bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon release from submarine seeps at the Costa Rica fore arc: Implications for the volatile cycle at the Central America convergent margin
Authors: Füri Evelyn , Hilton David R. , Tryon Michael D. , Brown Kevin M. , McMurtry Gary M. , Brückmann Warner , Wheat C. Geoffrey
Published: March 2010

We report total dissolved inorganic carbon (DIC) abundances and isotope ratios, as well as helium isotope ratios (3He/4He), of cold seep fluids sampled at the Costa Rica fore arc in order to evaluate the extent of carbon loss from the submarine segment of the Central America convergent margin. Seep fluids were collected over a 12 month period at Mound 11, Mound 12, and Jaco Scar using copper tubing attached to submarine flux meters operating in continuous pumping mode. The fluids show minimum 3He/4He ratios of 1.3 RA (where RA is air 3He/4He), consistent with a small but discernable contribution of mantle‐derived helium. At Mound 11, δ13C∑CO2 values between −23.9‰ and −11.6‰ indicate that DIC is predominantly derived from deep methanogenesis and is carried to the surface by fluids derived from sediments of the subducting slab. In contrast, at Mound 12, most of the ascending dissolved methane is oxidized due to lower flow rates, giving extremely low δ13C∑CO2 values ranging from −68.2‰ to −60.3‰. We estimate that the carbon flux (CO2 plus methane) through submarine fluid venting at the outer fore arc is 8.0 × 105 g C km−1 yr−1, which is virtually negligible compared to the total sedimentary carbon input to the margin and the output at the volcanic front. Unless there is a significant but hitherto unidentified carbon flux at the inner fore arc, the implication is that most of the carbon being subducted in Costa Rica must be transferred to the (deeper) mantle, i.e., beyond the depth of arc magma generation.
Ferromanganese crusts as archives of deep water Cd isotope compositions
Authors: Horner T. J. , Schönbächler M. , Rehkämper M. , Nielsen S. G. , Williams H. , Halliday A. N. , Xue Z. , Hein J. R.
Published: March 2010

The geochemistry of Cd in seawater has attracted significant attention owing to the nutrient‐like properties of this element. Recent culturing studies have demonstrated that Cd is a biologically important trace metal that plays a role in the sequestration of inorganic carbon. This conclusion is supported by recent isotope data for Cd dissolved in seawater and incorporated in cultured phytoplankton. These results show that plankton features isotopically light Cd while Cd‐depleted surface waters typically exhibit complimentary heavy Cd isotope compositions. Seawater samples from below 900 m depth display a uniform and intermediate isotope composition of ε114/110Cd = +3.3 ± 0.5. This study investigates whether ferromanganese (Fe‐Mn) crusts are robust archives of deep water Cd isotope compositions. To this end, Cd isotope data were obtained for the recent growth surfaces of 15 Fe‐Mn crusts from the Atlantic, Pacific, Indian, and Southern oceans and two USGS Fe‐Mn reference nodules using double spike multiple collector inductively coupled plasma mass spectrometry. The Fe‐Mn crusts yield a mean ε114/110Cd of +3.2 ± 0.4 (2 SE, n = 14). Data for all but one of the samples are identical, within the analytical uncertainty of ±1.1ε114/110Cd (2 SD), to the mean deep water Cd isotope value. This indicates that Fe‐Mn crusts record seawater Cd isotope compositions without significant isotope fractionation. A single sample from the Southern Ocean exhibits a light Cd isotope composition of ε114/110Cd = 0.2 ± 1.1. The origin of this signature is unclear, but it may reflect variations in deep water Cd isotope compositions related to differences in surface water Cd utilization or long‐term changes in seawater ε114/110Cd. The results suggest that time series analyses of Fe‐Mn crusts may be utilized to study changes in marine Cd utilization.
Sustained rapid shrinkage of Yukon glaciers since the 1957–1958 International Geophysical Year
Authors: Barrand N. E. , Sharp M. J.
Published: March 2010

Glaciers in the Yukon, NW Canada, lost 22% of their surface area during the 50 years following the 1957–58 International Geophysical Year, coincident with increases in average winter and summer air temperatures and decreases in winter precipitation. Scaling these results to ice volume change, we obtain a total mass loss of 406 ± 177 Gt, which accounts for 1.12 ± 0.49 mm of global sea‐level rise. Yukon glaciers thinned by 0.78 ± 0.34 m yr−1 water equivalent, a regional thinning rate exceeded only by mountain glaciers in Patagonia and Alaska. Our scaling analysis suggests the remaining glaciers have the capacity to contribute a further 5.02 mm to global sea‐level rise.
Crustal structure beneath Montserrat, Lesser Antilles, constrained by xenoliths, seismic velocity structure and petrology
Authors: Kiddle E. J. , Edwards B. R. , Loughlin S. C. , Petterson M. , Sparks R. S. J. , Voight B.
Published: March 2010

