bluuebunny/crossref_metadata_2025 huggingface dataset:
Worldwide Geomagnetic Data Collection and Management
Authors: Mandea Mioara , Papitashvili Vladimir
Published: November 2009

Geomagnetic data provided by different platforms piece together a global picture of Earth's magnetic field and its interaction with geospace. Furthermore, a great diversity of the geomagnetic field changes, from secular (over decades to centuries) to short time variations (down to minutes and seconds), can be detected only through continued observations. An international effort to watch and record geomagnetic changes first began in the 1830s with a network of scientific observers organized by Karl Friedrich Gauss in Germany, and this effort has continued since then.
The April 2009 Abruzzi, Italy, Earthquake: Impact on Site Seismic Hazard Estimation
Authors: Rapolla Antonio , Di Fiore Vincenzo , Di Nocera Silvio , Matano Fabio , Paoletti Valeria
Published: November 2009

At 0132 UTC (0332 local time) on 6 April 2009, a major earthquake (ML = 5.8, Mw = 6.3) occurred a few kilometers southwest of the city of L'Aquila in the Abruzzi region of central Italy (http://earthquake.usgs.gov/eqcenter/eqinthenews/2009/us2009fcaf/). The quake was preceded by a long and often intense seismic sequence, and it was followed by a series of aftershocks. The extensive damage from the major earthquake resulted in about 300 fatalities, 1200 injuries, and 40,000 evacuees, suggesting widespread ground motioneffects and Mercalli‐Cancani‐Sieberg (MCS) scale intensities of up to level IX (http://portale.ingv.it/ primo‐piano‐1/news‐archive/2009‐news/april‐6‐earthquake/copythe‐l‐aquila‐seismic‐sequence‐april‐2009/view?set_language=en). Such intensity levels correspond to an impact on buildings, in terms of maximum ground horizontal acceleration, as great as 0.6 g, where g is the acceleration of gravity. An acceleration of about 0.6 g actually was measured by accelerometric stations in the L'Aquila valley (http://mceer.buffalo.edu/infoservice/disasters/ground‐motion‐summary.pdf).
Decreased water use in the U.S.
Authors: Showstack Randy
Published: November 2009

Estimated water use in the United States in 2005 was slightly less than the estimated use in 2000 and about 5% less than total withdrawals in the peak year of 1980, despite a 30% population increase during the past 25 years, according to a new report from the U.S. Geological Survey (USGS), “Estimated use of water in the United States in 2005,” issued on 29 October.
Comment on “Developing and Implementing an Effective Public Outreach Program”
Authors: Schon Samuel C.
Published: November 2009

J. A. Harrison et al. (Eos, 90(38), 333–334, 22 September 2009) provide a laudable overview of scientific outreach and the steps required to support a robust public outreach effort. However, it is unfortunate that issues related to energy were absent from the profiled list of outreach resources. Energy issues unite geoscience disciplines ranging from rock mechanics to atmospheric kinetics. Furthermore, energy issues make up a large and important part of the public discourse about economic recovery, security, and environmental protection.
Stagnant lid convection and carbonate metasomatism of the deep continental lithosphere
Authors: Sleep Norman H.
Published: November 2009

The current (and past) mantle adiabat beneath continents is hot enough that ascending carbonate‐rich domains partially melt liberating kimberlites. Over the last 2 Ga, most of these kimberlites have been trapped and frozen in the deep continental lithosphere, forming a massive CO2 reservoir. Geochemical studies of kimberlites that reached the surface indicate the pervasiveness of their effects within the deep lithosphere. These magmas extensively reacted with the deep lithosphere on the way up. Conversely, studies of deep mantle xenoliths brought up in kimberlites detect repeated episodes of metasomatism by these fluids. The heat balance between convection and conduction through the lithosphere provides gross constraints on the cumulative global effects of this process. Stagnant lid (including chemical lid) convection supplies heat to the base of continental lithosphere in equilibrium with the conductive heat flow. The thermal gradient beneath continents is constrained by xenolith geotherms and mantle heat flow q is ∼20 mW m−2. The upwelling velocity V at the base of the thermal boundary layer is ∼q/TηρC, where ρC is volume specific heat, 4 MJ m−3 and Tη is the temperature to change viscosity by a factor of e, ∼60 K. The upwelling velocity is thus ∼2 km per million years; the mass of the mantle circulates beneath continents over ∼2 Ga. The rate that plate tectonics recirculates the mantle is comparable and limits the supply carbonate‐rich undepleted material to the melting zone of upwelling stagnant lid convection and thus the production of kimberlites. Overall the amount of CO2 emplaced by kimberlites into continental lithosphere is a significant fraction (∼1/2) of that in the convecting mantle, resulting in a major deep lithospheric reservoir of CO2 of ∼5000 × 1018 moles, an equivalent thickness of ∼2 km carbonatized rock. This process, however, is insufficient to affect the overall density of deep lithosphere. The observed linearity of the xenolith geotherm precludes equivalent thicknesses of several kilometers depending on the radioactive element concentration of actual kimberlites. Kimberlites are partial melts often of subducted carbonatized oceanic crust and hence have CO2 to radioactive element ratios higher than the bulk mantle. Most kimberlites remain within the deep lithosphere because ascending dikes do not usually penetrate the region of horizontal compression in the strong cool part of the lithosphere. Conversely stresses relax quickly within the warm deep lithosphere allowing dikes to repeatedly intrude.
Role of molecular size in cloud droplet activation
Authors: Petters M. D. , Kreidenweis S. M. , Prenni A. J. , Sullivan R. C. , Carrico C. M. , Koehler K. A. , Ziemann P. J.
Published: November 2009

