bluuebunny/crossref_metadata_2025 huggingface dataset:
Bottom turbulence on the muddy Atchafalaya Shelf, Louisiana, USA
Authors: Safak Ilgar , Sheremet Alexandru , Allison Mead A. , Hsu Tian‐Jian
Published: December 2010

Wave, current, and sediment observations collected in approximately 5 m depth on the muddy Atchafalaya clinoform, LA, USA, are used to study the interaction between near‐bed wave‐induced turbulent flows and suspended sediment characteristics in a muddy environment. Low wave‐bias estimates of near‐bed Reynolds stresses are strongly correlated with flow accelerations and suspended sediment concentration, as previously observed on sandy beaches, where accelerations have been associated with bed fluidization and sediment transport. A detailed numerical analysis of the observations is performed, based on a uni‐dimensional boundary layer model that accounts for the coupling between the fluid and the cohesive sediment phases. The numerical simulations suggest that sediment‐induced stratification effects are of the same order of magnitude as turbulent dissipation, and thus play a significant role in the turbulent kinetic energy balance within the tidal boundary layer. However, inside the wave boundary layer, the ratio of stratification to shear‐induced turbulence production (i.e., gradient Richardson number) decreases significantly, and shear‐induced turbulence production dominates. For these observations, the vertical structures of currents and Reynolds stresses are relatively insensitive to the exact floc size.
Volume, heat, and freshwater transports from the South China Sea to Indonesian seas in the boreal winter of 2007–2008
Authors: Fang Guohong , Susanto R. Dwi , Wirasantosa Sugiarta , Qiao Fangli , Supangat Agus , Fan Bin , Wei Zexun , Sulistiyo Budi , Li Shujiang
Published: December 2010

Acoustic Doppler current profiler observations were carried out at two stations along a transect northwest of the Karimata Strait from December 2007 to November 2008. One month and 10 months of full‐depth current data were obtained at the western and eastern stations, respectively. The observations show that the South China Sea (SCS) water flows persistently to the Indonesian seas (ISs) in boreal winter. On the basis of current, temperature, and salinity observations by conductivity‐temperature‐depth casts and bottom‐mounted sensors, the volume, heat, and freshwater transport from the SCS to ISs in the month from 13 January to 12 February 2008 are estimated to be 3.6 ± 0.8 Sv (Sv = 106 m3/s), 0.36 ± 0.08 PW, and 0.14 ± 0.04 Sv, respectively. The corresponding transport‐weighted temperature is 27.99°C. A downward sea surface slope from north to south at the study area in boreal winter is also found. The observations confirm the existence of the SCS branch of the Pacific‐to‐Indian‐Ocean throughflow in boreal winter and the reversal of the Karimata Strait transport in boreal summer. The seasonal variability in the Karimata Strait transport can exceed 5 Sv. It is proposed that the Karimata Strait throughflow plays a double role in the total Indonesian Throughflow transport, which is especially evident in boreal winter. The negative effect of the double role is reducing the Makassar Strait volume and heat transports; the positive effect is that the Karimata Strait throughflow itself can contribute volume and heat transports to the total Indonesian Throughflow.
Optical determination of phytoplankton size composition from global SeaWiFS imagery
Authors: Mouw Colleen B. , Yoder James A.
Published: December 2010

Phytoplankton cell size is important to biogeochemical and food web processes. The goal of this study is to estimate phytoplankton cell size distribution from satellite imagery of spectral remote sensing reflectance (Rrs(λ)). Previous studies have indicated phytoplankton size classes have distinctive absorption spectra despite the physiological and taxonomic variability within an assemblage. For this study, the chlorophyll specific absorption spectra for phytoplankton size class extremes, pico‐ and microphytoplankton, are weighted by the percent microplankton (Sfm) and are the basis of phytoplankton size retrieval from SeaWiFS imagery. Satellite retrievals of Sfm are done through implementation of a forward optical model look‐up table (LUT) that incorporates the range of absorption and scattering variability due to phytoplankton size, chlorophyll concentration ([Chl]) and dissolved and detrital matter (acdm(443)) in the global ocean from which Rrs(λ) is calculated by the radiative transfer software, Hydrolight. The Hydrolight modeled Rrs(λ) options for a given combination of [Chl] and acdm(443) within the LUT vary only due to Sfm. For a given pixel, the LUT search space was limited by satellite imagery of [Chl] and acdm(443). Within the narrowed search space, SeaWiFS Rrs(λ) was matched with the closest LUT Rrs(λ) option and the associated Sfm was assigned. Thresholds at which changes in Rrs(λ) due to Sfm could be discerned were established in terms of [Chl] and acdm(443). In situ high‐precision liquid chromatography–derived estimates of cell size are used in conjunction with matched daily satellite estimates of Sfm for validation and agree well. A single month is displayed as an example of the Sfm retrieval.
Surface drifter pair spreading in the North Atlantic
Authors: Lumpkin Rick , Elipot Shane
Published: December 2010

