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Sample records for bias stress effects

  1. Effects of bias stress on ZnO nanowire field-effect transistors fabricated with organic gate nanodielectrics

    OpenAIRE

    Ju, Sanghyun; Janes, David B.; Lu, Gang; Facchetti, Antonio; Marks, Tobin J.

    2006-01-01

    The effects of bias stress gate stress or drain stress on nanowire field-effect transistor NW-FET stability were investigated as a function of stress bias and stress time. The n-channel NW-FETs used a nanoscopic self-assembled organic gate insulator, and each device contained a single ZnO nanowire. Before stress, the off current is limited by a leakage current in the 1 nA range, which increases as the gate to source bias becomes increasingly negative. The devices also exhibited significan...

  2. Effect of Reverse Bias Stress on Leakage Currents and Breakdown Voltages of Solid Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander A.

    2011-01-01

    the processes under reverse bias conditions. In practice, there were instances when, due to unforeseen events, the system operated at conditions when capacitors experience periodically a relatively small reverse bias for some time followed by normal, forward bias conditions. In such a case an assessment should be made on the degree to which these capacitors are degraded by application of low-voltage reverse bias, and whether this degradation can be reversed by normal operating conditions. In this study, reverse currents in different types of tantalum capacitors were monitored at different reverse voltages below 15%VR and temperatures in the range from room to 145 C for up to 150 hours to get better understanding of the degradation process and determine conditions favorable to the unstable mode of operation. The reversibility of RB degradation has been evaluated after operation of the capacitors at forward bias conditions. The effect of reverse bias stress (RBS) on reliability at normal operating conditions was evaluated using highly accelerated life testing at voltages of 1.5VR and 2 VR and by analysis of changes in distributions of breakdown voltages. Possible mechanisms of RB degradation are discussed.

  3. The influence of cognitive biases on psychophysiological vulnerability to stress

    OpenAIRE

    Randall, Kate

    2012-01-01

    Individuals who disproportionately attend to negative aspects of a situation (attention bias), or who unduly interpret ambiguity in a negative manner (interpretive bias) report more psychological ill-effects of stress than those with balanced or positively-skewed inclinations. Cognitive Bias Modification (CBM) techniques improve maladaptive biases through implicitly-based association learning, with induced positive biases buffering the future perception of stress. Six experimen...

  4. Effects of stress conditions on the generation of negative bias temperature instability-associated interface traps

    International Nuclear Information System (INIS)

    The exponent n of the generation of an interface trap (Nit), which contributes to the power-law negative bias temperature instability (NBTI) degradation, and the exponent's time evolution are investigated by simulations with varying the stress voltage Vg and temperature T. It is found that the exponent n in the diffusion-limited phase of the degradation process is irrelevant to both Vg and T. The time evolution of the exponent n is affected by the stress conditions, which is reflected in the shift of the onset of the diffusion-limited phase. According to the diffusion profiles, the generation of the atomic hydrogen species, which is equal to the buildup of Nit, is strongly correlated with the stress conditions, whereas the diffusion of the hydrogen species shows Vg-unaffected but T-affected relations through the normalized results

  5. The effects of juvenile stress on anxiety, cognitive bias and decision making in adulthood: a rat model.

    Directory of Open Access Journals (Sweden)

    Nichola M Brydges

    Full Text Available Stress experienced in childhood is associated with an increased risk of developing psychiatric disorders in adulthood. These disorders are particularly characterized by disturbances to emotional and cognitive processes, which are not currently fully modeled in animals. Assays of cognitive bias have recently been used with animals to give an indication of their emotional/cognitive state. We used a cognitive bias test, alongside a traditional measure of anxiety (elevated plus maze, to investigate the effects of juvenile stress (JS on adulthood behaviour using a rodent model. During the cognitive bias test, animals were trained to discriminate between two reward bowls based on a stimulus (rough/smooth sandpaper encountered before they reached the bowls. One stimulus (e.g. rough was associated with a lower value reward than the other (e.g. smooth. Once rats were trained, their cognitive bias was explored through the presentation of an ambiguous stimulus (intermediate grade sandpaper: a rat was classed as optimistic if it chose the bowl ordinarily associated with the high value reward. JS animals were lighter than controls, exhibited increased anxiety-like behaviour in the elevated plus maze and were more optimistic in the cognitive bias test. This increased optimism may represent an optimal foraging strategy for these underweight animals. JS animals were also faster than controls to make a decision when presented with an ambiguous stimulus, suggesting altered decision making. These results demonstrate that stress in the juvenile phase can increase anxiety-like behaviour and alter cognitive bias and decision making in adulthood in a rat model.

  6. Effect of top gate bias on photocurrent and negative bias illumination stress instability in dual gate amorphous indium-gallium-zinc oxide thin-film transistor

    Science.gov (United States)

    Lee, Eunji; Chowdhury, Md Delwar Hossain; Park, Min Sang; Jang, Jin

    2015-12-01

    We have studied the effect of top gate bias (VTG) on the generation of photocurrent and the decay of photocurrent for back channel etched inverted staggered dual gate structure amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Upon 5 min of exposure of 365 nm wavelength and 0.7 mW/cm2 intensity light with negative bottom gate bias, the maximum photocurrent increases from 3.29 to 322 pA with increasing the VTG from -15 to +15 V. By changing VTG from negative to positive, the Fermi level (EF) shifts toward conduction band edge (EC), which substantially controls the conversion of neutral vacancy to charged one (VO → VO+/VO2+ + e-/2e-), peroxide (O22-) formation or conversion of ionized interstitial (Oi2-) to neutral interstitial (Oi), thus electron concentration at conduction band. With increasing the exposure time, more carriers are generated, and thus, maximum photocurrent increases until being saturated. After negative bias illumination stress, the transfer curve shows -2.7 V shift at VTG = -15 V, which gradually decreases to -0.42 V shift at VTG = +15 V. It clearly reveals that the position of electron quasi-Fermi level controls the formation of donor defects (VO+/VO2+/O22-/Oi) and/or hole trapping in the a-IGZO /interfaces.

  7. Effect of top gate bias on photocurrent and negative bias illumination stress instability in dual gate amorphous indium-gallium-zinc oxide thin-film transistor

    International Nuclear Information System (INIS)

    We have studied the effect of top gate bias (VTG) on the generation of photocurrent and the decay of photocurrent for back channel etched inverted staggered dual gate structure amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Upon 5 min of exposure of 365 nm wavelength and 0.7 mW/cm2 intensity light with negative bottom gate bias, the maximum photocurrent increases from 3.29 to 322 pA with increasing the VTG from −15 to +15 V. By changing VTG from negative to positive, the Fermi level (EF) shifts toward conduction band edge (EC), which substantially controls the conversion of neutral vacancy to charged one (VO → VO+/VO2+ + e−/2e−), peroxide (O22−) formation or conversion of ionized interstitial (Oi2−) to neutral interstitial (Oi), thus electron concentration at conduction band. With increasing the exposure time, more carriers are generated, and thus, maximum photocurrent increases until being saturated. After negative bias illumination stress, the transfer curve shows −2.7 V shift at VTG = −15 V, which gradually decreases to −0.42 V shift at VTG = +15 V. It clearly reveals that the position of electron quasi-Fermi level controls the formation of donor defects (VO+/VO2+/O22−/Oi) and/or hole trapping in the a-IGZO /interfaces

  8. Effect of top gate bias on photocurrent and negative bias illumination stress instability in dual gate amorphous indium-gallium-zinc oxide thin-film transistor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunji; Chowdhury, Md Delwar Hossain; Park, Min Sang; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

    2015-12-07

    We have studied the effect of top gate bias (V{sub TG}) on the generation of photocurrent and the decay of photocurrent for back channel etched inverted staggered dual gate structure amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Upon 5 min of exposure of 365 nm wavelength and 0.7 mW/cm{sup 2} intensity light with negative bottom gate bias, the maximum photocurrent increases from 3.29 to 322 pA with increasing the V{sub TG} from −15 to +15 V. By changing V{sub TG} from negative to positive, the Fermi level (E{sub F}) shifts toward conduction band edge (E{sub C}), which substantially controls the conversion of neutral vacancy to charged one (V{sub O} → V{sub O}{sup +}/V{sub O}{sup 2+} + e{sup −}/2e{sup −}), peroxide (O{sub 2}{sup 2−}) formation or conversion of ionized interstitial (O{sub i}{sup 2−}) to neutral interstitial (O{sub i}), thus electron concentration at conduction band. With increasing the exposure time, more carriers are generated, and thus, maximum photocurrent increases until being saturated. After negative bias illumination stress, the transfer curve shows −2.7 V shift at V{sub TG} = −15 V, which gradually decreases to −0.42 V shift at V{sub TG} = +15 V. It clearly reveals that the position of electron quasi-Fermi level controls the formation of donor defects (V{sub O}{sup +}/V{sub O}{sup 2+}/O{sub 2}{sup 2−}/O{sub i}) and/or hole trapping in the a-IGZO /interfaces.

  9. Investigating degradation behavior of InGaZnO thin-film transistors induced by charge-trapping effect under DC and AC gate bias stress

    International Nuclear Information System (INIS)

    This paper investigates the degradation mechanism of amorphous InGaZnO thin-film transistors under DC and AC gate bias stress. Comparing the degradation behavior at equal accumulated effective stress time, more pronounced threshold voltage shift under AC positive gate bias stress in comparison with DC stress indicates extra electron-trapping phenomenon that occurs in the duration of rising/falling time in pulse. Contrarily, illuminated AC negative gate bias stress exhibits much less threshold voltage shift than DC stress, suggesting that the photo-generated hole does not have sufficient time to drift to the interface of IGZO/gate insulator and causes hole-trapping under AC operation. Since the evolution of threshold voltage fits the stretched-exponential equation well, the different degradation tendencies under DC/AC stress can be attributed to the different electron- and hole-trapping efficiencies, and this is further verified by varying pulse waveform. - Highlights: ► Static and dynamic gate bias stresses are imposed on InGaZnO TFTs. ► Dynamic positive gate bias induces more pronounced threshold voltage shift. ► Static negative-bias illumination stress induces more severe threshold voltage shift. ► Evolution of threshold voltage fits the stretched-exponential equation well

  10. Effect of indium low doping in ZnO based TFTs on electrical parameters and bias stress stability

    Energy Technology Data Exchange (ETDEWEB)

    Cheremisin, Alexander B., E-mail: acher612@gmail.com; Kuznetsov, Sergey N.; Stefanovich, Genrikh B. [Physico-Technical Department, Petrozavodsk State University, Petrozavodsk 185910 (Russian Federation)

    2015-11-15

    Some applications of thin film transistors (TFTs) need the bottom-gate architecture and unpassivated channel backside. We propose a simple routine to fabricate indium doped ZnO-based TFT with satisfactory characteristics and acceptable stability against a bias stress in ambient room air. To this end, a channel layer of 15 nm in thickness was deposited on cold substrate by DC reactive magnetron co-sputtering of metal Zn-In target. It is demonstrated that the increase of In concentration in ZnO matrix up to 5% leads to negative threshold voltage (V{sub T}) shift and an increase of field effect mobility (μ) and a decrease of subthreshold swing (SS). When dopant concentration reaches the upper level of 5% the best TFT parameters are achieved such as V{sub T} = 3.6 V, μ = 15.2 cm{sup 2}/V s, SS = 0.5 V/dec. The TFTs operate in enhancement mode exhibiting high turn on/turn off current ratio more than 10{sup 6}. It is shown that the oxidative post-fabrication annealing at 250{sup o}C in pure oxygen and next ageing in dry air for several hours provide highly stable operational characteristics under negative and positive bias stresses despite open channel backside. A possible cause of this effect is discussed.

  11. Effect of indium low doping in ZnO based TFTs on electrical parameters and bias stress stability

    International Nuclear Information System (INIS)

    Some applications of thin film transistors (TFTs) need the bottom-gate architecture and unpassivated channel backside. We propose a simple routine to fabricate indium doped ZnO-based TFT with satisfactory characteristics and acceptable stability against a bias stress in ambient room air. To this end, a channel layer of 15 nm in thickness was deposited on cold substrate by DC reactive magnetron co-sputtering of metal Zn-In target. It is demonstrated that the increase of In concentration in ZnO matrix up to 5% leads to negative threshold voltage (VT) shift and an increase of field effect mobility (μ) and a decrease of subthreshold swing (SS). When dopant concentration reaches the upper level of 5% the best TFT parameters are achieved such as VT = 3.6 V, μ = 15.2 cm2/V s, SS = 0.5 V/dec. The TFTs operate in enhancement mode exhibiting high turn on/turn off current ratio more than 106. It is shown that the oxidative post-fabrication annealing at 250oC in pure oxygen and next ageing in dry air for several hours provide highly stable operational characteristics under negative and positive bias stresses despite open channel backside. A possible cause of this effect is discussed

  12. Effect of indium low doping in ZnO based TFTs on electrical parameters and bias stress stability

    Science.gov (United States)

    Cheremisin, Alexander B.; Kuznetsov, Sergey N.; Stefanovich, Genrikh B.

    2015-11-01

    Some applications of thin film transistors (TFTs) need the bottom-gate architecture and unpassivated channel backside. We propose a simple routine to fabricate indium doped ZnO-based TFT with satisfactory characteristics and acceptable stability against a bias stress in ambient room air. To this end, a channel layer of 15 nm in thickness was deposited on cold substrate by DC reactive magnetron co-sputtering of metal Zn-In target. It is demonstrated that the increase of In concentration in ZnO matrix up to 5% leads to negative threshold voltage (VT) shift and an increase of field effect mobility (μ) and a decrease of subthreshold swing (SS). When dopant concentration reaches the upper level of 5% the best TFT parameters are achieved such as VT = 3.6 V, μ = 15.2 cm2/V s, SS = 0.5 V/dec. The TFTs operate in enhancement mode exhibiting high turn on/turn off current ratio more than 106. It is shown that the oxidative post-fabrication annealing at 250oC in pure oxygen and next ageing in dry air for several hours provide highly stable operational characteristics under negative and positive bias stresses despite open channel backside. A possible cause of this effect is discussed.

