bluuebunny/crossref_metadata_2025_split huggingface dataset:
Twinkling fractal theory of the glass transition
Authors: Wool Richard P. 
Published: November 2008

AbstractIn this paper we propose a solution to an unsolved problem in solid state physics, namely, the nature and structure of the glass transition in amorphous materials. The development of dynamic percolating fractal structures near Tg is the main element of the Twinkling Fractal Theory (TFT) presented herein and the percolating fractal twinkles with a frequency spectrum F(ω) ∼ ωdf–1 exp −|ΔE|/kT as solid and liquid clusters interchange with frequency ω. The Orbach vibrational density of states for a fractal is g(ω) ∼ ωdf–1, where df = 4/3 and the temperature dependent activation energy behaves as ΔE ∼ (T2 − T). The key concept of the TFT derives from the Boltzmann population of excited states in the anharmonic intermolecular potential between atoms, coupled with percolating solid fractal structures near Tg. The twinkling fractal spectrum F(ω) at Tg predicts the correct dynamic heterogeneity behavior via the spatio‐temporal thermal fluctuation autocorrelation relaxation function C(t). This function behaves as C(t) ∼ t−1/3 (short times), C(t) ∼ t−4/3 (long times) and C(t) ∼ t−2 (ω < ωc), which were found to be in excellent agreement with published nanoscale AFM dielectric force fluctuation experiments on a glassy polymer near Tg. Using the Morse potential, the TFT predicts that Tg = 2Do/9k, where Do is the interatomic bonding energy ∼ 2–5 kcal/mol and is comparable to the heat of fusion ΔHf. Because anharmonicity controls both the thermal expansion coefficient αL and Tg, the TFT uniquely predicts that αL×Tg ≈ 0.03, which is found to be universal for a broad range of glassy materials from Pyrex to polymers to glycerol. Below Tg, the glassy structure attains a frustrated nonequilibrium state by getting constrained on the fractal structure and the thermal expansion in the glass is reduced by the percolation threshold pc as αg ≈ pcαL. The change in heat capacity ΔCp = CpL–Cpg at Tg was found to be related to the change in dimensionality from Df to 3 in the Debye approximation as the ratio CpL/Cpg = 3/Df, where Df is the fractal dimension of the glass. For polymers, the TFT describes the molecular weight dependence of Tg, the role of crosslinks on Tg, the Flory‐Fox rule of mixtures and the WLF relation for the time‐temperature shift factor aT, which are traditionally viewed in terms of Free‐Volume theory. The TFT offers new insight into the behavior of nano‐confined glassy materials and the dynamics of physical aging. It also predicts the relation between the melting point Tm and Tg as Tm/Tg = 1/[1−pc] ≈ 2. The TFT is universal to all glass forming liquids. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2765–2778, 2008
Spectral time moment analysis of microgel deswelling. Effect of the heating rate
Authors: Streletzky Kiril A. , Mckenna John T. 
Published: November 2008

AbstractMicrogel nanoparticles were synthesized in aqueous solutions of neutral polymer hydroxypropylcellulose (HPC) through the self‐association of amphiphilic HPC molecules and the subsequent cross linking at room temperature. Dynamic Light Scattering was used to study the transport properties of HPC microgels below and above the volume phase transition. Highly nonexponential, multimodal microgel spectra were observed and successfully analyzed by spectral time moment analysis. This article expands earlier results and focuses on the effect of the heating rate on microgel deswelling. During the fast heating two identified microgel modes with apparent hydrodynamic radii (RH) of 25–30 nm and 400–650 nm collapse into one mode with RH = 100–150 nm. This indicates the shrinkage of microgel size distribution and an apparent decrease in the radius of larger microgels. During the slow heating, however, both microgel‐identified modes remain present above Tc. Although equally represented below the transition, the dominance of larger microgels' mode increases almost two fold with rising temperature above 40°C. Moreover, RH for this mode increases from 250–300 nm to about 800–850 nm with a multi‐step temperature change from 40 to 42.5°C, indicating the growth (and not shrinkage) of microgels. The second mode is represented by the temperature independent RH, but its contribution goes down from about 50% to less than 10%. © 2008Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2792–2802, 2008
Moderate and vigorous exercise programs in children with asthma: Safety, parental satisfaction, and asthma outcomes
Authors: Weisgerber Michael , Webber Kathryn , Meurer John , Danduran Michael , Berger Stuart , Flores Glenn 
Published: November 2008

