bluuebunny/crossref_metadata_2025 huggingface dataset:
Droplet size and efficacy of an adulticide–larvicide ultralow‐volume formulation on Aedes aegypti using different solvents and spray application methods
Authors: Harburguer Laura , Seccacini Emilia , Licastro Susana , Zerba Eduardo , Masuh Héctor
Published: June 2011

BACKGROUND: When cases of dengue are reported or the density of adult Aedes aegypti (L.) becomes too high, ultralow‐volume (ULV) application of insecticides is the recommended control method. The droplet size of an aerosol insecticide influences its efficiency in killing adult mosquitoes. Many studies have been carried out to determine the optimum droplet size that maximises vector control efforts, but only a few have determined droplet‐size spectra for specific equipment using different solvents and comparing thermal and non‐thermal aerosols.

RESULTS: The present study showed that the droplet size for a water‐based adulticide–larvicide formulation was larger than for the same formulation diluted in gasoil or biodiesel. No significant differences in adult mortality were observed between sprayers and solvents, but efficacy decreased with distance from the sprayer nozzle. Adult emergence inhibition was more than 90% when using water as a solvent for both thermal and cold foggers, and the efficacy did not decrease with distance from the sprayer nozzle. On the other hand, oil‐based solvents became less effective with distance.

CONCLUSION: The use of water as a solvent with both thermal and cold foggers improves the efficacy of the studied formulation containing permethrin as adulticide and pyriproxyfen as larvicide in scaled‐up assays. Moreover, it reduces the environmental impact and costs of spraying by comparison with formulations using oil solvents. Copyright © 2011 Society of Chemical Industry
Magneto‐elasticity in amorphous ferromagnets: Basic principles and applications
Authors: Barandiarán J. M. , Gutiérrez J. , García‐Arribas A.
Published: June 2011

Ferromagnetic metallic glasses (FMG) show a very special combination of magnetic, elastic, and magnetostrictive properties that have rocketed their most extended technological applications, mainly in the field of sensors and surveillance labels. The amorphous structure results in the cancellation of the magnetic anisotropy as a result of the averaging out of the atomic scale local anisotropy in a region of the order of the exchange correlation length. Magnetostriction, however, does not cancel out, and values similar to the corresponding crystalline alloys are displayed by the amorphous ones. The absolute values of magnetostriction are not very high, but the extremely magnetic softness of the alloys does balance the competition between stress and magnetic field. In particular, the magnetoelastic coupling coefficient can reach values as high as 0.98, the highest in any known material. Magnetoelasticity, defined as the magnetization change caused by stress, reaches outstanding values in FMGs and a number of applications do use such properties for sensing applications. We can briefly review some of them, either based on static or magnetoelastic wave resonance operation. The most widely extended application is their use as magnetoelastic resonant elements in electronic surveillance labels. New applications of FMGs are under development. Hybrid magnetoelectric (magnetostrictive/piezoelectric) materials have been devised, using highly magnetostrictive amorphous alloys working at resonance. Possible applications of such new materials are briefly discussed.
Structural and enthalpy relaxation processes in pure ethanol
Authors: Kabtoul B. , Ramos M. A.
Published: June 2011

In this work, we present new calorimetric and thermodynamic measurements conducted on pure ethanol for its two kinds of glass transition, namely the conventional or structural glass transition and also the dynamical freezing of the plastic crystal (PC) state into an orientationally‐disordered crystal (or glassy crystal), that are found to occur exactly at the same temperature (Tg ≈ 97 K) and with comparable discontinuities in the specific heat. We have studied the dependence of the corresponding fictive temperatures on the different cooling rates and/or thermal annealing processes followed. The apparent activation energy and the concomitant fragility index were thus calculated for each glassy phase of ethanol, finding that the PC is a stronger “glass former” than the supercooled liquid.
Lithium niobosilicate glass doped with samarium: Dielectric and optical analysis
Authors: Nico C. , Graça M. P. F. , Monteiro T. , Valente M. A.
Published: June 2011

Lithium niobate (LiNbO3 – LN) is a large bandgap [3.78 eV at room temperature (RT)] semiconductor mainly known by its ferroelectric behaviour and excellent non‐linear optical, electro‐optical and piezoelectric properties. In this study 91SiO2–4Li2O–4Nb2O5–1Sm2O3 (mol%) glasses were prepared by sol–gel. Glass–ceramics were obtained through heat‐treatments (HTs) of the dried gel. The samples structure was studied by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The HT above 600 °C promotes the crystallization of LiNbO3 and SmNbO4. For heat HT above 800 °C, SiO2 crystallites also precipitate. SEM micrographs indicate that the size of the particles and aggregation phenomena is promoted with the increase of the HT temperature. The electric characterization was performed as a function of the temperature and frequency. The main contribution for the electric conductivity behaviour is the number of network modifier ions, which decreases with the increase of the HT temperature. The dielectric constant and loss value decrease with the increase of the HT temperature. Dielectric relaxation mechanisms were observed in the samples HT below 800 °C. At RT, the photoluminescence (PL) spectra, revealed a red light emission, due to the 4G5/2 → 6HJ = 5/2,7/2,9/2 transitions of Sm3+ ion. The results suggest that the intraionic emission is promoted when the lanthanide ions are inserted in the amorphous matrix. Auto‐absorptions of the samarium ion and large emission bands were detected and assigned to the crystalline and amorphous phases of SiO2. The obtained results reflect the decisive effect of HT temperature in the structural, electric and optical properties of these glasses.
Enhanced coercivity of as‐prepared and chemically modified multiwalled carbon nanotubes
Authors: Kuryliszyn‐Kudelska I. , Małolepszy A. , Mazurkiewicz M. , Stobinski L. , Kurzydłowski K. J. , Dobrowolski W.
Published: June 2011

