WorldWideScience

Sample records for energy dependent bias

  1. Heavy Ion Induced Degradation in SiC Schottky Diodes: Bias and Energy Deposition Dependence

    Science.gov (United States)

    Javanainen, Arto; Galloway, Kenneth F.; Nicklaw, Christopher; Bosser, Alexandre L.; Ferlet-Cavrois, Veronique; Lauenstein, Jean-Marie; Pintacuda, Francesco; Reed, Robert A.; Schrimpf, Ronald D.; Weller, Robert A.; hide

    2016-01-01

    Experimental results on ion-induced leakage current increase in 4H-SiC Schottky power diodes are presented. Monte Carlo and TCAD simulations show that degradation is due to the synergy between applied bias and ion energy deposition. This degradation is possibly related to thermal spot annealing at the metal semiconductor interface. This thermal annealing leads to an inhomogeneity of the Schottky barrier that could be responsible for the increase leakage current as a function of fluence.

  2. Bias-dependent oscillatory electron transport of monatomic sulfur chains

    KAUST Repository

    Yu, Jing-Xin; Cheng, Yan; Sanvito, Stefano; Chen, Xiang-Rong

    2012-01-01

    The bias-dependent oscillatory electron transport of monatomic sulfur chains sandwiched between gold electrodes is investigated with density functional theory and non-equilibrium Green's function method. At zero bias, in contrast to the typical odd-even oscillations observed in most metallic chains, we find that the conductance oscillates with a period of four atoms. However, as the bias voltage is increased the current displays a two-atom periodicity. This emerges gradually, first for the longer chains and then, at voltages larger than 0.7 V, for lengths. The oscillatory behaviors are analyzed by the density of states and the energy-dependent and bias-dependent transmission coefficients. © 2012 American Institute of Physics.

  3. Bias-dependent oscillatory electron transport of monatomic sulfur chains

    KAUST Repository

    Yu, Jing-Xin

    2012-01-01

    The bias-dependent oscillatory electron transport of monatomic sulfur chains sandwiched between gold electrodes is investigated with density functional theory and non-equilibrium Green\\'s function method. At zero bias, in contrast to the typical odd-even oscillations observed in most metallic chains, we find that the conductance oscillates with a period of four atoms. However, as the bias voltage is increased the current displays a two-atom periodicity. This emerges gradually, first for the longer chains and then, at voltages larger than 0.7 V, for lengths. The oscillatory behaviors are analyzed by the density of states and the energy-dependent and bias-dependent transmission coefficients. © 2012 American Institute of Physics.

  4. Study of the Dependency on Magnetic Field and Bias Voltage of an AC-Biased TES Microcalorimeter

    Science.gov (United States)

    Gottardi, L.; Bruijn, M.; denHartog, R.; Hoevers, H.; deKorte, P.; vanderKuur, J.; Linderman, M.; Adams, J.; Bailey, C.; Bandler, S.; hide

    2012-01-01

    At SRON we are studying the performance of a Goddard Space Flight Center single pixel TES microcalorimeter operated in an AC bias configuration. For x-ray photons at 6 keV the pixel shows an x-ray energy resolution Delta E(sub FWHM) = 3.7 eV, which is about a factor 2 worse than the energy resolution observed in an identical DC-biased pixel. In order to better understand the reasons for this discrepancy we characterized the detector as a function of temperature, bias working point and applied perpendicular magnetic field. A strong periodic dependency of the detector noise on the TES AC bias voltage is measured. We discuss the results in the framework of the recently observed weak-link behaviour of a TES microcalorimeter.

  5. Alcohol-related interpretation bias in alcohol-dependent patients

    NARCIS (Netherlands)

    Woud, M.L.; Pawelczack, S.; Rinck, M.; Lindenmeyer, J.; Souren, P.M.; Wiers, R.W.H.J.; Becker, E.S.

    2014-01-01

    Background Models of addictive behaviors postulate that implicit alcohol-related memory associations and biased interpretation processes contribute to the development and maintenance of alcohol misuse and abuse. The present study examined whether alcohol-dependent patients (AP) show an

  6. Alcohol‐related interpretation bias in alcohol-dependent patients

    NARCIS (Netherlands)

    Woud, M.L.; Pawelczak, S.; Rinck, M.; Lindenmeyer, J.; Souren, P.; Wiers, R.W.; Becker, E.S.

    2014-01-01

    Background: Models of addictive behaviors postulate that implicit alcohol-related memory associations and biased interpretation processes contribute to the development and maintenance of alcohol misuse and abuse. The present study examined whether alcohol-dependent patients (AP) show an

  7. Energy India 'dependence

    International Nuclear Information System (INIS)

    Cygler, C.

    2007-01-01

    India has an economic growth between 8 to 10 % by year. To become a great country of the twenty first century and to stop poverty it is necessary to keep this growth but the growth of India is dependant of its ability to supply electric power necessary to increase the industrial production. The country has to multiply by four its energy production. The electric production comes from thermal power plants for 65%, 26% from hydroelectric power plants, 6% from renewable energy sources and 3% from nuclear energy. Between solar energy ( India has three hundred solar days by years) and nuclear energy using thorium that can be increased India has to choose an energy policy to answer its energy demand and independence need. (N.C.)

  8. Revealing the Cosmic Web-dependent Halo Bias

    Science.gov (United States)

    Yang, Xiaohu; Zhang, Youcai; Lu, Tianhuan; Wang, Huiyuan; Shi, Feng; Tweed, Dylan; Li, Shijie; Luo, Wentao; Lu, Yi; Yang, Lei

    2017-10-01

    Halo bias is the one of the key ingredients of the halo models. It was shown at a given redshift to be only dependent, to the first order, on the halo mass. In this study, four types of cosmic web environments—clusters, filaments, sheets, and voids—are defined within a state-of-the-art high-resolution N-body simulation. Within these environments, we use both halo-dark matter cross correlation and halo-halo autocorrelation functions to probe the clustering properties of halos. The nature of the halo bias differs strongly between the four different cosmic web environments described here. With respect to the overall population, halos in clusters have significantly lower biases in the {10}11.0˜ {10}13.5 {h}-1 {M}⊙ mass range. In other environments, however, halos show extremely enhanced biases up to a factor 10 in voids for halos of mass ˜ {10}12.0 {h}-1 {M}⊙ . Such a strong cosmic web environment dependence in the halo bias may play an important role in future cosmological and galaxy formation studies. Within this cosmic web framework, the age dependency of halo bias is found to be only significant in clusters and filaments for relatively small halos ≲ {10}12.5 {h}-1 {M}⊙ .

  9. Anisotropic bias dependent transport property of defective phosphorene layer

    Science.gov (United States)

    Umar Farooq, M.; Hashmi, Arqum; Hong, Jisang

    2015-01-01

    Phosphorene is receiving great research interests because of its peculiar physical properties. Nonetheless, no systematic studies on the transport properties modified due to defects have been performed. Here, we present the electronic band structure, defect formation energy and bias dependent transport property of various defective systems. We found that the defect formation energy is much less than that in graphene. The defect configuration strongly affects the electronic structure. The band gap vanishes in single vacancy layers, but the band gap reappears in divacancy layers. Interestingly, a single vacancy defect behaves like a p-type impurity for transport property. Unlike the common belief, we observe that the vacancy defect can contribute to greatly increasing the current. Along the zigzag direction, the current in the most stable single vacancy structure was significantly increased as compared with that found in the pristine layer. In addition, the current along the armchair direction was always greater than along the zigzag direction and we observed a strong anisotropic current ratio of armchair to zigzag direction. PMID:26198318

  10. Bias-corrected estimation of stable tail dependence function

    DEFF Research Database (Denmark)

    Beirlant, Jan; Escobar-Bach, Mikael; Goegebeur, Yuri

    2016-01-01

    We consider the estimation of the stable tail dependence function. We propose a bias-corrected estimator and we establish its asymptotic behaviour under suitable assumptions. The finite sample performance of the proposed estimator is evaluated by means of an extensive simulation study where...

  11. Bias Voltage-Dependent Impedance Spectroscopy Analysis of Hydrothermally Synthesized ZnS Nanoparticles

    Science.gov (United States)

    Dey, Arka; Dhar, Joydeep; Sil, Sayantan; Jana, Rajkumar; Ray, Partha Pratim

    2018-04-01

    In this report, bias voltage-dependent dielectric and electron transport properties of ZnS nanoparticles were discussed. ZnS nanoparticles were synthesized by introducing a modified hydrothermal process. The powder XRD pattern indicates the phase purity, and field emission scanning electron microscope image demonstrates the morphology of the synthesized sample. The optical band gap energy (E g = 4.2 eV) from UV measurement explores semiconductor behavior of the synthesized material. The electrical properties were performed at room temperature using complex impedance spectroscopy (CIS) technique as a function of frequency (40 Hz-10 MHz) under different forward dc bias voltages (0-1 V). The CIS analysis demonstrates the contribution of bulk resistance in conduction mechanism and its dependency on forward dc bias voltages. The imaginary part of the impedance versus frequency curve exhibits the existence of relaxation peak which shifts with increasing dc forward bias voltages. The dc bias voltage-dependent ac and dc conductivity of the synthesized ZnS was studied on thin film structure. A possible hopping mechanism for electrical transport processes in the system was investigated. Finally, it is worth to mention that this analysis of bias voltage-dependent dielectric and transport properties of as-synthesized ZnS showed excellent properties for emerging energy applications.

  12. Redshift space correlations and scale-dependent stochastic biasing of density peaks

    Science.gov (United States)

    Desjacques, Vincent; Sheth, Ravi K.

    2010-01-01

    We calculate the redshift space correlation function and the power spectrum of density peaks of a Gaussian random field. Our derivation, which is valid on linear scales k≲0.1hMpc-1, is based on the peak biasing relation given by Desjacques [Phys. Rev. DPRVDAQ1550-7998, 78, 103503 (2008)10.1103/PhysRevD.78.103503]. In linear theory, the redshift space power spectrum is Ppks(k,μ)=exp⁡(-f2σvel2k2μ2)[bpk(k)+bvel(k)fμ2]2Pδ(k), where μ is the angle with respect to the line of sight, σvel is the one-dimensional velocity dispersion, f is the growth rate, and bpk(k) and bvel(k) are k-dependent linear spatial and velocity bias factors. For peaks, the value of σvel depends upon the functional form of bvel. When the k dependence is absent from the square brackets and bvel is set to unity, the resulting expression is assumed to describe models where the bias is linear and deterministic, but the velocities are unbiased. The peak model is remarkable because it has unbiased velocities in this same sense—peak motions are driven by dark matter flows—but, in order to achieve this, bvel must be k dependent. We speculate that this is true in general: k dependence of the spatial bias will lead to k dependence of bvel even if the biased tracers flow with the dark matter. Because of the k dependence of the linear bias parameters, standard manipulations applied to the peak model will lead to k-dependent estimates of the growth factor that could erroneously be interpreted as a signature of modified dark energy or gravity. We use the Fisher formalism to show that the constraint on the growth rate f is degraded by a factor of 2 if one allows for a k-dependent velocity bias of the peak type. Our analysis also demonstrates that the Gaussian smoothing term is part and parcel of linear theory. We discuss a simple estimate of nonlinear evolution and illustrate the effect of the peak bias on the redshift space multipoles. For k≲0.1hMpc-1, the peak bias is deterministic but k

  13. The evolution of social learning rules: payoff-biased and frequency-dependent biased transmission.

    Science.gov (United States)

    Kendal, Jeremy; Giraldeau, Luc-Alain; Laland, Kevin

    2009-09-21

    Humans and other animals do not use social learning indiscriminately, rather, natural selection has favoured the evolution of social learning rules that make selective use of social learning to acquire relevant information in a changing environment. We present a gene-culture coevolutionary analysis of a small selection of such rules (unbiased social learning, payoff-biased social learning and frequency-dependent biased social learning, including conformism and anti-conformism) in a population of asocial learners where the environment is subject to a constant probability of change to a novel state. We define conditions under which each rule evolves to a genetically polymorphic equilibrium. We find that payoff-biased social learning may evolve under high levels of environmental variation if the fitness benefit associated with the acquired behaviour is either high or low but not of intermediate value. In contrast, both conformist and anti-conformist biases can become fixed when environment variation is low, whereupon the mean fitness in the population is higher than for a population of asocial learners. Our examination of the population dynamics reveals stable limit cycles under conformist and anti-conformist biases and some highly complex dynamics including chaos. Anti-conformists can out-compete conformists when conditions favour a low equilibrium frequency of the learned behaviour. We conclude that evolution, punctuated by the repeated successful invasion of different social learning rules, should continuously favour a reduction in the equilibrium frequency of asocial learning, and propose that, among competing social learning rules, the dominant rule will be the one that can persist with the lowest frequency of asocial learning.

  14. Angular dependence of the exchange bias for the bistable state

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yuhao [College of Physics and Electronic Information, Shanxi Normal University, Linfen 041004 (China); Research College of materials science, Shanxi Normal University, Linfen 041004 (China); Xu, Xiaohong, E-mail: xuxh@dns.sxnu.edu.cn [Research College of materials science, Shanxi Normal University, Linfen 041004 (China); Key Laboratory of Magnetic Molecules and Magnetic Information Materials, Ministry of Education, Shanxi Normal University, Linfen 041004 (China)

    2017-06-15

    The angular dependence of the exchange bias (ADEB) has been investigated in detail when the exchange-coupled ferromagnetic (FM)/antiferromagnetic (AFM) bilayer is in the bistable state. Complete and incomplete jump phenomena were found at the intrinsic easy and hard axes, when they pass through two special positions making the angular deviation of 58.2826° and 121.7174° from the easy axis of the uniaxial anisotropy, respectively. The combination of these different types of the jump phenomena at the intrinsic easy and hard axes yields five distinct types of the ADEB. The physical condition for each type of ADEB is established. Additionally, the extreme value problem of the exchange bias field and coercivity are also discussed, which is an important technological issue in the design of the magnetoresistive and spintronic devices. These results enable us to make a comprehensive understanding of the experimental ADEB curves.

  15. Nonmonotonic energy harvesting efficiency in biased exciton chains

    NARCIS (Netherlands)

    Vlaming, S.M.; Malyshev, V.A.; Knoester, J.

    2007-01-01

    We theoretically study the efficiency of energy harvesting in linear exciton chains with an energy bias, where the initial excitation is taking place at the high-energy end of the chain and the energy is harvested (trapped) at the other end. The efficiency is characterized by means of the average

  16. Tilted dipole model for bias-dependent photoluminescence pattern

    Energy Technology Data Exchange (ETDEWEB)

    Fujieda, Ichiro, E-mail: fujieda@se.ritsumei.ac.jp; Suzuki, Daisuke; Masuda, Taishi [Department of Electrical and Electronic Engineering, Ritsumeikan University, Kusatsu 525-8577 (Japan)

    2014-12-14

    In a guest-host system containing elongated dyes and a nematic liquid crystal, both molecules are aligned to each other. An external bias tilts these molecules and the radiation pattern of the system is altered. A model is proposed to describe this bias-dependent photoluminescence patterns. It divides the liquid crystal/dye layer into sub-layers that contain electric dipoles with specific tilt angles. Each sub-layer emits linearly polarized light. Its radiation pattern is toroidal and is determined by the tilt angle. Its intensity is assumed to be proportional to the power of excitation light absorbed by the sub-layer. This is calculated by the Lambert-Beer's Law. The absorption coefficient is assumed to be proportional to the cross-section of the tilted dipole moment, in analogy to the ellipsoid of refractive index, to evaluate the cross-section for each polarized component of the excitation light. Contributions from all the sub-layers are added to give a final expression for the radiation pattern. Self-absorption is neglected. The model is simplified by reducing the number of sub-layers. Analytical expressions are derived for a simple case that consists of a single layer with tilted dipoles sandwiched by two layers with horizontally-aligned dipoles. All the parameters except for the tilt angle can be determined by measuring transmittance of the excitation light. The model roughly reproduces the bias-dependent photoluminescence patterns of a cell containing 0.5 wt. % coumarin 6. It breaks down at large emission angles. Measured spectral changes suggest that the discrepancy is due to self-absorption and re-emission.

  17. Shape Biased Low Power Spin Dependent Tunneling Magnetic Field Sensors

    Science.gov (United States)

    Tondra, Mark; Qian, Zhenghong; Wang, Dexin; Nordman, Cathy; Anderson, John

    2001-10-01

    Spin Dependent Tunneling (SDT) devices are leading candidates for inclusion in a number of Unattended Ground Sensor applications. Continued progress at NVE has pushed their performance to 1OOs of pT I rt. Hz 1 Hz. However, these sensors were designed to use an applied field from an on-chip coil to create an appropriate magnetic sensing configuration. The power required to generate this field (^100mW) is significantly greater than the power budget (^lmW) for a magnetic sensor in an Unattended Ground Sensor (UGS) application. Consequently, a new approach to creating an ideal sensing environment is required. One approach being used at NVE is "shape biasing." This means that the physical layout of the SDT sensing elements is such that the magnetization of the sensing film is correct even when no biasing field is applied. Sensors have been fabricated using this technique and show reasonable promise for UGS applications. Some performance trade-offs exist. The power is easily tinder 1 MW, but the sensitivity is typically lower by a factor of 10. This talk will discuss some of the design details of these sensors as well as their expected ultimate performance.

  18. Energy distribution extraction of negative charges responsible for positive bias temperature instability

    International Nuclear Information System (INIS)

    Ren Shang-Qing; Yang Hong; Wang Wen-Wu; Tang Bo; Tang Zhao-Yun; Wang Xiao-Lei; Xu Hao; Luo Wei-Chun; Zhao Chao; Yan Jiang; Chen Da-Peng; Ye Tian-Chun

    2015-01-01

    A new method is proposed to extract the energy distribution of negative charges, which results from electron trapping by traps in the gate stack of nMOSFET during positive bias temperature instability (PBTI) stress based on the recovery measurement. In our case, the extracted energy distribution of negative charges shows an obvious dependence on energy, and the energy level of the largest energy density of negative charges is 0.01 eV above the conduction band of silicon. The charge energy distribution below that energy level shows strong dependence on the stress voltage. (paper)

  19. Bias dependent charge trapping in MOSFETs during 1 and 6 MeV electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S. [Department of Chemical Engineering, Mie University, 5148507 (Japan); Kulkarni, V.R.; Mathakari, N.L.; Bhoraskar, V.N. [Department of Physics, Univeristy of Pune, Pune 411007 (India); Dhole, S.D. [Department of Physics, Univeristy of Pune, Pune 411007 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-06-15

    To study irradiation-induced charge trapping in SiO{sub 2} and around the SiO{sub 2}-Si interface, depletion n-MOSFETs (metal-oxide-semiconductor field effect transistor) were used. The devices were gate biased during 1 and 6 MeV pulsed electron irradiation. The I{sub D}-V{sub DS} (drain current versus drain voltage) and I{sub D}-V{sub GS} (drain current versus gate voltage) characteristics were measured before and after irradiation. The shift in threshold voltage {delta}V{sub T} (difference in threshold voltage V{sub T} before and after irradiation) exhibited trends depending on the applied gate bias during 1 MeV electron irradiation. This behavior can be associated to the contribution of irradiation-induced negative charge {delta}N{sub IT} buildup around the SiO{sub 2}-Si interface to {delta}V{sub T}, which is sensitive to the electron tunneling from the substrates. However, only weak gate bias dependence was observed in 6 MeV electron irradiated devices. Independent of the energy loss and applied bias, the positive oxide trapped charge {delta}N{sub OT} is marginal and can be associated to thin and good quality of SiO{sub 2}. These results are explained using screening of free and acceptor states by the applied bias during irradiation, thereby reducing the total irradiation-induced charges.

  20. Low noise constant current source for bias dependent noise measurements

    International Nuclear Information System (INIS)

    Talukdar, D.; Bose, Suvendu; Bardhan, K. K.; Chakraborty, R. K.

    2011-01-01

    A low noise constant current source used for measuring the 1/f noise in disordered systems in ohmic as well as nonohmic regime is described. The source can supply low noise constant current starting from as low as 1 μA to a few tens of milliampere with a high voltage compliance limit of around 20 V. The constant current source has several stages, which can work in a standalone manner or together to supply the desired value of load current. The noise contributed by the current source is very low in the entire current range. The fabrication of a low noise voltage preamplifier modified for bias dependent noise measurements and based on the existing design available in the MAT04 data sheet is also described.

  1. The own-age face recognition bias is task dependent.

    Science.gov (United States)

    Proietti, Valentina; Macchi Cassia, Viola; Mondloch, Catherine J

    2015-08-01

    The own-age bias (OAB) in face recognition (more accurate recognition of own-age than other-age faces) is robust among young adults but not older adults. We investigated the OAB under two different task conditions. In Experiment 1 young and older adults (who reported more recent experience with own than other-age faces) completed a match-to-sample task with young and older adult faces; only young adults showed an OAB. In Experiment 2 young and older adults completed an identity detection task in which we manipulated the identity strength of target and distracter identities by morphing each face with an average face in 20% steps. Accuracy increased with identity strength and facial age influenced older adults' (but not younger adults') strategy, but there was no evidence of an OAB. Collectively, these results suggest that the OAB depends on task demands and may be absent when searching for one identity. © 2014 The British Psychological Society.

  2. Uranium energy dependence

    International Nuclear Information System (INIS)

    Erkes, P.

    1981-06-01

    Uranium supply and demand as projected by the Uranium Institute is discussed. It is concluded that for the industrialized countries, maximum energy independence is a necessity. Hence it is necessary to achieve assurance of supply for uranium used in thermal power reactors in current programs and eventually to move towards breeders

  3. Hidden biases in Australian energy policy

    International Nuclear Information System (INIS)

    Schlaepfer, August

    2009-01-01

    The challenges in developing technology for the capture and storage of CO 2 from coal, oil and gas power generation, as well as those associated with the storage of nuclear waste, are widely regarded as solvable. According to proponents of clean coal, oil and gas technologies, as well as the proponents of nuclear technology, it is only a matter of time and resources to find a solution to their waste problems. Similarly, the Australian Government argues that our main efforts need to be concentrated on clean coal technologies, as well as considering the nuclear option. However, when it comes to the challenges associated with renewable energy technologies, like intermittency of wind generated grid power, storage of electricity from renewable energy and so on, there seems to be an attitude amongst Australian energy planners that these challenges represent insurmountable technical and financial problems, and will, at least in the short to medium term, prevent them from becoming a viable alternative to coal, oil, gas and uranium based energy technologies. (author)

  4. Frequency and temperature dependence of ferromagnetic linewidth in exchange biased Permalloy

    International Nuclear Information System (INIS)

    Lubitz, P.; Rubinstein, M.; Krebs, J. J.; Cheng, S.-F.

    2001-01-01

    Ferromagnetic resonance linewidths were measured at 9.5 and 35 GHz and in the temperature range from 77 to 350 K for thin Permalloy (Py) films exchange biased by adjacent layers of NiO, CoO, or IrMn. Compared to unoxidized Py alone, for which the linewidth is nearly temperature independent in this range and scales linearly with frequency, exchange biased Py has broader lines with distinctive temperature dependences for each bias material at 9.5 GHz. Different temperature dependences were observed at 35 GHz. Our results are consistent with relaxation related to thermally driven reversal of the antiferromagnetic grains. Intrinsic damping and inhomogeneities also add to the widths. The qualitative features of the temperature and frequency dependences of the linewidths can be described with the usual expression for the slow relaxation linewidth mechanism. The temperature dependence of the relaxation time is taken from Neel's expression for the reversal time using appropriate rate prefactors and activation energies. [copyright] 2001 American Institute of Physics

  5. Bias-dependent hybrid PKI empirical-neural model of microwave FETs

    Science.gov (United States)

    Marinković, Zlatica; Pronić-Rančić, Olivera; Marković, Vera

    2011-10-01

    Empirical models of microwave transistors based on an equivalent circuit are valid for only one bias point. Bias-dependent analysis requires repeated extractions of the model parameters for each bias point. In order to make model bias-dependent, a new hybrid empirical-neural model of microwave field-effect transistors is proposed in this article. The model is a combination of an equivalent circuit model including noise developed for one bias point and two prior knowledge input artificial neural networks (PKI ANNs) aimed at introducing bias dependency of scattering (S) and noise parameters, respectively. The prior knowledge of the proposed ANNs involves the values of the S- and noise parameters obtained by the empirical model. The proposed hybrid model is valid in the whole range of bias conditions. Moreover, the proposed model provides better accuracy than the empirical model, which is illustrated by an appropriate modelling example of a pseudomorphic high-electron mobility transistor device.

  6. Cannabis dependence, cognitive control and attentional bias for cannabis words

    NARCIS (Netherlands)

    Cousijn, J.; Watson, P.; Koenders, L.; Vingerhoets, W.A.M.; Goudriaan, A.E.; Wiers, R.W.

    2013-01-01

    One of the characteristics of people suffering from addictive behaviors is the tendency to be distracted by drug cues. This attentional bias for drug cues is thought to lead to increased craving and drug use, and may draw individuals into a vicious cycle of drug addiction. In the current study we

  7. Italy's recurrent energy dependency dilemma

    International Nuclear Information System (INIS)

    Ippolito, F.

    1993-01-01

    This paper first critically assesses the objectives of Italy's 1988 National Energy Plan which, in light of the moratorium on nuclear energy, called for moderate but steady reductions in imported energy supplies through the implementation of energy conservation programs and the development of available domestic conventional and renewable energy sources. The economics and energy analyses evidence that, in view this nation's current troubled economic situation, the Energy Plan's target for the year 2000 of a 76% dependency on foreign oil is just not good enough and not in line with stricter European environmental normatives limiting carbon dioxide emissions. It is argued that in order to effectively reduce the nation's excessively high energy costs, keep pace with other industrialized countries in a highly competitive market (Italy's energy tariffs are almost 55% greater than those of Germany and France), and to respect new European anti-pollution laws, Italy must restart its nuclear program and take advantage of the recent advances being made in passive reactor safety systems

  8. Bespoke Bias for Obtaining Free Energy Differences within Variationally Enhanced Sampling.

    Science.gov (United States)

    McCarty, James; Valsson, Omar; Parrinello, Michele

    2016-05-10

    Obtaining efficient sampling of multiple metastable states through molecular dynamics and hence determining free energy differences is central for understanding many important phenomena. Here we present a new biasing strategy, which employs the recent variationally enhanced sampling approach (Valsson and Parrinello Phys. Rev. Lett. 2014, 113, 090601). The bias is constructed from an intuitive model of the local free energy surface describing fluctuations around metastable minima and depends on only a few parameters which are determined variationally such that efficient sampling between states is obtained. The bias constructed in this manner largely reduces the need of finding a set of collective variables that completely spans the conformational space of interest, as they only need to be a locally valid descriptor of the system about its local minimum. We introduce the method and demonstrate its power on two representative examples.

  9. Implicit and Explicit Memory Bias in Opiate Dependent, Abstinent and Normal Individuals

    Directory of Open Access Journals (Sweden)

    Jafar Hasani

    2013-07-01

    Full Text Available Objective: The aim of current research was to assess implicit and explicit memory bias to drug related stimuli in opiate Dependent, abstinent and normal Individuals. Method: Three groups including opiate Dependent, abstinent and normal Individuals (n=25 were selected by available sampling method. After matching on the base of age, education level and type of substance use all participants assessed by recognition task (explicit memory bias and stem completion task (implicit memory bias. Results: The analysis of data showed that opiate dependent and abstinent groups in comparison with normal individual had implicit memory bias, whereas in explicit memory only opiate dependent individuals showed bias. Conclusion: The identification of explicit and implicit memory governing addiction may have practical implications in diagnosis, treatment and prevention of substance abuse.

  10. Fricke xylenol gel energy dependence

    International Nuclear Information System (INIS)

    Costa, Rosangela T.; Moreira, Marcos V.; Almeida, Adelaide de

    2009-01-01

    The advancement of technology has increasingly use the of ionizing radiation mainly in the areas of medicine, industry and research. The development of instruments and methods for an effective performance for detection and measurement of each radiation area was crucial. The literature have demonstrated the effectiveness of the Fricke Xylenol Gel (FXG) as an adequate chemical sensor to be used for dosimetry, once its effective atomic number and density are near to those of the soft tissue. The use of photon beams for therapeutic purpose requires knowledge of their characteristics that can vary for each equipment. Therefore, is important to know all parameters involved for the patient irradiation as the total geometry involved, type of radiation, target material composition and beam energy, that have to be taken into account in the beam dosimetry for the treatment success being the energy parameter is one of the most important. This work was developed to study the energetic dependence of the FXG dosimeter. This chemical solution is made with gelatine 300 Bloom, ferrous ammonium sulfate, xylenol orange, sulfuric acid and Milli-Q water and is based on the Fe +2 oxidation to Fe +3 , due to the ionizing radiation leading to the xylenol orange - ferric complex formation, that is linear depend on the absorbed dose. The FXG samples were irradiated with photons of different energies and the absorbance measurements were done with the spectrophotometric technique at the 585 nm, FXG highest absorption peak. The energetic dependence results presented a stronger dependence for low energies and almost independence for high energies, as expected by the interaction of radiation with matter. (author)

  11. Temperature Dependence of Faraday Effect-Induced Bias Error in a Fiber Optic Gyroscope.

    Science.gov (United States)

    Li, Xuyou; Liu, Pan; Guang, Xingxing; Xu, Zhenlong; Guan, Lianwu; Li, Guangchun

    2017-09-07

    Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environments, such as magnetic field and temperature field variation, is necessary for its practical applications. This paper presents an investigation of Faraday effect-induced bias error of IFOG under varying temperature. Jones matrix method is utilized to formulize the temperature dependence of Faraday effect-induced bias error. Theoretical results show that the Faraday effect-induced bias error changes with the temperature in the non-skeleton polarization maintaining (PM) fiber coil. This phenomenon is caused by the temperature dependence of linear birefringence and Verdet constant of PM fiber. Particularly, Faraday effect-induced bias errors of two polarizations always have opposite signs that can be compensated optically regardless of the changes of the temperature. Two experiments with a 1000 m non-skeleton PM fiber coil are performed, and the experimental results support these theoretical predictions. This study is promising for improving the bias stability of IFOG.

  12. Energy-dependent proton damage in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Donegani, Elena Maria

    2017-09-29

    Non Ionizing Energy Loss (NIEL) in the sensor bulk is a limiting factor for the lifetime of silicon detectors. In this work, the proton-energy dependent bulkdamage is studied in n- and p-type silicon pad diodes. The samples are thin (200 μm thick), and oxygen enriched (bulk material types: MCz, standard or deepdiffused FZ). Irradiations are performed with 23 MeV, 188 MeV and 23 GeV protons; the 1 MeV neutron equivalent fluence assumes selected values in the range [0.1,3].10{sup 14} cm{sup -2}. In reverse bias, Current-Voltage (IV) and Capacitance-Voltage (CV) measurements are performed to electrically characterise the samples; in forward bias, IV and CV measurements point out the transition from lifetime to relaxationlike semiconductor after irradiation. By means of Thermally Stimulated Current (TSC) measurements, 13 bulk defects have been found after proton irradiation. Firstly, TSC spectra are analysed to obtain defect concentrations after defect filling at the conventional temperature T{sub fill} =10 K. Secondly, temperature dependent capture coefficients of bulk defects are explained, according to the multi-phonon process, from the analysis of TSC measurements at higher filling temperatures (T{sub fill}<130 K). Thirdly, a new method based on the SRH statistics and accounting for cluster-induced shift in activation energy is proposed; it allows to fully characterise bulk defects (in terms of activation energy, concentration and majority capture cross-section) and to distinguish between point- and cluster-like defects. A correlation is noted between the leakage current and the concentration of three deep defects (namely the V{sub 2}, V{sub 3} and H(220K) defects), for all the investigated bulk materials and types, and after all the considered proton energies and fluences. At least five defects are found to be responsible for the space charge, with positive contributions from the E(30K) and B{sub i}O{sub i} defects, or negative contributions from three deep

  13. Energy-dependent proton damage in silicon

    International Nuclear Information System (INIS)

    Donegani, Elena Maria

    2017-01-01

    Non Ionizing Energy Loss (NIEL) in the sensor bulk is a limiting factor for the lifetime of silicon detectors. In this work, the proton-energy dependent bulkdamage is studied in n- and p-type silicon pad diodes. The samples are thin (200 μm thick), and oxygen enriched (bulk material types: MCz, standard or deepdiffused FZ). Irradiations are performed with 23 MeV, 188 MeV and 23 GeV protons; the 1 MeV neutron equivalent fluence assumes selected values in the range [0.1,3].10 14 cm -2 . In reverse bias, Current-Voltage (IV) and Capacitance-Voltage (CV) measurements are performed to electrically characterise the samples; in forward bias, IV and CV measurements point out the transition from lifetime to relaxationlike semiconductor after irradiation. By means of Thermally Stimulated Current (TSC) measurements, 13 bulk defects have been found after proton irradiation. Firstly, TSC spectra are analysed to obtain defect concentrations after defect filling at the conventional temperature T fill =10 K. Secondly, temperature dependent capture coefficients of bulk defects are explained, according to the multi-phonon process, from the analysis of TSC measurements at higher filling temperatures (T fill <130 K). Thirdly, a new method based on the SRH statistics and accounting for cluster-induced shift in activation energy is proposed; it allows to fully characterise bulk defects (in terms of activation energy, concentration and majority capture cross-section) and to distinguish between point- and cluster-like defects. A correlation is noted between the leakage current and the concentration of three deep defects (namely the V 2 , V 3 and H(220K) defects), for all the investigated bulk materials and types, and after all the considered proton energies and fluences. At least five defects are found to be responsible for the space charge, with positive contributions from the E(30K) and B i O i defects, or negative contributions from three deep acceptors H(116K), H(140K) and H(152K).

  14. Substrate bias voltage and deposition temperature dependence on ...

    Indian Academy of Sciences (India)

    Thin films or a coating of any sort prior to its application into real world has to be studied for the dependence of ..... For line focusing, incident beam mask was employed with ..... org/content/avs/journal/jvst/11/4/10.1116/1.1312732. Thornton J A ...

  15. Gender anomalies in stated preference surveys – are biases really gender dependent?

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Olsen, Søren Bøye

    2010-01-01

    The potential for a number of common but severe biases in stated preference method surveys being gender dependent has been largely overlooked in the literature. In this paper we summarize results from three Choice Experiment studies that find evidence in favor of gender differences in vulnerability...... set up a novel theoretical model, which provides an explanation for gender specific susceptibility to biases. We conclude that biases can indeed be gender dependent. Hence, researchers should not simply disregard potential gender differences, but rather take them into account and examine the extent...... of them when performing surveys. Finally, we give suggestions for future research in this area....

  16. Randomized controlled trial of attention bias modification in a racially diverse, socially anxious, alcohol dependent sample.

    Science.gov (United States)

    Clerkin, Elise M; Magee, Joshua C; Wells, Tony T; Beard, Courtney; Barnett, Nancy P

    2016-12-01

    Attention biases may be an important treatment target for both alcohol dependence and social anxiety. This is the first ABM trial to investigate two (vs. one) targets of attention bias within a sample with co-occurring symptoms of social anxiety and alcohol dependence. Additionally, we used trial-level bias scores (TL-BS) to capture the phenomena of attention bias in a more ecologically valid, dynamic way compared to traditional attention bias scores. Adult participants (N = 86; 41% Female; 52% African American; 40% White) with elevated social anxiety symptoms and alcohol dependence were randomly assigned to an 8-session training condition in this 2 (Social Anxiety ABM vs. Social Anxiety Control) by 2 (Alcohol ABM vs. Alcohol Control) design. Symptoms of social anxiety, alcohol dependence, and attention bias were assessed across time. Multilevel models estimated the trajectories for each measure within individuals, and tested whether these trajectories differed according to the randomized training conditions. Across time, there were significant or trending decreases in all attention TL-BS parameters (but not traditional attention bias scores) and most symptom measures. However, there were not significant differences in the trajectories of change between any ABM and control conditions for any symptom measures. These findings add to previous evidence questioning the robustness of ABM and point to the need to extend the effects of ABM to samples that are racially diverse and/or have co-occurring psychopathology. The results also illustrate the potential importance of calculating trial-level attention bias scores rather than only including traditional bias scores. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Randomized Controlled Trial of Attention Bias Modification in a Racially Diverse, Socially Anxious, Alcohol Dependent Sample

    Science.gov (United States)

    Clerkin, Elise M.; Magee, Joshua C.; Wells, Tony T.; Beard, Courtney; Barnett, Nancy P.

    2016-01-01

    Objective Attention biases may be an important treatment target for both alcohol dependence and social anxiety. This is the first ABM trial to investigate two (vs. one) targets of attention bias within a sample with co-occurring symptoms of social anxiety and alcohol dependence. Additionally, we used trial-level bias scores (TL-BS) to capture the phenomena of attention bias in a more ecologically valid, dynamic way compared to traditional attention bias scores. Method Adult participants (N=86; 41% Female; 52% African American; 40% White) with elevated social anxiety symptoms and alcohol dependence were randomly assigned to an 8-session training condition in this 2 (Social Anxiety ABM vs. Social Anxiety Control) by 2 (Alcohol ABM vs. Alcohol Control) design. Symptoms of social anxiety, alcohol dependence, and attention bias were assessed across time. Results Multilevel models estimated the trajectories for each measure within individuals, and tested whether these trajectories differed according to the randomized training conditions. Across time, there were significant or trending decreases in all attention TL-BS parameters (but not traditional attention bias scores) and most symptom measures. However, there were not significant differences in the trajectories of change between any ABM and control conditions for any symptom measures. Conclusions These findings add to previous evidence questioning the robustness of ABM and point to the need to extend the effects of ABM to samples that are racially diverse and/or have co-occurring psychopathology. The results also illustrate the potential importance of calculating trial-level attention bias scores rather than only including traditional bias scores. PMID:27591918

  18. Domain-size-dependent exchange bias in Co/LaFeO3

    Energy Technology Data Exchange (ETDEWEB)

    Scholl, A.; Nolting, F.; Seo, J.W.; Ohldag, H.; Stohr, J.; Raoux,S.; Locquet, J.-P.; Fompeyrine, J.

    2004-09-22

    X-ray microscopy using magnetic linear dichroism of a zero-field-grown, multi-domain Co/LaFeO{sub 3} ferromagnet/antiferromagnet sample shows a local exchange bias of random direction and magnitude. A statistical analysis of the local bias of individual, micron-size magnetic domains demonstrates an increasing bias field with decreasing domain size as expected for a random distribution of pinned, uncompensated spins, which are believed to mediate the interface coupling. A linear dependence with the inverse domain diameter is found.

  19. Bias voltage dependence of a flux-sensitive Al/GaAs/Al (SNS) interferometer

    DEFF Research Database (Denmark)

    Kutchinsky, Jonatan; Taboryski, Rafael Jozef; Hansen, Jørn Bindslev

    1999-01-01

    bias voltage the fabricated interferometers typically exhibit 3% sinusoidal modulation of the conductance as a function of a magnetic field applied perpendicular to the loop. The conductance modulation is caused by resonant Andreev states in the normal GaAs region of the device. With increasing bias...... voltage of the order of a few microvolts the device is driven out of resonance and the conductance oscillations are extinguished. However, at higher bias voltage corresponding to the superconducting energy gap of Al (178 mu V) the conductance oscillations reappear but with reduced amplitude...

  20. Exactly solvable energy-dependent potentials

    International Nuclear Information System (INIS)

    Garcia-Martinez, J.; Garcia-Ravelo, J.; Pena, J.J.; Schulze-Halberg, A.

    2009-01-01

    We introduce a method for constructing exactly-solvable Schroedinger equations with energy-dependent potentials. Our method is based on converting a general linear differential equation of second order into a Schroedinger equation with energy-dependent potential. Particular examples presented here include harmonic oscillator, Coulomb and Morse potentials with various types of energy dependence.

  1. Influence of compulsivity of drug abuse on dopaminergic modulation of attentional bias in stimulant dependence.

    Science.gov (United States)

    Ersche, Karen D; Bullmore, Edward T; Craig, Kevin J; Shabbir, Shaila S; Abbott, Sanja; Müller, Ulrich; Ooi, Cinly; Suckling, John; Barnes, Anna; Sahakian, Barbara J; Merlo-Pich, Emilio V; Robbins, Trevor W

    2010-06-01

    There are no effective pharmacotherapies for stimulant dependence but there are many plausible targets for development of novel therapeutics. We hypothesized that dopamine-related targets are relevant for treatment of stimulant dependence, and there will likely be individual differences in response to dopaminergic challenges. To measure behavioral and brain functional markers of drug-related attentional bias in stimulant-dependent individuals studied repeatedly after short-term dosing with dopamine D(2)/D(3) receptor antagonist and agonist challenges. Randomized, double-blind, placebo-controlled, parallel-groups, crossover design using pharmacological functional magnetic resonance imaging. Clinical research unit (GlaxoSmithKline) and local community in Cambridge, England. Stimulant-dependent individuals (n = 18) and healthy volunteers (n = 18). Amisulpride (400 mg), pramipexole dihydrochloride (0.5 mg), or placebo were administered in counterbalanced order at each of 3 repeated testing sessions. Attentional bias for stimulant-related words was measured during functional magnetic resonance imaging by a drug-word Stroop paradigm; trait impulsivity and compulsivity of dependence were assessed at baseline by questionnaire. Drug users demonstrated significant attentional bias for drug-related words, which was correlated with greater activation of the left prefrontal and right cerebellar cortex. Attentional bias was greater in people with highly compulsive patterns of stimulant abuse; the effects of dopaminergic challenges on attentional interference and related frontocerebellar activation were different between high- and low-compulsivity subgroups. Greater attentional bias for and greater prefrontal activation by stimulant-related words constitute a candidate neurocognitive marker for dependence. Individual differences in compulsivity of stimulant dependence had significant effects on attentional bias, its brain functional representation, and its short-term modulation

  2. Signatures of asymmetric and inelastic tunneling on the spin torque bias dependence

    KAUST Repository

    Manchon, Aurelien; Zhang, S.; Lee, K.-J.

    2010-01-01

    The influence of structural asymmetries (barrier height and exchange splitting), as well as inelastic scattering (magnons and phonons) on the bias dependence of the spin transfer torque in a magnetic tunnel junction is studied theoretically using the free-electron model. We show that they modify the “conventional” bias dependence of the spin transfer torque, together with the bias dependence of the conductance. In particular, both structural asymmetries and bulk (inelastic) scattering add antisymmetric terms to the perpendicular torque (∝V and ∝je|V|) while the interfacial inelastic scattering conserves the junction symmetry and only produces symmetric terms (∝|V|n, n∊N). The analysis of spin torque and conductance measurements displays a signature revealing the origin (asymmetry or inelastic scattering) of the discrepancy.

  3. Signatures of asymmetric and inelastic tunneling on the spin torque bias dependence

    KAUST Repository

    Manchon, Aurelien

    2010-11-15

    The influence of structural asymmetries (barrier height and exchange splitting), as well as inelastic scattering (magnons and phonons) on the bias dependence of the spin transfer torque in a magnetic tunnel junction is studied theoretically using the free-electron model. We show that they modify the “conventional” bias dependence of the spin transfer torque, together with the bias dependence of the conductance. In particular, both structural asymmetries and bulk (inelastic) scattering add antisymmetric terms to the perpendicular torque (∝V and ∝je|V|) while the interfacial inelastic scattering conserves the junction symmetry and only produces symmetric terms (∝|V|n, n∊N). The analysis of spin torque and conductance measurements displays a signature revealing the origin (asymmetry or inelastic scattering) of the discrepancy.

  4. Quantification of tension to explain bias dependence of driven polymer translocation dynamics

    Science.gov (United States)

    Suhonen, P. M.; Piili, J.; Linna, R. P.

    2017-12-01

    Motivated by identifying the origin of the bias dependence of tension propagation, we investigate methods for measuring tension propagation quantitatively in computer simulations of driven polymer translocation. Here, the motion of flexible polymer chains through a narrow pore is simulated using Langevin dynamics. We measure tension forces, bead velocities, bead distances, and bond angles along the polymer at all stages of translocation with unprecedented precision. Measurements are done at a standard temperature used in simulations and at zero temperature to pin down the effect of fluctuations. The measured quantities were found to give qualitatively similar characteristics, but the bias dependence could be determined only using tension force. We find that in the scaling relation τ ˜Nβfdα for translocation time τ , the polymer length N , and the bias force fd, the increase of the exponent β with bias is caused by center-of-mass diffusion of the polymer toward the pore on the cis side. We find that this diffusion also causes the exponent α to deviate from the ideal value -1 . The bias dependence of β was found to result from combination of diffusion and pore friction and so be relevant for polymers that are too short to be considered asymptotically long. The effect is relevant in experiments all of which are made using polymers whose lengths are far below the asymptotic limit. Thereby, our results also corroborate the theoretical prediction by Sakaue's theory [Polymers 8, 424 (2016), 10.3390/polym8120424] that there should not be bias dependence of β for asymptotically long polymers. By excluding fluctuations we also show that monomer crowding at the pore exit cannot have a measurable effect on translocation dynamics under realistic conditions.

  5. Assessing the utility of frequency dependent nudging for reducing biases in biogeochemical models

    Science.gov (United States)

    Lagman, Karl B.; Fennel, Katja; Thompson, Keith R.; Bianucci, Laura

    2014-09-01

    Bias errors, resulting from inaccurate boundary and forcing conditions, incorrect model parameterization, etc. are a common problem in environmental models including biogeochemical ocean models. While it is important to correct bias errors wherever possible, it is unlikely that any environmental model will ever be entirely free of such errors. Hence, methods for bias reduction are necessary. A widely used technique for online bias reduction is nudging, where simulated fields are continuously forced toward observations or a climatology. Nudging is robust and easy to implement, but suppresses high-frequency variability and introduces artificial phase shifts. As a solution to this problem Thompson et al. (2006) introduced frequency dependent nudging where nudging occurs only in prescribed frequency bands, typically centered on the mean and the annual cycle. They showed this method to be effective for eddy resolving ocean circulation models. Here we add a stability term to the previous form of frequency dependent nudging which makes the method more robust for non-linear biological models. Then we assess the utility of frequency dependent nudging for biological models by first applying the method to a simple predator-prey model and then to a 1D ocean biogeochemical model. In both cases we only nudge in two frequency bands centered on the mean and the annual cycle, and then assess how well the variability in higher frequency bands is recovered. We evaluate the effectiveness of frequency dependent nudging in comparison to conventional nudging and find significant improvements with the former.

  6. Scale-dependent bias from the reconstruction of non-Gaussian distributions

    International Nuclear Information System (INIS)

    Chongchitnan, Sirichai; Silk, Joseph

    2011-01-01

    Primordial non-Gaussianity introduces a scale-dependent variation in the clustering of density peaks corresponding to rare objects. This variation, parametrized by the bias, is investigated on scales where a linear perturbation theory is sufficiently accurate. The bias is obtained directly in real space by comparing the one- and two-point probability distributions of density fluctuations. We show that these distributions can be reconstructed using a bivariate Edgeworth series, presented here up to an arbitrarily high order. The Edgeworth formalism is shown to be well-suited for ''local'' cubic-order non-Gaussianity parametrized by g NL . We show that a strong scale dependence in the bias can be produced by g NL of order 10 5 , consistent with cosmic microwave background constraints. On a separation length of ∼100 Mpc, current constraints on g NL still allow the bias for the most massive clusters to be enhanced by 20-30% of the Gaussian value. We further examine the bias as a function of mass scale, and also explore the relationship between the clustering and the abundance of massive clusters in the presence of g NL . We explain why the Edgeworth formalism, though technically challenging, is a very powerful technique for constraining high-order non-Gaussianity with large-scale structures.

  7. US oil dependency and energy security

    International Nuclear Information System (INIS)

    Noel, P.

    2002-01-01

    The three papers of this document were written in the framework of a seminar organized the 30 may 2002 by the IFRI in the framework of its program Energy and Climatic Change. The first presentation deals with the american oil policy since 1980 (relation between the oil dependence and the energy security, the Reagan oil policy, the new oil policy facing the increase of the dependence). The second one deals with the US energy security (oil security, domestic energy security, policy implications). The last presentation is devoted to the US oil dependence in a global context and the problems and policies of international energy security. (A.L.B.)

  8. Is technological change biased toward energy? A multi-sectoral analysis for the French economy

    International Nuclear Information System (INIS)

    Karanfil, Fatih; Yeddir-Tamsamani, Yasser

    2010-01-01

    Since the adoption and implementation of new technologies has an important influence on the structure and performance of the economy in both developed and developing countries, many research papers are devoted to the technology-economy nexus. Motivated by the fact that the impact of technical progress on the demand for different production factors may vary depending on the bias of the technological change, in this paper, by estimating a translog cost-share system and using state-space modeling technique, we investigate to what extent the direction of technical change is biased toward energy and away from other factors. By applying this methodology to the French economy for the period 1978-2006 the obtained results suggest that: first, technical change has a non-neutral impact on factor demands; second, capital-saving technical progress is present in the majority of the sectors studied; third, energy demand has increased in all sectors but electricity and gas. These findings may have important policy implications for environmental and energy issues in France.

  9. Exponential dependence of potential barrier height on biased voltages of inorganic/organic static induction transistor

    International Nuclear Information System (INIS)

    Zhang Yong; Yang Jianhong; Cai Xueyuan; Wang Zaixing

    2010-01-01

    The exponential dependence of the potential barrier height φ c on the biased voltages of the inorganic/organic static induction transistor (SIT/OSIT) through a normalized approach in the low-current regime is presented. It shows a more accurate description than the linear expression of the potential barrier height. Through the verification of the numerical calculated and experimental results, the exponential dependence of φ c on the applied biases can be used to derive the I-V characteristics. For both SIT and OSIT, the calculated results, using the presented relationship, are agreeable with the experimental results. Compared to the previous linear relationship, the exponential description of φ c can contribute effectively to reduce the error between the theoretical and experimental results of the I-V characteristics. (semiconductor devices)

  10. Systematic Biases in Weak Lensing Cosmology with the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Samuroff, Simon [Manchester U.

    2017-01-01

    This thesis sets out a practical guide to applying shear measurements as a cosmological tool. We first present one of two science-ready galaxy shape catalogues from Year 1 of the Dark Energy Survey (DES Y1), which covers 1500 square degrees in four bands $griz$, with a median redshift of $0.59$. We describe the shape measurement process implemented by the DES Y1 imshape catalogue, which contains 21.9 million high-quality $r$-band bulge/disc fits. In Chapter 3 a new suite of image simulations, referred to as Hoopoe, are presented. The Hoopoe dataset is tailored to DES Y1 and includes realistic blending, spatial masks and variation in the point spread function. We derive shear corrections, which we show are robust to changes in calibration method, galaxy binning and variance within the simulated dataset. Sources of systematic uncertainty in the simulation-based shear calibration are discussed, leading to a final estimate of the $1\\sigma$ uncertainties in the residual multiplica tive bias after calibration of 0.025. Chapter 4 describes an extension of the analysis on the Hoopoe simulations into a detailed investigation of the impact of galaxy neighbours on shape measurement and shear cosmology. Four mechanisms by which neighbours can have a non-negligible influence on shear measurement are identified. These effects, if ignored, would contribute a net multiplicative bias of $m \\sim 0.03 - 0.09$ in DES Y1, though the precise impact will depend on both the measurement code and the selection cuts applied. We use the cosmological inference pipeline of DES Y1 to explore the cosmological implications of neighbour bias and show that omitting blending from the calibration simulation for DES Y1 would bias the inferred clustering amplitude $S_8 \\equiv \\sigma_8 (\\omegam /0.3)^{0.5}$ by $1.5 \\sigma$ towards low values. Finally, we use the Hoopoe simulations to test the effect of neighbour-induced spatial correlations in the multiplicative bias. We find the cosmo logical

  11. Inter-dependence not Over-dependence: Reducing Urban Transport Energy Dependence

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Michael James; Rodrigues da Silva, Antonio Nelson

    2007-07-01

    A major issue of concern in today's world is urban transport energy dependence and energy supply security. In an energy inter-dependent world, energy over-dependence brings risks to urban transport systems. Many urban areas are over-dependent on finite petroleum resources for transport. New technology and the development and integration of renewable resources into transport energy systems may reduce some of the current transport energy dependence of urban areas. However, the most effective means of reducing energy dependence is to first design urban areas for this condition. An urban policy framework is proposed that requires transport energy dependence to be measured and controlled in the urban development process. A new tool has been created for this purpose, the Transport Energy Specification (TES), which measures transport energy dependence of urban areas. This creates the possibility for cities to regulate urban development with respect to energy dependence. Trial assessments were performed in Germany, New Zealand and Brazil; initial analysis by transport and government professionals shows promise of this tool being included into urban policy. The TES combined with a regulatory framework has the potential to significantly reduce transport energy consumption and dependence in urban areas in the future. (auth)

  12. Atomoxetine effects on attentional bias to drug-related cues in cocaine dependent individuals.

    Science.gov (United States)

    Passamonti, Luca; Luijten, M; Ziauddeen, H; Coyle-Gilchrist, I T S; Rittman, T; Brain, S A E; Regenthal, R; Franken, I H A; Sahakian, B J; Bullmore, E T; Robbins, T W; Ersche, K D

    2017-08-01

    Biased attention towards drug-related cues and reduced inhibitory control over the regulation of drug-intake characterize drug addiction. The noradrenaline system has been critically implicated in both attentional and response inhibitory processes and is directly affected by drugs such as cocaine. We examined the potentially beneficial effects of the noradrenaline reuptake inhibitor atomoxetine in improving cognitive control during two tasks that used cocaine- and non-cocaine-related stimuli. A double-blind, placebo-controlled, and cross-over psycho-pharmacological design was employed. A single oral dose of atomoxetine (40 mg) was administered to 28 cocaine-dependent individuals (CDIs) and 28 healthy controls. All participants performed a pictorial attentional bias task involving both cocaine- and non-cocaine-related pictures as well as a verbal go/no-go task composed of cocaine- and food-related words. As expected, CDIs showed attentional bias to cocaine-related cues whilst controls did not. More importantly, however, atomoxetine, relative to placebo, significantly attenuated attentional bias in CDIs (F 26  = 6.73, P = 0.01). During the go/no-go task, there was a treatment × trial × group interaction, although this finding only showed a trend towards statistical significance (F 26  = 3.38, P = 0.07). Our findings suggest that atomoxetine reduces attentional bias to drug-related cues in CDIs. This may result from atomoxetine's modulation of the balance between tonic/phasic activity in the locus coeruleus and the possibly parallel enhancement of noradrenergic neurotransmission within the prefrontal cortex. Studying how cognitive enhancers such as atomoxetine influence key neurocognitive indices in cocaine addiction may help to develop reliable biomarkers for patient stratification in future clinical trials.

  13. Scale dependence of halo and galaxy bias: Effects in real space

    International Nuclear Information System (INIS)

    Smith, Robert E.; Scoccimarro, Roman; Sheth, Ravi K.

    2007-01-01

    We examine the scale dependence of dark matter halo and galaxy clustering on very large scales (0.01 -1 ] -1 ] -1 ], and only show amplification on smaller scales, whereas low mass haloes show strong, ∼5%-10%, suppression over the range 0.05 -1 ]<0.15. These results were primarily established through the use of the cross-power spectrum of dark matter and haloes, which circumvents the thorny issue of shot-noise correction. The halo-halo power spectrum, however, is highly sensitive to the shot-noise correction; we show that halo exclusion effects make this sub-Poissonian and a new correction is presented. Our results have special relevance for studies of the baryon acoustic oscillation features in the halo power spectra. Nonlinear mode-mode coupling: (i) damps these features on progressively larger scales as halo mass increases; (ii) produces small shifts in the positions of the peaks and troughs which depend on halo mass. We show that these effects on halo clustering are important over the redshift range relevant to such studies (0< z<2), and so will need to be accounted for when extracting information from precision measurements of galaxy clustering. Our analytic model is described in the language of the ''halo model.'' The halo-halo clustering term is propagated into the nonlinear regime using ''1-loop'' perturbation theory and a nonlinear halo bias model. Galaxies are then inserted into haloes through the halo occupation distribution. We show that, with nonlinear bias parameters derived from simulations, this model produces predictions that are qualitatively in agreement with our numerical results. We then use it to show that the power spectra of red and blue galaxies depend differently on scale, thus underscoring the fact that proper modeling of nonlinear bias parameters will be crucial to derive reliable cosmological constraints. In addition to showing that the bias on very large scales is not simply linear, the model also shows that the halo-halo and halo

  14. Misconceptions and Biases in German Students' Perception of Multiple Energy Sources: Implications for Science Education

    Science.gov (United States)

    Lee, Roh Pin

    2016-01-01

    Misconceptions and biases in energy perception could influence people's support for developments integral to the success of restructuring a nation's energy system. Science education, in equipping young adults with the cognitive skills and knowledge necessary to navigate in the confusing energy environment, could play a key role in paving the way…

  15. Angular dependence of SiO2 etch rate at various bias voltages in a high density CHF3 plasma

    International Nuclear Information System (INIS)

    Lee, Gyeo-Re; Hwang, Sung-Wook; Min, Jae-Ho; Moon, Sang Heup

    2002-01-01

    The dependence of the SiO 2 etch rate on the angle of ions incident on the substrate surface was studied over a bias voltage range from -20 to -600 V in a high-density CHF 3 plasma using a Faraday cage to control the ion incident angle. The effect of the bottom plane on the sidewall etching was also examined. Differences in the characteristics of the etch rate as a function of the ion angle were observed for different bias voltage regions. When the absolute value of the bias voltage was smaller than 200 V, the normalized etch rate (NER) defined as the etch rate normalized by the rate on the horizontal surface, changed following a cosine curve with respect to the ion incident angle, defined as the angle between the ion direction and the normal of the substrate surface. When the magnitude of the bias voltage was larger than 200 V, the NER was deviated to higher values from those given by a cosine curve at ion angles between 30 deg. and 70 deg. , and then drastically decreased at angles higher than 70 deg. until a net deposition was observed at angles near 90 deg. . The characteristic etch-rate patterns at ion angles below 70 deg. were determined by the ion energy transferred to the surface, which affected the SiO 2 etch rate and, simultaneously, the rate of removal of a fluorocarbon polymer film formed on the substrate surface. At high ion angles, particles emitted from the bottom plane contributed to polymer formation on and affected the etching characteristics of the substrate

  16. Bias-dependent high saturation solar LBIC scanning of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Vorster, F.J.; van Dyk, E.E. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2007-06-15

    A light beam-induced current measurement system that uses concentrated solar radiation as a beam probe to map spatially distributed defects on a solar cell has been developed and tested [F.J. Vorster, E.E. van Dyk, Rev. Sci. Instrum., submitted for review]. The induced current response from a flat plate EFG Si solar cell was mapped as a function of surface position and cell bias by using a solar light beam induced current (S-LBIC) mapping system while at the same time dynamically biasing the whole cell with an external voltage. This paper examines the issues relating to transient capacitive effects as well as the electrical behaviour of typical solar cell defect mechanisms under spot illumination. By examining the bias dependence of the S-LBIC maps, various defect mechanisms of photovoltaic (PV) cells under concentrated solar irradiance may be identified. The techniques employed to interpret the spatially distributed IV curves as well as initial results are discussed. (author)

  17. Bias-dependent amino-acid-induced conductance changes in short semi-metallic carbon nanotubes

    International Nuclear Information System (INIS)

    Abadir, G B; Walus, K; Pulfrey, D L

    2010-01-01

    We study the interaction between short semi-metallic carbon nanotubes and different amino acids using molecular dynamics and ab initio (density functional theory/non-equilibrium Green's function) simulations. We identify two different mechanisms of nanotube conductance change upon adsorption of amino acids: one due to the change of the coordinates of the nanotube arising from van der Waals forces of interaction with the adsorbed amino acid; and one due to electrostatic interactions, which appear only in the case of charged amino acids. We also find that the transport mechanism and the changes in the conductance of the tube upon amino acid adsorption are bias dependent.

  18. European Union concerns with its energy dependence

    International Nuclear Information System (INIS)

    Commeau, N.

    2001-01-01

    European Union (E.U.) produces only half its needs concerning energy. It is expected that by 2030, the energy balance will be 86% for fossil energies, 8% for renewable energies and 6% for nuclear energy. Different scenario show that the dependence of E.U will worsen and reach 70% unless a common strategy is launched to curb the tendency. E.U is elaborating a common policy concerning energy, this policy rests on 4 axis: 1) monitoring the increase of the energy consumption by promoting energy savings in housing and transport, 2) directing the energy demand towards less polluting energy by using taxes, public funding and European regulations as incentive tools, 3) sustaining a constant dialogues with energy exporting countries in order to get a more stable energy market and have a benefiting influence on prices, and 4) developing new routes of importation of energy by for instance contributing to the construction of new oil or gas pipeline networks. (A.C.)

  19. Sex bias in copy number variation of olfactory receptor gene family depends on ethnicity

    Directory of Open Access Journals (Sweden)

    Farideh eShadravan

    2013-03-01

    Full Text Available Gender plays a pivotal role in the human genetic identity and is also manifested in many genetic disorders particularly mental retardation. In this study its effect on copy number variation (CNV, known to cause genetic disorders was explored. As the olfactory receptor (OR repertoire comprises the largest human gene family, it was selected for this study, which was carried out within and between three populations, derived from 150 individuals from the 1000 Genome Project. Analysis of 3872 CNVs detected among 791 OR loci, in which 307 loci showed CNV, revealed the following novel findings: Sex bias in CNV was significantly more prevalent in uncommon than common CNV variants of OR pseudogenes, in which the male genome showed more CNVs; and in one-copy number loss compared to complete deletion of OR pseudogenes; both findings implying a more recent evolutionary role for gender. Sex bias in copy number gain was also detected. Another novel finding was that the observed six bias was largely dependent on ethnicity and was in general absent in East Asians. Using a CNV public database for sick children (ISCA the application of these findings for improving clinical molecular diagnostics is discussed by showing an example of sex bias in CNV among kids with autism. Additional clinical relevance is discussed, as the most polymorphic CNV-enriched OR cluster in the human genome, located on chr 15q11.2, is found near the PWS/AS bi-directionally imprinted region associated with two well-known mental retardation syndromes. As olfaction represents the primitive cognition in most mammals, arguably in competition with the development of a larger brain, the extensive retention of OR pseudogenes in females of this study, might point to a parent-of-origin indirect regulatory role for OR pseudogenes in the embryonic development of human brain. Thus any perturbation in the temporal regulation of olfactory system could lead to developmental delay disorders including

  20. Self-reverse-biased solar panel optical receiver for simultaneous visible light communication and energy harvesting.

    Science.gov (United States)

    Shin, Won-Ho; Yang, Se-Hoon; Kwon, Do-Hoon; Han, Sang-Kook

    2016-10-31

    We propose a self-reverse-biased solar panel optical receiver for energy harvesting and visible light communication. Since the solar panel converts an optical component into an electrical component, it provides both energy harvesting and communication. The signal component can be separated from the direct current component, and these components are used for communication and energy harvesting. We employed a self-reverse-biased receiver circuit to improve the communication and energy harvesting performance. The reverse bias on the solar panel improves the responsivity and response time. The proposed system achieved 17.05 mbps discrete multitone transmission with a bit error rate of 1.1 x 10-3 and enhanced solar energy conversion efficiency.

  1. Proton energy dependence of slow neutron intensity

    International Nuclear Information System (INIS)

    Teshigawara, Makoto; Harada, Masahide; Watanabe, Noboru; Kai, Tetsuya; Sakata, Hideaki; Ikeda, Yujiro

    2001-01-01

    The choice of the proton energy is an important issue for the design of an intense-pulsed-spallation source. The optimal proton beam energy is rather unique from a viewpoint of the leakage neutron intensity but no yet clear from the slow-neutron intensity view point. It also depends on an accelerator type. Since it is also important to know the proton energy dependence of slow-neutrons from the moderators in a realistic target-moderator-reflector assembly (TMRA). We studied on the TMRA proposed for Japan Spallation Neutron Source. The slow-neutron intensities from the moderators per unit proton beam power (MW) exhibit the maximum at about 1-2 GeV. At higher proton energies the intensity per MW goes down; at 3 and 50 GeV about 0.91 and 0.47 times as low as that at 1 GeV. The proton energy dependence of slow-neutron intensities was found to be almost the same as that of total neutron yield (leakage neutrons) from the same bare target. It was also found that proton energy dependence was almost the same for the coupled and decoupled moderators, regardless the different moderator type, geometry and coupling scheme. (author)

  2. Energy price, Environmental policy, and technological bias of photovoltaics

    International Nuclear Information System (INIS)

    Stambouli, A. Boudghene; Larbi, N.; Traversa, E.

    2006-01-01

    Energy is the most important resource for the development of a country and the utilisation of energy per capita is increasing tremendously. In fact energy security, economic growth and environmental protection (the three E's) are the national energy policy drivers of any country of the world. Utilisation on conventional energy will course environment pollution such as major environmental accidents, water pollution, maritime pollution, land use and sitting impact, radiation and radioactivity, solid waste disposal, hazardous air pollutions, ambient air quality (CO, CO2, SOx, NOx effluent gas emissions), acid rain, stratospheric ozone depletion, and global warming. The world's energy consumption today is estimated to 40 billion kWh per year, about 10 billion metric tons carbon equivalent of greenhouse gas emission are released in the atmosphere to meet this energy demand. Approximately 80% is due to carbon emissions from the combustion of energy fuels. In fact 14 billion tons of greenhouse gas, that contributes to global warming entered the atmosphere in 2003. World Energy Council (WEC) study found that without any change in our current practice, the world energy demand expectation in 2020 would be 53 billion kWh or 50 to 80% higher than 1990 levels. Such ever-increasing demand could place significant strain on the current energy infrastructure and potentially damage the world environment and people's health with over 700.000 deaths resulting each year, according to the World Bank. World emissions of carbon are expected to increase by 54% above 1990 levels by 2020 making the earth likely a warm 1.7-4.9 degree centigrade over the period 1990-2100. During the past century, global surface temperatures have increased at a rate near 0.6 degree centigrade/century. This trend has dramatically increased during the past 25 years and the average temperature of the Atlantic, Pacific and Indian Oceans has risen by 0.06 degree centigrade since 1995. Global temperatures in 2001were

  3. The fluctuations of China’s energy intensity: Biased technical change

    International Nuclear Information System (INIS)

    Wang, Ce; Liao, Hua; Pan, Su-Yan; Zhao, Lu-Tao; Wei, Yi-Ming

    2014-01-01

    Highlights: • Biased technical change is considered in the adjusting the input–output tables. • The level of biased technical change is determined by TFP and energy efficiency. • The increase in energy intensity was mostly attributed to the structural change. • The changes in the production technology actually decreased the energy intensity. • The decomposition results are sensitive to the level of biased technical change. - Abstract: The fluctuations of China’s energy intensity have attracted the attention of many scholars, but fewer studies consider the data quality of official input–output tables. This paper conducts a decomposition model by using the Divisia method based on the input–output tables. Because of the problems with input–output tables and price deflators, we first produce constant prices to deflate the input–output tables. And then we consider different levels of biased technical change for different sectors in the adjusting the input–output table. Finally, we use RAS technique to adjust input–output matrix. Then the decomposition model is employed to empirically analyze the change of China’s energy intensity. We compare the decomposition results with and without biased technical change and do sensitive analysis on the level of biased technical change. The decomposition results are that during 2002–2007, the energy intensity of coal and electricity increased, the changes were mostly attributed to the structural change and the contribution was 594.08%, 73.88%, respectively; as for crude oil and refined oil, the energy intensity decreased, the changes were mostly attributed to the changes in the production technology and the contribution was 978.89%, 246.95%, respectively. And the results of sensitive analysis shows that 1% variation of the level of biased technical change will cause at most 0.6% change of decomposition results. Therefore, we can draw our conclusions: compared to the decomposition without biased technical

  4. Exchange bias energy in Co/Pt/IrMn multilayers with perpendicular and in-plane anisotropy

    International Nuclear Information System (INIS)

    Czapkiewicz, M.; Stobiecki, T.; Rak, R.; Zoladz, M.; Dijken, S. van

    2007-01-01

    The magnetization reversal process in perpendicularly biased [Pt/Co] 3 /d Pt Pt/IrMn and in-plane biased Co/d Pt Pt/IrMn multilayers with 0nm= Pt = Pt =0.1nm. In both cases, the existence of large exchange bias fields correlates with a high domain density during magnetization reversal. The interface exchange coupling energy is larger for the in-plane biased films than for the perpendicularly biased multilayers

  5. Detection unit with corrected energy dependence

    International Nuclear Information System (INIS)

    Viererbl, L.

