bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas permeability and mechanical properties of PDMS mixed with PMPS nanofibers produced by electrospinning
Authors: Nakano Atsushi , Miki Norihisa , Hishida Koichi , Hotta Atsushi 
Published: March 2012

ABSTRACTPolymethylphenylsilicone (PMPS), a siloxane polymer with a phenyl group, was first successfully electrospun to fabricate different diameters of silicone fibers ranging from 500 nm to 10 μm by considering solubility parameters of 12 different solvents. The resulting PMPS fibers were mixed with polydimethylsiloxane (PDMS) by retaining their original nanofiber structures to produce a polysiloxane-based nanofibrous composite. As for the mechanical properties, the PMPS/PDMS composite presented higher Young’s modulus and higher fracture strain than pure PDMS. The gas permeability test revealed that the PMPS/PDMS composite exhibited higher CO2 permeability than the pure PDMS membrane. Moreover, CO2 permeability gradually increased by raising the compounding ratio of PMPS-fibers in the PMPS/PDMS composite and by decreasing the diameter of PMPS-fibers. The enhancement mechanism observed in both mechanical properties and CO2 permeability was discussed from the viewpoint of the interface between PMPS and PDMS along with the nanofiber network structures.
Multi-Frequency Atomic Force Microscopy Combining Amplitude- and Frequency-Modulation Techniques
Authors: Solares Santiago D. , Chawla Gaurav 
Published: March 2012

ABSTRACTMulti-frequency atomic force microscopy (AFM) offers additional response signals in comparison to traditional dynamic AFM. Furthermore, depending on the mode of operation used, the higher eigenmode responses are generally not directly influenced by the topographical acquisition control loops, such that they can explore a fuller range of tip-sample interactions. In this work we describe the implementation of multi-frequency imaging schemes that enable the acquisition of topographical, phase and frequency shift contrast in tapping-mode operation. This type of characterization can be especially useful for soft, highly dissipative samples, such as polymers, for which the various response channels can exhibit significantly different response, thus providing complementary information. We discuss typical results obtained as well as important challenges that need to be addressed in order to develop a fully quantitative technique.
Nanoscale Dynamic Viscoelastic Measurements at Elevated Temperature
Authors: Ye Jiping , Shimizu Satoshi 
Published: March 2012

ABSTRACTA nanoscale dynamic mechanical analysis (nano-DMA) measurement method has been successfully developed for use in evaluating nanoscale dynamic viscoelastic properties in small-scale polymer materials over a range of non-ambient temperatures from -120 oC to 500 oC. Measurements have been obtained with a nanoindentation measurement system, in which two key techniques are applied. One is a thermal protection system for control and prevention of thermal drift and noise. The other is an environmental control system for preventing corrosion at high temperatures and dew condensation at low temperatures. Measurement reliability was examined by using a combination of a thermal-mechanically stable fused silica and a homogeneous sample of isotropic polyethylene terephthalate (PET). Constant hardness and modulus values of the fused silica from -120 oC to 500 oC indicated that the measurements were not affected by thermal load drift and noise even at elevated temperatures. The PET sample exhibited no significant difference in temperature dispersions of storage elastic modulus, loss elastic modulus and loss tangent between the nanoindentation measurement data and bulk data measured with a conventional DMA method. A practical application involving surface-deteriorated polyethylene (PE) tubes was used to demonstrate the validity and usefulness of this nano-DMA method. Infrared spectroscopic imaging revealed that the surface layer of the PE tubes was oxidized to form a carbonylated (O=C<) layer. The storage elastic modulus and glass-transition temperature of the surface layer were much higher than the corresponding values of the interior. These data indicate a plausible reason for why the PE tube surface deteriorates to form brittle cracks.
Field Emission Device Made from Multiwalled Carbon Nanotube Sheet
Authors: Van Hai H. , Zhang Mei , Wang Ben , Zhang Chuck 
Published: March 2012