The systematic magnetic and structural properties of as‐prepared, “Fe” catalyst based multiwalled carbon nanotubes (MWCNTs), and chemically modified MWCNTs were studied. The structural characterization by means of transmission electron microscopy, X‐ray diffraction, and Raman spectroscopy was performed. DC magnetization up to 9 T was studied. We examined the influence of chemical treatment (purification procedure) on the magnetic properties of MWCNT's. The significant changes in the saturation magnetization after chemical treatment were observed. However, we noticed high magnetic coercivity values for as‐prepared as well as chemically modified samples.
Role of energy level alignment in solar cells sensitized with a metal‐free organic dye: A combined experimental and theoretical approach
Authors: Oprea Corneliu I. , Dumbravă Anca , Enache Irina , Lungu Jeanina , Georgescu Adrian , Moscalu Florin , Oprea Camelia , Gîrţu Mihai A.
Published: June 2011

We report results of combined experimental and theoretical studies of dye‐sensitized solar cells (DSSCs) using 5‐(4‐sulfophenylazo)salicylic acid disodium salt, known as Mordant Yellow 10 (MY‐10), as TiO2 sensitizer. We focus on a single dye but vary the solvent and the pH of the solution as well as the photoelectrode preparation conditions to determine the conditions for best photovoltaic conversion efficiency. We found experimentally that the efficiency, measured under standard air mass 1.5 global (AM 1.5G) conditions, was higher in solutions of ethanol than of water, but still small (up to 0.174%), although the fill factor (FF) was large (up to 0.73). Of the dyes in ethanol, MY‐10 in alkaline solution showed the best matching of the solar spectrum but displayed the lowest efficiency. Density functional theory (DFT) calculations provided the optimized geometry, electronic structure, and electronic spectrum of the dye in fully protonated as well as partially and totally deprotonated forms, in solution. The calculated optical spectra are consistent with the experimental data, with strong absorption in the visible range only for the alkaline dye solution. The low device efficiency is very likely related to the weak optical absorption in the visible range. The much higher photovoltaic conversion efficiency of the DSSCs fabricated using acid or roughly neutral pH solutions, corresponding to the protonated and partially deprotonated forms of MY‐10, respectively, is likely caused by the better alignment of the ground state of the dye with the redox level of the electrolyte. The decrease with pH of the dye solution of the short‐circuit current was linked to a weaker charge injection from the excited state of the dye to the conduction band of the oxide, which is correlated with the shifting of the excited state of the dye deeper into the CB edge of the semiconductor. The variation of the open‐circuit voltage with the pH of the solution was linked to the adjustment of the conduction band edge of TiO2, depending on the number of protons transferred from the dye to the oxide surface. Based on our results, we analyze the relative importance of the main criteria that should be met by a dye to be used in a DSSC.
Effect of annealing temperature on the magnetic properties of Zn0.97Al0.03O nanoparticles
Authors: Gao Hua , Gao Daqiang , Yang Guijin , Zhang Jing , Zhang Jinlin , Shi Zhenhua , Xue Desheng
Published: June 2011

Al doped ZnO nanoparticles were synthesized by the sol‐gel technique. X‐ray diffraction, selected area electron diffraction, inductively coupled plasma‐atomic emission and X‐ray photoelectron spectroscopy results ruled out impurity and other phases in Zn0.97Al0.03O nanoparticles annealing at different temperatures. Magnetic measurements indicate that all the samples have the obvious room temperature ferromagnetism. With the increase of annealing temperatures from 500 to 900 °C, the saturation magnetization of nanoparticles decreases with the reduction of defect‐related emission. Together with the electron paramagnetic resonance results, the observed ferromagnetic ordering of Zn0.97Al0.03O nanoparticles annealing at different temperatures is consider to be related to the singly charged oxygen vacancies.
Polymer light‐emitting diodes with doped hole‐transport layers
Authors: Lu Mingtao , Nicolai Herman T. , Kuik Martijn , Wetzelaer Gert‐Jan A. H. , Wildeman Jurjen , Palmaerts Arne , Blom Paul W. M.
Published: June 2011