    1989-01-01

    The detection unit consists of a plastic scintillator with a layer of a powder semicrystalline scintillator deposited on its surface. An inorgaic monocrystalline scintillator is placed inside the plastic scintillator and surrounded with an absorption layer, except for the window. The advantage of the detection unit is a reduced energy dependence of response, especially in the energy range 100 to 400 keV. (E.J.). 3 figs

  6. Energy dependence corrections to MOSFET dosimetric sensitivity

    International Nuclear Information System (INIS)

    Cheung, T.; Yu, P.K.N.; Butson, M.J.; Illawarra Cancer Care Centre, Crown St, Wollongong

    2009-01-01

    Metal Oxide Semiconductor Field Effect Transistors (MOSFET's) are dosimeters which are now frequently utilized in radiotherapy treatment applications. An improved MOSFET, clinical semiconductor dosimetry system (CSDS) which utilizes improved packaging for the MOSFET device has been studied for energy dependence of sensitivity to x-ray radiation measurement. Energy dependence from 50 kVp to 10 MV x-rays has been studied and found to vary by up to a factor of 3.2 with 75 kVp producing the highest sensitivity response. The detectors average life span in high sensitivity mode is energy related and ranges from approximately 100 Gy for 75 kVp x-rays to approximately 300 Gy at 6MV x-ray energy. The MOSFET detector has also been studied for sensitivity variations with integrated dose history. It was found to become less sensitive to radiation with age and the magnitude of this effect is dependant on radiation energy with lower energies producing a larger sensitivity reduction with integrated dose. The reduction in sensitivity is however approximated reproducibly by a slightly non linear, second order polynomial function allowing corrections to be made to reading to account for this effect to provide more accurate dose assessments both in phantom and in-vivo.

  7. Energy dependence corrections to MOSFET dosimetric sensitivity.

    Science.gov (United States)

    Cheung, T; Butson, M J; Yu, P K N

    2009-03-01

    Metal Oxide Semiconductor Field Effect Transistors (MOSFET's) are dosimeters which are now frequently utilized in radiotherapy treatment applications. An improved MOSFET, clinical semiconductor dosimetry system (CSDS) which utilizes improved packaging for the MOSFET device has been studied for energy dependence of sensitivity to x-ray radiation measurement. Energy dependence from 50 kVp to 10 MV x-rays has been studied and found to vary by up to a factor of 3.2 with 75 kVp producing the highest sensitivity response. The detectors average life span in high sensitivity mode is energy related and ranges from approximately 100 Gy for 75 kVp x-rays to approximately 300 Gy at 6 MV x-ray energy. The MOSFET detector has also been studied for sensitivity variations with integrated dose history. It was found to become less sensitive to radiation with age and the magnitude of this effect is dependant on radiation energy with lower energies producing a larger sensitivity reduction with integrated dose. The reduction in sensitivity is however approximated reproducibly by a slightly non linear, second order polynomial function allowing corrections to be made to readings to account for this effect to provide more accurate dose assessments both in phantom and in-vivo.

  8. Wireless Energy Transfer Using Zero Bias Schottky Diodes Rectenna Structures

    International Nuclear Information System (INIS)

    Marian, V.; Adami, S.E.; Vollaire, Ch.; Allard, B.; Verdier, J.

    2011-01-01

    This paper presents several RF-to-DC converter topologies and compares their performances based on measurements made on fabricated prototypes. A medium range wireless low power transmission experiment is presented. A low power DC-DC boost converter designed rectenna-generated energy conditioning is also discussed. (author)

  9. Rapidity dependence of strangeness enhancement factor at FAIR energies

    International Nuclear Information System (INIS)

    Dey, Kalyan; Bhattacharjee, B.

    2014-01-01

    Strange particles are produced only at the time of collisions and thus expected to carry important information of collision dynamics. Strangeness enhancement is considered to be one of the traditional signatures of formation of Quark Gluon Plasma (QGP). Due to the limitation of the detector acceptance, the past and ongoing heavy ion experiments could measure the strangeness enhancement at midrapidity only. But the future heavy ion experiment CBM at FAIR will have the access to the entire forward rapidity hemisphere and thus the experimental determination of rapidity dependent strangeness enhancement is a possibility. In this work, an attempt has therefore been made to study the rapidity dependent strangeness enhancement at FAIR energies with the help of a string based hadronic model (UrQMD). A sum of 93 million minimum biased UrQMD events have been used for the present analysis

  10. Energy dependence of pMOS dosemeters

    International Nuclear Information System (INIS)

    Savic, Z.; Stankovic, S.; Kovacevic, M.; Petrovic, M.

    1996-01-01

    The results are presented of experimental work and numerical simulations of the energy response for pMOS dosimetric transistors in their custom packages. Specially produced radiation soft pMOS transistors were used in this experimental work. The irradiation of pMOS dosemeters was done using 60 Co and 137 Cs sources, a dosimetric X ray unit, and a radiotherapeutic linear accelerator in the range of photon energies from 21 keV to 8 MeV. The results show that package geometry and materials can significantly affect and smooth the energy dependence of pMOS transistors and that in custom transistor packages they are not tissue-equivalent dosemeters. Their response in the photon energy range of 45 to 250 keV is significantly larger than it should be (maximum dose enhancement factor can be as high as 8) and some energy compensation techniques must be used in order to fulfill the requirements of corresponding standards. (Author)

  11. Eye Movement Evidence of Attentional Bias for Substance-Related Cues in Heroin Dependents on Methadone Maintenance Therapy.

    Science.gov (United States)

    Zhao, Hui; Yang, Bo; Zhu, Qian; Zhang, Guangqun; Xiao, Yuqin; Guo, Xiao; Huang, Xiu; Zhang, Zhuo

    2017-03-21

    Attentional biases toward substance-related stimuli might play a contributing role in addictive behaviors. This study investigated the selective attention to substance-related stimuli in heroin dependents receiving methadone maintenance therapy. Thirty outpatients receiving methadone maintenance treatment for heroin dependence and 38 healthy controls completed a visual probe task with concurrent eye movement monitoring. The results showed that the heroin group reacted faster to probes associated with substance-related pictures than neutral pictures, and they directed more initial fixations and maintained longer initial fixation durations toward substance-related pictures than neutral pictures. However, attentional bias was not correlated with addiction severity in the heroin group. These findings suggest that attentional bias towards substance-related cues occurs in heroin dependents, although this bias might not be associated with the severity of drug-using behavior.

  12. Temperature dependence of exchange bias in (NiFe/IrMn)n multilayer films studied through static and dynamic techniques

    Science.gov (United States)

    Adams, Daniel J.; Khanal, Shankar; Khan, Mohammad Asif; Maksymov, Artur; Spinu, Leonard

    2018-05-01

    The in-plane temperature dependence of exchange bias was studied through both dc magnetometry and ferromagnetic resonance spectroscopy in a series of [NiFe/IrMn]n multilayer films, where n is the number of layer repetitions. Major hysteresis loops were recorded in the temperature range of 300 K to 2 K to reveal the effect of temperature on the exchange bias in the static regime while temperature-dependent continuous-wave ferromagnetic resonance for frequencies from 3 to 16 GHz was used to determine the exchange bias dynamically. Strong divergence between the values of exchange bias determined using the two different types of measurements as well as a peak in temperature dependence of the resonance linewidth were observed. These results are explained in terms of the slow-relaxer mechanism.

  13. Energy dependence of nonlocal optical potentials

    Science.gov (United States)

    Lovell, A. E.; Bacq, P.-L.; Capel, P.; Nunes, F. M.; Titus, L. J.

    2017-11-01

    Recently, a variety of studies have shown the importance of including nonlocality in the description of reactions. The goal of this work is to revisit the phenomenological approach to determining nonlocal optical potentials from elastic scattering. We perform a χ2 analysis of neutron elastic scattering data off 40Ca, 90Zr, and 208Pb at energies E ≈5 -40 MeV, assuming a Perey and Buck [Nucl. Phys. 32, 353 (1962), 10.1016/0029-5582(62)90345-0] or Tian et al. [Int. J. Mod. Phys. E 24, 1550006 (2015), 10.1142/S0218301315500068] nonlocal form for the optical potential. We introduce energy and asymmetry dependencies in the imaginary part of the potential and refit the data to obtain a global parametrization. Independently of the starting point in the minimization procedure, an energy dependence in the imaginary depth is required for a good description of the data across the included energy range. We present two parametrizations, both of which represent an improvement over the original potentials for the fitted nuclei as well as for other nuclei not included in our fit. Our results show that, even when including the standard Gaussian nonlocality in optical potentials, a significant energy dependence is required to describe elastic-scattering data.

  14. Treatment in hospital for alcohol-dependent patients decreases attentional bias

    Directory of Open Access Journals (Sweden)

    Flaudias V

    2013-05-01

    Full Text Available Valentin Flaudias,1,2 Georges Brousse,1,2 Ingrid De Chazeron,1,2 François Planche,2 Julien Brun,2 Pierre-Michel Llorca1,2 1Clermont Université, EA 7280 NPsy-Sydo, Clermont-Ferrand, France; 2Pôle Psychiatrie B, CHU Gabriel-Montpied, Clermont-Ferrand, France Background and objectives: Previous studies in alcohol-dependent patients have shown an attentional bias (AB under related substance cues, which can lead to relapse. This AB can be evaluated by the alcohol Stroop test (AST. The AST is a modified Stroop task in which participants have to name the color of an alcohol-related word or a neutral word. AB is the response-time difference between these two types of words. The goal of the current study was to examine modification of AB during specialized hospitalization for alcohol dependence, with the suppression of a training bias that could be present in within-subject design. Methods: Individuals with alcohol-dependence disorders (Diagnostic and Statistical Manual of Mental Disorders, 4th edition and admitted for withdrawal in the addiction unit of the University Hospital of Clermont-Ferrand (test group, n = 42 and persons with no alcohol or psychiatric disorder (control group, n = 16, recruited among colleagues and friends of the staff, performed the AST. A subgroup of the test group performed the AST in admission (admission group, n = 19, and another subgroup undertook the test immediately before discharge (discharge group, n = 23. Results: Results showed an AB only for patients seen at admission (F[1,55] = 3.283, P = 0.075. Moreover, we observed that the AB in the admission group (mean = 34 ms, standard deviation [SD] = 70.06 was greater than the AB in the control group (mean = 23 ms, SD = 93.42, itself greater than the AB in the discharge group (mean = −12 ms, SD = 93.55 (t[55] = −1.71; P = 0.09. Conclusion: Although the results are preliminary, the present study provides evidence for changes in the AB during alcohol-addiction treatment

  15. Comparison of the linear bias models in the light of the Dark Energy Survey

    Science.gov (United States)

    Papageorgiou, A.; Basilakos, S.; Plionis, M.

    2018-05-01

    The evolution of the linear and scale independent bias, based on the most popular dark matter bias models within the Λ cold dark matter (ΛCDM) cosmology, is confronted to that of the Dark Energy Survey (DES) luminous red galaxies (LRGs). Applying a χ2 minimization procedure between models and data, we find that all the considered linear bias models reproduce well the LRG bias data. The differences among the bias models are absorbed in the predicted mass of the dark-matter halo in which LRGs live and which ranges between ˜6 × 1012 and 1.4 × 1013 h-1 M⊙, for the different bias models. Similar results, reaching however a maximum value of ˜2 × 1013 h-1 M⊙, are found by confronting the SDSS (2SLAQ) Large Red Galaxies clustering with theoretical clustering models, which also include the evolution of bias. This later analysis also provides a value of Ωm = 0.30 ± 0.01, which is in excellent agreement with recent joint analyses of different cosmological probes and the reanalysis of the Planck data.

  16. Energy dependence of polymer gels in the orthovoltage energy range

    Directory of Open Access Journals (Sweden)

    Yvonne Roed

    2014-03-01

    Full Text Available Purpose: Ortho-voltage energies are often used for treatment of patients’ superficial lesions, and also for small- animal irradiations. Polymer-Gel dosimeters such as MAGAT (Methacrylic acid Gel and THPC are finding increasing use for 3-dimensional verification of radiation doses in a given treatment geometry. For mega-voltage beams, energy dependence of MAGAT has been quoted as nearly energy-independent. In the kilo-voltage range, there is hardly any literature to shade light on its energy dependence.Methods: MAGAT was used to measure depth-dose for 250 kVp beam. Comparison with ion-chamber data showed a discrepancy increasing significantly with depth. An over-response as much as 25% was observed at a depth of 6 cm.Results and Conclusion: Investigation concluded that 6 cm water in the beam resulted in a half-value-layer (HVL change from 1.05 to 1.32 mm Cu. This amounts to an effective-energy change from 81.3 to 89.5 keV. Response measurements of MAGAT at these two energies explained the observed discrepancy in depth-dose measurements. Dose-calibration curves of MAGAT for (i 250 kVp beam, and (ii 250 kVp beam through 6 cm of water column are presented showing significant energy dependence.-------------------Cite this article as: Roed Y, Tailor R, Pinksy L, Ibbott G. Energy dependence of polymer gels in the orthovoltage energy range. Int J Cancer Ther Oncol 2014; 2(2:020232. DOI: 10.14319/ijcto.0202.32 

  17. Experimental energy-dependent nuclear spin distributions

    International Nuclear Information System (INIS)

    Egidy, T. von; Bucurescu, D.

    2009-01-01

    A new method is proposed to determine the energy-dependent spin distribution in experimental nuclear-level schemes. This method compares various experimental and calculated moments in the energy-spin plane to obtain the spin-cutoff parameter σ as a function of mass A and excitation energy using a total of 7202 levels with spin assignment in 227 nuclei between F and Cf. A simple formula, σ 2 =0.391 A 0.675 (E-0.5Pa ' ) 0.312 , is proposed up to about 10 MeV that is in very good agreement with experimental σ values and is applied to improve the systematics of level-density parameters.

  18. Misconceptions and biases in German students' perception of multiple energy sources: implications for science education

    Science.gov (United States)

    Lee, Roh Pin

    2016-04-01

    Misconceptions and biases in energy perception could influence people's support for developments integral to the success of restructuring a nation's energy system. Science education, in equipping young adults with the cognitive skills and knowledge necessary to navigate in the confusing energy environment, could play a key role in paving the way for informed decision-making. This study examined German students' knowledge of the contribution of diverse energy sources to their nation's energy mix as well as their affective energy responses so as to identify implications for science education. Specifically, the study investigated whether and to what extent students hold mistaken beliefs about the role of multiple energy sources in their nation's energy mix, and assessed how misconceptions could act as self-generated reference points to underpin support/resistance of proposed developments. An in-depth analysis of spontaneous affective associations with five key energy sources also enabled the identification of underlying concerns driving people's energy responses and facilitated an examination of how affective perception, in acting as a heuristic, could lead to biases in energy judgment and decision-making. Finally, subgroup analysis differentiated by education and gender supported insights into a 'two culture' effect on energy perception and the challenge it poses to science education.

  19. Incident energy dependence of pt correlations at relativistic energies

    CERN Document Server

    Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhasin, A; Bhati, A K; Bhatia, V S; Bichsel, H; Bielcik, J; Bielcikova, J; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; De Moura, M M; Dedovich, T G; Derevshchikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta, M R; Mazumdar; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Geurts, F; Ghazikhanian, V; Ghosh, P; González, J E; Gos, H; Grachov, O; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guo, Y; Sen-Gupta, A; Gutíerrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Jedynak, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kowalik, K L; Krämer, M; Kravtsov, P; Kravtsov, V I; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; Le Vine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnik, Yu M; Meschanin, A; Miller, M L; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D; Pruneau, C A; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Reinnarth, J; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimansky, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sørensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; Van Leeuwen, M; Van der Molen, A M; Varma, R; Vasilevski, I M; Vasilev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zborovský, I; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

    2005-01-01

    We present results for two-particle transverse momentum correlations, , as a function of event centrality for Au+Au collisions at sqrt(sNN) = 20, 62, 130, and 200 GeV at the Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy and the centrality dependence may show evidence of processes such as thermalization, minijet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or no beam energy dependence and generally agrees with previous measurements at the Super Proton Synchrotron.

  20. Field angle dependence of voltage-induced ferromagnetic resonance under DC bias voltage

    International Nuclear Information System (INIS)

    Shiota, Yoichi; Miwa, Shinji; Tamaru, Shingo; Nozaki, Takayuki; Kubota, Hitoshi; Fukushima, Akio; Suzuki, Yoshishige; Yuasa, Shinji

    2016-01-01

    We studied the rectification function of microwaves in CoFeB/MgO-based magnetic tunnel junctions using voltage-induced ferromagnetic resonance (FMR). Our findings reveal that the shape of the structure of the spectrum depends on the rotation angle of the external magnetic field, providing clear evidence that FMR dynamics are excited by voltage-induced magnetic anisotropy changes. Further, enhancement of the rectified voltage was demonstrated under a DC bias voltage. In our experiments, the highest microwave detection sensitivity obtained was 350 mV/mW, at an RF frequency of 1.0 GHz and field angle of θ_H=80°, ϕ_H=0°. The experimental results correlated with those obtained via simulation, and the calculated results revealed the magnetization dynamics at the resonance state. - Highlights: • Examined voltage-induced ferromagnetic resonance (FMR) under various field angles. • FMR dynamics are excited by voltage-induced magnetic anisotropy changes. • Microwave detection sensitivity depends on input RF and elevation angle. • Microwave detection sensitivity=350 mV/mW at RF=1.0 GHz, θ_H=80°, ϕ_H=0°.

  1. Energy dependence of pMOS dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Savic, Z. [Military Technical Institute, Belgrade (Yugoslavia); Stankovic, S.; Kovacevic, M.; Petrovic, M. [Institute of Nuclear Sciences, Belgrade (Yugoslavia). Radiation Protection Dept.

    1996-10-01

    The results are presented of experimental work and numerical simulations of the energy response for pMOS dosimetric transistors in their custom packages. Specially produced radiation soft pMOS transistors were used in this experimental work. The irradiation of pMOS dosemeters was done using {sup 60}Co and {sup 137}Cs sources, a dosimetric X ray unit, and a radiotherapeutic linear accelerator in the range of photon energies from 21 keV to 8 MeV. The results show that package geometry and materials can significantly affect and smooth the energy dependence of pMOS transistors and that in custom transistor packages they are not tissue-equivalent dosemeters. Their response in the photon energy range of 45 to 250 keV is significantly larger than it should be (maximum dose enhancement factor can be as high as 8) and some energy compensation techniques must be used in order to fulfill the requirements of corresponding standards. (Author).

  2. Giant exchange bias and its angular dependence in Co/CoO core-shell nanowire assemblies

    International Nuclear Information System (INIS)

    Gandha, Kinjal; Chaudhary, Rakesh P.; Mohapatra, Jeotikanta; Koymen, Ali R.; Liu, J. Ping

    2017-01-01

    The exchange-bias field (H EB ) and its angular dependence are systematically investigated in Co/CoO core-shell nanowire assemblies (∼15 nm in diameter and ∼200 nm in length) consisting of single-crystalline Co core and polycrystalline CoO shell. Giant exchange-bias field (H EB ) up to 2.4 kOe is observed below a blocking temperature (T EB ∼150 K) in the aligned Co/CoO nanowire assemblies. It is also found that there is an angular dependence between the H EB and the applied magnetization direction. The H EB showed a peak at 30° between the applied field and the nanowire aligned direction, which may be attributed to the noncollinear spin orientations at the interface between the ferromagnetic core and the antiferromagnetic shell. This behavior is quantitatively supported by an analytical calculation based on Stoner–Wohlfarth model. This study underlines the importance of the competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. - Highlights: • Giant exchange bias is observed in oriented Co/CoO core-shell nanowire assemblies. • Study of angular and temperature dependence of the exchange bias effect. • Competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. • Effect of misaligned spins in FM/AFM interface on angular dependence of exchange bias. • We explain the analytical model that accounts for experimental results.

  3. Predictions of ion energy distributions and radical fluxes in radio frequency biased inductively coupled plasma etching reactors

    Science.gov (United States)

    Hoekstra, Robert J.; Kushner, Mark J.

    1996-03-01

    Inductively coupled plasma (ICP) reactors are being developed for low gas pressure (radio frequency (rf) bias is applied to the substrate. One of the goals of these systems is to independently control the magnitude of the ion flux by the inductively coupled power deposition, and the acceleration of ions into the substrate by the rf bias. In high plasma density reactors the width of the sheath above the wafer may be sufficiently thin that ions are able to traverse it in approximately 1 rf cycle, even at 13.56 MHz. As a consequence, the ion energy distribution (IED) may have a shape typically associated with lower frequency operation in conventional reactive ion etching tools. In this paper, we present results from a computer model for the IED incident on the wafer in ICP etching reactors. We find that in the parameter space of interest, the shape of the IED depends both on the amplitude of the rf bias and on the ICP power. The former quantity determines the average energy of the IED. The latter quantity controls the width of the sheath, the transit time of ions across the sheath and hence the width of the IED. In general, high ICP powers (thinner sheaths) produce wider IEDs.

  4. Freezing field dependence of the exchange bias in uniaxial FeF sub 2 -CoPt heterosystems with perpendicular anisotropy

    CERN Document Server

    Kagerer, B; Kleemann, W

    2000-01-01

    The exchange bias effect is measured for the first time in FeF sub 2 -CoPt heterosystems with perpendicular anisotropy. The exchange field exhibits a strong dependence on the axial freezing field. This behavior is explained in terms of the microscopic spin structure at the interface, which is established on cooling to below T sub N. We calculate the dependence of the spin structure on the freezing field within the framework of an Ising model. It takes into account the Zeeman energy as well as an antiferromagnetic exchange coupling between the adjacent layers at the interface.

  5. Forward-biased nanophotonic detector for ultralow-energy dissipation receiver

    Science.gov (United States)

    Nozaki, Kengo; Matsuo, Shinji; Fujii, Takuro; Takeda, Koji; Shinya, Akihiko; Kuramochi, Eiichi; Notomi, Masaya

    2018-04-01

    Generally, reverse-biased photodetectors (PDs) are used for high-speed optical receivers. The forward voltage region is only utilized in solar-cells, and this photovoltaic operation would not be concurrently obtained with high efficiency and high speed operation. Here we report that photonic-crystal waveguide PDs enable forward-biased high-speed operation at 40 Gbit/s with keeping high responsivity (0.88 A/W). Within our knowledge, this is the first demonstration of the forward-biased PDs with high responsivity. This achievement is attributed to the ultracompactness of our PD and the strong light confinement within the absorber and depleted regions, thereby enabling efficient photo-carrier generation and fast extraction. This result indicates that it is possible to construct a high-speed and ultracompact photo-receiver without an electrical amplifier nor an external bias circuit. Since there is no electrical energy required, our estimation shows that the consumption energy is just the optical energy of the injected signal pulse which is about 1 fJ/bit. Hence, it will lead to an ultimately efficient and highly integrable optical-to-electrical converter in a chip, which will be a key ingredient for dense nanophotonic communication and processors.

  6. Forward-biased nanophotonic detector for ultralow-energy dissipation receiver

    Directory of Open Access Journals (Sweden)

    Kengo Nozaki

    2018-04-01

    Full Text Available Generally, reverse-biased photodetectors (PDs are used for high-speed optical receivers. The forward voltage region is only utilized in solar-cells, and this photovoltaic operation would not be concurrently obtained with high efficiency and high speed operation. Here we report that photonic-crystal waveguide PDs enable forward-biased high-speed operation at 40 Gbit/s with keeping high responsivity (0.88 A/W. Within our knowledge, this is the first demonstration of the forward-biased PDs with high responsivity. This achievement is attributed to the ultracompactness of our PD and the strong light confinement within the absorber and depleted regions, thereby enabling efficient photo-carrier generation and fast extraction. This result indicates that it is possible to construct a high-speed and ultracompact photo-receiver without an electrical amplifier nor an external bias circuit. Since there is no electrical energy required, our estimation shows that the consumption energy is just the optical energy of the injected signal pulse which is about 1 fJ/bit. Hence, it will lead to an ultimately efficient and highly integrable optical-to-electrical converter in a chip, which will be a key ingredient for dense nanophotonic communication and processors.

  7. US oil dependency and energy security

    International Nuclear Information System (INIS)

    Noel, P.

    2002-12-01

    As an introduction to the seminar of the 30 May 2002 on the US oil dependency and energy security, the author analyzes the different factors which characterize the american petroleum market situation today. A special interest is thus done to the price increase of 1999-2000 due to the legislation evolution, the gas market tensions, the impact and the power of the OPEC on the international markets, the 11 September 2001 attempts and their political and military consequences. The author also discusses about three papers written after the seminar. (A.L.B.)

  8. Energy dependence of double photoionization in He

    International Nuclear Information System (INIS)

    Berrah, N.; Wehlitz, R.; Levin, J.; Whitfield, S.B.; Viefhaus, J.; Sellin, I.A.; Becker, U.

    1993-01-01

    The ratio of double-to-single ionization of He has been measured between 280 eV and 1210 eV to investigate its energy dependence in the intermediate region. The new intermediate energy measurement, compared with the most recent theories of Pan and Kelly and of Hino and Hino et al., show the importance of including not only ground state but also final state correlations. They also appear to indicate the importance of including higher-order effects in the theory. The previously reported high energy measurements between 2-12 keV give a ratio of 1.5 (2)% in good agreement with older shake calculations of Byron and Joachain and of Aberg, as well as with recent many-body perturbation theory of Ishihara et al., calculations of Dalgarno and Sadeghpour, and of Andersson and Burgdoerfer. In contrast to the intermediate energy behavior, consideration of final state correlations proves inessential as discussed by Dalgarno and Sadeghpour. (orig.)

  9. Emotional bias of sleep-dependent processing shifts from negative to positive with aging.

    Science.gov (United States)

    Jones, Bethany J; Schultz, Kurt S; Adams, Sydney; Baran, Bengi; Spencer, Rebecca M C

    2016-09-01

    Age-related memory decline has been proposed to result partially from impairments in memory consolidation over sleep. However, such decline may reflect a shift toward selective processing of positive information with age rather than impaired sleep-related mechanisms. In the present study, young and older adults viewed negative and neutral pictures or positive and neutral pictures and underwent a recognition test after sleep or wake. Subjective emotional reactivity and affect were also measured. Compared with waking, sleep preserved valence ratings and memory for positive but not negative pictures in older adults and negative but not positive pictures in young adults. In older adults, memory for positive pictures was associated with slow wave sleep. Furthermore, slow wave sleep predicted positive affect in older adults but was inversely related to positive affect in young adults. These relationships were strongest for older adults with high memory for positive pictures and young adults with high memory for negative pictures. Collectively, these results indicate preserved but selective sleep-dependent memory processing with healthy aging that may be biased to enhance emotional well-being. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Neural Correlates of Drug-Related Attentional Bias in Heroin Dependence

    Directory of Open Access Journals (Sweden)

    Qinglin Zhao

    2018-01-01

    Full Text Available The attention of drug-dependent persons tends to be captured by stimuli associated with drug consumption. This involuntary cognitive process is considered as attentional bias (AB. AB has been hypothesized to have causal effects on drug abuse and drug relapse, but its underlying neural mechanisms are still unclear. This study investigated the neural basis of AB in abstinent heroin addicts (AHAs, combining event-related potential (ERP analysis and source localization techniques. Electroencephalography data were collected in 21 abstinent heroin addicts and 24 age- and gender-matched healthy controls (HCs during a dot-probe task. In the task, a pair of drug-related image and neutral image was presented randomly in left and right side of the cross fixation, followed by a dot probe replacing one of the images. Behaviorally, AHAs had shorter reaction times (RTs for the congruent condition compared to the incongruent condition, whereas this was not the case in the HCs. This finding demonstrated the presence of AB towards drug cues in AHAs. Furthermore, the image-evoked ERPs in AHAs had significant shorter P1 latency compared to HCs, as well as larger N1, N2, and P2 amplitude, suggesting that drug-related stimuli might capture attention early and overall require more attentional resources in AHAs. The target-related P3 had significantly shorter latency and lower amplitude in the congruent than incongruent condition in AHAs compared to HCs. Moreover, source localization of ERP components revealed increased activity for AHAs as compared to HCs in the dorsal posterior cingulate cortex (dPCC, superior parietal lobule and inferior frontal gyrus (IFG for image-elicited responses, and decreased activity in the occipital and the medial parietal lobes for target-elicited responses. Overall, the results of our study confirmed that AHAs may exhibit AB in drug-related contexts, and suggested that the bias might be related to an abnormal neural activity, both in

  11. Bias-Flip Technique for Frequency Tuning of Piezo-Electric Energy Harvesting Devices

    Directory of Open Access Journals (Sweden)

    Jianguo Ma

    2013-06-01

    Full Text Available Devices that harvest electrical energy from mechanical vibrations have the problem that the frequency of the source vibration is often not matched to the resonant frequency of the energy harvesting device. Manufacturing tolerances make it difficult to match the Energy Harvesting Device (EHD resonant frequency to the source vibration frequency, and the source vibration frequency may vary with time. Previous work has recognized that it is possible to tune the resonant frequency of an EHD using a tunable, reactive impedance at the output of the device. The present paper develops the theory of electrical tuning, and proposes the Bias-Flip (BF technique, to implement this tunable, reactive impedance.

  12. Systematic spatial bias in DNA microarray hybridization is caused by probe spot position-dependent variability in lateral diffusion.

    Science.gov (United States)

    Steger, Doris; Berry, David; Haider, Susanne; Horn, Matthias; Wagner, Michael; Stocker, Roman; Loy, Alexander

    2011-01-01

    The hybridization of nucleic acid targets with surface-immobilized probes is a widely used assay for the parallel detection of multiple targets in medical and biological research. Despite its widespread application, DNA microarray technology still suffers from several biases and lack of reproducibility, stemming in part from an incomplete understanding of the processes governing surface hybridization. In particular, non-random spatial variations within individual microarray hybridizations are often observed, but the mechanisms underpinning this positional bias remain incompletely explained. This study identifies and rationalizes a systematic spatial bias in the intensity of surface hybridization, characterized by markedly increased signal intensity of spots located at the boundaries of the spotted areas of the microarray slide. Combining observations from a simplified single-probe block array format with predictions from a mathematical model, the mechanism responsible for this bias is found to be a position-dependent variation in lateral diffusion of target molecules. Numerical simulations reveal a strong influence of microarray well geometry on the spatial bias. Reciprocal adjustment of the size of the microarray hybridization chamber to the area of surface-bound probes is a simple and effective measure to minimize or eliminate the diffusion-based bias, resulting in increased uniformity and accuracy of quantitative DNA microarray hybridization.

  13. Bias-voltage dependence of perpendicular spin-transfer torque in asymmetric MgO-based magnetic tunnel junctions

    KAUST Repository

    Oh, Se Chung; Park, Seung Young; Manchon, Aurelien; Chshiev, Mairbek; Han, Jae Ho; Lee, Hyun Woo; Lee, Jang Eun; Nam, Kyung Tae; Jo, Younghun; Kong, Yo Chan; Dieny, Bernard; Lee, Kyung Jin

    2009-01-01

    Spin-transfer torque (STT) allows the electrical control of magnetic states in nanostructures. The STT in magnetic tunnel junctions (MTJs) is of particular importance owing to its potential for device applications. It has been demonstrated that the MTJ has a sizable perpendicular STT (, field-like torque), which substantially affects STT-driven magnetization dynamics. In contrast to symmetric MTJs where the bias dependence of is quadratic, it is theoretically predicted that the symmetry breaking of the system causes an extra linear bias dependence. Here, we report experimental results that are consistent with the predicted linear bias dependence in asymmetric MTJs. The linear contribution is quite significant and its sign changes from positive to negative as the asymmetry is modified. This result opens a way to design the bias dependence of the field-like term, which is useful for device applications by allowing, in particular, the suppression of the abnormal switching-back phenomena. © 2009 Macmillan Publishers Limited. All rights reserved.

  14. Bias-voltage dependence of perpendicular spin-transfer torque in asymmetric MgO-based magnetic tunnel junctions

    KAUST Repository

    Oh, Se Chung

    2009-10-25

    Spin-transfer torque (STT) allows the electrical control of magnetic states in nanostructures. The STT in magnetic tunnel junctions (MTJs) is of particular importance owing to its potential for device applications. It has been demonstrated that the MTJ has a sizable perpendicular STT (, field-like torque), which substantially affects STT-driven magnetization dynamics. In contrast to symmetric MTJs where the bias dependence of is quadratic, it is theoretically predicted that the symmetry breaking of the system causes an extra linear bias dependence. Here, we report experimental results that are consistent with the predicted linear bias dependence in asymmetric MTJs. The linear contribution is quite significant and its sign changes from positive to negative as the asymmetry is modified. This result opens a way to design the bias dependence of the field-like term, which is useful for device applications by allowing, in particular, the suppression of the abnormal switching-back phenomena. © 2009 Macmillan Publishers Limited. All rights reserved.

  15. Exchange bias energy in Co/Pt/IrMn multilayers with perpendicular and in-plane anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Czapkiewicz, M. [Department of Electronics, AGH University of Science and Technology, 30-059 Cracow (Poland)]. E-mail: czapkiew@agh.edu.pl; Stobiecki, T. [Department of Electronics, AGH University of Science and Technology, 30-059 Cracow (Poland); Rak, R. [Department of Electronics, AGH University of Science and Technology, 30-059 Cracow (Poland); Zoladz, M. [Department of Electronics, AGH University of Science and Technology, 30-059 Cracow (Poland); Dijken, S. van [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

    2007-09-15

    The magnetization reversal process in perpendicularly biased [Pt/Co]{sub 3}/d{sub Pt} Pt/IrMn and in-plane biased Co/d{sub Pt} Pt/IrMn multilayers with 0nm=bias field decreases monotonically with Pt insertion layer thickness, while its coercivity remains constant. The samples with perpendicular magnetic anisotropy, on the other hand, exhibit maximum exchange bias and minimum coercivity for d{sub Pt}=0.1nm. In both cases, the existence of large exchange bias fields correlates with a high domain density during magnetization reversal. The interface exchange coupling energy is larger for the in-plane biased films than for the perpendicularly biased multilayers.

  16. Giant exchange bias and its angular dependence in Co/CoO core-shell nanowire assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Gandha, Kinjal; Chaudhary, Rakesh P.; Mohapatra, Jeotikanta; Koymen, Ali R.; Liu, J. Ping, E-mail: pliu@uta.edu

    2017-07-12

    The exchange-bias field (H{sub EB}) and its angular dependence are systematically investigated in Co/CoO core-shell nanowire assemblies (∼15 nm in diameter and ∼200 nm in length) consisting of single-crystalline Co core and polycrystalline CoO shell. Giant exchange-bias field (H{sub EB}) up to 2.4 kOe is observed below a blocking temperature (T{sub EB} ∼150 K) in the aligned Co/CoO nanowire assemblies. It is also found that there is an angular dependence between the H{sub EB} and the applied magnetization direction. The H{sub EB} showed a peak at 30° between the applied field and the nanowire aligned direction, which may be attributed to the noncollinear spin orientations at the interface between the ferromagnetic core and the antiferromagnetic shell. This behavior is quantitatively supported by an analytical calculation based on Stoner–Wohlfarth model. This study underlines the importance of the competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. - Highlights: • Giant exchange bias is observed in oriented Co/CoO core-shell nanowire assemblies. • Study of angular and temperature dependence of the exchange bias effect. • Competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. • Effect of misaligned spins in FM/AFM interface on angular dependence of exchange bias. • We explain the analytical model that accounts for experimental results.

  17. Smoking addiction: the shift from head to hands: Approach bias towards smoking-related cues in low-dependent versus dependent smokers.

    Science.gov (United States)

    Detandt, Sandrine; Bazan, Ariane; Quertemont, Etienne; Verbanck, Paul

    2017-07-01

    The dual process theory is central to several models of addiction, implying both an increase of stimulus salience and deficits in inhibitory control. Our major aim is to provide behavioral evidence for an approach bias tendency in smokers and more specifically during smoking cue exposure. The second aim is to examine whether this bias differs in low-dependent versus dependent smokers. Thirty-two smokers (17 low dependent and 15 dependent; cut-off FTND of 4) and 28 non-smokers performed a modified Go/NoGo task using tobacco-related words and neutral words as stimuli. Smokers generally made more mistakes and tended to be faster for smoking-related cues specifically. Low dependents acknowledged more their dependency in declarative questionnaires while making more errors and being slower specifically on smoking cues; dependent smokers were less prone to indicate their addiction, but were faster and accurate when it came to picking the smoking cues. These results suggest that a shift has operated from a mental preoccupation with smoking in the low-dependent group, to smoking as a motor habit in our dependent group. This finding invites experts to rethink smoking addiction in the light of this crucial moment, namely, the shift "from head to hands".

  18. Maximum magnitude in bias-dependent spin accumulation signals of CoFe/MgO/Si on insulator devices

    International Nuclear Information System (INIS)

    Ishikawa, M.; Sugiyama, H.; Inokuchi, T.; Tanamoto, T.; Saito, Y.; Hamaya, K.; Tezuka, N.

    2013-01-01

    We study in detail how the bias voltage (V bias ) and interface resistance (RA) depend on the magnitude of spin accumulation signals (|ΔV| or |ΔV|/I, where I is current) as detected by three-terminal Hanle measurements in CoFe/MgO/Si on insulator (SOI) devices with various MgO layer thicknesses and SOI carrier densities. We find the apparent maximum magnitude of spin polarization as a function of V bias and the correlation between the magnitude of spin accumulation signals and the shape of differential conductance (dI/dV) curves within the framework of the standard spin diffusion model. All of the experimental results can be explained by taking into account the density of states (DOS) in CoFe under the influence of the applied V bias and the quality of MgO tunnel barrier. These results indicate that it is important to consider the DOS of the ferromagnetic materials under the influence of an applied V bias and the quality of tunnel barrier when observing large spin accumulation signals in Si

  19. Bias voltage dependence of tunneling magnetoresistance in granular C60–Co films with current-perpendicular-to-plane geometry

    International Nuclear Information System (INIS)

    Sakai, Seiji; Mitani, Seiji; Matsumoto, Yoshihiro; Entani, Shiro; Avramov, Pavel; Ohtomo, Manabu; Naramoto, Hiroshi; Takanashi, Koki

    2012-01-01

    Voltage-dependence of the tunneling magnetoresistance effect in the granular C 60 –Co films has been investigated for the samples with the current-perpendicular-to-plane geometry. The transport measurements under this geometry demonstrate that the granular C 60 –Co films show an unusual exponential bias voltage dependence of the magnetoresistance ratio down to zero voltage. Small characteristic energies of less than 10's meV are derived from the temperature dependences of the characteristic voltage in the exponential relationship. Considering the magnitudes of the voltage drop between Co nanoparticles and also the effect of cotunneling on the energy values, the characteristic energies for the voltage-induced degradation of the spin polarization are found to show a satisfactory agreement with that for the thermally-induced one. It can be reasonably expected that the onset of magnetic disorder to the localized d-electron spins at the interface region of the C 60 -based matrix (C 60 –Co compound) with Co nanoparticles leading to the unusual voltage and temperature dependence of the magnetoresistance ratio and the spin polarization at low temperatures. - Highlights: ► Unusual voltage dependence of the TMR effect in granular C 60 –Co films is studied. ► Linear temperature-characteristic voltage dependence in the MR–V relationship. ► Spin-flip scattering by the exchange-coupled d-electron spins at the interface.

  20. Bias to negative emotions: a depression state-dependent marker in adolescent major depressive disorder.

    Science.gov (United States)

    Maalouf, Fadi T; Clark, Luke; Tavitian, Lucy; Sahakian, Barbara J; Brent, David; Phillips, Mary L

    2012-06-30

    The aim of the current research was to examine for the first time the extent to which bias to negative emotions in an inhibitory control paradigm is a state or trait marker in major depressive disorder (MDD) in adolescents. We administered the affective go/no go task which measures the ability to switch attention to or away from positive or negative emotional stimuli to 40 adolescents with MDD (20 in acute episode (MDDa) and 20 in remission (MDDr)) and 17 healthy controls (HC). MDDa were significantly faster on the shift to negative target blocks as compared to shift to positive target blocks while HC and MDDr displayed the opposite pattern as measured by an "emotional bias index" (EBI=latency (shift to negative targets)-latency (shift to positive targets)). There was also a trend for an effect of group on commission errors, suggesting more impulsive responding by MDDa than both MDDr and HC independently of stimulus valence throughout the task. Negative bias was not associated with depression severity or medication status. In conclusion, bias to negative emotional stimuli appears to be present in the acute stage of MDD and absent in remission suggesting that it is a depression state-specific marker of MDD in adolescents. Latency emerges as a better proxy of negative bias than commission errors and accuracy on this inhibitory control task in adolescents with MDD. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. The electric field at hole injecting metal/organic interfaces as a cause for manifestation of exponential bias-dependent mobility

    International Nuclear Information System (INIS)

    Cvikl, B.

    2014-01-01

    It is shown that the well-known empirical exponential bias-dependent mobility is an approximation function of the relevant term emerging in the Mott–Gurney space charge limited current model when the constant non-zero electric field at the hole injecting metal/organic interface E int is taken into account. The term in question is the product of the bias-independent (but organic layer thickness-dependent) effective mobility coefficient and the algebraic function, f(λ), of the argument λ = E int /E a , where E a is the externally applied electric field. On account of the non-zero interfacial field, E int , the singularity of the spatial dependence of the hole current density, p(x), is removed. The resulting hole drift current density, j, is tested as a function of E a against a number of published room temperature hole current j–E a data sets, all characterized by good ohmic contact at the hole injecting interface. It is shown that the calculated current density provides a very good fit to the measurements within a high range of E a intervals. Low values of E a , are investigated analytically under the assumption of hole drift-diffusion. The extremely large internal electric fields at the anode/organic junction indicate drift-diffusion to be an improbable process for the structures investigated. However, a description of hole transport throughout the whole interval of experimental E a values may be obtained at low values of E a by an extended Mark–Helfrich drift model with traps occupying the exponentially distributed energy levels, followed by the extended Mott–Gurney model description within the remaining part of the E a interval. In both models the same (bias-independent) effective mobility coefficient is incorporated into the calculations. The results present evidence that within the framework of the extended Mott–Gurney expression the properly derived term should replace the empirical exponential bias-dependent mobility, making it redundant in the

  2. Nuclear three-body problem and energy-dependent potentials

    International Nuclear Information System (INIS)

    Abdurakhmanov, A.; Akhmadkhodzhaev, B.; Zubarev, A.L.; Irgaziev, B.F.

    1985-01-01

    Energy-dependent potentials in the three-body problem are being considered. Three-particle equations for the case of pairing energy-dependent potentials are generalized and the problems related to this ambiguous generalization are investigated. In terms of the equations obtained the tritium binding energy and vertex coupling constants (Tdn) and (Tdν) are evaluated. The binding energy and, especially, coupling constants are shown to be sensitive to a shape of the energy-dependent potential

  3. Estimating the price elasticity of beer: meta-analysis of data with heterogeneity, dependence, and publication bias.

    Science.gov (United States)

    Nelson, Jon P

    2014-01-01

    Precise estimates of price elasticities are important for alcohol tax policy. Using meta-analysis, this paper corrects average beer elasticities for heterogeneity, dependence, and publication selection bias. A sample of 191 estimates is obtained from 114 primary studies. Simple and weighted means are reported. Dependence is addressed by restricting number of estimates per study, author-restricted samples, and author-specific variables. Publication bias is addressed using funnel graph, trim-and-fill, and Egger's intercept model. Heterogeneity and selection bias are examined jointly in meta-regressions containing moderator variables for econometric methodology, primary data, and precision of estimates. Results for fixed- and random-effects regressions are reported. Country-specific effects and sample time periods are unimportant, but several methodology variables help explain the dispersion of estimates. In models that correct for selection bias and heterogeneity, the average beer price elasticity is about -0.20, which is less elastic by 50% compared to values commonly used in alcohol tax policy simulations. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Time scales of bias voltage effects in FE/MgO-based magnetic tunnel junctions with voltage-dependent perpendicular anisotropy

    International Nuclear Information System (INIS)

    Lytvynenko, Ia.M.; Hauet, T.; Montaigne, F.; Bibyk, V.V.; Andrieu, S.

    2015-01-01

    Interplay between voltage-induced magnetic anisotropy transition and voltage-induced atomic diffusion is studied in epitaxial V/Fe (0.7 nm)/ MgO/ Fe(5 nm)/Co/Au magnetic tunnel junction where thin Fe soft electrode has in-plane or out-of-plane anisotropy depending on the sign of the bias voltage. We investigate the origin of the slow resistance variation occurring when switching bias voltage in opposite polarity. We demonstrate that the time to reach resistance stability after voltage switching is reduced when increasing the voltage amplitude or the temperature. A single energy barrier of about 0.2 eV height is deduced from temperature dependence. Finally, we demonstrate that the resistance change is not correlated to a change in soft electrode anisotropy. This conclusion contrasts with observations recently reported on analogous systems. - Highlights: • Voltage-induced time dependence of resistance is studied in epitaxial Fe/MgO/Fe. • Resistance change is not related to the bottom Fe/MgO interface. • The effect is thermally activated with an energy barrier of the order of 0.2 eV height

  5. Ion energy distributions in bipolar pulsed-dc discharges of methane measured at the biased cathode

    Energy Technology Data Exchange (ETDEWEB)

    Corbella, C; Rubio-Roy, M; Bertran, E; Portal, S; Pascual, E; Polo, M C; Andujar, J L, E-mail: corbella@ub.edu [FEMAN Group, IN2UB, Departament de Fisica Aplicada i Optica, Universitat de Barcelona, c/ MartI i Franques 1, 08028 Barcelona (Spain)

    2011-02-15

    The ion fluxes and ion energy distributions (IED) corresponding to discharges in methane (CH{sub 4}) were measured in time-averaged mode with a compact retarding field energy analyser (RFEA). The RFEA was placed on a biased electrode at room temperature, which was powered by either radiofrequency (13.56 MHz) or asymmetric bipolar pulsed-dc (250 kHz) signals. The shape of the resulting IED showed the relevant populations of ions bombarding the cathode at discharge parameters typical in the material processing technology: working pressures ranging from 1 to 10 Pa and cathode bias voltages between 100 and 200 V. High-energy peaks in the IED were detected at low pressures, whereas low-energy populations became progressively dominant at higher pressures. This effect is attributed to the transition from collisionless to collisional regimes of the cathode sheath as the pressure increases. On the other hand, pulsed-dc plasmas showed broader IED than RF discharges. This fact is connected to the different working frequencies and the intense peak voltages (up to 450 V) driven by the pulsed power supply. This work improves our understanding in plasma processes at the cathode level, which are of crucial importance for the growth and processing of materials requiring controlled ion bombardment. Examples of industrial applications with these requirements are plasma cleaning, ion etching processes during fabrication of microelectronic devices and plasma-enhanced chemical vapour deposition of hard coatings (diamond-like carbon, carbides and nitrides).

  6. Atomoxetine effects on attentional bias to drug-related cues in cocaine dependent individuals

    NARCIS (Netherlands)

    Passamonti, L. (Luca); M. Luijten (Maartje); Ziauddeen, H.; I. Coyle-Gilchrist (Ian); Rittman, T.; Brain, S.A.E.; Regenthal, R.; I.H.A. Franken (Ingmar); Sahakian, B.J.; Bullmore, E.T.; Robbins, T.W.; Ersche, K.D.

    2017-01-01

    textabstractRationale: Biased attention towards drug-related cues and reduced inhibitory control over the regulation of drug-intake characterize drug addiction. The noradrenaline system has been critically implicated in both attentional and response inhibitory processes and is directly affected by

  7. Measurement bias dependence of enhanced bipolar gain degradation at low dose rates

    International Nuclear Information System (INIS)

    Witczak, S.C.; Lacoe, R.C.; Mayer, D.C.; Fleetwood, D.M.

    1998-03-01

    Oxide trapped charge, field effects from emitter metallization, and high level injection phenomena moderate enhanced gain degradation of lateral pnp transistors at low dose rates. Hardness assurance tests at elevated irradiation temperatures require larger design margins for low power measurement biases

  8. Centrality dependence of multiplicity, transverse energy, and elliptic flow from hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, Peter F.; Heinz, Ulrich; Huovinen, Pasi; Eskola, Kari J.; Tuominen, Kimmo

    2001-03-21

    The centrality dependence of the charged multiplicity, transverse energy, and elliptic flow coefficient is studied in a hydrodynamic model, using a variety of different initializations which model the initial energy or entropy production process as a hard or soft process, respectively. While the charged multiplicity depends strongly on the chosen initialization, the p{sub T}-integrated elliptic flow for charged particles as a function of charged particle multiplicity and the p{sub T}-differential elliptic flow for charged particles in minimum bias events turn out to be almost independent of the initialization.

  9. Non-Gaussian Halo Bias Re-examined: Mass-dependent Amplitude from the Peak-Background Split and Thresholding

    International Nuclear Information System (INIS)

    Desjacques, Vincent; Jeong, Donghui; Schmidt, Fabian

    2011-01-01

    Recent results of N-body simulations have shown that current theoretical models are not able to correctly predict the amplitude of the scale-dependent halo bias induced by primordial non-Gaussianity, for models going beyond the simplest, local quadratic case. Motivated by these discrepancies, we carefully examine three theoretical approaches based on (1) the statistics of thresholded regions, (2) a peak-background split method based on separation of scales, and (3) a peak-background split method using the conditional mass function. We first demonstrate that the statistics of thresholded regions, which is shown to be equivalent at leading order to a local bias expansion, cannot explain the mass-dependent deviation between theory and N-body simulations. In the two formulations of the peak-background split on the other hand, we identify an important, but previously overlooked, correction to the non-Gaussian bias that strongly depends on halo mass. This new term is in general significant for any primordial non-Gaussianity going beyond the simplest local f NL model. In a separate paper (to be published in PRD rapid communication), the authors compare these new theoretical predictions with N-body simulations, showing good agreement for all simulated types of non-Gaussianity.

  10. Collisional effects on ion energy and angular distributions incident on RF-biased electrodes

    International Nuclear Information System (INIS)

    Qiu Huatan; Wang Younian; Ma Tengcai

    2002-01-01

    Taking into account elastic collisions and charge-exchange collisions between ions and neutral particles, the authors established a self-consistent model describing the dynamics of radio-frequency (RF) sheath driven by a sinusoidal current source, and also, using the Monte-Carlo Method, simulated energy and angle distributions of ions bombarding on RF-biased substrates. It has been shown from numerical results that as increasing the discharge pressure, bimodal-peaks distributions for the ion energy become gradually a single-peak distribution, and low-energy ions increase. The authors also found that the angle distribution of ions is narrow and almost do not change with increasing the discharge pressure

  11. Application of source biasing technique for energy efficient DECODER circuit design: memory array application

    Science.gov (United States)

    Gupta, Neha; Parihar, Priyanka; Neema, Vaibhav

    2018-04-01

    Researchers have proposed many circuit techniques to reduce leakage power dissipation in memory cells. If we want to reduce the overall power in the memory system, we have to work on the input circuitry of memory architecture i.e. row and column decoder. In this research work, low leakage power with a high speed row and column decoder for memory array application is designed and four new techniques are proposed. In this work, the comparison of cluster DECODER, body bias DECODER, source bias DECODER, and source coupling DECODER are designed and analyzed for memory array application. Simulation is performed for the comparative analysis of different DECODER design parameters at 180 nm GPDK technology file using the CADENCE tool. Simulation results show that the proposed source bias DECODER circuit technique decreases the leakage current by 99.92% and static energy by 99.92% at a supply voltage of 1.2 V. The proposed circuit also improves dynamic power dissipation by 5.69%, dynamic PDP/EDP 65.03% and delay 57.25% at 1.2 V supply voltage.

  12. Is in-group bias culture-dependent? A meta-analysis across 18 societies.

    Science.gov (United States)

    Fischer, Ronald; Derham, Crysta

    2016-01-01

    We report a meta-analysis on the relationship between in-group bias and culture. Our focus is on whether broad macro-contextual variables influence the extent to which individuals favour their in-group. Data from 21,266 participants from 18 societies included in experimental and survey studies were available. Using Hofstede's (1980) and Schwartz (2006) culture-level predictors in a 3-level mixed-effects meta-analysis, we found strong support for the uncertainty-reduction hypothesis. An interaction between Autonomy and real vs artificial groups suggested that in low autonomy contexts, individuals show greater in-group bias for real groups. Implications for social identity theory and intergroup conflict are outlined.

  13. Bias-dependent model of the electrical impedance of ionic polymer-metal composites.

    Science.gov (United States)

    Cha, Youngsu; Porfiri, Maurizio

    2013-02-01

    In this paper, we analyze the charge dynamics of ionic polymer-metal composites (IPMCs) in response to voltage inputs composed of a large dc bias and a small superimposed time-varying voltage. The IPMC chemoelectrical behavior is described through the modified Poisson-Nernst-Planck framework, in which steric effects are taken into consideration. The physics of charge build-up and mass transfer in the proximity of the high surface electrodes is modeled by schematizing the IPMC as the stacked sequence of five layers, in which the ionomeric membrane is separated from the metal electrodes by two composite layers. The method of matched asymptotic expansions is used to derive a semianalytical solution for the concentration of mobile counterions and the electric potential in the IPMC, which is, in turn, used to establish an equivalent circuit model for the IPMC electrical response. The circuit model consists of the series connection of a resistor and two complex elements, each constituted by the parallel connection of a capacitor and a Warburg impedance. The resistor is associated with ion transport in the ionomeric membrane and is independent of the dc bias. The capacitors and the Warburg impedance idealize charge build-up and mass transfer in the vicinity of the electrodes and their value is controlled by the dc bias. The proposed approach is validated against experimental results on in-house fabricated IPMCs and the accuracy of the equivalent circuit is assessed through comparison with finite element results.

  14. A working memory bias for alcohol-related stimuli depends on drinking score.

    Science.gov (United States)

    Kessler, Klaus; Pajak, Katarzyna Malgorzata; Harkin, Ben; Jones, Barry

    2013-03-01

    We tested 44 participants with respect to their working memory (WM) performance on alcohol-related versus neutral visual stimuli. Previously an alcohol attentional bias (AAB) had been reported using these stimuli, where the attention of frequent drinkers was automatically drawn toward alcohol-related items (e.g., beer bottle). The present study set out to provide evidence for an alcohol memory bias (AMB) that would persist over longer time-scales than the AAB. The WM task we used required memorizing 4 stimuli in their correct locations and a visual interference task was administered during a 4-sec delay interval. A subsequent probe required participants to indicate whether a stimulus was shown in the correct or incorrect location. For each participant we calculated a drinking score based on 3 items derived from the Alcohol Use Questionnaire, and we observed that higher scorers better remembered alcohol-related images compared with lower scorers, particularly when these were presented in their correct locations upon recall. This provides first evidence for an AMB. It is important to highlight that this effect persisted over a 4-sec delay period including a visual interference task that erased iconic memories and diverted attention away from the encoded items, thus the AMB cannot be reduced to the previously reported AAB. Our finding calls for further investigation of alcohol-related cognitive biases in WM, and we propose a preliminary model that may guide future research. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  15. Nuclear symmetry energy in density dependent hadronic models

    International Nuclear Information System (INIS)

    Haddad, S.

    2008-12-01

    The density dependence of the symmetry energy and the correlation between parameters of the symmetry energy and the neutron skin thickness in the nucleus 208 Pb are investigated in relativistic Hadronic models. The dependency of the symmetry energy on density is linear around saturation density. Correlation exists between the neutron skin thickness in the nucleus 208 Pb and the value of the nuclear symmetry energy at saturation density, but not with the slope of the symmetry energy at saturation density. (author)

  16. On the model-dependence of the relation between minimum-bias and inelastic proton-proton cross sections

    International Nuclear Information System (INIS)

    Ostapchenko, S.

    2011-01-01

    The model-dependence of the relation between the inelastic and various minimum-bias proton-proton cross sections is analyzed, paying a special attention to the sensitivity of minimum-bias triggers to diffractive collisions. Concentrating on the trigger selections of the ATLAS experiment, the measured cross sections are compared to predictions of a number of hadronic Monte Carlo models used in the cosmic ray field. It is demonstrated that the ATLAS results are able to discriminate between different models and between certain theoretical approaches for soft multi-particle production. On the other hand, the strong model-dependence of the selection efficiency of the minimum-bias triggers prevents one from inferring high mass diffraction rate from the discussed data. Moreover, the measured cross sections prove to be insensitive to the production of low mass diffractive states in proton-proton collisions. Consequently, a reliable determination of the total inelastic cross section requires forward proton tracking by a dedicated experiment.

  17. A Self-Biased Active Voltage Doubler for Energy Harvesting Systems

    KAUST Repository

    Tayyab, Umais

    2017-12-03

    An active voltage doubler utilizing a single supply op-amp for energy harvesting system is presented. The proposed doubler is used for rectification process to achieve both acceptably high power conversion efficiency (PCE) and large rectified DC voltage. The incorporated op-amp is self-biased, meaning no external supply is needed but rather it uses part of the harvested energy for its biasing. The proposed active doubler achieves maximum power conversion efficiency (PCE) of 61.7% for a 200 Hz sinusoidal input of 0.8 V for a 20 K load resistor. This efficiency is 2 times more when compared with the passive voltage doubler. The rectified DC voltage is almost 2 times more than conventional passive doubler. The relation between PCE and the load resistor is also presented. The proposed active voltage doubler is designed and simulated in LF 0.15 μm CMOS process technology using Cadence virtuoso tool.

  18. Temperature dependence of grain boundary free energy and elastic constants

    International Nuclear Information System (INIS)

    Foiles, Stephen M.

    2010-01-01

    This work explores the suggestion that the temperature dependence of the grain boundary free energy can be estimated from the temperature dependence of the elastic constants. The temperature-dependent elastic constants and free energy of a symmetric Σ79 tilt boundary are computed for an embedded atom method model of Ni. The grain boundary free energy scales with the product of the shear modulus times the lattice constant for temperatures up to about 0.75 the melting temperature.

  19. Occupation number dependence of molecular energy levels

    International Nuclear Information System (INIS)

    Giambiagi, M.S. de; Giambiagi, M.; Ferreira, R.

    1977-08-01

    The Roothaan expression for the energy of a closed-shell molecular system is generalized in order to apply to open shells. A continuous variation from 0 to 2 is supposed for each level's occupation number, extending to this range tbe correction due to the spurious repulsion appearing in the half-electron method. The characteristic equations of the Xα method are applied to the energy expressions. The one level case is discussed in detail. Ionic and excited states of the 1,3 transbutadiene π system are analyzed

  20. Scale dependence of the halo bias in general local-type non-Gaussian models I: analytical predictions and consistency relations

    International Nuclear Information System (INIS)

    Nishimichi, Takahiro

    2012-01-01

    The large-scale clustering pattern of biased tracers is known to be a powerful probe of the non-Gaussianities in the primordial fluctuations. The so-called scale-dependent bias has been reported in various type of models of primordial non-Gaussianities. We focus on local-type non-Gaussianities, and unify the derivations in the literature of the scale-dependent bias in the presence of multiple Gaussian source fields as well as higher-order coupling to cover the models described by frequently-discussed f NL , g NL and t NL parameterization. We find that the resultant power spectrum is characterized by two parameters responsible for the shape and the amplitude of the scale-dependent bias in addition to the Gaussian bias factor. We show how (a generalized version of) Suyama-Yamaguchi inequality between f NL and t NL can directly be accessible from the observed power spectrum through the dependence on our new parameter which controls the shape of the scale-dependent bias. The other parameter for the amplitude of the scale-dependent bias is shown to be useful to distinguish the simplest quadratic non-Gaussianities (i.e., f NL -type) from higher-order ones (g NL and higher), if one measures it from multiple species of galaxies or clusters of galaxies. We discuss the validity and limitations of our analytic results by comparison with numerical simulations in an accompanying paper

  1. Non-linear corrections to the cosmological matter power spectrum and scale-dependent galaxy bias: implications for parameter estimation

    International Nuclear Information System (INIS)

    Hamann, Jan; Hannestad, Steen; Melchiorri, Alessandro; Wong, Yvonne Y Y

    2008-01-01

    We explore and compare the performances of two non-linear correction and scale-dependent biasing models for the extraction of cosmological information from galaxy power spectrum data, especially in the context of beyond-ΛCDM (CDM: cold dark matter) cosmologies. The first model is the well known Q model, first applied in the analysis of Two-degree Field Galaxy Redshift Survey data. The second, the P model, is inspired by the halo model, in which non-linear evolution and scale-dependent biasing are encapsulated in a single non-Poisson shot noise term. We find that while the two models perform equally well in providing adequate correction for a range of galaxy clustering data in standard ΛCDM cosmology and in extensions with massive neutrinos, the Q model can give unphysical results in cosmologies containing a subdominant free-streaming dark matter whose temperature depends on the particle mass, e.g., relic thermal axions, unless a suitable prior is imposed on the correction parameter. This last case also exposes the danger of analytic marginalization, a technique sometimes used in the marginalization of nuisance parameters. In contrast, the P model suffers no undesirable effects, and is the recommended non-linear correction model also because of its physical transparency

  2. Non-linear corrections to the cosmological matter power spectrum and scale-dependent galaxy bias: implications for parameter estimation

    Science.gov (United States)

    Hamann, Jan; Hannestad, Steen; Melchiorri, Alessandro; Wong, Yvonne Y. Y.

    2008-07-01

    We explore and compare the performances of two non-linear correction and scale-dependent biasing models for the extraction of cosmological information from galaxy power spectrum data, especially in the context of beyond-ΛCDM (CDM: cold dark matter) cosmologies. The first model is the well known Q model, first applied in the analysis of Two-degree Field Galaxy Redshift Survey data. The second, the P model, is inspired by the halo model, in which non-linear evolution and scale-dependent biasing are encapsulated in a single non-Poisson shot noise term. We find that while the two models perform equally well in providing adequate correction for a range of galaxy clustering data in standard ΛCDM cosmology and in extensions with massive neutrinos, the Q model can give unphysical results in cosmologies containing a subdominant free-streaming dark matter whose temperature depends on the particle mass, e.g., relic thermal axions, unless a suitable prior is imposed on the correction parameter. This last case also exposes the danger of analytic marginalization, a technique sometimes used in the marginalization of nuisance parameters. In contrast, the P model suffers no undesirable effects, and is the recommended non-linear correction model also because of its physical transparency.

  3. Influence of Bias on the Friction Imaging of Ferroelectric Domains in Single Crystal Barium Titanate Energy Storage Materials

    Directory of Open Access Journals (Sweden)

    Lan Chen

    2014-01-01

    Full Text Available The friction imaging of newlycleaved surface domains of single crystal BaTiO3 energy storage materials under both positive and negative voltage bias is investigated by scanning force microscope. When the bias was applied and reversed, three regions with different brightness and contrast in friction image indicated different response to the biases: the friction image of domain A displayed a great change in brightness while domains B and C displayed only a very small change. Possible mechanisms of the interesting phenomena originating from different static force between different charged tip and the periodical array of surface charges inside the inplane domains were proposed. These results provide a new method for the determination of the polarization direction for the domain parallel to the surface and may be useful in the investigation of ferroelectric energy storage materials, especially the relationship between the polarization direction of domain and the bias.

  4. On the photon energy moments and their 'bias' corrections in B->Xs+γ

    International Nuclear Information System (INIS)

    Benson, D.; Bigi, I.I.; Uraltsev, N.

    2005-01-01

    Photon energy moments in B->X s +γ and the impact of experimental cuts are analyzed, including the biases exponential in the effective hardness missed in the conventional OPE. We incorporate the perturbative corrections fully implementing the Wilsonian momentum separation ab initio. This renders perturbative effects numerically suppressed while leaving heavy quark parameters and the corresponding light-cone distribution function well defined and preserving their physical properties. The moments of the distribution function are given by the heavy quark expectation values of which many have been extracted from the B->X c -bar ν decays. The quantitative estimates for the biases in the heavy quark parameters determined from the photon moments show they cannot be neglected for E cut -bar 1.85 GeV, and grow out of theory control for E cut above 2.1 GeV. Implications for the moments in the B->X c -bar ν decays at high cuts are briefly addressed

  5. A thermalization energy analysis of the threshold voltage shift in amorphous indium gallium zinc oxide thin film transistors under positive gate bias stress

    Energy Technology Data Exchange (ETDEWEB)

    Niang, K. M.; Flewitt, A. J., E-mail: ajf@eng.cam.ac.uk [Electrical Engineering Division, Cambridge University, J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Barquinha, P. M. C.; Martins, R. F. P. [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica (Portugal); Cobb, B. [Holst Centre/TNO, High Tech Campus 31, 5656AE Eindhoven (Netherlands); Powell, M. J. [252, Valley Drive, Kendal LA9 7SL (United Kingdom)

    2016-02-29

    Thin film transistors (TFTs) employing an amorphous indium gallium zinc oxide (a-IGZO) channel layer exhibit a positive shift in the threshold voltage under the application of positive gate bias stress (PBS). The time and temperature dependence of the threshold voltage shift was measured and analysed using the thermalization energy concept. The peak energy barrier to defect conversion is extracted to be 0.75 eV and the attempt-to-escape frequency is extracted to be 10{sup 7} s{sup −1}. These values are in remarkable agreement with measurements in a-IGZO TFTs under negative gate bias illumination stress (NBIS) reported recently (Flewitt and Powell, J. Appl. Phys. 115, 134501 (2014)). This suggests that the same physical process is responsible for both PBS and NBIS, and supports the oxygen vacancy defect migration model that the authors have previously proposed.

  6. Scale Dependence of Dark Energy Antigravity

    Science.gov (United States)

    Perivolaropoulos, L.

    2002-09-01

    We investigate the effects of negative pressure induced by dark energy (cosmological constant or quintessence) on the dynamics at various astrophysical scales. Negative pressure induces a repulsive term (antigravity) in Newton's law which dominates on large scales. Assuming a value of the cosmological constant consistent with the recent SnIa data we determine the critical scale $r_c$ beyond which antigravity dominates the dynamics ($r_c \\sim 1Mpc $) and discuss some of the dynamical effects implied. We show that dynamically induced mass estimates on the scale of the Local Group and beyond are significantly modified due to negative pressure. We also briefly discuss possible dynamical tests (eg effects on local Hubble flow) that can be applied on relatively small scales (a few $Mpc$) to determine the density and equation of state of dark energy.

  7. US oil dependency and energy security; Dependance petroliere et securite energetique americaine

    Energy Technology Data Exchange (ETDEWEB)

    Noel, P [Institut francais des Relations Internationals, 75 - Paris (France); [Universite Pierre Mendes-France-IEPE-CNRS, 38 - Grenoble (France)

    2002-07-01

    The three papers of this document were written in the framework of a seminar organized the 30 may 2002 by the IFRI in the framework of its program Energy and Climatic Change. The first presentation deals with the american oil policy since 1980 (relation between the oil dependence and the energy security, the Reagan oil policy, the new oil policy facing the increase of the dependence). The second one deals with the US energy security (oil security, domestic energy security, policy implications). The last presentation is devoted to the US oil dependence in a global context and the problems and policies of international energy security. (A.L.B.)