ABSTRACTA new type of cathode for electron field emission (FE) was fabricated. The cathode was made from ultra-thin multiwalled carbon nanotube (CNT) sheets. These sheets were drawn directly from a CNT forest, stacked layer-by-layer together and densified by isopropyl alcohol. CNT emitters were formed by utilizing laser beam to cut the sheet. The FE performance of the proposed devices has been enhanced dramatically. The threshold field for electron emission (at which the emission current is 10 mA/cm2) was 0.88 V/μm. The current density of 36 A/cm2 was achieved at the electric field of 2 V/μm. The enhanced performance is the result of the thin, uniformly distributed and aligned array of the CNT emitters.
Nonlinear Dielectric and Piezoelectric Responses in (Bi, La)FeO3-Pb(Ti, Mn)O3 Ceramics
Authors: Shi Guiyang , Bu Shundong , Dai Rui , Yu Shengwen , Cheng Jinrong 
Published: March 2012

ABSTRACTPolycrystalline solutions of 0.6(Bi0.9La0.1)FeO3-0.4Pb(Ti1-xMnx)O3(BLF-PTM, x=0 and 0.01)have been fabricated by the so-gel process combined with a solid state reaction method. BLF-PTM exhibits the nonlinear dielectric and piezoelectric responses under applied fields. Rayleigh law has been used to evaluate the irreversible contribution of the domain walls movement to the nonlinear dielectric response. Rayleigh analysis reveals that a mechanism with no associated loss exists in the BLF-PTM of x=0.01. The real part piezoelectric coefficient of BLF-PTM linearly increases with increasing the electric fields. The dielectric and piezoelectric nonlinear coefficient of 0.17×10-3 m/V and 0.897 ×10-17 m2/V2 respectively are obtained for BLF-PTM of x=0.01,which are smaller than those of 0.22×10-3 m/V and 1.19 ×10-17 m2/V2 for BLF-PTM of x=0. Our results indicate that Mn doping increase the intrinsic piezoelectric properties of BLF-PTM reducing the extrinsic contributions to piezoelectric responses.
Abundance and extinction in Ordovician–Silurian brachiopods, Cincinnati Arch, Ohio and Kentucky
Authors: Zaffos Andrew , Holland Steven M. 
Published: March 2012

A basic hypothesis in extinction theory predicts that more abundant taxa have an evolutionary advantage over less abundant taxa, which should manifest as increased survivorship during major extinction events and longer fossil-record durations. Despite this, various paleontologic studies have found conflicting patterns, indicating a more complex relationship between abundance and extinction in the geologic past. This study tests the relationship between abundance and extinction among brachiopod genera within seven third-order depositional sequences spanning the Late Ordovician to Early Silurian (Katian–Aeronian) of the Cincinnati Arch.Contrary to predictions, abundance is not positively correlated with duration in this study. Abundance and duration range from strongly negatively correlated to uncorrelated depending on the spatial scale of analysis and the geologic intervals included, but correlations never indicate that abundance is an evolutionary advantage. In contrast, abundance was an advantageous trait prior to the Ordovician/Silurian extinction, and brachiopods with higher abundances were more likely to survive the event than less abundant brachiopods. While this result is in keeping with common models of extinction, it has not been observed previously at a mass extinction boundary. This may be further evidence that the Ordovician/Silurian extinction was not accompanied by a shift in the macroevolutionary selectivity regime.
Risk Factors for Dialysis Withdrawal
Authors: Chan Hoi Wong , Clayton Philip A. , McDonald Stephen P. , Agar John W.M. , Jose Matthew D. 
Published: March 2012

Summary

Background and objectives
Dialysis withdrawal (DW) in patients with ESRD is increasing in importance. This study assessed causes of death and risk factors for DW in Australia and New Zealand in the first year of dialysis.

Design, setting, participants, & measurements
This retrospective observational cohort study included all adult Australians and New Zealanders beginning renal replacement therapy in 1999–2008.

Results
A total of 24,884 patients with 10,073 deaths were included. Deaths from cardiac and social causes (predominantly DW) accounted for 38% and 28% of all deaths, respectively. Cumulative incidence of DW was 3.5% at 1 year (95% confidence interval [CI], 3.3%–3.8%), 9.0% at 3 years (95% CI, 8.6%–9.4%), and 13.4% at 5 years (95% CI, 12.8%–13.9%). In multivariate analysis, predictors for DW in the first year were older age (subhazard ratio [SHR], 1.70 per decade [95% CI, 1.59–1.83]; P<0.001), late referral (SHR, 1.83 [95% CI, 1.59–2.11]; P<0.001), comorbid conditions (SHR, 1.33 per each additional comorbid condition [95% CI, 1.25–1.41]; P<0.001), and diabetes (SHR, 1.16 [95% CI, 1.00–1.34]; P=0.05). Negative predictors for DW included male sex (SHR, 0.75 [95% CI, 0.66–0.87]; P<0.001), indigenous ethnicity (SHR, 0.74 [95% CI, 0.58–0.95]; P=0.02), other nonwhite race (SHR, 0.66 [95% CI, 0.48–0.91]; P=0.01), and peritoneal dialysis user (SHR, 0.59 [95% CI, 0.49–0.72]; P<0.001).