This study examines spreading of surface drifter pairs deployed as part of the CLIVAR Mode Water Dynamic Experiment (CLIMODE) project in the Gulf Stream region. The spreading is resolved at hourly resolution and quantified by relative dispersion and finite‐scale Lyapunov exponents. At scales from 1–3 km to 300–500 km, the dispersion follows Richardson's law, indicating stirring by eddies comparable in scale to the pair separation distance. At larger scales, the spreading becomes a random walk described by a constant diffusivity. The behavior from 1–3 km to the local deformation radius is inconsistent with the enstrophy cascade of 2‐D quasigeostrophic turbulence. To test various hypotheses for this result, drifter pair spreading is examined for pairs that were not launched together, pairs deployed in the eastern subtropical North Atlantic, and CLIMODE pairs subsampled to daily temporal resolution. Our results indicate the presence of significant energy at the submesoscale in the Gulf Stream region which flattens the wave number spectrum and dominates surface stirring at this scale range. Results in the less energetic subtropical eastern Atlantic are more equivocal.
Global correlations between winds and ocean chlorophyll
Authors: Kahru M. , Gille S. T. , Murtugudde R. , Strutton P. G. , Manzano‐Sarabia M. , Wang H. , Mitchell B. G.
Published: December 2010

Global time series of satellite‐derived winds and surface chlorophyll concentration (Chl‐a) show patterns of coherent areas with either positive or negative correlations. The correlation between Chl‐a and wind speed is generally negative in areas with deep mixed layers and positive in areas with shallow mixed layers. These patterns are interpreted in terms of the main limiting factors that control phytoplankton growth, i.e., either nutrients that control phytoplankton biomass in areas with positive correlation between Chl‐a and wind speed or light that controls phytoplankton biomass in areas with negative correlation between Chl‐a and wind speed. More complex patterns are observed in the equatorial regions due to regional specificities in physical‐biological interactions. These correlation patterns can be used to map out the biogeochemical provinces of the world ocean in an objective way.
Ground‐based measurements and dual‐Doppler analysis of 3‐D wind fields and atmospheric circulations induced by a meso‐γ‐scale inland lake
Authors: Asefi‐Najafabady Salvi , Knupp Kevin , Mecikalski John R. , Welch Ronald M. , Phillips Dustin
Published: December 2010

This paper presents a high‐resolution dual‐Doppler analysis of lake breeze mesoscale circulation induced by an elongated reservoir with a mean width of ∼2 km and an area of 125 km2. Compared to previous meso‐γ‐scale lake breeze studies based on point measurements or aircraft observations, the present study provides both a unique quantification and a high‐resolution spatial and temporal 3‐D visualization (several hundred meters and 5 min, respectively) of the kinematic structure of the lake breeze initiation and evolution. Visible satellite images show a cloud‐free zone over the lake and adjacent land areas that was promoted by subsidence associated with the lake breeze circulation. The background synoptic‐scale wind flow was almost parallel to the major axis of the lake, and distinct lake breeze frontal zones formed along both shorelines spanning the length of the lake. Dual‐Doppler analyses showed updrafts in the frontal zones, perturbation horizontal velocities of 1.5 m s−1 on both sides of the lake, and maximum downdrafts of 2 m s−1 centered over the lake. Vertical vorticity in the boundary layer was produced by differential friction between the smooth lake and adjacent land. The circulations are robust and are maintained during the day against a minor change in background wind direction. The study shows that the circulations produced by a small lake can generate significant mesoscale circulations that influence local climatology and identifies the importance of including such small mesoscale processes in global forecast models.
A critical remark on the applicability of E‐OBS European gridded temperature data set for validating control climate simulations
Authors: Kyselý Jan , Plavcová Eva
Published: December 2010

The study compares daily maximum (Tmax) and minimum (Tmin) temperatures in two data sets interpolated from irregularly spaced meteorological stations to a regular grid: the European gridded data set (E‐OBS), produced from a relatively sparse network of stations available in the European Climate Assessment and Dataset (ECA&D) project, and a data set gridded onto the same grid from a high‐density network of stations in the Czech Republic (GriSt). We show that large differences exist between the two gridded data sets, particularly forTmin. The errors tend to be larger in tails of the distributions. In winter, temperatures below the 10% quantile ofTmin, which is still far from the very tail of the distribution, are too warm by almost 2°C in E‐OBS on average. A large bias is found also for the diurnal temperature range. Comparison with simple average series from stations in two regions reveals that differences between GriSt and the station averages are minor relative to differences between E‐OBS and either of the two data sets. The large deviations between the two gridded data sets affect conclusions concerning validation of temperature characteristics in regional climate model (RCM) simulations. The bias of the E‐OBS data set and limitations with respect to its applicability for evaluating RCMs stem primarily from (1) insufficient density of information from station observations used for the interpolation, including the fact that the stations available may not be representative for a wider area, and (2) inconsistency between the radii of the areal average values in high‐resolution RCMs and E‐OBS. Further increases in the amount and quality of station data available within ECA&D and used in the E‐OBS data set are essentially needed for more reliable validation of climate models against recent climate on a continental scale.
Microwave absorption of supercooled clouds and implications for the dielectric properties of water
Authors: Mätzler Christian , Rosenkranz Philip W. , Cermak Jan
Published: December 2010