  13. Hardness and residual stress in nanocrystalline ZrN films: Effect of bias voltage and heat treatment

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the effects of both bias voltage and heat treatment on the composition, microstructure, and associated mechanical properties of the zirconium nitride (ZrN) thin films deposited on AISI 304 stainless steel substrates by a filtered cathodic arc ion-plating (FCA-IP) system. The depositions were carried out by varying negative substrate bias voltage, from -40 Vb to -80 Vb. The deposited film specimens were heat-treated at 800 deg. C for 1 h. X-ray diffraction (XRD) revealed that (a) texture coefficients of (1 1 1) plane increased with negative bias, and (b) the grain size was approximately less than 15 nm, i.e. nano-scale grain size. The hardness of the deposited ZrN films was correlated with point defects, (1 1 1) texture coefficient, and crystallinity characterized for the films. For the as-deposited films, it was found that the hardness increased with decreasing (1 1 1) full width of the peak at half maximum (FWHM) and increasing (1 1 1) texture coefficient, suggesting a better crystallinity and lower grain boundary mobility in the highly textured films. The decrease in film hardness after heat treatment may be attributed mainly to the reduction of point defects present in the films. Measurements performed for the intrinsic residual stress reported a significant 5.5 GPa release in the heat-treated films, due to recovery of point defects by heat treatment

  14. Gate-bias stress-dependent photoconductive characteristics of multi-layer MoS2 field-effect transistors

    International Nuclear Information System (INIS)

    We investigated the photoconductive characteristics of molybdenum disulfide (MoS2) field-effect transistors (FETs) that were fabricated with mechanically exfoliated multi-layer MoS2 flakes. Upon exposure to UV light, we observed an increase in the MoS2 FET current because of electron–hole pair generation. The MoS2 FET current decayed after the UV light was turned off. The current decay processes were fitted using exponential functions with different decay characteristics. Specifically, a fast decay was used at the early stages immediately after turning off the light to account for the exciton relaxation, and a slow decay was used at later stages long after turning off the light due to charge trapping at the oxygen-related defect sites on the MoS2 surface. This photocurrent decay phenomenon of the MoS2 FET was influenced by the measurement environment (i.e., vacuum or oxygen environment) and the electrical gate-bias stress conditions (positive or negative gate biases). The results of this study will enhance the understanding of the influence of environmental and measurement conditions on the optical and electrical properties of MoS2 FETs. (paper)

  15. Effect of combined external uniaxial stress and dc bias on the dielectric property of BaTiO3-based dielectrics in multilayer ceramic capacitor: thermodynamics and experiments

    Science.gov (United States)

    Yang, Gang; Yue, Zhenxing; Sun, Tieyu; Gou, Huanlin; Li, Longtu

    2008-02-01

    The dielectric properties of (Nb, Y)-doped BaTiO3 in a multilayer ceramic capacitor (MLCC) under combined external uniaxial compressive stress and dc bias field were investigated at room temperature by using a modified Ginsburg-Landau-Devonshire thermodynamic theory and the dielectric measurement. It is found that although dc bias decreases the dielectric properties dominantly, the influence of the external uniaixial compressive stress should not be neglected. When applied along a direction perpendicular to the internal electrode layer in the MLCC, the external uniaixal compressive stress will strengthen the negative effect of dc bias. In contrast, the external uniaxial compressive stress along a direction parallel to the internal electrode layer in the MLCC will increase the dielectric permittivity under dc bias field, i.e. improve the ɛ-V response of the MLCC. Furthermore, although there is a difference between the calculated permittivity and the measured permittivity, the effects of the combined external uniaxial compressive stress and dc bias field on the dielectric permittivity described through two approaches are in good agreement.

  16. Effect of external stress and bias magnetic field on transformation strain of heusler alloy Ni-Mn-Ga

    Institute of Scientific and Technical Information of China (English)

    高智勇; 蔡伟; 赵连城; 吴光恒; 陈京兰; 詹文山

    2003-01-01

    The influence of external field(magnetic field and stress field) on the transformation strain of Ni52.9-Mn24.4Ga22.7 single crystal were investigated and its mechanism was also discussed. When thermally martensitictransformation occurs, about 0.25% transformation strain is obtained which may be obviously enhanced to about0. 8% by a 6 000 Oe magnetic bias field. However, the strain decreases by the external compress stress loaded alongthe strain-measured direction. When the external compress stress and bias magnetic field are simultaneously applied,the transformation strain decreases with increasing the magnetic field, which is related to the rearrangement of themartensite variants influenced by the external field.

  17. Effect of top gate potential on bias-stress for dual gate amorphous indium-gallium-zinc-oxide thin film transistor

    Science.gov (United States)

    Chun, Minkyu; Um, Jae Gwang; Park, Min Sang; Chowdhury, Md Delwar Hossain; Jang, Jin

    2016-07-01

    We report the abnormal behavior of the threshold voltage (VTH) shift under positive bias Temperature stress (PBTS) and negative bias temperature stress (NBTS) at top/bottom gate in dual gate amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). It is found that the PBTS at top gate shows negative transfer shift and NBTS shows positive transfer shift for both top and bottom gate sweep. The shift of bottom/top gate sweep is dominated by top gate bias (VTG), while bottom gate bias (VBG) is less effect than VTG. The X-ray photoelectron spectroscopy (XPS) depth profile provides the evidence of In metal diffusion to the top SiO2/a-IGZO and also the existence of large amount of In+ under positive top gate bias around top interfaces, thus negative transfer shift is observed. On the other hand, the formation of OH- at top interfaces under the stress of negative top gate bias shows negative transfer shift. The domination of VTG both on bottom/top gate sweep after PBTS/NBTS is obviously occurred due to thin active layer.

  18. For whom the bell tolls: Neurocognitive individual differences in the acute stress-reduction effects of an attention bias modification game for anxiety.

    Science.gov (United States)

    Dennis-Tiwary, Tracy A; Egan, Laura J; Babkirk, Sarah; Denefrio, Samantha

    2016-02-01

    The efficacy of attention bias modification training (ABMT) for anxiety is debated, in part because individual differences in task engagement and pre-training threat bias impact training efficacy. In the present study, an engaging, gamified ABMT mobile application, or "app," was utilized in 42 (21 females) trait-anxious adults. EEG was recorded during pre- and post-training threat bias assessment to generate scalp-recorded event-related potentials (ERPs) reflecting neurocognitive responses to threat. Following app play (ABMT versus placebo), subjective anxiety and stress responses (observed and self-reported) were measured. ABMT, versus placebo, resulted in improved behavioral performance during the stress task for females, and in potentiation of the N2 ERP to threat for males, suggesting increased attention control. Training groups did not differ in self-reported anxiety. ABMT also resulted in improved performance during the stress task among those evidencing specific pre-training ERP responses: decreased P1, suggesting less attention allocation, but potentiated N170, suggesting enhanced attention selection and discrimination. Differences in behavioral threat bias did not moderate training effects. Results suggest that efficient allocation of attention to threat combined with enhanced discrimination between threat and non-threat may facilitate stress-reduction effects of ABMT. Targeting neurocognitive responses to threat to personalize ABMT and develop more effective methods of treatment delivery, such as gamification, are discussed. PMID:26745621

  19. Attention Bias Variability and Symptoms of Posttraumatic Stress Disorder

    OpenAIRE

    Iacoviello, Brian M.; Wu, Gang; Abend, Rany; Murrough, James W.; Feder, Adriana; Fruchter, Eyal; Levinstein, Yoav; Wald, Ilan; Bailey, Christopher R.; Pine, Daniel S.; Neumeister, Alexander; Bar-Haim, Yair; Charney, Dennis S.

    2014-01-01

    Cognitive theories implicate information-processing biases in the etiology of anxiety disorders. Results of attention-bias studies in posttraumatic stress disorder (PTSD) have been inconsistent, suggesting biases towards and away from threat. Within-subject variability of attention biases in posttraumatic patients may be a useful marker for attentional control impairment and the development of posttrauma symptoms. This study reports 2 experiments investigating threat-related attention biases,...

  20. Preconscious Processing Biases Predict Emotional Reactivity to Stress

    OpenAIRE

    Fox, Elaine; Cahill, Shanna; Zougkou, Konstantina

    2010-01-01

    Background Anxiety vulnerability is associated with biases in attention: a tendency to selectively process negative relative to neutral or positive information. It is not clear whether this bias is: 1) related to the physiological response to stressful events, and 2) causally related to the development of anxiety disorders. Methods We tested the predictive value of both preconscious and conscious attention biases in a prospective study of stress reactivity in a nonclinical sample. One hundred...

  1. Potential effects of bias and nitrogen pressure on structural-stress state and properties of nitride coatings, obtained by evaporation of high-entropy alloys by vacuum arc

    International Nuclear Information System (INIS)

    A study of the influence of the negative bias potential and pressure of the atmosphere of nitrogen on the structural properties of the stress state and vacuum-arc nitride coatings. The comparison data for the three groups of coatings: 1 - (Ti, V, Zr, Nb, Hf) N, 2 - (Ti, V, Zr, Nb, Hf, Ta) N , and 3 - TiN. Excluding the drop component, multielement nitride coatings deposited in nitrogen are single phase with cubic fcc lattice (structural type NaCl). At the level of substructure in these coatings increase the nitrogen pressure leads to an increase in the crystallite size and micro strain relaxation , and increase the capacity of displacement - the opposite effect. The absolute value of micro deformation in such coatings is higher and the size of crystallites - less than mononitrides. Maximum hardness of 70 GPa achieved nitride coatings deposited by vacuum arc evaporation (Ti, V, Zr, Nb, Hf) alloy at a nitrogen pressure of 0.35 Pa

  2. Effect of the 2010 Chilean Earthquake on Posttraumatic Stress Reducing Sensitivity to Unmeasured Bias Through Study Design

    OpenAIRE

    Zubizarreta, José R.; Cerdá, Magdalena; Rosenbaum, Paul R.

    2013-01-01

    In 2010, a magnitude 8.8 earthquake hit Chile, devastating parts of the country. Having just completed its national socioeconomic survey, the Chilean government reinterviewed a subsample of respondents, creating unusual longitudinal data about the same persons before and after a major disaster. The follow-up evaluated posttraumatic stress symptoms (PTSS) using Davidson’s Trauma Scale. We use these data with two goals in mind. Most studies of PTSS after disasters rely on recall to characterize...

  3. Stress effects

    International Nuclear Information System (INIS)

    This chapter reviews the manner in which the influence of stress on a composite Cu/Ti-Nb superconductor brings about a deterioration of its electrical properties and those of the magnet wound from it. Training and electrical fatigue are considered. Static and dynamic stress effects are discussed as are dynamic stress effects -- repeated tension. The authors also examine dynamic stress effects--tension-compression. Several extensive case studies have been undertaken of the effects of both static and dynamic tensile and compressive stresses on the current-carrying properties of composite superconductors. Single-core and multi-filamentary Cu- or Al-stabilized monoliths, as well as cables, have been investigated and several representative studies are reviewed

  4. Bias-induced stress transitions in sputtered TiN films

    OpenAIRE

    Kattelus, H. P.; Tandon, J. L.; Sala, C; Nicolet, M.-A.

    1986-01-01

    We report on intrinsic stress properties of magnetron sputtered titanium nitride films deposited under different conditions. By proper selection of processing parameters, films with low stress can be obtained. Unstressed film formation is favored by low substrate bias voltage, high pressure, or use of heavy sputtering gases. Stress relief is, however, accompanied by an increase in resistivity and a decrease in film density. As a result of these changes the effectiveness of such titanium nitri...

  5. Ion polarization behavior in alumina under pulsed gate bias stress

    International Nuclear Information System (INIS)

    Alkali metal ion incorporation in alumina significantly increases alumina capacitance by ion polarization. With high capacitance, ion-incorporated aluminas become promising high dielectric constant (high-k) gate dielectric materials in field-effect transistors (FETs) to enable reduced operating voltage, using oxide or organic semiconductors. Alumina capacitance can be manipulated by incorporation of alkali metal ions, including potassium (K+), sodium (Na+), and lithium (Li+), having different bond strengths with oxygen. To investigate the electrical stability of zinc tin oxide-based transistors using ion incorporated alumina as gate dielectrics, pulsed biases at different duty cycles (20%, 10%, and 2% representing 5 ms, 10 ms, and 50 ms periods, respectively) were applied to the gate electrode, sweeping the gate voltage over series of these cycles. We observed a particular bias stress-induced decrease of saturation field-effect mobility accompanied by threshold voltage shifts (ΔVth) in potassium and sodium-incorporated alumina (abbreviated as PA and SA)-based FETs at high duty cycle that persisted over multiple gate voltage sweeps, suggesting a possible creation of new defects in the semiconductor. This conclusion is also supported by the greater change in the mobility-capacitance (μC) product than in capacitance itself. Moreover, a more pronounced ΔVth over shorter times was observed in lithium-incorporated alumina (abbreviated as LA)-based transistors, suggesting trapping of electrons in existing interfacial states. ΔVth from multiple gate voltage sweeps over time were fit to stretched exponential forms. All three dielectrics show good stability using 50-ms intervals (20-Hz frequencies), corresponding to 2% duty cycles

  6. Attentional bias to threat: roles of trait anxiety, stressful events, and awareness.

    Science.gov (United States)

    Mogg, K; Bradley, B P; Hallowell, N

    1994-11-01

    Attentional biases for threat stimuli were assessed in high and low trait anxious subjects (n = 66) using a probe detection task. To examine the effects of trait anxiety and situational stressors, each subject was tested three times: Under no stress, laboratory-induced stress, and examination-induced stress. To evaluate the role of awareness, half the word stimuli were presented very briefly (14 msec) and masked, and the other half were presented for 500 msec without a mask. Results showed that high trait anxious subjects under exam stress showed an attentional bias towards unmasked threat stimuli compared with low trait subjects. This effect was not found under lab-induced stress, suggesting that the attentional bias for unmasked threat in high trait subjects may be a function of a prolonged stressor, rather than a transient increase in state anxiety. The results from the masked exposure condition were not predicted; high trait anxious subjects shifted attention towards the spatial location of threat words despite lack of awareness of their lexical content, but this bias was only apparent in the no-stress condition. The results are discussed in relation to recent cognitive theories of anxiety. PMID:7809399

  7. Effect of direct current sputtering power on the behavior of amorphous indium-gallium-zinc-oxide thin-film transistors under negative bias illumination stress: A combination of experimental analyses and device simulation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jun Tae; Kim, Dong Myong; Choi, Sung-Jin; Kim, Dae Hwan, E-mail: khs3297@cnu.ac.kr, E-mail: drlife@kookmin.ac.kr [School of Electrical Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Park, Jozeph [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Ahn, Byung Du [School of Electrical and Electronic Engineering, Yonsei University, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, Hyun-Suk, E-mail: khs3297@cnu.ac.kr, E-mail: drlife@kookmin.ac.kr [Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2015-03-23

    The effect of direct current sputtering power of indium-gallium-zinc-oxide (IGZO) on the performance and stability of the corresponding thin-film transistor devices was studied. The field effect mobility increases as the IGZO sputter power increases, at the expense of device reliability under negative bias illumination stress (NBIS). Device simulation based on the extracted sub-gap density of states indicates that the field effect mobility is improved as a result of the number of acceptor-like states decreasing. The degradation by NBIS is suggested to be induced by the formation of peroxides in IGZO rather than charge trapping.