Noritic anorthosite, gabbroic anorthosite and hornblende‐gabbro xenoliths are ubiquitous in the host andesite at Montserrat. Other xenoliths include quartz diorite, metamorphosed biotite‐gabbro, plagioclase‐hornblendite and plagioclase‐clinopyroxenite. Mineral compositions suggest a majority of the xenoliths are cognate. Cumulate, hypabyssal and crescumulate textures are present. A majority of the xenoliths are estimated to have seismic velocities of 6.7–7.0 km/s for pore‐free assemblages. These estimates are used in conjunction with petrological models to constrain the SEA CALIPSO seismic data and the structure of the crust beneath Montserrat. Andesitic upper crust is interpreted to overlie a lower crust dominated by amphibole and plagioclase. Xenolith textures and seismic data indicate the presence of hypabyssal intrusions in the shallow crust. The structure of the crust is consistent with petrological models indicating that fractionation is the dominant process producing andesite at Montserrat.
Magnetic energy distribution in the four‐dimensional frequency and wave vector domain in the solar wind
Authors: Narita Y. , Sahraoui F. , Goldstein M. L. , Glassmeier K.‐H.
Published: March 2010

We present a measurement of the energy distribution in the four‐dimensional (4‐D) frequency and wave vector domain of magnetic field fluctuations in the solar wind. The measurement makes use of the wave telescope technique that has been developed particularly for multispacecraft data analysis. We review briefly the theoretical background and then present a numerical test using synthetic data; the technique is then applied to magnetic field data obtained while the Cluster spacecraft was in the solar wind. The energy distribution is determined in the flow rest frame in the frequency range below 0.2 rad/s and the wave number range below 0.0015 rad/km, corrected for the Doppler shift. We find the following properties in the energy distribution in the rest frame: (1) a double anisotropy in the wave vector domain associated with the mean magnetic field and the flow directions, (2) a symmetric distribution with respect to the sign of wave vector, and (3) no evidence for a linear dispersion relation in the frequency and wave number domain. Since the flow direction in the analyzed time interval is close to the normal direction to the bow shock, the anisotropy may well be associated with the bow shock. These results suggest that the solar wind is in a state of well‐developed strong turbulence and justifies the theoretical picture of quasi‐two‐dimensional turbulence that obtains in the presence of a (relatively) strong DC magnetic field. However, the fluctuations are not axisymmetric around the mean field and the energy distribution is extended in the perpendicular direction to the flow or shock normal. Anisotropy associated with the boundary is reminiscent of previously reported magnetosheath turbulence. This study opens a way to investigate solar wind turbulence in the full 4‐D frequency and wave vector space.
How much is the western Mediterranean really warming and salting?
Authors: Vargas‐Yáñez Manuel , Zunino Patricia , Benali Ayoub , Delpy Michael , Pastre Flora , Moya Francina , García‐Martínez Maria del Carmen , Tel Elena
Published: March 2010

Instrumental biases and data processing methods can modify temperature trend estimations and enhance decadal variability in the upper ocean. These questions have not been specifically addressed in the western Mediterranean (WMED), a region where warming and salting trends have been detected during the second half of the twentieth century. In this work we test the sensitivity of these trends and decadal variability in the WMED to the use of bathythermograph data and data processing methods. We analyze different subbasins in order to detect distinct local responses. Our results show that deep waters in the WMED are increasing their temperature and salinity at a rate of 0.002°C/yr and 9.2 × 10−4 yr−1, respectively, from 1943. These trends are spatially homogeneous, not affected by instrumental biases, data processing methods, or changes in the period of time analyzed. The heat absorbed by the whole WMED is equivalent to a surface heat flux of 0.29 ± 0.19 W/m2. This figure encloses recent estimates of 0.36 ± 0.06 W/m2 for the global ocean. The intermediate layer increased its salinity at a rate of 1.3 × 10−4 yr−1 and this result can also be considered as robust. The intermediate layer temperature and the upper layer salinity show strong time variability and in our opinion long‐term changes cannot be statistically distinguished from decadal variability during the period 1943–2000. The upper layer shows a temperature and heat increase for the overall period, but it is caused by a steep warming trend initiated in the early 1980s.
A general circulation model ensemble study of the atmospheric circulation of Venus
Authors: Lee C. , Richardson M. I.
Published: March 2010

The response of three numerical model dynamical cores to Venus‐like forcing and friction is described in this paper. Each dynamical core simulates a super‐rotating atmospheric circulation with equatorial winds of 35 ± 10 m/s, maintained by horizontally propagating eddies leaving the equatorial region and inducing a momentum convergence there. We discuss the balance between the mean circulation and eddies with reference to the production of a super‐rotating equatorial flow. The balance between the horizontal eddies and vertical eddies in the polar region is discussed and shown to produce an indirect overturning circulation above the jet. The indirect overturning may be related to the observed region of the polar dipole in the Venus atmosphere. Reservoirs of energy and momentum are calculated for each dynamical core and explicit sources and sinks are diagnosed from the general circulation model (GCM). The effect of a strong “sponge layer” damping to rest is compared with eddy damping and found to change significantly the momentum balance within the top “sponge layer” but does not significantly affect the super‐rotation of the bulk of the atmosphere. The Lorenz (1955) energy cycle is calculated and the circulation is shown to be dominated by energy conversion between the mean potential energy and mean kinetic energy reservoirs, with barotropic energy conversion between the mean kinetic energy and eddy kinetic energy reservoirs. We suggest modifications to the GCM parameterizations on the basis of our analysis of the atmospheric circulation and discuss the effect of numerical parameterizations on the simulated atmosphere.
Packing variations on a ripple of nearly monodisperse dry sand
Authors: Louge M. Y. , Valance A. , Ould el‐Moctar A. , Dupont P.
Published: March 2010