Conclusions
DW is common among dialysis patients in Australia and New Zealand. Risk factors include older age, female sex, white race, diabetes, higher comorbidity burden, hemodialysis user, and late referral to nephrologist.
Thermodiffusion motion of electrically charged nanoparticles
Authors: Mezulis Ansis , Maiorov Mikhail , Petricenko Oksana 
Published: March 2012

Abstract
The present work deals with experimental studies to examine the theoretical model of thermodiffusion of electrically charged nanoparticles. Three different ionic magnetic colloid samples have been synthesized and profoundly analyzed. The theoretical model is a classical one, based on the calculation of the temperature and the electric potential distribution around nanoparticles. The discrepancy between experimental data and theory turns out not to exceed 20%. We focus on applying different approximations between calculated electrical double layer in the theoretical model and experimental determination of the surface charge density of colloidal particles. We assume this is the main reason for obtained discrepancy.
Patellofemoral Pain: Proximal, Distal, and Local Factors—2nd International Research Retreat, August 31–September 2, 2011, Ghent, Belgium
Authors: Powers Christopher M. , Bolgla Lori A. , Callaghan Michael J. , Collins Natalie , Sheehan Frances T. 
Published: March 2012

Patellofemoral pain (PFP) is one of the most common lower extremity conditions seen in orthopaedic practice. The mission of the second International Patellofemoral Pain Research Retreat was to bring together scientists and clinicians from around the world who are conducting research aimed at understanding the factors that contribute to the development and, consequently, the treatment of PFP. The format of the 2.5-day retreat included 2 keynote presentations, interspersed with 6 podium and 4 poster sessions. An important element of the retreat was the development of consensus statements that summarized the state of the research in each of the 4 presentation categories. In this supplement, you will find the consensus documents from the meeting, as well as the keynote addresses, schedule, and platform and poster presentation abstracts. J Orthop Sports Phys Ther 2012;42(6):A1–A54. doi:10.2519/jospt.2012.0301
Suggestions From the Field for Return to Sports Participation Following Anterior Cruciate Ligament Reconstruction: Soccer
Authors: Bizzini Mario , Hancock Dave , Impellizzeri Franco 
Published: March 2012

Synopsis Successful return to play remains a challenge for a soccer player after anterior cruciate ligament reconstruction. In addition to a successful surgical intervention, a soccer-specific functional rehabilitation program is essential to achieve this goal. Soccer-like elements should be incorporated in the early stages of rehabilitation to provide neuromuscular training specific to the needs of the player. Gym-based and, later, field-based drills are gradually intensified and progressed until the player demonstrates the ability to return to team practice. In addition to the recovery of basic attributes such as mobility, flexibility, strength, and agility, the surgically repaired knee must also regain soccer-specific neuromuscular control and conditioning for an effective return to sports. The individual coaching of the player by the sports physiotherapist and compliance with the training program by the player are key factors in the rehabilitation process. To minimize reinjury risk and to maximize the player's career, concepts of soccer-specific injury prevention programs should be incorporated into the training routine during and after the rehabilitation of players post-ACL reconstruction. Level of Evidence Therapy, level 5.
Suggestions From the Field for Return to Sports Participation Following Anterior Cruciate Ligament Reconstruction: American Football
Authors: Verstegen Mark , Falsone Susan , Orr Russell , Smith Steve 
Published: March 2012

