Self-Reference Refractive Index Sensor Based on Independently Controlled Double Resonances in Side-Coupled U-Shaped Resonators.

PubMed

Ren, Xiaobin; Ren, Kun; Ming, Chengguo

2018-04-28

A plasmonic, refractive, index nanosensor is investigated theoretically and numerically in two U-shaped cavities side-coupled to a metal⁻dielectric⁻metal (MDM) waveguide. A transparency window between two transmission dips is observed. The physical origin of the transmission phenomenon is revealed by mapping the magnetic field distribution. Independent double resonances are realized through the proposed design. Double resonances showed diverse responses to the variations of the structural dimensions. In particular, they presented different dependences on a refraction index of the medium in an individual resonator. One resonance exhibited a remarkable shift with the increase of the refraction index; however, the other resonance remained unchanged. On the basis of this unique characteristic of differing sensitivities, self-reference sensing is discussed. The nanosensor yielded a high sensitivity of 917 nm/RIU and a figure of merit of 180 RIU −1 . This work is helpful in terms of the design of on-chip optical sensors with high sensitivity and improved detection accuracy in complicated environments.

Influence of intra-molecular flexibility on the elastic property of double-stranded DNA film on a substrate

NASA Astrophysics Data System (ADS)

Wu, Jun-Zheng; Meng, Wei-Lie; Tang, Heng-Song; Zhang, Neng-Hui

2017-05-01

DNA film self-assembled or nanografted on a substrate, as a kind of soft matter, consists of fixed DNA chains endowed with negative charges and an aqueous solution full of cations, anions and water molecules. Their thermal/electrical/mechanical properties are closely related to the complex biodetection signals in nano-/micro-scale biosensors and other new genome technologies. This makes it important to properly characterize these properties. In this paper, the effect of flexible micro-scale configurations on the elastic moduli of DNA films is investigated. First, illuminated by Qiu’s sphere model, an alternative bead-chain model in terms of the Yukawa potential is presented for flexible intra-DNA configurations to describe interactions between DNA fragments. The effective charges of coarse-grained DNA beads could be derived, in which the empirical parameters are identified by curve fitting with Qiu’s experimental data. Second, the updated mesoscopic bead-chain model and the thought experiment of a continuum compression bar are used to compare the elastic moduli of double-stranded DNA (dsDNA) films prepared by self-assembling and nanografting techniques. Configurational sampling is achieved via Monte Carlo simulation. Our predictions quantitatively or qualitatively agree well with the relevant experiments on the effective charge of dsDNA from low to moderate monovalent counterion concentration, immobilization deflection of single-stranded DNA (ssDNA) or dsDNA microcantilever with the variation of salt concentration, and elastic modulus of ssDNA film in the air. The results reveal that different solution environment stimulates the diverse mechanical properties of dsDNA film on a substrate, and the end effect (i.e. terminal group effect) makes self-assembling dsDNA film stiffer in the sense of the same average packing density.

Oxytocin receptor gene variation predicts subjective responses to MDMA.

PubMed

Bershad, Anya K; Weafer, Jessica J; Kirkpatrick, Matthew G; Wardle, Margaret C; Miller, Melissa A; de Wit, Harriet

2016-12-01

3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") enhances desire to socialize and feelings of empathy, which are thought to be related to increased oxytocin levels. Thus, variation in the oxytocin receptor gene (OXTR) may influence responses to the drug. Here, we examined the influence of a single OXTR nucleotide polymorphism (SNP) on responses to MDMA in humans. Based on findings that carriers of the A allele at rs53576 exhibit reduced sensitivity to oxytocin-induced social behavior, we hypothesized that these individuals would show reduced subjective responses to MDMA, including sociability. In this three-session, double blind, within-subjects study, healthy volunteers with past MDMA experience (N = 68) received a MDMA (0, 0.75 mg/kg, and 1.5 mg/kg) and provided self-report ratings of sociability, anxiety, and drug effects. These responses were examined in relation to rs53576. MDMA (1.5 mg/kg) did not increase sociability in individuals with the A/A genotype as it did in G allele carriers. The genotypic groups did not differ in responses at the lower MDMA dose, or in cardiovascular or other subjective responses. These findings are consistent with the idea that MDMA-induced sociability is mediated by oxytocin, and that variation in the oxytocin receptor gene may influence responses to the drug.

Oxytocin receptor gene variation predicts subjective responses to MDMA

PubMed Central

Bershad, Anya K.; Weafer, Jessica J.; Kirkpatrick, Matthew G.; Wardle, Margaret C.; Miller, Melissa A.; de Wit, Harriet

2016-01-01

3,4-Methylenedioxymethamphetamine (MDMA, “ecstasy”) enhances desire to socialize and feelings of empathy, which are thought to be related to increased oxytocin levels. Thus, variation in the oxytocin receptor gene (OXTR) may influence responses to the drug. Here, we examined the influence of a single OXTR nucleotide polymorphism (SNP) on responses to MDMA in humans. Based on findings that carriers of the A allele at rs53576 exhibit reduced sensitivity to oxytocin-induced social behavior, we hypothesized that these individuals would show reduced subjective responses to MDMA, including sociability. In this three-session, double blind, within-subjects study, healthy volunteers with past MDMA experience (N = 68) received a MDMA (0, 0.75 mg/kg, and 1.5 mg/kg) and provided self-report ratings of sociability, anxiety, and drug effects. These responses were examined in relation to rs53576. MDMA (1.5 mg/kg) did not increase sociability in individuals with the A/A genotype as it did in G allele carriers. The genotypic groups did not differ in responses at the lower MDMA dose, or in cardiovascular or other subjective responses. These findings are consistent with the idea that MDMA-induced sociability is mediated by oxytocin, and that variation in the oxytocin receptor gene may influence responses to the drug. PMID:26787430

An efficient variational method to study the denaturation of DNA induced by superhelical stress

NASA Astrophysics Data System (ADS)

Jost, Daniel; Everaers, Ralf

2010-03-01

Many fundamental biological processes, like transcription or replication, need the opening of the double-stranded DNA. One common way to control the local denaturation is to impose superhelical stress to the DNA using protein machineries. To describe superhelical effect for circular molecules, Benham introduced a model where the standard thermodynamic description of base-pairing is coupled with torsional stress energetics. Here, we introduce an efficient mean-field approximation of the Benham model. Our self-consistent solution is confident and computationally-fast, compared to the full treatment of the model. In particular, our formulation allows to compute the probability of bubble formation for given length and position along the sequence. Evolution of this probability as a function of the superhelical stress could inform us on the ability for organisms to control the strength of superhelicity acting on their genomes.

Gas Chromatographic Determination of Fatty Acids in Oils with Regard to the Assessment of Fire Hazard

NASA Astrophysics Data System (ADS)

Bartošová, Alica; Štefko, Tomáš

2017-06-01

The aim of the paper was to study and research the application of processing gas chromatographic method for the rapid and accurate determination of the composition of different types of oils, such as substances with the possibility of an adverse event spontaneous combustion or self-heating. Tendency to spontaneous combustion is chemically characterized mainly by the amount of unsaturated fatty acids, which have one or more double bonds in their molecule. Vegetable oils essentially consist of the following fatty acids: palmitic, stearic, oleic, linoleic, and linoleic. For the needs of assessment, the fire hazard must be known, in which the double bond is present, as well as their number in a molecule. As an analytical method, GCMS was used for determination of oils content. Three types of oil were used - rapeseed, sunflower, and coconut oil. Owing to the occurrence of linoleic acid C18:2 (49.8 wt.%) and oleic acid C18:1 (43.3 wt.%) with double bonds, sunflower oil is the most prone to self-heating. The coconut and rapeseed oils contain double bond FAME in lesser amount, and their propensity to self-heating is relatively low.

Random phenotypic variation of yeast (Saccharomyces cerevisiae) single-gene knockouts fits a double pareto-lognormal distribution.

PubMed

Graham, John H; Robb, Daniel T; Poe, Amy R

2012-01-01

Distributed robustness is thought to influence the buffering of random phenotypic variation through the scale-free topology of gene regulatory, metabolic, and protein-protein interaction networks. If this hypothesis is true, then the phenotypic response to the perturbation of particular nodes in such a network should be proportional to the number of links those nodes make with neighboring nodes. This suggests a probability distribution approximating an inverse power-law of random phenotypic variation. Zero phenotypic variation, however, is impossible, because random molecular and cellular processes are essential to normal development. Consequently, a more realistic distribution should have a y-intercept close to zero in the lower tail, a mode greater than zero, and a long (fat) upper tail. The double Pareto-lognormal (DPLN) distribution is an ideal candidate distribution. It consists of a mixture of a lognormal body and upper and lower power-law tails. If our assumptions are true, the DPLN distribution should provide a better fit to random phenotypic variation in a large series of single-gene knockout lines than other skewed or symmetrical distributions. We fit a large published data set of single-gene knockout lines in Saccharomyces cerevisiae to seven different probability distributions: DPLN, right Pareto-lognormal (RPLN), left Pareto-lognormal (LPLN), normal, lognormal, exponential, and Pareto. The best model was judged by the Akaike Information Criterion (AIC). Phenotypic variation among gene knockouts in S. cerevisiae fits a double Pareto-lognormal (DPLN) distribution better than any of the alternative distributions, including the right Pareto-lognormal and lognormal distributions. A DPLN distribution is consistent with the hypothesis that developmental stability is mediated, in part, by distributed robustness, the resilience of gene regulatory, metabolic, and protein-protein interaction networks. Alternatively, multiplicative cell growth, and the mixing of lognormal distributions having different variances, may generate a DPLN distribution.

Inkjet Assisted Creation of Self-Healing Layers Between Composite Plies

DTIC Science & Technology

2013-07-29

technology into a prepreg manufacturing process. The approach consisted of depositing novel thermoplastic low-viscosity microdroplets with chemically and...mechanically comparable properties to epoxy matrix in aerospace grade composites onto fiber-reinforced epoxy prepregs before curing using an ink-jet... prepreg Cycom977-2. Double cantilever beam (DCB) and short beam shear (SBS) tests were used to evaluate the self-healing efficiency. It was shown

Theoretical nuclear physics

NASA Astrophysics Data System (ADS)

Rost, E.; Shephard, J. R.

1992-08-01

This report discusses the following topics: Exact 1-loop vacuum polarization effects in 1 + 1 dimensional QHD; exact 1-fermion loop contributions in 1 + 1 dimensional solitons; exact scalar 1-loop contributions in 1 + 3 dimensions; exact vacuum calculations in a hyper-spherical basis; relativistic nuclear matter with self-consistent correlation energy; consistent RHA-RPA for finite nuclei; transverse response functions in the (triangle)-resonance region; hadronic matter in a nontopological soliton model; scalar and vector contributions to (bar p)p yields (bar lambda)lambda reaction; 0+ and 2+ strengths in pion double-charge exchange to double giant-dipole resonances; and nucleons in a hybrid sigma model including a quantized pion field.

Measurement of isotope abundance variations in nature by gravimetric spiking isotope dilution analysis (GS-IDA).

PubMed

Chew, Gina; Walczyk, Thomas

2013-04-02

Subtle variations in the isotopic composition of elements carry unique information about physical and chemical processes in nature and are now exploited widely in diverse areas of research. Reliable measurement of natural isotope abundance variations is among the biggest challenges in inorganic mass spectrometry as they are highly sensitive to methodological bias. For decades, double spiking of the sample with a mix of two stable isotopes has been considered the reference technique for measuring such variations both by multicollector-inductively coupled plasma mass spectrometry (MC-ICPMS) and multicollector-thermal ionization mass spectrometry (MC-TIMS). However, this technique can only be applied to elements having at least four stable isotopes. Here we present a novel approach that requires measurement of three isotope signals only and which is more robust than the conventional double spiking technique. This became possible by gravimetric mixing of the sample with an isotopic spike in different proportions and by applying principles of isotope dilution for data analysis (GS-IDA). The potential and principle use of the technique is demonstrated for Mg in human urine using MC-TIMS for isotopic analysis. Mg is an element inaccessible to double spiking methods as it consists of three stable isotopes only and shows great potential for metabolically induced isotope effects waiting to be explored.

SCF and CI calculations of the dipole moment function of ozone. [Self-Consistent Field and Configuration-Interaction

NASA Technical Reports Server (NTRS)

Curtiss, L. A.; Langhoff, S. R.; Carney, G. D.

1979-01-01

The constant and linear terms in a Taylor series expansion of the dipole moment function of the ground state of ozone are calculated with Cartesian Gaussian basis sets ranging in quality from minimal to double zeta plus polarization. Results are presented at both the self-consistent field and configuration-interaction levels. Although the algebraic signs of the linear dipole moment derivatives are all established to be positive, the absolute magnitudes of these quantities, as well as the infrared intensities calculated from them, vary considerably with the level of theory.

Faraday rotation measure variations in the Cygnus region and the spectrum of interstellar plasma turbulence

NASA Technical Reports Server (NTRS)

Lazio, T. Joseph; Spangler, Steven R.; Cordes, James M.

1990-01-01

Linear polarization observations were made of eight double-lobed radio galaxies viewed through the galactic plane in the Cygnus region. These observations have been used to determine intra- and intersource rotation measure differences; in some cases, unambiguous rotation measures have been extracted. The rotation measures are dominated by foreground magnetoionic material. The differences in rotation measure between pairs of sources correlate with angular separation for separations from 10 arcsec to 1.5 deg. These rotation measure fluctuations are consistent with a model in which the electron density varies on roughly 0.1-200 pc scales. The amplitudes of these variations are, in turn, consistent with those electron density variations that cause diffractive interstellar scattering on scales less than 10 to the 11th cm.

The doubling of stellar black hole nuclei

NASA Astrophysics Data System (ADS)

Kazandjian, Mher V.; Touma, J. R.

2013-04-01

It is strongly believed that Andromeda's double nucleus signals a disc of stars revolving around its central supermassive black hole on eccentric Keplerian orbits with nearly aligned apsides. A self-consistent stellar dynamical origin for such apparently long-lived alignment has so far been lacking, with indications that cluster self-gravity is capable of sustaining such lopsided configurations if and when stimulated by external perturbations. Here, we present results of N-body simulations which show unstable counter-rotating stellar clusters around supermassive black holes saturating into uniformly precessing lopsided nuclei. The double nucleus in our featured experiment decomposes naturally into a thick eccentric disc of apo-apse aligned stars which is embedded in a lighter triaxial cluster. The eccentric disc reproduces key features of Keplerian disc models of Andromeda's double nucleus; the triaxial cluster has a distinctive kinematic signature which is evident in Hubble Space Telescope observations of Andromeda's double nucleus, and has been difficult to reproduce with Keplerian discs alone. Our simulations demonstrate how the combination of an eccentric disc and a triaxial cluster arises naturally when a star cluster accreted over a preexisting and counter-rotating disc of stars drives disc and cluster into a mutually destabilizing dance. Such accretion events are inherent to standard galaxy formation scenarios. They are here shown to double stellar black hole nuclei as they feed them.

Chemically Doped Double-Walled Carbon Nanotubes: Cylindrical Molecular Capacitors

NASA Astrophysics Data System (ADS)

Chen, Gugang; Bandow, S.; Margine, E. R.; Nisoli, C.; Kolmogorov, A. N.; Crespi, Vincent H.; Gupta, R.; Sumanasekera, G. U.; Iijima, S.; Eklund, P. C.

2003-06-01

A double-walled carbon nanotube is used to study the radial charge distribution on the positive inner electrode of a cylindrical molecular capacitor. The outer electrode is a shell of bromine anions. Resonant Raman scattering from phonons on each carbon shell reveals the radial charge distribution. A self-consistent tight-binding model confirms the observed molecular Faraday cage effect, i.e., most of the charge resides on the outer wall, even when this wall was originally semiconducting and the inner wall was metallic.

Chemically doped double-walled carbon nanotubes: cylindrical molecular capacitors.

PubMed

Chen, Gugang; Bandow, S; Margine, E R; Nisoli, C; Kolmogorov, A N; Crespi, Vincent H; Gupta, R; Sumanasekera, G U; Iijima, S; Eklund, P C

2003-06-27

A double-walled carbon nanotube is used to study the radial charge distribution on the positive inner electrode of a cylindrical molecular capacitor. The outer electrode is a shell of bromine anions. Resonant Raman scattering from phonons on each carbon shell reveals the radial charge distribution. A self-consistent tight-binding model confirms the observed molecular Faraday cage effect, i.e., most of the charge resides on the outer wall, even when this wall was originally semiconducting and the inner wall was metallic.

Identification of the formation of metal-vinylidene interfacial bonds of alkyne-capped platinum nanoparticles by isotopic labeling.

PubMed

Hu, Peiguang; Chen, Limei; Deming, Christopher P; Bonny, Lewis W; Lee, Hsiau-Wei; Chen, Shaowei

2016-10-07

Stable platinum nanoparticles were prepared by the self-assembly of 1-dodecyne and dodec-1-deuteroyne onto bare platinum colloid surfaces. The nanoparticles exhibited consistent core size and optical properties. FTIR and NMR measurements confirmed the formation of Pt-vinylidene (Pt[double bond, length as m-dash]C[double bond, length as m-dash]CH-) interfacial linkages rather than Pt-acetylide (Pt-C[triple bond, length as m-dash]C-) and platinum-hydride (Pt-H) bonds.

Inversion of Solid Earth's Varying Shape 2: Using Self-Consistency to Infer Static Ocean Topography

NASA Astrophysics Data System (ADS)

Blewitt, G.; Clarke, P. J.

2002-12-01

We have developed a spectral approach to invert for the redistribution of mass on the Earth's surface given precise global geodetic measurements of the solid Earth's geometrical shape. We used the elastic load Love number formalism to characterize the redistributed mass as a spherical harmonic expansion, truncated at some degree and order n. [Clarke and Blewitt, this meeting]. Here we incorporate the additional physical constraint that the sea surface in hydrostatic equilibrium corresponds to an equipotential surface, to infer the non-steric component of static ocean topography. Our model rigorously accounts for self-gravitation of the ocean, continental surface mass, and the deformed solid Earth, such that the sea surface adopts a new equipotential surface consistent with ocean-land mass exchange, deformation of the geoid, deformation of the sea floor, and the geographical configuration of the oceans and continents. We develop a self-consistent spectral inversion method to solve for the distribution of continental surface mass that would generate geographic variations in relative mean sea level such that the total (ocean plus continental) mass distribution agrees with the original geodetic estimates to degree and order n. We apply this theory to study the contribution of seasonal inter-hemispheric (degree-1) mass transfer to seasonal variation in static ocean topography, using a published empirical seasonal model for degree-1 surface loading derived using GPS coordinate time series from the global IGS network [Blewitt et al., Science 294, 2,342-2,345, 2001]. The resulting predictions of seasonal variations of relative sea level strongly depend on location, with peak variations ranging from 3 mm to 19 mm. The largest peak variations are predicted in mid-August around Antarctica and the southern hemisphere in general; the lowest variations are predicted in the northern hemisphere. Corresponding maximum continental loading occurs in Canada and Siberia at the water-equivalent level of 200 mm. The RMS spatial variability about global mean sea level at any given time is 20% for geocentric sea level (as measured by satellite altimetry) versus relative sea level, which is a consequence of degree-1 sea floor displacement in the center of figure frame. While land-ocean mass exchange governs global mean relative sea level, at any given point the contribution of geoid deformation to relative sea level can be of similar magnitude, and so can almost cancel or double the effect of change in global mean sea level.While the sea surface takes on the shape of the deformed geoid, the sea surface everywhere seasonally oscillates about the deformed geoid with annual amplitude 6.1 mm. This effect is due mainly to an 8.0+/- 0.7~mm contribution from land-ocean mass exchange, which is then reduced by a 1.9 mm seasonal variation in the mean geoid height above the sea floor (to which a mass-conserved ocean cannot respond). Of this, 0.4 mm is due to the mean geocentric height of the sea floor, and 1.5 mm is due to the mean geocentric height of the geoid over oceanic areas. The seasonal gradients predicted by our inversion might be misinterpreted as basin-scale dynamics. Also, the oceans amplify a land degree-1 load by 20--30%, which suggests that deformation (and models of geocenter displacements) would be sensitive to the accuracy of ocean bottom pressure, particularly in the southern hemisphere.

Two-dimensional collective electron magnetotransport, oscillations, and chaos in a semiconductor superlattice

NASA Astrophysics Data System (ADS)

Bonilla, L. L.; Carretero, M.; Segura, A.

2017-12-01

When quantized, traces of classically chaotic single-particle systems include eigenvalue statistics and scars in eigenfuntions. Since 2001, many theoretical and experimental works have argued that classically chaotic single-electron dynamics influences and controls collective electron transport. For transport in semiconductor superlattices under tilted magnetic and electric fields, these theories rely on a reduction to a one-dimensional self-consistent drift model. A two-dimensional theory based on self-consistent Boltzmann transport does not support that single-electron chaos influences collective transport. This theory agrees with existing experimental evidence of current self-oscillations, predicts spontaneous collective chaos via a period doubling scenario, and could be tested unambiguously by measuring the electric potential inside the superlattice under a tilted magnetic field.

Two-dimensional collective electron magnetotransport, oscillations, and chaos in a semiconductor superlattice.

PubMed

Bonilla, L L; Carretero, M; Segura, A

2017-12-01

When quantized, traces of classically chaotic single-particle systems include eigenvalue statistics and scars in eigenfuntions. Since 2001, many theoretical and experimental works have argued that classically chaotic single-electron dynamics influences and controls collective electron transport. For transport in semiconductor superlattices under tilted magnetic and electric fields, these theories rely on a reduction to a one-dimensional self-consistent drift model. A two-dimensional theory based on self-consistent Boltzmann transport does not support that single-electron chaos influences collective transport. This theory agrees with existing experimental evidence of current self-oscillations, predicts spontaneous collective chaos via a period doubling scenario, and could be tested unambiguously by measuring the electric potential inside the superlattice under a tilted magnetic field.

Disorder induced magnetism and electrical conduction in La doped Ca2FeMoO6 double perovskite

NASA Astrophysics Data System (ADS)

Poddar, Asok; Bhowmik, R. N.; Muthuselvam, I. Panneer

2010-11-01

We report the magnetism and electrical transport properties of La doped Ca2FeMoO6 double perovskite. Reduction in magnetic moment, nonmonotonic variation in magnetic ordering temperature (TC), increasing magnetic hardness, low temperature resistivity upturn, and loss of metallic conductivity are some of the major changes that we observed due to La doping induced disorder in double perovskite structure. The increase in magnetic disorder in La doped samples and its effect on TC is more consistent with the mean field theory. The modification in electronic band structure due to La doping is understood by establishing a correlation between the temperature dependence of electrical conductivity and thermoelectric power.

A fluid description of plasma double-layers

NASA Technical Reports Server (NTRS)

Levine, J. S.; Crawford, F. W.

1979-01-01

The space-charge double-layer that forms between two plasmas with different densities and thermal energies was investigated using three progressively realistic models which are treated by fluid theory, and take into account four species of particles: electrons and ions reflected by the double-layer, and electrons and ions transmitted through it. The two plasmas are assumed to be cold, and the self-consistent potential, electric field and space-charge distributions within the double-layer are determined. The effects of thermal velocities are taken into account for the reflected particles, and the modifications to the cold plasma solutions are established. Further modifications due to thermal velocities of the transmitted particles are examined. The applicability of a one dimensional fluid description, rather than plasma kinetic theory, is discussed. Theoretical predictions are compared with double layer potentials and lengths deduced from laboratory and space plasma experiments.

Spontaneous formation of non-uniform double helices for elastic rods under torsion

NASA Astrophysics Data System (ADS)

Li, Hongyuan; Zhao, Shumin; Xia, Minggang; He, Siyu; Yang, Qifan; Yan, Yuming; Zhao, Hanqiao

2017-02-01

The spontaneous formation of double helices for filaments under torsion is common and significant. For example, the research on the supercoiling of DNA is helpful for understanding the replication and transcription of DNA. Similar double helices can appear in carbon nanotube yarns, cables, telephone wires and so forth. We noticed that non-uniform double helices can be produced due to the surface friction induced by the self-contact. Therefore an ideal model was presented to investigate the formation of double helices for elastic rods under torque. A general equilibrium condition which is valid for both the smooth surface and the rough surface situations is derived by using the variational method. By adding further constraints, the smooth and rough surface situations are investigated in detail respectively. Additionally, the model showed that the specific process of how to twist and slack the rod can determine the surface friction and hence influence the configuration of the double helix formed by rods with rough surfaces. Based on this principle, a method of manufacturing double helices with designed configurations was proposed and demonstrated. Finally, experiments were performed to verify the model and the results agreed well with the theory.

Barotropic instability with divergence - Theory and applications to Venus

NASA Technical Reports Server (NTRS)

Dobrovolskis, Anthony R.; Diner, David J.

1990-01-01

IR images of Venus reveal a curious double-lobed hot spot in the polar region. Elson (1982) has suggested that this dipole represents a barotropic instability associated with a high-latitude jet. Unfortunately, the classical theory of barotropic instability cannot predict temperature variations. This paper generalizes the theory to include horizontal divergence, vertical motions, and temperature variations, and applies it to the stratosphere of Venus. The fastest-growing barotropic instability in the nominal model matches the observed dipole in period and horizontal temperature pattern. The accompanying wind variations are comparable to the speed of the mean jet, indicating strong nonlinear effects. It is concluded that the Venus dipole may represent the self-limited stage of a barotropic instability with divergence.

The effectiveness of nutrition education for overweight/obese mothers with stunted children (NEO-MOM) in reducing the double burden of malnutrition in Indonesia: study protocol for a randomized controlled trial.

PubMed

Mahmudiono, Trias; Nindya, Triska Susila; Andrias, Dini Ririn; Megatsari, Hario; Rosenkranz, Richard R

2016-06-08

Nutrition transition in developing countries were induced by rapid changes in food patterns and nutrient intake when populations adopt modern lifestyles during economic and social development, urbanization and acculturation. Consequently, these countries suffer from the double burden of malnutrition, consisting of unresolved undernutrition and the rise of overweight/obesity. The prevalence of the double burden of malnutrition tends to be highest for moderate levels (third quintile) of socioeconomic status. Evidence suggests that modifiable factors such as intra-household food distribution and dietary diversity are associated with the double burden of malnutrition, given household food security. This article describes the study protocol of a behaviorally based nutrition education intervention for overweight/obese mothers with stunted children (NEO-MOM) in reducing the double burden of malnutrition. NEO-MOM is a randomized controlled trial with a three-month behavioral intervention for households involving pairs of 72 stunted children aged 2-5 years old and overweight/obese mothers (SCOWT) in urban Indonesia. The SCOWT pairs were randomly assigned to either an intervention group or to a comparison group that received usual care plus printed educational materials. The intervention consisted of six classroom sessions on nutrition education and home visits performed by trained community health workers using a motivational interviewing approach. The primary outcomes of this study are the prevalence of double burden of malnutrition as measured in SCOWT, child's height-for-age z-score (HAZ) and maternal body mass index (BMI). Because previous studies are mainly observational in nature, this study advances understanding of the double burden of malnutrition through a fully powered randomized controlled trial. The intervention assists participants in self-administered goal setting to improve diet and child feeding behaviors by improving self-efficacy. Maternal self-efficacy may be enhanced through vicarious and active mastery of experiences gained during six sessions of nutrition education and verbal persuasion during home visits. The Universal Trial Number (UTN) for this study is U1111-1175-5834. This trial was registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) and is allocated the registration number: ACTRN12615001243505 on 12 November 2015.

A neural-network-based approach to the double traveling salesman problem.

PubMed

Plebe, Alessio; Anile, Angelo Marcello

2002-02-01

The double traveling salesman problem is a variation of the basic traveling salesman problem where targets can be reached by two salespersons operating in parallel. The real problem addressed by this work concerns the optimization of the harvest sequence for the two independent arms of a fruit-harvesting robot. This application poses further constraints, like a collision-avoidance function. The proposed solution is based on a self-organizing map structure, initialized with as many artificial neurons as the number of targets to be reached. One of the key components of the process is the combination of competitive relaxation with a mechanism for deleting and creating artificial neurons. Moreover, in the competitive relaxation process, information about the trajectory connecting the neurons is combined with the distance of neurons from the target. This strategy prevents tangles in the trajectory and collisions between the two tours. Results of tests indicate that the proposed approach is efficient and reliable for harvest sequence planning. Moreover, the enhancements added to the pure self-organizing map concept are of wider importance, as proved by a traveling salesman problem version of the program, simplified from the double version for comparison.

Quantum-continuum simulation of the electrochemical response of pseudocapacitor electrodes under realistic conditions

NASA Astrophysics Data System (ADS)

Keilbart, Nathan; Okada, Yasuaki; Feehan, Aion; Higai, Shin'ichi; Dabo, Ismaila

2017-03-01

Pseudocapacitors are energy-storage devices characterized by fast and reversible redox reactions that enable them to store large amounts of electrical energy at high rates. We simulate the response of pseudocapacitive electrodes under realistic conditions to identify the microscopic factors that determine their performance, focusing on ruthenia (RuO2) as a prototypical electrode material. Electronic-structure methods are used together with a self-consistent continuum solvation (SCCS) model to build a complete data set of free energies as the surface of the charged electrode is gradually covered with protons under applied voltage. The resulting data set is exploited to compute hydrogen-adsorption isotherms and charge-voltage responses by means of grand-canonical sampling, finding close agreement with experimental voltammetry. These simulations reveal that small changes on the order of 5 μ F /cm2 in the intrinsic double-layer capacitance of the electrode-electrolyte interface can induce variations of up to 40 μ F /cm2 in the overall pseudocapacitance.

Electrostatic Structure and Double-Probe Performance in Tenuous Plasmas

NASA Astrophysics Data System (ADS)

Cully, C. M.; Ergun, R. E.

2006-12-01

Many in-situ plasma instruments are affected by the local electrostatic structure surrounding the spacecraft. In order to better understand this structure, we have developed a fully 3-dimensional self-consistent model that uses realistic spacecraft geometry, including thin (<1 mm) wires and long (>100m) booms, with open boundary conditions. One of the more surprising results is that in tenuous plasmas, the charge on the booms can dominate over the charge on the spacecraft body. For instruments such as electric field double probes and boom-mounted low-energy particle detectors, this challenges the existing paradigm: long booms do not allow the probes to escape the spacecraft potential. Instead, the potential structure simply expands as the boom is deployed. We then apply our model to the double-probe Electric Field and Waves (EFW) instruments on Cluster, and predict the magnitudes of the main error sources. The overall error budget is consistent with experiment, and the model yields some additional interesting insights. We show that the charge in the photoelectron cloud is relatively unimportant, and that the spacecraft potential is typically underestimated by about 20% by double-probe experiments.

Spatial and Temporal Variations of a Screening Current Induced Magnetic Field in a Double-Pancake HTS Insert of an LTS/HTS NMR Magnet

PubMed Central

Ahn, Min Cheol; Yagai, Tsuyoshi; Hahn, Seungyong; Ando, Ryuya; Bascuñán, Juan; Iwasa, Yukikazu

2010-01-01

This paper presents experimental and simulation results of a screening current induced magnetic field (SCF) in a high temperature superconductor (HTS) insert that constitutes a low-/high-temperature superconductor (LTS/HTS) NMR magnet. In this experiment, the HTS insert, a stack of 50 double-pancake coils, each wound with Bi2223 tape, was operated at 77 K. A screening current was induced in the HTS insert by three magnetic field sources: 1) a self field from the HTS insert; 2) an external field from a 5-T background magnet; and 3) combinations of 1) and 2). For each field excitation, which induced an SCF, its axial field distribution and temporal variations were measured and compared with simulation results based on the critical state model. Agreement on field profile between experiment and simulation is satisfactory but more work is needed to make the simulation useful for designing shim coils that will cancel the SCF. PMID:20401187

Self-consistent field model for strong electrostatic correlations and inhomogeneous dielectric media.

PubMed

Ma, Manman; Xu, Zhenli

2014-12-28

Electrostatic correlations and variable permittivity of electrolytes are essential for exploring many chemical and physical properties of interfaces in aqueous solutions. We propose a continuum electrostatic model for the treatment of these effects in the framework of the self-consistent field theory. The model incorporates a space- or field-dependent dielectric permittivity and an excluded ion-size effect for the correlation energy. This results in a self-energy modified Poisson-Nernst-Planck or Poisson-Boltzmann equation together with state equations for the self energy and the dielectric function. We show that the ionic size is of significant importance in predicting a finite self energy for an ion in an inhomogeneous medium. Asymptotic approximation is proposed for the solution of a generalized Debye-Hückel equation, which has been shown to capture the ionic correlation and dielectric self energy. Through simulating ionic distribution surrounding a macroion, the modified self-consistent field model is shown to agree with particle-based Monte Carlo simulations. Numerical results for symmetric and asymmetric electrolytes demonstrate that the model is able to predict the charge inversion at high correlation regime in the presence of multivalent interfacial ions which is beyond the mean-field theory and also show strong effect to double layer structure due to the space- or field-dependent dielectric permittivity.

Phase-field approach to implicit solvation of biomolecules with Coulomb-field approximation

NASA Astrophysics Data System (ADS)

Zhao, Yanxiang; Kwan, Yuen-Yick; Che, Jianwei; Li, Bo; McCammon, J. Andrew

2013-07-01

A phase-field variational implicit-solvent approach is developed for the solvation of charged molecules. The starting point of such an approach is the representation of a solute-solvent interface by a phase field that takes one value in the solute region and another in the solvent region, with a smooth transition from one to the other on a small transition layer. The minimization of an effective free-energy functional of all possible phase fields determines the equilibrium conformations and free energies of an underlying molecular system. All the surface energy, the solute-solvent van der Waals interaction, and the electrostatic interaction are coupled together self-consistently through a phase field. The surface energy results from the minimization of a double-well potential and the gradient of a field. The electrostatic interaction is described by the Coulomb-field approximation. Accurate and efficient methods are designed and implemented to numerically relax an underlying charged molecular system. Applications to single ions, a two-plate system, and a two-domain protein reveal that the new theory and methods can capture capillary evaporation in hydrophobic confinement and corresponding multiple equilibrium states as found in molecular dynamics simulations. Comparisons of the phase-field and the original sharp-interface variational approaches are discussed.

Charging in the ac Conductance of a Double Barrier Resonant Tunneling Structure

NASA Technical Reports Server (NTRS)

Anantram, M. P.; Saini, Subhash (Technical Monitor)

1998-01-01

There have been many studies of the linear response ac conductance of a double barrier resonant tunneling structure (DBRTS), both at zero and finite dc biases. While these studies are important, they fail to self consistently include the effect of the time dependent charge density in the well. In this paper, we calculate the ac conductance at both zero and finite do biases by including the effect of the time dependent charge density in the well in a self consistent manner. The charge density in the well contributes to both the flow of displacement currents in the contacts and the time dependent potential in the well. We find that including these effects can make a significant difference to the ac conductance and the total ac current is not equal to the simple average of the non-selfconsistently calculated conduction currents in the two contacts. This is illustrated by comparing the results obtained with and without the effect of the time dependent charge density included correctly. Some possible experimental scenarios to observe these effects are suggested.

The convergence of complete active space self-consistent-field configuration interaction including all single and double excitation energies to the complete basis set limit

NASA Astrophysics Data System (ADS)

Petersson, George A.; Malick, David K.; Frisch, Michael J.; Braunstein, Matthew

2006-07-01

Examination of the convergence of full valence complete active space self-consistent-field configuration interaction including all single and double excitation (CASSCF-CISD) energies with expansion of the one-electron basis set reveals a pattern very similar to the convergence of single determinant energies. Calculations on the lowest four singlet states and the lowest four triplet states of N2 with the sequence of n-tuple-ζ augmented polarized (nZaP) basis sets (n =2, 3, 4, 5, and 6) are used to establish the complete basis set limits. Full configuration-interaction (CI) and core electron contributions must be included for very accurate potential energy surfaces. However, a simple extrapolation scheme that has no adjustable parameters and requires nothing more demanding than CAS(10e -,8orb)-CISD/3ZaP calculations gives the Re, ωe, ωeXe, Te, and De for these eight states with rms errors of 0.0006Å, 4.43cm-1, 0.35cm-1, 0.063eV, and 0.018eV, respectively.

Development of Self-Potential Tomography for Early Warning System of rainfall induced Landslides: Electro-kinetic Effects and Sandbox Experiments

NASA Astrophysics Data System (ADS)

Hattori, K.; Yamazaki, T.; Terajima, T.; Huang, Q.

2017-12-01

Electro-kinetic effects is one of the possible mechanism for ULF electromagnetic phenomena preceeding landlisdes and large earthquakes. To understand general tendencies of electromagnetic changes related to electro-kinetic effects, we struggle with the integrated research to clarify the coupling among hydrological, geotechnical, and electromagnetic changes. Our final goal is to understand the ULF elecromagnetic phenomena in order to develop a simple technology for earthquake monitoring/forecasting. So, in this paper, we first show the observed waveforms possibly related to the Boso slow slip events in 2003 and 2007 and indoor landslide experiments with artificial rainfall. Then, numerical computations on the self-potential variation by the simulated groundwater flow, and compare the results with those observed by laboratory experiments. In the result, the simulated self-potential variation is consistent with observed one. FInally, we developed self-potential tomography to estimate the ground water condition. And we also characterize the pressure from the self-potential data, and compare the result with observed pressure head that is measured by pore-pressure gauge and found that the inverted pressure head is consistent with observed one. In addition, we apply the self-potential data observed by the flume test. The estimated pressure head from observed self-potential data shows the consistency with observed pressure head. And estimated pressure head also show the characteristic distribution before the landslide occurred. These facts are highly suggestive in effectiveness of the self-potential tomography to monitor groundwater changes associated with landslide. The details will be given in our presentation.

Electric double-layer capacitor based on zinc metaphosphate glass-derived hydrogel

NASA Astrophysics Data System (ADS)

Akamatsu, Takafumi; Kasuga, Toshihiro; Nogami, Masayuki

2006-04-01

The present work reports the electrochemical characteristics of an electric double-layer capacitor (EDC) cell with an electrolyte consisting of a glass-derived zinc metaphosphate hydrogel (ZP gel) or H3PO4 solution. The EDC cell showed specific discharge capacities of 2.06 and 3.21F/g using the ZP gel and H3PO4 solution, respectively. The EDC cell performed higher voltage retentionability for self-discharge behavior after constant voltage using the ZP gel (0.83V after 24h) than using H3PO4 solution (0.45V after 24h). Self-discharge behaviors of the ZP gel and H3PO4 solution were controlled by a diffusion and current leakage process, respectively. These results show that the ZP gel has a great potential for practical use as an EDC electrolyte.

Self Modeling: Expanding the Theories of Learning

ERIC Educational Resources Information Center

Dowrick, Peter W.

2012-01-01

Self modeling (SM) offers a unique expansion of learning theory. For several decades, a steady trickle of empirical studies has reported consistent evidence for the efficacy of SM as a procedure for positive behavior change across physical, social, educational, and diagnostic variations. SM became accepted as an extreme case of model similarity;…

A pilot study into a possible relationship between diet and stuttering.

PubMed

Hum, Jean; Rietveld, Toni; Wiedijk, Piet; van Lieshout, Pascal

2017-06-01

There are theoretical and empirical reasons to consider a potential role for copper metabolism in the brain in how it could influence stuttering. However, a link between stuttering and dietary intake has never been researched in a systematic way. This pilot study therefore aimed to explore a possible association between ingested amounts of copper and thiamine (vitamin B1) with stuttering frequency using a double blind cross-over longitudinal paradigm. 19 adults who stutter between 20 and 51 years old filled out an online survey for 9 consecutive weeks. The survey consisted of self-assessed fluency and mood state scales, as well as food journals. After 4 weeks, the participants consumed either copper or thiamine supplements for 2 weeks, followed by a 1-week washout period, and another period of two weeks taking the other supplement. Formal speech assessments were done pre/post baseline and at the end of each supplement intake. Participants were not informed about the nature of the supplements during the experiment and the investigators were blinded to the order of the supplements. The results demonstrated that copper and thiamine had no measurable effect on the amount of stuttering (self and formal assessments) but there was a moderate, significant correlation between mood state and fluency. The findings do not support notions of dietary influences of ingested copper or thiamine on stuttering but do provide modest support for a relationship between variations in stuttering and self-perceived anxiety. Copyright © 2017 Elsevier Inc. All rights reserved.

Design of the forward straw tube tracker for the PANDA experiment

NASA Astrophysics Data System (ADS)

Smyrski, J.; Apostolou, A.; Biernat, J.; Czyżycki, W.; Filo, G.; Fioravanti, E.; Fiutowski, T.; Gianotti, P.; Idzik, M.; Korcyl, G.; Korcyl, K.; Lisowski, E.; Lisowski, F.; Płażek, J.; Przyborowski, D.; Przygoda, W.; Ritman, J.; Salabura, P.; Savrie, M.; Strzempek, P.; Swientek, K.; Wintz, P.; Wrońska, A.

2017-06-01

The design of the Forward Tracker for the Forward Spectrometer of the PANDA experiment is described. The tracker consists of 6 tracking stations, each comprising 4 planar double layers of straw tube detectors, and has a total material budget of only 2% X0. The straws are made self-supporting by a 1 bar over-pressure of the working gas mixture (Ar/CO2). This allows to use lightweight and compact rectangular support frames for the double layers and to split the frames into pairs of C-shaped half-frames for an easier installation on the beam line.

Present-day secular variations in the zonal harmonics of earth's geopotential

NASA Technical Reports Server (NTRS)

Mitrovica, J. X.; Peltier, W. R.

1993-01-01

The mathematical formulation required for predicting secular variation in the geopotential is developed for the case of a spherically symmetric, self-gravitating, viscoelastic earth model and an arbitrary surface load which can include a gravitational self-consistent ocean loading component. The theory is specifically applied to predict the present-day secular variation in the zonal harmonics of the geopotenial arising from the surface mass loading associated with the late Pleistocene glacial cycles. A procedure is outlined in which predictions of the present-day geopotential signal due to the late Pleistocene glacial cycles may be used to derive bounds on the net present-day mass flux from the Antarctic and Greenland ice sheets to the local oceans.

Alphavirus-based DNA vaccine breaks immunological tolerance by activating innate antiviral pathways

PubMed Central

Leitner, Wolfgang W.; Hwang, Leroy N.; Deveer, Michael J.; Zhou, Aimin; Silverman, Robert H.; Williams, Bryan R.G.; Dubensky, Thomas W.; Ying, Han; Restifo, Nicholas P.

2006-01-01

Cancer vaccines targeting ‘self’ antigens that are expressed at consistently high levels by tumor cells are potentially useful in immunotherapy, but immunological tolerance may block their function. Here, we describe a novel, naked DNA vaccine encoding an alphavirus replicon (self-replicating mRNA) and the self/tumor antigen tyrosinase-related protein-1. Unlike conventional DNA vaccines, this vaccine can break tolerance and provide immunity to melanoma. The vaccine mediates production of double-stranded RNA, as evidenced by the autophosphorylation of protein kinase R. Double-stranded RNA is critical to vaccine function because both the immunogenicity and the anti-tumor activity of the vaccine are blocked in mice deficient for the RNase L enzyme, a key component of the 2′,5′-linked oligoadenylate synthetase antiviral pathway involved in double-stranded RNA recognition. This study shows for the first time that alphaviral replicon-encoding DNA vaccines activate innate immune pathways known to drive antiviral immune responses, and points the way to strategies for improving the efficacy of immunization with naked DNA. PMID:12496961

Sensitivity of the 6300 A twilight airglow to neutral composition

NASA Technical Reports Server (NTRS)

Melendez-Alvira, D. J.; Torr, D. G.; Richards, P. G.; Swift, W. R.; Torr, M. R.; Baldridge, T.; Rassoul, H.

1995-01-01

The field line interhemispheric plasma (FLIP) model is used to study the 6300 A line intensity measured during three morning twilights from the McDonald Observatory in Texas. The Imaging Spectrometric Observatory (ISO) measured the 6300 A intensity during the winter of 1987 and the spring and summer of 1988. The FLIP model reproduces the measured intensity and its variation through the twilight well on each day using neutral densities from the MSIS-86 empirical model. This is in spite of the fact that different component sources dominate the integrated volume emission rate on each of the days analyzed. The sensitivity of the intensity to neutral composition is computed by varying the N2, O2, and O densities in the FLIP model and comparing to the intensity computed with the unmodified MSIS-86 densities. The ion densities change self-consistently. Thus the change in neutral composition also changes the electron density. The F2 peak height is unchanged in the model runs for a given day. The intensity changes near 100 deg SZA are comparable to within 10% when either (O2), (N2), or (O) is changed, regardless of which component source is dominant. There is strong sensitivity to changes in (N2) when dissociative recombination is dominant, virtually no change in the nighttime (SZA greater than or equal to 108 deg) intensity with (O2) doubled, and sensitivity of over 50% to doubling or halving (O) at night. When excitation by conjugate photoelectrons is the dominant nighttime component source, the relative intensity change with (O) doubled or halved is very small. This study shows the strong need for simultaneous measurements of electron density and of emissions proportional to photoelectron fluxes if the 6300 A twilight airglow is to be used to retrieve neutral densities.

An adaptive supramolecular hydrogel comprising self-sorting double nanofibre networks

NASA Astrophysics Data System (ADS)

Shigemitsu, Hajime; Fujisaku, Takahiro; Tanaka, Wataru; Kubota, Ryou; Minami, Saori; Urayama, Kenji; Hamachi, Itaru

2018-02-01

Novel soft materials should comprise multiple supramolecular nanostructures whose responses (for example, assembly and disassembly) to external stimuli can be controlled independently. Such multicomponent systems are present in living cells and control the formation and break-up of a variety of supramolecular assemblies made of proteins, lipids, DNA and RNA in response to external stimuli; however, artificial counterparts are challenging to make. Here, we present a hybrid hydrogel consisting of a self-sorting double network of nanofibres in which each network responds to an applied external stimulus independent of the other. The hydrogel can be made to change its mechanical properties and rates of release of encapsulated proteins by adding Na2S2O4 or bacterial alkaline phosphatase. Notably, the properties of the gel depend on the order in which the external stimuli are applied. Multicomponent hydrogels comprising orthogonal stimulus-responsive supramolecular assemblies would be suitable for designing novel adaptive materials.

Positive Illusions of Preference Consistency: When Remaining Eluded by One's Preferences Yields Greater Subjective Well-Being and Decision Outcomes

ERIC Educational Resources Information Center

Wells, Rachael E.; Iyengar, Sheena S.

2005-01-01

Psychological research has repeatedly demonstrated two seemingly irreconcilable human tendencies. People are motivated towards internal consistency, or acting in accordance with stable, self-generated preferences. Simultaneously though, people demonstrate considerable variation in the content of their preferences, often induced by subtle external…

DOE Office of Scientific and Technical Information (OSTI.GOV)

AlHallak, M.; Chamoun, N.; Physikalisches Institut der Universität Bonn,Nußalle 12, D-53115 Bonn

We present a model of power law inflation generated by variation of the strong coupling constant. We then extend the model to two varying coupling constants which leads to a potential consisting of a linear combination of exponential terms. Some variants of the latter may be self-consistent and can accommodate the experimental data of the Planck 2015 and other recent experiments.

The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

2013-06-15

Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of themore » frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.« less

Simulation of free energies of bicontinuous morphologies formed through block copolymer/homopolymer self-assembly

NASA Astrophysics Data System (ADS)

Padmanabhan, Poornima; Martinez-Veracoechea, Francisco; Escobedo, Fernando

Different types of bicontinuous phases can be formed from A-B diblock copolymers by the addition of A-type homopolymers over a range of compositions and relative chain lengths. Particle-based molecular simulations were used to study three bicontinuous phases - double gyroid (G), double diamond (D) and plumber's nightmare (P) - near their triple point of coexistence. For 3-D ordered phases, the stability of the morphology formed in simulation is highly sensitive to box size whose exact size is unknown a-priori. Accurate free energy estimates are required to ascertain the stable phase, particularly when multiple competing phases spontaneously form at the conditions of interest. A variant of thermodynamic integration was implemented to obtain free energies and hence identify the stable phases and their optimal box sizes by tracing a reversible path that connects the ordered and disordered phases. Clear evidence was found of D-G and D-P phase coexistence, consistent with previous predictions for the same blend using Self-consistent field theory. Our simulations also allowed us to examine the microscopic details of these coexisting bicontinuous phases and detect key differences between the microstructure of their nodes and struts.

Current-free double layers: A review

NASA Astrophysics Data System (ADS)

Singh, Nagendra

2011-12-01

During the last decade, there has been an upsurge in the research on current-free DLs (CFDLs). Research includes theory, laboratory measurements, and various applications of CFDLs ranging from plasma thrusters to acceleration of charged particles in space and astrophysical plasmas. The purpose of this review is to present a unified understanding of the basic plasma processes, which lead to the formation of CFDLs. The review starts with the discussion on early research on electric fields and double layers (DLs) and ion acceleration in planar plasma expansion. The review continues with the formation of DLs and rarefaction shocks (RFS) in expanding plasma with two electron populations with different temperatures. The basic theory mitigating the formation of a CFDL by two-electron temperature population is reviewed; we refer to such CFDLs as double layers structures formation by two-temperature electron populations (TET-CFDLs). Application of TET-CFDLS to ion acceleration in laboratory and space plasmas was discussed including the formation of stationary steady-state DLs. A quite different type of CFDLs forms in a helicon plasma device (HPD), in which plasma abruptly expands from a narrow plasma source tube into a wide diffusion tube with abruptly diverging magnetic fields. The formation mechanism of the CFDL in HPD, referred here as current free double layer structure in helicon plasma device (HPD-CFDL), and its applications are reviewed. The formation of a TET-CFDL is due to the self-consistent separation of the two electron populations parallel to the ambient magnetic field. In contrast, a HPD-CFDL forms due to self-consistent separation of electrons and ion perpendicular to the abruptly diverging magnetic field in conjunction with the conducting wall of the expansion chamber in the HPD. One-dimensional theoretical models of CFDLs based on steady-state solution of Vlasov-Poisson system of equations are briefly discussed. Applications of CFDLs ranging from helicon double-layer thrusters (HDLTs) to the accelerations of ions in space and astrophysical plasmas are summarized.

Self-consistent adjoint analysis for topology optimization of electromagnetic waves

NASA Astrophysics Data System (ADS)

Deng, Yongbo; Korvink, Jan G.

2018-05-01

In topology optimization of electromagnetic waves, the Gâteaux differentiability of the conjugate operator to the complex field variable results in the complexity of the adjoint sensitivity, which evolves the original real-valued design variable to be complex during the iterative solution procedure. Therefore, the self-inconsistency of the adjoint sensitivity is presented. To enforce the self-consistency, the real part operator has been used to extract the real part of the sensitivity to keep the real-value property of the design variable. However, this enforced self-consistency can cause the problem that the derived structural topology has unreasonable dependence on the phase of the incident wave. To solve this problem, this article focuses on the self-consistent adjoint analysis of the topology optimization problems for electromagnetic waves. This self-consistent adjoint analysis is implemented by splitting the complex variables of the wave equations into the corresponding real parts and imaginary parts, sequentially substituting the split complex variables into the wave equations with deriving the coupled equations equivalent to the original wave equations, where the infinite free space is truncated by the perfectly matched layers. Then, the topology optimization problems of electromagnetic waves are transformed into the forms defined on real functional spaces instead of complex functional spaces; the adjoint analysis of the topology optimization problems is implemented on real functional spaces with removing the variational of the conjugate operator; the self-consistent adjoint sensitivity is derived, and the phase-dependence problem is avoided for the derived structural topology. Several numerical examples are implemented to demonstrate the robustness of the derived self-consistent adjoint analysis.

The role and behavior of spin in gravitational physics

NASA Technical Reports Server (NTRS)

Ray, John R.

1987-01-01

A self-consistent method of introducing spin into any Lagrangian based theory of gravitation was developed. The metric variation of the Lagrangian in the theory leads to an improved energy-momentum tensor which represents the source term in the gravitational field equations. The goal of the research is the construction of a theory general enough to be used to investigate spin effects in astrophysical objects and cosmology, and also to serve as a basis for discussion of the theoretical ideas tested by the NASA Gyroscope Experiment (aboard Gravity Probe B). Specific accomplishments in the following areas are summarized: the inclusion of electromagnetism into the variational principle for spinning matter, formulation of a self-consistent theory for the case of a fluid in which particle production processes occur, and the derivation of the Raychaudhuri equation in the case of spinning matter.

Double counting in the density functional plus dynamical mean-field theory of transition metal oxides

NASA Astrophysics Data System (ADS)

Dang, Hung

2015-03-01

Recently, the combination of density functional theory (DFT) and dynamical mean-field theory (DMFT) has become a widely-used beyond-mean-field approach for strongly correlated materials. However, not only is the correlation treated in DMFT but also in DFT to some extent, a problem arises as the correlation is counted twice in the DFT+DMFT framework. The correction for this problem is still not well-understood. To gain more understanding of this ``double counting'' problem, I provide a detailed study of the metal-insulator transition in transition metal oxides in the subspace of oxygen p and transition metal correlated d orbitals using DFT+DMFT. I will show that the fully charge self-consistent DFT+DMFT calculations with the standard ``fully-localized limit'' (FLL) double counting correction fail to predict correctly materials such as LaTiO3, LaVO3, YTiO3 and SrMnO3 as insulators. Investigations in a wide range of the p- d splitting, the d occupancy, the lattice structure and the double counting correction itself will be presented to understand the reason behind this failure. I will also show that if the double counting correction is chosen to reproduce the p- d splitting consistent with experimental data, the DFT+DMFT approach can still give reasonable results in comparison with experiments.

Double-gated myocardial ASL perfusion imaging is robust to heart rate variation.

PubMed

Do, Hung Phi; Yoon, Andrew J; Fong, Michael W; Saremi, Farhood; Barr, Mark L; Nayak, Krishna S

2017-05-01

Cardiac motion is a dominant source of physiological noise (PN) in myocardial arterial spin labeled (ASL) perfusion imaging. This study investigates the sensitivity to heart rate variation (HRV) of double-gated myocardial ASL compared with the more widely used single-gated method. Double-gating and single-gating were performed on 10 healthy volunteers (n = 10, 3F/7M; age, 23-34 years) and eight heart transplant recipients (n = 8, 1F/7M; age, 26-76 years) at rest in the randomized order. Myocardial blood flow (MBF), PN, temporal signal-to-noise ratio (SNR), and HRV were measured. HRV ranged from 0.2 to 7.8 bpm. Double-gating PN did not depend on HRV, while single-gating PN increased with HRV. Over all subjects, double-gating provided a significant reduction in global PN (from 0.20 ± 0.15 to 0.11 ± 0.03 mL/g/min; P = 0.01) and per-segment PN (from 0.33 ± 0.23 to 0.21 ± 0.12 mL/g/min; P < 0.001), with significant increases in global temporal SNR (from 11 ± 8 to 18 ± 8; P = 0.02) and per-segment temporal SNR (from 7 ± 4 to 11 ± 12; P < 0.001) without significant difference in measured MBF. Single-gated myocardial ASL suffers from reduced temporal SNR, while double-gated myocardial ASL provides consistent temporal SNR independent of HRV. Magn Reson Med 77:1975-1980, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

High-Maneuverability Airframe: Initial Investigation of Configuration’s Aft End for Increased Stability, Range, and Maneuverability

DTIC Science & Technology

2013-09-01

including the interaction effects between the fins and canards. 2. Solution Technique 2.1 Computational Aerodynamics The double-precision solver of a...and overset grids (unified-grid). • Total variation diminishing discretization based on a new multidimensional interpolation framework. • Riemann ... solvers to provide proper signal propagation physics including versions for preconditioned forms of the governing equations. • Consistent and

Anharmonic frequencies of CX2Y2 (X, Y = O, N, F, H, D) isomers and related systems obtained from vibrational multiconfiguration self-consistent field theory.

PubMed

Pfeiffer, Florian; Rauhut, Guntram

2011-10-13

Accurate anharmonic frequencies are provided for molecules of current research, i.e., diazirines, diazomethane, the corresponding fluorinated and deuterated compounds, their dioxygen analogs, and others. Vibrational-state energies were obtained from state-specific vibrational multiconfiguration self-consistent field theory (VMCSCF) based on multilevel potential energy surfaces (PES) generated from explicitly correlated coupled cluster, CCSD(T)-F12a, and double-hybrid density functional calculations, B2PLYP. To accelerate the vibrational structure calculations, a configuration selection scheme as well as a polynomial representation of the PES have been exploited. Because experimental data are scarce for these systems, many calculated frequencies of this study are predictions and may guide experiments to come.

Self-organized criticality: An interplay between stable and turbulent regimes of multiple anodic double layers in glow discharge plasma

NASA Astrophysics Data System (ADS)

Alex, Prince; Carreras, Benjamin Andres; Arumugam, Saravanan; Sinha, Suraj Kumar

2018-05-01

The role of self-organized criticality (SOC) in the transformation of multiple anodic double layers (MADLs) from the stable to turbulent regime has been investigated experimentally as the system approaches towards critical behavior. The experiment was performed in a modified glow discharge plasma setup, and the initial stable state of MADL comprising three concentric perceptible layers was produced when the drift velocity of electrons towards the anode exceeds the electron thermal velocity (νd ≥ 1.3νte). The macroscopic arrangement of both positive and negative charges in opposite layers of MADL is attributed to the self-organization scenario. Beyond νd ≥ 3νte, MADL begins to collapse and approaches critical and supercritical states through layer reduction which continue till the last remaining layer of the double layer is transformed into a highly unstable radiant anode glow. The avalanche resulting from the collapse of MADL leads to the rise of turbulence in the system. Long-range correlations, a key signature of SOC, have been explored in the turbulent floating potential fluctuations using the rescaled-range analysis technique. The result shows that the existence of the self-similarity regime with self-similarity parameter H varies between 0.55 and 0.91 for time lags longer than the decorrelation time. The power law tail in the rank function, slowly decaying tail of the autocorrelation function, and 1/f behavior of the power spectra of the fluctuations are consistent with the fact that SOC plays a conclusive role in the transformation of MADL from the stable to turbulent regime. Since the existence of SOC gives a measure of complexity in the system, the result provides the condition under which complexity arises in cold plasma.

A general MHD formulation for plasmas with flow and resistive walls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guazzotto, L.; Freidberg, J. P.; Betti, R.

2006-11-30

Toroidal rotation, either induced by means of neutral beams (e.g. in NSTX and DIII-D) or appearing spontaneously (e.g. in Alcator C-Mod, JET and Tore Supra) is routinely observed in modem tokamak experiments. Poloidal rotation is also commonly observed, in particular in the edge region of the plasma. Plasma rotation has a major effect on plasma stability. Flow and flow shear stabilize external modes such as the resistive wall mode (as observed e.g. in DIII-D), suppress turbulence when the flow shear is large enough, and also have a significant influence on the stability and nonlinear evolution of the internal kink andmore » ballooning modes. Flow shear can in particular have both a stabilizing (by breaking up unstable structures) and destabilizing (through the Kelvin-Helmoltz mechanism) effect. A self-consistent analysis of the effect of rotation requires the use of numerical tools. In this work, we present a general eigenvalue formulation based on a variational principle stability analysis, including arbitrary (both toroidal and poloidal) plasma rotation and a thin resistive wall of arbitrary shape and resistivity. It is shown that the problem can always be reduced to a classic eigenvalue formulation of the kind i{omega}A double underbar {center_dot} {zeta}-vector = B double underbar {center_dot} {zeta}-vector, where {zeta}-vector is the unknown eigenvector related to the plasma displacement, and {omega} the (complex) evolution frequency of the perturbation. The formulation is well suited for a finite element analysis.« less

Identifying Oneself with the Face of Someone Else Impairs the Egocentered Visuo-spatial Mechanisms: A New Double Mirror Paradigm to Study Self–other Distinction and Interaction

PubMed Central

Thirioux, Bérangère; Wehrmann, Moritz; Langbour, Nicolas; Jaafari, Nematollah; Berthoz, Alain

2016-01-01

Looking at our face in a mirror is one of the strongest phenomenological experiences of the Self in which we need to identify the face as reflected in the mirror as belonging to us. Recent behavioral and neuroimaging studies reported that self-face identification not only relies upon visual-mnemonic representation of one’s own face but also upon continuous updating and integration of visuo-tactile signals. Therefore, bodily self-consciousness plays a major role in self-face identification, with respect to interplay between unisensory and multisensory processing. However, if previous studies demonstrated that the integration of multisensory body-related signals contributes to the visual processing of one’s own face, there is so far no data regarding how self-face identification, inversely, contributes to bodily self-consciousness. In the present study, we tested whether self–other face identification impacts either the egocentered or heterocentered visuo-spatial mechanisms that are core processes of bodily self-consciousness and sustain self–other distinction. For that, we developed a new paradigm, named “Double Mirror.” This paradigm, consisting of a semi-transparent double mirror and computer-controlled Light Emitting Diodes, elicits self–other face merging illusory effect in ecologically more valid conditions, i.e., when participants are physically facing each other and interacting. Self-face identification was manipulated by exposing pairs of participants to an Interpersonal Visual Stimulation in which the reflection of their faces merged in the mirror. Participants simultaneously performed visuo-spatial and mental own-body transformation tasks centered on their own face (egocentered) or the face of their partner (heterocentered) in the pre- and post-stimulation phase. We show that self–other face identification altered the egocentered visuo-spatial mechanisms. Heterocentered coding was preserved. Our data suggest that changes in self-face identification induced a bottom-up conflict between the current visual representation and the stored mnemonic representation of one’s own face which, in turn, top-down impacted bodily self-consciousness. PMID:27610095

Second order Møller-Plesset and coupled cluster singles and doubles methods with complex basis functions for resonances in electron-molecule scattering

DOE PAGES

White, Alec F.; Epifanovsky, Evgeny; McCurdy, C. William; ...

2017-06-21

The method of complex basis functions is applied to molecular resonances at correlated levels of theory. Møller-Plesset perturbation theory at second order and equation-of-motion electron attachment coupled-cluster singles and doubles (EOM-EA-CCSD) methods based on a non-Hermitian self-consistent-field reference are used to compute accurate Siegert energies for shape resonances in small molecules including N 2 - , CO - , CO 2 - , and CH 2 O - . Analytic continuation of complex θ-trajectories is used to compute Siegert energies, and the θ-trajectories of energy differences are found to yield more consistent results than those of total energies.more » Furthermore, the ability of such methods to accurately compute complex potential energy surfaces is investigated, and the possibility of using EOM-EA-CCSD for Feshbach resonances is explored in the context of e-helium scattering.« less

Anisotropic magnetotail equilibrium and convection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hau, L.N.

This paper reports on self-consistent two-dimensional equilibria with anisotropic plasma pressure for the Earth's magnetotail. These configurations are obtained by numerically solving the generalized Grad-Shafranov equation, describing anisotropic plasmas with p[parallel] [ne] p[perpendicular], including the Earth's dipolar field. Consistency between these new equilibria and the assumption of steady-state, sunward convection, described by the double-adiabatic laws, is examined. As for the case of isotropic pressure [Erickson and Wolf, 1980], there exists a discrepancy between typical quite-time magnetic field models and the assumption of steady-state double-adiabatic lossless plasma sheet convection. However, unlike that case, this inconsistency cannot be removed by the presencemore » of a weak equatorial normal magnetic field strength in the near tail region: magnetic field configurations of this type produce unreasonably large pressure anisotropies, p[parallel] > p[perpendicular], in the plasma sheet. 16 refs., 5 figs.« less

Second order Møller-Plesset and coupled cluster singles and doubles methods with complex basis functions for resonances in electron-molecule scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, Alec F.; Epifanovsky, Evgeny; McCurdy, C. William

The method of complex basis functions is applied to molecular resonances at correlated levels of theory. Møller-Plesset perturbation theory at second order and equation-of-motion electron attachment coupled-cluster singles and doubles (EOM-EA-CCSD) methods based on a non-Hermitian self-consistent-field reference are used to compute accurate Siegert energies for shape resonances in small molecules including N 2 - , CO - , CO 2 - , and CH 2 O - . Analytic continuation of complex θ-trajectories is used to compute Siegert energies, and the θ-trajectories of energy differences are found to yield more consistent results than those of total energies.more » Furthermore, the ability of such methods to accurately compute complex potential energy surfaces is investigated, and the possibility of using EOM-EA-CCSD for Feshbach resonances is explored in the context of e-helium scattering.« less

Ab initio study of the molecular structure and vibrational spectrum of nitric acid and its protonated forms

NASA Technical Reports Server (NTRS)

Lee, Timothy J.; Rice, Julia E.

1992-01-01

The equilibrium structures, harmonic vibrational frequencies, IR intensities, and relative energetics of HNO3 and its protonated form H2NO3+ were investigated using double-zeta plus polarization and triple-zeta plus polarization basis sets in conjunction with high-level ab initio methods. The latter include second-order Moller-Plesset perturbation theory, the single and double excitation coupled cluster (CCSD) methods, a perturbational estimate of the effects of connected triple excitations (CCSD(T)), and the self-consistent field. To determine accurate energy differences CCSD(T) energies were computed using large atomic natural orbital basis sets. Four different isomers of H2NO3+ were considered. The lowest energy form of protonated nitric acid was found to correspond to a complex between H2O and NO2+, which is consistent with earlier theoretical and experimental studies.

Observation of acoustic Dirac-like cone and double zero refractive index

PubMed Central

Dubois, Marc; Shi, Chengzhi; Zhu, Xuefeng; Wang, Yuan; Zhang, Xiang

2017-01-01

Zero index materials where sound propagates without phase variation, holds a great potential for wavefront and dispersion engineering. Recently explored electromagnetic double zero index metamaterials consist of periodic scatterers whose refractive index is significantly larger than that of the surrounding medium. This requirement is fundamentally challenging for airborne acoustics because the sound speed (inversely proportional to the refractive index) in air is among the slowest. Here, we report the first experimental realization of an impedance matched acoustic double zero refractive index metamaterial induced by a Dirac-like cone at the Brillouin zone centre. This is achieved in a two-dimensional waveguide with periodically varying air channel that modulates the effective phase velocity of a high-order waveguide mode. Using such a zero-index medium, we demonstrated acoustic wave collimation emitted from a point source. For the first time, we experimentally confirm the existence of the Dirac-like cone at the Brillouin zone centre. PMID:28317927

Transdermal solid delivery of epigallocatechin-3-gallate using self-double-emulsifying drug delivery system as vehicle: Formulation, evaluation and vesicle-skin interaction.

PubMed

Hu, Caibiao; Gu, Chengyu; Fang, Qiao; Wang, Qiang; Xia, Qiang

2016-02-01

The present study investigated a self-double-emulsifying drug delivery system loaded with epigallocatechin-3-gallate to improve epigallocatechin-3-gallate skin retention. The long chain solid lipids (cetostearyl alcohol) and macadamia oil were utilized as a carrier to deliver the bioactive ingredient. Response surface methodology was used to optimize the formulation, and the solid lipid to total lipid weight ratio, concentration of epigallocatechin-3-gallate and hydrophilic surfactant on skin retention were found to be the principal factors. The optimum formulation with high encapsulation efficiency (95.75%), self-double-emulsification performance (99.58%) and skin retention (87.24%) were derived from the fitted models and experimentally examined, demonstrating a reasonable agreement between experimental and predicted values. Epigallocatechin-3-gallate-self-double-emulsifying drug delivery system was found to be stable for 3 months. Transdermal studies could explain a higher skin diffusion of epigallocatechin-3-gallate from the self-double-emulsifying drug delivery system compared with EGCG aqueous solution. In vitro cytotoxicity showed that epigallocatechin-3-gallate-self-double-emulsifying drug delivery system did not exert hazardous effect on L929 cells up to 1:10. © The Author(s) 2015.

The electric double layer at a metal electrode in pure water

NASA Astrophysics Data System (ADS)

Brüesch, Peter; Christen, Thomas

2004-03-01

Pure water is a weak electrolyte that dissociates into hydronium ions and hydroxide ions. In contact with a charged electrode a double layer forms for which neither experimental nor theoretical studies exist, in contrast to electrolytes containing extrinsic ions like acids, bases, and solute salts. Starting from a self-consistent solution of the one-dimensional modified Poisson-Boltzmann equation, which takes into account activity coefficients of point-like ions, we explore the properties of the electric double layer by successive incorporation of various correction terms like finite ion size, polarization, image charge, and field dissociation. We also discuss the effect of the usual approximation of an average potential as required for the one-dimensional Poisson-Boltzmann equation, and conclude that the one-dimensional approximation underestimates the ion density. We calculate the electric potential, the ion distributions, the pH-values, the ion-size corrected activity coefficients, and the dissociation constants close to the electric double layer and compare the results for the various model corrections.

Determination of temperature dependence of full matrix material constants of PZT-8 piezoceramics using only one sample.

PubMed

Zhang, Yang; Tang, Liguo; Tian, Hua; Wang, Jiyang; Cao, Wenwu; Zhang, Zhongwu

2017-08-15

Resonant ultrasound spectroscopy (RUS) was used to determine the temperature dependence of full matrix material constants of PZT-8 piezoceramics from room temperature to 100 °C. Property variations from sample to samples can be eliminated by using only one sample, so that data self-consistency can be guaranteed. The RUS measurement system error was estimated to be lower than 2.35%. The obtained full matrix material constants at different temperatures all have excellent self-consistency, which can help accurately predict device performance at high temperatures using finite element simulations.