Dielectric measurements reveal that bulk density on the surface of recently mobilized dry ripples of a nearly monodisperse desert sand varies from the random jammed packing at troughs to the minimum value for a stable packing at crests, suggesting that active ripples are relatively loose structures moving above a more consolidated substratum. Although the wind‐driven evolution of static pressure on the surface induces air seepage through sand, we show that such internal flow is not strong enough to swell the bed and explain variations of bulk density on the surface.
Seepage‐induced penetration of water vapor and dust beneath ripples and dunes
Authors: Louge M. Y. , Valance A. , Mint Babah H. , Moreau‐Trouvé J.‐C. , Ould el‐Moctar A. , Dupont P. , Ould Ahmedou D.
Published: March 2010

We present stratigraphic measurements of humidity and bulk density beneath the surface of a barchan dune obtained with a capacitance probe. A model shows that air seeping through the sand bed in response to spatial variations of static pressure along the ripple surface guides water vapor through ripple crests and gradually stores dust beneath troughs. The accumulated dust remains trapped beneath the relatively compact trough surface until wind is violent enough to mobilize sand deeply.
Slow Slip Event at Kilauea Volcano
Authors: Poland Michael , Miklius Asta , Wilson David , Okubo Paul , Montgomery‐Brown Emily , Segall Paul , Brooks Benjamin , Foster James , Wolfe Cecily , Syracuse Ellen , Thurbe Clifford
Published: March 2010

Early in the morning of 1 February 2010 (UTC; early afternoon 31 January 2010 local time), continuous Global Positioning System (GPS) and tilt instruments detected a slow slip event (SSE) on the south flank of Kilauea volcano, Hawaii. The SSE lasted at least 36 hours and resulted in a maximum of about 3 centimeters of seaward displacement. About 10 hours after the start of the slip, a flurry of small earthquakes began (Figure 1) in an area of the south flank recognized as having been seismically active during past SSEs [Wolfe et al., 2007], suggesting that the February earthquakes were triggered by stress associated with slip [Segall et al., 2006].
Les effets de l'obstruction des voies aériennes nasales
Authors: Rubin Robert M.
Published: March 2010

Il existe un grand nombre d'évidences pour accréditer la théorie selon laquelle la relation spatiale mandibule — complexe cranio-facial est influencée par la fonction des muscles élévateurs de la mandibule.

Un des facteurs agissant sur les muscles élévateurs est la position de repos de la mandibule, elle-même influencée par le mode respiratoire. L'obstruction des voies aériennes nasales est accompagnée d'un affaissement de la mandibule de telle sorte qu'elle permette un passage buccal de l'air.

Ce changement postural peut avoir une influence significative sur la croissance de la face aboutissant au syndrome de face longue (Long Face Syndrome) (L.F.S.).

Le pédodontiste et l'orthodontiste sont particulièrement bien placés pour reconnaître les stigmates d'un syndrome de face longue en voie de développement et diriger le patient vers les spécialistes qui l'aideront à trouver un mode normal de respiration.
Point de vue d'un chercheur biomédical sur le rat comme modèle expérimental en orthodontie
Authors: Petrovic Alexandre
Published: March 2010

L'expérimentation animale est souvent une étape utile, voire indispensable, en recherche orthodontique. Le choix de l'espèce animale dépend de la structure étudiée, du problème envisagé, du niveau d'observation et des moyens techniques. C'est le degré de SIMILITUDE BIOLOGIQUE — qu'il convient de rechercher et d'étudier de façon approfondie à divers niveaux d'organisation — qui conditionne la PROBABILITE qu'auront les concepts formulés à partir de l'expérimentation animale à être CORROBORÉS chez l'homme. Il serait mal fondé de se prononcer sur les propriétés BIOLOGIQUES des cellules du cartilage condylien en spéculant à partir des seuls caractères anatomo-microscopiques des travées osseuses de la mandibule chez le rat et chez l'homme.
L'orthodontie, traitement d'interception des parodontopathies
Authors: Germain-Morelli Jacqueline
Published: March 2010

Si les malpositions dentaires sont quelquefois très bien acceptées par les tissus de soutien, le premier signe de récession ou d'inflammation gingivale doit être considéré avec attention, afin d'intercepter l'établissement de la lésion parodontale. L'interception orthodontique doit être appropriée à la dysmorphose, en association avec une maintenance rigoureuse de l'hygiène. Il est nécessaire, tout au long du traitement, d'effectuer un contrôle de la présence d'éventuelles prématurités.
La consommation des praticiens français en attaches orthodontiques
Authors: Sorel Olivier , El Alam Rajah
Published: March 2010

Cette étude a pour objectif de cerner les habitudes de consommation des praticiens français, en attaches orthodontiques.

Un questionnaire adressé aux différents fournisseurs de produits orthodontiques nous a permis d'établir, en pourcentages, une répartition des ventes en fonction des sociétés et des techniques.

Les résultats bruts montrent qu'il existe une spécialité suivant les sociétés de distribution :

- le matériel d'arc plan représente plus de la moitié des ventes en attaches orthodontiques ;

- la comparaison aux études antérieures faites Outre-Atlantique montre une similitude entre l'état actuel en France et celui des États-Unis dans les années 1986.

