ALBERT

Description: During the 2007-2008 antarctic campaign, the Italian PNRA installed a Low Power Magnetometer within the framework of the AIMNet (Antarctic International Magnetometer Network) project, proposed and coordinated by BAS. The magnetometer is situated at Talos Dome, around 300 km geographically North-West from Mario Zucchelli Station (MZS), and approximately at the same geomagnetic latitude as MZS. In this work we present a preliminary analysis of the geomagnetic field 1-min data, and a comparison with simultaneous data from different Antarctic stations.

Description: Published

Description: Vienna, Austria

Description: 1.6. Osservazioni di geomagnetismo

Description: open

Description: In this study temporal variations of coccolithophore blooms are investigated using satellite data. Eight years, from 2003 to 2010, of data of SCIAMACHY, a hyper-spectral satellite sensor on-board ENVISAT, were processed by the PhytoDOAS method to 5 monitor the biomass of coccolithophores in three selected regions. These regions are characterized by frequent occurrence of large coccolithophore blooms. The retrieval results, shown as monthly mean time-series, were compared to related satellite products, including the total surface phytoplankton, i.e., total chlorophyll-a (from GlobColour merged data) and the particulate inorganic carbon (from MODIS-Aqua). The 10 inter-annual variations of the phytoplankton bloom cycles and their maximum monthly mean values have been compared in the three selected regions to the variations of the geophysical parameters: sea-surface temperature (SST), mixed-layer depth (MLD) and surface wind speed, which are known to affect phytoplankton dynamics. For each region the anomalies and linear trends of the monitored parameters over the period of this 15 study have been computed. The patterns of total phytoplankton biomass and specific dynamics of coccolithophores chlorophyll-a in the selected regions are discussed in relation to other studies. The PhytoDOAS results are consistent with the two other ocean color products and support the reported dependencies of coccolithophore biomass’ dynamics to the compared geophysical variables. This suggests, that PhytoDOAS 20 is a valid method for retrieving coccolithophore biomass and for monitoring its bloom developments in the global oceans. Future applications of time-series studies using the PhytoDOAS data set are proposed, also using the new upcoming generations of hyper-spectral satellite sensors with improved spatial resolution.

Description: The gradual cooling of the climate during the Cenozoic has generally been attributed to a decrease in CO2 concentration in the atmosphere. The lack of transient climate models and in particular the lack of high-resolution proxy records of CO2, beyond the ice-core record prohibit however a full understanding of for example the inception of the Northern Hemisphere glaciation and mid-Pleistocene transition. Here we elaborate on an inverse modelling technique to reconstruct a continuous CO2 series over the past 20 million year (Myr), by decomposing the global deep-sea benthic d18O record into a mutually consistent temperature and sea level record, using a set of 1-D models of the major Northern and Southern Hemisphere ice sheets. We subsequently compared the modelled temperature record with ice core and proxy-derived CO2 data to create a continuous CO2 reconstruction over the past 20 Myr. Results show a gradual decline from 450 ppmv around 15 Myr ago to 225 ppmv for mean conditions of the glacial-interglacial cycles of the last 1 Myr, coinciding with a gradual cooling of the global surface temperature of 10 K. Between 13 to 3 Myr ago there is no long-term sea level variation caused by ice-volume changes. We find no evidence for a change in the long-term relation between temperature change and CO2, other than the effect following from the saturation of the absorption bands for CO2. The reconstructed CO2 record shows that the Northern Hemisphere glaciation starts once the long-term average CO2 concentration drops below 265 ppmv after a period of strong decrease in CO2. Finally, only a small long-term decline of 23 ppmv is found during the mid-Pleistocene transition, constraining theories on this major transition in the climate system. The approach is not accurate enough to revise current ideas about climate sensitivity.

Description: A. R. McInroy, A. Uhl, T. Lear, T. M. Klapotke, S. Shaikhutdinov et al. A series of five alumina-supported palladium catalysts have previously been prepared and characterised by a combination of CO chemisorption and infrared spectroscopy. The reactive attributes of these catalysts are examined using the hydrogenation of crotonaldehyde as a test reaction, using a modifie ... [J. Chem. Phys. 134, 214704 (2011)] published Tue Jun 7, 2011.

Description: K. Coulembier and H. De Bie In superspace a realization of [fraktur sl] is generated by the super Laplace operator and the generalized norm squared. In this paper, an inner product on superspace for which this representation is skew-symmetric is considered. This inner product was already defined for spaces of weighted polynomi ... [J. Math. Phys. 52, 063504 (2011)] published Mon Jun 6, 2011.

Description: Kinematics of a mass movement constrained by sparse and inhomogeneous data Natural Hazards and Earth System Science, 11, 1609-1618, 2011 Author(s): M. Karbon, E. Brückl, E. Hegedüs, and A. Preh On 12 February 2008, a landslide occurred along a 50 m high bank of the Danube river near Dunaszekcsö, Hungary. The initial state is only incompletely documented and the geodetic data acquired after the mass movement are sparse. A generalized 3-D topographic model of the landslide and its surrounding area was assembled and a representative longitudinal profile extracted. The reconstruction of the original surface is based on an orthophoto as well as on morphological considerations. Recorded observations include the locations of the outcrops of basal sliding surfaces, displacements at the main scarp and in the lower part of the slide, and a value to describe the total mass transport. Such sparse and inhomogeneous data were insufficient to derive a comprehensive documentation of the landslide or obtain adequate constraints for an accurate numerical analysis. Therefore, slider block models were fitted to the field data, which have only a small number of free parameters. A general view on the morphology of the mass movement justifies its classification as a rotational slide. A double slider block model fits all observational parameters within their error margin and supplies valuable information on the geometry of the slide. Estimates of the residual friction angles were derived and the question of reactivation was addressed. Finite Difference (FD) modelling and the application of conventional stability analysis support the geometry of the slider blocks and the computed average residual friction angles. Generally, the results are assumed to represent preliminary information, which could only be attained by the combination of the thinly distributed geodetic data with qualitative morphological observations and the implementation of a model. This type of information can be gained quickly and may be valuable for preliminary hazard mitigation measures or the planning of a comprehensive exploration and monitoring program.

Description: North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation Ocean Science, 7, 389-404, 2011 Author(s): I. Medhaug and T. Furevik Output from a total of 24 state-of-the-art Atmosphere-Ocean General Circulation Models is analyzed. The models were integrated with observed forcing for the period 1850–2000 as part of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. All models show enhanced variability at multi-decadal time scales in the North Atlantic sector similar to the observations, but with a large intermodel spread in amplitudes and frequencies for both the Atlantic Multidecadal Oscillation (AMO) and the Atlantic Meridional Overturning Circulation (AMOC). The models, in general, are able to reproduce the observed geographical patterns of warm and cold episodes, but not the phasing such as the early warming (1930s–1950s) and the following colder period (1960s–1980s). This indicates that the observed 20th century extreme in temperatures are due to primarily a fortuitous phasing of intrinsic climate variability and not dominated by external forcing. Most models show a realistic structure in the overturning circulation, where more than half of the available models have a mean overturning transport within the observed estimated range of 13–24 Sverdrup. Associated with a stronger than normal AMOC, the surface temperature is increased and the sea ice extent slightly reduced in the North Atlantic. Individual models show potential for decadal prediction based on the relationship between the AMO and AMOC, but the models strongly disagree both in phasing and strength of the covariability. This makes it difficult to identify common mechanisms and to assess the applicability for predictions.

Description: Sensitivity analysis of an ocean carbon cycle model in the North Atlantic: an investigation of parameters affecting the air-sea CO 2 flux, primary production and export of detritus Ocean Science, 7, 405-419, 2011 Author(s): V. Scott, H. Kettle, and C. J. Merchant The sensitivity of the biological parameters in a nutrient-phytoplankton-zooplankton-detritus (NPZD) model in the calculation of the air-sea CO 2 flux, primary production and detrital export is analysed. We explore the effect on these outputs of variation in the values of the twenty parameters that control ocean ecosystem growth in a 1-D formulation of the UK Met Office HadOCC NPZD model used in GCMs. We use and compare the results from one-at-a-time and all-at-a-time perturbations performed at three sites in the EuroSITES European Ocean Observatory Network: the Central Irminger Sea (60° N 40° W), the Porcupine Abyssal Plain (49° N 16° W) and the European Station for Time series in the Ocean Canary Islands (29° N 15° W). Reasonable changes to the values of key parameters are shown to have a large effect on the calculation of the air-sea CO 2 flux, primary production, and export of biological detritus to the deep ocean. Changes in the values of key parameters have a greater effect in more productive regions than in less productive areas. The most sensitive parameters are generally found to be those controlling well-established ocean ecosystem parameterisations widely used in many NPZD-type models. The air-sea CO 2 flux is most influenced by variation in the parameters that control phytoplankton growth, detrital sinking and carbonate production by phytoplankton (the rain ratio). Primary production is most sensitive to the parameters that define the shape of the photosynthesis-irradiance curve. Export production is most sensitive to the parameters that control the rate of detrital sinking and the remineralisation of detritus.

