bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amorphous “Ti3N4” and Formation of Nanocrystalline TiN
Authors: Hector Andrew L. , Jackson Andrew W. , McMillan Paul F. , Shebanova Olga 
Published: April 2011

ABSTRACTThe existence of Ti3N4 was proposed as the first product of the thermal decomposition of precipitates obtained in ammonolysis reactions of titanium(IV) dialkylamides. The evidence is re-evaluated and further evidence is presented to demonstrate that these materials are probably TiN contaminated with carbon. However, this precursor system is demonstrated to be a good route to finely divided, nanocrystalline TiN powders.
Preparation and characterization of porous TiO2-SiO2 mixed oxide
Authors: Peng Ang Thiam , Ziyi Zhong , Highfield James 
Published: April 2011

ABSTRACTA study on the comparison of porous TiO2-SiO2 mixed oxides synthesized variously via the “amine directed” method is reported. The amine capping groups were octylamine, dodecylamine, octyldecylamine, aniline, and isobutylamine. The mixed oxide is characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), infrared spectroscopy (IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Brunauer-Emmett-Teller analysis (BET). While XRD, SEM and TEM provide mainly (bulk) structural information on the mixed oxide preparations, BET (N2 physisorption) probes into their surface area and texture. IR evidence suggests that intimate chemical mixing of both oxides has occurred, while BET measurements show that high surface areas are attainable and that the mixed oxide is more thermally stable than pure (control) samples of TiO2.
Electrostatic Spinning, Pyrolysis, and Characterization of Boron Carbide Nanofibers Prepared from Poly(norbornenyldecaborane) - a Polymeric Ceramic Precursor
Authors: Welna Daniel T. , Wei Xiaolan , Bender Jared D. , Krogman Nick R. , Sneddon Larry G. , Allcock Harry R. 
Published: April 2011

ABSTRACTElectrostatic spinning is a well-developed technique for the fabrication of fibers in the nanoscale domain. Novel boron carbide nanofibers were generated by the electrostatic spinning and ceramic conversion of poly(norbornenyldecaborane) (PND) - a polymeric ceramic precursor. The prepyrolyzed fibers were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The ceramic fibers were characterized by SEM, X-ray diffraction (XRD), 11B magic-angle spinning nuclear magnetic resonance (MAS NMR) and DRIFT spectroscopy. SEM analysis showed retention of the nanostructure in the pre- and postpyrolyzed fibers.
The Effect of Dopant Additions on the Microstructure of Boron Fibers Before and After Reaction to MgB2
Authors: Marzik James V. , Suplinskas Raymond J. , Croft William J. , MoberlyChan Warren J. , DeFouw John D. , Dunand David C. 
Published: April 2011

ABSTRACTBoron fibers made by a commercial chemical vapor deposition (CVD) process have been used as precursors for the formation of magnesium diboride (MgB2) superconducting wires. Prior to a reaction with magnesium, the addition of dopants such as carbon and titanium to the boron fiber has been shown to enhance the superconducting properties of MgB2. These dopants also influence the kinetics of the reaction with magnesium. In this study, the effect of carbon dopant additions on the microstructure of boron fibers was investigated using powder x-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, bundles of boron fibers were pressure infiltrated with molten magnesium and reacted at elevated temperatures. The microstructure and microchemistry of the fiber-metal interfaces were investigated by TEM and energy dispersive x-ray analysis (EDS).
Substitution effects on the ruthenium, strontium and gadolinium sites in the RuSr2GdCu2O8 compound.
Authors: Chavira E. , Abatal M. , Filippini C. , Tholence J. L. , García-Vázquez V. , Pérez J. C. , Sulpice A. , Noël Henri 
Published: April 2011