We examine the observed relationships between molar volume (the ratio of molar mass and density) and cloud condensation nuclei (CCN) activity for sufficiently soluble organic compounds found in atmospheric particulate matter. Our data compilation includes new CCN data for certain carbohydrates and oligoethylene glycols, as well as published data for organic compounds. We compare predictions of CCN activity using water activities based on Raoult's law and Flory‐Huggins theory to observations. The Flory‐Huggins water activity expression, with an assumed surface tension of pure water, generally predicts CCN activity within a factor of two over the full range of molar volumes considered. CCN activity is only weakly dependent on molar volume for values exceeding 600 cm3 mol−1, and the diminishing sensitivity to molar volume, combined with the significant scatter in the data, limits the accuracy with which molar volume can be inferred from CCN measurements.
Deep ocean heat uptake as a major source of spread in transient climate change simulations
Authors: Boé J. , Hall A. , Qu X.
Published: November 2009

Two main mechanisms can potentially explain the spread in the magnitude of global warming simulated by climate models: deep ocean heat uptake and climate feedbacks. Here, we show that deep oceanic heat uptake is a major source of spread in simulations of 21st century climate change. Models with deeper baseline polar mixed layers are associated with larger deep ocean warming and smaller global surface warming. Based on this result, we set forth an observational constraint on polar vertical oceanic mixing. This constraint suggests that many models may overestimate the efficiency of polar oceanic mixing and therefore may underestimate future surface warming. Thus to reduce climate change uncertainties at time‐scales relevant for policy‐making, improved understanding and modelling of oceanic mixing at high latitudes is crucial.
On the use of 14CO2 as a tracer for fossil fuel CO2: Quantifying uncertainties using an atmospheric transport model
Authors: Turnbull Jocelyn , Rayner Peter , Miller John , Naegler Tobias , Ciais Philippe , Cozic Anne
Published: November 2009

Δ14CO2 observations are increasingly used to constrain recently added fossil fuel CO2 in the atmosphere. We use the LMDZ global atmospheric transport model to examine the pseudo‐Lagrangian framework commonly used to determine recently added fossil fuel CO2 (CO2ff). Our results confirm that Δ14CO2 spatial variability in the Northern Hemisphere troposphere is dominated by the effect of CO2ff, whereas in the Southern Hemisphere, ocean CO2 exchange is more important. The model indicates that the free troposphere, at 3–5 km altitude, is a good choice for “background,” relative to which the recently added fossil fuel CO2 can be calculated, although spatial variability in free tropospheric Δ14CO2 contributes additional uncertainty to the CO2ff calculation. Comparison of model and observations suggests that care must be taken in using high‐altitude mountain sites as a proxy for free tropospheric air, since these sites may be occasionally influenced by (polluted) boundary layer air, especially in summer. Other sources of CO2 which have Δ14C different than that of the atmosphere contribute a bias, which, over the Northern Hemisphere land, is mostly due to the terrestrial biosphere, whereas ocean CO2 exchange and nuclear industry and natural cosmogenic production of 14C contribute only weakly. The model indicates that neglecting this bias leads to a consistent underestimation of CO2ff, typically between 0.2 and 0.5ppm of CO2, with a maximum in summer. While our analysis focuses on fossil fuel CO2, our conclusions, particularly the choice of background site, can also be applied to other trace gases emitted at the surface.
Local air‐sea interaction in Intertropical Convergence Zone simulations
Authors: Duan Anmin , Sui Chung‐Hsiung , Wu Guoxiong
Published: November 2009

We investigate how air‐sea interaction affects an Intertropical Convergence Zone (ITCZ) simulation in the SAMIL2.08 atmospheric general circulation model (AGCM). In a control experiment (Exp1) with the observed sea surface temperature (SST) prescribed in the AGCM, there exists a problem of excessive precipitation over much of the Tropics and insufficient precipitation over the equatorial Indian Ocean and the Pacific. The equatorial drought belt arises from the compensatory descending motion associated with exaggerated deep convection over the tropics in both hemispheres. A double ITCZ disappears in a coupled experiment (Exp2) with the same AGCM as used in Exp1 coupled to an interactive ocean mixed layer within the great warm pool. This finding demonstrates that local air‐sea interaction can modify the SST pattern, thereby regulating the climate mean state via the following processes. Local air‐sea flux exchanges in tropical convective regions such as the ITCZ tend to cool SST via negative cloud‐radiation and wind‐evaporation feedbacks. Such changes further modify the tropical atmospheric circulation structure such that the equatorial compensatory descent in Exp1 is replaced by the equatorial convergence zone, as seen in nature. A third sensitivity experiment (Exp3), with the AGCM driven by the monthly SST field derived from the coupled experiment, yielded similar results to those obtained in Exp2. Overall, the results indicate that a reasonable depiction of the air‐sea coupling process is important to successfully simulating the tropical precipitation pattern, as the atmosphere is closely coupled with the ocean over the tropics.
Overcoming the Ontology Enrichment Bottleneck with Quick Term Templates
Authors: Peters Bjoern , Ruttenberg Alan , Greenbaum Jason , Courtot Melanie , Brinkman Ryan , Whetzel Patricia , Schober Daniel , Sansone Susanna Assunta , Scheuerman Richard , Rocca-Serra Philippe
Published: November 2009