Les traditions de confidentialité ont évidemment limité notre travail.
Nous avons interrogé certains utilisateurs expérimentés du "Straight Wire Appliance"
Authors: Bonnefont René
Published: March 2010

L'auteur a interrogé certains utilisateurs expérimentés du "Straight Wire Appliance" dans l'intention de faire connaître cette technique à ceux qui ne la pratiquent pas, et d'en préciser les conditions d'utilisation au moyen de réponses à des questions retenues pour leur aspect pratique.
IUPAC-NIST Solubility Data Series. 88. Esters with Water—Revised and Updated. Part 2. C5 and C6 Esters
Authors: Mączyński Andrzej , Oracz Pawel , Wiśniewska-Gocłowska Barbara , Owczarek Iwona , Blazej Krystyna
Published: March 2010

The mutual solubilities and related liquid-liquid equilibria of 33 binary systems of C5 and C6 esters with water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2007 are compiled. For 19 systems, sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a method based on the evaluation of all experimental data for a given series of esters was used.
Tables of Atomic Transition Probabilities for Beryllium and Boron
Authors: Fuhr J. R. , Wiese W. L.
Published: March 2010

We have carried out a comprehensive critical compilation of the atomic transition probabilities for the spectra of beryllium and boron. We tabulated these data for a total of about 1400 allowed and forbidden transitions and covered all stages of ionization. The hydrogenlike ions are included with relations scaled to the data for neutral hydrogen. The tables are arranged in multiplets, and these are ordered in increasing excitation energies.
Zirconia based nucleic acid sensor for Mycobacterium tuberculosis detection
Authors: Das Maumita , Sumana Gajjala , Nagarajan R. , Malhotra B. D.
Published: March 2010

Nanostructured zirconium oxide (ZrO2) film (particle size∼35 nm), electrochemically deposited onto gold(Au) surface, has been used to immobilize 21-mer oligonucleotide probe (ssDNA) specific to Mycobacterium tuberculosis by utilizing affinity between oxygen atom of phosphoric group and zirconium to fabricate DNA biosensor. This DNA-ZrO2/Au bioelectrode, characterized using x-ray diffraction, Fourier transform infrared spectroscopy, cyclic voltammetry, and scanning electron microscopy techniques, can be used for early and rapid diagnosis of M. tuberculosis with detection limit of 0.065 ng/μL within 60s.
High-precision measurements of the equation of state of hydrocarbons at 1–10 Mbar using laser-driven shock waves
Authors: Barrios M. A. , Hicks D. G. , Boehly T. R. , Fratanduono D. E. , Eggert J. H. , Celliers P. M. , Collins G. W. , Meyerhofer D. D.
Published: March 2010

The equation of state (EOS) of polystyrene and polypropylene were measured using laser-driven shock waves with pressures from 1 to 10 Mbar. Precision data resulting from the use of α-quartz as an impedance-matching (IM) standard tightly constrains the EOS of these hydrocarbons, even with the inclusion of systematic errors inherent to IM. The temperature at these high pressures was measured, which, combined with kinematic measurements, provide a complete shock EOS. Both hydrocarbons were observed to reach similar compressions and temperatures as a function of pressure. The materials were observed to transition from transparent insulators to reflecting conductors at pressures of 1 to 2 Mbar.
Small valence-band offset of In0.17Al0.83N/GaN heterostructure grown by metal-organic vapor phase epitaxy
Authors: Akazawa M. , Matsuyama T. , Hashizume T. , Hiroki M. , Yamahata S. , Shigekawa N.
Published: March 2010

The valence-band offset of a lattice-matched In0.17Al0.83N/GaN heterostructure grown by metal-organic vapor phase epitaxy (MOVPE) was investigated by x-ray photoelectron spectroscopy (XPS). Atomic force microscopy and angle-resolved XPS indicated that a thin In0.17Al0.83N (2.5 nm) layer was successfully grown by MOVPE on GaN. The XPS result showed that the valence band offset was 0.2±0.3 eV. This result indicates that the conduction-band offset at the In0.17Al0.83N/GaN interface is large, i.e., 0.9 to 1.0 eV, and occupies a large part of the entire band discontinuity.
Photolithographic patterning of subwavelength top emitting colloidal quantum dot based inorganic light emitting diodes on silicon
Authors: Gopal Ashwini , Hoshino Kazunori , Zhang Xiaojing
Published: March 2010

The combination of lithographic patterning and nanostamping methods makes it possible to accurately define diffraction-limited multicolor (wavelengths 560–620 nm) light sources on a silicon substrate. We demonstrate a postprocessing technique that utilizes standard photolithography process to pattern the cathode of top emitting diode. Correlation of electroluminescence, photoluminescence, and atomic force microscopy topography showed that the emission region is well defined through the robust multiscale patterning techniques, with the fineness of the emitting area mainly limited by the point spread function of the observing microscope.
Effect of contamination on the electronic structure and hole-injection properties of MoO3/organic semiconductor interfaces
Authors: Meyer J. , Shu A. , Kröger M. , Kahn A.
Published: March 2010

