bluuebunny/crossref_metadata_2025_split huggingface dataset:
Health Care Providers' Perceived Role in Changing Environments to Promote Healthy Eating and Physical Activity: Baseline Findings From Health Care Providers Participating in the Healthy Eating, Active Communities Program
Authors: Boyle Maria , Lawrence Sally , Schwarte Liz , Samuels Sarah , McCarthy William J. 
Published: May 2009

BACKGROUND. The California Endowment's Healthy Eating, Active Communities program was designed to reduce disparities in the incidence of obesity by improving food and physical-activity environments for low-income children. It was recognized at the outset that to succeed, the program needed support from community advocates. Health care providers can be effective advocates to mobilize community members and influence policy makers.
OBJECTIVE. This study was conducted to describe how health care providers address obesity prevention in clinical practice and to assess health care providers' level of readiness to advocate for policies to prevent childhood obesity.
METHODS. The study included two data-collection methods, (1) a self-administered survey of health care providers (physicians, dietitians, nurses, nurse practitioners, medical assistants, and community health workers) and (2) stakeholder interviews with health care facility administrators, health department staff, and health insurance organization representatives. Two-hundred and forty-eight health care providers participated in the provider survey and the health care stakeholder interviews were conducted with 56 respondents.
RESULTS. The majority (65%) of health care providers usually or always discussed the importance of physical-activity, reducing soda consumption, and breastfeeding (as appropriate) during clinical pediatric visits. More than 90% of the providers perceived home or neighborhood environments and parental resistance as barriers to their efforts to prevent childhood obesity in clinical practice. More than 75% of providers reported not having engaged in any policy/advocacy activities related to obesity-prevention. Most (88%) of the stakeholders surveyed thought that health care professionals should advocate for policies to reduce obesity, especially around insurance coverage for obesity-prevention.
CONCLUSIONS. Providers perceived that changing the food and physical-activity environments in neighborhoods and schools was likely to be the most effective way to support their clinical obesity-prevention efforts. Health care providers need time, training, resources, and institutional support to improve their ability to communicate obesity-prevention messages in both clinical practice and as community policy advocates.
West Nile Virus Disease in Children, United States, 1999–2007
Authors: Lindsey Nicole P. , Hayes Edward B. , Staples J. Erin , Fischer Marc 
Published: May 2009

BACKGROUND. Although West Nile virus (WNV) disease has occurred predominantly among adults in the United States, children are also susceptible. Epidemiological data describing WNV disease in children are limited.
METHODS. We described the epidemiological features of WNV disease among children (&lt;18 years of age) reported to the Centers for Disease Control and Prevention from 1999 through 2007 and compared features of pediatric and adult West Nile neuroinvasive disease (WNND).
RESULTS. Of 1478 pediatric WNV cases reported from 1999 through 2007, 443 (30%) were classified as WNND, 1009 (68%) were classified as West Nile fever, and 26 (2%) were of unknown clinical presentation. Three WNND cases were fatal. The vast majority of reported case subjects (92%) had onset of illness between July and September. Children accounted for only 4% of all of the WNND case subjects reported from 1999 to 2007, with a median annual incidence of 0.07 case subjects per 100 000 children (range: 0.00–0.19 case subjects). In children and younger adults WNND most often manifested as meningitis, in contrast to the predominance of encephalitis among older adults with WNND. The geographic distribution and temporal trends were of pediatric and adult WNND.
CONCLUSIONS. The epidemiological characteristics of WNV disease in children are similar to adult case subjects; however, WNND is more likely to manifest as meningitis in children than in older adults. WNV should be considered in the differential diagnosis for pediatric patients presenting with febrile illness, meningitis, encephalitis, or acute flaccid paralysis, particularly during seasonal outbreaks in endemic areas.
Composition, Size, Structure, and Magnetic Characterization of Iron-Platinum Nano-particles
Authors: Parekh N. , Young G. , Singh A. , Parvin K. , Kaur M. , Bruck D. , Wong S. 
Published: June 2009

