bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes induced by chronic in vivo load alteration in the tibiofemoral joint of mature rabbits
Authors: Roemhildt Maria L. , Beynnon Bruce D. , Gardner‐Morse Mack , Badger Gary , Grant Calsey 
Published: February 2012

AbstractWe investigated the relationship between the magnitude and duration of chronic compressive load alteration and the development and progression of degenerative changes in the rabbit tibiofemoral joint. Varus loading devices were attached to the hind limb of mature NZW rabbits. Altered compressive loads of 0%, 50%, and 80% body weight (BW) were applied to the tibiofemoral joint for 12 h per day for 12 and 24 weeks (n = 4 animals/group). Compartment‐specific assessment of the tibial plateau included histological assessments (articular cartilage, calcified cartilage, and subchondral bone thicknesses, degeneration score, and articular cartilage cellularity) and biomechanical measures (aggregate modulus, permeability, Poisson's ratio). Analyses of variance techniques were used to examine the relationship between each outcome measure with load magnitude and duration as independent variables in the model. Degenerative changes developed in the medial compartment with increased magnitude of compressive loading and included fibrillation, increased degeneration score, and reduced cellularity of the articular cartilage. Increased calcified cartilage thickness was observed in both the medial and lateral compartments following exposure to altered loading of 80% BW for 24 weeks. This work demonstrates that in vivo chronic compressive load alteration to the tibiofemoral joint can initiate progressive macroscopic and histological‐based degenerative changes analogous to the early changes occurring in OA. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1413–1422, 2012
Collaborative Marketing in a Regional Destination: Evidence from Central Florida
Authors: Wang Youcheng , Hutchinson Joe , Okumus Fevzi , Naipaul Sandra 
Published: February 2012

ABSTRACTThis paper aims to explore a collaborative approach to regional destination marketing. Research questions were constructed for empirical data collection via documentary analysis and semistructured interviews with senior executives of destination marketing organizations (DMOs) in the Central Florida region. The research findings suggest that collaboration among DMOs is beneficial in terms of cost reduction and market penetration. Several issues emerge as inhibiting factors to their collaborative destination marketing efforts. Discussions and implications are provided both from a theoretical and practical perspective on the basis of the findings of the study. Copyright © 2012 John Wiley & Sons, Ltd.
Seaside sparrow reproductive success in relation to prescribed fire
Authors: Kern Rebecca A. , Shriver W. Gregory , Bowman Jacob L. , Mitchell Laura R. , Bounds Dixie L. 
Published: February 2012

AbstractIn North American tidal marshes, prescribed burning has been used to manage waterfowl, furbearers, invasive plants, and fuels, but its effects on non‐target species, such as marsh birds, are relatively unknown, particularly in the mid‐Atlantic region. To address this informational need, we studied seaside sparrows (Ammodramus maritimus) in Dorchester County, Maryland, where prescribed marsh burning has been conducted since at least the 1930s. We compared the effects of 4 fire treatments (<1 yr since burn, 1–2 yr since burn, 3–4 yr since burn, and ≥5 yr since burn) on seaside sparrow density and reproductive output, and examined the impact of fire treatment, nest‐site characteristics, and weather on nest survival from 2007 to 2009. We found that nest and territory densities were greatest on marshes <1 year post‐burn, indicating that burning did not displace seaside sparrows. Nest and territory densities also declined as time since burn increased, and were about 50% less on marshes that were ≥5 years post‐burn compared to marshes <1 year post‐burn. Egg density (the number of eggs produced per ha) was 50% greater on marshes burned <1 year ago than on marshes burned 3–4 years ago, but we found no difference in fledgling density, indicating that predation may have disproportionately affected recently‐burned marshes. Study year and percent cover of smooth cordgrass (Spartina alterniflora) best explained nest survival, which was lowest in 2009, a year with high precipitation and tides. We recommend that prescribed burning continue to be used at 1–4 year intervals to maintain habitat quality for breeding seaside sparrows in the mid‐Atlantic, but suggest that the effects of fire management may be less influential than predicted impacts of global climate change. © 2012 The Wildlife Society.
Estimating breeding season abundance of golden‐cheeked warblers in Texas, USA
Authors: Mathewson Heather A. , Groce Julie E. , Mcfarland Tiffany M. , Morrison Michael L. , Newnam J. Cal , Snelgrove R. Todd , Collier Bret A. , Wilkins R. Neal 
Published: February 2012