  8. Negative bias-and-temperature stress-assisted activation of oxygen-vacancy hole traps in 4H-silicon carbide metal-oxide-semiconductor field-effect transistors

    International Nuclear Information System (INIS)

    We use hybrid-functional density functional theory-based Charge Transition Levels (CTLs) to study the electrical activity of near-interfacial oxygen vacancies located in the oxide side of 4H-Silicon Carbide (4H-SiC) power Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs). Based on the “amorphousness” of their local atomic environment, oxygen vacancies are shown to introduce their CTLs either within (permanently electrically active) or outside of (electrically inactive) the 4H-SiC bandgap. The “permanently electrically active” centers are likely to cause threshold voltage (Vth) instability at room temperature. On the other hand, we show that the “electrically inactive” defects could be transformed into various “electrically active” configurations under simultaneous application of negative bias and high temperature stresses. Based on this observation, we present a model for plausible oxygen vacancy defects that could be responsible for the recently observed excessive worsening of Vth instability in 4H-SiC power MOSFETs under high temperature-and-gate bias stress. This model could also explain the recent electrically detected magnetic resonance observations in 4H-SiC MOSFETs

  9. Investigation of abnormal negative threshold voltage shift under positive bias stress in input/output n-channel metal-oxide-semiconductor field-effect transistors with TiN/HfO2 structure using fast I-V measurement

    International Nuclear Information System (INIS)

    This letter investigates abnormal negative threshold voltage shifts under positive bias stress in input/output (I/O) TiN/HfO2 n-channel metal-oxide-semiconductor field-effect transistors using fast I-V measurement. This phenomenon is attributed to a reversible charge/discharge effect in pre-existing bulk traps. Moreover, in standard performance devices, threshold-voltage (Vt) shifts positively during fast I-V double sweep measurement. However, in I/O devices, Vt shifts negatively since electrons escape from bulk traps to metal gate rather than channel electrons injecting to bulk traps. Consequently, decreasing pre-existing bulk traps in I/O devices, which can be achieved by adopting HfxZr1−xO2 as gate oxide, can reduce the charge/discharge effect

  10. Effect of bias voltage on microstructure of DC magnetron sputtered Al coatings on uranium

    Institute of Scientific and Technical Information of China (English)

    L(U) Xue-chao; WANG Xiao-lin; LANG Ding-mu; DONG Ping

    2004-01-01

    The effect of different bias voltages on microstructure of Al coatings on uranium was investigated by using scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray stress analyzer, respectively. The results indicate that the microstructure is influenced strongly by bias voltage. At low bias voltages, especially at -100 V, the structure of Al coatings is more densely packed than that at high bias voltages of - 300 V and - 400 V,where the structure looks like open dentritic. On the whole, the peak (111) orientation is predominant with the increase of bias voltage, but at -400 V, the diffractive intensity of main peaks (111) and (200) is close to the standard reference. The residual stress on Al coatings surface is small, which has a change from tensile to compressive stress with the increase of bias voltage.

  11. Effect of substrate bias on negative bias temperature instability of ultra-deep sub-micro p-channel metal–oxide–semiconductor field-effect transistors

    International Nuclear Information System (INIS)

    The effect of substrate bias on the degradation during applying a negative bias temperature (NBT) stress is studied in this paper. With a smaller gate voltage stress applied, the degradation of negative bias temperature instability (NBTI) is enhanced, and there comes forth an inflexion point. The degradation pace turns larger when the substrate bias is higher than the inflexion point. The substrate hot holes can be injected into oxide and generate additional oxide traps, inducing an inflexion phenomenon. When a constant substrate bias stress is applied, as the gate voltage stress increases, an inflexion comes into being also. The higher gate voltage causes the electrons to tunnel into the substrate from the poly, thereby generating the electron–hole pairs by impact ionization. The holes generated by impact ionization and the holes from the substrate all can be accelerated to high energies by the substrate bias. More additional oxide traps can be produced, and correspondingly, the degradation is strengthened by the substrate bias. The results of the alternate stress experiment show that the interface traps generated by the hot holes cannot be annealed, which is different from those generated by common holes. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  12. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    The role of education in the process of socioeconomic attainment is a topic of long standing interest to sociologists and economists. Recently there has been growing interest not only in estimating the average causal effect of education on outcomes such as earnings, but also in estimating how...... causal effects might vary over individuals or groups. In this paper we point out one of the under-appreciated hazards of seeking to estimate heterogeneous causal effects: conventional selection bias (that is, selection on baseline differences) can easily be mistaken for heterogeneity of causal effects...

  13. Negative Bias Temperature Instability "Recovery" under Negative Stress Voltage with Different Oxide Thicknesses

    Institute of Scientific and Technical Information of China (English)

    CAO Yan-Rong; MA Xiao-Hua; HAO Yue; ZHU Min-Bo; TIAN Wen-Chao; ZHANG Yue

    2011-01-01

    Different phenomena are observed under negative gate voltage stress which is smaller than the previous degradation stress in PMOSFETs with different oxide thicknesses. We adopt the real time method to make a point of the drain current to study the degradation and recovery of negative bias temperature instability (NBTI). For the device with thin oxide, recovery phenomenon appears when smaller negative voltage stress was applied, due to the more influencing oxide charges detrapping effects than the interface states. For the device with thick oxide, not recovery but degradation phenomenon comes forth. As many charges are trapped in the deeper position and higher energy level in the oxide, these charges can not be detrapped. Therefore, the effect of the charge detrapping is smaller than that of the interface states in the thick oxide. The degradation presents itself during the 'recovery' time.

  14. Drain bias effect on the instability of amorphous indium gallium zinc oxide thin film transistor

    International Nuclear Information System (INIS)

    We fabricated amorphous indium gallium zinc oxide thin film transistors (TFTs) in a top gate structure on a glass substrate. We investigated the effect of drain bias on the instability of the device. Although the device showed highly stable characteristics under both positive and negative gate bias stress, it showed significant degradation in the transfer characteristics under drain bias stress. The degradation phenomena are somewhat similar to those of negative gate bias illumination stress (NBIS). In the case of NBIS, degradation mechanisms have been confused between two kinds of illustrations, one of which is hole trapping in the gate insulator and the other is an increase of electron density in the active layer. Our experimental results revealed that the degradation mechanism of drain bias stress is closer to the latter mechanism of NBIS in amorphous oxide TFTs. - Highlights: ► Drain bias also degrades amorphous oxide thin film transistors. ► Increase of electron density near the drain junction occurs under drain bias stress. ► Oxygen vacancies can be ionized through the impingement of fast electrons

  15. Placebo effect studies are susceptible to response bias and to other types of biases

    DEFF Research Database (Denmark)

    Hróbjartsson, Asbjørn; Kaptchuk, Ted J; Miller, Franklin G

    2011-01-01

    Investigations of the effect of placebo are often challenging to conduct and interpret. The history of placebo shows that assessment of its clinical significance has a real potential to be biased. We analyze and discuss typical types of bias in studies on placebo....

  16. The effect of optimism bias on time preference

    OpenAIRE

    Tal Shavit

    2013-01-01

    This paper examines the effect of optimism bias on monetary time preference and risk tolerance. The results of a survey show that preference towards the present increases with optimism bias. I argue that the factor which affects time preference is the individual’s concern regarding future events, as measured by optimism bias.

  17. Capacitance-voltage characteristics and device simulation of bias temperature stressed a-Si:H TFTs

    Science.gov (United States)

    Tang, Z.; Wie, C. R.

    2010-03-01

    In this paper, the degradation of hydrogenated amorphous silicon thin film transistors under a self-heating stress (SHS) condition is investigated by analyzing the capacitance-voltage characteristics of gate-to-drain capacitance ( Cgd) and gate-to-source capacitance ( Cgs). The very different characteristics of Cgd- V g and Cgs- V g show different stress-induced density of states (DOS) property at the drain side and source side of channel. In a long channel device, the Cgd and Cgs characteristics could be explained by the deep states profile which corresponds to the non-uniform threshold voltage profile induced by the bias temperature stress only. The capacitance-voltage and current-voltage curves, simulated using the ATLAS 2D simulator based on the non-uniform defect states profile, agreed well with the measured data. In a short channel device, the simulation fitting of the Cgd and Cgs data required a non-uniform defect states profile, which is substantially modified from the long channel profile. This was interpreted in terms of a significant contribution of the non-uniform temperature distribution, caused by stress-induced self-heating effect in the short channel device, to the defect states density profile in the channel. A decreased density of conduction band tail states at the source end, corresponding to the increased deep Gaussian states, enabled a good simulation fit in the short channel device.

  18. Anomalous degradation behaviors under illuminated gate bias stress in a-Si:H thin film transistor

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Ming-Yen [Department of Photonics, National Sun Yat-Sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Chang, Ting-Chang [Department of Physics, National Sun Yat-Sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Chu, Ann-Kuo [Department of Photonics, National Sun Yat-Sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Hsieh, Tien-Yu; Lin, Kun-Yao; Wu, Yi-Chun; Huang, Shih-Feng [Department of Physics, National Sun Yat-Sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Chiang, Cheng-Lung; Chen, Po-Lin; Lai, Tzu-Chieh; Lo, Chang-Cheng [Shenzhen China Star Optoelectronics Technology Co., Ltd, Guangdong (China); Lien, Alan [TCL Corporate Research, Guangdong (China)

    2014-12-01

    This study investigates the impact of gate bias stress with and without light illumination in a-Si:H thin film transistors. It has been observed that the I–V curve shifts toward the positive direction after negative and positive gate bias stress due to interface state creation at the gate dielectric. However, this study found that threshold voltages shift negatively and that the transconductance curve maxima are anomalously degraded under illuminated positive gate bias stress. In addition, threshold voltages shift positively under illuminated negative gate bias stress. These degradation behaviors can be ascribed to charge trapping in the passivation layer dominating degradation instability and are verified by a double gate a-Si:H device. - Highlights: • There is abnormal V{sub T} shift induced by illuminated gate bias stress in a-Si:H thin film transistors. • Electron–hole pair is generated via trap-assisted photoexcitation. • Abnormal transconductance hump is induced by the leakage current from back channel. • Charge trapping in the passivation layer is likely due to the fact that a constant voltage has been applied to the top gate.

  19. Anomalous degradation behaviors under illuminated gate bias stress in a-Si:H thin film transistor

    International Nuclear Information System (INIS)

    This study investigates the impact of gate bias stress with and without light illumination in a-Si:H thin film transistors. It has been observed that the I–V curve shifts toward the positive direction after negative and positive gate bias stress due to interface state creation at the gate dielectric. However, this study found that threshold voltages shift negatively and that the transconductance curve maxima are anomalously degraded under illuminated positive gate bias stress. In addition, threshold voltages shift positively under illuminated negative gate bias stress. These degradation behaviors can be ascribed to charge trapping in the passivation layer dominating degradation instability and are verified by a double gate a-Si:H device. - Highlights: • There is abnormal VT shift induced by illuminated gate bias stress in a-Si:H thin film transistors. • Electron–hole pair is generated via trap-assisted photoexcitation. • Abnormal transconductance hump is induced by the leakage current from back channel. • Charge trapping in the passivation layer is likely due to the fact that a constant voltage has been applied to the top gate

  20. A stabilized, high stress self-biasing shape memory alloy actuator

    Science.gov (United States)

    Panton, B.; Zhou, Y. N.; Khan, M. I.

    2016-09-01

    A shape memory alloy (SMA) actuator that is biased internally would not need an external bias to achieve multiple actuation cycles. This would reduce cost, complexity and weight compared to standard one-way SMAs. The self-biasing actuators that have been developed to date have a lack of geometric and actuation stability. The current study developed a self-biasing NiTi actuator using a laser based vaporization process to alter the bulk composition of different regions. The martensitic laser processed NiTi region was the actuator, and un-processed austenitic base metal region was the internal bias. It was discovered that the laser processed region of the self-biasing actuator was unstable during high stress thermomechanical cycling due to the coarse grained microstructure. Cold-working of the half martensitic and half austenitic component resulted in similar deformation characteristics to single phase NiTi, which enabled the formation of a uniform nanocrystalline microstructure in both regions. When thermomechanically cycled 6000 times under stresses ranging from 180 to 400 MPa, it was discovered that this treated self-biasing actuator exhibited the stabilization behavior of traditional one-way actuators. This behavior was due to the uniform nanocrystalline microstructure, which impeded dislocation activity and ensured minimal plastic deformation.

  1. When bias binds: Effect of implicit outgroup bias on ingroup affiliation.

    Science.gov (United States)

    Jacoby-Senghor, Drew S; Sinclair, Stacey; Smith, Colin Tucker

    2015-09-01

    We tested a novel process we term implicit homophily in which perceivers' implicit outgroup bias shapes their affiliative responses toward ingroup targets with outgroup friends as a function of perceived similarity. Across 4 studies, we tested implicit homophily in the context of racial groups. We found that White participants with higher implicit anti-Black bias reported less affiliative responses toward White targets with Black friends compared with White targets with White friends, and this effect persisted above and beyond the effects of implicit pro-White bias and explicit racial bias (Studies 1-3). We further found evidence that this relationship between implicit anti-Black bias and affiliation exists because participants infer how comfortable targets are around outgroup members (Preliminary Study) and use this information to infer similarity on this dimension (Studies 1-3). Our findings also suggested that stigma transference and expectancy violation were not viable alternative mediators (Preliminary Study and Study 1). Finally, women's implicit anti-Black bias predicted their likelihood of having Facebook friends with Black friends, providing ecological and behavioral evidence of implicit homophily (Study 4). Implications for research on stigma by association, extended contact, affiliation, and network formation are discussed. PMID:26280842

  2. Perceived stress and risk of ischemic heart disease: causation or bias?

    DEFF Research Database (Denmark)

    Nielsen, Naja Rod; Kristensen, Tage S; Prescott, Eva; Strandberg-Larsen, Katrine; Schnohr, Peter; Grønbaek, Morten

    2006-01-01

    BACKGROUND: It is unclear whether the commonly recognized link between stress and cardiovascular disease is causal or the result of reporting bias. The objective of this study was to address the association between perceived stress and first incidence of ischemic heart disease and to evaluate the...... suggested reporting bias by addressing subdiagnoses of ischemic heart disease separately. METHODS: The 11,839 men and women who participated in the Copenhagen City Heart Study were at baseline (1981-1983) asked about their stress level. The participants were followed in nationwide registries until the year...... 2000, and fewer than 0.1% were lost to follow-up. During follow-up, 2316 individuals were diagnosed with ischemic heart disease. RESULTS: High levels of stress were associated with slightly higher risk of incident ischemic heart disease in both women (hazard ratio = 1.23; 95% confidence interval = 1...