Description: Damodar Prasad Goswami, Dewaki Nandan Tibarewala, and Dilip Kumar Bhattacharya In this article, the heart rate variability signal taken from subjects practising different types of meditations have been investigated to find the underlying similarity among them and how they differ from the non-meditative condition. Four different groups of subjects having different meditation te ... [J. Appl. Phys. 109, 114703 (2011)] published Wed Jun 8, 2011.

Description: Vijay Nalladega, Shamachary Sathish, Terry Murray, Eunsung Shin, Kumar V. Jata et al. The interaction of low-frequency electromagnetic waves with metallic nanostructure consisting of nanoparticles has been investigated. The existence of helicons in metallic nanostructure is predicted based on the enhancement of effective mass of the electrons in metallic mesostructures in low-frequen ... [J. Appl. Phys. 109, 114907 (2011)] published Wed Jun 8, 2011.

Description: Somik Banerjee and A. Kumar Conductivity relaxation and charge transport mechanisms in polypyrrole (PPy) nanofibers synthesized using a micellar polymerization technique with varying surfactant concentration has been investigated by dielectric relaxation spectroscopy. TEM micrographs depict that the increasing surfactant conce ... [J. Appl. Phys. 109, 114313 (2011)] published Wed Jun 8, 2011.

Description: Lijun Guo, Xuebang Wu, and Zhengang Zhu The relaxation dynamics of the primary alpha and secondary beta processes in NdFeCoAl bulk metallic glass has been investigated by using low-frequency mechanical spectroscopy, differential scanning calorimetry (DSC) and x-ray diffraction. From the shift of internal friction peaks by the frequency ch ... [J. Appl. Phys. 109, 113524 (2011)] published Wed Jun 8, 2011.

Description: Y. Langlois, P. Chapelle, A. Jardy, and F. Gentils A 2D two-fluid numerical model is developed for the description of the diffuse arc in a vacuum interrupter under the possible influence of an axial magnetic field (AMF). This model incorporates the energy balance equations for both ions and electrons and takes into account the three components of th ... [J. Appl. Phys. 109, 113306 (2011)] published Wed Jun 8, 2011.

Description: Jie Chen, Wei-Kan Chen, and Peter M. Rentzepis We utilize 100 fs optical pulses as a means of heating 150 nm thick single Au (111) crystals, below the melting point and monitor the subsequent structural evolution with subpicosecond time resolution using 0.6 ps, 8.04 KeV x-ray pulses. By monitoring the energy and time dependent modulation of the ... [J. Appl. Phys. 109, 113522 (2011)] published Wed Jun 8, 2011.

Description: Y. Z. Chen, E. Stamate, N. Pryds, J. R. Sun, B. G. Shen et al. When depositing amorphous SrTiO (STO) films on crystalline STO substrates by pulsed laser deposition, metallic interfaces are observed, though both materials are band-gap insulators. The interfacial conductivity exhibits strong dependence on oxygen pressure during film growth, which is closely relat ... [Appl. Phys. Lett. 98, 232105 (2011)] published Wed Jun 8, 2011.

Description: Kyohei Ogawa, Takashi Nakamura, Yasuhiko Terada, Katsumi Kose, and Tomoyuki Haishi We have developed the first magnetic resonance (MR) microscope using a high critical-temperature superconducting bulk magnet. The bulk magnet comprises six annular bulk superconductors (60 mm outer diameter, 28 mm inner diameter, 20 mm high) made of c-axis oriented single-domain EuBaCuO crystals. Th ... [Appl. Phys. Lett. 98, 234101 (2011)] published Thu Jun 9, 2011.

Description: Xiao-Yu Peng, Xin-Hai Zhang, Jing-Hua Teng, Hong-Cheng Guo, and Yong-Lim Foo The approach to realize the optimal chirped probe pulse length for an arbitrary pulsed terahertz (THz) signal measured with the spectral-encoding technique was investigated by simulation. It was found that either the maximum positive peak or the absolute value of the strongest negative peak of the n ... [Appl. Phys. Lett. 98, 231111 (2011)] published Thu Jun 9, 2011.

Description: Bin Gao, Jinfeng Kang, Lifeng Liu, Xiaoyan Liu, and Bin Yu A physical model based on ion-transport-recombination effect is proposed to quantify the RESET behavior of bipolar metal-oxide-based resistive random access memory devices. In the model, RESET process is attributed to the recombination of mobile oxygen ions with low-electron-occupied oxygen vacancie ... [Appl. Phys. Lett. 98, 232108 (2011)] published Thu Jun 9, 2011.

Description: Gopinadhan Kalon, Young Jun Shin, and Hyunsoo Yang Tunable and highly reproducible metalinsulator transitions have been observed in bilayer graphene upon thermal annealing at 400 K under high vacuum conditions. Before annealing, the sample is metallic in the whole temperature regime of study. Upon annealing, the conductivity changes from metallic to ... [Appl. Phys. Lett. 98, 233108 (2011)] published Thu Jun 9, 2011.

Description: Ignacio Martin-Bragado A lattice kinetic Monte Carlo model for defect generation during solid phase epitaxial regrowth (SPER) is presented. It assumes two simple causes for defective Si formation: amorphous atoms in local {111} configurations having a probability to become defective and random nucleation and growth creati ... [Appl. Phys. Lett. 98, 233109 (2011)] published Thu Jun 9, 2011.

Description: Li Huang, X. W. Fang, C. Z. Wang, M. J. Kramer, Z. J. Ding et al. Medium-range order in ZrPd metallic glass was studied using a combination of x-ray diffraction experiment and atomistic simulations. We show that, in contrast to earlier experimental interpretations, the icosahedral-like polyhedron is centered around Pd, rather than Zr. Furthermore, we find that the ... [Appl. Phys. Lett. 98, 231906 (2011)] published Thu Jun 9, 2011.

Description: S. T. Teklemichael, W. M. Hlaing Oo, M. D. McCluskey, E. D. Walter, and D. W. Hoyt While zinc oxide (ZnO) has potential for optoelectronic applications, the lack of reliable p-type doping remains a major challenge. We provide evidence that ZnO nanocrystals contain uncompensated acceptors. IR absorption peaks at liquid-helium temperatures suggest a hydrogenic acceptor with a hole b ... [Appl. Phys. Lett. 98, 232112 (2011)] published Thu Jun 9, 2011.

Description: Didit Yudistira, Sarah Benchabane, Davide Janner, and Valerio Pruneri We show that an appropriate mass-loading, placed on the surface and in between the electrodes of a coplanar acoustic LiNbO superlattice, can counteract lateral diffraction of surface acoustic waves (SAWs). The strong confinement corresponds to a SAW mode, whose displacement is measured using laser i ... [Appl. Phys. Lett. 98, 233504 (2011)] published Thu Jun 9, 2011.

Description: Soshi Sato, Wei Li, Kuniyuki Kakushima, Kenji Ohmori, Kenji Natori et al. Interfacial states of silicon nanowire field-effect transistors with rectangular-like cross-sections (wire height of 10 nm and widths of 9 and 18 nm) have been evaluated from the transfer characteristics in the subthreshold region measured at cryogenic temperatures, where kinks in the drain current ... [Appl. Phys. Lett. 98, 233506 (2011)] published Thu Jun 9, 2011.

Description: J. L. Wang, S. J. Campbell, J. M. Cadogan, A. J. Studer, R. Zeng et al. A giant magnetocaloric effect has been observed in NdMnGeSi associated with the first-order magnetic phase transition from antiferromagnetism to ferromagnetism around T=36 K. The magnetic entropy change DeltaS and adiabatic temperature change DeltaT have been determined from magnetization and speci ... [Appl. Phys. Lett. 98, 232509 (2011)] published Thu Jun 9, 2011.

Description: Takafumi Akiho, Tetsuya Uemura, Masanobu Harada, Ken-ichi Matsuda, and Masafumi Yamamoto The effects of MgO tunnel barriers on both junction resistance and tunneling anisotropic magnetoresistance (TAMR) characteristics of CoMnSi(CMS)/MgO/n-GaAs junctions and CoFe(CoFe)/MgO/n-GaAs junctions were investigated. The resistance-area (RA) product of the CMS/MgO/n-GaAs junctions showed an expo ... [Appl. Phys. Lett. 98, 232109 (2011)] published Thu Jun 9, 2011.

Description: Soo Kyung Kim, Chul-Joon Heo, Jong Young Choi, Su Yeon Lee, Se Gyu Jang et al. Photothermolysis technique via array of gold nanograils had been developed by illuminating near infrared laser light onto captured bacteria in metal nanostructure. The strong electromagnetic field enhancement at the sharp edges of the gold nanograils produced local heating that was sufficient to bre ... [Appl. Phys. Lett. 98, 233701 (2011)] published Thu Jun 9, 2011.

Description: Alexander S. Solntsev, Andrey A. Sukhorukov, Dragomir N. Neshev, Rumen Iliew, Reinhard Geiss et al. We predict highly efficient third harmonic generation through simultaneous phase-matching of second-harmonic generation and sum-frequency generation in lithium niobate nanowaveguides, enabled due to strong modal dispersion. We demonstrate that the waveguide size which corresponds to phase-matching i ... [Appl. Phys. Lett. 98, 231110 (2011)] published Thu Jun 9, 2011.