Self-consistent-field perturbation theory for the Schröautdinger equation

NASA Astrophysics Data System (ADS)

Goodson, David Z.

1997-06-01

A method is developed for using large-order perturbation theory to solve the systems of coupled differential equations that result from the variational solution of the Schröautdinger equation with wave functions of product form. This is a noniterative, computationally efficient way to solve self-consistent-field (SCF) equations. Possible applications include electronic structure calculations using products of functions of collective coordinates that include electron correlation, vibrational SCF calculations for coupled anharmonic oscillators with selective coupling of normal modes, and ab initio calculations of molecular vibration spectra without the Born-Oppenheimer approximation.

"I know you self-handicapped last exam": gender differences in reactions to self-handicapping.

PubMed

Hirt, Edward R; McCrea, Sean M; Boris, Hillary I

2003-01-01

Past research has shown that self-handicapping involves the trade-off of ability-related attributional benefits for interpersonal costs. Study 1 examined whether perceiver or target sex moderates impressions of self-handicapping targets. Although target sex was not an important factor, female perceivers were consistently more critical of behavioral self-handicappers. Two additional studies replicated this gender difference with variations of the handicap. Study 3 examined the motives inferred by perceivers and found that women not only view self-handicappers as more unmotivated but also report greater suspicion of self-handicapping motives; furthermore, these differences in perceived motives mediated sex differences in reactions to self-handicappers. Implications for the effectiveness of self-handicapping as an impression management strategy are discussed.

AN EFFICIENT, COMPACT, AND VERSATILE FIBER DOUBLE SCRAMBLER FOR HIGH PRECISION RADIAL VELOCITY INSTRUMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halverson, Samuel; Roy, Arpita; Mahadevan, Suvrath

2015-06-10

We present the design and test results of a compact optical fiber double-scrambler for high-resolution Doppler radial velocity instruments. This device consists of a single optic: a high-index n ∼ 2 ball lens that exchanges the near and far fields between two fibers. When used in conjunction with octagonal fibers, this device yields very high scrambling gains (SGs) and greatly desensitizes the fiber output from any input illumination variations, thereby stabilizing the instrument profile of the spectrograph and improving the Doppler measurement precision. The system is also highly insensitive to input pupil variations, isolating the spectrograph from telescope illumination variationsmore » and seeing changes. By selecting the appropriate glass and lens diameter the highest efficiency is achieved when the fibers are practically in contact with the lens surface, greatly simplifying the alignment process when compared to classical double-scrambler systems. This prototype double-scrambler has demonstrated significant performance gains over previous systems, achieving SGs in excess of 10,000 with a throughput of ∼87% using uncoated Polymicro octagonal fibers. Adding a circular fiber to the fiber train further increases the SG to >20,000, limited by laboratory measurement error. While this fiber system is designed for the Habitable-zone Planet Finder spectrograph, it is more generally applicable to other instruments in the visible and near-infrared. Given the simplicity and low cost, this fiber scrambler could also easily be multiplexed for large multi-object instruments.« less

Transgenic plants with enhanced growth characteristics

DOEpatents

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

2016-09-06

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

Communication: Time-dependent optimized coupled-cluster method for multielectron dynamics

NASA Astrophysics Data System (ADS)

Sato, Takeshi; Pathak, Himadri; Orimo, Yuki; Ishikawa, Kenichi L.

2018-02-01

Time-dependent coupled-cluster method with time-varying orbital functions, called time-dependent optimized coupled-cluster (TD-OCC) method, is formulated for multielectron dynamics in an intense laser field. We have successfully derived the equations of motion for CC amplitudes and orthonormal orbital functions based on the real action functional, and implemented the method including double excitations (TD-OCCD) and double and triple excitations (TD-OCCDT) within the optimized active orbitals. The present method is size extensive and gauge invariant, a polynomial cost-scaling alternative to the time-dependent multiconfiguration self-consistent-field method. The first application of the TD-OCC method of intense-laser driven correlated electron dynamics in Ar atom is reported.

Communication: Time-dependent optimized coupled-cluster method for multielectron dynamics.

PubMed

Sato, Takeshi; Pathak, Himadri; Orimo, Yuki; Ishikawa, Kenichi L

2018-02-07

Time-dependent coupled-cluster method with time-varying orbital functions, called time-dependent optimized coupled-cluster (TD-OCC) method, is formulated for multielectron dynamics in an intense laser field. We have successfully derived the equations of motion for CC amplitudes and orthonormal orbital functions based on the real action functional, and implemented the method including double excitations (TD-OCCD) and double and triple excitations (TD-OCCDT) within the optimized active orbitals. The present method is size extensive and gauge invariant, a polynomial cost-scaling alternative to the time-dependent multiconfiguration self-consistent-field method. The first application of the TD-OCC method of intense-laser driven correlated electron dynamics in Ar atom is reported.

Exchange and Correlation Effects in a Double Barrier Quantum Well

NASA Astrophysics Data System (ADS)

Hasbun, J. E.

2003-03-01

Studies of electronic properties in double barrier resonant tunneling systems usually involve the solution of the BenDaniel-Duke equation (BDK) in the presence of an applied voltage. Electron interactions are included by means of the Hartree term and the wavefunction is self-consistently obtained by coupling the BDK with the Poisson equation. In this work, we go beyond the Hartree approximation by including exchange and correlation effects (v_xc) through the local density functional theory. The analytically parametrized v_xc of Hedin and Lunqvist footnote[1]L. Hedin and B. I. Lundqvist, J. Phys C: Solid. St. Phys. 4, 2064(1971) is employed. While the calculation of v_xc involves extra self-consistency conditions, it is shown that the inclusion of exchange and correlation effects may be important in the electronic characteristics of these devices. For our earlier model footnote[2]J. E. Hasbun, APS Bull. 47, 914(2002) the v_xc potential is comparable to the Hartree electron term at low electric field values, but less so for much higher field. The v_xc employed here ^2 is not appreciably different from the more sophisticated one of Perdew and Zunger footnote[3]J. P. Perdew and A. Zunger, Phys. Rev. B 23, 5048(1981). JH wishes to thank Mei-Yin Chou for helpful discussions

Generalized self-consistent method for predicting the effective elastic properties of composites with random hybrid structures

NASA Astrophysics Data System (ADS)

Pan'kov, A. A.

1997-05-01

The feasibility of using a generalized self-consistent method for predicting the effective elastic properties of composites with random hybrid structures has been examined. Using this method, the problem is reduced to solution of simpler special averaged problems for composites with single inclusions and corresponding transition layers in the medium examined. The dimensions of the transition layers are defined by correlation radii of the composite random structure of the composite, while the heterogeneous elastic properties of the transition layers take account of the probabilities for variation of the size and configuration of the inclusions using averaged special indicator functions. Results are given for a numerical calculation of the averaged indicator functions and analysis of the effect of the micropores in the matrix-fiber interface region on the effective elastic properties of unidirectional fiberglass—epoxy using the generalized self-consistent method and compared with experimental data and reported solutions.

The other self: psychopathology and literature.

PubMed

Macías, Javier Saavedra; Núñez, Rafael Velez

2011-12-01

The figure of the "double" or the other self is an important topic in the history of literature. Many centuries before Jean Paul Richter coined the term, "doppelgänger," at the beginning of the Romantic Movement in the year 1796, it is possible to find the figure of the double in myths and legends. The issue of the double emphaszses the contradictory character of the human being and invokes a sinister dimension of the psychological world, what has been called in German as "umheimlich." However, does multiciplicity always involve pathology? Related to this figure in literary history, a new perspective from clinical psychology called "dialogical self" defines the self as a multi-voice reality. Along the same line, postmodernist psychology considers the self a discursive construction. From these perspectives, the "self" is situated a long way away from the classical essential conception of the self. In this paper, we review briefly some important landmarks of the figure of the double in the literature, and we compare the coincidences of the "double" experiencies described in literature with the experiences of our patients. Finally, we discuss how this literary tradition can help us to understand new psychological perspectives.

Self-efficacy, stress, and acculturation as predictors of first year science success among Latinos at a South Texas university

NASA Astrophysics Data System (ADS)

McNamara, Mark W.

The study tested the hypothesis that self-efficacy, stress, and acculturation are useful predictors of academic achievement in first year university science, independent of high school GPA and SAT scores, in a sample of Latino students at a South Texas Hispanic serving institution of higher education. The correlational study employed a mixed methods explanatory sequential model. The non-probability sample consisted of 98 university science and engineering students. The study participants had high science self-efficacy, low number of stressors, and were slightly Anglo-oriented bicultural to strongly Anglo-oriented. As expected, the control variables of SAT score and high school GPA were statistically significant predictors of the outcome measures. Together, they accounted for 19.80% of the variation in first year GPA, 13.80% of the variation in earned credit hours, and 11.30% of the variation in intent to remain in the science major. After controlling for SAT scores and high school GPAs, self-efficacy was a statistically significant predictor of credit hours earned and accounted for 5.60% of the variation; its unique contribution in explaining the variation in first year GPA and intent to remain in the science major was not statistically significant. Stress and acculturation were not statistically significant predictors of any of the outcome measures. Analysis of the qualitative data resulted in six themes (a) high science self-efficacy, (b) stressors, (c) positive role of stress, (d) Anglo-oriented, (e) bicultural, and (f) family. The quantitative and qualitative results were synthesized and practical implications were discussed.

Double Brillouin frequency spaced multiwavelength Brillouin-erbium fiber laser with 50 nm tuning range

NASA Astrophysics Data System (ADS)

Zhao, J. F.; Liao, T. Q.; Zhang, C.; Zhang, R. X.; Miao, C. Y.; Tong, Z. R.

2012-09-01

A 50 nm tuning range multiwavelength Brillouin-erbium fiber laser (MWBEFL) with double Brillouin frequency spacing is presented. Two separated gain blocks with symmetrical architecture, consisted by erbium-doped fiber amplifiers (EDFAs) and Brillouin gain media, are used to generate double Brillouin frequency spacing. The wider tuning range is realized by eliminating the self-lasing cavity modes existing in conventional MWBEFLs because of the absence of the physical mirrors at the ends of the linear cavity. The Brillouin pump (BP) is preamplified by the EDFA before entering the single-mode fiber (SMF), which leads to the reduction of threshold power and the generation enhancement of Brillouin Stokes (BS) signals. Four channels with 0.176 nm spacing are achieved at 2 mW BP power and 280 mW 980 nm pump power which can be tuned from 1525 to 1575 nm.

Compression member response of double steel angles on truss structure with member length variation

NASA Astrophysics Data System (ADS)

Hasibuan, Purwandy; Panjaitan, Arief; Haiqal, Muhammad

2018-05-01

One type of structures that implements steel angles as its members is truss system of telecommunication tower. For this structure, reinforcements on tower legs are also needed when antennas and microwaves installation placed on the peak of tower increases in quantity. One type of reinforcement methods commonly used is by increasing areas section capacity, where tower leg consisted of single angle section will be reinforced to be double angle sections. Regarding this case, this research discussed behavior two types of double angle steel section 2L 30.30.3 that were designed identically in area section but vary in length: 103 cm and 83 cm. At the first step, compression member together with tension member was formed to be a truss system, where compression and tension member were met at the joint plate. Schematic loading was implemented by giving tension loading on the joint plate, and this loading was terminated when each specimen reached its failure. Research findings showed that implementing shorter double angle (83 cm) sections, increased compression strength of steel angle section up to 13 %. Significant deformation occurring only on the flange for both of specimens indicated that implementing double angle is effective to prevent lateral-torsional buckling.

Space confinement and rotation stress induced self-organization of double-helix nanostructure: a nanotube twist with a moving catalyst head.

PubMed

Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Huang, Jia-Qi; Wei, Fei

2012-05-22

Inorganic materials with double-helix structure have attracted intensive attention due to not only their elegant morphology but also their amazing morphology-related potential applications. The investigation on the formation mechanism of the inorganic double-helix nanostructure is the first step for the fundamental studies of their materials or physical properties. Herein, we demonstrated the space confinement and rotation stress induced self-organization mechanism of the carbon nanotube (CNT)-array double helices under scanning electron microscopy by directly observing their formation process from individual layered double hydroxide flakes, which is a kind of hydrotalcite-like material composed of positively charged layers and charge-balancing interlayer anions. Space confinement is considered to be the most important extrinsic factor for the formation of CNT-array double helices. Synchronous growth of the CNT arrays oppositely from LDH flakes with space confinement on both sides at the same time is essential for the growth of CNT-array double helices. Coiling of the as-grown CNT arrays into double helices will proceed by self-organization, tending to the most stable morphology in order to release their internal rotation stress. Based on the demonstrated mechanism, effective routes were carried out to improve the selectivity for CNT-array double helices. The work provides a promising method for the fabrication of double-helix nanostructures with their two helices connected at the end by self-assembly.

Self-Consistent Monte Carlo Study of the Coulomb Interaction under Nano-Scale Device Structures

NASA Astrophysics Data System (ADS)

Sano, Nobuyuki

2011-03-01

It has been pointed that the Coulomb interaction between the electrons is expected to be of crucial importance to predict reliable device characteristics. In particular, the device performance is greatly degraded due to the plasmon excitation represented by dynamical potential fluctuations in high-doped source and drain regions by the channel electrons. We employ the self-consistent 3D Monte Carlo (MC) simulations, which could reproduce both the correct mobility under various electron concentrations and the collective plasma waves, to study the physical impact of dynamical potential fluctuations on device performance under the Double-gate MOSFETs. The average force experienced by an electron due to the Coulomb interaction inside the device is evaluated by performing the self-consistent MC simulations and the fixed-potential MC simulations without the Coulomb interaction. Also, the band-tailing associated with the local potential fluctuations in high-doped source region is quantitatively evaluated and it is found that the band-tailing becomes strongly dependent of position in real space even inside the uniform source region. This work was partially supported by Grants-in-Aid for Scientific Research B (No. 2160160) from the Ministry of Education, Culture, Sports, Science and Technology in Japan.

Intermodel spread of the double-ITCZ bias in coupled GCMs tied to land surface temperature in AMIP GCMs

NASA Astrophysics Data System (ADS)

Zhou, Wenyu; Xie, Shang-Ping

2017-08-01

Global climate models (GCMs) have long suffered from biases of excessive tropical precipitation in the Southern Hemisphere (SH). The severity of the double-Intertropical Convergence Zone (ITCZ) bias, defined here as the interhemispheric difference in zonal mean tropical precipitation, varies strongly among models in the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble. Models with a more severe double-ITCZ bias feature warmer tropical sea surface temperature (SST) in the SH, coupled with weaker southeast trades. While previous studies focus on coupled ocean-atmosphere interactions, here we show that the intermodel spread in the severity of the double-ITCZ bias is closely related to land surface temperature biases, which can be further traced back to those in the Atmosphere Model Intercomparison Project (AMIP) simulations. By perturbing land temperature in models, we demonstrate that cooler land can indeed lead to a more severe double-ITCZ bias by inducing the above coupled SST-trade wind pattern in the tropics. The response to land temperature can be consistently explained from both the dynamic and energetic perspectives. Although this intermodel spread from the land temperature variation does not account for the ensemble model mean double-ITCZ bias, identifying the land temperature effect provides insights into simulating a realistic ITCZ for the right reasons.

No-insulation multi-width winding technique for high temperature superconducting magnet.

PubMed

Hahn, Seungyong; Kim, Youngjae; Keun Park, Dong; Kim, Kwangmin; Voccio, John P; Bascuñán, Juan; Iwasa, Yukikazu

2013-10-21

We present a No-Insulation ( NI ) Multi-Width ( MW ) winding technique for an HTS (high temperature superconductor) magnet consisting of double-pancake (DP) coils. The NI enables an HTS magnet self-protecting and the MW minimizes the detrimental anisotropy in current-carrying capacity of HTS tape by assigning tapes of multiple widths to DP coils within a stack, widest tape to the top and bottom sections and the narrowest in the midplane section. This paper presents fabrication and test results of an NI-MW HTS magnet and demonstrates the unique features of the NI-MW technique: self-protecting and enhanced field performance, unattainable with the conventional technique.

Seeing double, being double: longing, belonging, recognition, and evasion in psychodynamic work with immigrants.

PubMed

Boulanger, Ghislaine

2015-09-01

Psychically immigrants live double lives, simultaneously dwelling in the world they have left and the world in which they live, and into which most try to fit to avoid the alienating experience of being "other". Doubleness is not a conscious act, but it is a preconscious counterpoint to just about every social interaction. I argue that successful psychodynamic treatment allows immigrants to take the doubleness for granted, in effect seeing double and being double. In this way they come to effortlessly privilege one self-state over the other. The recognition and acceptance of competing self-states proves transformative in any treatment, but never more so than in working with immigrants who contend with several culturally competing selves in their daily lives and seek one relationship in which they can all be seen and heard. I describe treating an immigrant who, when I began to work with her, excelled at seeing double, but being double posed a terrifying dilemma. At least two self-states were engaged in a tug of war; she feared that the winner would take all.

Insecurity, stress, and symptoms of psychopathology: contrasting results from self-reports versus interviews of adult attachment.

PubMed

Fortuna, Keren; Roisman, Glenn I

2008-03-01

This report was designed to clarify links among self-reports of psychiatric symptomatology, stress, and adult attachment insecurity, as operationalized using measures drawn from both the developmental and social psychological literatures. Based on a sample of 160 college students, this study demonstrated that insecurity reflected in the Adult Attachment Interview (AAI) was associated with self-reports of psychiatric symptomatology principally for individuals experiencing high levels of life stress (consistent with a diathesis-stress model) whereas self-reports of attachment-related avoidance and anxiety correlated robustly with psychopathology under conditions of both relatively high and low life stress (consistent with a risk model). Results provide further evidence that social psychological and developmental approaches to the assessment of adult attachment-related variation are associated with domains of adaptation central to Bowlby's account of human development in empirically distinct ways.

Shot-to-shot reproducibility of a self-magnetically insulated ion diode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pushkarev, A. I.; Isakova, Yu. I.; Khailov, I. P.

In this paper we present the analysis of shot to shot reproducibility of the ion beam which is formed by a self-magnetically insulated ion diode with an explosive emission graphite cathode. The experiments were carried out with the TEMP-4M accelerator operating in double-pulse mode: the first pulse is of negative polarity (300-500 ns, 100-150 kV), and this is followed by a second pulse of positive polarity (150 ns, 250-300 kV). The ion current density was 10-70 A/cm{sup 2} depending on the diode geometry. The beam was composed from carbon ions (80%-85%) and protons. It was found that shot to shotmore » variation in the ion current density was about 35%-40%, whilst the diode voltage and current were comparatively stable with the variation limited to no more than 10%. It was shown that focusing of the ion beam can improve the stability of the ion current generation and reduces the variation to 18%-20%. In order to find out the reason for the shot-to-shot variation in ion current density we examined the statistical correlation between the current density of the accelerated beam and other measured characteristics of the diode, such as the accelerating voltage, total current, and first pulse duration. The correlation between the ion current density measured simultaneously at different positions within the cross-section of the beam was also investigated. It was shown that the shot-to-shot variation in ion current density is mainly attributed to the variation in the density of electrons diffusing from the drift region into the A-K gap.« less

Shot-to-shot reproducibility of a self-magnetically insulated ion diode.

PubMed

Pushkarev, A I; Isakova, Yu I; Khailov, I P

2012-07-01

In this paper we present the analysis of shot to shot reproducibility of the ion beam which is formed by a self-magnetically insulated ion diode with an explosive emission graphite cathode. The experiments were carried out with the TEMP-4M accelerator operating in double-pulse mode: the first pulse is of negative polarity (300-500 ns, 100-150 kV), and this is followed by a second pulse of positive polarity (150 ns, 250-300 kV). The ion current density was 10-70 A/cm(2) depending on the diode geometry. The beam was composed from carbon ions (80%-85%) and protons. It was found that shot to shot variation in the ion current density was about 35%-40%, whilst the diode voltage and current were comparatively stable with the variation limited to no more than 10%. It was shown that focusing of the ion beam can improve the stability of the ion current generation and reduces the variation to 18%-20%. In order to find out the reason for the shot-to-shot variation in ion current density we examined the statistical correlation between the current density of the accelerated beam and other measured characteristics of the diode, such as the accelerating voltage, total current, and first pulse duration. The correlation between the ion current density measured simultaneously at different positions within the cross-section of the beam was also investigated. It was shown that the shot-to-shot variation in ion current density is mainly attributed to the variation in the density of electrons diffusing from the drift region into the A-K gap.

The Thomas-Fermi model in the theory of systems of charged particles above the surface of liquid dielectrics

NASA Astrophysics Data System (ADS)

Lytvtnenko, D. M.; Slyusarenko, Yu. V.; Kirdin, A. I.

2012-10-01

A consistent theory of equilibrium states of same sign charges above the surface of liquid dielectric film located on solid substrate in the presence of external attracting constant electric field is proposed. The approach to the development of the theory is based on the Thomas-Fermi model generalized to the systems under consideration and on the variational principle. The using of self-consistent field model allows formulating a theory containing no adjustable constants. In the framework of the variational principle we obtain the self-consistency equations for the parameters describing the system: the distribution function of charges above the liquid dielectric surface, the electrostatic field potentials in all regions of the system and the surface profile of the liquid dielectric. The self-consistency equations are used to describe the phase transition associated with the formation of spatially periodic structures in the system of charges on liquid dielectric surface. Assuming the non-degeneracy of the gas of charges above the surface of liquid dielectric film the solutions of the self-consistency equations near the critical point are obtained. In the case of the symmetric phase we obtain the expressions for the potentials and electric fields in all regions of the studied system. The distribution of the charges above the surface of liquid dielectric film for the symmetric phase is derived. The system parameters of the phase transition to nonsymmetric phase - the states with a spatially periodic ordering are obtained. We derive the expression determining the period of two-dimensional lattice as a function of physical parameters of the problem - the temperature, the external attractive electric field, the number of electrons per unit of the flat surface area of the liquid dielectric, the density of the dielectric, its surface tension and permittivity, and the permittivity of the solid substrate. The possibility of generalizing the developed theory in the case of degenerate gas of like-charged particles above the liquid dielectric surface is discussed.

Self-consistent modelling of the polar thermosphere and ionosphere to magnetospheric convection and precipitation (invited review)

NASA Technical Reports Server (NTRS)

Rees, D.; Fuller-Rowell, T.; Quegan, S.; Moffett, R.

1986-01-01

It has recently been demonstrated that the dramatic effects of plasma precipitation and convection on the composition and dynamics of the polar thermosphere and ionosphere include a number of strong interactive, or feedback, processes. To aid the evaluation of these feedback processes, a joint three dimensional time dependent global model of the Earth's thermosphere and ionosphere was developed in a collaboration between University College London and Sheffield University. This model includes self consistent coupling between the thermosphere and the ionosphere in the polar regions. Some of the major features in the polar ionosphere, which the initial simulations indicate are due to the strong coupling of ions and neutrals in the presence of strong electric fields and energetic electron precipitation are reviewed. The model is also able to simulate seasonal and Universal time variations in the polar thermosphere and ionospheric regions which are due to the variations of solar photoionization in specific geomagnetic regions such as the cusp and polar cap.

Computational insight into the capacitive performance of graphene edge planes

DOE PAGES

Zhan, Cheng; Zhang, Yu; Cummings, Peter T.; ...

2017-02-01

Recent experiments have shown that electric double-layer capacitors utilizing electrodes consisting of graphene edge plane exhibit higher capacitance than graphene basal plane. However, theoretical understanding of this capacitance enhancement is still limited. Here we applied a self-consistent joint density functional theory calculation on the electrode/electrolyte interface and found that the capacitance of graphene edge plane depends on the edge type: zigzag edge has higher capacitance than armchair edge due to the difference in their electronic structures. We further examined the quantum, dielectric, and electric double-layer (EDL) contributions to the total capacitance of the edge-plane electrodes. Classical molecular dynamics simulation foundmore » that the edge planes have higher EDL capacitance than the basal plane due to better adsorption of counter-ions and higher solvent accessible surface area. Finally, our work therefore has elucidated the capacitive energy storage in graphene edge planes that take into account both the electrode's electronic structure and the EDL structure.« less

Ab initio potential energy and dipole moment surfaces of the F(-)(H2O) complex.

PubMed

Kamarchik, Eugene; Toffoli, Daniele; Christiansen, Ove; Bowman, Joel M

2014-02-05

We present full-dimensional, ab initio potential energy and dipole moment surfaces for the F(-)(H2O) complex. The potential surface is a permutationally invariant fit to 16,114 coupled-cluster single double (triple)/aVTZ energies, while the dipole surface is a covariant fit to 11,395 CCSD(T)/aVTZ dipole moments. Vibrational self-consistent field/vibrational configuration interaction (VSCF/VCI) calculations of energies and the IR-spectrum are presented both for F(-)(H2O) and for the deuterated analog, F(-)(D2O). A one-dimensional calculation of the splitting of the ground state, due to equivalent double-well global minima, is also reported. Copyright © 2013 Elsevier B.V. All rights reserved.

Transgenic plants with enhanced growth characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of themore » double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.« less

Surface chemical structure for soft contact lenses as a function of polymer processing.

PubMed

Grobe, G L; Valint, P L; Ammon, D M

1996-09-01

The surface chemistry and topography of cast-molded Etafilcon-A and doubled-sided lathed Etafilcon-A soft contact lenses were determined to be significantly different. The variations in surface chemical and morphologic structure between the two lenses were the result of contact lens manufacturing methods. The surface of the cast-molded Etafilcon-A had a consistently less rough surface compared to the doubled sided lathed Etafilcon-A as determined by atomic force microscopy. The surface of the doubled sided lathed Etafilcon-A contained primarily silicone and wax contamination in addition to minute amounts of HEMA. The cast-molded Etafilcon-A had an elemental and chemical content which was consistent with the polymer stoichiometry. Contact angle wettability profiles revealed inherent wettability differences between the two lenses types. The cast-molded Etafilcon-A had an inherently greater water wettability, polarity, and critical surface tension. This means that these two lenses cannot be compared as similar or identical lens materials in terms of surface composition. The manufacturing method used to produce a soft contact lens directly determines the surface elemental and chemical structure as well as the morphology of the finished lens material. These results suggest possible differences in the clinical comfort, spoilage, and lubricity felt during patient wear.

Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets.

PubMed

Francisconi, Manoela Fávaro; Janson, Guilherme; Henriques, José Fernando Castanha; Freitas, Karina Maria Salvatore de

2016-01-01

The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05). Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires.

Sildenafil citrate improves self-esteem, confidence, and relationships in men with erectile dysfunction: Results from an international, multi-center, double-blind, placebo-controlled trial.

PubMed

Althof, Stanley E; O'leary, Michael P; Cappelleri, Joseph C; Hvidsten, Kyle; Stecher, Vera J; Glina, Sidney; King, Rosie; Siegel, Richard L

2006-05-01

Erectile dysfunction (ED) can significantly impact a man's relationships and well-being. We assessed changes in self-esteem, confidence, sexual relationship satisfaction, and overall relationship satisfaction in men with ED using the validated Self-Esteem And Relationship questionnaire (SEAR). This was a 12-week, double-blind, placebo-controlled, flexible-dose (25, 50, 100 mg, as needed) international study of sildenafil in men > or =18 years of age in Mexico, Brazil, Australia, and Japan. The primary study outcome was change in self-esteem from baseline to the end of treatment. Secondary study measures were changes in other SEAR components, International Index of Erectile Function (IIEF) domains, percentage of intercourse attempts that were successful, and the response to a global efficacy question at the end of treatment. Patients were well balanced for age and duration of ED (placebo = 149 and sildenafil = 151). Compared with placebo, sildenafil significantly improved self-esteem, confidence, sexual relationship satisfaction, and overall relationship satisfaction (P < 0.0001). The psychosocial measures of well-being assessed with the SEAR were positively correlated (range 0.60-0.86, P < 0.0001) with erectile function, the frequency of achieving erections that allowed satisfactory sexual intercourse, the percentage of successful sexual intercourse attempts, and global treatment efficacy. Significant improvements in self-esteem, confidence, sexual relationship satisfaction, and overall relationship satisfaction after treatment of ED with sildenafil were consistent among countries. These data suggest a substantial cross-cultural improvement in well-being after successful treatment of ED with sildenafil.

Microfluidic preparation and self diffusion PFG-NMR analysis of monodisperse water-in-oil-in-water double emulsions.

PubMed

Hughes, Eric; Maan, Abid Aslam; Acquistapace, Simone; Burbidge, Adam; Johns, Michael L; Gunes, Deniz Z; Clausen, Pascal; Syrbe, Axel; Hugo, Julien; Schroen, Karin; Miralles, Vincent; Atkins, Tim; Gray, Richard; Homewood, Philip; Zick, Klaus

2013-01-01

Monodisperse water-in-oil-in-water (WOW) double emulsions have been prepared using microfluidic glass devices designed and built primarily from off the shelf components. The systems were easy to assemble and use. They were capable of producing double emulsions with an outer droplet size from 100 to 40 μm. Depending on how the devices were operated, double emulsions containing either single or multiple water droplets could be produced. Pulsed-field gradient self-diffusion NMR experiments have been performed on the monodisperse water-in-oil-in-water double emulsions to obtain information on the inner water droplet diameter and the distribution of the water in the different phases of the double emulsion. This has been achieved by applying regularization methods to the self-diffusion data. Using these methods the stability of the double emulsions to osmotic pressure imbalance has been followed by observing the change in the size of the inner water droplets over time. Copyright © 2012 Elsevier Inc. All rights reserved.

Conceptualizing and Measuring Self-Criticism as Both a Personality Trait and a Personality State.

PubMed

Zuroff, David C; Sadikaj, Gentiana; Kelly, Allison C; Leybman, Michelle J

2016-01-01

Blatt's ( 2004 , 2008 ) conceptualization of self-criticism is consistent with a state-trait model that postulates meaningful variation in self-criticism both between persons (traits) and within person (states). We tested the state-trait model in a 7-day diary study with 99 college student participants. Each evening they completed a 6-item measure of self-criticism, as well as measures of perceived social support, positive and negative affect, compassionate and self-image goals during interactions with others, and interpersonal behavior, including overt self-criticism and given social support. As predicted, self-criticism displayed both trait-like variance between persons and daily fluctuations around individuals' mean scores for the week; slightly more than half of the total variance was between persons (ICC = .56). Numerous associations at both the between-persons and within-person levels were found between self-criticism and the other variables, indicating that individuals' mean levels of self-criticism over the week, and level of self-criticism on a given day relative to their personal mean, were related to their cognitions, affect, interpersonal goals, and behavior. The results supported the construct validity of the daily self-criticism measure. Moreover, the findings were consistent with the state-trait model and with Blatt's theoretical analysis of self-critical personality.

Cognitive consistency and math-gender stereotypes in Singaporean children.

PubMed

Cvencek, Dario; Meltzoff, Andrew N; Kapur, Manu

2014-01-01

In social psychology, cognitive consistency is a powerful principle for organizing psychological concepts. There have been few tests of cognitive consistency in children and no research about cognitive consistency in children from Asian cultures, who pose an interesting developmental case. A sample of 172 Singaporean elementary school children completed implicit and explicit measures of math-gender stereotype (male=math), gender identity (me=male), and math self-concept (me=math). Results showed strong evidence for cognitive consistency; the strength of children's math-gender stereotypes, together with their gender identity, significantly predicted their math self-concepts. Cognitive consistency may be culturally universal and a key mechanism for developmental change in social cognition. We also discovered that Singaporean children's math-gender stereotypes increased as a function of age and that boys identified with math more strongly than did girls despite Singaporean girls' excelling in math. The results reveal both cultural universals and cultural variation in developing social cognition. Copyright © 2013 Elsevier Inc. All rights reserved.

The tight binding model study of the role of anisotropic AFM spin ordering in the charge ordered CMR manganites

NASA Astrophysics Data System (ADS)

Kar, J. K.; Panda, Saswati; Rout, G. C.

2017-05-01

We propose here a tight binding model study of the interplay between charge and spin orderings in the CMR manganites taking anisotropic effect due to electron hoppings and spin exchanges. The Hamiltonian consists of the kinetic energies of eg and t2g electrons of manganese ion. It further includes double exchange and Heisenberg interactions. The charge density wave interaction (CDW) describes an extra mechanism for the insulating character of the system. The CDW gap and spin parameters are calculated using Zubarev's Green's function technique and computed self-consistently. The results are reported in this communication.

Effect of double-layer application on bond quality of adhesive systems.

PubMed

Fujiwara, Satoshi; Takamizawa, Toshiki; Barkmeier, Wayne W; Tsujimoto, Akimasa; Imai, Arisa; Watanabe, Hidehiko; Erickson, Robert L; Latta, Mark A; Nakatsuka, Toshiyuki; Miyazaki, Masashi

2018-01-01

The aim of this study was to determine the effect of double-layer application of universal adhesives on the bond quality and compare to other adhesive systems. Two universal adhesives used were in this study: Scotchbond Universal (SU), [3M ESPE] and Prime & Bond elect (PE), [Dentsply Caulk]. The conventional single-step self-etch adhesives G-ӕnial Bond (GB), [GC Corporation.] and BeautiBond (BB), [Shofu Inc.], and a two-step self-etch adhesive, Optibond XTR (OX), [Kerr Corporation], were used as comparison adhesives. Shear bond strengths (SBS) and shear fatigue strengths (SFS) to human enamel and dentin were measured in single application mode and double application mode. For each test condition, 15 specimens were prepared for SBS testing and 30 specimens for SFS testing. Enamel and dentin SBS of the universal adhesives in the double application mode were significantly higher than those of the single application mode. In addition, the universal adhesives in the double application mode had significantly higher dentin SFS values than those of the single application mode. The two-step self-etch adhesive OX tended to have lower bond strengths in the double application mode, regardless of the test method or adherent substrate. The double application mode is effective in enhancing SBS and SFS of universal adhesives, but not conventional two-step self-etch adhesives. These results suggest that, although the double application mode may enhance the bonding quality of a universal adhesive, it may be counter-productive for two-step self-etch adhesives in clinical use. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of alumina ceramic encapsulation for self-healing materials on thermal barrier coating

NASA Astrophysics Data System (ADS)

Golim, O. P.; Prastomo, N.; Izzudin, H.; Hastuty, S.; Sundawa, R.; Sugiarti, E.; Thosin, K. A. Z.

2018-03-01

Durability of Thermal Barrier Coating or TBC can be optimized by inducing Self-Healing capabilities with intermetallic materials MoSi2. Nevertheless, high temperature operation causes the self-healing materials to become oxidized and lose its healing capabilities. Therefore, a method to introduce ceramic encapsulation for MoSi2 is needed to protect it from early oxidation. The encapsulation process is synthesized through a simple precipitation method with colloidal aluminum hydroxide as precursor and variations on calcination process. Semi-quantitative analysis on the synthesized sample is done by using X-ray diffraction (XRD) method. Meanwhile, qualitative analysis on the morphology of the encapsulation was carried out by using Scanning Electron Microscope (SEM) and Field Emission Scanning Electron Microscope (FESEM) equipped with dual Focus Ion Beam (FIB). The result of the experiment shows that calcination process significantly affects the final characteristic of encapsulation. The optimum encapsulation process was synthesized by colloidal aluminum hydroxide as a precursor, with a double step calcination process in low pressure until 900 °C.

Does a strategy to promote shared decision-making reduce medical practice variation in the choice of either single or double embryo transfer after in vitro fertilisation? A secondary analysis of a randomised controlled trial.

PubMed

Brabers, Anne E M; van Dijk, Liset; Groenewegen, Peter P; van Peperstraten, Arno M; de Jong, Judith D

2016-05-06

The hypothesis that shared decision-making (SDM) reduces medical practice variations is increasingly common, but no evidence is available. We aimed to elaborate further on this, and to perform a first exploratory analysis to examine this hypothesis. This analysis, based on a limited data set, examined how SDM is associated with variation in the choice of single embryo transfer (SET) or double embryo transfer (DET) after in vitro fertilisation (IVF). We examined variation between and within hospitals. A secondary analysis of a randomised controlled trial. 5 hospitals in the Netherlands. 222 couples (woman aged <40 years) on a waiting list for a first IVF cycle, who could choose between SET and DET (ie, ≥2 embryos available). SDM via a multifaceted strategy aimed to empower couples in deciding how many embryos should be transferred. The strategy consisted of decision aid, support of IVF nurse and the offer of reimbursement for an extra treatment cycle. Control group received standard IVF care. Difference in variation due to SDM in the choice of SET or DET, both between and within hospitals. There was large variation in the choice of SET or DET between hospitals in the control group. Lower variation between hospitals was observed in the group with SDM. Within most hospitals, variation in the choice of SET or DET appeared to increase due to SDM. Variation particularly increased in hospitals where mainly DET was chosen in the control group. Although based on a limited data set, our study gives a first insight that including patients' preferences through SDM results in less variation between hospitals, and indicates another pattern of variation within hospitals. Variation that results from patient preferences could be potentially named the informed patient rate. Our results provide the starting point for further research. NCT00315029; Post-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

GW and Bethe-Salpeter study of small water clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blase, Xavier, E-mail: xavier.blase@neel.cnrs.fr; Boulanger, Paul; Bruneval, Fabien

We study within the GW and Bethe-Salpeter many-body perturbation theories the electronic and optical properties of small (H{sub 2}O){sub n} water clusters (n = 1-6). Comparison with high-level CCSD(T) Coupled-Cluster at the Single Double (Triple) levels and ADC(3) Green’s function third order algebraic diagrammatic construction calculations indicates that the standard non-self-consistent G{sub 0}W{sub 0}@PBE or G{sub 0}W{sub 0}@PBE0 approaches significantly underestimate the ionization energy by about 1.1 eV and 0.5 eV, respectively. Consequently, the related Bethe-Salpeter lowest optical excitations are found to be located much too low in energy when building transitions from a non-self-consistent G{sub 0}W{sub 0} description ofmore » the quasiparticle spectrum. Simple self-consistent schemes, with update of the eigenvalues only, are shown to provide a weak dependence on the Kohn-Sham starting point and a much better agreement with reference calculations. The present findings rationalize the theory to experiment possible discrepancies observed in previous G{sub 0}W{sub 0} and Bethe-Salpeter studies of bulk water. The increase of the optical gap with increasing cluster size is consistent with the evolution from gas to dense ice or water phases and results from an enhanced screening of the electron-hole interaction.« less

On microscopic theory of radiative nuclear reaction characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamerdzhiev, S. P.; Achakovskiy, O. I., E-mail: oachakovskiy@ippe.ru; Avdeenkov, A. V.

2016-07-15

A survey of some results in the modern microscopic theory of properties of nuclear reactions with gamma rays is given. First of all, we discuss the impact of Phonon Coupling (PC) on the Photon Strength Function (PSF) because it represents the most natural physical source of additional strength found for Sn isotopes in recent experiments that could not be explained within the standard HFB + QRPA approach. The self-consistent version of the Extended Theory of Finite Fermi Systems in the Quasiparticle Time Blocking Approximation is applied. It uses the HFB mean field and includes both the QRPA and PC effectsmore » on the basis of the SLy4 Skyrme force. With our microscopic E1 PSFs, the following properties have been calculated for many stable and unstable even–even semi-magic Sn and Ni isotopes as well as for double-magic {sup 132}Sn and {sup 208}Pb using the reaction codes EMPIRE and TALYS with several Nuclear Level Density (NLD) models: (1) the neutron capture cross sections; (2) the corresponding neutron capture gamma spectra; (3) the average radiative widths of neutron resonances. In all the properties considered, the PC contribution turned out to be significant, as compared with the standard QRPA one, and necessary to explain the available experimental data. The results with the phenomenological so-called generalized superfluid NLD model turned out to be worse, on the whole, than those obtained with the microscopic HFB + combinatorial NLD model. The very topical question about the M1 resonance contribution to PSFs is also discussed.Finally, we also discuss the modern microscopic NLD models based on the self-consistent HFB method and show their relevance to explain the experimental data as compared with the phenomenological models. The use of these self-consistent microscopic approaches is of particular relevance for nuclear astrophysics, but also for the study of double-magic nuclei.« less

The optimization of self-phased arrays for diurnal motion tracking of synchronous satellites

NASA Technical Reports Server (NTRS)

Theobold, D. M.; Hodge, D. B.

1977-01-01

The diurnal motion of a synchronous satellite necessitates mechanical tracking when a large aperture, high gain antenna is employed at the earth terminal. An alternative solution to this tracking problem is to use a self phased array consisting of a number of fixed pointed elements, each with moderate directivity. Non-mechanical tracking and adequate directive gain are achieved electronically by phase coherent summing of the element outputs. The element beamwidths provide overlapping area coverage of the satellite motion but introduce a diurnal variation into the array gain. The optimum element beamwidth and pointing direction of these elements can be obtained under the condition that the array gain is maximized simultaneously with the minimization of the diurnal variation.

Neoclassical simulation of tokamak plasmas using the continuum gyrokinetic code TEMPEST.

PubMed

Xu, X Q

2008-07-01

We present gyrokinetic neoclassical simulations of tokamak plasmas with a self-consistent electric field using a fully nonlinear (full- f ) continuum code TEMPEST in a circular geometry. A set of gyrokinetic equations are discretized on a five-dimensional computational grid in phase space. The present implementation is a method of lines approach where the phase-space derivatives are discretized with finite differences, and implicit backward differencing formulas are used to advance the system in time. The fully nonlinear Boltzmann model is used for electrons. The neoclassical electric field is obtained by solving the gyrokinetic Poisson equation with self-consistent poloidal variation. With a four-dimensional (psi,theta,micro) version of the TEMPEST code, we compute the radial particle and heat fluxes, the geodesic-acoustic mode, and the development of the neoclassical electric field, which we compare with neoclassical theory using a Lorentz collision model. The present work provides a numerical scheme for self-consistently studying important dynamical aspects of neoclassical transport and electric field in toroidal magnetic fusion devices.

Neoclassical simulation of tokamak plasmas using the continuum gyrokinetic code TEMPEST

NASA Astrophysics Data System (ADS)

Xu, X. Q.

2008-07-01

We present gyrokinetic neoclassical simulations of tokamak plasmas with a self-consistent electric field using a fully nonlinear (full- f ) continuum code TEMPEST in a circular geometry. A set of gyrokinetic equations are discretized on a five-dimensional computational grid in phase space. The present implementation is a method of lines approach where the phase-space derivatives are discretized with finite differences, and implicit backward differencing formulas are used to advance the system in time. The fully nonlinear Boltzmann model is used for electrons. The neoclassical electric field is obtained by solving the gyrokinetic Poisson equation with self-consistent poloidal variation. With a four-dimensional (ψ,θ,γ,μ) version of the TEMPEST code, we compute the radial particle and heat fluxes, the geodesic-acoustic mode, and the development of the neoclassical electric field, which we compare with neoclassical theory using a Lorentz collision model. The present work provides a numerical scheme for self-consistently studying important dynamical aspects of neoclassical transport and electric field in toroidal magnetic fusion devices.

No-insulation multi-width winding technique for high temperature superconducting magnet

PubMed Central

Hahn, Seungyong; Kim, Youngjae; Keun Park, Dong; Kim, Kwangmin; Voccio, John P.; Bascuñán, Juan; Iwasa, Yukikazu

2013-01-01

We present a No-Insulation (NI) Multi-Width (MW) winding technique for an HTS (high temperature superconductor) magnet consisting of double-pancake (DP) coils. The NI enables an HTS magnet self-protecting and the MW minimizes the detrimental anisotropy in current-carrying capacity of HTS tape by assigning tapes of multiple widths to DP coils within a stack, widest tape to the top and bottom sections and the narrowest in the midplane section. This paper presents fabrication and test results of an NI-MW HTS magnet and demonstrates the unique features of the NI-MW technique: self-protecting and enhanced field performance, unattainable with the conventional technique. PMID:24255549

Outcomes of short course interprofessional training in domestic violence and child protection.

PubMed

Szilassy, Eszter; Carpenter, John; Patsios, Demi; Hackett, Simon

2013-11-01

The interrelationship between domestic violence and child protection is well established, yet deficiencies in interprofessional collaboration have been reported and training is advocated as a solution. This study evaluates the outcomes of short interagency and interprofessional training in domestic abuse. Participants' attitudes and knowledge were assessed using a self-report scale and compared in a double-baseline time-series design. Participants (N = 177) were recruited from a range of agencies in England. There were consistent, statistically significant improvements in participants' attitudes, knowledge, and self-confidence between the start and end of course (p < .001). The long-term outcomes of training and the implementation of learning, however, remain uncertain.

Mira variables: An informal review

NASA Technical Reports Server (NTRS)

Wing, R. F.

1980-01-01

The structure of the Mira variables is discussed with particular emphasis on the extent of their observable atmospheres, the various methods for measuring the sizes of these atmospheres, and the manner in which the size changes through the cycle. The results obtained by direct, photometric and spectroscopic methods are compared, and the problems of interpretation are addressed. Also, a simple model for the atmospheric structure and motions of Miras based on recent observations of the doubling of infrared molecualr times is described. This model, consisting of two atmospheric layers plus a circumstellar shell, provides a physically plausible picture of the atmosphere which is consistent with the photometrically measured magnitude and temperature variations as well as the spectroscopic data.

Effects of drain bias on the statistical variation of double-gate tunnel field-effect transistors

NASA Astrophysics Data System (ADS)

Choi, Woo Young

2017-04-01

The effects of drain bias on the statistical variation of double-gate (DG) tunnel field-effect transistors (TFETs) are discussed in comparison with DG metal-oxide-semiconductor FETs (MOSFETs). Statistical variation corresponds to the variation of threshold voltage (V th), subthreshold swing (SS), and drain-induced barrier thinning (DIBT). The unique statistical variation characteristics of DG TFETs and DG MOSFETs with the variation of drain bias are analyzed by using full three-dimensional technology computer-aided design (TCAD) simulation in terms of the three dominant variation sources: line-edge roughness (LER), random dopant fluctuation (RDF) and workfunction variation (WFV). It is observed than DG TFETs suffer from less severe statistical variation as drain voltage increases unlike DG MOSFETs.

Biological monitoring of environmental quality: The use of developmental instability

USGS Publications Warehouse

Freeman, D.C.; Emlen, J.M.; Graham, J.H.; Hough, R. A.; Bannon, T.A.

1994-01-01

Distributed robustness is thought to influence the buffering of random phenotypic variation through the scale-free topology of gene regulatory, metabolic, and protein-protein interaction networks. If this hypothesis is true, then the phenotypic response to the perturbation of particular nodes in such a network should be proportional to the number of links those nodes make with neighboring nodes. This suggests a probability distribution approximating an inverse power-law of random phenotypic variation. Zero phenotypic variation, however, is impossible, because random molecular and cellular processes are essential to normal development. Consequently, a more realistic distribution should have a y-intercept close to zero in the lower tail, a mode greater than zero, and a long (fat) upper tail. The double Pareto-lognormal (DPLN) distribution is an ideal candidate distribution. It consists of a mixture of a lognormal body and upper and lower power-law tails.

Stabilizing Various Bicontinuous Morphologies via Polydispersity of Diblock Copolymers

NASA Astrophysics Data System (ADS)

Lai, Chi To; Shi, An-Chang

Diblock copolymers are macromolecules composed of two chemically distinct homopolymers covalently bound end-to-end. The ability to self-assembly into a wide variety of ordered periodic structures, as means of minimizing the free energy, is their most well-studied property. There are many factors affecting the observed equilibrium morphology, one of which is polydispersity. The phase behaviour of polydispersed diblock copolymers is more rich, and diverse when compared to their monodispersed counterpart. The rich behaviour of polydispersed diblock copolymers provides an opportunity to engineer novel morphologies which are not available in monodispersed systems. Using the self-consistent field theory (SCFT), we explore the possibility of exploiting polydispersity of diblock copolymers in binary mixtures to stabilize the various bicontinuous phases, such as the double-diamond morphology. Specifically, solutions of the SCFT equations corresponding to different bicontinuous phases are obtained numerically for binary mixtures of diblock copolymers. The relative stability of the different ordered phases is examined by comparing their free energy. From the study, we determine optimal sets of parameters that stabilize the double-diamond or other exotic morphologies.

[Spectral analysis of fiber bragg grating modulated by double long period grating and its application in smart structure monitoring].

PubMed

Lu, Ji-Yun; Liang, Da-Kai; Zhang, Xiao-Li; Zhu, Zhu

2009-12-01

Spectrum of fiber bragg grating (FBG) sensor modulated by double long period grating (LPFG) is proposed in the paper. Double LPFG consists of two LPFGS whose center wavelengths are the same and reflection spectrum of FBG sensor is located in linear range of double LPFG transmission spectrum. Based on spectral analysis of FBG and double LPFG, reflection spectrum of FBG modulated by double LPFG is obtained and studied by use of band-hider filter characteristics for double LPFG. An FBG sensor is attached on the surface of thin steel beam, which is strained by bending, and the center wavelength of FBG sensor will shift. The spectral peak of FBG sensor modulated by double LPFG is changed correspondingly, and the spectral change will lead to variation in exit light intensity from double LPFG. Experiment demonstrates that the relation of filtering light intensity from double LPFG monitored by optical power meter to center wavelength change of FBG sensor is linear and the minimum strain of material (steel beam) detected by the modulation and demodulation system is 1.05 microepsilon. This solution is used in impact monitoring of optical fibre smart structure, and FBG sensor is applied for impulse response signal monitoring induced by low-velocity impact, when impact pendulum is loaded to carbon fiber-reinforced plastics (CFP). The acquired impact response signal and fast Fourier transform of the signal detected by FBG sensor agree with the measurement results of eddy current displacement meter attached to the FBG sensor. From the results, the present method using FBG sensor is found to be effective for monitoring the impact. The research provides a practical reference in dynamic monitoring of optical fiber smart structure field.

Dual-wavelength green laser with a 4.5 THz frequency difference based on self-frequency- doubling in Nd3+ -doped aperiodically poled lithium niobate.

PubMed

Maestre, H; Torregrosa, A J; Fernández-Pousa, C R; Rico, M L; Capmany, J

2008-05-01

We report a dual-wavelength continuous-wave laser at 542.4 and 546.8 nm based on an Nd(3+)-doped aperiodically poled lithium niobate crystal. Two fundamental infrared (IR) wavelengths at 1084.8 and 1093.6 nm are simultaneously oscillated and self-frequency-doubled to green. The aperiodic domain distribution patterned in the crystal allows for quasi-phase matched self-frequency-doubling of both IR fundamentals while avoiding their sum-frequency mixing.

Thermal fatigue and oxidation data of TAZ-8A and M22 alloys and variations

NASA Technical Reports Server (NTRS)

Hofer, K. E.; Humphreys, V. E.

1981-01-01

Thermal fatigue and oxidation data were obtained on 36 specimens, representing 18 distinct variations (including the base systems) of TAZ-8A and M22 alloys. Double-edge wedge specimens for these systems were cycled between fluidized beds maintained at 1088 C and 316 C with a 180 s immersion in each bed. The systems included alloys TAZ-8A, M22, and 16 variations of these alloys. Each alloy variation consisted of a unique composition with an alternation in the percentage of carbon (C1 and C2), molydenum (M1 and M2), tungsten (W1 and W2), columbium (CB1, CB2, and CB3), tantalium (T1, T2, and T3), or boron (B1, B2, and B3) present. All of the alloys showed little weight change due to oxidation compared with other alloys previously tested in fluidized beds. Only both C1 alloy variation specimens survived 3500 cycles without cracking in the small radius, although substantial cracks were present, emanating from the end notches which were used for holding the specimens.

Parental HIV/AIDS and psychosocial adjustment among rural Chinese children.

PubMed

Fang, Xiaoyi; Li, Xiaoming; Stanton, Bonita; Hong, Yan; Zhang, Liying; Zhao, Guoxiang; Zhao, Junfeng; Lin, Xiuyun; Lin, Danhua

2009-01-01

To assess the relationship between parental HIV/AIDS and psychosocial adjustment of children in rural central China. Participants included 296 double AIDS orphans (children who had lost both their parents to AIDS), 459 single orphans (children who had lost one parent to AIDS), 466 vulnerable children who lived with HIV-infected parents, and 404 comparison children who did not experience HIV/AIDS-related illness and death in their families. The measures included depressive symptoms, loneliness, self-esteem, future expectations, hopefulness about the future, and perceived control over the future. AIDS orphans and vulnerable children consistently demonstrated poorer psychosocial adjustment than comparison children in the same community. The level of psychosocial adjustment was similar between single orphans and double orphans, but differed by care arrangement among double orphans. The findings underscore the urgency and importance of culturally and developmentally appropriate intervention efforts targeting psychosocial problems among children affected by AIDS and call for more exploration of risk and resilience factors, both individual and contextual, affecting the psychosocial wellbeing of these children.

Formation of the Electric Double Layer and its Effects on Moving Bodies in a Space Plasma Environment

NASA Technical Reports Server (NTRS)

Yang, Qianli; Wu, S. T.; Stone, N. H.; Li, Xiaoquing

1996-01-01

In this paper we solve the self-consistent Vlasov and Poisson equations by a numerical method to determine the local distribution function of the ion and the electron, within a thin layer near the moving body, respectively. Using these ion and electron distributions, the number density for the ions and electrons are determined, such that, the electric potential is obtained within this thin layer (i.e., measured by Debye length). Numerical results are presented for temporal evolution of the electron and ion density and its corresponding electric potential within the layer which shows the formation of electric double layer and its structures. From these numerical results, we are able to determine the maximum conditions of the electric potential, it may create satellite anomaly.

No double detonations but core carbon ignitions in high-resolution, grid-based simulations of binary white dwarf mergers

NASA Astrophysics Data System (ADS)

Fenn, D.; Plewa, T.; Gawryszczak, A.

2016-11-01

We study the violent phase of the merger of massive binary white dwarf systems. Our aim is to characterize the conditions for explosive burning to occur, and identify a possible explosion mechanism of Type Ia supernovae. The primary components of our model systems are carbon-oxygen (C/O) white dwarfs, while the secondaries are made either of C/O or of pure helium. We account for tidal effects in the initial conditions in a self-consistent way, and consider initially well-separated systems with slow inspiral rates. We study the merger evolution using an adaptive mesh refinement, reactive, Eulerian code in three dimensions, assuming symmetry across the orbital plane. We use a corotating reference frame to minimize the effects of numerical diffusion, and solve for self-gravity using a multigrid approach. We find a novel detonation mechanism in C/O mergers with massive primaries. Here, the detonation occurs in the primary's core and relies on the combined action of tidal heating, accretion heating, and self-heating due to nuclear burning. The exploding structure is compositionally stratified, with a reverse shock formed at the surface of the dense ejecta. The existence of such a shock has not been reported elsewhere. The explosion energy (1.6 × 1051 erg) and 56Ni mass (0.86 M⊙) are consistent with an SN Ia at the bright end of the luminosity distribution, with an approximated decline rate of Δm15(B) ≈ 0.99. Our study does not support double-detonation scenarios in the case of a system with a 0.6 M⊙ helium secondary and a 0.9 M⊙ primary. Although the accreted helium detonates, it fails to ignite carbon at the base of the boundary layer or in the primary's core.

Ultracold Fermions in the P-Orbital Band of an Optical Lattice

DTIC Science & Technology

2015-07-27

introduces (1) a new degree of freedom due to orbital degeneracy and (2) a tunneling anisotropy which depends on the orientation of the orbital wavefunction...demonstrated this new technique with a diode -pumped solid-state laser operating at 1342 nm that could be frequency doubled to provide 671 nm light for laser...Figure 3: Self-injection locked, diode -pumped solid-state laser for laser cooling of Li atoms. The solid-state Nd:YVO4 laser at the top consists of a

An ab initio study on the four electronically lowest-lying states of CH 2 using the state-averaged complete active space second-order configuration interaction method

NASA Astrophysics Data System (ADS)

Yamaguchi, Yukio; Schaefer, Henry F., III

1997-12-01

Four electronically lowest-lying ( X˜ 3B 1, ã 1A 1, b˜ 1B 1, and c˜ 1A 1) states of CH 2 have been investigated systematically using ab initio electronic structure theory. Complete active space (CAS) self-consistent-field (SCF) second-order configuration interaction (SOCI) and state-averaged (SA) CASSCF-SOCI levels of theory have been employed. The CASSCF reference wave function was constructed by minimizing the total energy of a specified state, while the SACASSCF reference wave function was obtained by minimizing the equally weighted total energy of the four ( X˜ 3B 1, ã 1A 1, b˜ 1B 1, and c˜ 1A 1) states. The third excited state ( c˜ 1A 1 or 2 1A 1) is of particular theoretical interest because it is represented by the second root of CASSCF and SOCI Hamiltonian matrices. Theoretical treatments of states not the lowest of their symmetry require special attention due to their tendency of variational collapse to the lower-lying state(s). For these four lowest-lying states total energies and physical properties including dipole moments, harmonic vibrational frequencies, and associated infrared (IR) intensities were determined and compared with the results from the configuration interaction with single and double excitations (CISD) method and available experimental values. The CASSCF-SOCI method should provide the most reliable energetics and physical properties in the present study owing to its fully variational nature in the molecular orbital (MO) and CI spaces for a given state. It is demonstrated that the SACASSCF-SOCI wave functions produce results which are quite consistent with those from the CASSCF-SOCI method. Thus significantly increased application of the SACASSCF-SOCI method to the excited states of a wide variety of molecular systems is expected.

Self-compression of spatially limited laser pulses in a system of coupled light-guides

NASA Astrophysics Data System (ADS)

Balakin, A. A.; Litvak, A. G.; Mironov, V. A.; Skobelev, S. A.

2018-04-01

The self-action features of wave packets propagating in a 2D system of equidistantly arranged fibers are studied analytically and numerically on the basis of the discrete nonlinear Schrödinger equation. Self-consistent equations for the characteristic scales of a Gaussian wave packet are derived on the basis of the variational approach, which are proved numerically for powers P < 10 P_cr , slightly exceeding the critical one for self-focusing. At higher powers, the wave beams become filamented, and their amplitude is limited due to the nonlinear breaking of the interaction between neighboring light-guides. This makes it impossible to collect a powerful wave beam in a single light-guide. Variational analysis shows the possibility of the adiabatic self-compression of soliton-like laser pulses in the process of 3D self-focusing on the central light-guide. However, further increase of the field amplitude during self-compression leads to the development of longitudinal modulation instability and the formation of a set of light bullets in the central fiber. In the regime of hollow wave beams, filamentation instability becomes predominant. As a result, it becomes possible to form a set of light bullets in optical fibers located on the ring.

Structural and functional characterization of the product of disease-related factor H gene conversion.

PubMed

Herbert, Andrew P; Kavanagh, David; Johansson, Conny; Morgan, Hugh P; Blaum, Bärbel S; Hannan, Jonathan P; Barlow, Paul N; Uhrín, Dušan

2012-03-06

Numerous complement factor H (FH) mutations predispose patients to atypical hemolytic uremic syndrome (aHUS) and other disorders arising from inadequately regulated complement activation. No unifying structural or mechanistic consequences have been ascribed to these mutants beyond impaired self-cell protection. The S1191L and V1197A mutations toward the C-terminus of FH, which occur in patients singly or together, arose from gene conversion between CFH encoding FH and CFHR1 encoding FH-related 1. We show that neither single nor double mutations structurally perturbed recombinant proteins consisting of the FH C-terminal modules, 19 and 20 (FH19-20), although all three FH19-20 mutants were poor, compared to wild-type FH19-20, at promoting hemolysis of C3b-coated erythrocytes through competition with full-length FH. Indeed, our new crystal structure of the S1191L mutant of FH19-20 complexed with an activation-specific complement fragment, C3d, was nearly identical to that of the wild-type FH19-20:C3d complex, consistent with mutants binding to C3b with wild-type-like affinity. The S1191L mutation enhanced thermal stability of module 20, whereas the V1197A mutation dramatically decreased it. Thus, although mutant proteins were folded at 37 °C, they differ in conformational rigidity. Neither single substitutions nor double substitutions increased measurably the extent of FH19-20 self-association, nor did these mutations significantly affect the affinity of FH19-20 for three glycosaminoglycans, despite critical roles of module 20 in recognizing polyanionic self-surface markers. Unexpectedly, FH19-20 mutants containing Leu1191 self-associated on a heparin-coated surface to a higher degree than on surfaces coated with dermatan or chondroitin sulfates. Thus, potentially disease-related functional distinctions between mutants, and between FH and FH-related 1, may manifest in the presence of specific glycosaminoglycans.

Applying AFM-based nanofabrication for measuring the thickness of nanopatterns: the role of head groups in the vertical self-assembly of omega-functionalized n-alkanethiols.

PubMed

Kelley, Algernon T; Ngunjiri, Johnpeter N; Serem, Wilson K; Lawrence, Steve O; Yu, Jing-Jiang; Crowe, William E; Garno, Jayne C

2010-03-02

Molecules of n-alkanethiols with methyl head groups typically form well-ordered monolayers during solution self-assembly for a wide range of experimental conditions. However, we have consistently observed that, for either carboxylic acid or thiol-terminated n-alkanethiols, under certain conditions nanografted patterns are generated with a thickness corresponding precisely to a double layer. To investigate the role of head groups for solution self-assembly, designed patterns of omega-functionalized n-alkanethiols were nanografted with systematic changes in concentration. Nanografting is an in situ approach for writing patterns of thiolated molecules on gold surfaces by scanning with an AFM tip under high force, accomplished in dilute solutions of desired ink molecules. As the tip is scanned across the surface of a self-assembled monolayer under force, the matrix molecules are displaced from the surface and are immediately replaced with fresh molecules from solution to generate nanopatterns. In this report, side-by-side comparison of nanografted patterns is achieved for different matrix molecules using AFM images. The chain length and head groups (i.e., carboxyl, hydroxyl, methyl, thiol) were varied for the nanopatterns and matrix monolayers. Interactions such as head-to-head dimerization affect the vertical self-assembly of omega-functionalized n-alkanethiol molecules within nanografted patterns. At certain threshold concentrations, double layers were observed to form when nanografting with head groups of carboxylic acid and dithiols, whereas single layers were generated exclusively for nanografted patterns with methyl and hydroxyl groups, regardless of changes in concentration.

Local house prices and mental health.

PubMed

Joshi, Nayan Krishna

2016-03-01

This paper examines the impact of local (county-level) house prices on individual self-reported mental health using individual level data from the United States Behavioral Risk Factor Surveillance System between 2005 and 2011. Exploiting a fixed-effects model that relies on within-county variations, relative to the corresponding changes in other counties, I find that while individuals are likely to experience worse self-reported mental health when local house prices decline, this association is most pronounced for individuals who are least likely to be homeowners. This finding is not consistent with a prediction from a pure wealth mechanism but rather with the hypothesis that house prices act as an economic barometer. I also demonstrate that the association between self-reported mental health and local house prices is not driven by unemployment or foreclosure. The primary result-that lower local house prices have adverse impact on self-reported mental health of homeowners and renters-is consistent with studies using data from the United Kingdom.

Lateral temperature variations at the core-mantle boundary deduced from the magnetic field

NASA Technical Reports Server (NTRS)

Bloxham, Jeremy; Jackson, Andrew

1990-01-01

Recent studies of the secular variation of the earth's magnetic field over periods of a few centuries have suggested that the pattern of fluid motion near the surface of earth's outer core may be strongly influenced by lateral temperature variations in the lowermost mantle. This paper introduces a self-consistent method for finding the temperature variations near the core surface by assuming that the dynamical balance there is geostrophic and that lateral density variations there are thermal in origin. As expected, the lateral temperature variations are very small. Some agreement is found between this pattern and the pattern of topography of the core-mantle boundary, but this does not conclusively answer to what extent core surface motions are controlled by the mantle, rather than being determined by processes in the core.

A New Equivalence Theory Method for Treating Doubly Heterogeneous Fuel - I. Theory

DOE PAGES

Williams, Mark L.; Lee, Deokjung; Choi, Sooyoung

2015-03-04

A new methodology has been developed to treat resonance self-shielding in doubly heterogeneous very high temperature gas-cooled reactor systems in which the fuel compact region of a reactor lattice consists of small fuel grains dispersed in a graphite matrix. This new method first homogenizes the fuel grain and matrix materials using an analytically derived disadvantage factor from a two-region problem with equivalence theory and intermediate resonance method. This disadvantage factor accounts for spatial self-shielding effects inside each grain within the framework of an infinite array of grains. Then the homogenized fuel compact is self-shielded using a Bondarenko method to accountmore » for interactions between the fuel compact regions in the fuel lattice. In the final form of the equations for actual implementations, the double-heterogeneity effects are accounted for by simply using a modified definition of a background cross section, which includes geometry parameters and cross sections for both the grain and fuel compact regions. With the new method, the doubly heterogeneous resonance self-shielding effect can be treated easily even with legacy codes programmed only for a singly heterogeneous system by simple modifications in the background cross section for resonance integral interpolations. This paper presents a detailed derivation of the new method and a sensitivity study of double-heterogeneity parameters introduced during the derivation. The implementation of the method and verification results for various test cases are presented in the companion paper.« less

Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets

PubMed Central

Francisconi, Manoela Fávaro; Janson, Guilherme; Henriques, José Fernando Castanha; de Freitas, Karina Maria Salvatore

2016-01-01

ABSTRACT Objective: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Material and Methods: Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05). Results: Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Conclusions: Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires. PMID:27812620

Polarized atomic orbitals for self-consistent field electronic structure calculations

NASA Astrophysics Data System (ADS)

Lee, Michael S.; Head-Gordon, Martin

1997-12-01

We present a new self-consistent field approach which, given a large "secondary" basis set of atomic orbitals, variationally optimizes molecular orbitals in terms of a small "primary" basis set of distorted atomic orbitals, which are simultaneously optimized. If the primary basis is taken as a minimal basis, the resulting functions are termed polarized atomic orbitals (PAO's) because they are valence (or core) atomic orbitals which have distorted or polarized in an optimal way for their molecular environment. The PAO's derive their flexibility from the fact that they are formed from atom-centered linear-combinations of the larger set of secondary atomic orbitals. The variational conditions satisfied by PAO's are defined, and an iterative method for performing a PAO-SCF calculation is introduced. We compare the PAO-SCF approach against full SCF calculations for the energies, dipoles, and molecular geometries of various molecules. The PAO's are potentially useful for studying large systems that are currently intractable with larger than minimal basis sets, as well as offering potential interpretative benefits relative to calculations in extended basis sets.

Patterns of thought: Population variation in the associations between large-scale network organisation and self-reported experiences at rest.

PubMed

Wang, Hao-Ting; Bzdok, Danilo; Margulies, Daniel; Craddock, Cameron; Milham, Michael; Jefferies, Elizabeth; Smallwood, Jonathan

2018-08-01

Contemporary cognitive neuroscience recognises unconstrained processing varies across individuals, describing variation in meaningful attributes, such as intelligence. It may also have links to patterns of on-going experience. This study examined whether dimensions of population variation in different modes of unconstrained processing can be described by the associations between patterns of neural activity and self-reports of experience during the same period. We selected 258 individuals from a publicly available data set who had measures of resting-state functional magnetic resonance imaging, and self-reports of experience during the scan. We used machine learning to determine patterns of association between the neural and self-reported data, finding variation along four dimensions. 'Purposeful' experiences were associated with lower connectivity - in particular default mode and limbic networks were less correlated with attention and sensorimotor networks. 'Emotional' experiences were associated with higher connectivity, especially between limbic and ventral attention networks. Experiences focused on themes of 'personal importance' were associated with reduced functional connectivity within attention and control systems. Finally, visual experiences were associated with stronger connectivity between visual and other networks, in particular the limbic system. Some of these patterns had contrasting links with cognitive function as assessed in a separate laboratory session - purposeful thinking was linked to greater intelligence and better abstract reasoning, while a focus on personal importance had the opposite relationship. Together these findings are consistent with an emerging literature on unconstrained states and also underlines that these states are heterogeneous, with distinct modes of population variation reflecting the interplay of different large-scale networks. Copyright © 2018 Elsevier Inc. All rights reserved.

Angular momentum exchange in white dwarf binaries accreting through direct impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sepinsky, J. F.; Kalogera, V., E-mail: jeremy.sepinsky@scranton.edu, E-mail: vicky@northwestern.edu

We examine the exchange of angular momentum between the component spins and the orbit in semi-detached double white dwarf binaries undergoing mass transfer through direct impact of the transfer stream. We approximate the stream as a series of discrete massive particles ejected in the ballistic limit at the inner Lagrangian point of the donor toward the accretor. This work improves upon similar earlier studies in a number of ways. First, we self-consistently calculate the total angular momentum of the orbit at all times. This includes changes in the orbital angular momentum during the ballistic trajectory of the ejected mass, asmore » well as changes during the ejection/accretion due to the radial component of the particle's velocity. Second, we calculate the particle's ballistic trajectory for each system, which allows us to determine the precise position and velocity of the particle upon accretion. We can then include specific information about the radius of the accretor as well as the angle of impact. Finally, we ensure that the total angular momentum is conserved, which requires the donor star spin to vary self-consistently. With these improvements, we calculate the angular momentum change of the orbit and each binary component across the entire parameter space of direct impact double white dwarf binary systems. We find a significant decrease in the amount of angular momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular momentum of the orbit at the expense of the spin angular momentum of the donor. We conclude that, unlike earlier claims in the literature, mass transfer through direct impact need not destabilize the binary and that the quantity and sign of the orbital angular momentum transfer depends on the binary properties, particularly the masses of the double white dwarf binary component stars. This stabilization may significantly impact the population synthesis calculations of the expected numbers of events/systems for which double white dwarfs may be a progenitor, e.g., Type Ia supernovae, Type.Ia supernovae, and AM CVn.« less

Self-Organized Mantle Layering After the Magma-Ocean Period

NASA Astrophysics Data System (ADS)

Hansen, U.; Dude, S.