The electronic structure and hole-injection properties of ambient contaminated molybdenum trioxide (MoO3) surfaces are studied by ultraviolet and inverse photoemission spectroscopy, and current-voltage measurements. Contamination reduces the work function (WF), electron affinity (EA) and ionization energy by about 1 eV with respect to the freshly evaporated film, to values of 5.7 eV, 5.5 eV, and 8.6 eV, respectively. However, the WF and EA remain sufficiently large that the hole-injection properties of MoO3 are not affected by contamination. The results are of particular importance in view of potential applications of transition metal oxides for low-cost manufacturing of devices in low-vacuum or nonvacuum environment.
Separation of gases from gas–water mixtures using carbon nanotubes
Authors: Lee Joonho , Aluru N. R.
Published: March 2010

We investigate equilibrium transport of gas–water mixtures, such as CO2–water, O2–water and H2–water mixtures, in carbon nanotubes using molecular dynamics simulations. Our results indicate that gases are selectively physisorbed in carbon nanotubes forming single-file gas chains. Once the single-file gas chains are formed, they prevent entry of water into the nanotube, suggesting that the presence of gas molecules can significantly affect the equilibrium transport of water in carbon nanotubes. The diffusion of single-file gas chains in nanotubes for gas–water mixtures is found to be lower compared to the single-file diffusion of gases in gas–only cases.
Thermopile antennas for detection of millimeter waves
Authors: Szentpáli B. , Basa P. , Fürjes P. , Battistig G. , Bársony I. , Károlyi G. , Berceli T. , Rymanov V. , Stöhr A.
Published: March 2010

A thermopile structure is proposed for the detection of microwave/millimeter wave radiation. The thermopairs in the suggested linear arrangement function as antennas. 5.58 V/W responsivity was achieved at 100 GHz with 40 serial connected thermopairs. The experimentally observed polarity and frequency dependence convincingly verify the proper detector operation.
Violet electroluminescence from p-GaN thin film/n-GaN nanowire homojunction
Authors: Ahn Jaehui , Mastro Michael A. , Hite Jennifer , Eddy Charles R. , Kim Jihyun
Published: March 2010

The difficulty associated with the precise positioning of nanowires has been one of the most significant issues hindering nanoelectronic integration. In this paper, we employed dielectrophoretic force to manipulate n-type GaN nano- and microwires onto a p-type GaN thin film to form a pristine p-n homojunction. The GaN wires were attracted to the n-type Ohmic metal in a direction parallel to the electric field, which was consistent with our simulation results. Violet electroluminescence emanated from the point of the n-GaN wire in contact with the p-GaN thin film. This p-n homojunction device displayed forward conduction above 6–9 V and current rectifying behavior down to a −20 V reverse bias. The current-voltage characteristics are distinctive of a p-n homojunction formed without deleterious damage or contamination.
Plasma treatment of multiwall carbon nanotubes for dispersion improvement in water
Authors: Chen Changlun , Ogino Akihisa , Wang Xiangke , Nagatsu Masaaki
Published: March 2010

Microwave excited Ar/H2O surface-wave plasma was used to treat multiwall carbon nanotubes (MWCNTs) to modify their surface characteristics and thus improve their dispersion capability in water. Changes in the atom composition and structure properties of MWCNTs were analyzed using x-ray photoelectron spectroscopy and Raman spectroscopy, and the surface morphology of MWCNTs was observed by field emission scanning electron microscopy and scanning transmission electron microscopy. The results indicated that Ar/H2O plasma treatment greatly enhanced the content of oxygen, and modified surface microstructure properties. The integrity of nanotube patterns, however, was not damaged.
InGaN gallium nitride light-emitting diodes with reflective electrode pads and textured gallium-doped ZnO contact layer
Authors: Tu S. H. , Lan C. J. , Wang S. H. , Lee M. L. , Chang K. H. , Lin R. M. , Chang J. Y. , Sheu J. K.
Published: March 2010

We demonstrate a GaN-based light-emitting diode (LED) with nonalloyed metal contacts and textured Ga-doped ZnO (GZO) contact layer to serve as the n- and p-type electrode pads, respectively. Compared with the conventional LEDs with flat surface and Cr/Au metal contacts, the nonalloyed Ag/Cr/Au contacts used in the present experimental LEDs play the role of reflector to prevent the emitted light from absorption by the opaque electrode pads. Enhancement of light output power observed from the experimental LEDs is also due to the textured GZO layer that can disperse the angular distribution of photons at the GZO/air interface. With an injection current of 20 mA, the output power of experimental LEDs can be improved markedly by a magnitude of 30% compared with conventional GaN-based LEDs.
Organic light emitting field effect transistors based on an ambipolar p-i-n layered structure
Authors: Maiorano V. , Bramanti A. , Carallo S. , Cingolani R. , Gigli G.
Published: March 2010

A bottom contact/top gate ambipolar “p-i-n” layered light emitting field effect transistor with the active medium inserted between two doped transport layers, is reported. The doping profile results crucial to the capability of emitting light, as well as to the electrical characteristics of the device. In this sense, high output current at relative low applied gate/drain voltage and light emission along the whole large area transistor channel are observed, putting the basis to full integration of organic light emitting field effect transistors in planar complex devices.
Microwave determination of electron-hole recombination dynamics from spontaneous to stimulated emission in a quantum-well microcavity laser
Authors: Wu C. H. , Then H. W. , Feng M. , Holonyak N.
Published: March 2010