  8. Magnetic field dependence of vortex activation energy

    Indian Academy of Sciences (India)

    ... the resistance as a function of temperature and magnetic field in clean polycrystalline samples of NbSe2, MgB2 and Bi2Sr2Ca2Cu3O10 (BSCCO) superconductors. Thermally activated flux flow behaviour is seen in all the three systems and clearly identified in bulk MgB2. While the activation energy at low fields for MgB2 ...

  9. Extended Adaptive Biasing Force Algorithm. An On-the-Fly Implementation for Accurate Free-Energy Calculations.

    Science.gov (United States)

    Fu, Haohao; Shao, Xueguang; Chipot, Christophe; Cai, Wensheng

    2016-08-09

    Proper use of the adaptive biasing force (ABF) algorithm in free-energy calculations needs certain prerequisites to be met, namely, that the Jacobian for the metric transformation and its first derivative be available and the coarse variables be independent and fully decoupled from any holonomic constraint or geometric restraint, thereby limiting singularly the field of application of the approach. The extended ABF (eABF) algorithm circumvents these intrinsic limitations by applying the time-dependent bias onto a fictitious particle coupled to the coarse variable of interest by means of a stiff spring. However, with the current implementation of eABF in the popular molecular dynamics engine NAMD, a trajectory-based post-treatment is necessary to derive the underlying free-energy change. Usually, such a posthoc analysis leads to a decrease in the reliability of the free-energy estimates due to the inevitable loss of information, as well as to a drop in efficiency, which stems from substantial read-write accesses to file systems. We have developed a user-friendly, on-the-fly code for performing eABF simulations within NAMD. In the present contribution, this code is probed in eight illustrative examples. The performance of the algorithm is compared with traditional ABF, on the one hand, and the original eABF implementation combined with a posthoc analysis, on the other hand. Our results indicate that the on-the-fly eABF algorithm (i) supplies the correct free-energy landscape in those critical cases where the coarse variables at play are coupled to either each other or to geometric restraints or holonomic constraints, (ii) greatly improves the reliability of the free-energy change, compared to the outcome of a posthoc analysis, and (iii) represents a negligible additional computational effort compared to regular ABF. Moreover, in the proposed implementation, guidelines for choosing two parameters of the eABF algorithm, namely the stiffness of the spring and the mass

  10. Constraints on cosmological birefringence energy dependence from CMB polarization data

    International Nuclear Information System (INIS)

    Gubitosi, G.; Paci, F.

    2013-01-01

    We study the possibility of constraining the energy dependence of cosmological birefringence by using CMB polarization data. We consider four possible behaviors, characteristic of different theoretical scenarios: energy-independent birefringence motivated by Chern-Simons interactions of the electromagnetic field, linear energy dependence motivated by a 'Weyl' interaction of the electromagnetic field, quadratic energy dependence, motivated by quantum gravity modifications of low-energy electrodynamics, and inverse quadratic dependence, motivated by Faraday rotation generated by primordial magnetic fields. We constrain the parameters associated to each kind of dependence and use our results to give constraints on the models mentioned. We forecast the sensitivity that Planck data will be able to achieve in this respect

  11. The association of energy intake bias with psychological scores of women.

    Science.gov (United States)

    Taren, D L; Tobar, M; Hill, A; Howell, W; Shisslak, C; Bell, I; Ritenbaugh, C

    1999-07-01

    Assess the association between reporting bias of dietary energy intake and the behavioral and psychological profiles in women. At baseline a series of questionnaires were administered to 37 women, (the Marlowe-Crowne Social Desirability Scale, Weinberger Adjustment Inventory (WAI), the Eating Disorder Inventory (EDI), the Restraint Scale and Sorensen-Stunkard's silhouettes). Subjects received training on how to record dietary records. Subjects recorded three days of dietary records to measure energy intake (EI) during a study to determine total energy expenditure (TEE) using doubly labeled water. Reporting accuracy (RA = EI/TEE x 100) was determined for each subject. Statistical analysis of the data used a mixed effects model accounting for within subject variability to determine if the psychological scores were associated with reporting accuracy. Women were recruited with local advertisements in Tucson, Arizona. The women had a mean ( +/- 1 s.d.) age of 43.6 +/- 9.3 yrs, body mass index (BMI) of 28.7 +/- 8.5 kg/m2 and total body fat (%TBF) of 31.9 +/- 7.3%. Age and %TBF were significantly and inversely associated with RA. Furthermore, Social Desirability was negatively associated with RA. Body dissatisfaction and associating a smaller body size than one's own as being more healthy were also associated with a lower RA. These results suggest that Social Desirability and self image of body shape are associated with RA. Modifications in subject training may reduce the effect of these factors on RA.

  12. Bias voltage dependence of magnetic tunnel junctions comprising amorphous ferromagnetic CoFeSiB layer with double barriers

    International Nuclear Information System (INIS)

    Yim, H.I.; Lee, S.Y.; Hwang, J.Y.; Rhee, J.R.; Chun, B.S.; Wang, K.L.; Kim, Y.K.; Kim, T.W.; Lee, S.S.; Hwang, D.G.

    2008-01-01

    Double-barrier magnetic tunnel junctions (DMTJs) with and without an amorphous ferromagnetic material such as CoFeSiB 10, CoFe 5/CoFeSiB 5, and CoFe 10 (nm) were prepared and compared to investigate the bias voltage dependence of the tunneling magnetoresistance (TMR) ratio. Typical DMTJ structures were Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlO x /free layer 10/AlO x /CoFe 7/IrMn 10/Ru 60 (in nanometers). The interlayer coupling field and the normalized TMR ratios at the applied voltages of +0.4 and -0.4 V of the amorphous CoFeSiB free-layer DMTJ offer lower and higher values than that of the polycrystalline CoFe free-layer DMTJ, respectively. An amorphous ferromagnetic CoFeSiB layer improves the interface roughness of the free layer/tunnel barrier and, as a result, the interlayer coupling field and bias voltage dependence of the TMR ratio are suppressed at a given voltage. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Energy dependence of ion guiding through nanocapillaries

    International Nuclear Information System (INIS)

    Schiessl, K.; Lemell, C.; Burgdoerfer, J.; Toekesi, K.

    2008-01-01

    Complete text of publication follows. In this work, we model the transmission of Ne 7+ ions with varying kinetic energies ranging from 2 to 9 keV through Polyethyleneterephthalate (PET) nanocapillaries with a diameter of 200 nm (see Fig. 1). We have simulated the ion transmission through insulating nanocapillaries using a mean-field classical-transport theory (see Fig. 2.). Ion trajectories are propagated in the combined fields of charges deposited on the capillary wall, their polarization charges, the projectile image charge, and the macroscopic field from neighboring capillaries. The simulation avoids any freely adjustable parameters in order to be predictive and to provide qualitative insights into underlying mechanisms. We have varied projectile energy and angle of incidence and have tested different models of dielectric shielding. Best agreement with experimental data is found for dielectrically screened surfaces charges. Response and transport employs linear response only. Reasonable agreement with data could be found employing only macroscopic material parameters of PET like dielectric constant, surface and bulk conductivity

  14. Energy dependence of opaqueness for pp collisions at high energies

    CERN Document Server

    Chou, T T

    1978-01-01

    Opaqueness of pp collisions is evaluated at three CERN-ISR energies. Comparisons with predictions of the factorisable eikonal models and the scaling hypothesis are made. It appears that results are in favour of the factorisable models. (20 refs).

  15. Robust and bias-corrected estimation of the coefficient of tail dependence

    DEFF Research Database (Denmark)

    Dutang, C.; Goegebeur, Y.; Guillou, A.

    2014-01-01

    We introduce a robust and asymptotically unbiased estimator for the coefficient of tail dependence in multivariate extreme value statistics. The estimator is obtained by fitting a second order model to the data by means of the minimum density power divergence criterion. The asymptotic properties ...

  16. Spatial structure arising from neighbour-dependent bias in collective cell movement

    Directory of Open Access Journals (Sweden)

    Rachelle N. Binny

    2016-02-01

    Full Text Available Mathematical models of collective cell movement often neglect the effects of spatial structure, such as clustering, on the population dynamics. Typically, they assume that individuals interact with one another in proportion to their average density (the mean-field assumption which means that cell–cell interactions occurring over short spatial ranges are not accounted for. However, in vitro cell culture studies have shown that spatial correlations can play an important role in determining collective behaviour. Here, we take a combined experimental and modelling approach to explore how individual-level interactions give rise to spatial structure in a moving cell population. Using imaging data from in vitro experiments, we quantify the extent of spatial structure in a population of 3T3 fibroblast cells. To understand how this spatial structure arises, we develop a lattice-free individual-based model (IBM and simulate cell movement in two spatial dimensions. Our model allows an individual’s direction of movement to be affected by interactions with other cells in its neighbourhood, providing insights into how directional bias generates spatial structure. We consider how this behaviour scales up to the population level by using the IBM to derive a continuum description in terms of the dynamics of spatial moments. In particular, we account for spatial correlations between cells by considering dynamics of the second spatial moment (the average density of pairs of cells. Our numerical results suggest that the moment dynamics description can provide a good approximation to averaged simulation results from the underlying IBM. Using our in vitro data, we estimate parameters for the model and show that it can generate similar spatial structure to that observed in a 3T3 fibroblast cell population.

  17. Spatial structure arising from neighbour-dependent bias in collective cell movement.

    Science.gov (United States)

    Binny, Rachelle N; Haridas, Parvathi; James, Alex; Law, Richard; Simpson, Matthew J; Plank, Michael J

    2016-01-01

    Mathematical models of collective cell movement often neglect the effects of spatial structure, such as clustering, on the population dynamics. Typically, they assume that individuals interact with one another in proportion to their average density (the mean-field assumption) which means that cell-cell interactions occurring over short spatial ranges are not accounted for. However, in vitro cell culture studies have shown that spatial correlations can play an important role in determining collective behaviour. Here, we take a combined experimental and modelling approach to explore how individual-level interactions give rise to spatial structure in a moving cell population. Using imaging data from in vitro experiments, we quantify the extent of spatial structure in a population of 3T3 fibroblast cells. To understand how this spatial structure arises, we develop a lattice-free individual-based model (IBM) and simulate cell movement in two spatial dimensions. Our model allows an individual's direction of movement to be affected by interactions with other cells in its neighbourhood, providing insights into how directional bias generates spatial structure. We consider how this behaviour scales up to the population level by using the IBM to derive a continuum description in terms of the dynamics of spatial moments. In particular, we account for spatial correlations between cells by considering dynamics of the second spatial moment (the average density of pairs of cells). Our numerical results suggest that the moment dynamics description can provide a good approximation to averaged simulation results from the underlying IBM. Using our in vitro data, we estimate parameters for the model and show that it can generate similar spatial structure to that observed in a 3T3 fibroblast cell population.

  18. Energy-dependent inversion of p+16O scattering data

    International Nuclear Information System (INIS)

    Cooper, S.G.

    1997-01-01

    A fast iterative procedure is developed to determine potentials by inversion from elastic cross section, analysing powers and reaction cross-section measurements covering a wide energy range. The procedure incorporates both energy and parity dependence. The method is applied to extensive p+ 16 O scattering data for an energy range from 27.3 to 46.1 MeV, giving a solution which simultaneously reproduces the data at all energies. The wide angle data is well reproduced by including parity dependence and a linear energy dependence is established for the real potential, including the parity-dependent component. The real terms agree qualitatively with potentials derived from the single channel RGM, but the central and spin-orbit imaginary components have distinct features strongly suggestive of further non-local contributions, possibly arising from channel coupling. The large data set is found essential to reduce the potential ambiguities present when fitting scattering data. (orig.)

  19. Tackling Dependency: The EU and its Energy Security Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Robert L.

    2007-10-15

    Europe is facing a future of augmenting energy demands, domestic depletion, high prices and other energy-political challenges. Climate change, infrastructure resilience, producers' coercive energy policy and the EU's internal market failures have put stress on the EU's emerging energy policy and inspired the union to address its challenges with greater enthusiasm than before. Some of the EU's challenges call for strategic choices of a magnitude that EU is not used to handle. The aim of this report is therefore to identify, analyse and assess the political side of Europe's energy predicament and import dependency. Against the background of increasing dependence on energy imports, the report tries to answer questions: what are the key dimensions of Europe's energy security and what are their consequences?

  20. Tackling Dependency: The EU and its Energy Security Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Robert L

    2007-10-15

    Europe is facing a future of augmenting energy demands, domestic depletion, high prices and other energy-political challenges. Climate change, infrastructure resilience, producers' coercive energy policy and the EU's internal market failures have put stress on the EU's emerging energy policy and inspired the union to address its challenges with greater enthusiasm than before. Some of the EU's challenges call for strategic choices of a magnitude that EU is not used to handle. The aim of this report is therefore to identify, analyse and assess the political side of Europe's energy predicament and import dependency. Against the background of increasing dependence on energy imports, the report tries to answer questions: what are the key dimensions of Europe's energy security and what are their consequences?

  1. Tackling Dependency: The EU and its Energy Security Challenges

    International Nuclear Information System (INIS)

    Larsson, Robert L.

    2007-10-01

    Europe is facing a future of augmenting energy demands, domestic depletion, high prices and other energy-political challenges. Climate change, infrastructure resilience, producers' coercive energy policy and the EU's internal market failures have put stress on the EU's emerging energy policy and inspired the union to address its challenges with greater enthusiasm than before. Some of the EU's challenges call for strategic choices of a magnitude that EU is not used to handle. The aim of this report is therefore to identify, analyse and assess the political side of Europe's energy predicament and import dependency. Against the background of increasing dependence on energy imports, the report tries to answer questions: what are the key dimensions of Europe's energy security and what are their consequences?

  2. Bias-polarity-dependent UV/visible transferable electroluminescence from ZnO nanorod array LED with graphene oxide electrode supporting layer

    Science.gov (United States)

    Liu, Weizhen; Wang, Wei; Xu, Haiyang; Li, Xinghua; Yang, Liu; Ma, Jiangang; Liu, Yichun

    2015-09-01

    A simple top electrode preparation process, employing continuous graphene oxide films as electrode supporting layers, was adopted to fabricate a ZnO nanorod array/p-GaN heterojunction LED. The achieved LED demonstrated different electroluminescence behaviors under forward and reverse biases: a yellow-red emission band was observed under forward bias, whereas a blue-UV emission peak was obtained under reverse bias. Electroluminescence spectra under different currents and temperatures, as well as heterojunction energy-band alignments, reveal that the yellow-red emission under forward bias originates from recombinations related to heterointerface defects, whereas the blue-UV electroluminescence under reverse bias is ascribed to transitions from near-band-edge and Mg-acceptor levels in p-GaN.

  3. A random energy model for size dependence : recurrence vs. transience

    NARCIS (Netherlands)

    Külske, Christof

    1998-01-01

    We investigate the size dependence of disordered spin models having an infinite number of Gibbs measures in the framework of a simplified 'random energy model for size dependence'. We introduce two versions (involving either independent random walks or branching processes), that can be seen as

  4. Simulation of Electron Energy Spectra of a Biased Paracentric Hemispherical Deflection Analyzer as a Function of Entry Bias: Effects of Misalignments

    Directory of Open Access Journals (Sweden)

    O. Sise

    2014-01-01

    Full Text Available The performance of a biased paracentric hemispherical deflection analyzer (HDA, including fringing fields and their effect on focusing and energy resolution, is investigated using numerical methods. Electron energy spectra are calculated for three entry positions R0=84 mm, 100 mm, and 112 mm and compared with the recent experimental measurements. In both experiment and calculation, the two different paracentric entry positions R0=84 mm and R0=112 mm, on either side of the mean radius of 100 mm, are found to have a base energy resolution of about two times better than the conventional centric entry position R0=100 mm. In order to explain the discrepancies (6–30% between the simulated and the experimental resolutions the focusing characteristics are further investigated for different displacements of the input lens (ΔR0 with respect to the entry position R0 and the tilted input beam axis by αshift in the dispersive direction. We have found that the blame does not in fact lie with the theory and we have shown that the input lens may have been misaligned in the experiment. Slight misalignments affect both the true energy resolution measurement and the transmission of the beam.

  5. Impulsivity and attentional bias as predictors of modafinil treatment outcome for retention and drug use in crack-cocaine dependent patients: Results of a randomised controlled trial

    NARCIS (Netherlands)

    Nuijten, Mascha; Blanken, Peter; van den Brink, Wim; Goudriaan, Anna E.; Hendriks, Vincent M.

    2016-01-01

    High impulsivity and attentional bias are common in cocaine-dependent patients and predict poor treatment outcomes. The pharmacological agent modafinil is studied for its cognitive-enhancing capacities and may therefore improve clinical outcomes in crack-cocaine dependent patients. In this study, we

  6. Attentional bias and executive control in treatment-seeking substance-dependent adolescents : A cross-sectional and follow-up study

    NARCIS (Netherlands)

    van Hemel-Ruiter, M.E.; Wiers, R.W.; Brook, F.G.; de Jong, P.J.

    2016-01-01

    BACKGROUND: Research in adults shows that substance dependent individuals demonstrate attentional bias (AB) for substance-related stimuli. This study investigated the role of AB in adolescents diagnosed with alcohol, cannabis, amphetamine or GHB dependency on entering therapy and six months later,

  7. Energy-dependent collisional deactivation of vibrationally excited azulene

    International Nuclear Information System (INIS)

    Shi, J.; Barker, J.R.

    1988-01-01

    Collisional energy transfer parameters for highly vibrationally excited azulene have been deduced from new infrared fluorescence (IRF) emission lifetime data with an improved calibration relating IRF intensity to vibrational energy [J. Shi, D. Bernfeld, and J. R. Barker, J. Chem. Phys. 88, XXXX (1988), preceding paper]. In addition, data from previous experiments [M. J. Rossi, J. R. Pladziewicz, and J. R. Barker, J. Chem. Phys. 78, 6695 (1983)] have been reanalyzed based on the improved calibration. Inversion of the IRF decay curves produced plots of energy decay, which were analyzed to determine , the average energy transferred per collision. Master equation simulations reproduced both the original IRF decays and the deduced energy decays. A third (simple) method of determination agrees well with the other two. The results show to be nearly directly proportional to the vibrational energy of the excited azulene from ∼8000 to 33 000 cm -1 . At high energies, there are indications that the energy dependence may be slightly reduced

  8. Equivalence between deep energy-dependent and shallow angular momentum dependent potentials

    International Nuclear Information System (INIS)

    Fiedeldey, H.; Sofianos, S.A.; Papastylianos, A.; Amos, K.A.; Allen, L.J.

    1989-01-01

    Recently Baye showed that supersymmetry can be applied to determine a shallow l-dependent potential phase equivalent to a deep potential, assumed to be energy-independent and have Panli forbidden states (PFS), for α-α scattering. The PFS are eliminated by this procedure. Such deep potentials are generated as equivalent local potentials (ELP) to the Resonating Group Model (RGM) and are generally energy-dependent. To eliminate this E-dependence as required for the application of Baye's method, l-dependent, but E-independent, deep local potentials were generated by the exact inversion method of Marchenko. Subsequently, the supersymmetric method was used to eliminate the PFS, ensuring that the generalized Levinson theorem is satisfied. As an example, the method was applied to the simple model of two dineutrons scattering in the RGM, where the deep ELP of Horiuchi has a substantial energy-dependence and one PFS only for l=O. 16 refs., 5 figs

  9. Role of renewable energy policies in energy dependency in Finland: System dynamics approach

    International Nuclear Information System (INIS)

    Aslani, Alireza; Helo, Petri; Naaranoja, Marja

    2014-01-01

    Highlights: • A system dynamics model for evaluating renewable energy policies on dependency is proposed. • The model considers the role of diversification on dependency and security of energy supply in Finland. • Dependency on imported sources will decrease depends on the defined scenarios in Finland. - Abstract: Objective: We discuss the role of diversification on dependency and security of energy supply. A system dynamics model with especial focus on the role of renewable energy resources (as a portfolio) on Finland’s energy dependency is developed. The purpose is also to cover a part of research gap exists in the system dynamics modeling of energy security investigations. Methods: A causal loops diagram and a system dynamics model evaluate Finnish scenarios of renewable energy policies. The analysis describes the relationship between dynamic factors such as RE encouragement packages, dependency, and energy demand. Results: A causal loops diagram and a system dynamics model evaluate three different Finnish scenarios of renewable energy policies by 2020. Conclusion: Analysis shows that despite 7% electricity/heat consumption growth by 2020 in Finland, dependency on imported sources will decrease between 1% and 7% depend on the defined scenarios. Practice Implications: The proposed model not only helps decision makers to test their scenarios related to renewable energy polices, it can be implemented by other countries

  10. Energy-dependent point interactions in one dimension

    International Nuclear Information System (INIS)

    Coutinho, F A B; Nogami, Y; Tomio, Lauro; Toyama, F M

    2005-01-01

    We consider a new type of point interaction in one-dimensional quantum mechanics. It is characterized by a boundary condition at the origin that involves the second and/or higher order derivatives of the wavefunction. The interaction is effectively energy dependent. It leads to a unitary S-matrix for the transmission-reflection problem. The energy dependence of the interaction can be chosen such that any given unitary S-matrix (or the transmission and reflection coefficients) can be reproduced at all energies. Generalization of the results to coupled-channel cases is discussed

  11. Study of excitation energy dependence of nuclear level density parameter

    International Nuclear Information System (INIS)

    Mohanto, G.; Nayak, B.K.; Saxena, A.

    2016-01-01

    In the present study, we have populated CN by fusion reaction and excitation energy of the intermediate nuclei is determined after first chance α-emission to investigate excitation energy dependence of the NLD parameter. Evaporated neutron spectra were measured following alpha evaporation for obtaining NLD parameter for the reaction 11 B + 197 Au, populating CN 208 Po. This CN after evaporating an α-particle populates intermediate nucleus 204 Pb. The 204 Pb has magic number of Z=82. Our aim is to study the excitation energy dependence of NLD parameter for closed shell nuclei

  12. DEPENDENCE OF ENERGY EFFICIENCY AND COST OF PRODUCTION

    Directory of Open Access Journals (Sweden)

    D. Sklyarov

    2016-01-01

    Full Text Available Economic systems exist on condition of receipt and spending of energy. Energy consumption is a necessary condition for the existence and functioning of the economic systems of any scale: macroeconomics, microeconomics, regional economy or the world economy.The economic system operates on the scale at which it is able to produce energy and get access to energy. Moreover, receipt and consumption of energy in the operation of the economic system is mainly determined by, the level of energy production from energy sources, since this level is determined by the level of energy consumption by industries and enterprises of the economy.Currently, the economic system does not produce energy in reserve. Thus, the question of energy effi ciency and energy saving was always acute.The article describes the energy efficiency and energy saving effect on the cost of production. Were used two methods: “costs and release” matrix and “price - value added” matrix. The result is the equation of dependence of energy efficiency and costs.

  13. Density and starting-energy dependent effective interaction

    International Nuclear Information System (INIS)

    Yamaguchi, Norio; Nagata, Sinobu; Kasuga, Teruo

    1979-01-01

    A new effective potential constructed from the reaction matrix calculation of nuclear matters is proposed, taking three-body effects into account. Starting from the two-body scattering equation for nuclear matters, an equation with averaged momentum is introduced as the definition of effective interaction. The parameters in the equation are the Fermi momentum and the starting energy. The nuclear density dependence and the starting energy dependence are independently treated in the potential. The effective interactions including three-body effects were calculated. The dependence on the starting energy is large. The effective interaction is more attractive in the triplet E state, and assures overall saturation without any artificial renormalization. The reaction matrix calculation can be well reproduced by the calculation with this effective potential. The results of calculation for the binding energy of He-4 and O-16 and the shell model matrix elements of O-16 are represented. (Kato, T.)

  14. Channel length dependence of negative-bias-illumination-stress in amorphous-indium-gallium-zinc-oxide thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Um, Jae Gwang; Mativenga, Mallory; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center, Department of Information Display, Kyung Hee University, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Migliorato, Piero [Advanced Display Research Center, Department of Information Display, Kyung Hee University, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Electrical Engineering Division, Department of Engineering, Cambridge University, Cambridge CB3 0FA (United Kingdom)

    2015-06-21

    We have investigated the dependence of Negative-Bias-illumination-Stress (NBIS) upon channel length, in amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). The negative shift of the transfer characteristic associated with NBIS decreases for increasing channel length and is practically suppressed in devices with L = 100-μm. The effect is consistent with creation of donor defects, mainly in the channel regions adjacent to source and drain contacts. Excellent agreement with experiment has been obtained by an analytical treatment, approximating the distribution of donors in the active layer by a double exponential with characteristic length L{sub D} ∼ L{sub n} ∼ 10-μm, the latter being the electron diffusion length. The model also shows that a device with a non-uniform doping distribution along the active layer is in all equivalent, at low drain voltages, to a device with the same doping averaged over the active layer length. These results highlight a new aspect of the NBIS mechanism, that is, the dependence of the effect upon the relative magnitude of photogenerated holes and electrons, which is controlled by the device potential/band profile. They may also provide the basis for device design solutions to minimize NBIS.

  15. Energy-dependent effects of resveratrol in Saccharomyces cerevisiae.

    Science.gov (United States)

    Madrigal-Perez, Luis Alberto; Canizal-Garcia, Melina; González-Hernández, Juan Carlos; Reynoso-Camacho, Rosalia; Nava, Gerardo M; Ramos-Gomez, Minerva

    2016-06-01

    The metabolic effects induced by resveratrol have been associated mainly with the consumption of high-calorie diets; however, its effects with standard or low-calorie diets remain unclear. To better understand the interactions between resveratrol and cellular energy levels, we used Saccharomyces cerevisiae as a model. Herein it is shown that resveratrol: (a) decreased cell viability in an energy-dependent manner; (b) lessening of cell viability occurred specifically when cells were under cellular respiration; and (c) inhibition of oxygen consumption in state 4 occurred at low and standard energy levels, whereas at high energy levels oxygen consumption was promoted. These findings indicate that the effects of resveratrol are dependent on the cellular energy status and linked to metabolic respiration. Importantly, our study also revealed that S. cerevisiae is a suitable and useful model to elucidate the molecular targets of resveratrol under different nutritional statuses. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Limit on possible energy-dependent velocities for massless particles

    International Nuclear Information System (INIS)

    Haines, T.J.; Alexandreas, D.E.; Allen, R.C.; Biller, S.; Berley, D.; Burman, R.L.; Cady, D.R.; Chang, C.Y.; Dingus, B.L.; Dion, G.M.; Ellsworth, R.W.; Goodman, J.A.; Hoffman, C.M.; Lloyd-Evans, J.; Nagle, D.E.; Potter, M.; Sandberg, V.D.; Wilkinson, C.A.; Yodh, G.B.

    1990-01-01

    A basic tenet of special relativity is that all massless particles travel at a constant, energy-independent velocity. Astrophysical data, including observation of the Crab pulsar at ∼100 MeV and the recent detection of the pulsar in Hercules X-1 at energies ≥100 TeV, are used to place new experimental constraints on energy-dependent deviations from constant velocity for massless particles. Previous experiments reached energies ∼10 GeV; this analysis improves the previous constraints by 7 orders of magnitude

  17. Energy drink consumption and increased risk for alcohol dependence.

    Science.gov (United States)

    Arria, Amelia M; Caldeira, Kimberly M; Kasperski, Sarah J; Vincent, Kathryn B; Griffiths, Roland R; O'Grady, Kevin E

    2011-02-01

    Energy drinks are highly caffeinated beverages that are increasingly consumed by young adults. Prior research has established associations between energy drink use and heavier drinking and alcohol-related problems among college students. This study investigated the extent to which energy drink use might pose additional risk for alcohol dependence over and above that from known risk factors. Data were collected via personal interview from 1,097 fourth-year college students sampled from 1 large public university as part of an ongoing longitudinal study. Alcohol dependence was assessed according to DSM-IV criteria. After adjustment for the sampling design, 51.3%(wt) of students were classified as "low-frequency" energy drink users (1 to 51 days in the past year) and 10.1%(wt) as "high-frequency" users (≥52 days). Typical caffeine consumption varied widely depending on the brand consumed. Compared to the low-frequency group, high-frequency users drank alcohol more frequently (141.6 vs. 103.1 days) and in higher quantities (6.15 vs. 4.64 drinks/typical drinking day). High-frequency users were at significantly greater risk for alcohol dependence relative to both nonusers (AOR = 2.40, 95% CI = 1.27 to 4.56, p = 0.007) and low-frequency users (AOR = 1.86, 95% CI = 1.10, 3.14, p = 0.020), even after holding constant demographics, typical alcohol consumption, fraternity/sorority involvement, depressive symptoms, parental history of alcohol/drug problems, and childhood conduct problems. Low-frequency energy drink users did not differ from nonusers on their risk for alcohol dependence. Weekly or daily energy drink consumption is strongly associated with alcohol dependence. Further research is warranted to understand the possible mechanisms underlying this association. College students who frequently consume energy drinks represent an important target population for alcohol prevention. Copyright © 2010 by the Research Society on Alcoholism.

  18. Simulated building energy demand biases resulting from the use of representative weather stations

    Energy Technology Data Exchange (ETDEWEB)

    Burleyson, Casey D.; Voisin, Nathalie; Taylor, Z. Todd; Xie, Yulong; Kraucunas, Ian

    2018-01-01

    Numerical building models are typically forced with weather data from a limited number of “representative cities” or weather stations representing different climate regions. The use of representative weather stations reduces computational costs, but often fails to capture spatial heterogeneity in weather that may be important for simulations aimed at understanding how building stocks respond to a changing climate. We quantify the potential reduction in bias from using an increasing number of weather stations over the western U.S. The approach is based on deriving temperature and load time series using incrementally more weather stations, ranging from 8 to roughly 150, to capture weather across different seasons. Using 8 stations, one from each climate zone, across the western U.S. results in an average absolute summertime temperature bias of 7.2°F with respect to a spatially-resolved gridded dataset. The mean absolute bias drops to 2.8°F using all available weather stations. Temperature biases of this magnitude could translate to absolute summertime mean simulated load biases as high as 13.8%, a significant error for capacity expansion planners who may use these types of simulations. Increasing the size of the domain over which biases are calculated reduces their magnitude as positive and negative biases may cancel out. Using 8 representative weather stations can lead to a 20-40% overestimation of peak building loads during both summer and winter. Using weather stations close to population centers reduces both mean and peak load biases. This approach could be used by others designing aggregate building simulations to understand the sensitivity to their choice of weather stations used to drive the models.

  19. Energy based model for temperature dependent behavior of ferromagnetic materials

    International Nuclear Information System (INIS)

    Sah, Sanjay; Atulasimha, Jayasimha

    2017-01-01

    An energy based model for temperature dependent anhysteretic magnetization curves of ferromagnetic materials is proposed and benchmarked against experimental data. This is based on the calculation of macroscopic magnetic properties by performing an energy weighted average over all possible orientations of the magnetization vector. Most prior approaches that employ this method are unable to independently account for the effect of both inhomogeneity and temperature in performing the averaging necessary to model experimental data. Here we propose a way to account for both effects simultaneously and benchmark the model against experimental data from ~5 K to ~300 K for two different materials in both annealed (fewer inhomogeneities) and deformed (more inhomogeneities) samples. This demonstrates that this framework is well suited to simulate temperature dependent experimental magnetic behavior. - Highlights: • Energy based model for temperature dependent ferromagnetic behavior. • Simultaneously accounts for effect of temperature and inhomogeneities. • Benchmarked against experimental data from 5 K to 300 K.

  20. Energy dependence on the electric activities of a neuron

    International Nuclear Information System (INIS)

    Song Xin-Lin; Ma Jun; Jin Wu-Yin

    2015-01-01

    A nonlinear circuit can be designed by using inductor, resistor, capacitor and other electric devices, and the electromagnetic field energy can be released from the circuit in the oscillating state. The generation of spikes or bursting states in neurons could be energetically a costly process. Based on the Helmholtz’s theorem, a Hamilton energy function is defined to detect the energy shift induced by transition of electric modes in a Hindmarsh–Rose neuron. It is found that the energy storage is dependent on the external forcing, and energy release is associated with the electric mode. As a result, the bursting state and chaotic state could be helpful to release the energy in the neuron quickly. (paper)

  1. The dielectric environment dependent exchange self-energy of the energy structure in graphene

    International Nuclear Information System (INIS)

    Yang, C.H.; Xu, W.

    2010-01-01

    We theoretically calculate the energy dispersion in the presence of the screened exchange self-energy in extrinsic monolayer graphene. It is found that the exchange self-energy enhances the renormalized Fermi velocity. With decreasing the dielectric constant, the screening effect and the electron correlation effect increase which induces the Fermi velocity increasing. The screened exchange energy has an energy shift at the Dirac points. The self-energy from the valance band carriers gives the main contribution to the effective energy. We also discuss the electron density dependence of the self-energy.

  2. The dielectric environment dependent exchange self-energy of the energy structure in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.H., E-mail: chyang@nuist.edu.c [Faculty of Maths and Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Xu, W. [Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2010-10-01

    We theoretically calculate the energy dispersion in the presence of the screened exchange self-energy in extrinsic monolayer graphene. It is found that the exchange self-energy enhances the renormalized Fermi velocity. With decreasing the dielectric constant, the screening effect and the electron correlation effect increase which induces the Fermi velocity increasing. The screened exchange energy has an energy shift at the Dirac points. The self-energy from the valance band carriers gives the main contribution to the effective energy. We also discuss the electron density dependence of the self-energy.

  3. Normalization of energy-dependent gamma survey data.

    Science.gov (United States)

    Whicker, Randy; Chambers, Douglas

    2015-05-01

    Instruments and methods for normalization of energy-dependent gamma radiation survey data to a less energy-dependent basis of measurement are evaluated based on relevant field data collected at 15 different sites across the western United States along with a site in Mongolia. Normalization performance is assessed relative to measurements with a high-pressure ionization chamber (HPIC) due to its "flat" energy response and accurate measurement of the true exposure rate from both cosmic and terrestrial radiation. While analytically ideal for normalization applications, cost and practicality disadvantages have increased demand for alternatives to the HPIC. Regression analysis on paired measurements between energy-dependent sodium iodide (NaI) scintillation detectors (5-cm by 5-cm crystal dimensions) and the HPIC revealed highly consistent relationships among sites not previously impacted by radiological contamination (natural sites). A resulting generalized data normalization factor based on the average sensitivity of NaI detectors to naturally occurring terrestrial radiation (0.56 nGy hHPIC per nGy hNaI), combined with the calculated site-specific estimate of cosmic radiation, produced reasonably accurate predictions of HPIC readings at natural sites. Normalization against two to potential alternative instruments (a tissue-equivalent plastic scintillator and energy-compensated NaI detector) did not perform better than the sensitivity adjustment approach at natural sites. Each approach produced unreliable estimates of HPIC readings at radiologically impacted sites, though normalization against the plastic scintillator or energy-compensated NaI detector can address incompatibilities between different energy-dependent instruments with respect to estimation of soil radionuclide levels. The appropriate data normalization method depends on the nature of the site, expected duration of the project, survey objectives, and considerations of cost and practicality.

  4. Energy-dependent losses in pulsed-feedback preamplifiers

    International Nuclear Information System (INIS)

    Landis, D.A.; Madden, N.W.; Goulding, F.S.

    1978-11-01

    Energy dependent counting losses occur in most pulsed-feedback preamplifiers due to the loss of those pulses which activate the recharge system. A pulsed-feedback system that overcomes this inefficiency is described. Pulsed-light feedback as used with germanium gamma-ray spectrometers is discussed as used at high energies and high rates where those losses become significant. Experimental results are presented

  5. Ideal gas scattering kernel for energy dependent cross-sections

    International Nuclear Information System (INIS)

    Rothenstein, W.; Dagan, R.

    1998-01-01

    A third, and final, paper on the calculation of the joint kernel for neutron scattering by an ideal gas in thermal agitation is presented, when the scattering cross-section is energy dependent. The kernel is a function of the neutron energy after scattering, and of the cosine of the scattering angle, as in the case of the ideal gas kernel for a constant bound atom scattering cross-section. The final expression is suitable for numerical calculations

  6. Efficient Determination of Free Energy Landscapes in Multiple Dimensions from Biased Umbrella Sampling Simulations Using Linear Regression.

    Science.gov (United States)

    Meng, Yilin; Roux, Benoît

    2015-08-11

    The weighted histogram analysis method (WHAM) is a standard protocol for postprocessing the information from biased umbrella sampling simulations to construct the potential of mean force with respect to a set of order parameters. By virtue of the WHAM equations, the unbiased density of state is determined by satisfying a self-consistent condition through an iterative procedure. While the method works very effectively when the number of order parameters is small, its computational cost grows rapidly in higher dimension. Here, we present a simple and efficient alternative strategy, which avoids solving the self-consistent WHAM equations iteratively. An efficient multivariate linear regression framework is utilized to link the biased probability densities of individual umbrella windows and yield an unbiased global free energy landscape in the space of order parameters. It is demonstrated with practical examples that free energy landscapes that are comparable in accuracy to WHAM can be generated at a small fraction of the cost.

  7. Temperature dependent energy levels of methylammonium lead iodide perovskite

    Science.gov (United States)

    Foley, Benjamin J.; Marlowe, Daniel L.; Sun, Keye; Saidi, Wissam A.; Scudiero, Louis; Gupta, Mool C.; Choi, Joshua J.

    2015-06-01

    Temperature dependent energy levels of methylammonium lead iodide are investigated using a combination of ultraviolet photoemission spectroscopy and optical spectroscopy. Our results show that the valence band maximum and conduction band minimum shift down in energy by 110 meV and 77 meV as temperature increases from 28 °C to 85 °C. Density functional theory calculations using slab structures show that the decreased orbital splitting due to thermal expansion is a major contribution to the experimentally observed shift in energy levels. Our results have implications for solar cell performance under operating conditions with continued sunlight exposure and increased temperature.

  8. Temperature dependent energy levels of methylammonium lead iodide perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Benjamin J.; Marlowe, Daniel L.; Choi, Joshua J., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Sun, Keye; Gupta, Mool C., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Saidi, Wissam A. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Scudiero, Louis, E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Chemistry Department and Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164 (United States)

    2015-06-15

    Temperature dependent energy levels of methylammonium lead iodide are investigated using a combination of ultraviolet photoemission spectroscopy and optical spectroscopy. Our results show that the valence band maximum and conduction band minimum shift down in energy by 110 meV and 77 meV as temperature increases from 28 °C to 85 °C. Density functional theory calculations using slab structures show that the decreased orbital splitting due to thermal expansion is a major contribution to the experimentally observed shift in energy levels. Our results have implications for solar cell performance under operating conditions with continued sunlight exposure and increased temperature.

  9. Study of heavy quarkonium with energy dependent potential

    International Nuclear Information System (INIS)

    Gupta, Pramila; Mehrotra, I

    2009-01-01

    It is well known that charmonium and bottonium states can be calculated by using a nonrelativistic Schrodinger equation. The basic reasons are: 1) the mass of charm and bottom quarks is much larger than QCD scale, which makes this system free of strong normalization effects and 2) the binding energy is small compared to the mass energy ψ and γ states in terms of nonrelativistic qq system governed by more or less phenomenological potentials. In the present work we have studied mass spectra of charmonium and bottonium using the following energy dependent model in the framework of nonrelativistic Schrodinger equation

  10. Dependence of the giant dipole strength function on excitation energy

    International Nuclear Information System (INIS)

    Draper, J.E.; Newton, J.O.; Sobotka, L.G.; Lindenberger, H.; Wozniak, G.J.; Moretto, L.G.; Stephens, F.S.; Diamond, R.M.; McDonald, R.J.

    1982-01-01

    Spectra of γ rays associated with deep-inelastic products from the 1150-MeV 136 Xe+ 181 Ta reaction have been measured. The yield of 10--20-MeV γ rays initially increases rapidly with the excitation energy of the products and then more slowly for excitation energies in excess of 120 MeV. Statistical-model calculations with ground-state values of the giant dipole strength function fail to reproduce the shape of the measured γ-ray spectra. This suggests a dependence of the giant dipole strength function on excitation energy

  11. Magnetic-field and temperature dependence of the energy gap in InN nanobelt

    Directory of Open Access Journals (Sweden)

    K. Aravind

    2012-03-01

    Full Text Available We present tunneling measurements on an InN nanobelt which shows signatures of superconductivity. Superconducting transition takes place at temperature of 1.3K and the critical magnetic field is measured to be about 5.5kGs. The energy gap extrapolated to absolute temperature is about 110μeV. As the magnetic field is decreased to cross the critical magnetic field, the device shows a huge zero-bias magnetoresistance ratio of about 400%. This is attributed to the suppression of quasiparticle subgap tunneling in the presence of superconductivity. The measured magnetic-field and temperature dependence of the superconducting gap agree well with the reported dependences for conventional metallic superconductors.

  12. Dependability of wind energy generators with short-term energy storage.

    Science.gov (United States)

    Sørensen, B

    1976-11-26

    Power fluctuations and power duration curves for wind energy generators, including energy storage facilities of a certain capacity, are compared to those of typical nuclear reactors. A storage system capable of delivering the yearly average power output for about 10 hours already makes the dependability of the wind energy system comparable to that of a typical nuclear plant.

  13. The three body problem with energy dependent potentials

    International Nuclear Information System (INIS)

    Kim, Y.E.; McKay, C.M.; McKellar, B.H.J.

    1975-10-01

    It is shown how to generalize the three body equations of Faddeev, and of Karlsson and Zeiger, to include the case when the two body potential is energy dependent. Such generalizations will prove useful in the three nucleon problem and in three body models of nuclear reactions. (author)

  14. Inelastic surface vibrations versus energy-dependent nucleus ...

    Indian Academy of Sciences (India)

    Limitations of the static Woods–Saxon potential and the applicability of the energy dependent Woods–Saxon potential (EDWSP) model within the framework of one-dimensional Wong formula to explore the sub-barrier fusion data are highlighted. The inelastic surface excitations of the fusing nuclei are found to be ...

  15. Inelastic surface vibrations versus energy-dependent nucleus ...

    Indian Academy of Sciences (India)

    Abstract. Limitations of the static Woods–Saxon potential and the applicability of the energy- dependent Woods–Saxon potential (EDWSP) model within the framework of one-dimensional. Wong formula to explore the sub-barrier fusion data are highlighted. The inelastic surface exci- tations of the fusing nuclei are found to ...

  16. On recoil energy dependent void swelling in pure copper: Theoretical treatment

    International Nuclear Information System (INIS)

    Golubov, S.I.; Singh, B.N.; Trinkaus, H.

    2000-06-01

    Over the years, an enormous amount of experimental results have been reported on damage accumulation (e.g. void swelling) in metals and alloys irradiated under vastly different recoil energy conditions. Unfortunately, however, very little is known either experimentally or theoretically about the effect of recoil energy on damage accumulation. Recently, dedicated irradiation experiments using 2.5 MeV electrons, 3.0 MeV protons and fission neutrons have been carried out to determine the effect of recoil energy on the damage accumulation behaviour in pure copper and the results have been reported in Part I of this paper (Singh, Eldrup, Horsewell, Ehrhart and Dworschak 2000). The present paper attempts to provide a theoretical framework within which the effect of recoil energy on damage accumulation behaviour can be understood. The damage accumulation under Frenkel pair production (e.g. 2.5 MeV electron) has been treated in terms of the standard rate theory (SRT) model whereas the evolution of the defect microstructure under cascade damage conditions (e.g. 3.0 MeV protons and fission neutrons) has been calculated within the framework of the production bias model (PBM). Theoretical results, in agreement with experimental results, show that the damage accumulation behaviour is very sensitive to recoil energy and under cascade damage conditions can be treated only within the framework of the PBM. The intracascade clustering of self-interstitial atoms (SIAs) and the properties of SIA clusters such as one-dimensional diffusional transport and thermal stability are found to be the main reasons for the recoil energy dependent vacancy supersaturation. The vacancy supersaturation is the main driving force for the void nucleation and void swelling. In the case of Frenkel pair production, the experimental results are found to be consistent with the SRT model with a dislocation bias value of 2 %. (au)

  17. Energy dependence of critical state of single-component systems

    International Nuclear Information System (INIS)

    Volchenkova, R.A.

    1985-01-01

    Equations of critical states of the single-component systems: Psub(cr)(/Psub(o)=(Tsub(cr)/Tsub(o))x0.73, Tsub(cr)=K(Tsub(boil))sup(1.116) and Hsub(cr)(/Hsub(B)=Tsub(sr)/Tsub(B))sup(1.48) where Tsub(B)=1K, Hsub(B)-2 kcal/g-at, K-dimension factor are presented. It is shown that the revealed dependence Hsub(cr)=H(Tsub(cr)) is an energy boundary of a liquid-vapour phase state of the single-component systems beyond limits of which difference between liquid and vapour phases vanishes in increasing the system energy content. The given equations of state are true for all the single-component systems and permit to consider physicomechanical properties of substances in dynamic state depending on external conditions. Critical temperatures and dependences for elements from the most fusible He to infusible W and Re have been calculated

  18. Correction of gene expression data: Performance-dependency on inter-replicate and inter-treatment biases.

    Science.gov (United States)

    Darbani, Behrooz; Stewart, C Neal; Noeparvar, Shahin; Borg, Søren

    2014-10-20

    This report investigates for the first time the potential inter-treatment bias source of cell number for gene expression studies. Cell-number bias can affect gene expression analysis when comparing samples with unequal total cellular RNA content or with different RNA extraction efficiencies. For maximal reliability of analysis, therefore, comparisons should be performed at the cellular level. This could be accomplished using an appropriate correction method that can detect and remove the inter-treatment bias for cell-number. Based on inter-treatment variations of reference genes, we introduce an analytical approach to examine the suitability of correction methods by considering the inter-treatment bias as well as the inter-replicate variance, which allows use of the best correction method with minimum residual bias. Analyses of RNA sequencing and microarray data showed that the efficiencies of correction methods are influenced by the inter-treatment bias as well as the inter-replicate variance. Therefore, we recommend inspecting both of the bias sources in order to apply the most efficient correction method. As an alternative correction strategy, sequential application of different correction approaches is also advised. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Asymmetrical effects of adaptation to left- and right-shifting prisms depends on pre-existing attentional biases.

    Science.gov (United States)

    Goedert, Kelly M; Leblanc, Andrew; Tsai, Sen-Wei; Barrett, Anna M

    2010-09-01

    Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the postadaptation performance of individuals trained with left- versus right-shifting prisms (e.g., Colent, Pisella, & Rossetti, 2000). A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., Jewell & McCourt, 2000). In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left- and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.

  20. Proposed Use of Zero Bias Diode Arrays as Thermal Electric Noise Rectifiers and Non-Thermal Energy Harvesters

    Science.gov (United States)

    Valone, Thomas F.

    2009-03-01

    The well known built-in voltage potential for some select semiconductor p-n junctions and various rectifying devices is proposed to be favorable for generating DC electricity at "zero bias" (with no DC bias voltage applied) in the presence of Johnson noise or 1/f noise which originates from the quantum vacuum (Koch et al., 1982). The 1982 Koch discovery that certain solid state devices exhibit measurable quantum noise has also recently been labeled a finding of dark energy in the lab (Beck and Mackey, 2004). Tunnel diodes are a class of rectifiers that are qualified and some have been credited with conducting only because of quantum fluctuations. Microwave diodes are also good choices since many are designed for zero bias operation. A completely passive, unamplified zero bias diode converter/detector for millimeter (GHz) waves was developed by HRL Labs in 2006 under a DARPA contract, utilizing a Sb-based "backward tunnel diode" (BTD). It is reported to be a "true zero-bias diode." It was developed for a "field radiometer" to "collect thermally radiated power" (in other words, 'night vision'). The diode array mounting allows a feed from horn antenna, which functions as a passive concentrating amplifier. An important clue is the "noise equivalent power" of 1.1 pW per root hertz and the "noise equivalent temperature difference" of 10° K, which indicate sensitivity to Johnson noise (Lynch, et al., 2006). There also have been other inventions such as "single electron transistors" that also have "the highest signal to noise ratio" near zero bias. Furthermore, "ultrasensitive" devices that convert radio frequencies have been invented that operate at outer space temperatures (3 degrees above zero point: 3° K). These devices are tiny nanotech devices which are suitable for assembly in parallel circuits (such as a 2-D array) to possibly produce zero point energy direct current electricity with significant power density (Brenning et al., 2006). Photovoltaic p-n junction

  1. Computing more proper covariances of energy dependent nuclear data

    International Nuclear Information System (INIS)

    Vanhanen, R.

    2016-01-01

    Highlights: • We present conditions for covariances of energy dependent nuclear data to be proper. • We provide methods to detect non-positive and inconsistent covariances in ENDF-6 format. • We propose methods to find nearby more proper covariances. • The methods can be used as a part of a quality assurance program. - Abstract: We present conditions for covariances of energy dependent nuclear data to be proper in the sense that the covariances are positive, i.e., its eigenvalues are non-negative, and consistent with respect to the sum rules of nuclear data. For the ENDF-6 format covariances we present methods to detect non-positive and inconsistent covariances. These methods would be useful as a part of a quality assurance program. We also propose methods that can be used to find nearby more proper energy dependent covariances. These methods can be used to remove unphysical components, while preserving most of the physical components. We consider several different senses in which the nearness can be measured. These methods could be useful if a re-evaluation of improper covariances is not feasible. Two practical examples are processed and analyzed. These demonstrate some of the properties of the methods. We also demonstrate that the ENDF-6 format covariances of linearly dependent nuclear data should usually be encoded with the derivation rules.

  2. Bremsstrahlung of La and its dependence on electron energy

    International Nuclear Information System (INIS)

    Riehle, F.

    1977-01-01

    Measurements of La-bremsstrahlung isocromates with high resolution for quantum energies between 135 eV and 1867 eV are presented and discussed. In the whole energy range investigated, the isocromate structure, identified with the 4f band of La, is placed 5,45 +- 10,1 eV above the Fermi level. This is in contradiction with a calculation of Gloetzel, which predicts the 4f band maximum about 3eV above the Fermi level. This discrepancy is explained in the present work by the fact that the La electronic density of states depends on the occupation number of the states. The bremsstrahlung isocromate has to be considered as a direct copy of the La ion density of states, consisting of the La-atom and the additional primary electron. Resonance like intensity modulations of the x-ray radiation, resulting from transitions of the primary electron in f-like final states, are observed in an analysis of the La-bremsstrahlung isochromate energy dependence. For transitions of the primary electron in d-like final states, no resonances have been found. The energy dependence of the scattering probability in f-like final states can be explained by a model which assumes the final state as composed by a continuum state and a discrete state. (orig.) [de

  3. Galaxy bias from the Dark Energy Survey Science Verification data: combining galaxy density maps and weak lensing maps

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.; Pujol, A.; Gaztañaga, E.; Amara, A.; Réfrégier, A.; Bacon, D.; Becker, M. R.; Bonnett, C.; Carretero, J.; Castander, F. J.; Crocce, M.; Fosalba, P.; Giannantonio, T.; Hartley, W.; Jarvis, M.; Kacprzak, T.; Ross, A. J.; Sheldon, E.; Troxel, M. A.; Vikram, V.; Zuntz, J.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Rosell, A. Carnero; Kind, M. Carrasco; Cunha, C. E.; D' Andrea, C. B.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Estrada, J.; Evrard, A. E.; Flaugher, B.; Frieman, J.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; Jain, B.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Lima, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Nichol, R. C.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.

    2016-04-15

    We measure the redshift evolution of galaxy bias from a magnitude-limited galaxy sample by combining the galaxy density maps and weak lensing shear maps for a $\\sim$116 deg$^{2}$ area of the Dark Energy Survey (DES) Science Verification data. This method was first developed in Amara et al. (2012) and later re-examined in a companion paper (Pujol et al., in prep) with rigorous simulation tests and analytical treatment of tomographic measurements. In this work we apply this method to the DES SV data and measure the galaxy bias for a magnitude-limited galaxy sample. We find the galaxy bias and 1$\\sigma$ error bars in 4 photometric redshift bins to be 1.33$\\pm$0.18 (z=0.2-0.4), 1.19$\\pm$0.23 (z=0.4-0.6), 0.99$\\pm$0.36 ( z=0.6-0.8), and 1.66$\\pm$0.56 (z=0.8-1.0). These measurements are consistent at the 1-2$\\sigma$ level with mea- surements on the same dataset using galaxy clustering and cross-correlation of galaxies with CMB lensing. In addition, our method provides the only $\\sigma_8$-independent constraint among the three. We forward-model the main observational effects using mock galaxy catalogs by including shape noise, photo-z errors and masking effects. We show that our bias measurement from the data is consistent with that expected from simulations. With the forthcoming full DES data set, we expect this method to provide additional constraints on the galaxy bias measurement from more traditional methods. Furthermore, in the process of our measurement, we build up a 3D mass map that allows further exploration of the dark matter distribution and its relation to galaxy evolution.

  4. Essays in energy policy and planning modeling under uncertainty: Value of information, optimistic biases, and simulation of capacity markets

    Science.gov (United States)

    Hu, Ming-Che

    Optimization and simulation are popular operations research and systems analysis tools for energy policy modeling. This dissertation addresses three important questions concerning the use of these tools for energy market (and electricity market) modeling and planning under uncertainty. (1) What is the value of information and cost of disregarding different sources of uncertainty for the U.S. energy economy? (2) Could model-based calculations of the performance (social welfare) of competitive and oligopolistic market equilibria be optimistically biased due to uncertainties in objective function coefficients? (3) How do alternative sloped demand curves perform in the PJM capacity market under economic and weather uncertainty? How does curve adjustment and cost dynamics affect the capacity market outcomes? To address the first question, two-stage stochastic optimization is utilized in the U.S. national MARKAL energy model; then the value of information and cost of ignoring uncertainty are estimated for three uncertainties: carbon cap policy, load growth and natural gas prices. When an uncertainty is important, then explicitly considering those risks when making investments will result in better performance in expectation (positive expected cost of ignoring uncertainty). Furthermore, eliminating the uncertainty would improve strategies even further, meaning that improved forecasts of future conditions are valuable ( i.e., a positive expected value of information). Also, the value of policy coordination shows the difference between a strategy developed under the incorrect assumption of no carbon cap and a strategy correctly anticipating imposition of such a cap. For the second question, game theory models are formulated and the existence of optimistic (positive) biases in market equilibria (both competitive and oligopoly markets) are proved, in that calculated social welfare and producer profits will, in expectation, exceed the values that will actually be received

  5. Generalized Energy-Dependent Q Values for Fission

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R

    2010-03-31

    We extend Madland's parameterization of the energy release in fission to obtain the dependence of the fission Q value for major and minor actinides on the incident neutron energies in the range 0 {le} E{sub n} {le} 20 MeV. Our parameterization is based on the actinide evaluations recommended for the ENDF/B-VII.1 release. This paper describes the calculation of energydependent fission Q values based on the calculation of the prompt energy release in fission by Madland. This calculation was adopted for use in the LLNL ENDL database and then generalized to obtain the prompt fission energy release for all actinides. Here the calculation is further generalized to the total energy release in fission. There are several stages in a fission event, depending on the time scale. Neutrons and gammas may be emitted at any time during the fission event.While our discussion here is focussed on compound nucleus creation by an incident neutron, similar parameterizations could be obtained for incident gammas or spontaneous fission.

  6. Getting to Grips Again with Dependency. Japan's Energy Strategy

    International Nuclear Information System (INIS)

    Chrisstoffels, J.H.

    2007-08-01

    Japan has had to deal with a high level of dependency on energy imports for many decades. Today the country faces an increasingly competitive global energy market that forces it to reinvent its traditional security of supply policies. Unfortunately for Japan, the rise of China and India is increasing the competition for scarce energy supplies among consumer countries, whereas in the past supplier countries competed for access to the attractive Japanese market. To confront the challenges of the new environment the Japanese government has drafted a New National Energy Strategy. This paper analyses the strength of the strategy's proposals and targets, in particular those aimed at improving security of oil and gas supply. To assess the impact of the strategy we place it firmly against the background of Japan's history of energy security policy, as well as Japan's recent experiences with 'strategic resource projects'. This paper finds that Japan's policies in post-1973 history have been impeded by a complex set of factors. Traditionally this set has included Japan's troubled bilateral relations with Russia and China, and Japan's security dependence on the United States. Other factors are Japan's inability to synchronise national and corporate interests, and a lack of cooperation between domestic energy companies. More recently, rising oil prices, growing resource competition with China and lacklustre domestic demand-growth for energy have increased anxiety about security of supply amongst policymakers in Tokyo. In three case studies the paper illustrates in detail how these factors - in combination or by themselves - have structurally compromised Japanese initiatives to improve security of supply. The case studies discuss the Azadegan oil development project in Iran, plans for a pan-Siberian oil pipeline, and the oil and gas projects on Russia's Sakhalin Island. Our analysis of the New National Energy Strategy confirms that energy security is back on Japan's policy

  7. Study of energy dependence of a extrapolation chamber in low energy X-rays beams

    International Nuclear Information System (INIS)

    Bastos, Fernanda M.; Silva, Teogenes A. da

    2014-01-01

    This work was with the main objective to study the energy dependence of extrapolation chamber in low energy X-rays to determine the value of the uncertainty associated with the variation of the incident radiation energy in the measures in which it is used. For studying the dependence of energy, were conducted comparative ionization current measurements between the extrapolation chamber and two ionization chambers: a chamber mammography, RC6M model, Radcal with energy dependence less than 5% and a 2575 model radioprotection chamber NE Technology; both chambers have very thin windows, allowing its application in low power beams. Measurements were made at four different depths of 1.0 to 4.0 mm extrapolation chamber, 1.0 mm interval, for each reference radiation. The study showed that there is a variable energy dependence on the volume of the extrapolation chamber. In other analysis, it is concluded that the energy dependence of extrapolation chamber becomes smaller when using the slope of the ionization current versus depth for the different radiation reference; this shows that the extrapolation technique, used for the absorbed dose calculation, reduces the uncertainty associated with the influence of the response variation with energy radiation

  8. Model dependence of energy-weighted sum rules

    International Nuclear Information System (INIS)

    Kirson, M.W.

    1977-01-01

    The contribution of the nucleon-nucleon interaction to energy-weighted sum rules for electromagnetic multipole transitions is investigated. It is found that only isoscalar electric transitions might have model-independent energy-weighted sum rules. For these transitions, explicit momentum and angular momentum dependence of the nuclear force give rise to corrections to the sum rule which are found to be negligibly small, thus confirming the model independence of these specific sum rules. These conclusions are unaffected by correlation effects. (author)

  9. The electron trap parameter extraction-based investigation of the relationship between charge trapping and activation energy in IGZO TFTs under positive bias temperature stress

    Science.gov (United States)

    Rhee, Jihyun; Choi, Sungju; Kang, Hara; Kim, Jae-Young; Ko, Daehyun; Ahn, Geumho; Jung, Haesun; Choi, Sung-Jin; Myong Kim, Dong; Kim, Dae Hwan

    2018-02-01

    Experimental extraction of the electron trap parameters which are associated with charge trapping into gate insulators under the positive bias temperature stress (PBTS) is proposed and demonstrated for the first time in amorphous indium-gallium-zinc-oxide thin-film transistors. This was done by combining the PBTS/recovery time-evolution of the experimentally decomposed threshold voltage shift (ΔVT) and the technology computer-aided design (TCAD)-based charge trapping simulation. The extracted parameters were the trap density (NOT) = 2.6 × 1018 cm-3, the trap energy level (ΔET) = 0.6 eV, and the capture cross section (σ0) = 3 × 10-19 cm2. Furthermore, based on the established TCAD framework, the relationship between the electron trap parameters and the activation energy (Ea) is comprehensively investigated. It is found that Ea increases with an increase in σ0, whereas Ea is independent of NOT. In addition, as ΔET increases, Ea decreases in the electron trapping-dominant regime (low ΔET) and increases again in the Poole-Frenkel (PF) emission/hopping-dominant regime (high ΔET). Moreover, our results suggest that the cross-over ΔET point originates from the complicated temperature-dependent competition between the capture rate and the emission rate. The PBTS bias dependence of the relationship between Ea and ΔET suggests that the electric field dependence of the PF emission-based electron hopping is stronger than that of the thermionic field emission-based electron trapping.

  10. Possible energy dependence of Θ13 in neutrino oscillations

    International Nuclear Information System (INIS)

    Klinkhamer, Frans R.

    2005-01-01

    A simple three-flavor neutrino-oscillation model is discussed which has both nonzero mass differences and timelike Fermi-point splittings, together with a combined bi-maximal and trimaximal mixing pattern. One possible consequence would be new effects in ν μ →ν e oscillations, characterized by an energy-dependent effective mixing angle Θ 13 . Future experiments such as T2K and NOνA, and perhaps even the current MINOS experiment, could look for these effects

  11. Dependence of balance energy on isospin degrees of freedom

    International Nuclear Information System (INIS)

    Gautam, S.; Sood, Aman D.; Puri, Rajeev K.; Hartnack, Ch.; Aichelin, J.

    2009-01-01

    Collective transverse in-plane flow in heavy ion collisions has been a subject of intensive theoretical and experimental studies, as it can provide information about the nuclear matter equation of state (EOS) as well as in medium nucleon-nucleon (nn) cross section. The study of dependence of collective transverse flow on various entrance channel parameters as beam energy and impact parameter has revealed much interesting physics about the origin and properties of the collective flow. From these studies, it has been found that the transverse in plane flow disappears at an incident energy termed as balance energy (E bal ), where attractive part of the nuclear interactions balances the repulsive part. Presently, due to availability of the radioactive beams, role of isospin degrees of freedom in EOS can be studied. The collective transverse in-plane flow has been found to depend on isospin of the colliding system. Here, we aim to study the dependence of E bal on N/Z ratio of the colliding system using IQMD model

  12. Proof and implementation of the stochastic formula for ideal gas, energy dependent scattering kernel

    International Nuclear Information System (INIS)

    Becker, B.; Dagan, R.; Lohnert, G.

    2009-01-01

    The ideal gas, scattering kernel for heavy nuclei with pronounced resonances was developed [Rothenstein, W., Dagan, R., 1998. Ann. Nucl. Energy 25, 209-222], proved and implemented [Rothenstein, W., 2004 Ann. Nucl. Energy 31, 9-23] in the data processing code NJOY [Macfarlane, R.E., Muir, D.W., 1994. The NJOY Nuclear Data Processing System Version 91, LA-12740-M] from which the scattering probability tables were prepared [Dagan, R., 2005. Ann. Nucl. Energy 32, 367-377]. Those tables were introduced to the well known MCNP code [X-5 Monte Carlo Team. MCNP - A General Monte Carlo N-Particle Transport Code version 5 LA-UR-03-1987 code] via the 'mt' input cards in the same manner as it is done for light nuclei in the thermal energy range. In this study we present an alternative methodology for solving the double differential energy dependent scattering kernel which is based solely on stochastic consideration as far as the scattering probabilities are concerned. The solution scheme is based on an alternative rejection scheme suggested by Rothenstein [Rothenstein, W. ENS conference 1994 Tel Aviv]. Based on comparison with the above mentioned analytical (probability S(α,β)-tables) approach it is confirmed that the suggested rejection scheme provides accurate results. The uncertainty concerning the magnitude of the bias due to the enhanced multiple rejections during the sampling procedure are proved to lie within 1-2 standard deviations for all practical cases that were analysed.

  13. Biomass energy from wood chips: Diesel fuel dependence?

    International Nuclear Information System (INIS)

    Timmons, Dave; Mejia, Cesar Viteri

    2010-01-01

    Most renewable energy sources depend to some extent on use of other, non-renewable sources. In this study we explore use of diesel fuel in producing and transporting woody biomass in the state of New Hampshire, USA. We use two methods to estimate the diesel fuel used in woody biomass production: 1) a calculation based on case studies of diesel consumption in different parts of the wood chip supply chain, and 2) to support extrapolating those results to a regional system, an econometric study of the variation of wood-chip prices with respect to diesel fuel prices. The econometric study relies on an assumption of fixed demand, then assesses variables impacting supply, with a focus on how the price of diesel fuel affects price of biomass supplied. The two methods yield similar results. The econometric study, representing overall regional practices, suggests that a $1.00 per liter increase in diesel fuel price is associated with a $5.59 per Mg increase in the price of wood chips. On an energy basis, the diesel fuel used directly in wood chip production and transportation appears to account for less than 2% of the potential energy in the wood chips. Thus, the dependence of woody biomass energy production on diesel fuel does not appear to be extreme. (author)

  14. Observations of sensor bias dependent cluster centroid shifts in a prototype sensor for the LHCb Vertex Locator detector

    CERN Document Server

    Papadelis, Aras

    2006-01-01

    We present results from a recent beam test of a prototype sensor for the LHCb Vertex Locator detector, read out with the Beetle 1.3 front-end chip. We have studied the effect of the sensor bias voltage on the reconstructed cluster positions in a sensor placed in a 120GeV pion beam at a 10° incidence angle. We find an unexplained sysematic shift in the reconstructed cluster centroid when increasing the bias voltage on an already overdepleted sensor. The shift is independent of strip pitch and sensor thickness.

  15. Do the early attentional components of ERPs reflect attentional bias in depression? It depends on the stimulus presentation time.

    Science.gov (United States)

    Mingtian, Zhong; Xiongzhao, Zhu; Jinyao, Yi; Shuqiao, Yao; Atchley, Ruth Ann

    2011-07-01

    The study aimed to utilize behavioral and electrophysiological data to investigate whether depressed patients show an attentional bias in a task that allows for explicit insight into the time course of selective attention processes. Event-related potentials (ERPs) were collected from 24 patients with major depressive disorder (MDD) and 25 never-depressed individuals (ND) during a dot-probe task, using pairs of affectively valenced pictures as cues. Cue presentation time was either 100 ms or 500 ms. When the cue presentation time was 500 ms, bias scores for positive-neutral picture pairs (POS-NEU) were negative for the MDD group and positive for the ND group which means ND individuals were able to successfully select positive information. These behavioral effects were supported by ERP results. In the ND group, at the right parietal-occipital region, P1 amplitude during valid POS-NEU pairs was significantly larger than that during invalid POS-NEU pairs; this pattern did not appear in the MDD group. These results suggest that MDD patients are characterized by a deficit in protection bias, meaning that these participants cannot avoid attending to negative information in their environment, but only when negative stimuli are presented for a sufficient period of time. Attentional bias is modulated by duration of emotional pictures presentation in depression. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Influence of time dependent longitudinal magnetic fields on the cooling process, exchange bias and magnetization reversal mechanism in FM core/AFM shell nanoparticles: a Monte Carlo study.

    Science.gov (United States)

    Yüksel, Yusuf; Akıncı, Ümit

    2016-12-07

    Using Monte Carlo simulations, we have investigated the dynamic phase transition properties of magnetic nanoparticles with ferromagnetic core coated by an antiferromagnetic shell structure. Effects of field amplitude and frequency on the thermal dependence of magnetizations, magnetization reversal mechanisms during hysteresis cycles, as well as on the exchange bias and coercive fields have been examined, and the feasibility of applying dynamic magnetic fields on the particle have been discussed for technological and biomedical purposes.

  17. A 'putty-practically-clay' vintage model with R and D driven biases in energy-saving technical change

    International Nuclear Information System (INIS)

    Van Zon, A.; Lontzek, T.