  3. Improvement in gate bias stress instability of amorphous indium-gallium-zinc oxide thin-film transistors using microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Kwang-Won; Cho, Won-Ju, E-mail: chowj@kw.ac.kr [Department of Electronic Materials Engineering, Kwangwoon University, 447-1, Wolgye-dong, Nowon-gu, Seoul 139-701 (Korea, Republic of)

    2014-11-24

    In this study, we evaluated the effects of microwave irradiation (MWI) post-deposition-annealing (PDA) treatment on the gate bias stress instability of amorphous indium-gallium-zinc oxide thin-film transistors (a-IGZO TFTs) and compared the results with a conventional thermal annealing PDA treatment. The MWI-PDA-treated a-IGZO TFTs exhibited enhanced electrical performance as well as improved long-term stability with increasing microwave power. The positive turn-on voltage shift (ΔV{sub ON}) as a function of stress time with positive bias and varying temperature was precisely modeled on a stretched-exponential equation, suggesting that charge trapping is a dominant mechanism in the instability of MWI-PDA-treated a-IGZO TFTs. The characteristic trapping time and average effective barrier height for electron transport indicate that the MWI-PDA treatment effectively reduces the defects in a-IGZO TFTs, resulting in a superior resistance against gate bias stress.

  4. Opportunistic biases: Their origins, effects, and an integrated solution.

    Science.gov (United States)

    DeCoster, Jamie; Sparks, Erin A; Sparks, Jordan C; Sparks, Glenn G; Sparks, Cheri W

    2015-09-01

    Researchers commonly explore their data in multiple ways before deciding which analyses they will include in the final versions of their papers. While this improves the chances of researchers finding publishable results, it introduces an "opportunistic bias," such that the reported relations are stronger or otherwise more supportive of the researcher's theories than they would be without the exploratory process. The magnitudes of opportunistic biases can often be stronger than those of the effects being investigated, leading to invalid conclusions and a lack of clarity in research results. Authors typically do not report their exploratory procedures, so opportunistic biases are very difficult to detect just by reading the final version of a research report. In this article, we explain how a number of accepted research practices can lead to opportunistic biases, discuss the prevalence of these practices in psychology, consider the different effects that opportunistic biases have on psychological science, evaluate the strategies that methodologists have proposed to prevent or correct for the effects of these biases, and introduce an integrated solution to reduce the prevalence and influence of opportunistic biases. The recent prominence of articles discussing questionable research practices both in scientific journals and in the public media underscores the importance of understanding how opportunistic biases are created and how we might undo their effects. PMID:26348333

  5. Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence

    Directory of Open Access Journals (Sweden)

    Lauren eChaby

    2013-07-01

    Full Text Available Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid stress hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g. isolation, crowding, cage tilt were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias (F1,12 = 5.000, P < 0.05, altered coping response (T1,14 = 2.216, P = 0.04, and accelerated decision making (T1,14 = 3.245, P = 0.01. Exposure to chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object (T1,14 = 2.240, P = 0.04; T1,14 = 2.419, P = 0.03, respectively. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions. Stress during adolescence also induced short-term changes in the way animals moved around a novel environment.

  6. Information Processing Bias in Post-traumatic Stress Disorder.

    Science.gov (United States)

    Weber, Darren L

    2008-01-01

    This review considers theory and evidence for abnormal information processing in post-traumatic stress disorder (PTSD). Cognitive studies have indicated sensitivity in PTSD for traumatic information, more so than general emotional information. These findings were supported by neuroimaging studies that identify increased brain activity during traumatic cognition, especially in affective networks (including the amygdala, orbitofrontal and anterior cingulate cortex). In theory, it is proposed that traumatic cognition may interfere with neutral cognition and there is evidence of abnormal neutral stimulus processing in PTSD. Firstly, PTSD patients perform poorly on a variety of neuropsychology tasks that involve attention and memory for neutral information. The evidence from event-related potentials and functional neuroimaging also indicates abnormal results in PTSD during neutral stimulus processing. The research evidence generally provides support for theories of trauma sensitivity and abnormal neutral stimulus processing in PTSD. However, there is only tentative evidence that trauma cognition concurrently interferes with neutral cognition. There is even some evidence that traumatic or novelty arousal processes can increase the capacity for attentive processing, thereby enhancing cognition for neutral stimulus information. Research on this topic has not yet fully explored the mechanisms of interaction between traumatic and neutral content in the cognitive dynamics of PTSD. PMID:19639038

  7. Stress anisotropy compensation of the sputter-deposited metal thin films by variable bias voltage

    International Nuclear Information System (INIS)

    We introduce a new technique for compensating stress anisotropy across the thickness of sputter-deposited metal films. Our technique balances the film vertical stress gradient by altering the substrate bias during sputtering and by controlling the ion flux and energy that bombards the growing film. Sputter-deposited metal films are appealing materials for microfabrication of freestanding and out-of-plane structures, especially because of their low thermal budget. These microstructures extend the design space of micro-electro-mechanical systems (MEMS)-based devices, and they overcome some of the limitations of in-plane processing. Unfortunately, most elemental metals and alloys when sputter deposited have a substantial stress gradient across their thickness that can deteriorate their mechanical properties and severely distort the shape of the fabricated freestanding microstructures. The stress gradient across the thickness of a sputtered film can be compensated (balanced) by embedding a layer in the film with the opposite stress polarity compared to that of the bulk of the film. The force exerted by the stress mismatch between this layer and the bulk of the film easily overcomes the film's vertical stress gradient. This compensating force guarantees that a released freestanding structure remains flat and does not curl upward. This virtual layer is introduced to the growing film by altering the substrate bias voltage during the sputtering process. The substrate bias voltage controls the ion flux and energy that bombards the film, and it enables tailoring the film stress parameters. This technique has enabled us to fabricate freestanding microstructures up to 500 µm long with negligible stress-related deformation. (paper)

  8. Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress

    Directory of Open Access Journals (Sweden)

    Jong Woo Jin

    2016-08-01

    Full Text Available Oxide semiconductor thin-film transistors can show anomalous behavior under bias stress. Two types of anomalies are discussed in this paper. The first is the shift in threshold voltage (VTH in a direction opposite to the applied bias stress, and highly dependent on gate dielectric material. We attribute this to charge trapping/detrapping and charge migration within the gate dielectric. We emphasize the fundamental difference between trapping/detrapping events occurring at the semiconductor/dielectric interface and those occurring at gate/dielectric interface, and show that charge migration is essential to explain the first anomaly. We model charge migration in terms of the non-instantaneous polarization density. The second type of anomaly is negative VTH shift under high positive bias stress, with logarithmic evolution in time. This can be argued as electron-donating reactions involving H2O molecules or derived species, with a reaction rate exponentially accelerated by positive gate bias and exponentially decreased by the number of reactions already occurred.

  9. The distinct effects of internalizing weight bias: An experimental study.

    Science.gov (United States)

    Pearl, Rebecca L; Puhl, Rebecca M

    2016-06-01

    Both experiencing and internalizing weight bias are associated with negative mental and physical health outcomes, but internalization may be a more potent predictor of these outcomes. The current study aimed to differentiate between causal effects of experiencing versus internalizing weight bias on emotional responses and psychological well-being. Adults with overweight/obesity (N=260) completed an online experiment in which they were randomly assigned to focus on either the experience or internalization of weight bias, and completed measures of affect, self-esteem, and body dissatisfaction. Results indicated that the Internalization condition led to more negative affect, less positive affect, and lower self-esteem than the Experience condition. The Internalization condition also led to heightened body dissatisfaction among men, but not women. These findings suggest that weight bias internalization may be a stronger predictor of poor mental and physical health than experiences alone, and carry implications for developing weight bias interventions. PMID:26927688

  10. Electrical, optical, and material characterizations of blue InGaN light emitting diodes submitted to reverse-bias stress in water vapor condition

    International Nuclear Information System (INIS)

    In this paper, we investigate degradation of InGaN/GaN light emitting diodes (LEDs) under reverse-bias operations in water vapor and dry air. To examine failure origins, electrical characterizations including current-voltage, breakdown current profiles, optical measurement, and multiple material analyses were performed. Our findings indicate that the diffusion of indium atoms in water vapor can expedite degradation. Investigation of reverse-bias stress can help provide insight into the effects of water vapor on LEDs

  11. Unified nonequilibrium dynamical theory for exchange bias and training effects

    Institute of Scientific and Technical Information of China (English)

    Zhang Kai-Cheng; Liu Bang-Gui

    2009-01-01

    We have investigated the exchange bias and training effect in the ferromagnetie/antiferromagnetic (FM/AF)heterostructures using a unified Monte Carlo dynamical approach. The magnetization of the uncompensated AF layer is still open after the first field cycling is finished. Our simulated results show obvious shift of hysteresis loops (exchange bias) and cycling dependence of exchange bias (training effect) when the temperature is below 45 K. The exchange bias field decreases with decreasing cooling rate or increasing temperature and the number of the field cycling. Essentially,these two effects can be explained on the basis of the microscopical coexistence of both reversible and irreversible moment reversals of the AF domains. Our simulations are useful to understand the real magnetization dynamics of such magnetic heterostructures.

  12. Sex-biased dispersal promotes adaptive parental effects

    OpenAIRE

    Franc Alain; Revardel Emmanuelle; Petit Rémy J

    2010-01-01

    Abstract Background In heterogeneous environments, sex-biased dispersal could lead to environmental adaptive parental effects, with offspring selected to perform in the same way as the parent dispersing least, because this parent is more likely to be locally adapted. We investigate this hypothesis by simulating varying levels of sex-biased dispersal in a patchy environment. The relative advantage of a strategy involving pure maternal (or paternal) inheritance is then compared with a strategy ...

  13. Temperature-dependent bias-stress-induced electrical instability of amorphous indium-gallium-zinc-oxide thin-film transistors

    Science.gov (United States)

    Qian, Hui-Min; Yu, Guang; Lu, Hai; Wu, Chen-Fei; Tang, Lan-Feng; Zhou, Dong; Ren, Fang-Fang; Zhang, Rong; Zheng, You-Liao; Huang, Xiao-Ming

    2015-07-01

    The time and temperature dependence of threshold voltage shift under positive-bias stress (PBS) and the following recovery process are investigated in amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. It is found that the time dependence of threshold voltage shift can be well described by a stretched exponential equation in which the time constant τ is found to be temperature dependent. Based on Arrhenius plots, an average effective energy barrier Eτstress = 0.72 eV for the PBS process and an average effective energy barrier Eτrecovery = 0.58 eV for the recovery process are extracted respectively. A charge trapping/detrapping model is used to explain the threshold voltage shift in both the PBS and the recovery process. The influence of gate bias stress on transistor performance is one of the most critical issues for practical device development. Project supported by the National Basic Research Program of China (Grant Nos. 2011CB301900 and 2011CB922100) and the Priority Academic Program Development of Jiangsu Higher Education Institutions, China

  14. Ferromagnetic behavior and exchange bias effect in akaganeite nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Tadic, Marin, E-mail: marint@vinca.rs [Condensed Matter Physics Laboratory, Vinca Institute of Nuclear Science, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Milosevic, Irena; Motte, Laurence [Laboratoire CSPBAT, UMR 7244 CNRS Université Paris 13, 93017 Bobigny Cedex (France); Kralj, Slavko [Department for Materials Synthesis, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Saboungi, Marie-Louise [CNRS, University of Orleans, F-45071 Orleans 2 (France); IMPMC, Sorbonne Univ-UPMC Univ Paris 06, UMR CNRS 7590, Museum National d' Histoire Naturelle, IRD UMR 206, 4 Place Jussieu, F-75005 Paris (France)

    2015-05-04

    We report ferromagnetic-like properties and exchange bias effect in akaganeite (β-FeOOH) nanorods. They exhibit a Néel temperature T{sub N} = 259 K and ferromagnetic-like hysteresis behavior both below and above T{sub N}. An exchange bias effect is observed below T{sub N} and represents an interesting behavior for akaganeite nanorods. These results are explained on the basis of a core-shell structure in which the core has bulk akaganeite magnetic properties (i.e., antiferromagnetic ordering) while the shell exhibits a disordered spin state. Thus, the nanorods show ferromagnetic properties and an exchange bias effect at the same time, increasing their potential for use in practical applications.

  15. Biases from omitted risk effects in standard gamble utilities.

    Science.gov (United States)

    Pope, Robin

    2004-07-01

    Utilities elicited under the "probability equivalence" version of the standard gamble procedure systematically exaggerate the utility increments of expensive health interventions that bring the recipient towards full health. Switching to the alternative "certainty equivalence" version would introduce the reverse bias. The biases arise from anticipated pre- and post-decision risk effects that expected utility theory omits. To include these risk effects, partition the future by changes in knowledge into: (1) pre-choice periods; (2) the pre-outcome future before the chosen act's outcome becomes known; and (3) the more distant post-outcome future, when that outcome will have become known. PMID:15587695

  16. Josephson effects in an alternating current biased transition edge sensor

    CERN Document Server

    Gottardi, Luciano; Akamatsu, Hiroki; van der Kuur, Jan; Bruijn, Marcel P; Hartog, Roland H den; Hijmering, Richard; Khosropanah, Pourya; Lambert, Colin; van der Linden, Anton J; Ridder, Marcel L; Suzuki, Toyo; Gao, Jan R

    2016-01-01

    We report the experimental evidence of the ac Josephson effect in a transition edge sensor (TES) operating in a frequency domain multiplexer and biased by ac voltage at MHz frequencies. The effect is observed by measuring the non-linear impedance of the sensor. The TES is treated as a weakly linked superconducting system and within the resistively shunted junction model framework. We provide a full theoretical explanation of the results by finding the analytic solution of the non-inertial Langevian equation of the system and calculating the non-linear response of the detector to a large ac bias current in the presence of noise.

  17. Empirical analyses of the factors affecting confirmation bias and the effects of confirmation bias on software developer/tester performance

    OpenAIRE

    Calikli, Gul; Bener, Ayse

    2010-01-01

    Background: During all levels of software testing, the goal should be to fail the code. However, software developers and testers are more likely to choose positive tests rather than negative ones due to the phenomenon called confirmation bias. Confirmation bias is defined as the tendency of people to verify their hypotheses rather than refuting them. In the literature, there are theories about the possible effects of confirmation bias on software development and testing. Due to the tendency t...

  18. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    The role of education in the process of socioeconomic attainment is a topic of long standing interest to sociologists and economists. Recently there has been growing interest not only in estimating the average causal effect of education on outcomes such as earnings, but also in estimating how cau...

  19. [Study on the bias axis stress-strain relationship of the human mandible].