The developers of the Ontology of Biomedical Investigations (OBI) primarily use Protégé for editing. However, adding many classes with similar patterns of logical definition is time consuming, error prone, and requires the editor to have some expertise in OWL. Therefore, the process is poorly suited for a large number of domain experts who have limited experience Protégé and ontology development. We have developed a procedure to ease this task and allow such domain experts to add terms to the ontology in a way that both effectively includes complex logical definitions yet requires minimal manual intervention by OBI developers. The procedure is based on editing a Quick Term Template in a spreadsheet format which is subsequently converted into an OWL file. This procedure promises to be a robust and scalable approach for ontology enrichment.
A benchmark study on the thermal conductivity of nanofluids
Authors: Buongiorno Jacopo , Venerus David C. , Prabhat Naveen , McKrell Thomas , Townsend Jessica , Christianson Rebecca , Tolmachev Yuriy V. , Keblinski Pawel , Hu Lin-wen , Alvarado Jorge L. , Bang In Cheol , Bishnoi Sandra W. , Bonetti Marco , Botz Frank , Cecere Anselmo , Chang Yun , Chen Gang , Chen Haisheng , Chung Sung Jae , Chyu Minking K. , Das Sarit K. , Di Paola Roberto , Ding Yulong , Dubois Frank , Dzido Grzegorz , Eapen Jacob , Escher Werner , Funfschilling Denis , Galand Quentin , Gao Jinwei , Gharagozloo Patricia E. , Goodson Kenneth E. , Gutierrez Jorge Gustavo , Hong Haiping , Horton Mark , Hwang Kyo Sik , Iorio Carlo S. , Jang Seok Pil , Jarzebski Andrzej B. , Jiang Yiran , Jin Liwen , Kabelac Stephan , Kamath Aravind , Kedzierski Mark A. , Kieng Lim Geok , Kim Chongyoup , Kim Ji-Hyun , Kim Seokwon , Lee Seung Hyun , Leong Kai Choong , Manna Indranil , Michel Bruno , Ni Rui , Patel Hrishikesh E. , Philip John , Poulikakos Dimos , Reynaud Cecile , Savino Raffaele , Singh Pawan K. , Song Pengxiang , Sundararajan Thirumalachari , Timofeeva Elena , Tritcak Todd , Turanov Aleksandr N. , Van Vaerenbergh Stefan , Wen Dongsheng , Witharana Sanjeeva , Yang Chun , Yeh Wei-Hsun , Zhao Xiao-Zheng , Zhou Sheng-Qi
Published: November 2009

This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady-state methods, and optical methods. The nanofluids tested in the exercise were comprised of aqueous and nonaqueous basefluids, metal and metal oxide particles, near-spherical and elongated particles, at low and high particle concentrations. The data analysis reveals that the data from most organizations lie within a relatively narrow band (±10% or less) about the sample average with only few outliers. The thermal conductivity of the nanofluids was found to increase with particle concentration and aspect ratio, as expected from classical theory. There are (small) systematic differences in the absolute values of the nanofluid thermal conductivity among the various experimental approaches; however, such differences tend to disappear when the data are normalized to the measured thermal conductivity of the basefluid. The effective medium theory developed for dispersed particles by Maxwell in 1881 and recently generalized by Nan et al. [J. Appl. Phys. 81, 6692 (1997)], was found to be in good agreement with the experimental data, suggesting that no anomalous enhancement of thermal conductivity was achieved in the nanofluids tested in this exercise.
A practical use of the Melnikov homoclinic method
Authors: Castilho César , Marchesin Marcelo
Published: November 2009

Using cutoff functions and periodic extensions, we prove that the Melnikov homoclinic method gives a criterium to show that for a finite time interval [−T,T], with T arbitrarily large, the perturbed system is conjugated to a chaotic one for quite general classes of perturbation functions. The method is applied to specific perturbations of the pendulum and of the Gylden’s problem.
Tunable propagation of light through a coupled-bent dielectric-loaded plasmonic waveguides
Authors: Chu Hong-Son , Ewe Wei-Bin , Li Er-Ping
Published: November 2009

We numerically show that it is easy to tune, both passively and actively, the transmission power delivered at different output ports of two coupled-bent dielectric-loaded plasmonic waveguides by varying the gap distance and refractive index of driven material between two dielectric stripes. We also investigate the near-field intensity to demonstrate that the power transmitted at different output ports can be varied to realize either equal or unequal levels, depending on the design specifications. A simple expression is proposed to predict the power transmitted to different output ports for a set of given dimensions and refractive index of the driven material.
X-ray irradiation effects on the trapping properties of Cd1−xZnxTe detectors
Authors: Fraboni B. , Pasquini L. , Castaldini A. , Cavallini A. , Siffert P.
Published: November 2009

CdZnTe-based detectors possess unique properties as room-temperature x- and gamma-ray detectors. We report on the effects of x-ray irradiation on CdZnTe and CdTe:Cl detectors with increasing x-ray doses. We correlate the “macroscopic” performance of the detectors, investigated by gamma-ray spectroscopy to the “microscopic” effects induced by the impinging radiation, i.e., the defective states introduced in the crystal lattice. The electrical activity of the defects and their activation energy have been investigated by photo induced current transient spectroscopy and by space charge limited current analyses. We identify the x-ray dose that induces a significant degradation in the detector performance, and by cross-correlating the results obtained, we achieve a reliable estimate of the actual concentration of electrically active deep states and assess the potentiality of these experimental methods as tools for quantitative analyses of high resistivity materials.
Frequency response of cantilever beams immersed in compressible fluids with applications to the atomic force microscope
Authors: Van Eysden Cornelis A. , Sader John E.
Published: November 2009