    2005-01-01

    This paper deals with the problem of tackling the adverse effect of output growth on environmental quality. For this purpose we use an intermediate sector that builds 'putty-practically-clay' capital consisting of an energy-raw capital amalgam used for final goods production. The putty-practically-clay model is a strongly simplified version of a full putty-clay model, that mimics all the relevant behaviour of a full puttyclay model, but that does not entail the administrative hassle of a full putty-clay vintage model. In addition to this, we introduce an R and D sector that develops renewable- and conventional energy-based technologies. The allocation of R and D activities over these two uses of R and D gives rise to an induced bias in technical change. In the context of our model, this implies that technological progress is primarily driven by the desire to counteract the upward pressure on production cost implied by a continuing price increase of conventional energy resources. Hotelling's rule suggests that this price rise is unavoidable in the face of the ongoing depletion of conventional energy reserves. By means of some illustrative model simulations we study the effects of energy policy on the dynamics of the model for alternative policy options aimed at achieving GHG emission reductions. We identify the conditions under which energy policy might partly backfire and present some non-standard policy implications

  18. Energy dependence of strangeness production and event-byevent fluctuations

    Directory of Open Access Journals (Sweden)

    Rustamov Anar

    2018-01-01

    Full Text Available We review the energy dependence of strangeness production in nucleus-nucleus collisions and contrast it with the experimental observations in pp and p-A collisions at LHC energies as a function of the charged particle multiplicities. For the high multiplicity final states the results from pp and p-Pb reactions systematically approach the values obtained from Pb-Pb collisions. In statistical models this implies an approach to the thermodynamic limit, where differences of mean multiplicities between various formalisms, such as Canonical and Grand Canonical Ensembles, vanish. Furthermore, we report on event-by-event net-proton fluctuations as measured by STAR at RHIC/BNL and by ALICE at LHC/CERN and discuss various non-dynamical contributions to these measurements, which should be properly subtracted before comparison to theoretical calculations on dynamical net-baryon fluctuations.

  19. The energy dependence of neutron-proton charge exchange

    International Nuclear Information System (INIS)

    Bouquet, A.; Diu, R.

    1978-01-01

    The new Fermilab data on up charge exchange are analysed phenomenologically, to determine the energy dependence of the amplitudes in the corresponding domain (60 2 trajectories. If one imposes the presence of standard rho-A 2 terms (three-component analysis), one has to introduce a pomeronlike contribution, with a trajectory α approximately equal to 1.0+0.25t. In both cases, the resulting parametrization gives a good description of the data from Psub(lab)=1GeV/c up to 300GeV/c

  20. Criticality problems in energy dependent neutron transport theory

    International Nuclear Information System (INIS)

    Victory, H.D. Jr.

    1979-01-01

    The criticality problem is considered for energy dependent neutron transport in an isotropically scattering, homogeneous slab. Under a positivity assumption on the scattering kernel, an expression can be found relating the thickness of the slab to a parameter characterizing production by fission. This is accomplished by exploiting the Perron-Frobenius-Jentsch characterization of positive operators (i.e. those leaving invariant a normal, reproducing cone in a Banach space). It is pointed out that those techniques work for classes of multigroup problems were the Case singular eigenfunction approach is not as feasible as in the one-group theory, which is also analyzed

  1. Energy-dependent applications of the transfer matrix method

    International Nuclear Information System (INIS)

    Oeztunali, O.I.; Aronson, R.

    1975-01-01

    The transfer matrix method is applied to energy-dependent neutron transport problems for multiplying and nonmultiplying media in one-dimensional plane geometry. Experimental cross sections are used for total, elastic, and inelastic scattering and fission. Numerical solutions are presented for the problem of a unit point isotropic source in an infinite medium of water and for the problem of the critical 235 U slab with finite water reflectors. No iterations were necessary in this method. Numerical results obtained are consistent with physical considerations and compare favorably with the moments method results for the problem of the unit point isotropic source in an infinite water medium. (U.S.)

  2. Action dependent heuristic dynamic programming based residential energy scheduling with home energy inter-exchange

    International Nuclear Information System (INIS)

    Xu, Yancai; Liu, Derong; Wei, Qinglai

    2015-01-01

    Highlights: • The algorithm is developed in the two-household energy management environment. • We develop the absent energy penalty cost for the first time. • The algorithm has ability to keep adapting in real-time operations. • Its application can lower total costs and achieve better load balancing. - Abstract: Residential energy scheduling is a hot topic nowadays in the background of energy saving and environmental protection worldwide. To achieve this objective, a new residential energy scheduling algorithm is developed for energy management, based on action dependent heuristic dynamic programming. The algorithm works under the circumstance of residential real-time pricing and two adjacent housing units with energy inter-exchange, which can reduce the overall cost and enhance renewable energy efficiency after long-term operation. It is designed to obtain the optimal control policy to manage the directions and amounts of electricity energy flux. The algorithm’s architecture is mainly constructed based on neural networks, denoting the learned characteristics in the linkage of layers. To get close to real situations, many constraints such as maximum charging/discharging power of batteries are taken into account. The absent energy penalty cost is developed for the first time as a part of the performance index function. When the environment changes, the residential energy scheduling algorithm gains new features and keeps adapting in real-time operations. Simulation results show that the developed algorithm is beneficial to energy conversation

  3. Novel scatter compensation with energy and spatial dependent corrections in positron emission tomography

    International Nuclear Information System (INIS)

    Guerin, Bastien

    2010-01-01

    We developed and validated a fast Monte Carlo simulation of PET acquisitions based on the SimSET program modeling accurately the propagation of gamma photons in the patient as well as the block-based PET detector. Comparison of our simulation with another well validated code, GATE, and measurements on two GE Discovery ST PET scanners showed that it models accurately energy spectra (errors smaller than 4.6%), the spatial resolution of block-based PET scanners (6.1%), scatter fraction (3.5%), sensitivity (2.3%) and count rates (12.7%). Next, we developed a novel scatter correction incorporating the energy and position of photons detected in list-mode. Our approach is based on the reformulation of the list-mode likelihood function containing the energy distribution of detected coincidences in addition to their spatial distribution, yielding an EM reconstruction algorithm containing spatial and energy dependent correction terms. We also proposed using the energy in addition to the position of gamma photons in the normalization of the scatter sinogram. Finally, we developed a method for estimating primary and scatter photons energy spectra from total spectra detected in different sectors of the PET scanner. We evaluated the accuracy and precision of our new spatio-spectral scatter correction and that of the standard spatial correction using realistic Monte Carlo simulations. These results showed that incorporating the energy in the scatter correction reduces bias in the estimation of the absolute activity level by ∼ 60% in the cold regions of the largest patients and yields quantification errors less than 13% in all regions. (author)

  4. Effects of symmetry energy and momentum dependent interaction on low-energy reaction mechanisms

    Directory of Open Access Journals (Sweden)

    Zheng H.

    2016-01-01

    Full Text Available We study the dipole response associated with the Pygmy Dipole Resonance (PDR and the Isovector Giant Dipole Resonance (IVGDR, in connection with specific properties of the nuclear effective interaction (symmetry energy and momentum dependence, in the neutron-rich systems 68Ni, 132Sn and 208Pb. We perform our investigation within a microscopic transport model based on the Landau-Vlasov kinetic equation.We observe that the peak energies of PDR and IVGDR are shifted to higher values when employing momentum dependent interactions, with respect to the results obtained neglecting momentum dependence. The calculated energies are close to the experimental values and similar to the results obtained in Hartree-Fock (HF with Random Phase Approximation (RPA calculations.

  5. Bias magnetic field and test period dependences of direct and converse magnetoelectric hysteresis of tri-layered magnetoelectric composite

    Science.gov (United States)

    Zhou, Yun; Li, Xiao-Hong; Wang, Jian-Feng; Zhou, Hao-Miao; Cao, Dan; Jiao, Zhi-Wei; Xu, Long; Li, Qi-Hao

    2018-04-01

    The direct and converse magnetoelectric hysteresis behavior for a tri-layered composite has been comparatively investigated and significant similarities have been observed. The results show that both the direct and converse magnetoelectric hysteresis is deeply affected by the bias magnetic field and test period. The test time hysteresis caused by a fast varying bias magnetic field can be reduced by prolonging the test period. The observed coercive field, remanence, and ratio of remanence of the direct and converse magnetoelectric effects with the test period obey an exponential decay law. A hysteretic nonlinear magnetoelectric theoretical model for the symmetrical tri-layered structure has been proposed based on a nonlinear constitutive model and pinning effect. The numerical calculation shows that the theoretical results are in good agreement with the experimental results. These findings not only provide insight into the examination and practical applications of magnetoelectric materials, but also propose a theoretical frame for studying the hysteretic characteristics of the magnetoelectric effect.

  6. Bias voltage dependence of molecular orientation of dialkyl ketone and fatty acid alkyl ester at the liquid–graphite interface

    Energy Technology Data Exchange (ETDEWEB)

    Hibino, Masahiro, E-mail: hibino@mmm.muroran-it.ac.jp [Department of Applied Sciences, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran 050-8585 (Japan); Tsuchiya, Hiroshi [Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)

    2014-10-30

    Graphical abstract: - Highlights: • Self-assembled monolayers (SAMs) of 18-pentatriacontanone (as ketone) and stearyl stearate (as ester) were formed on a graphite surface at the liquid–solid interface. • Orientations of the molecules in SAMs on the substrate were studied by scanning tunneling microscopy. • A perpendicular carbon skeleton-plane orientation with the CO pointing up on the surface is favorable for a substrate with negative charge and vice versa. - Abstract: Molecular orientations of self-assembled 18-pentatriacontanone (as ketone) and stearyl stearate (as ester) monolayers adsorbed on a graphite surface were studied by scanning tunneling microscopy (STM) at the liquid–solid interface. At a positive sample bias, the central areas of the dialkyl ketone and fatty acid alkyl ester molecules in the STM images appeared as two bright regions on both sides of a dim spot and a bright region on one side of a dim spot, whereas at a negative sample bias, the areas appeared dim. This contrast variation indicates that a perpendicular carbon skeleton-plane orientation with the CO pointing down on the surface is favorable for a substrate with positive charge and vice versa because of the greater electronegativity of the oxygen atom. Upon the bias voltage reversal, the delay time for the STM image contrast change in the region was observed on a time scale of minutes. The difference between the delay time lengths for the direction of bias polarity change indicates that the perpendicular configuration with CO pointing up is more stable than that with CO pointing down. These results indicate that the use of an electric field along a direction vertical to the monolayer on the substrate provides control over the orientations of the molecules between two stable states at the liquid–solid interface.

  7. A G Protein-biased Designer G Protein-coupled Receptor Useful for Studying the Physiological Relevance of Gq/11-dependent Signaling Pathways.

    Science.gov (United States)

    Hu, Jianxin; Stern, Matthew; Gimenez, Luis E; Wanka, Lizzy; Zhu, Lu; Rossi, Mario; Meister, Jaroslawna; Inoue, Asuka; Beck-Sickinger, Annette G; Gurevich, Vsevolod V; Wess, Jürgen

    2016-04-08

    Designerreceptorsexclusivelyactivated by adesignerdrug (DREADDs) are clozapine-N-oxide-sensitive designer G protein-coupled receptors (GPCRs) that have emerged as powerful novel chemogenetic tools to study the physiological relevance of GPCR signaling pathways in specific cell types or tissues. Like endogenous GPCRs, clozapine-N-oxide-activated DREADDs do not only activate heterotrimeric G proteins but can also trigger β-arrestin-dependent (G protein-independent) signaling. To dissect the relative physiological relevance of G protein-mediatedversusβ-arrestin-mediated signaling in different cell types or physiological processes, the availability of G protein- and β-arrestin-biased DREADDs would be highly desirable. In this study, we report the development of a mutationally modified version of a non-biased DREADD derived from the M3muscarinic receptor that can activate Gq/11with high efficacy but lacks the ability to interact with β-arrestins. We also demonstrate that this novel DREADD is activein vivoand that cell type-selective expression of this new designer receptor can provide novel insights into the physiological roles of G protein (Gq/11)-dependentversusβ-arrestin-dependent signaling in hepatocytes. Thus, this novel Gq/11-biased DREADD represents a powerful new tool to study the physiological relevance of Gq/11-dependent signaling in distinct tissues and cell types, in the absence of β-arrestin-mediated cellular effects. Such studies should guide the development of novel classes of functionally biased ligands that show high efficacy in various pathophysiological conditions but display a reduced incidence of side effects. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. The Comparison of Attention Biases to Opiates in Substance Dependent and Treated Clients of Therapeutic Clinics and Narcotics Anonymous Memberships

    Directory of Open Access Journals (Sweden)

    Javad Enayat

    2012-11-01

    Full Text Available Aim: The purpose of this study was to compare the attention bias about tempting incentives related to opium materials in treated, addicted and normal people. Duration of consumption and treating were also considered. Method: In this causal-comparative study population was all addicted people who were referred to the rehabilitation offices, addiction treatment clinic, rebirthing centers and Narcotics Anonymous of East Azerbaijan. This study consisted of five groups of men, including addicted to opium materials which are divided into two groups namely: long consumption period and people with short consumption period, also, treated people including long term treated and short term treated, and a normal control group. Altogether, 103 selected people were studied. Sample groups were similar in terms of age, education, and sex. For measuring attention bias towards tempting stimuli related opiates, a words recognition test was used. This test included three subtests and one recognition test. The recognition scores for the three categories of words were measured. Results: The findings indicated that there was a difference in attention against opium material incentives between control group and the mild and severe consumers groups. Also there were significant differences between treated people with the short time distance and control group, and control group had less temptation and biases in comparison to the other groups. Finally, those who have mild consumption are threatened more in comparison with the control group. Conclusion: The findings have applied implications.

  9. Doping dependent magnetism and exchange bias in CaMn{sub 1−x}W{sub x}O{sub 3} manganites

    Energy Technology Data Exchange (ETDEWEB)

    Markovich, V., E-mail: markoviv@bgu.ac.il; Gorodetsky, G. [Department of Physics, Ben-Gurion University of the Negev, 84105 Beer-Sheva (Israel); Fita, I. [Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02-668 Warsaw (Poland); Donetsk Institute for Physics and Technology, National Academy of Sciences, 83114 Donetsk (Ukraine); Wisniewski, A.; Puzniak, R. [Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02-668 Warsaw (Poland); Mogilyansky, D. [The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Naumov, S. V.; Mostovshchikova, E. V.; Telegin, S. V. [Institute of Metal Physics, Ural Branch of RAS, Kovalevskaya Street 18, Ekaterinburg 620990 (Russian Federation); Jung, G. [Department of Physics, Ben-Gurion University of the Negev, 84105 Beer-Sheva (Israel); Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02-668 Warsaw (Poland)

    2014-09-07

    Magnetic properties of CaMn{sub 1−x}W{sub x}O{sub 3} (0 ≤ x ≤ 0.1) have been investigated, and the research was focused on the exchange bias (EB) phenomenon in CaMn{sub 0.93}W{sub 0.07}O{sub 3}. Magnetic ground state was found to be dependent on tungsten doping level and the following states were distinguished: (i) G-type antiferromagnetic (AFM) state with a weak ferromagnetic (FM) component at x = 0 and 0.04; (ii) mostly orbitally ordered C-type AFM at x = 0.07 and 0.1. For the studied manganites, spontaneous magnetization increases sharply with increasing doping level reaching M{sub 0} ≈ 9.5 emu/g at T = 10 K for x = 0.04, and then decreases rapidly reaching zero for x = 0.1. Exchange bias effect, manifested by vertical and horizontal shifts in the hysteresis loop for field cooled sample, has been observed in CaMn{sub 0.93}W{sub 0.07}O{sub 3}. Exchange bias field, coercivity, remanence asymmetry, and magnetic coercivity depend strongly on temperature, cooling field, and maximal measuring field. Horizontal and vertical shifts of magnetization loop sharply decrease with increasing temperature and vanish above 70 K, whereas coercivity and magnetic coercivity disappear only above 100 K (temperature of transition to the G-type AFM state). The exchange bias field H{sub EB} increases with increasing cooling field H{sub cool} and goes through a broad maximum at 40 kOe, while the remanence asymmetry increases monotonously in the entire investigated cooling field range, up to 50 kOe. For the compound with x = 0.07, the size of the FM regions ≈2 nm was estimated from the dependence of exchange bias field H{sub EB} upon H{sub cool}. It is suggested that the exchange bias originates from interface exchange coupling between small FM clusters and the G-type AFM phase inside the primary C-type orbitally ordered AFM phase.

  10. Low energy neutron scattering for energy dependent cross sections. General considerations

    Energy Technology Data Exchange (ETDEWEB)

    Rothenstein, W; Dagan, R [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Mechanical Engineering

    1996-12-01

    We consider in this paper some aspects related to neutron scattering at low energies by nuclei which are subject to thermal agitation. The scattering is determined by a temperature dependent joint scattering kernel, or the corresponding joint probability density, which is a function of two variables, the neutron energy after scattering, and the cosine of the angle of scattering, for a specified energy and direction of motion of the neutron, before the interaction takes place. This joint probability density is easy to calculate, when the nucleus which causes the scattering of the neutron is at rest. It can be expressed by a delta function, since there is a one to one correspondence between the neutron energy change, and the cosine of the scattering angle. If the thermal motion of the target nucleus is taken into account, the calculation is rather more complicated. The delta function relation between the cosine of the angle of scattering and the neutron energy change is now averaged over the spectrum of velocities of the target nucleus, and becomes a joint kernel depending on both these variables. This function has a simple form, if the target nucleus behaves as an ideal gas, which has a scattering cross section independent of energy. An energy dependent scattering cross section complicates the treatment further. An analytic expression is no longer obtained for the ideal gas temperature dependent joint scattering kernel as a function of the neutron energy after the interaction and the cosine of the scattering angle. Instead the kernel is expressed by an inverse Fourier Transform of a complex integrand, which is averaged over the velocity spectrum of the target nucleus. (Abstract Truncated)

  11. A Self-Biased Active Voltage Doubler for Energy Harvesting Systems

    KAUST Repository

    Tayyab, Umais; Alzaher, Hussain A.

    2017-01-01

    An active voltage doubler utilizing a single supply op-amp for energy harvesting system is presented. The proposed doubler is used for rectification process to achieve both acceptably high power conversion efficiency (PCE) and large rectified DC

  12. Experimental high Energy Physics in Spain: The first forty years, a personal and biased view

    International Nuclear Information System (INIS)

    Aguilar-Benitez, M.

    2005-01-01

    In this contribution I present a brief description of the evolution of Experimental High Energy Physics in spain during the last forth years and a personal assessment of the present situation. (Author)

  13. Energy and zenith angle dependence of atmospheric muons

    CERN Document Server

    Maeda, K

    1973-01-01

    The recently proposed new process for energetic-muon production in the atmosphere should be tested at Mt. Chacaltaya. Rigorous calculations of zenith-angle distribution of atmospheric muons have been made for the altitude of 5200 m above sea level with energy range from 100 GeV to 100 TeV and for zenith angles from 0 degrees to 92.3 degrees . Calculations are based on the extension of the Chapman function to the case of a non-isothermal atmosphere, taking into account (i) energy- dependent nuclear-interaction mean free path of cosmic-ray hadrons in air, (ii) different magnitudes of photonuclear cross-section in the energy-loss process of muons in the atmosphere, (iii) contributions of atmospheric muons arriving below the horizontal directions, and (iv) atmospheric structure and geomagnetic deflection. Results are compared with those corresponding to sea level. Range straggling, particularly its effect on horizontally incident muons, is investigated by Monte Carlo calculation, indicating that its effects and t...

  14. Energy dependence of radiation interaction parameters of some organic compounds

    Science.gov (United States)

    Singh, Mohinder; Tondon, Akash; Sandhu, B. S.; Singh, Bhajan

    2018-04-01

    Gamma rays interact with a material through photoelectric absorption, Compton scattering, Rayleigh scattering and Pair production in the intermediate energy range. The probability of occurrence of a particular type of process depends on the energy of incident gamma rays, atomic number of the material, scattering angle and geometrical conditions. Various radiological parameters for organic compounds, namely ethylene glycol (C2H6O2), propylene glycol (C3H8O2), glycerin (C3H8O3), isoamyl alcohol (C5H12O), butanone (C4H8O), acetophenone (C8H8O2), cyclohexanone (C6H10O), furfural (C5H4O2), benzaldehyde (C7H6O), cinnamaldehyde (C9H8O), glutaraldehyde (C5H8O2), aniline (C6H7N), benzyl amine (C6H7N), nitrobenzene (C6H5NO2), ethyl benzene (C8H10), ethyl formate (C3H6O2) and water (H2O) are presented at 81, 122, 356 and 511 keV energies employing NaI(Tl) scintillation detector in narrow-beam transmission geometry. The radiation interaction parameters such as mass attenuation, molar extinction and mass energy absorption coefficients, half value layer, total atomic and effective electronic cross-sections and CT number have been evaluated for these organic compounds. The general trend of values of mass attenuation coefficients, half value layer, molar extinction coefficients, total atomic and effective electronic cross-sections and mass energy absorption coefficients shows a decrease with increase in incident gamma photon energy. The values of CT number are found to increases linearly with increase of effective atomic number (Zeff). The variation in CT number around Zeff ≈ 3.3 shows the peak like structure with respect to water and the correlation between CT number and linear attenuation coefficient is about 0.99. Appropriate equations are fitted to these experimentally determined parameters for the organic compounds at incident photon energy ranging from 81 keV to 511 keV used in the present study. Experimental values are compared with the theoretical data obtained using Win

  15. Are Health State Valuations from the General Public Biased? A Test of Health State Reference Dependency Using Self-assessed Health and an Efficient Discrete Choice Experiment.

    Science.gov (United States)

    Jonker, Marcel F; Attema, Arthur E; Donkers, Bas; Stolk, Elly A; Versteegh, Matthijs M

    2017-12-01

    Health state valuations of patients and non-patients are not the same, whereas health state values obtained from general population samples are a weighted average of both. The latter constitutes an often-overlooked source of bias. This study investigates the resulting bias and tests for the impact of reference dependency on health state valuations using an efficient discrete choice experiment administered to a Dutch nationally representative sample of 788 respondents. A Bayesian discrete choice experiment design consisting of eight sets of 24 (matched pairwise) choice tasks was developed, with each set providing full identification of the included parameters. Mixed logit models were used to estimate health state preferences with respondents' own health included as an additional predictor. Our results indicate that respondents with impaired health worse than or equal to the health state levels under evaluation have approximately 30% smaller health state decrements. This confirms that reference dependency can be observed in general population samples and affirms the relevance of prospect theory in health state valuations. At the same time, the limited number of respondents with severe health impairments does not appear to bias social tariffs as obtained from general population samples. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Thickness and bilayer number dependence on exchange bias in ferromagnetic/antiferromagnetic multilayers based on La{sub 1−x}Ca{sub x}MnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Restrepo-Parra, E., E-mail: erestrepopa@unal.edu.co [Departamento de Física y Química, Universidad Nacional de Colombia-Sede Manizales, A.A. 127 Manizales (Colombia); Agudelo-Giraldo, J.D. [Departamento de Física y Química, Universidad Nacional de Colombia-Sede Manizales, A.A. 127 Manizales (Colombia); Grupo de Investigación y Desarrollo en Informática y Telecomunicaciones, Universidad de Manizales, Manizales (Colombia); Restrepo, J. [Grupo de Magnetismo y Simulación, Instituto de Física, Universidad de Antioquia, A.A. 1226 Medellín (Colombia)

    2014-05-01

    In this work, simulations of ferromagnetic/antiferromagnetic multilayers of La{sub 1−x}Ca{sub x}MnO{sub 3} have been carried out by using the Monte Carlo method combined with the Metropolis algorithm and the classical Heisenberg model. In the Hamiltonian we have considered three contributions: nearest neighbor exchange interaction, magnetocrystalline anisotropy and Zeeman interaction. Samples were built by including three types of Mn ions depending on their valence state and type of ionic orbital. Both the number of layers and the antiferromagnetic layer thickness influence on the exchange bias phenomenon are analyzed. Hysteresis loops results exhibit not only a shift as evidence of exchange bias but also the formation of plateaus or steps caused by the presence of more than one interface and the low layers thickness. Each layer presents a strong magnetic behavior because the magneto static energy favors formation of multi-domains in contrast with the single-domains of a single layer FM producing one sub-Loop of each domain (each layer). On the other hand, as the number of layers (n) increases, the sub-cycles tend to disappear. As the plateaus disappear, the system is more effective, increasing the coercive and bias fields. Moreover, domain sizes (layers thickness) also affect the shape of the hysteresis loop. On increasing the thickness of the AFM layer, a decrease in the plateaus produced by the uncoupling is generated.

  17. Dependence of Indian monsoon rainfall on moisture fluxes across the Arabian Sea and the impact of coupled model sea surface temperature biases

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Richard C. [Met Office Hadley Centre, Devon (United Kingdom); Turner, Andrew G. [University of Reading, NCAS-Climate, Department of Meteorology, Reading (United Kingdom)

    2012-06-15

    The Arabian Sea is an important moisture source for Indian monsoon rainfall. The skill of climate models in simulating the monsoon and its variability varies widely, while Arabian Sea cold sea surface temperature (SST) biases are common in coupled models and may therefore influence the monsoon and its sensitivity to climate change. We examine the relationship between monsoon rainfall, moisture fluxes and Arabian Sea SST in observations and climate model simulations. Observational analysis shows strong monsoons depend on moisture fluxes across the Arabian Sea, however detecting consistent signals with contemporaneous summer SST anomalies is complicated in the observed system by air/sea coupling and large-scale induced variability such as the El Nino-Southern Oscillation feeding back onto the monsoon through development of the Somali Jet. Comparison of HadGEM3 coupled and atmosphere-only configurations suggests coupled model cold SST biases significantly reduce monsoon rainfall. Idealised atmosphere-only experiments show that the weakened monsoon can be mainly attributed to systematic Arabian Sea cold SST biases during summer and their impact on the monsoon-moisture relationship. The impact of large cold SST biases on atmospheric moisture content over the Arabian Sea, and also the subsequent reduced latent heat release over India, dominates over any enhancement in the land-sea temperature gradient and results in changes to the mean state. We hypothesize that a cold base state will result in underestimation of the impact of larger projected Arabian Sea SST changes in future climate, suggesting that Arabian Sea biases should be a clear target for model development. (orig.)

  18. Energy dependence evaluation of a ZnO detector for diagnostic X-ray beam

    International Nuclear Information System (INIS)

    Valença, C.P.V.; Silveira, M.A.L.; Macedo, M.A.; Santos, M.A.

    2015-01-01

    In the last decades the international organizations of human health and radiation protection have recommended certain care for using X-ray as a diagnosis tool. The current concern is to avoid any type of radiological accident or overdose to the patient. This can be done assessing the parameters of the X-ray equipment and there are various types of detectors available for that: ionizing chamber, semiconductor devices, etc. These detectors must be calibrated so that they can be used for any energy range and such a procedure is correlated with what is called the energy dependence of the detector. In accordance with the stated requirements of IEC 61267, the standard radiation quality beams and irradiation conditions (RQRs) are the tools and techniques for calibrating diagnostic X-Ray instruments and detectors. The purpose of this work is to evaluate the behavior of the energy dependence of a detector fabricated from a zinc oxide (ZnO) nanofilm. A Pantak industrial X-ray equipment was used to generate the RQR radiation quality beams and test three ZnO detector samples. A 6430 sub-femto-ammeter, Keithley, was used to bias the ZnO detector and simultaneously perform the output readings. The results showed that the ZnO device has some increase in its sensitivity to the ionizing radiation as the X-ray effective energy decreases unlike other types of semiconductor electronic devices typically used as an X-ray detector. We can be concluded that, after calibration, the ZnO device can be used as a diagnostic X-ray detector. (author)

  19. Evaluation of the energy dependence of a zinc oxide nanofilm X-ray detector

    International Nuclear Information System (INIS)

    Valenca, C.P.V.; Silveira, M.A.L.; Macedo, M.A.; Santos, L.A.P

    2015-01-01

    International organizations of human health and radiation protection have recommended certain care for using of the X-ray as a diagnosis tool to avoid any type of radiological accident or overdose to the patient. This can be done assessing the parameters of the X-ray equipment and there are various types of detectors available for that: ionizing chamber, electronic semiconductor devices, etc. These detectors must be calibrated so that they can be used for any energy range and such a procedure is correlated with what is called the energy dependence of the detector. In accordance with the stated requirements of IEC 61267, the standard radiation quality beams and irradiation conditions (RQRs) are the tools and techniques for calibrating diagnostic X-Ray instruments and detectors. The purpose of this work is to evaluate the behavior of the energy dependence of a detector fabricated from a zinc oxide (ZnO) nanofilm. A Pantak industrial X-ray equipment was used to generate the RQR radiation quality beams and test three ZnO detector samples. A 6430 sub-femto-ammeter, Keithley, was used to bias the ZnO detector and simultaneously perform the output readings. The results showed that the ZnO device has some increase in its sensitivity to the ionizing radiation as the X-ray effective energy decreases unlike other types of semiconductor electronic devices typically used as an X-ray detector. We can conclude that the ZnO device can be used as a diagnostic X-ray detector with an appropriate calibration. (author)

  20. Correction Technique for Raman Water Vapor Lidar Signal-Dependent Bias and Suitability for Water Wapor Trend Monitoring in the Upper Troposphere

    Science.gov (United States)

    Whiteman, D. N.; Cadirola, M.; Venable, D.; Calhoun, M.; Miloshevich, L; Vermeesch, K.; Twigg, L.; Dirisu, A.; Hurst, D.; Hall, E.; hide

    2012-01-01

    The MOHAVE-2009 campaign brought together diverse instrumentation for measuring atmospheric water vapor. We report on the participation of the ALVICE (Atmospheric Laboratory for Validation, Interagency Collaboration and Education) mobile laboratory in the MOHAVE-2009 campaign. In appendices we also report on the performance of the corrected Vaisala RS92 radiosonde measurements during the campaign, on a new radiosonde based calibration algorithm that reduces the influence of atmospheric variability on the derived calibration constant, and on other results of the ALVICE deployment. The MOHAVE-2009 campaign permitted the Raman lidar systems participating to discover and address measurement biases in the upper troposphere and lower stratosphere. The ALVICE lidar system was found to possess a wet bias which was attributed to fluorescence of insect material that was deposited on the telescope early in the mission. Other sources of wet biases are discussed and data from other Raman lidar systems are investigated, revealing that wet biases in upper tropospheric (UT) and lower stratospheric (LS) water vapor measurements appear to be quite common in Raman lidar systems. Lower stratospheric climatology of water vapor is investigated both as a means to check for the existence of these wet biases in Raman lidar data and as a source of correction for the bias. A correction technique is derived and applied to the ALVICE lidar water vapor profiles. Good agreement is found between corrected ALVICE lidar measurments and those of RS92, frost point hygrometer and total column water. The correction is offered as a general method to both quality control Raman water vapor lidar data and to correct those data that have signal-dependent bias. The influence of the correction is shown to be small at regions in the upper troposphere where recent work indicates detection of trends in atmospheric water vapor may be most robust. The correction shown here holds promise for permitting useful upper

  1. Simulations of Polarization Levels and Spin Tune Biases in High Energy Leptons Storage Rings

    Energy Technology Data Exchange (ETDEWEB)

    Gianfelice, E. [Fermilab

    2016-01-01

    The use of resonant depolarization has been suggested for precise beam energy measurements in the 100 km long Future Circular Collider e+e-. The principle behind resonant depolarization is that a vertically polarized beam excited through an oscillating horizontal magnetic field gets depolarized when the excitation frequency is in a given relationship with the beam energy. In this paper the possibility of self- polarized leptons at 45 GeV (Z resonance) and 80 GeV (WW in presence of quadrupole vertical misalignment is investigated.

  2. Effects of acute dopamine precusor depletion on immediate reward selection bias and working memory depend on catechol-O-methyltransferase genotype.

    Science.gov (United States)

    Kelm, Mary Katherine; Boettiger, Charlotte A

    2013-12-01

    Little agreement exists as to acute dopamine (DA) manipulation effects on intertemporal choice in humans. We previously found that catechol-O-methyltransferase (COMT) Val158Met genotype predicts individual differences in immediate reward selection bias among adults. Moreover, we and others have shown that the relationship between COMT genotype and immediate reward bias is inverted in adolescents. No previous pharmacology studies testing DA manipulation effects on intertemporal choice have accounted for COMT genotype, and many have included participants in the adolescent age range (18-21 years) as adults. Moreover, many studies have included female participants without strict cycle phase control, although recent evidence demonstrates that cyclic estradiol elevations interact with COMT genotype to affect DA-dependent cognition. These factors may have interacted with DA manipulations in past studies, potentially occluding detection of effects. Therefore, we predicted that, among healthy male adults (ages 22-40 years), frontal DA tone, as indexed by COMT genotype, would interact with acute changes in DA signaling to affect intertemporal choice. In a double-blind, placebo-controlled design, we decreased central DA via administration of an amino acid beverage deficient in the DA precursors, phenylalanine and tyrosine, and tested effects on immediate reward bias in a delay-discounting (DD) task and working memory (WM) in an n-back task. We found no main effect of beverage on DD or WM performance but did find significant beverage*genotype effects. These results suggest that the effect of DA manipulations on DD depends on individual differences in frontal DA tone, which may have impeded some past efforts to characterize DA's role in immediate reward bias in humans.

  3. Internet-based attentional bias modification training as add-on to regular treatment in alcohol and cannabis dependent outpatients: a study protocol of a randomized control trial.

    Science.gov (United States)

    Heitmann, Janika; van Hemel-Ruiter, Madelon E; Vermeulen, Karin M; Ostafin, Brian D; MacLeod, Colin; Wiers, Reinout W; DeFuentes-Merillas, Laura; Fledderus, Martine; Markus, Wiebren; de Jong, Peter J

    2017-05-23

    The automatic tendency to attend to and focus on substance-related cues in the environment (attentional bias), has been found to contribute to the persistence of addiction. Attentional bias modification (ABM) interventions might, therefore, contribute to treatment outcome and the reduction of relapse rates. Based on some promising research findings, we designed a study to test the clinical relevance of ABM as an add-on component of regular intervention for alcohol and cannabis patients. The current protocol describes a study which will investigate the effectiveness and cost-effectiveness of a newly developed home-delivered, multi-session, internet-based ABM (iABM) intervention as an add-on to treatment as usual (TAU). TAU consists of cognitive behavioural therapy-based treatment according to the Dutch guidelines for the treatment of addiction. Participants (N = 213) will be outpatients from specialized addiction care institutions diagnosed with alcohol or cannabis dependency who will be randomly assigned to one of three conditions: TAU + iABM; TAU + placebo condition; TAU-only. Primary outcome measures are substance use, craving, and rates of relapse. Changes in attentional bias will be measured to investigate whether changes in primary outcome measures can be attributed to the modification of attentional bias. Indices of cost-effectiveness and secondary physical and psychological complaints (depression, anxiety, and stress) are assessed as secondary outcome measures. This randomized control trial will be the first to investigate whether a home-delivered, multi-session iABM intervention is (cost-) effective in reducing relapse rates in alcohol and cannabis dependency as an add-on to TAU, compared with an active and a waiting list control group. If proven effective, this ABM intervention could be easily implemented as a home-delivered component of current TAU. Netherlands Trial Register, NTR5497 , registered on 18th September 2015.

  4. Personnel β-dosimetry method for reducing energy dependence

    International Nuclear Information System (INIS)

    Gesell, T.F.; Jones, D.E.; Gupta, V.P.; Kalbeitzer, F.L.; Cusimano, J.P.

    1979-03-01

    Current practices for the measurement of skin dose are reviewed and found to be inadequate. The current INEL dosimeter was examined for systematic and random error. Systematic (i.e., variation with energy) error was found to range over a factor of 10 while the random error was reasonably small for the larger β/γ ratios. Other designs with thicker windows as is more common would show even larger systematic errors. Various methods for improving beta dosimetry were reviewed. A new dosimeter design utilizing three chips, each having a window of difference thickness, was proposed. According to the calculations, this dosimeter should markedly reduce systematic error but will introduce somewhat more random error. Preliminary measurements were carried out related to angular dependence and charged particle equilibrium. The proposed dosimeter design was tested with betas from a uranium slab. The average of the seven results was in excellent agreement with the known dose rate and the standard deviation of the result was 16%

  5. Dose energy dependence in proton imaging with thin detector

    Energy Technology Data Exchange (ETDEWEB)

    Denyak, V.V., E-mail: denyak@gmail.com [National Science Centre Kharkov Institute of Physics and Technology, St. Akademicheskaya 1, Kharkov 61108 (Ukraine); Federal University of Technology - Parana, Av. Sete de Setembro 3165, Curitiba 80230-901 (Brazil); Schelin, H.R. [Pele Pequeno Principe Research Institute, Av. Silva Jardim 1632, Curitiba 80250-200 (Brazil); Federal University of Technology - Parana, Av. Sete de Setembro 3165, Curitiba 80230-901 (Brazil); Silva, R.C.L.; Kozuki, C.; Paschuk, S.A.; Milhoretto, E. [Federal University of Technology - Parana, Av. Sete de Setembro 3165, Curitiba 80230-901 (Brazil)

    2012-07-15

    Since the earliest works proposing the use of protons for imaging, the main advantage of protons over X-rays was expected to be a result of the specific property of the proton flux dropping off very steeply at the end of the particle range. This idea was declared but was not checked. In the present work, this assumption was investigated using the Monte Carlo simulation for the case of registration of protons with a thin detector. - Highlights: Black-Right-Pointing-Pointer Principal idea of proton imaging 'to work at the end of the range' was tested. Black-Right-Pointing-Pointer The case of thin detector was investigated. Black-Right-Pointing-Pointer The dose energy dependence was calculated using computer simulation.

  6. Dependable Benchmarking for Storage Systems in High-Energy Physics

    CERN Document Server

    Fleri Soler, Edward

    2017-01-01

    In high-energy physics, storage systems play a crucial role to store and secure very valuable data produced by complex experiments. The effectiveness and efficiency of data acquisition systems of such experiments depends directly on those of these storage systems. Coping with present day rates and reliability requirements of such experiments implies operating high-performance hardware under the best possible conditions, with a broad set of hardware and software parameters existing along the hierarchical levels, from networks down to drives. An extensive number of tests are required for the tuning of parameters to achieve optimised I/O operations. Current approaches to I/O optimisation generally consist of manual test execution and result taking. This approach lacks appropriate modularity, durability and reproducibility, attainable through dedicated testing facilities. The aim of this project is to conceive a user-friendly, dedicated storage benchmarking tool for the improved comparison of I/O parameters in re...

  7. Directional dependence of the threshold displacement energies in metal oxides

    Science.gov (United States)

    Cowen, Benjamin J.; El-Genk, Mohamed S.

    2017-12-01

    Molecular dynamics (MD) simulations are performed to investigate the directional dependence and the values of the threshold energies (TDEs) for the displacements of the oxygen and metal atoms and for producing stable Frenkel pairs in five metal oxides of Cr2O3, Al2O3, TiO2, SiO2, and MgO. The TDEs for the Frenkel pairs and atoms displacement are calculated in 66 crystallographic directions, on both the anion and cation sublattices. The performed simulations are for metal and oxygen PKA energies up to 350 and 400 eV, respectively. The calculated probability distributions for the atoms displacement and average number of Frenkel pairs produced in the different oxides are compared. The results revealed unique symmetrical patterns of the TDEs for the displacement of the atoms and the formation of stable Frenkel pairs, confirming the strong dependence on the direction and the crystalline structure of the oxides. Results also showed that the formation of stable Frenkel pairs is associated with the displacements of the PKAs and/or of the SKAs. The probabilities of the TDEs for the displacement of the oxygen and metal PKAs are consistently lower than those of the atoms in the crystal. In SiO2, TDEs for the displacement of oxygen and metal atoms and those for the formation of stable Frenkel pairs are the lowest, while those in TiO2 are among the highest. The results for Cr2O3 and Al2O3, which have the same crystal structure, are similar. The calculated TDEs for MgO, Al2O3 and TiO2 are generally in good agreement with the experimental values and the probability distributions of the TDEs for the PKAs in TiO2 are in good agreement with reported MD simulation results.

  8. Electron transfer in organic glass. Distance and energy dependence

    International Nuclear Information System (INIS)

    Krongauz, V.V.

    1992-01-01

    The authors have investigated the distance and energy dependence of electron transfer in rigid organic glasses containing randomly dispersed electron donor and electron acceptor molecules. Pulsed radiolysis by an electron beam from a linear accelerator was used for ionization resulting in charge deposition on donor molecules. The disappearance kinetics of donor radical anions due to electron transfer to acceptor was monitored spectroscopically by the change in optical density at the wavelength corresponding to that of donor radical anion absorbance. It was found that the rate of the electron transfer observed experimentally was higher than that computed using the Marcus-Levich theory assuming that the electron-transfer activation barrier is equal to the binding energy of electron on the donor molecule. This discrepancy between the experimental and computed results suggests that the open-quotes inertclose quotes media in which electron-transfer reaction takes place may be participating in the process, resulting in experimentally observed higher electron-transfer rates. 32 refs., 3 figs., 2 tabs

  9. Variable Entry Biased Paracentric Hemispherical Deflector: Experimental results on energy resolution for different entry positions

    Science.gov (United States)

    Dogan, Mevlut; Ulu, Melike; Gennerakis, Giannis; Zouros, Theo J. M.

    2014-04-01

    A new hemispherical deflector analyzer (HDA) which is designed for electron energy analysis in atomic collisions has been constructed and tested. Using the crossed beam technique at the electron spectrometer, test measurements were performed for electron beam (200 eV) - Helium atoms interactions. These first experimental results show that the paracentric entries give almost twice as good resolution as that for the conventional entry. Supporting simulations of the entire lens+HDA spectrometer are found in relatively good agreement with experiment.

  10. Experimental energy resolution of a paracentric hemispherical deflector analyzer for different entry positions and bias

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, M.; Ulu, M. [eCOL Laboratory, Department of Physics, Science and Arts Faculty, Afyon Kocatepe University, 03200 Afyonkarahisar (Turkey); Gennarakis, G. G.; Zouros, T. J. M. [Atomic Collisions and Electron Spectroscopy Laboratory, Department of Physics, University of Crete, P.O. Box 2208, 71003 Heraklion, Crete (Greece)

    2013-04-15

    A specially designed hemispherical deflector analyzer (HDA) with 5-element input lens having a movable entry position R{sub 0} suitable for electron energy analysis in atomic collisions was constructed and tested. The energy resolution of the HDA was experimentally determined for three different entry positions R{sub 0}= 84, 100, 112 mm as a function of the nominal entry potential V(R{sub 0}) under pre-retardation conditions. The resolution for the (conventional) entry at the mean radius R{sub 0}= 100 mm was found to be a factor of 1.6-2 times worse than the resolution for the two (paracentric) positions R{sub 0}= 84 and 112 mm at particular values of V(R{sub 0}). These results provide the first experimental verification and a proof of principle of the utility of such a paracentric HDA, while demonstrating its advantages over the conventional HDA: greater dispersion with reduced angular aberrations resulting in better energy resolution without the use of any additional fringing field correction electrodes. Supporting simulations of the entire lens plus HDA spectrometer are also provided and mostly found to be within 20%-30% of experimental values. The paracentric HDA is expected to provide a lower cost and/or more compact alternative to the conventional HDA particularly useful in modern applications utilizing a position sensitive detector.

  11. Experimental energy resolution of a paracentric hemispherical deflector analyzer for different entry positions and bias

    International Nuclear Information System (INIS)

    Dogan, M.; Ulu, M.; Gennarakis, G. G.; Zouros, T. J. M.

    2013-01-01

    A specially designed hemispherical deflector analyzer (HDA) with 5-element input lens having a movable entry position R 0 suitable for electron energy analysis in atomic collisions was constructed and tested. The energy resolution of the HDA was experimentally determined for three different entry positions R 0 = 84, 100, 112 mm as a function of the nominal entry potential V(R 0 ) under pre-retardation conditions. The resolution for the (conventional) entry at the mean radius R 0 = 100 mm was found to be a factor of 1.6-2 times worse than the resolution for the two (paracentric) positions R 0 = 84 and 112 mm at particular values of V(R 0 ). These results provide the first experimental verification and a proof of principle of the utility of such a paracentric HDA, while demonstrating its advantages over the conventional HDA: greater dispersion with reduced angular aberrations resulting in better energy resolution without the use of any additional fringing field correction electrodes. Supporting simulations of the entire lens plus HDA spectrometer are also provided and mostly found to be within 20%–30% of experimental values. The paracentric HDA is expected to provide a lower cost and/or more compact alternative to the conventional HDA particularly useful in modern applications utilizing a position sensitive detector.

  12. Experimental energy resolution of a paracentric hemispherical deflector analyzer for different entry positions and bias

    Science.gov (United States)

    Dogan, M.; Ulu, M.; Gennarakis, G. G.; Zouros, T. J. M.

    2013-04-01

    A specially designed hemispherical deflector analyzer (HDA) with 5-element input lens having a movable entry position R0 suitable for electron energy analysis in atomic collisions was constructed and tested. The energy resolution of the HDA was experimentally determined for three different entry positions R0 = 84, 100, 112 mm as a function of the nominal entry potential V(R0) under pre-retardation conditions. The resolution for the (conventional) entry at the mean radius R0 = 100 mm was found to be a factor of 1.6-2 times worse than the resolution for the two (paracentric) positions R0 = 84 and 112 mm at particular values of V(R0). These results provide the first experimental verification and a proof of principle of the utility of such a paracentric HDA, while demonstrating its advantages over the conventional HDA: greater dispersion with reduced angular aberrations resulting in better energy resolution without the use of any additional fringing field correction electrodes. Supporting simulations of the entire lens plus HDA spectrometer are also provided and mostly found to be within 20%-30% of experimental values. The paracentric HDA is expected to provide a lower cost and/or more compact alternative to the conventional HDA particularly useful in modern applications utilizing a position sensitive detector.

  13. Density dependence of the nuclear energy-density functional

    Science.gov (United States)

    Papakonstantinou, Panagiota; Park, Tae-Sun; Lim, Yeunhwan; Hyun, Chang Ho

    2018-01-01

    Background: The explicit density dependence in the coupling coefficients entering the nonrelativistic nuclear energy-density functional (EDF) is understood to encode effects of three-nucleon forces and dynamical correlations. The necessity for the density-dependent coupling coefficients to assume the form of a preferably small fractional power of the density ρ is empirical and the power is often chosen arbitrarily. Consequently, precision-oriented parametrizations risk overfitting in the regime of saturation and extrapolations in dilute or dense matter may lose predictive power. Purpose: Beginning with the observation that the Fermi momentum kF, i.e., the cubic root of the density, is a key variable in the description of Fermi systems, we first wish to examine if a power hierarchy in a kF expansion can be inferred from the properties of homogeneous matter in a domain of densities, which is relevant for nuclear structure and neutron stars. For subsequent applications we want to determine a functional that is of good quality but not overtrained. Method: For the EDF, we fit systematically polynomial and other functions of ρ1 /3 to existing microscopic, variational calculations of the energy of symmetric and pure neutron matter (pseudodata) and analyze the behavior of the fits. We select a form and a set of parameters, which we found robust, and examine the parameters' naturalness and the quality of resulting extrapolations. Results: A statistical analysis confirms that low-order terms such as ρ1 /3 and ρ2 /3 are the most relevant ones in the nuclear EDF beyond lowest order. It also hints at a different power hierarchy for symmetric vs. pure neutron matter, supporting the need for more than one density-dependent term in nonrelativistic EDFs. The functional we propose easily accommodates known or adopted properties of nuclear matter near saturation. More importantly, upon extrapolation to dilute or asymmetric matter, it reproduces a range of existing microscopic

  14. CTCF-dependent chromatin bias constitutes transient epigenetic memory of the mother at the H19-Igf2 imprinting control region in prospermatogonia.

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Lee

    2010-11-01

    Full Text Available Genomic imprints-parental allele-specific DNA methylation marks at the differentially methylated regions (DMRs of imprinted genes-are erased and reestablished in germ cells according to the individual's sex. Imprint establishment at paternally methylated germ line DMRs occurs in fetal male germ cells. In prospermatogonia, the two unmethylated alleles exhibit different rates of de novo methylation at the H19/Igf2 imprinting control region (ICR depending on parental origin. We investigated the nature of this epigenetic memory using bisulfite sequencing and allele-specific ChIP-SNuPE assays. We found that the chromatin composition in fetal germ cells was biased at the ICR between the two alleles with the maternally inherited allele exhibiting more H3K4me3 and less H3K9me3 than the paternally inherited allele. We determined genetically that the chromatin bias, and also the delayed methylation establishment in the maternal allele, depended on functional CTCF insulator binding sites in the ICR. Our data suggest that, in primordial germ cells, maternally inherited allele-specific CTCF binding sets up allele-specific chromatin differences at the ICR. The erasure of these allele-specific chromatin marks is not complete before the process of de novo methylation imprint establishment begins. CTCF-dependent allele-specific chromatin composition imposes a maternal allele-specific delay on de novo methylation imprint establishment at the H19/Igf2 ICR in prospermatogonia.

  15. Observation of bias-dependent noise sources in a TiOx/TiOy bipolar resistive switching frame

    International Nuclear Information System (INIS)

    Hyung Kim, Joo; Rahm Lee, Ah; Cheol Bae, Yoon; Ho Baek, Kwang; Sik Im, Hyun; Pyo Hong, Jin

    2014-01-01

    We report the conduction features associated with the evolution of oxygen ions (or vacancies) under bias for a TiO x (oxygen ion-rich)/TiO y (oxygen ion-deficient) bi-layer cell by identifying low-frequency noise sources. It is believed that a low resistance state enhances the formation of conductive filaments exchanging electrons through a nearest-neighbor hopping process, while a high resistance state (HRS) emphasizes the rupture of conductive filaments inside the insulating TiO x layer and a reduction/oxidation reaction at the oxide interfaces. The high resolution transmission electron microscope images of as-grown and HRS cells are also discussed

  16. Energy dependence of ulrathin LiF-dosemeters for high energy electrons and high energy X-radiation

    International Nuclear Information System (INIS)

    Kupfer, T.

    1977-02-01

    The energy dependence of ultrathin LiF-dosemeters for high energy electrons (5-40 MeV) and high energy X-radiation (6 MV, 42 MV) is experimentally determined. The experimental values are compared to values calculted earlier by other authors. The influence of the thickness of the dosemeters have been considered by comparison of experimental values for 0.03 mm thick dosemeters and theoretical values for 0.13 mm and 0.38 mm thick ones. Also different commersially available dosemeters have been compared by experiments. It is difficult to draw any other conclutions about the energy dependence than that the variation of the relative responce is within +- 3 percent (2S). However the results seems to be sulficient for clinical applications

  17. Energy dependent response of plastic scintillation detectors to photon radiation of low to medium energy.

    Science.gov (United States)

    Ebenau, Melanie; Radeck, Désirée; Bambynek, Markus; Sommer, Holger; Flühs, Dirk; Spaan, Bernhard; Eichmann, Marion

    2016-08-01

    Plastic scintillation detectors are promising candidates for the dosimetry of low- to medium-energy photons but quantitative knowledge of their energy response is a prerequisite for their correct use. The purpose of this study was to characterize the energy dependent response of small scintillation detectors (active volume <1 mm(3)) made from the commonly used plastic scintillator BC400. Different detectors made from BC400 were calibrated at a number of radiation qualities ranging from 10 to 280 kV and at a (60)Co beam. All calibrations were performed at the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany. The energy response in terms of air kerma, dose to water, and dose to the scintillator was determined. Conversion factors from air kerma to dose to water and to dose to the scintillator were derived from Monte Carlo simulations. In order to quantitatively describe the energy dependence, a semiempirical model known as unimolecular quenching or Birks' formula was fitted to the data and from this the response to secondary electrons generated within the scintillator material BC400 was derived. The detector energy response in terms of air kerma differs for different scintillator sizes and different detector casings. It is therefore necessary to take attenuation within the scintillator and in the casing into account when deriving the response in terms of dose to water from a calibration in terms of air kerma. The measured energy response in terms of dose to water for BC400 cannot be reproduced by the ratio of mean mass energy-absorption coefficients for polyvinyl toluene to water but shows evidence of quenching. The quenching parameter kB in Birks' formula was determined to be kB = (12.3 ± 0.9) mg MeV(-1) cm(-2). The energy response was quantified relative to the response to (60)Co which is the common radiation quality for the calibration of therapy dosemeters. The observed energy dependence could be well explained with the

  18. Energy dependent response of plastic scintillation detectors to photon radiation of low to medium energy

    Energy Technology Data Exchange (ETDEWEB)

    Ebenau, Melanie, E-mail: melanie.ebenau@tu-dortmunde.de; Sommer, Holger; Spaan, Bernhard; Eichmann, Marion [Fakultät Physik, Technische Universität Dortmund, Otto-Hahn Str. 4a, 44221 Dortmund (Germany); Radeck, Désirée; Bambynek, Markus [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Flühs, Dirk [Universitätsklinikum Essen, Hufelandstr. 55, 45147 Essen (Germany)

    2016-08-15

    Purpose: Plastic scintillation detectors are promising candidates for the dosimetry of low- to medium-energy photons but quantitative knowledge of their energy response is a prerequisite for their correct use. The purpose of this study was to characterize the energy dependent response of small scintillation detectors (active volume <1 mm{sup 3}) made from the commonly used plastic scintillator BC400. Methods: Different detectors made from BC400 were calibrated at a number of radiation qualities ranging from 10 to 280 kV and at a {sup 60}Co beam. All calibrations were performed at the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany. The energy response in terms of air kerma, dose to water, and dose to the scintillator was determined. Conversion factors from air kerma to dose to water and to dose to the scintillator were derived from Monte Carlo simulations. In order to quantitatively describe the energy dependence, a semiempirical model known as unimolecular quenching or Birks’ formula was fitted to the data and from this the response to secondary electrons generated within the scintillator material BC400 was derived. Results: The detector energy response in terms of air kerma differs for different scintillator sizes and different detector casings. It is therefore necessary to take attenuation within the scintillator and in the casing into account when deriving the response in terms of dose to water from a calibration in terms of air kerma. The measured energy response in terms of dose to water for BC400 cannot be reproduced by the ratio of mean mass energy-absorption coefficients for polyvinyl toluene to water but shows evidence of quenching. The quenching parameter kB in Birks’ formula was determined to be kB = (12.3 ± 0.9) mg MeV{sup −1} cm{sup −2}. Conclusions: The energy response was quantified relative to the response to {sup 60}Co which is the common radiation quality for the calibration of therapy dosemeters. The

  19. Gate-bias and temperature dependence of charge transport in dinaphtho[2,3-b:2‧,3‧-d]thiophene thin-film transistors with MoO3/Au electrodes

    Science.gov (United States)

    Shaari, Safizan; Naka, Shigeki; Okada, Hiroyuki

    2018-04-01

    We investigated the gate-bias and temperature dependence of the voltage-current (V-I) characteristics of dinaphtho[2,3-b:2‧,3‧-d]thiophene with MoO3/Au electrodes. The insertion of the MoO3 layer significantly improved the device performance. The temperature dependent V-I characteristics were evaluated and could be well fitted by the Schottky thermionic emission model with barrier height under forward- and reverse-biased regimes in the ranges of 33-57 and 49-73 meV, respectively. However, at a gate voltage of 0 V, at which a small activation energy was obtained, we needed to consider another conduction mechanism at the grain boundary. From the obtained results, we concluded that two possible conduction mechanisms governed the charge injection at the metal electrode-organic semiconductor interface: the Schottky thermionic emission model and the conduction model in the organic thin-film layer and grain boundary.

  20. A composition dependent energy scale and the determination of the cosmic ray primary mass in the ankle region

    Science.gov (United States)

    Supanitsky, A. D.; Etchegoyen, A.; Melo, D.; Sanchez, F.

    2015-08-01

    At present there are still several open questions about the origin of the ultra high energy cosmic rays. However, great progress in this area has been made in recent years due to the data collected by the present generation of ground based detectors like the Pierre Auger Observatory and Telescope Array. In particular, it is believed that the study of the composition of the cosmic rays as a function of energy can play a fundamental role for the understanding of the origin of the cosmic rays. The observatories belonging to this generation are composed of arrays of surface detectors and fluorescence telescopes. The duty cycle of the fluorescence telescopes is ∼10% in contrast with the ∼100% of the surface detectors. Therefore, the energy calibration of the events observed by the surface detectors is performed by using a calibration curve obtained from a set of high quality events observed in coincidence by both types of detectors. The advantage of this method is that the reconstructed energy of the events observed by the surface detectors becomes almost independent of simulations of the showers because just a small part of the reconstructed energy (the missing energy), obtained from the fluorescence telescopes, comes from simulations. However, the calibration curve obtained in this way depends on the composition of the cosmic rays, which can introduce biases in composition analyses when parameters with a strong dependence on primary energy are considered. In this work we develop an analytical method to study these effects. We consider AMIGA (Auger Muons and Infill for the Ground Array), the low energy extension of the Pierre Auger Observatory corresponding to the surface detectors, to illustrate the use of the method. In particular, we study the biases introduced by an energy calibration dependent on composition on the determination of the mean value of the number of muons, at a given distance to the showers axis, which is one of the parameters most sensitive to

  1. A bias-tunable electron-spin filter based on a two-dimensional electron gas modulated by ferromagnetic-Schottky metal stripes

    Energy Technology Data Exchange (ETDEWEB)

    Lu Jianduo, E-mail: l_j316@163.co [Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081 (China); Li Yunbao; Yun Meijuan [Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081 (China); Zheng Wei [Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077 (China)

    2011-03-28

    We investigate the effect of the bias in an electron-spin filter based on a two-dimensional electron gas modulated by ferromagnetic-Schottky metal stripes. The numerical results show that the electron transmission and the conductance as well as the spin polarization are strongly dependent on the bias applied to the device. - Research highlights: We propose a bias-tunable electron-spin filter. The transmission and the conductance depend on the bias and the electron energy. The spin polarization depends on the bias and the electron energy. The results are helpful for making new types of bias-tunable spin filters.

  2. Charge-dependent and A-dependent effects in isotope shifts of Coulomb displacement energies

    International Nuclear Information System (INIS)

    Sherr, R.

    1977-01-01

    Coulomb displacement energies in a series of isotopes generally decrease with A. This decrease can arise from an increase with A of the average distance of interaction between pairs of protons. In the shell model a decrease can also result from charge-independence-breaking effects if the neutron-proton interaction for the valence nucleons is more attractive than the neutron-neutron interaction. Using the model recently proposed by Sherr and Talmi for the 1d/sub 3/2/ shell, existing data for this shell and also the 1d/sub 5/2/ and 1f/sub 7/2/ shells were analyzed allowing all matrix elements to vary as A/sup -lambda/3/. Least squares calculations of the rms deviation sigma were carried out for varying values of lambda from -2 to +2. It was found that although there was a minimum in sigma vs lambda it was too shallow to exclude any lambda for -1 to +1 in the 1d/sub 3/2/ and 1f/sub 7/2/ shells or 0 to +1 in the 1d/sub 5/2/ shell. It is therefore not possible to distinguish between A dependence and charge dependence in this model. The magnitude of the latter as expressed in terms of (np-nn) matrix elements depends strongly on the former. As lambda increases from -1 to +1, these (np-nn) matrix elements decrease roughly linearly in absolute magnitude and eventually change sign. For lambda = 0 they have appreciable and reasonable magnitudes for the 1d/sub 3/2/ and 1f/sub 7/2/ shells but for the 1d/sub 5/2/ shell the values are too small to be considered significant

  3. Sex-biased dispersal creates spatial genetic structure in a parthenogenetic ant with a dependent-lineage reproductive system.

    Science.gov (United States)

    Kuhn, A; Bauman, D; Darras, H; Aron, S

    2017-10-01

    Reproduction and dispersal are key aspects of species life history that influence spatial genetic structure in populations. Several ant species in the genus Cataglyphis have evolved a unique breeding system in which new reproductives (that is, queens and males) are produced asexually by parthenogenesis; in contrast, non-reproductives (that is, workers) are produced via sexual reproduction by mates from distinct genetic lineages. We investigated how these two coexisting reproductive methods affect population-level spatial genetic structure using the ant Cataglyphis mauritanica as a model. We obtained genotypes for queens and their male mates from 338 colonies, and we found that the two lineages present in the study population occurred with equal frequency. Furthermore, analysis of spatial genetic structure revealed strong sex-biased dispersal. Because queens were produced by parthenogenesis and because they dispersed over short distances, there was an extreme level of spatial structuring: a mosaic of patches composed of clonal queens was formed. Males, on the other hand, dispersed over several hundred metres and, thus, across patches, ensuring successful interlineage mating.

  4. Left truncation results in substantial bias of the relation between time-dependent exposures and adverse events

    NARCIS (Netherlands)

    Hazelbag, Christijan M; Klungel, Olaf H; van Staa, Tjeerd P; de Boer, Anthonius; Groenwold, Rolf H H

    PURPOSE: To assess the impact of random left truncation of data on the estimation of time-dependent exposure effects. METHODS: A simulation study was conducted in which the relation between exposure and outcome was based on an immediate exposure effect, a first-time exposure effect, or a cumulative

  5. Left truncation results in substantial bias of the relation between time-dependent exposures and adverse events

    NARCIS (Netherlands)

    Hazelbag, Christijan M.; Klungel, Olaf H.; van Staa, Tjeerd P.; de Boer, Anthonius; Groenwold, Rolf H H

    2015-01-01

    PURPOSE: To assess the impact of random left truncation of data on the estimation of time-dependent exposure effects. METHODS: A simulation study was conducted in which the relation between exposure and outcome was based on an immediate exposure effect, a first-time exposure effect, or a cumulative

  6. Attentional bias and executive control in treatment-seeking substance-dependent adolescents: A cross-sectional and follow-up study.

    Science.gov (United States)

    van Hemel-Ruiter, Madelon E; Wiers, Reinout W; Brook, Frank G; de Jong, Peter J

    2016-02-01

    Research in adults shows that substance dependent individuals demonstrate attentional bias (AB) for substance-related stimuli. This study investigated the role of AB in adolescents diagnosed with alcohol, cannabis, amphetamine or GHB dependency on entering therapy and six months later, and the role of executive control (EC) as a moderator of the relationship between problem severity and AB. Seventy-eight young substance-dependent (SD) patients (mean age=19.5), and 64 healthy controls (HC; mean age=19.0) were tested. Thirty-eight SD patients took part at 6-month follow-up (FU). AB was indexed by a visual probe task, EC by the attention network task, problem severity by the short alcohol (or drug) use disorder identification test and the severity of dependence questionnaire. SD patients demonstrated an AB for substance stimuli presented for 500 ms and 1250 ms, with the latter related to severity of dependence. There was a nonsignificant tendency indicating that EC was higher in HC than SD participants, but EC did not moderate the relationship between AB and dependency. Substance use, dependency, EC and AB remained unchanged in the 6 month FU period. Young SD patients showed a stronger relatively early as well as maintained AB toward substance cues. A stronger maintained attention was related to higher severity of dependence. Further, there were some indications that EC might play a role in adolescent substance use. The finding that at FU AB and problem severity were not decreased, and EC was not increased underlines the persistent character of addiction. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Temperature dependence magnetic properties and exchange bias effect in CuFe{sub 2}O{sub 4} nanoparticles embedded in NiO matrix

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Kashif [Physics Department, Quaid-i-Azam University, Islamabad (Pakistan); Physics Department, International Islamic University, Islamabad (Pakistan); Physics Department, University of Gujrat, Gujrat (Pakistan); Sarfraz, A.K., E-mail: sarfraz.ak1@gmail.com [Physics Department, Quaid-i-Azam University, Islamabad (Pakistan); Physics Department, International Islamic University, Islamabad (Pakistan); Physics Department, University of Gujrat, Gujrat (Pakistan); Ali, Atif; Mumtaz, A.; Hasanain, S.K. [Physics Department, Quaid-i-Azam University, Islamabad (Pakistan); Physics Department, International Islamic University, Islamabad (Pakistan); Physics Department, University of Gujrat, Gujrat (Pakistan)

    2014-11-15

    The effect of temperature on the magnetic properties of CuFe{sub 2}O{sub 4}/NiO nanocomposites of (1−x) NiO/xCuFe{sub 2}O{sub 4} (x=0.5) has been investigated. The (1−x)NiO/xCuFe{sub 2}O{sub 4} (x=0.5) nanoparticles were synthesized by co-precipitation route and their crystallographic structure was confirmed through X-ray diffraction (XRD) analysis. The average crystallite sizes of the nanoparticles as determined from the XRD were found to lie in the range of 20–31 nm. Magnetic characterization including coercivity and magnetization were measured with effect of particle size and temperature. During magnetic measurement it is observed that the hysteresis loop displaces along negative field axis with exchange bias field (H{sub EB}) about 75 Oe at 5 K and vanish at 150 K which is irreversible temperature T{sub irr}. The temperature dependence of coercively follows Kneller's law while the saturation magnetization followed Bloch's law with exponent α=3/2. - Highlights: • Synthesis of (1−x)NiO/xCuFe{sub 2}O{sub 4} (x=0.5) nanoparticles by co-precipitation route. • Magnetic characterization with particle size and temperature variation. • Exchange bias effect: monotonic decrease in exchange field with temperature. • Temperature dependence of coercivity follows Kneller's law. • Temperature dependence of saturation magnetization follows Bloch's law.

  8. Angular dependence of energy and particle fluxes in a magnetized plasma

    International Nuclear Information System (INIS)

    Koch, B.; Bohmeyer, W.; Fussmann, G.

    2005-01-01

    A flat probe allowing simultaneous measurements of energy flux and current density as functions of a bias voltage was rotated in a spatially homogeneous plasma. The experiments were conducted at the PSI-2 facility, a linear divertor simulator with moderate magnetic field strength. Sheath parameters (ion current density j i , floating potential U f , energy flux density q, ion energy reflection coefficient R E and sheath energy transmission coefficient γ) were determined as functions of the angle α between the probe surface normal and the magnetic field. A geometric model has been developed to explain the ion flux density at grazing incidence

  9. To be or not to be threatening, but what was the question? Biased face evaluation in social anxiety and depression depends on how you frame the query

    Directory of Open Access Journals (Sweden)

    Wolf-Gero eLange

    2013-04-01

    Full Text Available Scientific evidence is equivocal on whether Social Anxiety Disorder (SAD is characterized by a biased negative evaluation of facial expressions, even though it is assumed that such a bias plays a crucial role in the maintenance of the disorder. The way of framing the evaluation question may play an important role in the inconsistencies of earlier results. To investigate this issue, an unselected sample of 95 participants (11 male with varying degrees of social anxiety and depressive symptoms rated facial crowds with different ratios of neutral-disgust, neutral-sad, neutral-happy and neutral-surprised expressions in terms of friendliness, approval, difficulty to make contact, and threat. It appeared that the impact of social anxiety on ratings was highly dependent on the type of question that was asked, but not on the type of emotion that was shown: A high degree of social anxiety was related to a more positive evaluation of crowds when friendliness was assessed. When asking about the difficulty to make contact, social anxiety was related to more difficulty. When the threat evoked by a crowd had to be evaluated, higher degrees of social anxiety were tendentiously correlated with higher threat ratings. Degree of depression, on the other hand, was negatively correlated only to approval-ratings. In addition, with an increasing degree of depression, the negative impact that any additional emotional face had on approval ratings increased as well. The theoretical and methodological implications of the results are discussed.