AbstractPopulation abundance estimates using predictive models are important for describing habitat use and responses to population‐level impacts, evaluating conservation status of a species, and for establishing monitoring programs. The golden‐cheeked warbler (Setophaga chrysoparia) is a neotropical migratory bird that was listed as federally endangered in 1990 because of threats related to loss and fragmentation of its woodland habitat. Since listing, abundance estimates for the species have mainly relied on localized population studies on public lands and qualitative‐based methods. Our goal was to estimate breeding population size of male warblers using a predictive model based on metrics for patches of woodland habitat throughout the species' breeding range. We first conducted occupancy surveys to determine range‐wide distribution. We then conducted standard point‐count surveys on a subset of the initial sampling locations to estimate density of males. Mean observed patch‐specific density was 0.23 males/ha (95% CI = 0.197–0.252, n = 301). We modeled the relationship between patch‐specific density of males and woodland patch characteristics (size and landscape composition) and predicted patch occupancy. The probability of patch occupancy, derived from a model that used patch size and landscape composition as predictor variables while addressing effects of spatial relatedness, best predicted patch‐specific density. We predicted patch‐specific densities as a function of occupancy probability and estimated abundance of male warblers across 63,616 woodland patches accounting for 1.678 million ha of potential warbler habitat. Using a Monte Carlo simulation, our approach yielded a range‐wide male warbler population estimate of 263,339 (95% CI: 223,927–302,620). Our results provide the first abundance estimate using habitat and count data from a sampling design focused on range‐wide inference. Managers can use the resulting model as a tool to support conservation planning and guide recovery efforts. © 2012 The Wildlife Society.
Calcium carbonate composite hydrogel films: Particle packing and optical properties
Authors: Guvendiren Murat , Soshinski Andre A. , Gambogi Robert J. , Yang Shu 
Published: February 2012

AbstractComposite hydrogel films are prepared by photocrosslinking of partially polymerized poly(2‐hydroxyethyl methacrylate‐co‐methyl methacrylate) prepolymer solution dispersed with aragonite precipitated calcium carbonate (PCC) particles. The effects of PCC aspect ratio (AR, 4.2–6.6) and volume fraction (ϕPCC) are studied with respect to the prepolymer viscosity, the maximum packing fraction (ϕm), and optical properties. ϕmobtained from Kreigher–Dougherty fitting is found to decrease with increasing AR of PCC particles, from ϕm= 0.33 (AR = 4.2) to ϕm= 0.21 (AR = 6.6). Scanning electron microscopy images revealed that the particles are uniformly dispersed and randomly orientated in the polymer network when ϕPCC< ϕm. Optically transparent neat hydrogel films become opaque with increasing particle concentration and AR because of random light scattering from the PCC particles. A whiteness up to 80 is obtained from 100 μm thick composite hydrogel film in the wet state with PCC AR = 6.6 and ϕPCC= 0.19 (near ϕm). POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
The rheological, thermostable, and mechanical properties of polypropylene/fullerene C60 nanocomposites with improved interfacial interaction
Authors: Wan Dong , Wang Yujie , Wen Xin , Qiu Jian , Jiang Zhiwei , Tan Haiying , Tang Tao 
Published: February 2012

AbstractPolypropylene (PP)/C60 nanocomposites with improved interfacial interaction were prepared via in situ melt radical reaction. It was found that the relaxation time of PP/C60 nanocomposites containing peroxide increased due to the reaction between C60 and PP macroradicals and the formation of long chain branched or crosslinking structure. Thermogravimetric analysis (TGA) results showed that the thermal stability of PP/C60 nanocomposites was enhanced. The initial decomposition temperatures and activation energy of PP/C60 nancomposites were strongly influenced by the content of unreacted C60. Because of the improved interfacial interaction, PP/C60 nanocomposites containing peroxide showed obvious increase in tensile strength, Young' modulus, flexural strength, flexural modulus, and impact strength, compared to PP/C60 nanocomposites (without peroxide) containing the same content of C60. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
A new microcellular injection molding process for polycarbonate using water as the physical blowing agent
Authors: Peng Jun , Turng Lih‐Sheng , Peng Xiang‐Fang 
Published: February 2012