AbstractBackgroundPrevious research suggests that physical activity programs may improve fitness and reduce symptoms in children with asthma, but few studies have included severe asthmatics and focused on safety and parental satisfaction with the programs.ObjectiveTo examine safety, parental satisfaction, and pre‐ to post‐intervention changes in symptoms and quality of life (QOL) in a pilot study of the impact of vigorous physical activity (swimming) and moderate‐intensity activity (golf) on inner‐city children with asthma.Design/MethodsChildren with asthma (7–14 years old) residing in Milwaukee's highest asthma prevalence zip codes were randomized to a 9‐week swimming or golf program. Pre‐ and post‐intervention data were obtained on safety, parental satisfaction, asthma symptoms, quality of life, and urgent asthma physician visits.ResultsTwenty‐eight children in the swimming group and 17 in the golf group completed the program. Combined group analysis (N = 45) revealed that only six symptom exacerbations occurred during 1,125 person‐sessions of swimming and golf (all resolved with bronchodilator therapy), 92% of parents were very or extremely satisfied with the program, and post‐exercise decreases were observed in asthma symptom severity scores (9.3–7.3, P < 0.001), improved parental QOL (4.9–5.4, P < 0.001), and reduced urgent physician visits for asthma (1.3–0.2 visits per person, P = 0.04). The study lacked sufficient power to perform intergroup comparisons.ConclusionsFindings from this pilot study indicate that vigorous (swimming) and moderate‐intensity (golf) physical activity programs are well‐tolerated, safe, and achieve high parental satisfaction. Participants and parents reported reduced childhood asthma symptoms and physician office visits and improved parental QOL. These findings suggest a potentially beneficial role for moderate to vigorous physical activity in childhood asthma. Pediatr. Pulmonol. 2008; 43:1175–1182. © 2008 Wiley‐Liss, Inc.
Six‐minute walk test in obese children and adolescents: Reproducibility and validity
Authors: Morinder Gunilla , Mattsson Eva , Sollander Clara , Marcus Claude , Larsson Ulla Evers 
Published: November 2008

AbstractBackground and Purpose. The six‐minute walk test (6MWT) is increasingly used in clinical practice. The aims of this study were to determine the reproducibility of the 6MWT in obese children and adolescents, to describe walking capacity in this population and compare the results with values from normal‐weight children (known group validity), and, finally, to describe the correlation between distance walked and estimated maximum oxygen uptake (VO2max). Methods. Reproducibility was determined by a test–retest design and known group validity by a comparative design. The 6MWT was first test–retested in 49 obese children (30 boys, 19 girls, 8–16 years, body mass index [BMI] 24.9–52.1 kg?m−2). Then, for validation, 250 obese children (126 boys, 124 girls, 8–16 years, BMI 23.2–57 kg/m2) and 97 normal‐weight children (48 boys, 49 girls, 8–16 years, BMI 13.3–23.2 kg·m−2) performed the 6MWT. The obese children also performed a sub‐maximal bicycle ergometry test. Results. In the test–retest, the obese children walked 571 m the first test and 57 m the second (p = 0.578). The measurement error (Sw) was 24 m, coefficient of variation (CV): 4.3% and the intraclass correlation (ICC1:1): 0.84. Repeatability was 68 m, and limits of agreement were +71 and −65 m. In comparison mean (standard deviation), six‐minute walk distance (6MWD) in the obese children was 571 m (65.5), and in the normal‐weight children, 663 m (61.1) (p < 0.001). The correlation between 6MWD and estimated VO2max (r = 0.34) was low. Conclusions. The 6MWT showed good reproducibility and known group validity, and can be recommended for use in clinical practice in the studied population. To evaluate individual outcomes after intervention, the 6MWD needs to change by >68 m to be statistically significant. The 6MWD performed by obese children averaged 86% of the distance normal‐weight children walked. In obese children, the correlation between 6MWD and estimated VO2max was low, hence the 6MWT cannot substitute a bicycle ergometry test. Copyright © 2008 John Wiley & Sons, Ltd.
Spectral properties and thermoluminescence of codoped PbWO4:(Mo,Y) and PbWO4:(F,Y) crystals
Authors: Xie Jian‐jun , Shi Ying , Yuan Hui , Cheng Hao‐hong , Wu Wei‐ping , Liao Jing‐ying 
Published: November 2008