Description: J. Gao, L. R. Vale, J. A. B. Mates, D. R. Schmidt, G. C. Hilton et al. We measure frequency- and dissipation-quadrature noise in superconducting microresonators with sensitivity near the vacuum noise level using a Josephson parametric amplifier. At an excitation power of 100 nW, frequency noise rises orders of magnitude above the vacuum noise, but no excess dissipation ... [Appl. Phys. Lett. 98, 232508 (2011)] published Thu Jun 9, 2011.

Description: Jung Won Seo, Seung Jae Baik, Sang Jung Kang, Yun Ho Hong, Ji Hwan Yang et al. We report cross-bar array resistive random access memory (RRAM) devices based on a ZnO thin film fabricated at room temperature. To prevent the sneak current path in a conventional cross-bar array device, two types of heterostructure diodes, a NiO/ZnO p-n junction and a WO/ZnO tunnel barrier both st ... [Appl. Phys. Lett. 98, 233505 (2011)] published Thu Jun 9, 2011.

Description: Y.-C. Tsai, R. Fardel, and C. B. Arnold While nanofabricated structures find an increasingly large number of applications, few techniques are able to pattern rough or uneven surfaces, or surfaces with pre-existing structure. In this letter we show that optical trap assisted nanopatterning (OTAN), a near-field laser based technique, is abl ... [Appl. Phys. Lett. 98, 233110 (2011)] published Thu Jun 9, 2011.

Description: M. Cerchez and T. Heinzel It is demonstrated how the correction factor alpha used in Hall magnetometry of localized magnetic field profiles depends on the sample geometry and the electron mean free path, in the quasiballistic and ballistic regimes. The frequently used approximation of a constant correction factor close to 1 ... [Appl. Phys. Lett. 98, 232111 (2011)] published Thu Jun 9, 2011.

Description: Theoretical basis for convective invigoration due to increased aerosol concentration Atmospheric Chemistry and Physics, 11, 5407-5429, 2011 Author(s): Z. J. Lebo and J. H. Seinfeld The potential effects of increased aerosol loading on the development of deep convective clouds and resulting precipitation amounts are studied by employing the Weather Research and Forecasting (WRF) model as a detailed high-resolution cloud resolving model (CRM) with both detailed bulk and bin microphysics schemes. Both models include a physically-based activation scheme that incorporates a size-resolved aerosol population. We demonstrate that the aerosol-induced effect is controlled by the balance between latent heating and the increase in condensed water aloft, each having opposing effects on buoyancy. It is also shown that under polluted conditions, increases in the CCN number concentration reduce the cumulative precipitation due to the competition between the sedimentation and evaporation/sublimation timescales. The effect of an increase in the IN number concentration on the dynamics of deep convective clouds is small and the resulting decrease in domain-averaged cumulative precipitation is shown not to be statistically significant, but may act to suppress precipitation. It is also shown that even in the presence of a decrease in the domain-averaged cumulative precipitation, an increase in the precipitation variance, or in other words, andincrease in rainfall intensity, may be expected in more polluted environments, especially in moist environments. A significant difference exists between the predictions based on the bin and bulk microphysics schemes of precipitation and the influence of aerosol perturbations on updraft velocity within the convective core. The bulk microphysics scheme shows little change in the latent heating rates due to an increase in the CCN number concentration, while the bin microphysics scheme demonstrates significant increases in the latent heating aloft with increasing CCN number concentration. This suggests that even a detailed two-bulk microphysics scheme, coupled to a detailed activation scheme, may not be sufficient to predict small changes that result from perturbations in aerosol loading.

Description: Analysis of HCl and ClO time series in the upper stratosphere using satellite data sets Atmospheric Chemistry and Physics, 11, 5321-5333, 2011 Author(s): A. Jones, J. Urban, D. P. Murtagh, C. Sanchez, K. A. Walker, N. J. Livesey, L. Froidevaux, and M. L. Santee Previous analyses of satellite and ground-based measurements of hydrogen chloride (HCl) and chlorine monoxide (ClO) have suggested that total inorganic chlorine in the upper stratosphere is on the decline. We create HCl and ClO time series using satellite data sets extended to November 2008, so that an update can be made on the long term evolution of these two species. We use the HALogen Occultation Experiment (HALOE) and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) data for the HCl analysis, and the Odin Sub-Millimetre Radiometer (SMR) and the Aura Microwave Limb Sounder (Aura-MLS) measurements for the study of ClO. Altitudes between 35 and 45 km and two mid-latitude bands: 30° S–50° S and 30° N–50° N, for HCl, and 20° S–20° N for ClO and HCl are studied. ACE-FTS and HALOE HCl anomaly time series (with QBO and seasonal contributions removed) are combined to produce all instrument average time series, which show HCl to be reducing from peak 1997 values at a linear estimated rate of −5.1 % decade −1 in the Northern Hemisphere and −5.2 % decade −1 in the Southern Hemisphere, while the tropics show a linear trend of −5.8 % per decade (although we do not remove the QBO contribution there due to sparse data). Trend values are significantly different from a zero trend at the 2 sigma level. ClO is decreasing in the tropics by −7.1 % ± 7.8 % decade −1 based on measurements made from December 2001 to November 2008. The statistically significant downward trend found in HCl after 1997 and the apparent downward ClO trend since 2001 (although not statistically significant) confirm how effective the 1987 Montreal protocol objectives and its amendments have been in reducing the total amount of inorganic chlorine.

Description: Bayesian statistical modeling of spatially correlated error structure in atmospheric tracer inverse analysis Atmospheric Chemistry and Physics, 11, 5365-5382, 2011 Author(s): C. Mukherjee, P. S. Kasibhatla, and M. West We present and discuss the use of Bayesian modeling and computational methods for atmospheric chemistry inverse analyses that incorporate evaluation of spatial structure in model-data residuals. Motivated by problems of refining bottom-up estimates of source/sink fluxes of trace gas and aerosols based on satellite retrievals of atmospheric chemical concentrations, we address the need for formal modeling of spatial residual error structure in global scale inversion models. We do this using analytically and computationally tractable conditional autoregressive (CAR) spatial models as components of a global inversion framework. We develop Markov chain Monte Carlo methods to explore and fit these spatial structures in an overall statistical framework that simultaneously estimates source fluxes. Additional aspects of the study extend the statistical framework to utilize priors on source fluxes in a physically realistic manner, and to formally address and deal with missing data in satellite retrievals. We demonstrate the analysis in the context of inferring carbon monoxide (CO) sources constrained by satellite retrievals of column CO from the Measurement of Pollution in the Troposphere (MOPITT) instrument on the TERRA satellite, paying special attention to evaluating performance of the inverse approach using various statistical diagnostic metrics. This is developed using synthetic data generated to resemble MOPITT data to define a proof-of-concept and model assessment, and then in analysis of real MOPITT data. These studies demonstrate the ability of these simple spatial models to substantially improve over standard non-spatial models in terms of statistical fit, ability to recover sources in synthetic examples, and predictive match with real data.

Description: Understanding evolution of product composition and volatility distribution through in-situ GC × GC analysis: a case study of longifolene ozonolysis Atmospheric Chemistry and Physics, 11, 5335-5346, 2011 Author(s): G. Isaacman, D. R. Worton, N. M. Kreisberg, C. J. Hennigan, A. P. Teng, S. V. Hering, A. L. Robinson, N. M. Donahue, and A. H. Goldstein A method for predicting volatility and polarity based on chromatographic information was developed and applied to the smog chamber ozonolysis of the sesquiterpene longifolene. The products were collected and analyzed using a GC × GC Thermal Desorption Aerosol Gas Chromatograph/Mass Spectrometer (2D-TAG) and a quadrupole Aerodyne Aerosol Mass Spectrometer (AMS). All the secondary organic aerosol (SOA) was produced within the first half hour of the experiment. However, the oxidation level of the organic aerosol, as inferred from the fraction of ion m/z 44, suggested continued evolution of the SOA over the subsequent hours. Measurements of speciated organic compounds using 2D-TAG confirm that the composition of the particles changed over the course of the experiment. Nearly 200 oxidation products (thought to be mostly ketones and acids) were observed with 2D-TAG, but most could not be identified definitively due to a lack of standards and the absence of likely sesquiterpene oxidation products in available mass spectral databases. To categorize the observed products, the vapor pressure and oxygen-to-carbon ratio (O/C) of observed compounds were estimated based on their two-dimensional chromatographic retention times relative to those of known standards, establishing a retention time correlation (RTC) method for using 2D-TAG to better constrain important modelling parameters. The product distribution continuously evolved in volatility and oxygenation during 5 h of oxidation. Using peak area as the best available proxy for mass, we conclude that the product mixture includes many non-negligible products; the most abundant 3 compounds accounted for only half of the total observed peak area and 80 % of peak area was spread across 15 compounds. The data provide evidence for three conclusions: (1) 2D-TAG provides valuable volatility and oxygenation information even in the absence of definitive species identification, (2) complex particle-phase chemistry causes continued evolution of particle composition after new particles formation, and (3) minor products contribute significantly to SOA from the ozonolysis of longifolene.