ABSTRACTIron-platinum (FePt) nano-particles were synthesized using a hot metal salt reduction reaction with iron chloride and platinum acetylacetonate as the precursor salts. The synthesis route was based upon work done previously by Sun et Al.[6]. The size and composition of the FePt nano-particles were controlled by varying the surfactant to reagent molar ratio and refluxing time during synthesis. The average size of FePt nano-particles synthesized ranged from 4.08 nm to 5.23 nm. The composition of the nano-particles ranged from Fe60Pt40 to Fe55Pt45. The size was shown to increase as the surfactant to reagent molar ratio was changed from 1:6 to 1:1. The platinum composition increased from 40 % to 45 % with an increase in the refluxing time from 30 minutes to 60 minutes. The X-ray analysis (XRD) showed that the unannealed nano-particles had a FCC crystal structure. The FCC FePt nano-particles were superparamagnetic at room temperature. A blocking temperature (Tb) of 35 K was measured for 5.23 nm Fe55Pt45 nano-particles. Annealing of the Fe55Pt45 nano-particles induced a FCT crystal structure with hard-magnetic properties. Coercivity (Hc) of approximately 13000 Oe was measured at room temperature.(a) Department of Chemical and Materials Engineering, San Jose State University(b) Department of Physics and Astronomy, San Jose State University(c) Department of Biological Sciences, San Jose State University
Superhydrophobic Nanocrystalline Nickel Films Inspired by Lotus Leaf
Authors: Shafiei Mehdi , Alpas Ahmet T. 
Published: June 2009

ABSTRACTA new method to fabricate superhydrophobic hard films is described. Surface texture of lotus leaf was replicated on an acetate film, on which a nanocrystalline (NC) Ni coating with a grain size of 30 ± 4 nm and a hardness of 4.42 GPa was electrodeposited. The surface texture consisted of conical protuberances with a height of 10.0 ± 2.0 0m and a tip radius of 2.5 ± 0.5 0m. An additional electrodeposition for 120 s and 300 s was used to locally modify the surface structure by depositing ‘Ni crowns' on the protuberances that increased their height to 14.0 ± 2.0 0m and their tip radius to 6.0 ± 0.5 0m. The modified structures were then treated with a perfluoropolyether (PFPE) solution, which provided a high water contact angle of 156°, i.e., comparable to the naturally superhydrophobic lotus leaf. The increased hydrophobicity as a result of surface structure and chemistry modifications was evident compared to a smooth NC Ni sample, which had a contact angle of 64°.
Para-sexiphenyl-CdSe Nanocrystals Hybrid Light Emitting Diodes with Optimized Layer Thickness and Interfaces
Authors: Simbrunner Clemens , Hernandez-Sosa Gerardo , Baumgartner Eugen , Hesser Günter , Roither Jürgen , Heiss Wolfgang , Sitter Helmut 
Published: June 2009

AbstractCdSe/ZnS nanocrystals are embedded in para-sexiphenyl (p-6P) based hybrid light emitting diode devices providing red, green and blue (RGB) emission compatible to the HDTV color triangle. By structural and optical investigations the device parameters are optimized. The device performance is analyzed in respect to electrical and spectral response resulting in current-voltage characteristics with small leakage currents and low onset voltages. Furthermore the devices provide high color purity and stability which is demonstrated by their narrow emission line widths. All these results underline the ability of the presented device configuration to act as a future candidate for display applications.
Introduction of Innovative Dopant Concentration Profiles to Broaden the Recombination Zone of Phosphorescent OVPD-Processed Organic Light Emitting Diodes
Authors: Bösing Manuel , Zimmermann Christoph , Lindla Florian , Jessen Frank , van Gemmern Philipp , Bertram Dietrich , Meyer Nico , Keiper Dietmar , Heuken M. , Kalisch Holger , Jansen Rolf H. 
Published: June 2009

AbstractOLED with non-constant dopant concentration profiles have been processed by means of organic vapour phase deposition (OVPD) and were compared with regard to their luminous current efficiencies. Especially when driven at ultra-high luminance (>10,000 cd/A), OLED with a dopant concentration profile starting with a rather high dopant concentration on the anode side of the emissive layer showed improved luminous current efficiencies compared to their conventional counterparts.To further investigate this effect, the width and location of the recombination zone have been simulated for all investigated concentration profiles by numerical solution of the semiconductor device equations using experimentally determined doping-dependent charge carrier mobilities. The obtained theoretical results are discussed with regard to the accomplished experiments.
Epitaxial Phase Change Materials: Growth and Switching of Ge2Sb2Te5 on GaSb(001)
Authors: Braun Wolfgang , Shayduk Roman , Flissikowski Timur , Grahn Holger T. , Riechert Henning , Fons Paul , Kolobov Alex 
Published: June 2009