2017-12-01

The thermal history of the Earth, it's chemical differentiation and also the reaction of the interior with the atmosphere is largely determined by convective processes within the Earth's mantle. A simple physical model, resembling the situation, shortly after core formation, consists of a compositionally stable stratified mantle, as resulting from fractional crystallization of the magma ocean. The early mantle is subject to heating from below by the Earth's core and cooling from the top through the atmosphere. Additionally internal heat sources will serve to power the mantle dynamics. Under such circumstances double diffusive convection will eventually lead to self -organized layer formation, even without the preexisting jumps is material properties. We have conducted 2D and 3D numerical experiments in Cartesian and spherical geometry, taking into account mantle realistic values, especially a strong temperature dependent viscosity and a pressure dependent thermal expansivity . The experiments show that in a wide parameter range. distinct convective layers evolve in this scenario. The layering strongly controls the heat loss from the core and decouples the dynamics in the lower mantle from the upper part. With time, individual layers grow on the expense of others and merging of layers does occur. We observe several events of intermittent breakdown of individual layers. Altogether an evolution emerges, characterized by continuous but also spontaneous changes in the mantle structure, ranging from multiple to single layer flow. Such an evolutionary path of mantle convection allows to interpret phenomena ranging from stagnation of slabs at various depth to variations in the chemical signature of mantle upwellings in a new framework.

Self-consistent electrostatic simulations of reforming double layers in the downward current region of the aurora

NASA Astrophysics Data System (ADS)

Gunell, H.; Andersson, L.; De Keyser, J.; Mann, I.

2015-10-01

The plasma on a magnetic field line in the downward current region of the aurora is simulated using a Vlasov model. It is found that an electric field parallel to the magnetic fields is supported by a double layer moving toward higher altitude. The double layer accelerates electrons upward, and these electrons give rise to plasma waves and electron phase-space holes through beam-plasma interaction. The double layer is disrupted when reaching altitudes of 1-2 Earth radii where the Langmuir condition no longer can be satisfied due to the diminishing density of electrons coming up from the ionosphere. During the disruption the potential drop is in part carried by the electron holes. The disruption creates favourable conditions for double layer formation near the ionosphere and double layers form anew in that region. The process repeats itself with a period of approximately 1 min. This period is determined by how far the double layer can reach before being disrupted: a higher disruption altitude corresponds to a longer repetition period. The disruption altitude is, in turn, found to increase with ionospheric density and to decrease with total voltage. The current displays oscillations around a mean value. The period of the oscillations is the same as the recurrence period of the double layer formations. The oscillation amplitude increases with increasing voltage, whereas the mean value of the current is independent of voltage in the 100 to 800 V range covered by our simulations. Instead, the mean value of the current is determined by the electron density at the ionospheric boundary.

High-temperature fcc phase of Pr:  Negative thermal expansion and intermediate valence state

NASA Astrophysics Data System (ADS)

Kuznetsov, A. Yu.; Dmitriev, V. P.; Bandilet, O. I.; Weber, H.-P.

2003-08-01

A high-temperature angle-dispersive synchrotron radiation diffraction study has revealed the double hexagonal-close-packed-to-face-centered-cubic (dhcp-to-fcc) transformation in the Pr metal occurring martensitically between 575 and 1035 K. The high-temperature fcc phase shows a negative thermal expansion in the range 600 800 K, attributed to the 4f-electron delocalization. A phenomenological theory is developed, which explains consistently the observed effect in terms of the mean valence variation of the metal as a function of temperature; it also predicts the existence of an isostructural phase transition and of a critical end point of a gas-liquid type in compressed Pr. The analysis of published data on P-T variation of conductivity of Pr supports this prediction.

Suspended sub-50 nm vanadium dioxide membrane transistors: fabrication and ionic liquid gating studies

NASA Astrophysics Data System (ADS)

Sim, Jai S.; Zhou, You; Ramanathan, Shriram

2012-10-01

We demonstrate a robust lithographic patterning method to fabricate self-supported sub-50 nm VO2 membranes that undergo a phase transition. Utilizing such self-supported membranes, we directly observed a shift in the metal-insulator transition temperature arising from stress relaxation and consistent opening of the hysteresis. Electric double layer transistors were then fabricated with the membranes and compared to thin film devices. The ionic liquid allowed reversible modulation of channel resistance and distinguishing bulk processes from the surface effects. From the shift in the metal-insulator transition temperature, the carrier density doped through electrolyte gating is estimated to be 1 × 1020 cm-3. Hydrogen annealing studies showed little difference in resistivity between the film and the membrane indicating rapid diffusion of hydrogen in the vanadium oxide rutile lattice consistent with previous observations. The ability to fabricate electrically-wired, suspended VO2 ultra-thin membranes creates new opportunities to study mesoscopic size effects on phase transitions and may also be of interest in sensor devices.

Effects of 3,4-methylenedioxymethamphetamine on socioemotional feelings, authenticity, and autobiographical disclosure in healthy volunteers in a controlled setting.

PubMed

Baggott, Matthew J; Coyle, Jeremy R; Siegrist, Jennifer D; Garrison, Kathleen J; Galloway, Gantt P; Mendelson, John E

2016-04-01

The drug 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy", "molly") is a widely used illicit drug and experimental adjunct to psychotherapy. MDMA has unusual, poorly understood socioemotional effects, including feelings of interpersonal closeness and sociability. To better understand these effects, we conducted a small (n=12) within-subjects double-blind placebo controlled study of the effects of 1.5 mg/kg oral MDMA on social emotions and autobiographical disclosure in a controlled setting. MDMA displayed both sedative- and stimulant-like effects, including increased self-report anxiety. At the same time, MDMA positively altered evaluation of the self (i.e. increasing feelings of authenticity) while decreasing concerns about negative evaluation by others (i.e. decreasing social anxiety). Consistent with these feelings, MDMA increased how comfortable participants felt describing emotional memories. Overall, MDMA produced a prosocial syndrome that seemed to facilitate emotional disclosure and that appears consistent with the suggestion that it represents a novel pharmacological class. © The Author(s) 2016.

Hybrid configuration mixing model for odd nuclei

NASA Astrophysics Data System (ADS)

Colò, G.; Bortignon, P. F.; Bocchi, G.

2017-03-01

In this work, we introduce a new approach which is meant to be a first step towards complete self-consistent low-lying spectroscopy of odd nuclei. So far, we essentially limit ourselves to the description of a double-magic core plus an extra nucleon. The model does not contain any free adjustable parameter and is instead based on a Hartree-Fock (HF) description of the particle states in the core, together with self-consistent random-phase approximation (RPA) calculations for the core excitations. We include both collective and noncollective excitations, with proper care of the corrections due to the overlap between them (i.e., due to the nonorthonormality of the basis). As a consequence, with respect to traditional particle-vibration coupling calculations in which one can only address single-nucleon states and particle-vibration multiplets, we can also describe states of shell-model types like 2 particle-1 hole. We will report results for 49Ca and 133Sb and discuss future perspectives.

Towards a fully self-consistent inversion combining historical and paleomagnetic data for geomagnetic field reconstructions

NASA Astrophysics Data System (ADS)

Arneitz, P.; Leonhardt, R.; Fabian, K.; Egli, R.

2017-12-01

Historical and paleomagnetic data are the two main sources of information about the long-term geomagnetic field evolution. Historical observations extend to the late Middle Ages, and prior to the 19th century, they consisted mainly of pure declination measurements from navigation and orientation logs. Field reconstructions going back further in time rely solely on magnetization acquired by rocks, sediments, and archaeological artefacts. The combined dataset is characterized by a strongly inhomogeneous spatio-temporal distribution and highly variable data reliability and quality. Therefore, an adequate weighting of the data that correctly accounts for data density, type, and realistic error estimates represents the major challenge for an inversion approach. Until now, there has not been a fully self-consistent geomagnetic model that correctly recovers the variation of the geomagnetic dipole together with the higher-order spherical harmonics. Here we present a new geomagnetic field model for the last 4 kyrs based on historical, archeomagnetic and volcanic records. The iterative Bayesian inversion approach targets the implementation of reliable error treatment, which allows different record types to be combined in a fully self-consistent way. Modelling results will be presented along with a thorough analysis of model limitations, validity and sensitivity.

Quantitative Trait Loci Differentiating the Outbreeding Mimulus Guttatus from the Inbreeding M. Platycalyx

PubMed Central

Lin, J. Z.; Ritland, K.

1997-01-01

Theoretical predictions about the evolution of selfing depend on the genetic architecture of loci controlling selfing (monogenic vs. polygenic determination, large vs. small effect of alleles, dominance vs. recessiveness), and studies of such architecture are lacking. We inferred the genetic basis of mating system differences between the outbreeding Mimulus guttatus and the inbreeding M. platycalyx by quantitative trait locus (QTL) mapping using random amplified polymorphic DNA and isozyme markers. One to three QTL were detected for each of five mating system characters, and each QTL explained 7.6-28.6% of the phenotypic variance. Taken together, QTL accounted for up to 38% of the variation in mating system characters, and a large proportion of variation was unaccounted for. Inferred QTL often affected more than one trait, contributing to the genetic correlation between those traits. These results are consistent with the hypothesis that quantitative variation in plant mating system characters is primarily controlled by loci with small effect. PMID:9215912

Microscopic calculations of the characteristics of radiative nuclear reactions for double-magic nuclei

NASA Astrophysics Data System (ADS)

Achakovskiy, Oleg; Kamerdzhiev, Sergei; Tselyaev, Victor; Shitov, Mikhail

2016-01-01

The neutron capture cross sections and average radiative widths Γγ of neutron resonances for two double-magic nuclei 132Sn and 208Pb have been calculated using the microscopic photon strength functions (PSF), which were obtained within the microscopic self-consistent version of the extended theory of finite Fermi systems in the time blocking approximation. For the first time, the microscopic PSFs have been obtained within the fully self-consistent approach with exact accounting for the single particle continuum (for 208Pb). The approach includes phonon coupling effects in addition to the standard RPA approach. The known Skyrme force has been used. The calculations of nuclear reaction characteristics have been performed with the EMPIRE 3.1 nuclear reaction code. Here, three nuclear level density (NLD) models have been used: the so-called phenomenological GSM, the EMPIRE specific (or Enhanced GSM) and the microscopical combinatorial HFB NLD models. For both considered characteristics we found a significant disagreement between the results obtained with the GSM and HFB NLD models. For 208Pb, a reasonable agreement has been found with systematic for the Γγ values with HFB NLD and with the experimental data for the HFB NLD average resonance spacing D0, while for these two quantities the differences between the values obtained with GSM and HFB NLD are of several orders of magnitude. The discrepancies between the results with the phenomenological EGLO PSF and microscopic RPA or TBA are much less for the same NLD model.

Breeding system variation in 10 evening primroses (Oenothera sections Anogra and Kleinia; Onagraceae).

PubMed

Theiss, Kathryn E; Holsinger, Kent E; Evans, Margaret E K

2010-06-01

We examined two accounts of the relationship between breeding system and life history variation in a clade of evening primroses (Oenothera, Onagraceae): (1) selection for reproductive assurance should generate an association between self-compatibility and monocarpy and (2) phylogenetic conservatism leads to retention of breeding system and life history traits among closely related taxa. • We performed over 4000 hand pollinations under greenhouse conditions to determine the compatibility of 10 Oenothera taxa (sections Anogra [17 taxa] and Kleinia [2 taxa)] for which breeding systems had not previously been reported. We used generalized linear mixed models to evaluate the influence of pollination treatment, parents, and population on fruiting success. • Among the taxa tested, six were self-incompatible, two were variable in compatibility, and two were self-compatible. We combined these data with published studies in Anogra and Kleinia and mapped breeding system and life history onto a published phylogeny. • We found no evidence for phylogenetic conservatism, but detected considerable evolutionary lability in both traits. Additionally, we found no evidence for a consistent relationship between breeding system and life history. Only eight of 19 taxa followed the predicted association between self-incompatibility and polycarpy vs. self-compatibility and monocarpy. Instead, many taxa have retained self-incompatibility, regardless of monocarpy or polycarpy.

Individual and culture-level components of survey response styles: A multi-level analysis using cultural models of selfhood.

PubMed

Smith, Peter B; Vignoles, Vivian L; Becker, Maja; Owe, Ellinor; Easterbrook, Matthew J; Brown, Rupert; Bourguignon, David; Garðarsdóttir, Ragna B; Kreuzbauer, Robert; Cendales Ayala, Boris; Yuki, Masaki; Zhang, Jianxin; Lv, Shaobo; Chobthamkit, Phatthanakit; Jaafar, Jas Laile; Fischer, Ronald; Milfont, Taciano L; Gavreliuc, Alin; Baguma, Peter; Bond, Michael Harris; Martin, Mariana; Gausel, Nicolay; Schwartz, Seth J; Des Rosiers, Sabrina E; Tatarko, Alexander; González, Roberto; Didier, Nicolas; Carrasco, Diego; Lay, Siugmin; Nizharadze, George; Torres, Ana; Camino, Leoncio; Abuhamdeh, Sami; Macapagal, Ma Elizabeth J; Koller, Silvia H; Herman, Ginette; Courtois, Marie; Fritsche, Immo; Espinosa, Agustín; Villamar, Juan A; Regalia, Camillo; Manzi, Claudia; Brambilla, Maria; Zinkeng, Martina; Jalal, Baland; Kusdil, Ersin; Amponsah, Benjamin; Çağlar, Selinay; Mekonnen, Kassahun Habtamu; Möller, Bettina; Zhang, Xiao; Schweiger Gallo, Inge; Prieto Gil, Paula; Lorente Clemares, Raquel; Campara, Gabriella; Aldhafri, Said; Fülöp, Márta; Pyszczynski, Tom; Kesebir, Pelin; Harb, Charles

2016-12-01

Variations in acquiescence and extremity pose substantial threats to the validity of cross-cultural research that relies on survey methods. Individual and cultural correlates of response styles when using 2 contrasting types of response mode were investigated, drawing on data from 55 cultural groups across 33 nations. Using 7 dimensions of self-other relatedness that have often been confounded within the broader distinction between independence and interdependence, our analysis yields more specific understandings of both individual- and culture-level variations in response style. When using a Likert-scale response format, acquiescence is strongest among individuals seeing themselves as similar to others, and where cultural models of selfhood favour harmony, similarity with others and receptiveness to influence. However, when using Schwartz's (2007) portrait-comparison response procedure, acquiescence is strongest among individuals seeing themselves as self-reliant but also connected to others, and where cultural models of selfhood favour self-reliance and self-consistency. Extreme responding varies less between the two types of response modes, and is most prevalent among individuals seeing themselves as self-reliant, and in cultures favouring self-reliance. As both types of response mode elicit distinctive styles of response, it remains important to estimate and control for style effects to ensure valid comparisons. © 2016 International Union of Psychological Science.

Impact of inhomogeneity on SH-type wave propagation in an initially stressed composite structure

NASA Astrophysics Data System (ADS)

Saha, S.; Chattopadhyay, A.; Singh, A. K.

2018-02-01

The present analysis has been made on the influence of distinct form of inhomogeneity in a composite structure comprised of double superficial layers lying over a half-space, on the phase velocity of SH-type wave propagating through it. Propagation of SH-type wave in the said structure has been examined in four distinct cases of inhomogeneity viz. when inhomogeneity in double superficial layer is due to exponential variation in density only (Case I); when inhomogeneity in double superficial layers is due to exponential variation in rigidity only (Case II); when inhomogeneity in double superficial layer is due to exponential variation in rigidity, density and initial stress (Case III) and when inhomogeneity in double superficial layer is due to linear variation in rigidity, density and initial stress (Case IV). Closed-form expression of dispersion relation has been accomplished for all four aforementioned cases through extensive application of Debye asymptotic analysis. Deduced dispersion relations for all the cases are found in well-agreement to the classical Love-wave equation. Numerical computation has been carried out to graphically demonstrate the effect of inhomogeneity parameters, initial stress parameters as well as width ratio associated with double superficial layers in the composite structure for each of the four aforesaid cases on dispersion curve. Meticulous examination of distinct cases of inhomogeneity and initial stress in context of considered problem has been carried out with detailed analysis in a comparative approach.

Self-powered wireless disposable sensor for welfare application.

PubMed

Douseki, Takakuni; Tanaka, Ami

2013-01-01

A self-powered urinary incontinence sensor consisting of a flexible urine-activated battery and a wireless transmitter has been developed as an application for wireless biosensor networks. The flexible urine-activated battery is embedded in a disposal diaper and makes possible both the sensing of urine leakage and self-powered operation. An intermittent power-supply circuit that uses an electric double-layer capacitor (EDLC) with a small internal resistance suppresses the supply voltage drop due to the large internal resistance of the battery. This circuit supplies the power to a wireless transmitter. A 315-MHz-band wireless transmitter performs low-power operation. To verify the effectiveness of the circuit scheme, we fabricated a prototype sensor system. When 80 cc of urine is poured onto the diaper, the battery outputs a voltage of 1 V; and the sensor can transmit an ID signal over a distance of 5 m.

General Second-Order Scalar-Tensor Theory and Self-Tuning

NASA Astrophysics Data System (ADS)

Charmousis, Christos; Copeland, Edmund J.; Padilla, Antonio; Saffin, Paul M.

2012-02-01

Starting from the most general scalar-tensor theory with second-order field equations in four dimensions, we establish the unique action that will allow for the existence of a consistent self-tuning mechanism on Friedmann-Lemaître-Robertson-Walker backgrounds, and show how it can be understood as a combination of just four base Lagrangians with an intriguing geometric structure dependent on the Ricci scalar, the Einstein tensor, the double dual of the Riemann tensor, and the Gauss-Bonnet combination. Spacetime curvature can be screened from the net cosmological constant at any given moment because we allow the scalar field to break Poincaré invariance on the self-tuning vacua, thereby evading the Weinberg no-go theorem. We show how the four arbitrary functions of the scalar field combine in an elegant way opening up the possibility of obtaining nontrivial cosmological solutions.

Two-dimensional vibrational spectroscopy of the amide I band of crystalline acetanilide: Fermi resonance, conformational substates, or vibrational self-trapping?

NASA Astrophysics Data System (ADS)

Edler, J.; Hamm, P.

2003-08-01

Two-dimensional infrared (2D-IR) spectroscopy is applied to investigate acetanilide, a molecular crystal consisting of quasi-one-dimensional hydrogen bonded peptide units. The amide-I band exhibits a double peak structure, which has been attributed to different mechanisms including vibrational self-trapping, a Fermi resonance, or the existence of two conformational substates. The 2D-IR spectrum of crystalline acetanilide is compared with that of two different molecular systems: (i) benzoylchloride, which exhibits a strong symmetric Fermi resonance and (ii) N-methylacetamide dissolved in methanol which occurs in two spectroscopically distinguishable conformations. Both 2D-IR spectra differ significantly from that of crystalline acetanilide, proving that these two alternative mechanisms cannot account for the anomalous spectroscopy of crystalline acetanilide. On the other hand, vibrational self-trapping of the amide-I band can naturally explain the 2D-IR response.

A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer.

PubMed

Corrigan, Damion K; Vezza, Vincent; Schulze, Holger; Bachmann, Till T; Mount, Andrew R; Walton, Anthony J; Terry, Jonathan G

2018-06-09

For analytical applications involving label-free biosensors and multiple measurements, i.e., across an electrode array, it is essential to develop complete sensor systems capable of functionalization and of producing highly consistent responses. To achieve this, a multi-microelectrode device bearing twenty-four equivalent 50 µm diameter Pt disc microelectrodes was designed in an integrated 3-electrode system configuration and then fabricated. Cyclic voltammetry and electrochemical impedance spectroscopy were used for initial electrochemical characterization of the individual working electrodes. These confirmed the expected consistency of performance with a high degree of measurement reproducibility for each microelectrode across the array. With the aim of assessing the potential for production of an enhanced multi-electrode sensor for biomedical use, the working electrodes were then functionalized with 6-mercapto-1-hexanol (MCH). This is a well-known and commonly employed surface modification process, which involves the same principles of thiol attachment chemistry and self-assembled monolayer (SAM) formation commonly employed in the functionalization of electrodes and the formation of biosensors. Following this SAM formation, the reproducibility of the observed electrochemical signal between electrodes was seen to decrease markedly, compromising the ability to achieve consistent analytical measurements from the sensor array following this relatively simple and well-established surface modification. To successfully and consistently functionalize the sensors, it was necessary to dilute the constituent molecules by a factor of ten thousand to support adequate SAM formation on microelectrodes. The use of this multi-electrode device therefore demonstrates in a high throughput manner irreproducibility in the SAM formation process at the higher concentration, even though these electrodes are apparently functionalized simultaneously in the same film formation environment, confirming that the often seen significant electrode-to-electrode variation in label-free SAM biosensing films formed under such conditions is not likely to be due to variation in film deposition conditions, but rather kinetically controlled variation in the SAM layer formation process at these microelectrodes.

Self-consistent pseudopotential calculation of the bulk properties of Mo and W

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zunger, A.; Cohen, M.L.

The bulk properties of Mo and W are calculated using the recently developed momentum-space approach for calculating total energy via a nonlocal pseudopotential. This approach avoids any shape approximation to the variational charge density (e.g., muffin tins), is fully self-consistent, and replaces the multidimensional and multicenter integrals akin to real-space representations by simple and readily convergent reciprocal-space lattice sums. We use first-principles atomic pseudopotentials which have been previously demonstrated to yield band structures and charge densities for both semiconductors and transition metals in good agreement with experiment and all-electron calculations. Using a mixed-basis representation for the crystalline wave function, wemore » are able to accurately reproduce both the localized and itinerant features of the electronic states in these systems. These first-principles pseudopotentials, together with the self-consistent density-functional representation for both the exchange and the correlation screening, yields agreement with experiment of 0.2% in the lattice parameters, 2% and 11% for the binding energies of Mo and W, respectively, and 12% and 7% for the bulk moduli of Mo and W, respectively.« less

Neoclassical Simulation of Tokamak Plasmas using Continuum Gyrokinetc Code TEMPEST

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, X Q

We present gyrokinetic neoclassical simulations of tokamak plasmas with self-consistent electric field for the first time using a fully nonlinear (full-f) continuum code TEMPEST in a circular geometry. A set of gyrokinetic equations are discretized on a five dimensional computational grid in phase space. The present implementation is a Method of Lines approach where the phase-space derivatives are discretized with finite differences and implicit backwards differencing formulas are used to advance the system in time. The fully nonlinear Boltzmann model is used for electrons. The neoclassical electric field is obtained by solving gyrokinetic Poisson equation with self-consistent poloidal variation. Withmore » our 4D ({psi}, {theta}, {epsilon}, {mu}) version of the TEMPEST code we compute radial particle and heat flux, the Geodesic-Acoustic Mode (GAM), and the development of neoclassical electric field, which we compare with neoclassical theory with a Lorentz collision model. The present work provides a numerical scheme and a new capability for self-consistently studying important aspects of neoclassical transport and rotations in toroidal magnetic fusion devices.« less

Elastic plastic self-consistent (EPSC) modeling of plastic deformation in fayalite olivine

DOE PAGES

Burnley, Pamela C

2015-07-01

Elastic plastic self-consistent (EPSC) simulations are used to model synchrotron X-ray diffraction observations from deformation experiments on fayalite olivine using the deformation DIA apparatus. Consistent with results from other in situ diffraction studies of monomineralic polycrystals, the results show substantial variations in stress levels among grain populations. Rather than averaging the lattice reflection stresses or choosing a single reflection to determine the macroscopic stress supported by the specimen, an EPSC simulation is used to forward model diffraction data and determine a macroscopic stress that is consistent with lattice strains of all measured diffraction lines. The EPSC simulation presented here includesmore » kink band formation among the plastic deformation mechanisms in the simulation. The inclusion of kink band formation is critical to the success of the models. This study demonstrates the importance of kink band formation as an accommodation mechanism during plastic deformation of olivine as well as the utility of using EPSC models to interpret diffraction from in situ deformation experiments.« less

Experimental evidence of a double layer in a large volume helicon reactor.

PubMed

Sutherland, O; Charles, C; Plihon, N; Boswell, R W

2005-11-11

The self-consistently generated current-free electric double layer (DL) is shown to scale up with the source tube diameter and appears not to be affected by rf driving frequency and changes in reactor geometry. This Letter presents the first simultaneous measurements of local plasma potential and beam energy as a function of axial position. The DL is shown to be no more than 5 mm thick (20 D lengths) and positioned just downstream of the maximum in the magnetic field gradient. Furthermore, its position relative to the magnetic field is observed to be invariant as the magnetic field is translated axially. Measurements of the potential drop across the DL are presented for pressures down to 0.09 mTorr and the DL strength (phiDL/T(e)) is determined to be between 5 and 7.

Prototype Stilbene Neutron Collar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prasad, M. K.; Shumaker, D.; Snyderman, N.

2016-10-26

A neutron collar using stilbene organic scintillator cells for fast neutron counting is described for the assay of fresh low enriched uranium (LEU) fuel assemblies. The prototype stilbene collar has a form factor similar to standard He-3 based collars and uses an AmLi interrogation neutron source. This report describes the simulation of list mode neutron correlation data on various fuel assemblies including some with neutron absorbers (burnable Gd poisons). Calibration curves (doubles vs 235U linear mass density) are presented for both thermal and fast (with Cd lining) modes of operation. It is shown that the stilbene collar meets or exceedsmore » the current capabilities of He-3 based neutron collars. A self-consistent assay methodology, uniquely suited to the stilbene collar, using triples is described which complements traditional assay based on doubles calibration curves.« less

Brief Self-Report Scales Assessing Life History Dimensions of Mating and Parenting Effort.

PubMed

Kruger, Daniel J

2017-01-01

Life history theory (LHT) is a powerful evolutionary framework for understanding physiological, psychological, and behavioral variation both between and within species. Researchers and theorists are increasingly integrating LHT into evolutionary psychology, as it provides a strong foundation for research across many topical areas. Human life history variation has been represented in psychological and behavioral research in several ways, including indicators of conditions in the developmental environment, indicators of conditions in the current environment, and indicators of maturation and life milestones (e.g., menarche, initial sexual activity, first pregnancy), and in self-report survey scale measures. Survey scale measures have included constructs such as time perspective and future discounting, although the most widely used index is a constellation of indicators assessing the K-factor, thought to index general life history speed (from fast to slow). The current project examined the utility of two brief self-report survey measures assessing the life history dimensions of mating effort and parenting effort with a large undergraduate sample in the United States. Consistent with the theory, items reflected two inversely related dimensions. In regressions including the K-factor, the Mating Effort Scale proved to be a powerful predictor of other constructs and indicators related to life history variation. The Parenting Effort Scale had less predictive power overall, although it explained unique variance across several constructs and was the only unique predictor of the number of long-term (serious and committed) relationships. These scales may be valuable additions to self-report survey research projects examining life history variation.

A FORTRAN Program for Computing Refractive Index Using the Double Variation Method.

ERIC Educational Resources Information Center

Blanchard, Frank N.

1984-01-01

Describes a computer program which calculates a best estimate of refractive index and dispersion from a large number of observations using the double variation method of measuring refractive index along with Sellmeier constants of the immersion oils. Program listing with examples will be provided on written request to the author. (Author/JM)

Systematic Convergence in Applying Variational Method to Double-Well Potential

ERIC Educational Resources Information Center

Mei, Wai-Ning

2016-01-01

In this work, we demonstrate the application of the variational method by computing the ground- and first-excited state energies of a double-well potential. We start with the proper choice of the trial wave functions using optimized parameters, and notice that accurate expectation values in excellent agreement with the numerical results can be…

DNA conformation on surfaces measured by fluorescence self-interference.

PubMed

Moiseev, Lev; Unlü, M Selim; Swan, Anna K; Goldberg, Bennett B; Cantor, Charles R

2006-02-21

The conformation of DNA molecules tethered to the surface of a microarray may significantly affect the efficiency of hybridization. Although a number of methods have been applied to determine the structure of the DNA layer, they are not very sensitive to variations in the shape of DNA molecules. Here we describe the application of an interferometric technique called spectral self-interference fluorescence microscopy to the precise measurement of the average location of a fluorescent label in a DNA layer relative to the surface and thus determine specific information on the conformation of the surface-bound DNA molecules. Using spectral self-interference fluorescence microscopy, we have estimated the shape of coiled single-stranded DNA, the average tilt of double-stranded DNA of different lengths, and the amount of hybridization. The data provide important proofs of concept for the capabilities of novel optical surface analytical methods of the molecular disposition of DNA on surfaces. The determination of DNA conformations on surfaces and hybridization behavior provide information required to move DNA interfacial applications forward and thus impact emerging clinical and biotechnological fields.

Comparison of Digital 12-Lead ECG and Digital 12-Lead Holter ECG Recordings in Healthy Male Subjects: Results from a Randomized, Double-Blinded, Placebo-Controlled Clinical Trial.

PubMed

Wang, Duolao; Bakhai, Ameet; Arezina, Radivoj; Täubel, Jörg

2016-11-01

Electrocardiogram (ECG) variability is greatly affected by the ECG recording method. This study aims to compare Holter and standard ECG recording methods in terms of central locations and variations of ECG data. We used the ECG data from a double-blinded, placebo-controlled, randomized clinical trial and used a mixed model approach to assess the agreement between two methods in central locations and variations of eight ECG parameters (Heart Rate, PR, QRS, QT, RR, QTcB, QTcF, and QTcI intervals). A total of 34 heathy male subjects with mean age of 25.7 ± 4.78 years were randomized to receive either active drug or placebo. Digital 12-lead ECG and digital 12-lead Holter ECG recordings were performed to assess ECG variability. There are no significant differences in least square mean between the Holter and the standard method for all ECG parameters. The total variance is consistently higher for the Holter method than the standard method for all ECG parameters except for QRS. The intraclass correlation coefficient (ICC) values for the Holter method are consistently lower than those for the standard method for all ECG parameters except for QRS, in particular, the ICC for QTcF is reduced from 0.86 for the standard method to 0.67 for the Holter method. This study suggests that Holter ECGs recorded in a controlled environment are not significantly different but more variable than those from the standard method. © 2016 Wiley Periodicals, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bleiziffer, Patrick, E-mail: patrick.bleiziffer@fau.de; Krug, Marcel; Görling, Andreas

A self-consistent Kohn-Sham method based on the adiabatic-connection fluctuation-dissipation (ACFD) theorem, employing the frequency-dependent exact exchange kernel f{sub x} is presented. The resulting SC-exact-exchange-only (EXX)-ACFD method leads to even more accurate correlation potentials than those obtained within the direct random phase approximation (dRPA). In contrast to dRPA methods, not only the Coulomb kernel but also the exact exchange kernel f{sub x} is taken into account in the EXX-ACFD correlation which results in a method that, unlike dRPA methods, is free of self-correlations, i.e., a method that treats exactly all one-electron systems, like, e.g., the hydrogen atom. The self-consistent evaluation ofmore » EXX-ACFD total energies improves the accuracy compared to EXX-ACFD total energies evaluated non-self-consistently with EXX or dRPA orbitals and eigenvalues. Reaction energies of a set of small molecules, for which highly accurate experimental reference data are available, are calculated and compared to quantum chemistry methods like Møller-Plesset perturbation theory of second order (MP2) or coupled cluster methods [CCSD, coupled cluster singles, doubles, and perturbative triples (CCSD(T))]. Moreover, we compare our methods to other ACFD variants like dRPA combined with perturbative corrections such as the second order screened exchange corrections or a renormalized singles correction. Similarly, the performance of our EXX-ACFD methods is investigated for the non-covalently bonded dimers of the S22 reference set and for potential energy curves of noble gas, water, and benzene dimers. The computational effort of the SC-EXX-ACFD method exhibits the same scaling of N{sup 5} with respect to the system size N as the non-self-consistent evaluation of only the EXX-ACFD correlation energy; however, the prefactor increases significantly. Reaction energies from the SC-EXX-ACFD method deviate quite little from EXX-ACFD energies obtained non-self-consistently with dRPA orbitals and eigenvalues, and the deviation reduces even further if the Coulomb kernel is scaled by a factor of 0.75 in the dRPA to reduce self-correlations in the dRPA correlation potential. For larger systems, such a non-self-consistent EXX-ACFD method is a competitive alternative to high-level wave-function-based methods, yielding higher accuracy than MP2 and CCSD methods while exhibiting a better scaling of the computational effort than CCSD or CCSD(T) methods. Moreover, EXX-ACFD methods were shown to be applicable in situation characterized by static correlation.« less

Diurnal variation of tropospheric relative humidity in tropical regions

NASA Astrophysics Data System (ADS)

Moradi, Isaac; Arkin, Philip; Ferraro, Ralph; Eriksson, Patrick; Fetzer, Eric

2016-06-01

Despite the importance of water vapor especially in the tropical region, the diurnal variations of water vapor have not been completely investigated in the past due to the lack of adequate observations. Measurements from Sondeur Atmosphérique du Profil d'Humidité Intertropicale par Radiométrie (SAPHIR) onboard the low inclination Megha-Tropiques satellite with frequent daily revisits provide a valuable dataset for investigating the diurnal and spatial variation of tropospheric relative humidity in the tropical region. In this study, we first transformed SAPHIR observations into layer-averaged relative humidity, then partitioned the data based on local observation time into 24 bins with a grid resolution of one degree. Afterwards, we fitted Fourier series to the binned data. Finally, the mean, amplitude, and diurnal peak time of relative humidity in tropical regions were calculated for each grid point using either the measurements or Fourier series. The results were separately investigated for different SAPHIR channels as well as for relative humidity with respect to both liquid and ice phases. The results showed that the wet and dry regions are, respectively, associated with convective and subsidence regions which is consistent with the previous studies. The mean tropospheric humidity values reported in this study are generally 10 to 15 % higher than those reported using infrared observations which is because of strict cloud screening for infrared measurements. The results showed a large inhomogeneity in diurnal variation of tropospheric relative humidity in tropical region. The diurnal amplitude was larger over land than over ocean and the oceanic amplitude was larger over convective regions than over subsidence regions. The results showed that the diurnal amplitude is less than 10 % in middle and upper troposphere, but it is up to 30 % in lower troposphere over land. Although the peak of RH generally occurs over night or in early morning, there are several regions where the diurnal peak occurs at other times of the day. The early morning peak time is because of a peak in convective activities in early morning. Additionally, a double peak was observed in tropospheric humidity over some regions which is consistent with double peak in precipitation.

77 FR 7640 - Self-Regulatory Organizations; BATS Y-Exchange, Inc.; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

... 30 days after the date of the filing, or such shorter time as the Commission may designate, it has...-4(f)(6)(iii) \\8\\ permits the Commission to designate a shorter time if such action is consistent... without further delay. The Exchange notes that the introduction of the additional optional variation of...

Chronobiometric assessment of autogenic training effects upon blood pressure and heart rate.

PubMed

Watanabe, Y; Halberg, F; Cornélissen, G; Saito, Y; Fukuda, K; Otsuka, K; Kikuchi, T

1996-12-01

Autogenic training, a method of self-hypnosis, lowers the extent of within-day variation of systolic blood pressure assessed by the circadian double amplitude. The blood pressure and heart rate of ten patients, conventionally diagnosed as having hypertension or white-coat hypertension, were automatically monitored at 30-min intervals for 7 days before autogenic training and again for 7 days, at 1 or 2 months after the start of autogenic training (practiced three times daily). The circadian double amplitude of systolic blood pressure of the patients investigated was 3 to 17 mm Hg lower on autogenic training. In 5 patients, reductions by 7 to 17 mm Hg were statistically significant. These results are regarded as provisional statistics, the utility of which depends on replication. By contrast, the over-all group reduction of the circadian double amplitude of systolic blood pressure by 8 mm Hg on the average can be taken at face value. Autogenic training also lowered the circadian double amplitude of diastolic blood pressure, but the effect was small as was the effect of autogenic training upon the MESOR (a rhythm adjusted mean) and acrophase (a measure of the timing of over-all high values recurring each day). The effect of autogenic training upon the circadian double amplitude of systolic blood pressure suggests its trial as first-line treatment of patients with an excessive circadian blood pressure amplitude, a condition which, even in the absence of an elevated 24-hr, average of blood pressure, is associated with a large increase in the risk of developing ischemic stroke or nephropathy.

Self-potential characteristics of the dormant period of Izu-Oshima volcano

NASA Astrophysics Data System (ADS)

Matsushima, Nobuo; Nishi, Yuji; Onizawa, Shin'ya; Takakura, Shinichi; Hase, Hideaki; Ishido, Tsuneo

2017-12-01

Continuous self-potential (SP) monitoring has been conducted at Izu-Oshima volcano to detect signals resulting from volcanic activity since the installation of an SP monitoring network in March 2006. Since the installation, annual variations of up to 100 mV have been recorded. If we exclude these annual variations, temporal variations in SP do not show notable changes. This is consistent with the volcano being in a state of quiescence during the measurement period. The annual variations have the different amplitudes and mean levels between stations. To investigate the causes of these annual variations, we carried out numerical simulations of SP generation associated with downward meteoric water flow through electrokinetic coupling in a 550 m thick unsaturated layer. The results show that the vertical electric potential gradient varies with changes in liquid-phase saturation in the unsaturated layer. These changes are caused by variations in the rate of meteoric water percolation. This, in turn, correlates with fluctuations in daily precipitation, thus explaining the annual SP variation recorded at the ground surface. Differences in the amplitude and mean level of SP variation are shown to be associated with different rock properties, especially permeability, porosity, and electrical conductivity. Our results indicate that observable SP changes will appear at stations near the summit if the distributions of liquid-phase saturation and/or pertinent parameters controlling the electrokinetic coupling in the thick unsaturated layer are modified the upward flow of volcanic gas.

Core-Shell Double Gyroid Structure Formed by Linear ABC Terpolymer Thin Films.

PubMed

Antoine, Ségolène; Aissou, Karim; Mumtaz, Muhammad; Telitel, Siham; Pécastaings, Gilles; Wirotius, Anne-Laure; Brochon, Cyril; Cloutet, Eric; Fleury, Guillaume; Hadziioannou, Georges

2018-05-01

The synthesis and self-assembly in thin-film configuration of linear ABC triblock terpolymer chains consisting of polystyrene (PS), poly(2-vinylpyridine) (P2VP), and polyisoprene (PI) are described. For that purpose, a hydroxyl-terminated PS-b-P2VP (45 kg mol -1 ) building block and a carboxyl-terminated PI (9 kg mol -1 ) are first separately prepared by anionic polymerization, and then are coupled via a Steglich esterification reaction. This quantitative and metal-free catalyst synthesis route reveals to be very interesting since functionalization and purification steps are straightforward, and well-defined terpolymers are produced. A solvent vapor annealing (SVA) process is used to promote the self-assembly of frustrated PS-b-P2VP-b-PI chains into a thin-film core-shell double gyroid (Q 230 , space group: Ia3¯d) structure. As terraces are formed within PS-b-P2VP-b-PI thin films during the SVA process under a CHCl 3 vapor, different plane orientations of the Q 230 structure ((211), (110), (111), and (100)) are observed at the polymer-air interface depending on the film thickness. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Process variation challenges and resolution in the negative-tone develop double patterning for 20nm and below technology node

NASA Astrophysics Data System (ADS)

Mehta, Sohan S.; Ganta, Lakshmi K.; Chauhan, Vikrant; Wu, Yixu; Singh, Sunil; Ann, Chia; Subramany, Lokesh; Higgins, Craig; Erenturk, Burcin; Srivastava, Ravi; Singh, Paramjit; Koh, Hui Peng; Cho, David

2015-03-01

Immersion based 20nm technology node and below becoming very challenging to chip designers, process and integration due to multiple patterning to integrate one design layer . Negative tone development (NTD) processes have been well accepted by industry experts for enabling technologies 20 nm and below. 193i double patterning is the technology solution for pitch down to 80 nm. This imposes tight control in critical dimension(CD) variation in double patterning where design patterns are decomposed in two different masks such as in litho-etch-litho etch (LELE). CD bimodality has been widely studied in LELE double patterning. A portion of CD tolerance budget is significantly consumed by variations in CD in double patterning. The objective of this work is to study the process variation challenges and resolution in the Negative Tone Develop Process for 20 nm and Below Technology Node. This paper describes the effect of dose slope on CD variation in negative tone develop LELE process. This effect becomes even more challenging with standalone NTD developer process due to q-time driven CD variation. We studied impact of different stacks with combination of binary and attenuated phase shift mask and estimated dose slope contribution individually from stack and mask type. Mask 3D simulation was carried out to understand theoretical aspect. In order to meet the minimum insulator requirement for the worst case on wafer the overlay and critical dimension uniformity (CDU) budget margins have slimmed. Besides the litho process and tool control using enhanced metrology feedback, the variation control has other dependencies too. Color balancing between the two masks in LELE is helpful in countering effects such as iso-dense bias, and pattern shifting. Dummy insertion and the improved decomposition techniques [2] using multiple lower priority constraints can help to a great extent. Innovative color aware routing techniques [3] can also help with achieving more uniform density and color balanced layouts.

Compression member response of steel angle on truss structure with variation of single and double sections

NASA Astrophysics Data System (ADS)

Panjaitan, Arief; Hasibuan, Purwandy

2018-05-01

Implementation of an axial compression load on the steel angle can be found at the various structure such as truss system on telecommunication tower. For telecommunication tower, steel angle section can be suggested as an alternative solution due to its assembling easiness as well as its strength. But, antennas and microwaves installation that keep increases every time on this structure demand reinforcement on each leg of the tower structure. One solution suggested is reinforcement with increasing areas section capacity, where tower leg consisted of single angle section will be reinforced to be double angle section. Regarding this case, this research discussed the behavior of two types of steel angle section: single angle of L.30.30.3 and double angles of 2L.30.30.3. These two sections were designed identically in length (103 cm) and tested by axial compression load. At the first step, compression member together with tension member was formed to be a truss system, where compression and tension member were met at a joint plate. Schematic loading was implemented by giving tension loading on the joint plate until failure of specimens. Experimental work findings showed that implementing double angle sections (103 cm) significantly increased compression capacity of steel angle section up to 118 %.

Temperature shift of intraband absorption peak in tunnel-coupled QW structure

NASA Astrophysics Data System (ADS)

Akimov, V.; Firsov, D. A.; Duque, C. A.; Tulupenko, V.; Balagula, R. M.; Vinnichenko, M. Ya.; Vorobjev, L. E.

2017-04-01

An experimental study of the intersubband light absorption by the 100-period GaAs/Al0.25Ga0.75As double quantum well heterostructure doped with silicon is reported and interpreted. Small temperature redshift of the 1-3 intersubband absorption peak is detected. Numerical calculations of the absorption coefficient including self-consistent Hartree calculations of the bottom of the conduction band show good agreement with the observed phenomena. The temperature dependence of energy gap of the material and the depolarization shift should be accounted for to explain the shift.

Modeling of the EAST ICRF antenna with ICANT Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qin Chengming; Zhao Yanping; Colas, L.

2007-09-28

A Resonant Double Loop (RDL) antenna for ion-cyclotron range of frequencies (ICRF) on Experimental Advanced Superconducting Tokamak (EAST) is under construction. The new antenna is analyzed using the antenna coupling code ICANT which self-consistently determines the surface currents on all antenna parts. In this work, the modeling of the new ICRF antenna using this code is to assess the near-fields in front of the antenna and analysis its coupling capabilities. Moreover, the antenna reactive radiated power computed by ICANT and shows a good agreement with deduced from Transmission Line (TL) theory.

Modeling of the EAST ICRF antenna with ICANT Code

NASA Astrophysics Data System (ADS)

Qin, Chengming; Zhao, Yanping; Colas, L.; Heuraux, S.

2007-09-01

A Resonant Double Loop (RDL) antenna for ion-cyclotron range of frequencies (ICRF) on Experimental Advanced Superconducting Tokamak (EAST) is under construction. The new antenna is analyzed using the antenna coupling code ICANT which self-consistently determines the surface currents on all antenna parts. In this work, the modeling of the new ICRF antenna using this code is to assess the near-fields in front of the antenna and analysis its coupling capabilities. Moreover, the antenna reactive radiated power computed by ICANT and shows a good agreement with deduced from Transmission Line (TL) theory.

Collisionless dissipation in quasi-perpendicular shocks. [in terresrial bow waves

NASA Technical Reports Server (NTRS)

Forslund, D. W.; Quest, K. B.; Brackbill, J. U.; Lee, K.

1984-01-01

Microscopic dissipation processes in quasi-perpendicular shocks are studied by two-dimensional plasma simulations in which electrons and ions are treated as particles moving in self-consistent electric and magnetic fields. Cross-field currents induce substantial turbulence at the shock front reducing the reflected ion fraction, increasing the bulk ion temperature behind the shock, doubling the average magnetic ramp thickness, and enhancing the upstream field aligned electron heat flow. The short scale length magnetic fluctuations observed in the bow shock are probably associated with this turbulence.

Spectral characterization of a supercontinuum source based on nonlinear broadening in an aqueous K_2ZnCl_4 salt solution

DOE PAGES

Robinson, Timothy S.; Patankar, Siddharth; Floyd, Emma; ...

2017-01-01

We report on investigations concerning the shot-to-shot spectral stability properties of a supercontinuum source based on nonlinear processes such as self-phase modulation and optical wave-breaking in a highly concentrated K 2ZnCl 4 double salt solution. The use of a liquid medium offers both damage resistance and high third-order optical nonlinearity. Approximately 40 μJ pulses spanning a spectral range between 390 and 960 nm were produced with 3.8% RMS energy stability, using infrared input pulses of 500±50 fs FWHM durations and 2.42±0.04 mJ energies with an RMS stability of 2%. The spectral stability was quantified via acquiring single-shot spectra and studyingmore » shot-to-shot variation across a spectral range of 200–1100 nm, as well as by considering spectral correlations. The regional spectral correlation variations were indicative of nonlinear processes leading to sideband generation. Spectral stability and efficiency of energy transfer into the supercontinuum were found to weakly improve with increasing driver pulse energy, suggesting that the nonlinear broadening processes are more stable when driven more strongly, or that self-guiding effects in a filament help to stabilize the supercontinuum generation.« less

Spectral characterization of a supercontinuum source based on nonlinear broadening in an aqueous K_2ZnCl_4 salt solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, Timothy S.; Patankar, Siddharth; Floyd, Emma

We report on investigations concerning the shot-to-shot spectral stability properties of a supercontinuum source based on nonlinear processes such as self-phase modulation and optical wave-breaking in a highly concentrated K 2ZnCl 4 double salt solution. The use of a liquid medium offers both damage resistance and high third-order optical nonlinearity. Approximately 40 μJ pulses spanning a spectral range between 390 and 960 nm were produced with 3.8% RMS energy stability, using infrared input pulses of 500±50 fs FWHM durations and 2.42±0.04 mJ energies with an RMS stability of 2%. The spectral stability was quantified via acquiring single-shot spectra and studyingmore » shot-to-shot variation across a spectral range of 200–1100 nm, as well as by considering spectral correlations. The regional spectral correlation variations were indicative of nonlinear processes leading to sideband generation. Spectral stability and efficiency of energy transfer into the supercontinuum were found to weakly improve with increasing driver pulse energy, suggesting that the nonlinear broadening processes are more stable when driven more strongly, or that self-guiding effects in a filament help to stabilize the supercontinuum generation.« less

Mixed Single/Double Precision in OpenIFS: A Detailed Study of Energy Savings, Scaling Effects, Architectural Effects, and Compilation Effects

NASA Astrophysics Data System (ADS)

Fagan, Mike; Dueben, Peter; Palem, Krishna; Carver, Glenn; Chantry, Matthew; Palmer, Tim; Schlacter, Jeremy

2017-04-01

It has been shown that a mixed precision approach that judiciously replaces double precision with single precision calculations can speed-up global simulations. In particular, a mixed precision variation of the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF) showed virtually the same quality model results as the standard double precision version (Vana et al., Single precision in weather forecasting models: An evaluation with the IFS, Monthly Weather Review, in print). In this study, we perform detailed measurements of savings in computing time and energy using a mixed precision variation of the -OpenIFS- model. The mixed precision variation of OpenIFS is analogous to the IFS variation used in Vana et al. We (1) present results for energy measurements for simulations in single and double precision using Intel's RAPL technology, (2) conduct a -scaling- study to quantify the effects that increasing model resolution has on both energy dissipation and computing cycles, (3) analyze the differences between single core and multicore processing, and (4) compare the effects of different compiler technologies on the mixed precision OpenIFS code. In particular, we compare intel icc/ifort with gnu gcc/gfortran.

Electrochemical capacitance modulation in an interacting mesoscopic capacitor induced by internal charge transfer

NASA Astrophysics Data System (ADS)

Liu, Wei; He, Jianhong; Guo, Huazhong; Gao, Jie

2018-04-01

We report experiments on the dynamic response of an interacting mesoscopic capacitor consisting of a quantum dot with two confined spin-split levels of the lowest Landau level. In high magnetic fields, states inside the dot are regulated by a mixture of Coulomb interaction and Landau-level quantization, and electrons distribute on two spatially separated regions. Quantum point contact voltage and magnetic field are employed to manipulate the number and distribution of electrons inside the quantum dot. We find that the periodicity of the electrochemical capacitance oscillations is dominated by the charging energy, and their amplitudes, due to internal charge transfer and strong internal capacitive coupling, show rich variations of modulations. Magnetocapacitance displays a sawtoothlike manner and may differ in tooth directions for different voltages, which, we demonstrate, result from a sawtoothlike electrochemical potential change induced by internal charge transfer and field-sensitive electrostatic potential. We further build a charge stability diagram, which, together with all other capacitance properties, is consistently interpreted in terms of a double-dot model. The demonstrated technique is of interest as a tool for fast and sensitive charge state readout of a double-quantum-dot qubit in the gigahertz frequency quantum electronics.

Cultural bases for self-evaluation: seeing oneself positively in different cultural contexts.

PubMed

Becker, Maja; Vignoles, Vivian L; Owe, Ellinor; Easterbrook, Matthew J; Brown, Rupert; Smith, Peter B; Bond, Michael Harris; Regalia, Camillo; Manzi, Claudia; Brambilla, Maria; Aldhafri, Said; González, Roberto; Carrasco, Diego; Paz Cadena, Maria; Lay, Siugmin; Schweiger Gallo, Inge; Torres, Ana; Camino, Leoncio; Özgen, Emre; Güner, Ülkü E; Yamakoğlu, Nil; Silveira Lemos, Flávia Cristina; Trujillo, Elvia Vargas; Balanta, Paola; Macapagal, Ma Elizabeth J; Cristina Ferreira, M; Herman, Ginette; de Sauvage, Isabelle; Bourguignon, David; Wang, Qian; Fülöp, Márta; Harb, Charles; Chybicka, Aneta; Mekonnen, Kassahun Habtamu; Martin, Mariana; Nizharadze, George; Gavreliuc, Alin; Buitendach, Johanna; Valk, Aune; Koller, Silvia H

2014-05-01

Several theories propose that self-esteem, or positive self-regard, results from fulfilling the value priorities of one's surrounding culture. Yet, surprisingly little evidence exists for this assertion, and theories differ about whether individuals must personally endorse the value priorities involved. We compared the influence of four bases for self-evaluation (controlling one's life, doing one's duty, benefitting others, achieving social status) among 4,852 adolescents across 20 cultural samples, using an implicit, within-person measurement technique to avoid cultural response biases. Cross-sectional and longitudinal analyses showed that participants generally derived feelings of self-esteem from all four bases, but especially from those that were most consistent with the value priorities of others in their cultural context. Multilevel analyses confirmed that the bases of positive self-regard are sustained collectively: They are predictably moderated by culturally normative values but show little systematic variation with personally endorsed values.

Parental HIV/AIDS and Psychosocial Adjustment among Rural Chinese Children

PubMed Central

Fang, Xiaoyi; Stanton, Bonita; Hong, Yan; Zhang, Liying; Zhao, Guoxiang; Zhao, Junfeng; Lin, Xiuyun; Lin, Danhua

2009-01-01

Objective To assess the relationship between parental HIV/AIDS and psychosocial adjustment of children in rural central China. Methods Participants included 296 double AIDS orphans (children who had lost both their parents to AIDS), 459 single orphans (children who had lost one parent to AIDS), 466 vulnerable children who lived with HIV-infected parents, and 404 comparison children who did not experience HIV/AIDS-related illness and death in their families. The measures included depressive symptoms, loneliness, self-esteem, future expectations, hopefulness about the future, and perceived control over the future. Results AIDS orphans and vulnerable children consistently demonstrated poorer psychosocial adjustment than comparison children in the same community. The level of psychosocial adjustment was similar between single orphans and double orphans, but differed by care arrangement among double orphans. Conclusion The findings underscore the urgency and importance of culturally and developmentally appropriate intervention efforts targeting psychosocial problems among children affected by AIDS and call for more exploration of risk and resilience factors, both individual and contextual, affecting the psychosocial wellbeing of these children. PMID:19208701

The effect of radio-frequency self bias on ion acceleration in expanding argon plasmas in helicon sources

NASA Astrophysics Data System (ADS)

Wiebold, Matthew D.

Time-averaged plasma potential differences up to ˜ 165 V over several hundred Debye lengths are observed in low pressure (pn < 1 mTorr) expanding argon plasmas in the Madison Helicon Experiment. The potential gradient leads to ion acceleration exceeding Ei ≈ 7 kTe in some cases. Up to 1 kW of 13.56 MHz RF power is supplied to a half-turn, double-helix antenna in the presence of a nozzle magnetic field up to 1 kG. An RPA measures the IEDF and an emissive probe measures the plasma potential. Single and double probes measure the electron density and temperature. Two distinct mode hops, the capacitive-inductive (E-H) and inductive-helicon (H-W) transitions, are identified by jumps in electron density as RF power is increased. In the capacitive mode, large fluctuations of the plasma potential (Vp--p ≳ 140 V, Vp--p/Vp ≈ 150%) exist at the RF frequency, leading to formation of a self-bias voltage. The mobile electrons can flow from the upstream region during an RF cycle whereas ions cannot, leading to an initial imbalance of flux, and the self-bias voltage builds as a result. The plasma potential in the expansion chamber is held near the floating potential for argon (Vp ≈ 5kTe/e). In the capacitive mode, the ion acceleration is not well described by an ambipolar relation. The accelerated population decay is consistent with that predicted by charge-exchange collisions. Grounding the upstream endplate increases the self-bias voltage compared to a floating endplate. In the inductive and helicon modes, the ion acceleration more closely follows an ambipolar relation, a result of decreased capacitive coupling due to the decreased RF skin depth. The scaling of the potential gradient with the argon flow rate, magnetic field and RF power are investigated, with the highest potential gradients observed for the lowest flow rates in the capacitive mode. The magnitude of the self-bias voltage agrees well with that predicted for RF sheaths. Use of the self-bias effect in a plasma thruster is explored, possibly for a low thrust, high specific impulse mode in a multi-mode helicon thruster. This work could also explain similar potential gradients in expanding helicon plasmas that are ascribed to double layer formation in the literature.

An electrochemical biosensor for double-stranded Wnt7B gene detection based on enzymatic isothermal amplification.

PubMed

Li, Junlong; Chen, Zhongping; Xiang, Yu; Zhou, Lili; Wang, Ting; Zhang, Zhang; Sun, Kexin; Yin, Dan; Li, Yi; Xie, Guoming

2016-12-15

Wnt7B gene plays an important role in the development and progression of breast cancer, gastric cancer, esophageal cancer and pancreatic cancer. While, the natural state of DNA is double stranded, which makes it difficult to be directly detected. Here, we develop an electrochemical biosensor method for Wnt7B gene detection without the need to denature the target. This method firstly used nicking enzyme for exploiting in the double-stranded DNA (dsDNA). Then, long single-stranded DNA (ssDNA) was generated from the cutting site through polymerase extension reaction. Whereafter, the long ssDNA triggered a hairpin self-assembly recycling reaction, which gave rise to another isothermal amplification reaction. Last, short ssDNA was formed after the this amplification process, which could hybridize with the capture probe immobilized on Au electrode and result in signal variation. This method showed excellent analytical performance for dsDNA, of which the linear range was 2fM to 500pM and the detection limit was 1.6fM (S/N=3). It also showed an good results when applied to the real sample of Wnt7B gene detection. Copyright © 2016 Elsevier B.V. All rights reserved.

Josephson oscillation and self-trapping in momentum space

NASA Astrophysics Data System (ADS)

Zheng, Yi; Feng, Shiping; Yang, Shi-Jie

2018-04-01

The Creutz ladder model is studied in the presence of unconventional flux induced by complex tunneling rates along and between the two legs. In the vortex phase, the double-minima band structure is regarded as a double well. By introducing a tunable coupling between the two momentum minima, we demonstrate a phenomenon of Josephson oscillations in momentum space. The condensate density locked in one of the momentum valleys is referred to as macroscopic quantum self-trapping. The on-site interaction of the lattice provides an effective analogy to the double-well model within the two-mode approximation which allows for a quantitative understanding of the Josephson effect and the self-trapping in momentum space.

Effect of evaporation of solvents from one-step, self-etching adhesives.

PubMed

Furuse, Adilson Yoshio; Peutzfeldt, Anne; Asmussen, Erik

2008-02-01

To investigate whether and to what extent the bonding capacity of one-step, self-etching adhesives is influenced by the degree to which solvent is evaporated. Seven one-step, self-etching adhesives were tested (Adper Prompt L-Pop, Clearfil S3 Bond, Futurabond NR, G-Bond, Hybrid Bond, iBond, Xeno III). The variation in degree of evaporation was obtained by varying the duration of the air-blowing step. The duration required to immobilize the adhesive layer, as established in a pilot study, was used as control. Two experimental air-blowing durations, shorter (half the control duration) and longer (double the control duration) than the control duration, were chosen. The resin composite Herculite XRV was bonded to flat human dentin surfaces treated with one of the adhesives following manufacturer's instructions, except for the air-blowing duration after application. After being stored in water at 37 degrees C for 1 week, the bonded specimens were broken in shear. Failure modes were evaluated under stereomicroscope. Air-blowing duration and brand of adhesive both had an effect on shear bond strength. An interaction was found between adhesive and air-blowing duration. Some adhesives were insensitive to variations in air-drying duration, but in general, air-blowing durations shorter than the control duration produced lower shear bond strengths. Significant effects of adhesive and air-blowing duration were also detected in relation to failure mode. More adhesive failures were observed with shorter air-blowing durations. A significant negative correlation between number of adhesive failures and bond strength was found. On the basis of this in vitro study, it may be concluded that the one-step, self-etching adhesives evaluated were sensitive to degree of evaporation of the solvents.

Self-actuating and self-diagnosing plastically deforming piezo-composite flapping wing MAV

NASA Astrophysics Data System (ADS)

Harish, Ajay B.; Harursampath, Dineshkumar; Mahapatra, D. Roy

2011-04-01

In this work, we propose a constitutive model to describe the behavior of Piezoelectric Fiber Reinforced Composite (PFRC) material consisting of elasto-plastic matrix reinforced by strong elastic piezoelectric fibers. Computational efficiency is achieved using analytical solutions for elastic stifness matrix derived from Variational Asymptotic Methods (VAM). This is extended to provide Structural Health Monitoring (SHM) based on plasticity induced degradation of flapping frequency of PFRC. Overall this work provides an effective mathematical tool that can be used for structural self-health monitoring of plasticity induced flapping degradation of PFRC flapping wing MAVs. The developed tool can be re-calibrated to also provide SHM for other forms of failures like fatigue, matrix cracking etc.

Dissociating medial frontal and posterior cingulate activity during self-reflection.

PubMed

Johnson, Marcia K; Raye, Carol L; Mitchell, Karen J; Touryan, Sharon R; Greene, Erich J; Nolen-Hoeksema, Susan

2006-06-01

Motivationally significant agendas guide perception, thought and behaviour, helping one to define a 'self' and to regulate interactions with the environment. To investigate neural correlates of thinking about such agendas, we asked participants to think about their hopes and aspirations (promotion focus) or their duties and obligations (prevention focus) during functional magnetic resonance imaging and compared these self-reflection conditions with a distraction condition in which participants thought about non-self-relevant items. Self-reflection resulted in greater activity than distraction in dorsomedial frontal/anterior cingulate cortex and posterior cingulate cortex/precuneus, consistent with previous findings of activity in these areas during self-relevant thought. For additional medial areas, we report new evidence of a double dissociation of function between medial prefrontal/anterior cingulate cortex, which showed relatively greater activity to thinking about hopes and aspirations, and posterior cingulate cortex/precuneus, which showed relatively greater activity to thinking about duties and obligations. One possibility is that activity in medial prefrontal cortex is associated with instrumental or agentic self-reflection, whereas posterior medial cortex is associated with experiential self-reflection. Another, not necessarily mutually exclusive, possibility is that medial prefrontal cortex is associated with a more inward-directed focus, while posterior cingulate is associated with a more outward-directed, social or contextual focus.

Short-term effectiveness of a culturally tailored educational intervention on foot self-care among type 2 diabetes patients in Morocco.

PubMed

Adarmouch, Latifa; Elyacoubi, Abdelhadi; Dahmash, Latifeh; El Ansari, Nawal; Sebbani, Majda; Amine, Mohamed

2017-03-01

Self-management education (SME) is an important yet unacknowledged aspect of diabetes care. Despite the raise of diabetes and its complications with significant burden in developing countries, research on SME interventions in Morocco is lacking. To assess the effectiveness of a culturally tailored SME intervention on foot-care self-management practices among type 2 diabetes patients and to identify factors associated with practices variation. We designed a pre-post prospective quasi-experimental study and recruited patients with type 2 diabetes aged 30 years old or above. The intervention consisted of an interactive group discussion using different materials: a narrative video, a PowerPoint presentation and a printed guide. Foot-care practices were assessed prior to the session and one month later using 2 items from the Summary of Diabetes Self-Care Activities (SDSCA). Binary logistic regression was performed to identify factors associated with a favorable variation, defined as an increase in the mean frequency score of foot-care by a minimum of 1 day/week. A total of 199 participants were recruited and 133 completed the second assessment. Mean age was 55.2 ± 11.2 years old. Women represented 67% and 72% of participants was illiterate. The foot-care score mean increased from 3.5 ± 2.9 days to 5.9 ± 1.8 days one month after the intervention (mean variation was 2.4 ± 3.1 days; p < 0.001). A favorable variation was found among 75 (37.7%) participants. In multivariate analysis, literacy was associated with higher likelihood of a favorable variation of foot-care practices (OR = 2.82; 95%CI: 1.09-7.31) while previous education about diabetic foot was associated with lower likelihood of a favorable variation (OR = 0.26; 95%CI: 0.08-0.78). There was a general improvement in foot-care practices after the intervention. Our findings suggest the role of literacy and previous patient education in shaping the observed variation. Culturally tailored interventions targeting other disease management domains are needed in our context.

Self-assembly of concentric quantum double rings.

PubMed

Mano, Takaaki; Kuroda, Takashi; Sanguinetti, Stefano; Ochiai, Tetsuyuki; Tateno, Takahiro; Kim, Jongsu; Noda, Takeshi; Kawabe, Mitsuo; Sakoda, Kazuaki; Kido, Giyuu; Koguchi, Nobuyuki

2005-03-01

We demonstrate the self-assembled formation of concentric quantum double rings with high uniformity and excellent rotational symmetry using the droplet epitaxy technique. Varying the growth process conditions can control each ring's size. Photoluminescence spectra emitted from an individual quantum ring complex show peculiar quantized levels that are specified by the carriers' orbital trajectories.

Theoretical dissociation energies for ionic molecules

NASA Technical Reports Server (NTRS)

Langhoff, S. R.; Bauschlicher, C. W., Jr.; Partridge, H.

1986-01-01

Ab initio calculations at the self-consistent-field and singles plus doubles configuration-interaction level are used to determine accurate spectroscopic parameters for most of the alkali and alkaline-earth fluorides, chlorides, oxides, sulfides, hydroxides, and isocyanides. Numerical Hartree-Fock (NHF) calculations are performed on selected systems to ensure that the extended Slater basis sets employed for the diatomic systems are near the Hartree-Fock limit. Extended Gaussian basis sets of at least triple-zeta plus double polarization equality are employed for the triatomic system. With this model, correlation effects are relatively small, but invariably increase the theoretical dissociation energies. The importance of correlating the electrons on both the anion and the metal is discussed. The theoretical dissociation energies are critically compared with the literature to rule out disparate experimental values. Theoretical (sup 2)Pi - (sup 2)Sigma (sup +) energy separations are presented for the alkali oxides and sulfides.

In Situ Formation of Decavanadate-Intercalated Layered Double Hydroxide Films on AA2024 and their Anti-Corrosive Properties when Combined with Hybrid Sol Gel Films

PubMed Central

Wu, Junsheng; Peng, Dongdong; He, Yuntao; Du, Xiaoqiong; Zhang, Zhan; Zhang, Bowei; Li, Xiaogang; Huang, Yizhong

2017-01-01

A layered double hydroxide (LDH) film was formed in situ on aluminum alloy 2024 through a urea hydrolysis method, and a decavanadate-intercalated LDH (LDH-V) film fabricated through the dip coating method. The microstructural and morphological characteristics were investigated by scanning electron microscopy (SEM). The corrosion-resistant performance was analyzed by electrochemical impedance spectroscopy (EIS), scanning electrochemical microscopy (SECM), and a salt-spray test (SST).The SEM results showed that a complete and defect-free surface was formed on the LDH-VS film. The anticorrosion results revealed that the LDH-VS film had better corrosion-resistant properties than the LDH-S film, especially long-term corrosion resistance. The mechanism of corrosion protection was proposed to consist of the self-healing effect of the decavanadate intercalation and the shielding effect of the sol-gel film. PMID:28772785

PIC Modeling of Argon Plasma Flow in MNX

NASA Astrophysics Data System (ADS)

Cohen, Samuel; Sefkow, Adam

2007-11-01

A linear helicon-heated plasma device - the Magnetic Nozzle Experiment (MNX) at the Princeton Plasma Physics Laboratory - is used for studies of the formation of strong electrostatic double layers near mechanical and magnetic apertures and the acceleration of plasma ions into supersonic directed beams. In order to characterize the role of the aperture and its involvement with ion acceleration, detailed particle-in-cell simulations are employed to study the effects of the surrounding boundary geometry on the plasma dynamics near the aperture region, within which the transition from a collisional to collisionless regime occurs. The presence of a small superthermal electron population is examined, and the model includes a background neutral population which can be ionized by energetic electrons. By self-consistently evaluating the temporal evolution of the plasma in the vicinity of the aperture, the formation mechanism of the double layer is investigated.

A double-layer based model of ion confinement in electron cyclotron resonance ion source.

PubMed

Mascali, D; Neri, L; Celona, L; Castro, G; Torrisi, G; Gammino, S; Sorbello, G; Ciavola, G

2014-02-01

The paper proposes a new model of ion confinement in ECRIS, which can be easily generalized to any magnetic configuration characterized by closed magnetic surfaces. Traditionally, ion confinement in B-min configurations is ascribed to a negative potential dip due to superhot electrons, adiabatically confined by the magneto-static field. However, kinetic simulations including RF heating affected by cavity modes structures indicate that high energy electrons populate just a thin slab overlapping the ECR layer, while their density drops down of more than one order of magnitude outside. Ions, instead, diffuse across the electron layer due to their high collisionality. This is the proper physical condition to establish a double-layer (DL) configuration which self-consistently originates a potential barrier; this "barrier" confines the ions inside the plasma core surrounded by the ECR surface. The paper will describe a simplified ion confinement model based on plasma density non-homogeneity and DL formation.

Characteristic length of the knotting probability revisited

NASA Astrophysics Data System (ADS)

Uehara, Erica; Deguchi, Tetsuo

2015-09-01

We present a self-avoiding polygon (SAP) model for circular DNA in which the radius of impermeable cylindrical segments corresponds to the screening length of double-stranded DNA surrounded by counter ions. For the model we evaluate the probability for a generated SAP with N segments having a given knot K through simulation. We call it the knotting probability of a knot K with N segments for the SAP model. We show that when N is large the most significant factor in the knotting probability is given by the exponentially decaying part exp(-N/NK), where the estimates of parameter NK are consistent with the same value for all the different knots we investigated. We thus call it the characteristic length of the knotting probability. We give formulae expressing the characteristic length as a function of the cylindrical radius rex, i.e. the screening length of double-stranded DNA.

Method of calibrating an interferometer and reducing its systematic noise

NASA Technical Reports Server (NTRS)

Hammer, Philip D. (Inventor)

1997-01-01

Methods of operation and data analysis for an interferometer so as to eliminate the errors contributed by non-responsive or unstable pixels, interpixel gain variations that drift over time, and spurious noise that would otherwise degrade the operation of the interferometer are disclosed. The methods provide for either online or post-processing calibration. The methods apply prescribed reversible transformations that exploit the physical properties of interferograms obtained from said interferometer to derive a calibration reference signal for subsequent treatment of said interferograms for interpixel gain variations. A self-consistent approach for treating bad pixels is incorporated into the methods.