AbstractThis article presents a new process for producing microcellular injection molded plastic parts using water as the physical blowing agent and micro‐scaled particles as the cell nucleating agents. Distilled water with dissolved salt were fed through the hopper of an injection molding machine at a preset rate and mixed with polycarbonate (PC) in the machine barrel. Microcellular PC tensile bars were then injection molded with different shot volumes, water/salt solution feed rates, and salt concentrations. Tiny salt crystals of 10–20 μm recrystallized during molding acted as nucleating agents in the PC foamed parts. The surface roughness, mechanical properties, and microstructure of the solid and foamed parts were measured and compared with microcellular injection molded parts using supercritical fluid (SCF) nitrogen as the physical blowing agent. At a similar weight reduction of about 10%, the water foamed PC parts have a smooth surface comparable to that of solid injection molded parts. They also possess similar, if not better, mechanical properties compared to SCF nitrogen foamed PC parts. Without the nucleating agent, PC/water foamed parts exhibit much larger and fewer bubbles within the molded parts. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Preparation and characteristics of a novel nano‐sized calcium carbonate (nano‐CaCo3)‐supported nucleating agent of poly(L‐lactide)
Authors: Han Lijing , Han Changyu , Bian Junjia , Bian Yijie , Lin Haijuan , Wang Xuemei , Zhang Huiliang , Dong Lisong 
Published: February 2012

AbstractNano‐sized calcium carbonate (nano‐CaCO3)‐supported nucleating agent for poly(L‐lactide) (PLLA) was prepared by supporting calcium phenylphosphonate (PPCa) on nano‐CaCO3 surface. The thermal properties of phenylphosphonic acid (PPOA) and nano‐CaCO3‐supported nucleating agent and its dispersion in PLLA matrix were investigated by differential scanning calorimetry and field emission scanning electron microscopy. The results indicated that the formation of nucleating agent supported on nano‐CaCO3 was attributed to the chemical reaction between nano‐CaCO3 and PPOA. The nano‐CaCO3‐supported nucleating agents were dispersed evenly in the PLLA matrix even with 5 wt% loading. The supported nucleating agent was added to PLLA to examine its nucleating ability for PLLA. The results of the investigation showed that the nano‐CaCO3‐supported nucleating agent exhibited higher nucleation ability compared to PPCa nucleating agent. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
New Takes on Nitrate Ester Chemistry: Salts with Oxygen‐Rich Ammonium Cations
Authors: Drake Gregory W. , Bolden Sarah , Dailey Jami , McQuaid Michael J. , Parrish Damon 
Published: February 2012

AbstractNitrate (anion) salts with nitroxy‐functionalized ammonium cations were synthesized. Several revealed surprising thermal and hydrolytic stability. Various physical properties were measured, and Gibbs free energy (ΔGr(298)) differences between the salts and postulated products of their thermal decomposition were computed. The computed differences indicate that salts with cations that have more than one nitroxy group are endothermic at 298 K. Nevertheless, the stability observed for some salts with this property indicates that kinetic barriers are sufficient to prevent facile decomposition at this temperature. This is in contrast to the case observed for nitrate salts of nitroxy‐functionalized ammonium cations with acidic protons.
Vapor Pressure of Explosives: A Critical Review
Authors: Östmark Henric , Wallin Sara , Ang How Ghee 
Published: February 2012