Description: The Level 2 research product algorithms for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) Atmospheric Measurement Techniques Discussions, 4, 3593-3645, 2011 Author(s): P. Baron, J. Urban, H. Sagawa, J. Möller, D. P. Murtagh, J. Mendrok, E. Dupuy, T. O. Sato, S. Ochiai, K. Suzuki, T. Manabe, T. Nishibori, K. Kikuchi, R. Sato, M. Takayanagi, Y. Murayama, M. Shiotani, and Y. Kasai This paper describes the algorithms of the level-2 research (L2r) processing chain developed for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES). The chain has been developed in parallel to the operational chain for conducting researches on calibration and retrieval algorithms. L2r chain products are available to the scientific community. The objective of version 2 is the retrieval of the vertical distribution of trace gases in the altitude range of 18–90 km. An theoretical error analysis is conducted to estimate the retrieval feasibility of key parameters of the processing: line-of-sight elevation tangent altitudes (or angles), temperature and O 3 profiles. The line-of-sight tangent altitudes are retrieved between 20 and 50 km from the strong ozone (O 3 ) line at 625.371 GHz, with low correlation with the O 3 volume-mixing ratio and temperature retrieved profiles. Neglecting the non-linearity of the radiometric gain in the calibration procedure is the main systematic error. It is large for the retrieved temperature (between 5–10 K). Therefore, atmospheric pressure can not be derived from the retrieved temperature, and, then, in the altitude range where the line-of-sight tangent altitudes are retrieved, the retrieved trace gases profiles are found to be better represented on pressure levels than on altitude levels. The error analysis for the retrieved HOCl profile demonstrates that best results for inverting weak lines can be obtained by using narrow spectral windows. Future versions of the L2r algorithms will improve the temperature/pressure retrievals and also provide information in the upper tropospheric/lower stratospheric region (e.g., water vapor, ice content, O 3 ) and on stratospheric and mesospheric line-of-sight winds.

Description: Deciphering the spatio-temporal complexity of climate change of the last deglaciation: a model analysis Climate of the Past, 7, 591-602, 2011 Author(s): D. M. Roche, H. Renssen, D. Paillard, and G. Levavasseur Understanding the sequence of events occuring during the last major glacial to interglacial transition (21 ka BP to 9 ka BP) is a challenging task that has the potential to unveil the mechanisms behind large scale climate changes. Though many studies have focused on the understanding of the complex sequence of rapid climatic change that accompanied or interrupted the deglaciation, few have analysed it in a more theoretical framework with simple forcings. In the following, we address when and where the first significant temperature anomalies appeared when using slow varying forcing of the last deglaciation. We used here coupled transient simulations of the last deglaciation, including ocean, atmosphere and vegetation components to analyse the spatial timing of the deglaciation. To keep the analysis in a simple framework, we did not include freshwater forcings that potentially cause rapid climate shifts during that time period. We aimed to disentangle the direct and subsequent response of the climate system to slow forcing and moreover, the location where those changes are more clearly expressed. In a data – modelling comparison perspective, this could help understand the physically plausible phasing between known forcings and recorded climatic changes. Our analysis of climate variability could also help to distinguish deglacial warming signals from internal climate variability. We thus are able to better pinpoint the onset of local deglaciation, as defined by the first significant local warming and further show that there is a large regional variability associated with it, even with the set of slow forcings used here. In our model, the first significant hemispheric warming occurred simultaneously in the North and in the South and is a direct response to the obliquity forcing.

Description: Impact of changes in grain size and pore space on the hydraulic conductivity and spectral induced polarization response of sand Hydrology and Earth System Sciences, 15, 1785-1794, 2011 Author(s): K. Koch, A. Kemna, J. Irving, and K. Holliger Understanding the influence of pore space characteristics on the hydraulic conductivity and spectral induced polarization (SIP) response is critical for establishing relationships between the electrical and hydrological properties of surficial unconsolidated sedimentary deposits, which host the bulk of the world's readily accessible groundwater resources. Here, we present the results of laboratory SIP measurements on industrial-grade, saturated quartz samples with granulometric characteristics ranging from fine sand to fine gravel. We altered the pore space characteristics by changing (i) the grain size spectra, (ii) the degree of compaction, and (iii) the level of sorting. We then examined how these changes affect the SIP response, the hydraulic conductivity, and the specific surface area of the considered samples. In general, the results indicate a clear connection between the SIP response and the granulometric as well as pore space characteristics. In particular, we observe a systematic correlation between the hydraulic conductivity and the relaxation time of the Cole-Cole model describing the observed SIP effect for the entire range of considered grain sizes. The results do, however, also indicate that the detailed nature of these relations depends strongly on variations in the pore space characteristics, such as, for example, the degree of compaction. This underlines the complexity of the origin of the SIP signal as well as the difficulty to relate it to a single structural factor of a studied sample, and hence raises some fundamental questions with regard to the practical use of SIP measurements as site- and/or sample-independent predictors of the hydraulic conductivity.

Description: S. Papernov, A. Tait, W. Bittle, A. W. Schmid, J. B. Oliver et al. Localized absorption in hafnium dioxide used as a high-index component in multilayer coatings for near-ultraviolet, nanosecond-pulse-laser applications is directly linked to laser-induced damage. The nature of the absorbing species and their physical properties remains unknown because of their extre ... [J. Appl. Phys. 109, 113106 (2011)] published Thu Jun 9, 2011.

Description: WRF simulation of a precipitation event over the Tibetan Plateau, China – an assessment using remote sensing and ground observations Hydrology and Earth System Sciences, 15, 1795-1817, 2011 Author(s): F. Maussion, D. Scherer, R. Finkelnburg, J. Richters, W. Yang, and T. Yao Meteorological observations over the Tibetan Plateau (TiP) are scarce, and precipitation estimations over this remote region are difficult. The constantly improving capabilities of numerical weather prediction (NWP) models offer the opportunity to reduce this problem by providing precipitation fields and other meteorological variables of high spatial and temporal resolution. Longer time periods of years to decades can be simulated by NWP models by successive model runs of shorter periods, which can be described by the term "regional atmospheric reanalysis". In this paper, we assess the Weather Research and Forecasting (WRF) models capacity in retrieving rain- and snowfall on the TiP in such a configuration using a nested approach: the simulations are conducted with three nested domains at spatial resolutions of 30, 10, and 2 km. A validation study is carried out for a one-month period with a special focus on one-week (22–28 October 2008), during which strong rain- and snowfall was observed on the TiP. The output of the model in each resolution is compared to the Tropical Rainfall Measuring Mission (TRMM) data set for precipitation and to the Moderate Resolution Imaging Spectroradiometer (MODIS) data set for snow extent. TRMM and WRF data are then compared to weather-station measurements. Our results suggest an overall improvement from WRF over TRMM with respect to weather-station measurements. Various configurations of the model with different nesting and forcing strategies, as well as physical parameterisation schemes are compared to propose a suitable design for a regional atmospheric reanalysis over the TiP. The WRF model showed good accuracy in simulating snow- and rainfall on the TiP for a one-month simulation period. Our study reveals that there is nothing like an optimal model strategy applicable for the high-altitude TiP, its fringing high-mountain areas of extremely complex topography and the low-altitude land and sea regions from which much of the precipitation on the TiP is originating. The choice of the physical parameterisation scheme will thus be always a compromise depending on the specific purpose of a model simulation. Our study demonstrates the high importance of orographic precipitation, but the problem of the orographic bias remains unsolved since reliable observational data are still missing. The results are relevant for anyone interested in carrying out a regional atmospheric reanalysis. Many hydrological analyses and applications like rainfall-runoff modelling or the analysis of flood events require precipitation rates at daily or even hourly intervals. Thus, our study offers a process-oriented alternative for retrieving precipitation fields of high spatio-temporal resolution in regions like the TiP, where other data sources are limited.

Description: D. Panda, A. Dhar, and S. K. Ray Abstract not available. [J. Appl. Phys. 109, 119902 (2011)] published Fri Jun 10, 2011.

Description: A. Shafiei, C. Oprea, A. Alfantazi, and T. Troczynski Structural modifications of the lead zirconate titanate [Pb(Zr,Ti)O] or PZT, subjected to hydrogen, are investigated using online monitoring of the electrical properties of PZT. The changes in PZT properties (dielectric constant and resistance) can be described using well known nucleation and growth ... [J. Appl. Phys. 109, 114108 (2011)] published Fri Jun 10, 2011.

Description: T. Lahiri and T. Pal Majumder It was clearly indicative that the polymer chains make a tremendous interaction with the tilt angle in case of a polymer stabilized ferroelectric liquid crystal (PSFLC). After suitable consideration of such interaction, we expanded the Landau free energy for a PSFLC system. We theoretically demonstr ... [J. Appl. Phys. 109, 114109 (2011)] published Fri Jun 10, 2011.

Description: Tanushree Sinha and Yashashree Kulkarni Nanotwinned structures have shown strong promise as optimal motifs for strength, ductility, and grain stability in fcc metalsin sharp contrast to their nano-grained counterparts where gains in strength are disappointingly offset by loss of ductility. However, their high temperature stability has rem ... [J. Appl. Phys. 109, 114315 (2011)] published Fri Jun 10, 2011.