Variations in Daily Sleep Quality and Type 1 Diabetes Management in Late Adolescents

PubMed Central

Queen, Tara L.; Butner, Jonathan; Wiebe, Deborah; Berg, Cynthia A.

2016-01-01

Objective To determine how between- and within-person variability in perceived sleep quality were associated with adolescent diabetes management. Methods A total of 236 older adolescents with type 1 diabetes reported daily for 2 weeks on sleep quality, self-regulatory failures, frequency of blood glucose (BG) checks, and BG values. Average, inconsistent, and daily deviations in sleep quality were examined. Results Hierarchical linear models indicated that poorer average and worse daily perceived sleep quality (compared with one’s average) was each associated with more self-regulatory failures. Sleep quality was not associated with frequency of BG checking. Poorer average sleep quality was related to greater risk of high BG. Furthermore, inconsistent and daily deviations in sleep quality interacted to predict higher BG, with more consistent sleepers benefitting more from a night of high-quality sleep. Conclusions Good, consistent sleep quality during late adolescence may benefit diabetes management by reducing self-regulatory failures and risk of high BG. PMID:26994852

Influence of the solution pH in the 6-mercaptopurine self-assembled monolayer (6MP-SAM) on a Au(111) single-crystal electrode.

PubMed

Madueño, Rafael; García-Raya, Daniel; Viudez, Alfonso J; Sevilla, José M; Pineda, Teresa; Blázquez, Manuel

2007-10-23

Self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) have been prepared on a Au(111) single-crystal electrode by immersion of the metal surface in a 100 microM 6MP and 0.01 M HClO4 solution. The 6MP-SAM Au(111) single-crystal electrodes were transferred to the cell and allowed to equilibrate with the different aqueous working solutions before the electrochemical experiments. The influence of the solution pH was studied by cyclic voltammetry, double layer capacitance curves, and electrochemical impedance spectroscopy. The electrochemical behavior of the 6MP-SAM in acetic acid at pH 4 presents important differences in comparison to that obtained in 0.1 M KOH solutions. Cyclic voltammograms for the reductive desorption process in acid medium are broad and show some features that can be explained by a phase transition between a chemisorbed and a physisorbed state of the 6MP molecules. The low solubility of these molecules in acid medium could explain this phenomenon and the readsorption of the complete monolayer when the potential is scanned in the positive direction. The variation of the double-layer capacitance values in the potential range of monolayer stability with the pH suggests that the acid-base chemistry of the 6MP molecules is playing a role. This fact has been studied by following the variations of the electron-transfer rate constant of the highly charged redox probes as are Fe(CN)(6)-3/-4 and Ru(NH3)(6)+3/+2 as a function of solution pH. The apparent surface pKa value for the 6MP-SAM (pKa approximately 8) is explained by the total conversion of the different 6MP tautomers that exist in solution to the thiol species in the adsorbed state.

Time-series Spectroscopy of Two Candidate Double Degenerates in the Open Cluster NGC 6633

NASA Astrophysics Data System (ADS)

Williams, Kurtis A.; Serna-Grey, Donald; Chakraborty, Subho; Gianninas, A.; Canton, Paul A.

2015-12-01

SNe Ia are heavily used tools in precision cosmology, yet we still are not certain what the progenitor systems are. General plausibility arguments suggest there is potential for identifying double degenerate SN Ia progenitors in intermediate-age open star clusters. We present time-resolved high-resolution spectroscopy of two white dwarfs (WDs) in the field of the open cluster NGC 6633 that had previously been identified as candidate double degenerates in the cluster. However, three hours of continuous observations of each candidate failed to detect any significant radial velocity variations at the ≳10 km s-1 level, making it highly unlikely that either WD is a double degenerate that will merge within a Hubble Time. The WD LAWDS NGC 6633 4 has a radial velocity inconsistent with cluster membership at the 2.5σ level, while the radial velocity of LAWDS NGC 6633 7 is consistent with cluster membership. We conservatively conclude that LAWDS 7 is a viable massive double degenerate candidate, though unlikely to be a Type Ia progenitor. Astrometric data from GAIA will likely be needed to determine if either WD is truly a cluster member. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Bifurcations and Chaos of AN Immersed Cantilever Beam in a Fluid and Carrying AN Intermediate Mass

NASA Astrophysics Data System (ADS)

AL-QAISIA, A. A.; HAMDAN, M. N.

2002-06-01

The concern of this work is the local stability and period-doubling bifurcations of the response to a transverse harmonic excitation of a slender cantilever beam partially immersed in a fluid and carrying an intermediate lumped mass. The unimodal form of the non-linear dynamic model describing the beam-mass in-plane large-amplitude flexural vibration, which accounts for axial inertia, non-linear curvature and inextensibility condition, developed in Al-Qaisia et al. (2000Shock and Vibration7 , 179-194), is analyzed and studied for the resonance responses of the first three modes of vibration, using two-term harmonic balance method. Then a consistent second order stability analysis of the associated linearized variational equation is carried out using approximate methods to predict the zones of symmetry breaking leading to period-doubling bifurcation and chaos on the resonance response curves. The results of the present work are verified for selected physical system parameters by numerical simulations using methods of the qualitative theory, and good agreement was obtained between the analytical and numerical results. Also, analytical prediction of the period-doubling bifurcation and chaos boundaries obtained using a period-doubling bifurcation criterion proposed in Al-Qaisia and Hamdan (2001 Journal of Sound and Vibration244, 453-479) are compared with those of computer simulations. In addition, results of the effect of fluid density, fluid depth, mass ratio, mass position and damping on the period-doubling bifurcation diagrams are studies and presented.

Effects of the lercanidipine-enalapril combination vs. the corresponding monotherapies on home blood pressure in hypertension: evidence from a large database.

PubMed

Mancia, Giuseppe; Omboni, Stefano; Chazova, Irina; Coca, Antonio; Girerd, Xavier; Haller, Hermann; Parati, Gianfranco; Pauletto, Paolo; Pupek-Musialik, Danuta; Svyshchenko, Yevgeniya

2016-01-01

To compare a combination of a dihydropyridine calcium-channel blocker with an angiotensin converting enzyme inhibitor vs. monotherapy with one or the other drug and placebo for their effects on home blood pressure (HBP). After a 2-week placebo wash-out, patients with an elevated office blood pressure (BP) (diastolic 100-109 and systolic <180 mmHg) and HBP (diastolic ≥85 mmHg) were randomized double-blind to a 10-week treatment with placebo, lercanidipine, 10 or 20 mg daily, enalapril, 10 or 20 mg daily, or the four possible combinations. In addition to office BP, HBP was self-measured via a validated semiautomatic device twice in the morning and twice in the evening during the 7 days before randomization and at the end of treatment. Baseline and treatment HBP values were separately averaged for each day, morning, evening or the whole monitoring period, excluding the first day. Day-by-day HBP variability was defined as the SD or the variation coefficient of the daily BP averages. Eight hundred and fifty-four patients with valid HBP recordings at baseline and at the end of treatment were analyzed (intention-to-treat population). From the baseline value (147.0±11.6 mmHg) systolic/diastolic HBP showed a small reduction (average baseline-adjusted change: -1.8/-1.6 mmHg) with placebo, a more marked significant fall with monotherapies (-8.8/-5.9 mmHg, P < 0.001/<0.001 vs. placebo) and even more with combination treatment (11.6/-7.6 mmHg, P < 0.001/ < 0.001 vs. placebo and P < 0.01/ < 0.05 vs. monotherapy). A similar pattern was observed for each of the days of the BP self-monitoring period as well as for either morning or evening values, although the difference between mono and combination treatment appeared to be consistently significant for the morning values only. Day-by-day systolic BP-SD was unaffected by placebo and slightly reduced by drug treatments, with no, however, significant changes in SBP-variation coefficient. Baseline and end of treatment HBP values showed a limited correlation with office BP values, this being particularly the case for treatment-induced changes (correlation coefficients: 0.37 for systolic and 0.45 for diastolic BP). This large HBP database shows that the lercanidipine-enalapril combination lowers HBP more effectively than the corresponding monotherapies and placebo, and that this greater effect is consistent between days. ClinicalTrials.gov identifier: NCT01093807.

Measurements of Enthalpy of Sublimation of Ne, N2, O2, Ar, CO2, Kr, Xe, and H2O using a Double Paddle Oscillator.

PubMed

Shakeel, Hamza; Wei, Haoyan; Pomeroy, Joshua M

2018-03-01

We report precise experimental values of the enthalpy of sublimation (Δ H s ) of quenched condensed films of neon (Ne), nitrogen (N 2 ), oxygen (O 2 ), argon (Ar), carbon dioxide (CO 2 ), krypton (Kr), xenon (Xe), and water (H 2 O) vapor using a single consistent measurement platform. The experiments are performed well below the triple point temperature of each gas and fall in the temperature range where existing experimental data is very limited. A 6 cm 2 and 400 µm thick double paddle oscillator (DPO) with high quality factor (Q ≈ 4 × 10 5 at 298K) and high frequency stability (33 parts per billion) is utilized for the measurements. The enthalpies of sublimation are derived by measuring the rate of mass loss during temperature programmed desorption. The mass change is detected due to change in the resonance frequency of the self-tracking oscillator. Our measurements typically remain within 10% of the available literature, theory, and National Institute of Standards and Technology (NIST) Web Thermo Tables ( WTT ) values, but are performed using an internally consistent method across different gases.

Effect of double-layer application on dentin bond durability of one-step self-etch adhesives.

PubMed

Taschner, M; Kümmerling, M; Lohbauer, U; Breschi, L; Petschelt, A; Frankenberger, R

2014-01-01

The aim of this in vitro study was 1) to analyze the influence of a double-layer application technique of four one-step self-etch adhesive systems on dentin and 2) to determine its effect on the stability of the adhesive interfaces stored under different conditions. Four different one-step self-etch adhesives were selected for the study (iBondSE, Clearfil S(3) Bond, XenoV(+), and Scotchbond Universal). Adhesives were applied according to manufacturers' instructions or with a double-layer application technique (without light curing of the first layer). After bonding, resin-dentin specimens were sectioned for microtensile bond strength testing in accordance with the nontrimming technique and divided into 3 subgroups of storage: a) 24 hours (immediate bond strength, T0), b) six months (T6) in artificial saliva at 37°C, or c) five hours in 10 % NaOCl at room temperature. After storage, specimens were stressed to failure. Fracture mode was assessed under a light microscope. At T0, iBond SE showed a significant increase in microtensile bond strength when the double-application technique was applied. All adhesive systems showed reduced bond strengths after six months of storage in artificial saliva and after storage in 10% NaOCl for five hours; however at T6, iBond SE, Clearfil S(3) Bond, and XenoV(+) showed significantly higher microtensile bond strength results for the double-application technique compared with the single-application technique. Scotchbond Universal showed no difference between single- or double-application, irrespective of the storage conditions. The results of this study show that improvements in bond strength of one-step self-etch adhesives by using the double-application technique are adhesive dependent.

An integrative review of ethnic and cultural variation in socialization and children's self-regulation.

PubMed

LeCuyer, Elizabeth A; Zhang, Yi

2015-04-01

To examine the evidence for cross-cultural variation in socialization and children's normative self-regulation, based on a contextual-developmental perspective. Nurses and healthcare workers in multi-cultural societies must understand diversity in socializing influences (including parenting) and in children's behaviour. A contextual-developmental perspective implies that normative cultural and ethnic values will influence socializing processes and behaviour, which in turn will influence children's self-regulation. Integrative review. Studies were located using five major search engines from 1990-2011. Domains of a contextual-developmental perspective and a comprehensive definition of self-regulation assisted the generation of search terms. Selected studies compared at least two ethnic or cultural groups and addressed contextual-developmental domains: (1) culturally specific social values, beliefs, or attitudes; (2) socializing behaviours; and (3) children's normative self-regulation. Eleven studies about children's self-regulation were found to have data consistent with a contextual-developmental perspective. Studies used descriptive correlational or comparative designs with primarily convenience sampling; eight confirmed stated hypotheses, three were exploratory. Findings across studies evidenced coherent patterns of sociocultural influence on children's attention, compliance, delay of gratification, effortful control and executive function. A contextual-developmental perspective provided a useful perspective to examine normative differences in values, socializing behaviours and children's self-regulation. This perspective and these findings are expected to guide future research, to assist nurses and healthcare providers to understand diversity in parenting and children's behaviour. © 2014 John Wiley & Sons Ltd.

Assessing Self-concept as a Mediator Between Anger and Resilience in Adolescents With Cancer in Taiwan.

PubMed

Wu, Wei-Wen; Chang, Joanne T; Tsai, Shao-Yu; Liang, Shu-Yuan

Anger is considered a common method used by patients to relieve emotional frustrations. However, this emotional response is not a common research focus for adolescents with cancer. The aim of this study was to determine whether self-concept mediated the relationship between anger and resilience for adolescent patients currently being treated for cancer. A cross-sectional study of 40 adolescents with cancer was conducted. The instruments included the Chinese Beck Self-Concept Inventory, the Chinese Beck Anger Inventory, and the Chinese Resilience Scale. Mediation analysis was also conducted. The results indicate that (1) variations in anger significantly account for 6.86% of observed variations in self-concept, (2) variations in self-concept significantly account for 52.83% of observed variations in resilience, (3) variations in anger significantly account for 10.96% of observed variations in resilience, and (4) when paths in conditions 1 and 2 were controlled, variations in anger through self-concept significantly account for 54.04% of observed variations in resilience, and variations in anger did not significantly account for observed variations in resilience. Gender and age might affect anger control. Despite worse physical functioning and an impacted appearance, participants had normative-to-positive self-concept levels, suggesting that their self-concept might not be affected by cancer. Self-concept might play a mediating role between anger and resilience, thus helping to bridge this knowledge gap. The current gap in knowledge regarding the mediating relationship necessitates the implementation of a large-scale study designed to verify the mediating role of self-concept between anger and resilience.

A Wortmannin-Cetuximab As A Double Drug

PubMed Central

Smith, R. Adam; Yuan, Hushan; Weissleder, Ralph; Cantley, Lewis C.; Josephson, Lee

2012-01-01

Double drugs are obtained when two pharmacologically active entities are covalently joined to improve potency. We conjugated the viridin Wm with a self-activating linkage to cetuximab and demonstrated the retention of immunoreactivity by the conjugate. Though cetuximab lacked a growth inhibitory activity against A549 cells, the Wmcetuximab conjugate had an anti-proliferative IC50 of 155 nM in vitro. The chemistry of attaching a self-releasing Wm to clinically approved antibodies is general and, in selected instances, may yield antibody-based double drugs with improved efficacy. PMID:19883074

Superthermal Electron Energy Interchange in the Ionosphere-Plasmasphere System

NASA Technical Reports Server (NTRS)

Khazanov, G. V.; Glocer, A.; Liemohn, M. W.; Himwich, E. W.

2013-01-01

A self-consistent approach to superthermal electron (SE) transport along closed field lines in the inner magnetosphere is used to examine the concept of plasmaspheric transparency, magnetospheric trapping, and SE energy deposition to the thermal electrons. The dayside SE population is generated both by photoionization of the thermosphere and by secondary electron production from impact ionization when the photoelectrons collide with upper atmospheric neutral particles. It is shown that a self-consistent approach to this problem produces significant changes, in comparison with other approaches, in the SE energy exchange between the plasmasphere and the two magnetically conjugate ionospheres. In particular, plasmaspheric transparency can vary by a factor of two depending on the thermal plasma content along the field line and the illumination conditions of the two conjugate ionospheres. This variation in plasmaspheric transparency as a function of thermal plasma and ionospheric conditions increases with L-shell, as the field line gets longer and the equatorial pitch angle extent of the fly-through zone gets smaller. The inference drawn from these results is that such a self-consistent approach to SE transport and energy deposition should be included to ensure robustness in ionosphere-magnetosphere modeling networks.

Dissociating medial frontal and posterior cingulate activity during self-reflection

PubMed Central

Johnson, Marcia K.; Raye, Carol L.; Mitchell, Karen J.; Touryan, Sharon R.; Greene, Erich J.; Nolen-Hoeksema, Susan

2006-01-01

Motivationally significant agendas guide perception, thought and behaviour, helping one to define a ‘self’ and to regulate interactions with the environment. To investigate neural correlates of thinking about such agendas, we asked participants to think about their hopes and aspirations (promotion focus) or their duties and obligations (prevention focus) during functional magnetic resonance imaging and compared these self-reflection conditions with a distraction condition in which participants thought about non-self-relevant items. Self-reflection resulted in greater activity than distraction in dorsomedial frontal/anterior cingulate cortex and posterior cingulate cortex/precuneus, consistent with previous findings of activity in these areas during self-relevant thought. For additional medial areas, we report new evidence of a double dissociation of function between medial prefrontal/anterior cingulate cortex, which showed relatively greater activity to thinking about hopes and aspirations, and posterior cingulate cortex/precuneus, which showed relatively greater activity to thinking about duties and obligations. One possibility is that activity in medial prefrontal cortex is associated with instrumental or agentic self-reflection, whereas posterior medial cortex is associated with experiential self-reflection. Another, not necessarily mutually exclusive, possibility is that medial prefrontal cortex is associated with a more inward-directed focus, while posterior cingulate is associated with a more outward-directed, social or contextual focus. PMID:18574518

A high level Ab initio study of the anionic hydrogen-bonded complexes FH-CN-, FH-NC-, H2O-CN- and H2O-NC-

NASA Technical Reports Server (NTRS)

Lee, Timothy J.

1989-01-01

HF, H2O, CN- and their hydrogen-bonded complexes were studied using state-of-the-art ab initio quantum mechanical methods. A large Gaussian one particle basis set consisting of triple zeta plus double polarization plus diffuse s and p functions (TZ2P + diffuse) was used. The theoretical methods employed include self consistent field, second order Moller-Plesset perturbation theory, singles and doubles configuration interaction theory and the singles and doubles coupled cluster approach. The FH-CN- and FH-NC- and H2O-CN-, H2O-NC- pairs of complexes are found to be essentially isoenergetic. The first pair of complexes are predicted to be bound by approx. 24 kcal/mole and the latter pair bound by approximately 15 kcal/mole. The ab initio binding energies are in good agreement with the experimental values. The two being shorter than the analogous C-N hydrogen bond. The infrared (IR) spectra of the two pairs of complexes are also very similar, though a severe perturbation of the potential energy surface by proton exchange means that the accurate prediction of the band center of the most intense IR mode requires a high level of electronic structure theory as well as a complete treatment of anharmonic effects. The bonding of anionic hydrogen-bonded complexes is discussed and contrasted with that of neutral hydrogen-bonded complexes.

Experimental dissociation of individual quality, food and timing of breeding effects on double-brooding in a migratory songbird.

PubMed

O'Brien, Erin L; Dawson, Russell D

2013-07-01

Annual reproductive success in many species is influenced by the number of breeding attempts within a season. Although previous studies have shown isolated effects of female quality, food, and timing of breeding on the probability of female birds producing second broods, to our knowledge, none have tested the relative importance of multiple factors and their interactions using simultaneous manipulations within populations of free-living birds. In this study, we show that individual quality and timing of breeding interact to affect the probability of double-brooding in female mountain bluebirds (Sialia currucoides). High-quality females (those that naturally initiated clutches early in the season) were more likely to double-brood, regardless of whether their hatching date was advanced or delayed, whereas later breeding, lower quality females were much less likely to double-brood when their first attempt was delayed. This indicates that annual fecundity of poorer quality (or younger) female bluebirds may be more sensitive to seasonal variation in environmental conditions. In addition, birds that were provided with supplemental food throughout first breeding attempts were more likely to double-brood in one of the study years, suggesting that female bluebirds may be energetically limited in their capacity to initiate a second brood. Females that had their first brood delayed also had a shorter inter-brood interval and were moulting fewer feathers during second broods compared to controls, while females in better condition showed more advanced moult in second breeding attempts. Taken together, our results demonstrate the combined effects of age- or individual quality-mediated energetic trade-offs between current and future reproduction, and between investments in offspring and self-maintenance, on annual fecundity of female birds.

0{nu}{beta}{beta}-decay nuclear matrix elements with self-consistent short-range correlations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simkovic, Fedor; Bogoliubov Laboratory of Theoretical Physics, JINR, RU-141 980 Dubna, Moscow region; Department of Nuclear Physics, Comenius University, Mlynska dolina F1, SK-842 15 Bratislava

A self-consistent calculation of nuclear matrix elements of the neutrinoless double-beta decays (0{nu}{beta}{beta}) of {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 116}Cd, {sup 128}Te, {sup 130}Te, and {sup 136}Xe is presented in the framework of the renormalized quasiparticle random phase approximation (RQRPA) and the standard QRPA. The pairing and residual interactions as well as the two-nucleon short-range correlations are for the first time derived from the same modern realistic nucleon-nucleon potentials, namely, from the charge-dependent Bonn potential (CD-Bonn) and the Argonne V18 potential. In a comparison with the traditional approach of using the Miller-Spencer Jastrow correlations, matrix elementsmore » for the 0{nu}{beta}{beta} decay are obtained that are larger in magnitude. We analyze the differences among various two-nucleon correlations including those of the unitary correlation operator method (UCOM) and quantify the uncertainties in the calculated 0{nu}{beta}{beta}-decay matrix elements.« less

Implementation of the infinite-range exterior complex scaling to the time-dependent complete-active-space self-consistent-field method

NASA Astrophysics Data System (ADS)

Orimo, Yuki; Sato, Takeshi; Scrinzi, Armin; Ishikawa, Kenichi L.

2018-02-01

We present a numerical implementation of the infinite-range exterior complex scaling [Scrinzi, Phys. Rev. A 81, 053845 (2010), 10.1103/PhysRevA.81.053845] as an efficient absorbing boundary to the time-dependent complete-active-space self-consistent field method [Sato, Ishikawa, Březinová, Lackner, Nagele, and Burgdörfer, Phys. Rev. A 94, 023405 (2016), 10.1103/PhysRevA.94.023405] for multielectron atoms subject to an intense laser pulse. We introduce Gauss-Laguerre-Radau quadrature points to construct discrete variable representation basis functions in the last radial finite element extending to infinity. This implementation is applied to strong-field ionization and high-harmonic generation in He, Be, and Ne atoms. It efficiently prevents unphysical reflection of photoelectron wave packets at the simulation boundary, enabling accurate simulations with substantially reduced computational cost, even under significant (≈50 % ) double ionization. For the case of a simulation of high-harmonic generation from Ne, for example, 80% cost reduction is achieved, compared to a mask-function absorption boundary.

Self-consistent many-electron theory of electron work functions and surface potential characteristics for selected metals

NASA Technical Reports Server (NTRS)

Smith, J. R.

1969-01-01

Electron work functions, surface potentials, and electron number density distributions and electric fields in the surface region of 26 metals were calculated from first principles within the free electron model. Calculation proceeded from an expression of the total energy as a functional of the electron number density, including exchange and correlation energies, as well as a first inhomogeneity term. The self-consistent solution was obtained via a variational procedure. Surface barriers were due principally to many-body effects; dipole barriers were small only for some alkali metals, becoming quite large for the transition metals. Surface energies were inadequately described by this model, which neglects atomistic effects. Reasonable results were obtained for electron work functions and surface potential characteristics, maximum electron densities varying by a factor of over 60.

Self-Paced Prioritized Curriculum Learning With Coverage Penalty in Deep Reinforcement Learning.

PubMed

Ren, Zhipeng; Dong, Daoyi; Li, Huaxiong; Chen, Chunlin; Zhipeng Ren; Daoyi Dong; Huaxiong Li; Chunlin Chen; Dong, Daoyi; Li, Huaxiong; Chen, Chunlin; Ren, Zhipeng

2018-06-01

In this paper, a new training paradigm is proposed for deep reinforcement learning using self-paced prioritized curriculum learning with coverage penalty. The proposed deep curriculum reinforcement learning (DCRL) takes the most advantage of experience replay by adaptively selecting appropriate transitions from replay memory based on the complexity of each transition. The criteria of complexity in DCRL consist of self-paced priority as well as coverage penalty. The self-paced priority reflects the relationship between the temporal-difference error and the difficulty of the current curriculum for sample efficiency. The coverage penalty is taken into account for sample diversity. With comparison to deep Q network (DQN) and prioritized experience replay (PER) methods, the DCRL algorithm is evaluated on Atari 2600 games, and the experimental results show that DCRL outperforms DQN and PER on most of these games. More results further show that the proposed curriculum training paradigm of DCRL is also applicable and effective for other memory-based deep reinforcement learning approaches, such as double DQN and dueling network. All the experimental results demonstrate that DCRL can achieve improved training efficiency and robustness for deep reinforcement learning.

Affective disorders and completed suicide by self-poisoning, trend of using antidepressants as a method of self-poisoning.

PubMed

Löfman, Sanna; Hakko, Helinä; Mainio, Arja; Riipinen, Pirkko

2017-09-01

The aim of this research was to study the role and trend of antidepressant use as a method of suicide in completed self-poisoning suicides in patients with affective disorders during a 23-year follow up period. The data consisted of 483 completed self-poisoning suicides from 1988 to 2011 in the province of Oulu in Northern Finland (286 men and 197 women). Of the self-poisoning victims, 26.9% (n=130) had hospital-treated unipolar depression and 3.1% (n=15) hospital-treated bipolar disorder. Further, 53.8% (n=70) of those with unipolar depression and 53.3% (n=8) of those with bipolar depression died by suicide using antidepressants. During the 23-year follow-up period, the proportion of those using antidepressants doubled among all self-poisoning victims of suicide. A significant decline was observed in the use of tricyclic antidepressants in self- poisoning suicides while a linear increase was found in the use of SSRIs (selective serotonin reuptake inhibitors) and other antidepressants. During recent years one in five self-poisoning suicides involved the use of antiepileptics. A limitation of our study was that the psychiatric diagnoses only include hospital inpatient episodes. In conclusion, the use of new antidepressants has increased rapidly, but the risk of their use in self-poisoning suicide has perhaps been underestimated. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Variational formulation of macroparticle models for electromagnetic plasma simulations

DOE PAGES

Stamm, Alexander B.; Shadwick, Bradley A.; Evstatiev, Evstati G.

2014-06-01

A variational method is used to derive a self-consistent macroparticle model for relativistic electromagnetic kinetic plasma simulations. Extending earlier work, discretization of the electromagnetic Low Lagrangian is performed via a reduction of the phase-space distribution function onto a collection of finite-sized macroparticles of arbitrary shape and discretization of field quantities onto a spatial grid. This approach may be used with lab frame coordinates or moving window coordinates; the latter can greatly improve computational efficiency for studying some types of laser-plasma interactions. The primary advantage of the variational approach is the preservation of Lagrangian symmetries, which in our case leads tomore » energy conservation and thus avoids difficulties with grid heating. In addition, this approach decouples particle size from grid spacing and relaxes restrictions on particle shape, leading to low numerical noise. The variational approach also guarantees consistent approximations in the equations of motion and is amenable to higher order methods in both space and time. We restrict our attention to the 1.5-D case (one coordinate and two momenta). Lastly, simulations are performed with the new models and demonstrate energy conservation and low noise.« less

Culture modulates implicit ownership-induced self-bias in memory.

PubMed

Sparks, Samuel; Cunningham, Sheila J; Kritikos, Ada

2016-08-01

The relation of incoming stimuli to the self implicitly determines the allocation of cognitive resources. Cultural variations in the self-concept shape cognition, but the extent is unclear because the majority of studies sample only Western participants. We report cultural differences (Asian versus Western) in ownership-induced self-bias in recognition memory for objects. In two experiments, participants allocated a series of images depicting household objects to self-owned or other-owned virtual baskets based on colour cues before completing a surprise recognition memory test for the objects. The 'other' was either a stranger or a close other. In both experiments, Western participants showed greater recognition memory accuracy for self-owned compared with other-owned objects, consistent with an independent self-construal. In Experiment 1, which required minimal attention to the owned objects, Asian participants showed no such ownership-related bias in recognition accuracy. In Experiment 2, which required attention to owned objects to move them along the screen, Asian participants again showed no overall memory advantage for self-owned items and actually exhibited higher recognition accuracy for mother-owned than self-owned objects, reversing the pattern observed for Westerners. This is consistent with an interdependent self-construal which is sensitive to the particular relationship between the self and other. Overall, our results suggest that the self acts as an organising principle for allocating cognitive resources, but that the way it is constructed depends upon cultural experience. Additionally, the manifestation of these cultural differences in self-representation depends on the allocation of attentional resources to self- and other-associated stimuli. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Second-order perturbation theory with a density matrix renormalization group self-consistent field reference function: theory and application to the study of chromium dimer.

PubMed

Kurashige, Yuki; Yanai, Takeshi

2011-09-07

We present a second-order perturbation theory based on a density matrix renormalization group self-consistent field (DMRG-SCF) reference function. The method reproduces the solution of the complete active space with second-order perturbation theory (CASPT2) when the DMRG reference function is represented by a sufficiently large number of renormalized many-body basis, thereby being named DMRG-CASPT2 method. The DMRG-SCF is able to describe non-dynamical correlation with large active space that is insurmountable to the conventional CASSCF method, while the second-order perturbation theory provides an efficient description of dynamical correlation effects. The capability of our implementation is demonstrated for an application to the potential energy curve of the chromium dimer, which is one of the most demanding multireference systems that require best electronic structure treatment for non-dynamical and dynamical correlation as well as large basis sets. The DMRG-CASPT2/cc-pwCV5Z calculations were performed with a large (3d double-shell) active space consisting of 28 orbitals. Our approach using large-size DMRG reference addressed the problems of why the dissociation energy is largely overestimated by CASPT2 with the small active space consisting of 12 orbitals (3d4s), and also is oversensitive to the choice of the zeroth-order Hamiltonian. © 2011 American Institute of Physics

A Wireless Self-Powered Urinary Incontinence Sensor System

NASA Astrophysics Data System (ADS)

Tanaka, Ami; Utsunomiya, Fumiyasu; Douseki, Takakuni

A self-powered urinary incontinence sensor system consisting of a urine-activated coin battery and a wireless transmitter has been developed as an application for wireless biosensor networks. The urine-activated battery makes possible both the sensing of urine leakage and self-powered operation. An intermittent power-supply circuit that uses an electric double-layer capacitor (EDLC) with a small internal resistance suppresses the supply voltage drop due to the large internal resistance of the battery. This circuit and a 1-V surface acoustic wave (SAW) oscillator reduce the power dissipation of a wireless transmitter. The SAW oscillator quickly responds to the on-off control of the power supply, which is suitable for intermittent operation. To verify the effectiveness of the circuit scheme, the authors fabricated a prototype sensor system. When the volume of urine is 0.2 ml, the battery outputs a voltage of over 1.3 V; and the sensor system can transmit signals over a distance of 5 m.

Spectroscopic imaging of self-organization in high power impulse magnetron sputtering plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersson, Joakim; Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore; Ni, Pavel

Excitation and ionization conditions in traveling ionization zones of high power impulse magnetron sputtering plasmas were investigated using fast camera imaging through interference filters. The images, taken in end-on and side-on views using light of selected gas and target atom and ion spectral lines, suggest that ionization zones are regions of enhanced densities of electrons, and excited atoms and ions. Excited atoms and ions of the target material (Al) are strongly concentrated near the target surface. Images from the highest excitation energies exhibit the most localized regions, suggesting localized Ohmic heating consistent with double layer formation.

Spectroscopic imaging of self-organization in high power impulse magnetron sputtering plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore; Andersson, Joakim; Ni, Pavel

Excitation and ionization conditions in traveling ionization zones of high power impulse magnetron sputtering plasmas were investigated using fast camera imaging through interference filters. The images, taken in end-on and side on views using light of selected gas and target atom and ion spectral lines, suggest that ionization zones are regions of enhanced densities of electrons, and excited atoms and ions. Excited atoms and ions of the target material (Al) are strongly concentrated near the target surface. Images from the highest excitation energies exhibit the most localized regions, suggesting localized Ohmic heating consistent with double layer formation.

Room-temperature healing of a thermosetting polymer using the Diels-Alder reaction.

PubMed

Peterson, Amy M; Jensen, Robert E; Palmese, Giuseppe R

2010-04-01

Self-healing materials are particularly desirable for load-bearing applications because they offer the potential for increased safety and material lifetimes. A furan-functionalized polymer network was designed that can heal via covalent bonding across the crack surface with the use of a healing agent consisting of a bismaleimide in solution. Average healing efficiencies of approximately 70% were observed. The healing ability of fiber-reinforced composite specimens was investigated with flexural, short beam shear, and double cantilever beam specimens. It was found that solvent amount and maleimide concentration play key roles in determining healing efficiency.

Objective Molecular Dynamics with Self-consistent Charge Density Functional Tight-Binding (SCC-DFTB) Method

NASA Astrophysics Data System (ADS)

Dumitrica, Traian; Hourahine, Ben; Aradi, Balint; Frauenheim, Thomas

We discus the coupling of the objective boundary conditions into the SCC density functional-based tight binding code DFTB+. The implementation is enabled by a generalization to the helical case of the classical Ewald method, specifically by Ewald-like formulas that do not rely on a unit cell with translational symmetry. The robustness of the method in addressing complex hetero-nuclear nano- and bio-fibrous systems is demonstrated with illustrative simulations on a helical boron nitride nanotube, a screw dislocated zinc oxide nanowire, and an ideal double-strand DNA. Work supported by NSF CMMI 1332228.

Thickness determination of thin solid films by angle-resolved X-ray fluorescence spectrometry using monochromatized synchrotron radiation

NASA Astrophysics Data System (ADS)

Schmitt, W.; Drotbohm, P.; Rothe, J.; Hormes, J.; Ottermann, C. R.; Bange, K.

1995-05-01

Thickness measurements by the method of angle-resolved, self-ratio X-ray fluorescence spectrometry (AR/SR/XFS) have been carried out on thin solid films using monochromatized synchrotron radiation at the Bonn storage ring ELSA. Synchrotron radiation was monochromatized by means of a double-crystal monochromator and fluorescence radiation was detected by a Si(Li) semiconductor detector. The results for sample systems consisting of Au on Si, Cr on SiO2 and TiO2 on alkali-free glass are very satisfactory and agree well with results obtained by other methods.

[Verification of the double dissociation model of shyness using the implicit association test].

PubMed

Fujii, Tsutomu; Aikawa, Atsushi

2013-12-01

The "double dissociation model" of shyness proposed by Asendorpf, Banse, and Mtücke (2002) was demonstrated in Japan by Aikawa and Fujii (2011). However, the generalizability of the double dissociation model of shyness was uncertain. The present study examined whether the results reported in Aikawa and Fujii (2011) would be replicated. In Study 1, college students (n = 91) completed explicit self-ratings of shyness and other personality scales. In Study 2, forty-eight participants completed IAT (Implicit Association Test) for shyness, and their friends (n = 141) rated those participants on various personality scales. The results revealed that only the explicit self-concept ratings predicted other-rated low praise-seeking behavior, sociable behavior and high rejection-avoidance behavior (controlled shy behavior). Only the implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). The results of this study are similar to the findings of the previous research, which supports generalizability of the double dissociation model of shyness.

In-depth analysis and modelling of self-heating effects in nanometric DGMOSFETs

NASA Astrophysics Data System (ADS)

Roldán, J. B.; González, B.; Iñiguez, B.; Roldán, A. M.; Lázaro, A.; Cerdeira, A.

2013-01-01

Self-heating effects (SHEs) in nanometric symmetrical double-gate MOSFETs (DGMOSFETs) have been analysed. An equivalent thermal circuit for the transistors has been developed to characterise thermal effects, where the temperature and thickness dependency of the thermal conductivity of the silicon and oxide layers within the devices has been included. The equivalent thermal circuit is consistent with simulations using a commercial technology computer-aided design (TCAD) tool (Sentaurus by Synopsys). In addition, a model for DGMOSFETs has been developed where SHEs have been considered in detail, taking into account the temperature dependence of the low-field mobility, saturation velocity, and inversion charge. The model correctly reproduces Sentaurus simulation data for the typical bias range used in integrated circuits. Lattice temperatures predicted by simulation are coherently reproduced by the model for varying silicon layer geometry.

Theoretical studies for the rates and kinetic isotope effects of the excited-state double proton transfer in the 1:1 7-azaindole:H2O complex using variational transition state theory including multidimensional tunneling.

PubMed

Duong, My Phu Thi; Kim, Yongho

2010-03-18

Variational transition state theory calculations including multidimensional tunneling (VTST/MT) for excited-state tautomerization in the 1:1 7-azaindole:H(2)O complex were performed. Electronic structures and energies for reactant, product, transition state, and potential energy curves along the reaction coordinate were computed at the CASSCF(10,9)/6-31G(d,p) level of theory. The potential energies were corrected by second-order multireference perturbation theory to take the dynamic electron correlation into consideration. The final potential energy curves along the reaction coordinate were generated at the MRPT2//CASSCF(10,9)/6-31G(d,p) level. Two protons in the excited-state tautomerization are transferred concertedly, albeit asynchronously. The position of the variational transition state is very different from the conventional transition state, and is highly dependent on isotopic substitution. Rate constants were calculated using VTST/MT, and were on the order of 10(-6) s(-1) at room temperature. The HH/DD kinetic isotope effects are consistent with experimental observations; consideration of both tunneling and variational effects was essential to predict the experimental values correctly.

Chromosome doubling method

DOEpatents

Kato, Akio

2006-11-14

The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

Biobehavioral effects of baclofen in anxious alcohol-dependent individuals: a randomized, double-blind, placebo-controlled, laboratory study

PubMed Central

Farokhnia, M; Schwandt, M L; Lee, M R; Bollinger, J W; Farinelli, L A; Amodio, J P; Sewell, L; Lionetti, T A; Spero, D E; Leggio, L

2017-01-01

Baclofen has been suggested as a potential pharmacotherapy for alcohol use disorder, but the clinical data are conflicting. Here we investigated the biobehavioral effects of baclofen in a sample of anxious alcohol-dependent individuals. This was a randomized, double-blind, placebo-controlled, human laboratory study in non-treatment seeking alcohol-dependent individuals with high trait anxiety (N=34). Participants received baclofen (30 mg per day) or placebo for at least 8 days, then performed an experimental session consisting of alcohol cue-reactivity followed by alcohol administration procedure (alcohol priming, then alcohol self-administration). Total amount of alcohol self-administered was the primary outcome; alcohol craving, subjective/physiological responses and mood/anxiety symptoms were also evaluated. There was no significant medication effect on the total amount of alcohol consumed during the alcohol self-administration (P=0.76). Baclofen blunted the positive association between maximum breath alcohol concentration during priming and the amount of alcohol consumption (significant interaction, P=0.03). Ratings of feeling intoxicated were significantly higher in the baclofen group after consuming the priming drink (P=0.006). During the self-administration session, baclofen significantly increased ratings of feeling high (P=0.01) and intoxicated (P=0.01). A significant reduction in heart rate (P<0.001) and a trend-level increase in diastolic blood pressure (P=0.06) were also detected in the baclofen group during the alcohol laboratory session. In conclusion, baclofen was shown to affect subjective and physiological responses to alcohol drinking in anxious alcohol-dependent individuals. These results do not support an anti-craving or anti-reinforcing effect of baclofen, but rather suggest that baclofen may act as a substitution medication for alcohol use disorder. PMID:28440812

Biobehavioral effects of baclofen in anxious alcohol-dependent individuals: a randomized, double-blind, placebo-controlled, laboratory study.

PubMed

Farokhnia, M; Schwandt, M L; Lee, M R; Bollinger, J W; Farinelli, L A; Amodio, J P; Sewell, L; Lionetti, T A; Spero, D E; Leggio, L

2017-04-25

Baclofen has been suggested as a potential pharmacotherapy for alcohol use disorder, but the clinical data are conflicting. Here we investigated the biobehavioral effects of baclofen in a sample of anxious alcohol-dependent individuals. This was a randomized, double-blind, placebo-controlled, human laboratory study in non-treatment seeking alcohol-dependent individuals with high trait anxiety (N=34). Participants received baclofen (30 mg per day) or placebo for at least 8 days, then performed an experimental session consisting of alcohol cue-reactivity followed by alcohol administration procedure (alcohol priming, then alcohol self-administration). Total amount of alcohol self-administered was the primary outcome; alcohol craving, subjective/physiological responses and mood/anxiety symptoms were also evaluated. There was no significant medication effect on the total amount of alcohol consumed during the alcohol self-administration (P=0.76). Baclofen blunted the positive association between maximum breath alcohol concentration during priming and the amount of alcohol consumption (significant interaction, P=0.03). Ratings of feeling intoxicated were significantly higher in the baclofen group after consuming the priming drink (P=0.006). During the self-administration session, baclofen significantly increased ratings of feeling high (P=0.01) and intoxicated (P=0.01). A significant reduction in heart rate (P<0.001) and a trend-level increase in diastolic blood pressure (P=0.06) were also detected in the baclofen group during the alcohol laboratory session. In conclusion, baclofen was shown to affect subjective and physiological responses to alcohol drinking in anxious alcohol-dependent individuals. These results do not support an anti-craving or anti-reinforcing effect of baclofen, but rather suggest that baclofen may act as a substitution medication for alcohol use disorder.

The Effect of Variation in Permittivity of Different Tissues on Induced Electric Field in the Brain during Transcranial Magnetic Stimulation

NASA Astrophysics Data System (ADS)

Hadimani, Ravi; Porzig, Konstantin; Crowther, Lawrence; Brauer, Hartmut; Toepfer, Hannes; Jiles, David; Department of Electrical and Computer Engineering, Iowa State University Team; Department of Advanced Electromagnetics, Ilmenau University of Technology Team

2013-03-01

Estimation of electric field in the brain during Transcranial Magnetic Stimulation (TMS) requires knowledge of the electric property of brain tissue. Grey and white matters have unusually high relative permittivities of ~ 106 at low frequencies. However, relative permittivity of cerebrospinal fluid is ~ 102. With such a variation it is necessary to consider the effect of boundaries. A model consisting of 2 hemispheres was used in the model with the properties of one hemisphere kept constant at σ1 = 0.1Sm-1 and ɛr 1 = 10 while the properties of the second hemisphere were changed kept at σ2 = 0.1Sm-1 to 2Sm-1 and ɛr 2 = 102 to 105. A 70 mm diameter double coil was used as the source of the magnetic field. The amplitude of the current in the coil was 5488 A at a frequency of 2.9 kHz. The results show that the electric field, E induced during magnetic stimulation is independent of the relative permittivity, ɛr and varies with the conductivity. Thus the variation in E, calculated with homogeneous and heterogeneous head models was due to variation in conductivity of the tissues and not due to variation in permittivities.

Identification of crop cultivars with consistently high lignocellulosic sugar release requires the use of appropriate statistical design and modelling

PubMed Central

2013-01-01

Background In this study, a multi-parent population of barley cultivars was grown in the field for two consecutive years and then straw saccharification (sugar release by enzymes) was subsequently analysed in the laboratory to identify the cultivars with the highest consistent sugar yield. This experiment was used to assess the benefit of accounting for both the multi-phase and multi-environment aspects of large-scale phenotyping experiments with field-grown germplasm through sound statistical design and analysis. Results Complementary designs at both the field and laboratory phases of the experiment ensured that non-genetic sources of variation could be separated from the genetic variation of cultivars, which was the main target of the study. The field phase included biological replication and plot randomisation. The laboratory phase employed re-randomisation and technical replication of samples within a batch, with a subset of cultivars chosen as duplicates that were randomly allocated across batches. The resulting data was analysed using a linear mixed model that incorporated field and laboratory variation and a cultivar by trial interaction, and ensured that the cultivar means were more accurately represented than if the non-genetic variation was ignored. The heritability detected was more than doubled in each year of the trial by accounting for the non-genetic variation in the analysis, clearly showing the benefit of this design and approach. Conclusions The importance of accounting for both field and laboratory variation, as well as the cultivar by trial interaction, by fitting a single statistical model (multi-environment trial, MET, model), was evidenced by the changes in list of the top 40 cultivars showing the highest sugar yields. Failure to account for this interaction resulted in only eight cultivars that were consistently in the top 40 in different years. The correspondence between the rankings of cultivars was much higher at 25 in the MET model. This approach is suited to any multi-phase and multi-environment population-based genetic experiment. PMID:24359577

Importance of the efficiency of double-stranded DNA formation in cDNA synthesis for the imprecision of microarray expression analysis.

PubMed

Thormar, Hans G; Gudmundsson, Bjarki; Eiriksdottir, Freyja; Kil, Siyoen; Gunnarsson, Gudmundur H; Magnusson, Magnus Karl; Hsu, Jason C; Jonsson, Jon J

2013-04-01

The causes of imprecision in microarray expression analysis are poorly understood, limiting the use of this technology in molecular diagnostics. Two-dimensional strandness-dependent electrophoresis (2D-SDE) separates nucleic acid molecules on the basis of length and strandness, i.e., double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), and RNA·DNA hybrids. We used 2D-SDE to measure the efficiency of cDNA synthesis and its importance for the imprecision of an in vitro transcription-based microarray expression analysis. The relative amount of double-stranded cDNA formed in replicate experiments that used the same RNA sample template was highly variable, ranging between 0% and 72% of the total DNA. Microarray experiments showed an inverse relationship between the difference between sample pairs in probe variance and the relative amount of dsDNA. Approximately 15% of probes showed between-sample variation (P < 0.05) when the dsDNA percentage was between 12% and 35%. In contrast, only 3% of probes showed between-sample variation when the dsDNA percentage was 69% and 72%. Replication experiments of the 35% dsDNA and 72% dsDNA samples were used to separate sample variation from probe replication variation. The estimated SD of the sample-to-sample variation and of the probe replicates was lower in 72% dsDNA samples than in 35% dsDNA samples. Variation in the relative amount of double-stranded cDNA synthesized can be an important component of the imprecision in T7 RNA polymerase-based microarray expression analysis. © 2013 American Association for Clinical Chemistry

There's More than Meets the Eye: Complex Associations of Daily Pain, Physical Symptoms, and Self-Efficacy with Activity in Middle and Older Adulthood.

PubMed

Curtis, Rachel G; Windsor, Tim D; Mogle, Jacqueline A; Bielak, Allison A M

2017-01-01

Participation in activities is associated with a range of positive outcomes in adulthood. Research has shown that pain and physical symptoms are associated with less activity in older adults, whereas higher self-efficacy is associated with more activity. Such research tends to examine cross-sectional or long-term between-person change, limiting the opportunity to explore dynamic within-person processes that unfold over shorter time periods. This study aimed to (1) replicate previous between-person associations of self-efficacy with engagement in activity and (2) examine whether daily variation in pain, physical symptoms, and self-efficacy corresponded with daily within-person variation in different types of activity. We predicted that participants would engage in less activity on days when they experienced more pain or physical symptoms than their average (a negative within-person association) and that participants would engage in more activity on days when self-efficacy was higher than average (a positive within-person association). This study used an online diary study to assess self- reported daily pain, physical symptoms, self-efficacy, and engagement in activity among 185 adults aged 51-84 years for up to 7 days. Multilevel modelling was used to examine whether between-person (average) and daily within-person variability in pain, physical symptoms, and self-efficacy were associated with social, physical, and mental activity. In line with previous research, between-person self-efficacy was positively associated with social and physical activity. Supporting the hypotheses, within-person self-efficacy was also positively associated with social and physical activity. The results for pain and physical symptoms were less consistent. Between-person pain was positively associated with social activity. Age interactions indicated that within-person pain was negatively associated with social activity and positively associated with physical activity among older adults. Within-person physical symptoms were positively related to social and mental activity. Stable individual differences as well as short-term within-person variation in physical and psychological functioning are associated with day-to-day variation in activity. Between-person associations did not always reflect within-person associations (e.g., for pain). These complex associations may be influenced by a range of factors including the type of activity and how it is defined (e.g., specific activities and their difficulty), the type of physical symptoms experienced, and age. © 2016 S. Karger AG, Basel.

Chiral self-discrimination of the enantiomers of alpha-phenylethylamine derivatives in proton NMR.

PubMed

Huang, Shao-Hua; Bai, Zheng-Wu; Feng, Ji-Wen

2009-05-01

Two types of chiral analytes, the urea and amide derivatives of alpha-phenylethylamine, were prepared. The effect of inter-molecular hydrogen-bonding interaction on self-discrimination of the enantiomers of analytes has been investigated using high-resolution (1)H NMR. It was found that the urea derivatives with double-hydrogen-bonding interaction exhibit not only the stronger hydrogen-bonding interaction but also better self-recognition abilities than the amide derivatives (except for one bearing two NO(2) groups). The present results suggest that double-hydrogen-bonding interaction promotes the self-discrimination ability of the chiral compounds. Copyright (c) 2009 John Wiley & Sons, Ltd.

Self-replication of chemical systems based on recognition within a double or a triple helix - A realistic hypothesis

NASA Technical Reports Server (NTRS)

Kanavarioti, Anastassia

1992-01-01

A scenario is proposed for the non-enzymatic self-replication of short RNA molecules. The self-replication of an oligopyrimidine strand is considered and the process of template-directed synthesis based on recognition within a double helix is discussed. Replication mechanisms are suggested for selected oligonucleotides. The mechanisms are based on Watson-Crick base pairing between complementary nucleotides as well as Hoogsteen base pairing between a duplex and the complementary third strand. It is suggested that self-replication based on these mechanisms may be accomplished but may result in a substantial amount of misinformation transfer when mixed oligonucleotides are used.

Surviving at high elevations: an inter- and intra-specific analysis in a mountain bird community.

PubMed

Bastianelli, G; Tavecchia, G; Meléndez, L; Seoane, J; Obeso, J R; Laiolo, P

2017-06-01

Elevation represents an important selection agent on self-maintenance traits and correlated life histories in birds, but no study has analysed whether life-history variation along this environmental cline is consistent among and within species. In a sympatric community of passerines, we analysed how the average adult survival of 25 open-habitat species varied with their elevational distribution and how adult survival varied with elevation at the intra-specific level. For such purpose, we estimated intra-specific variation in adult survival in two mountainous species, the Water pipit (Anthus spinoletta) and the Northern wheatear (Oenanthe oenanthe) in NW Spain, by means of capture-recapture analyses. At the inter-specific level, high-elevation species showed higher survival values than low elevation ones, likely because a greater allocation to self-maintenance permits species to persist in alpine environments. At the intra-specific level, the magnitude of survival variation was lower by far. Nevertheless, Water pipit survival slightly decreased at high elevations, while the proportion of transient birds increased. In contrast, no such relationships were found in the Northern wheatear. Intra-specific analyses suggest that living at high elevation may be costly, such as for the Water pipit in our case study. Therefore, it seems that a species can persist with viable populations in uplands, where extrinsic mortality is high, by increasing the investment in self-maintenance and prospecting behaviours.

Dynamics of double-polarity subduction: application to the Western Mediterranean

NASA Astrophysics Data System (ADS)

Peral, M.; Zlotnik, S.; Fernandez, M.; Verges, J.; Jiménez-Munt, I.; Torne, M.

2015-12-01

The evolution of the Western Mediterranean is a highly debated question by geologists and geophysicists. Even though most scientists agree in considering slab roll-back to be the driving mechanism of the tectonic evolution of this area, there is still no consensus about the initial setup and its time evolution. A recent model proposed by Vergés and Fernàndez (2012) suggests a lateral change in subduction polarity of the Ligurian-Thetys oceanic domain to explain the formation and evolution of the Betic-Rif orogenic system and the associated Alboran back-arc basin. Such geodynamic scenario is also proposed for different converging regions. The aim of this study is to analyze the dynamic evolution of a double-polarity subduction process and its consequences in order to test the physical feasibility of this interaction and provide geometries and evolutions comparable to those proposed for the Western Mediterranean. The 3D numerical model of double-polarity subduction is carried out via the Underworld framework. Tectonic plate behavior is described by equations of fluid dynamics in the presence of several different phases. Underworld solves a non-linear Stokes flow problem using Finite Elements combined with particle-in-cell approach, thus the discretization combines a standard Eulerian Finite Element mesh with Lagrangian particles to track the location of the phases. The final model consists of two oceanic plates with viscoplastic rheology subducting into the upper mantle and the problem is driven by Rayleigh-Taylor instability. The main factors to be studied are the interaction between the two plates, the poloidal and toroidal mantle fluxes, the velocity variations of slabs, the stress distribution and the variations in the trench morphology.

Sibling genes as environment: Sibling dopamine genotypes and adolescent health support frequency dependent selection.

PubMed

Rauscher, Emily; Conley, Dalton; Siegal, Mark L

2015-11-01

While research consistently suggests siblings matter for individual outcomes, it remains unclear why. At the same time, studies of genetic effects on health typically correlate variants of a gene with the average level of behavioral or health measures, ignoring more complicated genetic dynamics. Using National Longitudinal Study of Adolescent Health data, we investigate whether sibling genes moderate individual genetic expression. We compare twin variation in health-related absences and self-rated health by genetic differences at three locations related to dopamine regulation and transport to test sibship-level cross-person gene-gene interactions. Results suggest effects of variation at these genetic locations are moderated by sibling genes. Although the mechanism remains unclear, this evidence is consistent with frequency dependent selection and suggests much genetic research may violate the stable unit treatment value assumption. Copyright © 2015 Elsevier Inc. All rights reserved.

Refraction index sensor based on phase resonances in a subwavelength structure with double period.

PubMed

Skigin, Diana C; Lester, Marcelo

2016-10-01

In this paper, we numerically demonstrate a refraction index sensor based on phase resonance excitation in a subwavelength-slit structure with a double period. The sensor consists of a metal layer with subwavelength slots arranged in a bi-periodic form, separated from a high refraction index medium. Between the metallic structure and the incident medium, a dielectric waveguide is formed whose refraction index is going to be determined. Variations in the refraction index of the waveguide are detected as shifts in the peaks of transmitted intensity originated by resonant modes supported by the compound metallic structure. At normal incidence, the spectral position of these resonant peaks exhibits a linear or a quadratic dependence with the refraction index, which permits us to obtain the unknown refraction index value with a high precision for a wide range of wavelengths. Since the operating principle of the sensor is due to the morphological resonances of the slits' structure, this device can be scaled to operate in different wavelength ranges while keeping similar characteristics.

Molecular Simulations of The Formation of Gold-Molecule-Gold Junctions

NASA Astrophysics Data System (ADS)

Wang, Huachuan

2013-03-01

We perform classical molecular simulations by combining grand canonical Monte Carlo (GCMC) sampling with molecular dynamics (MD) simulation to explore the dynamic gold nanojunctions in a Alkenedithiol (ADT) solvent. With the aid of a simple driving-spring model, which can reasonably represent the long-range elasticity of the gold electrode, the spring forces are obtained during the dynamic stretching procedure. A specific multi-time-scale double reversible reference system propagator (double-RESPA) algorithm has been designed for the metal-organic complex in MD simulations to identify the detailed metal-molecule bonding geometry at metal-molecule-metal interface. We investigate the variations of bonding sites of ADT molecules on gold nanojunctions at Au (111) surface at a constant chemical potential. Simulation results show that an Au-ADT-Au interface is formed on Au nanojunctions, bond-breaking intersection is at 1-1 bond of the monatomic chain of the cross-section, instead of at the Au-S bond. Breaking force is around 1.5 nN. These are consistent with the experimental measurements.

Evidence of Mixed-mode oscillations and Farey arithmetic in double plasma system in presence of fireball

NASA Astrophysics Data System (ADS)

Mitra, Vramori; Sarma, Bornali; Sarma, Arun

2017-10-01

Plasma fireballs are luminous glowing region formed around a positively biased electrode. The present work reports the observation of mix mode oscillation (MMO) in the dynamics of plasma oscillations that are excited in the presence of fireball in a double plasma device. Source voltage and applied electrode voltage are considered as the controlling parameters for the experiment. Many sequences of distinct multi peaked periodic states reflects the presence of MMO with the variation of control parameter. The sequences of states with two patterns are characterized well by Farey arithmetic, which provides rational approximations of irrational numbers. These states can be characterized by a firing number, the ratio of the number of small amplitude oscillations to the total number of oscillations per period. The dynamical transition in plasma fireball is also demonstrated by spectral analysis, recurrence quantification analysis (RQA) and by statistical measures viz., skewness and kurtosis. The mix mode phenomenon observed in the experiment is consistent with a model that describes the dynamics of ionization instabilities.

True Shear Parallel Plate Viscometer

NASA Technical Reports Server (NTRS)

Ethridge, Edwin; Kaukler, William

2010-01-01

This viscometer (which can also be used as a rheometer) is designed for use with liquids over a large temperature range. The device consists of horizontally disposed, similarly sized, parallel plates with a precisely known gap. The lower plate is driven laterally with a motor to apply shear to the liquid in the gap. The upper plate is freely suspended from a double-arm pendulum with a sufficiently long radius to reduce height variations during the swing to negligible levels. A sensitive load cell measures the shear force applied by the liquid to the upper plate. Viscosity is measured by taking the ratio of shear stress to shear rate.

Variational calculation of macrostate transition rates

NASA Astrophysics Data System (ADS)

Ulitsky, Alex; Shalloway, David

1998-08-01

We develop the macrostate variational method (MVM) for computing reaction rates of diffusive conformational transitions in multidimensional systems by a variational coarse-grained "macrostate" decomposition of the Smoluchowski equation. MVM uses multidimensional Gaussian packets to identify and focus computational effort on the "transition region," a localized, self-consistently determined region in conformational space positioned roughly between the macrostates. It also determines the "transition direction" which optimally specifies the projected potential of mean force for mean first-passage time calculations. MVM is complementary to variational transition state theory in that it can efficiently solve multidimensional problems but does not accommodate memory-friction effects. It has been tested on model 1- and 2-dimensional potentials and on the 12-dimensional conformational transition between the isoforms of a microcluster of six-atoms having only van der Waals interactions. Comparison with Brownian dynamics calculations shows that MVM obtains equivalent results at a fraction of the computational cost.

Arthroscopic Double-Row Transosseous Equivalent Rotator Cuff Repair with a Knotless Self-Reinforcing Technique.

PubMed

Mook, William R; Greenspoon, Joshua A; Millett, Peter J

2016-01-01

Rotator cuff tears are a significant cause of shoulder morbidity. Surgical techniques for repair have evolved to optimize the biologic and mechanical variables critical to tendon healing. Double-row repairs have demonstrated superior biomechanical advantages to a single-row. The preferred technique for rotator cuff repair of the senior author was reviewed and described in a step by step fashion. The final construct is a knotless double row transosseous equivalent construct. The described technique includes the advantages of a double-row construct while also offering self reinforcement, decreased risk of suture cut through, decreased risk of medial row overtensioning and tissue strangulation, improved vascularity, the efficiency of a knotless system, and no increased risk for subacromial impingement from the burden of suture knots. Arthroscopic knotless double row rotator cuff repair is a safe and effective method to repair rotator cuff tears.

Arthroscopic Double-Row Transosseous Equivalent Rotator Cuff Repair with a Knotless Self-Reinforcing Technique

PubMed Central

Mook, William R.; Greenspoon, Joshua A.; Millett, Peter J.

2016-01-01

Background: Rotator cuff tears are a significant cause of shoulder morbidity. Surgical techniques for repair have evolved to optimize the biologic and mechanical variables critical to tendon healing. Double-row repairs have demonstrated superior biomechanical advantages to a single-row. Methods: The preferred technique for rotator cuff repair of the senior author was reviewed and described in a step by step fashion. The final construct is a knotless double row transosseous equivalent construct. Results: The described technique includes the advantages of a double-row construct while also offering self reinforcement, decreased risk of suture cut through, decreased risk of medial row overtensioning and tissue strangulation, improved vascularity, the efficiency of a knotless system, and no increased risk for subacromial impingement from the burden of suture knots. Conclusion: Arthroscopic knotless double row rotator cuff repair is a safe and effective method to repair rotator cuff tears. PMID:27733881

CONTRIBUTIONS OF CHEMICAL AND DIFFUSIVE EXCHANGE TO T1ρ DISPERSION

PubMed Central

Cobb, Jared Guthrie; Xie, Jingping; Gore, John C.

2012-01-01

Variations in local magnetic susceptibility may induce magnetic field gradients that affect the signals acquired for MR imaging. Under appropriate diffusion conditions, such fields produce effects similar to slow chemical exchange. These effects may also be found in combination with other chemical exchange processes at multiple time scales. We investigate these effects with simulations and measurements to determine their contributions to rotating frame (R1ρ) relaxation in model systems. Simulations of diffusive and chemical exchange effects on R1ρ dispersion were performed using the Bloch equations. Additionally, R1ρ dispersion was measured in suspensions of Sephadex and latex beads with varying spin locking fields at 9.4T. A novel analysis method was used to iteratively fit for apparent chemical and diffusive exchange rates with a model by Chopra et al. Single- and double-inflection points in R1ρ dispersion profiles were observed, respectively, in simulations of slow diffusive exchange alone and when combined with rapid chemical exchange. These simulations were consistent with measurements of R1ρ in latex bead suspensions and small-diameter Sephadex beads that showed single- and double-inflection points, respectively. These observations, along with measurements following changes in temperature and pH, are consistent with the combined effects of slow diffusion and rapid −OH exchange processes. PMID:22791589

Excited State Studies of Polyacenes Using the All-Order Constricted Variational Density Functional Theory with Orbital Relaxation.

PubMed

Senn, Florian; Krykunov, Mykhaylo

2015-10-22

For the polyacenes series from naphthalene to hexacene, we present the vertical singlet excitation energies 1 (1)La and 1 (1)Lb, as well as the first triplet excitation energies obtained by the all-order constricted variational density functional theory with orbital relaxation (R-CV(∞)-DFT). R-CV(∞)-DFT is a further development of variational density functional theory (CV(∞)-DFT), which has already been successfully applied for the calculation of the vertical singlet excitation energies (1)La and (1)Lb for polyacenes,15 and we show that one obtains consistent excitation energies using the local density approximation as a functional for singlet as well as for triplet excitations when going beyond the linear response theory. Furthermore, we apply self-consistent field density functional theory (ΔSCF-DFT) and compare the obtained excitation energies for the first triplet excitations T1, where, due to the character of the transition, ΔSCF-DFT and R-CV(∞)-DFT become numerically equivalent, and for the singlet excitations 1 (1)La and 1 (1)Lb, where the two methods differ.

Breaking the Double-Edged Sword of Effort/Trying Hard: Developmental Equilibrium and Longitudinal Relations among Effort, Achievement, and Academic Self-Concept

ERIC Educational Resources Information Center

Marsh, Herbert W.; Pekrun, Reinhard; Lichtenfeld, Stephanie; Guo, Jiesi; Arens, A. Katrin; Murayama, Kou

2016-01-01

Ever since the classic research of Nicholls (1976) and others, effort has been recognized as a double-edged sword: while it might enhance achievement, it undermines academic self-concept (ASC). However, there has not been a thorough evaluation of the longitudinal reciprocal effects of effort, ASC, and achievement, in the context of modern…

Estimating Terra MODIS Polarization Effect Using Ocean Data

NASA Technical Reports Server (NTRS)

Wald, Andrew E.; Brinkmann, Jake; Wu, Aisheng; Xiong, Jack

2016-01-01

Terra MODIS has been known since pre-launch to have polarization sensitivity, particularly in shortest-wavelength bands 8 and 9. On-orbit reflectance trending of pseudo-invariant sites show a variation in reflectance as a function of band and scan mirror angle of incidence consistent with time-dependent polarization effects from the rotating double-sided scan mirror. The MODIS Characterization Support Team [MCST] estimates the Mueller matrix trending from this variation as observed from a single desert site, but this effect is not included in Collection 6 [C6] calibration. Here we extend the MCSTs current polarization sensitivity monitoring to two ocean sites distributed over latitude to helpestimate the uncertainties in the derived Mueller matrix. The Mueller matrix elements derived for polarization-sensitive Band 8 for a given site are found to be fairly insensitive to surface brdf modeling. The site-to-site variation is a measure of the uncertainty in the Mueller estimation.Results for band 8 show that the polarization correction reduces mirror-side striping by up to 50% and reduces the instrument polarization effect on reflectance time series of an ocean target.

Compensation for Lithography Induced Process Variations during Physical Design

NASA Astrophysics Data System (ADS)

Chin, Eric Yiow-Bing

This dissertation addresses the challenge of designing robust integrated circuits in the deep sub micron regime in the presence of lithography process variability. By extending and combining existing process and circuit analysis techniques, flexible software frameworks are developed to provide detailed studies of circuit performance in the presence of lithography variations such as focus and exposure. Applications of these software frameworks to select circuits demonstrate the electrical impact of these variations and provide insight into variability aware compact models that capture the process dependent circuit behavior. These variability aware timing models abstract lithography variability from the process level to the circuit level and are used to estimate path level circuit performance with high accuracy with very little overhead in runtime. The Interconnect Variability Characterization (IVC) framework maps lithography induced geometrical variations at the interconnect level to electrical delay variations. This framework is applied to one dimensional repeater circuits patterned with both 90nm single patterning and 32nm double patterning technologies, under the presence of focus, exposure, and overlay variability. Studies indicate that single and double patterning layouts generally exhibit small variations in delay (between 1--3%) due to self compensating RC effects associated with dense layouts and overlay errors for layouts without self-compensating RC effects. The delay response of each double patterned interconnect structure is fit with a second order polynomial model with focus, exposure, and misalignment parameters with 12 coefficients and residuals of less than 0.1ps. The IVC framework is also applied to a repeater circuit with cascaded interconnect structures to emulate more complex layout scenarios, and it is observed that the variations on each segment average out to reduce the overall delay variation. The Standard Cell Variability Characterization (SCVC) framework advances existing layout-level lithography aware circuit analysis by extending it to cell-level applications utilizing a physically accurate approach that integrates process simulation, compact transistor models, and circuit simulation to characterize electrical cell behavior. This framework is applied to combinational and sequential cells in the Nangate 45nm Open Cell Library, and the timing response of these cells to lithography focus and exposure variations demonstrate Bossung like behavior. This behavior permits the process parameter dependent response to be captured in a nine term variability aware compact model based on Bossung fitting equations. For a two input NAND gate, the variability aware compact model captures the simulated response to an accuracy of 0.3%. The SCVC framework is also applied to investigate advanced process effects including misalignment and layout proximity. The abstraction of process variability from the layout level to the cell level opens up an entire new realm of circuit analysis and optimization and provides a foundation for path level variability analysis without the computationally expensive costs associated with joint process and circuit simulation. The SCVC framework is used with slight modification to illustrate the speedup and accuracy tradeoffs of using compact models. With variability aware compact models, the process dependent performance of a three stage logic circuit can be estimated to an accuracy of 0.7% with a speedup of over 50,000. Path level variability analysis also provides an accurate estimate (within 1%) of ring oscillator period in well under a second. Another significant advantage of variability aware compact models is that they can be easily incorporated into existing design methodologies for design optimization. This is demonstrated by applying cell swapping on a logic circuit to reduce the overall delay variability along a circuit path. By including these variability aware compact models in cell characterization libraries, design metrics such as circuit timing, power, area, and delay variability can be quickly assessed to optimize for the correct balance of all design metrics, including delay variability. Deterministic lithography variations can be easily captured using the variability aware compact models described in this dissertation. However, another prominent source of variability is random dopant fluctuations, which affect transistor threshold voltage and in turn circuit performance. The SCVC framework is utilized to investigate the interactions between deterministic lithography variations and random dopant fluctuations. Monte Carlo studies show that the output delay distribution in the presence of random dopant fluctuations is dependent on lithography focus and exposure conditions, with a 3.6 ps change in standard deviation across the focus exposure process window. This indicates that the electrical impact of random variations is dependent on systematic lithography variations, and this dependency should be included for precise analysis.

The Effects of Self-Discharge on the Performance of Symmetric Electric Double-Layer Capacitors and Active Electrolyte-Enhanced Supercapacitors: Insights from Modeling and Simulation

NASA Astrophysics Data System (ADS)

Ike, Innocent S.; Sigalas, Iakovos; Iyuke, Sunny E.

2017-02-01

The effects of self-discharge on the performance of symmetric electric double-layer capacitors (EDLCs) and active electrolyte-enhanced supercapacitors were examined by incorporating self-discharge into electrochemical capacitor models during charging and discharging. The sources of self-discharge in capacitors were side reactions or redox reactions and several impurities and electric double-layer (EDL) instability. The effects of self-discharge during capacitor storage was negligible since it took a fully charged capacitor a minimum of 14.0 days to be entirely discharged by self-discharge in all conditions studied, hence self-discharge in storage condition can be ignored. The first and second charge-discharge cycle energy efficiencies η_{{{{E}}1}} and η_{{{{E}}2}} of a capacitor of electrode effective conductivity α1 = 0.05 S/cm with only EDL instability self-discharge with current density J_{{VR}} = 1.25 × 10-3 A/cm2 were 72.33% and 72.34%, respectively. Also, energy efficiencies η_{{{{E}}1}} and η_{{{{E}}2}} of a similar capacitor with both side reactions and redox reactions and EDL instability self-discharges with current densities J_{{VR}} = 0.00125 A/cm2 and J_{{{{VR}}1}} = 0.0032 A/cm2 were 38.13% and 38.14% respectively, compared with 84.24% and 84.25% in a similar capacitor without self-discharge. A capacitor with only EDL instability self-discharge and that with both side reactions and redox reactions and EDL instability self-discharge lost 9.73 Wh and 28.38 Wh of energy, respectively, through self-discharge during charging and discharging. Hence, EDLCs charging and discharging time is significantly dependent on the self-discharge rate which are too large to be ignored.