ABSTRACTWe present the more relevant results of various cationic substitutions in the RuSr2GdCu2O8 (Ru-1:2:1:2 ) compound. The substitutions were synthesized by solid-state reaction at ambient pressure in the following systems: Ru1−xSr2GdCu2+xO8 (0.0 < x < 1.0), Ru(Sr2-xCax)GdCu2O8 (0 < x < 2.0) and RuSr2(Gd1-xLnx)Cu2O8 (0 < x < 0.9) with Ln = Dy, Ho, Er, Yb and Lu. All of them were isostructural to Ru-1:2:1:2 compound with tetragonal unit cells. The phases have been characterized by X-Ray powder Diffraction (XRD), observing a solid solution (ss ) up to x = 0.4 for Ru ions replaced by Cu ions, x = 0.1 when we substitute Sr atoms by Ca atoms, and x = 0.7 changing Gd ions by Ln ions. As a result of the Scanning Electron Microscopy (SEM), the grain sizes were discovered to be 1 – 10 μm. The Energy Dispersive X-ray spectroscopy (EDX) analysis permitted us to analyze the impurities that we did not detect with XRD. We observed semiconducting, isolated and ferromagnetic behaviors. No superconducting transition could be observed for these ambient preparation conditions.
Structural Stability and Optical Properties of hexagonal and cubic CdSe Nanocrystals synthesized in MgO
Authors: Eijt S.W.H. , Huis van , Mijnarends P.E. , Kooi B.J. , Nanu M. 
Published: April 2011

ABSTRACTWe present a study of CdSe nanocrystals synthesized in MgO by precipitation of Cd and Se supersaturated solid solutions, created in MgO single crystals by ion implantation, in the temperature range between 300 °C and 1100 °C. For high-dose ion implantation, optical absorption spectroscopy revealed the presence of the ∼1.8 eV CdSe semiconductor band-edge. Small sized nanocrystals adopt the rocksalt instead of the wurtzite structure because the former fits better in the MgO matrix and results in lower interface energies. A better understanding of these structural changes and optical properties is obtained from ab-initio total energy calculations on wurtzite, zincblende and rocksalt CdSe using the VASP pseudopotential code. The calculated electronic band structures are compared of zincblende CdSe, a direct band-gap semiconductor, and rocksalt CdSe, which has an indirect optical band-gap.
ZnO nanorods grown by a Pulsed Laser Deposition process
Authors: Park Jae-Hwan , Choi Young-Jin , Ko Won-Jun , Whang In-Sung , Park Jae-Gwan 
Published: April 2011

ABSTRACTZnO nanorods were synthesized by a hot-wall type pulsed laser ablation process. At temperatures 500∼800°C, ZnO thin films and wrinkles were synthesized. Above 800°C, vertically aligned ZnO nanorods were grown on the Si and sapphire substrate without any catalysts. The range of diameter was 100∼300nm. When Au catalyst were deposited on the substrate prior to the deposition, the process range of ZnO nanorod become wider and the diameter of ZnO narrower. Especially, ZnO could be grown selectively along the pattern of Au catalyst with the aid of Au-Zn alloy.
Morphology Development Associated With Polymer Blends
Authors: Hashida Tomoko , Hua Ying , Hsu Shaw Ling , Paul Charles W. 
Published: April 2011

ABSTRACTMorphology development of crystallizable polymer blends has been investigated using optical microscopy, thermal analysis, and vibrational spectroscopy. The blends studied involve crystallizable polyesters of poly(hexamethylene adipate) (PHMA) and poly(hexamethylene sebacate) (PHMS) and non-crystallizable poly(propylene glycol) (PPG). Although these polyesters possess similar chemical structure, they exhibit different phase behavior. Ternary blends including a high glass transition temperature (Tg) component were also studied. Crystallization kinetics in these blends was obtained utilizing Fourier transform infrared spectroscopy. Micro-Raman spectroscopy capable of achieving high spatial resolution (1 μm2) revealed detailed morphological differences in the phase-separated structures. This technique made possible for the first time characterization of the chemical composition of the blends and distribution of crystallites. The role of the third relative immobile component significantly changed both chemical distribution and the degree of crystallinity.
Treatment of 3‐Wall Intrabony Defects in Patients With Chronic Periodontitis With Autologous Platelet‐Rich Fibrin: A Randomized Controlled Clinical Trial
Authors: Sharma Anuj , Pradeep A.R. 
Published: April 2011