  10. Temperature Dependency and Alpha Response of Semi-Insulating GaAs Schottky Radiation Detector at Low Bias Voltage

    International Nuclear Information System (INIS)

    Kang, Sang Mook; Ha, Jang Ho; Park, Se Hwan; Kim, Han Soo; Kim, Yong Kyun

    2009-01-01

    The last decade has seen a growing interest in semiconductor radiation detectors operated at room or nearly room temperature. Great efforts have been invested in the development of radiation detectors based on semi-insulating (SI) GaAs. The main reasons are as follows: (i) high resistance against radiation damage; (ii) it possesses a good energy resolution, which relates to its active volume; (iii) such a detector also exhibits fast signal rise times, which results from a high mobility and drift velocity of charge carriers; (iv) its large band gap energy allows a SI GaAs detector to operate at room temperature. Other important features are a good technology base and low production and operating costs. An alpha particle monitoring method for the detection of Pu-238 and U-235 is becoming important in homeland security. Alpha measurement in a vacuum is known to provide a good resolution sufficient to separate an isotope abundance in nuclear materials. However, in order to apply it to a high radiation field like a spent fuel treatment facility, a nuclear material loading and unloading process in a vacuum is one of the great disadvantages. Therefore, the main technical issue is to develop a detector for alpha detection at air condition and low power operation for integration type device. In this study we fabricated GaAs Schottky detector by using semi-insulating (SI) wafer and measured current-voltage characteristic curve and alpha response with 5.5 MeV Am-241 source

  11. Is there dependence and systemic risk between oil and renewable energy stock prices?

    International Nuclear Information System (INIS)

    Reboredo, Juan C.

    2015-01-01

    We study systemic risk and dependence between oil and renewable energy markets using copulas to characterize the dependence structure and to compute the conditional value-at-risk as a measure of systemic risk. We found significant time-varying average and symmetric tail dependence between oil returns and several global and sectoral renewable energy indices. Our evidence on systemic risk indicates that oil price dynamics significantly contributes around 30% to downside and upside risk of renewable energy companies. These results have important implications for risk management and renewable energy policies. - Highlights: • We study systemic risk and dependence between oil and renewable energy markets. • Dependence and conditional value-at-risk is obtained through copulas. • Oil and renewable energy displayed time-varying average and symmetric tail dependence. • Oil price contribution to the downside and upside risks of renewable energy companies was around 30%

  12. Current-voltage characteristics of quantum-point contacts in the closed-channel regime: Transforming the bias voltage into an energy scale

    DEFF Research Database (Denmark)

    Gloos, K.; Utko, P.; Aagesen, M.

    2006-01-01

    We investigate the I(V) characteristics (current versus bias voltage) of side-gated quantum-point contacts, defined in GaAs/AlxGa1-xAs heterostructures. These point contacts are operated in the closed-channel regime, that is, at fixed gate voltages below zero-bias pinch-off for conductance. Our....... Such a built-in energy-voltage calibration allows us to distinguish between the different contributions to the electron transport across the pinched-off contact due to thermal activation or quantum tunneling. The first involves the height of the barrier, and the latter also its length. In the model that we...

  13. Conservation law of plants' energy value dependence of plants ...

    African Journals Online (AJOL)

    The plants differences in biochemical composition are analyzed, and the conservation law of energy value in plants is obtained. The link between the need for the nutrients and the plants biochemical composition is examined, Liebig's law is specified. Keywords: plant's biochemical composition, biochemistry, energy value in ...

  14. Neutron-energy-dependent cell survival and oncogenic transformation.

    Science.gov (United States)

    Miller, R C; Marino, S A; Martin, S G; Komatsu, K; Geard, C R; Brenner, D J; Hall, E J

    1999-12-01

    Both cell lethality and neoplastic transformation were assessed for C3H10T1/2 cells exposed to neutrons with energies from 0.040 to 13.7 MeV. Monoenergetic neutrons with energies from 0.23 to 13.7 MeV and two neutron energy spectra with average energies of 0.040 and 0.070 MeV were produced with a Van de Graaff accelerator at the Radiological Research Accelerator Facility (RARAF) in the Center for Radiological Research of Columbia University. For determination of relative biological effectiveness (RBE), cells were exposed to 250 kVp X rays. With exposures to 250 kVp X rays, both cell survival and radiation-induced oncogenic transformation were curvilinear. Irradiation of cells with neutrons at all energies resulted in linear responses as a function of dose for both biological endpoints. Results indicate a complex relationship between RBEm and neutron energy. For both survival and transformation, RBEm was greatest for cells exposed to 0.35 MeV neutrons. RBEm was significantly less at energies above or below 0.35 MeV. These results are consistent with microdosimetric expectation. These results are also compatible with current assessments of neutron radiation weighting factors for radiation protection purposes. Based on calculations of dose-averaged LET, 0.35 MeV neutrons have the greatest LET and therefore would be expected to be more biologically effective than neutrons of greater or lesser energies.

  15. Beyond existence and aiming outside the laboratory: estimating frequency-dependent and pay-off-biased social learning strategies.

    Science.gov (United States)

    McElreath, Richard; Bell, Adrian V; Efferson, Charles; Lubell, Mark; Richerson, Peter J; Waring, Timothy

    2008-11-12

    The existence of social learning has been confirmed in diverse taxa, from apes to guppies. In order to advance our understanding of the consequences of social transmission and evolution of behaviour, however, we require statistical tools that can distinguish among diverse social learning strategies. In this paper, we advance two main ideas. First, social learning is diverse, in the sense that individuals can take advantage of different kinds of information and combine them in different ways. Examining learning strategies for different information conditions illuminates the more detailed design of social learning. We construct and analyse an evolutionary model of diverse social learning heuristics, in order to generate predictions and illustrate the impact of design differences on an organism's fitness. Second, in order to eventually escape the laboratory and apply social learning models to natural behaviour, we require statistical methods that do not depend upon tight experimental control. Therefore, we examine strategic social learning in an experimental setting in which the social information itself is endogenous to the experimental group, as it is in natural settings. We develop statistical models for distinguishing among different strategic uses of social information. The experimental data strongly suggest that most participants employ a hierarchical strategy that uses both average observed pay-offs of options as well as frequency information, the same model predicted by our evolutionary analysis to dominate a wide range of conditions.

  16. Temperature effects on the nuclear symmetry energy and symmetry free energy with an isospin and momentum dependent interaction

    International Nuclear Information System (INIS)

    Xu, Jun; Ma, Hong-Ru; Chen, Lie-Wen; Li, Bao-An

    2007-01-01

    Within a self-consistent thermal model using an isospin and momentum dependent interaction (MDI) constrained by the isospin diffusion data in heavy-ion collisions, we investigate the temperature dependence of the symmetry energy E sym (ρ,T) and symmetry free energy F sym (ρ,T) for hot, isospin asymmetric nuclear matter. It is shown that the symmetry energy E sym (ρ,T) generally decreases with increasing temperature while the symmetry free energy F sym (ρ,T) exhibits opposite temperature dependence. The decrement of the symmetry energy with temperature is essentially due to the decrement of the potential energy part of the symmetry energy with temperature. The difference between the symmetry energy and symmetry free energy is found to be quite small around the saturation density of nuclear matter. While at very low densities, they differ significantly from each other. In comparison with the experimental data of temperature dependent symmetry energy extracted from the isotopic scaling analysis of intermediate mass fragments (IMF's) in heavy-ion collisions, the resulting density and temperature dependent symmetry energy E sym (ρ,T) is then used to estimate the average freeze-out density of the IMF's

  17. Impact of density-dependent symmetry energy and Coulomb ...

    Indian Academy of Sciences (India)

    2014-03-07

    Mar 7, 2014 ... The IMF production increases with the stiffness of symmetry energy. .... to clusterization using minimum spanning tree MST(M) method .... To understand the direct role of Coulomb interactions, we display in figure 4 the mean.

  18. Energy dependence of isotopic spectra from spallation residues

    International Nuclear Information System (INIS)

    Audouin, L.

    2003-09-01

    Spallation reactions are collisions between heavy nuclei and light particle with an energy of a few hundreds MeV. The y are considered as a suitable way to create high- flux neutrons sources, which may used for example for the transmutation of nuclear wastes (hybrid reactors). The study of the residues from such reactions is both a way to understand the physics of the spallation and to provide information required for the design of industrial targets. The residues from the spallation of lead by proton at 500 MeV have been measured using the inverse kinematics technique in the FRS (fragments recoil separator). spectrometer from GSI (Barmstadt). This low energy required the use of new technique, for the experimental setup as well as during the analysis. The fragments were identified in-flight, prior to β decay. Complete isotopic distributions are obtained with an accuracy ranging between 10 and 30%. Detailed information on the reaction kinematics are also obtained. Data are in excellent agreement with radio-chemical measurements, and bring new insights about the spallation process. The comparison with data measured on the same system with an incident energy of 1 GeV allows to discuss the influence of the projectile energy on the residues formation. It is concluded that the independence of the shape of the isobaric production cross sections regarding mass and energy of the projectile is preserved at low incident energies. The behaviour of Monte-Carlo codes is discussed with respect to those sets of data. The calculations show an improving agreement with decreasing energy, indicating that high-energy phenomena, for which some common assumptions become questionable, are the main reason for the observed discrepancies. (author)

  19. Numerical method to calculate the quantum transmission, resonance and eigenvalue energies: application to a biased multibarrier systems

    Energy Technology Data Exchange (ETDEWEB)

    Maiz, F., E-mail: fethimaiz@gmail.com [University of Cartage, Nabeul Engineering Preparatory Institute, Merazka, 8000 Nabeul (Tunisia); King Khalid University, Faculty of Science, Physics Department, PO Box 9004, Abha 61413 (Saudi Arabia)

    2015-04-15

    A novel method to calculate the quantum transmission, resonance and eigenvalue energies forming the sub-bands structure of non-symmetrical, non-periodical semiconducting heterostructure potential has been proposed in this paper. The method can be applied on a multilayer system with varying thickness of the layer and effective mass of electrons and holes. Assuming an approximated effective mass and using Bastard's boundary conditions, Schrödinger equation at each media is solved and then using a confirmed recurrence method, the transmission and reflection coefficients and the energy quantification condition are expressed. They are simple combination of coupled equations. Schrödinger's equation solutions are Airy functions or plane waves, depending on the electrical potential energy slope. To illustrate the feasibility of the proposed method, the N barriers – (N−1) wells structure for N=3, 5, 8, 9, 17 and 35 are studied. All results show very good agreements with previously published results obtained from applying different methods on similar systems.

  20. Image Dependent Energy-Constrained Local Backlight Dimming

    DEFF Research Database (Denmark)

    Burini, Nino; Nadernejad, Ehsan; Korhonen, Jari

    2012-01-01

    In this work, we consider and propose two extensions to an optimization-based image dependent backlight dimming algorithm. The first extension introduces error weighting based on human perception of luminance, aiming to improve the perceived image quality; the second extension adds an adjustable ...

  1. Magnetic field dependence of vortex activation energy: A ...

    Indian Academy of Sciences (India)

    follows a parabolic behaviour unlike a power-law dependence seen in Bi2Sr2Ca2Cu3O10. ..... SP thanks Department of Science of Technology, India and SDK thanks. Council of Scientific and Industrial Research, India for financial support.

  2. Contact angle dependence on the fluid-wall dispersive energy

    NARCIS (Netherlands)

    Horsch, M.; Heitzig, M.; Dan, C.M.; Harting, J.D.R.; Hasse, H.; Vrabec, J.

    2010-01-01

    Menisci of the truncated and shifted Lennard-Jones fluid between parallel planar walls are investigated by molecular dynamics simulation. Thereby, the characteristic energy of the unlike dispersive interaction between fluid molecules and wall atoms is systematically varied to determine its influence

  3. Energy dependence of the molecular effect in sputtering

    International Nuclear Information System (INIS)

    Oliva-Florio, A.R.; Alonso, E.V.; Baragiola, R.A.; Ferron, J.; Jakas, M.M.

    1979-01-01

    Measurements are reported of sputtering yields of Au for Xe + and Xe 2 + impact in the energy range 1 to 50 keV. It was found that non-linear effects exist well outside the range predicted in a recent thermal spike model. (author)

  4. Energy dependence of the molecular effect in sputtering

    International Nuclear Information System (INIS)

    Oliva-Florio, A.R.; Alonso, E.V.; Baragiola, R.A.; Ferron, J.; Jakas, M.M.

    1979-01-01

    Measurements of sputtering yields of Au for Xe + and Xe + 2 impact in the energy range 1-50 keV are given. It was found that non-linear effects exist well outside the range predicted in a recent thermal spike model. (author)

  5. Energy dependence of the emittance of damping ring beams

    International Nuclear Information System (INIS)

    Stiening, R.

    1985-01-01

    The energy at which the SLC damping rings are operated was chosen to be 1.21 GeV. At the time that that specification was made, the repetition rate of the SLC was expected to be 180 Hz. It is now anticipated that the repetition rate during the initial year of operation of the SLC will be 120 Hz. The following curves which show the output emittance of the damping rings as a function of input emittance and energy suggest that there is a range of energies over which the rings can be operated without changing the SLC luminosity. It should be noted that in the era of polarized beams, the damping ring energy will be fixed at the design value on account of the spin precession required in the LTR and RTL transport lines. The SLC design output emittance of the damping rings is 3 x 10 -5 radian-meters. Because of space charge disruption and quantum emission downstream of the damping rings, much lower values than the design value may not have a large beneficial effect on the luminosity. 3 figures

  6. Generating energy dependent neutron flux maps for effective ...

    African Journals Online (AJOL)

    For activation analysis and irradiation scheme of miniature neutron source reactor, designers or engineers usually require information on thermal neutron flux levels and other energy group flux levels (such as fast, resonance and epithermal). A methodology for readily generating such flux maps and flux profiles for any ...

  7. Energy dependence of isotopic spectra from spallation residues; Dependance en energie des spectres isotopiques de residus de spallation

    Energy Technology Data Exchange (ETDEWEB)

    Audouin, L

    2003-09-01

    Spallation reactions are collisions between heavy nuclei and light particle with an energy of a few hundreds MeV. The y are considered as a suitable way to create high- flux neutrons sources, which may used for example for the transmutation of nuclear wastes (hybrid reactors). The study of the residues from such reactions is both a way to understand the physics of the spallation and to provide information required for the design of industrial targets. The residues from the spallation of lead by proton at 500 MeV have been measured using the inverse kinematics technique in the FRS (fragments recoil separator). spectrometer from GSI (Barmstadt). This low energy required the use of new technique, for the experimental setup as well as during the analysis. The fragments were identified in-flight, prior to {beta} decay. Complete isotopic distributions are obtained with an accuracy ranging between 10 and 30%. Detailed information on the reaction kinematics are also obtained. Data are in excellent agreement with radio-chemical measurements, and bring new insights about the spallation process. The comparison with data measured on the same system with an incident energy of 1 GeV allows to discuss the influence of the projectile energy on the residues formation. It is concluded that the independence of the shape of the isobaric production cross sections regarding mass and energy of the projectile is preserved at low incident energies. The behaviour of Monte-Carlo codes is discussed with respect to those sets of data. The calculations show an improving agreement with decreasing energy, indicating that high-energy phenomena, for which some common assumptions become questionable, are the main reason for the observed discrepancies. (author)

  8. Collisional energy dependence of molecular ionization by metastable rare gas atoms

    International Nuclear Information System (INIS)

    Martin, R.M.; Parr, T.P.

    1979-01-01

    The collisional energy dependence of several molecular total ionization cross sections by metastable rare gas atoms was studied over the thermal energy region using the crossed molecular beam time-of-flight method. Results are reported for the collision systems He, Ne, and Ar ionizing the geometric isomers cis- and trans-dichloroethylene and ortho- and para-dichlorobenzene. The He ionization cross sections oscillate about an energy dependence of E/sup -1/2/ over the energy range 0.004--1.0 eV, and the Ar*+para-dichlorobenzene cross section oscillates about an energy dependence of E/sup -2/5/ over the energy range 0.011--0.64 eV. The remaining systems are characterized by ''bent'' E/sup -m/ dependences with m values of 0.56--0.70 at low energies changing to 0.07--0.29 at higher energies. Comparison with the slopes of the He* systems and the Ar*+para-dichlorobenzene system shows that the ''bent'' and ''oscillating'' energy dependences are similar except for the form of the cross section functions at the lowest energies. No systematic differences are found between the cross section energy dependences for ionization of different geometric isomers or for ionization by the different metastable rare gas atoms

  9. Sympathetic bias.

    Science.gov (United States)

    Levy, David M; Peart, Sandra J

    2008-06-01

    We wish to deal with investigator bias in a statistical context. We sketch how a textbook solution to the problem of "outliers" which avoids one sort of investigator bias, creates the temptation for another sort. We write down a model of the approbation seeking statistician who is tempted by sympathy for client to violate the disciplinary standards. We give a simple account of one context in which we might expect investigator bias to flourish. Finally, we offer tentative suggestions to deal with the problem of investigator bias which follow from our account. As we have given a very sparse and stylized account of investigator bias, we ask what might be done to overcome this limitation.

  10. Energy dependence of the Cronin effect from nonlinear QCD evolution

    International Nuclear Information System (INIS)

    Albacete, Javier L.; Armesto, Nestor; Salgado, Carlos A.; Wiedemann, Urs Achim; Kovner, Alex

    2004-01-01

    The nonlinear evolution of dense partonic systems has been suggested as a novel physics mechanism relevant for the dynamics of p-A and A-A collisions at collider energies. Here we study to what extent the description of Cronin enhancement in the framework of this nonlinear evolution is consistent with the recent observation in √(s)=200 GeV d-Au collisions at the Relativistic Heavy Ion Collider. We solve the Balitsky-Kovchegov evolution equation numerically for several initial conditions encoding Cronin enhancement. We find that the properly normalized nuclear gluon distribution is suppressed at all momenta relative to that of a single nucleon. For the resulting spectrum of produced gluons in p-A and A-A collisions, the nonlinear QCD evolution is unable to generate a Cronin-type enhancement, and it quickly erases any such enhancement which may be present at lower energies

  11. Domain shape dependence of semiclassical corrections to energy

    International Nuclear Information System (INIS)

    Kwiatkowski, Grzegorz

    2017-01-01

    Stationary solution of a one-dimensional sine-Gordon system is embedded in a multidimensional theory with an explicitly finite domain in the added spatial dimensions. Semiclassical corrections to energy are calculated for a static kink solution with emphasis on the impact of the scale of the domain as well as the choice of boundary conditions on the results for a rectangular cross-section. (paper)

  12. Energy dependence of fast neutron dosimetry using electrochemical etching

    International Nuclear Information System (INIS)

    Su, S.J.; Morgan, K.Z.

    1978-01-01

    Registration of fast-neutron induced recoil tracks by the electrochemical etching technique as applied to sensitive Lexan polycarbonate foils provides a simple and inexpensive means of fast neutron personnel dosimetry. The sensitivity (tracks/neutron) of recoil particle registration is given as a function of neutron energy. Neutrons of 7 Li (p,n) 7 Be, 3 T (d,n) 4 He and 9 B, respectively. Results are compared with other studies using other neutron sources and conventional etching method

  13. Energy Analysis of the Danish Food Production System: Food-EROI and Fossil Fuel Dependency

    DEFF Research Database (Denmark)

    Markussen, Mads Ville; Østergård, Hanne

    2013-01-01

    Modern food production depends on limited natural resources for providing energy and fertilisers. We assess the fossil fuel dependency for the Danish food production system by means of Food Energy Returned on fossil Energy Invested (Food-EROI) and by the use of energy intensive nutrients from....... Furthermore, nutrients in commercial fertiliser and imported feed account for 84%, 90% and 90% of total supply of N, P and K, respectively. We conclude that the system is unsustainable because it is embedded in a highly fossil fuel dependent system based on a non-circular flow of nutrients. As energy and thus...... imported livestock feed and commercial fertilisers. The analysis shows that the system requires 221 PJ of fossil energy per year and that for each joule of fossil energy invested in farming, processing and transportation, 0.25 J of food energy is produced; 0.28 when crediting for produced bioenergy...

  14. Effect of temperature-dependent energy-level shifts on a semiconductor's Peltier heat

    International Nuclear Information System (INIS)

    Emin, D.

    1984-01-01

    The Peltier heat of a charge carrier in a semiconductor is calculated for the situation in which the electronic energy levels are temperature dependent. The temperature dependences of the electronic energy levels, generally observed optically, arise from their dependences on the vibrational energy of the lattice (e.g., as caused by thermal expansion). It has been suggested that these temperature dependences will typically have a major effect on the Peltier heat. The Peltier heat associated with a given energy level is a thermodynamic quantity; it is the product of the temperature and the change of the entropy of the system when a carrier is added in that level. As such, the energy levels cannot be treated as explicitly temperature dependent. The electron-lattice interaction causing the temperature dependence must be expressly considered. It is found that the carrier's interaction with the atomic vibrations lowers its electronic energy. However, the interaction of the carrier with the atomic vibrations also causes an infinitesimal lowering (approx.1/N) of each of the N vibrational frequencies. As a result, there is a finite carrier-induced increase in the average vibrational energy. Above the Debye temperature, this cancels the lowering of the carrier's electronic energy. Thus, the standard Peltier-heat formula, whose derivation generally ignores the temperature dependence of the electronic energy levels, is regained. This explains the apparent success of the standard formula in numerous analyses of electronic transport experiments

  15. Energy dependence of a local equivalent potential for RGM phase shifts for 16O + 16O

    International Nuclear Information System (INIS)

    Ait-Tahar, S.; Mackintosh, R.S.; Cooper, S.G.; Wada, T.

    1993-01-01

    We have found, using the IP inversion method, the local representation of a potential that in S(l) equivalent to the RGM nonlocal potential of Wada and Horiuchi. Phase shifts corresponding to RGM calculations at laboratory energies 30, 41, 49, 59, 150, 350 and 500 MeV were inverted and the resulting local potentials compared with the local (but l-dependent) potentials obtained previously in the WKB-RGM scheme. The present l-independent potentials exhibit a smooth radial variation and show marked differences from previous results. The energy dependence arises from that of the exchange term and from the conversion of the l-dependence into an additional energy dependence. In particular, we show that the energy dependence of the volume integrals in this energy region is different from earlier WKB-RGM predictions. (orig.)

  16. Energy dependences of absorption in beryllium windows and argon gas

    International Nuclear Information System (INIS)

    Chantler, C.T.; Staudenmann, J-P.

    1994-01-01

    In part of an ongoing work on x-ray form factors, new absorption coefficients are being evaluated for all elements, across the energy range from below 100 eV to above 100 keV. These new coefficients are applied herein to typical problems in synchrotron radiation stations, namely the use of beryllium windows and argon gas detectors. Results are compared with those of other authors. The electron-ion pair production process in ionization chambers is discussed, and the effects of 3d-element impurities are indicated. 15 refs., 6 figs

  17. Interatomic scattering in energy dependent photoelectron spectra of Ar clusters

    Energy Technology Data Exchange (ETDEWEB)

    Patanen, M.; Benkoula, S.; Nicolas, C.; Goel, A. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Antonsson, E. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Physikalische und Theoretische Chemie Institut für Chemie und Biochemie, Fachbereich Biologie, Chemie, Pharmazie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin (Germany); Neville, J. J. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick E3B 6E2 (Canada); Miron, C., E-mail: Catalin.Miron@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Extreme Light Infrastructure - Nuclear Physics (ELI-NP), ‘Horia Hulubei’ National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125 Măgurele, Jud. Ilfov (Romania)

    2015-09-28

    Soft X-ray photoelectron spectra of Ar 2p levels of atomic argon and argon clusters are recorded over an extended range of photon energies. The Ar 2p intensity ratios between atomic argon and clusters’ surface and bulk components reveal oscillations similar to photoelectron extended X-ray absorption fine structure signal (PEXAFS). We demonstrate here that this technique allows us to analyze separately the PEXAFS signals from surface and bulk sites of free-standing, neutral clusters, revealing a bond contraction at the surface.

  18. Mass- and energy-dependence of (π+,π-) double isobaric analog transitions at low energies

    International Nuclear Information System (INIS)

    Anderl, T.

    1988-01-01

    Transitions to double isobaric analog states (DIAT) have been measured in the double charge exchange (DCX) reaction (π + ,π - ) for the nuclei 26 Mg, 56 Fe at Tsub(π+) = 49 MeV and for 18 O at Tsub(π+) = 24 MeV, 33 MeV, 49 MeV, 64 MeV and 79 MeV for several angles. The experiments have been performed at the pion channels M13 and M11 of TRIUMF using the low energy pion spectrometer QQD. The forward angle cross sections for 18 O can be understood in a quark model as well as in conventional models where the reaction is mainly proceeding through intermediate deltas or low lying excited states of the intermediate nucleus. The angular distribution of 26 Mg at 49 MeV is found to be almost identical to those of 14 C and 18 O while the cross section remarkedly drops for 56 Fe. The forward angle excitation function of 18 O exhibits a maximum at around 35 MeV. The present results are compared to theoretical predictions. Two approaches for a unified study of SCX and DCX at energies ranging from 20 MeV up to 300 MeV are presented. The first is carried out in a mean free path model for investigations of geometry effects in the reaction. For the second, the optical model code PIESDEX is employed. Both studies indicate that the observed mass dependence for DCX at 50 MeV can be explained partly by geometry considerations and partly by details in the nuclear matter distributions of core neutrons and valence neutrons. Furthermore, the optical model investigation reveals the need of shifting the free πN-SCX amplitude down by 30 MeV in order to achieve good agreement with experimental data. (orig.)

  19. Energy decay of a variable-coefficient wave equation with nonlinear time-dependent localized damping

    Directory of Open Access Journals (Sweden)

    Jieqiong Wu

    2015-09-01

    Full Text Available We study the energy decay for the Cauchy problem of the wave equation with nonlinear time-dependent and space-dependent damping. The damping is localized in a bounded domain and near infinity, and the principal part of the wave equation has a variable-coefficient. We apply the multiplier method for variable-coefficient equations, and obtain an energy decay that depends on the property of the coefficient of the damping term.

  20. An efficient and accurate method to obtain the energy-dependent Green function for general potentials

    International Nuclear Information System (INIS)

    Kramer, T; Heller, E J; Parrott, R E

    2008-01-01

    Time-dependent quantum mechanics provides an intuitive picture of particle propagation in external fields. Semiclassical methods link the classical trajectories of particles with their quantum mechanical propagation. Many analytical results and a variety of numerical methods have been developed to solve the time-dependent Schroedinger equation. The time-dependent methods work for nearly arbitrarily shaped potentials, including sources and sinks via complex-valued potentials. Many quantities are measured at fixed energy, which is seemingly not well suited for a time-dependent formulation. Very few methods exist to obtain the energy-dependent Green function for complicated potentials without resorting to ensemble averages or using certain lead-in arrangements. Here, we demonstrate in detail a time-dependent approach, which can accurately and effectively construct the energy-dependent Green function for very general potentials. The applications of the method are numerous, including chemical, mesoscopic, and atomic physics

  1. Energy dependency and sustainable regional development in the Baltic states: A review

    Directory of Open Access Journals (Sweden)

    Štreimikienė Dalia

    2016-01-01

    Full Text Available Energy security is one of the most important indicators of sustainable regional development and 'green' growth in implementation of EU strategy Europe 2020. It can provide the harmonized development and cohesion of 'old' and 'new' EU member states. Our paper conducts a comparative study of energy dependency and energy security indicators in the Baltic States. The Baltic countries achieved enormous progress in the use of renewable energy sources and energy efficiency since their EU accession in 2004. The increase of renewable energy capacities in Baltic States also contributed to the reduction of energy intensity and carbon intensity of economy and energy import dependency. Our results show that amongst all three states, it was Estonia that had achieved the best results in increased use of renewables and energy efficiency improvements and had distinguished itself with the best indicators and economic and regional policy outcomes.

  2. Importance of the energy-dependent geometry in the 16O+ 16O optical model potential

    International Nuclear Information System (INIS)

    Pantis, G.; Ioannidis, K.; Poirier, P.

    1985-01-01

    Optical model potentials with various forms of energy-dependent geometry have been considered for the description of 16 O+ 16 O elastic scattering. It is shown that the variation with energy of the imaginary radius leads to a reasonable fit of the cross-section data, throughout the energy range

  3. Time-dependent flux from pulsed neutrons revealed by superconducting Nb current-biased kinetic inductance detector with "1"0B converter operated at 4 K

    International Nuclear Information System (INIS)

    Miyajima, Shigeyuki; Narukami, Yoshito; Shishido, Hiroaki; Yoshioka, Naohito; Ishida, Takekazu; Fujimaki, Akira; Hidaka, Mutsuo; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Arai, Masatoshi

    2015-01-01

    We have demonstrated a new superconducting detector for a neutron based on Nb superconductor meanderline with a "1"0B conversion layer. We use a current-biased kinetic inductance detector (CB-KID), which is composed of a meanderline, for detection of a neutron with high spatial resolution and fast response. The thickness of Nb meanderlines is 40 nm and widths are 3 μm, 1 μm, and 0.6 μm. The CB-KIDs are fabricated at the center of the Si chip of the size 22 mm × 22 mm and the total area of CB-KIDs covers 8 mm × 8 mm. The chip was cooled to a temperature lower than 4 K below the transition temperature of Nb using a Gifford-McMahon (GM) cryocooler. The Nb CB-KIDs with a "1"0B conversion layer output the voltage by irradiating pulsed neutrons at the material life science experimental facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC) center. The response time of CB-KIDs is about a few tens ns. We have also obtained the time dependence of neutron flux generated from pulsed neutrons using a CB-KID. Experimental results were in good agreement with the simulated results. (author)

  4. Internet-based attentional bias modification training as add-on to regular treatment in alcohol and cannabis dependent outpatients : A study protocol of a randomized control trial

    NARCIS (Netherlands)

    Heitmann, J.; van Hemel-Ruiter, M.E.; Vermeulen, K.M.; Ostafin, B.D.; MacLeod, C.; Wiers, R.W.; DeFuentes-Merillas, L.; Fledderus, M.; Markus, W.; de Jong, P.J.

    2017-01-01

    Background The automatic tendency to attend to and focus on substance-related cues in the environment (attentional bias), has been found to contribute to the persistence of addiction. Attentional bias modification (ABM) interventions might, therefore, contribute to treatment outcome and the

  5. Eigenvalue-dependent neutron energy spectra: Definitions, analyses, and applications

    International Nuclear Information System (INIS)

    Cacuci, D.G.; Ronen, Y.; Shayer, Z.; Wagschal, J.J.; Yeivin, Y.

    1982-01-01

    A general qualitative analysis of spectral effects that arise from solving the kappa-, α-, γ-, and sigma-eigenvalue formulations of the neutron transport equation for nuclear systems that deviate (to first order) from criticality is presented. Hierarchies of neutron spectra softness are established and expressed concisely in terms of the newly introduced spatialdependent local spectral indices for the core and for the reflector. It is shown that each hierarchy is preserved, regardless of the nature of the specific physical mechanism that cause the system to deviate from criticality. Qualitative conclusions regarding the general behavior of the spectrum-dependent integral spectral indices and ICRs corresponding to the kappa-, α-, γ-, and sigma-eigenvalue formalisms are also presented. By defining spectral indices separately for the core and for the reflector, it is possible to account for the characteristics of neutron spectra in both the core and the reflector. The distinctions between the spectra in the core and in the reflector could not have been accounted for by using a single type of spectral index (e.g., a spectral index for the entire system or a spectral index solely for the core)

  6. Energy Dependence of Proton Radiation Damage in Si-Sensors

    CERN Document Server

    AUTHOR|(CDS)2084399; Neubüser, C.

    2014-01-01

    Irradiation experiments on silicon sensors are used to mimic the radiation environment at collider experiments with the aim to forecast the change of the electrical properties of a detector with irradiation. Measurements on irradiated sensors are invaluable in choosing a material well suited for a silicon tracking detector. This is especially true for the upgraded detectors to be used in the high-luminosity phase of the LHC (HL-LHC), where silicon sensors as currently used would suffer severe loss in signal from irradiation with charged and neutral hadrons.\\\\ The CMS Tracker Collaboration has initiated irradiation studies with protons with energies ranging from 23 MeV to 23 GeV. They are often used instead of charged hadrons, their radiation induced damage to the silicon being rather similar. However, in oxygen rich silicon, NIEL violation concerning the full depletion voltage has been observed.\\\\ In this paper results from investigations on bulk defects compared to the change of the electrical properties of ...

  7. Approximate calculation of electronic energy levels of axially symmetric quantum dot and quantum ring by using energy dependent effective mass

    International Nuclear Information System (INIS)

    Yu-Min, Liu; Zhong-Yuan, Yu; Xiao-Min, Ren

    2009-01-01

    Calculations of electronic structures about the semiconductor quantum dot and the semiconductor quantum ring are presented in this paper. To reduce the calculation costs, for the quantum dot and the quantum ring, their simplified axially symmetric shapes are utilized in our analysis. The energy dependent effective mass is taken into account in solving the Schrödinger equations in the single band effective mass approximation. The calculated results show that the energy dependent effective mass should be considered only for relatively small volume quantum dots or small quantum rings. For large size quantum materials, both the energy dependent effective mass and the parabolic effective mass can give the same results. The energy states and the effective masses of the quantum dot and the quantum ring as a function of geometric parameters are also discussed in detail. (general)

  8. Management of solar energy in microgrids using IoT-based dependable control

    OpenAIRE

    Phung, Manh Duong; De La Villefromoy, Michel; Ha, Quang

    2017-01-01

    Solar energy generation requires efficient monitoring and management in moving towards technologies for net-zero energy buildings. This paper presents a dependable control system based on the Internet of Things (IoT) to control and manage the energy flow of renewable energy collected by solar panels within a microgrid. Data for optimal control include not only measurements from local sensors but also meteorological information retrieved in real-time from online sources. For system fault toler...

  9. Stimulus- and state-dependence of systematic bias in spatial attention: additive effects of stimulus-size and time-on-task.

    Science.gov (United States)

    Benwell, Christopher S Y; Harvey, Monika; Gardner, Stephanie; Thut, Gregor

    2013-03-01

    Systematic biases in spatial attention are a common finding. In the general population, a systematic leftward bias is typically observed (pseudoneglect), possibly as a consequence of right hemisphere dominance for visuospatial attention. However, this leftward bias can cross-over to a systematic rightward bias with changes in stimulus and state factors (such as line length and arousal). The processes governing these changes are still unknown. Here we tested models of spatial attention as to their ability to account for these effects. To this end, we experimentally manipulated both stimulus and state factors, while healthy participants performed a computerized version of a landmark task. State was manipulated by time-on-task (>1 h) leading to increased fatigue and a reliable left- to rightward shift in spatial bias. Stimulus was manipulated by presenting either long or short lines which was associated with a shift of subjective midpoint from a reliable leftward bias for long to a more rightward bias for short lines. Importantly, we found time-on-task and line length effects to be additive suggesting a common denominator for line bisection across all conditions, which is in disagreement with models that assume that bisection decisions in long and short lines are governed by distinct processes (Magnitude estimation vs Global/local distinction). Our findings emphasize the dynamic rather than static nature of spatial biases in midline judgement. They are best captured by theories of spatial attention positing that spatial bias is flexibly modulated, and subject to inter-hemispheric balance which can change over time or conditions to accommodate task demands or reflect fatigue. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Analysis of bias voltage dependent spectral response in Ga0.51In0.49P/Ga0.99In0.01As/Ge triple junction solar cell

    International Nuclear Information System (INIS)

    Sogabe, Tomah; Ogura, Akio; Okada, Yoshitaka

    2014-01-01

    Spectral response measurement plays great role in characterizing solar cell device because it directly reflects the efficiency by which the device converts the sunlight into an electrical current. Based on the spectral response results, the short circuit current of each subcell can be quantitatively determined. Although spectral response dependence on wavelength, i.e., the well-known external quantum efficiency (EQE), has been widely used in characterizing multijunction solar cell and has been well interpreted, detailed analysis of spectral response dependence on bias voltage (SR −V bias ) has not been reported so far. In this work, we have performed experimental and numerical studies on the SR −V bias for Ga 0.51 In 0.49 P/Ga 0.99 In 0.01 As/Ge triple junction solar cell. Phenomenological description was given to clarify the mechanism of operation matching point variation in SR −V bias measurements. The profile of SR−V bias curve was explained in detail by solving the coupled two-diode current-voltage characteristic transcend formula for each subcell

  11. Analysis of bias voltage dependent spectral response in Ga{sub 0.51}In{sub 0.49}P/Ga{sub 0.99}In{sub 0.01}As/Ge triple junction solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Sogabe, Tomah, E-mail: Sogabe@mbe.rcast.u-tokyo.ac.jp; Ogura, Akio; Okada, Yoshitaka [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo 4-6-1 Komaba, Meguro-ku, Tokyo 153-8504 (Japan)

    2014-02-21

    Spectral response measurement plays great role in characterizing solar cell device because it directly reflects the efficiency by which the device converts the sunlight into an electrical current. Based on the spectral response results, the short circuit current of each subcell can be quantitatively determined. Although spectral response dependence on wavelength, i.e., the well-known external quantum efficiency (EQE), has been widely used in characterizing multijunction solar cell and has been well interpreted, detailed analysis of spectral response dependence on bias voltage (SR −V{sub bias}) has not been reported so far. In this work, we have performed experimental and numerical studies on the SR −V{sub bias} for Ga{sub 0.51}In{sub 0.49}P/Ga{sub 0.99}In{sub 0.01}As/Ge triple junction solar cell. Phenomenological description was given to clarify the mechanism of operation matching point variation in SR −V{sub bias} measurements. The profile of SR−V{sub bias} curve was explained in detail by solving the coupled two-diode current-voltage characteristic transcend formula for each subcell.

  12. Characterization of the energy-dependent uncertainty and correlation in silicon neutron displacement damage metrics

    Directory of Open Access Journals (Sweden)

    Griffin Patrick

    2017-01-01

    Full Text Available A rigorous treatment of the uncertainty in the underlying nuclear data on silicon displacement damage metrics is presented. The uncertainty in the cross sections and recoil atom spectra are propagated into the energy-dependent uncertainty contribution in the silicon displacement kerma and damage energy using a Total Monte Carlo treatment. An energy-dependent covariance matrix is used to characterize the resulting uncertainty. A strong correlation between different reaction channels is observed in the high energy neutron contributions to the displacement damage metrics which supports the necessity of using a Monte Carlo based method to address the nonlinear nature of the uncertainty propagation.

  13. A thermalization energy analysis of the threshold voltage shift in amorphous indium gallium zinc oxide thin film transistors under simultaneous negative gate bias and illumination

    Energy Technology Data Exchange (ETDEWEB)

    Flewitt, A. J., E-mail: ajf@eng.cam.ac.uk [Electrical Engineering Division, Cambridge University, J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Powell, M. J. [252, Valley Drive, Kendal LA9 7SL (United Kingdom)

    2014-04-07

    It has been previously observed that thin film transistors (TFTs) utilizing an amorphous indium gallium zinc oxide (a-IGZO) semiconducting channel suffer from a threshold voltage shift when subjected to a negative gate bias and light illumination simultaneously. In this work, a thermalization energy analysis has been applied to previously published data on negative bias under illumination stress (NBIS) in a-IGZO TFTs. A barrier to defect conversion of 0.65–0.75 eV is extracted, which is consistent with reported energies of oxygen vacancy migration. The attempt-to-escape frequency is extracted to be 10{sup 6}−10{sup 7} s{sup −1}, which suggests a weak localization of carriers in band tail states over a 20–40 nm distance. Models for the NBIS mechanism based on charge trapping are reviewed and a defect pool model is proposed in which two distinct distributions of defect states exist in the a-IGZO band gap: these are associated with states that are formed as neutrally charged and 2+ charged oxygen vacancies at the time of film formation. In this model, threshold voltage shift is not due to a defect creation process, but to a change in the energy distribution of states in the band gap upon defect migration as this allows a state formed as a neutrally charged vacancy to be converted into one formed as a 2+ charged vacancy and vice versa. Carrier localization close to the defect migration site is necessary for the conversion process to take place, and such defect migration sites are associated with conduction and valence band tail states. Under negative gate bias stressing, the conduction band tail is depleted of carriers, but the bias is insufficient to accumulate holes in the valence band tail states, and so no threshold voltage shift results. It is only under illumination that the quasi Fermi level for holes is sufficiently lowered to allow occupation of valence band tail states. The resulting charge localization then allows a negative threshold voltage

  14. SU-F-T-561: Energy Dependence of a Scintillation Detector

    Energy Technology Data Exchange (ETDEWEB)

    Volotskova, O; Xu, A; Jozsef, G [NYU Medical Center, New York, NY (United States)

    2016-06-15

    Purpose: To investigate the response and dose rate dependence of a scintillation detector over a wide energy range. Methods: The energy dependence of W1 scintillation detector was tested with: 1) 50–225 keV beams generated by an animal irradiator, 2) a Leksell Gamma Knife Perfexion Co-60 source, 3) 6MV, 6FFF, 10FFF and 15MV photon beams, and 4) 6–20MeV electron beams from a linac. Calibrated linac beams were used to deliver 100 cGy to the detector at dmax in water under reference conditions. The gamma-knife measurement was performed in solid water (100 cGy with 16mm collimator). The low energy beams were calibrated with an ion chamber in air (TG-61), and the scintillation detector was placed at the same location as the ionization chamber during calibration. For the linac photon and electron beams, dose rate dependence was tested for 100–2400 and 100–800 MU/min. Results: The scintillation detector demonstrated strong energy dependence in the range of 50–225keV. The measured values were lower than the delivered dose and increased as the energy increased. Therapeutic photon beams showed energy independence with variations less than 1%. Therapeutic electron beams displayed the same sensitivity of ∼2–3% at their corresponding dmax depths. The change in dose-rate of photon and electron beams within the therapeutic energy range did not affect detector output (<0.5%). Measurements acquired with the gamma knife showed that the output data agreed with the delivered dose up to 3%. Conclusion: W1 scintillation detector output has a strong energy dependence in the diagnostic and orthovoltage energy range. Therapeutic photon beams exhibited energy independence with no observable dose-rate dependence. This study may aid in the implementation of a scintillation detector in QA programs by providing energy calibration factors.

  15. Role of quantum-confined stark effect on bias dependent photoluminescence of N-polar GaN/InGaN multi-quantum disk amber light emitting diodes

    Science.gov (United States)

    Tangi, Malleswararao; Mishra, Pawan; Janjua, Bilal; Prabaswara, Aditya; Zhao, Chao; Priante, Davide; Min, Jung-Wook; Ng, Tien Khee; Ooi, Boon S.

    2018-03-01

    We study the impact of quantum-confined stark effect (QCSE) on bias dependent micro-photoluminescence emission of the quantum disk (Q-disk) based nanowires light emitting diodes (NWs-LED) exhibiting the amber colored emission. The NWs are found to be nitrogen polar (N-polar) verified using KOH wet chemical etching and valence band spectrum analysis of high-resolution X-ray photoelectron spectroscopy. The crystal structure and quality of the NWs were investigated by high-angle annular dark field - scanning transmission electron microscopy. The LEDs were fabricated to acquire the bias dependent micro-photoluminescence spectra. We observe a redshift and a blueshift of the μPL peak in the forward and reverse bias conditions, respectively, with reference to zero bias, which is in contrast to the metal-polar InGaN well-based LEDs in the literature. Such opposite shifts of μPL peak emission observed for N-polar NWs-LEDs, in our study, are due to the change in the direction of the internal piezoelectric field. The quenching of PL intensity, under the reverse bias conditions, is ascribed to the reduction of electron-hole overlap. Furthermore, the blueshift of μPL emission with increasing excitation power reveals the suppression of QCSE resulting from the photo-generated carriers. Thereby, our study confirms the presence of QCSE for NWs-LEDs from both bias and power dependent μPL measurements. Thus, this study serves to understand the QCSE in N-polar InGaN Q-disk NWs-LEDs and other related wide-bandgap nitride nanowires, in general.

  16. Role of quantum-confined stark effect on bias dependent photoluminescence of N-polar GaN/InGaN multi-quantum disk amber light emitting diodes

    KAUST Repository

    Tangi, Malleswararao

    2018-03-09

    We study the impact of quantum-confined stark effect (QCSE) on bias dependent micro-photoluminescence emission of the quantum disk (Q-disk) based nanowires light emitting diodes (NWs-LED) exhibiting the amber colored emission. The NWs are found to be nitrogen polar (N-polar) verified using KOH wet chemical etching and valence band spectrum analysis of high-resolution X-ray photoelectron spectroscopy. The crystal structure and quality of the NWs were investigated by high-angle annular dark field - scanning transmission electron microscopy. The LEDs were fabricated to acquire the bias dependent micro-photoluminescence spectra. We observe a redshift and a blueshift of the μPL peak in the forward and reverse bias conditions, respectively, with reference to zero bias, which is in contrast to the metal-polar InGaN well-based LEDs in the literature. Such opposite shifts of μPL peak emission observed for N-polar NWs-LEDs, in our study, are due to the change in the direction of the internal piezoelectric field. The quenching of PL intensity, under the reverse bias conditions, is ascribed to the reduction of electron-hole overlap. Furthermore, the blueshift of μPL emission with increasing excitation power reveals the suppression of QCSE resulting from the photo-generated carriers. Thereby, our study confirms the presence of QCSE for NWs-LEDs from both bias and power dependent μPL measurements. Thus, this study serves to understand the QCSE in N-polar InGaN Q-disk NWs-LEDs and other related wide-bandgap nitride nanowires, in general.

  17. Energy dependence of contrast-detail-dose and object-detectability-dose curves for CT scanners

    International Nuclear Information System (INIS)

    Wagner, L.K.; Cohen, G.

    1982-01-01

    The energy dependence of contrast-detail-dose (CdD) and object-detectability-dose (OdD) curves for computed tomographic scanners is investigated. The effects of changes in beam energy on perceptibility are shown to be due to changes in signal-to-noise ratio resulting from changes in contrast and photon statistics. Energy-dependence analysis of OdD curves is shown to depend on the atomic composition of the phantom used to generate the curves, while such an analysis of CdD curves is independent of the atomic composition of the phantom. It is also shown that any OdD curve can be generated from CdD curves and that use of this fact rectifies any potential energy-dependent interpretation of CdD curves

  18. Microstructure and mechanical properties of Ti/Al co-doped DLC films: Dependence on sputtering current, source gas, and substrate bias

    International Nuclear Information System (INIS)

    Guo, Ting; Kong, Cuicui; Li, Xiaowei; Guo, Peng; Wang, Zhenyu; Wang, Aiying

    2017-01-01

    Highlights: • Ti/Al co-doped diamond-like carbon films were fabricated by a hybrid ion beam method. • Process parameters affected the structure and chemical state of co-doped Ti and Al. • The relation between microstructure and properties was investigated systematically. • The guidance to tailor the Ti/Al-DLC films with high performance was provided. - Abstract: Co-doping two metal elements into diamond-like carbon (DLC) films can reach the desirable combined properties, but the preparation and commercialized application of metal co-doped DLC films with well-defined structural properties are currently hindered by the non-comprehensive understanding of structural evolutions under different process parameters. Here, we fabricated the Ti/Al-DLC films using a unique hybrid ion beam system which enabled the independent control of metal content and carbon structure. The evolutions of microstructure, residual compressive stress and mechanical properties induced by the different process parameters including sputtering currents, C_2H_2 or CH_4 source gases and bias voltages were investigated systematically in order to perform in-depth analysis on the relation between the structure and properties in Ti/Al-DLC films. Results revealed that the variations of process parameters seriously affected the concentration and chemical bond state of co-doped Ti/Al atoms in amorphous carbon matrix or incident energies of C ions, which brought the complicated effect on amorphous carbon structures, accounting for the change of residual compressive stress, hardness and toughness. The present results provide the guidance for suitable, effective parameters selection to tailor the Ti/Al-DLC films with high performance for further applications.

  19. Microstructure and mechanical properties of Ti/Al co-doped DLC films: Dependence on sputtering current, source gas, and substrate bias

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Ting [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); School of Materials Science and Engineering, Shanghai University, Shanghai 200444 (China); Kong, Cuicui [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Ningbo University, Ningbo 315201 (China); Li, Xiaowei, E-mail: lixw@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Guo, Peng; Wang, Zhenyu [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Aiying, E-mail: aywang@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2017-07-15

    Highlights: • Ti/Al co-doped diamond-like carbon films were fabricated by a hybrid ion beam method. • Process parameters affected the structure and chemical state of co-doped Ti and Al. • The relation between microstructure and properties was investigated systematically. • The guidance to tailor the Ti/Al-DLC films with high performance was provided. - Abstract: Co-doping two metal elements into diamond-like carbon (DLC) films can reach the desirable combined properties, but the preparation and commercialized application of metal co-doped DLC films with well-defined structural properties are currently hindered by the non-comprehensive understanding of structural evolutions under different process parameters. Here, we fabricated the Ti/Al-DLC films using a unique hybrid ion beam system which enabled the independent control of metal content and carbon structure. The evolutions of microstructure, residual compressive stress and mechanical properties induced by the different process parameters including sputtering currents, C{sub 2}H{sub 2} or CH{sub 4} source gases and bias voltages were investigated systematically in order to perform in-depth analysis on the relation between the structure and properties in Ti/Al-DLC films. Results revealed that the variations of process parameters seriously affected the concentration and chemical bond state of co-doped Ti/Al atoms in amorphous carbon matrix or incident energies of C ions, which brought the complicated effect on amorphous carbon structures, accounting for the change of residual compressive stress, hardness and toughness. The present results provide the guidance for suitable, effective parameters selection to tailor the Ti/Al-DLC films with high performance for further applications.

  20. ENERGY-DEPENDENT TIME LAGS IN THE SEYFERT 1 GALAXY NGC 4593

    International Nuclear Information System (INIS)

    Sriram, K.; Agrawal, V. K.; Rao, A. R.

    2009-01-01

    We investigate the energy-time lag dependence of the source NGC 4593 using XMM-Newton/EPIC pn data. We found that the time lag dependency is linear in nature with respect to the logarithm of different energy bands. We also investigate the frequency-dependent time lags and identify that at some frequency range (5 x 10 -5 Hz to 2 x 10 -4 Hz) the X-ray emission is highly coherent, mildly frequency dependent, and very strongly energy dependent. These observations can be explained in the framework of the thermal Comptonization process, and they indicate a truncated accretion disk very close to the black hole. We discuss the plausible spectral state to explain the phenomenon and conclude that the observed properties bear a close resemblance to the intermediate state or the steep power-law state, found in galactic black hole sources.

  1. To be or Not to be Threatening, but What was the Question? Biased Face Evaluation in Social Anxiety and Depression Depends on How You Frame the Query

    OpenAIRE

    Lange, Wolf-Gero; Rinck, Mike; Becker, Eni S.

    2013-01-01

    Scientific evidence is equivocal on whether Social Anxiety Disorder (SAD) is characterized by a biased negative evaluation of facial expressions, even though it is assumed that such a bias plays a crucial role in the maintenance of the disorder. The way of framing the evaluation question may play an important role in the inconsistencies of earlier results. To investigate this issue, an unselected sample of 95 participants (11 males) with varying degrees of social anxiety and depressive sympto...

  2. Quantum models with energy-dependent potentials solvable in terms of exceptional orthogonal polynomials

    International Nuclear Information System (INIS)

    Schulze-Halberg, Axel; Roy, Pinaki

    2017-01-01

    We construct energy-dependent potentials for which the Schrödinger equations admit solutions in terms of exceptional orthogonal polynomials. Our method of construction is based on certain point transformations, applied to the equations of exceptional Hermite, Jacobi and Laguerre polynomials. We present several examples of boundary-value problems with energy-dependent potentials that admit a discrete spectrum and the corresponding normalizable solutions in closed form.

  3. Quantum models with energy-dependent potentials solvable in terms of exceptional orthogonal polynomials

    Energy Technology Data Exchange (ETDEWEB)

    Schulze-Halberg, Axel, E-mail: axgeschu@iun.edu [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary IN 46408 (United States); Department of Physics, Indiana University Northwest, 3400 Broadway, Gary IN 46408 (United States); Roy, Pinaki, E-mail: pinaki@isical.ac.in [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700108 (India)

    2017-03-15

    We construct energy-dependent potentials for which the Schrödinger equations admit solutions in terms of exceptional orthogonal polynomials. Our method of construction is based on certain point transformations, applied to the equations of exceptional Hermite, Jacobi and Laguerre polynomials. We present several examples of boundary-value problems with energy-dependent potentials that admit a discrete spectrum and the corresponding normalizable solutions in closed form.

  4. Energy-dependent microscopic optical potential for scattering of nucleons on light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Farag, M.Y.H.; Esmael, E.H. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Maridi, H.M. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Taiz University, Physics Department, Faculty of Applied Science, Taiz (Yemen)

    2014-06-15

    We present an energy-dependent microscopic optical model potential for elastic scattering of nucleons on light nuclei. The single-folding model is used for the real part of the optical potential (OP), while the imaginary part is derived within the high-energy approximation theory. The energy dependence of the OP is determined from the parameterization of the volume integrals those calculated from the best-fit OP that fit the experimental data of the cross sections and analyzing powers. This energy-dependent OP is successfully applied to analyze the proton elastic scattering of {sup 4,6,i8}He, {sup 6,7}Li, and {sup 9,10}Be nuclei at low and intermediate incident energies up to 200MeV/nucleon. (orig.)

  5. The Evaluation of the Impact of a Stand-Biased Desk on Energy Expenditure and Physical Activity for Elementary School Students

    Science.gov (United States)

    Benden, Mark E.; Zhao, Hongwei; Jeffrey, Christina E.; Wendel, Monica L.; Blake, Jamilia J.

    2014-01-01

    Due to the increasing prevalence of childhood obesity, the association between classroom furniture and energy expenditure as well as physical activity was examined using a standing-desk intervention in three central-Texas elementary schools. Of the 480 students in the 24 classrooms randomly assigned to either a seated or stand-biased desk equipped classroom, 374 agreed to participate in a week-long data collection during the fall and spring semesters. Each participant’s data was collected using Sensewear® armbands and was comprised of measures of energy expenditure (EE) and step count. A hierarchical linear mixed effects model showed that children in seated desk classrooms had significantly lower (EE) and fewer steps during the standardized lecture time than children in stand-biased classrooms after adjusting for grade, race, and gender. The use of a standing desk showed a significant higher mean energy expenditure by 0.16 kcal/min (p < 0.0001) in the fall semester, and a higher EE by 0.08 kcal/min (p = 0.0092) in the spring semester. PMID:25211776

  6. The Evaluation of the Impact of a Stand-Biased Desk on Energy Expenditure and Physical Activity for Elementary School Students

    Directory of Open Access Journals (Sweden)

    Mark E. Benden

    2014-09-01

    Full Text Available Due to the increasing prevalence of childhood obesity, the association between classroom furniture and energy expenditure as well as physical activity was examined using a standing-desk intervention in three central-Texas elementary schools. Of the 480 students in the 24 classrooms randomly assigned to either a seated or stand-biased desk equipped classroom, 374 agreed to participate in a week-long data collection during the fall and spring semesters. Each participant’s data was collected using Sensewear® armbands and was comprised of measures of energy expenditure (EE and step count. A hierarchical linear mixed effects model showed that children in seated desk classrooms had significantly lower (EE and fewer steps during the standardized lecture time than children in stand-biased classrooms after adjusting for grade, race, and gender. The use of a standing desk showed a significant higher mean energy expenditure by 0.16 kcal/min (p < 0.0001 in the fall semester, and a higher EE by 0.08 kcal/min (p = 0.0092 in the spring semester.

  7. Dynamic temperature dependence patterns in future energy demand models in the context of climate change

    International Nuclear Information System (INIS)

    Hekkenberg, M.; Moll, H.C.; Uiterkamp, A.J.M. Schoot

    2009-01-01

    Energy demand depends on outdoor temperature in a 'u' shaped fashion. Various studies have used this temperature dependence to investigate the effects of climate change on energy demand. Such studies contain implicit or explicit assumptions to describe expected socio-economic changes that may affect future energy demand. This paper critically analyzes these implicit or explicit assumptions and their possible effect on the studies' outcomes. First we analyze the interaction between the socio-economic structure and the temperature dependence pattern (TDP) of energy demand. We find that socio-economic changes may alter the TDP in various ways. Next we investigate how current studies manage these dynamics in socio-economic structure. We find that many studies systematically misrepresent the possible effect of socio-economic changes on the TDP of energy demand. Finally, we assess the consequences of these misrepresentations in an energy demand model based on temperature dependence and climate scenarios. Our model results indicate that expected socio-economic dynamics generally lead to an underestimation of future energy demand in models that misrepresent such dynamics. We conclude that future energy demand models should improve the incorporation of socio-economic dynamics. We propose dynamically modeling several key parameters and using direct meteorological data instead of degree days. (author)

  8. The effect of ν-bar(E) energy dependence at E 239Pu in the lower energy groups

    International Nuclear Information System (INIS)

    Gusejnov, A.G.; Gusejnov, M.A.; Rabotnov, N.S.

    1994-01-01

    The effect of the energy dependence of the average number of prompt neutrons on the 239 Pu fission BNAB-26 group cross-sections has been estimated. It was also found that the values of ν-bar(E) are lowered by approximately 1% when the temperature increases from 300 deg. K to 2000 deg. K. Taking this dependence into account may improve the predictability of the plutonium-fueled reactor characteristics. (author). 7 refs, 1 fig., 2 tabs

  9. A method for energy window optimization for quantitative tasks that includes the effects of model-mismatch on bias: application to Y-90 bremsstrahlung SPECT imaging

    International Nuclear Information System (INIS)

    Rong Xing; Du Yong; Frey, Eric C

    2012-01-01

    Quantitative Yttrium-90 ( 90 Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging has shown great potential to provide reliable estimates of 90 Y activity distribution for targeted radionuclide therapy dosimetry applications. One factor that potentially affects the reliability of the activity estimates is the choice of the acquisition energy window. In contrast to imaging conventional gamma photon emitters where the acquisition energy windows are usually placed around photopeaks, there has been great variation in the choice of the acquisition energy window for 90 Y imaging due to the continuous and broad energy distribution of the bremsstrahlung photons. In quantitative imaging of conventional gamma photon emitters, previous methods for optimizing the acquisition energy window assumed unbiased estimators and used the variance in the estimates as a figure of merit (FOM). However, for situations, such as 90 Y imaging, where there are errors in the modeling of the image formation process used in the reconstruction there will be bias in the activity estimates. In 90 Y bremsstrahlung imaging this will be especially important due to the high levels of scatter, multiple scatter, and collimator septal penetration and scatter. Thus variance will not be a complete measure of reliability of the estimates and thus is not a complete FOM. To address this, we first aimed to develop a new method to optimize the energy window that accounts for both the bias due to model-mismatch and the variance of the activity estimates. We applied this method to optimize the acquisition energy window for quantitative 90 Y bremsstrahlung SPECT imaging in microsphere brachytherapy. Since absorbed dose is defined as the absorbed energy from the radiation per unit mass of tissues in this new method we proposed a mass-weighted root mean squared error of the volume of interest (VOI) activity estimates as the FOM. To calculate this FOM, two analytical expressions were derived for

  10. A method for energy window optimization for quantitative tasks that includes the effects of model-mismatch on bias: application to Y-90 bremsstrahlung SPECT imaging.

    Science.gov (United States)

    Rong, Xing; Du, Yong; Frey, Eric C

    2012-06-21

    Quantitative Yttrium-90 ((90)Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging has shown great potential to provide reliable estimates of (90)Y activity distribution for targeted radionuclide therapy dosimetry applications. One factor that potentially affects the reliability of the activity estimates is the choice of the acquisition energy window. In contrast to imaging conventional gamma photon emitters where the acquisition energy windows are usually placed around photopeaks, there has been great variation in the choice of the acquisition energy window for (90)Y imaging due to the continuous and broad energy distribution of the bremsstrahlung photons. In quantitative imaging of conventional gamma photon emitters, previous methods for optimizing the acquisition energy window assumed unbiased estimators and used the variance in the estimates as a figure of merit (FOM). However, for situations, such as (90)Y imaging, where there are errors in the modeling of the image formation process used in the reconstruction there will be bias in the activity estimates. In (90)Y bremsstrahlung imaging this will be especially important due to the high levels of scatter, multiple scatter, and collimator septal penetration and scatter. Thus variance will not be a complete measure of reliability of the estimates and thus is not a complete FOM. To address this, we first aimed to develop a new method to optimize the energy window that accounts for both the bias due to model-mismatch and the variance of the activity estimates. We applied this method to optimize the acquisition energy window for quantitative (90)Y bremsstrahlung SPECT imaging in microsphere brachytherapy. Since absorbed dose is defined as the absorbed energy from the radiation per unit mass of tissues in this new method we proposed a mass-weighted root mean squared error of the volume of interest (VOI) activity estimates as the FOM. To calculate this FOM, two analytical expressions were

  11. Modelling Reliability of Supply and Infrastructural Dependency in Energy Distribution Systems

    OpenAIRE

    Helseth, Arild

    2008-01-01

    This thesis presents methods and models for assessing reliability of supply and infrastructural dependency in energy distribution systems with multiple energy carriers. The three energy carriers of electric power, natural gas and district heating are considered. Models and methods for assessing reliability of supply in electric power systems are well documented, frequently applied in the industry and continuously being subject to research and improvement. On the contrary, there are compar...

  12. Journal bias or author bias?

    Science.gov (United States)

    Harris, Ian

    2016-01-01

    I read with interest the comment by Mark Wilson in the Indian Journal of Medical Ethics regarding bias and conflicts of interest in medical journals. Wilson targets one journal (the New England Journal of Medicine: NEJM) and one particular "scandal" to make his point that journals' decisions on publication are biased by commercial conflicts of interest (CoIs). It is interesting that he chooses the NEJM which, by his own admission, had one of the strictest CoI policies and had published widely on this topic. The feeling is that if the NEJM can be guilty, they can all be guilty.

  13. High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

    International Nuclear Information System (INIS)

    Bizen, Teruhiko; Asano, Yoshihiro; Marechal, Xavier-Marie; Seike, Takamitsu; Aoki, Tsuyoshi; Fukami, Kenji; Hosoda, Naoyasu; Yonehara, Hiroto; Takagi, Tetsuya; Hara, Toru; Tanaka, Takashi; Kitamura, Hideo

    2007-01-01

    High-energy electron-beam bombardment of Nd 2 Fe 14 B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small

  14. High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

    Energy Technology Data Exchange (ETDEWEB)

    Bizen, Teruhiko [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)]. E-mail: bizen@spring8.or.jp; Asano, Yoshihiro [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Marechal, Xavier-Marie [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Seike, Takamitsu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Aoki, Tsuyoshi [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukami, Kenji [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yonehara, Hiroto [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takagi, Tetsuya [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hara, Toru [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Tanaka, Takashi [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kitamura, Hideo [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    2007-05-11

    High-energy electron-beam bombardment of Nd{sub 2}Fe{sub 14}B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small.

  15. Direct observation and theory of trajectory-dependent electronic energy losses in medium-energy ion scattering.

    Science.gov (United States)

    Hentz, A; Parkinson, G S; Quinn, P D; Muñoz-Márquez, M A; Woodruff, D P; Grande, P L; Schiwietz, G; Bailey, P; Noakes, T C Q

    2009-03-06

    The energy spectrum associated with scattering of 100 keV H+ ions from the outermost few atomic layers of Cu(111) in different scattering geometries provides direct evidence of trajectory-dependent electronic energy loss. Theoretical simulations, combining standard Monte Carlo calculations of the elastic scattering trajectories with coupled-channel calculations to describe inner-shell ionization and excitation as a function of impact parameter, reproduce the effects well and provide a means for far more complete analysis of medium-energy ion scattering data.

  16. Energy dependence of commercially available diode detectors for in-vivo dosimetry

    International Nuclear Information System (INIS)

    Saini, Amarjit S.; Zhu, Timothy C.

    2007-01-01

    The energy dependence of commercially available diode detectors was measured for nominal accelerating potential ranging between Co-60 and 17 MV. The measurements were performed in a liquid water phantom at 5 cm depth for 10x10 cm 2 collimator setting and source-to-detector distance of 100 cm. The response (nC/Gy) was normalized to Co-60 beam after corrections for the dose rate and temperature dependences for each diode. The energy dependence, calculated by taking the percent difference between the maximum and minimum sensitivity normalized to Co-60 beam, varied by 39% for the n-type Isorad Red, 26% for the n-type Isorad Electron, 19% for the QED Red (p-type), 15% for the QED Electron (p-type), 11% for the QED Blue (p-type), and 6% for the EDP10 diode for nominal accelerating potential between Co-60 and 17 MV. It varied by 34% for the Isorad-3 Gold 1 and 2, 35% for the Veridose Green, 15% for the Veridose Yellow, 9% for the Veridose Electron, 21% for the n-type QED Gold, 24% for the n-type QED Red, 3% for the EDP2 3G , 2% for the PFD (photon field detector), 7% for the EDP10 3G , and 16% for the EDP20 3G for nominal accelerating potential between Co-60 and 15 MV. The magnitude of the energy dependence is verified by Monte Carlo simulation. We concluded that the energy dependence does not depend on whether the diode is n- or p-type but rather depends mainly on the material around the die such as the buildup and the geometry of the buildup material. As a result, the value of the energy dependence can vary for each individual diode depending on the actual geometry and should be used with caution

  17. Wood-energy: success depends on the price of fossil energies and on the carbon tax level

    International Nuclear Information System (INIS)

    Defaye, Serge; Maindrault, Marc

    2016-01-01

    Illustrated by several graphs indicating the structure of fossil energy prices, the comparison between domestic fuel and wood-energy for public network exploitation, the levels of fossil prices and carbon tax for non-subsidised projects, this article analyses the development of biomass (and more particularly wood-energy), the success of which depends on the price of fossil energies and on the carbon tax level. It outlines the differences of price-building elements between fossil and renewable heat, that subsidies are necessary if reference prices are low. It discusses the influence of carbon tax level and of fossil prices. It finally identifies conditions to be met (reduction of fossil energy supply and therefore higher fossil prices, introduction of a carbon tax) to reach COP objectives

  18. Bombarding energy dependence of nucleon exchange and energy dissipation in the strongly damped reaction 209Bi + 136Xe

    International Nuclear Information System (INIS)

    Wilcke, W.W.; Schroeder, W.U.; Huizenga, J.R.; Birkelund, J.R.; Randrup, J.

    1980-01-01

    Although considerable progress has been achieved in the understanding of strongly damped reactions at energies several MeV/u above the Coulomb barrier, some important experimental results are not yet clearly understood. Among these is the degree of correlation between the nucleon exchange and the large energy losses observed. Experimental evidence suggesting nucleon exchange as described by a one-body model to be the major component of the dissipation mechanism is discussed. It is concluded that the previously unexplained bombarding energy dependence between energy loss and fragment charge dispersion can be understood on the basis of a nucleon exchange model, provided the Pauli exclusion principle is taken into account. No necessity is seen to invoke further energy dissipation mechanisms. 7 figures

  19. Energy-Dependent microscopic optical potential for p+{sup 9}Be elastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Maridi, H. M., E-mail: h.maridi@gmail.com [Physics Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Physics Department, Faculty of Applied Science, Taiz University, Taiz (Yemen); Farag, M. Y. H., E-mail: yehiafarag@cu.edu.eg; Esmael, E. H. [Physics Department, Faculty of Applied Science, Taiz University, Taiz (Yemen)

    2016-06-10

    The p+{sup 9}Be elastic scattering at an energy range up to 200 MeV/nucleon is analyzed using the single-folding model. The density- and isospin-dependent M3Y-Paris nucleon-nucleon (NN) interaction is used for the real part and the NN-scattering amplitude of the high-energy approximation for the imaginary one. The analysis reveals that the cross-section data are reproduced well at energies up to 100 MeV/nucleon by use of the partial-wave expansion. For higher energies, the eikonal approximation give results better than the partial-wave expansion calculations. The volume integrals of the optical-potential parts have systematic energy dependencies, and they are parameterized in empirical formulas.

  20. Biased Supervision

    OpenAIRE

    Josse Delfgaauw; Michiel Souverijn

    2014-01-01

    markdownabstract__Abstract__ When verifiable performance measures are imperfect, organizations often resort to subjective performance pay. This may give supervisors the power to direct employees towards tasks that mainly benefit the supervisor rather than the organization. We cast a principal-supervisor-agent model in a multitask setting, where the supervisor has an intrinsic preference towards specific tasks. We show that subjective performance pay based on evaluation by a biased supervisor ...