Body knowledge in brain-damaged children: a double-dissociation in self and other's body processing.

PubMed

Frassinetti, Francesca; Fiori, Simona; D'Angelo, Valentina; Magnani, Barbara; Guzzetta, Andrea; Brizzolara, Daniela; Cioni, Giovanni

2012-01-01

Bodies are important element for self-recognition. In this respect, in adults it has been recently shown a self vs other advantage when small parts of the subjects' body are visible. This advantage is lost following a right brain lesion underlying a role of the right hemisphere in self body-parts processing. In order to investigate the bodily-self processing in children and the development of its neuronal bases, 57 typically developing healthy subjects and 17 subjects with unilateral brain damage (5 right and 12 left sided), aged 4-17 years, were submitted to a matching-to-sample task. In this task, three stimuli vertically aligned were simultaneously presented at the centre of the computer screen. Subjects were required which of two stimuli (the upper or the lower one) matched the central target stimulus, half stimuli representing self and half stimuli representing other people's body-parts and face-parts. The results showed that corporeal self recognition is present since at least 4 years of age and that self and others' body parts processing are different and sustained by separate cerebral substrates. Indeed, a double dissociation was found: right brain damaged patients were impaired in self but not in other people's body parts, showing a self-disadvantage, whereas left brain damaged patients were impaired in others' but not in self body parts processing. Finally, since the double dissociation self/other was found for body-parts but not for face parts, the corporal self seems to be dissociated for body and face-parts. This opens the possibility of independent and lateralized functional modules for the processing of self and other body parts during development. Copyright © 2011 Elsevier Ltd. All rights reserved.

Exercise economy in skiing and running

PubMed Central

Losnegard, Thomas; Schäfer, Daniela; Hallén, Jostein

2014-01-01

Substantial inter-individual variations in exercise economy exist even in highly trained endurance athletes. The variation is believed to be determined partly by intrinsic factors. Therefore, in the present study, we compared exercise economy in V2-skating, double poling, and uphill running. Ten highly trained male cross-country skiers (23 ± 3 years, 180 ± 6 cm, 75 ± 8 kg, VO2peak running: 76.3 ± 5.6 mL·kg−1·min−1) participated in the study. Exercise economy and VO2peak during treadmill running, ski skating (V2 technique) and double poling were compared based on correlation analysis. There was a very large correlation in exercise economy between V2-skating and double poling (r = 0.81) and large correlations between V2-skating and running (r = 0.53) and double poling and running (r = 0.58). There were trivial to moderate correlations between exercise economy and the intrinsic factors VO2peak (r = 0.00–0.23), cycle rate (r = 0.03–0.46), body mass (r = −0.09–0.46) and body height (r = 0.11–0.36). In conclusion, the inter-individual variation in exercise economy could be explained only moderately by differences in VO2peak, body mass and body height. Apparently other intrinsic factors contribute to the variation in exercise economy between highly trained subjects. PMID:24478718

Combined input shaping and feedback control for double-pendulum systems

NASA Astrophysics Data System (ADS)

Mar, Robert; Goyal, Anurag; Nguyen, Vinh; Yang, Tianle; Singhose, William

2017-02-01

A control system combining input shaping and feedback is developed for double-pendulum systems subjected to external disturbances. The proposed control method achieves fast point-to-point response similar to open-loop input-shaping control. It also minimizes transient deflections during the motion of the system, and disturbance-induced residual swing using the feedback control. Effects of parameter variations such as the mass ratio of the double pendulum, the suspension length ratio, and the move distance were studied via numerical simulation. The most important results were also verified with experiments on a small-scale crane. The controller effectively suppresses the disturbances and is robust to modelling uncertainties and task variations.

Double external jugular vein and other rare venous variations of the head and neck.

PubMed

Shenoy, Varsha; Saraswathi, Perumal; Raghunath, Gunapriya; Karthik, Jayakumar Sai

2012-12-01

Superficial veins of the head and neck are utilised for central venous cannulation, oral reconstruction and parenteral nutrition in debilitated patients. Clinical and sonological examinations of these veins may provide clues toward underlying cardiac pathology. Hence, although variations in these vessels are common, a sound knowledge of such variations becomes clinically important to surgeons, radiologists and interventional anaesthetists. We report a rare case of a left-sided double external jugular vein where the common facial vein continued as the second external jugular vein, and where there was a communicating channel between the internal jugular vein on the same side and the anterior jugular vein.

"Economic man" in cross-cultural perspective: behavioral experiments in 15 small-scale societies.

PubMed

Henrich, Joseph; Boyd, Robert; Bowles, Samuel; Camerer, Colin; Fehr, Ernst; Gintis, Herbert; McElreath, Richard; Alvard, Michael; Barr, Abigail; Ensminger, Jean; Henrich, Natalie Smith; Hill, Kim; Gil-White, Francisco; Gurven, Michael; Marlowe, Frank W; Patton, John Q; Tracer, David

2005-12-01

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model - based on self-interest - fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life.

Line-frequency doubling of directed self-assembly patterns for single-digit bit pattern media lithography

NASA Astrophysics Data System (ADS)

Patel, K. C.; Ruiz, R.; Lille, J.; Wan, L.; Dobiz, E.; Gao, H.; Robertson, N.; Albrecht, T. R.

2012-03-01

Directed self-assembly is emerging as a promising technology to define sub-20nm features. However, a straightforward path to scale block copolymer lithography to single-digit fabrication remains challenging given the diverse material properties found in the wide spectrum of self-assembling materials. A vast amount of block copolymer research for industrial applications has been dedicated to polystyrene-b-methyl methacrylate (PS-b-PMMA), a model system that displays multiple properties making it ideal for lithography, but that is limited by a weak interaction parameter that prevents it from scaling to single-digit lithography. Other block copolymer materials have shown scalability to much smaller dimensions, but at the expense of other material properties that could delay their insertion into industrial lithographic processes. We report on a line doubling process applied to block copolymer patterns to double the frequency of PS-b-PMMA line/space features, demonstrating the potential of this technique to reach single-digit lithography. We demonstrate a line-doubling process that starts with directed self-assembly of PS-b-PMMA to define line/space features. This pattern is transferred into an underlying sacrificial hard-mask layer followed by a growth of self-aligned spacers which subsequently serve as hard-masks for transferring the 2x frequency doubled pattern to the underlying substrate. We applied this process to two different block copolymer materials to demonstrate line-space patterns with a half pitch of 11nm and 7nm underscoring the potential to reach single-digit critical dimensions. A subsequent patterning step with perpendicular lines can be used to cut the fine line patterns into a 2-D array of islands suitable for bit patterned media. Several integration challenges such as line width control and line roughness are addressed.

A microscopic derivation of nuclear collective rotation-vibration model and its application to nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gulshani, P., E-mail: matlap@bell.net

We derive a microscopic version of the successful phenomenological hydrodynamic model of Bohr-Davydov-Faessler-Greiner for collective rotation-vibration motion of an axially symmetric deformed nucleus. The derivation is not limited to small oscillation amplitude. The nuclear Schrodinger equation is canonically transformed to collective co-ordinates, which is then linearized using a constrained variational method. The associated constraints are imposed on the wavefunction rather than on the particle co-ordinates. The approach yields three self-consistent, time-reversal invariant, cranking-type Schrodinger equations for the rotation-vibration and intrinsic motions, and a self-consistency equation. For harmonic oscillator mean-field potentials, these equations are solved in closed forms for excitation energy,more » cut-off angular momentum, and other nuclear properties for the ground-state rotational band in some deformed nuclei. The results are compared with measured data.« less

MCSCF wave functions for excited states of polar molecules - Application to BeO. [Multi-Configuration Self-Consistent Field

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.; Yarkony, D. R.

1980-01-01

A previously reported multi-configuration self-consistent field (MCSCF) algorithm based on the generalized Brillouin theorem is extended in order to treat the excited states of polar molecules. In particular, the algorithm takes into account the proper treatment of nonorthogonality in the space of single excitations and invokes, when necessary, a constrained optimization procedure to prevent the variational collapse of excited states. In addition, a configuration selection scheme (suitable for use in conjunction with extended configuration interaction methods) is proposed for the MCSCF procedure. The algorithm is used to study the low-lying singlet states of BeO, a system which has not previously been studied using an MCSCF procedure. MCSCF wave functions are obtained for three 1 Sigma + and two 1 Pi states. The 1 Sigma + results are juxtaposed with comparable results for MgO in order to assess the generality of the description presented here.

Feelings or Words? Understanding the Content in Self-Report Ratings of Experienced Emotion

PubMed Central

Barrett, Lisa Feldman

2005-01-01

People differ in the extent to which their verbal reports of experienced emotion are valence focused or arousal focused. Three multimethod studies are reported to explore whether differential focus reflects individual differences in the cognitive structure of emotion language versus differences in phenomenological experience. Although there was some evidence that valence focus and arousal focus were linked to variations differences in cognitive structure, the findings are also consistent with the view that self-report ratings are being driven by the properties of the feelings that are being reported. Implications for the study of experienced emotion are discussed. PMID:15301632

Self-template synthesis of double shelled ZnS-NiS1.97 hollow spheres for electrochemical energy storage

NASA Astrophysics Data System (ADS)

Wei, Chengzhen; Ru, Qinglong; Kang, Xiaoting; Hou, Haiyan; Cheng, Cheng; Zhang, Daojun

2018-03-01

In this work, double shelled ZnS-NiS1.97 hollow spheres have been achieved via a simple self-template route, which involves the synthesis of Zn-Ni solid spheres precursors as the self-template and then transformation into double shelled ZnS-NiS1.97 hollow spheres by sulfidation treatment. The as-prepared double shelled ZnS-NiS1.97 hollow spheres possess a high surface area (105.26 m2 g-1) and porous structures. Benefiting from the combined characteristics of novel structures, multi-component, high surface area and porous. When applied as electrode materials for supercapacitors, the double shelled ZnS-NiS1.97hollow spheres deliver a large specific capacitance of 696.8C g-1 at 5.0 A g-1 and a remarkable long lifespan cycling stability (less 5.5% loss after 6000 cycles). Moreover, an asymmetric supercapacitor (ASC) was assembled by utilizing ZnS-NiS1.97 (positive electrode) and activated carbon (negative electrode) as electrode materials. The as-assembled device possesses an energy density of 36 W h kg-1, which can be yet retained 25.6 W h kg-1 even at a power density of 2173.8 W Kg-1, indicating its promising applications in electrochemical energy storage. More importantly, the self-template route is a simple and versatile strategy for the preparation of metal sulfides electrode materials with desired structures, chemical compositions and electrochemical performances.

Self-Calibration and Laser Energy Monitor Validations for a Double-Pulsed 2-Micron CO2 Integrated Path Differential Absorption Lidar Application

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Singh, Upendra N.; Petros, Mulugeta; Remus, Ruben; Yu, Jirong

2015-01-01

Double-pulsed 2-micron integrated path differential absorption (IPDA) lidar is well suited for atmospheric CO2 remote sensing. The IPDA lidar technique relies on wavelength differentiation between strong and weak absorbing features of the gas normalized to the transmitted energy. In the double-pulse case, each shot of the transmitter produces two successive laser pulses separated by a short interval. Calibration of the transmitted pulse energies is required for accurate CO2 measurement. Design and calibration of a 2-micron double-pulse laser energy monitor is presented. The design is based on an InGaAs pin quantum detector. A high-speed photo-electromagnetic quantum detector was used for laser-pulse profile verification. Both quantum detectors were calibrated using a reference pyroelectric thermal detector. Calibration included comparing the three detection technologies in the single-pulsed mode, then comparing the quantum detectors in the double-pulsed mode. In addition, a self-calibration feature of the 2-micron IPDA lidar is presented. This feature allows one to monitor the transmitted laser energy, through residual scattering, with a single detection channel. This reduces the CO2 measurement uncertainty. IPDA lidar ground validation for CO2 measurement is presented for both calibrated energy monitor and self-calibration options. The calibrated energy monitor resulted in a lower CO2 measurement bias, while self-calibration resulted in a better CO2 temporal profiling when compared to the in situ sensor.

Doubling sockeye salmon production in the Fraser River—Is this sustainable development?

NASA Astrophysics Data System (ADS)

Henderson, Michael A.; Healey, Michael C.

1993-11-01

We evaluate a proposal to double sockeye salmon production from the Fraser River and conclude that significant changes will be required to current management processes, particularly the way available catch is allocated, if the plan is to be consistent with five major principles embodied in the concept of sustainable development. Doubling sockeye salmon production will not, in itself, increase economic equity either regionally or globally. Developing nations may actually be hindered in their attempts to institute other, nonsalmon fisheries in the North Pacific Ocean as a result of the possible interception of salmon. Further, other users of the Fraser River basin will have to forgo opportunities so that salmon habitat can be conserved. If doubling sockeye salmon production is to meet the goal of doing more with less, it will be necessary to develop more efficient technologies to harvest the fish. If increasing salmon production is to reflect the integration of environmental and economic decision making at the highest level, then a serious attempt must be made to incorporate environmental assets into national economic accounting. Finally, to promote biodiversity and cultural self-sufficiency within the Fraser River basin, it will be important to safeguard the small, less-productive salmon stocks as well as the large ones and to allocate a substantial portion of the increased production to the Native Indian community.

Bromine-doped DWNTs: A Molecular Faraday Cage

NASA Astrophysics Data System (ADS)

Chen, Gugang; Margine, Roxana; Gupta, Rajeev; Crespi, Vincent; Eklund, Peter; Sumanasekera, Gamini; Bandow, Shunji; Iijima, S.

2003-03-01

Raman scattering is used to probe the charge transfer distribution in Bromine-doped double-walled carbon nanotubes (DWNT). Using 1064 nm and 514.5 nm laser excitation we are able to study the charge-transfer sensitive phonons in the inner ( (5,5)) and outer ( (10,10)) tubes of the double-walled pair. The experimental results are compared to our tight binding band structure calculations that include a self-consistent electrostatic term sensitive to the average net charge density on each tube. Upon doping, the nanotube tangential and radial Raman bands from the outer (primary) tubes were observed to shift dramatically to higher frequencies, consistent with a C-C bond contraction driven by the acceptor-doping. The peak intensities of these bands significantly decreased with increasing doping exposure, and they eventually vanished, consistent with a deep depression in the Fermi energy that extinguishes the resonant Raman effect. Interestingly, at the same time, we observed little or no change for the tangential and radial Raman features identified with the inner (secondary) tubes during the bromine doping. Our electronic structure calculations show that the charge distribution between the outer and inner tubes depends on doping level and also, to some extent, on specific tube chirality combinations. In general, in agreement with experiment, the calculations find a very small net charge on the inner tube, consistent with a "Molecular Faraday Effect", e.g., a DWNT of (10, 10)/ (5, 5) configuration that exhibits 0.5 holes/Å total charge transfer, has only 0.04 holes/Å on the inner (secondary) tube.

Fabrication of Self-Healable and Patternable Polypyrrole/Agarose Hybrid Hydrogels for Smart Bioelectrodes.

PubMed

Park, Nokyoung; Chae, Seung Chul; Kim, Il Tae; Hur, Jaehyun

2016-02-01

We present a new class of electrically conductive, mechanically moldable, and thermally self-healable hybrid hydrogels. The hybrid gels consist of polypyrrole and agarose as the conductive component and self-healable matrix, respectively. By using the appropriate oxidizing agent under conditions of mild temperature, the polymerization of pyrrole occurred along the three-dimensional network of the agarose hydrogel matrix. In contrast to most commercially available hydrogels, the physical crosslinking of agarose gel allows for reversible gelation in the case of our hybrid gel, which could be manipulated by temperature variation, which controls the electrical on/off behavior of the hybrid gel electrode. Exploiting this property, we fabricated a hybrid conductive hydrogel electrode which also self-heals thermally. The novel composite material we report here will be useful for many technological and biological applications, especially in reactive biomimetic functions and devices, artificial muscles, smart membranes, smart full organic batteries, and artificial chemical synapses.

A Controlled Study to Assess the Clinical Efficacy of Totally Self-Administered Systematic Desensitization

ERIC Educational Resources Information Center

Rosen, Gerald M.; And Others

1976-01-01

Highly anxious self-referred snake phobics received either (a) therapist-administered desensitization, (b) self-administered desensitization with weekly therapist phone calls, (c) totally self-administered desensitization, (d) self-administered double-blind placebo control, or (e) no treatment. Pretreatment to posttreatment measures revealed…

Statistical inference based on the nonparametric maximum likelihood estimator under double-truncation.

PubMed

Emura, Takeshi; Konno, Yoshihiko; Michimae, Hirofumi

2015-07-01

Doubly truncated data consist of samples whose observed values fall between the right- and left- truncation limits. With such samples, the distribution function of interest is estimated using the nonparametric maximum likelihood estimator (NPMLE) that is obtained through a self-consistency algorithm. Owing to the complicated asymptotic distribution of the NPMLE, the bootstrap method has been suggested for statistical inference. This paper proposes a closed-form estimator for the asymptotic covariance function of the NPMLE, which is computationally attractive alternative to bootstrapping. Furthermore, we develop various statistical inference procedures, such as confidence interval, goodness-of-fit tests, and confidence bands to demonstrate the usefulness of the proposed covariance estimator. Simulations are performed to compare the proposed method with both the bootstrap and jackknife methods. The methods are illustrated using the childhood cancer dataset.

Open-ended formulation of self-consistent field response theory with the polarizable continuum model for solvation.

PubMed

Di Remigio, Roberto; Beerepoot, Maarten T P; Cornaton, Yann; Ringholm, Magnus; Steindal, Arnfinn Hykkerud; Ruud, Kenneth; Frediani, Luca

2016-12-21

The study of high-order absorption properties of molecules is a field of growing importance. Quantum-chemical studies can help design chromophores with desirable characteristics. Given that most experiments are performed in solution, it is important to devise a cost-effective strategy to include solvation effects in quantum-chemical studies of these properties. We here present an open-ended formulation of self-consistent field (SCF) response theory for a molecular solute coupled to a polarizable continuum model (PCM) description of the solvent. Our formulation relies on the open-ended, density matrix-based quasienergy formulation of SCF response theory of Thorvaldsen, et al., [J. Chem. Phys., 2008, 129, 214108] and the variational formulation of the PCM, as presented by Lipparini et al., [J. Chem. Phys., 2010, 133, 014106]. Within the PCM approach to solvation, the mutual solute-solvent polarization is represented by means of an apparent surface charge (ASC) spread over the molecular cavity defining the solute-solvent boundary. In the variational formulation, the ASC is an independent, variational degree of freedom. This allows us to formulate response theory for molecular solutes in the fixed-cavity approximation up to arbitrary order and with arbitrary perturbation operators. For electric dipole perturbations, pole and residue analyses of the response functions naturally lead to the identification of excitation energies and transition moments. We document the implementation of this approach in the Dalton program package using a recently developed open-ended response code and the PCMSolver libraries and present results for one-, two-, three-, four- and five-photon absorption processes of three small molecules in solution.

Single crystal growth and nonlinear optical properties of Nd3+ doped STGS crystal for self-frequency-doubling application

NASA Astrophysics Data System (ADS)

Chen, Feifei; Wang, Lijuan; Wang, Xinle; Cheng, Xiufeng; Yu, Fapeng; Wang, Zhengping; Zhao, Xian

2017-11-01

The self-frequency-doubling crystal is an important kind of multi-functional crystal materials. In this work, Nd3+ doped Sr3TaGa3Si2O14 (Nd:STGS) single crystals were successfully grown by using Czochralski pulling method, in addition, the nonlinear and laser-frequency-doubling properties of Nd:STGS crystals were studied. The continuous-wave laser at 1064 nm was demonstrated along different physical axes, where the maximum output power was obtained to be 295 mW for the Z-cut samples, much higher than the Y-cut (242 mW) and X-cut (217 mW) samples. Based on the measured refractive indexes, the phase matching directions were discussed and determined for type I (42.5°, 30°) and type II (69.5°, 0°) crystal cuts. As expected, self-frequency-doubling green laser at 529 nm was achieved with output powers being around 16 mW and 12 mW for type I and type II configurations, respectively.

Nanomaterials Based on DNA

PubMed Central

Seeman, Nadrian C.

2012-01-01

The combination of synthetic stable branched DNA and sticky ended cohesion has led to the development of structural DNA nanotechnology over the past 30 years. The basis of this enterprise is that it is possible to construct novel DNA-based materials by combining these features in a self-assembly protocol. Thus, simple branched molecules lead directly to the construction of polyhedra whose edges consist of double helical DNA, and whose vertices correspond to the branch points. Stiffer branched motifs can be used to produce self-assembled two-dimensional and three-dimensional periodic lattices of DNA (crystals). DNA has also been used to make a variety of nanomechanical devices, including molecules that change their shapes, and molecules that can walk along a DNA sidewalk. Devices have been incorporated into two-dimensional DNA arrangements; sequence-dependent devices are driven by increases in nucleotide pairing at each step in their machine cycles. PMID:20222824

Influence of Self-generated Anchors on the Voice Handicap Index-10 (VHI-10).

PubMed

Canals-Fortuny, Elisabet; Vila-Rovira, Josep

2017-03-01

The aim of this research is to study whether the presentation of the Voice Handicap Index-10 questionnaire administered at the beginning of the treatment impinged on the results of the responses from the end of the treatment. The questionnaire was administered at the beginning of the treatment to a total of 308 patients. After the treatment, a group of 235 patients answered the questionnaire again without any reference to their responses on the initial administration. The other group of participants, consisting of 73 subjects, completed the questionnaire with the answer sheet of their initial self-assessment in sight. The data obtained show that patients who responded to the anchored answer test show less dispersion and a smaller coefficient of variation (0.90) than those who responded to the nonanchored answer test (coefficient of variation = 1.66). The method of administration of the Voice Handicap Index-10 at the end of a treatment influences the dispersion of the results. We recommend that the patient be anchored to the initial answer sheet while responding to the final self-assessment. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

A 1 kW-class multi-stage heat-driven thermoacoustic cryocooler system operating at liquefied natural gas temperature range

NASA Astrophysics Data System (ADS)

Zhang, L. M.; Hu, J. Y.; Wu, Z. H.; Luo, E. C.; Xu, J. Y.; Bi, T. J.

2015-07-01

This article introduces a multi-stage heat-driven thermoacoustic cryocooler capable of reaching cooling capacity about 1 kW at liquefied natural gas temperature range without any moving mechanical parts. The cooling system consists of an acoustically resonant double-acing traveling wave thermoacoustic heat engine and three identical pulse tube coolers. Unlike other traditional traveling wave thermoacoustic heat engines, the acoustically resonant double-acting thermoacoustic heat engine is a closed-loop configuration consists of three identical thermoacoustic conversion units. Each pulse tube cooler is bypass driven by one thermoacoustic heat engine unit. The device is acoustically completely symmetric and therefore "self-matching" for efficient traveling-wave thermoacoustic conversion. In the experiments, with 7 MPa helium gas as working gas, when the heating temperature reaches 918 K, total cooling capacity of 0.88 kW at 110 K is obtained with a resonant frequency of about 55 Hz. When the heating temperature is 903 K, a maximum total cooling capacity at 130 K of 1.20 kW is achieved, with a thermal-to-cold exergy efficiency of 8%. Compared to previously developed heat-driven thermoacoustic cryocoolers, this device has higher thermal efficiency and higher power density. It shows a good prospect of application in the field of natural gas liquefaction and recondensation.

Form-function analysis of the effect of canopy morphology on leaf self-shading in the seagrass Thalassia testudinum.

PubMed

Enríquez, Susana; Pantoja-Reyes, Norma I

2005-09-01

The variation in seagrass morphology and the magnitude of leaf self-shading within the canopy of Thalassia testudinum, were compared among nine sites in a fringing reef lagoon. We found a significant variation in the growth-form of T. testudinum reflected in a 5.4-fold variation in the attenuation coefficient (K (d)) within the canopy. The largest morphological variation was observed in shoot density. Leaf biomass, leaf area index (LAI), and shoot density were positively associated with canopy-K (d) and with the percentage of surface irradiance received by the top of the seagrass canopy (% Es). These results provide an explanation for the consistent pattern of depth reduction in seagrass leaf biomass and shoot density reported in the literature. Shoot density and shoot size are two descriptors of the growth-form of T. testudinum related to its clonal life-form. Shoot size was not significantly correlated with canopy-K (d), nevertheless, it showed a significant effect on the slope of the relationship between shoot density and canopy-K (d). According to this model, shoot size also contributes to light attenuation within the seagrass canopy by increasing the effect of shoot density. This form-function analysis suggests that light may have a relevant role in the regulation of the optimal plant balance between horizontal (variation in shoot density) and vertical (variation in shoot size) growth of seagrasses. Other environmental factors and interactions also need to be examined to fully understand the mechanistic bases of the morphological responses of seagrasses to the environment.

Fresh and mechanical properties of self-compacting concrete with coarse aggregate replacement using Waste of Oil Palm Shell

NASA Astrophysics Data System (ADS)

Prayuda, Hakas; Saleh, Fadillawaty; Ilham Maulana, Taufiq; Monika, Fanny

2018-05-01

Self-compacting Concrete (SCC) is a real innovation that can solidify itself without the help of tools to ease field practice. In its implementation, SCC can use alternative materials to reduce waste, such as Oil Palm Shell (OPS). In this research, OPS used as a replacement of crushed stone as the main coarse aggregate. The concrete mixture used consists of cement, sand, crushed stone, OPS as a variation of aggregate substitutes, palm oil fuel ash, and superplasticizer. OPS used were variated with 0%, 5%, 10%, 25% and 50% of crushed stone aggregate weight with age up to 28 days. Tests were conducted on fresh and mechanical properties. From the results, it is known that replacement of aggregate using OPS meets fresh properties criteria and although the compressive strength of OPS concrete mixture is lower than normal SCC, OPS still can be an alternative in making SCC and reducing palm oil industrial waste.

Corrosion resistance of Zn-Al layered double hydroxide/poly(lactic acid) composite coating on magnesium alloy AZ31

NASA Astrophysics Data System (ADS)

Zeng, Rong-Chang; Li, Xiao-Ting; Liu, Zhen-Guo; Zhang, Fen; Li, Shuo-Qi; Cui, Hong-Zhi

2015-12-01

A Zn-Al layered double hydroxide (ZnAl-LDH) coating consisted of uniform hexagonal nano-plates was firstly synthesized by co-precipitation and hydrothermal treatment on the AZ31 alloy, and then a poly(lactic acid) (PLA) coating was sealed on the top layer of the ZnAl-LDH coating using vacuum freeze-drying. The characteristics of the ZnAl-LDH/PLA composite coatings were investigated by means of XRD, SEM, FTIR and EDS. The corrosion resistance of the coatings was assessed by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the ZnAl-LDH coating contained a compact inner layer and a porous outer layer, and the PLA coating with a strong adhesion to the porous outer layer can prolong the service life of the ZnAl-LDH coating. The excellent corrosion resistance of this composite coating can be attributable to its barrier function, ion-exchange and self-healing ability.

Layered double hydroxide-based nanomaterials as highly efficient catalysts and adsorbents.

PubMed

Li, Changming; Wei, Min; Evans, David G; Duan, Xue

2014-11-01

Layered double hydroxides (LDHs) are a class of anion clays consisting of brucite-like host layers and interlayer anions, which have attracted increasing interest in the fields of catalysis/adsorption. By virtue of the versatility in composition, morphology, and architecture of LDH materials, as well as their unique structural properties (intercalation, topological transformation, and self-assembly with other functional materials), LDHs display great potential in the design and fabrication of nanomaterials applied in photocatalysis, heterogeneous catalysis, and adsorption/separation processes. Taking advantage of the structural merits and various control synthesis strategies of LDHs, the active center structure (e.g., crystal facets, defects, geometric and electronic states, etc.) and macro-nano morphology can be facilely manipulated for specific catalytic/adsorbent processes with largely enhanced performances. In this review, the latest advancements in the design and preparation of LDH-based functional nanomaterials for sustainable development in catalysis and adsorption are summarized. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Green House Model of Nursing Home Care in Design and Implementation.

PubMed

Cohen, Lauren W; Zimmerman, Sheryl; Reed, David; Brown, Patrick; Bowers, Barbara J; Nolet, Kimberly; Hudak, Sandra; Horn, Susan

2016-02-01

To describe the Green House (GH) model of nursing home (NH) care, and examine how GH homes vary from the model, one another, and their founding (or legacy) NH. Data include primary quantitative and qualitative data and secondary quantitative data, derived from 12 GH/legacy NH organizations February 2012-September 2014. This mixed methods, cross-sectional study used structured interviews to obtain information about presence of, and variation in, GH-relevant structures and processes of care. Qualitative questions explored reasons for variation in model implementation. Interview data were analyzed using related-sample tests, and qualitative data were iteratively analyzed using a directed content approach. GH homes showed substantial variation in practices to support resident choice and decision making; neither GH nor legacy homes provided complete choice, and all GH homes excluded residents from some key decisions. GH homes were most consistent with the model and one another in elements to create a real home, such as private rooms and baths and open kitchens, and in staff-related elements, such as self-managed work teams and consistent, universal workers. Although variation in model implementation complicates evaluation, if expansion is to continue, it is essential to examine GH elements and their outcomes. © Health Research and Educational Trust.

A molecularly based theory for electron transfer reorganization energy.

PubMed

Zhuang, Bilin; Wang, Zhen-Gang

2015-12-14

Using field-theoretic techniques, we develop a molecularly based dipolar self-consistent-field theory (DSCFT) for charge solvation in pure solvents under equilibrium and nonequilibrium conditions and apply it to the reorganization energy of electron transfer reactions. The DSCFT uses a set of molecular parameters, such as the solvent molecule's permanent dipole moment and polarizability, thus avoiding approximations that are inherent in treating the solvent as a linear dielectric medium. A simple, analytical expression for the free energy is obtained in terms of the equilibrium and nonequilibrium electrostatic potential profiles and electric susceptibilities, which are obtained by solving a set of self-consistent equations. With no adjustable parameters, the DSCFT predicts activation energies and reorganization energies in good agreement with previous experiments and calculations for the electron transfer between metallic ions. Because the DSCFT is able to describe the properties of the solvent in the immediate vicinity of the charges, it is unnecessary to distinguish between the inner-sphere and outer-sphere solvent molecules in the calculation of the reorganization energy as in previous work. Furthermore, examining the nonequilibrium free energy surfaces of electron transfer, we find that the nonequilibrium free energy is well approximated by a double parabola for self-exchange reactions, but the curvature of the nonequilibrium free energy surface depends on the charges of the electron-transferring species, contrary to the prediction by the linear dielectric theory.

Lidar observations of the planetary boundary layer

NASA Technical Reports Server (NTRS)

Melfi, S. H.; Spinhirne, J. D.; Palm, S. P.

1985-01-01

The application of an airborne downward-looking lidar to the study of organized cellular convection in the planetary boundary layer (PBL) over the ocean is described. The lidar consisted of a frequency doubled Nd-YAG 530 mm-wavelength laser whose axis was aligned colinearly with the optical axis of an all-reflecting 40 mm-diameter Newtonian telescope. The airborne lidar provided a unique observation of both microscale and mesoscale variations of the PBL top. The lidar data, presented as constant backscatter isopleth soundings, provide a visual indication of the presence of vertically organized convection cells. Comparisons of the lidar-derived PBL structure with both a conceptual model of the PBL and laboratory simulations of Deardorf et al. (1980) of a developing convective PBL showed that the observations are consistent with a model of mixing in the PBL, which involves a field of organized updrafts separated by downdrafts.

Translational Mini-Review Series on Complement Factor H: Structural and functional correlations for factor H

PubMed Central

Schmidt, C Q; Herbert, A P; Hocking, H G; Uhrín, D; Barlow, P N

2008-01-01

The 155-kDa glycoprotein, complement factor H (CFH), is a regulator of complement activation that is abundant in human plasma. Three-dimensional structures of over half the 20 complement control protein (CCP) modules in CFH have been solved in the context of single-, double- and triple-module segments. Proven binding sites for C3b occupy the N and C termini of this elongated molecule and may be brought together by a bend in CFH mediated by its central CCP modules. The C-terminal CCP 20 is key to the ability of the molecule to adhere to polyanionic markers on self-surfaces where CFH acts to regulate amplification of the alternative pathway of complement. The surface patch on CCP 20 that binds to model glycosaminoglycans has been mapped using nuclear magnetic resonance (NMR), as has a second glycosaminoglycan-binding patch on CCP 7. These patches include many of the residue positions at which sequence variations have been linked to three complement-mediated disorders: dense deposit disease, age-related macular degeneration and atypical haemolytic uraemic syndrome. In one plausible model, CCP 20 anchors CFH to self-surfaces via a C3b/polyanion composite binding site, CCP 7 acts as a ‘proof-reader’ to help discriminate self- from non-self patterns of sulphation, and CCPs 1–4 disrupt C3/C5 convertase formation and stability. PMID:18081691

Development of a hybrid battery system for an implantable biomedical device, especially a defibrillator/cardioverter (ICD)

NASA Astrophysics Data System (ADS)

Drews, Jürgen; Wolf, R.; Fehrmann, G.; Staub, R.

An implantable defibrillator battery has to provide pulse power capabilities as well as high energy density. Low self-discharge rates are mandatory and a way to check the remaining available capacity is necessary. These requirements are accomplished by a system consisting of a lithium/manganese dioxide 6 V battery, plus a lithium/iodine-cell. The use of a high rate 6 V double-cell design in combination with a high energy density cell reduces the total volume required by the power source within an implantable defibrillator. The design features and performance data of the hybrid system are described.

Enthalpy of sublimation as measured using a silicon oscillator

NASA Astrophysics Data System (ADS)

Shakeel, Hamza; Pomeroy, J. M.

In this study, we report the enthalpy of sublimation of common gases (nitrogen, oxygen, argon, carbon dioxide, neon, krypton, xenon, and water vapor) using a large area silicon oscillator with a sub-ng (~0.027 ng/cm2) mass sensitivity. The double paddle oscillator design enables high frequency stability (17 ppb) at cryogenic temperatures and provides a consistent technique for enthalpy measurements. The enthalpies of sublimation are derived from the rate of mass loss during programmed thermal desorption and are detected as a change in the resonance frequency of the self-tracking oscillator. These measured enthalpy values show excellent agreement with the accepted literature values.

QGene 4.0, an extensible Java QTL-analysis platform.

PubMed

Joehanes, Roby; Nelson, James C

2008-12-01

Of many statistical methods developed to date for quantitative trait locus (QTL) analysis, only a limited subset are available in public software allowing their exploration, comparison and practical application by researchers. We have developed QGene 4.0, a plug-in platform that allows execution and comparison of a variety of modern QTL-mapping methods and supports third-party addition of new ones. The software accommodates line-cross mating designs consisting of any arbitrary sequence of selfing, backcrossing, intercrossing and haploid-doubling steps that includes map, population, and trait simulators; and is scriptable. Software and documentation are available at http://coding.plantpath.ksu.edu/qgene. Source code is available on request.

Branes in Extended Spacetime: Brane Worldvolume Theory Based on Duality Symmetry.

PubMed

Sakatani, Yuho; Uehara, Shozo

2016-11-04

We propose a novel approach to the brane worldvolume theory based on the geometry of extended field theories: double field theory and exceptional field theory. We demonstrate the effectiveness of this approach by showing that one can reproduce the conventional bosonic string and membrane actions, and the M5-brane action in the weak-field approximation. At a glance, the proposed 5-brane action without approximation looks different from the known M5-brane actions, but it is consistent with the known nonlinear self-duality relation, and it may provide a new formulation of a single M5-brane action. Actions for exotic branes are also discussed.

Comparison of junctionless and inversion-mode p-type metal-oxide-semiconductor field-effect transistors in presence of hole-phonon interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dib, E., E-mail: elias.dib@for.unipi.it; Carrillo-Nuñez, H.; Cavassilas, N.

Junctionless transistors are being considered as one of the alternatives to conventional metal-oxide field-effect transistors. In this work, it is then presented a simulation study of silicon double-gated p-type junctionless transistors compared with its inversion-mode counterpart. The quantum transport problem is solved within the non-equilibrium Green's function formalism, whereas hole-phonon interactions are tackled by means of the self-consistent Born approximation. Our findings show that junctionless transistors should perform as good as a conventional transistor only for ultra-thin channels, with the disadvantage of requiring higher supply voltages in thicker channel configurations.

Spatial filter system as an optical relay line

DOEpatents

Hunt, John T.; Renard, Paul A.

1979-01-01

A system consisting of a set of spatial filters that are used to optically relay a laser beam from one position to a downstream position with minimal nonlinear phase distortion and beam intensity variation. The use of the device will result in a reduction of deleterious beam self-focusing and produce a significant increase in neutron yield from the implosion of targets caused by their irradiation with multi-beam glass laser systems.

A double commutant theorem for Murray–von Neumann algebras

PubMed Central

Liu, Zhe

2012-01-01

Murray–von Neumann algebras are algebras of operators affiliated with finite von Neumann algebras. In this article, we study commutativity and affiliation of self-adjoint operators (possibly unbounded). We show that a maximal abelian self-adjoint subalgebra of the Murray–von Neumann algebra associated with a finite von Neumann algebra is the Murray–von Neumann algebra , where is a maximal abelian self-adjoint subalgebra of and, in addition, is . We also prove that the Murray–von Neumann algebra with the center of is the center of the Murray–von Neumann algebra . Von Neumann’s celebrated double commutant theorem characterizes von Neumann algebras as those for which , where , the commutant of , is the set of bounded operators on the Hilbert space that commute with all operators in . At the end of this article, we present a double commutant theorem for Murray–von Neumann algebras. PMID:22543165

Evaluation of the NAL-NL1 and the DSL v.4.1 prescriptions for children: Paired-comparison intelligibility judgments and functional performance ratings.

PubMed

Ching, Teresa Y C; Scollie, Susan D; Dillon, Harvey; Seewald, Richard; Britton, Louise; Steinberg, Jane; Gilliver, Megan; King, Katrina A

2010-01-01

This paper reports intelligibility judgments and real-life functional performance of 48 children in a double-blind, cross-over trial comparing the NAL-NL1 and the DSL v.4.1 prescriptions. Intelligibility judgments were obtained by using a paired-comparisons procedure with audiovisual stimuli. Functional performance of children during two eight-week periods, each with hearing aids adjusted to one prescription, was assessed by parents and teachers (PEACH and TEACH) and by children's self reports (SELF). Consistently across reports, performance was significantly better in quiet than in noise. On average, better performance in noise (a higher Noise subscale score) was associated with NAL-NL1 than with DSL v.4.1, both for the PEACH and the SELF. This difference was significant for the SELF in Australia. Intelligibility judgments revealed preferences that were equally split between prescriptions in both countries, on average. In the Australian sample, intelligibility judgments agreed with the questionnaire ratings and with parents' ratings. An increase in preference for NAL was significantly associated with lesser hearing loss. The effect was not significant in the Canadian sample.

BMP Sustains Embryonic Stem Cell Self-Renewal through Distinct Functions of Different Krüppel-like Factors.

PubMed

Morikawa, Masato; Koinuma, Daizo; Mizutani, Anna; Kawasaki, Natsumi; Holmborn, Katarina; Sundqvist, Anders; Tsutsumi, Shuichi; Watabe, Tetsuro; Aburatani, Hiroyuki; Heldin, Carl-Henrik; Miyazono, Kohei

2016-01-12

Bone morphogenetic protein (BMP) signaling exerts paradoxical roles in pluripotent stem cells (PSCs); it sustains self-renewal of mouse embryonic stem cells (ESCs), while it induces differentiation in other PSCs, including human ESCs. Here, we revisit the roles of BMP-4 using mouse ESCs (mESCs) in naive and primed states. SMAD1 and SMAD5, which transduce BMP signals, recognize enhancer regions together with KLF4 and KLF5 in naive mESCs. KLF4 physically interacts with SMAD1 and suppresses its activity. Consistently, a subpopulation of cells with active BMP-SMAD can be ablated without disturbing the naive state of the culture. Moreover, Smad1/5 double-knockout mESCs stay in the naive state, indicating that the BMP-SMAD pathway is dispensable for it. In contrast, the MEK5-ERK5 pathway mediates BMP-4-induced self-renewal of mESCs by inducing Klf2, a critical factor for the ground state pluripotency. Our study illustrates that BMP exerts its self-renewing effect through distinct functions of different Krüppel-like factors. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Early parenting program as intervention strategy for emotional distress in first-time mothers: a propensity score analysis.

PubMed

Okamoto, Miwako; Ishigami, Hideaki; Tokimoto, Kumiko; Matsuoka, Megumi; Tango, Ryoko

2013-08-01

The purpose of this study is to evaluate the effectiveness of a single session intervention designed to reduce emotional distress in first-time mothers. We held a parenting class for first-time mothers who had given birth at a university hospital in Tokyo, Japan. The program of the class consists of lectures on infant care and group discussion, which is a common form of intervention in Japan. The effectiveness of intervention is assessed according to differences in emotional distress experienced by class participants and nonparticipants, and analyzed by the use of a propensity score method to avoid self-selection bias. In order to be more confident about our results, we employ several variations of this method. Results from statistical analysis show that although the effectiveness of the intervention was limited, it was able to alleviate subjects' loss of self-confidence as mothers. Because this outcome shows a good degree of consistency across methods, it can be considered robust. Moreover, it is roughly consistent with previous studies. Effectiveness can probably be increased by developing a program that improves upon the intervention.

Mucopolysaccharidosis IVA: Four new exonic mutations in patients with N-acetylgalactosamine-6-sulfate sulfatase deficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomatsu, Shunji; Fukuda, Seiji; Yamagishi, Atsushi

1996-05-01

We report four new mutations in Japanese patients with mucopolysaccharidosis IVA (MPSIVA) who were heterozygous for a common double gene deletion. A nonsense mutation of CAG to TAG at codon 148 in exon 4 was identified, resulting in a change of Q to a stop codon and three missense mutations: V (GTC) to A (GCC) at codon 138 in exon 4, P (CCC) to S (TCC) at codon 151 in exon 5, and P (CCC) to L (CTC) at codon 151 in exon 5. Introduction of these mutations into the normal GALNS cDNA and transient expression in cultured fibroblasts resultedmore » in a significant decrease in the enzyme activity. V138A and Q148X mutations result in changes of restriction site, which were analyzed by restriction-enzyme assay. P151S and P151L mutations that did not alter the restriction site were detected by direct sequencing or allele specific oligohybridization. Detection of the double gene deletion was initially done using Southern blots and was confirmed by PCR. Haplotypes were determined using seven polymorphisms to the GALNS locus in families with the double gene deletion. Haplotype analysis showed that the common double gene deletion occurred on a single haplotype, except for some variation in a VNTR-like polymorphism. This finding is consistent with a common founder for all individuals with this mutation. 48 refs., 5 figs., 1 tab.« less

Adsorption and oligomerization of 1,3-phenylene diisocyanide on Au(111)

DOE PAGES

Kestell, John; Walker, Joshua; Bai, Yun; ...

2016-04-18

The adsorption and self-assembly of 1,3-phenylene diisocyanide (1,3-PDI) are studied on Au(111) using reflection–adsorption infrared spectroscopy (RAIRS), scanning tunneling microscopy (STM), and temperature-programmed desorption (TPD) supplemented by density functional theory (DFT) calculations and the results compared with the structures formed from 1,4-PDI where it assembled to form –(Au–PDI)– oligomer chains that incorporate gold adatoms. The infrared spectra display a single isocyanide feature consistent with the isocyanide binding to gold adatoms, while DFT calculations confirm that isocyanide binding to gold adatoms is more energetically favorable than binding to the surface. STM images show that 1,3-PDI forms zigzag chains containing hairpin bendsmore » that cause the chains to double back on each other, consistent with the 120° angle between the isocyanide groups. Hexagonal structural motifs are also observed that are proposed to be due to the self-assembly of three isocyanides as well as small structures that are assigned to 1,3-PDI dimers. Furthermore, the results suggest that the formation of gold-containing oligomers from isocyanide-containing molecules is a general phenomenon.« less

Measuring self-rated health status among resettled adult refugee populations to inform practice and policy - a scoping review.

PubMed

Dowling, Alison; Enticott, Joanne; Russell, Grant

2017-12-08

The health status of refugees is a significant factor in determining their success in resettlement and relies heavily on self-rated measures of refugee health. The selection of robust and appropriate self-rated health measurement tools is challenging due to the number and methodological variation in the use of assessment tools across refugee health studies. This study describes the existing self-report health measures which have been used in studies of adult refugees living in the community to allow us to address the challenges of selecting appropriate assessments to measure health within refugee groups. Electronic databases of Ovid Medline, CINAHL, SCOPUS, Embase and Scopus. This review identified 45 different self-rated health measurements in 183 studies. Most of the studies were cross sectional explorations of the mental health status of refugees living in community settings within Western nations. A third of the tools were designed specifically for use within refugee populations. More than half of the identified measurement tools have been evaluated for reliability and/or validity within refugee populations. Much variation was found in the selection, development and testing of measurement tools across the reviewed studies. This review shows that there are currently a number of reliable and valid tools available for use in refugee health research; however, further work is required to achieve consistency in the quality and in the use of these tools. Methodological guidelines are required to assist researchers and clinicians in the development and testing of self-rated health measurement tools for use in refugee research.

Earth's structure and evolution inferred from topography, gravity, and seismicity.

NASA Astrophysics Data System (ADS)

Watkinson, A. J.; Menard, J.; Patton, R. L.

2016-12-01

Earth's wavelength-dependent response to loading, reflected in observed topography, gravity, and seismicity, can be interpreted in terms of a stack of layers under the assumption of transverse isotropy. The theory of plate tectonics holds that the outermost layers of this stack are mobile, produced at oceanic ridges, and consumed at subduction zones. Their toroidal motions are generally consistent with those of several rigid bodies, except in the world's active mountain belts where strains are partitioned and preserved in tectonite fabrics. Even portions of the oceanic lithosphere exhibit non-rigid behavior. Earth's gravity-topography cross-spectrum exhibits notable variations in signal amplitude and character at spherical harmonic degrees l=13, 116, 416, and 1389. Corresponding Cartesian wavelengths are approximately equal to the respective thicknesses of Earth's mantle, continental mantle lithosphere, oceanic thermal lithosphere, and continental crust, all known from seismology. Regional variations in seismic moment release with depth, derived from the global Centroid Moment Tensor catalog, are also evident in the crust and mantle lithosphere. Combined, these observations provide powerful constraints for the structure and evolution of the crust, mantle lithosphere, and mantle as a whole. All that is required is a dynamically consistent mechanism relating wavelength to layer thickness and shear-strain localization. A statistically-invariant 'diharmonic' relation exhibiting these properties appears as the leading order approximation to toroidal motions on a self-gravitating body of differential grade-2 material. We use this relation, specifically its predictions of weakness and rigidity, and of folding and shear banding response as a function of wavelength-to-thickness ratio, to interpret Earth's gravity, topography, and seismicity in four-dimensions. We find the mantle lithosphere to be about 255-km thick beneath the Himalaya and the Andes, and the long-wavelength (l < 14) low-amplitude portion of Earth's gravity field to be consistent with loading of the mesosphere by subducted slabs. The Earth that emerges from this work might be characterized as a self-gravitating, self-peeling onion.

Effects of meridional flow variations on solar cycles 23 and 24

DOE Office of Scientific and Technical Information (OSTI.GOV)

Upton, Lisa; Hathaway, David H., E-mail: lisa.a.upton@vanderbilt.edu, E-mail: lar0009@uah.edu, E-mail: david.hathaway@nasa.gov

2014-09-10

The faster meridional flow that preceded the solar cycle 23/24 minimum is thought to have led to weaker polar field strengths, producing the extended solar minimum and the unusually weak cycle 24. To determine the impact of meridional flow variations on the sunspot cycle, we have simulated the Sun's surface magnetic field evolution with our newly developed surface flux transport model. We investigate three different cases: a constant average meridional flow, the observed time-varying meridional flow, and a time-varying meridional flow in which the observed variations from the average have been doubled. Comparison of these simulations shows that the variationsmore » in the meridional flow over cycle 23 have a significant impact (∼20%) on the polar fields. However, the variations produced polar fields that were stronger than they would have been otherwise. We propose that the primary cause of the extended cycle 23/24 minimum and weak cycle 24 was the weakness of cycle 23 itself—with fewer sunspots, there was insufficient flux to build a big cycle. We also find that any polar counter-cells in the meridional flow (equatorward flow at high latitudes) produce flux concentrations at mid-to-high latitudes that are not consistent with observations.« less

Double-outlet left ventricle with L-malposition of the great arteries and subpulmonary ventricular septal defect.

PubMed

Vukomanovic, Vladislav; Prijic, Sergej; Bjelakovic, Bojko

2013-02-01

Double-outlet left ventricle is a very rare congenital cardiac anomaly with various anatomic types. This report describes an infant with the aorta anterior and to the left of the pulmonary trunk, a subpulmonary ventricular septal defect, and pulmonary artery stenosis. This variation has not been described to date in patients with a double-outlet left ventricle.

Spatial patterns of self-recruitment of a coral reef fish in relation to island-scale retention mechanisms.

PubMed

Beldade, Ricardo; Holbrook, Sally J; Schmitt, Russell J; Planes, Serge; Bernardi, Giacomo

2016-10-01

Oceanographic features influence the transport and delivery of marine larvae, and physical retention mechanisms, such as eddies, can enhance self-recruitment (i.e. the return of larvae to their natal population). Knowledge of exact locations of hatching (origin) and settlement (arrival) of larvae of reef animals provides a means to compare observed patterns of self-recruitment 'connectivity' with those expected from water circulation patterns. Using parentage inference based on multiple sampling years in Moorea, French Polynesia, we describe spatial and temporal variation in self-recruitment of the anemonefish Amphiprion chrysopterus, evaluate the consistency of net dispersal distances of self-recruits against the null expectation of passive particle dispersal and test the hypothesis that larvae originating in certain reef habitats (lagoons and passes) would be retained and thus more likely to self-recruit than those originating on the outer (fore) reef. Estimates of known self-recruitment were consistent across the sampling years (~25-27% of sampled recruits). For most (88%) of these self-recruits, the net distance between hatching and settlement locations was within the maximum dispersal distance expected for a neutrally buoyant passive particle based on the longest duration of the larval dispersive phase and the average direction and speed of current flow around Moorea. Furthermore, a parent of a given body size on the outer (fore) reef of Moorea was less likely to produce self-recruits than those in passes. Our findings show that even a simple dispersal model based on net average flow and direction of alongshore currents can provide insight into landscape-scale retention patterns of reef fishes. © 2016 John Wiley & Sons Ltd.

Social challenges faced by queer Latino college men: Navigating negative responses to coming out in a double minority sample of emerging adults.

PubMed

Eaton, Asia A; Rios, Desdamona

2017-10-01

In this paper, we qualitatively examine the social challenges experienced by queer, Latino college men in the coming out process. Using an intersectional perspective informed by the double jeopardy hypothesis, intersectional invisibility, and Latino/a cultural norms, we asked 22 queer Latino college men to describe the major challenges they experienced with their sexual identities. To examine the subjective experiences of participants' multiple minority identities, we conducted semistructured interviews. Our sample consisted of 22 college student men who identified as Latino, queer, and cisgender. Participant ages ranged from 18 to 29 (M = 21.50, SD = 3.70). For race/ethnicity, all participants identified with the broad category Latino. For sexual orientation, 18 participants self-identified as gay or homosexual, 3 identified as "other," and 1 identified as bisexual. Sixty-eight percent of participants (15/22) described encountering negative social responses to their sexual identity disclosure, including Loss of Relationships, Aggression, Pathologizing, and Self-Serving Responses. Additionally, 55% spontaneously reinterpreted or Cognitively Reframed their negative experiences (12/22), including the subthemes of It's never happened to me, Minimizing, and Victim Blame. We relate each subtheme to potentially influential social and cultural norms among queer, Latino college men, such as collectivistic values and familismo. Suggestions for research and practice with individuals at this identity intersection are described. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A pilot test of a self-guided, home-based intervention to improve condom-related sexual experiences, attitudes, and behaviors among young women.

PubMed

Yarber, William L; Milhausen, Robin R; Beavers, Karly A; Ryan, Rebecca; Sullivan, Margaret J; Vanterpool, Karen B; Sanders, Stephanie A; Graham, Cynthia A; Crosby, Richard A

2018-07-01

To conduct a pilot test of a brief, self-guided, home-based program designed to improve male condom use attitudes and behaviors among young women. Women aged 18-24 years from a large Midwestern University reporting having had penile-vaginal sex with two or more partners in the past 3 months. Sixty-seven enrolled; 91.0% completed the study. A repeated measures design was used, with assessments occurring at baseline, immediately  post intervention (T2), and 30 days subsequent (T3). Condom use errors and problems decreased, condom-related attitudes and self-efficacy improved, and experiences of condom-protected sex were rated more positively when comparing baseline with T2 and T3 scores. Further, the proportion of condom-protected episodes more than doubled between T1 and T3 for those in the lowest quartile for condom use at baseline. This low-resource, home-based program improved condom-related attitudes and promoted the correct and consistent use of condoms.

Rectification of graphene self-switching diodes: First-principles study

NASA Astrophysics Data System (ADS)

Ghaziasadi, Hassan; Jamasb, Shahriar; Nayebi, Payman; Fouladian, Majid

2018-05-01

The first principles calculations based on self-consistent charge density functional tight-binding have performed to investigate the electrical properties and rectification behavior of the graphene self-switching diodes (GSSD). The devices contained two structures called CG-GSSD and DG-GSSD which have metallic or semiconductor gates depending on their side gates have a single or double hydrogen edge functionalized. We have relaxed the devices and calculated I-V curves, transmission spectrums and maximum rectification ratios. We found that the DG-MSM devices are more favorable and more stable. Also, the DG-MSM devices have better maximum rectification ratios and current. Moreover, by changing the side gates widths and behaviors from semiconductor to metal, the threshold voltages under forward bias changed from +1.2 V to +0.3 V. Also, the maximum currents are obtained from 1.12 μA to 10.50 μA. Finally, the MSM and SSS type of all devices have minimum and maximum values of voltage threshold and maximum rectification ratios, but the 769-DG devices don't obey this rule.

Reducing errors through a web-based self-management support system.

PubMed

Ekstedt, Mirjam; Børøsund, Elin; Svenningsen, Ina K; Ruland, Cornelia M

2014-01-01

Web-based self-management support systems SMSS, can successfully assist a wide range of patients with information and self-management support. O or as a stand-alone service, are e-messages. This study describes how one component of a multi component SMSS, an e-message service, in which patients with breast cancer could direct questions to nurses, physicians or social workers at the hospital where they were being treated, had an influence on safety and continuity of care. Ninety-one dialogues consisting of 284 messages were analysed. The communications between patients and the healthcare team revealed that the e-messages service served as a means for quality assurance of information, for double-checking and for coordination of care. We give examples of how an e-mail service may improve patients' knowledge in a process of taking control over their own care - increasingly important in a time of growing complexity and specialization in healthcare. It remains to be tested whether an e-message service can improve continuity of care and prevent or mitigate medical mishaps.

Near-infrared lasers and self-frequency-doubling in Nd:YCOB cladding waveguides.

PubMed

Ren, Yingying; Chen, Feng; Vázquez de Aldana, Javier R

2013-05-06

A design of cladding waveguides in Nd:YCOB nonlinear crystals is demonstrated in this work. Compact Fabry-Perot oscillation cavities are employed for waveguide laser generation at 1062 nm and self-frequency-doubling at 531 nm, under optical pump at 810 nm. The waveguide laser shows slope efficiency as high as 55% at 1062 nm. The SFD green waveguide laser emits at 531 nm with a maximum power of 100 μW.

A study on parameter variation effects on battery packs for electric vehicles

NASA Astrophysics Data System (ADS)

Zhou, Long; Zheng, Yuejiu; Ouyang, Minggao; Lu, Languang

2017-10-01

As one single cell cannot meet power and driving range requirement in an electric vehicle, the battery packs with hundreds of single cells connected in parallel and series should be constructed. The most significant difference between a single cell and a battery pack is cell variation. Not only does cell variation affect pack energy density and power density, but also it causes early degradation of battery and potential safety issues. The cell variation effects on battery packs are studied, which are of great significant to battery pack screening and management scheme. In this study, the description for the consistency characteristics of battery packs was first proposed and a pack model with 96 cells connected in series was established. A set of parameters are introduced to study the cell variation and their impacts on battery packs are analyzed through the battery pack capacity loss simulation and experiments. Meanwhile, the capacity loss composition of the battery pack is obtained and verified by the temperature variation experiment. The results from this research can demonstrate that the temperature, self-discharge rate and coulombic efficiency are the major affecting parameters of cell variation and indicate the dissipative cell equalization is sufficient for the battery pack.

Portable, universal, and visual ion sensing platform based on the light emitting diode-based self-referencing-ion selective field-effect transistor.

PubMed

Zhang, Xiaowei; Han, Yanchao; Li, Jing; Zhang, Libing; Jia, Xiaofang; Wang, Erkang

2014-02-04

In this work, a novel and universal ion sensing platform was presented, which enables the visual detection of various ions with high sensitivity and selectivity. Coaxial potential signals (millivolt-scale) of the sample from the self-referencing (SR) ion selective chip can be transferred into the ad620-based amplifier with an output of volt-scale potentials. The amplified voltage is high enough to drive a light emitting diode (LED), which can be used as an amplifier and indicator to report the sample information. With this double amplification device (light emitting diode-based self-referencing-ion selective field-effect transistor, LED-SR-ISFET), a tiny change of the sample concentration can be observed with a distinguishable variation of LED brightness by visual inspection. This LED-based luminescent platform provided a facile, low-cost, and rapid sensing strategy without the need of additional expensive chemiluminescence reagent and instruments. Moreover, the SR mode also endows this device excellent stability and reliability. With this innovative design, sensitive determination of K(+), H(+), and Cl(-) by the naked eye was achieved. It should also be noticed that this sensing strategy can easily be extended to other ions (or molecules) by simply integrating the corresponding ion (or molecule) selective electrode.

"Self-Peel-Off" Transfer Produces Ultrathin Polyvinylidene-Fluoride-Based Flexible Nanodevices.

PubMed

Tai, Yanlong; Lubineau, Gilles

2017-04-01

Here, a new strategy, self-peel-off transfer, for the preparation of ultrathin flexible nanodevices made from polyvinylidene-fluoride (PVDF) is reported. In this process, a functional pattern of nanoparticles is transferred via peeling from a temporary substrate to the final PVDF film. This peeling process takes advantage of the differences in the work of adhesion between the various layers (the PVDF layer, the nanoparticle-pattern layer and the substrate layer) and of the high stresses generated by the differential thermal expansion of the layers. The work of adhesion is mainly guided by the basic physical/chemical properties of these layers and is highly sensitive to variations in temperature and moisture in the environment. The peeling technique is tested on a variety of PVDF-based functional films using gold/palladium nanoparticles, carbon nanotubes, graphene oxide, and lithium iron phosphate. Several PVDF-based flexible nanodevices are prepared, including a single-sided wireless flexible humidity sensor in which PVDF is used as the substrate and a double-sided flexible capacitor in which PVDF is used as the ferroelectric layer and the carrier layer. Results show that the nanodevices perform with high repeatability and stability. Self-peel-off transfer is a viable preparation strategy for the design and fabrication of flexible, ultrathin, and light-weight nanodevices.

Addendum to "Colored-noise-induced discontinuous transitions in symbiotic ecosystems".

PubMed

Sauga, Ako; Mankin, Romi

2005-06-01

A symbiotic ecosystem with Gompertz self-regulation and with adaptive competition between populations is studied by means of a N-species Lotka-Volterra stochastic model. The influence of fluctuating environment on the carrying capacity of a population is modeled as a dichotomous noise. The study is a follow up of previous investigations of symbiotic ecosystems subjected to the generalized Verhulst self-regulation [Phys. Rev. E 69, 061106 (2004); 65, 051108 (2002)]. In the framework of mean-field approximation the behavior of the solutions of the self-consistency equation for a stationary system is examined analytically in the full phase space of system parameters. Depending on the mutual interplay of symbiosis and competition of species, variation of noise parameters (amplitude, correlation time) can induce doubly unidirectional discontinuous transitions as well as single unidirectional discontinuous transitions of the mean population size.

Addendum to ``Colored-noise-induced discontinuous transitions in symbiotic ecosystems''

NASA Astrophysics Data System (ADS)

Sauga, Ako; Mankin, Romi

2005-06-01

A symbiotic ecosystem with Gompertz self-regulation and with adaptive competition between populations is studied by means of a N -species Lotka-Volterra stochastic model. The influence of fluctuating environment on the carrying capacity of a population is modeled as a dichotomous noise. The study is a follow up of previous investigations of symbiotic ecosystems subjected to the generalized Verhulst self-regulation [Phys. Rev. E 69, 061106 (2004); 65, 051108 (2002)]. In the framework of mean-field approximation the behavior of the solutions of the self-consistency equation for a stationary system is examined analytically in the full phase space of system parameters. Depending on the mutual interplay of symbiosis and competition of species, variation of noise parameters (amplitude, correlation time) can induce doubly unidirectional discontinuous transitions as well as single unidirectional discontinuous transitions of the mean population size.

Self-organized criticality in a cold plasma

NASA Astrophysics Data System (ADS)

Alex, Prince; Carreras, Benjamin Andres; Arumugam, Saravanan; Sinha, Suraj Kumar

2017-12-01

We present direct evidence for the existence of self-organized critical behavior in cold plasma. A multiple anodic double layer structure generated in a double discharge plasma setup shows critical behavior for the anode bias above a threshold value. Analysis of the floating potential fluctuations reveals the existence of long-range time correlations and power law behavior in the tail of the probability distribution function of the fluctuations. The measured Hurst exponent and the power law tail in the rank function are strong indication of the self-organized critical behavior of the system and hence provide a condition under which complexities arise in cold plasma.

The 4-Day Wave as Observed from the Upper Atmosphere Research Satellite Microwave Limb Sounder

NASA Technical Reports Server (NTRS)

Allen, D. R.; Stanford, J. L.; Elson, L. S.; Fishbein, E. F.; Froidevaux, L.; Waters, J. W.

1997-01-01

The "4-day wave" is an eastward moving quasi-nondispersive feature with period near 4 days occurring near the winter polar stratopause. This paper presents evidence of the 4-day feature in Microwave Limb Sounder (MLS) temperature, geopotential height, and ozone data from the late southern winters of 1992 and 1993. Space-time spectral analyses reveal a double-peaked temperature structure consisting of one peak near the stratopause and another in the lower mesosphere, with an out-of-phase relationship between the two peaks. This double- peaked structure is reminiscent of recent three-dimensional barotropic/baroclinic instability model predictions and is observed here for the first time. The height variation of the 4-day ozone signal is shown to compare well with a linear advective-photochemical tracer model. Negative regions of quasigeostrophic potential vorticity (PV) gradient and positive Eliassen-Palm flux divergence are shown to occur, consistent with instability dynamics playing a role in wave forcing. Spectral analyses of PV derived from MLS geopotential height fields reveal a 4-day signal peaking near the polar stratopause. The three-dimensional structure of the 4-day wave resembles the potential vorticity "charge" concept, wherein a PV anomaly in the atmosphere (analogous to an electrical charge in a dielectric material) induces a geopotential field, a vertically oriented temperature dipole, and circulation about the vertical axis.

Double-β decay within a consistent deformed approach

NASA Astrophysics Data System (ADS)

Delion, D. S.; Suhonen, J.

2015-05-01

In this paper we present a timely application of the proton-neutron deformed quasiparticle random-phase approximation (p n -dQRPA), designed to describe in a consistent way the 1+ Gamow-Teller states in odd-odd deformed nuclei. For this purpose we apply a projection before variation procedure by using a single-particle basis with projected angular momentum, provided by the diagonalization of a spherical mean field plus quadrupole-quadrupole interaction. The residual Hamiltonian contains pairing plus proton-neutron dipole terms in particle-hole and particle-particle channels, with constant strengths. As an example we describe the two-neutrino double-beta (2 ν β β ) decay of 150Nd to the ground state of 150Sm. The experimental (p ,n ) type of strength in 150Nd and the (n ,p ) type of strength in 150Sm are reasonably reproduced and the 2 ν β β decay matrix element depicts a strong dependence upon the particle-particle strength gp p. The experimental half-life is reproduced for gp p=0.05 . It turns out that the measured half-lives for 2 ν β β transitions between other deformed superfluid partners with mass numbers A =82 ,96,100,128,130,238 are reproduced with fairly good accuracy by using this value of gp p.

Contributions of chemical and diffusive exchange to T1ρ dispersion.

PubMed

Cobb, Jared Guthrie; Xie, Jingping; Gore, John C

2013-05-01

Variations in local magnetic susceptibility may induce magnetic field gradients that affect the signals acquired for MR imaging. Under appropriate diffusion conditions, such fields produce effects similar to slow chemical exchange. These effects may also be found in combination with other chemical exchange processes at multiple time scales. We investigate these effects with simulations and measurements to determine their contributions to rotating frame (R1ρ ) relaxation in model systems. Simulations of diffusive and chemical exchange effects on R1ρ dispersion were performed using the Bloch equations. Additionally, R1ρ dispersion was measured in suspensions of Sephadex and latex beads with varying spin locking fields at 9.4 T. A novel analysis method was used to iteratively fit for apparent chemical and diffusive exchange rates with a model by Chopra et al. Single- and double-inflection points in R1ρ dispersion profiles were observed, respectively, in simulations of slow diffusive exchange alone and when combined with rapid chemical exchange. These simulations were consistent with measurements of R1ρ in latex bead suspensions and small-diameter Sephadex beads that showed single- and double-inflection points, respectively. These observations, along with measurements following changes in temperature and pH, are consistent with the combined effects of slow diffusion and rapid -OH exchange processes. Copyright © 2012 Wiley Periodicals, Inc.

[Single or double moral standards? Professional ethics of psychiatrists regarding self-determination, rights of third parties and involuntary treatment].

PubMed

Pollmächer, T

2015-09-01

The current intensive discussion on the legal and moral aspects of involuntary treatment of psychiatric patients raises a number of ethical issues. Physicians are unambiguously obligated to protect patient welfare and autonomy; however, in psychiatric patients disease-related restrictions in the capacity of self-determination and behaviors endangering the rights of third parties can seriously challenge this unambiguity. Therefore, psychiatry is assumed to have a double function and is also obligated to third parties and to society in general. Acceptance of such a kind of double obligation carries the risk of double moral standards, placing the psychiatrist ethically outside the community of physicians and questioning the unrestricted obligation towards the patient. The present article formulates a moral position, which places the psychiatrist, like all other physicians, exclusively on the side of the patient in terms of professional ethics and discusses the practical problems arising from this moral position.

Saturation of the Hosing Instability in Quasilinear Plasma Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehe, R.; Schroeder, C. B.; Vay, J. -L.

The beam hosing instability is analyzed theoretically for a witness beam in the quasilinear regime of plasma accelerators. In this regime, the hosing instability saturates, even for a monoenergetic bunch, at a level much less than standard scalings predict. Analytic expressions are derived for the saturation distance and amplitude and are in agreement with numerical results. Saturation is due to the natural head-to-tail variations in the focusing force, including the self-consistent transverse beam loading.

Saturation of the Hosing Instability in Quasilinear Plasma Accelerators

DOE PAGES

Lehe, R.; Schroeder, C. B.; Vay, J. -L.; ...

2017-12-13

The beam hosing instability is analyzed theoretically for a witness beam in the quasilinear regime of plasma accelerators. In this regime, the hosing instability saturates, even for a monoenergetic bunch, at a level much less than standard scalings predict. Analytic expressions are derived for the saturation distance and amplitude and are in agreement with numerical results. Saturation is due to the natural head-to-tail variations in the focusing force, including the self-consistent transverse beam loading.

Nouvelles bornes et estimations pour les milieux poreux à matrice rigide parfaitement plastique

NASA Astrophysics Data System (ADS)

Bilger, Nicolas; Auslender, François; Bornert, Michel; Masson, Renaud

We derive new rigorous bounds and self-consistent estimates for the effective yield surface of porous media with a rigid perfectly plastic matrix and a microstructure similar to Hashin's composite spheres assemblage. These results arise from a homogenisation technique that combines a pattern-based modelling for linear composite materials and a variational formulation for nonlinear media. To cite this article: N. Bilger et al., C. R. Mecanique 330 (2002) 127-132.

The Silicon Tracking System of the CBM experiment at FAIR

NASA Astrophysics Data System (ADS)

Teklishyn, Maksym

2018-03-01

The Silicon Tracking System (STS) is the central detector in the Compressed Baryonic Matter (CBM) experiment at FAIR. Operating in the 1Tm dipole magnetic field, the STS will enable pile-up free detection and momentum measurement of the charged particles originating from beam-target nuclear interactions at rates up to 10 MHz. The STS consists of 8 tracking stations based on double-sided silicon micro-strip sensors equipped with fast, self-triggering read-out electronics. With about two million read-out channels, the STS will deliver a high-rate stream of time-stamped data that is transferred to a computing farm for on-line event determination and analysis. The functional building block is a detector module consisting of a sensor, micro-cables and two front-end electronics boards. In this contribution, the development status of the STS components and the system integration is discussed and an outlook on the detector construction is given.