The absorption of liquid clouds was determined in the frequency range from 21 to 31 GHz and over the temperature range from 246 to 279 K. The information was derived from continuous surface‐based microwave and infrared radiometer observations at Bern, Switzerland, from 2006 to 2010 and using satellite data for cloud‐top temperature. The results indicate that common dielectric models of liquid water are inaccurate at temperatures below 265 K, possibly owing to the poor representation of the main relaxation frequency of water. The best agreement with our observations is found for a model published in report form in 1995. Part of the scatter in the temperature dependence of the analyzed data can be explained by correlated fluctuations in water vapor and liquid water. The results are relevant for remote sensing of supercooled clouds using passive and active microwave techniques and, more generally, for the physics of water.
High‐speed video observations of positive lightning flashes to ground
Authors: Saba Marcelo M. F. , Schulz Wolfgang , Warner Tom A. , Campos Leandro Z. S. , Schumann Carina , Krider E. Philip , Cummins Kenneth L. , Orville Richard E.
Published: December 2010

Although positive lightning flashes to ground are not as frequent as negative flashes, their large amplitudes and destructive characteristics make understanding their parameters an important issue. This study summarizes the characteristics of 103 positive cloud‐to‐ground (+CG) flashes that have been recorded using high‐speed video cameras (up to 11,800 frames per second) in three countries together with time‐correlated data provided by lightning location systems (LLS). A large fraction of the +CG flashes (81%) produced just a single stroke, and the average multiplicity was 1.2 strokes per flash. All the subsequent strokes in multiple‐stroke +CG flashes created a new ground termination except one. The geometric mean of 21 interstroke time intervals was 94 ms, which is about 1.5 times larger than the average interstroke interval in negative CG flashes (∼60 ms); 75% of the +CG flashes contained at least one long continuing current (LCC) ≥ 40 ms, and this percentage is significantly larger than in the negative flashes that produce LCCs (approximately 30%). The median estimated peak current (Ip) for 116 positive strokes that created new ground terminations was 39.4 kA. Positive strokes with a large Ip were usually followed by a LCC, and both of these parameters are threats in lightning protection. The characteristics presented here include the multiplicities of strokes and ground contacts, the percentage of single‐stroke flashes, the average interstroke time interval, the durations of the continuing current, and the distributions of Ip, the total flash durations, and the 2‐D leader speeds.
Overview and early results of the Superconducting Submillimeter‐Wave Limb‐Emission Sounder (SMILES)
Authors: Kikuchi Ken‐ichi , Nishibori Toshiyuki , Ochiai Satoshi , Ozeki Hiroyuki , Irimajiri Yoshihisa , Kasai Yasuko , Koike Makoto , Manabe Takeshi , Mizukoshi Kazuo , Murayama Yasuhiro , Nagahama Tomoo , Sano Takuki , Sato Ryota , Seta Masumichi , Takahashi Chikako , Takayanagi Masahiro , Masuko Harunobu , Inatani Junji , Suzuki Makoto , Shiotani Masato
Published: December 2010

The Superconducting Submillimeter‐Wave Limb‐Emission Sounder (SMILES) was successfully launched and attached to the Japanese Experiment Module (JEM) on the International Space Station (ISS) on 25 September 2009. It has been making atmospheric observations since 12 October 2009 with the aid of a 4 K mechanical cooler and superconducting mixers for submillimeter limb‐emission sounding in the frequency bands of 624.32–626.32 GHz and 649.12–650.32 GHz . On the basis of the observed spectra, the data processing has been retrieving vertical profiles for the atmospheric minor constituents in the middle atmosphere, such as O3 with isotopes, HCl, ClO, HO2, BrO, and HNO3. Results from SMILES have demonstrated its high potential to observe atmospheric minor constituents in the middle atmosphere. Unfortunately, SMILES observations have been suspended since 21 April 2010 owing to the failure of a critical component.
Stable isotopic compositions in Australian precipitation
Authors: Liu Jianrong , Fu Guobin , Song Xianfang , Charles Stephen P. , Zhang Yinghua , Han Dongmei , Wang Shiqin
Published: December 2010

Stable deuterium (δD) and oxygen‐18 (δ18O) isotopes in 1962 to 2002 precipitation from the seven Australian stations of the Global Network of Isotopes in Precipitation (GNIP) were used to investigate isotope characteristics including temporal and spatial distributions across different regions of Australia. On the basis of 1534 samples, the local meteoric water line (LMWL) was established as δD = 7.10δ18O + 8.21. δ18O showed a depletion trend from north and south to central Australia (a continental effect) and from west to east. Precipitation amount effects were generally greater than temperature effects, with quadratic or logarithmic correlations describing δ/T and δ/P better than linear relationships. Nonlinear stepwise regression was used to determine the significant meteorological control factors for each station, explaining about 50% or more of the δ18O variations. Geographical control factors for δ18O were given by the relationship δ18O (‰) = −0.005 longitude (°) − 0.034 latitude (°)‐0.003 altitude (m) − 4.753. Four different types of d‐excess patterns demonstrated particular precipitation formation conditions for four major seasonal rainfall zones. Finally, wavelet coherence (WTC) between δ18O and SOI confirmed that the influence of ENSO decreased from east and north to west Australia.
CH4 retrievals from space‐based solar backscatter measurements: Performance evaluation against simulated aerosol and cirrus loaded scenes
Authors: Butz A. , Hasekamp O. P. , Frankenberg C. , Vidot J. , Aben I.
Published: December 2010