Description: Soyeon Lee, Yoshifumi Oshima, Hidetaka Sawada, Fumio Hosokawa, Eiji Okunishi et al. As a new microscopic method to reveal lithium ion behavior in lithium ion batteries, we demonstrated that lithium atoms in the diffusion channel of the spinel structure (LiVO crystal) were visualized and their number was countable one-by-one by using annular bright field imaging method in conjunctio ... [J. Appl. Phys. 109, 113530 (2011)] published Fri Jun 10, 2011.

Description: V. G. Bozhkov and A. V. Shmargunov A numerical investigation of current-voltage characteristics (IVCs) of the ideal metal-semiconductor Schottky-barrier contact (SBC) metal-n-GaAs in the wide range of temperatures, contact diameters and doping levels considering the influence of image force and tunneling effects is presented. The ana ... [J. Appl. Phys. 109, 113718 (2011)] published Fri Jun 10, 2011.

Description: E. Almeida, L. de S. Menezes, Cid B. de Araujo, and A. A. Lipovskii Photoluminescence (PL) and degenerate four-wave-mixing (DFWM) experiments were performed in a silicaniobic composite containing NaNbO nanocrystals. The PL results indicate the presence of in-gap states attributed to excitons in the nanocrystals and defect centers. The luminescence of the samples bec ... [J. Appl. Phys. 109, 113108 (2011)] published Fri Jun 10, 2011.

Description: Anatoly A. Barybin and Edval J. P. Santos An analytical theory of nonuniformly doped or shaped pn-junction diodes subjected to large signals at high frequencies is presented. The resulting expressions can be useful to evaluate the performance of semiconductor device modeling software. The transverse averaging technique is employed to reduce ... [J. Appl. Phys. 109, 114510 (2011)] published Fri Jun 10, 2011.

Description: Daeyul Baek, Hirokazu Hasegawa, and Yasuhiro Ohshima We experimentally investigate the nonadiabatic rotational excitation process of a symmetric-top molecule, benzene, in the electronic ground state irradiated by intense nonresonant ultrafast laser fields. The initial rotational-state distribution was restricted mostly to the five lowest levels with d ... [J. Chem. Phys. 134, 224302 (2011)] published Fri Jun 10, 2011.

Description: T. Suemoto, H. Nakao, M. Nakajima, and H. Kitagawa The out-of-phase and in-phase ladder type Br-bridged Pt complexes are investigated by time-resolved luminescence spectroscopy in pico- and femtosecond time regions. The observed luminescence spectra have peaks at 0.87 and 0.94 eV in out-of-phase and in-phase materials, respectively, and are assigned ... [J. Chem. Phys. 134, 224503 (2011)] published Fri Jun 10, 2011.

Description: Annett Thogersen, Margrethe Rein, Edouard Monakhov, Jeyanthinath Mayandi, and Spyros Diplas The atomic structure and composition of noninterfacial ITO and ITO-Si interfaces were studied with transmission electron microscopy and x-ray photoelectron spectroscopy (XPS). The films were deposited by dc magnetron sputtering on monocrystalline p-type (100) Si wafers. Both as deposited and heat tr ... [J. Appl. Phys. 109, 113532 (2011)] published Fri Jun 10, 2011.

Description: Francesco A. Evangelista We report a general implementation of alternative formulations of single-reference coupled cluster theory (extended, unitary, and variational) with arbitrary-order truncation of the cluster operator. These methods are applied to compute the energy of Ne and the equilibrium properties of HF and C. Po ... [J. Chem. Phys. 134, 224102 (2011)] published Fri Jun 10, 2011.

Description: Prabir K. Mukherjee A model for coupled tilt angle and lattice distortion parameter is proposed to describe the R R transition in n-alkane. The model is treated in the framework of a Landau mean-field theory and renormalization-group theory. The influence of gauche conformations and molecular flexibility on the R R t ... [J. Chem. Phys. 134, 224502 (2011)] published Fri Jun 10, 2011.

Description: Marco A. Blanco, Erinc Sahin, Yi Li, and Christopher J. Roberts The classic analysis of Rayleigh light scattering (LS) is re-examined for multi-component protein solutions, within the context of Kirkwood-Buff (KB) theory as well as a more generalized canonical treatment. Significant differences arise when traditional treatments that approximate constant pressure ... [J. Chem. Phys. 134, 225103 (2011)] published Fri Jun 10, 2011.

Description: C. W. Rischau, C. S. Schnohr, E. Wendler, and W. Wesch Damage formation in - and -oriented CdTe single crystals irradiated at room temperature and 15 K with 270 keV Ar or 730 keV Sb ions was investigated in situ using Rutherford backscattering spectroscopy (RBS) in channeling configuration. Defect profiles were calculated from the RBS spectra using the ... [J. Appl. Phys. 109, 113531 (2011)] published Fri Jun 10, 2011.

Description: U. Buchenau The asymmetry model for the highly viscous flow postulates thermally activated jumps from a practically undistorted ground state to strongly distorted, but stable structures, with a pronounced Eshelby backstress from the distorted surroundings. The viscosity is ascribed to those stable distorted str ... [J. Chem. Phys. 134, 224501 (2011)] published Fri Jun 10, 2011.

Description: Michael Nolan, Run Long, Niall J. English, and Damian A. Mooney The large intrinsic bandgap of NiO hinders its potential application as a photocatalyst under visible-light irradiation. In this study, we have performed first-principles screened exchange hybrid density functional theory with the HSE06 functional calculations of N- and C-doped NiO to investigate th ... [J. Chem. Phys. 134, 224703 (2011)] published Fri Jun 10, 2011.

Description: Near infrared nadir sounding of vertical column densities: methodology and application to SCIAMACHY Atmospheric Measurement Techniques Discussions, 4, 3685-3737, 2011 Author(s): S. Gimeno García, F. Schreier, G. Lichtenberg, and S. Slijkhuis Nadir observations with the shortwave infrared channels of SCIAMACHY onboard the ENVISAT satellite can be used to derive information on atmospheric gases such as CO, CH 4 , N 2 O, CO 2 , and H 2 O. For the operational level 1b–2 processing of SCIAMACHY data a new retrieval code BIRRA (Beer InfraRed Retrieval Algorithm) has been developed: BIRRA performs a nonlinear least squares fit of the measured radiance, where molecular concentration vertical profiles are scaled to fit the observed data. Here we present the forward modeling (radiative transfer) and inversion (least squares optimization) fundamentals of the code along with the further processing steps required to generate higher level products such as global distributions and time series. Moreover, various aspects of level 1 (observed spectra) and auxiliary input data relevant for successful retrievals are discussed. BIRRA is currently used for operational analysis of carbon monoxide vertical column densities from SCIAMACHY channel 8 observations, and is being prepared for methane retrievals using channel 6 spectra. A set of representative CO retrievals and first CH 4 results are presented to demonstrate BIRRA's capabilities.

Description: Volatilizable biogenic organic compounds (VBOCs) with two dimensional gas chromatography-time of flight mass spectrometry (GC × GC-TOFMS): sampling methods, VBOC complexity, and chromatographic retention data Atmospheric Measurement Techniques Discussions, 4, 3647-3684, 2011 Author(s): J. F. Pankow, W. Luo, A. N. Melnychenko, K. C. Barsanti, L. M. Isabelle, C. Chen, A. B. Guenther, and T. N. Rosenstiel Two dimensional gas chromatography (GC × GC) with detection by time-of-flight mass spectrometry (TOFMS) was applied in the rapid analysis of air samples containing highly complex mixtures of volatilizable biogenic organic compounds (VBOCs). VBOC analytical methodologies are briefly reviewed, and optimal conditions are discussed for sampling with both adsorption/thermal desorption (ATD) cartridges and solid-phase microextraction (SPME) fibers. Air samples containing VBOC emissions from leaves of two tree species ( Cedrus atlantica and Calycolpus moritzianus ) were obtained by both ATD and SPME. The optimized gas chromatographic conditions utilized a 45 m, 0.25 mm I.D. low-polarity primary column (DB-VRX, 1.4 μm film) and a 1.5 m, 0.25 mm I.D. polar secondary column (Stabilwax® 0.25 μm film). Excellent separation was achieved in a 36 min temperature programmed GC × GC chromatogram. Thousands of VBOC peaks were present in the sample chromatograms; hundreds of tentative identifications by NIST mass spectral matching are provided. Very few of the tentatively identified compounds are currently available as authentic standards. Method detection limit values for a 5 l ATD sample were 3.5 pptv (10 ng m −3 ) for isoprene, methyl vinyl ketone, and methacrolein, and ~1.5 pptv (~10 ng m −3 ) for monoterpenes and sesquiterpenes. Kovats-type chromatographic retention index values on the primary column and relative retention time values on the secondary column are provided for 21 standard compounds and for 417 tentatively identified VBOCs. 19 of the 21 authentic standard compounds were found in one of the Cedrus atlantica SPME samples. In addition, easily quantifiable levels of at least 13 sesquiterpenes were found in an ATD sample obtained from a branch enclosure of Calycolpus moritzianus . Overall, the results obtained via GC × GC-TOFMS highlight an extreme, and largely uncharacterized diversity of VBOCs, consistent with the hypothesis that sesquiterpenes and other compounds beyond the current list of typically determined VBOC analytes may well be important contributors to global atmospheric levels of organic particulate matter.