We demonstrate a solution processed bi‐layer PLED based on poly(p‐phenylene vinylene) derivatives using orthogonal solvents. To lower the voltage drop the hole transport layer (HTL) based on poly[2,5‐bis(2′‐ethylhexyloxy)‐co‐2,5‐bis(butoxy)‐1,4‐phenylenevinylene] (BEH/BB‐PPV (1:3)) is doped with tetracyano‐tetrafluoro‐quinodimethane (F4TCNQ). The conductivity of BEH/BB‐PPV (1:3) was observed to increase by two orders of magnitude upon doping with F4TCNQ. The doped HTL was observed to lower the operating voltage of a double layer PLED, but suffers from additional quenching by the dopant at higher voltages due to the lack of an electron blocking functionality.
Catalytic growth of hexagonally aligned ZnO nanorods
Authors: Madel Manfred , Xie Yong , Tischer Ingo , Neuschl Benjamin , Feneberg Martin , Frey Reinhard , Thonke Klaus
Published: June 2011

Aligned ZnO nanorods were prepared using colloid‐based self‐assembling techniques to structure the gold catalyst. Two different processes were used and are compared. The ZnO nanorods were grown with diameters between 200 and 500 nm and adjustable length by a chemical vapor deposition process in a horizontal tube furnace. They show high crystalline quality as confirmed by photoluminescence and spatially and spectrally resolved cathodoluminescence measurements. Hexagonal ordering of the nanorods has been achieved for areas of several square millimeters.
Structural, electronic, and magnetic properties of tungsten oxycarbides WC1–xOx and WO3–xCx from first principles calculations
Authors: Suetin Dmitrii V. , Shein Igor R. , Ivanovskii Alexander L.
Published: June 2011

Ab initio total energy calculations using the full‐potential linearized augmented plane wave method (FP‐LAPW) with the generalized gradient approximation (GGA) for the exchange‐correlation potential have been performed to predict the structural, cohesive, electronic, and magnetic properties for tungsten oxycarbides. Two possible stoichiometries have been considered: WC1–xOx, formed by partial substitution of oxygen atoms for carbon in hexagonal WC, and WO3–xCx, which appear in the carburization process of WO3. The optimized lattice parameters, theoretical density, cohesive energies, as well as electronic densities of states have been obtained and analyzed for the first time. We have found that these two systems differ substantially: WC1–xOx behave as d metals, whereas WO3–xCx behave as sp metals. The unexpected d0‐magnetism due to the C 2p ↓↑ spin splitting for some WO3–xCx solid solutions (SSs) was predicted. The chemical composition and O/C atomic ordering type are two main factors responsible for the properties of these materials.
The reactive sites in faceted anatase nanoparticles
Authors: Wang Hong , Lewis James P.
Published: June 2011

Considering both (001) and (101) surfaces, we construct two models of anatase nanoparticles with size ranging between 182 and 774 atoms. We choose nanoparticles where the majority surface (101) decreases in surface percentage as the size of the nanoparticle increases; the minority surface (001) decreases correspondingly. Upon optimization, significant structural changes occur in the edged Ti atoms which are junctures between the (001) and (101) facets; original four‐coordinated Ti atoms become three coordinated upon optimization. Analyzing the electronic properties, we observe frontier orbitals occurring as small peaks in the band gap region approximately 1 eV lower than the conduction band. We find that these mid‐gap peak states are highly localized at the edged Ti atoms. Therefore, we propose that these edged Ti atoms are a key to understanding the reactivity properties exhibited in anatase nanoparticles.
Effects of Armepavine Against Hepatic Fibrosis Induced by Thioacetamide in Rats
Authors: Weng Ting‐Chun , Shen Chien‐Chang , Chiu Yung‐Tsung , Lin Yun‐Lian , Huang Yi‐Tsau
Published: June 2011

The aim of this study was to investigate if armepavine (Arm, C19H23O3N) could exert inhibitory effects against hepatic fibrosis in rats. A cell line of rat hepatic stellate cells (HSC‐T6) was stimulated with tumour necrosis factor‐α (TNF‐α) to evaluate the inhibitory effects of Arm. Rats were injected with thioacetamide (TAA; 300 mg/kg, intraperitoneally) thrice a week for 4 weeks to induce hepatic fibrosis, with Arm (3 or 10 mg/kg) given by gavage twice a day. Liver sections were taken for western blotting, fibrosis scoring and immunofluorescence staining. Arm (1–10 µm) concentration‐dependently attenuated TNF‐α‐stimulated: (i) protein expressions of α‐smooth muscle actin (α‐SMA), collagen type I and angiopoietin‐1; (ii) H2O2 production; and (iii) NF‐κB, JunD and C/EBPß (cytidine‐cytidine‐adenosine‐adenosine‐thymidine (CCAAT)/enhancer binding protein‐ß (EBPß)) nuclear translocations in HSC‐T6 cells. In vivo Arm treatment significantly reduced plasma aspartate transaminase and alanine transaminase levels, hepatic α‐SMA expression and collagen contents, and fibrosis scores of TAA‐injected rats. Moreover, Arm treatment decreased α‐SMA‐ and NF‐κB‐positive cells in immunohistochemical staining, and mRNA expression levels of IL‐6, TGF‐ß1, TIMP‐1, col1α2, iNOS and ICAM‐1 genes, but up‐regulated the metallothionein gene in the livers of TAA‐injected rats. Our results indicated that Arm exerted both in vitro and in vivo antifibrotic effects in rats, with inhibition of NF‐κB, JunD and C/EBPß pathways. Copyright © 2011 John Wiley & Sons, Ltd.
Protective Effect of Pycnogenol® on Ovariectomy‐induced Bone Loss in Rats
Authors: Mei Lin , Mochizuki Miyako , Hasegawa Noboru
Published: June 2011