  1. Biased Brownian dynamics for rate constant calculation.

    OpenAIRE

    Zou, G; Skeel, R D; Subramaniam, S

    2000-01-01

    An enhanced sampling method-biased Brownian dynamics-is developed for the calculation of diffusion-limited biomolecular association reaction rates with high energy or entropy barriers. Biased Brownian dynamics introduces a biasing force in addition to the electrostatic force between the reactants, and it associates a probability weight with each trajectory. A simulation loses weight when movement is along the biasing force and gains weight when movement is against the biasing force. The sampl...

  2. Periodic position dependence of the energy measured in the CMS electromagnetic calorimeter

    CERN Document Server

    Descamps, Julien

    2006-01-01

    A uniform energy measurement response of the CMS electromagnetic calorimeter ECAL is essential for precision physics at the LHC. The ECAL barrel calorimeter consists of 61200 lead tungstate crystals arranged in a quasi-projective geometry. The energy of photons reaching the ECAL will be reconstructed by summing the channels corresponding to matrices of 3x3 or 5x5 crystals centred on the crystal with the largest energy deposit. The energy measured using such matrices of fixed size has been studied using electron test beam data taken in 2004. The variation of the energy containment with the incident electron impact position on the central crystal leads to a degradation of the energy resolution. A method using only the calorimeter information is presented to correct for the position dependent response. After correction, the energy resolution performance for uniform impact distributions of the electrons on the front face of a crystal approaches that obtained for maximal containment with a central impact. The univ...

  3. Space-time dependence between energy sources and climate related energy production

    Science.gov (United States)

    Engeland, Kolbjorn; Borga, Marco; Creutin, Jean-Dominique; Ramos, Maria-Helena; Tøfte, Lena; Warland, Geir

    2014-05-01

    The European Renewable Energy Directive adopted in 2009 focuses on achieving a 20% share of renewable energy in the EU overall energy mix by 2020. A major part of renewable energy production is related to climate, called "climate related energy" (CRE) production. CRE production systems (wind, solar, and hydropower) are characterized by a large degree of intermittency and variability on both short and long time scales due to the natural variability of climate variables. The main strategies to handle the variability of CRE production include energy-storage, -transport, -diversity and -information (smart grids). The three first strategies aim to smooth out the intermittency and variability of CRE production in time and space whereas the last strategy aims to provide a more optimal interaction between energy production and demand, i.e. to smooth out the residual load (the difference between demand and production). In order to increase the CRE share in the electricity system, it is essential to understand the space-time co-variability between the weather variables and CRE production under both current and future climates. This study presents a review of the literature that searches to tackle these problems. It reveals that the majority of studies deals with either a single CRE source or with the combination of two CREs, mostly wind and solar. This may be due to the fact that the most advanced countries in terms of wind equipment have also very little hydropower potential (Denmark, Ireland or UK, for instance). Hydropower is characterized by both a large storage capacity and flexibility in electricity production, and has therefore a large potential for both balancing and storing energy from wind- and solar-power. Several studies look at how to better connect regions with large share of hydropower (e.g., Scandinavia and the Alps) to regions with high shares of wind- and solar-power (e.g., green battery North-Sea net). Considering time scales, various studies consider wind

  4. Energy and angular dependence of the personal dosemeter in use at ITN-DPRSN

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Joao G. [Departamento de Proteccao Radiologica e Seguranca Nuclear, Instituto Tecnologico e Nuclear, EN 10, 2686-953 Sacavem (Portugal)], E-mail: jgalves@itn.pt; Calado, Ana M.; Cardoso, Joao V.; Santos, Luis M. [Departamento de Proteccao Radiologica e Seguranca Nuclear, Instituto Tecnologico e Nuclear, EN 10, 2686-953 Sacavem (Portugal)

    2008-02-15

    In this paper the characterization of the dosimetry system and of the personal dosemeter in terms of the stability of the reader calibration factors and of the linearity of the response for the 137Cs reference radiation is presented. The energy and angular dependence of the whole body dosemeter are also shown. The energy dependence was determined performing irradiations with the X-ray narrow series beams N30, N40, N60, N80, N100, N120 and with the gamma reference radiations of 137Cs and 60Co [ISO 4037-1, 1996. X and Gamma Reference Radiation for Calibrating Dosemeters and Doserate Meters and for Determining Their Response as a Function of Photon Energy-Part 1: Radiation Characteristics and Production Methods. International Organization for Standardization, Geneva] in terms of Hp(10) incident on the ISO water slab phantom. The angular dependence of the dosemeter was determined for the angles 0 deg., {+-}20 deg., {+-}40 deg. and {+-}60 deg. with normal using the above mentioned radiation fields. All irradiations were performed at the Laboratorio de Metrologia das Radiacoes lonizantes of ITN-DPRSN. The experiments presented in this paper show the thermoluminescence dosimetry (TLD) system is stable and presents a linear behaviour over and extended dose range. The measurements allowed the determination of the energy dependence at normal incidence and of the angular dependence of the dosemeter currently in use. Further studies are being carried out in order to implement correction factors for supralinearity and low energy measurements.

  5. Using Data-Dependent Priors to Mitigate Small Sample Bias in Latent Growth Models: A Discussion and Illustration Using M"plus"

    Science.gov (United States)

    McNeish, Daniel M.

    2016-01-01

    Mixed-effects models (MEMs) and latent growth models (LGMs) are often considered interchangeable save the discipline-specific nomenclature. Software implementations of these models, however, are not interchangeable, particularly with small sample sizes. Restricted maximum likelihood estimation that mitigates small sample bias in MEMs has not been…

  6. Racial Bias in Personality Assessment: Using the MMPI-2 to Predict Psychiatric Diagnoses of African American and Caucasian Chemical Dependency Inpatients

    Science.gov (United States)

    Monnot, Matthew J.; Quirk, Stuart W.; Hoerger, Michael; Brewer, Linda

    2009-01-01

    An assessment of predictive bias was conducted on numerous scales of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; J. N. Butcher, W. G. Dahlstrom, J. R. Graham, A. Tellegen, & B. Kaemmer, 1989), including the Restructured Clinical (RC) scales, in the prediction of clinical diagnostic status for African American and Caucasian male…

  7. Exchange bias in nearly perpendicularly coupled ferromagnetic/ferromagnetic system

    International Nuclear Information System (INIS)

    Bu, K.M.; Kwon, H.Y.; Oh, S.W.; Won, C.

    2012-01-01

    Exchange bias phenomena appear not only in ferromagnetic/antiferromagnetic systems but also in ferromagnetic/ferromagnetic systems in which two layers are nearly perpendicularly coupled. We investigated the origin of the symmetry-breaking mechanism and the relationship between the exchange bias and the system's energy parameters. We compared the results of computational Monte Carlo simulations with those of theoretical model calculation. We found that the exchange bias exhibited nonlinear behaviors, including sign reversal and singularities. These complicated behaviors were caused by two distinct magnetization processes depending on the interlayer coupling strength. The exchange bias reached a maximum at the transition between the two magnetization processes. - Highlights: ► Exchange bias phenomena are found in perpendicularly coupled F/F systems. ► Exchange bias exhibits nonlinear behaviors, including sign reversal and singularities. ► These complicated behaviors were caused by two distinct magnetization processes. ► Exchange bias reached a maximum at the transition between the two magnetization processes. ► We established an equation to maximize the exchange bias in perpendicularly coupled F/F system.

  8. The significance of temperature dependence on the piezoelectric energy harvesting by using a phononic crystal

    Science.gov (United States)

    Aly, Arafa H.; Nagaty, Ahmed; Khalifa, Zaki; Mehaney, Ahmed

    2018-05-01

    In this study, an acoustic energy harvester based on a two-dimensional phononic crystal has been constructed. The present structure consists of silicon cylinders in the air background with a polyvinylidene fluoride cylinder as a defect to confine the acoustic energy. The presented energy harvester depends on the piezoelectric effect (using the piezoelectric material polyvinylidene fluoride) that converts the confined acoustic energy to electric energy. The maximum output voltage obtained equals 170 mV. Moreover, the results revealed that the output voltage can be increased with increasing temperature. In addition, the effects of the load resistance and the geometry of the piezoelectric material on the output voltage have been studied theoretically. Based on these results, all previous studies about energy harvesting in phononic structures must take temperature effects into account.

  9. Trajectory-dependent energy loss for swift He atoms axially scattered off a silver surface

    Energy Technology Data Exchange (ETDEWEB)

    Ríos Rubiano, C.A. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28, 1428 Buenos Aires (Argentina); Bocan, G.A. [Centro Atómico Bariloche, Comisión Nacional de Energía Ató mica, and Consejo Nacional de Investigaciones Científicas y Técnicas, S.C. de Bariloche, Río Negro (Argentina); Juaristi, J.I. [Departamento de Física de Materiales, Facultad de Químicas, UPV/EHU, 20018 San Sebastián (Spain); Donostia International Physics Center (DIPC) and Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 San Sebastián (Spain); Gravielle, M.S., E-mail: msilvia@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28, 1428 Buenos Aires (Argentina)

    2014-12-01

    Angle- and energy-loss-resolved distributions of helium atoms grazingly scattered from a Ag(110) surface along low indexed crystallographic directions are investigated considering impact energies in the few keV range. Final projectile distributions are evaluated within a semi-classical formalism that includes dissipative effects due to electron–hole excitations through a friction force. For mono-energetic beams impinging along the [11{sup ¯}0],[11{sup ¯}2] and [001] directions, the model predicts the presence of multiple peak structures in energy-loss spectra. Such structures provide detailed information about the trajectory-dependent energy loss. However, when the experimental dispersion of the incident beam is taken into account, these energy-loss peaks are completely washed out, giving rise to a smooth energy-loss distribution, in fairly good agreement with available experimental data.

  10. A method for solving a three-body problem with energy-dependent interactions

    International Nuclear Information System (INIS)

    Safronov, A.N.

    1994-01-01

    A method is proposed for solving a three-body problem with energy-dependent interactions. This method is based on introducing the dependence of scattering operators and state vectors on an additional external parameter. Effects caused by the energy dependence of the interaction operator are investigated by using the unitary condition for the amplitude of the 2 → 2 and 2 → 3 transitions. It is shown, in particular, that taking this dependence into account leads to a change in the relation between the asymptotic normalization factor of the wave function of the three-body bound state and the vertex constant of virtual dissociation (synthesis) of the system into two fragments. 15 refs

  11. The change from fossil fuel dependence to sustainable energy sources in Nigeria

    International Nuclear Information System (INIS)

    Chukwu, C.; Ajedegba, J.

    2006-01-01

    Nigeria faces a serious energy crisis due to declining electricity generation from domestic power plants. Although the country is highly dependent on fossil fuel resources, Nigeria has a range of unexploited biomass and hydro power resources, as well as extensive solar energy potential. This paper presented a current energy balance of Nigeria and examined ways of reaching an environmentally sustainable energy balance through the use of a mix of renewable resources. Supply and consumption details of domestic, industrial and transportation sectors as well as electricity production statistics were presented. Total hydropower potential based on the country's river system was estimated to be 10,000 MW. It was estimated that Nigeria has an average of 1.804 x 10 15 of incident solar energy annually, which is 27 times the nation's total conventional energy resources in energy units. It was noted that Nigeria also possesses a significant amount of biomass resources from several large forests that may be used to supply domestic cooking and heating needs as well as for ethanol production. It was noted that wind energy may not be a viable alternative for large scale electricity production in Nigeria. Recommendations to promote the use of renewable resources in the national energy mix included encouraging the decentralization of energy supplies; discouraging the use of wood as fuel; promoting efficient methods in the use of biomass energy resources; private sector participation; and global partnerships. 15 refs., 7 tabs

  12. Analysis of optical near-field energy transfer by stochastic model unifying architectural dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, Makoto, E-mail: naruse@nict.go.jp [Photonic Network Research Institute, National Institute of Information and Communications Technology, 4-2-1 Nukui-kita, Koganei, Tokyo 184-8795 (Japan); Nanophotonics Research Center, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Akahane, Kouichi; Yamamoto, Naokatsu [Photonic Network Research Institute, National Institute of Information and Communications Technology, 4-2-1 Nukui-kita, Koganei, Tokyo 184-8795 (Japan); Holmström, Petter [Laboratory of Photonics and Microwave Engineering, Royal Institute of Technology (KTH), SE-164 40 Kista (Sweden); Thylén, Lars [Laboratory of Photonics and Microwave Engineering, Royal Institute of Technology (KTH), SE-164 40 Kista (Sweden); Hewlett-Packard Laboratories, Palo Alto, California 94304 (United States); Huant, Serge [Institut Néel, CNRS and Université Joseph Fourier, 25 rue des Martyrs BP 166, 38042 Grenoble Cedex 9 (France); Ohtsu, Motoichi [Nanophotonics Research Center, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Electrical Engineering and Information Systems, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2014-04-21

    We theoretically and experimentally demonstrate energy transfer mediated by optical near-field interactions in a multi-layer InAs quantum dot (QD) structure composed of a single layer of larger dots and N layers of smaller ones. We construct a stochastic model in which optical near-field interactions that follow a Yukawa potential, QD size fluctuations, and temperature-dependent energy level broadening are unified, enabling us to examine device-architecture-dependent energy transfer efficiencies. The model results are consistent with the experiments. This study provides an insight into optical energy transfer involving inherent disorders in materials and paves the way to systematic design principles of nanophotonic devices that will allow optimized performance and the realization of designated functions.

  13. Analysis of optical near-field energy transfer by stochastic model unifying architectural dependencies

    International Nuclear Information System (INIS)

    Naruse, Makoto; Akahane, Kouichi; Yamamoto, Naokatsu; Holmström, Petter; Thylén, Lars; Huant, Serge; Ohtsu, Motoichi

    2014-01-01

    We theoretically and experimentally demonstrate energy transfer mediated by optical near-field interactions in a multi-layer InAs quantum dot (QD) structure composed of a single layer of larger dots and N layers of smaller ones. We construct a stochastic model in which optical near-field interactions that follow a Yukawa potential, QD size fluctuations, and temperature-dependent energy level broadening are unified, enabling us to examine device-architecture-dependent energy transfer efficiencies. The model results are consistent with the experiments. This study provides an insight into optical energy transfer involving inherent disorders in materials and paves the way to systematic design principles of nanophotonic devices that will allow optimized performance and the realization of designated functions

  14. Dependence of the quasipotential on the total energy of a two-particle system

    International Nuclear Information System (INIS)

    Kapshai, V.N.; Savrin, V.I.; Skachkov, N.B.

    1987-01-01

    For a system of two relativistic particles described in the Logunov-Tavkhelidze one-time approach the dependence of the quasipotential of one-boson exchange on the total energy of the system is calculated. It is shown that despite the nonlocal form of the obtained quasipotential the three-dimensional equations for the waves function can be reduced by a partial expansion to one-dimensional equations. The influence of the energy dependence of the quasipotential on its behavior in the coordinate representation is discussed

  15. On the dependence of quasipotential on the total energy of a two-particle system

    International Nuclear Information System (INIS)

    Kapshaj, V.N.; Savrin, V.I.

    1986-01-01

    For a system of two relativistic particles described in the framework of the Logunov-Tavkhelidze one-time approach the dependence is calculated of the one-boson exchange potential on the total energy of the system. It is shown that in spite of a nonlocal form of the quasipotential obtained, three-dimensional equations for the wave function are reduced to one-dimensional ones by means of partial expansion. Influence of the energy dependence of the quasipotential on its behaviour in the coordinate representation is discussed

  16. Nanoporous metal film: An energy-dependent transmission device for electron waves

    International Nuclear Information System (INIS)

    Grech, S.; Degiovanni, A.; Lapena, L.; Morin, R.

    2011-01-01

    We measure electron transmission through free-standing ultrathin nanoporous gold films, using the coherent electron beam emitted by sharp field emission tips in a low energy electron projection microscope setup. Transmission coefficient versus electron wavelength plots show periodic oscillations between 75 and 850 eV. These oscillations result from the energy dependence of interference between paths through the gold and paths through the nanometer-sized pores of the film. We reveal that these films constitute high transmittance quantum devices acting on electron waves through a wavelength-dependent complex transmittance defined by the porosity and the thickness of the film.

  17. Energy and Beam-Offset dependence of the Luminosity weighted depolarization for CLIC

    CERN Document Server

    Esberg, Jakob; Uggerhoj, Ulrik; Dalena, Barbara

    2011-01-01

    We report on simulations of e+e- depolarization due to beam-beam effects. These effects are studied for CLIC at 3 TeV, using GUINEA PIG++. We find a strong energy dependence of the luminosity weighted depolarization. In the luminosity peak at CLIC the total luminosity weighted depolarization remains below the one per-mil level. The effect of a vertical offset on the energy dependent depolarization is investigated. The depolarization in the luminosity peak remains below per-cent level even for 5sy offsets.

  18. Experimental investigation of the energy and temperature dependence of beryllium self sputtering

    International Nuclear Information System (INIS)

    Korshunov, S.N.; Guseva, M.I.; Stolijarova, V.G.

    1995-01-01

    The low-Z metal beryllium is considered as plasma facing material (PFM) for the ITER. It is expected that operation temperature range of beryllium PFM will be (670 - 1070) K. While experimental Be-sputtering data bases exist for H + , D + and He + -ions, the self-sputtering yields of Be have only been estimated by computer simulation. In this paper we report the experimental results on the energy and temperature dependence of the beryllium self-sputtering yield (S). The energy dependence of S s in the energy range (0.5 - 10.0) keV was measured at 670 K. The self-sputtering yield of Be attains its maximal value at the ion energy of 1.5 keV, being equal to 0.32 ± at./ion. Comparison of the experimental results and theoretical prediction shows a good agreement for energy dependence of S s . The temperature dependence of S s in the temperature range (370-1070)K was obtained for 0.9keV Be + -ions. The value of S s is not changed up to 870 K. It sharply increases at the temperatures above 870 attaining the value of 0.75 at./ion at 1070 K

  19. Systematic studies of binding energy dependence of neutron-proton momentum correlation function

    International Nuclear Information System (INIS)

    Wei, Y B; Ma, Y G; Shen, W Q; Ma, G L; Wang, K; Cai, X Z; Zhong, C; Guo, W; Chen, J G; Fang, D Q; Tian, W D; Zhou, X F

    2004-01-01

    Hanbury Brown-Twiss (HBT) results of the neutron-proton correlation function have been systematically investigated for a series of nuclear reactions with light projectiles with the help of the isospin-dependent quantum molecular dynamics model. The relationship between the binding energy per nucleon of the projectiles and the strength of the neutron-proton HBT at small relative momentum has been obtained. Results show that neutron-proton HBT results are sensitive to the binding energy per nucleon

  20. Energy dependence of the 16O + 12C potential of interaction

    Directory of Open Access Journals (Sweden)

    O. A. Ponkratenko

    2013-09-01

    Full Text Available The 16O + 12C scattering data originating from various measurements in the energy range from 1 to 100 MeV/nucleon have been analyzed within optical model (OM. As a result the global energy dependent 16O + 12C - OM-potential has been obtained. Satisfactory description of experimental data is achieved. While analyzing differential cross sections of the elastic scattering and fusion cross sections were calculated using var-ious types of optical potentials.

  1. On the energy dependence of the D{sup +}/D{sup −} production asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Cazaroto, E.R., E-mail: cazaroto@if.usp.br [Instituto de Física, Universidade de São Paulo, C.P. 66318, CEP 05315-970, São Paulo, SP (Brazil); Goncalves, V.P. [Instituto de Física e Matemática, Universidade Federal de Pelotas, C.P. 354, CEP 96010-900, Pelotas, RS (Brazil); Navarra, F.S.; Nielsen, M. [Instituto de Física, Universidade de São Paulo, C.P. 66318, CEP 05315-970, São Paulo, SP (Brazil)

    2013-07-09

    In this Letter we discuss the origin of the asymmetry present in D meson production and its energy dependence. In particular, we have applied the meson cloud model to calculate the asymmetries in D{sup −}/D{sup +} meson production in high energy pp collisions and find a good agreement with recent LHCb data. Although small, this non-vanishing asymmetry may shed light on the role played by the charm meson cloud of the proton.

  2. Change of energy dependence for X-rays of photodiode detector

    International Nuclear Information System (INIS)

    Silva, M.F. da; Freitas, L.C. de

    1992-01-01

    The energy dependence of photodiode Siemens SFH-206 for X-rays beams of 24 kV to 50 kV was studied and compared with the ionization chamber of parallel plates. The photodiode presented 450% of maxim change response for the energy band studied. A study was made, using aluminium, acrylic, mylar aluminized and mylar graphitized filters and showed that the two last reduce this maxim change response to 101% and 108%, respectively. (C.G.C.)

  3. Beam energy and centrality dependence of two-pion Bose-Einstein correlations at SPS energies

    International Nuclear Information System (INIS)

    Adamova, D.; Agakichiev, G.; Appelshaeuser, H.; Belaga, V.; Braun-Munzinger, P.; Campagnolo, R.; Castillo, A.; Cherlin, A.; Damjanovic, S.; Dietel, T.; Dietrich, L.; Drees, A.; Esumi, S.I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glaessel, P.; Hering, G.; Holeczek, J.; Kushpil, V.; Lenkeit, B.; Ludolphs, W.; Maas, A.; Marin, A.; Milosevic, J.; Milov, A.; Miskowiec, D.; Musa, L.; Panebrattsev, Yu.; Petchenova, O.; Petracek, V.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Rehak, P.; Richter, M.; Sako, H.; Schmitz, W.; Schukraft, J.; Sedykh, S.; Seipp, W.; Sharma, A.; Shimansky, S.; Slivova, J.; Specht, H.J.; Stachel, J.; Sumbera, M.; Tilsner, H.; Tserruya, I.; Wessels, J.P.; Wienold, T.; Windelband, B.; Wurm, J.P.; Xie, W.; Yurevich, S.; Yurevich, V.V.

    2003-01-01

    Results are presented of a two-pion interferometry (HBT) analysis in Pb+Au collisions at 40, 80, and 158 A GeV. A detailed study of the Bertsch-Pratt HBT radius parameters has been performed as function of the mean pair transverse momentum k t and in bins of the centrality of the collision. From these results we extract model-dependent information about the space-time evolution of the reaction. An investigation of the effective volume of the pion emitting system provides an important tool to study the properties of thermal pion freeze-out

  4. Beam energy and centrality dependence of two-pion Bose-Einstein correlations at SPS energies

    Energy Technology Data Exchange (ETDEWEB)

    Adamova, D.; Agakichiev, G.; Appelshaeuser, H. E-mail: appels@physi.uni-heidelberg.de; Belaga, V.; Braun-Munzinger, P.; Campagnolo, R.; Castillo, A.; Cherlin, A.; Damjanovic, S.; Dietel, T.; Dietrich, L.; Drees, A.; Esumi, S.I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glaessel, P.; Hering, G.; Holeczek, J.; Kushpil, V.; Lenkeit, B.; Ludolphs, W.; Maas, A.; Marin, A.; Milosevic, J.; Milov, A.; Miskowiec, D.; Musa, L.; Panebrattsev, Yu.; Petchenova, O.; Petracek, V.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Rehak, P.; Richter, M.; Sako, H.; Schmitz, W.; Schukraft, J.; Sedykh, S.; Seipp, W.; Sharma, A.; Shimansky, S.; Slivova, J.; Specht, H.J.; Stachel, J.; Sumbera, M.; Tilsner, H.; Tserruya, I.; Wessels, J.P.; Wienold, T.; Windelband, B.; Wurm, J.P.; Xie, W.; Yurevich, S.; Yurevich, V.V

    2003-02-10

    Results are presented of a two-pion interferometry (HBT) analysis in Pb+Au collisions at 40, 80, and 158 A GeV. A detailed study of the Bertsch-Pratt HBT radius parameters has been performed as function of the mean pair transverse momentum k{sub t} and in bins of the centrality of the collision. From these results we extract model-dependent information about the space-time evolution of the reaction. An investigation of the effective volume of the pion emitting system provides an important tool to study the properties of thermal pion freeze-out.

  5. Latitudinal Dependence of the Energy Input into the Mesosphere by High Energy Electrons

    Science.gov (United States)

    Wagner, C. U.; Nikutowski, B.; Ranta, H.

    1984-01-01

    Night-time ionspheric absorption measurements give the possibility to study the precipitation of high energy electrons into the mesosphere during and after magnetospheric storms. The uniform Finnish riometer network was used together with measurements from Kuhlungsborn and Collm (GDR) to investigate the night-time absorption as a function of latitude (L=6.5 to 2.5) and storm-time for seven storms. The common trends visible in all these events are summarized in a schematic average picture, showing the distribution of increased ionospheric absorption as a function of latitude (L value) and storm-time.

  6. Scaling-law for the energy dependence of anatomic power spectrum in dedicated breast CT

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, Srinivasan; Shi, Linxi; Glick, Stephen J.; Karellas, Andrew [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States)

    2013-01-15

    Purpose: To determine the x-ray photon energy dependence of the anatomic power spectrum of the breast when imaged with dedicated breast computed tomography (CT). Methods: A theoretical framework for scaling the empirically determined anatomic power spectrum at one x-ray photon energy to that at any given x-ray photon energy when imaged with dedicated breast CT was developed. Theory predicted that when the anatomic power spectrum is fitted with a power curve of the form k f{sup -{beta}}, where k and {beta} are fit coefficients and f is spatial frequency, the exponent {beta} would be independent of x-ray photon energy (E), and the amplitude k scales with the square of the difference in energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues. Twenty mastectomy specimens based numerical phantoms that were previously imaged with a benchtop flat-panel cone-beam CT system were converted to 3D distribution of glandular weight fraction (f{sub g}) and were used to verify the theoretical findings. The 3D power spectrum was computed in terms of f{sub g} and after converting to linear attenuation coefficients at monoenergetic x-ray photon energies of 20-80 keV in 5 keV intervals. The 1D power spectra along the axes were extracted and fitted with a power curve of the form k f{sup -{beta}}. The energy dependence of k and {beta} were analyzed. Results: For the 20 mastectomy specimen based numerical phantoms used in the study, the exponent {beta} was found to be in the range of 2.34-2.42, depending on the axis of measurement. Numerical simulations agreed with the theoretical predictions that for a power-law anatomic spectrum of the form k f{sup -{beta}}, {beta} was independent of E and k(E) =k{sub 1}[{mu}{sub g}(E) -{mu}{sub a}(E)]{sup 2}, where k{sub 1} is a constant, and {mu}{sub g}(E) and {mu}{sub a}(E) represent the energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues, respectively. Conclusions: Numerical

  7. New formula for dependence of molecular electronic energy on internuclear distance

    International Nuclear Information System (INIS)

    Rebane, T.K.

    1988-01-01

    We formulate an integral virial theorem which connects the change in the molecular electronic energy during finite changes in the size of the nuclear core (in the case of a diatomic molecule, during finite changes of the internuclear distance) with a matrix element of the kinetic electronic energy operator and with an overlap integral between wave functions. Our results can be used to calculate the dependence of the molecular electronic energy on the internuclear distance, as well as to check the quality of, and to improve, the approximate electronic wave functions. The theory is illustrated by the simplest example of the approximate MO LCAO wave function for the hydrogen molecular ion

  8. GDH-Dependent Glutamate Oxidation in the Brain Dictates Peripheral Energy Substrate Distribution

    DEFF Research Database (Denmark)

    Karaca, Melis; Frigerio, Francesca; Migrenne, Stephanie

    2015-01-01

    in a central energy-deprivation state with increased ADP/ATP ratios and phospho-AMPK in the hypothalamus. This induced changes in the autonomous nervous system balance, with increased sympathetic activity promoting hepatic glucose production and mobilization of substrates reshaping peripheral energy stores...... glutamate dehydrogenase (GDH) activity. Here, we investigated the significance of glutamate as energy substrate for the brain. Upon glutamate exposure, astrocytes generated ATP in a GDH-dependent way. The observed lack of glutamate oxidation in brain-specific GDH null CnsGlud1(-/-) mice resulted...

  9. Local charge nonequilibrium and anomalous energy dependence of normalized moments in narrow rapidity windows

    International Nuclear Information System (INIS)

    Wu Yuanfang; Liu Lianshou

    1990-01-01

    From the study of even and odd multiplicity distributions for hadron-hadron collision in different rapidity windows, we propose a simple picture for charge correlation with nonzero correlation length and calculate the multiplicity distributions and the normalized moments in different rapidity windows at different energies. The results explain the experimentally observed coincidence and separation of even and odd distributions and also the anomalous energy dependence of normalized moments in narrow rapidity windows. The reason for the separation of even-odd distributions, appearing first at large multiplicities, is shown to be energy conservation. The special role of no-particle events in narrow rapidity windows is pointed out

  10. SYMMETRY PROPERTIES OF THE COULOMB POTENTIAL WITH A LINEAR DEPENDENCE ON ENERGY

    Directory of Open Access Journals (Sweden)

    Radu Budaca

    2017-12-01

    Full Text Available The D-dimensional Schr ̈odinger equation for a Coulomb potential with a coupling constant depending linearly on energy is analytically solved. The energy spectrum in the asymptotic regime of the slope parameter is found to be fully determined up to a scale only by its quantum numbers. The raising and lowering operators for this limiting model are determined from the recurrence properties of the associated solutions. It is shown that they satisfy the commutation relations of an SU(1,1 algebra and act on wave-functions which are normalized differently from the case of the usual bound state problem for an energy independent Coulomb potential.

  11. Photon energy dependence and angular response of glass display used in mobile phones for accident dosimetry

    International Nuclear Information System (INIS)

    Discher, Michael; Greiter, Matthias; Woda, Clemens

    2014-01-01

    Previous studies have shown that glass displays extracted from mobile phones are suitable as emergency dosimeters in case of an accidental radiation overexposure using the thermoluminescence (TL) method. So far these studies have focused only on recovering the absorbed dose to the material. However, dose in air or dose to the victim carrying the device might be significantly different. Therefore the aim of this work was to investigate photon energy dependence and angular response of glass display used in modern mobile phones. An over-response of about a factor of five is observed for low photon energies compared to the response to Cs-137 (662 keV) which is in reasonable agreement with calculated values mass energy-absorption coefficients of glass and air. Little variation in the energy dependence can be seen for glass displays coming from three different mobile phone models. The angular response for display glass is flat with regard to air kerma within the incident angle of ±60°, independent of the irradiation setup used (with a water phantom or with air kerma reference conditions). For incident angles of 90° the shielding effect of the mobile phones becomes important. With the dosimetric characterization of the photon energy and angular dependencies the absorbed dose in a glass display can be transferred to a reference air kerma dose and provides a useful option for retrospective accident dosimetry. - Highlights: • Determination of the photon energy dependence and angular response for display glass used as an accident dosimeter. • Over-response of about a factor of five for low photon energies. • Flat angular response within incident angles between ±60°

  12. Computational scheme for pH-dependent binding free energy calculation with explicit solvent.

    Science.gov (United States)

    Lee, Juyong; Miller, Benjamin T; Brooks, Bernard R

    2016-01-01

    We present a computational scheme to compute the pH-dependence of binding free energy with explicit solvent. Despite the importance of pH, the effect of pH has been generally neglected in binding free energy calculations because of a lack of accurate methods to model it. To address this limitation, we use a constant-pH methodology to obtain a true ensemble of multiple protonation states of a titratable system at a given pH and analyze the ensemble using the Bennett acceptance ratio (BAR) method. The constant pH method is based on the combination of enveloping distribution sampling (EDS) with the Hamiltonian replica exchange method (HREM), which yields an accurate semi-grand canonical ensemble of a titratable system. By considering the free energy change of constraining multiple protonation states to a single state or releasing a single protonation state to multiple states, the pH dependent binding free energy profile can be obtained. We perform benchmark simulations of a host-guest system: cucurbit[7]uril (CB[7]) and benzimidazole (BZ). BZ experiences a large pKa shift upon complex formation. The pH-dependent binding free energy profiles of the benchmark system are obtained with three different long-range interaction calculation schemes: a cutoff, the particle mesh Ewald (PME), and the isotropic periodic sum (IPS) method. Our scheme captures the pH-dependent behavior of binding free energy successfully. Absolute binding free energy values obtained with the PME and IPS methods are consistent, while cutoff method results are off by 2 kcal mol(-1) . We also discuss the characteristics of three long-range interaction calculation methods for constant-pH simulations. © 2015 The Protein Society.

  13. Quantum transfer energy in the framework of time-dependent dipole-dipole interaction

    Science.gov (United States)

    El-Shishtawy, Reda M.; Haddon, Robert C.; Al-Heniti, Saleh H.; Raffah, Bahaaudin M.; Berrada, K.; Abdel-Khalek, S.; Al-Hadeethi, Yas F.

    2018-03-01

    In this work, we examine the process of the quantum transfer of energy considering time-dependent dipole-dipole interaction in a dimer system characterized by two-level atom systems. By taking into account the effect of the acceleration and speed of the atoms in the dimer coupling, we demonstrate that the improvement of the probability for a single-excitation transfer energy extremely benefits from the incorporation of atomic motion effectiveness and the energy detuning. We explore the relevance between the population and entanglement during the time-evolution and show that this kind of nonlocal correlation may be generated during the process of the transfer of energy. Our work may provide optimal conditions to implement realistic experimental scenario in the transfer of the quantum energy.

  14. Dependency of non-homogeneity energy dispersion on absorbance line-shape of luminescent polymers

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcelo Castanheira da, E-mail: mar_castanheira@yahoo.com.br [Centro de Ciências Biológicas e da Natureza, Universidade Federal do Acre, CP 500, 69915-900 Rio Branco, AC (Brazil); Instituto de Física, Universidade Federal de Uberlândia, CP 593, 38400-902 Uberlândia, MG (Brazil); Santos Silva, H.; Silva, R.A.; Marletta, Alexandre [Instituto de Física, Universidade Federal de Uberlândia, CP 593, 38400-902 Uberlândia, MG (Brazil)

    2013-01-16

    In this paper, we study the importance of the non-homogeneity energy dispersion on absorption line-shape of luminescent polymers. The optical transition probability was calculated based on the molecular exciton model, Franck–Condon states, Gaussian distribution of non-entangled chains with conjugate degree n, semi-empirical parameterization of energy gap, electric dipole moment, and electron-vibrational mode coupling. Based on the approach of the energy gap functional dependence 1/n, the inclusion of the non-homogeneity energy dispersion 1/n{sup 2} is essential to obtain good experimental data agreement, mainly, where the absorption spectra display peaks width of about 65 meV. For unresolved absorption spectra, such as those observed for a large number of conjugated polymers processed via spin-coating technique, for example, the non-homogeneity energy dispersion parameterization is not significant. Results were supported by the application of the model for poly (p-phenylene vinylene) films.

  15. A Simple Method to Calculate the Temperature Dependence of the Gibbs Energy and Chemical Equilibrium Constants

    Science.gov (United States)

    Vargas, Francisco M.

    2014-01-01

    The temperature dependence of the Gibbs energy and important quantities such as Henry's law constants, activity coefficients, and chemical equilibrium constants is usually calculated by using the Gibbs-Helmholtz equation. Although, this is a well-known approach and traditionally covered as part of any physical chemistry course, the required…

  16. Asymptotic dependence of Gross–Tulub polaron ground-state energy in the strong coupling region

    Directory of Open Access Journals (Sweden)

    N.I. Kashirina

    2017-12-01

    Full Text Available The properties of translationally invariant polaron functional have been investigated in the region of strong and extremely strong coupling. It has been shown that the Gross–Tulub polaron functional obtained earlier using the methods of field theory was derived only for the region , where is the Fröhlich constant of the electron-phonon coupling. Various representations of exact and approximate polaron functionals have been considered. Asymptotic dependences of the polaron energy have been obtained using a functional extending the Gross–Tulub functional to the region of extremely strong coupling. The asymptotic dependence of polaron energies for an extremely strong coupling are (for the one-parameter variational function fk, and (for a two-parameter function . It has been shown that the virial theorem 1:3:4 holds for the two-parameter function . Minimization of the approximate functional obtained by expanding the exact Gross–Tulub functional in a series on leads to a quadratic dependence of the polaron energy. This approximation is justified for . For a two-parameter function , the corresponding dependence has the form . However, the use of approximate functionals, in contrast to the strict variational procedure, when the exact polaron functional varies, does not guarantee obtaining the upper limit for the polaron energy.

  17. Study on the energy dependence of gamma radiation detectors for 137Cs and 60Co

    International Nuclear Information System (INIS)

    Nonato, Fernanda B.C.; Diniz, Raphael E.; Carvalho, Valdir S.; Vivolo, Vitor; Caldas, Linda V.E.

    2009-01-01

    38 Geiger-Mueller radiation detectors and 9 ionization chambers were calibrated, viewing to study the energy dependence of the monitor response for gamma radiation fields ( 137 Cs and 60 Co). The results were considered satisfactory only for ionization chambers and for some Geiger-Mueller detectors

  18. Darboux Transformations for Energy-Dependent Potentials and the Klein–Gordon Equation

    International Nuclear Information System (INIS)

    Schulze-Halberg, Axel

    2013-01-01

    We construct explicit Darboux transformations for a generalized Schrödinger-type equation with energy-dependent potential, a special case of which is the stationary Klein–Gordon equation. Our results complement and generalize former findings (Lin et al., Phys Lett A 362:212–214, 2007).

  19. On the A dependence in the process of dilepton production by high-energy nucleons

    International Nuclear Information System (INIS)

    Gevorkyan, S.R.; Zhamkochyan, V.M.

    1978-01-01

    The process of lepton pair production in nucleon-nucleus collisions for high energies is considered. It is shown, that with due regard for the N → π → μ + μ - inelastic transitions the experimentally observed A dependence of the cross section of the NA → μ + μ - X process can be explained in the framework of the multiple scattering theory

  20. Energy dependence of solar-neutrino--electron scattering as a test of neutral currents

    International Nuclear Information System (INIS)

    Kwong, W.; Rosen, S.P.

    1992-01-01

    The energy dependence of ν-e scattering of solar neutrinos is investigated in the framework of neutrino oscillations and the nonadiabatic Mikheyev-Smirnov-Wolfenstein effect. It is shown that, with sufficient data, it will be possible to establish unambiguously whether neutrino oscillations are actually occurring and whether the electron neutrino oscillates into active or inactive (sterile) neutrino flavors

  1. Calculation of the Energy Dependence of Dosimeter Response to Ionizing Photons

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1982-01-01

    Using a program in BASIC applied to a desk-top calculator, simplified calculations provide approximate energy dependence correction factors of dosimeter readings of absorbed dose according to Bragg-Gray cavity theories. Burlin's general cavity theory is applied in the present calculations, and ce...

  2. Dependence of electron inelastic mean free paths on electron energy and materials at low energy region, 1

    International Nuclear Information System (INIS)

    Tanuma, Shigeo; Powell, C.J.; Penn, D.R.

    1990-01-01

    We have proposed a general formula of electron inelastic mean free path (IMFP) to describe the calculated IMFPs over the 50-2000 eV energy range based on the Inokuti's modified Bethe formula for the inelastic scattering cross section. The IMFPs for 50-2000 eV electrons in 27 elements were calculated using Penn's algorithm. The IMFP dependence on electron energy in the range 50-200 eV varies considerably from material to material. These variations are associated with substantial differences in the electron energy-loss functions amongst the material. We also found that the modified Bethe formula by Inokuti could be fitted to the calculated IMFPs in the range 50-2000 eV within 3% relative error. (author)

  3. Extended exergy concept to facilitate designing and optimization of frequency-dependent direct energy conversion systems

    International Nuclear Information System (INIS)

    Wijewardane, S.; Goswami, Yogi

    2014-01-01

    Highlights: • Proved exergy method is not adequate to optimize frequency-dependent energy conversion. • Exergy concept is modified to facilitate the thermoeconomic optimization of photocell. • The exergy of arbitrary radiation is used for a practical purpose. • The utility of the concept is illustrated using pragmatic examples. - Abstract: Providing the radiation within the acceptable (responsive) frequency range(s) is a common method to increase the efficiency of the frequency-dependent energy conversion systems, such as photovoltaic and nano-scale rectenna. Appropriately designed auxiliary items such as spectrally selective thermal emitters, optical filters, and lenses are used for this purpose. However any energy conversion method that utilizes auxiliary components to increase the efficiency of a system has to justify the potential cost incurred by those auxiliary components through the economic gain emerging from the increased system efficiency. Therefore much effort should be devoted to design innovative systems, effectively integrating the auxiliary items and to optimize the system with economic considerations. Exergy is the widely used method to design and optimize conventional energy conversion systems. Although the exergy concept is used to analyze photovoltaic systems, it has not been used effectively to design and optimize such systems. In this manuscript, we present a modified exergy method in order to effectively design and economically optimize frequency-dependent energy conversion systems. Also, we illustrate the utility of this concept using examples of thermophotovoltaic, Photovoltaic/Thermal and concentrated solar photovoltaic

  4. Field-dependent molecular ionization and excitation energies: Implications for electrically insulating liquids

    Directory of Open Access Journals (Sweden)

    N. Davari

    2014-03-01

    Full Text Available The molecular ionization potential has a relatively strong electric-field dependence as compared to the excitation energies which has implications for electrical insulation since the excited states work as an energy sink emitting light in the UV/VIS region. At some threshold field, all the excited states of the molecule have vanished and the molecule is a two-state system with the ground state and the ionized state, which has been hypothesized as a possible origin of different streamer propagation modes. Constrained density-functional theory is used to calculate the field-dependent ionization potential of different types of molecules relevant for electrically insulating liquids. The low singlet-singlet excitation energies of each molecule have also been calculated using time-dependent density functional theory. It is shown that low-energy singlet-singlet excitation of the type n → π* (lone pair to unoccupied π* orbital has the ability to survive at higher fields. This type of excitation can for example be found in esters, diketones and many color dyes. For alkanes (as for example n-tridecane and cyclohexane on the other hand, all the excited states, in particular the σ → σ* excitations vanish in electric fields higher than 10 MV/cm. Further implications for the design of electrically insulating dielectric liquids based on the molecular ionization potential and excitation energies are discussed.

  5. Angular dependence of Si3N4 etch rates and the etch selectivity of SiO2 to Si3N4 at different bias voltages in a high-density C4F8 plasma

    International Nuclear Information System (INIS)

    Lee, Jin-Kwan; Lee, Gyeo-Re; Min, Jae-Ho; Moon, Sang Heup

    2007-01-01

    The dependence of Si 3 N 4 etch rates and the etch selectivity of SiO 2 to Si 3 N 4 on ion-incident angles was studied for different bias voltages in a high-density C 4 F 8 plasma. A Faraday cage and specially designed substrate holders were used to accurately control the angles of incident ions on the substrate surface. The normalized etch yield (NEY), defined as the etch yield obtained at a given ion-incident angle normalized to that obtained on a horizontal surface, was unaffected by the bias voltage in Si 3 N 4 etching, but it increased with the bias voltage in SiO 2 etching in the range of -100 to -300 V. The NEY changed showing a maximum with an increase in the ion-incident angle in the etching of both substrates. In the Si 3 N 4 etching, a maximum NEY of 1.7 was obtained at 70 deg. in the above bias voltage range. However, an increase in the NEY at high ion-incident angles was smaller for SiO 2 than for Si 3 N 4 and, consequently, the etch selectivity of SiO 2 to Si 3 N 4 decreased with an increase in the ion-incident angle. The etch selectivity decreased to a smaller extent at high bias voltage because the NEY of SiO 2 had increased. The characteristic changes in the NEY for different substrates could be correlated with the thickness of a steady-state fluorocarbon (CF x ) film formed on the substrates

  6. Angular momentum and incident-energy dependence of nucleus-nucleus interaction

    International Nuclear Information System (INIS)

    Yamaguchi, S.

    1991-01-01

    The purpose of this paper is to understand intuitively the origin of the angular momentum and incident-energy dependence of the nucleus-nucleus interaction on the basis of the totally- antisymmetrized many-body theory. With the aim of understanding the structure of the nucleus-nucleus interaction, we show first that the nucleus-nucleus interaction can be written by the use of the density-distribution function and the phase-space distribution function instead of using the many-body wave function itself. And we show that the structure change of the density-distribution function with the increase of the angular momentum causes the angular momentum dependence of the nucleus-nucleus interaction and that the incident-energy dependence of the nucleus-nucleus interaction originates from the structure change of the phase-space distribution function

  7. On the energy dependence of DIS in the diffraction region of low x

    Energy Technology Data Exchange (ETDEWEB)

    Schildknecht, D. [Bielefeld, Univ., Fakultat fur Physik (Germany)

    2005-07-01

    The energy dependence of the virtual photoabsorption cross-section in deep inelastic scattering (DIS) at low x = Q{sup 2}/W{sup 2} < 0.1 may be described in terms of the saturation scale that in our approach depends on the energy, {lambda}{sup 2}{sub sat} = {lambda}{sup 2}{sub sat}(W{sup 2}). We briefly summarize our recent findings that allow us to predict the exponent C{sub 2} of {lambda}{sup 2}{sub sat}(W{sup 2}) {approx} (W{sup 2}){sup C{sub 2}} in agreement with the previous result obtained from fitting the experimental data. The exponent C{sub 2} depending on the relative magnitude of the longitudinal and transverse contribution to the structure function, direct measurements of the longitudinal part are urgently needed. (author)

  8. Bohr Hamiltonian with an energy-dependent γ-unstable Coulomb-like potential

    Energy Technology Data Exchange (ETDEWEB)

    Budaca, R. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania)

    2016-10-15

    An exact analytical solution for the Bohr Hamiltonian with an energy-dependent Coulomb-like γ-unstable potential is presented. Due to the linear energy dependence of the potential's coupling constant, the corresponding spectrum in the asymptotic limit of the slope parameter resembles the spectral structure of the spherical vibrator, however with a different state degeneracy. The parameter free energy spectrum as well as the transition rates for this case are given in closed form and duly compared with those of the harmonic U(5) dynamical symmetry. The model wave functions are found to exhibit properties that can be associated to shape coexistence. A possible experimental realization of the model is found in few medium nuclei with a very low second 0{sup +} state known to exhibit competing prolate, oblate and spherical shapes. (orig.)

  9. Free energy of activation. Definition, properties, and dependent variables with special reference to linear free energy relations

    International Nuclear Information System (INIS)

    Levine, R.D.

    1979-01-01

    The reaction rate constant is expressed as Z exp(-G/sub a//RT). Z is the binary collision frequency. G/sub a/, the free energy of activation, is shown to be the difference between the free energy of the reactive reactants and the free energy of all reactants. The results are derived from both a statistical mechanical and a collision theoretic point of view. While the later is more suitable for an ab-initio computation of the reaction rate, it is the former that lends itself to the search of systematics and of correlations and to compaction of data. Different thermodynamic-like routes to the characterization of G/sub a/ are thus explored. The two most promising ones appear to be the use of thermodynamic type cycles and the changes of dependent variables using the Legendre transform technique. The dependence of G/sub a/ on ΔG 0 , the standard free energy change in the reaction, is examined from the later point of view. It is shown that one can rigorously express this dependence as G/sub a/ = αΔG 0 + G/sub a/ 0 M(α). Here α is the Bronsted slope, α = -par. delta ln k(T)/par. delta(ΔG 0 /RT), G/sub a/ 0 is independent of ΔG 0 and M(α), the Legendre transform of G/sub a/, is a function only of α. For small changes in ΔG 0 , the general result reduces to the familiar ''linear'' free energy relation delta G/sub a/ = α delta ΔG 0 . It is concluded from general considerations that M(α) is a symmetric, convex function of α and hence that α is a monotonically increasing function of ΔG 0 . Experimental data appear to conform well to the form α = 1/[1 + exp(-ΔG 0 /G/sub s/ 0 )]. A simple interpretation of the ΔG 0 dependence of G/sub a/, based on an interpolation of the free energy from that of the reagents to that of the products, is offered. 4 figures, 69 references

  10. Reconstructing Space- and Energy-Dependent Exciton Generation in Solution-Processed Inverted Organic Solar Cells.

    Science.gov (United States)

    Wang, Yuheng; Zhang, Yajie; Lu, Guanghao; Feng, Xiaoshan; Xiao, Tong; Xie, Jing; Liu, Xiaoyan; Ji, Jiahui; Wei, Zhixiang; Bu, Laju

    2018-04-25

    Photon absorption-induced exciton generation plays an important role in determining the photovoltaic properties of donor/acceptor organic solar cells with an inverted architecture. However, the reconstruction of light harvesting and thus exciton generation at different locations within organic inverted device are still not well resolved. Here, we investigate the film depth-dependent light absorption spectra in a small molecule donor/acceptor film. Including depth-dependent spectra into an optical transfer matrix method allows us to reconstruct both film depth- and energy-dependent exciton generation profiles, using which short-circuit current and external quantum efficiency of the inverted device are simulated and compared with the experimental measurements. The film depth-dependent spectroscopy, from which we are able to simultaneously reconstruct light harvesting profile, depth-dependent composition distribution, and vertical energy level variations, provides insights into photovoltaic process. In combination with appropriate material processing methods and device architecture, the method proposed in this work will help optimizing film depth-dependent optical/electronic properties for high-performance solar cells.

  11. Energy-dependent imaging in digital radiography: a review on acquisition, processing and display technique

    International Nuclear Information System (INIS)

    Coppini, G.; Maltinti, G.; Valli, G.; Baroni, M.; Buchignan, M.; Valli, G.

    1986-01-01

    The capabilities of energy-dependent imaging in digital radiography are analyzed paying particular attention to digital video systems. The main techniques developed in recent years for selective energy imaging are reviewed following a unified approach. Discussion about advantages and limits of energy methods is carried out by a comparative analysis of computer simulated data and experimental results as obtained by standard x-ray equipments coupled to a digital video unit. Geometric phantoms are used as test object, as also images of a chest phantom are produced. Since signal-to-noise ratio degradation is one of the major problems when dealing with selective imaging, a particular effort is made to investigate noise effects. In this perspective, an original colour encoding display of energy sequences is presented. By mapping the various energy measurements on different colour bands (typically those of an RGB TV-monitor), an increased image conspicuity is obtained without a significant noise degradation: this is ensured by the energy dependence of attenuation coefficients and by the integrating characteristics of the display device

  12. Energy dependent modulation of the ulf ion flux oscillations observed at small pitch angles

    International Nuclear Information System (INIS)

    Su, S.; Konradi, A.; Fritz, T.A.

    1979-01-01

    The characteristics of the ultralow frequency oscillations in the ion fluxes observed at small pitch angles by the National Oceanic and Atmospheric Adminstration detector telescopes on board ATS 6 are again examined. The present report concentrates on the dramatic variation of the flux modulations detected in various energy channels during a single event which occurred on February 18, 1975. The wave amplitude is observed to be larger in a higher energy channel with energies from 100 keV to 150 keV and to decrease toward the lower energy channels. The lowest-energy protons (25--33 keV) in general are seldom seen to be oscillating, but in this event they display a low-amplitude oscillation which is 180 0 out of p ase with the adjacent channel. Such energy dependent modulation of the flux oscillation is thought to be a consequence of the wave particle resonant interaction. However, the prediction of the bounce resonant interaction is not consistent with the observations of both the energy dependent variation of the flux amplitudes and a 180 0 change in the oscillation phase in the adjacent low-energy channels that occurred in the February 18, 1975, event. Since the shape of the undisturned particle distribution can also determine the variation of the particle perturbation at various energies, the first-order particle distribution derived in a homogeneous plasma with a uniform magnetic field is examined without any specification of the wave mode. When the average particle distribution during the wave observation is used together with a parallel wave electric field that presumably causes the flux modulation at small pitch angles, a reasonable agreement is found between the variation of flux modulation derived from the slope of the average particle distribution and that from the experimental observation

  13. Studying the collision energy dependence of elliptic and triangular flow with a hybrid model

    Energy Technology Data Exchange (ETDEWEB)

    Auvinen, Jussi [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Petersen, Hannah [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Institut fuer Theoretische Physik, Goethe Universitaet, Frankfurt am Main (Germany)

    2014-07-01

    Elliptic flow has been one of the key observables for establishing the finding of the quark-gluon plasma (QGP) at the highest energies of Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). As a sign of collectively behaving matter, the elliptic flow is expected to decrease at lower beam energies, where the QGP is not produced. However, in the recent RHIC beam energy scan, it has been found that the inclusive charged hadron elliptic flow changes relatively little in magnitude within the energy range 7.7-39 GeV per nucleon-nucleon collision. We study the collision energy dependence of the elliptic and triangular flow utilizing a Boltzmann+hydrodynamics hybrid model. Such a hybrid model provides a natural framework for the transition from high collision energies, where the hydrodynamical description is essential, to smaller energies, where the hadron transport dominates. This approach is thus suitable for investigating the relative importance of these two mechanisms for the production of the collective flow at different beam energies.

  14. Dependence of Energetic Electron Precipitation on the Geomagnetic Index Kp and Electron Energy

    Directory of Open Access Journals (Sweden)

    Mi-Young Park

    2013-12-01

    Full Text Available It has long been known that the magnetospheric particles can precipitate into the atmosphere of the Earth. In this paper we examine such precipitation of energetic electrons using the data obtained from low-altitude polar orbiting satellite observations. We analyze the precipitating electron flux data for many periods selected from a total of 84 storm events identified for 2001-2012. The analysis includes the dependence of precipitation on the Kp index and the electron energy, for which we use three energies E1 > 30 keV, E2 > 100 keV, E3 > 300 keV. We find that the precipitation is best correlated with Kp after a time delay of < 3 hours. Most importantly, the correlation with Kp is notably tighter for lower energy than for higher energy in the sense that the lower energy precipitation flux increases more rapidly with Kp than does the higher energy precipitation flux. Based on this we suggest that the Kp index reflects excitation of a wave that is responsible for scattering of preferably lower energy electrons. The role of waves of other types should become increasingly important for higher energy, for which we suggest to rely on other indicators than Kp if one can identify such an indicator.

  15. Ion mass dependence for low energy channeling in single-wall nanotubes

    International Nuclear Information System (INIS)

    Zheng Liping; Zhu Zhiyuan; Li Yong; Zhu Dezhang; Xia Huihao

    2008-01-01

    An Monte Carlo (MC) simulation program has been used to study ion mass dependence for the low energy channeling of natural- and pseudo-Ar ions in single-wall nanotubes. The MC simulations show that the channeling critical angle Ψ C obeys the (E) -1/2 and the (M 1 ) -1/2 rules, where E is the incident energy and M 1 is the ion mass. The reason for this may be that the motion of the channeled (or de-channeled) ions should be correlated with both the incident energy E and the incident momentum (2M 1 E) 1/2 , in order to obey the conservation of energy and momentum

  16. Study of the SEY dependence on the electron beams dose and energy

    International Nuclear Information System (INIS)

    Commisso, M.

    2011-01-01

    During operation, the internal walls of modern particle accelerators are subjected to synchrotron radiation irradiation and/or electron bombardment. Such phenomena do affect surface properties such as the secondary electron yield, (SEY). A low SEY is a key parameter to control and overcome any detrimental effect on the accelerator performance eventually induced by the build-up of an Electron Cloud (E C). In laboratory experiments SEY reduction (called scrubbing) has been studied as a function of dose but the actual kinetic energy dependence has never been considered as an important parameter. For this reason and given the peculiar behavior observed for low-energy electrons, we decided to study this dependence accurately. Here we report results of SEY measurements performed bombarding Cu samples obtained from the Large Hadron Collider (Lhc) with different doses of electron beam with energy in the range 10-500 eV. Our results demonstrate that the potentiality of an electron beam to reduce the SEY does not only depend on its dose, but also on its energy. Furthermore, since E C build-up was predicted and observed also the DAΦNE ring, we report some preliminary measurements on the conditioning of Al samples. An overview of future experiments which we will perform in LNF is then given.

  17. Analysis of incident-energy dependence of delayed neutron yields in actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, Mohamad Nasrun bin Mohd, E-mail: monasr211@gmail.com; Metorima, Kouhei, E-mail: kohei.m2420@hotmail.co.jp; Ohsawa, Takaaki, E-mail: ohsawa@mvg.biglobe.ne.jp; Hashimoto, Kengo, E-mail: kengoh@pp.iij4u.or.jp [Graduate School of Science and Engineering, Kindai University, Kowakae, Higashi-Osaka, 577-8502 (Japan)

    2015-04-29

    The changes of delayed neutron yields (ν{sub d}) of Actinides have been analyzed for incident energy up to 20MeV using realized data of precursor after prompt neutron emission, from semi-empirical model, and delayed neutron emission probability data (P{sub n}) to carry out a summation method. The evaluated nuclear data of the delayed neutron yields of actinide nuclides are still uncertain at the present and the cause of the energy dependence has not been fully understood. In this study, the fission yields of precursor were calculated considering the change of the fission fragment mass yield based on the superposition of fives Gaussian distribution; and the change of the prompt neutrons number associated with the incident energy dependence. Thus, the incident energy dependent behavior of delayed neutron was analyzed.The total number of delayed neutron is expressed as ν{sub d}=∑Y{sub i} • P{sub ni} in the summation method, where Y{sub i} is the mass yields of precursor i and P{sub ni} is the delayed neutron emission probability of precursor i. The value of Y{sub i} is derived from calculation of post neutron emission mass distribution using 5 Gaussian equations with the consideration of large distribution of the fission fragments. The prompt neutron emission ν{sub p} increases at higher incident-energy but there are two different models; one model says that the fission fragment mass dependence that prompt neutron emission increases uniformly regardless of the fission fragments mass; and the other says that the major increases occur at heavy fission fragments area. In this study, the changes of delayed neutron yields by the two models have been investigated.

  18. U.S. oil dependence 2014: Is energy independence in sight?

    International Nuclear Information System (INIS)

    Greene, David L.; Liu, Changzheng

    2015-01-01

    The importance of reducing U.S. oil dependence may have changed in light of developments in the world oil market over the past two decades. Since 2005, increased domestic production and decreased oil use have cut U.S. import dependence in half. The direct costs of oil dependence to the U.S. economy are estimated under four U.S. Energy Information Administration Scenarios to 2040. The key premises of the analysis are that the primary oil market failure is the use of market power by OPEC and that U.S. economic vulnerability is a result of the quantity of oil consumed, the lack of readily available, economical substitutes and the quantity of oil imported. Monte Carlo simulations of future oil market conditions indicate that the costs of U.S. oil dependence are likely to increase in constant dollars but decrease relative to U.S. gross domestic product unless oil resources are larger than estimated by the U.S. Energy Information Administration. Reducing oil dependence therefore remains a valuable goal for U.S. energy policy and an important co-benefit of mitigating greenhouse gas emissions. -- Highlights: •Increased oil production and decreased use caused U.S. oil imports to fall from 60% in 2005 to 27% in 2014. •OPEC's market power appears to have increased due to lower oil price elasticities. •Future costs of oil dependence to the U.S. are likely to increase but decrease relative to GDP. •If U.S. oil resources are far larger than EIA estimates, the U.S. could be oil independent by 2040

  19. Combined alcohol and energy drink use: hedonistic motives, adenosine, and alcohol dependence.

    Science.gov (United States)

    Marczinski, Cecile A

    2014-07-01

    Consumption of alcohol mixed with energy drinks (AmED) has been associated with both short- and long-term risks beyond those observed with alcohol alone. AmED use has been associated with heavy episodic (binge) drinking, risky behaviors, and risk of alcohol dependence. Laboratory research has demonstrated that AmED beverages lead to greater motivation to drink versus the same amount of alcohol consumed alone. However, the reason consumers find AmED beverages particularly appealing has been unclear. A recent report by Droste and colleagues (Alcohol Clin Exp Res 2014; 38:2087-2095) is the first study to investigate motivations related to AmED consumption and to determine which motives predict AmED consumption patterns, experience of drinking-related harms, and risk of alcohol dependence. The findings of this study significantly enhance our understanding of why AmED consumption is related to the risk of alcohol dependence and change our understanding of why consumers choose AmED beverages. The authors report that hedonistic motives strongly predicted AmED use and the harms associated with use. While intoxication-reduction motives predicted self-reported accidents and injuries, these motives did not predict AmED consumption patterns and risk of dependence. The risk of alcohol dependence may arise from repeated experiences when drinking alcohol is more pleasurable when energy drinks are consumed with the alcohol. This commentary will focus on why energy drinks might increase the rewarding properties of alcohol in social drinkers. In addition, discussion is provided explaining why more research on the neurotransmitter, adenosine, may actually inform us about the mechanisms contributing to the development of alcohol dependence. Copyright © 2014 by the Research Society on Alcoholism.

  20. Combined Alcohol and Energy Drink Use: Hedonistic Motives, Adenosine, and Alcohol Dependence

    Science.gov (United States)

    Marczinski, Cecile A.

    2014-01-01

    Consumption of alcohol mixed with energy drinks (AmED) has been associated with both short and long-term risks beyond those observed with alcohol alone. AmED use has been associated with heavy episodic (binge) drinking, risky behaviors, and risk of alcohol dependence. Laboratory research has demonstrated that AmED beverages lead to greater motivation to drink versus the same amount of alcohol consumed alone. However, the reason consumers find AmED beverages particularly appealing has been unclear. A recent report by Droste and colleagues (2014) is the first study to investigate motivations related to AmED consumption and to determine which motives predict AmED consumption patterns, experience of drinking-related harms, and risk of alcohol dependence. The findings of this study significantly enhance our understanding of why AmED consumption is related to the risk of alcohol dependence and change our understanding of why consumers chose AmED beverages. The authors report that hedonistic motives strongly predicted AmED use and the harms associated with use. While intoxication-reduction motives predicted self-reported accidents and injuries, these motives did not predict AmED consumption patterns and risk of dependence. The risk of alcohol dependence may arise from repeated experiences when drinking alcohol is more pleasurable when energy drinks are consumed with the alcohol. This commentary will focus on why energy drinks might increase the rewarding properties of alcohol in social drinkers. In addition, discussion is provided explaining why more research on the neurotransmitter, adenosine, may actually inform us about the mechanisms contributing to the development of alcohol dependence. PMID:25040590

  1. Analysis of cavity effect on space- and time-dependent fast and thermal neutron energy spectra

    International Nuclear Information System (INIS)

    Kudo, Katsuhisa; Narita, Masakuni; Ozawa, Yasutomo.

    1975-01-01

    The effects of the presence of a central cavity on the space- and time-dependent neutron energy spectra in both thermal and fast neutron systems are analyzed theoretically with use made of the multi-group one-dimensional time-dependent Ssub(n) method. The thermal neutron field is also analyzed for the case of a fundamental time eigenvalue problem with the time-dependent P 1 approximation. The cavity radius is variable, and the system radius for graphite is 120 cm and for the other materials 7 cm. From the analysis of the time-dependent Ssub(n) calculations in the non-multiplying systems of polythene, light water and graphite, cavity heating is the dominant effect for the slowing-down spectrum in the initial period following fast neutron burst, and when the slowing-down spectrum comes into the thermal energy region, cavity heating shifts to cavity cooling. In the multiplying system of 235 U, cavity cooling also takes place as the spectrum approaches equilibrium after the fast neutron burst is injected. The mechanism of cavity cooling is explained analytically for the case of thermal neutron field to illustrate its physical aspects, using the time-dependent P 1 approximation. An example is given for the case of light water. (auth.)

  2. Probing the density dependence of the symmetry potential in intermediate-energy heavy ion collisions

    International Nuclear Information System (INIS)

    Li Qingfeng; Li Zhuxia; Soff, Sven; Gupta, Raj K; Bleicher, Marcus; Stoecker, Horst

    2005-01-01

    Based on the ultrarelativistic quantum molecular dynamics model, the effects of the density-dependent symmetry potential for baryons and of the Coulomb potential for produced mesons are investigated for neutron-rich heavy ion collisions at intermediate energies. The calculated results of the Δ - /Δ ++ and π - /π + production ratios show a clear beam-energy dependence on the density-dependent symmetry potential, which is stronger for the π - /π + ratio close to the pion production threshold. The Coulomb potential of the mesons changes the transverse momentum distribution of the π - /π + ratio significantly, though it alters only slightly the π - and π + total yields. The π - yields, especially at midrapidity or at low transverse momenta and the π - /π + ratios at low transverse momenta are shown to be sensitive probes of the density-dependent symmetry potential in dense nuclear matter. The effect of the density-dependent symmetry potential on the production of both K 0 and K + mesons is also investigated

  3. Assisted extraction of the energy level spacings and lever arms in direct current bias measurements of one-dimensional quantum wires, using an image recognition routine

    International Nuclear Information System (INIS)

    Lesage, A. A. J.; Smith, L. W.; Griffiths, J. P.; Farrer, I.; Jones, G. A. C.; Ritchie, D. A.; Smith, C. G.; Al-Taie, H.; Kelly, M. J.; See, P.

    2015-01-01

    A multiplexer technique is used to individually measure an array of 256 split gates on a single GaAs/AlGaAs heterostructure. This results in the generation of large volumes of data, which requires the development of automated data analysis routines. An algorithm is developed to find the spacing between discrete energy levels, which form due to transverse confinement from the split gate. The lever arm, which relates split gate voltage to energy, is also found from the measured data. This reduces the time spent on the analysis. Comparison with estimates obtained visually shows that the algorithm returns reliable results for subband spacing of split gates measured at 1.4 K. The routine is also used to assess direct current bias spectroscopy measurements at lower temperatures (50 mK). This technique is versatile and can be extended to other types of measurements. For example, it is used to extract the magnetic field at which Zeeman-split 1D subbands cross one another

  4. Measurements of time dependent energy spectra of neutrons in a small graphite assembly

    International Nuclear Information System (INIS)

    Fujita, Yoshiaki; Sakamoto, Shigeyasu; Aizawa, Otohiko; Takahashi, Akito; Sumita, Kenji.

    1975-01-01

    The time-dependent energy spectra of neutrons have been measured in a small 30x30x30 cm 3 graphite assembly by means of the linac-chopper method, with a view to establishing experimental evidence that there is no asymptotic spectrum in such a small assembly, and in order to study the non-asymptotic behavior of neutrons. The arrangement of a polyethylene pre-moderator adjacent to the assembly made the measurements possible with the improvement obtained thereby of the neutron counting statistics. It was indicated from calculation that the presence of the pre-moderator had little effect - at least above the Bragg cut-off energy - on the evolution in time of the energy spectra of neutrons in the graphite assembly. The experimental results indicated very probable disappearance of asymptotic spectra, and revealed significant enhancement of trapping at Bragg energies with the lapse of time. This is consistent with the results of pulsed neutron experiments in small assemblies conducted by Takahashi et al., and falls in line with de Saussure's approximation. The spectra in the graphite assembly showed significant space dependence, the spectra becoming harder with increasing distance from the pre-moderator. This hardening may be attributed to the relatively faster propagation of higher energy neutrons. (auth.)

  5. Nuclear-charge and positron-energy dependence of the single-quantum annihilation of positrons

    International Nuclear Information System (INIS)

    Palathingal, J.C.; Asoka-Kumar, P.; Lynn, K.G.; Wu, X.Y.

    1995-01-01

    We report an experimental study of the single-quantum annihilation of positrons in a number of elements having atomic numbers between 49 and 90, utilizing a monoenergetic positron beam. Measurements were made of the differential cross sections for the forward direction for the K, L, and M atomic shells in targets of Th, Pb, Au, Hf, Gd, and In, having thicknesses that vary between 2.7 and 4.4 mg/cm 2 . A shielded HPGe detector of high relative photopeak efficiency was used for recording the photon spectrum. Values for the individual atomic shells were obtained in the positron kinetic-energy range 1.02--2.24 MeV. It was observed that the differential cross sections measured for the forward direction varied with energy for each major shell almost alike so that the shell ratios appeared to remain constant while the positron energy varied. The dependence of the cross section on the atomic number Z of the target element was tested for each of the major shells at various energies of measurement. It was seen that the cross sections follow a Z ν relation with ν∼5.1 as the exponent for the K shell. For the higher shells, the exponent is approximately 6.4, which is significantly larger. It was also noted that this pattern is fairly independent of the positron energy. The results on the Z dependence are seen to be clearly at variance with the most updated theoretical predictions

  6. Rate-Independent Processes with Linear Growth Energies and Time-Dependent Boundary Conditions

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.