By studying the optical microwave frequency response of a microcavity quantum-well vertical cavity surface-emitting laser (VCSEL) in the transition, over a low (a spread-out) mode density, from spontaneous to coherent operation, we resolve the dynamics (spontaneous to stimulated) of electron-hole recombination and reveal the existence of “fast” spontaneous recombination (τBspon<159 ps) in a carrier population generally characterized by a large average lifetime of ∼1 ns (Δn/τav=Δn1/τfast+(Δn−Δn1)/τslow,τfast<τslow). The measured average spontaneous lifetime is not a constant but is altered by the device size, geometry, and boundary conditions (e. g., cavity and current input-output boundary conditions).
Acoustical mechanism for the extraordinary sound transmission through subwavelength apertures
Authors: Wang Xinlong
Published: March 2010

An acoustical theory is developed for sound transmitting through subwavelength apertures. We show that the excitation of evanescent high-order modes induces, on each end of an aperture (either a slit or a hole), an additional acoustical reactance, which is singular as incident wavelength approaches one of cutoff wavelengths of high modes. The anomaly of the induced reactance greatly changes the resonant behaviors of the aperture, and makes the conjugate impedance matching possible at a wavelength slightly longer than the cutoff, thus leading to the extraordinary full transmission.
Simulation and Validation of Human Movement in Building Spaces
Authors: Tabak Vincent , de Vries Bauke , Dijkstra Jan
Published: March 2010

Data on human movement are valuable input data for building-simulation tools such as indoor-climate simulation and working-condition assessment. However, reliable data on human movement in buildings are scarcely available. Existing human-movement models are, typically, developed for (semi)public spaces and lack applicability to indoor spaces. The research presented here focuses on indoor office-building spaces and normal working conditions. The simulation model was developed in conjunction with a validation method. Web-based diaries and radio frequency identification technology were used to collect data on human behaviour in a real-life situation. The performance of the model was tested against a set of newly developed criterion variables (for example, the usage of facilities or the movement behaviour of employees) related to human movement in building spaces. Observed and predicted movement patterns were compared for these criteria. Results indicate close correspondence between simulated and observed behaviour, providing evidence of the validity of the model. The model can be used to accurately predict the space utilisation of an organisation.
The Methodology of User-Sensitive Service Design within Urban Planning
Authors: Wallin Sirkku , Horelli Liisa
Published: March 2010

The increasingly complex living environment poses challenges in everyday life that traditional urban planning cannot meet. We argue that the methodology called the user-sensitive service design within urban planning is viable for many stakeholders in a situation where the infrastructure of everyday life is shattering and the uncertainty and ambiguity of the planning process and outcomes are prevailing. Our aim is to present the methodology and its application in the planning and development of digitised services in a neighbourhood of Helsinki. The methodology turns out to be a hybridiser and a bridge builder that embeds urban planning in the local context. In addition, it is a vehicle for transferring planning content to the phases of implementation and use, resulting in the emergence of glocal digital spaces.
Human Echolocation: Blind and Sighted Persons' Ability to Detect Sounds Recorded in the Presence of a Reflecting Object
Authors: Schenkman Bo N , Nilsson Mats E
Published: March 2010

Research suggests that blind people are superior to sighted in echolocation, but systematic psychoacoustic studies on environmental conditions such as distance to objects, signal duration, and reverberation are lacking. Therefore, two experiments were conducted. Noise bursts of 5, 50, or 500 ms were reproduced by a loudspeaker on an artificial manikin in an ordinary room and in an anechoic chamber. The manikin recorded the sounds binaurally in the presence and absence of a reflecting 1.5-mm thick aluminium disk, 0.5 m in diameter, placed in front, at distances of 0.5 to 5 m. These recordings were later presented to ten visually handicapped and ten sighted people, 30–62 years old, using a 2AFC paradigm with feedback. The task was to detect which of two sounds that contained the reflecting object. The blind performed better than the sighted participants. All performed well with the object at < 2 m distance. Detection increased with longer signal durations. Performance was slightly better in the ordinary room than in the anechoic chamber. A supplementary experiment on the two best blind persons showed that their superior performance at distances > 2 m was not by chance. Detection thresholds showed that blind participants could detect the object at longer distances in the conference room than in the anechoic chamber, when using the longer-duration sounds and also as compared to the sighted people. Audiometric tests suggest that equal hearing in both ears is important for echolocation. Possible echolocation mechanisms are discussed.
High clay contents, dense soils, and spatial variability are the principal subsoil constraints to cropping the higher rainfall land in south-eastern Australia
Authors: MacEwan R. J. , Crawford D. M. , Newton P. J. , Clune T. S.
Published: March 2010

Available soil information and unpublished data from soil survey indicate that high clay contents and high bulk density are the major subsoil constraints to crop growth in the high rainfall zone (HRZ) of south-eastern Australia. Seven high rainfall agroecological zones are proposed as sub-divisions of the region to focus future research and development. The HRZ is dominated by texture-contrast soils (69.9%) and soils with clay subsoil (89.4%) and high bulk density (mean 1.6 t/m3). Sodicity and acidity are also significant constraints to crop production in the HRZ. The physical limitations to root growth in the HRZ subsoils are best appreciated through the least-limiting water range concept and growth-limiting bulk densities. Management options and results of past research and intervention in soil loosening, drainage, raised beds, liming, and gypsum are reviewed. Climatic uncertainty raises questions about the future relevance of waterlogging as a constraint in the HRZ and confounds the development of reliable recommendations for engineering intervention.
Use of genetic tolerance in grain crops to overcome subsoil constraints in alkaline cropping soils
Authors: Nuttall J. G. , Hobson K. B. , Materne M. , Moody D. B. , Munns R. , Armstrong R. D.
Published: March 2010