The dynamics of microcantilever beams can be strongly affected by immersion in fluid. While the importance of viscosity for devices of microscale dimensions is well established, the significance of fluid compressibility has not been investigated in detail. Here, we present a rigorous theoretical model for the frequency response of a rectangular cantilever beam that is executing normal and torsional oscillations, and is immersed in a compressible fluid. Both the viscous case and the inviscid limit are considered, and the model is valid for arbitrary mode number. We find that compressibility becomes increasingly important as the mode number rises. This is particularly relevant for gases, where compressibility is found to be important for high mode numbers of practical interest.
Pr
3
+
-doped fluoro-oxide lithium glass as scintillator for nuclear fusion diagnostics
Authors: Arikawa Yasunobu , Yamanoi Kohei , Nakazato Tomoharu , Estacio Elmer Surat , Shimizu Toshihiko , Sarukura Nobuhiko , Nakai Mitsuo , Norimatsu Takayoshi , Azechi Hiroshi , Murata Takahiro , Fujino Shigeru , Yoshida Hideki , Kamada Kei , Usuki Yoshiyuki , Suyama Toshihisa , Yoshikawa Akira , Sato Nakahiro , Kan Hirofumi
Published: November 2009

Experimental results are presented on the neutron scintillating properties of a custom-designed Pr3+(praseodymium)-doped lithium (Li) glass. Luminescence was observed at 278 nm wavelength, originating from the 5d-4f transition. Time-resolved measurements yielded about 20 ns decay times for ultraviolet and x-ray excitation while much faster decay times of about 6 ns were observed for alpha particle and neutron excitation. Actual time-of-flight data in laser fusion experiments at the GEKKO XII facility of the Institute of Laser Engineering, Osaka University reveal that it can clearly discriminate fusion neutrons from the much stronger x-rays signals. This material can promise improved accuracy in future scattered neutron diagnostics.
Strategies for nanoplasmonic core-satellite biomolecular sensors: Theory-based Design
Authors: Ross Benjamin M. , Waldeisen John R. , Wang Tim , Lee Luke P.
Published: November 2009

We present a systematic theoretical study of core-satellite gold nanoparticle assemblies using the Generalized Multiparticle Mie formalism. We consider the importance of satellite number, satellite radius, the core radius, and the satellite distance, and we present approaches to optimize spectral shift due to satellite attachment or release. This provides clear strategies for improving the sensitivity and signal-to-noise ratio for molecular detection, enabling simple colorimetric assays. We quantify the performance of these strategies by introducing a figure of merit. In addition, we provide an improved understanding of the nanoplasmonic interactions that govern the optical response of core-satellite nanoassemblies.
Study on the paramagnetic relaxation mechanisms by R87b nuclear magnetic resonance in Rb2MnCl4 crystals of A2BX4 type
Authors: Lim Ae Ran
Published: November 2009

The spin-lattice relaxation time, T1, for R87b nuclei in Rb2MnCl4 crystals was investigated, and a phase transition was found near 383 K (=TC). The R87b spectrum changes near TC from two central resonance lines due to Rb(1) and Rb(2) to one Rb central resonance line, and this change is due to changes in the local symmetry of the Rb sites near TC. The central resonance lines for Rb nuclei in Rb2MnCl4 crystals are shifted to higher frequencies by the paramagnetic ions. Further, the relaxation times for the Rb(1) and Rb(2) nuclei in Rb2MnCl4 crystals are more or less continuous near TC. Below TC, the spin-lattice relaxation rates, T1−1, for Rb(1) and Rb(2) are proportional to T−2, which implies that these relaxations occur mainly via Raman processes. We also compare our results for Rb2MnCl4 with those reported previously for Rb2BCl4 (B=Co and Zn) and CsBCl3 (B=Mn, Cu, Zn, and Cd) crystals.
Relationship between oxygen defects and the photoluminescence property of ZnO nanoparticles: A spectroscopic view
Authors: Sharma Prashant K. , Pandey Avinash C. , Zolnierkiewicz Grzegorz , Guskos Nikos , Rudowicz Czeslaw
Published: November 2009

The present paper deals with the synthesis and characterization of ZnO nanoparticles obtained by coprecipitation method at three different pH conditions. Samples characterizations aimed at understanding their spectroscopic properties are carried out using a variety of experimental techniques. X-ray diffraction and transmission electron microscopic studies show significant increase in the particle size of the synthesized ZnO nanoparticles ranging from 3–40 nm with increasing pH values. Absorption spectra show particle size dependent blueshift in the energy band, which may be ascribed to quantum confinement effect. Fourier transform infrared (FTIR) spectroscopy reveals enhancement in the surface defects of the synthesized ZnO nanoparticles with increasing pH values. Electron paramagnetic resonance studies at room temperature (300 K) and several liquid helium temperatures (including the lowest temperature 13 K for all samples) indicate the presence of singly ionized oxygen vacancy defects (VO+) and O2− superoxide ions in the ZnO nanoparticles. These results are well supported by FTIR and photoluminescence spectroscopy. The emissions from these nanoparticles are also found to be size dependent, whereas the ratio of UV emission to oxygen vacancy related green emission is found to increase with increasing pH values. Furthermore, a plausible mechanism of the observed defect mediated green emission is proposed.
High sensitivity of O17 NMR to p-d hybridization in transition metal perovskites: First principles calculations of large anisotropic chemical shielding
Authors: Pechkis Daniel L. , Walter Eric J. , Krakauer Henry
Published: November 2009