Background: Platelet‐rich fibrin (PRF) is considered a second‐generation platelet concentrate that is widely used in osseous regeneration. The present study aims to explore the clinical and radiographic effectiveness of autologous PRF in the treatment of intrabony defects in patients with chronic periodontitis.Methods: Fifty‐six intrabony defects were treated with either autologous PRF with open‐flap debridement or open‐flap debridement alone. Clinical parameters such as the probing depth (PD) and periodontal attachment level (PAL) were recorded at baseline and 9 months postoperatively. The defect fill at baseline and 9 months was calculated on standardized radiographs by using image‐analysis software.Results: The mean PD reduction was greater in the test group (4.55 ± 1.87 mm) than in the control group (3.21 ± 1.64 mm), whereas the mean PAL gain was also greater in the test group (3.31 ± 1.76) compared to the control group (2.77 ± 1.44 mm). Furthermore, a significantly greater percentage of mean bone fill was found in the test group (48.26% ± 5.72%) compared to the control group (1.80% ± 1.56%).Conclusions: Within the limits of the present study, there was greater PD reduction, PAL gain, and bone fill at sites treated with PRF with conventional open‐flap debridement compared to conventional open‐flap debridement alone. However, a long‐term, multicentered randomized controlled clinical trial is required to know the clinical and radiographic effects of PRF on bone regeneration.
Fibroblast Proliferation due to Exposure to a Platelet Concentrate: An in vitro Study
Authors: Ahuja Shelly 
Published: April 2011

ABSTRACT

Introduction
The major cellular events in the tissue repair are mitogenesis, migration and metabolism. The proteins responsible for coordination of these events are called “growth factors”. The activated platelets at the wound margins release several growth factors, such as PDGF, TGF-β and EGF, etc., and plasma exudates also provide an important source of TGF-β factors.

Materials and methods
Periodontal ligament fibroblast obtained from third molar impaction surgery, periodontal ligaments were cultured under standard conditions and spread on 96 well tissue culture plates. Platelet concentrate was obtained after centrifugation of 350-400 ml of blood at 1000 and 5000 rpm. 15 μl of platelet concentrate was added to each well. The proliferation rate of test and control group was determined by Redox indicator (Alamar blue® assay). The number of cells were counted by neu bar counting chamber after 24, 48 and 72 hours.

Results
The proliferation activity of cells was considerably higher in the platelet concentrate group (test group) than the control group. The difference was highly significant upto 72 hours after addition of platelet concentrates (Mann-Whitney U test p < 0.001).

Conclusion
A cellular effect of the platelet concentrate is clearly discernible. It was concluded that the use of platelet concentrate is an effective modality of regeneration.
Chronic Odontogenic Sinus Tracts associated with an Impacted Tooth: Report of Two Cases
Authors: Mathur Abhishek , Anup Kumar G , Ashwin DP , Gowda Lagna 
Published: April 2011

ABSTRACT
Odontogenic sinus tracts in the face and neck region are relatively uncommon and may present a diagnostic problem. As specific dental symptoms usually are absent in these cases, patients generally visit physician first for the evaluation and treatment because of the absence of dental symptoms. These cutaneous sinus tracts are most commonly located on the chin, cheek or in the submandibular area and rarely in the nasal region. Diagnostic errors can result in multiple surgical excisions and biopsies, long-term antibiotic therapy and even radiation therapy or electrodessication.1 The primary odontogenic disorder that results in such cutaneous lesions is typically a chronic periapical abscess or an impacted tooth or a root piece. We report two cases of extraoral sinus tracts, which were diagnosed as cutaneous sinus tracts of dental origin only after the failure of initial misdirected therapy.
A Propensity Score Matching Application: Indications and Results of Adding Scleral Buckle to Vitrectomy: The Retina 1 Project: Report 3
Authors: Sanabria María R. , Fernández Itziar , Sala-Puigdollers Anna , Rojas Jimena , Alfaiate Mario , Elizalde Javier , Navea Amparo , Cordoves Luis , Ruiz-Miguel Miguel , Diaz-Llopis Manuel , Coco Rosa M. , De La Rúa Enrique Rodríguez , Pastor José C. 
Published: April 2011