AbstractLead tungstate, PbWO4 single crystals codoped with Mo6+/F– and Y3+ ions were grown using the modified Bridgman method. Optical transmission, X‐ray excited luminescence, photoluminescence, ultrashort pulsed X‐ray excited fluorescent lifetime and thermoluminescence have been investigated. Compared to pure PbWO4, the codoped PbWO4:(Mo,Y) and PbWO4:(F,Y) crystals exhibit improved transmittance in the short‐wavelength region. Luminescence and light‐yield measurements demonstrated that Mo6+/F– and Y3+ codoping could enhance the luminescence of PbWO4 and reduce slow decay components. Doped Mo6+ and F– ions in PbWO4 were tentatively considered to occupy W and O sites, while Y3+ ions codoped in PbWO4:Mo/F mostly occupy Pb sublattice sites. The second excitation peak at 335 nm, which is the second effective excitation for the enhanced blue‐green emission in as‐grown PbWO4:(Mo,Y) and PbWO4:(F,Y) crystals, should be related to MoO42– groups and O vacancies (VO). Thermoluminescence glow curve measurement between RT and 400 °C provides complementary information about trapping states and the effect of Y3+ ion codoping resulting in the reduction of stable and temporary hole centers. Further work is needed to explain the doping and energy‐transfer mechanism. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of experimentally determined inelastic mean free path and surface excitation parameter in Ni to Monte Carlo simulation of reflection electron energy loss spectrum
Authors: Nagatomi T. , Goto K. 
Published: November 2008

AbstractThe Monte Carlo (MC) simulation of reflection electron energy loss spectroscopy (REELS), in which energy losses by surface excitations were taken into account in addition to the bulk excitation, was developed. For the inelastic mean free path (IMFP), the surface excitation parameter (SEP), and the differential SEP (DSEP) required for the MC simulation as input data, those absolutely determined from absolute experimental REELS spectra were employed. The REELS spectra were simulated by using the present MC simulation for primary electrons of 300–3000 eV irradiated onto Ni. The simulated REELS spectra showed an excellent agreement with the experimental spectra, confirming that the MC simulation describes well the energy loss processes of electrons in the near surface region. The comparison of the spectra simulated with and without surface excitations has revealed that surface excitations play an important role in energy loss processes of electrons near surface region. Copyright © 2008 John Wiley & Sons, Ltd.
Security benchmarks of OSGi platforms: toward Hardened OSGi
Authors: Parrend P. , Frenot S. 
Published: November 2008

AbstractOSGi platforms are extensible component platforms, i.e. they support the dynamic and transparent installation of components that are provided by third party providers at runtime. This feature makes systems built using OSGi extensible and adaptable, but opens a dangerous attack vector that has not been considered as such until recently. Performing a security benchmark of the OSGi platform is therefore necessary to gather knowledge related to the weaknesses it introduces as well as to propose enhancements. A suitableVulnerability Patternis defined. The attacks that can be performed through malicious OSGi components are identified. Quantitative analysis is then performed so as to characterize the origin of the vulnerabilities and the target and consequences of the attacks. The assessment of the security status of the various implementations of the OSGi platform and of existing security mechanisms is done through a metric we introduce, theProtection rate(PR). Based on these benchmarks, OSGi‐specific security enhancements are identified and evaluated. First recommendations are given. Then evaluation is performed through the PR metric and performance analysis. Lastly, further requirements for building secure OSGi platforms are identified. Copyright © 2008 John Wiley & Sons, Ltd.
Nanocolumnar Preferentially Oriented PSZT Thin Films Deposited on Thermally Grown Silicon Dioxide
Authors: Sriram S , Bhaskaran M , Mitchell A , Mitchell DRG , Kostovski G 
Published: November 2008

Abstract
We report the first instance of deposition of preferentially oriented, nanocrystalline, and nanocolumnar strontium-doped lead zirconate titanate (PSZT) ferroelectric thin films directly on thermal silicon dioxide. No intermediate seed or activation layers were used between PSZT and silicon dioxide. The deposited thin films have been characterised using a combination of diffraction and microscopy techniques.
Do Twin Boundaries Always Strengthen Metal Nanowires?
Authors: Zhang Yongfeng , Huang Hanchen 
Published: November 2008