A first principles embedded cluster approach is used to calculate O chemical shielding tensors, σ̂, in prototypical transition metal oxide ABO3 perovskite crystals. Our principal findings are (1) a large anisotropy of σ̂ between deshielded σx≃σy and shielded σz components (z along the Ti–O bond); (2) a nearly linear variation, across all the systems studied, of the isotropic σiso and uniaxial σax components, as a function of the B-O-B bond asymmetry. We show that the anisotropy and linear variation arise from large paramagnetic contributions to σx and σy due to virtual transitions between O(2p) and unoccupied B(nd) states. The calculated isotropic δiso and uniaxial δax chemical shifts are in good agreement with recent BaTiO3 and SrTiO3 single crystal O17 NMR measurements. In PbTiO3 and PbZrO3, calculated δiso are also in good agreement with NMR powder spectrum measurements. In PbZrO3, δiso calculations of the five chemically distinct sites indicate a correction of the experimental assignments. The strong dependence of σ̂ on covalent O(2p)-B(nd) interactions seen in our calculations indicates that O17 NMR spectroscopy, coupled with first principles calculations, can be an especially useful tool to study the local structure in complex perovskite alloys.
A gas-tight Cu Kα x-ray transparent reaction chamber for high-temperature x-ray diffraction analyses of halide gas/solid reactions
Authors: Shian Samuel , Sandhage Kenneth H.
Published: November 2009

An externally heated, x-ray transparent reaction chamber has been developed to enable the dynamic high temperature x-ray diffraction (HTXRD) analysis of a gas/solid [TiF4(g)/SiO2(s)] reaction involving a halide gas reactant formed at elevated temperatures (up to 350 °C) from a condensed source (TiF4 powder) sealed within the chamber. The reaction chamber possessed x-ray transparent windows comprised of a thin (13 μm) internal layer of Al foil and a thicker (125 μm) external Kapton film. After sealing the SiO2 specimens (diatom frustules or Stöber spheres) above TiF4 powder within the reaction chamber, the chamber was heated to a temperature in the range of 160–350 °C to allow for internal generation of TiF4(g). The TiF4(g) underwent a metathetic reaction with the SiO2 specimen to yield a TiOF2(s) product. HTXRD analysis, using Cu Kα x rays passed through the Kapton/Al windows of the chamber, was used to track the extent of SiO2 consumption and/or TiOF2 formation with time. The Al foil inner layer of the windows protected the Kapton film from chemical attack by TiF4(g), whereas the thicker, more transparent Kapton film provided the mechanical strength needed to contain this gas. By selecting an appropriate combination of x-ray transparent materials to endow such composite windows with the required thermal, chemical, and mechanical performance, this inexpensive reaction chamber design may be applied to the HTXRD analyses of a variety of gas/solid reactions.
Resonance terahertz detection in ungated two-dimensional electron gas
Authors: Cheremisin M. V.
Published: November 2009

The response of an ungated two-dimensional electron gas to an external electromagnetic excitation is analyzed. The possibility of creating a single-mode resonance detector operating in the terahertz frequency range is demonstrated.
Effect of annealing on charge transfer in Ge nanocrystal based nonvolatile memory structure
Authors: Yang M. , Chen T. P. , Liu Z. , Wong J. I. , Zhang W. L. , Zhang S. , Liu Y.
Published: November 2009

Ge nanocrystals (nc-Ge) embedded in the gate oxide of the nonvolatile memory structure were synthesized by Ge ion implantation followed by thermal annealing at 800 °C for various durations. Large changes in the structural and chemical properties of the Ge+-implanted oxide have been observed, and they have been found to possess a significant impact on the charge transfer in the oxide layer. The distribution and concentration of the nc-Ge and dissolved Ge atoms which serve as both the charge storage and transfer sites in the oxide are affected by the annealing. Two charge transfer mechanisms, i.e., the lateral charge diffusion along the Ge-distributed layer and the charge leakage from the charge storage sites to the Si substrate via the charge transfer sites, have been identified based on the charge retention behaviors. Both mechanisms are enhanced by the annealing as a result of the change in the distribution and concentration of the charge transfer sites.
Ions in hyaluronic acid solutions
Authors: Horkay Ferenc , Basser Peter J. , Londono David J. , Hecht Anne-Marie , Geissler Erik
Published: November 2009