Pycnogenol® (PYC) is a natural plant extract from the bark of Pinus pinaster and has potent antioxidant activities. The protective effect of PYC on bone loss was studied in multiparous ovariectomized (OVX) female rats. Pycnogenol® (30 or 15 mg/kg body weight/day) was administered orally to 8‐month‐old OVX rats for 3 months. At the end of the experiment, bone strength was measured by a three‐point bending test and bone mineral density was estimated by peripheral quantitative computed tomography. Ovariectomy significantly decreased femur bone strength and bone density. Supplementation with PYC suppressed the bone loss induced by OVX. The OVX treatment significantly increased serum osteocalcin (OC) and C‐terminal telopeptide of type I collagen (CTx). Supplementation with PYC reduced the serum OC and CTx in OVX rats to a level similar to that of the sham‐operated group. The results indicated that orally administered PYC can decrease the bone turnover rate in OVX rats, resulting in positive effects on the biomechanical strength of bone and bone mineral density. Copyright © 2011 John Wiley & Sons, Ltd.
Chronic Intraperitoneal and Oral Treatments with Hesperidin Induce Central Nervous System Effects in Mice
Authors: Wasowski Cristina , Loscalzo Leonardo M. , Higgs Josefina , Marder Mariel
Published: June 2011

Hesperidin (HN) is a flavanone glycoside abundantly found in citrus fruits. This flavonoid mediated central nervous system activity following intraperitoneal (i.p.) acute treatment. The responses of mice after the chronic i.p. (4 and 30 mg/kg/day) or the oral intake administration of this drug (20, 50 and 100 mg/kg/day) were studied by using the holeboard, the plus‐maze and the locomotor activity tests. Hesperidin, chronically administered by the i.p. route, exerted a decrease in the locomotor and exploratory activities, thus evidencing a depressant activity. In turn, the chronic oral intake of this flavonoid induced anxiolytic‐like effects. These varied responses could be attributed to the different routes of administration that could lead to the production of diverse active metabolites. Copyright © 2011 John Wiley & Sons, Ltd.
Antimicrobial Activity of Cinnamaldehyde and Eugenol and Their Activity after Incorporation into Cellulose‐based Packaging Films
Authors: Sanla‐Ead Nutcha , Jangchud Anuvat , Chonhenchob Vanee , Suppakul Panuwat
Published: June 2011

Cinnamaldehyde and eugenol were investigated for their antimicrobial activity against 10 pathogenic and spoilage bacteria and three strains of yeast, using an agar‐well diffusion assay. The minimum inhibitory concentrations (MICs) of these compounds were determined using an agar dilution method. Finally, cinnamaldehyde‐incorporated and eugenol‐incorporated methyl cellulose films were prepared to obtain active antimicrobial packaging materials. These antimicrobial cellulose‐based packaging films were investigated for antimicrobial activity against target microorganisms using both an agar‐disc diffusion technique and a vapour diffusion technique. At a concentration of 50 µl/ml, cinnamaldehyde and eugenol revealed antimicrobial activity against all test strains. They showed zones of inhibition, ranging from 8.7 to 30.1 mm in diameter. Eugenol and cinnamaldehyde possessed ‘moderate−strong inhibitory’ and ‘strong−highly strong inhibitory’ characteristics, respectively. With MICs of 0.78−50 µl/ml, cinnamaldehyde and eugenol also inhibited the growth of all test microorganisms. Among the test microorganisms, Aeromonas hydrophila and Enterococcus faecalis were the most sensitive to cinnamaldehyde and eugenol. Cinnamaldehyde showed lower MICs against all test strains than those of eugenol. In an agar‐disc diffusion assay, cellulose‐based film containing cinnamaldehyde or eugenol totally failed to exhibit a clear inhibitory zone. However, it showed positive activity against all selected test strains in terms of size and enumeration of microbial colonies in a vapour diffusion assay. This study shows the potential use of cinnamaldehyde and eugenol for application in antimicrobial packaging film or coating. Copyright © 2011 John Wiley & Sons, Ltd.
Using model analysis and satellite data to assess cloud and precipitation in midlatitude cyclones
Authors: Field P. R. , Bodas‐Salcedo A. , Brooks M. E.
Published: June 2011

Midlatitude cyclones taken from 18 months of global operational Met Office Unified Model analysis archives were combined to form three‐dimensional composite cyclones. Given an accurate dynamical and thermodynamical representation of the atmosphere from 4D‐Var analysis, this study attributes differences between observations and the model cloud/precipitation to potential shortcomings in the physical parametrizations that control cloud/precipitation. Coincident ( ± 6 h) data from CloudSat radar, AMSR‐E microwave, and ISCCP flux products were collected into composites for comparison. Only cyclones over the ocean were analysed here. Considering all of the observations in a single composite shows that horizontal slices through the composite display qualitative agreement between the mean reflectivity structures seen in the UM and CloudSat data. Splitting the composite cyclone into quadrants reveals that the UM underpredicts fractions of reflectivities greater than –20 dBZ and + 10 dBZ at heights above 2 km in the poleward quadrants. This lack of cloud is manifested in smaller short‐wave top‐of‐atmosphere fluxes from the UM composite cyclone than from the observations. Comparison of UM precipitation rates with CloudSat shows agreement to within the assumed potential bias of the observations. Copyright © 2011 British Crown copyright, the Met Office. Published by John Wiley & Sons Ltd.
A simple model for the calculation of HOMO and LUMO energy levels of benzocatafusenes
Authors: Matamala Adelio R. , Alarcón Alejandro A.
Published: June 2011