Monitoring of atmospheric methane (CH4) concentrations from space‐based instruments such as the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) and the Greenhouse Gases Observing Satellite (GOSAT) relies on observations of sunlight backscattered to space by the Earth's surface and atmosphere. Retrieval biases occur due to unaccounted scattering effects by aerosols and thin cirrus that modify the lightpath. Here, we evaluate the accuracy of two retrieval methods that aim at minimizing such scattering induced errors. The lightpath “proxy” method, applicable to SCIAMACHY and GOSAT, retrieves CH4 and carbon dioxide (CO2) simultaneously and uses CO2 as a proxy for lightpath modification. The “physics‐based” method, which we propose for GOSAT, aims at simultaneously retrieving CH4 concentrations and scattering properties of the atmosphere. We evaluate performance of the methods against a trial ensemble of simulated aerosol and cirrus loaded scenes. More than 80% of the trials yield residual scattering induced CH4 errors below 0.6% and 0.8% for the proxy and the physics‐based approach, respectively. Very few cases result in errors greater than 2% for both methods. Advantages of the proxy approach are efficient and robust performance yielding more useful retrievals than the physics‐based method which reveals some nonconvergent cases. The major disadvantage of the proxy method is the uncertainty of the proxy CO2 concentration contributing to the overall error budget. Residual errors generally correlate with particle and surface properties and thus might impact inverse modeling of CH4 sources and sinks.
Multiangle Imaging SpectroRadiometer global aerosol product assessment by comparison with the Aerosol Robotic Network
Authors: Kahn Ralph A. , Gaitley Barbara J. , Garay Michael J. , Diner David J. , Eck Thomas F. , Smirnov Alexander , Holben Brent N.
Published: December 2010

A statistical approach is used to assess the quality of the Multiangle Imaging SpectroRadiometer (MISR) version 22 (V22) aerosol products. Aerosol optical depth (AOD) retrieval results are improved relative to the early postlaunch values reported by [Kahn et al. (2005)], which varied with particle type category. Overall, about 70% to 75% of MISR AOD retrievals fall within 0.05 or 20% × AOD of the paired validation data from the Aerosol Robotic Network (AERONET), and about 50% to 55% are within 0.03 or 10% × AERONET AOD, except at sites where dust or mixed dust and smoke are commonly found. Retrieved particle microphysical properties amount to categorical values, such as three size groupings: “small,” “medium,” and “large.” For particle size, ground‐based AERONET sun photometer Angstrom exponents are used to assess statistically the corresponding MISR values, which are interpreted in terms of retrieved size categories. Coincident single‐scattering albedo (SSA) and fraction AOD spherical data are too limited for statistical validation. V22 distinguishes two or three size bins, depending on aerosol type, and about two bins in SSA (absorbing vs. nonabsorbing), as well as spherical vs. nonspherical particles, under good retrieval conditions. Particle type sensitivity varies considerably with conditions and is diminished for midvisible AODs below about 0.15 or 0.2. On the basis of these results, specific algorithm upgrades are proposed and are being investigated by the MISR team for possible implementation in future versions of the product.
First‐order description of the mechanical fracture behavior of fine‐grained surficial marine sediments during gas bubble growth
Authors: Barry M. A. , Boudreau B. P. , Johnson B. D. , Reed A. H.
Published: December 2010

Bubbles in sediments, imaged via Computed Tomography (CT) scanning, and in surrogate transparent material (gelatin), are well‐described geometrically as eccentric oblate spheroids. While sediments are undoubtedly visco‐elasto‐plastic solids, only part of that complex behavior appears to influence significantly the formation and shape of gas bubbles. Specifically, the shape of these bubbles can be explained if the mechanical response of fine‐grained sediment is approximated by Linear Elastic Fracture Mechanics (LEFM). To determine the adequacy of the LEFM approximation for gas bubble growth in fine‐grained sediments, a number of gas bubbles were injected and grown in natural sediments, while monitoring the size and shape using an industrial CT scanner. A comparison of measured inverse aspect ratios (IARs) of the injected bubbles with calculated IARs from pressure records provides support for the LEFM theory. Deviations from LEFM are observable in the data, but as bubbles grow larger they trend more closely toward the theory. The use of LEFM has been shown to describe gas bubble growth in shallow coastal sediments to first order.
An improved approach for estimating observation and model error parameters in soil moisture data assimilation
Authors: Crow W. T. , van den Berg M. J.
Published: December 2010

The accurate specification of observing and/or modeling error statistics presents a remaining challenge to the successful implementation of many land data assimilation systems. Recent work has developed adaptive filtering approaches that address this issue. However, such approaches possess a number of known weaknesses, including a required assumption of serially uncorrelated error in assimilated observations. Recent validation results for remotely sensed surface soil moisture retrievals call this assumption into question. Here we propose and test an alternative system for tuning a soil moisture data assimilation system, which is robust to the presence of autocorrelated observing error. The approach is based on the application of a triple collocation approach to estimate the error variance of remotely sensed surface soil moisture retrievals. Using this estimate, the variance of assumed modeling perturbations is tuned until normalized filtering innovations have a temporal variance of one. Real data results over three highly instrumented watershed sites in the United States demonstrate that this approach is superior to a classical tuning strategy based on removing the serial autocorrelation in Kalman filtering innovations and nearly as accurate as a calibrated Colored Kalman filter in which autocorrelated observing errors are treated optimally.
Problematizing city/state relations: towards a geohistorical understanding of contemporary globalization
Authors: Taylor Peter J
Published: December 2010