Hyaluronic acid (HA) is an anionic biopolymer that is almost ubiquitous in biological tissues. An attempt is made to determine the dominant features that account for both its abundance and its multifunctional role, and which set it apart from other types of biopolymers. A combination of osmotic and scattering techniques is employed to quantify its dynamic and static properties in near-physiological solution conditions, where it is exposed both to mono- and divalent counterions. An equation of state is derived for the osmotic pressure Π in the semidilute concentration region, in terms of two variables, the polymer concentration c and the ionic strength J of the added salt, according to which Π=1.4×103c9/4/J3/4 kPa, where c and J are expressed in mole. Over the physiological ion concentration range, the effect of the sodium chloride and calcium chloride on the osmotic properties of HA solutions is fully accounted for by their contributions to the ionic strength. The absence of precipitation, even at high CaCl2 concentrations, distinguishes this molecule from other biopolymers such as DNA. Dynamic light scattering measurements reveal that the collective diffusion coefficient in HA solutions exceeds that in aqueous solutions of typical neutral polymers by a factor of approximately 5. This property ensures rapid adjustment to, and recovery from, stress applied to HA-containing tissue. Small angle x-ray scattering measurements confirm the absence of appreciable structural reorganization over the observed length scale range 10–1000 Å, as a result of calcium-sodium ion exchange. The scattered intensity in the transfer momentum range q>0.03 Å−1 varies as 1/q, indicating that the HA chain segments in semidilute solutions are linear over an extended concentration range. The osmotic compression modulus c∂Π/∂c, a high value of which is a prerequisite in structural biopolymers, is several times greater than in typical neutral polymer solutions.
Effect of surface stress on the stiffness of cantilever plates: Influence of cantilever geometry
Authors: Lachut Michael J. , Sader John E.
Published: November 2009

Numerous measurements have indicated that surface stress can significantly modify the stiffness of cantilever sensors. In contrast, theoretical calculations using classical beam theory predict that stiffness is independent of surface stress. Using a three-dimensional analysis, we recently showed that surface stress does indeed have an effect within the framework of linear elasticity. However, only cantilevers of rectangular geometry were explored. Here, we vary cantilever geometry and find that it plays a critical role, with V-shaped cantilevers displaying greatly enhanced sensitivity in comparison to rectangular cantilevers. Tuning cantilever geometry therefore provides a sensitive route to controlling the effects of surface stress.
Time-resolved proper orthogonal decomposition of liquid jet dynamics
Authors: Arienti Marco , Soteriou Marios C.
Published: November 2009

New insight into the mechanism of liquid jet in crossflow atomization is provided by an analysis technique based on proper orthogonal decomposition and spectral analysis. Data are provided in the form of high-speed videos of the jet near field from experiments over a broad range of injection conditions. For each condition, proper orthogonal modes (POMs) are generated and ordered by intensity variation relative to the time average. The feasibility of jet dynamics reduction by truncation of the POM series to the first few modes is then examined as a function of crossflow velocity for laminar and turbulent liquid injection. At conditions where the jet breaks up into large chunks of liquid, the superposition of specific orthogonal modes is observed to track long waves traveling along the liquid column. The temporal coefficients of these modes can be described as a bandpass spectrum that shifts toward higher frequencies as the crossflow velocity is increased. The dynamic correlation of these modes is quantified by their cross-power spectrum density. Based on the frequency and wavelength extracted from the videos, the observed traveling waves are linked to the linearly fastest growing wave of Kelvin–Helmholtz instability. The gas boundary layer thickness at the gas-liquid shear layer emerges at the end of this study as the dominant length scale of jet dynamics at moderate Weber numbers.
Terahertz detector based on a superconducting tunnel junction coupled to a thin superconductor film
Authors: Ariyoshi Seiichiro , Taino Tohru , Dobroiu Adrian , Sato Hiromi , Matsuo Hiroshi , Otani Chiko
Published: November 2009

The principle of a terahertz detector using a superconducting tunnel junction (STJ) coupled to a large terahertz-absorbing superconductor film is verified. We have detected terahertz radiation based on the Cooper-pair breaking process, and confirmed that the sensitivity has a sharp increase around 0.7 THz, a value that is in agreement with the gap frequency of the superconducting Nb. For high-sensitivity terahertz detection, we propose an improved design of the STJ detector composed of a smaller junction coupled to a thinner superconductor film. We also discuss the expected noise equivalent power of the optimized detector.
Agility of vortex-based nanocontact spin torque oscillators
Authors: Manfrini M. , Devolder T. , Kim Joo-Von , Crozat P. , Zerounian N. , Chappert C. , Van Roy W. , Lagae L. , Hrkac G. , Schrefl T.
Published: November 2009

We study the agility of current-tunable oscillators based on a magnetic vortex orbiting around a point contact in spin valves. The theory predicts that frequency tuning by currents occurs at constant orbital radius so an exceptional agility is anticipated. To test this, we have inserted an oscillator in a microwave interferometer to apply abrupt current variations while time resolving its emission. Using frequency shift keying, we show that the oscillator can switch between two stabilized frequencies differing by 25% in less than ten periods. With a wide frequency tunability and a good agility, such oscillators possess desirable figures of merit for modulation-based rf applications.
Calculation of the static electronic second hyperpolarizability or χ(3) tensor of three-dimensional periodic compounds with a local basis set
Authors: Orlando Roberto , Ferrero Mauro , Rérat Michel , Kirtman Bernard , Dovesi Roberto
Published: November 2009

The coupled perturbed Hartree–Fock (CPHF) method for evaluating static first (β) and second (γ) hyperpolarizability tensors of periodic systems has recently been implemented in the CRYSTAL code [Bishop et al., J. Chem. Phys. 114, 7633 (2001)]. We develop here an efficient and accurate computational protocol, along with the local basis sets needed for first and second row atoms. Application is made to several high symmetry three-dimensional systems including one (pyrope) with an 80 atom unit cell. CPHF second-order hyperpolarizabilities substantially undershoot experimental values, due to an overestimate of the band gap, but trends are satisfactorily reproduced for β as well as γ.
Robust atomic resolution imaging of light elements using scanning transmission electron microscopy
Authors: Findlay S. D. , Shibata N. , Sawada H. , Okunishi E. , Kondo Y. , Yamamoto T. , Ikuhara Y.
Published: November 2009