AbstractEpitaxial Ge2Sb2Te5 has been successfully grown on GaSb(001) by molecular beam epitaxy. The films show a tendency for void formation and rough morphology, but at the same time a very strong epitaxial orientation, cubic structure and a sharp interface to the substrate. The layers can be reversibly switched between the crystalline and amorphous phases using short laser pulses.
Cu-In and Cu-Zn-Sn Films as Precursors for Production of CuInSe2 and Cu2ZnSnSe4 Thin Films
Authors: Volobujeva Olga , Mellikov Enn , Raudoja Jaan , Bereznev Sergei , Pilvet Maris 
Published: June 2009

AbstractThe co-sputtered Cu-In precursor layers were characterized by bi-layer surface structure in which island-type crystals were formed in a small-crystalline matrix layer. The elemental composition of the island-type crystals corresponds to the compound CuIn2 and the matrix (area) consists of copper-rich Cu11In9 phase. The surface morphology of sequentially evaporated Cu-Zn-Sn precursor layers is determined by the deposition order of stacked consistent metal layers. Precursor Mo-Sn-Zn-Cu films exhibit a well-formed “mesa-like” structure of the surface in which larger crystals (about 1,5 μm) are located on a “small-crystalline” valley. For films with other sequences of metallic layers, the mesa like structure is not so well exposed and well formed flat precursor layers were produced replacing separate metallic Cu and Sn layers with Cu/Sn alloy layer. Selenization of both Cu-In and Cu-Zn-Sn precursor layers begins with the formation of binary Cu-selenides with compositions varying with the temperature. At temperatures higher than 3700C the selenization of Cu-In results in single-phase CuInSe2 films in contrast to the selenization of Sn-Zn-Cu films that results always in multi-phase films consisting of high quality Cu2ZnSnSe4 crystals and of separate small-crystalline phase of ZnSe.
Preparation and Properties of CdTe Films on Mo/Glass Substrates
Authors: Valdna Vello , Grossberg Maarja , Jaan Hiie , Kallavus Urve , Mikli Valdek , Traksmaa Rainer , Viljus Mart 
Published: June 2009

AbstractShort-bandgap group II-VI compound cadmium telluride is widely used for the infrared optics, radiation detectors, and solar cells where p-type CdTe is needed. p-type conductivity of CdTe is mainly caused by the chlorine-based A-centers, and in part, by the less stable copper-oxygen complexes. As a rule, CdTe films are recrystallized by the help of a cadmium chloride flux that saturates CdTe with chlorine. In chlorine-saturated CdTe A-centers are converted to isoelectronic complexes that cause resistivity increasement of CdTe up to 9 orders of magnitude. Excess copper and oxygen or group I elements as sodium also deteriorate the p-type conductivity of CdTe like excess chlorine. p-type conductivity of CdTe can be restored e.g. by the vacuum annealing which removes excess chlorine from the film. Unfortunately, treatment that betters p-type conductivity of the CdTe film degrades the junction of the superstrate configuration cells. In this work we investigate possibilities to prepare p-type CdTe films on the molybdenum coated glass substrates. Samples were prepared by the vacuum evaporation and dynamic recrystallization of 6N purity CdTe on the top of Mo-coated glass substrates. Then samples were recrystallized with cadmium chloride flux under tellurium vapour pressure. Results of the test studies on the structure and electronic parameters of samples are presented and discussed.
Thermoelectrics for High Temperatures: A Survey of State of the Art
Authors: Böttner Harald 
Published: June 2009

AbstractA survey of state of the art of the development of high temperature materials is presented and will be discussed in comparison to the situation in the 1990th. An attempt will be made to assess the state of the art of the materials thermoelectric properties, their technical level, and possible potential for standardized device technology. Also a first assessment based on current commodity prices for some important thermoelectric compounds will be made.
As a roundup advantages and drawbacks for some classical and upcoming compounds will be given. The main challenges, which will have to be overcome to finally enable thermoelectric power generation as a recycling technology of “nomadic” energy, will be summarized. As a result, thermoelectrics should play an important role in the field of green energies.
Investigation of Solid-State Immiscibility and Thermoelectric Properties of the System PbTe – PbS
Authors: Girard Steven N , He Jiaqing , Dravid Vinayak P , Kanatzidis Mercouri G 
Published: June 2009