    Science.gov (United States)

    Chen, X; Zhao, Y

    1991-06-01

    This paper presents our study on the bias axis elastic properties of the human mandible. The elastic coefficients were determined by the composite materials mechanical testing methods. From these values the "technical constants" were calculated to be: EL = 18.823GPa, ET = 12.777GPa, GLT = 5.564GPa, vLT = 0.302, vTL = 0.205. Variation of elastic constants of the human mandible with the orientation to its long axis was investigated. A brief description of the variation law is given. The bias axis stress-strain relationship of the human mandible is established. The data indicate that the human mandible is a living, anisotropic and nonhomogeneous composite biomaterial. Its mechanical properties have a close relation to its location, orientation and structure. PMID:1786953

  20. Improving positive and negative bias illumination stress stability in parylene passivated IGZO transistors

    Science.gov (United States)

    Kiazadeh, Asal; Gomes, Henrique L.; Barquinha, Pedro; Martins, Jorge; Rovisco, Ana; Pinto, Joana V.; Martins, Rodrigo; Fortunato, Elvira

    2016-08-01

    The impact of a parylene top-coating layer on the illumination and bias stress instabilities of indium-gallium-zinc oxide thin-film transistors (TFTs) is presented and discussed. The parylene coating substantially reduces the threshold voltage shift caused by continuous application of a gate bias and light exposure. The operational stability improves by 75%, and the light induced instability is reduced by 35%. The operational stability is quantified by fitting the threshold voltage shift with a stretched exponential model. Storage time as long as 7 months does not cause any measurable degradation on the electrical performance. It is proposed that parylene plays not only the role of an encapsulation layer but also of a defect passivation on the top semiconductor surface. It is also reported that depletion-mode TFTs are less sensitive to light induced instabilities. This is attributed to a defect neutralization process in the presence of free electrons.

  1. Reliability in Short-Channel p-Type Polycrystalline Silicon Thin-Film Transistor under High Gate and Drain Bias Stress

    Science.gov (United States)

    Sung-Hwan Choi,; Sun-Jae Kim,; Yeon-Gon Mo,; Hye-Dong Kim,; Min-Koo Han,

    2010-03-01

    We have investigated the electrical characteristics of short-channel p-type excimer laser annealed (ELA) polycrystalline silicon (poly-Si) thin-film transistors (TFTs) under high gate and drain bias stress. We found that the threshold voltage of short-channel TFTs was significantly shifted in the negative direction owing to high gate and drain bias stress (Δ VTH = -2.08 V), whereas that of long-channel TFTs was rarely shifted in the negative direction (Δ VTH = -0.10 V). This negative shift of threshold voltage in the short-channel TFT may be attributed to interface state generation near the source junction and deep trap state creation near the drain junction between the poly-Si film and the gate insulator layer. It was also found that the gate-to-drain capacitance (CGD) characteristic of the stressed TFT severely stretched for the gate voltage below the flat band voltage VFB. The effects of high gate and drain bias stress are related to hot-hole-induced donor like interface state generation. The transfer characteristics of the forward and reverse modes after the high gate and drain bias stress also indicate that the interface state generation at the gate insulator/channel interface occurred near the source junction region.

  2. Protopathic bias in observational studies on statin effectiveness

    OpenAIRE

    Korhonen, Maarit Jaana; Huupponen, Risto; Ruokoniemi, Päivi; Helin-Salmivaara, Arja

    2009-01-01

    Protopathic bias in observational studies on statin effectiveness phone: +350-40-3552901 (Korhonen, Maarit Jaana) (Korhonen, Maarit Jaana) Pharmacology, Drug Development and Therapeutics, University of Turku - 20014 - Turku - FINLAND (Korhonen, Maarit Jaana) School of Public Health and Clinical Nutrition, University of Kuopio - POB 1627 - 70211 - Kuopio - FINLAND (Korhonen, Maarit Jaana) Pharmacology, Drug Development and Therapeutics, University of T...

  3. Estimating heat stress from climate-based indicators: present-day biases and future spreads in the CMIP5 global climate model ensemble

    Science.gov (United States)

    Zhao, Y.; Ducharne, A.; Sultan, B.; Braconnot, P.; Vautard, R.

    2015-08-01

    The increased exposure of human populations to heat stress is one of the likely consequences of global warming, and it has detrimental effects on health and labor capacity. Here, we consider the evolution of heat stress under climate change using 21 general circulation models (GCMs). Three heat stress indicators, based on both temperature and humidity conditions, are used to investigate present-day model biases and spreads in future climate projections. Present day estimates of heat stress indicators from observational data shows that humid tropical areas tend to experience more frequent heat stress than other regions do, with a total frequency of heat stress 250-300 d yr-1. The most severe heat stress is found in the Sahel and south India. Present-day GCM simulations tend to underestimate heat stress over the tropics due to dry and cold model biases. The model based estimates are in better agreement with observation in mid to high latitudes, but this is due to compensating errors in humidity and temperature. The severity of heat stress is projected to increase by the end of the century under climate change scenario RCP8.5, reaching unprecedented levels in some regions compared with observations. An analysis of the different factors contributing to the total spread of projected heat stress shows that spread is primarily driven by the choice of GCMs rather than the choice of indicators, even when the simulated indicators are bias-corrected. This supports the utility of the multi-model ensemble approach to assess the impacts of climate change on heat stress.

  4. Investigation of the instability of low-temperature poly-silicon thin film transistors under a negative bias temperature stress

    Science.gov (United States)

    Kim, Yu-Mi; Jeong, Kwang-Seok; Yun, Ho-Jin; Yang, Seung-Dong; Lee, Sang-Youl; Lee, Hi-Deok; Lee, Ga-Won

    2013-10-01

    In this work, we analyzed and correlated the hysteresis characteristics and instability under negative bias temperature instability (NBTI) stress in p-channel low-temperature poly-silicon (LTPS) thin-film transistors (TFTs). Positive V TH shifts were observed under the NBTI stress. The hysteresis does not appear to be affected by the NBTI stress; however, when the VG stress voltage is -40 V at 100°C, the hysteresis increases as the stress time increases and V TH shifts with sub-threshold slope (SS) degradation. The hysteresis may increase under the extreme stress condition due to the generation of trap-states.

  5. Analysis of bias effects on the total ionizing dose response in a 180 nm technology

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhangli, E-mail: liuzhangli@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Hu Zhiyuan [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Zhengxuan; Shao Hua [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Chen Ming [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Bi Dawei [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Ning Bingxu [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zou Shichang [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

    2011-07-11

    The effects of gamma ray irradiation on the shallow trench isolation (STI) leakage current in a 180 nm technology are investigated. The radiation response is strongly influenced by the bias modes, gate bias during irradiation, substrate bias during irradiation and operating substrate bias after irradiation. We found that the worst case occurs under the ON bias condition for the ON, OFF and PASS bias mode. A positive gate bias during irradiation significantly enhances the STI leakage current, indicating the electric field influence on the charge buildup process during radiation. Also, a negative substrate bias during irradiation enhances the STI leakage current. However a negative operating substrate bias effectively suppresses the STI leakage current, and can be used to eliminate the leakage current produced by the charge trapped in the deep STI oxide. Appropriate substrate bias should be introduced to alleviate the total ionizing dose (TID) response, and lead to acceptable threshold voltage shift and subthreshold hump effect. Depending on the simulation results, we believe that the electric field distribution in the STI oxide is the key parameter influencing bias effects on the radiation response of transistor. - Highlights: > ON bias is the worst bias condition for the ON, PASS and OFF bias modes. > Larger gate bias during irradiation leads to more pronounced characteristic degradation. > TID induced STI leakage can be suppressed by negative operating substrate bias voltage. > Negative substrate bias during irradiation leads to larger increase of off-state leakage. > Electric field in the STI oxide greatly influences the device's radiation effect.

  6. Halo assembly bias and its effects on galaxy clustering

    CERN Document Server

    Croton, D J; White, S D M; Croton, Darren J.; Gao, Liang; White, Simon D. M.

    2006-01-01

    The clustering of dark halos depends not only on their mass but also on their assembly history, a dependence we term `assembly bias'. Using a galaxy formation model grafted onto the Millennium Simulation of the LCDM cosmogony, we study how assembly bias affects galaxy clustering. We compare the original simulation to `shuffled' versions where the galaxy populations are randomly swapped among halos of similar mass, thus isolating the effects of correlations between assembly history and environment at fixed mass. Such correlations are ignored in the halo occupation distribution models often used populate dark matter simulations with galaxies, but they are significant in our more realistic simulation. Assembly bias enhances 2-point correlations by 10% for galaxies with M_bJ-5logh brighter than -17, but suppresses them by a similar amount for galaxies brighter than -20. When such samples are split by colour, assembly bias is 5% stronger for red galaxies and 5% weaker for blue ones. Halo central galaxies are diffe...

  7. Memory effect versus exchange bias for maghemite nanoparticles

    International Nuclear Information System (INIS)

    We studied the temperature dependence of memory and exchange bias effects and their dependence on each other in maghemite (γ-Fe2O3) nanoparticles by using magnetization studies. Memory effect in zero field cooled process in nanoparticles is a fingerprint of spin-glass behavior which can be due to i) surface disordered spins (surface spin-glass) and/or ii) randomly frozen and interacting nanoparticles core spins (super spin-glass). Temperature region (25–70 K) for measurements has been chosen just below the average blocking temperature (TB=75 K) of the nanoparticles. Memory effect (ME) shows a non-monotonous behavior with temperature. It shows a decreasing trend with decreasing temperature and nearly vanishes below 30 K. However it also decreased again near the blocking temperature of the nanoparticles e.g., 70 K. Exchange bias (EB) in these nanoparticles arises due to core/shell interface interactions. The EB increases sharply below 30 K due to increase in core/shell interactions, while ME starts vanishing below 30 K. We conclude that the core/shell interface interactions or EB have not enhanced the ME but may reduce it in these nanoparticles. - Highlights: • We studied the T-dependent memory and exchange bias (EB) effects in maghemite nanoparticles. • EB causes spin-canting at the core/shell interface which may reduces the memory effect (ME). • Interface interactions does not increase the ME in these nanoparticles

  8. Memory effect versus exchange bias for maghemite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nadeem, K., E-mail: kashif.nadeem@iiu.edu.pk [Materials Research Laboratory, Department of Physics, International Islamic University, Islamabad (Pakistan); Krenn, H. [Institute of Physics, Karl-Franzens University Graz, Universitätsplatz 5, A-8010 Graz (Austria); Szabó, D.V. [Karlsruhe Institute of Technology, Institute for Applied Materials, 76344 Eggenstein-Leopoldshafen (Germany)

    2015-11-01

    We studied the temperature dependence of memory and exchange bias effects and their dependence on each other in maghemite (γ-Fe{sub 2}O{sub 3}) nanoparticles by using magnetization studies. Memory effect in zero field cooled process in nanoparticles is a fingerprint of spin-glass behavior which can be due to i) surface disordered spins (surface spin-glass) and/or ii) randomly frozen and interacting nanoparticles core spins (super spin-glass). Temperature region (25–70 K) for measurements has been chosen just below the average blocking temperature (T{sub B}=75 K) of the nanoparticles. Memory effect (ME) shows a non-monotonous behavior with temperature. It shows a decreasing trend with decreasing temperature and nearly vanishes below 30 K. However it also decreased again near the blocking temperature of the nanoparticles e.g., 70 K. Exchange bias (EB) in these nanoparticles arises due to core/shell interface interactions. The EB increases sharply below 30 K due to increase in core/shell interactions, while ME starts vanishing below 30 K. We conclude that the core/shell interface interactions or EB have not enhanced the ME but may reduce it in these nanoparticles. - Highlights: • We studied the T-dependent memory and exchange bias (EB) effects in maghemite nanoparticles. • EB causes spin-canting at the core/shell interface which may reduces the memory effect (ME). • Interface interactions does not increase the ME in these nanoparticles.

  9. Parasite-stress, cultures of honor, and the emergence of gender bias in purity norms.

    Science.gov (United States)

    Vandello, Joseph A; Hettinger, Vanessa E

    2012-04-01

    Of the many far-reaching implications of Fincher & Thornhill's (F&T's) theory, we focus on the consequences of parasite stress for mating strategies, marriage, and the differing roles and restrictions for men and women. In particular, we explain how examination of cultures of honor can provide a theoretical bridge between effects of parasite stress and disproportionate emphasis on female purity. PMID:22289148

  10. Influence of white light illumination on the performance of a-IGZO thin film transistor under positive gate-bias stress

    Science.gov (United States)

    Tang, Lan-Feng; Yu, Guang; Lu, Hai; Wu, Chen-Fei; Qian, Hui-Min; Zhou, Dong; Zhang, Rong; Zheng, You-Dou; Huang, Xiao-Ming

    2015-08-01

    The influence of white light illumination on the stability of an amorphous InGaZnO thin film transistor is investigated in this work. Under prolonged positive gate bias stress, the device illuminated by white light exhibits smaller positive threshold voltage shift than the device stressed under dark. There are simultaneous degradations of field-effect mobility for both stressed devices, which follows a similar trend to that of the threshold voltage shift. The reduced threshold voltage shift under illumination is explained by a competition between bias-induced interface carrier trapping effect and photon-induced carrier detrapping effect. It is further found that white light illumination could even excite and release trapped carriers originally exiting at the device interface before positive gate bias stress, so that the threshold voltage could recover to an even lower value than that in an equilibrium state. The effect of photo-excitation of oxygen vacancies within the a-IGZO film is also discussed. Project supported by the State Key Program for Basic Research of China (Grant Nos. 2011CB301900 and 2011CB922100) and the Priority Academic Program Development of Jiangsu Higher Education Institutions, China.

  11. Investigation of bias radiation effect on PV cell measurement

    Science.gov (United States)

    Huang, Xuebo; Quan, Chenggen; Chan, Joanne; Ng, Patrick

    2013-06-01

    Photovoltaic (PV) cells are photo-electrical devices that convert light energy directly into electricity through the photovoltaic effect. PV cell assemblies are used to make solar modules employed in a variety of ways ranging from space applications to domestic energy consumption. Characterisation and performance testing of PV cells are critical to the development of PV technologies and growth of the solar industry. As new solar products are being developed, its energy conversion efficiency and other critical parameters must be accurately measured and tested against globally recognised metrological standards. The differential spectral responsivity (DSR) measurement is one of the primary methods for calibrating reference PV cells. This is done by calculating its spectral responsivities through measuring the AC short-circuit current produced by a PV cell under a modulated monochromatic radiation and different levels of steady-state broadband bias light radiation. It is observed that different types of bias light source will produce different signal-to-noise levels and significantly influence measurement accuracy. This paper aims to investigate the noise sources caused by different types of bias light sources (e.g. xenon arc and tungsten-halogen lamps) and the relevant measurement uncertainties so as to propose a guideline for selection of bias light source which can improve the signal-to-noise level and measurement uncertainty. The DSRs of the PV cells are measured using a commercial DSR measurement system under different levels of bias radiation from 0 to 1 kWm-2. The data analysis and uncertainty evaluation are presented in this paper using experimental data and mathematical tools.

  12. Abnormal behavior of threshold voltage shift in bias-stressed a-Si:H thin film transistor under extremely high intensity illumination.