Description: The influence of land cover change in the Asian monsoon region on present-day and mid-Holocene climate Biogeosciences, 8, 1499-1519, 2011 Author(s): A. Dallmeyer and M. Claussen Using the general circulation model ECHAM5/JSBACH, we investigate the biogeophysical effect of large-scale afforestation and deforestation in the Asian monsoon domain on present-day and mid-Holocene climate. We demonstrate that the applied land cover change does not only modify the local climate but also change the climate in North Africa and the Middle East via teleconnections. Deforestation in the Asian monsoon domain enhances the rainfall in North Africa. In parts of the Sahara summer precipitation is more than doubled. In contrast, afforestation strongly decreases summer rainfall in the Middle East and even leads to the cessation of the rainfall-activity in some parts of this region. Regarding the local climate, deforestation results in a reduction of precipitation and a cooler climate as grass mostly has a higher albedo than forests. However, in the core region of the Asian monsoon the decrease in evaporative cooling in the monsoon season overcompensates this signal and results in a net warming. Afforestation has mainly the opposite effect, although the pattern of change is less clear. It leads to more precipitation in most parts of the Asian monsoon domain and a warmer climate except for the southern regions where a stronger evaporation decreases near-surface temperatures in the monsoon season. When prescribing mid-Holocene insolation, the pattern of local precipitation change differs. Afforestation particularly increases monsoon rainfall in the region along the Yellow River which was the settlement area of major prehistoric cultures. In this region, the effect of land cover change on precipitation is half as large as the orbitally-induced precipitation change. Thus, our model results reveal that mid- to late-Holocene land cover change could strongly have contributed to the decreasing Asian monsoon precipitation during the Holocene known from reconstructions.

Description: I. C. Moldovan-Doyen, G. Xu, L. Greusard, G. Sevin, E. Strupiechonski et al. We report the development of a scattering-type near-field scanning optical microscope (sNSOM) which operates at temperatures down to 100 K with a scanning range of up to 400 [mu]m. We have used this sNSOM to map the electromagnetic near-field on mid-IR and terahertz (THz) surface emitting quantum c ... [Appl. Phys. Lett. 98, 231112 (2011)] published Fri Jun 10, 2011.

Description: Sensing Hadley cell with space lidar Atmospheric Chemistry and Physics Discussions, 11, 16599-16610, 2011 Author(s): W. Sun and B. Lin This letter shows that the extent of the Hadley cell could reliably be estimated by measuring the height of the uppermost super-thin clouds in the troposphere with space-borne lidar. Through consecutive multi-year measurements of the height of the uppermost super-thin clouds, a good estimation of the expansion of the Hadley cell could be obtained.

Description: K. Bakke, H. Belich, and E. O. Silva Based on the discussions about the Aharonov-Casher effect in the Lorentz symmetry violation background, we show that the analogue of the relativistic Landau quantization in the Aharonov-Casher setup can be achieved in the Lorentz-symmetry violation background. ... [J. Math. Phys. 52, 063505 (2011)] published Fri Jun 10, 2011.

Description: Claudio Cremaschini, John C. Miller, and Massimo Tessarotto A kinetic treatment is developed for collisionless magnetized plasmas occurring in high-temperature, low-density astrophysical accretion disks, such as are thought to be present in some radiatively inefficient accretion flows onto black holes. Quasi-stationary configurations are investigated, within ... [Phys. Plasmas 18, 062901 (2011)] published Fri Jun 10, 2011.

Description: V. I. Sotnikov, S. Mudaliar, T. C. Genoni, D. V. Rose, B. V. Oliver et al. The stability of ion acoustic waves in a sheared-flow, partially-ionized compressible plasma sheath around a fast-moving vehicle in the upper atmosphere, is described and evaluated for different flow profiles. In a compressible plasma with shear flow, instability occurs for any velocity profile, not ... [Phys. Plasmas 18, 062104 (2011)] published Fri Jun 10, 2011.

Description: Xubing Lu, Takeo Minari, Akichika Kumatani, Chuan Liu, and Kazuhito Tsukagoshi We report the effect of air exposure on charge injection process through the metal/organic interface in organic field-effect transistors. Pentacene-based field-effect transistors and metal-insulator-semiconductor capacitors having gold or copper contact were fabricated without exposing to air. An ai ... [Appl. Phys. Lett. 98, 243301 (2011)] published Mon Jun 13, 2011.

Description: Karthikeyan Krishnamoorthy, Rajneesh Mohan, and S.-J. Kim The photocatalytic characteristics of graphene oxide (GO) nanostructures synthesized by modified Hummer's method were investigated by measuring reduction rate of resazurin (RZ) into resorufin (RF) as a function of UV irradiation time. The progress of the photocatalytic reaction was monitored by chan ... [Appl. Phys. Lett. 98, 244101 (2011)] published Mon Jun 13, 2011.

Description: Weibing Chen and Jingbo Li By modeling beta-ZnSb material as a ZnSb crystal with defects, the crystal structure and thermal properties of beta-ZnSb are studied by ab initio method to explain its extremely low thermal conductivity at moderate temperature. The formation and migration energies of defects are calculated and used ... [Appl. Phys. Lett. 98, 241901 (2011)] published Mon Jun 13, 2011.

Description: Sivapalan Baskaran, Xiangtong He, Qin Chen, and John Y. Fu We report observation of the giant direct flexoelectric effect in alpha-phase polyvinylidene fluoride (PVDF) films. This unexpected phenomenon was detected in the alpha-phase PVDF film undergoing elastic tensile stretching. Our results have shown that the physical mechanism behind the flexoelectrici ... [Appl. Phys. Lett. 98, 242901 (2011)] published Mon Jun 13, 2011.

Description: Feng-xian Xie, Wallace C. H. Choy, Xiaolong Zhu, Xiaolong Li, Zhong Li et al. We have investigated driving force effects on the ordering of polymer, which is a key factor of self-assembly of soft materials. By turning the substrate up-side-down, the downward driving force can form in solution film-growth process and affect the self-organization of polymer chains and domains. ... [Appl. Phys. Lett. 98, 243302 (2011)] published Mon Jun 13, 2011.

Description: M. S. Chung, A. Mayer, B. L. Weiss, N. M. Miskovsky, and P. H. Cutler We report a theoretical analysis of the cooling effect due to field emission from n-type PbTe, a typical thermoelectric material. We show that, by calculating the average energies of field and replacement electrons, the energy exchange in field emission from n-type PbTe always produces cooling. The ... [Appl. Phys. Lett. 98, 243502 (2011)] published Mon Jun 13, 2011.

Description: D. Q. Huang, X. S. Miao, Z. Li, J. J. Sheng, J. J. Sun et al. The ultrafast amorphization phenomenon induced by a single picosecond electric pulse was studied. The RESET operations were performed on phase change memory cells with 50 nm and 150 nm thick GeSbTe layers by a self-built test system, respectively. The ultrafast amorphization of only 0.2 ns was obser ... [Appl. Phys. Lett. 98, 242106 (2011)] published Mon Jun 13, 2011.

Description: C. Girardot, S. Pignard, F. Weiss, and J. Kreisel Rare earth nickelates RENiO (RE=rare earth), which attract interest due to their sharp metal-insulator phase transition, are instable in bulk form due to the necessity of an important oxygen pressure to stabilize Ni in its 3+ state of oxidation. Here, we report the stabilization of RE nickelates in ... [Appl. Phys. Lett. 98, 241903 (2011)] published Mon Jun 13, 2011.

Description: X. F. Kou, L. He, F. X. Xiu, M. R. Lang, Z. M. Liao et al. We report the experiment of high quality epitaxial growth of BiSe thin films on hexagonal CdS (0001) substrates using a solid source molecular-beam epitaxy system. Layer-by-layer growth of single crystal BiSe has been observed from the first quintuple layer. The size of surface triangular terraces h ... [Appl. Phys. Lett. 98, 242102 (2011)] published Mon Jun 13, 2011.

Description: Tianhua Yu, Chen-Wei Liang, Changdong Kim, and Bin Yu We demonstrated doping in monolayer graphene via local electrical stressing. The doping, confirmed by the resistance-voltage transfer characteristics of the graphene system, is observed to continuously tunable from N-type to P-type as the electrical stressing level (voltage) increases. Two major phy ... [Appl. Phys. Lett. 98, 243105 (2011)] published Mon Jun 13, 2011.

Description: Qing Li, Hidemasa Takana, Yi-Kang Pu, and Hideya Nishiyama A stable nonthermal quasiuniform planar plasma jet, originating from a planar dielectric duct with a rectangular exit and issuing into ambient air at atmospheric pressure, is reported in the present work. Current-voltage characteristics, one discharge current pulse per sinusoidal half voltage cycle, ... [Appl. Phys. Lett. 98, 241501 (2011)] published Mon Jun 13, 2011.

Description: M. A. Mangold, C. Weiss, B. Dirks, and A. W. Holleitner We study the impact of optical field-enhancement effects on the optoelectronic properties of metal nanoparticle arrays. Applying a focused ion beam lithography in combination with an electron beam induced deposition technique we pattern electrical contacts in a way that they give rise to an electrom ... [Appl. Phys. Lett. 98, 243108 (2011)] published Mon Jun 13, 2011.