AbstractA critical review of vapor pressure data for military, civilian, and homemade explosives, explosive precursors, and explosive taggants is presented. It gives reference to a large number of papers and reports presenting original vapor pressure measurements and additionally an overview of measurements techniques for vapor pressure measurements and data analysis of vapor pressure measurements. Vapor pressure data, including Clausius–Clapeyron parameters (A and B in: log10(p)=A−B/T), calculated vapor pressure at room temperature, and heat of sublimation or heat of vaporization are included. The following classes of compounds are treated; military explosives (TNT, RDX, HMX, PETN, HNS, TATB, AP), civilian explosives (NG, EGDN, AN), explosive taggants (EGDN, DNMB, 2‐NT, 4‐NT), home‐made explosives (TATP, DADP, HMTD). and explosive precursors [HP(aq), NM, IPN, DNT].
Explosion of fixed roof atmospheric storage tanks, part 3: Gas explosion and structural response simulations
Authors: Taveau Jérôme , Moras Benoît 
Published: February 2012

AbstractMany flammable products are stored in large tanks at atmospheric pressure. Ignition of a hydrocarbon–air mixture in such tanks can lead to an explosion and cause lethal casualties or damage the surrounding facilities and buildings. To apprehend this, safety distances for humans, structures, and equipments need to be defined. Several simple methodologies have been set up to estimate safety distances in case of an atmospheric storage tank explosion.This third and last article concerning fixed roof atmospheric storage tank explosions focuses on numerical modeling, including gas explosion and structural response simulations.Three‐dimensional gas explosion simulations using the CFD code FLACS have been performed to define a typical pressure load profile to apply on the inner side of the tank shell. Then, the structural response of the tank (deformation and displacement), under the loading conditions previously obtained, has been computed with LS–DYNA.Consequently, the findings question some of the assumptions used in analytical methods described previously.The specific input data needed to obtain a reasonably conservative estimation of the safety distances have been identified. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2012
Growth of AlN bulk single crystals on 4H‐SiC substrates and analyses of their structural quality and growth mode evolution
Authors: Sumathi R. R. , Barz R. U. , Gigler A. M. , Straubinger T. , Gille P. 
Published: February 2012

AbstractAluminium nitride (AlN) bulk single crystals were grown on off‐oriented 4H‐SiC substrates by the sublimation method. High‐quality crystals with about 25 mm in diameter and up to 5 mm in thickness were obtained with an optimized growth process. The crystals show hexagonal symmetry with well developed {10$\overline {1} $1} side facets. Confocal‐Raman spectroscopy and double‐crystal X‐ray diffraction rocking curve (DCXRD‐RC) measurements confirm the high structural quality of the grown crystals. In Raman spectroscopy, the full‐width at half maximum (FWHM) of E2(high) phonon mode decreases from 40 cm−1 for thin layers (800 µm) to 22 cm−1 for a 5 mm thick crystal, showing the improvement in quality with thickness. The DCXRD rocking curve FWHM obtained for a 5 mm thick crystal is about 120 arcsec. A basal plane bending of 100 arcsec is observed by rocking curve measurements while scanning 17 mm of the sample's diameter. Two kinds of growth modes namely, step flow growth and spiral growth modes were observed under similar growth conditions. This may be attributed to a slight variation of super‐saturation in the gas phase. In both cases, a single active hexagonal growth centre is formed. As‐grown surfaces have been found to be always Al‐polar. Wet chemical etching revealed both, threading type and basal‐plane dislocations (BPD) on the surfaces of the samples with total etch pit densities (EPDs) in the range of 8 × 105–1 × 106 cm−2.
Multiangle combined magnetic‐field annealing of Co‐based amorphous microwires for sensor applications
Authors: Liu Jing‐Shun , Zhang Da‐Yue , Cao Fu‐Yang , Xing Da‐Wei , Chen Dong‐Ming , Xue Xiang , Sun Jian‐Fei 
Published: February 2012