    Science.gov (United States)

    Han, Sang Youn; Park, Kyung Tea; Kim, Cheolkyu; Jeon, Sanghyun; Yang, Sung-Hoon; Kong, Hyang-Shik

    2015-07-22

    We report on the unusual behavior of threshold voltage turnaround in a hydrogenated amorphous silicon (a-Si:H) thin film transistor (TFT) when biased under extremely high intensity illumination. The threshold voltage shift changes from negative to positive gate bias direction after ∼30 min of bias stress even when the negative gate bias stress is applied under high intensity illumination (>400 000 Cd/cm(2)), which has not been observed in low intensity (∼6000 Cd/cm(2)). This behavior is more pronounced in a low work function gate metal structure (Al: 4.1-4.3 eV), compared to the high work function of Cu (4.5-5.1 eV). Also this is mainly observed in shorter wavelength of high photon energy illumination. However, this behavior is effectively prohibited by embedding the high energy band gap (∼8.6 eV) of SiOx in the gate insulator layer. These imply that this behavior could be originated from the injection of electrons from gate electrode, transported and trapped in the electron trap sites of the SiNx/a-Si:H interface, which causes the shift of threshold voltage toward positive gate bias direction. The results reported here can be applicable to the large-sized outdoor displays which are usually exposed to the extremely high intensity illumination. PMID:26132513

  13. Analysis of stability improvement in ZnO thin film transistor with dual-gate structure under negative bias stress

    Science.gov (United States)

    Yun, Ho-Jin; Kim, Young-Su; Jeong, Kwang-Seok; Kim, Yu-Mi; Yang, Seung-dong; Lee, Hi-Deok; Lee, Ga-Won

    2014-01-01

    In this study, we fabricated dual-gate zinc oxide thin film transistors (ZnO TFTs) without additional processes and analyzed their stability characteristics under a negative gate bias stress (NBS) by comparison with conventional bottom-gate structures. The dual-gate device shows superior electrical parameters, such as subthreshold swing (SS) and on/off current ratio. NBS of VGS = -20 V with VDS = 0 was applied, resulting in a negative threshold voltage (Vth) shift. After applying stress for 1000 s, the Vth shift is 0.60 V in a dual-gate ZnO TFT, while the Vth shift is 2.52 V in a bottom-gate ZnO TFT. The stress immunity of the dual-gate device is caused by the change in field distribution in the ZnO channel by adding another gate as the technology computer aided design (TCAD) simulation shows. Additionally, in flicker noise analysis, a lower noise level with a different mechanism is observed in the dual-gate structure. This can be explained by the top side of the ZnO film having a larger crystal and fewer grain boundaries than the bottom side, which is revealed by the enhanced SS and XRD results. Therefore, the improved stability of the dual-gate ZnO TFT is greatly related to the E-field cancellation effect and crystal quality of the ZnO film.

  14. Correcting for bias in estimation of quantitative trait loci effects

    Directory of Open Access Journals (Sweden)

    Ron Micha

    2005-09-01

    Full Text Available Abstract Estimates of quantitative trait loci (QTL effects derived from complete genome scans are biased, if no assumptions are made about the distribution of QTL effects. Bias should be reduced if estimates are derived by maximum likelihood, with the QTL effects sampled from a known distribution. The parameters of the distributions of QTL effects for nine economic traits in dairy cattle were estimated from a daughter design analysis of the Israeli Holstein population including 490 marker-by-sire contrasts. A separate gamma distribution was derived for each trait. Estimates for both the α and β parameters and their SE decreased as a function of heritability. The maximum likelihood estimates derived for the individual QTL effects using the gamma distributions for each trait were regressed relative to the least squares estimates, but the regression factor decreased as a function of the least squares estimate. On simulated data, the mean of least squares estimates for effects with nominal 1% significance was more than twice the simulated values, while the mean of the maximum likelihood estimates was slightly lower than the mean of the simulated values. The coefficient of determination for the maximum likelihood estimates was five-fold the corresponding value for the least squares estimates.

  15. Effects of Pacific Intertropical Convergence Zone precipitation bias on ENSO phase transition

    International Nuclear Information System (INIS)

    In this study, the effect of mean precipitation bias over the Pacific Intertropical Convergence Zone (ITCZ) on the El Niño southern oscillation (ENSO) transition is examined using CMIP3 and CMIP5 archives. It is found that the climate models with excessive mean precipitation over the central/eastern Pacific ITCZ tend to simulate slower phase transition of the ENSO. This is because a wetter climatology provides a favorable condition for anomalously strong convective activity; the El Niño-related convection anomaly tends to be increased over the central/eastern Pacific ITCZ with a local wet bias. This induces additional low-level westerlies over the central/eastern equatorial Pacific. As a result, the ENSO-related zonal wind stress anomaly over the central Pacific, which is south of the equator without the wet ITCZ bias during boreal winter, is shifted to the east, and its meridional width is expanded northward. It is found that both the eastward shift and northward expansion of ENSO-related wind stress can lead to slower ENSO phase transition as it takes longer time for the reflected Rossby waves to suppress the ENSO growth. This implies that the off-equatorial mean precipitation plays an important role in ENSO phase transition

  16. Effect of bias voltage on microstructure and mechanical properties of arc evaporated (Ti, Al)N hard coatings

    Indian Academy of Sciences (India)

    F Aliaj; N Syla; S Avdiaj; T Dilo

    2013-06-01

    In the present study, authors report on the effect that substrate bias voltage has on the microstructure and mechanical properties of (Ti, Al)N hard coatings deposited with cathodic arc evaporation (CAE) technique. The coatings were deposited from a Ti0.5Al0.5 powder metallurgical target in a reactive nitrogen atmosphere at three different bias voltages: UB = −25, −50 and −100 V. The coatings were characterized in terms of compositional, microstructural and mechanical properties. Microstructure of the coatings was investigated with the aid of X-ray diffraction in glancing angle mode, which revealed information on phase composition, crystallite size, stress-free lattice parameter and residual stress. Mechanical properties were deduced from nano-indentation measurements. The residual stress in all the coatings was compressive and increased with increasing bias voltage in a manner similar to that reported in literature for Ti–Al–N coatings deposited with CAE. The bias voltage was also found to significantly influence the phase composition and crystallite size. At −25 V bias voltage the coating was found in single phase fcc-(Ti, Al)N and with relatively large crystallites of ∼9 nm. At higher bias voltages (−50 and −100 V), the coatings were found in dual phase fcc-(Ti, Al)N and fcc-AlN and the size of crystallites reduced to approximately 5 nm. The reduction of crystallite size and the increase of compressive residual stress with increasing bias voltage both contributed to an increase in hardness of the coatings.

  17. Operational stability of solution based zinc tin oxide/SiO2 thin film transistors under gate bias stress

    Directory of Open Access Journals (Sweden)

    Asal Kiazadeh

    2015-06-01

    Full Text Available In this study, we report solution-processed amorphous zinc tin oxide transistors exhibiting high operational stability under positive gate bias stress, translated by a recoverable threshold voltage shift of about 20% of total applied stress voltage. Under vacuum condition, the threshold voltage shift saturates showing that the gate-bias stress is limited by trap exhaustion or balance between trap filling and emptying mechanism. In ambient atmosphere, the threshold voltage shift no longer saturates, stability is degraded and the recovering process is impeded. We suggest that the trapping time during the stress and detrapping time in recovering are affected by oxygen adsorption/desorption processes. The time constants extracted from stretched exponential fitting curves are ≈106 s and 105 s in vacuum and air, respectively.

  18. Genetic Diversity through the Looking Glass: Effect of Enrichment Bias

    OpenAIRE

    Dunbar, J.; White, S.; Forney, L

    1997-01-01

    The effect of enrichment bias on the diversity of 2,4-dichlorophenoxyacetate (2,4-D)-degrading (2,4-D(sup+)) bacteria recovered from soil was evaluated by comparing the diversity of isolates obtained by direct plating to the diversity of isolates obtained from 85 liquid batch cultures. By the two methods, a total of 159 isolates were purified from 1 g of soil and divided into populations based on repeated extragenic palindromic sequence PCR (rep-PCR) genomic fingerprints. Approximately 42% of...

  19. Investigations of mobile ion transport processes in thin layers upon bias-temperature stress

    International Nuclear Information System (INIS)

    Mobile ions can alter the properties of a MOSFET device e.g. by contamination of the gate oxide. Mobile sodium ions (Na+) are thereby a particular danger, since encountered in comparable large amounts. In order to investigate mobile ion incorporation from an external source into an underlying thin insulating or conductive material film and the subsequent transport therein, a developed methodology is presented. This comprises a stressing procedure by applying a bias voltage, while keeping the investigated sample at a constant temperature (B-T stress) and a final physical analysis by time of flight - secondary ion mass spectrometry (ToF-SIMS). But the determination of mobile ion distributions in insulating samples by means of ToF-SIMS depth profiling has always been a challenge. Such depth profiles exhibit severe artifacts in the mobile ion depth distribution, due to the appearance of an electric field within the insulator, arising by means of sample charging during the sputter process. This problem is addressed by investigation of the temperature dependence of Na migration. Including this feature, insulating and conductive films of high importance for the semiconductor devices are investigated: silicon dioxide (SiO2), silicon oxynitride (SiOxNy), silicon nitride (Si3N4), boron-phosphosilicat glass (BPSG) and an aluminum silicon-copper alloy. In particular SiO2 is examined in detail, both qualitatively and quantitatively: For the example of Na+, a comparison is given between the calculated provided amount in the host matrix with potentiostatic data from B-T stress and spectrometric data from quantification of ToF-SIMS depth profiles. Appropriate physico-chemical models are adapted on the present samples and thus parameters describing mobile ion transport in SiO2 are condensed out of potentiostatic data (activation energy, incorporation rate and diffusion constant). (author)

  20. The effect of academic stress and attachment stress on stress-eaters and stress-undereaters.

    Science.gov (United States)

    Emond, Michael; Ten Eycke, Kayla; Kosmerly, Stacey; Robinson, Adele Lafrance; Stillar, Amanda; Van Blyderveen, Sherry

    2016-05-01

    It is well established that stress is related to changes in eating patterns. Some individuals are more likely to increase their overall food intake under conditions of stress, whereas others are more likely to consume less food when stressed. Attachment style has been linked to disordered eating and eating disorders; however, comparisons of eating behaviors under attachment versus other types of stress have yet to be explored. The present laboratory study examined the eating patterns in self-identified stress-undereaters and stress-eaters under various types of stress. More specifically, the study examined the effects of academic and attachment stress on calorie, carbohydrate and sugar consumption within these two groups. Under the guise of critiquing student films, university students viewed either one of two stress-inducing videos (academic stress or attachment stress, both designed to be emotionally arousing) or a control video (designed to be emotionally neutral), and their food intake was recorded. Results demonstrated that the video manipulations were effective in inducing stress. Differential patterns of eating were noted based on group and stress condition. Specifically, stress-undereaters ate fewer calories, carbohydrates and sugars than stress-eaters in the academic stress condition, but not in the attachment stress or control condition. Findings suggest that specific types of stressors may influence eating behaviors differently. PMID:26850311

  1. Flat-roof phenomenon of dynamic equilibrium phase in the negative bias temperature instability effect on a power MOSFET

    International Nuclear Information System (INIS)

    The effect of the static negative bias temperature (NBT) stress on a p-channel power metal—oxide—semiconductor field-effect transistor (MOSFET) is investigated by experiment and simulation. The time evolution of the negative bias temperature instability (NBTI) degradation has the trend predicted by the reaction—diffusion (R—D) model but with an exaggerated time scale. The phenomena of the flat-roof section are observed under various stress conditions, which can be considered as the dynamic equilibrium phase in the R—D process. Based on the simulated results, the variation of the flat-roof section with the stress condition can be explained. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  2. Investigation of negative bias temperature instability dependence on fin width of silicon-on-insulator-fin-based field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Young, Chadwin D., E-mail: chadwin.young@utdallas.edu; Wang, Zhe [Materials Science and Engineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080 (United States); Neugroschel, Arnost [Department of Electrical and Computer Enginering, University of Florida, Gainesville, Florida 32611 (United States); Majumdar, Kausik; Matthews, Ken; Hobbs, Chris [SEMATECH, Albany, New York 12203 (United States)

    2015-01-21

    The fin width dependence of negative bias temperature instability (NBTI) of double-gate, fin-based p-type Field Effect Transistors (FinFETs) fabricated on silicon-on-insulator (SOI) wafers was investigated. The NBTI degradation increased as the fin width narrowed. To investigate this phenomenon, simulations of pre-stress conditions were employed to determine any differences in gate oxide field, fin band bending, and electric field profile as a function of the fin width. The simulation results were similar at a given gate stress bias, regardless of the fin width, although the threshold voltage was found to increase with decreasing fin width. Thus, the NBTI fin width dependence could not be explained from the pre-stress conditions. Different physics-based degradation models were evaluated using specific fin-based device structures with different biasing schemes to ascertain an appropriate model that best explains the measured NBTI dependence. A plausible cause is an accumulation of electrons that tunnel from the gate during stress into the floating SOI fin body. As the fin narrows, the sidewall device channel moves in closer proximity to the stored electrons, thereby inducing more band bending at the fin/dielectric interface, resulting in a higher electric field and hole concentration in this region during stress, which leads to more degradation. The data obtained in this work provide direct experimental proof of the effect of electron accumulation on the threshold voltage stability in FinFETs.

  3. Electrochemical migration in electronics: effect of contamination and bias conditions

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    – all together influence susceptibility of electronic PCBA to corrosion. When electronics is operating under humid conditions, the cleanliness of the PCBA becomes essential, since corrosion related failures in electronics can occur at extremely low levels of moisture and contamination. A synergetic...... climate, contamination, and bias conditions. In this work, the effect of ionic contamination such as sodium chloride and weak organic acids, as they are used in no-clean fluxes, was studied under water droplet and humidity elevation at room temperature conditions. The effect of pH and tin ion dissolution...... droplet. Overall the tendency of increase in time to electrochemical migration with decrease of duty cycle was observed. The testing of the printed circuit boards under humid conditions showed a correlation between the hygroscopic property of contaminants and leakage current measured on the boards...

  4. No effects of psychosocial stress on intertemporal choice.

    Directory of Open Access Journals (Sweden)

    Johannes Haushofer

    Full Text Available Intertemporal choices - involving decisions which trade off instant and delayed outcomes - are often made under stress. It remains unknown, however, whether and how stress affects intertemporal choice. We subjected 142 healthy male subjects to a laboratory stress or control protocol, and asked them to make a series of intertemporal choices either directly after stress, or 20 minutes later (resulting in four experimental groups. Based on theory and evidence from behavioral economics and cellular neuroscience, we predicted a bidirectional effect of stress on intertemporal choice, with increases in impatience or present bias immediately after stress, but decreases in present bias or impatience when subjects are tested 20 minutes later. However, our results show no effects of stress on intertemporal choice at either time point, and individual differences in stress reactivity (changes in stress hormone levels over time are not related to individual differences in intertemporal choice. Together, we did not find support for the hypothesis that psychosocial laboratory stressors affect intertemporal choice.

  5. Enhanced effects of combined cognitive bias modification and computerised cognitive behaviour therapy on social anxiety

    OpenAIRE

    Emma Butler; Sirous Mobini; Rapee, Ronald M; Bundy Mackintosh; Reynolds, Shirley A.