Abstract
It has been widely reported that twin boundaries strengthen nanowires regardless of their morphology—that is, the strength of nanowires goes up as twin spacing goes down. This article shows that twin boundaries do not always strengthen nanowires. Using classical molecular dynamics simulations, the authors show that whether twin boundaries strengthen nanowires depends on the necessary stress for dislocation nucleation, which in turn depends on surface morphologies. When nanowires are circular cylindrical, the necessary stress of dislocation nucleation is high and the presence of twin boundaries lowers this stress; twin boundaries soften nanowires. In contrast, when nanowires are square cylindrical, the necessary stress of dislocation nucleation is low, and a higher stress is required for dislocations to penetrate twin boundaries; they strengthen nanowires.
Frying Stability of Canola Oil Blended with Palm Olein, Olive, and Corn Oils
Authors: Farhoosh Reza , Esmaeilzadeh Kenari Reza , Poorazrang Hashem 
Published: November 2008

AbstractThe fatty acid composition, peroxide value (PV), acid value (AV), iodine value (IV), total tocopherols (TT) content, and total phenolics (TP) content of canola oil (CAO), palm olein oil (POO), olive oil (OLO), corn oil (COO), and the binary and ternary blends of the CAO with the POO, OLO, and COO were determined. The blends were prepared in the volume ratios of 75:25 (CAO/POO, CAO/OLO, CAO/COO) and 75:15:10 (CAO/POO/OLO, CAO/POO/COO). The CAO and its blends were used to fry potato pieces (7.0 × 0.5 × 0.3 cm) at 180 °C. During the frying process, the total polar compounds (TPC) content, AV, oil/oxidative stability index (OSI), and color index (CI) of the CAO/blends were measured. In general, frying stability of the CAO was significantly (P < 0.05) improved by the blending, and the frying performance of the ternary blends was found to be better than that of the binary blends.
Physiologic Alterations in the Murine Model after Nasal Fungal Antigenic Exposure
Authors: Khalid Ayesha N. , Woodworth Bradford A. , Prince Anthony , Quraishi Sadeq A. , Antunes Marcelo B. , Long Fenella H.A. , Bolger William E. , Chiu Alexander G. , Palmer James N. , Cohen Noam A. 
Published: November 2008

ObjectiveTo determine whether a recently developed murine model of fungus‐induced sinonasal inflammation demonstrated alterations in ciliary activity and expression of inflammatory cytokines.Study DesignA prospective randomized controlled study of rhinosinusitis after fungal antigenic sensitization was performed with intraperitoneal aspergillus antigen injection followed by intranasal antigen challenge for 4 weeks. Saline solution was used in a parallel fashion for control animals.Subjects and MethodsSix mice were used to validate the model. Additional 15 mice were used for ciliary beat frequency (CBF) analysis and cytokine expression with multiplex technology. Mean values for degree of inflammation, secretory hyperplasia, CBF, and cytokine expression were compared.ResultsHistologic analyses demonstrated dense chronic inflammation in aspergillus‐challenged animals versus sparse inflammatory cells in controls. Significant differences in mean of aspergillus‐challenged versus control animals were observed in degree of inflammation (P < 0.01), secretory hyperplasia (P < 0.01), CBF (P < 0.00002), IL‐1α (P < 0.0002), IL‐1β (P < 0.0003), IL‐4 (P < 0.02), TNF‐α (P < 0.02), and RANTES (P < 0.01).ConclusionAlteration in baseline CBF accompanied by increased expression of specific inflammatory cytokines was observed in aspergillus‐challenged mice.
The Relationship between Chronic Otitis Media‐Induced Hearing Loss and the Acquisition of Social Skills
Authors: Bidadi Sanam , Nejadkazem Mohammad , Naderpour Masoud 
Published: November 2008

