan , Fojta Miroslav , Hocek Michal 
Published: April 2011

AbstractAqueous Suzuki–Miyaura cross‐coupling reactions of halogenated nucleosides, nucleotides and nucleoside triphosphates derived from 5‐iodocytosine and 7‐iodo‐7‐deazaadenine with methyl‐, benzyl‐ and tritylsufanylphenylboronic acids gave the corresponding alkylsulfanylphenyl derivatives of nucleosides and nucleotides. The modified nucleoside triphosphates were incorporated into DNA by primer extension by using Vent(exo‐) polymerase. The electrochemical behaviour of the alkylsulfanylphenyl nucleosides indicated formation of compact layers on the electrode. Modified nucleotides and DNA with incorporated benzyl‐ or tritylsulfanylphenyl moieties produced signals in [Co(NH3)6]3+ ammonium buffer, attributed to the Brdička catalytic response, depending on the negative potential applied. Repeated constant current chronopotentiometric scans in this medium showed increased Brdička catalytic response, which suggests the deprotection of the alkylsulfanyl derivatives to free thiols under the conditions.
Sequential development of diffuse large B‐cell lymphoma in a patient with angioimmunoblastic T‐cell lymphoma
Authors: Huang Jing , Zhang Pei‐Hong , Gao Yu‐Huan , Qiu Lu‐Gui 
Published: April 2011

AbstractLymphoma of different histologic type can occur in the same patient. Here, we describe a 64‐year‐old male patient with angioimmunoblastic T‐cell lymphoma (AITL) who subsequently developed diffuse large B‐cell lymphoma (DLBCL). At the time of initial diagnosis, histologic examination of a left inguinal lymph node of the patient and a monoclonal pattern of TCRβ gene rearrangement showed typical features of AITL, and there was no evidence of a monoclonal B‐cell population. Twenty‐six months later, he had generalized lymphadenopathy and organs involvement by DLBCL. A monoclonal IgH gene rearrangement proved de novo development of secondary B‐cell lymphoma and excluded relapse of a primary composite lymphoma. The in situ hybridization analysis showed Epstein‐Barr‐encoded RNA (EBER) sporadic positivity in sample collected from AITL but extensive positivity in the immunoblasts collected from DLBCL. Our observation supports the hypothesis that Epstein‐Barr virus (EBV) is etiologically related to AITL in this case. Clonal expansion of EBV‐associated DLBCL is a secondary event in AITL via EBV infection or reactivation. Diagn. Cytopathol. 2011; © 2011 Wiley‐Liss, Inc.
Combined double CK5/P63 stain: Useful adjunct test for diagnosing pulmonary squamous cell carcinoma
Authors: Fatima Nazneen , Cohen Cynthia , Lawson Diane , Siddiqui Momin T. 
Published: April 2011

AbstractIncreasing demand for accurate differentiation of pulmonary squamous cell carcinoma (SQCC) from other subtypes can be challenging for pathologists. This is more so in fine‐needle aspirations (FNA) since the sample is small and SQCC may show degenerative changes and necrosis that distort the cellular features. Immunohistochemistry (IHC) is a valuable adjunct, and CK5/6 and P63 immunoreactivity is found to be basically restricted to SQCC. In our study, we evaluated the efficiency of CK5/P63 double staining in the diagnosis of pulmonary SQCC in cell blocks (CB) of lung FNA. We used a cohort including 24 CB of lung SQCC and 34 CB of lung adenocarcinomas (ADC). IHC was performed for CK5/P63 double stain. Seventeen of 24 (70%) lung SQCC were positive for the double stain CK5/P63. Two (8%) were positive for CK5 alone and two (8%) were positive for P63 alone. Thus, a total 19 of 24(79%) SQCC of the lung were positive for CK5 and P63 each. In ADC, no immunoreactivity was detected for CK5 alone or combined CK5/P63. Three of 34(8%) ADC were positive for P63. This first study of double staining of CK5/P63 in FNA CB shows a sensitivity of 70% and specificity of 100% for SQCC of the lung. When each marker staining alone is included, the sensitivity for CK5 and P63 increases to 79% each. This double stain can help in the diagnosis of pulmonary SQCC with an accuracy of 88% and a positive predictive value of 100%. Diagn. Cytopathol. 2012. © 2011 Wiley Periodicals, Inc.
Cooperative Catalytic Reactions Using Lewis Acids and Organocatalysts: Enantioselective Propargylic Alkylation of Propargylic Alcohols Bearing an Internal Alkyne with Aldehydes (Eur. J. Org. Chem. 12/2011)
Authors: Motoyama Kazuki , Ikeda Masahiro , Miyake Yoshihiro , Nishibayashi Yoshiaki 
Published: April 2011

AbstractThe cover picture shows that both wings are necessary for a butterfly to fly. Likewise, both a Lewis acid and an organocatalyst contribute cooperatively to the catalytic enantioselective propargylic alkylation of proparglylic alcohols bearing an internal alkyne moiety with aldehydes. Details are discussed in the article by Y. Nishibayashi et al. on p. 2239 ff.
Cyclic and Square‐Wave Voltammetric Signatures of Nitro‐Containing Explosives
Authors: Galik Michal , O'Mahony Aoife M. , Wang Joseph 
Published: April 2011

AbstractWhile cathodic voltammetric measurements based on the reduction of nitro‐containing explosive compounds have been well documented, little attention has been given for exploiting their anodic response, associated with the oxidation of their reaction products, for qualitative and quantitative security and forensic information. We demonstrate here that cyclic square‐wave volammetry, combining the cathodic and anodic signals, offers distinct electrochemical profiles for trace nitroaromatic, nitramine and nitrate ester explosives compared to analogous cyclic‐voltammetric and cathodic square‐wave‐voltammetric measurements. Unique electrochemical signatures are also obtained for commonly used explosive mixtures. Such distinct explosive signatures at disposable strip electrodes should facilitate rapid decentralized security screening applications.