    2015-01-01

    This study examines whether combined cognitive bias modification for interpretative biases (CBM-I) and computerised cognitive behaviour therapy (C-CBT) can produce enhanced positive effects on interpretation biases and social anxiety. Forty socially anxious students were randomly assigned into two conditions, an intervention group (positive CBM-I + C-CBT) or an active control (neutral CBM-I + C-CBT). At pre-test, participants completed measures of social anxiety, interpretative bias, cognitiv...

  6. Improvement in reliability of amorphous indium-gallium-zinc oxide thin-film transistors with Teflon/SiO2 bilayer passivation under gate bias stress

    Science.gov (United States)

    Fan, Ching-Lin; Tseng, Fan-Ping; Li, Bo-Jyun; Lin, Yu-Zuo; Wang, Shea-Jue; Lee, Win-Der; Huang, Bohr-Ran

    2016-02-01

    The reliability of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) with Teflon/SiO2 bilayer passivation prepared under positive and negative gate bias stresses (PGBS and NGBS, respectively) was investigated. Heavier electrical degradation was observed under PGBS than under NGBS, indicating that the environmental effects under PGBS are more evident than those under NGBS. The device with bilayer passivation under PGBS shows two-step degradation. The positive threshold voltage shifts during the initial stressing period (before 500 s), owing to the charges trapped in the gate insulator or at the gate insulator/a-IGZO active layer interface. The negative threshold voltage shift accompanies the increase in subthreshold swing (SS) for the continuous stressing period (after 500 s) owing to H2O molecules from ambience diffused within the a-IGZO TFTs. It is believed that Teflon/SiO2 bilayer passivation can effectively improve the reliability of the a-IGZO TFTs without passivation even though the devices are stressed under gate bias.

  7. Plasma acceleration using a radio frequency self-bias effect

    International Nuclear Information System (INIS)

    In this work plasma acceleration using a RF self-bias effect is experimentally studied. The experiments are conducted using a novel plasma accelerator system, called Neptune, consisting of an inductively coupled plasma source and a RF-biased set of grids. The plasma accelerator can operate in a steady state mode, producing a plasma flow with separately controlled plasma flux and velocity without any magnetic configuration. The operating pressure at the source output is as low as 0.2 mTorr and can further be decreased. The ion and electron flows are investigated by measuring the ion and electron energy distribution functions both space resolved and with different orientations with respect to the flow direction. It is found that the flow of electrons from the source is highly anisotropic and directed along the ion flow and this global flow of accelerated plasma is well localized in the plasma transport chamber. The maximum flux is about 7.5·1015 ions s−1 m−2 (at standard conditions) on the axis and decreasing to almost zero at a radial distances of more than 15 cm from the flow axis. Varying the RF acceleration voltage in the range 20–350 V, the plasma flow velocity can be changed between 10 and 35 km/s. The system is prospective for different technology such as space propulsion and surface modification and also interesting for fundamental studies for space-related plasma simulations and investigation of the dynamo effect using accelerated rotating plasmas

  8. Plasma acceleration using a radio frequency self-bias effect

    Energy Technology Data Exchange (ETDEWEB)

    Rafalskyi, D.; Aanesland, A. [Laboratoire de Physique des Plasmas (CNRS, Ecole Polytechnique, Sorbonne Universités, UPMC Univ Paris 06, Univ Paris-Sud), Ecole Polytechnique, 91128 Palaiseau (France)

    2015-06-15

    In this work plasma acceleration using a RF self-bias effect is experimentally studied. The experiments are conducted using a novel plasma accelerator system, called Neptune, consisting of an inductively coupled plasma source and a RF-biased set of grids. The plasma accelerator can operate in a steady state mode, producing a plasma flow with separately controlled plasma flux and velocity without any magnetic configuration. The operating pressure at the source output is as low as 0.2 mTorr and can further be decreased. The ion and electron flows are investigated by measuring the ion and electron energy distribution functions both space resolved and with different orientations with respect to the flow direction. It is found that the flow of electrons from the source is highly anisotropic and directed along the ion flow and this global flow of accelerated plasma is well localized in the plasma transport chamber. The maximum flux is about 7.5·10{sup 15} ions s{sup −1} m{sup −2} (at standard conditions) on the axis and decreasing to almost zero at a radial distances of more than 15 cm from the flow axis. Varying the RF acceleration voltage in the range 20–350 V, the plasma flow velocity can be changed between 10 and 35 km/s. The system is prospective for different technology such as space propulsion and surface modification and also interesting for fundamental studies for space-related plasma simulations and investigation of the dynamo effect using accelerated rotating plasmas.

  9. Reliability tests of electroless barriers against copper diffusion under bias-temperature stress with n- and p-type substrates

    Science.gov (United States)

    Ueno, Kazuyoshi; Fujishima, Shota; Yamashita, Makoto; Mitsumori, Akiyoshi

    2016-05-01

    To investigate the similarity and difference of substrate conduction type in the time-dependent dielectric breakdown (TDDB) tests for the barrier integrity against Cu diffusion under bias-temperature stress (BTS), the TDDB reliability of electroless NiB and CoWP/NiB was determined by metal oxide semiconductor (MOS) structures on n-type Si (n-Si) substrates, and the test results were compared with those using p-type Si (p-Si) substrates. The TDDB results and mechanism were observed to be qualitatively the same as Cu diffusion for both conduction types. However, the TDDB lifetime using p-Si was found to be potentially shorter because of the reverse bias conditions than that using n-Si under the forward bias conditions.

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

    International Nuclear Information System (INIS)

    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 LD ∼ Ln ∼ 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

  11. 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.

  12. Ironic effects of racial bias during interracial interactions.

    Science.gov (United States)

    Shelton, J Nicole; Richeson, Jennifer A; Salvatore, Jessica; Trawalter, Sophie

    2005-05-01

    Previous research has suggested that Blacks like White interaction partners who make an effort to appear unbiased more than those who do not. We tested the hypothesis that, ironically, Blacks perceive White interaction partners who are more racially biased more positively than less biased White partners, primarily because the former group must make more of an effort to control racial bias than the latter. White participants in this study completed the Implicit Association Test (IAT) as a measure of racial bias and then discussed race relations with either a White or a Black partner. Whites' IAT scores predicted how positively they were perceived by Black (but not White) interaction partners, and this relationship was mediated by Blacks' perceptions of how engaged the White participants were during the interaction. We discuss implications of the finding that Blacks may, ironically, prefer to interact with highly racially biased Whites, at least in short interactions. PMID:15869700

  13. Analysis of bias effects on the total ionizing dose response in a 180 nm technology

    Science.gov (United States)

    Liu, Zhangli; Hu, Zhiyuan; Zhang, Zhengxuan; Shao, Hua; Chen, Ming; Bi, Dawei; Ning, Bingxu; Zou, Shichang

    2011-07-01

    The effects of gamma ray irradiation on the shallow trench isolation (STI) leakage current in a 180 nm technology are investigated. The radiation response is strongly influenced by the bias modes, gate bias during irradiation, substrate bias during irradiation and operating substrate bias after irradiation. We found that the worst case occurs under the ON bias condition for the ON, OFF and PASS bias mode. A positive gate bias during irradiation significantly enhances the STI leakage current, indicating the electric field influence on the charge buildup process during radiation. Also, a negative substrate bias during irradiation enhances the STI leakage current. However a negative operating substrate bias effectively suppresses the STI leakage current, and can be used to eliminate the leakage current produced by the charge trapped in the deep STI oxide. Appropriate substrate bias should be introduced to alleviate the total ionizing dose (TID) response, and lead to acceptable threshold voltage shift and subthreshold hump effect. Depending on the simulation results, we believe that the electric field distribution in the STI oxide is the key parameter influencing bias effects on the radiation response of transistor.

  14. Posttraumatic stress and attentional bias towards cancer-related stimuli in parents of children recently diagnosed with cancer

    OpenAIRE

    Cernvall, Martin; Hovén, Emma; Ljungman, Lisa; Ljungman, Gustaf; Carlbring, Per; von Essen, Louise

    2016-01-01

    Objectives: To investigate whether posttraumatic stress symptoms (PTSS) are related to attentional bias towards cancer-related stimuli among parents of children recently diagnosed with cancer. Methods: Sixty-two parents completed questionnaires measuring PTSS, depression, and anxiety and the emotional Stroop task via the Internet. The emotional Stroop task included cancer-related words, cardiovascular disease-related words, and neutral words. Results: Participants were split in two groups bas...

  15. Bias in parametric estimation: Reduction and useful side-effects

    OpenAIRE

    Kosmidis, I.

    2014-01-01

    The bias of an estimator is defined as the difference of its expected value from the parameter to be estimated, where the expectation is with respect to the model. Loosely speaking, small bias reflects the desire that if an experiment is repeated indefinitely then the average of all the resultant estimates will be close to the parameter value that is estimated. The current article is a review of the still-expanding repository of methods that have been developed to reduce bias in the estimatio...

  16. Training effect of exchange biased iron - oxide/ferromagnet systems

    International Nuclear Information System (INIS)

    Substantial training effect in hysteresis loops was observed in ferromagnet (F) - antiferromagnet (AF) exchange coupled systems of the structure, Si(100)/iron - oxide(tAF)/F layer (5 nm)/Ta(10 nm), prepared by magnetron sputtering. The exchange bias field and the coercivity decrease with increasing number of loop cycles. The initially asymmetric hysteresis loop becomes more symmetric as the number of loop cycles increases. The effect is more prominent in the descending curve starting from the saturation in the positive (parallel to the pinned direction) direction than in the ascending curve of the hysteresis loop. The value of the ascending curve switching field vert-barHsw+vert-bar is rather unchanged while the switching field vert-barHsw-vert-bar in the descending curve decreases drastically with repeated hysteresis loop cycling as was observed in some CoO/Co and NiO/NiFe systems. Those phenomena can be interpreted by a modification of the extended model of Fulcomer and Charap's: the essential modification being the introduction of positive and negative exchange coupling between AF grains. [copyright] 2001 American Institute of Physics

  17. Fluid simulation of the bias effect in inductive/capacitive discharges

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu-Ru [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, Wilrijk, BE-2610 Antwerp (Belgium); Gao, Fei; Li, Xue-Chun; Wang, You-Nian, E-mail: ynwang@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bogaerts, Annemie [Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, Wilrijk, BE-2610 Antwerp (Belgium)

    2015-11-15

    Computer simulations are performed for an argon inductively coupled plasma (ICP) with a capacitive radio-frequency bias power, to investigate the bias effect on the discharge mode transition and on the plasma characteristics at various ICP currents, bias voltages, and bias frequencies. When the bias frequency is fixed at 13.56 MHz and the ICP current is low, e.g., 6 A, the spatiotemporal averaged plasma density increases monotonically with bias voltage, and the bias effect is already prominent at a bias voltage of 90 V. The maximum of the ionization rate moves toward the bottom electrode, which indicates clearly the discharge mode transition in inductive/capacitive discharges. At higher ICP currents, i.e., 11 and 13 A, the plasma density decreases first and then increases with bias voltage, due to the competing mechanisms between the ion acceleration power dissipation and the capacitive power deposition. At 11 A, the bias effect is still important, but it is noticeable only at higher bias voltages. At 13 A, the ionization rate is characterized by a maximum at the reactor center near the dielectric window at all selected bias voltages, which indicates that the ICP power, instead of the bias power, plays a dominant role under this condition, and no mode transition is observed. Indeed, the ratio of the bias power to the total power is lower than 0.4 over a wide range of bias voltages, i.e., 0–300 V. Besides the effect of ICP current, also the effect of various bias frequencies is investigated. It is found that the modulation of the bias power to the spatiotemporal distributions of the ionization rate at 2 MHz is strikingly different from the behavior observed at higher bias frequencies. Furthermore, the minimum of the plasma density appears at different bias voltages, i.e., 120 V at 2 MHz and 90 V at 27.12 MHz.

  18. Fluid simulation of the bias effect in inductive/capacitive discharges

    International Nuclear Information System (INIS)

    Computer simulations are performed for an argon inductively coupled plasma (ICP) with a capacitive radio-frequency bias power, to investigate the bias effect on the discharge mode transition and on the plasma characteristics at various ICP currents, bias voltages, and bias frequencies. When the bias frequency is fixed at 13.56 MHz and the ICP current is low, e.g., 6 A, the spatiotemporal averaged plasma density increases monotonically with bias voltage, and the bias effect is already prominent at a bias voltage of 90 V. The maximum of the ionization rate moves toward the bottom electrode, which indicates clearly the discharge mode transition in inductive/capacitive discharges. At higher ICP currents, i.e., 11 and 13 A, the plasma density decreases first and then increases with bias voltage, due to the competing mechanisms between the ion acceleration power dissipation and the capacitive power deposition. At 11 A, the bias effect is still important, but it is noticeable only at higher bias voltages. At 13 A, the ionization rate is characterized by a maximum at the reactor center near the dielectric window at all selected bias voltages, which indicates that the ICP power, instead of the bias power, plays a dominant role under this condition, and no mode transition is observed. Indeed, the ratio of the bias power to the total power is lower than 0.4 over a wide range of bias voltages, i.e., 0–300 V. Besides the effect of ICP current, also the effect of various bias frequencies is investigated. It is found that the modulation of the bias power to the spatiotemporal distributions of the ionization rate at 2 MHz is strikingly different from the behavior observed at higher bias frequencies. Furthermore, the minimum of the plasma density appears at different bias voltages, i.e., 120 V at 2 MHz and 90 V at 27.12 MHz

  19. The Effect of Age-Based Categorization on Memory Bias

    Czech Academy of Sciences Publication Activity Database

    Kouřilová, Sylvie; Freund, A.M.

    2008, s. 21-21. [Transfer of Knowledge Conference. Volterra (IT), 03.09.2008-07.09.2008] Institutional research plan: CEZ:AV0Z70250504 Keywords : social categorization * memory bias * age * intergroup perception Subject RIV: AN - Psychology

  20. Isotopic bias effects in resonance ionization mass spectrometry

    International Nuclear Information System (INIS)

    Resonance ionization mass spectrometry (RIMS) is developing into a useful method for isotope ratio measurements with high selectivity and sensitivity of the technique for a large number of elements. The sensitivity of the technique relies on a number of experimental factors. Of primary importance is the proper coupling of the tunable laser output with the atomization source, which is most often a thermal filament. Use of pulsed thermal atomization can also improve efficiency. An increase in temporal efficiency can be achieved by using a continuous wave (CW) laser coupled to a continuous atomization source. CW lasers, in general, therefore must be tightly focused to saturate the ionization step in a resonance ionization process. However, this results in a lowered efficiency due to geometrical factors. The accuracy of isotope ratio measurements is also influenced by the choice of laser system for RIMS. The combination of isotope shifts and the analyte element with the spectral output of the laser will result in wavelength-dependant bias effects which must be controlled to obtain optimum analytical results. This problem has been studied and the results for both pulsed and CW lasers are given. (author)

  1. Sustainability of teacher expectation bias effects on long-term student performance

    NARCIS (Netherlands)

    de Boer, Hester; Bosker, R.J.; Van der Werf, M.P.C.