We show that an annular detector placed within the bright field cone in scanning transmission electron microscopy allows direct imaging of light elements in crystals. In contrast to common high angle annular dark field imaging, both light and heavy atom columns are visible simultaneously. In contrast to common bright field imaging, the images are directly and robustly interpretable over a large range of thicknesses. We demonstrate this through systematic simulations and present a simple physical model to obtain some insight into the scattering dynamics.
Localized edge states in plane Couette flow
Authors: Duguet Yohann , Schlatter Philipp , Henningson Dan S.
Published: November 2009

The dynamics at the threshold of transition in plane Couette flow is investigated numerically in a large spatial domain for a certain type of localized initial perturbation, for Re between 350 and 1000. The corresponding edge state is an unsteady spotlike structure, localized in both streamwise and spanwise directions, which neither grows nor decays in size. We show that the localized nature of the edge state is numerically robust, and is not influenced by the size of the computational domain. The edge trajectory appears to transiently visit localized steady states. This suggests that basic spatiotemporally intermittent features of transition to turbulence, such as the growth of a turbulent spot, can be described as a dynamical system.
Remote monitoring of the behaviour and activity of captive southern hairy-nosed wombats (Lasiorhinus latifrons)
Authors: Hogan Lindsay A. , Phillips Clive J. C. , Lisle Allan , Horsup Alan B. , Janssen Tina , Johnston Steve D.
Published: November 2009

The nocturnal nature of wombats makes it difficult to learn about their behavioural ecology and activity rhythms in the wild. A facility was established at Rockhampton Zoo to house 12 adult southern hairy-nosed wombats in order to monitor their behaviour by means of video surveillance and provide detailed information on their activity patterns using movement-sensitive radio-transmitters. After one year of monitoring it was established that the wombats spent, on average, as a proportion of total time 69.9% sleeping, 8.8% lying resting, 5.2% feeding, 5.2% exploring, 4.3% performing stereotyped behaviour, 2.5% sitting resting and 4.1% in other activities. Feeding, lying resting and sleeping varied with season by ~5%. Temporal patterns were bimodal for 8 of the 12 behaviours described, with most ‘active’ behaviours being expressed between 1800 and 2000 hours and 0200 and 0500 hours. The activity pattern was characterised by a strong circadian rhythm, with most activity occurring nocturnally. Within active periods there was an alternating rhythm of active and rest periods and activity peaks at the beginning and end of each night. Comprehensive and reliable information on the behavioural ecology, as well as captive management, of southern hairy-nosed wombats was obtained from the remote video and radio-transmitter recordings.
A technique for sampling blood from cattle during transportation
Authors: Parker A. J. , Coleman C. J. , Fitzpatrick L. A.
Published: November 2009

A technique for the safe sampling of blood from cattle during transportation is described. The technique was validated using four 2.5-year-old Bos indicus steers held in stalls on a stationary body truck for 2 h, transported for 4 h and then held on a stationary truck for a further 2 h. The length of time required to take a blood sample from one animal using this technique was 30 s. Information gathered using this technique will be helpful in understanding the physiological reactions of cattle to transportation.
Lambing season and fertility of fat-tailed ewes under an extensive production system are associated with liveweight and body condition around mating
Authors: Esmailizadeh A. K. , Dayani O. , Mokhtari M. S.
Published: November 2009

The objective of this study was to investigate to what extent fertility and lambing season of fat-tailed ewes raised under an extensive production system are related to liveweight, body condition and changes around mating. Ewe liveweight and body condition score (BSC) were recorded in June, July and August over a period of 3 years (1999–2001) in 11 flocks (eight flocks of Kurdi breed and three flocks of Kurdi × Sanjabi crossbred). Both Kurdi and Sanjabi are native fat-tailed breeds in western Iran. In total, 3278 lambing records relating to 1592 ewes and data on mating date, liveweight and BCS of 1930 ewes (3975 records) were used for statistical analyses. The statistical model for bodyweight and body condition data included fixed effects of breed group, flock nested within breed group, year, the future lambing status following summer breeding (barren, autumn lambing and winter lambing), ewe age and all two-way interactions. Breed group had a significant effect on ewe liveweight (P < 0.01). However, there was no significant difference between BCS of the two breed groups around mating. Ewe liveweights measured in June, July and August had significant effects on fertility and lambing season (P < 0.01). Ewes that produced lambs were generally heavier at mating than barren ewes (P < 0.01). Autumn-lambing ewes were heavier than winter-lambing ewes in June and July (P < 0.01). Effects of changes in liveweight on fertility and lambing season were significant (P < 0.01). The effects of BCS in June, July and August (P < 0.01) and changes in BCS during the mating period (P < 0.05) on fertility and lambing season were also significant. The mean BCS (in June and July) of autumn-lambing ewes was greater than that of the winter-lambing and barren ewes (P < 0.05). The proportion of autumn-lambing ewes significantly increased as BCS in July increased, whereas the proportion of barren ewes decreased (P < 0.01). Fertility was associated with age so that as the age of the ewes increased from 2 to 7 years, the proportion of barren ewes significantly decreased from 29 to 5% (P < 0.01). There was a relatively high proportion of very thin ewes of 2 and 3 years of age. These findings imply that low body condition is a particular problem in younger ewes suggesting the importance of giving special nutritional treatment to younger ewes to reduce the proportion of barren ewes.
Ractopamine supplementation increases lean deposition in entire and immunocastrated male pigs
Authors: Moore K. L. , Dunshea F. R. , Mullan B. P. , Hennessy D. P. , D'Souza D. N.
Published: November 2009