Subsoil physicochemical constraints such as primary salinity and high boron (B) can significantly reduce grain yields across wide areas of Australia. Financially viable amelioration options are limited for cropping systems on these soils, which has raised interest in ‘genetic solutions’. Increasing the tolerance of crops to high salinity and boron that typically co-exist within alkaline soils offers the potential for substantial yield benefits. To assess the contribution that genetic variation can make to crop yield, closely related genotypes differing in B and/or Na+ tolerance of bread and durum wheat, barley, and lentil were compared by growing the different lines in intact soil cores of 2 Calcarosol profiles differing in level of subsoil constraints (‘hostile’/’benign’). The hostile profile had salinity increasing to EC1 : 5 ~1.2 dS/m and B ~18 mg/kg to 0.60 m, whereas in the benign soil EC1 : 5 did not exceed ~0.6 dS/m and B ~11 mg/kg. Grain yields were significantly less on the hostile soil than the benign soil for barley (34%), bread wheat (20%), durum wheat (31%), and lentil (38%). Accumulation of B in shoots was significantly lower on the hostile soil across all crop species, indicating high sodium within the soil was associated with inhibited uptake of B in plants. In contrast, accumulation of Na+ was greater for all cereal crops in the hostile soil compared with the benign soil. Lentil plants with reputed sodium tolerance (CIPAL415) produced a significant yield benefit on both the benign and hostile soil over the commercial line, Nugget. The lentil line with combined Na+ and B tolerance (02-355L*03Hs005) also produced an additional yield increase over CIPAL415 on the hostile soil; however, yield was equivalent on the benign soil. For durum wheat, 2 genotypes differing in Na+ tolerance, containing either the Nax1 or Nax2 genes, accumulated less sodium in the straw than the parent cv. Tamaroi within the hostile soil; however, this did not translate to a yield advantage. For barley, there was no difference in either grain yield or B uptake in either the grain or straw between the B-tolerance line 03_007D_087 and its parent cv. Buloke. Similarly, there was no difference in either grain yield or B uptake between the bread wheat Schomburgk and its B-tolerant near-isogenic line BT-Schomburgk. This study suggests that of the cereal lines tested, there was no obvious benefit in lines with potentially improved tolerance for a single, specific subsoil constraint on alkaline soils where multiple potential constraints exist. In contrast, in lentils, incorporating tolerance to Na+ and B did show promise for increased adaptation to soils with subsoil constraints.
Osmotic and ionic effects of various electrolytes on the growth of wheat
Authors: Rengasamy Pichu
Published: March 2010

Pot experiments were conducted using a sandy loam soil and various electrolyte solutions such as NaCl, CaCl2, Na2SO4, and Hoagland nutrient solution containing all macro- and micro-nutrient elements in appropriate proportions, inducing different electrical conductivity (EC) levels of the soil solution during the growth of Krichauff wheat while the water content in the pot soils was maintained at field capacity. The resulting differences in dry matter production after 40 days of growth clearly indicated the continuous operation of osmotic effect as the EC of the soil solution increased from 0.7 to 41.0 dS/m. However, the osmotic effect became dominant and severely restricted plant growth when the soil solution EC increased above a ‘threshold value’, which was 25 dS/m, corresponding to an osmotic pressure of 900 kPa, in this experiment. Below this EC value, particularly at low EC values, ionic effects due to Na+, Ca2+, SO42–, and Cl– were also evident, but it could not be concluded whether these effects were due to toxicity or ion imbalance. The osmotic effect at EC values above the threshold resulted in greatly reduced water uptake from pot soils, the unused water being in the range 89–96% of the field capacity of the soil. Water use efficiency is a major factor in profitable and sustainable dryland agriculture. Both soil management and selection and breeding of salt-tolerant plants should concentrate on ensuring that the threshold EC value for severe osmotic effects is not reached under field conditions.
Testing and classification of individual plants for fire behaviour: plant selection for the wildland - urban interface
Authors: White Robert H. , Zipperer Wayne C.
Published: March 2010

Knowledge of how species differ in their flammability characteristics is needed to develop more reliable lists of plants recommended for landscaping homes in the wildland–urban interface (WUI). As indicated by conflicting advice in such lists, such characterisation is not without difficulties and disagreements. The flammability of vegetation is often described as having four components (ignitability, combustibility, sustainability and consumability). No standards or generally recognised test procedures exist for evaluating these components in plants. Some measurements of flammability include times for ignition, rate of flame spread, flame height and heat release rate. Often, the fire behaviour characteristics of a plant are derived from its physical and chemical characteristics. Thermogravimetric analysis and other thermal analyses of ground samples have long been used to characterise the thermal degradation of vegetation. More recently, researchers have used the oxygen consumption methodology to measure the heat released due to combustion of the vegetation. Although oxygen consumption calorimetry is an improvement in characterising plant flammability, translation of laboratory results to field conditions can be problematic and tests can be expensive.
The wildland - urban interface fire problem - current approaches and research needs
Authors: Mell William E. , Manzello Samuel L. , Maranghides Alexander , Butry David , Rehm Ronald G.
Published: March 2010