Synopsis Returning an American football player to sport after an anterior cruciate ligament reconstruction is challenging on several fronts. First, there are approximately 15 different positions a football player could play, depending on how specifically you define the positions on the field. Each of these positions has specific demands for optimal size, strength, power, body composition, cardiovascular fitness, and movement. Understanding all of these factors is paramount to returning a football player not only to his sport but also to his specific position. Second, the chaotic, contact-rich nature of the sport requires that heavy demands be placed on the lower extremities to attenuate external contact forces from other players and from ground reaction forces associated with accelerating, decelerating, quick stops and starts, and changing direction. Finally, return to a competitive level of performance is further influenced by playing surface, shoe selection, the equipment the player wears, and various potential psychosocial factors. It is the responsibility of the clinician to provide a progressive and systematic rehabilitation program by first introducing preprogrammed movements that, once mastered, are progressed with elements of more reactive and random movement patterns. The precise nature of this systematic progression of advanced rehabilitation is key in developing return-to-play criteria and, ultimately, in readying an American football player for eventual return to sport and a particular position. Level of Evidence Therapy, level 5.
Characteristics of two mountain lion Puma concolor populations in Texas, USA
Authors: Harveson Patricia Moody , Harveson Louis A. , Hernandez‐Santin Lorna , Tewes Michael E. , Silvy Nova J. , Pittman Michael T. 
Published: March 2012

Influential factors associated with population dynamics of mountain lions Puma concolor include exploitation rates, prey availability, habitat structure and social structure. Throughout most of North America, mountain lion harvest is regulated by state or provincial quotas or is protected by federal laws. In Texas, however, they are not classified as a game or fur‐bearing animal so their harvest is not regulated. To better understand the differences between population characteristics of mountain lions in west Texas (WTX) and south Texas (STX), we initiated two ecological studies. We captured, radio‐marked and monitored mountain lions to ascertain survival, mortality factors, density, reproduction and population structure. We captured and monitored 19 and 21 mountain lions in the STX and WTX study sites, respectively. Average densities (No/100 km2) were different between our two study sites (STX = 0.269, WTX = 0.427) and were considerably lower than in previous studies. Mortality factors also differed between the two areas; in STX the causes were predominantly hunter harvest compared to trapping in WTX. Seasonal survival rates of mountain lions were lower during the general hunting season (STX = 0.783, WTX = 0.750) than during the non‐hunting season (STX = 0.962, WTX = 0.931). Because population characteristics differed between the two genetically separated populations (Walker et al. 2000), resource managers should consider evaluating regional, rather than statewide management plans for mountain lions in Texas.
Seed removal and survival in Asiatic black bear Ursus thibetanus faeces: effect of rodents as secondary seed dispersers
Authors: Koike Shinsuke , Morimoto Hideto , Kozakai Chinatsu , Arimoto Isao , Yamazaki Koji , Iwaoka Masahiro , Soga Masashi , Koganezawa Masaaki 
Published: March 2012

We investigated the fate of seeds of five tree species hill cherry Prunus jamasakura, Korean hill cherry P. verecunda, Japanese bird cherry P. grayana, giant dogwood Swida controversa and crimson glory vine Vitis coignetiae in the faeces of the Asiatic black bear Ursus thibetanus in a temperate forest in central Japan. Clarifying the fate of seeds dispersed by endozoochorous seed dispersers will enhance assessments of their roles as primary seed dispersers. We established several experimental treatments in the field. Each faeces sample was covered by cages with different mesh sizes which limited accessibility by animals (NM: no mesh, SM: 1 mm mesh and MM: 10 mm mesh). We examined whether seed removal varied among tree species and between mesh‐size treatments from 2004 to 2007 (N = 625 samples). We set up an automatic camera trap 1.5 m above the ground at all NM treatments. In the NM treatments, the number of seeds of all tree species decreased immediately after the faeces were set. In June of the following year, < 1% of the seeds from any species remained in the vicinity of the faeces. However, we found 3.0‐13.2% intact seeds of all species in the soil below the faeces, as well as within a 10‐m radius around the faeces. In the NM treatments, most seed removals were observed within four days after the faeces were set. For all tree species in the MM treatment, most of the seeds were present on the surface of the soil, and 1‐2% of the seeds germinated at the location where faeces were set. In the SM treatment, none of the seeds from any of the tree species disappeared and germinated. We took a total of 415 photographs at the NM sites, 97.8% of which were of rodents either holding or eating seeds. Many of the seeds contained in the bear faeces were removed and eaten by rodents. However, 2.1‐5.1% of the seeds survived and germinated, which implies that rodents may also act as secondary seed dispersers.
Biological evaluation of micro-nanoporous layer on Ti–Ag alloy for dental implant
Authors: Moon Seung-Kyun , Kim Chong-Kwan , Joo Uk-Hyon , Oh Keun-Taek , Kim Kyoung-Nam 
Published: March 2012