Description: Looking for evidence of climate change impacts in the eastern Irish Sea Natural Hazards and Earth System Science, 11, 1641-1656, 2011 Author(s): L. S. Esteves, J. J. Williams, and J. M. Brown Although storminess is often cited as a driver of long-term coastal erosion, a lack of suitable datasets has only allowed objective assessment of this claim in a handful of case studies. This reduces our ability to understand and predict how the coastline may respond to an increase in "storminess" as suggested by global and regional climate models. With focus on 16 km of the Sefton coastline bordering the eastern Irish Sea (UK), this paper analyses available measured datasets of water level, surge level, wave height, wind speed and barometric pressure with the objective of finding trends in metocean climate that are consistent with predictions. The paper then examines rates of change in shoreline position over the period 1894 to 2005 with the aim of establishing relationships with climatic variability using a range of measured and modelled metocean parameters (with time spans varying from two to eight decades). With the exception of the mean monthly wind speed, available metocean data do not indicate any statistically significant changes outside seasonal and decadal cycles. No clear relationship was found between changes in metocean conditions and rates of shoreline change along the Sefton coast. High interannual variability and the lack of long-term measurements make unambiguous correlations between climate change and shoreline evolution problematic. However, comparison between the North Atlantic Oscillation winter index (NAOw) and coastline changes suggest increased erosion at times of decreasing NAOw values and reduced erosion at times of increasing NAOw values. Erosion tends to be more pronounced when decreasing NAOw values lead to a strong negative NAO phase. At present, anthropogenic changes in the local sediment budget and the short-term impact of extreme events are still the largest threat likely to affect coastal flooding and erosion risk in the short- and medium-term. Nevertheless, the potential impacts of climate change in the long-term should not be ignored.

Description: Calculating the water and heat balances of the Eastern Mediterranean basin using ocean modelling and available meteorological, hydrological, and ocean data Ocean Science Discussions, 8, 1301-1338, 2011 Author(s): M. Shaltout and A. Omstedt This paper analyses the Eastern Mediterranean water and heat balances over a 52-yr period. The modelling uses a process-oriented approach resolving the one-dimensional equations of momentum, heat, and salt conservation, with turbulence modelled using a two-equation model. The exchange through the Sicily Channel connecting the Eastern and Western basins is calculated from satellite altimeter data. The results illustrates that calculated surface temperature and salinity follow the reanalysed data well and with biases of −0.4 °C and −0.004, respectively. Monthly and yearly temperature and salinity cycles are also satisfactory simulated. Reanalysed data and calculated water mass structure and heat balance components are in good agreement, indicating that the air-sea interaction and the turbulent mixing are realistically simulated. The study illustrates that the water balance in the Eastern Mediterranean basin is controlled by the difference between inflows/outflows through the Sicily Channel and by the net precipitation rates. The heat balance is controlled by the heat loss from the water surface, sun radiation into the sea, and heat flow through the Sicily Channel, the first two displaying both climate trends. An annual net heat loss of approximately 9 W m −2 was balanced by net heat in flow through the Sicily Channel.

Description: Extraction of spatial-temporal rules from mesoscale eddies in the South China Sea Based on rough set theory Ocean Science Discussions, 8, 1261-1300, 2011 Author(s): Y. Du, X. Fan, Z. He, F. Su, C. Zhou, H. Mao, and D. Wang In this paper, a rough set theory is introduced to represent spatial-temporal relationships and extract the corresponding rules from typical mesoscale-eddy states in the South China Sea (SCS). Three decision attributes are adopted in this study, which make the approach flexible in retrieving spatial-temporal rules with different features. Spatial-temporal rules of typical states in the SCS are extracted as three decision attributes, which then are confirmed by the previous works. The results demonstrate that this approach is effective in extracting spatial-temporal rules from typical mesoscale-eddy states, and therefore provides a powerful approach to forecasts in the future. Spatial-temporal rules in the SCS indicate that warm eddies following the rules are generally in the southeastern and central SCS around 2000 m isobaths in winter. Their intensity and vorticity are weaker than those of cold eddies. They usually move a shorter distance. By contrast, cold eddies are in 2000 m-deeper regions of the southwestern and northeastern SCS in spring and fall. Their intensity and vorticity are strong. Usually they move a long distance. In winter, a few rules are followed by cold eddies in the northern tip of the basin and southwest of Taiwan Island rather than warm eddies, indicating cold eddies may be well-regulated in the region. Several warm-eddy rules are achieved west of Luzon Island, indicating warm eddies may be well-regulated in the region as well. Otherwise, warm and cold eddies are distributed not only in the jet flow off southern Vietnam induced by intraseasonal wind stress in summer-fall, but also in the northern shallow water, which should be a focus of future study.

Description: Comparing historical-hydrogeomorphological reconstitution and hydrological-hydraulic modelling in the estimation of flood-prone areas – a case study in Central Portugal Natural Hazards and Earth System Science, 11, 1669-1681, 2011 Author(s): P. P. Santos, A. O. Tavares, and A. I. A. S. S. Andrade The Arunca River basin in Central Portugal has a historical record of hazardous events related to floods, causing widespread disturbance. This article describes the application of two approaches based on well-known methods for the estimation of flood-prone areas: (i) historical-hydrogeomorphological reconstitution, applied to the entire Arunca River basin, and (ii) hydrological-hydraulic modelling, applied to four sections selected from different (upper, middle and lower) sectors of the basin and including urban and rural areas along the Arunca River. The mapping of the flood-prone areas obtained by these two methods was compared in order to identify the main differences and similarities. Human interventions (river channel and floodplain morphological changes) were found to be the main factor explaining the differences and similarities between the results obtained by both methods. The application of hydrological-hydraulic modelling proved important in reinforcing the results of the historical-hydrogeomorphological method; it also helped in complementing the results produced by the latter method in urban areas and in areas with insufficient historical records. The application of the historical-hydrogeomorphological method, in turn, allowed for the size of the flood-prone areas to be determined where the primary data (e.g. geometry, roughness and flow) was not accurate enough for hydrological-hydraulic modelling. The methodological approach adopted demonstrates the strong complementary relationship between the different existing methods for estimating flood-prone areas, and may be reproduced for other drainage basins.

Description: Junjie Gao, Zhuo Xu, Fei Li, Chonghui Zhang, Yi Liu et al. The influence of the hydrostatic pressure on the piezoelectric response for tetragonal BaTiO and PbTiO monodomain crystals is investigated using LandauGinzburgDevonshire phenomenological approach. It is shown that hydrostatic pressure could enhance the piezoelectric properties in some directions of ... [J. Appl. Phys. 109, 114111 (2011)] published Tue Jun 14, 2011.

Description: Dhruba J. Kalita, Akshay Rao, Ishir Rajvanshi, and Ashish K. Gupta We have applied parametric equations of motion (PEM) to study photodissociation dynamics of H. The resonances are extracted using smooth exterior scaling method. This is the first application of PEM to non-Hermitian Hamiltonian that includes resonances and the continuum. Here, we have studied how th ... [J. Chem. Phys. 134, 224309 (2011)] published Tue Jun 14, 2011.

Description: On the influence of CMEs on the global 3-D coronal electron density Annales Geophysicae, 29, 1019-1028, 2011 Author(s): M. Kramar, J. Davila, H. Xie, and S. Antiochos In order to analize the influence of a Coronal Mass Ejection (CME) on the coronal streamer belt, we made 3-D reconstructions of the electron density in the corona at heliospheric distances from 1.5 to 4 R ⊙ for periods before and after a CME occured. The reconstructions were performed using a tomography technique. We studied two CME cases: (i) a slow CME on 1 June 2008; (ii) two fast CMEs on 31 December 2007 and 2 January 2008. For the first case of slow CME, it was found: (i) the potential magnetic field configuration in the CME initiation region before the CME does not agree with the coronal density structure while after the CME the agreement between the field and density is much better. This could be manifistation of that that the field was non-potential before the CME and after the CME the field relaxes towards a more potential state. (ii) It was shown that the dimming caused by the slow CME is not due to rotation of the corona and a line-of-sight (LOS) effect but a streamer blow out effect took place.

Description: Ignacio Spiousas, Daniel Torrent, and Jose Sanchez-Dehesa This letter demonstrates the mechanical tuning of modes confined in two-dimensional acoustic cavities based on anisotropic metafluids. The employed metafluids have been designed with effective parameters such that the radial component of the sound speed tensor keeps constant and the acoustic impedan ... [Appl. Phys. Lett. 98, 244102 (2011)] published Wed Jun 15, 2011.

Description: I-Chen Ho and X.-C. Zhang We report intense terahertz (THz) pulses inducing intervalley scattering and impact ionization mechanisms in doped InAs crystals by THz pump-THz probe measurements. Two competing mechanisms are observed by varying the impurity doping type of the semiconductors and the strength of the THz field. For ... [Appl. Phys. Lett. 98, 241908 (2011)] published Wed Jun 15, 2011.

Description: Q. G. Chi, X. Wang, W. L. Li, W. D. Fei, and Q. Q. Lei Taking advantage of the relatively low temperature crystallization and high orientation of thin films of PbLaCaTiO (PLCT), growth of a highly (100)-oriented PLCT/Pb(NbZrTi)O (PNZT) multilayer film on a Pt/Ti/SiO/Si substrate is achieved at a temperature as low as 450 degrees C. The interfacial diff ... [Appl. Phys. Lett. 98, 242903 (2011)] published Wed Jun 15, 2011.