AbstractWe have shown that (Pb1-mSnmTe)1-x(PbS)x where m = 0.05 and x = 0.08 exhibits a ZT of ˜1.4 at 700 K. This system incorporates two thermoelectric systems: PbSxTe1-x and Pb1-xSnxTe. Here we report the thermoelectric properties of PbSxTe1-x (x = 0.08 and 0.30). The material PbS0.08Te0.92 exhibits nucleation and growth of PbS precipitates, while PbS0.30Te0.70 exhibits PbS precipitation through spinodal decomposition phase separation. We report the thermoelectric properties of this system as a result of the differing precipitation phenomena.
Thermoelectric Properties of Sb-doped Sintered Mg2Si Fabricated using Commercial Polycrystalline Sources
Authors: Fukushima Naoki , Iida Tsutomu , Akasaka Masayasu , Nemoto Takashi , Sakamoto Tatsuya , Kobayashi Ryo , Taguchi Hirohisa , Nishio Keishi , Takanashi Yoshifumi 
Published: June 2009

AbstractThe thermoelectric (TE) properties, such as the Seebeck coefficient, the electrical and thermal conductivities, and the output power, of Sb-doped n-type Mg2Si were studied. A commercial polycrystalline source was used for the source material for the Mg2Si. TE elements with Ni electrodes were fabricated by using a monobloc plasma-activated sintering (PAS) technique. Compared with undoped samples, the ZT values of the Sb-doped samples were higher over the whole temperature range in which measurements were made; the maximum value for the Sb doped Mg2Si was 0.72 at 864 K. The TE characteristics of Sb-doped samples were found to be comparable to those of Bi-doped ones, and no significant difference in ZT value was observed between them. Provisional results showed that the maximum value of the output power was 6.75 mW for the undoped sample, 4.55 mW for a 0.5 at% Sb doped sample, and 5.25 mW for a 1 at% Sb doped sample with ΔT = 500 K (between 873 K and 373 K).
Phonon Bottleneck Effect in Organic Molecules
Authors: Bandyopadhyay S. , Kanchibotla Bhargava 
Published: June 2009

AbstractWe have measured the ensemble averaged transverse spin relaxation time T2* (associated with g = 4 resonance) in bulk powders of the organic molecule Alq3, and in samples containing 1-2 molecules confined in nanocavities of dimension ˜ 2 nm. Both T2* times are strongly temperature dependent indicating that they are determined by phonon-mediated spin relaxation. Interestingly, the T2* time in nanocavities is ˜2.5 times longer than in bulk powder over a wide temperature range. The longer T2* in the nanocavity is evidence of weakened electron-phonon interaction. We believe that electron-phonon interaction is suppressed because the cavity confines phonons and discretizes the phonon modes and phonon energies. As a result, the chances of a phonon induced (inelastic) spin relaxation event are reduced owing to the need to conserve energy in the relaxation process. This is a novel “phonon bottleneck effect” that to our knowledge has not been previously reported.
Theory of Thermal Conductivity of Micro- and Nano-structured Materials
Authors: Srivastava Gyaneshwar P. 
Published: June 2009

AbstractWe provide a brief discussion of the Boltzmann equation derived Callaway-Debye relaxation time theory of lattice thermal conductivity of micro- and nano-structured materials (of size greater than 20 nm. Incorporated in the theory is a comprehensive treatment of three-phonon scattering events. Using numerical results from this theory, we present a quantitative investigation of the magnitude and temperature variation of the conductivity of CVD polycrystalline diamond films, suspended GaAs nanostructures, Si nanowires, and AlN micro- and nano-ceramics.
Dopants in nanoscale ZnO
Authors: McCluskey Matt , Oo Win Maw Hlaing , Teklemichael Samuel 
Published: June 2009

AbstractZinc oxide (ZnO) is a metal-oxide semiconductor that has attracted resurgent interest as an electronic material for a range of device applications. In our work, we have focused on how defect properties change as one goes from the bulk to the nanoscale. Infrared (IR) reflectance spectra of as-grown and hydrogen-annealed ZnO nanoparticles were measured at near-normal incidence. The as-grown particles were electrically semi-insulating, and show reflectance spectra characteristic of insulating ionic crystals. Samples annealed in hydrogen showed a significant increase in electrical conductivity and free-carrier absorption. A difference was observed in the reststrahlen line shape of the conductive sample compared to that of the as-grown sample. In addition to hydrogen doping, we successfully doped ZnO nanoparticles with Cu. To probe the electronic transitions of Cu2+ impurities in ZnO nanoparticles, IR transmission spectra were taken at liquid-helium temperatures. Two absorption peaks were observed at energies of 5781 and 5821 cm-1. Finally, we tentatively assign a series of IR spectral lines to Na acceptors.
Structural Fingerprinting of Nanocrystals: Advantages of Precession Electron Diffraction, Automated Crystallite Orientation and Phase Maps
Authors: Moeck Peter , Rouvimov Sergei , Rauch Edgar , Nicolopoulos Stavros 
Published: June 2009