Abstract
This study examined the biocompatibility of the micro-nanoporous layer formed on a titanium-silver (Ti–Ag) alloy. The porous layer was formed by grit-blasting and anodic oxidation. The surface of the porous layer was rougher and more hydrophilic compared to a simple machined specimen and the expressions of bone-related genes were greater for cells grown on the porous layer compared to that of cells cultured on a control surface. Also the bone-to-plate contact rate in vivo test was significantly improved for porous layer plate compare to simple machined specimen (P < 0.05). The porous layer on Ti–Ag alloy enhanced the peri-implant bone formation at the early healing stage and it was believed that this porous layer on the Ti–Ag alloy will be suitable for dental implant applications.
The reoptimization of the binary Se–Te system
Authors: Gierlotka Wojciech , Wu Wei-Hsiang 
Published: March 2012

Abstract
Selenium–tellurium metal films are promising materials for optical reversible memories; thus, the possibility of modeling of the phase diagram and thermodynamic properties seems to be important for industry. The Calphad method was used for a new thermodynamic assessment of the binary Se–Te system. A good agreement between calculation and experimental information is obtained.
Thermophysical properties of solid phase Ti-6Al-4V alloy over a wide temperature range
Authors: Milošević Nenad , Aleksić Ivana 
Published: March 2012

Abstract
This paper presents experimental results on thermophysical properties of the most commonly used titanium alloy, Ti-6Al-4V, in its solid phase. The subsecond pulse calorimetry has been applied for measuring heat capacity, specific electrical resistivity, and hemispherical total and normal spectral emissivity, and the laser flash method for measuring thermal diffusivity. Specific heat capacity and specific electrical resistivity were measured from 250 to 1700 K, thermal diffusivity from 190 to 1530 K, hemispherical total emissivity from 780 to 1670 K, and normal spectral emissivity at 900 nm from 1300 to 1730 K. Thermal conductivity and Lorentz function were computed from experimental data in the range from about 190 to 1530 K. For necessary corrections literature data on thermal linear expansion were used. The results obtained are compared with available literature values.
Phase diagram of the Sm–Dy–Fe ternary system
Authors: Wang Bowen , Zhu Yulan , Dai Junqiu , Weng Ling , Huang Wenmei , Hao Yanming 
Published: March 2012

Abstract
The isothermal section at 800°C and vertical sections of SmFe2–DyFe2 and (Sm0.86Dy0.14) Fe
x
(1.6 ≤ x ≤ 2.4) in the Sm–Dy–Fe system were determined by using optical microscopy, X-ray diffraction analysis, electron probe microanalysis, and differential thermal analysis techniques. The isothermal section possesses 6 single-phase regions, 7 two-phase regions, and 3 three-phase regions. There are five intermetallic phases: (Sm, Dy) Fe2, (Sm, Dy) Fe3, (Sm, Dy)6Fe23, Th2Zn17-type (Sm, Dy)2Fe17, and Th2Ni17-type (Sm, Dy)2Fe17. No Sm6Fe23 and (Sm, Dy)2Fe7 phases exist in the ternary system. The vertical section of SmFe2–DyFe2 in the Sm–Dy–Fe system contains 2 single-phase regions, 2 two-phase regions, and 1 three-phase region. Investigation of the vertical section of (Sm0.86Dy0.14) Fe
x
(1.6 ≤ x ≤ 2.4) indicates that it consists of 2 single-phase regions, 5 two-phase regions, and 1 three-phase region.
Free-surface enhanced continuum model predicts size-effect for pillar compression at micro- and nano-scale
Authors: Brinckmann Steffen , Siegmund Thomas 
Published: March 2012

Abstract
It has recently been observed that micro- and nano-sized pillars under uniaxial compression and tension attain a higher flow-stress than samples of macroscopic size. Here it is hypothesized that such a mechanical size-effect is driven by the interaction of dislocations with the free surfaces. An extended continuum plasticity theory is presented to account for such an effect by considering the free-surface imagestresses on the dislocation motion immediately following dislocation nucleation. The model employs only fundamental material parameters, Young's modulus, Poisson's ratio, bulk yield-strength, and the Burgers vector. The model predicts the magnitude of the size-effects observed in the compression of Au and Cu micro- and nano-pillars.