Theoretical Studies of Routes to Synthesis of Tetrahedral N4

NASA Technical Reports Server (NTRS)

Lee, Timothy J.; Dateo, Christopher E.

2007-01-01

A paper [Chem. Phys. Lett. 345, 295 (2001)] describes theoretical studies of excited electronic states of nitrogen molecules, with a view toward utilizing those states in synthesizing tetrahedral N4, or Td N4 a metastable substance under consideration as a high-energy-density rocket fuel. Several ab initio theoretical approaches were followed in these studies, including complete active space self-consistent field (CASSCF), state-averaged CASSCF (SA-CASSCF), singles configuration interaction (CIS), CIS with second-order and third-order correlation corrections [CIS(D) and CIS(3)], and linear response singles and doubles coupled-cluster (LRCCSD). Standard double zeta polarized and triple zeta double polarized one-particle basis sets were used. The CASSCF calculations overestimated the excitation energies, while SACASSCF calculations partly corrected these overestimates. The accuracy of the CIS calculations varied, depending on the particular state, while the CIS(D), CIS(3), and LRCCSD results were in generally good agreement. The energies of the lowest six excited singlet states of Td N4 as calculated by the LRCCSD were compared with the energies of possible excited states of N2 + N2 fragments, leading to the conclusion that the most likely route for synthesis of Td N4 would involve a combination of two bound quintet states of N2.

Theoretical mean-field and experimental occupation probabilities in the double-beta decay system {sup 76}Ge to {sup 76}Se

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, O.; Moya de Guerra, E.; Sarriguren, P.

2010-04-15

Usual Woods-Saxon single-particle levels with BCS pairing are not able to reproduce the experimental occupation probabilities of the proton and neutron levels 1p{sub 3/2}, 1p{sub 1/2}, 0f{sub 5/2}, and 0g{sub 9/2} in the double-beta decay system {sup 76}Ge to {sup 76}Se. Shifting down the 0g{sub 9/2} level by hand can explain the data, but it is not satisfactory. Here it is shown that a self-consistent Hartree-Fock+BCS approach with experimental deformations for {sup 76}Ge and {sup 76}Se may decisively improve the agreement with the recent data on occupation probabilities by J. P. Schiffer et al. [Phys. Rev. Lett. 100, 112501 (2008)]more » and B. P. Kay et al. [Phys. Rev. C 79, 021301(R) (2009)]. Best agreement with available data on {sup 76}Ge and {sup 76}Se, as well as on neighbor isotopes, is obtained when the spin-orbit strength for neutrons is allowed to be larger than that for protons. The two-neutrino double-beta decay matrix element is also shown to agree with the data.« less

Characterization of Full Set Material Constants and Their Temperature Dependence for Piezoelectric Materials Using Resonant Ultrasound Spectroscopy

PubMed Central

Tang, Liguo; Cao, Wenwu

2016-01-01

During the operation of high power electromechanical devices, a temperature rise is unavoidable due to mechanical and electrical losses, causing the degradation of device performance. In order to evaluate such degradations using computer simulations, full matrix material properties at elevated temperatures are needed as inputs. It is extremely difficult to measure such data for ferroelectric materials due to their strong anisotropic nature and property variation among samples of different geometries. Because the degree of depolarization is boundary condition dependent, data obtained by the IEEE (Institute of Electrical and Electronics Engineers) impedance resonance technique, which requires several samples with drastically different geometries, usually lack self-consistency. The resonant ultrasound spectroscopy (RUS) technique allows the full set material constants to be measured using only one sample, which can eliminate errors caused by sample to sample variation. A detailed RUS procedure is demonstrated here using a lead zirconate titanate (PZT-4) piezoceramic sample. In the example, the complete set of material constants was measured from room temperature to 120 °C. Measured free dielectric constants and  were compared with calculated ones based on the measured full set data, and piezoelectric constants d15 and d33 were also calculated using different formulas. Excellent agreement was found in the entire range of temperatures, which confirmed the self-consistency of the data set obtained by the RUS. PMID:27168336

Analytic Energy Gradients for Variational Two-Electron Reduced-Density-Matrix-Driven Complete Active Space Self-Consistent Field Theory.

PubMed

Maradzike, Elvis; Gidofalvi, Gergely; Turney, Justin M; Schaefer, Henry F; DePrince, A Eugene

2017-09-12

Analytic energy gradients are presented for a variational two-electron reduced-density-matrix (2-RDM)-driven complete active space self-consistent field (CASSCF) method. The active-space 2-RDM is determined using a semidefinite programing (SDP) algorithm built upon an augmented Lagrangian formalism. Expressions for analytic gradients are simplified by the fact that the Lagrangian is stationary with respect to variations in both the primal and the dual solutions to the SDP problem. Orbital response contributions to the gradient are identical to those that arise in conventional CASSCF methods in which the electronic structure of the active space is described by a full configuration interaction (CI) wave function. We explore the relative performance of variational 2-RDM (v2RDM)- and CI-driven CASSCF for the equilibrium geometries of 20 small molecules. When enforcing two-particle N-representability conditions, full-valence v2RDM-CASSCF-optimized bond lengths display a mean unsigned error of 0.0060 Å and a maximum unsigned error of 0.0265 Å, relative to those obtained from full-valence CI-CASSCF. When enforcing partial three-particle N-representability conditions, the mean and maximum unsigned errors are reduced to only 0.0006 and 0.0054 Å, respectively. For these same molecules, full-valence v2RDM-CASSCF bond lengths computed in the cc-pVQZ basis set deviate from experimentally determined ones on average by 0.017 and 0.011 Å when enforcing two- and three-particle conditions, respectively, whereas CI-CASSCF displays an average deviation of 0.010 Å. The v2RDM-CASSCF approach with two-particle conditions is also applied to the equilibrium geometry of pentacene; optimized bond lengths deviate from those derived from experiment, on average, by 0.015 Å when using a cc-pVDZ basis set and a (22e,22o) active space.

Investigating the transverse optical structure of spider silk micro-fibers using quantitative optical microscopy

NASA Astrophysics Data System (ADS)

Little, Douglas J.; Kane, Deb M.

2017-01-01

The transverse optical structure of two orb-weaver (family Araneidae) spider dragline silks was investigated using a variant of the inverse-scattering technique. Immersing the silks in a closely refractive index-matched liquid, the minimum achievable image contrast was greater than expected for an optically homogeneous silk, given what is currently known about the optical absorption of these silks. This "excess contrast" indicated the presence of transverse optical structure within the spider silk. Applying electromagnetic scattering theory to a transparent double cylinder, the minimum achievable irradiance contrast for the Plebs eburnus and Argiope keyserlingi dragline silks was determined to be consistent with step index refractive index contrasts of 1-4×10-4 and 6-7×10-4, respectively, supposing outer-layer thicknesses consistent with previous TEM studies (50 nm and 100 nm, respectively). The possibility of graded index refractive index contrasts within the spider silks is also discussed. This is the strongest evidence, to date, that there is a refractive index contrast associated with the layered morphology of spider silks and/or variation of proportion of nanocrystalline components within the spider silk structure. The method is more generally applicable to optical micro-fibers, including those with refractive index variations on a sub-wavelength scale.

Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mai, Sebastian; Marquetand, Philipp; González, Leticia

2014-08-21

An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the COLUMBUS quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbitmore » coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.« less

The Red Queen model of recombination hot-spot evolution: a theoretical investigation.

PubMed

Latrille, Thibault; Duret, Laurent; Lartillot, Nicolas

2017-12-19

In humans and many other species, recombination events cluster in narrow and short-lived hot spots distributed across the genome, whose location is determined by the Zn-finger protein PRDM9. To explain these fast evolutionary dynamics, an intra-genomic Red Queen model has been proposed, based on the interplay between two antagonistic forces: biased gene conversion, mediated by double-strand breaks, resulting in hot-spot extinction, followed by positive selection favouring new PRDM9 alleles recognizing new sequence motifs. Thus far, however, this Red Queen model has not been formalized as a quantitative population-genetic model, fully accounting for the intricate interplay between biased gene conversion, mutation, selection, demography and genetic diversity at the PRDM9 locus. Here, we explore the population genetics of the Red Queen model of recombination. A Wright-Fisher simulator was implemented, allowing exploration of the behaviour of the model (mean equilibrium recombination rate, diversity at the PRDM9 locus or turnover rate) as a function of the parameters (effective population size, mutation and erosion rates). In a second step, analytical results based on self-consistent mean-field approximations were derived, reproducing the scaling relations observed in the simulations. Empirical fit of the model to current data from the mouse suggests both a high mutation rate at PRDM9 and strong biased gene conversion on its targets.This article is part of the themed issue 'Evolutionary causes and consequences of recombination rate variation in sexual organisms'. © 2017 The Authors.

The Red Queen model of recombination hot-spot evolution: a theoretical investigation

PubMed Central

Latrille, Thibault; Duret, Laurent

2017-01-01

In humans and many other species, recombination events cluster in narrow and short-lived hot spots distributed across the genome, whose location is determined by the Zn-finger protein PRDM9. To explain these fast evolutionary dynamics, an intra-genomic Red Queen model has been proposed, based on the interplay between two antagonistic forces: biased gene conversion, mediated by double-strand breaks, resulting in hot-spot extinction, followed by positive selection favouring new PRDM9 alleles recognizing new sequence motifs. Thus far, however, this Red Queen model has not been formalized as a quantitative population-genetic model, fully accounting for the intricate interplay between biased gene conversion, mutation, selection, demography and genetic diversity at the PRDM9 locus. Here, we explore the population genetics of the Red Queen model of recombination. A Wright–Fisher simulator was implemented, allowing exploration of the behaviour of the model (mean equilibrium recombination rate, diversity at the PRDM9 locus or turnover rate) as a function of the parameters (effective population size, mutation and erosion rates). In a second step, analytical results based on self-consistent mean-field approximations were derived, reproducing the scaling relations observed in the simulations. Empirical fit of the model to current data from the mouse suggests both a high mutation rate at PRDM9 and strong biased gene conversion on its targets. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109226

On the optimization of Gaussian basis sets

NASA Astrophysics Data System (ADS)

Petersson, George A.; Zhong, Shijun; Montgomery, John A.; Frisch, Michael J.

2003-01-01

A new procedure for the optimization of the exponents, αj, of Gaussian basis functions, Ylm(ϑ,φ)rle-αjr2, is proposed and evaluated. The direct optimization of the exponents is hindered by the very strong coupling between these nonlinear variational parameters. However, expansion of the logarithms of the exponents in the orthonormal Legendre polynomials, Pk, of the index, j: ln αj=∑k=0kmaxAkPk((2j-2)/(Nprim-1)-1), yields a new set of well-conditioned parameters, Ak, and a complete sequence of well-conditioned exponent optimizations proceeding from the even-tempered basis set (kmax=1) to a fully optimized basis set (kmax=Nprim-1). The error relative to the exact numerical self-consistent field limit for a six-term expansion is consistently no more than 25% larger than the error for the completely optimized basis set. Thus, there is no need to optimize more than six well-conditioned variational parameters, even for the largest sets of Gaussian primitives.

Microscopic theory of vortex interaction in two-band superconductors and type-1.5 superconductivity

NASA Astrophysics Data System (ADS)

Silaev, Mihail; Babaev, Egor

2011-03-01

In the framework of self-consistent microscopic theory we study the structure and interaction of vortices in two-gap superconductor taking into account the interband Josephson coupling. The asymptotical behavior of order parameter densities and magnetic field is studied analytically within the microscopic theory at low temperature. At higher temperatures, results consistent with Ginzburg-Landau theory are obtained. It is shown that under quite general conditions and in a wide temperature ranges (in particular outside the validity of the Ginzburg-Landau theory) there can exist an additional characteristic length scale of the order parameter density variation which exceeds the London penetration length of magnetic field due to the multi-component nature of superconducting state. Such behavior of order parameter density variation leads to the attractive long-range and repulsive short-range interaction between vortices. Supported by NSF CAREER Award DMR-0955902, Knut and Alice Wallenberg Foundation through the Royal Swedish Academy of Sciences and Swedish Research Council, ''Dynasty'' foundation and Russian Foundation for Basic Research.

Do TETRA (Airwave) base station signals have a short-term impact on health and well-being? A randomized double-blind provocation study.

PubMed

Wallace, Denise; Eltiti, Stacy; Ridgewell, Anna; Garner, Kelly; Russo, Riccardo; Sepulveda, Francisco; Walker, Stuart; Quinlan, Terence; Dudley, Sandra; Maung, Sithu; Deeble, Roger; Fox, Elaine

2010-06-01

"Airwave" is the new communication system currently being rolled out across the United Kingdom for the police and emergency services, based on the Terrestrial Trunked Radio Telecommunications System (TETRA). Some police officers have complained about skin rashes, nausea, headaches, and depression as a consequence of using their Airwave handsets. In addition, a small subgroup in the population self-report being sensitive to electromagnetic fields (EMFs) in general. We conducted a randomized double-blind provocation study to establish whether short-term exposure to a TETRA base station signal has an impact on the health and well-being of individuals with self-reported "electrosensitivity" and of participants who served as controls. Fifty-one individuals with self-reported electrosensitivity and 132 age- and sex-matched controls participated in an open provocation test; 48 sensitive and 132 control participants went on to complete double-blind tests in a fully screened semianechoic chamber. Heart rate, skin conductance, and blood pressure readings provided objective indices of short-term physiological response. Visual analog scales and symptom scales provided subjective indices of well-being. We found no differences on any measure between TETRA and sham (no signal) under double-blind conditions for either controls or electrosensitive participants, and neither group could detect the presence of a TETRA signal at rates greater than chance (50%). When conditions were not double blind, however, the self-reported electrosensitive individuals did report feeling worse and experienced more severe symptoms during TETRA compared with sham. Our findings suggest that the adverse symptoms experienced by electrosensitive individuals are due to the belief of harm from TETRA base stations rather than to the low-level EMF exposure itself.

Knotless double-row SutureBridge rotator cuff repairs have improved self-reinforcement compared with double-row SutureBridge repairs with tied medial knots: a biomechanical study using an ovine model.

PubMed

Smith, Geoffrey C S; Bouwmeester, Theresia M; Lam, Patrick H

2017-12-01

In double-row SutureBridge (Arthrex, Naples, FL, USA) rotator cuff repairs, increasing tendon load may generate progressively greater compression forces at the repair footprint (self-reinforcement). SutureBridge rotator cuff repairs using tied horizontal mattress sutures medially may limit this effect compared with a knotless construct. Rotator cuff repairs were performed in 9 pairs of ovine shoulders. One group underwent repair with a double-row SutureBridge construct with tied horizontal medial-row mattress sutures. The other group underwent repair in an identical fashion except that medial-row knots were not tied. Footprint contact pressure was measured at 0° and 20° of abduction under loads of 0 to 60 N. Pull-to-failure tests were then performed. In both repair constructs, each 10-N increase in rotator cuff tensile load led to a significant increase in footprint contact pressure (P < .0001). The rate of increase in footprint contact pressure was greater in the knotless construct (P < .00022; ratio, 1.69). The yield point approached the ultimate load to failure more closely in the knotless model than in the knotted construct (P = .00094). There was no difference in stiffness, ultimate failure load, or total energy to failure between the knotless and knotted techniques. In rotator cuff repair with a double-row SutureBridge configuration, self-reinforcement is seen in repairs with and without medial-row knots. Self-reinforcement is greater with the knotless technique. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Do TETRA (Airwave) Base Station Signals Have a Short-Term Impact on Health and Well-Being? A Randomized Double-Blind Provocation Study

PubMed Central

Wallace, Denise; Eltiti, Stacy; Ridgewell, Anna; Garner, Kelly; Russo, Riccardo; Sepulveda, Francisco; Walker, Stuart; Quinlan, Terence; Dudley, Sandra; Maung, Sithu; Deeble, Roger; Fox, Elaine

2010-01-01

Background “Airwave” is the new communication system currently being rolled out across the United Kingdom for the police and emergency services, based on the Terrestrial Trunked Radio Telecommunications System (TETRA). Some police officers have complained about skin rashes, nausea, headaches, and depression as a consequence of using their Airwave handsets. In addition, a small subgroup in the population self-report being sensitive to electromagnetic fields (EMFs) in general. Objectives We conducted a randomized double-blind provocation study to establish whether short-term exposure to a TETRA base station signal has an impact on the health and well-being of individuals with self-reported “electrosensitivity” and of participants who served as controls. Methods Fifty-one individuals with self-reported electrosensitivity and 132 age- and sex-matched controls participated in an open provocation test; 48 sensitive and 132 control participants went on to complete double-blind tests in a fully screened semianechoic chamber. Heart rate, skin conductance, and blood pressure readings provided objective indices of short-term physiological response. Visual analog scales and symptom scales provided subjective indices of well-being. Results We found no differences on any measure between TETRA and sham (no signal) under double-blind conditions for either controls or electrosensitive participants, and neither group could detect the presence of a TETRA signal at rates greater than chance (50%). When conditions were not double blind, however, the self-reported electrosensitive individuals did report feeling worse and experienced more severe symptoms during TETRA compared with sham. Conclusions Our findings suggest that the adverse symptoms experienced by electrosensitive individuals are due to the belief of harm from TETRA base stations rather than to the low-level EMF exposure itself. PMID:20075020

Self-discharge of electrochemical capacitors based on soluble or grafted quinone.

PubMed

Shul, Galyna; Bélanger, Daniel

2016-07-28

The self-discharge of hybrid electrochemical capacitors based on the redox activity of electrolyte additives or grafted species to the electrode material is investigated simultaneously for the cell and each individual electrode. Electrochemical capacitors using a redox-active electrolyte consisting in hydroquinone added to the electrolyte solution and a redox-active electrode based on anthraquinone-grafted carbon as a negative electrode are investigated. The results are analyzed by using Conway kinetic models and compared to those of a common electrochemical double layer capacitor. The self-discharge investigation is complemented by charge/discharge cycling and it is shown that processes affecting galvanostatic charge/discharge cycling and the self-discharge rate occurring at each electrode of an electrochemical capacitor are different but related to each other. The electrochemical capacitor containing hydroquinone in the electrolyte exhibits a much quicker self-discharge rate than that using a negative electrode based on grafted anthraquinone with a 50% decay of the cell voltage of the fully charged device in 0.6 and 6 h, respectively. The fast self-discharge of the former is due to the diffusion of benzoquinone molecules (formed at the positive electrode during charging) to the negative electrode, where they are reduced, causing a quick depolarization. The grafting of anthraquinone molecules on the carbon material of the negative electrode led to a much slower self-discharge, which nonetheless occurred, by the reaction of the reduced form of the grafted species with electrolyte species.

The Apollo 14 regolith - Petrology of cores 14210/14211 and 14220 and soils 14141, 14148, and 14149

NASA Technical Reports Server (NTRS)

Simon, S. B.; Papike, J. J.; Laul, J. C.

1982-01-01

New modal data are presented for continuous polished thin sections from double drive tube 14210/14211, and single drive tube 14220, and for polished grain mounts of four soils from the double drive tube, one from the single drive tube, and the soils 14148 (trench top), 14149 (trench bottom), and 14141 (Cone Crater). Modal data show that the Cone Crater soil is immature, whereas the 'smooth plains' soils are mature and rich in agglutinates and breccias. Neither core exhibits any major variations with depth. Microprobe analyses of mineral and glass fragments are consistent with derivation of the soils predominantly from the local rocks, with about 5-11% exotic mare component indicated by the modal data. About 4% of the glasses are SiO2- and K2O-rich granitic glasses which are comminuted mesostasis from the local melt rocks. The soils are depleted in feldspar relative to the source rocks. The preferred explanation for this depletion is that feldspar is concentrated in the less than 10 microns fines and is consumed in the formation of agglutinates, regolith breccias, and feldspathic glass.

Density functional plus dynamical mean-field theory of the metal-insulator transition in early transition-metal oxides

NASA Astrophysics Data System (ADS)

Dang, Hung T.; Ai, Xinyuan; Millis, Andrew J.; Marianetti, Chris A.

2014-09-01

The combination of density functional theory and single-site dynamical mean-field theory, using both Hartree and full continuous-time quantum Monte Carlo impurity solvers, is used to study the metal-insulator phase diagram of perovskite transition-metal oxides of the form ABO3 with a rare-earth ion A =Sr, La, Y and transition metal B =Ti, V, Cr. The correlated subspace is constructed from atomiclike d orbitals defined using maximally localized Wannier functions derived from the full p-d manifold; for comparison, results obtained using a projector method are also given. Paramagnetic DFT + DMFT computations using full charge self-consistency along with the standard "fully localized limit" (FLL) double counting are shown to incorrectly predict that LaTiO3, YTiO3, LaVO3, and SrMnO3 are metals. A more general examination of the dependence of physical properties on the mean p-d energy splitting, the occupancy of the correlated d states, the double-counting correction, and the lattice structure demonstrates the importance of charge-transfer physics even in the early transition-metal oxides and elucidates the factors underlying the failure of the standard approximations. If the double counting is chosen to produce a p-d splitting consistent with experimental spectra, single-site dynamical mean-field theory provides a reasonable account of the materials properties. The relation of the results to those obtained from "d-only" models in which the correlation problem is based on the frontier orbital p-d antibonding bands is determined. It is found that if an effective interaction U is properly chosen the d-only model provides a good account of the physics of the d1 and d2 materials.

Self-consistent vertical transport calculations in AlxGa1-xN/GaN based resonant tunneling diode

NASA Astrophysics Data System (ADS)

Rached, A.; Bhouri, A.; Sakr, S.; Lazzari, J.-L.; Belmabrouk, H.

2016-03-01

The formation of two-dimensional electron gases (2DEGs) at AlxGa1-xN/GaN hexagonal double-barriers (DB) resonant tunneling diodes (RTD) is investigated by numerical self-consistent (SC) solutions of the coupled Schrödinger and Poisson equations. Spontaneous and piezoelectric effects across the material interfaces are rigorously taken into account. Conduction band profiles, band edges and corresponding envelope functions are calculated in the AlxGa1-xN/GaN structures and likened to those where no polarization effects are included. The combined effect of the polarization-induced bound charge and conduction band offsets between the hexagonal AlGaN and GaN results in the formation of 2DEGs on one side of the DB and a depletion region on the other side. Using the transfer matrix formalism, the vertical transport (J-V characteristics) in AlGaN/GaN RTDs is calculated with a fully SC calculation in the ballistic regime. Compared to standard calculations where the voltage drop along the structure is supposed to be linear, the SC method leads to strong quantitative changes in the J-V characteristics showing that the applied electric field varies significantly in the active region of the structure. The influences of the aluminum composition and the GaN(AlGaN) thickness layers on the evolution of the current characteristics are also self-consistently investigated and discussed. We show that the electrical characteristics are very sensitive to the potential barrier due to the interplay between the potential symmetry and the barrier height and width. More interestingly, we demonstrate that the figures of merit namely the peak-to-valley ratio (PVR) of GaN/AlGaN RTDs can be optimized by increasing the quantum well width.

Self-Consistent Conversion of a Viscous Fluid to Particles and Heavy-Ion Physics Applications

NASA Astrophysics Data System (ADS)

Wolff, Zack J.

The most widely used theoretical framework to model the early stages of a heavy-ion collision is viscous hydrodynamics. Comparing hydrodynamic simulations to heavy-ion data inevitably requires the conversion of the fluid to particles. This conversion, typically done in the Cooper-Frye formalism, is ambiguous for viscous fluids. In this thesis work, self-consistent phase space corrections are calculated by solving the linearized Boltzmann equation. These species-dependent solutions are contrasted with those obtained using the ad-hoc ''democratic Grad'' ansatz typically employed in the literature in which coefficients are independent of particle dynamics. Solutions are calculated analytically for a massless gas and numerically for the general case of a hadron resonance gas. For example, it is found that for a gas of massless particles interacting via isotropic, energy-independent 2 → 2 scatterings, the shear viscous corrections variationally prefer a momentum dependence close to p3/2 rather than the quadratic dependence assumed in the Grad ansatz. The self-consistent phase space distributions are then used to calculate transverse momentum spectra and differential flow coefficients, v n(pT), to study the effects on heavy-ion identified particle observables. Using additive quark model cross sections, it is found that proton flow coefficients are higher than those for pions at moderately high pT in Pb + Pb collisions at LHC, especially for the coefficients v 4 and v6.

A Self-consistent Cloud Model for Brown Dwarfs and Young Giant Exoplanets: Comparison with Photometric and Spectroscopic Observations

NASA Astrophysics Data System (ADS)

Charnay, B.; Bézard, B.; Baudino, J.-L.; Bonnefoy, M.; Boccaletti, A.; Galicher, R.

2018-02-01

We developed a simple, physical, and self-consistent cloud model for brown dwarfs and young giant exoplanets. We compared different parametrizations for the cloud particle size, by fixing either particle radii or the mixing efficiency (parameter f sed), or by estimating particle radii from simple microphysics. The cloud scheme with simple microphysics appears to be the best parametrization by successfully reproducing the observed photometry and spectra of brown dwarfs and young giant exoplanets. In particular, it reproduces the L–T transition, due to the condensation of silicate and iron clouds below the visible/near-IR photosphere. It also reproduces the reddening observed for low-gravity objects, due to an increase of cloud optical depth for low gravity. In addition, we found that the cloud greenhouse effect shifts chemical equilibrium, increasing the abundances of species stable at high temperature. This effect should significantly contribute to the strong variation of methane abundance at the L–T transition and to the methane depletion observed on young exoplanets. Finally, we predict the existence of a continuum of brown dwarfs and exoplanets for absolute J magnitude = 15–18 and J-K color = 0–3, due to the evolution of the L–T transition with gravity. This self-consistent model therefore provides a general framework to understand the effects of clouds and appears well-suited for atmospheric retrievals.

Do Peers Matter in the Development of Self-Control? Evidence from a Longitudinal Study of Youth

ERIC Educational Resources Information Center

Meldrum, Ryan C.; Hay, Carter

2012-01-01

According to Gottfredson and Hirschi's self-control theory, child and adolescent variation in self-control results primarily from variations in parental socialization. Although much research reveals a link between parenting and self-control, many recent studies indicate that the etiology of self-control is more complex than what has been…

Broadband Spectral Modeling of the Extreme Gigahertz-peaked Spectrum Radio Source PKS B0008-421

NASA Astrophysics Data System (ADS)

Callingham, J. R.; Gaensler, B. M.; Ekers, R. D.; Tingay, S. J.; Wayth, R. B.; Morgan, J.; Bernardi, G.; Bell, M. E.; Bhat, R.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Deshpande, A. A.; Ewall-Wice, A.; Feng, L.; Greenhill, L. J.; Hazelton, B. J.; Hindson, L.; Hurley-Walker, N.; Jacobs, D. C.; Johnston-Hollitt, M.; Kaplan, D. L.; Kudrayvtseva, N.; Lenc, E.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Oberoi, D.; Offringa, A. R.; Ord, S. M.; Pindor, B.; Prabu, T.; Procopio, P.; Riding, J.; Srivani, K. S.; Subrahmanyan, R.; Udaya Shankar, N.; Webster, R. L.; Williams, A.; Williams, C. L.

2015-08-01

We present broadband observations and spectral modeling of PKS B0008-421 and identify it as an extreme gigahertz-peaked spectrum (GPS) source. PKS B0008-421 is characterized by the steepest known spectral slope below the turnover, close to the theoretical limit of synchrotron self-absorption, and the smallest known spectral width of any GPS source. Spectral coverage of the source spans from 0.118 to 22 GHz, which includes data from the Murchison Widefield Array and the wide bandpass receivers on the Australia Telescope Compact Array. We have implemented a Bayesian inference model fitting routine to fit the data with internal free-free absorption (FFA), single- and double-component FFA in an external homogeneous medium, FFA in an external inhomogeneous medium, or single- and double-component synchrotron self-absorption models, all with and without a high-frequency exponential break. We find that without the inclusion of a high-frequency break these models cannot accurately fit the data, with significant deviations above and below the peak in the radio spectrum. The addition of a high-frequency break provides acceptable spectral fits for the inhomogeneous FFA and double-component synchrotron self-absorption models, with the inhomogeneous FFA model statistically favored. The requirement of a high-frequency spectral break implies that the source has ceased injecting fresh particles. Additional support for the inhomogeneous FFA model as being responsible for the turnover in the spectrum is given by the consistency between the physical parameters derived from the model fit and the implications of the exponential spectral break, such as the necessity of the source being surrounded by a dense ambient medium to maintain the peak frequency near the gigahertz region. This implies that PKS B0008-421 should display an internal H i column density greater than 1020 cm-2. The discovery of PKS B0008-421 suggests that the next generation of low radio frequency surveys could reveal a large population of GPS sources that have ceased activity, and that a portion of the ultra-steep-spectrum source population could be composed of these GPS sources in a relic phase.

Variation of HPV Subtypes with Focus on HPV-Infection and Cancer in the Head and Neck Region.

PubMed

Wichmann, Gunnar

The human papillomavirus (HPV) comprises a heterogeneous group of double-strand DNA viruses with variable potential to infect human epithelial cells and trigger neoplastic transformation. Its 8 kb genome encodes proteins required for virus replication and self-organized formation of infectious particles but also for early proteins E6 and E7 able to trigger neoplastic transformation. E6 and E7 of high-risk (HR) HPV subtypes can bind to p53 or release E2F and abrogate replication control. Due to variable amino acid sequence (AAS) in the binding sites of E6 and E7 particular HR-HPV variants within subtypes are essentially heterogeneous in efficacy triggering neoplastic transformation and cancer development. This could explain differences in the clinical course of HPV-driven head and neck cancer.

Self-consistent atmosphere modeling with cloud formation for low-mass stars and exoplanets

NASA Astrophysics Data System (ADS)

Juncher, Diana; Jørgensen, Uffe G.; Helling, Christiane

2017-12-01

Context. Low-mass stars and extrasolar planets have ultra-cool atmospheres where a rich chemistry occurs and clouds form. The increasing amount of spectroscopic observations for extrasolar planets requires self-consistent model atmosphere simulations to consistently include the formation processes that determine cloud formation and their feedback onto the atmosphere. Aims: Our aim is to complement the MARCS model atmosphere suit with simulations applicable to low-mass stars and exoplanets in preparation of E-ELT, JWST, PLATO and other upcoming facilities. Methods: The MARCS code calculates stellar atmosphere models, providing self-consistent solutions of the radiative transfer and the atmospheric structure and chemistry. We combine MARCS with a kinetic model that describes cloud formation in ultra-cool atmospheres (seed formation, growth/evaporation, gravitational settling, convective mixing, element depletion). Results: We present a small grid of self-consistently calculated atmosphere models for Teff = 2000-3000 K with solar initial abundances and log (g) = 4.5. Cloud formation in stellar and sub-stellar atmospheres appears for Teff < 2700 K and has a significant effect on the structure and the spectrum of the atmosphere for Teff < 2400 K. We have compared the synthetic spectra of our models with observed spectra and found that they fit the spectra of mid- to late-type M-dwarfs and early-type L-dwarfs well. The geometrical extension of the atmospheres (at τ = 1) changes with wavelength resulting in a flux variation of 10%. This translates into a change in geometrical extension of the atmosphere of about 50 km, which is the quantitative basis for exoplanetary transit spectroscopy. We also test DRIFT-MARCS for an example exoplanet and demonstrate that our simulations reproduce the Spitzer observations for WASP-19b rather well for Teff = 2600 K, log (g) = 3.2 and solar abundances. Our model points at an exoplanet with a deep cloud-free atmosphere with a substantial day-night energy transport and no temperature inversion.

Enhancing memory self-efficacy during menopause through a group memory strategies program.

PubMed

Unkenstein, Anne E; Bei, Bei; Bryant, Christina A

2017-05-01

Anxiety about memory during menopause can affect quality of life. We aimed to improve memory self-efficacy during menopause using a group memory strategies program. The program was run five times for a total of 32 peri- and postmenopausal women, age between 47 and 60 years, recruited from hospital menopause and gynecology clinics. The 4-week intervention consisted of weekly 2-hour sessions, and covered how memory works, memory changes related to ageing, health and lifestyle factors, and specific memory strategies. Memory contentment (CT), reported frequency of forgetting (FF), use of memory strategies, psychological distress, and attitude toward menopause were measured. A double-baseline design was applied, with outcomes measured on two baseline occasions (1-month prior [T1] and in the first session [T2]), immediately postintervention (T3), and 3-month postintervention (T4). To describe changes in each variable between time points paired sample t tests were conducted. Mixed-effects models comparing the means of random slopes from T2 to T3 with those from T1 to T2 were conducted for each variable to test for treatment effects. Examination of the naturalistic changes in outcome measures from T1 to T2 revealed no significant changes (all Ps > 0.05). CT, reported FF, and use of memory strategies improved significantly more from T2 to T3, than from T1 to T2 (all Ps < 0.05). Neither attitude toward menopause nor psychological distress improved significantly more postintervention than during the double-baseline (all Ps > 0.05). Improvements in reported CT and FF were maintained after 3 months. The use of group interventions to improve memory self-efficacy during menopause warrants continued evaluation.

Esomeprazole treatment of frequent heartburn: two randomized, double-blind, placebo-controlled trials.

PubMed

Peura, David A; Traxler, Barry; Kocun, Christopher; Lind, Tore

2014-07-01

To determine the efficacy of a 14-day regimen of esomeprazole 20 mg for the treatment of frequent heartburn in subjects who are likely to self-treat with over-the-counter medications without consulting a health care provider. Adults with frequent heartburn ≥ 2 days per week in the past 4 weeks were randomly assigned to 14-day double-blind treatment with esomeprazole 20 mg once daily or placebo in 2 identical multicenter studies (ClinicalTrials.gov identifiers: NCT01370525, NCT01370538). The primary efficacy outcome was percentage of heartburn-free 24-hour days across 14 days. Secondary efficacy outcomes included heartburn resolution, defined as heartburn ≤ 2 days over 14 days, and percentages of subjects reporting ≤ 1 day with heartburn in the first and final weeks of treatment. Subjects recorded data in daily self-assessment diaries. The percentage of heartburn-free 24-hour days over 14 days was significantly higher (P < 0.0001) in subjects receiving esomeprazole 20 mg compared with placebo in study 1 (N = 331; 46.13% vs. 33.07%, respectively) and study 2 (N = 320; 48.00% vs 32.75%, respectively). Significantly more subjects treated with esomeprazole 20 mg had heartburn resolution over 14 days and in the first and final weeks compared with placebo. Within the first 4 days, the proportion of subjects with heartburn-free days was significantly greater with esomeprazole 20 mg versus placebo. Treatment was generally well tolerated, with a safety pattern consistent with the known profile for esomeprazole. A 14-day regimen of esomeprazole 20 mg once daily was effective for treating frequent heartburn in subjects who are likely to self-treat with over-the-counter medications.

Liquid crystal organization of self-assembling cyclic peptides.

PubMed

Amorín, Manuel; Pérez, Ana; Barberá, Joaquín; Ozores, Haxel Lionel; Serrano, José Luis; Granja, Juan R; Sierra, Teresa

2014-01-21

Self-assembling cyclic peptides decorated with mesogens form porous columnar mesophases in which, depending on the number of hydrocarbon chains, double or single channels are formed along each column.

Testing variations of the GW approximation on strongly correlated transition metal oxides: hematite (α-Fe2O3) as a benchmark.

PubMed

Liao, Peilin; Carter, Emily A

2011-09-07

Quantitative characterization of low-lying excited electronic states in materials is critical for the development of solar energy conversion materials. The many-body Green's function method known as the GW approximation (GWA) directly probes states corresponding to photoemission and inverse photoemission experiments, thereby determining the associated band structure. Several versions of the GW approximation with different levels of self-consistency exist in the field. While the GWA based on density functional theory (DFT) works well for conventional semiconductors, less is known about its reliability for strongly correlated semiconducting materials. Here we present a systematic study of the GWA using hematite (α-Fe(2)O(3)) as the benchmark material. We analyze its performance in terms of the calculated photoemission/inverse photoemission band gaps, densities of states, and dielectric functions. Overall, a non-self-consistent G(0)W(0) using input from DFT+U theory produces physical observables in best agreement with experiments. This journal is © the Owner Societies 2011

Does self-regulation capacity predict psychological well-being in physicians?

PubMed

Simon, Christopher R; Durand-Bush, Natalie

2015-01-01

Despite increasing research on physician well-being, factors appearing to account for individual variation in levels of optimal functioning are largely unclear. One such factor could be self-regulation, which reflects how individuals effectively manage their thoughts, emotions and behaviours, and cope with adversity in their environment. The purpose of this study was to determine if self-regulation capacity could significantly predict psychological well-being in a sample of Canadian physicians. A total of 132 physicians completed the Scales of Psychological Well-Being and the short form of the Self-Regulation Questionnaire. Regression analyses confirmed the hypothesis that a significant amount of variance in levels of psychological well-being would be explained by self-regulation capacity. There was a particularly strong relationship between self-regulation capacity and the dimensions of purpose in life and environmental mastery, which suggests that physicians who effectively self-manage may be better able to preserve a sense of purpose and an adequate work-life balance in their daily life. Physicians today face consistently growing demands stemming from increasingly challenging work environments. Results of this study mark an important step in increasing our understanding of a potentially valuable skill that may help physicians to achieve well-being.

Self-regulation, motivation, and math achievement in middle school: variations across grade level and math context.

PubMed

Cleary, Timothy J; Chen, Peggy P

2009-10-01

The current study examined grade level, achievement group, and math-course-type differences in student self-regulation and motivation in a sample of 880 suburban middle-school students. Analysis of variance was utilized to assess group differences in student self-regulation and motivation, and linear regression analysis was used to identify variables that best predicted students' use of regulatory strategies. A key finding was that although seventh graders exhibited a more maladaptive self-regulation and motivation profile than sixth graders, achievement groups in seventh grade (high, moderate, low) were more clearly differentiated across both self-regulation and motivation than achievement groups in sixth grade. The pattern of achievement group differences also varied across math course type, as self-regulation and motivation processes more consistently differentiated achievement groups in advanced classes than regular math courses. Finally, task interest was shown to be the primary motivational predictor of students' use of regulatory strategies during math learning. The study highlights the importance of identifying shifting student motivation and self-regulation during the early middle school years and the potential role that context may have on these processes.

Current and maintained health-enhancing physical activity in rheumatoid arthritis: a cross-sectional study.

PubMed

Demmelmaier, Ingrid; Bergman, Patrick; Nordgren, Birgitta; Jensen, Irene; Opava, Christina H

2013-07-01

To describe and identify the explanatory factors of variation in current and maintained health-enhancing physical activity (HEPA) in persons with rheumatoid arthritis (RA). In this cross-sectional study, current HEPA was assessed with the International Physical Activity Questionnaire and maintained HEPA with the Exercise Stage Assessment Instrument, the latter explicitly focusing on both aerobic physical activity and muscle strength training. Sociodemographic, disease-related, and psychosocial data were retrieved from the Swedish Rheumatology Quality (SRQ) registers and a postal questionnaire. The explained variations in the respective HEPA behaviors were analyzed with logistic regression. In all, 3,152 (58.5%) of 5,391 persons identified as eligible from the SRQ registers responded to the questionnaire. Current HEPA was reported by 69%, and maintained HEPA by 11% of the respondents. The most salient and consistent factors explaining variation in both current and maintained HEPA were self-efficacy, social support, and outcome expectations related to physical activity. To our knowledge, this is the first study exploring maintained physical activity in a large well-defined sample of persons with RA. Our results indicate that a minority perform maintained HEPA, including both aerobic physical activity and muscle strength training, and that psychosocial factors are the most salient and consistent in the explanation of HEPA variation. Copyright © 2013 by the American College of Rheumatology.

Predictors of adherence to a brief behavioral insomnia intervention: daily process analysis.

PubMed

Ruiter Petrov, Megan E; Lichstein, Kenneth L; Huisingh, Carrie E; Bradley, Laurence A

2014-05-01

Behavioral interventions for insomnia are effective in improving sleep, yet adherence is variable, and predictors of adherence have not been consistently replicated. The relationships between daily variations in state factors at the initiation of treatment and adherence have not been investigated. Using 2-week, self-report online logs, this study determined, among 53 college students with probable insomnia, the associations of pretreatment factors and daily factors during treatment on daily variations in adherence to one session of behavioral treatments for insomnia. These treatments included stimulus control therapy (SCT), sleep restriction therapy (SRT), and sleep hygiene (SH). Low self-efficacy was associated with poorer SCT and SH adherence. Participants with a "bed partner or pet" at least some of the time had better SCT adherence. Greater total sleep time and poorer sleep quality were associated with poor SCT and SRT adherence the following night. Greater sleep efficiency was related to greater next night SCT and SRT adherence. Alcohol consumption was related to poorer SRT and SH adherence the following night. Future studies should test the replicability of these findings. Adherence trials may want to test whether discouraging alcohol intake, enhancing treatment-related self-efficacy, and monitoring and providing feedback on sleep, early in treatment, affects adherence. Copyright © 2014. Published by Elsevier Ltd.

A non-conventional discontinuous Lagrangian for viscous flow

PubMed Central

Marner, F.

2017-01-01

Drawing an analogy with quantum mechanics, a new Lagrangian is proposed for a variational formulation of the Navier–Stokes equations which to-date has remained elusive. A key feature is that the resulting Lagrangian is discontinuous in nature, posing additional challenges apropos the mathematical treatment of the related variational problem, all of which are resolvable. In addition to extending Lagrange's formalism to problems involving discontinuous behaviour, it is demonstrated that the associated equations of motion can self-consistently be interpreted within the framework of thermodynamics beyond local equilibrium, with the limiting case recovering the classical Navier–Stokes equations. Perspectives for applying the new formalism to discontinuous physical phenomena such as phase and grain boundaries, shock waves and flame fronts are provided. PMID:28386415

Point spread function and depth-invariant focal sweep point spread function for plenoptic camera 2.0.

PubMed

Jin, Xin; Liu, Li; Chen, Yanqin; Dai, Qionghai

2017-05-01

This paper derives a mathematical point spread function (PSF) and a depth-invariant focal sweep point spread function (FSPSF) for plenoptic camera 2.0. Derivation of PSF is based on the Fresnel diffraction equation and image formation analysis of a self-built imaging system which is divided into two sub-systems to reflect the relay imaging properties of plenoptic camera 2.0. The variations in PSF, which are caused by changes of object's depth and sensor position variation, are analyzed. A mathematical model of FSPSF is further derived, which is verified to be depth-invariant. Experiments on the real imaging systems demonstrate the consistency between the proposed PSF and the actual imaging results.

A non-conventional discontinuous Lagrangian for viscous flow.

PubMed

Scholle, M; Marner, F

2017-02-01

Drawing an analogy with quantum mechanics, a new Lagrangian is proposed for a variational formulation of the Navier-Stokes equations which to-date has remained elusive. A key feature is that the resulting Lagrangian is discontinuous in nature, posing additional challenges apropos the mathematical treatment of the related variational problem, all of which are resolvable. In addition to extending Lagrange's formalism to problems involving discontinuous behaviour, it is demonstrated that the associated equations of motion can self-consistently be interpreted within the framework of thermodynamics beyond local equilibrium, with the limiting case recovering the classical Navier-Stokes equations. Perspectives for applying the new formalism to discontinuous physical phenomena such as phase and grain boundaries, shock waves and flame fronts are provided.

Around the world, adolescence is a time of heightened sensation seeking and immature self-regulation.

PubMed

Steinberg, Laurence; Icenogle, Grace; Shulman, Elizabeth P; Breiner, Kaitlyn; Chein, Jason; Bacchini, Dario; Chang, Lei; Chaudhary, Nandita; Giunta, Laura Di; Dodge, Kenneth A; Fanti, Kostas A; Lansford, Jennifer E; Malone, Patrick S; Oburu, Paul; Pastorelli, Concetta; Skinner, Ann T; Sorbring, Emma; Tapanya, Sombat; Tirado, Liliana Maria Uribe; Alampay, Liane Peña; Al-Hassan, Suha M; Takash, Hanan M S

2018-03-01

The dual systems model of adolescent risk-taking portrays the period as one characterized by a combination of heightened sensation seeking and still-maturing self-regulation, but most tests of this model have been conducted in the United States or Western Europe. In the present study, these propositions are tested in an international sample of more than 5000 individuals between ages 10 and 30 years from 11 countries in Africa, Asia, Europe and the Americas, using a multi-method test battery that includes both self-report and performance-based measures of both constructs. Consistent with the dual systems model, sensation seeking increased between preadolescence and late adolescence, peaked at age 19, and declined thereafter, whereas self-regulation increased steadily from preadolescence into young adulthood, reaching a plateau between ages 23 and 26. Although there were some variations in the magnitude of the observed age trends, the developmental patterns were largely similar across countries. © 2017 John Wiley & Sons Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaporozhets, Irina A.; Ivanov, Vladimir V.; Lyakh, Dmitry I.

The earlier proposed multi-reference state-specific coupled-cluster theory with the complete active space reference suffered from a problem of energy discontinuities when the formal reference state was changing in the calculation of the potential energy curve (PEC). A simple remedy to the discontinuity problem is found and is presented in this work. It involves using natural complete active space self-consistent field active orbitals in the complete active space coupled-cluster calculations. As a result, the approach gives smooth PECs for different types of dissociation problems, as illustrated in the calculations of the dissociation of the single bond in the hydrogen fluorine moleculemore » and of the symmetric double-bond dissociation in the water molecule.« less

Magnetoresistance in organic semiconductors: Including pair correlations in the kinetic equations for hopping transport

NASA Astrophysics Data System (ADS)

Shumilin, A. V.; Kabanov, V. V.; Dediu, V. I.

2018-03-01

We derive kinetic equations for polaron hopping in organic materials that explicitly take into account the double occupation possibility and pair intersite correlations. The equations include simplified phenomenological spin dynamics and provide a self-consistent framework for the description of the bipolaron mechanism of the organic magnetoresistance. At low applied voltages, the equations can be reduced to those for an effective resistor network that generalizes the Miller-Abrahams network and includes the effect of spin relaxation on the system resistivity. Our theory discloses the close relationship between the organic magnetoresistance and the intersite correlations. Moreover, in the absence of correlations, as in an ordered system with zero Hubbard energy, the magnetoresistance vanishes.

Role of phase breaking processes on resonant spin transfer torque nano-oscillators

NASA Astrophysics Data System (ADS)

Sharma, Abhishek; Tulapurkar, Ashwin A.; Muralidharan, Bhaskaran

2018-05-01

Spin transfer torque nano-oscillators (STNOs) based on magnetoresistance and spin transfer torque effects find potential applications in miniaturized wireless communication devices. Using the non-coherent non-equilibrium Green's function spin transport formalism self-consistently coupled with the stochastic Landau-Lifshitz-Gilbert-Slonczewski's equation and the Poisson's equation, we elucidate the role of elastic phase breaking on the proposed STNO design featuring double barrier resonant tunneling. Demonstrating the immunity of our proposed design, we predict that despite the presence of elastic dephasing, the resonant tunneling magnetic tunnel junction structures facilitate oscillator designs featuring a large enhancement in microwave power up to 8μW delivered to a 50Ω load.

Theoretical study of the dipole moments of selected alkaline-earth halides

NASA Technical Reports Server (NTRS)

Langhoff, S. R.; Bauschlicher, C. W., Jr.; Partridge, H.; Ahlrichs, R.

1986-01-01

Ab initio calculations at the self-consistent-field (SCF), singles-plus-doubles configuration-interaction (SDCI), and coupled-pair functional (CPF) level, are reported for the dipole moments and dipole derivatives of the X2Sigma(+) ground states of BeF, BeCl, MgF, MgCl, CaF, CaCl, and SrF. For comparison, analogous calculations are performed for the X1Sigma(+) state of KCl. The CPF results are found to be in remarkably better agreement with experiment than are the SCF and SDCI results. Apparently higher excitations are required to properly describe the radial extent along the bond axis of the remaining valence electron on the alkaline-earth metal.

Theoretical analysis of the transition-state spectrum of the cyclooctatetraene unimolecular reaction: Three degree-of-freedom model calculations

NASA Astrophysics Data System (ADS)

Yoshida, Takahiko; Tokizaki, Chihiro; Takayanagi, Toshiyuki

2015-08-01

A three degree-of-freedom potential energy surface of the cyclooctatetraene (COT) unimolecular reaction that can describe both ring-inversion (D2d ↔ D2d) and double bond-alternation (D4h ↔ D4h) processes was constructed using complete active space self-consistent field calculations. The potential energy surface was used to simulate the experimentally measured transition-state spectrum by calculating the photodetachment spectrum of the COT anion with time-dependent wave packet formalism. The calculated spectrum reproduces the experimental result well. We also analyzed wavefunction properties at spectral peak positions to understand the COT unimolecular reaction dynamics.

UMTS base station-like exposure, well-being, and cognitive performance.

PubMed

Regel, Sabine J; Negovetic, Sonja; Röösli, Martin; Berdiñas, Veronica; Schuderer, Jürgen; Huss, Anke; Lott, Urs; Kuster, Niels; Achermann, Peter

2006-08-01

Radio-frequency electromagnetic fields (RF EMF) of mobile communication systems are widespread in the living environment, yet their effects on humans are uncertain despite a growing body of literature. We investigated the influence of a Universal Mobile Telecommunications System (UMTS) base station-like signal on well-being and cognitive performance in subjects with and without self-reported sensitivity to RF EMF. We performed a controlled exposure experiment (45 min at an electric field strength of 0, 1, or 10 V/m, incident with a polarization of 45 degrees from the left back side of the subject, weekly intervals) in a randomized, double-blind crossover design. A total of 117 healthy subjects (33 self-reported sensitive, 84 nonsensitive subjects) participated in the study. We assessed well-being, perceived field strength, and cognitive performance with questionnaires and cognitive tasks and conducted statistical analyses using linear mixed models. Organ-specific and brain tissue-specific dosimetry including uncertainty and variation analysis was performed. In both groups, well-being and perceived field strength were not associated with actual exposure levels. We observed no consistent condition-induced changes in cognitive performance except for two marginal effects. At 10 V/m we observed a slight effect on speed in one of six tasks in the sensitive subjects and an effect on accuracy in another task in nonsensitive subjects. Both effects disappeared after multiple end point adjustment. In contrast to a recent Dutch study, we could not confirm a short-term effect of UMTS base station-like exposure on well-being. The reported effects on brain functioning were marginal and may have occurred by chance. Peak spatial absorption in brain tissue was considerably smaller than during use of a mobile phone. No conclusions can be drawn regarding short-term effects of cell phone exposure or the effects of long-term base station-like exposure on human health.

UMTS Base Station-like Exposure, Well-Being, and Cognitive Performance

PubMed Central

Regel, Sabine J.; Negovetic, Sonja; Röösli, Martin; Berdiñas, Veronica; Schuderer, Jürgen; Huss, Anke; Lott, Urs; Kuster, Niels; Achermann, Peter

2006-01-01

Background Radio-frequency electromagnetic fields (RF EMF) of mobile communication systems are widespread in the living environment, yet their effects on humans are uncertain despite a growing body of literature. Objectives We investigated the influence of a Universal Mobile Telecommunications System (UMTS) base station-like signal on well-being and cognitive performance in subjects with and without self-reported sensitivity to RF EMF. Methods We performed a controlled exposure experiment (45 min at an electric field strength of 0, 1, or 10 V/m, incident with a polarization of 45° from the left back side of the subject, weekly intervals) in a randomized, double-blind crossover design. A total of 117 healthy subjects (33 self-reported sensitive, 84 nonsensitive subjects) participated in the study. We assessed well-being, perceived field strength, and cognitive performance with questionnaires and cognitive tasks and conducted statistical analyses using linear mixed models. Organ-specific and brain tissue–specific dosimetry including uncertainty and variation analysis was performed. Results In both groups, well-being and perceived field strength were not associated with actual exposure levels. We observed no consistent condition-induced changes in cognitive performance except for two marginal effects. At 10 V/m we observed a slight effect on speed in one of six tasks in the sensitive subjects and an effect on accuracy in another task in nonsensitive subjects. Both effects disappeared after multiple end point adjustment. Conclusions In contrast to a recent Dutch study, we could not confirm a short-term effect of UMTS base station-like exposure on well-being. The reported effects on brain functioning were marginal and may have occurred by chance. Peak spatial absorption in brain tissue was considerably smaller than during use of a mobile phone. No conclusions can be drawn regarding short-term effects of cell phone exposure or the effects of long-term base station-like exposure on human health. PMID:16882538

Awareness is relative: dissociation as the organisation of meaning.

PubMed

Lesley, Joan

2006-09-01

This essay discusses how the organisation of mental material within the cognitive system can influence consciousness and awareness, and presents a theory of dissociation based on the premise that awareness is relative, contingent on the activated representation of the ongoing event being linked to the activated self-representation. It allows four possible variations of integration: (i) non-integrated experience--perceptions about an object/event are either not perceived or they remain at the sensory level: traditional dissociative states, amnesia, depersonalisation etc; (ii) variably integrated experience--activation of information of a specific valence about an object blocks activation of information of contrasting valence: splitting; (iii) alternatively integrated experience--experience is integrated into a specific, limited active self-representation: fugue and multiple identity states; (iv) dis-integrated experience-the ongoing experience of innate drives and needs is no longer consistently activated in the core self-representation: repression and isolation.

Accuracy enhanced distance measurement system using double-sideband modulated frequency scanning interferometry

NASA Astrophysics Data System (ADS)

Chen, Xilun; Wang, Xiangchuan; Pan, Shilong

2017-03-01

An implementation of a distance measurement system using double-sideband with suppressed carrier modulation (DSB-SC) frequency scanning interferometry is proposed to reduce the variations in the optical path and improve the measurement accuracy. In this proposed system, the electro-optic DSB-SC is used to create dual-swept signals with opposite scanning directions. For each swept signal, the relative distance between the reference arm and the measuring arm is determined by the beat frequency of signals from two arms. By multiplying both beat signals, measurement errors caused by variations in the optical path can be greatly reduced. As an experimental demonstration, a vibration was introduced in the optical path length. The experimental results show that the variations can be suppressed for over 19.9 dB.

Development of a Double-Gauss Lens Based Setup for Optoacoustic Applications

PubMed Central

Choi, Hojong; Ryu, Jae-Myung; Yeom, Jung-Yeol

2017-01-01

In optoacoustic (photoacoustic) systems, different echo signal intensities such as amplitudes, center frequencies, and bandwidths need to be compensated by utilizing variable gain or time-gain compensation amplifiers. However, such electronic components can increase system complexities and signal noise levels. In this paper, we introduce a double-Gauss lens to generate a large field of view with uniform light intensity due to the low chromatic aberrations of the lens, thus obtaining uniform echo signal intensities across the field of view of the optoacoustic system. In order to validate the uniformity of the echo signal intensities in the system, an in-house transducer was placed at various positions above a tissue sample and echo signals were measured and compared with each other. The custom designed double-Gauss lens demonstrated negligible light intensity variation (±1.5%) across the illumination field of view (~2 cm diameter). When the transducer was used to measure echo signal from an eye of a bigeye tuna within a range of ±1 cm, the peak-to-peak amplitude, center frequency, and their −6 dB bandwidth variations were less than 2 mV, 1 MHz, and 6%, respectively. The custom designed double-Gauss lens can provide uniform light beam across a wide area while generating insignificant echo signal variations, and thus can lower the burden of the receiving electronics or signal processing in the optoacoustic system. PMID:28273794

Reduced pollinator service and elevated pollen limitation at the geographic range limit of an annual plant.

PubMed

Moeller, David A; Geber, Monica A; Eckhart, Vincent M; Tiffin, Peter

2012-05-01

Mutualisms are well known to influence individual fitness and the population dynamics of partner species, but little is known about whether they influence species distributions and the location of geographic range limits. Here, we examine the contribution of plant-pollinator interactions to the geographic range limit of the California endemic plant Clarkia xantiana ssp. xantiana. We show that pollinator availability declined from the center to the margin of the geographic range consistently across four years of study. This decline in pollinator availability was caused to a greater extent by variation in the abundance of generalist rather than specialist bee pollinators. Climate data suggest that patterns of precipitation in the current and previous year drove variation in bee abundance because of its effects on cues for bee emergence in the current year and the abundance of floral resources in the previous year. Experimental floral manipulations showed that marginal populations had greater outcross pollen limitation of reproduction, in parallel with the decline in pollinator abundance. Although plants are self-compatible, we found no evidence that autonomous selfing contributes to reproduction, and thus no evidence that it alleviates outcross pollen limitation in marginal populations. Furthermore, we found no association between the distance to the range edge and selfing rate, as estimated from sequence and microsatellite variation, indicating that the mating system has not evolved in response to the pollination environment at the range periphery. Overall, our results suggest that dependence on pollinators for reproduction may be an important constraint limiting range expansion in this system.

Heritability and Fitness Correlates of Personality in the Ache, a Natural-Fertility Population in Paraguay

PubMed Central

Bailey, Drew H.; Walker, Robert S.; Blomquist, Gregory E.; Hill, Kim R.; Hurtado, A. Magdalena; Geary, David C.

2013-01-01

The current study assessed the heritability of personality in a traditional natural-fertility population, the Ache of eastern Paraguay. Self-reports (n = 110) and other-reports (n = 66) on the commonly used Big Five Personality Inventory (i.e., extraversion, agreeableness, conscientiousness, neuroticism, openness) were collected. Self-reports did not support the Five Factor Model developed with Western samples, and did not correlate with other-reports for three of the five measured personality factors. Heritability was assessed using factors that were consistent across self- and other-reports and factors assessed using other-reports that showed reliabilities similar to those found in Western samples. Analyses of these items in combination with a multi-generation pedigree (n = 2,132) revealed heritability estimates similar to those found in most Western samples, although we were not able to separately estimate the influence of the common environment on these traits. We also assessed relations between personality and reproductive success (RS), allowing for a test of several mechanisms that might be maintaining heritable variation in personality. Phenotypic analyses, based largely on other-reports, revealed that extraverted men had higher RS than other men, but no other dimensions of personality predicted RS in either sex. Mothers with more agreeable children had more children, and parents mated assortatively on personality. Of the evolutionary processes proposed to maintain variation in personality, assortative mating, selective neutrality, and temporal variation in selection pressures received the most support. However, the current study does not rule out other processes affecting the evolution and maintenance of individual differences in human personality. PMID:23527163

Acoustic wave-driven oxidized liquid metal-based energy harvester

NASA Astrophysics Data System (ADS)

Jeon, Jinpyo; Chung, Sang Kug; Lee, Jeong-Bong; Doo, Seok Joo; Kim, Daeyoung

2018-06-01

We report an oxidized liquid metal droplet-based energy harvester that converts acoustic energy into electrical energy by modulating an electrical double layer that originates from the deformation of the oxidized liquid metal droplet. Gallium-based liquid metal alloy has been developed for various applications owing to the outstanding material properties, such as its high electrical conductivity (metallic property) and unlimited deformability (liquid property). In this study, we demonstrated energy harvesting using an electrical double layer between the acoustic wave-modulated liquid metal droplet and two electrodes. The proposed energy harvester consisted of top and bottom electrodes covered with the dielectric layer and a Gallium-based liquid metal droplet placed between the electrodes. When we applied an external bias voltage and acoustic wave to the proposed device, the contact area between the liquid metal droplet and the electrodes changed, leading to the variation of the capacitance in the electrical double layer and the generation of electrical output current. Using the proposed energy harvester, the maximum output current of 41.2 nA was generated with an applied acoustic wave of 30 Hz. In addition, we studied the relationships between the maximum output current and a variety of factors, such as the size of the liquid metal droplet, the thickness of the hydrophobic layer, and the distance between the top and bottom electrode plates.

Double-observer approach to estimating egg mass abundance of vernal pool breeding amphibians

USGS Publications Warehouse

Grant, E.H.C.; Jung, R.E.; Nichols, J.D.; Hines, J.E.

2005-01-01

Interest in seasonally flooded pools, and the status of associated amphibian populations, has initiated programs in the northeastern United States to document and monitor these habitats. Counting egg masses is an effective way to determine the population size of pool-breeding amphibians, such as wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum). However, bias is associated with counts if egg masses are missed. Counts unadjusted for the proportion missed (i.e., without adjustment for detection probability) could lead to false assessments of population trends. We used a dependent double-observer method in 2002-2003 to estimate numbers of wood frog and spotted salamander egg masses at seasonal forest pools in 13 National Wildlife Refuges, 1 National Park, 1 National Seashore, and 1 State Park in the northeastern United States. We calculated detection probabilities for egg masses and examined whether detection probabilities varied by species, observers, pools, and in relation to pool characteristics (pool area, pool maximum depth, within-pool vegetation). For the 2 years, model selection indicated that no consistent set of variables explained the variation in data sets from individual Refuges and Parks. Because our results indicated that egg mass detection probabilities vary spatially and temporally, we conclude that it is essential to use estimation procedures, such as double-observer methods with egg mass surveys, to determine population sizes and trends of these species.

Current status of the Double Chooz experiment

NASA Astrophysics Data System (ADS)

Haser, J.; Double Chooz Collaboration

2016-04-01

The Double Chooz reactor antineutrino experiment aims for a precision measurement of the neutrino mixing angle θ13. Located at the Chooz nuclear power plant in France, it observes an energy dependent deficit in the electron antineutrino spectrum, currently with one detector filled with gadolinium-loaded liquid scintillator at a baseline of 1.05 km. The Double Chooz analysis utilizes different approaches to extract θ13: A combined rate and spectral shape fit as well as a background-model-independent analysis based on reactor power variations are performed, giving consistent results. Among the recent reactor-based oscillation experiments with comparable baseline it was the only one to observe reactor shutdown phases, during which all reactors are turned off. These enabled to measure the backgrounds solely, allowing to crosscheck the background models used in the oscillation analysis. At present an improved analysis was put forward with twice as much data statistics collected compared to the last publication. Revised selection criteria and background studies enhance the signal to background ratio while a decrease in the corresponding uncertainties is achieved. Along with an improved energy calibration the overall systematic uncertainty on θ13 is reduced, preparing for a two detector analysis. The new analysis obtains from 467.90 live days with 66.5 GW-ton-years of exposure (reactor power × detector mass × live time) a value of sin2 ⁡ 2θ13 =0.090-0.029+0.032(stat + syst).

Self-Reacting Friction Stir Welding for Aluminum Alloy Circumferential Weld Applications

NASA Technical Reports Server (NTRS)

Bjorkman, Gerry; Cantrell, Mark; Carter, Robert

2003-01-01

Friction stir welding is an innovative weld process that continues to grow in use, in the commercial, defense, and space sectors. It produces high quality and high strength welds in aluminum alloys. The process consists of a rotating weld pin tool that plasticizes material through friction. The plasticized material is welded by applying a high weld forge force through the weld pin tool against the material during pin tool rotation. The high weld forge force is reacted against an anvil and a stout tool structure. A variation of friction stir welding currently being evaluated is self-reacting friction stir welding. Self-reacting friction stir welding incorporates two opposing shoulders on the crown and root sides of the weld joint. In self-reacting friction stir welding, the weld forge force is reacted against the crown shoulder portion of the weld pin tool by the root shoulder. This eliminates the need for a stout tooling structure to react the high weld forge force required in the typical friction stir weld process. Therefore, the self-reacting feature reduces tooling requirements and, therefore, process implementation costs. This makes the process attractive for aluminum alloy circumferential weld applications. To evaluate the application of self-reacting friction stir welding for aluminum alloy circumferential welding, a feasibility study was performed. The study consisted of performing a fourteen-foot diameter aluminum alloy circumferential demonstration weld using typical fusion weld tooling. To accomplish the demonstration weld, weld and tack weld development were performed and fourteen-foot diameter rings were fabricated. Weld development consisted of weld pin tool selection and the generation of a process map and envelope. Tack weld development evaluated gas tungsten arc welding and friction stir welding for tack welding rings together for circumferential welding. As a result of the study, a successful circumferential demonstration weld was produced leading the way for future circumferential weld implementation.

Adapting Poisson-Boltzmann to the self-consistent mean field theory: Application to protein side-chain modeling

NASA Astrophysics Data System (ADS)

Koehl, Patrice; Orland, Henri; Delarue, Marc

2011-08-01

We present an extension of the self-consistent mean field theory for protein side-chain modeling in which solvation effects are included based on the Poisson-Boltzmann (PB) theory. In this approach, the protein is represented with multiple copies of its side chains. Each copy is assigned a weight that is refined iteratively based on the mean field energy generated by the rest of the protein, until self-consistency is reached. At each cycle, the variational free energy of the multi-copy system is computed; this free energy includes the internal energy of the protein that accounts for vdW and electrostatics interactions and a solvation free energy term that is computed using the PB equation. The method converges in only a few cycles and takes only minutes of central processing unit time on a commodity personal computer. The predicted conformation of each residue is then set to be its copy with the highest weight after convergence. We have tested this method on a database of hundred highly refined NMR structures to circumvent the problems of crystal packing inherent to x-ray structures. The use of the PB-derived solvation free energy significantly improves prediction accuracy for surface side chains. For example, the prediction accuracies for χ1 for surface cysteine, serine, and threonine residues improve from 68%, 35%, and 43% to 80%, 53%, and 57%, respectively. A comparison with other side-chain prediction algorithms demonstrates that our approach is consistently better in predicting the conformations of exposed side chains.

Self-Propelled Micromotors for Cleaning Polluted Water

PubMed Central

2013-01-01

We describe the use of catalytically self-propelled microjets (dubbed micromotors) for degrading organic pollutants in water via the Fenton oxidation process. The tubular micromotors are composed of rolled-up functional nanomembranes consisting of Fe/Pt bilayers. The micromotors contain double functionality within their architecture, i.e., the inner Pt for the self-propulsion and the outer Fe for the in situ generation of ferrous ions boosting the remediation of contaminated water.The degradation of organic pollutants takes place in the presence of hydrogen peroxide, which acts as a reagent for the Fenton reaction and as main fuel to propel the micromotors. Factors influencing the efficiency of the Fenton oxidation process, including thickness of the Fe layer, pH, and concentration of hydrogen peroxide, are investigated. The ability of these catalytically self-propelled micromotors to improve intermixing in liquids results in the removal of organic pollutants ca. 12 times faster than when the Fenton oxidation process is carried out without catalytically active micromotors. The enhanced reaction–diffusion provided by micromotors has been theoretically modeled. The synergy between the internal and external functionalities of the micromotors, without the need of further functionalization, results into an enhanced degradation of nonbiodegradable and dangerous organic pollutants at small-scale environments and holds considerable promise for the remediation of contaminated water. PMID:24180623

Active Glutaminase C Self-assembles into a Supratetrameric Oligomer That Can Be Disrupted by an Allosteric Inhibitor*

PubMed Central

Ferreira, Amanda Petrina Scotá; Cassago, Alexandre; Gonçalves, Kaliandra de Almeida; Dias, Marília Meira; Adamoski, Douglas; Ascenção, Carolline Fernanda Rodrigues; Honorato, Rodrigo Vargas; de Oliveira, Juliana Ferreira; Ferreira, Igor Monteze; Fornezari, Camila; Bettini, Jefferson; Oliveira, Paulo Sérgio Lopes; Paes Leme, Adriana Franco; Portugal, Rodrigo Villares; Ambrosio, Andre Luis Berteli; Dias, Sandra Martha Gomes

2013-01-01

The phosphate-dependent transition between enzymatically inert dimers into catalytically capable tetramers has long been the accepted mechanism for the glutaminase activation. Here, we demonstrate that activated glutaminase C (GAC) self-assembles into a helical, fiber-like double-stranded oligomer and propose a molecular model consisting of seven tetramer copies per turn per strand interacting via the N-terminal domains. The loop 321LRFNKL326 is projected as the major regulating element for self-assembly and enzyme activation. Furthermore, the previously identified in vivo lysine acetylation (Lys311 in humans, Lys316 in mouse) is here proposed as an important down-regulator of superoligomer assembly and protein activation. Bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide, a known glutaminase inhibitor, completely disrupted the higher order oligomer, explaining its allosteric mechanism of inhibition via tetramer stabilization. A direct correlation between the tendency to self-assemble and the activity levels of the three mammalian glutaminase isozymes was established, with GAC being the most active enzyme while forming the longest structures. Lastly, the ectopic expression of a fiber-prone superactive GAC mutant in MDA-MB 231 cancer cells provided considerable proliferative advantages to transformed cells. These findings yield unique implications for the development of GAC-oriented therapeutics targeting tumor metabolism. PMID:23935106

Self locking drive system for rotating plug of a nuclear reactor

DOEpatents

Brubaker, James E.

1979-01-01

This disclosure describes a self locking drive system for rotating the plugs on the head of a nuclear reactor which is able to restrain plug motion if a seismic event should occur during reactor refueling. A servomotor is engaged via a gear train and a bull gear to the plug. Connected to the gear train is a feedback control system which allows the motor to rotate the plug to predetermined locations for refueling of the reactor. The gear train contains a self locking double enveloping worm gear set. The worm gear set is utilized for its self locking nature to prevent unwanted rotation of the plugs as the result of an earthquake. The double enveloping type is used because its unique contour spreads the load across several teeth providing added strength and allowing the use of a conventional size worm.

Uncertainties in radon related to house-specific factors and proximity to geological boundaries in England.