Wildfires that spread into wildland–urban interface (WUI) communities present significant challenges on several fronts. In the United States, the WUI accounts for a significant portion of wildland fire suppression and wildland fuel treatment costs. Methods to reduce structure losses are focussed on fuel treatments in either wildland fuels or residential fuels. There is a need for a well-characterised, systematic testing of these approaches across a range of community and structure types and fire conditions. Laboratory experiments, field measurements and fire behaviour models can be used to better determine the exposure conditions faced by communities and structures. The outcome of such an effort would be proven fuel treatment techniques for wildland and residential fuels, risk assessment strategies, economic cost analysis models, and test methods with representative exposure conditions for fire-resistant building designs and materials.
Use of signalling nouns across L1 and L2 writer corpora
Authors: Flowerdew John
Published: March 2010

A signalling noun is the use of an abstract noun the full meaning (realisation) of which can only be made specific by reference to its linguistic context. Examples of nouns which can function as signalling nouns are attitude, consequence, difficulty, effect, process, reason and result. The realisation of a signalling noun may occur across clauses or within the clause. Using the ICLE Locness (L1 writers) corpus as a reference corpus and a learner English corpus written by Cantonese-speaking learners of English, this paper presents a comparison of the use of signalling nouns by these two L1 and L2 writer groups. Use of different functions, realisation patterns and selection and range of individual nouns are compared. In this way a profile is built up of the use of signalling nouns by the two target groups and areas for pedagogic intervention are identified.
From archive to corpus
Authors: Johnston Trevor
Published: March 2010

Annotations are an important resource in corpus-based linguistic research. In fact, the most important feature of a modern signed language corpus should be that it has been annotated rather than simply transcribed. Digital multi-media annotation software can now transform language recordings into machine-readable texts using gloss-based annotations without it first being necessary to transcribe these utterances, provided that sign tokens are identified and discriminated according to type. Further annotations can subsequently be appended to these units. However, unique identifiers of sign types (or ‘ID-glosses’) can only be used if a comprehensive reference lexical database of the language already exists. In order to create a basic multi-purpose reference signed language corpus, therefore, linguists should prioritize annotation using ID-glosses above transcription. The effort expended in creating a transcription that does not facilitate the unique identification of sign types will not result in a machine-readable corpus in any meaningful sense, contrary to expectations.
Intra-paradigmatic variation in Eleme verbal agreement
Authors: Bond Oliver
Published: March 2010

Mismatches in the morphosyntactic features of controllers and targets in the Eleme (Ogonoid, Niger-Congo) participant reference system allow for a subject agreement paradigm in which the person of the grammatical subject is indicated by a verbal prefix, while plural number is marked by a suffix on different targets — either lexical verbs or auxiliaries — based on the person value of the controller. I examine the distribution of Eleme ‘Default Subject’ agreement affixes and the intra-paradigmatic asymmetry found between second-person plural and third-person plural subjects in Auxiliary Verb Constructions (AVC) and Serial Verb Constructions (SVC). I argue that the criteria by which the various agreement affixes select an appropriate morphological host can be modelled in terms of agreement prerequisites even when distributional variation is paradigm internal.
Sentence-initial I think (that) and I believe (that)
Authors: Dehé Nicole , Wichmann Anne
Published: March 2010

Sentence-initial pronoun-verb combinations such as I think, I believe are ambiguous between main clause use on the one hand and adverbial or discourse use on the other hand. We approach the topic from a prosodic perspective. Based on corpus data from spoken British English the prosodic patterns of sentence-initial I think and I believe are analysed and related to their interpretation in context. We show that these expressions may function as main clause (MC), comment clause (CC) or discourse markers (DM) and that the speaker’s choice is reflected in the prosody. The key feature is prosodic prominence: MCs are reflected by accent placement on the pronoun, CCs by an accent on the verb, while DMs are unstressed.
Syllable structure and extrametricality
Authors: Gordon Matthew , Jany Carmen , Nash Carlos , Takara Nobutaka
Published: March 2010

This paper proposes a functional basis for final consonant extrametricality, the asymmetric status of CVC syllables as stress-attracting in non-final position of a word but stress-rejecting in final position. A typological study of phonemic vowel length pattern in 10 languages with this final vs. non-final stress asymmetry and 30 languages in which CVC attracts stress in final position indicates a robust asymmetry between languages differing in their stress system’s treatment of final CVC. Languages that asymmetrically allow stress on non-final but not on final CVC all lack phonemic vowel length contrast in final position, whereas those lacking the stress asymmetry often have contrastive length in final vowels. It is claimed that the absence of phonemic length in languages that do not stress final CVC facilitates the nearly universal pattern of phonetic final lengthening, which threatens to obscure the perception of phonemic length. The enhanced lengthening of final vowels in languages with final phonemic vowel length reduces the duration ratio of CVC relative to CV, thereby reducing CVC’s perceptual prominence and thus its propensity to attract stress in keeping with Lunden’s (2006) proportional duration theory of weight. A phonetic study of two languages differing in the stress-attracting ability of final CVC offers support for the proposed account. Arabic, which displays consonant extrametricality and largely lacks phonemic vowel length in final position, has substantial final vowel lengthening, whereas Kabardian, which stresses final CVC and contrasts vowel length in final position, lacks substantial final lengthening.