    2012-01-01

    Roč. 5, č. 3 (2012), s. 591-604 ISSN 1937-1632 R&D Projects: GA AV ČR IAA100750802 Grant - others:GA ČR(CZ) GAP201/10/0357 Institutional research plan: CEZ:AV0Z10750506 Keywords : concentrations * oscillations * time - dependent boundary conditions * rate-independent evolution Subject RIV: BA - General Mathematics http://library.utia.cas.cz/separaty/2011/MTR/kruzik-rate-independent processes with linear growth energies and time - dependent boundary conditions.pdf

  7. Doping dependence of low-energy quasiparticle excitations in superconducting Bi2212.

    Science.gov (United States)

    Ino, Akihiro; Anzai, Hiroaki; Arita, Masashi; Namatame, Hirofumi; Taniguchi, Masaki; Ishikado, Motoyuki; Fujita, Kazuhiro; Ishida, Shigeyuki; Uchida, Shinichi

    2013-12-05

    : The doping-dependent evolution of the d-wave superconducting state is studied from the perspective of the angle-resolved photoemission spectra of a high-Tc cuprate, Bi2Sr2CaCu2 O8+δ (Bi2212). The anisotropic evolution of the energy gap for Bogoliubov quasiparticles is parametrized by critical temperature and superfluid density. The renormalization of nodal quasiparticles is evaluated in terms of mass enhancement spectra. These quantities shed light on the strong coupling nature of electron pairing and the impact of forward elastic or inelastic scatterings. We suggest that the quasiparticle excitations in the superconducting cuprates are profoundly affected by doping-dependent screening.

  8. Berberine regulates neurite outgrowth through AMPK-dependent pathways by lowering energy status

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jiaqi; Cao, Yuanzhao; Cheng, Kuoyuan; Xu, Bo; Wang, Tianchang; Yang, Qi; Yang, Qin [State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing (China); Feng, Xudong, E-mail: xudong.feng@childrens.harvard.edu [Department of Medicine, Children' s Hospital Boston, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115 (United States); Xia, Qing, E-mail: xqing@hsc.pku.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing (China)

    2015-06-10

    As a widely used anti-bacterial agent and a metabolic inhibitor as well as AMP-activated protein kinase (AMPK) activator, berberine (BBR) has been shown to cross the blood–brain barrier. Its efficacy has been investigated in various disease models of the central nervous system. Neurite outgrowth is critical for nervous system development and is a highly energy-dependent process regulated by AMPK-related pathways. In the present study, we aimed to investigate the effects of BBR on AMPK activation and neurite outgrowth in neurons. The neurite outgrowth of primary rat cortical neurons at different stages of polarization was monitored after exposure of BBR. Intracellular energy level, AMPK activation and polarity-related pathways were also inspected. The results showed that BBR suppressed neurite outgrowth and affected cytoskeleton stability in the early stages of neuronal polarization, which was mediated by lowered energy status and AMPK activation. Liver kinase B1 and PI3K–Akt–GSK3β signaling pathways were also involved. In addition, mitochondrial dysfunction and endoplasmic reticulum stress contributed to the lowered energy status induced by BBR. This study highlighted the knowledge of the complex activities of BBR in neurons and corroborated the significance of energy status during the neuronal polarization. - Highlights: • BBR inhibited neurite outgrowth in early stages of neuronal development. • Lowered neuronal energy status was induced by BBR treatment. • Neuronal energy stress induced by BBR activated AMPK-related pathways. • BBR induced mitochondrial dysfunction and endoplasmic reticulum stress.

  9. Energy Dependent Divisible Load Theory for Wireless Sensor Network Workload Allocation

    Directory of Open Access Journals (Sweden)

    Haiyan Shi

    2012-01-01

    Full Text Available The wireless sensor network (WSN, consisting of a large number of microsensors with wireless communication abilities, has become an indispensable tool for use in monitoring and surveillance applications. Despite its advantages in deployment flexibility and fault tolerance, the WSN is vulnerable to failures due to the depletion of limited onboard battery energy. A major portion of energy consumption is caused by the transmission of sensed results to the master processor. The amount of energy used, in fact, is related to both the duration of sensing and data transmission. Hence, in order to extend the operation lifespan of the WSN, a proper allocation of sensing workload among the sensors is necessary. An assignment scheme is here formulated on the basis of the divisible load theory, namely, the energy dependent divisible load theory (EDDLT for sensing workload allocations. In particular, the amount of residual energies onboard sensors are considered while deciding the workload assigned to each sensor. Sensors with smaller amount of residual energy are assigned lighter workloads, thus, allowing for a reduced energy consumption and the sensor lifespan is extended. Simulation studies are conducted and results have illustrated the effectiveness of the proposed workload allocation method.

  10. Berberine regulates neurite outgrowth through AMPK-dependent pathways by lowering energy status

    International Nuclear Information System (INIS)

    Lu, Jiaqi; Cao, Yuanzhao; Cheng, Kuoyuan; Xu, Bo; Wang, Tianchang; Yang, Qi; Yang, Qin; Feng, Xudong; Xia, Qing

    2015-01-01

    As a widely used anti-bacterial agent and a metabolic inhibitor as well as AMP-activated protein kinase (AMPK) activator, berberine (BBR) has been shown to cross the blood–brain barrier. Its efficacy has been investigated in various disease models of the central nervous system. Neurite outgrowth is critical for nervous system development and is a highly energy-dependent process regulated by AMPK-related pathways. In the present study, we aimed to investigate the effects of BBR on AMPK activation and neurite outgrowth in neurons. The neurite outgrowth of primary rat cortical neurons at different stages of polarization was monitored after exposure of BBR. Intracellular energy level, AMPK activation and polarity-related pathways were also inspected. The results showed that BBR suppressed neurite outgrowth and affected cytoskeleton stability in the early stages of neuronal polarization, which was mediated by lowered energy status and AMPK activation. Liver kinase B1 and PI3K–Akt–GSK3β signaling pathways were also involved. In addition, mitochondrial dysfunction and endoplasmic reticulum stress contributed to the lowered energy status induced by BBR. This study highlighted the knowledge of the complex activities of BBR in neurons and corroborated the significance of energy status during the neuronal polarization. - Highlights: • BBR inhibited neurite outgrowth in early stages of neuronal development. • Lowered neuronal energy status was induced by BBR treatment. • Neuronal energy stress induced by BBR activated AMPK-related pathways. • BBR induced mitochondrial dysfunction and endoplasmic reticulum stress

  11. Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales.

    Science.gov (United States)

    Stickler, Claudia M; Coe, Michael T; Costa, Marcos H; Nepstad, Daniel C; McGrath, David G; Dias, Livia C P; Rodrigues, Hermann O; Soares-Filho, Britaldo S

    2013-06-04

    Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations' energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local "direct" effects (through changes in ET within the watershed) and the potential regional "indirect" effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world's largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4-8% and 10-12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6-36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry's own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests.

  12. Time-dependent density functional calculation of the energy loss of antiprotons colliding with metallic nanoshells

    International Nuclear Information System (INIS)

    Quijada, M.; Borisov, A.G.; Muino, R.D.

    2008-01-01

    Time-dependent density functional theory is used to study the interaction between antiprotons and metallic nanoshells. The ground state electronic properties of the nanoshell are obtained in the jellium approximation. The energy lost by the antiproton during the collision is calculated and compared to that suffered by antiprotons traveling in metal clusters. The resulting energy loss per unit path length of material in thin nanoshells is larger than the corresponding quantity for clusters. It is shown that the collision process can be interpreted as the antiproton crossing of two nearly bi-dimensional independent metallic systems. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Energy dependence of the Coulomb-nuclear interference at small momentum transfers

    International Nuclear Information System (INIS)

    Selyugin, O.V.

    1997-01-01

    The analyzing power of the elastic proton-proton scattering at small momentum transfers and the effect of the Coulomb-nuclear interference are examined on the basis of the available experimental data at p L from 6 up to 200 GeV/c taking account of a phenomenological analysis at p L =6 GeV/c and of the dynamic high energy spin model. The structure of the spin-dependent elastic scattering amplitude at small momentum transfers is obtained. The predictions for the analyzing power at RHIC energies are made

  14. Thermal neutron diffusion parameters dependent on the flux energy distribution in finite hydrogenous media

    International Nuclear Information System (INIS)

    Drozdowicz, K.

    1999-01-01

    Macroscopic parameters for a description of the thermal neutron transport in finite volumes are considered. A very good correspondence between the theoretical and experimental parameters of hydrogenous media is attained. Thermal neutrons in the medium possess an energy distribution, which is dependent on the size (characterized by the geometric buckling) and on the neutron transport properties of the medium. In a hydrogenous material the thermal neutron transport is dominated by the scattering cross section which is strongly dependent on energy. A monoenergetic treatment of the thermal neutron group (admissible for other materials) leads in this case to a discrepancy between theoretical and experimental results. In the present paper the theoretical definitions of the pulsed thermal neutron parameters (the absorption rate, the diffusion coefficient, and the diffusion cooling coefficient) are based on Nelkin's analysis of the decay of a neutron pulse. Problems of the experimental determination of these parameters for a hydrogenous medium are discussed. A theoretical calculation of the pulsed parameters requires knowledge of the scattering kernel. For thermal neutrons it is individual for each hydrogenous material because neutron scattering on hydrogen nuclei bound in a molecule is affected by the molecular dynamics (characterized with internal energy modes which are comparable to the incident neutron energy). Granada's synthetic model for slow-neutron scattering is used. The complete up-dated formalism of calculation of the energy transfer scattering kernel after this model is presented in the paper. An influence of some minor variants within the model on the calculated differential and integral neutron parameters is shown. The theoretical energy-dependent scattering cross section (of Plexiglas) is compared to experimental results. A particular attention is paid to the calculation of the diffusion cooling coefficient. A solution of an equation, which determines the

  15. Matrix elements of vibration kinetic energy operator of tetrahedral molecules in non-orthogonal-dependent coordinates

    Science.gov (United States)

    Protasevich, Alexander E.; Nikitin, Andrei V.

    2018-01-01

    In this work, we propose an algorithm for calculating the matrix elements of the kinetic energy operator for tetrahedral molecules. This algorithm uses the dependent six-angle coordinates (6A) and takes into account the full symmetry of molecules. Unlike A.V. Nikitin, M. Rey, and Vl. G. Tyuterev who operate with the kinetic energy operator only in Radau orthogonal coordinates, we consider a general case. The matrix elements are shown to be a sum of products of one-dimensional integrals.

  16. Pressure-dependent shallow donor binding energy in InGaN/GaN square QWWs

    International Nuclear Information System (INIS)

    Ghazi, Haddou El; Jorio, Anouar; Zorkani, Izeddine

    2013-01-01

    Using a variational approach, we perform a theoretical study of hydrostatic pressure effect on the ground-state of axial hydrogenic shallow-donor impurity binding energy in InGaN/GaN square quantum well wire (SQWWs) as a function of the side length within the effective-mass scheme and finite potential barrier. The pressure dependence of wire length, effective mass, dielectric constant and potential barrier are taken into account. Numerical results show that: (i) the binding energy is strongly affected by the wire length and the external applied pressure and (ii) its maximum moves to the narrow wire in particular for height pressure.

  17. LSND versus MiniBooNE: Sterile neutrinos with energy dependent masses and mixing?

    CERN Document Server

    Schwetz, Thomas

    2008-01-01

    Standard active-sterile neutrino oscillations do not provide a satisfactory description of the LSND evidence for neutrino oscillations together with the constraints from MiniBooNE and other null-result short-baseline oscillation experiments. However, if the mass or the mixing of the sterile neutrino depends in an exotic way on its energy all data become consistent. I explore the phenomenological consequences of the assumption that either the mass or the mixing scales with the neutrino energy as $1/E_\

  18. Energy Dependence of Particle Multiplicities in Central Au+Au Collisions

    Science.gov (United States)

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Corbo, J.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hicks, D.; Hofman, D.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Rafelski, M.; Rbeiz, M.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2002-01-01

    We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at (sNN) = 200 GeV. For the 6% most central collisions, we obtain dNch/dη\\|\\|η\\|<1 = 650+/-35(syst). Compared to collisions at (sNN) = 130 GeV, the highest energy studied previously, an increase by a factor of 1.14+/-0.05 at 90% confidence level, is found. The energy dependence of the pseudorapidity density is discussed in comparison with data from proton-induced collisions and theoretical predictions.

  19. Efficient method for the solution of the energy dependent integral Boltzmann transport equation in the resolved resonance energy region

    International Nuclear Information System (INIS)

    Schwenk, G.A. Jr.

    1980-01-01

    The calculation of neutron-nuclei reaction rates in the lower resolved resonance region (167 eV - 1.855 eV) is considered in this dissertation. Particular emphasis is placed on the calculation of these reaction rates for tight lattices where their accuracy is most important. The results of the continuous energy Monte Carlo code, VIM, are chosen as reference values for this study. The primary objective of this work is to develop a method for calculating resonance reaction rates which agree well with the reference solution, yet is efficient enough to be used by nuclear reactor fuel cycle designers on a production basis. A very efficient multigroup solution of the two spatial region energy dependent integral transport equation is developed. This solution, denoted the Broad Group Integral Method (BGIM), uses escape probabilities to obtain the spatial coupling between regions and uses an analytical flux shape within a multigroup to obtain weighted cross sections which account for the rapidly varying resonance cross sections. The multigroup lethargy widths chosen for the numerical integration of the two region energy-dependent neutron continuity equations can be chosen much wider (a factor of 30 larger) than in the direct numerical integration methods since the analytical flux shape is used to account for fine structure effects. The BGIM solution is made highly efficient through the use of these broad groups. It is estimated that for a 10 step unit cell fuel cycle depletion calculation, the computer running time for a production code such as EPRI-LEOPARD would be increased by only 6% through the use of the more accurate and intricate BGIM method in the lower resonance energy region

  20. The kinetic energy operator for distance-dependent effective nuclear masses: Derivation for a triatomic molecule.

    Science.gov (United States)

    Khoma, Mykhaylo; Jaquet, Ralph

    2017-09-21

    The kinetic energy operator for triatomic molecules with coordinate or distance-dependent nuclear masses has been derived. By combination of the chain rule method and the analysis of infinitesimal variations of molecular coordinates, a simple and general technique for the construction of the kinetic energy operator has been proposed. The asymptotic properties of the Hamiltonian have been investigated with respect to the ratio of the electron and proton mass. We have demonstrated that an ad hoc introduction of distance (and direction) dependent nuclear masses in Cartesian coordinates preserves the total rotational invariance of the problem. With the help of Wigner rotation functions, an effective Hamiltonian for nuclear motion can be derived. In the derivation, we have focused on the effective trinuclear Hamiltonian. All necessary matrix elements are given in closed analytical form. Preliminary results for the influence of non-adiabaticity on vibrational band origins are presented for H 3 + .

  1. Temperature Dependence of the Energy Band Diagram of AlGaN/GaN Heterostructure

    Directory of Open Access Journals (Sweden)

    Yanli Liu

    2018-01-01

    Full Text Available Temperature dependence of the energy band diagram of AlGaN/GaN heterostructure was investigated by theoretical calculation and experiment. Through solving Schrodinger and Poisson equations self-consistently by using the Silvaco Atlas software, the energy band diagram with varying temperature was calculated. The results indicate that the conduction band offset of AlGaN/GaN heterostructure decreases with increasing temperature in the range of 7 K to 200 K, which means that the depth of quantum well at AlGaN/GaN interface becomes shallower and the confinement of that on two-dimensional electron gas reduces. The theoretical calculation results are verified by the investigation of temperature dependent photoluminescence of AlGaN/GaN heterostructure. This work provides important theoretical and experimental basis for the performance degradation of AlGaN/GaN HEMT with increasing temperature.

  2. Evolving and energy dependent optical model description of heavy-ion elastic scattering

    International Nuclear Information System (INIS)

    Michaelian, K.

    1996-01-01

    We present the application of a genetic algorithm to the problem of determining an energy dependent optical model description of heavy-ion elastic scattering. The problem requires a search for the global best optical model potential and its energy dependence in a very rugged 12 dimensional parameter space of complex topographical features with many local minima. Random solutions are created in the first generation. The fitness of a solution is related to the χ 2 fit of the calculated differential cross sections with the experimental data. Best fit solutions are evolved through cross over and mutation following the biological example. This genetic algorithm approach combined with local gradient minimization is shown to provide a global, complete and extremely efficient search method, well adapted to complex fitness landscapes. These characteristics, combined with the facility of application, should make it the search method of choice for a wide variety of problems from nuclear physics. (Author)

  3. Measurement of the energy dependence of the total photon-proton cross section at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, H. [Tel Aviv Univ. (Israel). Raymond and Beverly Sackler Faculty of Exact Sciences; Univ. Coll. London (United Kingdom); Krakow Univ. of Technology (Poland). Faculty of Physics, Mathematics and Applied Computer Science; Abt, I. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Adamczyk, L. [AGH-Univ. of Science and Technology, Cracow (PL). Faculty of Physics and Applied Computer Science] (and others)

    2010-10-15

    The energy dependence of the photon-proton total cross section, {sigma}{sub tot}{sup {gamma}}{sup p}, was determined from e{sup +}p scattering data collected with the ZEUS detector at HERA at three values of the center-of-mass energy, W, of the {gamma}p system in the range 194dependence of {sigma}{sub tot}{sup {gamma}}{sup p} from a single experiment at high W. Parameterizing {sigma}{sub tot}{sup {gamma}}{sup p} {proportional_to} W{sup 2c}, {epsilon}=0.111{+-}0.009 (stat.){+-}0.036 (syst.) was obtained. (orig.)

  4. Excitation energy and angular momentum dependence of the nuclear level densities

    International Nuclear Information System (INIS)

    Razavi, R.; Kakavand, T.; Behkami, A. N.

    2007-01-01

    We have investigated the excitation energy (E) dependence of nuclear level density for Bethe formula and constant temperature model. The level density parameter aa nd the back shifted energy from the Bethe formula are obtained by fitting the complete level schemes. Also the level density parameters from the constant temperature model have been determined for several nuclei. we have shown that the microscopic theory provides more precise information on the nuclear level densities. On the other hand, the spin cut-off parameter and effective moment of inertia are determined by studying of the angular momentum (J) dependence of the nuclear level density, and effective moment of inertia is compared with rigid body value.

  5. Energy dependence of collective flow of neutrons and charged particles in 197Au+197Au collisions

    International Nuclear Information System (INIS)

    Blaich, T.; Freiesleben, H.; Holzmann, R.; Keller, J.G.; Prokopowicz, W.; Schuetter, C.; Wajda, E.; Zude, E.

    1994-01-01

    Our contribution focusses on one particular aspect of collective flow of nuclear matter: the so-called ''squeeze-out'', i.e. the preferential emission of mid-rapidity particles perpendicular to the reaction plane. The data were taken for the system 197 Au + 197 Au at 400, 600 and 800 MeV/u. We cover two topics, the comparison of neutrons and protons, and the bombarding energy dependence of the neutrons' squeeze-out. (orig.)

  6. Continuous Energy, Multi-Dimensional Transport Calculations for Problem Dependent Resonance Self-Shielding

    International Nuclear Information System (INIS)

    Downar, T.

    2009-01-01

    The overall objective of the work here has been to eliminate the approximations used in current resonance treatments by developing continuous energy multi-dimensional transport calculations for problem dependent self-shielding calculations. The work here builds on the existing resonance treatment capabilities in the ORNL SCALE code system. The overall objective of the work here has been to eliminate the approximations used in current resonance treatments by developing continuous energy multidimensional transport calculations for problem dependent self-shielding calculations. The work here builds on the existing resonance treatment capabilities in the ORNL SCALE code system. Specifically, the methods here utilize the existing continuous energy SCALE5 module, CENTRM, and the multi-dimensional discrete ordinates solver, NEWT to develop a new code, CENTRM( ) NEWT. The work here addresses specific theoretical limitations in existing CENTRM resonance treatment, as well as investigates advanced numerical and parallel computing algorithms for CENTRM and NEWT in order to reduce the computational burden. The result of the work here will be a new computer code capable of performing problem dependent self-shielding analysis for both existing and proposed GENIV fuel designs. The objective of the work was to have an immediate impact on the safety analysis of existing reactors through improvements in the calculation of fuel temperature effects, as well as on the analysis of more sophisticated GENIV/NGNP systems through improvements in the depletion/transmutation of actinides for Advanced Fuel Cycle Initiatives.

  7. Energy-dependency correction factors for the digital dosimeters using in NMD environment dose assessment

    International Nuclear Information System (INIS)

    Lai, Y.C.; Huang, Y. F.; Chen, Y.W.

    2008-01-01

    Full text: Short-term environment dose-rate assessments using real-time digital dosimeters within a Nuclear Medicine Department (NMD) are gaining more world-wide uses recently. In the past, conventional ion chamber-type survey-meters are used dominantly in environmental dose rates evaluation. Although it has suffered less gamma energy-dependency, but it is less sensitive in comparison with other digital dosimeters and more bulky in design that can hardly make it into a pocket size application. With modern electronic advancement and its shrinking in physical size, real-time personal dosimeter nowadays has gaining more popular to use a miniature G-M counter or a solid-state diode sensor, or even a NaI(Tl) scintillation device for ambient radiation monitoring. Radiation sensor operated in pulse-mode can never been used in doses or dose rates determination since each digital pulse has carried no energy information of the impinging gamma ray being interactive with, especially in the G-M counter or the diode sensor case. The raw count rates measured from a pulse-mode device are heavily dependent on the packaging of the sensor to make it less energy-sensitive. The doses or dose rates are then calculated by using a built-in conversion factor, based on a Cs-137 beam source calibration data conducted by various manufacturing vendors, to convert its raw counts into a so-called dose or dose-rate unit. In this study, we have focused our interests in the low energy response of the digital dosimeters from several brands currently for our in-house uses. Mainly, Tc-99m and I-131 in point sources and water phantoms detection configurations have been deployed to simulate our NMD outpatients for environment radiation monitoring purpose. The energy-dependent correction factors of the digital dosimeters will be evaluated by using calibrated Tc-99m or I-131 standard sources directly that has much lower gamma energy than the Cs-137 beam source of 661 keV. In the near future, we would

  8. Spin- and energy-dependent tunneling through a single molecule with intramolecular spatial resolution.

    Science.gov (United States)

    Brede, Jens; Atodiresei, Nicolae; Kuck, Stefan; Lazić, Predrag; Caciuc, Vasile; Morikawa, Yoshitada; Hoffmann, Germar; Blügel, Stefan; Wiesendanger, Roland

    2010-07-23

    We investigate the spin- and energy-dependent tunneling through a single organic molecule (CoPc) adsorbed on a ferromagnetic Fe thin film, spatially resolved by low-temperature spin-polarized scanning tunneling microscopy. Interestingly, the metal ion as well as the organic ligand show a significant spin dependence of tunneling current flow. State-of-the-art ab initio calculations including also van der Waals interactions reveal a strong hybridization of molecular orbitals and substrate 3d states. The molecule is anionic due to a transfer of one electron, resulting in a nonmagnetic (S=0) state. Nevertheless, tunneling through the molecule exhibits a pronounced spin dependence due to spin-split molecule-surface hybrid states.

  9. Dependency of energy and spatial distributions of photons on edge of object in brain SPECT

    CERN Document Server

    Deloar, H M; Kudomi, N; Kim, K M; Aoi, T; Iida, H

    2003-01-01

    Accurate mu maps are important for quantitative image reconstruction in SPECT. The Compton scatter energy window (CSW) technique has been proposed to define the outline of objects. In this technique, a lower energy window image is acquired in addition to the main photo-peak energy window. The image of the lower energy window is used to estimate the edge of the scanned object to produce a constant attenuation map. The aim of this study was to investigate the dependency of CSW on the spatial and energy distribution of radioisotope to predict the edges of objects. Two particular cases of brain study were considered, namely uniform distribution and non-uniform distribution using Monte Carlo simulation and experiments with uniform cylindrical phantom and hotspot phantom. The phantoms were filled with water and a radioactive solution of sup 9 sup 9 sup m Tc. For each phantom, 20%, 30%, 40% and 50% thresholds of the mean profile were applied to estimate E sub w sub t , the energy window for minimum difference betwee...

  10. Energy Dependence of Synchrotron X-Ray Rims in Tycho's Supernova Remnant

    Science.gov (United States)

    Tran, Aaron; Williams, Brian J.; Petre, Robert; Ressler, Sean M.; Reynolds, Stephen P.

    2015-01-01

    Several young supernova remnants exhibit thin X-ray bright rims of synchrotron radiation at their forward shocks. Thin rims require strong magnetic field amplification beyond simple shock compression if rim widths are only limited by electron energy losses. But, magnetic field damping behind the shock could produce similarly thin rims with less extreme field amplification. Variation of rim width with energy may thus discriminate between competing influences on rim widths. We measured rim widths around Tycho's supernova remnant in 5 energy bands using an archival 750 ks Chandra observation. Rims narrow with increasing energy and are well described by either loss-limited or damped scenarios, so X-ray rim width-energy dependence does not uniquely specify a model. But, radio counterparts to thin rims are not loss-limited and better reflect magnetic field structure. Joint radio and X-ray modeling favors magnetic damping in Tycho's SNR with damping lengths approximately 1-5% of remnant radius and magnetic field strengths approximately 50-400 micron G assuming Bohm diffusion. X-ray rim widths are approximately 1% of remnant radius, somewhat smaller than inferred damping lengths. Electron energy losses are important in all models of X-ray rims, suggesting that the distinction between loss-limited and damped models is blurred in soft X-rays. All loss-limited and damping models require magnetic fields approximately greater than 20 micron G, arming the necessity of magnetic field amplification beyond simple compression.

  11. Dependence of energy per molecule on sputtering yields with reactive gas cluster ions

    International Nuclear Information System (INIS)

    Toyoda, Noriaki; Yamada, Isao

    2010-01-01

    Gas cluster ions show dense energy deposition on a target surface, which result in the enhancement of chemical reactions. In reactive sputtering with gas cluster ions, the energy per atom or molecule plays an important role. In this study, the average cluster size (N, the number of atoms or molecules in a cluster ion) was controlled; thereby the dependences of the energy per molecule on the sputtering yields of carbon by CO 2 cluster ions and that of Si by SF 6 /Ar mixed gas cluster ions were investigated. Large CO 2 cluster ions with energy per molecule of 1 eV showed high reactive sputtering yield of an amorphous carbon film. However, these ions did not cause the formation of large craters on a graphite surface. It is possible to achieve very low damage etching by controlling the energy per molecule of reactive cluster ions. Further, in the case of SF 6 /Ar mixed cluster ions, it was found that reactive sputtering was enhanced when a small amount of SF 6 gas (∼10%) was mixed with Ar. The reactive sputtering yield of Si by one SF 6 molecule linearly increased with the energy per molecule.

  12. Effect of linear temperature dependence of thermoelectric properties on energy conversion efficiency

    International Nuclear Information System (INIS)

    Yamashita, Osamu

    2008-01-01

    New thermal rate equations were developed by taking the temperature dependences of the electrical resistivity ρ and thermal conductivity κ of the thermoelectric (TE) materials into the thermal rate equations on the assumption that they vary linearly with temperature T. The relative energy conversion efficiency η/η 0 for a single TE element was formulated by approximate analysis, where η and η 0 are the energy conversion efficiencies derived from the new and conventional thermal rate equations, respectively. Applying it to Si-Ge alloys, the temperature dependence of ρ is stronger than that of κ, so the former has a more significant effect on η/η 0 than the latter. However, the degree of contribution from both of them to η/η 0 was a little lower than 1% at the temperature difference ΔT of 600 K. When the temperature dependence of κ was increased to become equal to that of ρ, however, it was found that η/η 0 is increased by about 10% at ΔT = 600 K. It is clarified here that the temperature dependences of ρ and κ are also important factors for an improvement in η

  13. Temperature dependence of energy-transducing functions and inhibitor sensitivity in chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    Schuurmans, J.J.; Veerman, E.C.I.; Francke, J.A.; Torres-Pereira, J.M.G.; Kraayenhof, R.

    1984-01-01

    A comparative analysis of the temperature dependence of energy-transducing reactions in spinach (Spinacia oleracea) chloroplasts and their sensitivity for uncouplers and energy-transfer inhibitors at different temperatures is presented. Arrhenius plots reveal two groups of transitions, around 19/sup 0/C and around 12/sup 0/C. Activities that show transitions around 19/sup 0/C include linear electron flow from water to ferricyanide, its coupled photophosphorylation, the dark-release of the fluorescent probe atebrin, and the slow component of the 515 nm (carotenoid) absorbance decay after a flash. The transitions around 12/sup 0/C are observed with pyocyanine-mediated cyclic photophosphorylation, light- and dithioerythritol-activated ATP hydrolysis, the dark-release of protons, and the fast 515 nm decay component. It is suggested that both groups of temperature transitions are determined by proton displacements in different domains of the exposed thylakoid membranes. The effects of various uncouplers and an energy-transfer inhibitor are temperature dependent. Some uncouplers also show a different relative inhibition of proton uptake and ATP synthesis at lower temperatures. The efficiency of energy transduction (ATP/e/sub 3/) varied with temperature and was optimal around 10/sup 0/C.

  14. Material dependence of electron inelastic mean free paths at low energies

    International Nuclear Information System (INIS)

    Tanuma, S.; Powell, C.J.; Penn, D.R.

    1990-01-01

    We present and discuss electron inelastic mean free path (IMFP) data for aluminum and gold in the 50--200 eV range. These elements serve as examples of IMFP calculations that have been made for 50--2000 eV electrons in 31 materials (27 elements and 4 compounds). Substantial differences are found in the shapes of the IMFP versus energy curves for Al and Au and these can be understood in terms of the different inelastic scattering mechanisms in the two metals. The minimum IMFP value occurs at 40 eV in aluminum and at 120 eV in gold, a result which is consistent with the trends expected from free-electron IMFP calculations. This result differs, however, from that expected from the Seah and Dench attenuation length formula which shows essentially no material dependence at low energies. We have extended a general formula derived earlier to describe the calculated IMFPs over the 200--2000 eV energy range to give the IMFP dependences on material and energy from 50 to 2000 eV

  15. Coherent and incoherent J /ψ photonuclear production in an energy-dependent hot-spot model

    Science.gov (United States)

    Cepila, J.; Contreras, J. G.; Krelina, M.

    2018-02-01

    In a previous publication, we have presented a model for the photoproduction of J /ψ vector mesons off protons, where the proton structure in the impact-parameter plane is described by an energy-dependent hot-spot profile. Here we extend this model to study the photonuclear production of J /ψ vector mesons in coherent and incoherent interactions of heavy nuclei. We study two methods to extend the model to the nuclear case: using the standard Glauber-Gribov formalism and using geometric scaling to obtain the nuclear saturation scale. We find that the incoherent cross section changes sizably with the inclusion of subnucleonic hot spots and that this change is energy dependent. We propose to search for this behavior by measuring the ratio of the incoherent to coherent cross sections at different energies. We compare the results of our model to results from the Relativistic Heavy-Ion Collider (RHIC) and from run 1 at the Large Hadron Collider (LHC), finding satisfactory agreement. We also present predictions for the LHC at the new energies reached in run 2. The predictions include J /ψ production in ultraperipheral collisions, as well as the recently observed photonuclear production in peripheral collisions.

  16. Jet suppression and the flavor dependence of partonic energy loss with ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Kosek, Tomas

    2016-12-15

    In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. One manifestation of the energy loss of jets propagating through the medium is a lower yield of jets and hadrons emerging from this medium than expected in the absence of medium effects. Therefore modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. In this publication, the latest ATLAS results on single hadron suppression along with the complementary measurements of single jet suppression are presented. Rapidity dependence, which is sensitive to the relative energy loss between quark and gluon jets, is discussed. Finally, a new measurement of jet fragmentation functions is presented.

  17. Energy dependence of event shapes and of $\\alpha_s$ at LEP 2

    CERN Document Server

    Abreu, P; Adye, T; Adzic, P; Albrecht, Z; Alderweireld, T; Alekseev, G D; Alemany, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amapane, N; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Beillière, P; Belokopytov, Yu A; Belous, K S; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Branchini, P; Brenke, T; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschbeck, Brigitte; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camporesi, T; Canale, V; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Chapkin, M M; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cieslik, K; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crépé, S; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Ferro, F; Fichet, S; Firestone, A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Green, C; Grimm, H J; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Hansen, J; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hughes, G J; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Kersevan, Borut P; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kinvig, A; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kriznic, E; Krstic, J; Krumshtein, Z; Kubinec, P; Kurowska, J; Kurvinen, K L; Lamsa, J; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Maltezos, S; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Masik, J; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Moch, M; Møller, R; Mönig, K; Monge, M R; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Nassiakou, M; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neufeld, N; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolenko, M; Nomokonov, V P; Normand, Ainsley; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Royon, C; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schneider, H; Schwemling, P; Schwering, B; Schwickerath, U; Schyns, M A E; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Sekulin, R L; Shellard, R C; Sheridan, A; Siebel, M; Simard, L C; Simonetto, F; Sissakian, A N; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stanic, S; Stevenson, K; Stocchi, A; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tegenfeldt, F; Terranova, F; Thomas, J; Timmermans, J; Tinti, N; Tkatchev, L G; Todorova-Nová, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tzamarias, S; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Van Vulpen, I B; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Vollmer, C F; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G

    1999-01-01

    Infrared and collinear safe event shape distributions and their mean values are determined using the data taken at ve di erent centre of mass energies above $M_Z$ with the DELPHI detector at LEP. From the event shapes, the strong coupling $\\alpha_s$ is extracted in $O(\\alpha^2_s)$, NLLA and a combined scheme using hadronisation corrections evaluated with fragmentation model generators as well as using an analytical power ansatz. Comparing these measurements to those obtained at MZ, the energy dependence (running) of $\\alpha_s$ is accessible. The logarithmic energy slope of the inverse strong coupling is measured to be $d\\alpha_{s}^{-1}/d log(E_{cm}) = 1.39 \\pm 0.34(stat) \\pm 0.17(syst)$, in good agreement with the QCD expectation of 1.27.

  18. Global, finite energy, weak solutions for the NLS with rough, time-dependent magnetic potentials

    Science.gov (United States)

    Antonelli, Paolo; Michelangeli, Alessandro; Scandone, Raffaele

    2018-04-01

    We prove the existence of weak solutions in the space of energy for a class of nonlinear Schrödinger equations in the presence of a external, rough, time-dependent magnetic potential. Under our assumptions, it is not possible to study the problem by means of usual arguments like resolvent techniques or Fourier integral operators, for example. We use a parabolic regularisation, and we solve the approximating Cauchy problem. This is achieved by obtaining suitable smoothing estimates for the dissipative evolution. The total mass and energy bounds allow to extend the solution globally in time. We then infer sufficient compactness properties in order to produce a global-in-time finite energy weak solution to our original problem.

  19. Experimental observation of energy dependence of saturation thickness of multiply scattered gamma photons

    International Nuclear Information System (INIS)

    Singh, Manpreet; Singh, Gurvinderjit; Singh, Bhajan; Sandhu, B.S.

    2008-01-01

    The gamma photons continue to soften in energy as the number of scatterings increases in the target having finite dimensions both in depth and lateral dimensions. The number of multiply scattered photons increases with an increase in target thickness, and saturates at a particular value of the target thickness known as saturation thickness (depth). The present measurements are carried out to study the energy dependence of saturation thickness of multiply scattered gamma photons from targets of various thicknesses. The scattered photons are detected by a properly shielded NaI(Tl) gamma ray detector placed at 90 deg. to the incident beam. We observe that the saturation thickness increases with increasing incident gamma photon energy. Monte Carlo calculations based upon the package developed by Bauer and Pattison [Compton scattering experiments at the HMI (1981), HMI-B 364, pp. 1-106] support the present experimental results

  20. Incorporation of Hydrogen Bond Angle Dependency into the Generalized Solvation Free Energy Density Model.

    Science.gov (United States)

    Ma, Songling; Hwang, Sungbo; Lee, Sehan; Acree, William E; No, Kyoung Tai

    2018-04-23

    To describe the physically realistic solvation free energy surface of a molecule in a solvent, a generalized version of the solvation free energy density (G-SFED) calculation method has been developed. In the G-SFED model, the contribution from the hydrogen bond (HB) between a solute and a solvent to the solvation free energy was calculated as the product of the acidity of the donor and the basicity of the acceptor of an HB pair. The acidity and basicity parameters of a solute were derived using the summation of acidities and basicities of the respective acidic and basic functional groups of the solute, and that of the solvent was experimentally determined. Although the contribution of HBs to the solvation free energy could be evenly distributed to grid points on the surface of a molecule, the G-SFED model was still inadequate to describe the angle dependency of the HB of a solute with a polarizable continuum solvent. To overcome this shortcoming of the G-SFED model, the contribution of HBs was formulated using the geometric parameters of the grid points described in the HB coordinate system of the solute. We propose an HB angle dependency incorporated into the G-SFED model, i.e., the G-SFED-HB model, where the angular-dependent acidity and basicity densities are defined and parametrized with experimental data. The G-SFED-HB model was then applied to calculate the solvation free energies of organic molecules in water, various alcohols and ethers, and the log P values of diverse organic molecules, including peptides and a protein. Both the G-SFED model and the G-SFED-HB model reproduced the experimental solvation free energies with similar accuracy, whereas the distributions of the SFED on the molecular surface calculated by the G-SFED and G-SFED-HB models were quite different, especially for molecules having HB donors or acceptors. Since the angle dependency of HBs was included in the G-SFED-HB model, the SFED distribution of the G-SFED-HB model is well described

  1. Analysis of Reverse-Bias Leakage Current Mechanisms in Metal/GaN Schottky Diodes

    Directory of Open Access Journals (Sweden)

    P. Pipinys

    2010-01-01

    Full Text Available Temperature-dependent reverse-bias current-voltage characteristics obtained by other researchers for Schottky diodes fabricated on GaN are reinterpreted in terms of phonon-assisted tunneling (PhAT model. Temperature dependence of reverse-bias leakage current is shown could be caused by the temperature dependence of electron tunneling rate from traps in the metal-semiconductor interface to the conduction band of semiconductor. A good fit of experimental data with the theory is received in a wide temperature range (from 80 K to 500 K using for calculation the effective mass of 0.222 me. and for the phonon energy the value of 70 meV. The temperature and bias voltages dependences of an apparent barrier height (activation energy are also explicable in the framework of the PhAT model.

  2. The angular dependence of spin-state energy splittings in the ? core

    Science.gov (United States)

    Groß, Lynn; Steenbock, Torben; Herrmann, Carmen

    2013-07-01

    Spin-state energy splittings are highly relevant for catalysis, molecular magnetism, and materials science, yet continue to pose a challenge for electronic structure methods. For a Fe2O2+ 2 core, we evaluate the bridging angle dependence of energy splittings between ferromagnetically and antiferromagnetically coupled states for different exchange-correlation functionals, and compare with complete active space self-consistent field (CASSCF) values, also including second-order perturbative corrections (CASPT2). CASSCF and CASPT2 yield strong antiferromagnetic coupling, with the smallest coupling at 100°, and a smooth dependence on the angle for Fe-O-Fe angles of 70° to 120°. Interestingly, this is qualitatively the same behaviour as often found for stable dinuclear transition metal complexes. While all functionals show the same angular dependence as CASPT2, they favour the antiferromagnetic state less strongly. Pure functionals such as BP86, BLYP, SSB-D, and TPSS come closer to the CASPT2 results (with energy splittings by about 60 kJ/mol smaller than the CASPT2 ones) than hybrid functionals. The hybrid functionals B3LYP, B3LYP⋆, and PBE0 favour the antiferromagnetic state even less strongly, resulting in ferromagnetic coupling for angles around 100°. The good qualitative agreement between CASPT2 and CASSCF on the one hand and CASPT2 and density functional theory on the other hand for angles between 70° and 110° suggests that the chosen active space of 18 electrons in 14 orbitals may be adequate for spin-state energy splitting of Fe2O2+ 2 in that region (possibly due to error cancellation), while angles of 60° or 120° may require larger active spaces. This study is complemented by an analysis of local spins, local charges, and CASSCF natural orbitals.

  3. Charge-state dependence of binary-encounter-electron cross sections and peak energies

    International Nuclear Information System (INIS)

    Hidmi, H.I.; Richard, P.; Sanders, J.M.; Schoene, H.; Giese, J.P.; Lee, D.H.; Zouros, T.J.M.; Varghese, S.L.

    1993-01-01

    The charge-state dependence of the binary-encounter-electron (BEE) double-differential cross section (DDCS) at 0 degree with respect to the beam direction resulting from collisions of 1 MeV/amu H + , C q+ , N q+ , O q+ , F q+ , Si q+ , and Cl q+ , and 0.5 MeV/amu Cu q+ with H 2 is reported. The data show an enhancement in the BEE DDCS as the charge state of the projectile is decreased, in agreement with the data reported by Richard et al. [J. Phys. B 23, L213 (1990)]. The DDCS enhancement ratios observed for the three-electron isoelectronic sequence C 3+ :C 6+ , N 4+ :N 7+ , O 5+ :O 8+ , and F 6+ :F 9+ are about 1.35, whereas a DDCS enhancement of 3.5 was observed for Cu 4+ . The BEE enhancement with increasing electrons on the projectile has been shown by several authors to be due to the non-Coulomb static potential of the projectile and additionally to the e-e exchange interaction. An impulse-approximation (IA) model fits the shape of the BEE DDCS and predicts a Z p 2 dependence for the bare-ion cross sections. The IA also predicts a binary peak energy that is independent of q and Z p and below the classical value of 4t, where t is the energy of electrons traveling with the projectile velocity. We observed a BEE energy shift ΔE (ΔE=4t-E peak , where E peak is the measured energy at the peak of the binary encounter electrons) that is approximately independent of q for the low-Z p ions, whereas the measured ΔE values for Si, Cl, and Cu were found to be q dependent

  4. Simulating time-dependent energy transfer between crossed laser beams in an expanding plasma

    International Nuclear Information System (INIS)

    Hittinger, J.A.F.; Dorr, M.R.; Berger, R.L.; Williams, E.A.

    2005-01-01

    A coupled mode system is derived to investigate a three-wave parametric instability leading to energy transfer between co-propagating laser beams crossing in a plasma flow. The model includes beams of finite width refracting in a prescribed transverse plasma flow with spatial and temporal gradients in velocity and density. The resulting paraxial light equations are discretized spatially with a Crank-Nicholson-type scheme, and these algebraic constraints are nonlinearly coupled with ordinary differential equations in time that describe the ion acoustic response. The entire nonlinear differential-algebraic system is solved using an adaptive, backward-differencing method coupled with Newton's method. A numerical study is conducted in two dimensions that compares the intensity gain of the fully time-dependent coupled mode system with the gain computed under the further assumption of a strongly damped ion acoustic response. The results demonstrate a time-dependent gain suppression when the beam diameter is commensurate with the velocity gradient scale length. The gain suppression is shown to depend on time-dependent beam refraction and is interpreted as a time-dependent frequency shift

  5. Two-particle one-hole multiple-scattering contribution to 17O energies using an energy-dependent reaction matrix

    International Nuclear Information System (INIS)

    Bando, H.; Krenciglowa, E.M.

    1976-01-01

    The role of 2p1h correlations in 17 O is studied within a multiple-scattering formalism. An accurate, energy-dependent reaction matrix with orthogonalized plane-wave intermediate states is used to assess the relative importance of particle-particle and particle-hole correlations in the 17 O energies. The effect of energy dependence of the reaction matrix is closely examined. (Auth.)

  6. Measurement of time-dependent fast neutron energy spectra in a depleted uranium assembly

    International Nuclear Information System (INIS)

    Whittlestone, S.

    1980-10-01

    Time-dependent neutron energy spectra in the range 0.6 to 6.4 MeV have been measured in a depleted uranium assembly. By selecting windows in the time range 0.9 to 82 ns after the beam pulse, it was possible to observe the change of the neutron energy distributions from spectra of predominantly 4 to 6 MeV neutrons to spectra composed almost entirely of fission neutrons. The measured spectra were compared to a Monte Carlo calculation of the experiment using the ENDF/B-IV data file. At times and energies at which the calculation predicted a fission spectrum, the experiment agreed with the calculation, confirming the accuracy of the neutron spectroscopy system. However, the presence of discrepancies at other times and energies suggested that there are significant inconsistencies in the inelastic cross sections in the 1 to 6 MeV range. The time response generated concurrently with the energy spectra was compared to the Monte Carlo calculation. From this comparison, and from examination of time spectra measured by other workers using 235 U and 237 Np fission detectors, it would appear that there are discrepancies in the ENDF/B-IV cross sections below 1 MeV. The predicted decay rates were too low below and too high above 0.8 MeV

  7. Measurement of the energy dependence of X-ray-induced decomposition of potassium chlorate.

    Science.gov (United States)

    Pravica, Michael; Bai, Ligang; Sneed, Daniel; Park, Changyong

    2013-03-21

    We report the first measurements of the X-ray induced decomposition of KClO3 as a function of energy in two experiments. KClO3 was pressurized to 3.5 GPa and irradiated with monochromatic synchrotron X-rays ranging in energy from 15 to 35 keV in 5 keV increments. A systematic increase in the decomposition rate as the energy was decreased was observed, which agrees with the 1/E(3) trend for the photoelectric process, except at the lowest energy studied. A second experiment was performed to access lower energies (10 and 12 keV) using a beryllium gasket; suggesting an apparent resonance near 15 keV or 0.83 Ǻ maximizing the chemical decomposition rate. A third experiment was performed using KIO3 to ascertain the anionic dependence of the decomposition rate, which was observed to be far slower than in KClO3, suggesting that the O-O distance is the critical factor in chemical reactions. These results will be important for more efficiently initiating chemical decomposition in materials using selected X-ray wavelengths that maximize decomposition to aid useful hard X-ray-induced chemistry and contribute understanding of the mechanism of X-ray-induced decomposition of the chlorates.

  8. Results on the energy dependence of cosmic-ray charge composition

    Science.gov (United States)

    Balasubrahmanyan, V. K.; Ormes, J. F.

    1973-01-01

    Results of measurements by a balloon-borne ionization spectrometer of the energy dependence of high-energy cosmic-ray charge composition. The results presented are greatly improved over those obtained earlier by Ormes et al. (1971) by the use of a multidimensional charge analysis with more efficient background rejection, and a more accurate energy determination. Complex couplings between the charge, energy, and trajectory information were taken into account and are discussed. The spectra of individual elements up to oxygen and of groups of nuclei up through iron were measured up to almost 100 GeV per nucleon. The energy spectrum of the secondary nuclei, B + N, is found to be steeper than that of the primary nuclei, C + O, in agreement with Smith et al. (1973). The most dramatic finding is that the spectrum of the iron nuclei is flatter than that of the carbon and oxygen nuclei by 0.57 plus or minus 0.14 of a power.

  9. Determination of alpha effectiveness in ESR dating using nuclear accelerator techniques: methods and energy dependence

    International Nuclear Information System (INIS)

    Lyons, R.G.

    1988-01-01

    An important parameter in calculating the environmental dose rate for electron spin resonance (ESR) age estimates is the relative effectiveness of alpha and gamma radiation. A small research accelerator is used as a source of alpha particles of various pre-selected energies, corresponding to those found in the environment, to determine the effectiveness of alpha radiation of different energies. Preparation of sample targets is discussed, including the use of absolute ethanol, thorough etching and deposition by centrifuge. Preliminary results show that the alpha/gamma effectiveness ratio, k, depends on the energy of the incident alpha and must therefore be expressed in terms of a reference energy. The effectiveness of an alpha particle in causing ESR damage is found to vary linearly with its range or path length, not with its energy, a fact which must be considered when calculating effective dose-rates from environmental radionuclide concentrations. Failure to do so may lead to serious systematic errors in the effective alpha contribution to environmental dose-rates and consequently in age estimates. (author)

  10. Large-scale galaxy bias

    Science.gov (United States)

    Desjacques, Vincent; Jeong, Donghui; Schmidt, Fabian

    2018-02-01

    This review presents a comprehensive overview of galaxy bias, that is, the statistical relation between the distribution of galaxies and matter. We focus on large scales where cosmic density fields are quasi-linear. On these scales, the clustering of galaxies can be described by a perturbative bias expansion, and the complicated physics of galaxy formation is absorbed by a finite set of coefficients of the expansion, called bias parameters. The review begins with a detailed derivation of this very important result, which forms the basis of the rigorous perturbative description of galaxy clustering, under the assumptions of General Relativity and Gaussian, adiabatic initial conditions. Key components of the bias expansion are all leading local gravitational observables, which include the matter density but also tidal fields and their time derivatives. We hence expand the definition of local bias to encompass all these contributions. This derivation is followed by a presentation of the peak-background split in its general form, which elucidates the physical meaning of the bias parameters, and a detailed description of the connection between bias parameters and galaxy statistics. We then review the excursion-set formalism and peak theory which provide predictions for the values of the bias parameters. In the remainder of the review, we consider the generalizations of galaxy bias required in the presence of various types of cosmological physics that go beyond pressureless matter with adiabatic, Gaussian initial conditions: primordial non-Gaussianity, massive neutrinos, baryon-CDM isocurvature perturbations, dark energy, and modified gravity. Finally, we discuss how the description of galaxy bias in the galaxies' rest frame is related to clustering statistics measured from the observed angular positions and redshifts in actual galaxy catalogs.

  11. Large-scale galaxy bias

    Science.gov (United States)

    Jeong, Donghui; Desjacques, Vincent; Schmidt, Fabian

    2018-01-01

    Here, we briefly introduce the key results of the recent review (arXiv:1611.09787), whose abstract is as following. This review presents a comprehensive overview of galaxy bias, that is, the statistical relation between the distribution of galaxies and matter. We focus on large scales where cosmic density fields are quasi-linear. On these scales, the clustering of galaxies can be described by a perturbative bias expansion, and the complicated physics of galaxy formation is absorbed by a finite set of coefficients of the expansion, called bias parameters. The review begins with a detailed derivation of this very important result, which forms the basis of the rigorous perturbative description of galaxy clustering, under the assumptions of General Relativity and Gaussian, adiabatic initial conditions. Key components of the bias expansion are all leading local gravitational observables, which include the matter density but also tidal fields and their time derivatives. We hence expand the definition of local bias to encompass all these contributions. This derivation is followed by a presentation of the peak-background split in its general form, which elucidates the physical meaning of the bias parameters, and a detailed description of the connection between bias parameters and galaxy (or halo) statistics. We then review the excursion set formalism and peak theory which provide predictions for the values of the bias parameters. In the remainder of the review, we consider the generalizations of galaxy bias required in the presence of various types of cosmological physics that go beyond pressureless matter with adiabatic, Gaussian initial conditions: primordial non-Gaussianity, massive neutrinos, baryon-CDM isocurvature perturbations, dark energy, and modified gravity. Finally, we discuss how the description of galaxy bias in the galaxies' rest frame is related to clustering statistics measured from the observed angular positions and redshifts in actual galaxy catalogs.

  12. Bias against research on gender bias.

    Science.gov (United States)

    Cislak, Aleksandra; Formanowicz, Magdalena; Saguy, Tamar

    2018-01-01

    The bias against women in academia is a documented phenomenon that has had detrimental consequences, not only for women, but also for the quality of science. First, gender bias in academia affects female scientists, resulting in their underrepresentation in academic institutions, particularly in higher ranks. The second type of gender bias in science relates to some findings applying only to male participants, which produces biased knowledge. Here, we identify a third potentially powerful source of gender bias in academia: the bias against research on gender bias. In a bibliometric investigation covering a broad range of social sciences, we analyzed published articles on gender bias and race bias and established that articles on gender bias are funded less often and published in journals with a lower Impact Factor than articles on comparable instances of social discrimination. This result suggests the possibility of an underappreciation of the phenomenon of gender bias and related research within the academic community. Addressing this meta-bias is crucial for the further examination of gender inequality, which severely affects many women across the world.

  13. Energy dependency of mechanical properties on polymer impregnated concrete polymerized by radiation induced method

    International Nuclear Information System (INIS)

    Ono, Hironobu

    1978-01-01

    The purpose of this paper is to study the characteristics of polymerization on polymer impregnated concrete (PIC) polymerized by various radiation source which have the peculiar energy respectively as follows; Gamma-rays: 60 Co-1.25MeV, 137 Cs-0.66MeV, X-Ray: 0.88MeV and accelerated electron beam 4.0, 2.0 and 1.2MeV. This experimental program was carried out to investigate the effect of radiation energy, density of cementmortar, optimum irradiating conditions and other factors which have influence upon the polymerization and strength of PIC. The test results shows that the energy dependency on the accelerated electron was remarkable effect for relative absorption energy and strength of specimens (Fig. 5) and it can be estimate that the impregnation depth from the surface of specimens in ordinary mortar MMA-PIC were about 10 mm, 6 mm, and 3 mm as to 4.0, 2.0 and 1.2MeV respectively under curing 50 Mrads (Fig. 2). It is also show that the optimum total exposure dose on magnetic electro wave methods, estimate about 3 MR at 60 Co; 1 x 10 6 R/hr, 2 MR at 137 Cs; 4.5 x 10 4 R/hr and 2 MR at X-ray; 5 x 10 5 R/hr at curing temperature 20 0 C (Fig. 9, Fig. 10). We can see the fact that the energy dependency is noticiable only comparing same kinds of radiation source. (author)

  14. Energy dependence of the optical model of neutron scattering from niobium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.; Lawson, R.D.

    1985-05-01

    Neutron differential-elastic-scattering cross sections of niobium were measured from 1.5 to 10.0 MeV at intervals of less than or equal to200 keV below 4.0 MeV, and of approx. =500 keV from 4.0 to 10.0 MeV. Ten to more than fifty differential-cross-section values were determined at each incident energy, distributed over the angular range approx. =20 to 160 0 . The observed values were interpreted in the context of the spherical optical-statistical model. It was found that the volume integral of the real potential decreased with energy whereas the integral of the imaginary part increased. The energy dependence in both cases was consistent with a linear variation. There is a dispersion relationship between the real and imaginary potentials, and when this was used, in conjunction with the experimental imaginary potential, it was possible to predict the observed energy dependence of the real potential to a good degree of accuracy, thus supporting the consistency of the data and its analysis. The real-potential well depths needed to give the correct binding energies of the 2d/sub 5/2/, 3s/sub 1/2/, 2d/sub 3/2/ and 1g/sub 7/2/ particle states and of the 1g/sub 9/2/ hole state are in reasonable agreement with those given by a linear extrapolation of the scattering potential. However, the well depths needed to give the observed binding of the 2p/sub 3/2/, 1f/sub 5/2/ and 2p/sub 1/2/ hole states are about 10% less than the extrapolated values. 40 refs., 5 figs

  15. Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales

    Science.gov (United States)

    Stickler, Claudia M.; Coe, Michael T.; Costa, Marcos H.; Nepstad, Daniel C.; McGrath, David G.; Dias, Livia C. P.; Rodrigues, Hermann O.; Soares-Filho, Britaldo S.

    2013-01-01

    Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations’ energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local “direct” effects (through changes in ET within the watershed) and the potential regional “indirect” effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world’s largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4–8% and 10–12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6–36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry’s own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests. PMID:23671098

  16. Flux and energy dependence of methane production from graphite due to H+ impact

    International Nuclear Information System (INIS)

    Davis, J.W.; Haasz, A.A.; Stangeby, P.C.

    1986-06-01

    Carbon is in widespread use for limiter surfaces, as well as first wall coatings in current tokamaks. Chemical erosion via methane formation, due to energetic H + impact, is expected to contribute to the total erosion rate of carbon from these surfaces. Experimental results are presented for the methane yield from pyrolytic graphite due to H + exposure, using a mass analyzed ion beam. H + energies of 0.1-3 keV and flux densities of ∼ 5x10 13 to l0 16 H + /cm 2 s were used. The measured methane yield (CH 4 /H + ) initially increases with flux density, then reaches a maximum, which is followed by a gradual decrease. The magnitude of the maximum yield and the flux density at which it occurs depends on the graphite temperature. The yields obtained at temperatures corresponding to yield maxima at specific flux densities also show an initial increase, followed by a shallow maximum and a gradual decrease as a function of flux density; the maximum occurs at ∼10 15 H + /cm 2 s. Also presented are results on the methane production dependence on ion energy over the range 0.1 to 3 keV, and graphite temperature dependence measurements

  17. Simulation studies of optimum energies for DXA: dependence on tissue type, patient size and dose model

    International Nuclear Information System (INIS)

    Michael, G. J.; Henderson, C. J.

    1999-01-01

    Dual-energy x-ray absorptiometry (DXA) is a well established technique for measuring bone mineral density (BMD). However, in recent years DXA is increasingly being used to measure body composition in terms of fat and fat-free mass. DXA scanners must also determine the soft tissue baseline value from soft-tissue-only regions adjacent to bone. The aim of this work is to determine, using computer simulations, the optimum x- ray energies for a number of dose models, different tissues, i.e. bone mineral, average soft tissue, lean soft tissue and fat; and a range of anatomical sites and patient sizes. Three models for patient dose were evaluated total beam energy, entrance exposure and absorbed dose calculated by Monte Carlo modelling. A range of tissue compositions and thicknesses were chosen to cover typical patient variations for the three sites femoral neck, PA spine and lateral spine. In this work, the optimisation of the energies is based on (1) the uncertainty that arises from the quantum statistical nature of the number of x-rays recorded by the detector, and (2) the radiation dose received by the patient. This study has deliberately not considered other parameters such as detector response, electronic noise, x-ray tube heat load etc, because these are technology dependent parameters, not ones that are inherent to the measuring technique. Optimisation of the energies is achieved by minimisation of the product of variance of density measurement and dose which is independent of the absolute intensities of the x-ray beams. The results obtained indicate that if solving for bone density, then E-low in the range 34 to 42 keV, E-high in the range 100 to 200 keV and incident intensity ratio (low energy/high energy) in the range 3 to 10 is a reasonable compromise for the normal range of patient sizes. The choice of energies is complicated by the fact that the DXA unit must also solve for fat and lean soft tissue in soft- tissue-only regions adjacent to the bone. In this

  18. Energy shift and conduction-to-valence band transition mediated by a time-dependent potential barrier in graphene

    Science.gov (United States)

    Chaves, Andrey; da Costa, D. R.; de Sousa, G. O.; Pereira, J. M.; Farias, G. A.

    2015-09-01

    We investigate the scattering of a wave packet describing low-energy electrons in graphene by a time-dependent finite-step potential barrier. Our results demonstrate that, after Klein tunneling through the barrier, the electron acquires an extra energy which depends on the rate of change of the barrier height with time. If this rate is negative, the electron loses energy and ends up as a valence band state after leaving the barrier, which effectively behaves as a positively charged quasiparticle.

  19. Energy-dependent expansion of .177 caliber hollow-point air gun projectiles.

    Science.gov (United States)

    Werner, Ronald; Schultz, Benno; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias

    2017-05-01

    Amongst hundreds of different projectiles for air guns available on the market, hollow-point air gun pellets are of special interest. These pellets are characterized by a tip or a hollowed-out shape in their tip which, when fired, makes the projectiles expand to an increased diameter upon entering the target medium. This results in an increase in release of energy which, in turn, has the potential to cause more serious injuries than non-hollow-point projectiles. To the best of the authors' knowledge, reliable data on the terminal ballistic features of hollow-point air gun projectiles compared to standard diabolo pellets have not yet been published in the forensic literature. The terminal ballistic performance (energy-dependent expansion and penetration) of four different types of .177 caliber hollow-point pellets discharged at kinetic energy levels from approximately 3 J up to 30 J into water, ordnance gelatin, and ordnance gelatin covered with natural chamois as a skin simulant was the subject of this investigation. Energy-dependent expansion of the tested hollow-point pellets was observed after being shot into all investigated target media. While some hollow-point pellets require a minimum kinetic energy of approximately 10 J for sufficient expansion, there are also hollow-point pellets which expand at kinetic energy levels of less than 5 J. The ratio of expansion (RE, calculated by the cross-sectional area (A) after impact divided by the cross-sectional area (A 0 ) of the undeformed pellet) of hollow-point air gun pellets reached values up of to 2.2. The extent of expansion relates to the kinetic energy of the projectile with a peak for pellet expansion at the 15 to 20 J range. To conclude, this work demonstrates that the hollow-point principle, i.e., the design-related enlargement of the projectiles' frontal area upon impact into a medium, does work in air guns as claimed by the manufacturers.

  20. An investigation of the photon energy dependence of the EPR alanine dosimetry system

    International Nuclear Information System (INIS)

    Bergstrand, Eva Stabell; Shortt, Ken R; Ross, Carl K; Hole, Eli Olaug

    2003-01-01

    The electron paramagnetic resonance (EPR) alanine dosimetry system is based on EPR measurements of radicals formed in alanine by ionizing radiation. The system has been studied to determine its energy dependence for photons in the 10-30 MV region relative to those of 60 Co and to find out if the system would be suitable for dosimetry comparisons. The irradiations were carried out at the National Research Council, Ottawa, Canada and the doses ranged from 8 to 54 Gy. The EPR measurements were performed at the University of Oslo, Norway. The ratio of the slope of the alanine reading versus dose-to-water curve for a certain linac photon beam quality and the corresponding slope for a reference 60 Co γ-radiation gives an experimental measure of the relative dose-to-water response of the EPR alanine dosimetry system. For calculating the linear regression coefficients of these alanine reading versus dose curves, the method of weighted least squares was used. This method is assumed to produce more accurate regression coefficients when applied to EPR dosimetry than the common method of standard least squares. The overall uncertainty on the ratio of slopes was between 0.5 and 0.6% for all three linac energies. The relative response for all the linac beams compared to cobalt was less than unity: by about 0.5% for the 20 and 30 MV points but by more than 1% for the 10 MV point. The given standard uncertainties negate concluding that there is any significant internal variation in the measured response as a function of beam quality between the three linac energies. Thus, we calculated the average dose response for all three energies and found that the alanine response is 0.8% (±0.5%) lower for high energy x-rays than for 60 Co γ-rays. This result indicates a small energy dependence in the alanine response for the high-energy photons relative to 60 Co which may be significant. This result is specific to our dosimetry system (alanine with 20% polyethylene binder pressed into a

  1. Simulation of Probe Position-Dependent Electron Energy-Loss Fine Structure

    Energy Technology Data Exchange (ETDEWEB)

    Oxley, M. P.; Kapetanakis, M. D.; Prange, Micah P.; Varela, M.; Pennycook, Stephen J.; Pantelides, Sokrates T.

    2014-03-31

    We present a theoretical framework for calculating probe-position-dependent electron energy-loss near-edge structure for the scanning transmission electron microscope by combining density functional theory with dynamical scattering theory. We show how simpler approaches to calculating near-edge structure fail to include the fundamental physics needed to understand the evolution of near-edge structure as a function of probe position and investigate the dependence of near-edge structure on probe size. It is within this framework that density functional theory should be presented, in order to ensure that variations of near-edge structure are truly due to local electronic structure and how much from the diffraction and focusing of the electron beam.

  2. Technique for sensitivity analysis of space- and energy-dependent burn-up calculations

    International Nuclear Information System (INIS)

    Williams, M.L.; White, J.R.

    1979-01-01

    A practical method is presented for sensitivity analysis of the very complex, space-energy dependent burn-up equations, in which the neutron and nuclide fields are coupled nonlinearly. The adjoint burn-up equations that are given are in a form which can be directly implemented into multi-dimensional depletion codes, such as VENTURE/BURNER. The data sensitivity coefficients can be used to determine the effect of data uncertainties on time-dependent depletion responses. Initial condition sensitivity coefficients provide a very effective method for computing the change in end of cycle parameters (such as k/sub eff/, fissile inventory, etc.) due to changes in nuclide concentrations at beginning of cycle

  3. Dependence of effective spectrum width of synchrotron radiation on particle energy

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.G. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Institute of High Current Electronics, Tomsk (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); P.N. Lebedev Physical Institute, Moscow (Russian Federation); Levin, A.D. [University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Loginov, A.S.; Saprykin, A.D. [Tomsk State University, Department of Physics, Tomsk (Russian Federation)

    2017-05-15

    In the classical theory of synchrotron radiation, for the exact quantitative characterization of spectral properties, the concept of effective spectral width is introduced. In the first part of our work, published in EJPC 75 (2015), the effective spectral width as a function of the energy E of the radiating particle was obtained only in the ultra-relativistic approximation. In this article, which can be considered as a natural continuation of this work, a complete investigation is presented of the dependence of the effective width of the synchrotron radiation spectrum on energy for any values of E and for all the polarization components of the radiation. Numerical calculations were carried out for an effective width not exceeding 100 harmonics. (orig.)

  4. Energy dependence of the charged multiplicity in deep inelastic scattering at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Chekanov, S.; Derrick, M.; Magill, S. [Argonne National Laboratory, Argonne, IL (US)] (and others)

    2008-03-15

    The charged multiplicity distributions and the mean charged multiplicity have been investigated in inclusive neutral current deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 38.6 pb{sup -1}. The measurements were performed in the current region of the Breit frame, as well as in the current fragmentation region of the hadronic centre-of-mass frame. The KNO-scaling properties of the data were investigated and the energy dependence was studied using different energy scales. The data are compared to results obtained in e{sup +}e{sup -} collisions and to previous DIS measurements as well as to leading-logarithm parton-shower Monte Carlo predictions. (orig.)

  5. Energy dependence of the charged multiplicity in deep inelastic scattering at HERA

    International Nuclear Information System (INIS)

    Chekanov, S.; Derrick, M.; Magill, S.

    2008-03-01

    The charged multiplicity distributions and the mean charged multiplicity have been investigated in inclusive neutral current deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 38.6 pb -1 . The measurements were performed in the current region of the Breit frame, as well as in the current fragmentation region of the hadronic centre-of-mass frame. The KNO-scaling properties of the data were investigated and the energy dependence was studied using different energy scales. The data are compared to results obtained in e + e - collisions and to previous DIS measurements as well as to leading-logarithm parton-shower Monte Carlo predictions. (orig.)

  6. Determination of pulse energy dependence for skin denaturation from 585nm fibre laser

    Science.gov (United States)

    Mujica-Ascencio, S.; Velazquez-Gonzalez, J. S.; Mujica-Ascencio, C.; Alvarez-Chavez, J. A.

    2014-05-01

    In this paper, simulation and mathematical analysis for the determination of pulse energy from a Q-switched Yb3+-doped fibre laser is required in Port Wine Stain (PWS) treatment. The pulse energy depends on average power, gain, volume, repetition rate and pulse duration. In some treatments such as Selective Photothermolysis (SP), the peak power at the end of the optical fibre and pulse duration can be obtained and modified via a cavity design. For that purpose, a 585nm optical fibre laser full design which considers all of the above besides the average losses through the optical devices proposed for the design and the Ytterbium optical fibre overall gain will be presented.

  7. Energy dependence of fusion evaporation-residue cross sections in the 28Si+12C reaction

    International Nuclear Information System (INIS)

    Vineyard, M.F.; Mateja, J.F.; Beck, C.; Atencio, S.E.; Dennis, L.C.; Frawley, A.D.; Henderson, D.J.; Janssens, R.V.F.; Kemper, K.W.; Kovar, D.G.; Maguire, C.F.; Padalino, S.J.; Prosser, F.W.; Stephans, G.S.F.; Tiede, M.A.; Wilkins, B.D.; Zingarelli, R.A.