PubMed

Hunter, Nezahat; Muirhead, Colin R; Miles, Jon C H; Appleton, J Donald

2009-08-01

Data collected as a part of a survey on radon concentrations from about 40 000 dwellings in England for six contrasting geological units were analysed to evaluate the impact of house-specific factors (building characteristics and construction dates) and of proximity to geological boundaries. After adjusting for temperature and outdoor radon, geological unit, house type, double glazing and date of building were found to have a statistically significant influence on indoor radon concentrations and explained about 29 % of the total variation between dwellings in logarithmically transformed radon values. In addition, there were statistically significant differences in radon concentrations according to proximity to geological boundaries categories for most of the geological units, but no consistent pattern could be detected.

Hamiltonian structure of classical N-body systems of finite-size particles subject to EM interactions

NASA Astrophysics Data System (ADS)

Cremaschini, C.; Tessarotto, M.

2012-01-01

An open issue in classical relativistic mechanics is the consistent treatment of the dynamics of classical N-body systems of mutually interacting particles. This refers, in particular, to charged particles subject to EM interactions, including both binary interactions and self-interactions ( EM-interacting N- body systems). The correct solution to the question represents an overriding prerequisite for the consistency between classical and quantum mechanics. In this paper it is shown that such a description can be consistently obtained in the context of classical electrodynamics, for the case of a N-body system of classical finite-size charged particles. A variational formulation of the problem is presented, based on the N -body hybrid synchronous Hamilton variational principle. Covariant Lagrangian and Hamiltonian equations of motion for the dynamics of the interacting N-body system are derived, which are proved to be delay-type ODEs. Then, a representation in both standard Lagrangian and Hamiltonian forms is proved to hold, the latter expressed by means of classical Poisson Brackets. The theory developed retains both the covariance with respect to the Lorentz group and the exact Hamiltonian structure of the problem, which is shown to be intrinsically non-local. Different applications of the theory are investigated. The first one concerns the development of a suitable Hamiltonian approximation of the exact equations that retains finite delay-time effects characteristic of the binary interactions and self-EM-interactions. Second, basic consequences concerning the validity of Dirac generator formalism are pointed out, with particular reference to the instant-form representation of Poincaré generators. Finally, a discussion is presented both on the validity and possible extension of the Dirac generator formalism as well as the failure of the so-called Currie "no-interaction" theorem for the non-local Hamiltonian system considered here.

Three-level cobblestone-like TiO2 micro/nanocones for dual-responsive water/oil reversible wetting without fluorination

NASA Astrophysics Data System (ADS)

Zhou, Chen; Li, Guoqiang; Li, Chuanzong; Zhang, Zhen; Zhang, Yachao; Wu, Sizhu; Hu, Yanlei; Zhu, Wulin; Li, Jiawen; Chu, Jiaru; Hu, Zhijia; Wu, Dong; Yu, Liandong

2017-10-01

In this work, a kind of three-level cobblestone-like anatase TiO2 microcone array was fabricated on titanium sheets by femtosecond laser-induced self-assembly. This three level structure consisted of cobblestone-like features (15-25 μm in height and 20-35 μm in diameter), ˜460 nm ripple-like features, and smaller particles (10-500 nm). The formation of microcone arrays can be ascribed to the interaction of alternant laser beam ablation. TiO2 surfaces display dual-responsive water/oil reversible wetting via heat treatment and selective UV irradiation without fluorination. It is indicated that three-level scale surface roughness can amplify the wetting character of the Ti surface, and the mechanism for reversible switching between extreme wettabilities is caused by the conversion between Ti-OH and Ti-O. Moreover, the double-faced superhydrophobic and double-faced superhydrophilic Ti samples were constructed, which exhibited stable superhydrophobicity and underwater superoleophobicity in water-oil solution, respectively, even when strongly shaken. Finally, we present the hybrid-patterned TiO2 surface and realized reversible switching pattern wettability.

Simulation of ablation and plume dynamics under femtosecond double-pulse laser irradiation of aluminum: Comparison of atomistic and continual approaches

NASA Astrophysics Data System (ADS)

Fokin, Vladimir B.; Povarnitsyn, Mikhail E.; Levashov, Pavel R.

2017-02-01

We elaborated two numerical methods, two-temperature hydrodynamics and hybrid two-temperature molecular dynamics, which take into account basic mechanisms of a metal target response to ultrashort laser irradiation. The model used for the description of the electronic subsystem is identical for both approaches, while the ionic part is defined by an equation of state in hydrodynamics and by an interatomic potential in molecular dynamics. Since the phase diagram of the equation of state and corresponding potential match reasonably well, the dynamics of laser ablation obtained by both methods is quite similar. This correspondence can be considered as a first step towards the development of a self-consistent combined model. Two important processes are highlighted in simulations of double-pulse ablation: (1) the crater depth decrease as a result of recoil flux formation in the nascent plume when the delay between the pulses increases; (2) the plume reheating by the second pulse that gives rise to two- three-fold growth of the electron temperature with the delay varying from 0 to 200 ps.

Calculation of the electron wave function in a graded-channel double-heterojunction modulation-doped field-effect transistor

NASA Technical Reports Server (NTRS)

Mui, D. S. L.; Patil, M. B.; Morkoc, H.

1989-01-01

Three double-heterojunction modulation-doped field-effect transistor structures with different channel composition are investigated theoretically. All of these transistors have an In(x)Ga(1-x)As channel sandwiched between two doped Al(0.3)Ga(0.7)As barriers with undoped spacer layers. In one of the structures, x varies from 0 from either heterojunction to 0.15 at the center of the channel quadratically; in the other two, constant values of x of 0 and 0.15 are used. The Poisson and Schroedinger equations are solved self-consistently for the electron wave function in all three cases. The results showed that the two-dimensional electron gas (2DEG) concentration in the channel of the quadratically graded structure is higher than the x = 0 one and slightly lower than the x = 0.15 one, and the mean distance of the 2DEG is closer to the center of the channel for this transistor than the other two. These two effects have important implications on the electron mobility in the channel.

A Programmable DNA Double-Write Material: Synergy of Photolithography and Self-Assembly Nanofabrication.

PubMed

Song, Youngjun; Takahashi, Tsukasa; Kim, Sejung; Heaney, Yvonne C; Warner, John; Chen, Shaochen; Heller, Michael J

2017-01-11

We demonstrate a DNA double-write process that uses UV to pattern a uniquely designed DNA write material, which produces two distinct binding identities for hybridizing two different complementary DNA sequences. The process requires no modification to the DNA by chemical reagents and allows programmed DNA self-assembly and further UV patterning in the UV exposed and nonexposed areas. Multilayered DNA patterning with hybridization of fluorescently labeled complementary DNA sequences, biotin probe/fluorescent streptavidin complexes, and DNA patterns with 500 nm line widths were all demonstrated.

Effects of a probiotic intervention in acute canine gastroenteritis--a controlled clinical trial.

PubMed

Herstad, H K; Nesheim, B B; L'Abée-Lund, T; Larsen, S; Skancke, E

2010-01-01

To evaluate the effect of a probiotic product in acute self-limiting gastroenteritis in dogs. Thirty-six dogs suffering from acute diarrhoea or acute diarrhoea and vomiting were included in the study. The trial was performed as a randomised, double blind and single centre study with stratified parallel group design. The animals were allocated to equal looking probiotic or placebo treatment by block randomisation with a fixed block size of six. The probiotic cocktail consisted of thermo-stabilised Lactobacillus acidophilus and live strains of Pediococcus acidilactici, Bacillus subtilis, Bacillus licheniformis and Lactobacillus farciminis. The time from initiation of treatment to the last abnormal stools was found to be significantly shorter (P = 0.04) in the probiotic group compared to placebo group, the mean time was 1.3 days and 2.2 days, respectively. The two groups were found nearly equal with regard to time from start of treatment to the last vomiting episode. The probiotic tested may reduce the convalescence time in acute self-limiting diarrhoea in dogs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, Chih-Hao; Yue, Kan; Wang, Jing

Controlling self-assembled nanostructures in thin films allows the bottom-up fabrication of ordered nanoscale patterns. Here we report the unique thickness-dependent phase behavior in thin films of a bolaform-like giant surfactant, which consists of butyl- and hydroxyl-functionalized polyhedral oligomeric silsesquioxane (BPOSS and DPOSS) cages telechelically located at the chain ends of a polystyrene (PS) chain with 28 repeating monomers on average. In the bulk, BPOSS-PS28-DPOSS forms a double gyroid (DG) phase. Both grazing incidence small angle X-ray scattering and transmission electron microscopy techniques are combined to elucidate the thin film structures. Interestingly, films with thicknesses thinner than 200 nm exhibit anmore » irreversible phase transition from hexagonal perforated layer (HPL) to compressed hexagonally packed cylinders (c-HEX) at 130 °C, while films with thickness larger than 200 nm show an irreversible transition from HPL to DG at 200 °C. The thickness-controlled transition pathway suggests possibilities to obtain diverse patterns via thin film self-assembly.« less

Self-propagated combustion synthesis of few-layered graphene: an optical properties perspective.

PubMed

Mohandoss, Manonmani; Sen Gupta, Soujit; Kumar, Ramesh; Islam, Md Rabiul; Som, Anirban; Mohd, Azhardin Ganayee; Pradeep, T; Maliyekkal, Shihabudheen M

2018-04-26

This paper describes a labour efficient and cost-effective strategy to prepare few-layered of reduced graphene oxide like (RGOL) sheets from graphite. The self-propagated combustion route enables the bulk production of RGOL sheets. Microscopic and spectroscopic analyses confirmed the formation of few-layer graphene sheets of an average thickness of ∼3 nm and the presence of some oxygen functional groups with a C/O ratio of 8.74. A possible mechanistic pathway for the formation of RGOL sheets is proposed. The optical properties of the RGOL sample were studied in detail by means of Spectroscopic Ellipsometry (SE). The experimental abilities of SE in relating the optical properties with the number of oxygen functionalities present in the samples are explored. The data were analysed by a double-layered optical model along with the Drude-Lorentz oscillatory dispersion relation. The refractive index (n = 2.24), extinction coefficient (k = 2.03), and dielectric functions are obtained using point-by-point analysis and are also checked for Kramers-Kronig (KK) consistency.

Self-gravity, self-consistency, and self-organization in geodynamics and geochemistry

NASA Astrophysics Data System (ADS)

Anderson, Don L.

The results of seismology and geochemistry for mantle structure are widely believed to be discordant, the former favoring whole-mantle convection and the latter favoring layered convection with a boundary near 650 km. However, a different view arises from recognizing effects usually ignored in the construction of these models, including physical plausibility and dimensionality. Self-compression and expansion affect material properties that are important in all aspects of mantle geochemistry and dynamics, including the interpretation of tomographic images. Pressure compresses a solid and changes physical properties that depend on volume and does so in a highly nonlinear way. Intrinsic, anelastic, compositional, and crystal structure effects control seismic velocities; temperature is not the only parameter, even though tomographic images are often treated as temperature maps. Shear velocity is not a good proxy for density, temperature, and composition or for other elastic constants. Scaling concepts are important in mantle dynamics, equations of state, and wherever it is necessary to extend laboratory experiments to the parameter range of the Earth's mantle. Simple volume-scaling relations that permit extrapolation of laboratory experiments, in a thermodynamically self-consistent way, to deep mantle conditions include the quasiharmonic approximation but not the Boussinesq formalisms. Whereas slabs, plates, and the upper thermal boundary layer of the mantle have characteristic thicknesses of hundreds of kilometers and lifetimes on the order of 100 million years, volume-scaling predicts values an order of magnitude higher for deep-mantle thermal boundary layers. This implies that deep-mantle features are sluggish and ancient. Irreversible chemical stratification is consistent with these results; plausible temperature variations in the deep mantle cause density variations that are smaller than the probable density contrasts across chemical interfaces created by accretional differentiation and magmatic processes. Deep-mantle features may be convectively isolated from upper-mantle processes. Plate tectonics and surface geochemical cycles appear to be entirely restricted to the upper ˜1,000 km. The 650-km discontinuity is mainly an isochemical phase change but major-element chemical boundaries may occur at other depths. Recycling laminates the upper mantle and also makes it statistically heterogeneous, in agreement with high-frequency scattering studies. In contrast to standard geochemical models and recent modifications, the deeper layers need not be accessible to surface volcanoes. There is no conflict between geophysical and geochemical data, but a physical basis for standard geochemical and geodynamic mantle models, including the two-layer and whole-mantle versions, and qualitative tomographic interpretations has been lacking.

The Origin of Hierarchical Structure Formation in Highly Grafted Symmetric Supramolecular Double-Comb Diblock Copolymers.

PubMed

Hofman, Anton H; Reza, Mehedi; Ruokolainen, Janne; Ten Brinke, Gerrit; Loos, Katja

2017-09-01

Involving supramolecular chemistry in self-assembling block copolymer systems enables design of complex macromolecular architectures that, in turn, could lead to complex phase behavior. It is an elegant route, as complicated and sensitive synthesis techniques can be avoided. Highly grafted double-comb diblock copolymers based on symmetric double hydrogen bond accepting poly(4-vinylpyridine)-block-poly(N-acryloylpiperidine) diblock copolymers and donating 3-nonadecylphenol amphiphiles are realized and studied systematically by changing the molecular weight of the copolymer. Double perpendicular lamellae-in-lamellae are formed in all complexes, independent of the copolymer molecular weight. Temperature-resolved measurements demonstrate that the supramolecular nature and ability to crystallize are responsible for the formation of such multiblock-like structures. Because of these driving forces and severe plasticization of the complexes in the liquid crystalline state, this supramolecular approach can be useful for steering self-assembly of both low- and high-molecular-weight block copolymer systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toughening mystery of natural rubber deciphered by double network incorporating hierarchical structures

PubMed Central

Zhou, Weiming; Li, Xiangyang; Lu, Jie; Huang, Ningdong; Chen, Liang; Qi, Zeming; Li, Liangbin; Liang, Haiyi

2014-01-01

As an indispensible material for modern society, natural rubber possesses peerless mechanical properties such as strength and toughness over its artificial analogues, which remains a mystery. Intensive experimental and theoretical investigations have revealed the self-enhancement of natural rubber due to strain-induced crystallization. However a rigorous model on the self-enhancement, elucidating natural rubber's extraordinary mechanical properties, is obscured by deficient understanding of the local hierarchical structure under strain. With spatially resolved synchrotron radiation micro-beam scanning X-ray diffraction we discover weak oscillation in distributions of strain-induced crystallinity around crack tip for stretched natural rubber film, demonstrating a soft-hard double network structure. The fracture energy enhancement factor obtained by utilizing the double network model indicates an enhancement of toughness by 3 orders. It's proposed that upon stretching spontaneously developed double network structures integrating hierarchy at multi length-scale in natural rubber play an essential role in its remarkable mechanical performance. PMID:25511479

Dynamical Generation of Quasi-Stationary Alfvenic Double Layers and Charge Holes and Unified Theory of Quasi-Static and Alfvenic Auroral Arc Formation

NASA Astrophysics Data System (ADS)

Song, Y.; Lysak, R. L.

2015-12-01

Parallel E-fields play a crucial role for the acceleration of charged particles, creating discrete aurorae. However, once the parallel electric fields are produced, they will disappear right away, unless the electric fields can be continuously generated and sustained for a fairly long time. Thus, the crucial question in auroral physics is how to generate such a powerful and self-sustained parallel electric fields which can effectively accelerate charge particles to high energy during a fairly long time. We propose that nonlinear interaction of incident and reflected Alfven wave packets in inhomogeneous auroral acceleration region can produce quasi-stationary non-propagating electromagnetic plasma structures, such as Alfvenic double layers (DLs) and Charge Holes. Such Alfvenic quasi-static structures often constitute powerful high energy particle accelerators. The Alfvenic DL consists of localized self-sustained powerful electrostatic electric fields nested in a low density cavity and surrounded by enhanced magnetic and mechanical stresses. The enhanced magnetic and velocity fields carrying the free energy serve as a local dynamo, which continuously create the electrostatic parallel electric field for a fairly long time. The generated parallel electric fields will deepen the seed low density cavity, which then further quickly boosts the stronger parallel electric fields creating both Alfvenic and quasi-static discrete aurorae. The parallel electrostatic electric field can also cause ion outflow, perpendicular ion acceleration and heating, and may excite Auroral Kilometric Radiation.

Anatomy of triply-periodic network assemblies: characterizing skeletal and inter-domain surface geometry of block copolymer gyroids.

PubMed

Prasad, Ishan; Jinnai, Hiroshi; Ho, Rong-Ming; Thomas, Edwin L; Grason, Gregory M

2018-05-09

Triply-periodic networks (TPNs), like the well-known gyroid and diamond network phases, abound in soft matter assemblies, from block copolymers (BCPs), lyotropic liquid crystals and surfactants to functional architectures in biology. While TPNs are, in reality, volume-filling patterns of spatially-varying molecular composition, physical and structural models most often reduce their structure to lower-dimensional geometric objects: the 2D interfaces between chemical domains; and the 1D skeletons that thread through inter-connected, tubular domains. These lower-dimensional structures provide a useful basis of comparison to idealized geometries based on triply-periodic minimal, or constant-mean curvature surfaces, and shed important light on the spatially heterogeneous packing of molecular constituents that form the networks. Here, we propose a simple, efficient and flexible method to extract a 1D skeleton from 3D volume composition data of self-assembled networks. We apply this method to both self-consistent field theory predictions as well as experimental electron microtomography reconstructions of the double-gyroid phase of an ABA triblock copolymer. We further demonstrate how the analysis of 1D skeleton, 2D inter-domain surfaces, and combinations therefore, provide physical and structural insight into TPNs, across multiple length scales. Specifically, we propose and compare simple measures of network chirality as well as domain thickness, and analyze their spatial and statistical distributions in both ideal (theoretical) and non-ideal (experimental) double gyroid assemblies.

Self-Portrait of Curiosity Stunt Double

NASA Image and Video Library

2012-12-11

Camera and robotic-arm maneuvers for taking a self-portrait of the NASA Curiosity rover on Mars were checked first, at NASA Jet Propulsion Laboratory in Pasadena, Calif., using the main test rover for the Curiosity.

QCAD simulation and optimization of semiconductor double quantum dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielsen, Erik; Gao, Xujiao; Kalashnikova, Irina

2013-12-01

We present the Quantum Computer Aided Design (QCAD) simulator that targets modeling quantum devices, particularly silicon double quantum dots (DQDs) developed for quantum qubits. The simulator has three di erentiating features: (i) its core contains nonlinear Poisson, e ective mass Schrodinger, and Con guration Interaction solvers that have massively parallel capability for high simulation throughput, and can be run individually or combined self-consistently for 1D/2D/3D quantum devices; (ii) the core solvers show superior convergence even at near-zero-Kelvin temperatures, which is critical for modeling quantum computing devices; (iii) it couples with an optimization engine Dakota that enables optimization of gate voltagesmore » in DQDs for multiple desired targets. The Poisson solver includes Maxwell- Boltzmann and Fermi-Dirac statistics, supports Dirichlet, Neumann, interface charge, and Robin boundary conditions, and includes the e ect of dopant incomplete ionization. The solver has shown robust nonlinear convergence even in the milli-Kelvin temperature range, and has been extensively used to quickly obtain the semiclassical electrostatic potential in DQD devices. The self-consistent Schrodinger-Poisson solver has achieved robust and monotonic convergence behavior for 1D/2D/3D quantum devices at very low temperatures by using a predictor-correct iteration scheme. The QCAD simulator enables the calculation of dot-to-gate capacitances, and comparison with experiment and between solvers. It is observed that computed capacitances are in the right ballpark when compared to experiment, and quantum con nement increases capacitance when the number of electrons is xed in a quantum dot. In addition, the coupling of QCAD with Dakota allows to rapidly identify which device layouts are more likely leading to few-electron quantum dots. Very efficient QCAD simulations on a large number of fabricated and proposed Si DQDs have made it possible to provide fast feedback for design comparison and optimization.« less

Variation in floral morphology and plant reproductive success in four Ipomoea species (Convolvulaceae) with contrasting breeding systems.

PubMed

Delgado-Dávila, R; Martén-Rodríguez, S; Huerta-Ramos, G

2016-11-01

This study tested the hypothesis that self-compatibility would be associated with floral traits that facilitate autonomous self-pollination to ensure reproduction under low pollinator visitation. In a comparison of two pairs of Ipomoea species with contrasting breeding systems, we predicted that self-compatible (SC) species would have smaller, less variable flowers, reduced herkogamy, lower pollinator visitation and higher reproductive success than their self-incompatible (SI) congeners. We studied sympatric species pairs, I. hederacea (SC)- I. mitchellae (SI) and I. purpurea (SC)-I. indica (SI), in Mexico, over two years. We quantified variation in floral traits and nectar production, documented pollinator visitation, and determined natural fruit and seed set. Hand-pollination and bagging experiments were conducted to determine potential for autonomous self-pollination and apomixis. Self-compatible Ipomoea species had smaller flowers and lower nectar production than SI species; however, floral variation and integration did not vary according to breeding system. Bees were primary pollinators of all species, but visitation rates were seven times lower in SC than SI species. SC species had a high capacity for autonomous self-pollination due to reduced herkogamy at the highest anther levels. Self-compatible species had two to six times higher fruit set than SI species. Results generally support the hypothesis that self-compatibility and autonomous self-pollination ensure reproduction under low pollinator visitation. However, high variation in morphological traits of SC Ipomoea species suggests they maintain variation through outcrossing. Furthermore, reduced herkogamy was associated with high potential for autonomous self-pollination, providing a reproductive advantage that possibly underlies transitions to self-compatibility in Ipomoea. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Developmental Change and Time-Specific Variation in Global and Specific Aspects of Self-Concept in Adolescence and Association with Depressive Symptoms

PubMed Central

Kuzucu, Yasar; Bontempo, Daniel E.; Hofer, Scott M.; Stallings, Michael C.; Piccinin, Andrea M.

2014-01-01

Previous research has demonstrated that adolescents make differential self-evaluations in multiple domains that include physical appearance, academic competence, and peer acceptance. We report growth curve analyses over a seven year period from age 9 to age 16 on the six domains of the Harter Self-Perception Profile for Children. In general, we find little change in self-concept, on average, but do find substantial individual differences in level, rate of change, and time-specific variation in these self- evaluations. The results suggest that sex differences and adoptive status were related to only certain aspects of the participants’ self-concept. Depressive symptoms were found to have significant effects on individual differences in rate of change and on time-specific variation in general self-concept, as well as on some of the specific domains of self-concept. PMID:25143664

Hartree-Fock theory of the inhomogeneous electron gas at a jellium metal surface: Rigorous upper bounds to the surface energy and accurate work functions

NASA Astrophysics Data System (ADS)

Sahni, V.; Ma, C. Q.

1980-12-01

The inhomogeneous electron gas at a jellium metal surface is studied in the Hartree-Fock approximation by Kohn-Sham density functional theory. Rigorous upper bounds to the surface energy are derived by application of the Rayleigh-Ritz variational principle for the energy, the surface kinetic, electrostatic, and nonlocal exchange energy functionals being determined exactly for the accurate linear-potential model electronic wave functions. The densities obtained by the energy minimization constraint are then employed to determine work-function results via the variationally accurate "displaced-profile change-in-self-consistent-field" expression. The theoretical basis of this non-self-consistent procedure and its demonstrated accuracy for the fully correlated system (as treated within the local-density approximation for exchange and correlation) leads us to conclude these results for the surface energies and work functions to be essentially exact. Work-function values are also determined by the Koopmans'-theorem expression, both for these densities as well as for those obtained by satisfaction of the constraint set on the electrostatic potential by the Budd-Vannimenus theorem. The use of the Hartree-Fock results in the accurate estimation of correlation-effect contributions to these surface properties of the nonuniform electron gas is also indicated. In addition, the original work and approximations made by Bardeen in this attempt at a solution of the Hartree-Fock problem are briefly reviewed in order to contrast with the present work.

Experimental Study on Thermal Conductivity of Self-Compacting Concrete with Recycled Aggregate

PubMed Central

Fenollera, María; Míguez, José Luis; Goicoechea, Itziar; Lorenzo, Jaime

2015-01-01

The research focuses on the use of recycled aggregate (RA), from waste pieces generated during production in precast plants for self-compacting concrete (SCC) manufactured with a double sustainable goal: recycle manufacturing waste (consumption) and improvement of the thermal properties of the manufactured product (energy efficiency). For this purpose, a mechanical study to ensure technical feasibility of the concrete obtained has been conducted, as well as a thermal analysis of recycled SCC specimens of 50 N/mm2 resistance, with different RA doses (0%, 20%, 50% and 100%). The main parameters that characterize a SCC in both states, fresh (slump-flow) and hard (compressive strength), have been tested; also, a qualitative analysis of the thermal conductivity using infrared thermography (IRT) and quantitative analysis with heat flow meter at three temperatures 20 °C, 25 °C and 30 °C have been performed. The results suggest the existence of two different thermal behaviors: concretes with 0% and 20% of RA, and on the other hand concretes with 50% and 100% of RA. It has also demonstrated the validity of the IRT as sampling technique in estimating the thermal behavior of materials having reduced range of variation in parameters. PMID:28793449

Experimental Study on Thermal Conductivity of Self-Compacting Concrete with Recycled Aggregate.

PubMed

Fenollera, María; Míguez, José Luis; Goicoechea, Itziar; Lorenzo, Jaime

2015-07-20

The research focuses on the use of recycled aggregate (RA), from waste pieces generated during production in precast plants for self-compacting concrete (SCC) manufactured with a double sustainable goal: recycle manufacturing waste (consumption) and improvement of the thermal properties of the manufactured product (energy efficiency). For this purpose, a mechanical study to ensure technical feasibility of the concrete obtained has been conducted, as well as a thermal analysis of recycled SCC specimens of 50 N/mm² resistance, with different RA doses (0%, 20%, 50% and 100%). The main parameters that characterize a SCC in both states, fresh (slump-flow) and hard (compressive strength), have been tested; also, a qualitative analysis of the thermal conductivity using infrared thermography (IRT) and quantitative analysis with heat flow meter at three temperatures 20 °C, 25 °C and 30 °C have been performed. The results suggest the existence of two different thermal behaviors: concretes with 0% and 20% of RA, and on the other hand concretes with 50% and 100% of RA. It has also demonstrated the validity of the IRT as sampling technique in estimating the thermal behavior of materials having reduced range of variation in parameters.

Double layer mixed matrix membrane adsorbers improving capacity and safety hemodialysis

NASA Astrophysics Data System (ADS)

Saiful; Borneman, Z.; Wessling, M.

2018-05-01

Double layer mixed matrix membranes adsorbers have been developed for blood toxin removal by embedding activated carbon into cellulose acetate macroporous membranes. The membranes are prepared by phase inversion method via water vapor induced phase separation followed by an immersion precipitation step. Double layer MMM consisting of an active support and a separating layer. The active support layer consists of activated carbon particles embedded in macroporous cellulose acetate; the separating layer consists of particle free cellulose acetate. The double layer membrane possess an open and interconnected macroporous structure with a high loading of activated carbon available for blood toxins removal. The MMM AC has a swelling degree of 6.5 %, porosity of 53 % and clean water flux of 800 Lm-2h-1bar-1. The prepared membranes show a high dynamic Creatinine (Crt) removal during hemodilysis process. The Crt removal by adsorption contributes to amore than 83 % of the total removal. The double layer adsorptive membrane proves hemodialysis membrane can integrated with adsorption, in which blood toxins are removed in one step.

Self-healing Li-Al layered double hydroxide conversion coating modified with aspartic acid for 6N01 Al alloy

NASA Astrophysics Data System (ADS)

Zhang, Caixia; Luo, Xiaohu; Pan, Xinyu; Liao, Liying; Wu, Xiaosong; Liu, Yali

2017-02-01

A self-healing Li-Al layered double hydroxide conversion coating (LCC) modified with aspartic acid (ALCC) was prepared on 6N01 Al alloy for corrosion protection. Scanning electron microscopy (SEM) showed that a compact thin film has been successfully formed on the alloy. X-ray diffraction (XRD) and FT-IR spectra proved that species of aspartic acid anions were successfully intercalated into LCC. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and neutral salt spray (NSS) testing showed that the resultant ALCC could provide effective corrosion protection for the Al alloy. During immersion of the ALCC-coated alloy in 3.5% NaCl solution, new film was formed in the area of artificially introduced scratch, indicating its self-healing capability. XPS results demonstrated that Cl- anions exchange partial Asp anions according to the change content of element on conversion coating. From the above results, the possible mechanism via exchange/self-assembly was proposed to illustrate the phenomenon of self-healing.

Double-path acquisition of pulse wave transit time and heartbeat using self-mixing interferometry

NASA Astrophysics Data System (ADS)

Wei, Yingbin; Huang, Wencai; Wei, Zheng; Zhang, Jie; An, Tong; Wang, Xiulin; Xu, Huizhen

2017-06-01

We present a technique based on self-mixing interferometry for acquiring the pulse wave transit time (PWTT) and heartbeat. A signal processing method based on Continuous Wavelet Transform and Hilbert Transform is applied to extract potentially useful information in the self-mixing interference (SMI) signal, including PWTT and heartbeat. Then, some cardiovascular characteristics of the human body are easily acquired without retrieving the SMI signal by complicated algorithms. Experimentally, the PWTT is measured on the finger and the toe of the human body using double-path self-mixing interferometry. Experimental statistical data show the relation between the PWTT and blood pressure, which can be used to estimate the systolic pressure value by fitting. Moreover, the measured heartbeat shows good agreement with that obtained by a photoplethysmography sensor. The method that we demonstrate, which is based on self-mixing interferometry with significant advantages of simplicity, compactness and non-invasion, effectively illustrates the viability of the SMI technique for measuring other cardiovascular signals.

Compartmentalization Technologies via Self-Assembly and Cross-Linking of Amphiphilic Random Block Copolymers in Water.

PubMed

Matsumoto, Mayuko; Terashima, Takaya; Matsumoto, Kazuma; Takenaka, Mikihito; Sawamoto, Mitsuo

2017-05-31

Orthogonal self-assembly and intramolecular cross-linking of amphiphilic random block copolymers in water afforded an approach to tailor-make well-defined compartments and domains in single polymer chains and nanoaggregates. For a double compartment single-chain polymer, an amphiphilic random block copolymer bearing hydrophilic poly(ethylene glycol) (PEG) and hydrophobic dodecyl, benzyl, and olefin pendants was synthesized by living radical polymerization (LRP) and postfunctionalization; the dodecyl and benzyl units were incorporated into the different block segments, whereas PEG pendants were statistically attached along a chain. The copolymer self-folded via the orthogonal self-assembly of hydrophobic dodecyl and benzyl pendants in water, followed by intramolecular cross-linking, to form a single-chain polymer carrying double yet distinct hydrophobic nanocompartments. A single-chain cross-linked polymer with a chlorine terminal served as a globular macroinitiator for LRP to provide an amphiphilic tadpole macromolecule comprising a hydrophilic nanoparticle and a hydrophobic polymer tail; the tadpole thus self-assembled into multicompartment aggregates in water.

Radio to gamma-ray variability study of blazar S5 0716+714

DOE PAGES

Rani, B.; Krichbaum, T. P.; Fuhrmann, L.; ...

2013-03-13

In this paper, we present the results of a series of radio, optical, X-ray, and γ-ray observations of the BL Lac object S50716+714 carried out between April 2007 and January 2011. The multifrequency observations were obtained using several ground- and space-based facilities. The intense optical monitoring of the source reveals faster repetitive variations superimposed on a long-term variability trend on a time scale of ~350 days. Episodes of fast variability recur on time scales of ~60-70 days. The intense and simultaneous activity at optical and γ-ray frequencies favors the synchrotron self-Compton mechanism for the production of the high-energy emission. Twomore » major low-peaking radio flares were observed during this high optical/γ-ray activity period. The radio flares are characterized by a rising and a decaying stage and agrees with the formation of a shock and its evolution. We found that the evolution of the radio flares requires a geometrical variation in addition to intrinsic variations of the source. Different estimates yield robust and self-consistent lower limits of δ ≥ 20 and equipartition magnetic field B eq ≥ 0.36 G. Causality arguments constrain the size of emission region θ ≤ 0.004 mas. We found a significant correlation between flux variations at radio frequencies with those at optical and γ-rays. Theoptical/GeV flux variations lead the radio variability by ~65 days. The longer time delays between low-peaking radio outbursts and optical flares imply that optical flares are the precursors of radio ones. An orphan X-ray flare challenges the simple, one-zone emission models, rendering them too simple. Finally, here we also describe the spectral energy distribution modeling of the source from simultaneous data taken through different activity periods.« less

IN VITRO FLOW ANALYSIS OF NOVEL DOUBLE-CUTTING, OPEN-PORT, ULTRAHIGH-SPEED VITRECTOMY SYSTEMS.

PubMed

Zehetner, Claus; Moelgg, Marion; Bechrakis, Emmanouil; Linhart, Caroline; Bechrakis, Nikolaos E

2017-10-09

To analyze the performance and flow characteristics of novel double-cutting, open-port, 23-, 25-, and 27-gauge ultrahigh-speed vitrectomy systems. In vitro fluidic measurements were performed to assess the volumetric aspiration profiles of several vitrectomy systems in basic salt solution and egg white. Double-cutting open-port vitrectomy probes delivered stable aspiration flow rates that were less prone to flow variation affected by the cutting speed. Increase in cutting frequency to the maximum level resulted in flow reduction of less than 10% (0.0%-9.5%). Commercially available 23-, 25-, and 27-G double-cutting probes exhibited higher egg-white and basic salt solution flow rates at all evaluated cut rates, with aspirational efficiencies being 1.1 to 2.9 times the flow rates of standard single-blade vitrectomy probes of the same caliber at the maximum preset vacuum. The highest relative differences were observed at faster cut rates. The newly introduced double-cutting open-port vitrectomy probes delivered stable aspiration flow rates that were less prone to flow variation affected by the cutting speed. The fluidic principle of constant flow even at the highest cut rates and low vacuum levels might impact surgical strategies, especially when performing manipulations close to the retina.

Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

NASA Astrophysics Data System (ADS)

Li, Honghong; Qin, Li; Feng, Ying; Hu, Lihua; Zhou, Chunhua

2015-06-01

A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe3O4 magnetic nanoparticles (Fe3O4-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe3O4-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe3O4-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe3O4. Transmission electron microscopy (TEM) analysis confirmed that the Fe3O4-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe3O4-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe3O4-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe3O4-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature TB of Fe3O4-AOS-MN capped with double-layered AOS is 170 K.

NMR investigation of the short-chain ionic surfactant-water systems.

PubMed

Popova, M V; Tchernyshev, Y S; Michel, D

2004-02-03

The structure and dynamics of surfactant molecules [CH3(CH2)7COOK] in heavy water solutions were investigated by 1H and 2H NMR. A double-exponential attenuation of the spin-echo amplitude in a Carr-Purcell-Meiboom-Gill experiment was found. We expect correspondence to both bounded and monomeric states. At high concentrations in the NMR self-diffusion measurements also a double-exponential decay of the spin-echo signal versus the square of the dc magnetic gradient was observed. The slow component of the diffusion process is caused by micellar aggregates, while the fast component is the result of the self-diffusion of the monomers through the micelles. The self-diffusion studies indicate that the form of micelles changes with increasing total surfactant concentration. The critical temperature range for self-association is reflected in the 1H transverse relaxation.

Unconventional Tough Double-Network Hydrogels with Rapid Mechanical Recovery, Self-Healing, and Self-Gluing Properties.

PubMed

Jia, Haiyan; Huang, Zhangjun; Fei, Zhaofu; Dyson, Paul J; Zheng, Zhen; Wang, Xinling

2016-11-16

Hydrogels are polymeric materials that have a relatively high capacity for holding water. Recently, a double network (DN) technique was developed to fabricate hydrogels with a toughness comparable to rubber. The mechanical properties of DN hydrogels may be attributed to the brittle sacrificial bonding network of one hydrogel, facilitating stress dispersion, combined with ductile polymer chains of a second hydrogel. Herein, we report a novel class of tunable DN hydrogels composed of a polyurethane hydrogel and a stronger, dipole-dipole and H-bonding interaction reinforced (DHIR) hydrogel. Compared to conventional DN hydrogels, these materials show remarkable improvements in mechanical recovery, modulus, and yielding, with excellent self-healing and self-gluing properties. In addition, the new DN hydrogels exhibit excellent tensile and compression strengths and possess shape-memory properties, which make them promising for applications in engineering, biomedicine, and other domains where load bearing is required.

Role of Defects on Regioselectivity of Nano Pristine Graphene.

PubMed

Kudur Jayaprakash, Gururaj; Casillas, Norberto; Astudillo-Sánchez, Pablo D; Flores-Moreno, Roberto

2016-11-17

Here analytical Fukui functions based on density functional theory are applied to investigate the redox reactivity of pristine and defected graphene lattices. A carbon H-terminated graphene structure (with 96 carbon atoms) and a graphene defected surface with Stone-Wales rearrangement and double vacancy defects are used as models. Pristine sp 2 -hybridized, hexagonal arranged carbon atoms exhibit a symmetric reactivity. In contrast, common carbon atoms at reconstructed polygons in Stone-Wales and double vacancy graphene display large reactivity variations. The improved reactivity and the regioselectivity at defected graphene is correlated to structural changes that caused carbon-carbon bond length variations at defected zones.

Mapping of the Marangoni effect in soap films using Young's double-slit experiment

NASA Astrophysics Data System (ADS)

Emile, Janine; Emile, Olivier

2013-10-01

We report on the thickness variation measurement of a soap film due to a local perturbation, using Young's double-slit experiment configuration. We map a laser-heated deformation of a vertical free-standing draining thin soap film using the differential change of optical path in the interferometer. The experiment has a resolution of about 0.1 nm and enables to follow the liquid flow dynamics. We evidence a bottleneck formation in the heated region of the film that perturbs the usual flow. Such an experimental set-up could then be adapted to measure other tiny variations in fluctuating hydrodynamics such as capillary waves for example.

Solution-grown small-molecule organic semiconductor with enhanced crystal alignment and areal coverage for organic thin film transistors

DOE PAGES

Bi, Sheng; He, Zhengran; Chen, Jihua; ...

2015-07-24

Drop casting of small-molecule organic semiconductors typically forms crystals with random orientation and poor areal coverage, which leads to significant performance variations of organic thin-film transistors (OTFTs). In this study, we utilize the controlled evaporative self-assembly (CESA) method combined with binary solvent system to control the crystal growth. A small-molecule organic semiconductor,2,5-Di-(2-ethylhexyl)-3,6-bis(5"-n-hexyl-2,2',5',2"]terthiophen-5-yl)-pyrrolo[3,4-c]pyrrole-1,4-dione (SMDPPEH), is used as an example to demonstrate the effectiveness of our approach. By optimizing the double solvent ratios, well-aligned SMDPPEH crystals with significantly improved areal coverage were achieved. As a result, the SMDPPEH based OTFTs exhibit a mobility of 1.6 × 10 -2 cm 2/V s, whichmore » is the highest mobility from SMDPPEH ever reported.« less

Insights on energy selective contacts for thermal energy harvesting using double resonant tunneling contacts and numerical modeling

NASA Astrophysics Data System (ADS)

Julian, A.; Jehl, Z.; Miyashita, N.; Okada, Y.; Guillemoles, J.-F.

2016-12-01

Energy selective electrical contacts have been proposed as a way to approach ultimate efficiencies both for thermoelectric and photovoltaic devices as they allow a reduction of the entropy production during the energy conversion process. A self-consistent numerical model based on the transfer matrix approach in the effective mass and envelope function approximation has been developed to calculate the electronic properties of double resonant tunneling barriers used as energy selective contacts in hot carrier solar cells. It is found that the application of an external electric bias significantly degrades the electronic transmission of the structure, and thus the tunneling current in the current-voltage characteristic. This is due to a symmetry breaking which can be offset using finely tuned asymmetric double resonant tunneling barriers, leading to a full recovery of the tunneling current in our model. Moreover, we model the heterostructure using electrons temperature in the emitter higher than that of the lattice, providing insights on the interpretation of experimental devices functioning in hot carrier conditions, especially regarding the previously reported shift of the resonance peak (negative differential resistance), which we interpret as related to a shift in the hot electron distribution while the maximum remains at the conduction band edge of the emitter. Finally, experimental results are presented using asymmetric structure showing significantly improved resonant properties at room temperature with very sharp negative differential resistance.

Improved analysis techniques for cylindrical and spherical double probes.

PubMed

Beal, Brian; Johnson, Lee; Brown, Daniel; Blakely, Joseph; Bromaghim, Daron

2012-07-01

A versatile double Langmuir probe technique has been developed by incorporating analytical fits to Laframboise's numerical results for ion current collection by biased electrodes of various sizes relative to the local electron Debye length. Application of these fits to the double probe circuit has produced a set of coupled equations that express the potential of each electrode relative to the plasma potential as well as the resulting probe current as a function of applied probe voltage. These equations can be readily solved via standard numerical techniques in order to determine electron temperature and plasma density from probe current and voltage measurements. Because this method self-consistently accounts for the effects of sheath expansion, it can be readily applied to plasmas with a wide range of densities and low ion temperature (T(i)/T(e) ≪ 1) without requiring probe dimensions to be asymptotically large or small with respect to the electron Debye length. The presented approach has been successfully applied to experimental measurements obtained in the plume of a low-power Hall thruster, which produced a quasineutral, flowing xenon plasma during operation at 200 W on xenon. The measured plasma densities and electron temperatures were in the range of 1 × 10(12)-1 × 10(17) m(-3) and 0.5-5.0 eV, respectively. The estimated measurement uncertainty is +6%∕-34% in density and +∕-30% in electron temperature.

Velocity and stress autocorrelation decay in isothermal dissipative particle dynamics

NASA Astrophysics Data System (ADS)

Chaudhri, Anuj; Lukes, Jennifer R.

2010-02-01

The velocity and stress autocorrelation decay in a dissipative particle dynamics ideal fluid model is analyzed in this paper. The autocorrelation functions are calculated at three different friction parameters and three different time steps using the well-known Groot/Warren algorithm and newer algorithms including self-consistent leap-frog, self-consistent velocity Verlet and Shardlow first and second order integrators. At low friction values, the velocity autocorrelation function decays exponentially at short times, shows slower-than exponential decay at intermediate times, and approaches zero at long times for all five integrators. As friction value increases, the deviation from exponential behavior occurs earlier and is more pronounced. At small time steps, all the integrators give identical decay profiles. As time step increases, there are qualitative and quantitative differences between the integrators. The stress correlation behavior is markedly different for the algorithms. The self-consistent velocity Verlet and the Shardlow algorithms show very similar stress autocorrelation decay with change in friction parameter, whereas the Groot/Warren and leap-frog schemes show variations at higher friction factors. Diffusion coefficients and shear viscosities are calculated using Green-Kubo integration of the velocity and stress autocorrelation functions. The diffusion coefficients match well-known theoretical results at low friction limits. Although the stress autocorrelation function is different for each integrator, fluctuates rapidly, and gives poor statistics for most of the cases, the calculated shear viscosities still fall within range of theoretical predictions and nonequilibrium studies.

Self-consistent modeling of laminar electrohydrodynamic plumes from ultra-sharp needles in cyclohexane

NASA Astrophysics Data System (ADS)

Becerra, Marley; Frid, Henrik; Vázquez, Pedro A.

2017-12-01

This paper presents a self-consistent model of electrohydrodynamic (EHD) laminar plumes produced by electron injection from ultra-sharp needle tips in cyclohexane. Since the density of electrons injected into the liquid is well described by the Fowler-Nordheim field emission theory, the injection law is not assumed. Furthermore, the generation of electrons in cyclohexane and their conversion into negative ions is included in the analysis. Detailed steady-state characteristics of EHD plumes under weak injection and space-charge limited injection are studied. It is found that the plume characteristics far from both electrodes and under weak injection can be accurately described with an asymptotic simplified solution proposed by Vazquez et al. ["Dynamics of electrohydrodynamic laminar plumes: Scaling analysis and integral model," Phys. Fluids 12, 2809 (2000)] when the correct longitudinal electric field distribution and liquid velocity radial profile are used as input. However, this asymptotic solution deviates from the self-consistently calculated plume parameters under space-charge limited injection since it neglects the radial variations of the electric field produced by a high-density charged core. In addition, no significant differences in the model estimates of the plume are found when the simulations are obtained either with the finite element method or with a diffusion-free particle method. It is shown that the model also enables the calculation of the current-voltage characteristic of EHD laminar plumes produced by electron field emission, with good agreement with measured values reported in the literature.

The experimental results of a self tuning adaptive controller using online frequency identification. [for Galileo spacecraft

NASA Technical Reports Server (NTRS)

Chiang, W.-W.; Cannon, R. H., Jr.

1985-01-01

A fourth-order laboratory dynamic system featuring very low structural damping and a noncolocated actuator-sensor pair has been used to test a novel real-time adaptive controller, implemented in a minicomputer, which consists of a state estimator, a set of state feedback gains, and a frequency-locked loop for real-time parameter identification. The adaptation algorithm employed can correct controller error and stabilize the system for more than 50 percent variation in the plant's natural frequency, compared with a 10 percent stability margin in frequency variation for a fixed gain controller having the same performance as the nominal plant condition. The very rapid convergence achievable by this adaptive system is demonstrated experimentally, and proven with simple, root-locus methods.

Vibrational self-consistent field theory using optimized curvilinear coordinates.

PubMed

Bulik, Ireneusz W; Frisch, Michael J; Vaccaro, Patrick H

2017-07-28

A vibrational SCF model is presented in which the functions forming the single-mode functions in the product wavefunction are expressed in terms of internal coordinates and the coordinates used for each mode are optimized variationally. This model involves no approximations to the kinetic energy operator and does not require a Taylor-series expansion of the potential. The non-linear optimization of coordinates is found to give much better product wavefunctions than the limited variations considered in most previous applications of SCF methods to vibrational problems. The approach is tested using published potential energy surfaces for water, ammonia, and formaldehyde. Variational flexibility allowed in the current ansätze results in excellent zero-point energies expressed through single-product states and accurate fundamental transition frequencies realized by short configuration-interaction expansions. Fully variational optimization of single-product states for excited vibrational levels also is discussed. The highlighted methodology constitutes an excellent starting point for more sophisticated treatments, as the bulk characteristics of many-mode coupling are accounted for efficiently in terms of compact wavefunctions (as evident from the accurate prediction of transition frequencies).

X-ray flux variability of active galactic nuclei observed using NuSTAR

NASA Astrophysics Data System (ADS)

Rani, Priyanka; Stalin, C. S.; Rakshit, Suvendu

2017-04-01

We present results of a systematic study of flux variability on hourly time-scales in a large sample of active galactic nuclei (AGN) in the 3-79 keV band using data from Nuclear Spectroscopic Telescope Array. Our sample consists of four BL Lac objects (BL Lacs), three flat spectrum radio quasars (FSRQs) 24 Seyfert 1, 42 Seyfert 2 and eight narrow line Seyfert 1 (NLSy1) galaxies. We find that in the 3-79 keV band, about 65 per cent of the sources in our sample show significant variations on hourly time-scales. Using the Mann-Whitney U-test and the Kolmogorov-Smirnov test, we find no difference in the variability behaviour between Seyfert 1 and 2 galaxies. The blazar sources (FSRQs and BL Lacs) in our sample are more variable than Seyfert galaxies that include Seyfert 1 and Seyfert 2 in the soft (3-10 keV), hard (10-79 keV) and total (3-79 keV) bands. NLSy1 galaxies show the highest duty cycle of variability (87 per cent), followed by BL Lacs (82 per cent), Seyfert galaxies (56 per cent) and FSRQs (23 per cent). We obtained flux doubling/halving time in the hard X-ray band less than 10 min in 11 sources. The flux variations between the hard and soft bands in all the sources in our sample are consistent with zero lag.

Variational Bayesian identification and prediction of stochastic nonlinear dynamic causal models.

PubMed

Daunizeau, J; Friston, K J; Kiebel, S J

2009-11-01

In this paper, we describe a general variational Bayesian approach for approximate inference on nonlinear stochastic dynamic models. This scheme extends established approximate inference on hidden-states to cover: (i) nonlinear evolution and observation functions, (ii) unknown parameters and (precision) hyperparameters and (iii) model comparison and prediction under uncertainty. Model identification or inversion entails the estimation of the marginal likelihood or evidence of a model. This difficult integration problem can be finessed by optimising a free-energy bound on the evidence using results from variational calculus. This yields a deterministic update scheme that optimises an approximation to the posterior density on the unknown model variables. We derive such a variational Bayesian scheme in the context of nonlinear stochastic dynamic hierarchical models, for both model identification and time-series prediction. The computational complexity of the scheme is comparable to that of an extended Kalman filter, which is critical when inverting high dimensional models or long time-series. Using Monte-Carlo simulations, we assess the estimation efficiency of this variational Bayesian approach using three stochastic variants of chaotic dynamic systems. We also demonstrate the model comparison capabilities of the method, its self-consistency and its predictive power.

Development of a femoral template for computer-assisted tunnel placement in anatomical double-bundle ACL reconstruction.

PubMed

Luites, J W H; Wymenga, A B; Blankevoort, L; Kooloos, J M G; Verdonschot, N

2011-01-01

Femoral graft placement is an important factor in the success of anterior cruciate ligament (ACL) reconstruction. In addition to improving the accuracy of femoral tunnel placement, Computer Assisted Surgery (CAS) can be used to determine the anatomic location. This is achieved by using a 3D femoral template which indicates the position of the anatomical ACL center based on endoscopically measurable landmarks. This study describes the development and application of this method. The template is generated through statistical shape analysis of the ACL insertion, with respect to the anteromedial (AM) and posterolateral (PL) bundles. The ligament insertion data, together with the osteocartilage edge on the lateral notch, were mapped onto a cylinder fitted to the intercondylar notch surface (n = 33). Anatomic variation, in terms of standard variation of the positions of the ligament centers in the template, was within 2.2 mm. The resulting template was programmed in a computer-assisted navigation system for ACL replacement and its accuracy and precision were determined on 31 femora. It was found that with the navigation system the AM and PL tunnels could be positioned with an accuracy of 2.5 mm relative to the anatomic insertion centers; the precision was 2.4 mm. This system consists of a template that can easily be implemented in 3D computer navigation software. Requiring no preoperative images and planning, the system provides adequate accuracy and precision to position the entrance of the femoral tunnels for anatomical single- or double-bundle ACL reconstruction.

Numerical assessment of factors affecting nonlinear internal waves in the South China Sea

NASA Astrophysics Data System (ADS)

Li, Qiang

2014-02-01

Nonlinear internal waves in the South China Sea exhibit diverse characteristics, which are associated with the complex conditions in Luzon Strait, such as the double ridge topography, the Earth’s rotation, variations in stratification and the background current induced by the Kuroshio. These effects are individually assessed using the MITgcm. The performance of the model is first validated through comparison with field observations. Because of in-phased ray interaction, the western ridge in Luzon Strait intensifies the semidiurnal internal tides generated from the eastern ridge, thus reinforcing the formation of nonlinear internal waves. However, the ray interaction for K1 forcing becomes anti-phased so that the K1 internal tide generation is reduced by the western ridge. Not only does the rotational dispersion suppress internal tide generation, it also inhibits nonlinear steepening and consequent internal solitary wave formation. As a joint effect, the double ridges and the rotational dispersion result in a paradoxical phenomenon: diurnal barotropic tidal forcing is dominant in Luzon Strait, but semidiurnal internal tides prevail in the deep basin of the South China Sea. The seasonal variation of the Kuroshio is consistent with the seasonal appearance of nonlinear internal waves in the South China Sea. The model results show that the westward inflow due to the Kuroshio intrusion reduces the amplitude of internal tides in the South China Sea, causing the weakening or absence of internal solitary waves. Winter stratification cannot account for the significant reduction of nonlinear internal waves, because the amplitude growth of internal tides due to increased thermocline tilting counteracts the reduced nonlinearity caused by thermocline deepening.

Impact of the phase-mismatch in the SHG crystal and consequential self-action of the fundamental wave by cascaded second-order effects on the THG efficiency of a Q-switched 1342 nm Nd:YVO₄ laser.

PubMed

Koch, Peter; Bartschke, Juergen; L'huillier, Johannes A

2015-05-18

We report on the influence of self-focusing and self-defocusing in the phase-mismatched frequency doubling crystal on the third harmonic generation (THG) efficiency in a two crystal frequency tripling scheme. By detuning the temperature of the doubling crystal, the impact of a phase-mismatch in second harmonic generation (SHG) on the subsequent sum frequency mixing process was investigated. It was found that adjusting the temperature not only affected the power ratio of the second harmonic to the fundamental but also the beam diameter of the fundamental beam in the THG crystal, which was caused by self-focusing and self-defocusing of the fundamental beam, respectively. This self-action was induced by a cascaded χ(2) : χ(2) process in the phase-mismatched SHG crystal. Self-defocusing was observable for positive detuning and self-focusing for negative detuning of the phase-matching temperature. Hence, the THG efficiency was not symmetric with respect to the point of optimum phase-matching. Optimum THG was obtained for positive detuning and the resulting self-defocusing in combination with the focusing lens in front of the THG stage was also beneficial for the beam quality of the third harmonic.

The Internalized Homophobia Scale for Vietnamese Sexual Minority Women: Conceptualization, Factor Structure, Reliability, and Associations With Hypothesized Correlates.

PubMed

Nguyen, Trang Quynh; Poteat, Tonia; Bandeen-Roche, Karen; German, Danielle; Nguyen, Yen Hai; Vu, Loan Kieu-Chau; Nguyen, Nam Thi-Thu; Knowlton, Amy R

2016-08-01

We developed the first Vietnamese Internalized Homophobia (IH) scale for use with Vietnamese sexual minority women (SMW). Drawing from existing IH scales in the international literature and based on prior qualitative research about SMW in the Viet Nam context, the scale covers two domains: self-stigma (negative attitudes toward oneself as a sexual minority person) and sexual prejudice (negative attitudes toward homosexuality/same-sex relations in general). Scale items, including items borrowed from existing scales and items based on local expressions, were reviewed and confirmed by members of the target population. Quantitative evaluation used data from an anonymous web-based survey of Vietnamese SMW, including those who identified as lesbian (n = 1187), or as bisexual (n = 641) and those who were unsure about their sexual identity (n = 353). The scale was found to consist of two highly correlated factors reflecting self-stigma (not normal/wholesome and self-reproach and wishing away same-sex sexuality) and one factor reflecting sexual prejudice, and to have excellent internal consistency. Construct validity was evidenced by subscale associations with a wide range of hypothesized correlates, including perceived sexual stigma, outness, social support, connection to other SMW, relationship quality, psychological well-being, anticipation of heterosexual marriage, and endorsement of same-sex marriage legalization. Self-stigma was more strongly associated with psychosocial correlates, and sexual prejudice was more associated with endorsement of legal same-sex marriage. The variations in these associations across the hypothesized correlates and across sexual identity groups were consistent with the minority stress model and the IH literature, and exhibited context-specific features, which are discussed.

The Internalized Homophobia Scale for Vietnamese Sexual Minority Women (IHVN-W): Conceptualization, factor structure, reliability, and associations with hypothesized correlates

PubMed Central

Nguyen, Trang Quynh; Poteat, Tonia; Bandeen-Roche, Karen; German, Danielle; Nguyen, Yen Hai; Vu, Loan Kieu-Chau; Nguyen, Nam Thi-Thu; Knowlton, Amy R.

2016-01-01

We developed the first Vietnamese internalized homophobia (IH) scale, for use with Vietnamese sexual minority women (SMW). Drawing from existing IH scales in the international literature and based on prior qualitative research about SMW in the Viet Nam context, the scale covers two domains: self-stigma (negative attitudes toward oneself as a sexual minority person) and sexual prejudice (negative attitudes toward homosexuality/same-sex relations in general). Scale items, including items borrowed from existing scales and items based on local expressions, were reviewed and confirmed by members of the target population. Quantitative evaluation used data from an anonymous web-based survey of Vietnamese SMW, including those who identified as lesbian (n=1187), or as bisexual (n=641) and those who were unsure about their sexual identity (n=353). The scale was found to consist of two highly correlated factors reflecting self-stigma (not normal/wholesome and self-reproach and wishing away same-sex sexuality) and one factor reflecting sexual prejudice, and to have excellent internal consistency. Construct validity was evidenced by subscales’ associations with a wide range of hypothesized correlates including perceived sexual stigma, outness, social support, connection to other SMW, relationship quality, psychological well-being, anticipation of heterosexual marriage and endorsement of same-sex marriage legalization. Self-stigma was more strongly associated with psychosocial correlates and sexual prejudice was more associated with endorsement of legal same-sex marriage. The variations in these associations across the hypothesized correlates and across sexual identity groups were consistent with the Minority Stress Model and the IH literature, and exhibited context-specific features, which are discussed. PMID:27007469

Risk factors for technical failure of endoscopic double self-expandable metallic stent placement by partial stent-in-stent method.

PubMed

Kawakubo, Kazumichi; Kawakami, Hiroshi; Toyokawa, Yoshihide; Otani, Koichi; Kuwatani, Masaki; Abe, Yoko; Kawahata, Shuhei; Kubo, Kimitoshi; Kubota, Yoshimasa; Sakamoto, Naoya

2015-01-01

Endoscopic double self-expandable metallic stent (SEMS) placement by the partial stent-in-stent (PSIS) method has been reported to be useful for the management of unresectable hilar malignant biliary obstruction. However, it is technically challenging, and the optimal SEMS for the procedure remains unknown. The aim of this study was to identify the risk factors for technical failure of endoscopic double SEMS placement for unresectable malignant hilar biliary obstruction (MHBO). Between December 2009 and May 2013, 50 consecutive patients with MHBO underwent endoscopic double SEMS placement by the PSIS method. We retrospectively evaluated the rate of successful double SEMS placement and identified the risk factors for technical failure. The technical success rate for double SEMS placement was 82.0% (95% confidence interval [CI]: 69.2-90.2). On univariate analysis, the rate of technical failure was high in patients with metastatic disease and unilateral placement. Multivariate analysis revealed that metastatic disease was a significant risk factor for technical failure (odds ratio: 9.63, 95% CI: 1.11-105.5). The subgroup analysis after double guidewire insertion showed that the rate of technical success was higher in the laser-cut type SEMS with a large mesh and thick delivery system than in the braided type SEMS with a small mesh and thick delivery system. Metastatic disease was a significant risk factor for technical failure of double SEMS placement for unresectable MHBO. The laser-cut type SEMS with a large mesh and thin delivery system might be preferable for the PSIS procedure. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Mechanisms of increased lifespan in hypoxia in the alfalfa leafcutting bee, Megachile rotundata

USDA-ARS?s Scientific Manuscript database

Genetic variation accounts for a small amount of variation in lifespan, while environmental stressors are strong predictors. Hypoxia is an environmental stress that increases longevity in some contexts, but the mechanisms remain poorly understood. In the bee Megachile rotundata, lifespan doubles upo...

Body Knowledge in Brain-Damaged Children: A Double-Dissociation in Self and Other's Body Processing

ERIC Educational Resources Information Center

Frassinetti, Francesca; Fiori, Simona; D'Angelo, Valentina; Magnani, Barbara; Guzzetta, Andrea; Brizzolara, Daniela; Cioni, Giovanni

2012-01-01

Bodies are important element for self-recognition. In this respect, in adults it has been recently shown a self vs other advantage when small parts of the subjects' body are visible. This advantage is lost following a right brain lesion underlying a role of the right hemisphere in self body-parts processing. In order to investigate the bodily-self…

Multiple and configurable optical logic systems based on layered double hydroxides and chromophore assemblies.

PubMed

Shi, Wenying; Fu, Yi; Li, Zhixiong; Wei, Min

2015-01-14

Multiple and configurable fluorescence logic gates were fabricated via self-assembly of layered double hydroxides and various chromophores. These logic gates were operated by observation of different emissions with the same excitation wavelength, which achieve YES, NOT, AND, INH and INHIBIT logic operations, respectively.

Phase modulation of mid-infrared radiation in double-quantum-well structures under a lateral electric field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balagula, R. M.; Vinnichenko, M. Ya.; Makhov, I. S.

2017-03-15

The modulation of polarized radiation by GaAs/AlGaAs structures with tunnel-coupled double quantum wells in a strong lateral electric field is studied. The spectra of the variation in the refractive index under a lateral electric field in the vicinity of the intersubband resonance are experimentally investigated.

Preparation of microcapsules containing double-component lubricant and self-lubricating performance of polymer composites

NASA Astrophysics Data System (ADS)

Li, Haiyan; Shi, Nanqi; Ji, Jing; Wang, Huaiyuan

2018-05-01

Double-component microcapsules containing lubricant oil and SiO2 nanoparticles were prepared by solvent evaporation method. The synthesized microcapsules have the regular spherical structure with the mean diameter of 105 μm and wall thickness of 15 μm. The synthesized microcapsules have excellent thermal stability, and the lubricant oil content was 71.4 wt%. Self-lubricating polymer composites were fabricated by incorporating double-component microcapsules into epoxy matrix. When the SiO2 nanoparticles content was 3 wt% relative to the lubricant oil, 10 wt% microcapsules brought 60.8% and 93.3% decrease for epoxy composites in the friction coefficient and specific wear rate, respectively. The synergetic effect between lubricant oil and SiO2 nanoparticles play a positive role in improving the triboligical properties of polymer composites.

Motion perception during variable-radius swing motion in darkness.

PubMed

Rader, A A; Oman, C M; Merfeld, D M

2009-10-01

Using a variable-radius roll swing motion paradigm, we examined the influence of interaural (y-axis) and dorsoventral (z-axis) force modulation on perceived tilt and translation by measuring perception of horizontal translation, roll tilt, and distance from center of rotation (radius) at 0.45 and 0.8 Hz using standard magnitude estimation techniques (primarily verbal reports) in darkness. Results show that motion perception was significantly influenced by both y- and z-axis forces. During constant radius trials, subjects' perceptions of tilt and translation were generally almost veridical. By selectively pairing radius (1.22 and 0.38 m) and frequency (0.45 and 0.8 Hz, respectively), the y-axis acceleration could be tailored in opposition to gravity so that the combined y-axis gravitoinertial force (GIF) variation at the subject's ears was reduced to approximately 0.035 m/s(2) - in effect, the y-axis GIF was "nulled" below putative perceptual threshold levels. With y-axis force nulling, subjects overestimated their tilt angle and underestimated their horizontal translation and radius. For some y-axis nulling trials, a radial linear acceleration at twice the tilt frequency (0.25 m/s(2) at 0.9 Hz, 0.13 m/s(2) at 1.6 Hz) was simultaneously applied to reduce the z-axis force variations caused by centripetal acceleration and by changes in the z-axis component of gravity during tilt. For other trials, the phase of this radial linear acceleration was altered to double the magnitude of the z-axis force variations. z-axis force nulling further increased the perceived tilt angle and further decreased perceived horizontal translation and radius relative to the y-axis nulling trials, while z-axis force doubling had the opposite effect. Subject reports were remarkably geometrically consistent; an observer model-based analysis suggests that perception was influenced by knowledge of swing geometry.

Functions of Autobiographical Memory in Younger and Older Adults.

PubMed

Vranić, Andrea; Jelić, Margareta; Tonković, Mirjana

2018-01-01

Functional approach to autobiographical memory (AM) posits its three broad functions: directive, self, and social. Although these functions are probably universal, life stage and gender variations are expected. This research builds on previous studies investigating the validity of Thinking About Life Experiences Questionnaire (TALE; Bluck and Alea, 2011). A sample of 365 adults (56% female, mean age 43.3 years), divided in 2 age cohorts (young: 18-45 years, old: 46-90 years), used TALE, to rate their tendency of using AM for three different purposes, and measures of self-concept clarity, attachment in close relationships and time perspective. Confirmatory factor analysis of TALE confirmed the tripartite model of AM functions and further analysis showed partial factorial equivalence across age and gender groups. Young tend to use AM more for directing future behavior and social-bonding, while no age differences were found in the use of AM to serve self-function. As for gender variations, women tend to use AM more for directing their behavior, while no other gender differences in the use of AM were found. TALE showed good internal consistency and convergent validity of the three subscales. The theory-driven hypotheses that individuals with low self-concept clarity would use AM more often to serve a self-function, those with higher levels of attachment anxiety would use AM more often to serve a social function, and those past-oriented would use memory more often for directive purpose, were all confirmed. Also confirmed was the notion of Past Negative Orientation to be more related to the directive use of AM than Past Positive Time Orientation. Limitations and future directions are discussed.

Functions of Autobiographical Memory in Younger and Older Adults

PubMed Central

Vranić, Andrea; Jelić, Margareta; Tonković, Mirjana

2018-01-01

Functional approach to autobiographical memory (AM) posits its three broad functions: directive, self, and social. Although these functions are probably universal, life stage and gender variations are expected. This research builds on previous studies investigating the validity of Thinking About Life Experiences Questionnaire (TALE; Bluck and Alea, 2011). A sample of 365 adults (56% female, mean age 43.3 years), divided in 2 age cohorts (young: 18–45 years, old: 46–90 years), used TALE, to rate their tendency of using AM for three different purposes, and measures of self-concept clarity, attachment in close relationships and time perspective. Confirmatory factor analysis of TALE confirmed the tripartite model of AM functions and further analysis showed partial factorial equivalence across age and gender groups. Young tend to use AM more for directing future behavior and social-bonding, while no age differences were found in the use of AM to serve self-function. As for gender variations, women tend to use AM more for directing their behavior, while no other gender differences in the use of AM were found. TALE showed good internal consistency and convergent validity of the three subscales. The theory-driven hypotheses that individuals with low self-concept clarity would use AM more often to serve a self-function, those with higher levels of attachment anxiety would use AM more often to serve a social function, and those past-oriented would use memory more often for directive purpose, were all confirmed. Also confirmed was the notion of Past Negative Orientation to be more related to the directive use of AM than Past Positive Time Orientation. Limitations and future directions are discussed. PMID:29599732

Radio jet refraction in galactic atmospheres with static pressure gradients

NASA Technical Reports Server (NTRS)

Henriksen, R. N.; Vallee, J. P.; Bridle, A. H.

1981-01-01

A theory based on the refraction of radio jets in the extended atmosphere of an elliptical galaxy, is proposed for double radio sources with a Z or S morphology. The model describes a collimated jet of supersonic material that bends self-consistently under the influence of external static pressure gradients, and may alternatively be seen as a continuous-jet version of the buoyancy model proposed by Gull (1973). Emphasis is placed on (1) S-shaped radio sources identified with isolated galaxies, such as 3C 293, whose radio structures should be free of distortions resulting from motion relative to a cluster medium, and (2) small-scale, galaxy-dominated rather than environment-dominated S-shaped sources such as the inner jet structure of Fornax A.

Multilayered nano-architecture of variable sized graphene nanosheets for enhanced supercapacitor electrode performance.

PubMed

Biswas, Sanjib; Drzal, Lawrence T

2010-08-01

The diverse physical and chemical aspects of graphene nanosheets such as particle size surface area and edge chemistry were combined to fabricate a new supercapacitor electrode architecture consisting of a highly aligned network of large-sized nanosheets as a series of current collectors within a multilayer configuration of bulk electrode. Capillary driven self-assembly of monolayers of graphene nanosheets was employed to create a flexible, multilayer, free-standing film of highly hydrophobic nanosheets over large macroscopic areas. This nanoarchitecture exhibits a high-frequency capacitative response and a nearly rectangular cyclic voltammogram at 1000 mV/s scanning rate and possesses a rapid current response, small equivalent series resistance (ESR), and fast ionic diffusion for high-power electrical double-layer capacitor (EDLC) application.

Characterization of the Minimum Energy Paths and Energetics for the Reaction of Vinylidene with Acetylene

NASA Technical Reports Server (NTRS)

Walch, Stephen P.; Taylor, Peter R.

1995-01-01

The reaction of vinylidene (CH2C) with acetylene may be an initiating reaction in soot formation. We report minimum energy paths and accurate energetics for a pathway leading to vinyl-acetylene and for a number of isomers of C4H4. The calculations use complete active space self-consistent field (CASSCF) derivative methods to characterize the stationary points and internally contacted configuration interaction (ICCI) and/or coupled cluster singles and doubles with a perturbational estimate of triple excitations (CCSD(T)) to determine the energetics. We find an entrance channel barrier of about 5 kcal/mol for the addition of vinylidene to acetylene, but no barriers above reactants for the reaction pathway leading to vinyl-acetylene.

Characterization of the Minimum Energy Paths and Energetics for the reaction of Vinylidene with Acetylene

NASA Technical Reports Server (NTRS)

Walch, Stephen P.; Taylor, Peter R.

1995-01-01

The reaction of vinylidene (CH2C) with acetylene may be an initiating reaction in soot formation. We report minimum energy paths and accurate energetics for a pathway leading to vinylacetylene and for a number of isomers Of C4H4. The calculations use complete active space self-consistent field (CASSCF) derivative methods to characterize the stationary points and internally contacted configuration interaction (ICCI) and/or coupled cluster singles and doubles with a perturbational estimate of triple excitations (CCSD(T)) to determine the energetics. We find an entrance channel barrier of about 5 kcal/mol for the addition of vinylidene to acetylene, but no barriers above reactants for the reaction pathway leading to vinylacetylene.

The protonation of N2O reexamined - A case study on the reliability of various electron correlation methods for minima and transition states

NASA Technical Reports Server (NTRS)

Martin, J. M. L.; Lee, Timothy J.