A simple model for the calculation of HOMO and LUMO energy levels of benzocatafusenes (i.e., molecules that are only constituted by mutually condensed benzene rings and without interior carbon atoms, which belong to three benzene rings) is presented. Using semiempirical AM1 method, 615 benzocatafusenes were studied (29 normal and 586 branched). The relation between energy and molecular structure was coded by the three Hückel parameters: Coulomb integral, bond integral, and secular x eigenvalue. Analytical functions for HOMO and LUMO energy levels in terms of x parameter were obtained for normal benzocatafusenes, and energies for branched benzocatafusenes were satisfactorily modelled by the introduction of a simple correction function into the analytical functions describing normal benzocatafusenes. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Phase transitions driven by quasiparticle interactions. II
Authors: March Norman H. , Squire Richard H.
Published: June 2011

Quasiparticles and collective effects may have seemed exotic when first proposed in the 1930s, but their status has blossomed with their confirmation by today's sophisticated experiment techniques. Evidence has accumulated about the interactions of, say, magnons and rotons and with each other and also other quasiparticles (QPs). We briefly review the conjectures of their existence necessary to provide quantitative agreement with experiment which in the early period was their only reason for existence. Phase transitions in the Anderson model, the Kondo effect, roton–roton interactions, and highly correlated systems such as helium‐4, the quantum Hall effect, and Bose–Einstein condensates are discussed. Some insulator and superconductor theories seem to suggest that collective interactions of several QPs may be necessary to explain the behavior. We conclude with brief discussions of the possibility of using the Grüneisen parameter to detect quantum critical points and some background on bound states emerging from the continuum. Finally, we present a summary and conclusions and also discuss possible future directions. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Pandemic influenza: certain uncertainties
Authors: Morens David M. , Taubenberger Jeffery K.
Published: June 2011

For at least five centuries, major epidemics and pandemics of influenza have occurred unexpectedly and at irregular intervals. Despite the modern notion that pandemic influenza is a distinct phenomenon obeying such constant (if incompletely understood) rules such as dramatic genetic change, cyclicity, “wave” patterning, virus replacement, and predictable epidemic behavior, much evidence suggests the opposite. Although there is much that we know about pandemic influenza, there appears to be much more that we do not know. Pandemics arise as a result of various genetic mechanisms, have no predictable patterns of mortality among different age groups, and vary greatly in how and when they arise and recur. Some are followed by new pandemics, whereas others fade gradually or abruptly into long‐term endemicity. Human influenza pandemics have been caused by viruses that evolved singly or in co‐circulation with other pandemic virus descendants and often have involved significant transmission between, or establishment of, viral reservoirs within other animal hosts. In recent decades, pandemic influenza has continued to produce numerous unanticipated events that expose fundamental gaps in scientific knowledge. Influenza pandemics appear to be not a single phenomenon but a heterogeneous collection of viral evolutionary events whose similarities are overshadowed by important differences, the determinants of which remain poorly understood. These uncertainties make it difficult to predict influenza pandemics and, therefore, to adequately plan to prevent them. Published 2011. This article is a US Government work and is in the public domain in the USA.
Packing tight Hamilton cycles in 3‐uniform hypergraphs
Authors: Frieze Alan , Krivelevich Michael , Loh Po‐Shen
Published: June 2011

Let H be a 3‐uniform hypergraph with n vertices. A tight Hamilton cycle C ⊂ H is a collection of n edges for which there is an ordering of the vertices v1,…,vn such that every triple of consecutive vertices {vi,vi+1,vi+2} is an edge of C (indices are considered modulo n ). We develop new techniques which enable us to prove that under certain natural pseudo‐random conditions, almost all edges of H can be covered by edge‐disjoint tight Hamilton cycles, for n divisible by 4. Consequently, we derive the corollary that random 3‐uniform hypergraphs can be almost completely packed with tight Hamilton cycles whp, for n divisible by 4 and p not too small. Along the way, we develop a similar result for packing Hamilton cycles in pseudo‐random digraphs with even numbers of vertices. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 2011
Distributed anomaly detection using 1‐class SVM for vertically partitioned data
Authors: Das Kamalika , Bhaduri Kanishka , Votava Petr
Published: June 2011