This essay explores the contention that to understand contemporary globalization it is necessary to problematize city/state relations. Since the relation is unproblematized in modernity – cities are just parts of states – a transhistorical approach is adopted based upon Jacobs’ identification of contrary ‘moral syndromes’, commercial and guardian. The practices guided by these syndromes create different social spaces, spaces of flows and spaces of places respectively. Thus cities are interpreted as constellations of commercial practices, and states as constellations of guardian practices. Salient theories of cities and states are found in Jacobs’ description of cities as complex entities that expand economic life and Scott's description of states’ simplifying social relations in order to better control them. This abstract discussion is concretized through the specificities of modern cities and modern states. Six vignettes of city/state relations are sketched straddling the whole modern temporality. The conclusion rules out the popular ‘city‐state’ scenario as a globalization outcome.
YeastMed: An XML-Based System for Biological Data Integration of Yeast
Authors: Briache Abdelaali , Marrakchi Kamar , Kerzazi Amine , Navas-Delgado Ismael , Aldana Montes José F. , Rossi Hassani Badr Din , Lairini Khalid
Published: December 2010

A key goal of bioinformatics is to create database systems and software platforms capable of storing and analysing large sets of biological data. Hundreds of biological databases are now available and provide access to huge amount of biological data. SGD, Yeastract, CYGD-MIPS, BioGrid and PhosphoGrid are five of the most visited databases by the yeast community. These sources provide complementary data on biological entities. Biologists are brought systematically to query these data sources in order to analyse the results of their experiments. Because of the heterogeneity of these sources, querying them separately and then manually combining the returned result is a complex and laborious task. To provide transparent and simultaneous access to these sources, we have developed a mediator-based system called YeastMed. In this paper, we present YeastMed focusing on its architecture.
Stray light analysis for the Thomson scattering diagnostic of the ETE Tokamak
Authors: Berni L. A. , Albuquerque B. F. C.
Published: December 2010

Thomson scattering is a well-established diagnostic for measuring local electron temperature and density in fusion plasma, but this technique is particularly difficult to implement due to stray light that can easily mask the scattered signal from plasma. To mitigate this problem in the multipoint Thomson scattering system implemented at the ETE (Experimento Tokamak Esférico) a detailed stray light analysis was performed. The diagnostic system was simulated in ZEMAX software and scattering profiles of the mechanical parts were measured in the laboratory in order to have near realistic results. From simulation, it was possible to identify the main points that contribute to the stray signals and changes in the dump were implemented reducing the stray light signals up to 60 times.
A comparative study of argon ion irradiated pristine and fluorinated single-wall carbon nanotubes
Authors: Fedoseeva Yu. V. , Bulusheva L. G. , Okotrub A. V. , Vyalikh D. V. , Fonseca A.
Published: December 2010

Effect of Ar+ ion irradiation on the structure of pristine and fluorinated single-wall carbon nanotubes (SWCNTs) was examined using transmission electron microscopy (TEM), Raman, and x-ray photoelectron spectroscopy (XPS). The TEM analysis revealed retention of tubular structures in both irradiated samples while Raman spectroscopy and XPS data indicated a partial destruction of nanotubes and formation of oxygen-containing groups on the nanotube surface. From similarity of electronic states of carbon in the irradiated pristine and fluorinated SWCNTs observed by XPS, it was suggested that defluorination of nanotubes proceeded with breaking of C–F bonds.
Hydrogenation effects on the structure and morphology of graphene and single-walled carbon nanotubes
Authors: Muniz Andre R. , Maroudas Dimitrios
Published: December 2010

A systematic computational study is presented of the effects of atomic hydrogen chemisorption on the structure and morphology of graphene layers and single-walled carbon nanotubes (SWCNTs). The study is based on a combination of classical molecular-dynamics (MD) and Monte Carlo simulations of structural and compositional relaxation of the hydrogenated surfaces, employing hydrogen distributions consistent with experimental observations and first-principles calculations. Results are reported for the strains induced on the graphene and the SWCNTs, as a result of sp2-sp3 bonding transitions due to atomic H chemisorption, and their dependence on the H surface coverage, Θ, over the entire range 0≤Θ≤1 and on nanotube diameters and chiralities. Detailed structural analysis of the relaxed hydrogenated surfaces demonstrates a tendency for clustering of hydrogenated and of nonhydrogenated sites; this leads to surface morphologies characterized by ripples, which consist of hills that form due to clustering of hydrogenated sites and are surrounded by valleys appearing through the formation of long chains of nonhydrogenated sites. These features introduce surface roughness that depends on the degree of hydrogenation and reaches its maximum levels at intermediate levels of H coverage.
Local x-ray structure analysis of optically manipulated biological micro-objects
Authors: Cojoc Dan , Amenitsch Heinz , Ferrari Enrico , Santucci Silvia C. , Sartori Barbara , Rappolt Michael , Marmiroli Benedetta , Burghammer Manfred , Riekel Christian
Published: December 2010