AbstractStrategies for the structurally identification of nanocrystals from Precession Electron Diffraction (PED) patterns in a Transmission Electron Microscope (TEM) are outlined. A single-crystal PED pattern may be utilized for the structural identification of an individual nanocrystal. Ensembles of nanocrystals may be fingerprinted structurally from “powder PED patterns”. Highly reliable “crystal orientation & structure” maps may be obtained from automatically recorded and processed scanning-PED patterns at spatial resolutions that are superior to those of the competing electron backscattering diffraction technique of scanning electron microscopy. The analysis procedure of that automated technique has recently been extended to Fourier transforms of high resolution TEM images, resulting in similarly effective mappings. Open-access crystallographic databases are mentioned as they may be utilized in support of our structural fingerprinting strategies.
Structural Characterization of GeSn Alloy Nanocrystals Embedded in SiO2
Authors: Shin Swanee J. , Guzman Julian , Yuan Chun-Wei , Liao Christopher Y. , Stone Peter , Dubon Oscar D. , Minor Andrew M. , Watanabe Masashi , Ager Joel , Chrzan Daryl , Haller Eugene 
Published: June 2009

AbstractGeSn alloy nanocrystals were formed by implantation of Ge and Sn ions into an amorphous SiO2 matrix and subsequent thermal annealing. High resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy (STEM) with a high angle annular dark field (HAADF) detector were used to show that phase-segregated crystalline bi-lobe nanocrystals were formed. Rapid melting and solidification using a single excimer laser pulse transformed the bi-lobe structure into a homogeneously mixed amorphous structure. Raman spectroscopy was used to monitor the crystalline nature and approximate grain size of the Ge portion of the nanocrystals after each heat treatment, and the Raman spectra were compared with the TEM images.
In-situ TEM investigation of deformation behavior of metallic glass pillars
Authors: Chen Changqiang , Pei Yutao , De Hosson Jeff 
Published: June 2009

AbstractWe show results of in situ TEM (Transmission electron microscope) quantitative investigations on the compression behaviors of amorphous micropillars fabricated by focused ion beam from Cu47Ti33Zr11Ni6Sn2Si1 metallic glass (MG) ribbon. Pillars with well defined gauge sections and tip diameter ranging from 100 nm to 640 nm are studied. Quantitative compression tests were performed by a recently developed Picoindenter TEM holder, with the evolution of individual shear bands monitored in real time in TEM. It is found that the deformation of the MG pillars at the present size domain is still dominated by discrete shear banding as demonstrated by intermittent events in the load-displacement curves. However, the frequency, amplitude and distribution of these shear banding events are clearly size dependent at submicrometer scale, leading to an apparently transition in deformation mode from highly localized inhomogeneous deformation to less localized and more distributed deformation with decreasing pillars diameter. Deformation of a 105 nm diameter pillar having rounded tips is characterized with fully homogeneous bulge at the initial stage of deformation, indicating prompting effect of multi-axial stress state on transition to fully homogeneous deformation.
Numerical Simulations of Topologically Interlocked Materials Coupling DEM Methods and FEM Calculations: Comparison with Indentation Experiments
Authors: Brugger Charles , Fivel Marc C. , Bréchet Yves 
Published: June 2009

AbstractPlanar assemblies of interlocked cubic blocs have been tested in indentation. Experiments are performed on blocs made of plaster. Influence of key parameters such as the surface roughness, the compression stress and the number of blocs are investigated. A numerical modeling is then proposed based on discrete element method. Each bloc is represented by its centre coordinates. Constitutive equations obtained by finite element simulations are introduced to model the contact between the blocs. The numerical tool is then applied to the case of indentation loading. It is found that the model reproduces all the experimental tendencies.
Determination of the enthalpy of fusion of K3TaO2F4 and KTaF6
Authors: Kosa Ladislav , Macková Iveta , Netriová Zuzana 
Published: May 2009

AbstractAreas of fusion and crystallization peaks of K3TaO2F4 and KTaF6 were measured using the DSC mode of a high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities, considering the temperature dependence of the calorimeter sensitivity, values of the fusion enthalpy of K3TaO2F4 at the fusion temperature of 1181 K of (43 ± 4) kJ mol−1 and of KTaF6 at the fusion temperature of 760 K of (8 ± 1) kJ mol−1 were determined.