Purpose To identify the indications and differences in outcomes for adding a scleral buckle (SB) to pars plana vitrectomy (PPV) in a prospective series of rhegmatogenous retinal detachment (RD) by using propensity score matching (PSM) to analyze causal effects in observational studies. Methods Data were collected from the Retina 1 Project, a prospective, interventional, nonrandomized study of consecutive RDs. Case selection was based upon treatment with PPV or PPV+SB. Surgeons followed personal criteria for the inclusion of SB in the PPV. Propensity score matching corrected for selection biases. Outcomes were assessed by anatomic and visual criteria and the development of proliferative vitreoretinopathy. Results Of 523 patients analyzed, 251 had PPV and 272 had PPV+SB. Surgeons used PPV+SB more frequently in younger patients with RD, in those with posterior or unidentified breaks, in phakic eyes, in eyes with the posterior vitreous attached, and for more extended RDs. Overall single surgery anatomic success rate was 86.4%. Based on PSM, there were no difference in reattachment rates of the PPV group, 86.9%, and the PPV+SB group, 85.93%. The incidence of PVR was similar in both groups, with 8.5% in the PPV group and 10.5% in the PPV+SB group. Conclusions Data from the Retina 1 Project established the indications for adding SB to PPV in treating primary RD in this series. No anatomic or visual differences between PPV and PPV+SB were found.
Analysis of oxide and vanadate supports for catalytic hydrogen combustion: Kinetic and mechanistic investigations
Authors: Deshpande Parag A. , Polisetti Sneha , Madras Giridhar 
Published: March 2011

AbstractCombustion synthesized oxide and vanadate compounds (CeO2, Fe2O3, CeVO4, and FeVO4) were tested for catalytic hydrogen combustion. The compounds were characterized by X‐ray diffraction and X‐ray photoelectron spectroscopy. All the four compounds showed good activity and stability for catalytic hydrogen combustion and more than 95% conversion was observed over all the compounds within 500°C. The mechanisms for the reaction over the different classes of compounds (cerium‐based and iron‐based compounds) were proposed on the basis of spectroscopic observations. The main difference in the mechanisms was in the nature of adsorption of H2 over the sites. The elementary processes for the reaction were proposed, corresponding rate expressions were derived, and the rate parameters for the reaction were estimated using nonlinear regression. Langmuir‐Hinshelwood and Eley‐Rideal mechanisms were also tested for the reaction and the proposed mechanism was compared with these mechanisms. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Powder hydrophobicity and flow properties: Effect of feed frame design and operating parameters
Authors: Mendez Rafael , Muzzio Fernando J. , Velazquez Carlos 
Published: March 2011

AbstractThe effect of feed frames, a device used in rotary tablet presses to drive the powders into compression dies, on the properties of the powders entering the dies is systematically described in this article. The work focuses on the effect of blend composition, feed frame parameters (blade speed and residence time), and rotary die disc parameters (die disc speed and die diameter) on powder overlubrication, the flow properties of the blends, and the resulting tablet properties (tablet hardness and dissolution). For lubricated blends, the feed frame had a large impact on powder hydrophobicity and powder flow properties. Hydrophobicity results demonstrated that the shear applied by the feed frame caused overlubrication of the powders, which improved the powder flow properties but affected adversely the tablet hardness and dissolution. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Getting to value in neurological care: A roadmap for academic neurology
Authors: Holloway Robert G. , Ringel Steven P. 
Published: March 2011

AbstractAcademic neurology is undergoing transformational changes. The public investment in biomedical research and clinical care is enormous and there is a growing perception that the return on this huge investment is insufficient. Hospitals, departments, and individual neurologists should expect more scrutiny as information about their quality of care and financial relationships with industry are increasingly reported to the public. There are unprecedented changes occurring in the financing and delivery of health care and research that will have profound impact on the mission and operation of academic departments of neurology. With the passage of the Patient Protection and Affordable Care Act (PPACA) there will be increasing emphasis on research that demonstrates value and includes the patient's perspective. Here we review neurological investigations of our clinical and research enterprises that focus on quality of care and comparative effectiveness, including cost‐effectiveness. By highlighting progress made and the challenges that lie ahead, we hope to create a clinical, educational, and research roadmap for academic departments of neurology to thrive in today's increasingly regulated environment. Ann Neurol 2011;69:909–918
Modeling the tensile behavior of ultra‐high‐molecular‐weight polyethylene with a novel flow rule
Authors: Sweeney J. , Naz S. , Coates P. D. 
Published: March 2011