X-ray diffraction using micro- and nanofocused beams is well suited for nanostructure analysis at different sites of a biological micro-object. To conduct in vitro studies without mechanical contact, we developed object manipulation by optical tweezers in a microfluidic cell. Here we report x-ray microdiffraction analysis of a micro-object optically trapped in three dimensions. We revealed the nanostructure of a single starch granule at different points and investigated local radiation damage induced by repeated x-ray exposures at the same position, demonstrating high stability and full control of the granule orientation by multiple optical traps.
Temperature dependence of 1/f noise mechanisms in silicon nanowire biochemical field effect transistors
Authors: Rajan Nitin K. , Routenberg David A. , Chen Jin , Reed Mark A.
Published: December 2010

The 1/f noise of silicon nanowire biochemical field effect transistors is fully characterized from weak to strong inversion in the temperature range 100–300 K. At 300 K, our devices follow the correlated Δn-Δμ model. As the temperature is lowered, the correlated mobility fluctuations become insignificant and the low frequency noise is best modeled by the Δn-model. For some devices, evidence of random telegraph signals is observed at low temperatures, indicating that fewer traps are active and that the 1/f noise due to number fluctuations is further resolved to fewer fluctuators, resulting in a Lorentzian spectrum.
High performance ZnO nanorod strain driving transistor based complementary metal-oxide-semiconductor logic gates
Authors: Liu Nishuang , Fang Guojia , Zeng Wei , Zhou Hai , Long Hao , Zou Xiao , Liu Yuping , Zhao Xingzhong
Published: December 2010

ZnO nanorod strain driving transistor (SDT) with 107 scale “on”-“off” ratio has been fabricated on Kapton substrate by a single-step hydrothermal reaction. The transistor is driven by strain due to the change in Schottky barrier height caused by piezoelectric effect as well as the change of contact area between ZnO bridging nanorods. Moreover, via utilizing two SDTs on the top and bottom surfaces of the substrate as two complementary metal-oxide-semiconductor transistors, several logic operations such as inverter, NAND, NOR, XOR, MUX, and DEMUX with good rectifying behaviors have been demonstrated.
Eddy damped quasinormal Markovian simulations of superfluid turbulence in helium II
Authors: Tchoufag J. , Sagaut P.
Published: December 2010

A two fluid (the normal fluid and the superfluid) spectral model based on the HVBK equations is used to compute the energy spectra of developed turbulence in superfluid helium (helium II) at different temperatures and different values of mutual friction coefficients, looking for both asymptotic and realistic helium II solutions. An original computational model is proposed, based on the model suggested by L’vov, Nazarenko, and Skrbek [JLTP 145, 125 (2006)] for mutual friction term and an eddy damped quasinormal Markovian closure for the energy flux term. On the one hand, the four asymptotic solutions predicted by theoretical analysis are confirmed. On the other hand, we present results for normal and superfluid energy spectra in realistic cases using experimental values of the mutual friction coefficients corresponding to helium II. Good qualitative agreement in the small scale range is found with the direct numerical simulation results obtained by Roche, Barenghi, and Leveque [Europhys. Lett. 87, 54006 (2009)].
The influence of capillary flow on the fate of evaporating wetted imprint of the sessile droplet in porous medium
Authors: Markicevic B. , Navaz H. K.
Published: December 2010

The fate of a wetting liquid sessile droplet imbibed by a porous medium is formulated as a multiphase flow problem and a numerical solution is developed using the capillary network model with a microforce balance at the liquid∣gas interface. The liquid phase capillary flow and evaporation are solved simultaneously. An exclusive evidence for a multiphase flow is already found in the capillary flow, as a liquid wets a much larger volume of porous medium compared to the wetted volume, calculated by assuming that the medium imbibes the liquid in the single-phase flow. The physics of the multiphase capillary flow includes the formation of local gas clusters and liquid ganglia. The clusters and ganglia distribution is further altered by evaporation. The evaporation tends to shrink the ganglia sizes and open the gas clusters, both due to the liquid mass loss from the porous medium. Still, the capillarity tends to disperse the liquid back into the regions from where the liquid previously evaporated. These changes in the liquid saturation produce the changes in vapor concentration within the porous medium and changes in the mass fluxes. The imprint shape varies, where, for more spherical imprints, the evaporation is enhanced due to the capillary flow. The opposite is true for the elongated imprints for which the capillarity hinders the evaporation rate. Comparing the spherical and elongated imprints, the liquid dispersion differs and the capillary flow the into protrusion direction is pronounced for the elongated imprints. The changes in the liquid dispersion and imprint shape influence the vapor concentration within the porous medium, vapor phase mass fluxes, and liquid persistence time. Finally, the previous behavior is observed for hazardous materials and warfare agents, where predicting the fate of such kind of liquids and their vapors become especially important due to their harmful effects.
Double-wells and double-layers in dusty Fermi–Dirac plasmas: Comparison with the semiclassical Thomas–Fermi counterpart
Authors: Akbari-Moghanjoughi M.
Published: December 2010