There has been a tremendous increase in the volume of sensor data collected over the last decade for different monitoring tasks. For example, petabytes of earth science data are collected from modern satellites, in situ sensors and different climate models. Similarly, huge amount of flight operational data is downloaded for different commercial airlines. These different types of data sets need to be analyzed for finding outliers. Information extraction from such rich data sources using advanced data mining methodologies is a challenging task not only because of the massive volume of data but also because these data sets are physically stored at different geographical locations with only a subset of features available at any location. Moving these petabytes of data to a single location may waste a lot of bandwidth. To solve this problem, in this paper, we present a novel algorithm which can identify outliers in the entire data without moving all the data to a single location. The method we propose only centralizes a very small sample from the different data subsets at different locations. We analytically prove and experimentally verify that the algorithm offers high accuracy compared to complete centralization with only a fraction of the communication cost. We show that our algorithm is highly relevant to both earth sciences and aeronautics by describing applications in these domains. The performance of the algorithm is demonstrated on two large publicly available data sets: (i) the NASA MODIS satellite images and (ii) a simulated aviation data set generated by the ‘Commercial Modular Aero‐Propulsion System Simulation’ (CMAPSS). © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 393–406, 2011
Retrospective‐cost‐based adaptive model refinement for the ionosphere and thermosphere
Authors: D'Amato Anthony M. , Ridley Aaron J. , Bernstein Dennis S.
Published: June 2011

Mathematical models of physical phenomena are of critical importance in virtually all applications of science and technology. This paper addresses the problem of how to use data to improve the fidelity of a given model. We approach this problem using retrospective cost optimization, which uses data to recursively update an unknown subsystem interconnected to a known system. Applications of this technique are relevant to applications that depend on large‐scale models based on first‐principles physics, such as the global ionosphere–thermosphere model (GITM). Using GITM as the truth model, we demonstrate that measurements can be used to identify unknown physics. Specifically, we estimate static thermal conductivity parameters, as well as a dynamic cooling process. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 446–458, 2011
Using spatiotemporal relational random forests to improve our understanding of severe weather processes
Authors: McGovern Amy , John Gagne David , Troutman Nathaniel , Brown Rodger A. , Basara Jeffrey , Williams John K.
Published: June 2011

Major severe weather events can cause a significant loss of life and property. We seek to revolutionize our understanding of and our ability to predict such events through the mining of severe weather data. Because weather is inherently a spatiotemporal phenomenon, mining such data requires a model capable of representing and reasoning about complex spatiotemporal dynamics, including temporally and spatially varying attributes and relationships. We introduce an augmented version of the Spatiotemporal Relational Random Forest, which is a random forest that learns with spatiotemporally varying relational data. Our algorithm maintains the strength and performance of random forests but extends their applicability, including the estimation of variable importance, to complex spatiotemporal relational domains. We apply the augmented Spatiotemporal Relational Random Forest to three severe weather data sets. These are: predicting atmospheric turbulence across the continental United States, examining the formation of tornadoes near strong frontal boundaries, and understanding the spatial evolution of drought across the southern plains of the United States. The results on such a wide variety of real‐world domains demonstrate the extensive applicability of the Spatiotemporal Relational Random Forest. Our long‐term goal is to significantly improve the ability to predict and warn about severe weather events. We expect that the tools and techniques we develop will be applicable to a wide range of complex spatiotemporal phenomena. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 407–429, 2011
Novel approach to the semi‐empirical universal theory for secondary electron yield
Authors: Bundaleski N. , Shaw B. J. , Silva A. G. , Moutinho A. M. C. , Teodoro O. M. N. D.
Published: June 2011

The universal semi‐empirical equation has been commonly used to quantitatively describe the energy dependence of the secondary electron yield (SEY). It is even used as a first reliability test for experimental data. The equation is based on the assumption that the stopping power is constant along the electron trajectory. In this article, we derive a novel analytical expression based on a more advanced model which considers linear stopping power dependence on penetration depth. Although coinciding with the universal equation at low energies, the novel function has lower intensity in the higher energy range. The models were compared with experimental SEY data of different metals, taken from literature, as well as freshly cleaved highly oriented pyrolytic graphite, measured in the frame of this work. It is confirmed that the novel expression better describes the experimental data. SCANNING 33: 266–269, 2011. © 2011 Wiley Periodicals, Inc.
Mechanical properties of hydrogenated nanocrystalline silicon thin film with different indentation depths
Authors: Guo Liqiang , Ding Jianning , Yang Jichang , Cheng Guanggui , Ling Zhiyong
Published: June 2011

Hydrogenated nanocrystalline silicon thin films were prepared on Corning 7059 glasses by plasma enhanced chemical vapor technique with radio frequency and direct current bias stimulation. The surface topography and microstructure of sample were characterized with atomic force microscopy and X‐ray diffraction. The mechanical properties of the samples were investigated by TriboIndenter nanosystem. The elastic modulus E and hardness H of samples were calculated by means of Oliver and Pharr analysis method. The results show that with increasing the indentation depth from 70 to 180 nm, the maximum applied load Pmax increases from 500 to 2000 µN, while the elastic modulus E dives to 25 from 45 GPa, and the hardness H decreases from 4.9 to 3.8 GPa. After complete unloading, some plastic deformations occur on the films' surface and with the increase of the indentation depth, they become more obvious. This phenomenon is mainly connected with the film's growth mechanism. In this paper, we did an investigation and a discussion in detail about this phenomenon. Copyright © 2011 John Wiley & Sons, Ltd.
Commentary on ‘Multivariate meta‐analysis: potential and promise’
Authors: Harbord Roger M.
Published: June 2011