1993-01-01

The protonation of N2O and the intramolecular proton transfer in N2OH(+) are studied using various basis sets and a variety of methods, including second-order many-body perturbation theory (MP2), singles and doubles coupled cluster (CCSD), the augmented coupled cluster (CCSD/T/), and complete active space self-consistent field (CASSCF) methods. For geometries, MP2 leads to serious errors even for HNNO(+); for the transition state, only CCSD/T/ produces a reliable geometry due to serious nondynamical correlation effects. The proton affinity at 298.15 K is estimated at 137.6 kcal/mol, in close agreement with recent experimental determinations of 137.3 +/- 1 kcal/mol.

Track chambers based on precision drift tubes housed inside 30 mm mylar pipe

NASA Astrophysics Data System (ADS)

Borisov, A.; Bozhko, N.; Fakhrutdinov, R.; Kozhin, A.; Leontiev, B.; Levin, A.

2014-06-01

We describe drift chambers consisting of 3 layers of 30 mm (OD) drift tubes made of double sided aluminized mylar film with thickness 0.125 mm. A single drift tube is self-supported structure withstanding 350 g tension of 50 microns sense wire located in the tube center with 10 microns precision with respect to end-plug outer surface. Such tubes allow to create drift chambers with small amount of material, construction of such chambers doesn't require hard frames. Twenty six chambers with working area from 0.8 × 1.0 to 2.5 × 2.0 m2 including 4440 tubes have been manufactured for experiments at 70-GeV proton accelerator at IHEP(Protvino).

On the theory of quantum measurement

NASA Technical Reports Server (NTRS)

Haus, Hermann A.; Kaertner, Franz X.

1994-01-01

Many so called paradoxes of quantum mechanics are clarified when the measurement equipment is treated as a quantized system. Every measurement involves nonlinear processes. Self consistent formulations of nonlinear quantum optics are relatively simple. Hence optical measurements, such as the quantum nondemolition (QND) measurement of photon number, are particularly well suited for such a treatment. It shows that the so called 'collapse of the wave function' is not needed for the interpretation of the measurement process. Coherence of the density matrix of the signal is progressively reduced with increasing accuracy of the photon number determination. If the QND measurement is incorporated into the double slit experiment, the contrast ratio of the fringes is found to decrease with increasing information on the photon number in one of the two paths.

Communication: Hilbert-space partitioning of the molecular one-electron density matrix with orthogonal projectors

NASA Astrophysics Data System (ADS)

Vanfleteren, Diederik; Van Neck, Dimitri; Bultinck, Patrick; Ayers, Paul W.; Waroquier, Michel

2010-12-01

A double-atom partitioning of the molecular one-electron density matrix is used to describe atoms and bonds. All calculations are performed in Hilbert space. The concept of atomic weight functions (familiar from Hirshfeld analysis of the electron density) is extended to atomic weight matrices. These are constructed to be orthogonal projection operators on atomic subspaces, which has significant advantages in the interpretation of the bond contributions. In close analogy to the iterative Hirshfeld procedure, self-consistency is built in at the level of atomic charges and occupancies. The method is applied to a test set of about 67 molecules, representing various types of chemical binding. A close correlation is observed between the atomic charges and the Hirshfeld-I atomic charges.

Evolution and inheritance of early embryonic patterning in D. simulans and D. sechellia

PubMed Central

Lott, Susan E.; Ludwig, Michael Z.; Kreitman, Martin

2010-01-01

Pattern formation in Drosophila is a widely studied example of a robust developmental system. Such robust systems pose a challenge to adaptive evolution, as they mask variation which selection may otherwise act upon. Yet we find variation in the localization of expression domains (henceforth ‘stripe allometry’) in the pattern formation pathway. Specifically, we characterize differences in the gap genes giant and Kruppel, and the pair-rule gene even-skipped, which differ between the sibling species D. simulans and D. sechellia. In a double-backcross experiment, stripe allometry is consistent with maternal inheritance of stripe positioning and multiple genetic factors, with a distinct genetic basis from embryo length. Embryos produced by F1 and F2 backcross mothers exhibit novel spatial patterns of gene expression relative to the parental species, with no measurable increase in positional variance among individuals. Buffering of novel spatial patterns in the backcross genotypes suggests that robustness need not be disrupted in order for the trait to evolve, and perhaps the system is incapable of evolving to prevent the expression of all genetic variation. This limitation, and the ability of natural selection to act on minute genetic differences that are within the “margin of error” for the buffering mechanism, indicates that developmentally buffered traits can evolve without disruption of robustness PMID:21121913

Self-aligned blocking integration demonstration for critical sub-40nm pitch Mx level patterning

NASA Astrophysics Data System (ADS)

Raley, Angélique; Mohanty, Nihar; Sun, Xinghua; Farrell, Richard A.; Smith, Jeffrey T.; Ko, Akiteru; Metz, Andrew W.; Biolsi, Peter; Devilliers, Anton

2017-04-01

Multipatterning has enabled continued scaling of chip technology at the 28nm node and beyond. Selfaligned double patterning (SADP) and self-aligned quadruple patterning (SAQP) as well as Litho- Etch/Litho-Etch (LELE) iterations are widely used in the semiconductor industry to enable patterning at sub 193 immersion lithography resolutions for layers such as FIN, Gate and critical Metal lines. Multipatterning requires the use of multiple masks which is costly and increases process complexity as well as edge placement error variation driven mostly by overlay. To mitigate the strict overlay requirements for advanced technology nodes (7nm and below), a self-aligned blocking integration is desirable. This integration trades off the overlay requirement for an etch selectivity requirement and enables the cut mask overlay tolerance to be relaxed from half pitch to three times half pitch. Selfalignement has become the latest trend to enable scaling and self-aligned integrations are being pursued and investigated for various critical layers such as contact, via, metal patterning. In this paper we propose and demonstrate a low cost flexible self-aligned blocking strategy for critical metal layer patterning for 7nm and beyond from mask assembly to low -K dielectric etch. The integration is based on a 40nm pitch SADP flow with 2 cut masks compatible with either cut or block integration and employs dielectric films widely used in the back end of the line. As a consequence this approach is compatible with traditional etch, deposition and cleans tools that are optimized for dielectric etches. We will review the critical steps and selectivities required to enable this integration along with bench-marking of each integration option (cut vs. block).

Self-compensating design for reduction of timing and leakage sensitivity to systematic pattern dependent variation

NASA Astrophysics Data System (ADS)

Gupta, Puneet; Kahng, Andrew B.; Kim, Youngmin; Sylvester, Dennis

2006-03-01

Focus is one of the major sources of linewidth variation. CD variation caused by defocus is largely systematic after the layout is finished. In particular, dense lines "smile" through focus while isolated lines "frown" in typical Bossung plots. This well-defined systematic behavior of focus-dependent CD variation allows us to develop a self-compensating design methodology. In this work, we propose a novel design methodology that allows explicit compensation of focus-dependent CD variation, either within a cell (self-compensated cells) or across cells in a critical path (self-compensated design). By creating iso and dense variants for each library cell, we can achieve designs that are more robust to focus variation. Optimization with a mixture of iso and dense cell variants is possible both for area and leakage power, with the latter providing an interesting complement to existing leakage reduction techniques such as dual-Vth. We implement both heuristic and Mixed-Integer Linear Programming (MILP) solution methods to address this optimization, and experimentally compare their results. Our results indicate that designing with a self-compensated cell library incurs ~12% area penalty and ~6% leakage increase over original layouts while compensating for focus-dependent CD variation (i.e., the design meets timing constraints across a large range of focus variation). We observe ~27% area penalty and ~7% leakage increase at the worst-case defocus condition using only single-pitch cells. The area penalty of circuits after using either the heuristic or MILP optimization approach is reduced to ~3% while maintaining timing. We also apply our optimizations to leakage, which traditionally shows very large variability due to its exponential relationship with gate CD. We conclude that a mixed iso/dense library combined with a sensitivity-based optimization approach yields much better area/timing/leakage tradeoffs than using a self-compensated cell library alone. Self-compensated design shows an average of 25% leakage reduction at the worst defocus condition for the benchmark designs that we have studied.

Body image and psychological well-being in adolescents: the relationship between gender and school type.

PubMed

Delfabbro, Paul H; Winefield, Anthony H; Anderson, Sarah; Hammarström, Anne; Winefield, Helen

2011-01-01

Adolescents (N=1281; M age = 15.2 years, SD = 0.51 years) from a state-wide sample of schools provided information about their psychological well-being, family functioning, extraversion, and perceived physical attractiveness and weight, using a questionnaire completed at school. Consistent with previous research, girls were significantly more likely than boys to be dissatisfied with their weight and physical appearance, and these factors explained significantly more variation in self-esteem than in life satisfaction or other measures of psychological well-being. The strong relationship between body dissatisfaction and self-esteem for adolescent girls was not moderated by school type (single sex or educational). However, girls who were dissatisfied but psychologically well adjusted tended to be more extraverted, have more close friends and receive greater family support.

Flux-tube divergence, coronal heating, and the solar wind

NASA Technical Reports Server (NTRS)

Wang, Y.-M.

1993-01-01

Using model calculations based on a self-consistent treatment of the coronal energy balance, we show how the magnetic flux-tube divergence rate controls the coronal temperature and the properties of the solar wind. For a fixed input of mechanical and Alfven-wave energy at the coronal base, we find that as the divergence rate increases, the maximum coronal temperature decreases but the mass flux leaving the sun gradually increases. As a result, the asymptotic wind speed decreases with increasing expansion factor near the sun, in agreement with empirical studies. As noted earlier by Withbroe, the calculated mass flux at the sun is remarkably insensitive to parameter variations; when combined with magnetohydrodynamic considerations, this self-regulatory property of the model explains the observed constancy of the mass flux at earth.

Seismic waves in a self-gravitating planet

NASA Astrophysics Data System (ADS)

Brazda, Katharina; de Hoop, Maarten V.; Hörmann, Günther

2013-04-01

The elastic-gravitational equations describe the propagation of seismic waves including the effect of self-gravitation. We rigorously derive and analyze this system of partial differential equations and boundary conditions for a general, uniformly rotating, elastic, but aspherical, inhomogeneous, and anisotropic, fluid-solid earth model, under minimal assumptions concerning the smoothness of material parameters and geometry. For this purpose we first establish a consistent mathematical formulation of the low regularity planetary model within the framework of nonlinear continuum mechanics. Using calculus of variations in a Sobolev space setting, we then show how the weak form of the linearized elastic-gravitational equations directly arises from Hamilton's principle of stationary action. Finally we prove existence and uniqueness of weak solutions by the method of energy estimates and discuss additional regularity properties.

Molecular dynamics simulations of electrostatics and hydration distributions around RNA and DNA motifs

NASA Astrophysics Data System (ADS)

Marlowe, Ashley E.; Singh, Abhishek; Semichaevsky, Andrey V.; Yingling, Yaroslava G.

2009-03-01

Nucleic acid nanoparticles can self-assembly through the formation of complementary loop-loop interactions or stem-stem interactions. Presence and concentration of ions can significantly affect the self-assembly process and the stability of the nanostructure. In this presentation we use explicit molecular dynamics simulations to examine the variations in cationic distributions and hydration environment around DNA and RNA helices and loop-loop interactions. Our simulations show that the potassium and sodium ionic distributions are different around RNA and DNA motifs which could be indicative of ion mediated relative stability of loop-loop complexes. Moreover in RNA loop-loop motifs ions are consistently present and exchanged through a distinct electronegative channel. We will also show how we used the specific RNA loop-loop motif to design a RNA hexagonal nanoparticle.

28.1 VARIETIES OF SELF DISORDER: A BIO-PHENO-SOCIAL MODEL OF SCHIZOPHRENIA

PubMed Central

Nelson, Barnaby; Sass, Louis

2018-01-01

Abstract Background The self-disorder model offers a unifying way of conceptualizing schizophrenia’s highly diverse symptoms (positive, negative, disorganized), of capturing their distinctive bizarreness, and of conceiving their longitudinal development. These symptoms are viewed as differing manifestations of an underlying disorder of ‘core-self’: hyperreflexivity/diminished-self presence with accompanying disturbances of “grip” or “hold” on reality. Methods We have recently revised and tested this phenomenological model, in particular distinguishing primary versus-secondary factors, in offering a bio-pheno-social model of schizophrenia spectrum disorders. Results The revised model is consistent with recent empirical findings and offers several advantages: 1) It helps account for the temporal variations of the symptoms or syndrome, including longitudinal progression, but also the shorter-term, situationally-reactive, sometimes defensive, and possibly quasi-agentive variability of symptom-expression that can occur in schizophrenia (consistent with understanding some aspects of self-disturbance as dynamic and mutable, involving shifting attitudes or experiential orientations). 2) It accommodates the overlapping of some key schizophrenic symptoms with certain non-schizophrenia spectrum conditions involving dissociation (depersonalization and derealization), including Depersonalization Disorder and Panic Disorder, thereby acknowledging both shared and distinguishing symptoms. 3) It integrates recent neurocognitive, neurobiological, and psychosocial (e.g., influence of trauma and culture) findings into a coherent but multi-factorial neuropsychological account. Discussion An adequate model of schizophrenia will postulate shared disturbances of core-self experiences that nevertheless can follow several distinct pathways and occur in various forms. Such a model is preferable to uni-dimensional alternatives—whether of schizophrenia or core self disturbance—given its ability to account for distinctive yet varying experiential and neurocognitive abnormalities found in research on schizophrenia, and to integrate these with recent psychosocial as well as neurobiological findings.

A spectroscopic search for colliding stellar winds in O-type close binary systems. I - AO Cassiopeiae

NASA Technical Reports Server (NTRS)

Gies, Douglas R.; Wiggs, Michael S.

1991-01-01

AO Cas, a short-period, double-lined spectroscopic binary, is studied as part of a search for spectroscopic evidence of colliding stellar winds in binary systems of O-type stars. High S/N ratio spectra of the H-alpha and He I 6678-A line profiles are presented, and their orbital-phase-related variations are examined in order to derive the location and motions of high-density circumstellar gas in the system. These profile variations are compared with those observed in the UV stellar wind lines in IUE archival spectra. IUE spectra are also used to derive a system mass ratio by constructing cross-correlation functions of a single-lined phase spectrum with each of the other spectra. The resulting mass ratio is consistent with the rotational line broadening of the primary star, if the primary is rotating synchronously with the binary system. The best-fit models were found to have an inclination of 61.1 deg + or - 3.0 deg and have a primary which is close to filling its critical Roche lobe.

Modification of polymer velvet cathode via metallic Mo coating for enhancement of high-current electron emission performances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Ying; Wang, Bing; Yi, Yong

2013-09-15

The effect of surface Mo coating on the high-current electron emission performances for polymer velvet cathode has been investigated in a diode with A-K gap of 11.5 cm by the combination of time-resolved electrical diagnostic and temporal pressure variation. Compared with uncoated polymer velvet cathode under the single-pulsed emission mode, the Mo-coated one shows lower outgassing levels (∼0.40 Pa L), slower cathode plasma expansion velocity (∼2.30 cm/μs), and higher emission stability as evidences by the change in cathode current, temporal pressure variation, and diode perveance. Moreover, after Mo coating, the emission consistency of the polymer velvet cathode between two adjacentmore » pulses is significantly improved in double-pulsed emission mode with ∼500 ns interval between two pulses, which further confirms the effectiveness of Mo coating for enhancement of electron emission performance of polymer velvet cathodes. These results should be of interest to the high-repetitive high-power microwave systems with cold cathodes.« less

Skin Cancer, Irradiation, and Sunspots: The Solar Cycle Effect

PubMed Central

Zurbenko, Igor

2014-01-01

Skin cancer is diagnosed in more than 2 million individuals annually in the United States. It is strongly associated with ultraviolet exposure, with melanoma risk doubling after five or more sunburns. Solar activity, characterized by features such as irradiance and sunspots, undergoes an 11-year solar cycle. This fingerprint frequency accounts for relatively small variation on Earth when compared to other uncorrelated time scales such as daily and seasonal cycles. Kolmogorov-Zurbenko filters, applied to the solar cycle and skin cancer data, separate the components of different time scales to detect weaker long term signals and investigate the relationships between long term trends. Analyses of crosscorrelations reveal epidemiologically consistent latencies between variables which can then be used for regression analysis to calculate a coefficient of influence. This method reveals that strong numerical associations, with correlations >0.5, exist between these small but distinct long term trends in the solar cycle and skin cancer. This improves modeling skin cancer trends on long time scales despite the stronger variation in other time scales and the destructive presence of noise. PMID:25126567

A STRUCTURAL ANALYSIS OF THE MYELIN SHEATH IN THE CENTRAL NERVOUS SYSTEM

PubMed Central

Hirano, Asao; Dembitzer, Herbert M.

1967-01-01

The cerebral white matter of rats subjected to a variety of noxious experimental conditions was examined in the electron microscope. Several unusual configurations of the myelin sheath are identified in addition to the usual configuration. These variations include the presence of (a) formed organelles within the inner and outer loops, (b) isolated islands of cytoplasm in unfused portions of the major dense lines, (c) apparently unconnected cell processes between the sheath and the axon, and (d) concentric, double myelin sheaths. A generalized model of the myelin sheath based on a hypothetical unrolling of the sheath is described. It consists of a shovel-shaped myelin sheet surrounded by a continuous thickened rim of cytoplasm. Most of the unusual myelin configurations are explained as simple variations on this basic theme. With the help of this model, an explanation of the formation of the myelin sheath is offered. This explanation involves the concept that myelin formation can occur at all cytoplasmic areas adjacent to the myelin proper and that adjacent myelin lamellae can move in relation to each other. PMID:6035645

Complex between triple helix of collagen and double helix of DNA in aqueous solution.

PubMed

Mrevlishvili, George M; Svintradze, David V

2005-06-01

We demonstrate in this paper that one example of a biologically important and molecular self-assembling complex system is a collagen-DNA ordered aggregate which spontaneously forms in aqueous solutions. Interaction between the collagen and the DNA leads to destruction of the hydration shell of the triple helix and stabilization of the double helix structure. From a molecular biology point of view this nano-scale self-assembling superstructure could increase the stability of DNA against the nucleases during collagen diseases and the growth of collagen fibrills in the presence of DNA.

Persistence length of wormlike micelles composed of ionic surfactants: self-consistent-field predictions.

PubMed

Lauw, Y; Leermakers, F A M; Stuart, M A Cohen

2007-07-19

The persistence length of a wormlike micelle composed of ionic surfactants C(n)E(m)X(k) in an aqueous solvent is predicted by means of the self-consistent-field theory where C(n)E(m) is the conventional nonionic surfactant and X(k) is an additional sequence of k weakly charged (pH-dependent) segments. By considering a toroidal micelle at infinitesimal curvature, we evaluate the bending modulus of the wormlike micelle that corresponds to the total persistence length, consisting of an elastic/intrinsic and an electrostatic contribution. The total persistence length increases with pH and decreases with increasing background salt concentration. We estimate that the electrostatic persistence length l(p,e)(0) scales with respect to the Debye length kappa(-1) as l(p,e)(0) approximately kappa(-p) where p approximately 1.98 for wormlike micelles consisting of C(20)E(10)X(1) surfactants and p approximately 1.54 for wormlike micelles consisting of C(20)E(10)X(2) surfactants. The total persistence length l(p,t)(0) is a weak function of the head group length m but scales with the tail length n as l(p,t)(0) approximately n(x) where x approximately 2-2.6, depending on the corresponding head group length. Interestingly, l(p,t)(0) varies nonmonotonically with the number of charged groups k due to the opposing trends in the electrostatic and elastic bending rigidities upon variation of k.

Effects of doubling the portion size of fruit and vegetable side dishes on children's intake at a meal.

PubMed

Kral, Tanja V E; Kabay, April C; Roe, Liane S; Rolls, Barbara J

2010-03-01

Increasing the portion size of energy-dense entrées has been shown to increase children's energy intake during a meal. It remains to be investigated whether serving larger portions to children can be used to promote intake of more healthful foods, such as fruits and vegetables (F&V). The aim of the present study was to examine the effects of increasing the portion size of F&V side dishes on children's intake. Forty-three children (22 boys, 21 girls), aged 5-6 years, were served dinner once a week for 2 weeks. Each dinner consisted of pasta with tomato sauce, three F&V side dishes (broccoli, carrots, and applesauce), and milk. The portion size of the F&V was doubled between experimental conditions whereas the size of the pasta remained constant. Doubling the portion size of the side dishes resulted in a 43% increase in children's intake of the fruit side dish (P = 0.001), but did not affect children's intake of the two vegetable side dishes (P > 0.60). Further, when the portion size of F&V side dishes was doubled, children ate significantly less of the pasta (P = 0.04). The difference in meal energy intake between portion size conditions (19.5 +/- 16.3 kcal) was not significant (P = 0.24). Although more studies are needed to understand whether increases in portion size can influence vegetable intake, children did eat more in response to a large quantity of a preferred low energy-dense fruit side dish at meals. Thus variations in portion size can be used strategically to help children achieve the recommended intake of fruits.

Perceived exercise self-efficacy as a predictor of exercise behavior in individuals aging with spinal cord injury.

PubMed

Kroll, Thilo; Kratz, Anna; Kehn, Matthew; Jensen, Mark P; Groah, Suzanne; Ljungberg, Inger H; Molton, Ivan R; Bombardier, Charles

2012-08-01

The purpose of this study was to test the hypothesized association between exercise self-efficacy and exercise behavior, controlling for demographic variables and clinical characteristics, in a sample of individuals with spinal cord injuries. A cross-sectional national survey of 612 community-dwelling adults with spinal cord injury in the United States ranging from 18 to 89 yrs of age was conducted. Sample consisted of 63.1% men with a mean (SD) duration of 15.8 (12.79) yrs postinjury; 86.3% reported using a wheelchair. Self-efficacy was the only independent variable that consistently predicted all four exercise outcomes. Self-efficacy beliefs were significantly related to frequency and intensity of resistance training (R(2) change = 0.08 and 0.03, respectively; P < 0.01 for all) and aerobic training (R(2) change = 0.07 and 0.05, respectively; P < 0.01 for all), thus explaining between 3% and 8% of the variance. Hierarchical linear regression analysis revealed that controlling for other demographic and physical capability variables, the age-related variables made statistically significant contributions and explained between 1% and 3% of the variance in aerobic exercise frequency and intensity (R(2) change = 0.01 and 0.03, respectively; P < 0.01 for all). Clinical functional characteristics but not demographic variables explained participation in resistance exercise. Self-efficacy beliefs play an important role as predictors of exercise. Variations in exercise intensity along the age continuum have implications for exercise prescription and composition. Future research should replicate findings with objective activity measures.

Childhood general mental ability and midlife psychosocial work characteristics as related to mental distress, neck/shoulder pain and self-rated health in working women and men.

PubMed

Wulff, Cornelia; Lindfors, Petra; Sverke, Magnus

2011-01-01

Psychosocial work characteristics including high demands, lack of control and poor social support have consistently been linked to poor health as has poor general mental ability (GMA). However, less is known about the relationships between stable individual factors such as GMA, psychosocial work characteristics and health. The present study investigated how childhood mental ability and psychosocial work characteristics relate to health in terms of mental distress, neck/shoulder pain (NSP) and self-rated health (SRH). Data on childhood GMA, occupational level, self-reports of demands, control and social support and health (mental distress, NSP and SRH) in midlife came from working women (n=271) and men (n=291) included in a Swedish school cohort. Hierarchical regression analyses, controlling for occupational level, were used to examine associations between childhood GMA, self-reports of high demands, low control and poor social support and the three health indicators. Taking into consideration the gendered labor market and variations in health patterns between women and men, gender specific analyses were performed. There were no significant associations between childhood GMA and health indicators. Further, there were no significant interactions between GMA and psychosocial work factors. As regards the strength of the associations between GMA, psychosocial work factors and health, no consistent differences emerged between women and men. In a cohort of healthy and working middle-aged women and men, self-reports of current psychosocial work characteristics seem to be more strongly linked to health, than are stable childhood factors such as GMA.

Space-based Coronagraphic Imaging Polarimetry of the TW Hydrae Disk: Shedding New Light on Self-shadowing Effects

NASA Astrophysics Data System (ADS)

Poteet, Charles A.; Chen, Christine H.; Hines, Dean C.; Perrin, Marshall D.; Debes, John H.; Pueyo, Laurent; Schneider, Glenn; Mazoyer, Johan; Kolokolova, Ludmilla

2018-06-01

We present Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer coronagraphic imaging polarimetry of the TW Hydrae protoplanetary disk. These observations simultaneously measure the total and polarized intensity, allowing direct measurement of the polarization fraction across the disk. In accord with the self-shadowing hypothesis recently proposed by Debes et al., we find that the total and polarized intensity of the disk exhibits strong azimuthal asymmetries at projected distances consistent with the previously reported bright and dark ring-shaped structures (∼45–99 au). The sinusoidal-like variations possess a maximum brightness at position angles near ∼268°–300° and are up to ∼28% stronger in total intensity. Furthermore, significant radial and azimuthal variations are also detected in the polarization fraction of the disk. In particular, we find that regions of lower polarization fraction are associated with annuli of increased surface brightness, suggesting that the relative proportion of multiple-to-single scattering is greater along the ring and gap structures. Moreover, we find strong (∼20%) azimuthal variation in the polarization fraction along the shadowed region of the disk. Further investigation reveals that the azimuthal variation is not the result of disk flaring effects, but is instead from a decrease in the relative contribution of multiple-to-single scattering within the shadowed region. Employing a two-layer scattering surface, we hypothesize that the diminished contribution in multiple scattering may result from shadowing by an inclined inner disk, which prevents direct stellar light from reaching the optically thick underlying surface component.

D-cycloserine combined with cue exposure therapy fails to attenuate subjective and physiological craving in cocaine dependence.

PubMed

Santa Ana, Elizabeth J; Prisciandaro, James J; Saladin, Michael E; McRae-Clark, Aimee L; Shaftman, Stephanie R; Nietert, Paul J; Brady, Kathleen T

2015-04-01

Based on preclinical studies showing that the partial N-methyl-D-aspartate (NMDA) agonist D-cycloserine (DCS) facilitates extinction of cocaine self-administration and cocaine-induced conditioned place preference, we evaluated whether 50 mg of DCS would reduce craving to cocaine cues when combined with cue exposure (CE) in cocaine dependent humans. In this double-blind placebo-controlled pilot study, 47 cocaine dependent participants were randomized to DCS or placebo (PBO), plus CE. Participants received DCS or PBO 30 minutes prior to two CE sessions, conducted one day apart. Craving and heart rate was assessed prior to CE sessions, during CE trials, and after CE trials. These measures were assessed again at a 1-week follow-up (session 3) after the second CE session. DCS failed to significantly attenuate cocaine cue reactivity based on subjective craving and physiological reactivity (heart rate) compared to PBO. The CE protocol, consisting of repeated exposure to drug cues combined with skills training, resulted in extinction to cocaine cues as suggested by decreased craving within and between sessions in both treatment conditions. All participants exhibited elevated heart rate with repeated exposures, demonstrating a potentiation in heart rate between sessions. 50 mg of DCS may not be effective for extinguishing reactivity to drug cues for individuals with cocaine dependence. Future studies examining the effect of DCS on facilitating extinction to drug cues should examine variations in cue exposure length, number of CE presentations, and timing of DCS dose administration prior to cue exposures, which may differentially impact drug cue reactivity. © American Academy of Addiction Psychiatry.

Measuring visual discomfort associated with 3D displays

NASA Astrophysics Data System (ADS)

Lambooij, M.; Fortuin, M.; Ijsselsteijn, W. A.; Heynderickx, I.

2009-02-01

Some people report visual discomfort when watching 3D displays. For both the objective measurement of visual fatigue and the subjective measurement of visual discomfort, we would like to arrive at general indicators that are easy to apply in perception experiments. Previous research yielded contradictory results concerning such indicators. We hypothesize two potential causes for this: 1) not all clinical tests are equally appropriate to evaluate the effect of stereoscopic viewing on visual fatigue, and 2) there is a natural variation in susceptibility to visual fatigue amongst people with normal vision. To verify these hypotheses, we designed an experiment, consisting of two parts. Firstly, an optometric screening was used to differentiate participants in susceptibility to visual fatigue. Secondly, in a 2×2 within-subjects design (2D vs 3D and two-view vs nine-view display), a questionnaire and eight optometric tests (i.e. binocular acuity, fixation disparity with and without fusion lock, heterophoria, convergent and divergent fusion, vergence facility and accommodation response) were administered before and immediately after a reading task. Results revealed that participants found to be more susceptible to visual fatigue during screening showed a clinically meaningful increase in fusion amplitude after having viewed 3D stimuli. Two questionnaire items (i.e., pain and irritation) were significantly affected by the participants' susceptibility, while two other items (i.e., double vision and sharpness) were scored differently between 2D and 3D for all participants. Our results suggest that a combination of fusion range measurements and self-report is appropriate for evaluating visual fatigue related to 3D displays.

Influence of LTB4 on CD4-, CD8- thymocytes. Evidence that LTB4 plus IL-2 generate CD8+ suppressor thymocytes involved in tolerance to self. Effect of LTB4 and IL-2 on double negative thymocytes.

PubMed

Gualde, N; Cogny van Weydevelt, F; Buffière, F; Jauberteau, M O; Daculsi, R; Vaillier, D

1991-09-01

Leukotriene B4 (LTB4) is produced by a large variety of cells involved in immune response and it has been demonstrated that this arachidonic acid metabolite acts as an immunomodulator. Because LTB4 and IL-2 both influence the physiology of immature cells we studied the effects of the leukotriene on double negative thymocytes. For that purpose C57 Bl/6 double negative thymocytes were treated by LTB4 plus IL-2 in the presence of either autologous or allogenic red blood cells (RBC). Then, preincubated CD4- CD8- thymocytes were cocultured with red blood cells stimulated fresh splenocytes. We observed that fresh splenocytes responding to autologous RBC were CD4+ cells and that the proliferative response of spleen lymphocytes driven by RBC was inhibited by preincubated double negative thymocytes. On the other hand a majority of double negative thymocytes overnight preincubated in vitro in the presence of both IL-2 and LTB4 give rise to CD8+ CD4- cells. Therefore we speculate that LTB4 plus IL-2 generate CD8+ suppressor thymocytes among double negative thymocytes and that these suppressive T cells are involved in tolerance to self.

A Study on the Propulsive Mechanism of a Double Jointed Fish Robot Utilizing Self-Excitation Control

NASA Astrophysics Data System (ADS)

Nakashima, Motomu; Ohgishi, Norifumi; Ono, Kyosuke

This paper describes a numerical and experimental study of a double jointed fish robot utilizing self-excitation control. The fish robot is composed of a streamlined body and a rectangular caudal fin. The body length is 280mm and it has a DC motor to actuate its first joint and a potentiometer to detect the angle of its second joint. The signal from the potentiometer is fed back into the DC motor, so that the system can be self-excited. In order to obtain a stable oscillation and a resultant stable propulsion, a torque limiter circuit is employed. From the experiment, it has been found that the robot can stably propel using this control and the maximum propulsive speed is 0.42m/s.

Intra- and Inter-Individual Variation in Self-Reported Code-Switching Patterns of Adult Multilinguals

ERIC Educational Resources Information Center

Dewaele, Jean-Marc; Li, Wei

2014-01-01

The present study is a large-scale quantitative analysis of intra-individual variation (linked to type of interlocutor) and inter-individual variation (linked to multilingualism, sociobiographical variables and three personality traits) in self-reported frequency of code-switching (CS) among 2116 multilinguals. We found a significant effect of…

Monitoring of interaction of low-frequency electric field with biological tissues upon optical clearing with optical coherence tomography.

PubMed

Peña, Adrián F; Doronin, Alexander; Tuchin, Valery V; Meglinski, Igor

2014-08-01

The influence of a low-frequency electric field applied to soft biological tissues ex vivo at normal conditions and upon the topical application of optical clearing agents has been studied by optical coherence tomography (OCT). The electro-kinetic response of tissues has been observed and quantitatively evaluated by the double correlation OCT approach, utilizing consistent application of an adaptive Wiener filtering and Fourier domain correlation algorithm. The results show that fluctuations, induced by the electric field within the biological tissues are exponentially increased in time. We demonstrate that in comparison to impedance measurements and the mapping of the temperature profile at the surface of the tissue samples, the double correlation OCT approach is much more sensitive to the changes associated with the tissues' electro-kinetic response. We also found that topical application of the optical clearing agent reduces the tissues' electro-kinetic response and is cooling the tissue, thus reducing the temperature induced by the electric current by a few degrees. We anticipate that dcOCT approach can find a new application in bioelectrical impedance analysis and monitoring of the electric properties of biological tissues, including the resistivity of high water content tissues and its variations.

Evidence for a remodelling of DNA-PK upon autophosphorylation from electron microscopy studies

PubMed Central

Morris, Edward P.; Rivera-Calzada, Angel; da Fonseca, Paula C. A.; Llorca, Oscar; Pearl, Laurence H.; Spagnolo, Laura

2011-01-01

The multi-subunit DNA-dependent protein kinase (DNA-PK), a crucial player in DNA repair by non-homologous end-joining in higher eukaryotes, consists of a catalytic subunit (DNA-PKcs) and the Ku heterodimer. Ku recruits DNA-PKcs to double-strand breaks, where DNA-PK assembles prior to DNA repair. The interaction of DNA-PK with DNA is regulated via autophosphorylation. Recent SAXS data addressed the conformational changes occurring in the purified catalytic subunit upon autophosphorylation. Here, we present the first structural analysis of the effects of autophosphorylation on the trimeric DNA-PK enzyme, performed by electron microscopy and single particle analysis. We observe a considerable degree of heterogeneity in the autophosphorylated material, which we resolved into subpopulations of intact complex, and separate DNA-PKcs and Ku, by using multivariate statistical analysis and multi-reference alignment on a partitioned particle image data set. The proportion of dimeric oligomers was reduced compared to non-phosphorylated complex, and those dimers remaining showed a substantial variation in mutual monomer orientation. Together, our data indicate a substantial remodelling of DNA-PK holo-enzyme upon autophosphorylation, which is crucial to the release of protein factors from a repaired DNA double-strand break. PMID:21450809

Tissue-Specific Profiling Reveals Transcriptome Alterations in Arabidopsis Mutants Lacking Morphological Phenotypes[C][W

PubMed Central

Simon, Marissa; Bruex, Angela; Kainkaryam, Raghunandan M.; Zheng, Xiaohua; Huang, Ling; Woolf, Peter J.; Schiefelbein, John

2013-01-01

Traditional genetic analysis relies on mutants with observable phenotypes. Mutants lacking visible abnormalities may nevertheless exhibit molecular differences useful for defining gene function. To examine this, we analyzed tissue-specific transcript profiles from Arabidopsis thaliana transcription factor gene mutants with known roles in root epidermis development, but lacking a single-gene mutant phenotype due to genetic redundancy. We discovered substantial transcriptional changes in each mutant, preferentially affecting root epidermal genes in a manner consistent with the known double mutant effects. Furthermore, comparing transcript profiles of single and double mutants, we observed remarkable variation in the sensitivity of target genes to the loss of one or both paralogous genes, including preferential effects on specific branches of the epidermal gene network, likely reflecting the pathways of paralog subfunctionalization during evolution. In addition, we analyzed the root epidermal transcriptome of the transparent testa glabra2 mutant to clarify its role in the network. These findings provide insight into the molecular basis of genetic redundancy and duplicate gene diversification at the level of a specific gene regulatory network, and they demonstrate the usefulness of tissue-specific transcript profiling to define gene function in mutants lacking informative visible changes in phenotype. PMID:24014549

A model study of tunneling conductance spectra of ferromagnetically ordered manganites

NASA Astrophysics Data System (ADS)

Panda, Saswati; Kar, J. K.; Rout, G. C.

2018-02-01

We report here the interplay of ferromagnetism (FM) and charge density wave (CDW) in manganese oxide systems through the study of tunneling conductance spectra. The model Hamiltonian consists of strong Heisenberg coupling in core t2g band electrons within mean-field approximation giving rise to ferromagnetism. Ferromagnetism is induced in the itinerant eg electrons due to Kubo-Ohata type double exchange (DE) interaction among the t2g and eg electrons. The charge ordering (CO) present in the eg band giving rise to CDW interaction is considered as the extra-mechanism to explain the colossal magnetoresistance (CMR) property of manganites. The magnetic and CDW order parameters are calculated using Zubarev's Green's function technique and solved self-consistently and numerically. The eg electron density of states (DOS) calculated from the imaginary part of the Green's function explains the experimentally observed tunneling conductance spectra. The DOS graph exhibits a parabolic gap near the Fermi energy as observed in tunneling conductance spectra experiments.

Surface-dependent chemical equilibrium constants and capacitances for bare and 3-cyanopropyldimethylchlorosilane coated silica nanochannels.

PubMed

Andersen, Mathias Bækbo; Frey, Jared; Pennathur, Sumita; Bruus, Henrik

2011-01-01

We present a combined theoretical and experimental analysis of the solid-liquid interface of fused-silica nanofabricated channels with and without a hydrophilic 3-cyanopropyldimethylchlorosilane (cyanosilane) coating. We develop a model that relaxes the assumption that the surface parameters C(1), C(2), and pK(+) are constant and independent of surface composition. Our theoretical model consists of three parts: (i) a chemical equilibrium model of the bare or coated wall, (ii) a chemical equilibrium model of the buffered bulk electrolyte, and (iii) a self-consistent Gouy-Chapman-Stern triple-layer model of the electrochemical double layer coupling these two equilibrium models. To validate our model, we used both pH-sensitive dye-based capillary filling experiments as well as electro-osmotic current-monitoring measurements. Using our model we predict the dependence of ζ potential, surface charge density, and capillary filling length ratio on ionic strength for different surface compositions, which can be difficult to achieve otherwise. Copyright © 2010 Elsevier Inc. All rights reserved.

Monte Carlo generators for studies of the 3D structure of the nucleon

DOE PAGES

Avakian, Harut; D'Alesio, U.; Murgia, F.

2015-01-23

In this study, extraction of transverse momentum and space distributions of partons from measurements of spin and azimuthal asymmetries requires development of a self consistent analysis framework, accounting for evolution effects, and allowing control of systematic uncertainties due to variations of input parameters and models. Development of realistic Monte-Carlo generators, accounting for TMD evolution effects, spin-orbit and quark-gluon correlations will be crucial for future studies of quark-gluon dynamics in general and 3D structure of the nucleon in particular.

Sensitivity of equilibrium profile reconstruction to motional Stark effect measurements

NASA Astrophysics Data System (ADS)

Batha, S. H.; Levinton, F. M.; Hirshman, S. P.; Bell, M. G.; Wieland, R. M.

1996-09-01

The magnetic-field pitch-angle profile, gamma p(R) identical to tan-1(Bpol/Btor), is measured on TFTR using a motional Stark effect (MSE) polarimeter. Measured pitch angle profiles, along with kinetic profiles and external magnetic measurements, are used to compute a self-consistent equilibrium using the free-boundary variational moments equilibrium code VMEC. Uncertainties in the q profile due to uncertainties in gamma P(R), magnetic measurements and kinetic measurements are found to be small. Subsequent uncertainties in the VMEC-calculated current density and shear profiles are also small

Statistics of wormlike chains. II. Phase transition of polymer liquid crystals and its mixture with low molecular weight liquid crystals

NASA Astrophysics Data System (ADS)

Zhang, W. X.; Zhao, S. R.; Sun, C. P.

1997-02-01

A general self-consistent field (SCF) for the mixture of polymer and low molecular weight (LMW) molecules has been derived by variation principle. Considering a Maier-Saupe type of interaction, the analytical expressions of the SCF for polymer liquid crystals (PLCs) and the mixture of PLCs and LMW liquid crystals are obtained, from which the phase behaviors of PLCs as well as the mixture are studied. The theoretical results are in agreement with experimental results by adjusting a parameter.

Quantum mechanical/molecular mechanical/continuum style solvation model: linear response theory, variational treatment, and nuclear gradients.

PubMed

Li, Hui

2009-11-14

Linear response and variational treatment are formulated for Hartree-Fock (HF) and Kohn-Sham density functional theory (DFT) methods and combined discrete-continuum solvation models that incorporate self-consistently induced dipoles and charges. Due to the variational treatment, analytic nuclear gradients can be evaluated efficiently for these discrete and continuum solvation models. The forces and torques on the induced point dipoles and point charges can be evaluated using simple electrostatic formulas as for permanent point dipoles and point charges, in accordance with the electrostatic nature of these methods. Implementation and tests using the effective fragment potential (EFP, a polarizable force field) method and the conductorlike polarizable continuum model (CPCM) show that the nuclear gradients are as accurate as those in the gas phase HF and DFT methods. Using B3LYP/EFP/CPCM and time-dependent-B3LYP/EFP/CPCM methods, acetone S(0)-->S(1) excitation in aqueous solution is studied. The results are close to those from full B3LYP/CPCM calculations.

Analytic energy gradient of projected Hartree-Fock within projection after variation

NASA Astrophysics Data System (ADS)

Uejima, Motoyuki; Ten-no, Seiichiro

2017-03-01

We develop a geometrical optimization technique for the projection-after-variation (PAV) scheme of the recently refined projected Hartree-Fock (PHF) as a fast alternative to the variation-after-projection (VAP) approach for optimizing the structures of molecules/clusters in symmetry-adapted electronic states at the mean-field computational cost. PHF handles the nondynamic correlation effects by restoring the symmetry of a broken-symmetry single reference wavefunction and moreover enables a black-box treatment of orbital selections. Using HF orbitals instead of PHF orbitals, our approach saves the computational cost for the orbital optimization, avoiding the convergence problem that sometimes emerges in the VAP scheme. We show that PAV-PHF provides geometries comparable to those of the complete active space self-consistent field and VAP-PHF for the tested systems, namely, CH2, O3, and the [Cu2O2 ] 2 + core, where nondynamic correlation is abundant. The proposed approach is useful for large systems mainly dominated by nondynamic correlation to find stable structures in many symmetry-adapted states.

The Use of Learning Study in Designing Examples for Teaching Physics

NASA Astrophysics Data System (ADS)

Guo, Jian-Peng; Yang, Ling-Yan; Ding, Yi

2017-07-01

Researchers have consistently demonstrated that studying multiple examples is more effective than studying one example because comparing multiple examples can promote schema construction and facilitate discernment of critical aspects. Teachers, however, are usually absent from those self-led text-based studies. In this experimental study, a learning study approach based on variation theory was adopted to examine the effectiveness of teachers' different ways of designing multiple examples in helping students learn a physics principle. Three hundred and fifty-one tenth-grade students learned to distinguish action-reaction from equilibrium (a) by comparing examples that varied critical aspects first separately and then simultaneously, or (b) by comparing examples that separately varied critical aspects only. Results showed that students with average academic attainment benefited more from comparing examples in the first condition. Students with higher academic attainment learned equally within both conditions. This finding supports the advantage of simultaneous variation. The characteristics of students and instructional support should be taken into account when considering the effectiveness of patterns of variation.

A Double-Edged Sword? On the Benefit, Detriment, and Net Effect of Dimensional Comparison on Self-Concept

ERIC Educational Resources Information Center

Müller-Kalthoff, Hanno; Jansen, Malte; Schiefer, Irene M.; Helm, Friederike; Nagy, Nicole; Möller, Jens

2017-01-01

Dimensional comparison theory (DCT; Möller & Marsh, 2013) assumes that students compare their academic achievement intraindividually across domains to form domain-specific self-concepts. Upward dimensional comparisons are believed to lead to lower self-concepts in the worse-off domain, while downward dimensional comparisons should lead to…

A New Self-Consistent Field Model of Polymer/Nanoparticle Mixture

NASA Astrophysics Data System (ADS)

Chen, Kang; Li, Hui-Shu; Zhang, Bo-Kai; Li, Jian; Tian, Wen-De

2016-02-01

Field-theoretical method is efficient in predicting assembling structures of polymeric systems. However, it’s challenging to generalize this method to study the polymer/nanoparticle mixture due to its multi-scale nature. Here, we develop a new field-based model which unifies the nanoparticle description with the polymer field within the self-consistent field theory. Instead of being “ensemble-averaged” continuous distribution, the particle density in the final morphology can represent individual particles located at preferred positions. The discreteness of particle density allows our model to properly address the polymer-particle interface and the excluded-volume interaction. We use this model to study the simplest system of nanoparticles immersed in the dense homopolymer solution. The flexibility of tuning the interfacial details allows our model to capture the rich phenomena such as bridging aggregation and depletion attraction. Insights are obtained on the enthalpic and/or entropic origin of the structural variation due to the competition between depletion and interfacial interaction. This approach is readily extendable to the study of more complex polymer-based nanocomposites or biology-related systems, such as dendrimer/drug encapsulation and membrane/particle assembly.

Influences of misfit strains on liquid phase heteroepitaxial growth

NASA Astrophysics Data System (ADS)

Lu, Yanli; Peng, Yingying; Yu, Genggeng; Chen, Zheng

2017-10-01

Influences of misfit strains with different signs on liquid phase heteroepitaxial growth are studied by binary phase field crystal model. It is amazing to find that double islands are formed because of lateral and vertical separation. The morphological evolution of epitaxial layer depends on signs of misfit strains. The maximum atomic layer thickness of double islands under negative misfit strain is larger than that of under positive misfit strain at the same evolutional time, and size differences between light and dark islands is much smaller under negative misfit strain than that of under positive misfit strain. In addition, concentration field and density field approximately have similar variational law along x direction under the same misfit strain but show opposite variational trend under misfit strains with different signs. Generally, free energy of epitaxial growth systems keeps similar variational trend under misfit strains with different signs.

The ultraviolet variations of iota Cas

NASA Technical Reports Server (NTRS)

Molnar, M. R.; Mallama, A. D.; Soskey, D. G.; Holm, A. V.

1976-01-01

The Ap variable star iota Cas was observed with the photometers on OAO-2 covering the spectral range 1430-4250 A. The ultraviolet light curves show a double wave with primary minimum and maximum at phase ? 0.00 and 0.35, respectively. Secondary minimum light is at phase ? 0.65 with secondary maximum at phase ? 0.85. The light curves longward of 3150 A vary in opposition to those shortward of this 'null region'. Ground-based coude spectra show that the Fe II and Cr II line strengths have a double-wave variation such that maximum strength occurs at minimum ultraviolet light. We suggest that the strong ultraviolet opacities due to photoionization and line blanketing by these metals may cause the observed photometric variations. We have also constructed an oblique-rotator model which shows iron and chromium lying in a great circle band rather than in circular spots.

Does epigenetic polymorphism contribute to phenotypic variances in Jatropha curcas L.?

PubMed

Yi, Chengxin; Zhang, Shilu; Liu, Xiaokun; Bui, Ha T N; Hong, Yan

2010-11-23

There is a growing interest in Jatropha curcas L. (jatropha) as a biodiesel feedstock plant. Variations in its morphology and seed productivity have been well documented. However, there is the lack of systematic comparative evaluation of distinct collections under same climate and agronomic practices. With the several reports on low genetic diversity in jatropha collections, there is uncertainty on genetic contribution to jatropha morphology. In this study, five populations of jatropha plants collected from China (CN), Indonesia (MD), Suriname (SU), Tanzania (AF) and India (TN) were planted in one farm under the same agronomic practices. Their agronomic traits (branching pattern, height, diameter of canopy, time to first flowering, dormancy, accumulated seed yield and oil content) were observed and tracked for two years. Significant variations were found for all the agronomic traits studied. Genetic diversity and epigenetic diversity were evaluated using florescence Amplified Fragment Length Polymorphism (fAFLP) and methylation sensitive florescence AFLP (MfAFLP) methods. Very low level of genetic diversity was detected (polymorphic band <0.1%) within and among populations. In contrast, intermediate but significant epigenetic diversity was detected (25.3% of bands were polymorphic) within and among populations. More than half of CCGG sites surveyed by MfAFLP were methylated with significant difference in inner cytosine and double cytosine methylation among populations. Principal coordinates analysis (PCoA) based on Nei's epigenetic distance showed Tanzania/India group distinct from China/Indonesia/Suriname group. Inheritance of epigenetic markers was assessed in one F1 hybrid population between two morphologically distinct parent plants and one selfed population. 30 out of 39 polymorphic markers (77%) were found heritable and followed Mendelian segregation. One epiallele was further confirmed by bisulphite sequencing of its corresponding genomic region. Our study confirmed climate and practice independent differences in agronomic performance among jatropha collections. Such agronomic trait variations, however, were matched by very low genetic diversity and medium level but significant epigenetic diversity. Significant difference in inner cytosine and double cytosine methylation at CCGG sites was also found among populations. Most epigenetic differential markers can be inherited as epialleles following Mendelian segregation. These results suggest possible involvement of epigenetics in jatropha development.

Does epigenetic polymorphism contribute to phenotypic variances in Jatropha curcas L.?

PubMed Central

2010-01-01

Background There is a growing interest in Jatropha curcas L. (jatropha) as a biodiesel feedstock plant. Variations in its morphology and seed productivity have been well documented. However, there is the lack of systematic comparative evaluation of distinct collections under same climate and agronomic practices. With the several reports on low genetic diversity in jatropha collections, there is uncertainty on genetic contribution to jatropha morphology. Result In this study, five populations of jatropha plants collected from China (CN), Indonesia (MD), Suriname (SU), Tanzania (AF) and India (TN) were planted in one farm under the same agronomic practices. Their agronomic traits (branching pattern, height, diameter of canopy, time to first flowering, dormancy, accumulated seed yield and oil content) were observed and tracked for two years. Significant variations were found for all the agronomic traits studied. Genetic diversity and epigenetic diversity were evaluated using florescence Amplified Fragment Length Polymorphism (fAFLP) and methylation sensitive florescence AFLP (MfAFLP) methods. Very low level of genetic diversity was detected (polymorphic band <0.1%) within and among populations. In contrast, intermediate but significant epigenetic diversity was detected (25.3% of bands were polymorphic) within and among populations. More than half of CCGG sites surveyed by MfAFLP were methylated with significant difference in inner cytosine and double cytosine methylation among populations. Principal coordinates analysis (PCoA) based on Nei's epigenetic distance showed Tanzania/India group distinct from China/Indonesia/Suriname group. Inheritance of epigenetic markers was assessed in one F1 hybrid population between two morphologically distinct parent plants and one selfed population. 30 out of 39 polymorphic markers (77%) were found heritable and followed Mendelian segregation. One epiallele was further confirmed by bisulphite sequencing of its corresponding genomic region. Conclusion Our study confirmed climate and practice independent differences in agronomic performance among jatropha collections. Such agronomic trait variations, however, were matched by very low genetic diversity and medium level but significant epigenetic diversity. Significant difference in inner cytosine and double cytosine methylation at CCGG sites was also found among populations. Most epigenetic differential markers can be inherited as epialleles following Mendelian segregation. These results suggest possible involvement of epigenetics in jatropha development. PMID:21092236

How Much Is Enough in a Perfect World? Cultural Variation in Ideal Levels of Happiness, Pleasure, Freedom, Health, Self-Esteem, Longevity, and Intelligence.

PubMed

Hornsey, Matthew J; Bain, Paul G; Harris, Emily A; Lebedeva, Nadezhda; Kashima, Emiko S; Guan, Yanjun; González, Roberto; Chen, Sylvia Xiaohua; Blumen, Sheyla

2018-06-01

The maximization principle-that people aspire to the highest possible level of something good if all practical constraints are removed-is a common yet untested assumption about human nature. We predict that in holistic cultures-where contradiction, change, and context are emphasized-ideal states of being for the self will be more moderate than in other cultures. In two studies ( Ns = 2,392 and 6,239), we asked this question: If participants could choose their ideal level of happiness, pleasure, freedom, health, self-esteem, longevity, and intelligence, what level would they choose? Consistent with predictions, results showed that maximization was less pronounced in holistic cultures; members of holistic cultures aspired to less happiness, pleasure, freedom, health, self-esteem, longevity, and IQ than did members of other cultures. In contrast, no differences emerged on ideals for society. The studies show that the maximization principle is not a universal aspect of human nature and that there are predictable cultural differences in people's notions of perfection.

Analysis of photoelectron effect on the antenna impedance via Particle-In-Cell simulation

NASA Astrophysics Data System (ADS)

Miyake, Y.; Usui, H.

2008-08-01

We present photoelectron effects on the impedance of electric field antennas used for plasma wave investigations. To illustrate the photoelectron effects, we applied electromagnetic Particle-In-Cell simulation to the self-consistent antenna impedance analysis. We confirmed the formation of a dense photoelectron region around the sunlit surfaces of the antenna and the spacecraft. The dense photoelectrons enhance the real part, and decrease the absolute value of the imaginary part, of antenna impedance at low frequencies. We also showed that the antenna conductance can be analytically calculated from simulation results of the electron current flowing into or out of the antenna. The antenna impedance in the photoelectron environment is represented by a parallel equivalent circuit consisting of a capacitance and a resistance, which is consistent with empirical knowledge. The results also imply that the impedance varies with the spin of the spacecraft, which causes the variation of the photoelectron density around the antenna.

Relativistic Outflows from Advection-dominated Accretion Disks around Black Holes

NASA Astrophysics Data System (ADS)

Becker, Peter A.; Subramanian, Prasad; Kazanas, Demosthenes

2001-05-01

Advection-dominated accretion flows (ADAFs) have a positive Bernoulli parameter and are therefore gravitationally unbound. The Newtonian ADAF model has been generalized recently to obtain the ADIOS model that includes outflows of energy and angular momentum, thereby allowing accretion to proceed self-consistently. However, the utilization of a Newtonian gravitational potential limits the ability of this model to describe the inner region of the disk, where any relativistic outflows are likely to originate. In this paper we modify the ADIOS scenario to incorporate a pseudo-Newtonian potential, which approximates the effects of general relativity. The analysis yields a unique, self-similar solution for the structure of the coupled disk/wind system. Interesting features of the new solution include the relativistic character of the outflow in the vicinity of the radius of marginal stability, which represents the inner edge of the quasi-Keplerian disk in our model. Hence, our self-similar solution may help to explain the origin of relativistic jets in active galaxies. At large distances the radial dependence of the accretion rate approaches the unique form M~r1/2, with an associated density variation given by ρ~r-1. This density variation agrees with that implied by the dependence of the hard X-ray time lags on the Fourier frequency for a number of accreting galactic black hole candidates. While intriguing, the predictions made using our self-similar solution need to be confirmed in the future using a detailed model that includes a physical description of the energization mechanism that drives the outflow, which is likely to be powered by the shear of the underlying accretion disk.

Relativistic Outflows from ADAFs

NASA Astrophysics Data System (ADS)

Becker, Peter; Subramanian, Prasad; Kazanas, Demosthenes

2001-04-01

Advection-dominated accretion flows (ADAFs) have a positive Bernoulli parameter, and are therefore gravitationally bound. The Newtonian ADAF model has been generalized recently to obtain the ADIOS model that includes outflows of energy and angular momentum, thereby allowing accretion to proceed self-consistently. However, the utilization of a Newtonian gravitational potential limits the ability of this model to describe the inner region of the disk, where any relativistic outflows are likely to originate. In this paper we modify the ADIOS scenario to incorporate a seudo - Newtonian potential, which approximates the effects of general relativity. The analysis yields a unique, self - similar solution for the structure of the coupled disk/wind system. Interesting features of the new solution include the relativistic character of the outflow in the vicinity of the radius of marginal stability, which represents the inner edge of the quasi-Keplerian disk in our model. Our self - similar model may therefore help to explain the origin of relativistic jets in active galaxies. At large distances the radial dependence of the accretion rate approachs the unique form dot M ∝ r^1/2, with an associated density variation given by ρ ∝ r-1. This density variation agrees with that implied by the dependence of the X-ray hard time lags on the Fourier frequency for a number of accreting galactic black hole candidates. While intriguing, the results of our self-similar model need to be confirmed in the future by incorporating a detailed physical description of the energization mechanism that drives the outflow, which is likely to be powered by the shear of the underlying accretion disk.

Cultural variation in the motivational standards of self-enhancement and self-criticism among bicultural Asian American and Anglo American students.

PubMed

Zusho, Akane

2008-10-01

Recent work on biculturalism has made theoretical and methodological inroads into our understanding of the relation of cultural processes with psychological functioning. Through the use of cultural priming methodologies, investigators have demonstrated that biculturals, or individuals who have experienced and identify with more than one culture, can switch between various "cultural frames of reference" in response to corresponding social cues (Hong, Morris, Chiu, & Benet-Martinez, 2000). Drawing on this work on the cognitive implications of biculturalism, the purpose of the present study was to examine the assumption that independent and interdependent self-construals are associated with the motivational standards of self-enhancement and self-criticism, respectively. More specifically, the effects of differential primes of self on ratings of self-enhancement were investigated in a sample of bicultural Asian American (N = 42) and Anglo American (N = 60) college students; overall, more similarities than differences were noted between the two groups. It was hypothesized that Anglo American students would display marked tendencies toward self-enhancement. However, this hypothesis was not supported. Nevertheless, consistent prime effects were observed for a selected number of ratings related to academic virtues, with those who received an independent-self prime often exhibiting greater self-enhancing tendencies than those who received an interdependent-self prime. For example, participants in the independent-self condition reported on average significantly higher ratings for self-discipline and initiative, as well as the degree to which they perceived themselves to be hard working. Implications for the work on self-representations, motivation, and acculturation are discussed.

Variational method based on Retinex with double-norm hybrid constraints for uneven illumination correction

NASA Astrophysics Data System (ADS)

Li, Shuo; Wang, Hui; Wang, Liyong; Yu, Xiangzhou; Yang, Le

2018-01-01

The uneven illumination phenomenon reduces the quality of remote sensing image and causes interference in the subsequent processing and applications. A variational method based on Retinex with double-norm hybrid constraints for uneven illumination correction is proposed. The L1 norm and the L2 norm are adopted to constrain the textures and details of reflectance image and the smoothness of the illumination image, respectively. The problem of separating the illumination image from the reflectance image is transformed into the optimal solution of the variational model. In order to accelerate the solution, the split Bregman method is used to decompose the variational model into three subproblems, which are calculated by alternate iteration. Two groups of experiments are implemented on two synthetic images and three real remote sensing images. Compared with the variational Retinex method with single-norm constraint and the Mask method, the proposed method performs better in both visual evaluation and quantitative measurements. The proposed method can effectively eliminate the uneven illumination while maintaining the textures and details of the remote sensing image. Moreover, the proposed method using split Bregman method is more than 10 times faster than the method with the steepest descent method.

Concerning the Video Drift Method to Measure Double Stars

NASA Astrophysics Data System (ADS)

Nugent, Richard L.; Iverson, Ernest W.

2015-05-01

Classical methods to measure position angles and separations of double stars rely on just a few measurements either from visual observations or photographic means. Visual and photographic CCD observations are subject to errors from the following sources: misalignments from eyepiece/camera/barlow lens/micrometer/focal reducers, systematic errors from uncorrected optical distortions, aberrations from the telescope system, camera tilt, magnitude and color effects. Conventional video methods rely on calibration doubles and graphically calculating the east-west direction plus careful choice of select video frames stacked for measurement. Atmospheric motion is one of the larger sources of error in any exposure/measurement method which is on the order of 0.5-1.5. Ideally, if a data set from a short video can be used to derive position angle and separation, with each data set self-calibrating independent of any calibration doubles or star catalogues, this would provide measurements of high systematic accuracy. These aims are achieved by the video drift method first proposed by the authors in 2011. This self calibrating video method automatically analyzes 1,000's of measurements from a short video clip.

Why double-stranded RNA resists condensation

PubMed Central

Tolokh, Igor S.; Pabit, Suzette A.; Katz, Andrea M.; Chen, Yujie; Drozdetski, Aleksander; Baker, Nathan; Pollack, Lois; Onufriev, Alexey V.

2014-01-01

The addition of small amounts of multivalent cations to solutions containing double-stranded DNA leads to inter-DNA attraction and eventual condensation. Surprisingly, the condensation is suppressed in double-stranded RNA, which carries the same negative charge as DNA, but assumes a different double helical form. Here, we combine experiment and atomistic simulations to propose a mechanism that explains the variations in condensation of short (25 base-pairs) nucleic acid (NA) duplexes, from B-like form of homopolymeric DNA, to mixed sequence DNA, to DNA:RNA hybrid, to A-like RNA. Circular dichroism measurements suggest that duplex helical geometry is not the fundamental property that ultimately determines the observed differences in condensation. Instead, these differences are governed by the spatial variation of cobalt hexammine (CoHex) binding to NA. There are two major NA-CoHex binding modes—internal and external—distinguished by the proximity of bound CoHex to the helical axis. We find a significant difference, up to 5-fold, in the fraction of ions bound to the external surfaces of the different NA constructs studied. NA condensation propensity is determined by the fraction of CoHex ions in the external binding mode. PMID:25123663

Novel Diels-Alder based self-healing epoxies for aerospace composites

NASA Astrophysics Data System (ADS)

Coope, T. S.; Turkenburg, D. H.; Fischer, H. R.; Luterbacher, R.; van Bracht, H.; Bond, I. P.

2016-08-01

Epoxy resins containing Diels-Alder (DA) furan and maleimide moieties are presented with the capability to self-heal after exposure to an external heat source. A conventional epoxy amine system has been combined with furfuryl and maleimide functional groups in a two-step process, to avoid major side-reactions, and the concentration of a thermo-reversibly binding cross-linker was considered to balance thermoset and thermoplastic behaviours, and the subsequent self-healing performance. In the context of self-repair technologies an inbuilt ‘intrinsic’ self-healing system is deemed favourable as the healing agent can be placed in known ‘hot spot’ regions (i.e. skin-stringer run outs, ply drops and around drilled holes) where operational damage predominately occurs in load bearing aerospace structures. In this study, the mechanical and self-healing performance of furan functionalised epoxy resins containing varying amounts (10, 20, 30 or 40 pph) of bismaleimide were investigated using a bulk epoxy polymer tapered double cantilever beam test specimen geometry. Two forms, a thin film and a bulk material, were evaluated to account for future integration methods into fibre reinforced polymer (FRP) composites. The highest healing efficiency, with respect to the obtained initial load value, was observed from the 20 pph bulk material derivative. The polymers were successful in achieving consistent multiple (three) healing cycles when heated at 150 °C for 5 min. This novel investigated DA material exhibits favourable processing characteristics for FRP composites as preliminary studies have shown successful coextrution with reinforcing fibres to form free standing films and dry fibre impregnation.

The double quasar 0957+561: examination of the gravitational lens hypothesis using the very large array.

PubMed

Greenfield, P E; Roberts, D H; Burke, B F

1980-05-02

A full 12-hour synthesis at 6-centimeter wavelength with the Very Large Array confirms the major features previously reported for the double quasar 0957+561. In addition, the existence of radio jets apparently associated with both quasars is demonstrated. Gravitational lens models are now favored on the basis of recent optical observations, and the radio jets place severe constraints on such models. Further radio observations of the double quasar are needed to establish the expected relative time delay in variations between the images.

Automatic identification and location technology of glass insulator self-shattering

NASA Astrophysics Data System (ADS)

Huang, Xinbo; Zhang, Huiying; Zhang, Ye

2017-11-01

The insulator of transmission lines is one of the most important infrastructures, which is vital to ensure the safe operation of transmission lines under complex and harsh operating conditions. The glass insulator often self-shatters but the available identification methods are inefficient and unreliable. Then, an automatic identification and localization technology of self-shattered glass insulators is proposed, which consists of the cameras installed on the tower video monitoring devices or the unmanned aerial vehicles, the 4G/OPGW network, and the monitoring center, where the identification and localization algorithm is embedded into the expert software. First, the images of insulators are captured by cameras, which are processed to identify the region of insulator string by the presented identification algorithm of insulator string. Second, according to the characteristics of the insulator string image, a mathematical model of the insulator string is established to estimate the direction and the length of the sliding blocks. Third, local binary pattern histograms of the template and the sliding block are extracted, by which the self-shattered insulator can be recognized and located. Finally, a series of experiments is fulfilled to verify the effectiveness of the algorithm. For single insulator images, Ac, Pr, and Rc of the algorithm are 94.5%, 92.38%, and 96.78%, respectively. For double insulator images, Ac, Pr, and Rc are 90.00%, 86.36%, and 93.23%, respectively.

Are horses capable of mirror self-recognition? A pilot study.

PubMed

Baragli, Paolo; Demuru, Elisa; Scopa, Chiara; Palagi, Elisabetta

2017-01-01

Mirror Self-Recognition (MSR) unveils complex cognitive, social and emotional skills and it has been found only in humans and few other species, such as great apes, dolphins, elephants and magpies. In this pilot study, we tested if horses show the capacity of MSR. Four subjects living socially under naturalistic conditions were selected for the experiment. We adopted the classical mark test, which consists in placing a coloured mark on an out-of-view body part, visible only through mirror inspection. If the animal considers the image as its own, it will use its reflection to detect the mark and will try to explore it. We enhanced the classical paradigm by introducing a double-check control. Only in the presence of the reflecting surface, animals performed tactile and olfactory exploration of the mirror and looked behind it. These behaviors suggest that subjects were trying to associate multiple sensory cues (visual, tactile and olfactory) to the image in the mirror. The lack of correspondence between the collected stimuli in front of the mirror and the response to the colored mark lead us to affirm that horses are able to perceive that the reflected image is incongruent when compared with the memorized information of a real horse. However, without replication of data, the self-directed behavior towards the colored marks showed by our horses cannot be sufficient per se to affirm that horses are capable of self-recognition.

Effect of thermionic cathode heating current self-magnetic field on gaseous plasma generator characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopatin, I. V., E-mail: lopatin@opee.hcei.tsc.ru; Akhmadeev, Yu. H.; Koval, N. N.

2015-10-15

The performance capabilities of the PINK, a plasma generator with a thermionic cathode mounted in the cavity of a hollow cathode, depending for its operation on a non-self-sustained low-pressure gas discharge have been investigated. It has been shown that when a single-filament tungsten cathode 2 mm in diameter is used and the peak filament current is equal to or higher than 100 A, the self-magnetic field of the filament current significantly affects the discharge current and voltage waveforms. This effect is due to changes in the time and space distributions of the emission current density from the hot cathode. Whenmore » the electron mean free path is close to the characteristic dimensions of the thermionic cathode, the synthesized plasma density distribution is nonuniform and the cathode is etched nonuniformly. The cathode lifetime in this case is 8–12 h. Using a cathode consisting of several parallel-connected tungsten filaments ∼0.8 mm in diameter moderates the effect of the self-magnetic field of the filament current and nearly doubles the cathode lifetime. The use of this type of cathode together with a discharge igniting electrode reduces the minimum operating pressure in the plasma generator to about one third of that required for the generator operation with a single-filament cathode (to 0.04 Pa)« less

A Model of High-Frequency Self-Mixing in Double-Barrier Rectifier

NASA Astrophysics Data System (ADS)

Palma, Fabrizio; Rao, R.

2018-03-01

In this paper, a new model of the frequency dependence of the double-barrier THz rectifier is presented. The new structure is of interest because it can be realized by CMOS image sensor technology. Its application in a complex field such as that of THz receivers requires the availability of an analytical model, which is reliable and able to highlight the dependence on the parameters of the physical structure. The model is based on the hydrodynamic semiconductor equations, solved in the small signal approximation. The model depicts the mechanisms of the THz modulation of the charge in the depleted regions of the double-barrier device and explains the self-mixing process, the frequency dependence, and the detection capability of the structure. The model thus substantially improves the analytical models of the THz rectification available in literature, mainly based on lamped equivalent circuits.

A double-observer method for reducing bias in faecal pellet surveys of forest ungulates

USGS Publications Warehouse

Jenkins, K.J.; Manly, B.F.J.

2008-01-01

1. Faecal surveys are used widely to study variations in abundance and distribution of forest-dwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearance rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliability of faecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates. 3. Estimated detection probabilities of faecal groups ranged from < 0.2-1.0 depending upon the observer, whether the faecal group was from elk or deer, faecal group size, distance of the faecal group from the sampling transect, ground vegetation cover, and the interaction between faecal group size and distance from the transect. 4. Models of plot-clearing effects indicated that standing crop counts of deer faecal groups required 34% reduction on flat terrain and 53% reduction on sloping terrain to represent faeces accumulated over a standard 100-day interval, whereas counts of elk faecal groups required 0% and 46% reductions on flat and sloping terrain, respectively. 5. Synthesis and applications. Double-observer transect sampling provides a cost-effective means of reducing observational bias and variation in faecal decay rates that obscure the interpretation of faecal indices of large mammal abundance. Given the variation we observed in observational bias of faecal surveys and persistence of faeces, we emphasize the need for future researchers to account for these comparatively manageable sources of bias before comparing faecal indices spatially or temporally. Double-observer sampling methods are readily adaptable to study variations in faecal indices of large mammals at the scale of the large forest reserve, natural area, or other forested regions when direct estimation of populations is problematic. ?? 2008 The Authors.

High-rate lithium/manganese dioxide batteries; the double cell concept

NASA Astrophysics Data System (ADS)

Drews, Jürgen; Wolf, Rüdiger; Fehrmann, Gerd; Staub, Roland

An implantable defibrillator battery has to provide pulse-power capabilities as well as high energy density. Low self-discharge rates are mandatory and an ability to check the state of charge is required. To accomplish these requirements, a lithium/manganese dioxide battery with a modified active cathode mass has been developed. Usage of a double cell design increases significantly the battery performance within an implantable defibrillator. The design features of a high-rate, pulse-power, manganese dioxide double cell are described.