AbstractThe effect of multiangle combined magnetic‐field annealing (MCMFA) on the GMI performance of melt‐extracted Co‐based amorphous microwires for sensor applications is studied using a precision impedance analyzer. Experimental results indicated that MCMFA treatment can effectively improve the GMI effect comparing with as‐cast and conventional vacuum‐annealed (CVA) wires. The maximum GMI ratio [ΔZ/Zmax]max and field response sensitivity ξmax of transverse combined magnetic‐field annealed (TCMFA, α = 90°) wires can be increased at 10 MHz to 310.7 and 30.91%/Oe, respectively, through with circumferential anisotropy field expanded and GMI changed from single peak (SP) to double peaks (DPs). DPs behavior of TCMFA wire is due to the typically “nail‐sticked” action of magnetic moment rotation at relatively high frequency (up to ≥1 MHz). It can therefore be concluded that MCMFA could be used to develop Co‐based microwires with enhanced GMI effect for high‐resolution sensor applications.
Formation of defects in cubic GaN grown on nano‐patterned 3C‐SiC (001)
Authors: Kemper R. M. , Häberlen M. , Schupp T. , Weinl M. , Bürger M. , Ruth M. , Meier C. , Niendorf T. , Maier H. J. , Lischka K. , As D. J. , Lindner J. K. N. 
Published: February 2012

AbstractWe report an anisotropic formation of defects in cubic GaN grown on nano‐patterned 3C‐SiC/Si (001) by molecular beam epitaxy. Nano‐patterning of 3C‐SiC/Si (001) is achieved by nanosphere lithography and a reactive ion etching process. Atomic force microscopy and scanning electron microscopy show that the selective‐area‐grown cubic GaN nucleates in two structurally different domains, which most probably originate from the substrate. In adjacent domains the formation of defects, especially hexagonal inclusions, is different and leads to two different surface morphologies. The dominant phase within these domains was measured by electron backscatter diffraction. Optical properties were investigated by micro‐photoluminescence and cathodoluminescence spectroscopy (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and characterization of high‐k aluminium nitride (AlN) thin film for sensor and integrated circuits applications
Authors: Souza J. F. , Moreira M. A. , Doi I. , Diniz J. A. , Tatsch P. J. , Gonçalves J. L. 
Published: February 2012

AbstractIn last years considerable interest has been shown in aluminium nitride (AlN) films because of their optical, electrical, dielectric and acoustic properties. Owing to these characteristics, AlN thin films are suitable for the use in micro‐electronic applications. In this work, AlN thin films were deposited on p‐Si(100) and SiO2/p‐Si(100) substrates by dc reactive magnetron sputtering technique under the same deposition conditions (500 W of discharge power, 30 sccm N2 flow, 80 sccm Ar flow and deposition pressure of 3x10‐3 Pa). These conditions were defined by prior analysis in order to achieve films with smooth surface morphology, hexagonal wurtzite phase, and refractive index compatible with polycrystalline AlN films (between 2.0 and 2.2). The films were physically characterized using a variety of techniques such as atomic force microscopy (AFM), X‐ray diffraction spectroscopy (XRD), Fourier infrared spectroscopy (FTIR) and ellipsometry. Electrical characteristics of films were compared by using metal‐insulator‐semiconductor (MIS) structures. Using a set of metal insulator semiconductor field effect transistors (MISFETs) and electrolyte‐insulator‐semiconductor field effect transistors (EISFETs) fabricated, electrical characteristics and sensing properties were investigated. The electrical quality of the AlN film and AlN/SiO2/p‐Si interface obtained suggests that AlN is an adequate insulator on silicon device and pH sensors application (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stable structure of di‐amino‐terphenyl molecule on Si(001) surfaces
Authors: Oda Masato 
Published: February 2012

AbstractThe adsorption structures of 4,4''‐di‐amino‐terphenyl (DAT) on Si(001) surfaces are investigated using density functional theory. Comparison of the total energies of two adsorption models with that of a non‐adsorbed model reveals that the DAT molecule is stable when it is tilted at about 17° relative to the Si(001) dimer line. There are three important interactions between a DAT molecule and a Si surface: the center phenyl ring forms a butterfly‐like bond with a Si dimer and the two terminal amino groups covalently bond to a Si atom of a dimer. To form these three stable bonds, the DAT molecule needs to be tilted at about 17° relative to the Si(001) dimer line. These results agree with experimental results. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)