I thank Jackson, Riley, and White [1] for organising an enjoyable and stimulating meeting on multivariate meta‐analysis and congratulate them for providing an excellent overview of the topic. My interest in multivariate meta‐analysis is chiefly in its application to diagnostic test accuracy studies, illustrated by Example 1 in the paper. In these example data, which strictly concern prognostic accuracy rather than its diagnostic accuracy, the outcome is extremely rare, occurring in only 25 of the 567 patients across all the seven studies in the authors' Table 1 and with a mere six ‘false negatives’. Although this is an extreme example, sparse binomial data occur frequently in diagnostic accuracy studies. I will discuss some of the issues that arise in its analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Autonomous role discovery for collaborating agents
Authors: Ferrari Luca , Zhu Haibin
Published: June 2011

Role‐based collaboration is an emerging methodology to facilitate an organizational structure, provide orderly system behavior, and consolidate system security for both human and non‐human entities, like agents, that collaborate and coordinate their activities with or within systems. Interaction management must, however, be able to handle run‐time and dynamic scenarios. Hence, every role‐based collaboration system must provide a good level of dynamism, that is, provide an agent with the capability to assume, use, and release a role depending on run‐time conditions. Dynamism, however, does not suffice in adaptative scenarios: being able to use a role dynamically is important, but in order to enhance interagent communications, the capability to perceive a played role is important too. Role perceivability is the capability of an agent to autonomously recognize the role played by another entity without the need to ask a yellow‐page directory. Whereas dynamism has been achieved with different techniques and often through language support, role perceivability is more difficult to achieve and to some extent even more important because it can boost sociality among entities and agents. In object‐oriented programming languages, such as JAVA, role perceivability could be achieved with appropriate changes to the agent/entity class structure, but this requires compile time constraints that are, in their nature, not dynamic. This paper proposes an approach to remedy the above problems: maintaining an appropriate level of dynamism. The work presented here allows a JAVA agent to make its role perceivable to other entities as if it is applied at compile time. Copyright © 2011 John Wiley & Sons, Ltd.
Use of starch granules melting to control the properties of bio‐flour filled polypropylene and poly(butylene succinate) composites: Mechanical properties
Authors: Tran Thierry , Lee Byoung‐Ho , Yang Han‐Seung , Chotineeranat Sunee , Sriroth Klanarong , Kim Hyun‐Joong
Published: June 2011

The feasibility and industrial potential of using bio‐flours from tropical crop residues, in particular starch containing bio‐flours, for the manufacture of bio‐composites was investigated. Polypropylene (PP) and poly(butylene succinate) (PBS) were compounded with bio‐flours from pineapple skin (P) and from non‐destarched (CS) and destarched (C) cassava root by twin‐screw extrusion. In CS composites, two levels of starch granules melting were achieved by adjusting the extrusion temperature, enabling control of morphological and mechanical properties. The use of bio‐flours reduced tensile strength by 26–48% and impact strength by 14–40% when the proportion of bio‐flour was increased to 40% w/w, while flexural strength initially increased upon addition of bio‐flours, before decreasing at higher loads. The use of compatibilizers, in particular maleic anhydride‐polypropylene (MAPP) in PP composites with 30% bio‐flour resulted in tensile strength similar to non‐compatibilized composites with 10% bio‐flour (34–35 MPa). MAPP also increased flexural strength to higher levels than pure PP, resulting in a stronger, but less flexible material.
Networks of practice in science education research: A global context
Authors: Martin Sonya N. , Siry Christina
Published: June 2011

In this paper, we employ cultural sociology and Braj Kachru's model of World Englishes as theoretical and analytical tools for considering English as a form of capital necessary for widely disseminating research findings from local networks of practice to the greater science education research community. We present a brief analysis of recent authorship in top‐tier science journals to demonstrate the salience of English language dominance as an issue in our field and we share narrative reflections from 11 international science education researchers offering perspectives from the field about the challenges faced by researchers in local and global contexts. Using an interpretive research stance, we discuss these narrative reflections to illuminate the role of personal and collective responsibility of individuals, organizations and institutions within local social networks of practice to recognize the relationship between capital, power, and equitable participation within a global science education research community. We conclude by discussing some existing structures within local networks of practice that relegate some members of the community to peripheral participatory roles in the global community and we suggest new structures to support individuals to more equitably contribute to the production of knowledge in the field of science education in ways that benefit not only individuals, but also the global science education community. © 2011 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 592–623, 2011
Sequential climate change policy
Authors: Parson Edward A. , Karwat Darshan
Published: June 2011

Successfully managing global climate change will require a process of sequential, or iterative, decision‐making, whereby policies and other decisions are revised repeatedly over multiple decades in response to changes in scientific knowledge, technological capabilities, or other conditions. Sequential decisions are required by the combined presence of long lags and uncertainty in climate and energy systems. Climate decision studies have most often examined simple cases of sequential decisions, with two decision points at fixed times and initial uncertainties that are resolved at the second decision point. Studies using this formulation initially suggested that increasing uncertainty favors stronger immediate action, while the prospect of future learning favors weaker immediate action, but subsequent work with more general formulations showed that the direction of either effect is indeterminate, depending on multiple elements of model structure and parameter values. Current issues in sequential climate decision‐making include assessing responses to potential slow learning or negative learning, and examining the implications of various mechanisms by which current decision‐makers may seek to influence future decisions by altering the choice sets, knowledge states, marginal costs and benefits, or default procedural requirements faced by future decision‐makers.WIREs Clim Change2011 2 744–756 DOI: 10.1002/wcc.128