ObjectiveTo investigate the effects of hearing loss caused by chronic otitis media (COM) on acquiring social skills.Subjects and MethodsA case‐control study of 90 patients, including patients with COM, age range 15–30 years, was conducted in the otorhinolaryngology ward of Tabriz University Hospital. Social skills were assessed with a social skills questionnaire.ResultsSocial skill scores were found to be lower in hearing‐impaired COM patients compared with the control group (P < 0.001). Social skill disabilities in patients with bilateral COM were more severe than in patients with unilateral COM and the controls (P < 0.001). Correlation between social skills score and degree of hearing loss was significantly negative (P = 0.014, rho = −0.314). These data indicate an inverse relationship between hearing loss and social skills.ConclusionSocial skills and educational level of COM patients are affected because of hearing impairment. This study suggests that COM has effects on social development and education.
Relationship between Voice Quality and Vocal Nodule Size
Authors: Shah Rahul K. , Engel Samuel H. , Choi Sukgi S. 
Published: November 2008

ObjectiveTo determine the effect of vocal nodule size on voice in pediatric patients.Study DesignVocal nodules were graded according to a validated grading scale by three pediatric otolaryngologists.Subjects and MethodsPatients evaluated from 2003 to 2007 with a diagnosis of vocal nodules were included.ResultsForty patients (21 female) with a mean age of 7.5 years were identified. Vocal nodules were rated as grade 1 (17 patients), grade 2 (15 patients), and grade 3 (8 patients). Pitch range was reduced in patients with larger nodules (P = 0.001). There was no statistical association between nodule grade and fundamental frequency abnormality, perturbation, shimmer, decreased respiratory support, air loss, or significant muscle tension.ConclusionsVoice characteristics in patients with vocal nodules were evaluated. Other than pitch reduction, objective and subjective voice measurements are not statistically different in varying vocal nodule sizes; however, many of the measures did show a trend towards significance. Vocal rehabilitation is complex in children with nodules and may not directly correlate with vocal nodule size.
Clinical Characteristics of External Auditory Canal Cholesteatoma in Children
Authors: Yoon Yeo‐Hoon , Park Chan Hee , Eung‐Hyub Kim , Park Yong Ho 
Published: November 2008

ObjectiveThe purpose of this study was to investigate the characteristics of pediatric external auditory canal cholesteatoma (EACC).MethodsChart review of nine children with EACC between January 1, 2000 and December 31, 2007 was performed with subsequent analysis of etiologic factors, associated symptoms, otoscopic findings, imaging features, and treatment outcomes.ResultsThe average age of patients was 10.3 years (range 6–15 years). Five patients were girls and four were boys. There was greater incidence of EACC on the right side (eight of nine patients). Otorrhea and hearing impairment were the most common presenting symptoms. The inferior wall of the external auditory canal was most commonly involved. Five patients underwent cholesteatoma removal under general anesthesia. Surgical procedures were performed in four patients. No recurrence except in one patient was found during the follow‐up period.ConclusionsPediatric EACC is reported as a rare condition, but its low occurrence may be due to underreporting. Early diagnosis and treatment is essential in the management of pediatric EACC.
The diets of ungulates from the hominid fossil-bearing site of Elandsfontein, Western Cape, South Africa
Authors: Stynder Deano D. 
Published: November 2008

AbstractThe dietary regimes of 15 ungulate species from the middle Pleistocene levels of the hominid-bearing locality of Elandsfontein, South Africa, are investigated using the mesowear technique. Previous studies, using taxonomic analogy, classified twelve of the studied species as grazers (Redunca arundinum, Hippotragus gigas, Hippotragus leucophaeus, Antidorcas recki, Homoiceras antiquus, Damaliscus aff. lunatus, Connochaetes gnou laticornutus, Rabaticerus arambourgi, Damaliscus niro, Damaliscus sp. nov., an unnamed “spiral horn” antelope and Equus capensis), one as a mixed feeder (Taurotragus oryx) and two as browsers (Tragelaphus strepsiceros and Raphicerus melanotis). Although results from mesowear analysis sustain previous dietary classifications in the majority of cases, five species were reclassified. Three species previously classified as grazers, were reclassified as mixed feeders (H. gigas, D. aff. lunatus and R. arambourgi), one previously classified as a grazer, was reclassified as a browser (the “spiral horn” antelope), and one previously classified as a mixed feeder, was reclassified as a browser (T. oryx). While current results broadly support previous reconstructions of the Elandsfontein middle Pleistocene environment as one which included a substantial C3 grassy component, the reclassifications suggest that trees, broad-leaved bush and fynbos were probably more prominent than what was previously thought.