Based on the quantum hydrodynamics (QHD) model, a new relationship between the electrostatic-potential and the electron-density in the ultradense plasma is derived. Propagation of arbitrary amplitude nonlinear ion waves is, then, investigated in a completely degenerate dense dusty electron-ion plasma, using this new energy relation for the relativistic electrons, in the ground of quantum hydrodynamics model and the results are compared to the case of semiclassical Thomas–Fermi dusty plasma. Based on the standard pseudopotential approach, it is remarked that the Fermi–Dirac plasma, in contrast to the Thomas–Fermi counterpart, accommodates a wide variety of nonlinear excitations such as positive/negative-potential ion solitary and periodic waves, double-layers, and double-wells. It is also remarked that the relativistic degeneracy parameter which relates to the mass-density of plasma has significant effects on the allowed matching-speed range in Fermi–Dirac dusty plasmas.
Stopping the Unstoppable? A Discursive-Institutionalist Analysis of Renewable Transport Fuel Policy
Authors: Palmer James
Published: December 2010

From a discursive-institutionalist perspective I seek to establish the influence exerted over environmental agenda setting and policy change by ideas and discourse, through an examination of recent developments in the UK's flagship biofuels policy, the Renewable Transport Fuels Obligation (RTFO). Discursive institutionalism's central contention is that the intricate interactions between ideas and institutions should be at the centre of studies of the policy-making process. By elucidating the mutually reinforcing character of cognitive processes (including ‘framing’ and ‘boundary work’) and institutional factors (such as ‘standard operating procedures’ and path dependency), I show how, despite a raft of countervailing evidence, significant changes in both the form and objectives of the RTFO were precluded. Longer-term research is required to establish the precise precipitating circumstances enabling such stability to result from these feedbacks, however, as it is—theoretically at least—equally likely that far shorter periods of dramatic policy change, or ‘paradigm shifts’, will emerge.
Financing Urban Government in Transition Countries: Assessment Uniformity and the Property Tax
Authors: Connolly Katrina , Bell Michael
Published: December 2010

The area-based property tax has been gaining influence in developing and transitional countries around the world. While an area-based property tax is advocated for its simplicity and transparency, it is often criticized as being unfair because assessed values upon which property tax liabilities are based are not related to market values. We present a case study in Lithuania that explores the uniformity of assessments, and thus the implications for fairness of the distribution of property tax liabilities across properties, for an area-based tax as opposed to an ad valorem property tax. The findings suggest that, in Lithuania, assessments are more uniform, and the distribution of property tax liabilities across properties are more fair, for detached housing under the area-based assessment than under the market-based assessment; alternatively, uniformity and fairness of the distribution of tax liabilities for flats are better under market-based than area-based assessment.
Effect of Australian sweet lupin (Lupinus angustifolius L.) inclusion levels and enzyme supplementation on the performance, carcass composition and meat quality of grower/finisher pigs
Authors: Kim J. C. , Mullan B. P. , Nicholls R. R. , Pluske J. R.
Published: December 2010

Two hundred and twenty-four crossbred male pigs (Large White × Landrace, initial bodyweight 27.2 kg ± 0.22) were used to determine the influence of dietary Australian sweet lupin (ASL) inclusion level and enzyme supplementation on growth performance, carcass composition and meat quality. The experiment was a 4 × 2 factorial design with the respective factors being ASL inclusion level (Lupinus angustifolius L., cv. Mandelup; 200, 250, 300 and 350 g/kg, in replacement of soybean meal) and enzyme supplementation (without or with supplemental enzyme; Allzyme SSF). Pigs (7 pigs per pen × 4 replicates per treatment = 28 pigs per enzyme by lupin-level combination) were fed grower diets between 27 and 50 kg, finisher diets between 50 and 75 kg and pre-sale diets between 75 and 107 kg, and daily gain and feed intake were measured weekly. At ~107 kg liveweight, the pigs were slaughtered at a commercial abattoir and carcass composition was measured. Meat quality (pH, surface exudate, drip loss, cooking loss, meat colour and shear force) was measured from selected pigs (n = 18) fed the lowest and highest lupin diets without enzyme supplementation. Increasing the ASL inclusion level to 350 g/kg did not alter (P > 0.05) growth performance of pigs and did not influence (P > 0.05) carcass composition and meat quality. Likewise, addition of supplemental enzyme had no effect (P > 0.05) on growth performance and carcass composition. Lack of performance response to added enzyme complex is likely due either to the use of enzyme complex that was not substrate-specific for the lupin non-starch polysaccharides or to the high specification of the experimental diets, which was inevitable when increasing inclusion levels of lupins. The results show that a current variety (Mandelup) of ASL can be used in grower/finisher diets up to 350 g/kg without compromising growth, carcass composition or meat quality of pigs.
Syntax, Morphology, and Semantics of Ezafe
Authors: Parsafar Parviz
Published: December 2010

Although ezafe has been studied by many scholars for many years, it does not yet have a transparent grammatical status. Grammarians have regarded ezafe as a polysemous “word” carrying over ten different “meanings/functions.” After a brief review of the previous treatments of ezafe, this paper will present a syntactic analysis, followed by a morphological description and a semantic analysis of this ubiquitous morpheme. It will also compare the distributional properties of other relevant bound morphemes with those of the ezafe. It will finally conclude that ezafe is a dummy clitic-like morpheme which is semantically void, while syntactically it functions as an “associative marker” which subordinates its [+N] host, on the left, to its following complements.
Teaching Persian to Heritage Speakers
Authors: Sedighi Anousha
Published: December 2010