    1993-01-01

    Fusion evaporation-residue cross sections for the 28 Si+ 12 C reaction have been measured in the energy range 18≤E c.m. ≤136 MeV using time-of-flight techniques. Velocity distributions of mass-identified reaction products were used to identify evaporation residues and to determine the complete-fusion cross sections at high energies. The data are in agreement with previously established systematics which indicate an entrance-channel mass-asymmetry dependence of the incomplete-fusion evaporation-residue process. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with earlier measurements and the predictions of existing models

  8. Isotope effect with energy-dependent density of states and impurities

    International Nuclear Information System (INIS)

    Williams, P.J.; Carbotte, J.P.

    1992-01-01

    We have calculated the total isotope coefficient β in a model where there is energy-dependent structure in the electronic density of states. We model the structure with a simple Lorentzian. In our calculation, doping has the effect of shifting the Fermi level and broadening the structure in the density of states. We have treated the dopants both as normal and as magnetic impurities. The asymmetry observed in the experimental data is found in our results. However, the complete range of values observed is difficult to reproduce. We question also whether the shifts in Fermi level required in such models are reasonable

  9. A method for reducing energy dependence of thermoluminescence dosimeter response by means of filters

    International Nuclear Information System (INIS)

    Bapat, V.N.

    1980-01-01

    This work describes the application of the method of partial surface shielding for reducing the energy dependence of the X-ray and γ-ray response of a dosimeter containing a CaSO 4 :Dy thermoluminescent phosphor mixed with KCl. in pellet form. Results are given of approximate computation of filter combinations that accomplish this aim, and of experimental verifications. Incorporation of the described filter combination makes it possible to use this relatively sensitive dosimeter for environmental radiation monitoring. A similar approach could be applied to any type of dosimeter in the form of a thin pellet or wafer. (author)

  10. Evaluation of the energy dependence of ionization chambers pencil type calibrated beam tomography standards

    International Nuclear Information System (INIS)

    Fontes, Ladyjane Pereira; Potiens, Maria da Penha A.

    2015-01-01

    The Instrument Calibration Laboratory of IPEN (LCI - IPEN) performs calibrations of pencil-type ionization chambers (IC) used in measures of dosimetric survey on clinical systems of Computed Tomography (CT). Many users make mistakes when using a calibrated ionization chamber in their CT dosimetry systems. In this work a methodology for determination of factors of correction for quality (Kq) through the calibration curve that is specific for each ionization chamber was established. Furthermore, it was possible to demonstrate the energy dependence on an pencil-type Ionization Chamber(IC) calibrated at the LCI - IPEN. (author)

  11. Sub-LET Threshold SEE Cross Section Dependency with Ion Energy

    CERN Document Server

    Garcia Alia, Ruben; Brandenburg, Sytze; Brugger, Markus; Daly, Eamonn; Ferlet-Cavrois, Veronique; Gaillard, Remi; Hoeffgen, Stefan; Menicucci, Alessandra; Metzger, Stefan; Zadeh, Ali; Muschitiello, Michele; Noordeh, Emil; Santin, Giovanni; CERN. Geneva. ATS Department

    2015-01-01

    This study focuses on the ion species and energy dependence of the heavy ion SEE cross section in the sub-let threshold region through a set of experimental data. In addition, a Monte Carlo based model is introduced and applied, showing a good agreement with the data in the several hundred MeV/n range while evidencing large discrepancies with the measurements in the 10-30 MeV/n interval, notably for the NE ion. Such discrepancies are carefully analysed and discussed.

  12. Temperature dependence of the surface energy of mercury from 0 to 250 deg. C

    CERN Document Server

    Halas, S

    2002-01-01

    The surface energy (SE) for mercury was calculated on the basis of the free electron model in which the electron density parameter, r sub s , for bulk electrons was calculated from the density of mercury while the electron density parameter for surface electrons, r sub s sub s , was assumed to be higher by a factor that is linearly dependent on temperature. Ideal agreement of calculated SE values with experimental data was attained for the temperatures 0-250 deg. C assuming that r sub s sub s = r sub s x 1.0021 sup T sup / sup 1 sup 0 sup 0 deg. C. (letter to the editor)

  13. Criticality problems for slabs and spheres in energy dependent neutron transport theory

    International Nuclear Information System (INIS)

    Victory, H.D. Jr.

    1980-01-01

    The steady-state equation for energy-dependent neutron transport in isotropically scattering slabs and spheres is formulated as an integral equation. The Perron-Frobenius-Jentzsch theory of positive operators is used to analyze criticality problems for transport in slab and spherical media consisting of core and reflector. In addition, with an adroit selection of diffusion-like solutions, this theory is used to obtain an expression relating the critical radius of a homogeneous sphere to a parameter characterizing fission production. 21 refs

  14. Photon energy dependent intensity variations observed in Auger spectra of free argon clusters

    International Nuclear Information System (INIS)

    Lundwall, M; Lindblad, A; Bergersen, H; Rander, T; Oehrwall, G; Tchaplyguine, M; Peredkov, S; Svensson, S; Bjoerneholm, O

    2006-01-01

    Photon energy dependent intensity variations are experimentally observed in the L 2,3 M 2,3 M 2,3 Auger spectra of argon clusters. Two cluster sizes are examined in the present study. Extrinsic scattering effects, both elastic and inelastic, involving the photoelectron are discussed and suggested as the explanation of the variations in the Auger signal. The atoms in the first few coordination shells surrounding the core-ionized atom are proposed to be the main targets for the scattering processes

  15. The isospin dependence of the nucleus-nucleus inelastic cross-section at high energy

    International Nuclear Information System (INIS)

    Rashdan, M.; Farhan, A.M.; Hassib, E.; Kareem, W. Abdel

    2006-01-01

    The isospin dependence of the nucleus-nucleus inelastic cross-section at high energy is investigated within the multiple scattering theory. The multiple integrals are evaluated by Monte Carlo method as well as by the optical limit approximation of the Glauber model. Calculations are performed for 14-23 N, 16-24 O and 18-26 F isotopes colliding with carbon target around 1 GeV. It is found that rms radii and the density distributions show a halo structure of 22 N, 23 O and 24 F

  16. $A$--Dependence of $\\Lambda\\Lambda$ Bond Energies in Double---$\\Lambda$ Hypernuclei

    OpenAIRE

    Lanskoy, D. E.; Lurie, Yu. A.; Shirokov, A. M.

    1995-01-01

    The $A$-dependence of the bond energy $\\Delta B_{\\Lambda\\Lambda}$ of the ${\\Lambda\\Lambda}$ hypernuclear ground states is calculated in a three-body ${\\Lambda + \\Lambda + {^{A}Z}}$ model and in the Skyrme-Hartree-Fock approach. Various ${\\Lambda\\Lambda}$ and $\\Lambda$-nucleus or ${\\Lambda N}$ potentials are used and the sensitivity of $\\Delta B_{\\Lambda\\Lambda}$ to the interactions is discussed. It is shown that in medium and heavy ${\\Lambda\\Lambda}$ hypernuclei, $\\Delta B_{\\Lambda\\Lambda}$ i...

  17. Energy and target dependence of projectile breakup effect in the elastic scattering of 6Li

    International Nuclear Information System (INIS)

    Sakuragi, Y.

    1986-03-01

    Over the wide range of incident energy (E lab = 40 ∼ 170 MeV) and target mass number (A = 12 ∼ 208), projectile breakup effects in the elastic scattering of 6 Li have been investigated with a microscopic coupled-channel method. The coupling to the 6 Li → α + d breakup process is treated with the method of coupled discretized continuum channels (CDCC). 6 Li-target interactions are provided by the folding of the M3Y effective nucleon-nucleon potential with nucleon densities of colliding nuclei. The calculation well reproduces the observed elastic scattering for all the targets and incident energies without any renormalization in the real folding potentials. The breakup effect is found to depend little on the energy and target, which is confirmed by calculating the dynamical polarization potentials induced by the coupling to the breakup process. Almost irrespectively of energy and target, the potential has a repulsive real part with strength of about 40 % of the folding potential in addition to a negligible imaginary part, which explains well the empirical reduction factor of the double-folding model. Discussions are made on the origin of repulsive nature of the breakup effect. (author)

  18. Monte carlo calculation of energy-dependent response of high-sensitive neutron monitor, HISENS

    International Nuclear Information System (INIS)

    Imanaka, Tetsuji; Ebisawa, Tohru; Kobayashi, Keiji; Koide, Hiroaki; Seo, Takeshi; Kawano, Shinji

    1988-01-01

    A highly sensitive neutron monitor system, HISENS, has been developed to measure leakage neutrons from nuclear facilities. The counter system of HISENS contains a detector bank which consists of ten cylindrical proportional counters filled with 10 atm 3 He gas and a paraffin moderator mounted in an aluminum case. The size of the detector bank is 56 cm high, 66 cm wide and 10 cm thick. It is revealed by a calibration experiment using an 241 Am-Be neutron source that the sensitivity of HISENS is about 2000 times as large as that of a typical commercial rem-counter. Since HISENS is designed to have a high sensitivity in a wide range of neutron energy, the shape of its energy dependent response curve cannot be matched to that of the dose equivalent conversion factor. To estimate dose equivalent values from neutron counts by HISENS, it is necessary to know the energy and angular characteristics of both HISENS and the neutron field. The area of one side of the detector bank is 3700 cm 2 and the detection efficiency in the constant region of the response curve is about 30 %. Thus, the sensitivity of HISENS for this energy range is 740 cps/(n/cm 2 /sec). This value indicates the extremely high sensitivity of HISENS as compared with exsisting highly sensitive neutron monitors. (Nogami, K.)

  19. Beam energy dependence of d and d ‾ production in Au+Au collisions at RHIC

    Science.gov (United States)

    Yu, Ning; STAR Collaboration

    2017-11-01

    The binding energy of light nuclei is small compared to the temperature of the system created in heavy-ion collisions. Consequently, the yields of light nuclei can be used to probe the freeze-out properties, such as correlation volume and local baryon density of the medium created in high-energy nuclear collisions. In this paper, we report the results of deuteron and anti-deuteron production in Au+Au collision at √{sNN} = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV, measured by STAR at RHIC. The collision energy, centrality and transverse momentum dependence of the coalescence parameter B2 for deuteron and anti-deuteron production are discussed. We find the values of B2 for anti-deuterons are systematically lower than those for deuterons indicating the correlation volume of anti-baryon are larger than that of baryon. In addition, the values of B2 are found to vary with collision energy and show a broad minimum around √{sNN} = 20GeV, implying a change of the equation of state of the medium in these collisions.

  20. Phase-dependent dynamic potential of magnetically coupled two-degree-of-freedom bistable energy harvester.

    Science.gov (United States)

    Kim, Pilkee; Nguyen, Minh Sang; Kwon, Ojin; Kim, Young-Jin; Yoon, Yong-Jin

    2016-09-28

    A system of magnetically coupled oscillators has been recently considered as a promising compact structure to integrate multiple bistable energy harvesters (BEHs), but its design is not straightforward owing to its varying potential energy pattern, which has not been understood completely yet. This study introduces the concept of phase-dependent dynamic potential in a magnetically coupled BEH system with two degrees of freedom (DOFs) to explain the underlying principle of the complicated dynamics of the system. Through theoretical simulations and analyses, two distinct dynamic regimes, called the out-of-phase and in-phase mode regimes in this report, are found to exist in the frequency regions of the 1 st and 2 nd primary intrawell resonances. For the out-of-phase mode regime, the frequency displacement (and output power) responses of the 2-DOF BEH system exhibit typical double-well dynamics, whereas for the in-phase mode regime, only single-well dynamics is observed though the system is statically bistable. These dynamic regimes are also revealed to be caused by the difference in the dynamic potential energy trajectories propagating on a high-dimensional potential energy surface. The present approach to the dynamics of the 2-DOF BEH system can be extended and applied to higher-DOF systems, which sheds light on compact and efficient designs of magnetically coupled BEH chain structures.

  1. Guided transmission of highly charged ions through nanocapillaries in PET. Study of the energy dependencies

    International Nuclear Information System (INIS)

    Helhammer, R.; Pesic, Z.D.; Sobocinski, P.; Bundesmann, J.; Fink, D.; Stolterfoht, N.; Sulik, B.

    2004-01-01

    Full text: Recently we reported experiments in which slow highly charged ions are transmitted through nanocapillaries of 100nm diameter in an insulating PET foil of 10μm thickness [1]. The results of this work differ significantly from previous studies, which have been focused on capillaries in metals [2]. We measured the transmission of 3 keV Ne 7+ ions through the capillaries and focused the attention on ions whose charge has not changed during the passage through the capillary. The observation that the angular distribution for PET has a peak maximum whose position is equal to the tilt angle indicates a guiding of the Ne 7+ ion within the capillary. This guiding shows that the inner walls of the capillaries are charged up in a self-organizing process and collisions with the surface are finally prevented. We studied the time evolution of the capillary guiding as well as dependencies on the tilt angle [3]. Our most recent measurements were focussed on the investigation of the energy dependency for the guiding of Ne 7+ through capillaries. The measurements were done in an energy range from 2 keV up to 10 keV.We measured higher guiding efficiency for lower energies consistent with a previously developed model, which predicted an increase of the guiding efficiency with decreasing projectile energy [3]. In addition we found the effect of a narrower width of the angular distribution of transmitted ions. This effect is also well described by the model. However, further work is needed to explain the amount of charges to build up the deflection field at the end of the capillaries

  2. Large modification in insulator-metal transition of VO{sub 2} films grown on Al{sub 2}O{sub 3} (001) by high energy ion irradiation in biased reactive sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Azhan, Nurul Hanis; Okimura, Kunio, E-mail: okifn@keyaki.cc.u-tokai.ac.jp [Graduate School of Science and Technology, Tokai University, Hiratsuka 259-1292 (Japan); Ohtsubo, Yoshiyuki; Kimura, Shin-ichi [Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871 (Japan); Zaghrioui, Mustapha; Sakai, Joe [GREMAN, UMR 7347 CNRS, Université François Rabelais de Tours, Parc de Grandmont, 37200 Tours (France)

    2016-02-07

    High energy ion irradiation in biased reactive sputtering enabled significant modification of insulator-metal transition (IMT) properties of VO{sub 2} films grown on Al{sub 2}O{sub 3} (001). Even at a high biasing voltage with mean ion energy of around 325 eV induced by the rf substrate biasing power of 40 W, VO{sub 2} film revealed low IMT temperature (T{sub IMT}) at 309 K (36 °C) together with nearly two orders magnitude of resistance change. Raman measurements from −193 °C evidenced that the monoclinic VO{sub 2} lattice begins to transform to rutile-tetragonal lattice near room temperature. Raman spectra showed the in-plane compressive stress in biased VO{sub 2} films, which results in shortening of V–V distance along a-axis of monoclinic structure, a{sub M}-axis (c{sub R}-axis) and thus lowering the T{sub IMT}. In respect to that matter, significant effects in shortening the in-plane axis were observed through transmission electron microscopy observations. V2p{sub 3/2} spectra from XPS measurements suggested that high energy ion irradiation also induced oxygen vacancies and resulted for an early transition onset and rather broader transition properties. Earlier band gap closing against the temperature in VO{sub 2} film with higher biasing power was also probed by ultraviolet photoelectron spectroscopy. Present results with significant modification of IMT behavior of films deposited at high-energy ion irradiation with T{sub IMT} near the room temperature could be a newly and effective approach to both exploring mechanisms of IMT and further applications of this material, due to the fixed deposition conditions and rather thicker VO{sub 2} films.

  3. The photon energy dependence of the alanine/EPR dosimetry system, an experimental investigation

    International Nuclear Information System (INIS)

    Bergstrand, E.S.; Hole, E.O.; Shortt, K.R.; Ross, C.K.

    2002-01-01

    The energy dependence of a dosimetry system based on electron paramagnetic resonance (EPR) spectroscopy of alanine has been studied to determine its suitability for use in dose verification for radiotherapy. A few experiments with high-energy photon irradiation of alanine have been reported in the literature. However, the reported results disagree whether the ratio of dose in alanine to dose in water is independent of the radiation energy or whether there is a small dependence for photon energies of relevance to radiotherapy. The concentration of free radicals in alanine is proportional to the absorbed dose in alanine over a wide dose range covering three decades. The relative number of radicals may be determined by examining the EPR spectrum, and hence it is possible to determine the dose with a system that has been calibrated using a known dose of 60 Co radiation. In the present work, irradiations of alanine dosimeters were performed at the National Research Council (NRC), in Ottawa, Canada. The radiation qualities investigated were 10, 20 and 30 MV x-rays using the NRC linac. For each radiation quality, 30 dosimeters were irradiated in a water phantom with a level of absorbed dose to water ranging from 10 to 50 Gy. For reference purposes, irradiations using the NRC 60 Co source were performed on more or less the same day as the irradiations at each specific linac quality. In all beams, the dose to water was measured using a graphite-walled NE2571 ionisation chamber that was originally calibrated by comparison with a sealed-water calorimeter. The alanine dosimeters were evaluated at the EPR laboratory at the University of Oslo, Norway, using an X-band Bruker ESP300E spectrometer with a rectangular double resonator. One of the resonators contained a Mn 2+ /MgO sample that was read after each dosimeter reading, in order to provide independence from short-term sensitivity fluctuations in the spectrometer. All dosimeters irradiated at one specific linac quality were

  4. Centrality and pseudorapidity dependence of the transverse energy flow in pPb collisions at √{sNN} = 5.02 TeV

    Science.gov (United States)

    Bruner, Christopher; Murray, Michael

    2016-12-01

    The almost hermetic coverage of CMS is used to measure the distribution of transverse energy as a function of pseudo-rapidity for pPb collisions at √{sNN} = 5.02 TeV. For minimum bias collisions (1 / N) dET / dη reaches 23 GeV which implies an ET per participant pair comparable to that of peripheral PbPb collisions at √{sNN} = 2.76 TeV. The centrality dependence of transverse energy production has been studied using centrality measures defined in three different angular regions. There is a strong auto-correlation between (1 / N) dET / dη and the η range used to define centrality for data and the EPOS-LHC and HIJING event generators. The centrality dependence of the data is much stronger for η values on the lead side than the proton side and shows significant differences from that predicted by either event generator.

  5. New Trends in Magnetic Exchange Bias

    Science.gov (United States)

    Mougin, Alexandra; Mangin, Stéphane; Bobo, Jean-Francois; Loidl, Alois

    2005-05-01

    -of-plane exchange bias, depending on the field cooling direction. This is of particular interest since it allows probing of the three-dimensional spin structure of the AF layer. The interface magnetic configuration is extremely important in the perpendicular geometry, as the short-range exchange coupling competes with a long-range dipolar interaction; the induced uniaxial anisotropy must overcome the demagnetization energy to establish perpendicular anisotropy films. Those new studies are of primary importance for the magnetic media industry as perpendicular recording exhibits potential for strongly increased storage densities. 3. Parameters tuning exchange bias in polycrystalline samples and magnetic configurations: Different parameters can be used to tune the exchange bias coupling in polycrystalline samples similar to those used in devices. Particularly fascinating aspects are the questions of the appearance of exchange bias or coercivity in ferromagnet/antiferromagnet heterostructures, and its relation to magnetic configurations formed on either side of the interface. Several papers report on either growth choices or post preparation treatments that enable tuning of the exchange bias in bilayers. The additional complexity and novel features of the exchange coupled interface make the problem particularly rich. 4. Dynamics and magnetization reversal: Linear response experiments, such as ferromagnetic resonance, have been used with great success to identify interface, surface anisotropies and interlayer exchange in multilayer systems. The exchange bias structure is particularly well suited to study because interface driven changes in the spin wave frequencies in the ferromagnet can be readily related to interlayer exchange and anisotropy parameters associated with the antiferromagnet. Because the exchange bias is intimately connected with details of the magnetization process during reversal and the subsequent formation of hysteresis, considerations of time dependence and

  6. Energy and calcium ion dependence of proteolysis during sporulation of Bacillus subtilis cells

    International Nuclear Information System (INIS)

    O'Hara, M.B.; Hageman, J.H.

    1990-01-01

    The authors have shown, with an optimized [ 14 C]leucine-labeling and chasing procedure, that intracellular protein degradation in sporulating cells of Bacillus subtilis 168 (trpC2) is apparently energy dependent. Sodium arsenate, sodium azide, carbonyl cyanide m-chlorophenylhydrozone, and N,N'-dicyclohexylcarbodiimide, at levels which did not induce appreciable lysis (≤ 10%) over 10-h periods of sporulation, inhibited intracellular proteolysis by 13 to 93%. Exponentially growing cells acquired arsenate resistance. In contrast to earlier reports, the authors found that chloramphenicol strongly inhibited proteolysis even when added 6 h into the sporulation process. Restricting the calcium ion concentration in the medium had no effect on rates or extent of vegetative growth, strongly inhibited sporulation, and inhibited rates of proteolysis by 60% or more. Inhibitors of energy metabolism, at the same levels which inhibited proteolysis, did not affect the rate or degree of uptake of Ca 2+ by cells. Restricting the Ca 2+ concentration in the medium reduced by threefold of the specific activity in cells of the major intracellular serine proteinase after 12 h of sporulation. finally, cells of a mutant of B. subtilis bearing an insertionally inactivated gene for the Ca 2+ -dependent intracellular proteinase-1 degraded protein in chemically defined sporulation medium at a rate indistinguishable from that of the wild-type cells for period of 8 h

  7. Growth dynamics of the energy dependent economy. Die Wachstumsdynamik der energieabhaengigen Wirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Kuemmel, R

    1980-01-01

    In Part I the industrial process is analysed and a functional, quantitative definition of capital, by which (instrumental) capital is related to automation is proposed. In this way capital can be defined and measured precisely in terms of physical work done and information processes by machines. Pollution, defined as entropy increase in the economic system, is considered in its various manifestations and taken into account by a product of specific pollution functions. In Part II the role of creativity as a generator of growth intervals and system-characteristics is discussed. The conditions of integrability of the equation of growth are pointed out, thus elucidating the requirements for the existence of a production function which unequivocally depends upon capital, labor and energy. This results in a set of differential equations for the elasticities of production. The states of total automation and full capital employment are analyzed and the extremum principles which govern the quantitative input of the production factors are given. In Part III the dependence of the elasticities of production on the factors of production are examined with the help of the integrability conditions. The path of balanced economic growth is analyzed along which the growth of production within a growth-interval is described by a Cobb-Douglas production function. Scenarios of energy crises are calculated, and simple estimates are given.

  8. Dependence of Initial Oxygen Concentration on Ozone Yield Using Inductive Energy Storage System Pulsed Power Generator

    Science.gov (United States)

    Go, Tomio; Tanaka, Yasushi; Yamazaki, Nobuyuki; Mukaigawa, Seiji; Takaki, Koichi; Fujiwara, Tamiya

    Dependence of initial oxygen concentration on ozone yield using streamer discharge reactor driven by an inductive energy storage system pulsed power generator is described in this paper. Fast recovery type diodes were employed as semiconductor opening switch to interrupt a circuit current within 100 ns. This rapid current change produced high-voltage short pulse between a secondary energy storage inductor. The repetitive high-voltage short pulse was applied to a 1 mm diameter center wire electrode placed in a cylindrical pulse corona reactor. The streamer discharge successfully occurred between the center wire electrode and an outer cylinder ground electrode of 2 cm inner diameter. The ozone was produced with the streamer discharge and increased with increasing pulse repetition rate. The ozone yield changed in proportion to initial oxygen concentration contained in the injected gas mixture at 800 ns forward pumping time of the current. However, the decrease of the ozone yield by decreasing oxygen concentration in the gas mixture at 180 ns forward pumping time of the current was lower than the decrease at 800 ns forward pumping time of the current. This dependence of the initial oxygen concentration on ozone yield at 180 ns forward pumping time is similar to that of dielectric barrier discharge reactor.

  9. Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment.

    Science.gov (United States)

    Choi, J H; Choi, W Q; Choi, Y; Jang, H I; Jang, J S; Jeon, E J; Joo, K K; Kim, B R; Kim, H S; Kim, J Y; Kim, S B; Kim, S Y; Kim, W; Kim, Y D; Ko, Y; Lee, D H; Lim, I T; Pac, M Y; Park, I G; Park, J S; Park, R G; Seo, H; Seo, S H; Seon, Y G; Shin, C D; Siyeon, K; Yang, J H; Yeo, I S; Yu, I

    2016-05-27

    The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3}  eV^{2}.

  10. Review of relative biological effectiveness dependence on linear energy transfer for low-LET radiations

    International Nuclear Information System (INIS)

    Hunter, Nezahat; Muirhead, Colin R

    2009-01-01

    Information on Japanese A-bomb survivors exposed to gamma radiation has been used to estimate cancer risks for the whole range of photon (x-rays) and electron energies which are commonly encountered by radiation workers in the work place or by patients and workers in diagnostic radiology. However, there is some uncertainty regarding the radiation effectiveness of various low-linear energy transfer (low-LET) radiations (x-rays, gamma radiation and electrons). In this paper we review information on the effectiveness of low-LET radiations on the basis of epidemiological and in vitro radiobiological studies. Data from various experimental studies for chromosome aberrations and cell transformation in human lymphocytes and from epidemiological studies of the Japanese A-bomb survivors, patients medically exposed to radiation for diagnostic and therapeutic procedures, and occupational exposures of nuclear workers are considered. On the basis of in vitro cellular radiobiology, there is considerable evidence that the relative biological effectiveness (RBE) of high-energy low-LET radiation (gamma radiation, electrons) is less than that of low-energy low-LET radiation (x-rays, betas). This is a factor of about 3 to 4 for 29 kVp x-rays (e.g. as in diagnostic radiation exposures of the female breast) and for tritium beta-rays (encountered in parts of the nuclear industry) relative to Co-60 gamma radiation and 2-5 MeV gamma-rays (as received by the Japanese A-bomb survivors). In epidemiological studies, although for thyroid and breast cancer there appears to be a small tendency for the excess relative risks to decrease as the radiation energy increases for low-LET radiations, it is not statistically feasible to draw any conclusion regarding an underlying dependence of cancer risk on LET for the nominally low-LET radiations. (review)

  11. Optimal energy window setting depending on the energy resolution for radionuclides used in gamma camera imaging. Planar imaging evaluation

    International Nuclear Information System (INIS)

    Kojima, Akihiro; Watanabe, Hiroyuki; Arao, Yuichi; Kawasaki, Masaaki; Takaki, Akihiro; Matsumoto, Masanori

    2007-01-01

    In this study, we examined whether the optimal energy window (EW) setting depending on an energy resolution of a gamma camera, which we previously proposed, is valid on planar scintigraphic imaging using Tl-201, Ga-67, Tc-99m, and I-123. Image acquisitions for line sources and paper sheet phantoms containing each radionuclide were performed in air and with scattering materials. For the six photopeaks excluding the Hg-201 characteristic x-rays' one, the conventional 20%-width energy window (EW20%) setting and the optimal energy window (optimal EW) setting (15%-width below 100 keV and 13%-width above 100 keV) were compared. For the Hg-201 characteristic x-rays' photopeak, the conventional on-peak EW20% setting was compared with the off-peak EW setting (73 keV-25%) and the wider off-peak EW setting (77 keV-29%). Image-count ratio (defined as the ratio of the image counts obtained with an EW and the total image counts obtained with the EW covered the whole photopeak for a line source in air), image quality, spatial resolutions (full width half maximum (FWHM) and full width tenth maximum (FWTM) values), count-profile curves, and defect-contrast values were compared between the conventional EW setting and the optimal EW setting. Except for the Hg-201 characteristic x-rays, the image-count ratios were 94-99% for the EW20% setting, but 78-89% for the optimal EW setting. However, the optimal EW setting reduced scatter fraction (defined as the scattered-to-primary counts ratio) effectively, as compared with the EW20% setting. Consequently, all the images with the optimal EW setting gave better image quality than ones with the EW20% setting. For the Hg-201 characteristic x-rays, the off-peak EW setting showed great improvement in image quality in comparison with the EW20% setting and the wider off-peak EW setting gave the best results. In conclusion, from our planar imaging study it was shown that although the optimal EW setting proposed by us gives less image-count ratio by

  12. Study of the energy dependence of the underlying event in proton-antiproton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Nodulman, L.; Aaltonen, T; Albrow, M; Amerio, S.; Amidei, D; Anastassov, A.; Annovi, A; Antos, J; Apollinari, G.; Appel, J A; Arisawa, T

    2015-11-23

    We study charged particle production (p(T) > 0.5 GeV/c, vertical bar eta vertical bar < 0.8) in proton-antiproton collisions at total center-of-mass energies root s = 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of eta - phi space: "toward", "away", and "transverse." The average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the "underlying event." The transverse region is divided into a MAX and MIN transverse region, which helps separate the "hard component" (initial and final-state radiation) from the "beam-beam remnant" and multiple parton interaction components of the scattering. The center-of-mass energy dependence of the various components of the event is studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

  13. Direct Measurement of the Surface Energy of Bimetallic Nanoparticles: Evidence of Vegard's Rulelike Dependence.

    Science.gov (United States)

    Chmielewski, Adrian; Nelayah, Jaysen; Amara, Hakim; Creuze, Jérôme; Alloyeau, Damien; Wang, Guillaume; Ricolleau, Christian

    2018-01-12

    We use in situ transmission electron microscopy to monitor in real time the evaporation of gold, copper, and bimetallic copper-gold nanoparticles at high temperature. Besides, we extend the Kelvin equation to two-component systems to predict the evaporation rates of spherical liquid mono- and bimetallic nanoparticles. By linking this macroscopic model to experimental TEM data, we determine the surface energies of pure gold, pure copper, Cu_{50}Au_{50}, and Cu_{25}Au_{75} nanoparticles in the liquid state. Our model suggests that the surface energy varies linearly with the composition in the liquid Cu-Au nanoalloy; i.e., it follows a Vegard's rulelike dependence. To get atomic-scale insights into the thermodynamic properties of Cu-Au alloys on the whole composition range, we perform Monte Carlo simulations employing N-body interatomic potentials. These simulations at a microscopic level confirm the Vegard's rulelike behavior of the surface energy obtained from experiments combined with macroscopic modeling.

  14. Surface effects on sputtered atoms and their angular and energy dependence

    International Nuclear Information System (INIS)

    Hassanein, A.M.

    1985-04-01

    A comprehensive three-dimensional Monte Carlo computer code, Ion Transport in Materials and Compounds (ITMC), has been developed to study in detail the surfaces related phenomena that affect the amount of sputtered atoms and back-scattered ions and their angular and energy dependence. A number of important factors that can significantly affect the sputtering behavior of a surface can be studied in detail, such as having different surface properties and composition than the bulk and synergistic effects due to surface segregation of alloys. These factors can be important in determining and lifetime of fusion reactor first walls and limiters. The ITMC Code is based on Monte Carlo methods to track down the path and the damage produced by charged particles as they slow down in solid metal surfaces or compounds. The major advantages of the ITMC code are its flexibility and ability to use and compare all existing models for energy losses, all known interatomic potentials, and to use different materials and compounds with different surface and bulk composition to allow for dynamic surface composition to allow for dynamic surface composition changes. There is good agreement between the code and available experimental results without using adjusting parameters for the energy losses mechanisms. The ITMC Code is highly optimized, very fast to run and easy to use

  15. Coherent synchrotron radiation transient effects in the energy-dependent region

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Botman, Jan; Goloviznin, Vladimir; Wiel, Marnix van der

    2002-01-01

    Coherent synchrotron radiation (CSR) is a well known phenomenon that originates from coherent superposition of electromagnetic waves by ultrarelativistic electrons. CSR longitudinal effects during the passage of a Gaussian beam from a straight to a circular path have often been studied in a regime in which they are energy independent. Nevertheless, the approximations used in such a regime may fail in several practical situations, as in the case of low-energy injectors or for small-wavelength structures within the bunch distribution in CSR-related instability problems. These situations demand a deeper investigation of longitudinal transient effects in the region where the approximations above are no longer valid: a strong γ dependence is found, and described in this paper, in the rate of energy change induced by CSR during the transient of a Gaussian bunch between a straight and a circular path, which was studied with the help of the authors' previous work. Results show that the overall CSR longitudinal effects, in this case, are reduced. One of the outcomes of previous work by Saldin et al. was extended to this situation and very good agreement between the two studies was found

  16. Two-stage unified stretched-exponential model for time-dependence of threshold voltage shift under positive-bias-stresses in amorphous indium-gallium-zinc oxide thin-film transistors

    Science.gov (United States)

    Jeong, Chan-Yong; Kim, Hee-Joong; Hong, Sae-Young; Song, Sang-Hun; Kwon, Hyuck-In

    2017-08-01

    In this study, we show that the two-stage unified stretched-exponential model can more exactly describe the time-dependence of threshold voltage shift (ΔV TH) under long-term positive-bias-stresses compared to the traditional stretched-exponential model in amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). ΔV TH is mainly dominated by electron trapping at short stress times, and the contribution of trap state generation becomes significant with an increase in the stress time. The two-stage unified stretched-exponential model can provide useful information not only for evaluating the long-term electrical stability and lifetime of the a-IGZO TFT but also for understanding the stress-induced degradation mechanism in a-IGZO TFTs.

  17. The Energy Dependence of Flow in Ni Induced Collisions from 400A to 1970A MeV

    International Nuclear Information System (INIS)

    Chance, J.; Brady, F.; Cebra, D.; Kintner, J.; Partlan, M.; Romero, J.; Albergo, S.; Caccia, Z.; Costa, S.; Insolia, A.; Potenza, R.; Romanski, J.; Russo, G.; Tuve, C.; Bieser, F.; Cebra, D.; Lisa, M.; Matis, H.; McMahan, M.; McParland, C.; Olson, D.; Rai, G.; Rasmussen, J.; Ritter, H.; Symons, T.; Wieman, H.; Wienold, T.; Choi, Y.; Elliott, J.; Gilkes, M.; Hauger, J.; Hirsch, A.; Hjort, E.; Porile, N.; Scharenberg, R.; Srivastava, B.; Tincknell, M.; Warren, P.; Chacon, A.; Wolf, K.

    1997-01-01

    We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in (400 endash 1970)A MeV Ni+Au and (1000 endash 1970)A MeV Ni+Cu reactions. The flow increases with energy, appears to reach a maximum, and then to decrease at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a more-or-less common scaling behavior among flow values from different systems. copyright 1997 The American Physical Society

  18. Sex-dependent foraging effort and vigilance in coal-crested finches, Charitospiza eucosma (Aves: Emberizidae during the breeding season: evidence of female-biased predation?

    Directory of Open Access Journals (Sweden)

    Pedro Diniz

    2011-04-01

    Full Text Available Sexual dimorphism in birds is often attributed to sexual selection, but another interpretation suggests the evolution of this phenomenon by natural selection. Predation may be an important selective pressure, acting mainly on females. In this study, I tested the latter hypothesis on the coal-crested finch (Charitospiza eucosma Oberholser, 1905 in a neotropical savanna of the Central Brazil (Cerrado. I used capture methods for ascertaining the sex ratio in the population, and focal observations to gather behavioral data. My results show that the sex ratio is skewed toward males (1:1.39. Males were more vigilant, vocalized for longer periods of time, and used higher perches than females. Females foraged more, spent more time on parental care and remained on the ground for longer periods than males. These results support the 'foraging effort hypothesis, suggesting that females are more preyed upon because they spend more time foraging. Ultimately, this may reflect the fact that females invest more on parental care than males. The sex-dependent parental investment may favor the evolution of different antipredator strategies in males and females: the camouflage in females as a less efficient strategy than vigilance in males.

  19. The Temperature Condition of the Plate with Temperature-Dependent Thermal Conductivity and Energy Release

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    Full Text Available The temperature state of a solid body, in addition to the conditions of its heat exchange with the environment, can greatly depend on the heat release (or heat absorption processes within the body volume. Among the possible causes of these processes should be noted such as a power release in the fuel elements of nuclear reactors, exothermic or endothermic chemical reactions in the solid body material, which respectively involve heat release or absorbtion, heat transfer of a part of the electric power in the current-carrying conductors (so-called Joule’s heat or the energy radiation penetrating into the body of a semitransparent material, etc. The volume power release characterizes an intensity of these processes.The extensive list of references to the theory of heat conductivity of solids offers solutions to problems to determine a stationary (steady over time and non-stationary temperature state of the solids (as a rule, of the canonical form, which act as the sources of volume power release. Thus, in general case, a possibility for changing power release according to the body volume and in solving the nonstationary problems also a possible dependence of this value on the time are taken into consideration.However, in real conditions the volume power release often also depends on the local temperature, and such dependence can be nonlinear. For example, with chemical reactions the intensity of heat release or absorption is in proportion to their rate, which, in turn, is sensitive to the temperature value, and a dependence on the temperature is exponential. A further factor that in such cases makes the analysis of the solid temperature state complicated, is dependence on the temperature and the thermal conductivity of this body material, especially when temperature distribution therein  is significantly non-uniform. Taking into account the influence of these factors requires the mathematical modeling methods, which allow us to build an adequate

  20. Reentrant behavior in the superconducting phase-dependent resistance of a disordered two-dimensional electron gas

    NARCIS (Netherlands)

    den Hartog, S.G.; Wees, B.J.van; Klapwijk, T.M; Nazarov, Y.V.; Borghs, G.

    1997-01-01

    We have investigated the bias-voltage dependence of the phase-dependent differential resistance of a disordered T-shaped two-dimensional electron gas coupled to two superconducting terminals. The resistance oscillations first increase upon lowering the energy. For bias voltages below the Thouless

  1. Accurate Ground-State Energies of Solids and Molecules from Time-Dependent Density-Functional Theory

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian Sommer

    2014-01-01

    We demonstrate that ground-state energies approaching chemical accuracy can be obtained by combining the adiabatic-connection fluctuation-dissipation theorem with time-dependent densityfunctional theory. The key ingredient is a renormalization scheme, which eliminates the divergence...

  2. Deviation from an inverse cosine dependence of kinetic secondary electron emission for angle of incidence at keV energy

    International Nuclear Information System (INIS)

    Ohya, Kaoru; Kawata, Jun; Mori, Ichiro

    1989-01-01

    Incident angle dependence of kinetic secondary electron emission from metals resulting from incidence of keV ions is investigated by computer simulation with the TRIM Monte Carlo program of ion scattering in matter. The results show large deviations from the inverse cosine dependence, which derives from high-energy approximation, because of a series of elastic collisions of incident ions with metal atoms. In the keV energy region, the elastic collisions have two different effects on the angular dependence for relatively high-energy light ions and for low-energy heavy ions: they result in over- and under-inverse-cosine dependences, respectively. The properties are observed even with an experiment of the keV-neutral incidence on a contaminated surface. In addition, the effects of the thin oxide layer and roughness on the surface are examined with simplified models. (author)

  3. The dependence of the electronic coupling on energy gap and bridge conformation - Towards prediction of the distance dependence of electron transfer reactions

    International Nuclear Information System (INIS)

    Eng, Mattias P.; Albinsson, Bo

    2009-01-01

    The attenuation factor, β, for the distance dependence of electron exchange reactions is a sensitive function of the donor-bridge energy gap and bridge conformation. In this work the electronic coupling for electron and triplet excitation energy transfer has been investigated for five commonly used repeating bridge structures. The investigated bridge structures are OF (oligo fluorene), OP (oligo phenylene), OPE (oligo p-phenyleneethynylene), OPV (oligo phenylenevinylene), and OTP (oligo thiophene). Firstly, the impact of the donor-bridge energy gap was investigated by performing calculations with a variety of donors appended onto bridges that were kept in a planar conformation. This resulted in, to our knowledge, the first presented sets of bridge specific parameters to be inserted into the commonly used McConnell model. Secondly, since at experimental conditions large conformational flexibility is expected, a previously developed model that takes conformational disorder of the bridge into account has been applied to the investigated systems [M.P. Eng, T. Ljungdahl, J. Martensson, B. Albinsson, J. Phys. Chem. B 110 (2006) 6483]. This model is based on Boltzmann averaging and has been shown to describe the temperature dependence of the attenuation factor through OPE-bridges. Together, the parameters describing the donor-bridge energy gap dependence, for planar bridge structures, and the Boltzmann averaging procedure, describing the impact of rotational disorder, have the potential to a priori predict attenuation factors for electron and excitation energy transfer reactions through bridged donor-acceptor systems

  4. Measured energy dependence of L-shell photoelectric cross sections of lead in the energy region 17-50 keV

    Energy Technology Data Exchange (ETDEWEB)

    Arora, S K; Allawadhi, K L; Sood, B S [Punjabi Univ., Patiala (India). Nuclear Science Labs.

    1980-08-28

    The energy dependence of L-shell photoelectric cross sections for lead in the energy region 17-50 keV has been investigated. The method utilises external conversion x-rays as the source of photons and it yields relative rather than absolute cross sections, but is simpler and more accurate. The results show fairly good agreement with theory.

  5. Distance-dependent energy transfer between indole and anthracene moieties in Langmuir Blodgett films

    Science.gov (United States)

    Saha, D. C.; Bhattacharjee, D.; Misra, T. N.

    1998-09-01

    1,2-Diphenyl indole (DPI) and 9,10-diphenyl anthracene (DPA) are non-amphiphilic molecules but form excellent LB films when mixed with stearic acid (SA). Spectroscopic investigations of these films indicate formation of aggregates of DPI and DPA in the mixed LB films. DPA has been used as the quencher of the fluorescence of the DPI donor. Distance-dependent energy transfer between donor and acceptor monolayers in the LB film, where they can be precisely separated by inert spacers of stearic acid layers of varied thickness, is shown to satisfy Khun's quadratic equation. This suggests that the donor excitations are delocalized. The large critical transfer distance estimated from the experimental results has been attributed to the formation of aggregates of the molecules in a LB monolayer.

  6. Energy and orientation dependence of electron-irradiation-induced defects in InP

    International Nuclear Information System (INIS)

    Sibille, A.; Suski, J.; LeRoux, G.

    1984-01-01

    The concentration of several electron-irradiation-induced deep defect levels in InP has been measured by deep-level transient spectroscopy (DLTS) as a function of electron energy. The dominant centers exhibit a threshold at about 100 keV, which clearly points to a primary production event by electron--phosphorus-atom collision. This unambiguous determination allowed a test of the recently proposed orientation dependence technique to find the nature of the sublattice involved in the collision process for III-V compounds. A good quantitative agreement is obtained with a hard-sphere model for secondary collisions if disorientation of the beam in the sample is taken into account. Other traps exhibit higher thresholds which correspond either to indium-atom displacements or to the involvement of secondary collisions in the production event

  7. Multicomponent Time-Dependent Density Functional Theory: Proton and Electron Excitation Energies.

    Science.gov (United States)

    Yang, Yang; Culpitt, Tanner; Hammes-Schiffer, Sharon

    2018-04-05

    The quantum mechanical treatment of both electrons and protons in the calculation of excited state properties is critical for describing nonadiabatic processes such as photoinduced proton-coupled electron transfer. Multicomponent density functional theory enables the consistent quantum mechanical treatment of more than one type of particle and has been implemented previously for studying ground state molecular properties within the nuclear-electronic orbital (NEO) framework, where all electrons and specified protons are treated quantum mechanically. To enable the study of excited state molecular properties, herein the linear response multicomponent time-dependent density functional theory (TDDFT) is derived and implemented within the NEO framework. Initial applications to FHF - and HCN illustrate that NEO-TDDFT provides accurate proton and electron excitation energies within a single calculation. As its computational cost is similar to that of conventional electronic TDDFT, the NEO-TDDFT approach is promising for diverse applications, particularly nonadiabatic proton transfer reactions, which may exhibit mixed electron-proton vibronic excitations.

  8. Multi-dimensional relativistic simulations of core-collapse supernovae with energy-dependent neutrino transport

    International Nuclear Information System (INIS)

    Mueller, Bernhard

    2009-01-01

    In this thesis, we have presented the first multi-dimensional models of core-collapse supernovae that combine a detailed, up-to-date treatment of neutrino transport, the equation of state, and - in particular - general relativistic gravity. Building on the well-tested neutrino transport code VERTEX and the GR hydrodynamics code CoCoNuT, we developed and implemented a relativistic generalization of a ray-by-ray-plus method for energy-dependent neutrino transport. The result of these effort, the VERTEX-CoCoNuT code, also incorporates a number of improved numerical techniques that have not been used in the code components VERTEX and CoCoNuT before. In order to validate the VERTEX-CoCoNuT code, we conducted several test simulations in spherical symmetry, most notably a comparison with the one-dimensional relativistic supernova code AGILE-BOLTZTRAN and the Newtonian PROMETHEUSVERTEX code. (orig.)

  9. Does a deformation of special relativity imply energy dependent photon time delays?

    Science.gov (United States)

    Carmona, J. M.; Cortés, J. L.; Relancio, J. J.

    2018-01-01

    Theoretical arguments in favor of energy dependent photon time delays from a modification of special relativity (SR) have met with recent gamma ray observations that put severe constraints on the scale of such deviations. We review the case of the generality of this theoretical prediction in the case of a deformation of SR and find that, at least in the simple model based on the analysis of photon worldlines which is commonly considered, there are many scenarios compatible with a relativity principle which do not contain a photon time delay. This will be the situation for any modified dispersion relation which reduces to E=\\vert p\\vert for photons, independently of the quantum structure of spacetime. This fact opens up the possibility of a phenomenologically consistent relativistic generalization of SR with a new mass scale many orders of magnitude below the Planck mass.

  10. Composition-Dependent Energy Splitting between Bright and Dark Excitons in Lead Halide Perovskite Nanocrystals.

    Science.gov (United States)

    Chen, Lan; Li, Bin; Zhang, Chunfeng; Huang, Xinyu; Wang, Xiaoyong; Xiao, Min

    2018-03-14

    Perovskite semiconductor nanocrystals with different compositions have shown promise for applications in light-emitting devices. Dark excitonic states may suppress light emission from such nanocrystals by providing an additional nonradiative recombination channel. Here, we study the composition dependence of dark exciton dynamics in nanocrystals of lead halides by time-resolved photoluminescence spectroscopy at cryogenic temperatures. The presence of a spin-related dark state is revealed by magneto-optical spectroscopy. The energy splitting between bright and dark states is found to be highly sensitive to both halide elements and organic cations, which is explained by considering the effects of size confinement and charge screening, respectively, on the exchange interaction. These findings suggest the possibility of manipulating dark exciton dynamics in perovskite semiconductor nanocrystals by composition engineering, which will be instrumental in the design of highly efficient light-emitting devices.

  11. Multi-dimensional relativistic simulations of core-collapse supernovae with energy-dependent neutrino transport

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Bernhard

    2009-05-07

    In this thesis, we have presented the first multi-dimensional models of core-collapse supernovae that combine a detailed, up-to-date treatment of neutrino transport, the equation of state, and - in particular - general relativistic gravity. Building on the well-tested neutrino transport code VERTEX and the GR hydrodynamics code CoCoNuT, we developed and implemented a relativistic generalization of a ray-by-ray-plus method for energy-dependent neutrino transport. The result of these effort, the VERTEX-CoCoNuT code, also incorporates a number of improved numerical techniques that have not been used in the code components VERTEX and CoCoNuT before. In order to validate the VERTEX-CoCoNuT code, we conducted several test simulations in spherical symmetry, most notably a comparison with the one-dimensional relativistic supernova code AGILE-BOLTZTRAN and the Newtonian PROMETHEUSVERTEX code. (orig.)

  12. Energy and mass-number dependence of the dissociation temperature in hydrodynamical models

    International Nuclear Information System (INIS)

    Hama, Y.; Navarra, F.S.

    1990-10-01

    Transverse-momentum distributions of π and K have been analysed to obtain the √s dependence of the collective transverse and the dissociation temperature in pp- and p-barp induced multiparticle production reactions. A good fit of both the pion and kaon data has been obtained in terms of a previously proposed simple parametrization of the collective transverse rapidity distribution. The main outcomes are the logarithmically increasing average transverse rapidity squared and a slowly decreasing dissociation temperature T sub(d) as the incident energy √s increases. This last behaviour is in excellent agreement with early Landau's estimate. An extension of the same estimate to nucleus-nucleus collisions gives the correct low temperature component which has been observed in heavy-ion experiments. (author)

  13. Fitting methods for constructing energy-dependent efficiency curves and their application to ionization chamber measurements

    International Nuclear Information System (INIS)

    Svec, A.; Schrader, H.

    2002-01-01

    An ionization chamber without and with an iron liner (absorber) was calibrated by a set of radionuclide activity standards of the Physikalisch-Technische Bundesanstalt (PTB). The ionization chamber is used as a secondary standard measuring system for activity at the Slovak Institute of Metrology (SMU). Energy-dependent photon-efficiency curves were established for the ionization chamber in defined measurement geometry without and with the liner, and radionuclide efficiencies were calculated. Programmed calculation with an analytical efficiency function and a nonlinear regression algorithm of Microsoft (MS) Excel for fitting was used. Efficiencies from bremsstrahlung of pure beta-particle emitters were calibrated achieving a 10% accuracy level. Such efficiency components are added to obtain the total radionuclide efficiency of photon emitters after beta decay. The method yields differences of experimental and calculated radionuclide efficiencies for most of the photon-emitting radionuclides in the order of a few percent

  14. Energy Dependence of Nuclear Transparency in C (p,2p) Scattering

    Science.gov (United States)

    Leksanov, A.; Alster, J.; Asryan, G.; Averichev, Y.; Barton, D.; Baturin, V.; Bukhtoyarova, N.; Carroll, A.; Heppelmann, S.; Kawabata, T.; Makdisi, Y.; Malki, A.; Minina, E.; Navon, I.; Nicholson, H.; Ogawa, A.; Panebratsev, Yu.; Piasetzky, E.; Schetkovsky, A.; Shimanskiy, S.; Tang, A.; Watson, J. W.; Yoshida, H.; Zhalov, D.

    2001-11-01

    The transparency of carbon for (p,2p) quasielastic events was measured at beam momenta ranging from 5.9 to 14.5 GeV/c at 90° c.m. The four-momentum transfer squared (Q2) ranged from 4.7 to 12.7 (GeV/c)2. We present the observed beam momentum dependence of the ratio of the carbon to hydrogen cross sections. We also apply a model for the nuclear momentum distribution of carbon to obtain the nuclear transparency. We find a sharp rise in transparency as the beam momentum is increased to 9 GeV/c and a reduction to approximately the Glauber level at higher energies.

  15. Calculated energy dependence of CaSO4:Dy TL phosphor and phosphor embedded Teflon for X and gamma rays

    International Nuclear Information System (INIS)

    Chang, J.-K.; Nam, Y.-M.; Kim, J.-L.; Chang, S.-Y.; Kim, B.-H.

    2001-01-01

    The energy dependence of a CaSO 4 :Dy TL phosphor for 21 monoenergetic photons of energy ranging from 0.01 to 3 MeV was calculated by using MCNP4A code. The calculation results show good agreement with those of other authors within ± 5% relative error. Calculations and experiments are also performed to determine the energy dependence of CaSO 4 : Dy phosphor with Dy concentrations from 0.01 to 1.5 mol %, and with the compositions of TL-Teflon from 10 to 90 wt %. The calculated energy responses show good agreement with the experiment results within ± 20% relative error except for a concentration lower than 0.1 mol % Dy and the low energy regions of M30 (Eave.=20 keV) and M60 (Eave.=34 keV). For the TL-Teflon mixture, the energy dependence shows an decreasing trend with the increase of Teflon concentration in MCNP calculation but shows no dependence for TL-Teflon mixture proportions in experiment. These differences are due to the non-homogeneous distribution of Dy concentration and the effect of large grain size in the phosphors. The energy dependence of the 30 wt/o CaSO 4 (0.1 mol%;Dy) and 70 wt/o Teflon that is placed behind the filters of plastic, aluminum, copper, tin and lead with a thickness from 0.1 to 2 mm were calculated, respectively

  16. Combination of biased forecasts: Bias correction or bias based weights?

    OpenAIRE

    Wenzel, Thomas

    1999-01-01

    Most of the literature on combination of forecasts deals with the assumption of unbiased individual forecasts. Here, we consider the case of biased forecasts and discuss two different combination techniques resulting in an unbiased forecast. On the one hand we correct the individual forecasts, and on the other we calculate bias based weights. A simulation study gives some insight in the situations where we should use the different methods.

  17. Proteome analysis reveals an energy-dependent central process for Populus×canadensis seed germination.

    Science.gov (United States)

    Zhang, Hong; Zhou, Ke-Xin; Wang, Wei-Qing; Liu, Shu-Jun; Song, Song-Quan

    2017-06-01

    Poplar (Populus×canadensis) seeds rapidly germinated in darkness at 10, 15, and 20°C and reached 50% seed germination after about 22, 4.5, and 3.5h, respectively. Germination of poplar seeds was markedly inhibited by abscisic acid (ABA) at 50μM and cycloheximide (CHX) at 100μM, and these inhibitive roles were temperature-dependent. In the present study, mature poplar seeds were used to investigate the differentially changed proteome of seeds germinating in water, ABA, and CHX. A total of 130 protein spots showed a significant change (1.5-fold increase/decrease, Pgermination of poplar seeds is closely related with the increase in those proteins involved in amino acid and lipid metabolism, the tricarboxylic acid cycle and pentose phosphate pathway, protein synthesis and destination, cell defense and rescue, and degradation of storage proteins. ABA and CHX inhibit the germination of poplar seeds by decreasing the protein abundance associated with protein proteolysis, protein folding, and storage proteins. We conclude that poplar seed germination is an energy-dependent active process, and is accompanied by increasing amino acid activation, protein synthesis and destination, as well as cell defense and rescue, and degradation of storage proteins. Copyright © 2017 Elsevier GmbH. All rights reserved.

  18. A Study of the Energy Dependence of the Underlying Event in Proton-Antiproton Collisions

    CERN Document Server

    Aaltonen, Timo Antero; Amidei, Dante E; Anastassov, Anton Iankov; Annovi, Alberto; Antos, Jaroslav; Apollinari, Giorgio; Appel, Jeffrey A; Arisawa, Tetsuo; Artikov, Akram Muzafarovich; Asaadi, Jonathan A; Ashmanskas, William Joseph; Auerbach, Benjamin; Aurisano, Adam J; Azfar, Farrukh A; Badgett, William Farris; Bae, Taegil; Barbaro-Galtieri, Angela; Barnes, Virgil E; Barnett, Bruce Arnold; Barria, Patrizia; Bartos, Pavol; Bauce, Matteo; Bedeschi, Franco; Behari, Satyajit; Bellettini, Giorgio; Bellinger, James Nugent; Benjamin, Douglas P; Beretvas, Andrew F; Bhatti, Anwar Ahmad; Bland, Karen Renee; Blumenfeld, Barry J; Bocci, Andrea; Bodek, Arie; Bortoletto, Daniela; Boudreau, Joseph Francis; Boveia, Antonio; Brigliadori, Luca; Bromberg, Carl Michael; Brucken, Erik; Budagov, Ioulian A; Budd, Howard Scott; Burkett, Kevin Alan; Busetto, Giovanni; Bussey, Peter John; Butti, Pierfrancesco; Buzatu, Adrian; Calamba, Aristotle; Camarda, Stefano; Campanelli, Mario; Canelli, Florencia; Carls, Benjamin; Carlsmith, Duncan L; Carosi, Roberto; Carrillo Moreno, Salvador; Casal Larana, Bruno; Casarsa, Massimo; Castro, Andrea; Catastini, Pierluigi; Cauz, Diego; Cavaliere, Viviana; Cerri, Alessandro; Cerrito, Lucio; Chen, Yen-Chu; Chertok, Maxwell Benjamin; Chiarelli, Giorgio; Chlachidze, Gouram; Cho, Kihyeon; Chokheli, Davit; Clark, Allan Geoffrey; Clarke, Christopher Joseph; Convery, Mary Elizabeth; Conway, John Stephen; Corbo, Matteo; Cordelli, Marco; Cox, Charles Alexander; Cox, David Jeremy; Cremonesi, Matteo; Cruz Alonso, Daniel; Cuevas Maestro, Javier; Culbertson, Raymond Lloyd; D'Ascenzo, Nicola; Datta, Mousumi; de Barbaro, Pawel; Demortier, Luc M; Marchese, Luigi; Deninno, Maria Maddalena; Devoto, Francesco; D'Errico, Maria; Di Canto, Angelo; Di Ruzza, Benedetto; Dittmann, Jay Richard; D'Onofrio, Monica; Donati, Simone; Dorigo, Mirco; Driutti, Anna; Ebina, Koji; Edgar, Ryan Christopher; Erbacher, Robin D; Errede, Steven Michael; Esham, Benjamin; Farrington, Sinead Marie; Fernández Ramos, Juan Pablo; Field, Richard D; Flanagan, Gene U; Forrest, Robert David; Franklin, Melissa EB; Freeman, John Christian; Frisch, Henry J; Funakoshi, Yujiro; Galloni, Camilla; Garfinkel, Arthur F; Garosi, Paola; Gerberich, Heather Kay; Gerchtein, Elena A; Giagu, Stefano; Giakoumopoulou, Viktoria Athina; Gibson, Karen Ruth; Ginsburg, Camille Marie; Giokaris, Nikos D; Giromini, Paolo; Glagolev, Vladimir; Glenzinski, Douglas Andrew; Gold, Michael S; Goldin, Daniel; Golossanov, Alexander; Gomez, Gervasio; Gomez-Ceballos, Guillelmo; Goncharov, Maxim T; González López, Oscar; Gorelov, Igor V; Goshaw, Alfred T; Goulianos, Konstantin A; Gramellini, Elena; Grosso-Pilcher, Carla; Guimaraes da Costa, Joao; Hahn, Stephen R; Han, Ji-Yeon; Happacher, Fabio; Hara, Kazuhiko; Hare, Matthew Frederick; Harr, Robert Francis; Harrington-Taber, Timothy; Hatakeyama, Kenichi; Hays, Christopher Paul; Heinrich, Joel G; Herndon, Matthew Fairbanks; Hocker, James Andrew; Hong, Ziqing; Hopkins, Walter Howard; Hou, Suen Ray; Hughes, Richard Edward; Husemann, Ulrich; Hussein, Mohammad; Huston, Joey Walter; Introzzi, Gianluca; Iori, Maurizio; Ivanov, Andrew Gennadievich; James, Eric B; Jang, Dongwook; Jayatilaka, Bodhitha Anjalike; Jeon, Eun-Ju; Jindariani, Sergo Robert; Jones, Matthew T; Joo, Kyung Kwang; Jun, Soon Yung; Junk, Thomas R; Kambeitz, Manuel; Kamon, Teruki; Karchin, Paul Edmund; Kasmi, Azeddine; Kato, Yukihiro; Ketchum, Wesley Robert; Keung, Justin Kien; Kilminster, Benjamin John; Kim, DongHee; Kim, Hyunsoo; Kim, Jieun; Kim, Min Jeong; Kim, Soo Bong; Kim, Shin-Hong; Kim, Young-Kee; Kim, Young-Jin; Kimura, Naoki; Kirby, Michael H; Knoepfel, Kyle James; Kondo, Kunitaka; Kong, Dae Jung; Konigsberg, Jacobo; Kotwal, Ashutosh Vijay; Kreps, Michal; Kroll, IJoseph; Kruse, Mark Charles; Kuhr, Thomas; Kurata, Masakazu; Laasanen, Alvin Toivo; Lammel, Stephan; Lancaster, Mark; Lannon, Kevin Patrick; Latino, Giuseppe; Lee, Hyun Su; Lee, Jaison; Leo, Sabato; Leone, Sandra; Lewis, Jonathan D; Limosani, Antonio; Lipeles, Elliot David; Lister, Alison; Liu, Qiuguang; Liu, Tiehui Ted; Lockwitz, Sarah E; Loginov, Andrey Borisovich; Lucà, Alessandra; Lucchesi, Donatella; Lueck, Jan; Lujan, Paul Joseph; Lukens, Patrick Thomas; Lungu, Gheorghe; Lys, Jeremy E; Lysak, Roman; Madrak, Robyn Leigh; Maestro, Paolo; Malik, Sarah Alam; Manca, Giulia; Manousakis-Katsikakis, Arkadios; Margaroli, Fabrizio; Marino, Christopher Phillip; Matera, Keith; Mattson, Mark Edward; Mazzacane, Anna; Mazzanti, Paolo; McNulty, Ronan; Mehta, Andrew; Mehtala, Petteri; Mesropian, Christina; Miao, Ting; Mietlicki, David John; Mitra, Ankush; Miyake, Hideki; Moed, Shulamit; Moggi, Niccolo; Moon, Chang-Seong; Moore, Ronald Scott; Morello, Michael Joseph; Mukherjee, Aseet; Muller, Thomas; Murat, Pavel A; Mussini, Manuel; Nachtman, Jane Marie; Nagai, Yoshikazu; Naganoma, Junji; Nakano, Itsuo; Napier, Austin; Nett, Jason Michael; Nigmanov, Turgun S; Nodulman, Lawrence J; Noh, Seoyoung; Norniella Francisco, Olga; Oakes, Louise Beth; Oh, Seog Hwan; Oh, Young-do; Okusawa, Toru; Orava, Risto Olavi; Ortolan, Lorenzo; Pagliarone, Carmine Elvezio; Palencia, Jose Enrique; Palni, Prabhakar; Papadimitriou, Vaia; Parker, William Chesluk; Pauletta, Giovanni; Paulini, Manfred; Paus, Christoph Maria Ernst; Phillips, Thomas J; Piacentino, Giovanni M; Pianori, Elisabetta; Pilot, Justin Robert; Pitts, Kevin T; Plager, Charles; Pondrom, Lee G; Poprocki, Stephen; Potamianos, Karolos Jozef; Prokoshin, Fedor; Pranko, Aliaksandr Pavlovich; Ptohos, Fotios K; Punzi, Giovanni; Redondo Fernández, Ignacio; Renton, Peter B; Rescigno, Marco; Rimondi, Franco; Ristori, Luciano; Robson, Aidan; Rodriguez, Tatiana Isabel; Rolli, Simona; Ronzani, Manfredi; Roser, Robert Martin; Rosner, Jonathan L; Ruffini, Fabrizio; Ruiz Jimeno, Alberto; Russ, James S; Rusu, Vadim Liviu; Sakumoto, Willis Kazuo; Sakurai, Yuki; Santi, Lorenzo; Sato, Koji; Saveliev, Valeri; Savoy-Navarro, Aurore; Schlabach, Philip; Schmidt, Eugene E; Schwarz, Thomas A; Scodellaro, Luca; Scuri, Fabrizio; Seidel, Sally C; Seiya, Yoshihiro; Semenov, Alexei; Sforza, Federico; Shalhout, Shalhout Zaki; Shears, Tara G; Shepard, Paul F; Shimojima, Makoto; Shochet, Melvyn J; Shreyber-Tecker, Irina; Simonenko, Alexander V; Sliwa, Krzysztof Jan; Smith, John Rodgers; Snider, Frederick Douglas; Sorin, Maria Veronica; Song, Hao; Stancari, Michelle Dawn; St Denis, Richard Dante; Stentz, Dale James; Strologas, John; Sudo, Yuji; Sukhanov, Alexander I; Suslov, Igor M; Takemasa, Ken-ichi; Takeuchi, Yuji; Tang, Jian; Tecchio, Monica; Teng, Ping-Kun; Thom, Julia; Thomson, Evelyn Jean; Thukral, Vaikunth; Toback, David A; Tokar, Stanislav; Tollefson, Kirsten Anne; Tomura, Tomonobu; Tonelli, Diego; Torre, Stefano; Torretta, Donatella; Totaro, Pierluigi; Trovato, Marco; Ukegawa, Fumihiko; Uozumi, Satoru; Vázquez-Valencia, Elsa Fabiola; Velev, Gueorgui; Vellidis, Konstantinos; Vernieri, Caterina; Vidal Marono, Miguel; Vilar Cortabitarte, Rocio; Vizán Garcia, Jesus Manuel; Vogel, Marcelo; Volpi, Guido; Wagner, Peter; Wallny, Rainer S; Wang, Song-Ming; Waters, David S; Wester, William Carl; Whiteson, Daniel O; Wicklund, Arthur Barry; Wilbur, Scott; Williams, Hugh H; Wilson, Jonathan Samuel; Wilson, Peter James; Winer, Brian L; Wittich, Peter; Wolbers, Stephen A; Wolfe, Homer; Wright, Thomas Roland; Wu, Xin; Wu, Zhenbin; Yamamoto, Kazuhiro; Yamato, Daisuke; Yang, Tingjun; Yang, Un-Ki; Yang, Yu Chul; Yao, Wei-Ming; Yeh, Gong Ping; Yi, Kai; Yoh, John; Yorita, Kohei; Yoshida, Takuo; Yu, Geum Bong; Yu, Intae; Zanetti, Anna Maria; Zeng, Yu; Zhou, Chen; Zucchelli, Stefano

    2015-11-23

    We study charged particle production in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of eta-phi space; toward, away, and transverse. The average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the underlying event. The transverse region is divided into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The center-of-mass energy dependence of the various components of the event are studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

  19. Characterizing the spatio-temporal and energy-dependent response of riometer absorption to particle precipitation

    Science.gov (United States)

    Kellerman, Adam; Makarevich, Roman; Spanswick, Emma; Donovan, Eric; Shprits, Yuri

    2016-07-01

    Energetic electrons in the 10's of keV range precipitate to the upper D- and lower E-region ionosphere, and are responsible for enhanced ionization. The same particles are important in the inner magnetosphere, as they provide a source of energy for waves, and thus relate to relativistic electron enhancements in Earth's radiation belts.In situ observations of plasma populations and waves are usually limited to a single point, which complicates temporal and spatial analysis. Also, the lifespan of satellite missions is often limited to several years which does not allow one to infer long-term climatology of particle precipitation, important for affecting ionospheric conditions at high latitudes. Multi-point remote sensing of the ionospheric plasma conditions can provide a global view of both ionospheric and magnetospheric conditions, and the coupling between magnetospheric and ionospheric phenomena can be examined on time-scales that allow comprehensive statistical analysis. In this study we utilize multi-point riometer measurements in conjunction with in situ satellite data, and physics-based modeling to investigate the spatio-temporal and energy-dependent response of riometer absorption. Quantifying this relationship may be a key to future advancements in our understanding of the complex D-region ionosphere, and may lead to enhanced specification of auroral precipitation both during individual events and over climatological time-scales.

  20. Quantitatively identical orientation-dependent ionization energy and electron affinity of diindenoperylene

    Energy Technology Data Exchange (ETDEWEB)

    Han, W. N.; Yonezawa, K.; Makino, R.; Kato, K.; Hinderhofer, A.; Ueno, N.; Kera, S. [Graduate School of Advanced Integration Science, Chiba University 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Murdey, R.; Shiraishi, R.; Yoshida, H.; Sato, N. [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2013-12-16

    Molecular orientation dependences of the ionization energy (IE) and the electron affinity (EA) of diindenoperylene (DIP) films were studied by using ultraviolet photoemission spectroscopy and inverse photoemission spectroscopy. The molecular orientation was controlled by preparing the DIP films on graphite and SiO{sub 2} substrates. The threshold IE and EA of DIP thin films were determined to be 5.81 and 3.53 eV for the film of flat-lying DIP orientation, respectively, and 5.38 and 3.13 eV for the film of standing DIP orientation, respectively. The result indicates that the IE and EA for the flat-lying film are larger by 0.4 eV and the frontier orbital states shift away from the vacuum level compared to the standing film. This rigid energy shift is ascribed to a surface-electrostatic potential produced by the intramolecular polar bond (>C{sup −}-H{sup +}) for standing orientation and π-electron tailing to vacuum for flat-lying orientation.