Description: Seasonal variations and vertical features of aerosol particles in the Antarctic troposphere Atmospheric Chemistry and Physics, 11, 5471-5484, 2011 Author(s): K. Hara, K. Osada, C. Nishita-Hara, and T. Yamanouchi Tethered balloon-borne aerosol measurements were conducted at Syowa Station, Antarctica during the 46th Japanese Antarctic expedition (2005–2006). The CN concentration reached a maximum in the summer, although the number concentrations of fine particles ( D p 〉0.3 μm) and coarse particles ( D p 〉2.0 μm) increased during the winter–spring. The CN concentration was 30–2200 cm −3 near the surface (surface – 500 m) and 7–7250 cm −3 in the lower free troposphere (〉1500 m). During the austral summer, higher CN concentration was often observed in the lower free troposphere, where the number concentrations in fine and coarse modes were remarkably lower. The frequent appearance of higher CN concentrations in the free troposphere relative to continuous aerosol measurements at the ground strongly suggests that new particle formation is more likely to occur in the lower free troposphere in Antarctic regions. Seasonal variations of size distribution of fine-coarse particles show that the contribution of the coarse mode was greater in the winter–spring than in summer because of the dominance of sea-salt particles in the winter–spring. The number concentrations of fine and coarse particles were high in air masses from the ocean and mid-latitudes. Particularly, aerosol enhancement was observed not only in the boundary layer, but also in the lower free troposphere during and immediately after Antarctic haze events occurring in May, July and September.

Description: The fluorescence properties of aerosol larger than 0.8 μm in urban and tropical rainforest locations Atmospheric Chemistry and Physics, 11, 5491-5504, 2011 Author(s): A. M. Gabey, W. R. Stanley, M. W. Gallagher, and P. H. Kaye UV-LIF measurements were performed on ambient aerosol in Manchester, UK (urban city centre, winter) and Borneo, Malaysia (remote, tropical) using a Wide Issue Bioaerosol Spectrometer, version 3 (WIBS3). These sites are taken to represent environments with minor and significant primary biological aerosol (PBA) influences respectively, and the urban dataset describes the fluorescent background aerosol against which PBA must be identified by researchers using LIF. The ensemble aerosol at both sites was characterised over 2–3 weeks by measuring the fluorescence intensity and optical equivalent diameter ( D P ) of single particles sized 0.8 ≤ D P ≤ 20 μm. Filter samples were also collected for a subset of the Manchester campaign and analysed using energy dispersive X-Ray (EDX) spectroscopy and environmental scanning electron microscopy (ESEM), which revealed mostly non-PBA at D ≤ 1 μm. The WIBS3 features three fluorescence channels: the emission following a 280 nm excitation is recorded at 310–400 nm (channel F1) and 400–600 nm (F2), and fluorescence excited at 350 nm is detected at 400–600 nm (F3). In Manchester the primary size mode of fluorescent and non-fluorescent material was present at 0.8–1.2 μm, with a secondary fluorescent mode at 2–4 μm. In Borneo non-fluorescent material peaked at 0.8–1.2 μm and fluorescent at 3–4 μm. Agreement between fluorescent number concentrations in each channel differed at the two sites, with F1 and F3 reporting similar concentrations in Borneo but F3 outnumbering F1 by a factor of 2–3 across the size spectrum in Manchester. The fluorescence intensity in each channel generally rose with D P at both sites with the exception of F1 intensity in Manchester, which peaked at D P = 4 μm, causing a divergence between F1 and F3 intensity at larger D P . This divergence and the differing fluorescent particle concentrations demonstrate the additional discrimination provided by the F1 channel in Manchester. The relationships between fluorescence intensities in different pairs of channels were also investigated as a function of D P . Differences between these metrics were apparent at each site and provide some distinction between the two datasets. Finally, particle selection criteria based on the Borneo dataset were applied to identify a median concentration of 10 "Borneo-like" fluorescent particles per litre in Manchester.

Description: Sergio Ferrara, Alessio Marrani, Emanuele Orazi, Raymond Stora, and Armen Yeranyan We classify 2-center extremal black hole charge configurations through duality-invariant homogeneous polynomials, which are the generalization of the unique invariant quartic polynomial for single-center black holes based on homogeneous symmetric cubic special Ka hler geometries. A crucial role is p ... [J. Math. Phys. 52, 062302 (2011)] published Tue Jun 14, 2011.

Description: Yiping Tang A theory about first-order phase transition of pure fluids is proposed. The theory is developed by combining grand canonical ensemble with density functional for homogeneous fluids. It is based on the fact that the grand partition function of one macroscopic volume is the product of the grand partit ... [J. Chem. Phys. 134, 224508 (2011)] published Tue Jun 14, 2011.

Description: Domestic wells have high probability of pumping septic tank leachate Hydrology and Earth System Sciences Discussions, 8, 5701-5732, 2011 Author(s): J. E. Horn and T. Harter Onsite wastewater treatment systems such as septic systems are common in rural and semi-rural areas around the world; in the US, about 25–30 % of households are served by a septic system and a private drinking water well. Site-specific conditions and local groundwater flow are often ignored when installing septic systems and wells. Particularly in areas with small lots, thus a high septic system density, these typically shallow wells are prone to contamination by septic system leachate. Typically, mass balance approaches are used to determine a maximum septic system density that would prevent contamination of the aquifer. In this study, we estimate the probability of a well pumping partially septic system leachate. A detailed groundwater and transport model is used to calculate the capture zone of a typical drinking water well. A spatial probability analysis is performed to assess the probability that a capture zone overlaps with a septic system drainfield depending on aquifer properties, lot and drainfield size. We show that a high septic system density poses a high probability of pumping septic system leachate. The hydraulic conductivity of the aquifer has a strong influence on the intersection probability. We conclude that mass balances calculations applied on a regional scale underestimate the contamination risk of individual drinking water wells by septic systems. This is particularly relevant for contaminants released at high concentrations, for substances which experience limited attenuation, and those being harmful even in low concentrations.

Description: M. Ipatov, A. Chizhik, V. Zhukova, J. Gonzalez, and A. Zhukov The correlation between surface domain structure (SDS) and high frequency magneto-impedance (MI) in amorphous microwires has been systematically studied. First, we applied the magneto-optical polarizing microscopy to determine the SDS and found that it is considerably different in unstressed microwi ... [J. Appl. Phys. 109, 113924 (2011)] published Wed Jun 15, 2011.

Description: T. Aytug, Z. Chen, V. A. Maroni, D. J. Miller, C. Cantoni et al. This study reports on the fabrication of metal-organic chemical vapor deposited (MOCVD) YBaCuO (YBCO) films doped with varying amounts of Ce and Ho and the characterization of their electrical, microstructural, and chemical properties. The films are prepared by vapor phase deposition of a Y-Ba-Cu pr ... [J. Appl. Phys. 109, 113923 (2011)] published Wed Jun 15, 2011.

Description: Mikhail Zhernenkov, Michael S. Jablin, Amit Misra, Michael Nastasi, Yongqiang Wang et al. Neutron reflectometry is used to characterize physical vapor deposited [Cu/Nb]/Si layered nanocomposites exposed to extreme helium ion doses. The effects of He ions on the interfacial roughness, layer swelling, and chemical mixing have been measured. Regions of high He concentration were localized a ... [Appl. Phys. Lett. 98, 241913 (2011)] published Wed Jun 15, 2011.

Description: Hyung Jin Lee, Hoe Woong Kim, and Yoon Young Kim Subwavelength imaging was experimentally performed for ultrasonic elastic waves by using an angularly stratified plat, an elastic plate hyperlens. It consists of alternating layers of aluminum and air, exhibiting a large contrast in elastic stiffness. A specially configured experimental setup is use ... [Appl. Phys. Lett. 98, 241912 (2011)] published Wed Jun 15, 2011.

Description: C. K. Amuzuvi, S. Bull, J. W. Tomm, J. Nagle, B. Sumpf et al. We report on current competition and emitter power distributions of unaged 650 nm red-emitting and 980 nm infrared tapered high-power laser bars. We observe a correlation between temperature and packaging-induced strain with respect to the emitter output power. A frown-shaped profile of the output p ... [Appl. Phys. Lett. 98, 241108 (2011)] published Wed Jun 15, 2011.

Description: Tropopause height at 78° N 16° E: average seasonal variation 2007–2010 Atmospheric Chemistry and Physics, 11, 5485-5490, 2011 Author(s): C. M. Hall, G. Hansen, F. Sigernes, and K. M. Kuyeng Ruiz We present a seasonal climatology of tropopause altitude for 78° N 16° E derived from observations 2007–2010 by the SOUSY VHF radar on Svalbard. The spring minimum occurs one month later than that of surface air temperature and instead coincides with the maximum in ozone column density. This confirms similar studies based on radiosonde measurements in the arctic and demonstrates downward control by the stratosphere. If one is to exploit the potential of tropopause height as a metric for climate change at high latitude and elsewhere, it is imperative to observe and understand the processes which establish the tropopause – an understanding to which this study contributes.