AbstractA study of the tensile behavior of ultra‐high‐molecular‐weight polyethylene over a range of strain rates showed that its strain rate sensitivity was a function of the strain. This was related to a flow rule developed for this material in a previous study on compressive behavior. This flow rule is an adaptation of that of Hill, in which the anisotropy coefficients are power‐law functions of the extension ratios. It is used in conjunction with an Eyring process. The observed rate dependence of the tensile behavior conformed with that obtained with the power‐law flow rule and could be used to derive a value of the power‐law coefficient. Independent observations were made of the relationship between the axial and transverse strains in tensile specimens with inhomogeneous strain fields. A constitutive model was developed that incorporates the new flow rule and was implemented in a finite element analysis. When this analysis was used to model the inhomogeneous tensile specimens, it gave predictions of the axial and transverse strain that were consistent with the experiment when the power‐law coefficient was the same value as that derived from the study of the rate dependence. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Modulation of barrier properties of monolayer films from blends of polyethylene with ethylene‐co‐norbornene
Authors: Taglialatela Scafati S. , Boragno L. , Losio S. , Limbo S. , Castellano M. , Sacchi M. C. , Stagnaro P. 
Published: March 2011

AbstractFlexible monolayer films with modulated diffusional and optical properties were achieved from blends of a LDPE/LLDPE matrix and an ethylene/norbornene copolymer (COC). A significant decrease of O2 and CO2 permeability was observed for cast films with COC content from 5 to 20 wt %. SEM analysis showed that, despite the incompatibility of the blend components, good dispersion and distribution of the COC domains in the PE matrix were achieved; as a consequence, for COC content ranging from 5 to 10 wt % the film transparency results practically unchanged. The UV light transmission decreased on increasing the percentage of COC, which constitutes also a protection against UV radiations. A noticeable improvement was observed in the mechanical properties: adding only 5 wt % of COC, the elastic modulus becomes five times higher than that of the PE matrix. The rheological behavior of the blends keeps practically unchanged with respect to the matrix, allowing to use the typical LDPE processing conditions. Sustainable inexpensive flexible films answering the packaging requirements of specific categories of food were achieved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A novel method for the preparation of spherical cellulose‐tungsten carbide composite matrix with NMMO as nonderivatizing solvent
Authors: Phottraithip Wimonrat , Lin Dong‐Qiang , Shi Fei , Yao Shan‐Jing 
Published: March 2011

AbstractN‐methylmorpholine‐N‐oxide (NMMO) was used as the nonderivatizing solvent for dissolving cellulose, and the cellulose‐tungsten carbide composite particles were prepared with water‐in‐oil suspension and cooling regeneration. Some key factors, such as dissolution temperature and time, water content, cellulose concentration, dispersion, and cooling were optimized. The solubility of cellulose in the NMMO solution was greatly dependent on the water content, which should be controlled at the range of 11 to 15 wt %. In addition, the influences of water content of the cellulose/NMMO/water solution on the properties of composite beads were studied, including bead size, wet density, and pore properties. It was found that 13 wt % water content was most appropriate. The expansion and liquid mixing properties of composite beads in an expanded bed were also explored. The results indicated that the cellulose composite beads prepared could be used as the matrix for expanded bed adsorption processes. Compared with the traditional technology with cellulose xanthate viscose, new method based on the NMMO dissolution is more environment‐friendly, reduces the process time and shows a potential application for large scale preparation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Coincorporation of nano‐silica and nano‐calcium carbonate in polypropylene
Authors: Zhang Shilian , Zhu Aiping , Dai Sheng 
Published: March 2011

AbstractIn this study, various polypropylene (PP) nanocomposites were prepared by melt blending method. The effects of different spherical nanofillers, such as 50 nm CaCO3 and 20 nm SiO2, on the linear viscoelastic property, crystallization behavior, morphology and mechanical property of the resulting PP nanocomposites were examined. Rheological study indicated that coincorporation of nano‐SiO2 and nano‐CaCO3 favored the uniform dispersion of nanoparticles in the PP matrix. Differential scanning calorimeter (DSC) and polarizing optical microscopy (POM) studies revealed that the coincorporation of SiO2 and CaCO3 nanoparticles could effectively improve PP crystallizability, which gave rise to a lower supercooling temperature (ΔT), a shorter crystallization half‐life (t1/2) and a smaller spherulite size in comparison with those nanocomposites incorporating only one type of CaCO3 or SiO2 nanoparticles. The mechanical analysis results also showed that addition of two types of nanoparticles into PP matrix gave rise to enhanced performance than the nanocomposites containing CaCO3 or SiO2 individually. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011