This article is categorized under:

Climate Economics > Iterative Risk‐Management Policy Portfolios
Analyzing abrupt and nonlinear climate changes and their impacts
Authors: McNeall Doug , Halloran Paul R. , Good Peter , Betts Richard A.
Published: June 2011

The Earth system shows the tendency to change in nonlinear and sometimes abrupt ways; small changes in external forcing can lead to large and perhaps irreversible changes in outcome. The prospect of crossing important ‘tipping points’ and realizing their impacts poses unique challenges to decision makers within society, hoping to avoid damaging anthropogenic influence on Earth systems. Abrupt and nonlinear changes are by their very nature highly uncertain and difficult to predict, and so hard to avoid or adapt to. After briefly introducing key concepts in nonlinear dynamics, we summarize paleoclimate evidence for past abrupt and nonlinear changes in major Earth systems such as, ocean and atmospheric circulation patterns, sea ice and terrestrial ice sheets, atmospheric composition, and the terrestrial biosphere. For each of these systems we then review observational, theoretical, and modeling evidence for potential future abrupt changes, and associated impacts. We outline the extra challenges that are faced in predicting abrupt or nonlinear as opposed to more gradual climate change, and in providing a risk analysis for their impacts on Earth and societal systems. We examine the potential for early warning systems of abrupt change, and discuss differences in attitude to risk which may dictate societal response to low probability–high impact events. Finally, we outline the promising directions of research needed to better quantify the risk of abrupt and nonlinear climate change. WIREs Clim Change 2011 2 663–686 DOI: 10.1002/wcc.130

This article is categorized under:

Assessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change
Homodesmotic reactions for thermochemistry
Authors: Wheeler Steven E.
Published: June 2011

Achieving highly accurate thermochemical predictions from relatively low levels of electronic structure theory has long been a goal of computational chemistry. One route to such a goal is to exploit the systematic cancellation of errors. This approach was spearheaded by the Pople group in the 1970s with the introduction of isodesmic bond‐separation reactions, and then extended by other groups to homodesmotic (HD) and hyperhomodesmotic reactions over the ensuing years. Unfortunately, the propagation of multiple, nonequivalent definitions of HD reactions, accompanied by a panoply of related reaction classes, has lead to a great deal of confusion. We review recent efforts to introduce a refined hierarchy of HD reactions for use in thermochemical predictions and to quantify the degree of error cancellation that can be achieved. Examples of the use of reactions from the HD hierarchy from the literature are presented, as are current limitations of this HD hierarchy for thermochemistry. Although the use of such error‐balanced reactions are no longer mandatory for high‐accuracy thermochemical predictions of small molecules, they still offer significant advantages in this context, and offer one route to accurate thermochemical predictions of larger molecules. © 2011 John Wiley & Sons, Ltd.

This article is categorized under:

Structure and Mechanism > Molecular Structures
Software design of ACES III with the super instruction architecture
Authors: Deumens Erik , Lotrich Victor F. , Perera Ajith , Ponton Mark J. , Sanders Beverly A. , Bartlett Rodney J.
Published: June 2011

The Advanced Concepts in Electronic Structure (ACES) III software is a completely rewritten implementation for parallel computer architectures of the most used capabilities in ACES II, including the calculation of the electronic structure of molecular ground states and excited states, and determination of molecular geometries and of vibrational frequencies using many‐body and coupled cluster methods. To achieve good performance on modern parallel systems while simultaneously offering a software development environment that allows rapid implementation of new methods and algorithms, ACES III was written using a new software infrastructure, the super instruction architecture comprising a domain‐specific language, super instruction assembly language (SIAL), and a sophisticated runtime environment, super instruction processor (SIP). The architecture of ACES III is described as well as the inner workings of SIAL and SIP. The execution performance of ACES III and the productivity of programming in SIAL are discussed. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 895–901 DOI:10.1002/wcms.77

This article is categorized under:

Software > Quantum Chemistry
Recent developments in the PQS program
Authors: Baker Jon , Janowski Tomasz , Wolinski Krzysztof , Pulay Peter
Published: June 2011

An overview of the PQS quantum chemistry suite is presented, with emphasis on recent developments and features that are unique to the program. The capabilities of the program, in particular the parallel implementation, are briefly described. Topics discussed in more detail are coupled‐cluster and other high‐level correlation methods, second‐order Møller–Plesset perturbation theory for large molecules, the Fourier transform Coulomb method, geometry optimization, in particular constrained and enforced geometry optimization, and properties such as vibrational circular dichroism, scaled quantum mechanical force fields, spin densities, and spatially modulated polarizabilities. © 2011 John Wiley & Sons, Ltd.

This article is categorized under:

Software > Quantum Chemistry