Although Persian language instruction has been facing demand outside Iran, little research has been conducted and few findings are available on teaching Persian to heritage speakers. This work studies teaching Persian language to students with a Persian background or second-generation Persians who have been raised outside Iran. I study the characteristics of heritage Persian speakers and describe their linguistics abilities and attitudes. Heritage learners are different from both foreign learners of Persian and native speakers of Persian. This article provides an underlying foundation for the research within the field of teaching Persian to heritage Persian speakers. Providing this general sketch will hopefully draw more attention to the promotion of a stronger educational system and more research on preserving and revitalizing Persian language amongst the new generation of Iranians living abroad.
Success(ion): Second-Generation Iranian Americans
Authors: Bozorgmehr Mehdi , Douglas Daniel
Published: December 2010

More than a generation has passed since the substantial immigration of Iranians to the United States in the late 1970s, resulting in a sizable second-generation population (defined by convention as persons born in the United States and those who immigrated under the age of thirteen). This article presents a first look at the demographic and socioeconomic characteristics of the second generation at the national level, and compares them with those of the first generation (Iran- or foreign-born population). It uses the 2005–07 merged data set compiled by the United States Census in the American Community Survey (ACS). The results indicate a preliminary continuation of economic and educational success from the first- to the second-generation Iranians. Moreover, this achievement has become more balanced across gender lines in the second generation. Specifically, in terms of educational attainment and labor force participation, females have quickly closed the gap with their male counterparts. Because the second generation is still young, it is premature to assess the extent of intergenerational mobility among Iranians. But given this generation's initial achievements, one can only expect an upward trajectory.
The French Regional Industrial Clusters Policy: Lessons from the Lyon Urban Trucks and Bus Cluster
Authors: Guisard Delphine , Le Bas Christian , Nief Pascal
Published: December 2010

This article deals with a new approach to industrial policy in France to support the creation of regional research clusters. We address the topic as follows. Section 1 gives some general insights into this policy. Section 2 addresses the structure and the working of one of the Rhône-Alpes regional clusters — the Lyon Urban Trucks and Bus (LUTB) Cluster. Section 3 describes the type of knowledge management within the LUTB cluster which is considered to be crucial for discovering and exploring new directions for research.
“I Don't Need Your Help!” Peer Status, Race, and Gender during Peer Writing Interactions
Authors: Christianakis Mary
Published: December 2010

This article relies on year-long ethnographic data to examine how the intersection of peer status, gender, and race influenced the role stances children took in one urban fifth grade classroom while participating in three different writing pedagogies: peer tutoring, cooperative peer editing, and collaborative writing. Informed by the sociocultural theories of writing development and literature on peer pedagogies, the study explores the following research questions: (a) How do children enact peer status, gender, and race as they negotiate with one another during peer editing? (b) How do peer editing pedagogies shape opportunities for negotiation? (c) What are the consequences of these peer negotiations? Findings show how peer statuses related to perceptions of achievement, friendships, race, and gender complicate peer writing events. By focusing on how peer status, gender, and race intersected during various peer editing pedagogies, the present study contributes to understandings of how peer social worlds shape the classroom writing experiences of diverse students.
THE TOTAL IMPACT OF THE FAMILY ON EDUCATIONAL ATTAINMENT
Authors: Sieben Inge , De Graaf Paul M.
Published: December 2010

We employ a three-level model – with siblings nested in families nested in societies – to estimate the variability in family effects on educational attainment across countries and cohorts. To perform this comparative sibling analysis, we use survey data from eleven countries and six time periods. The results first of all show that 34 per cent of the individual variance in educational attainment can be attributed to the family, leaving 37 per cent at the individual sibling level and 28 per cent at the level of the societies investigated. Furthermore, the comparative sibling analysis makes clear that there are significant differences in family effects on educational attainment between countries and cohorts. We find that indicators of modernization, individualization, and socialism negatively influence the measured effects of parents’ socio-economic position on educational attainment. Total family impact does not vary with these societal characteristics in a systematic way, however. This seems to be in line with the reproduction hypothesis, which states that parents use compensating strategies to make up for the loss in effects of parents’ socio-economic position on educational attainment.
Heresy at Play: Academies and the Literary Underground in Counter-Reformation Siena*
Authors: McClure George
Published: December 2010

This article examines an anonymous manuscript from the Sienese academies, likely composed between 1584 and 1593, during the period in which these societies were closed by the Medici grand dukes. The work is a dialogue that depicts a contest between the emblems of the academies of the Intronati, the Accesi, and the Travagliati, all vying for cultural primacy. Purportedly written by a zealous monk who appraises these worldly emblems and mottoes in preposterously flattering, even blasphemous, religious terms, the dialogue is actually a hoax that mocks the proselytizing efforts of Counter-Reformation forces in the city. This article attempts to roughly date this underground work, identify its principal targets, and consider its importance: as a telling depiction of a contest between secular images and sacred symbols, as a parody of feigned orthodoxy, and as a possible expression of freethinking well before the Enlightenment.