Sixty entire male pigs (Large White × Landrace × Duroc crossbred) were individually reared from 45 to 114 kg liveweight in a 2 by 3 factorial experiment to determine the interactive effects of sex (entire male pigs v. male pigs immunologically castrated using Improvac with vaccinations administered at 13 weeks of age and 5 weeks before slaughter) and a ractopamine feeding program (constantly fed 0 or 5 ppm ractopamine for 26 days before slaughter v. a step-up program where 5 ppm of ractopamine was fed for 14 days followed by 10 ppm ractopamine for the final 12 days before slaughter) on growth performance, carcass composition and pork quality. Following the second vaccination, immunocastrated pigs ate more (P < 0.001) and grew faster (P < 0.05) than entire male pigs without affecting feed conversion efficiency. Dietary ractopamine supplementation for the last 26 days before slaughter improved feed conversion ratio (P = 0.024) and daily gain (P = 0.046). Dietary ractopamine supplementation also increased carcass total tissue (P = 0.023) and total lean (P = 0.027) content without affecting the objective meat quality (P > 0.05) in both entire and immunocastrated male pigs. The effects of dietary ractopamine and immunocastration were additive, such that pigs that were immunocastrated and received ractopamine grew 18% faster than control entire males. However, a step-up program of ractopamine supplementation did not provide further improvements in growth performance and carcass composition when compared with constant 5 ppm ractopamine supplementation. These findings indicate that ractopamine supplementation improved growth performance in entire and immunocastrated male pigs, thereby offering a means of improving growth performance of entire males without detrimental effects on pork quality.
Designer disordered materials with large, complete photonic band gaps
Authors: Florescu Marian , Torquato Salvatore , Steinhardt Paul J.
Published: November 2009

We present designs of 2D, isotropic, disordered, photonic materials of arbitrary size with complete band gaps blocking all directions and polarizations. The designs with the largest band gaps are obtained by a constrained optimization method that starts from a hyperuniform disordered point pattern, an array of points whose number variance within a spherical sampling window grows more slowly than the volume. We argue that hyperuniformity, combined with uniform local topology and short-range geometric order, can explain how complete photonic band gaps are possible without long-range translational order. We note the ramifications for electronic and phononic band gaps in disordered materials.
Crop growth and yield.
Authors: Heuvelink E. , Dorais M.
Published: November 2009

The processes that determine tomato crop growth and yield are considered in detail, with emphasis on the influence of environmental factors such as light, CO2, temperature, humidity and salinity. The main topics are as follows: Biomass production (leaf area and light interception, leaf and crop photosynthesis); Crop and fruit growth; Biomass partitioning (source strength, transport path, sink strength, shoot:root ratio, and influence of growing conditions and cultural practices); Fruit dry matter content; and Crop growth models (describing the TOMSIM model for tomato growth, development and yield, and its use in 2 case studies on optimum fruit number/truss and mitigation of salinity effects on yield by improving LAI).
Characteristics of important commercial apple cultivars.
Authors: Hampson C. R. , Kemp H.
Published: November 2009

The characteristics of the trees and fruits of the important apple cultivars Delicious, Golden Delicious, Fuji, Granny Smith, Gala, Jonathan, Jonagold, McIntosh, Rome Beauty, Braeburn, Elstar and Cox's Orange Pippin, as well as their production and breeding, are discussed in this chapter.
Water relations of apples.
Authors: Lakso A. N.
Published: November 2009

This chapter covers the basics of water relations in apples, including the concepts of water relations; measurement of apple tree water status; root system characteristics and its effects on plant water relations; water use by apple orchards; water deficits and apple tree growth, cropping and physiology; integration of water stress effects; and effects of rootstocks on apple water relations and drought tolerance.
Pruning and training physiology.
Authors: Ferree D. C. , Schupp J. R.
Published: November 2009

The types of pruning cuts and effects of pruning on the growth, flowering, fruiting and physiological processes in fruit trees are discussed, along with the physiological basis of training.
Apple-orchard planting systems.
Authors: Robinson T. L.
Published: November 2009

The different apple orchard planting systems including the spherical-shaped canopy, flat planar canopy and V-shaped canopy systems are described and compared in terms of field capacity and economics. The underlying principles of high-density orchard planting systems and orchard management practices for successful high-density orchards are discussed.
Endogenous hormones and bioregulator use on apples.
Authors: Greene D. W.
Published: November 2009

The classification, chemistry and application of plant growth regulators (PGR) are discussed. The effects of PGR on the growth, flowering and fruit set of apples, as well as their efficacy in controlling preharvest drop, improving fruit quality and influencing fruit maturity in the crop are presented.
Diseases of apple.
Authors: Grove G. G. , Eastwell K. C. , Jones A. L. , Sutton T. B.
Published: November 2009

This chapter covers diseases in apples caused by bacteria, fungi, viruses, viroids, phytoplasmas and virus-like or graft-transmissible diseases with no known causal agents. Postharvest diseases affecting the crop such as blue moulds caused by Penicillium sp. are also presented.