    2010-01-01

    In this article, we address the relationship between teacher expectation bias and student characteristics, its effect on long-term student performance, and the development of this effect over time. Expectation bias was defined as the difference between observed and predicted teacher expectation. The

  2. Environmental stresses can alleviate the average deleterious effect of mutations

    Directory of Open Access Journals (Sweden)

    Leibler Stanislas

    2003-05-01

    Full Text Available Abstract Background Fundamental questions in evolutionary genetics, including the possible advantage of sexual reproduction, depend critically on the effects of deleterious mutations on fitness. Limited existing experimental evidence suggests that, on average, such effects tend to be aggravated under environmental stresses, consistent with the perception that stress diminishes the organism's ability to tolerate deleterious mutations. Here, we ask whether there are also stresses with the opposite influence, under which the organism becomes more tolerant to mutations. Results We developed a technique, based on bioluminescence, which allows accurate automated measurements of bacterial growth rates at very low cell densities. Using this system, we measured growth rates of Escherichia coli mutants under a diverse set of environmental stresses. In contrast to the perception that stress always reduces the organism's ability to tolerate mutations, our measurements identified stresses that do the opposite – that is, despite decreasing wild-type growth, they alleviate, on average, the effect of deleterious mutations. Conclusions Our results show a qualitative difference between various environmental stresses ranging from alleviation to aggravation of the average effect of mutations. We further show how the existence of stresses that are biased towards alleviation of the effects of mutations may imply the existence of average epistatic interactions between mutations. The results thus offer a connection between the two main factors controlling the effects of deleterious mutations: environmental conditions and epistatic interactions.

  3. Investigating the effect of externalizing perspectives on cognitives biases

    DEFF Research Database (Denmark)

    Madsen, Fredrik Huitfeldt; Hicks, David L., David

    2007-01-01

    intelligence analysis. We propose that complexity of maintaining multiple different perspectives the same data is one of the reasons for this. We further propose that a tool that facillitates the externalization multiple perspectives would reduce these biases and hence increase the overall quality of...... the number of attacks that “get through”. There are many subproblems of this main problem, one of which is that relative quality of the intelligence analysis is too low [39, We observe that the analysts suffer from cognitive biases, and we assume that this is one of the reasons behind “low” quality of...... intelligence analyses....

  4. Preliminary analysis of the effects of confirmation bias on software defect density

    OpenAIRE

    Calikli, Gul; Bener, Ayse

    2010-01-01

    In cognitive psychology, confirmation bias is defined as the tendency of people to verify hypotheses rather than refuting them. During unit testing software developers should aim to fail their code. However, due to confirmation bias, most defects might be overlooked leading to an increase in software defect density. In this research, we empirically analyze the effect of confirmation bias of software developers on software defect density.

  5. Negative Interpretation Bias Mediates the Effect of Social Anxiety on State Anxiety

    OpenAIRE

    Beard, Courtney; Amir, Nader

    2010-01-01

    Cognitive models of social anxiety predict that interpretation bias mediates the relationship between level of social anxiety and state anxiety in response to social-evaluative threat. We tested this prediction in 67 socially anxious undergraduates. Participants completed self-report measures of social anxiety and interpretation bias, and two days later they completed an impromptu speech. Mediational analyses supported the hypothesis that interpretation bias mediates the effect of social anxi...

  6. Effects of constant voltage and constant current stress in PCBM:P3HT solar cells

    DEFF Research Database (Denmark)

    Cester, Andrea; Rizzo, Aldo; Bazzega, A.; Lago, N.; Favaro, J.; Barbato, M.; Wrachien, N.; Gevorgyan, Suren A.; Corazza, Michael; Krebs, Frederik C

    2015-01-01

    The aimof this work is the investigation of forward and reverse bias stress effects, cell self-heating and annealing in roll coated organic solar cells with PCBM:P3HT active layer. In reverse bias stress cells show a constant degradation over time. In forward current stress cells alternate...... degradation and annealing phases, which are explained through the high power dissipation during the current stress, and the consequent self-heating. The high temperature is able to recover the cell performances at least until a critical temperature is reached. The degradation can be explained by the following...

  7. Effect of frequency of dynamic bias to total dose effect of X-rays

    International Nuclear Information System (INIS)

    Bias voltage applied to MOSFET during irradiation has a major impact on the device response because charge yield, transport, and trapping in oxide are all bias dependent. NMOSFET and PMOSFET under different frequency of dynamic bias were irradiated by 10 keV X-rays to study the total dose effect. The shifts of threshold voltage of the MOSFETs before and after irradiation and effects of the radiation-induced charge on the threshold voltage of MOSFETs are analyzed in this paper. The results showed that the higher the frequency of pulse signal is, the less threshold shift and concentration of the radiation-induced charge were observed at the same pulsed voltage. (authors)

  8. Effects of standard and explicit cognitive bias modification and computer-administered cognitive-behaviour therapy on cognitive biases and social anxiety

    OpenAIRE

    Mobini, Sirous; Mackintosh, Bundy; Illingworth, Jo; Gega, Lina; Langdon, Peter E; Hoppitt, Laura

    2014-01-01

    Background and objectives - This study examines the effects of a single session of Cognitive Bias Modification to induce positive Interpretative bias (CBM-I) using standard or explicit instructions and an analogue of computer-administered CBT (c-CBT) program on modifying cognitive biases and social anxiety. Methods - A sample of 76 volunteers with social anxiety attended a research site. At both pre- and post-test, participants completed two computer-administered tests of interpretative a...

  9. Nouns cut slices: Effects of linguistic forms on intergroup bias

    Czech Academy of Sciences Publication Activity Database

    Graf, Sylvie; Bilewicz, M.; Finell, E.; Geschke, D.

    2013-01-01

    Roč. 32, č. 1 (2013), s. 46-61. ISSN 0261-927X R&D Projects: GA ČR GA13-25656S Institutional support: RVO:68081740 Keywords : nouns * adjectives * intergroup bias * intergroup attitudes Subject RIV: AN - Psychology Impact factor: 0.872, year: 2013

  10. Friendship Network in the Classroom: Parents Bias and Peer Effects

    DEFF Research Database (Denmark)

    Landini, Fabio; Montinari, Natalia; Pin, Paolo;

    We interview both parents and their children enrolled in six primary schools in the district of Treviso (Italy). We study the structural differences between the children network of friends reported by children and the one elicited asking their parents. We find that the parents’ network has a bias...

  11. Effects of sertraline, duloxetine, vortioxetine, and idazoxan in the rat affective bias test

    DEFF Research Database (Denmark)

    Refsgaard, Louise Konradsen; Haubro, Kia; Pickering, Darryl S;

    2016-01-01

    Rationale Affective biases seemingly play a crucial role for the onset and development of depression. Acute treatment with monoamine-based antidepressants positively influence emotional processing, and an early correction of biases likely results in repeated positive experiences that ultimately...... lead to improved mood. Objectives Using two conventional antidepressants, sertraline and duloxetine, we aimed to forward the characterization of a newly developed affective bias test (ABT) for rats. Further, we examined the effect of vortioxetine, a recently approved antidepressant, and the α2...... adrenoceptor antagonist idazoxan on affective biases....

  12. Improvement in the electrical performance and bias-stress stability of dual-active-layered silicon zinc oxide/zinc oxide thin-film transistor

    Science.gov (United States)

    Liu, Yu-Rong; Zhao, Gao-Wei; Lai, Pai-To; Yao, Ruo-He

    2016-08-01

    Si-doped zinc oxide (SZO) thin films are deposited by using a co-sputtering method, and used as the channel active layers of ZnO-based TFTs with single and dual active layer structures. The effects of silicon content on the optical transmittance of the SZO thin film and electrical properties of the SZO TFT are investigated. Moreover, the electrical performances and bias-stress stabilities of the single- and dual-active-layer TFTs are investigated and compared to reveal the effects of the Si doping and dual-active-layer structure. The average transmittances of all the SZO films are about 90% in the visible light region of 400 nm–800 nm, and the optical band gap of the SZO film gradually increases with increasing Si content. The Si-doping can effectively suppress the grain growth of ZnO, revealed by atomic force microscope analysis. Compared with that of the undoped ZnO TFT, the off-state current of the SZO TFT is reduced by more than two orders of magnitude and it is 1.5 × 10‑12 A, and thus the on/off current ratio is increased by more than two orders of magnitude. In summary, the SZO/ZnO TFT with dual-active-layer structure exhibits a high on/off current ratio of 4.0 × 106 and superior stability under gate-bias and drain-bias stress. Projected supported by the National Natural Science Foundation of China (Grant Nos. 61076113 and 61274085), the Natural Science Foundation of Guangdong Province (Grant No. 2016A030313474), and the University Development Fund (Nanotechnology Research Institute, Grant No. 00600009) of the University of Hong Kong, China.

  13. Effective stress coefficient for uniaxial strain condition

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    2012-01-01

    coefficient from one dimensional rock mechanical deformation. We further investigated the effect of boundary condition on the stress dependency of effective stress coefficient and discussed its application in reservoir study. As stress field in the reservoirs are most unlikely to be hydrostatic, effective...... stress determined under uniaxial strain condition will be more relevant in reservoir studies....

  14. Effective stress coefficient for uniaxial strain condition

    DEFF Research Database (Denmark)

    Alam, M.M.; Fabricius, I.L.

    2012-01-01

    coefficient from one dimensional rock mechanical deformation. We further investigated the effect of boundary condition on the stress dependency of effective stress coefficient and discussed its application in reservoir study. As stress field in the reservoirs are most unlikely to be hydrostatic, effective...... stress determined under uniaxial strain condition will be more relevant in reservoir studies. Copyright 2012 ARMA, American Rock Mechanics Association....

  15. The Effect of Rater Training on Reducing Social Style Bias in Peer Evaluation

    Science.gov (United States)

    May, Gary L.

    2008-01-01

    This study employed a quasiexperimental control group design in a university setting to test the effect of a rater-training program on reducing social style bias in intragroup peer evaluations after controlling for ability based on GPA. Comparison of rating scores of the test group to the control group indicated minimal social style rating bias in…

  16. Mind your language: The effect of linguistic abstractness on ingroup bias and black sheep effect

    Czech Academy of Sciences Publication Activity Database

    Bilewicz, M.; Kouřilová, Sylvie; Finell, E.; Geschke, D.

    Warsaw: Warsaw School of Social Sciences and Humanities, 2010. s. 21-21. [3rd Biennial Symposium on Personality and Social Psychology. 22.09.2010-2509.2010, Warsaw] R&D Projects: GA ČR GAP407/10/2394 Institutional research plan: CEZ:AV0Z70250504 Keywords : linguistic abstractness * ingroup bias * blacksheep effect Subject RIV: AN - Psychology

  17. Effects of Smoking Opportunity on Attentional Bias in Smokers

    OpenAIRE

    Wertz, Joan M.; Sayette, Michael A.

    2001-01-01

    The emotional Stroop task was used to examine the influence of opportunity to smoke on attentional bias to smoking-related stimuli. At the outset of the study, 92 nicotine-deprived smokers were told that they (a) would, (b) would not, or (c) might be able to smoke during the experiment. Next, participants completed an emotional Stroop task, in which they were presented with smoking-related or -unrelated words in an unblocked format. Smokers demonstrated interference to the smoking words, rela...

  18. A generalized local ansatz and its effect on halo bias

    CERN Document Server

    Shandera, Sarah; Huterer, Dragan

    2010-01-01

    Motivated by the properties of early universe scenarios that produce observationally large local non-Gaussianity, we perform N-body simulations with non-Gaussian initial conditions from a generalized local ansatz. The bispectra are schematically of the local shape, but with scale-dependent amplitude. We find that in such cases the size of the non-Gaussian correction to the bias of small and large mass objects depends on the amplitude of non-Gaussianity roughly on the scale of the object. In addition, some forms of the generalized bispectrum alter the scale dependence of the non-Gaussian term in the bias by a fractional power of k. These features may allow significant observational constraints on the particle physics origin of any observed local non-Gaussianity, distinguishing between scenarios where a single field or multiple fields contribute to the curvature fluctuations. While analytic predictions for the non-Gaussian bias agree qualitatively with the simulations, we find numerically a stronger observation...

  19. Effects of network-average magnitude bias on yield estimates for underground nuclear explosions

    International Nuclear Information System (INIS)

    The ISC body-wave magnitude, msub(b ISC), of presumed underground nuclear explosions in Kazakhstan, USSR, is shown to be systematically biased, by comparison to that recorded at the array station EKA (msub(b EKA)). This is found to be due in part to anelastic attenuation effects on msub(b EKA), but several characteristics of the ISC data demonstrate that the bias is also due to network-averaging effects. For the smaller explosions, those stations with a positive msub(b) bias dominate the data set, but the remainder of the network fails to detect the event. Conversely, for larger explosions, additional stations, with negative msub(b) bias will detect. Use of published station corrections for EKA allows estimation of an msub(b EKA): Y relationship and hence, a magnitude: yield relationship which takes account of network-average bias. (author)

  20. Effect sizes and standardization in neighbourhood models of forest stands: potential biases and misinterpretations

    OpenAIRE

    P. Stoll; Murrell, D. J.; Newbery, D. M.

    2015-01-01

    1. Effects of conspecific neighbours on survival and growth of trees have been found to be related to species abundance. Both positive and negative relationships may explain observed abundance patterns. Surprisingly, it is rarely tested whether such relationships could be biased or even spurious due to transforming neighbourhood variables or influences of spatial aggregation, distance decay of neighbour effects and standardization of effect sizes. 2. To investigate potential biases, co...

  1. Effects of differential mobility on biased diffusion of two species

    International Nuclear Information System (INIS)

    Using simulations and a simple mean-field theory, we investigate jamming transitions in a two-species lattice gas under non-equilibrium steady-state conditions. The two types of particles diffuse with different mobilities on a square lattice, subject to an excluded volume constraint and biased in opposite directions. Varying filling fraction, differential mobility and drive, we map out the phase diagram, identifying first order and continuous transitions between a free-flowing disordered and a spatially inhomogeneous jammed phase. Ordered structures are observed to drift, with a characteristic velocity, in the direction of the more mobile species

  2. Exchange bias-like effect in TbFeAl induced by atomic disorder

    Science.gov (United States)

    Nair, Harikrishnan S.; Strydom, André M.

    2016-05-01

    The exchange bias-like effect observed in the intermetallic compound TbFeAl, which displays a magnetic phase transition at T^hc ≈ 198 \\text{K} and a second one at T^lc ≈ 154 \\text{K} , is reported. Jump-like features are observed in the isothermal magnetization, M (H) , at 2 K which disappear above 8 K. The field-cooled magnetization isotherms below 10 K show loop shifts that are reminiscent of exchange bias, also supported by the training effect. A significant coercive field, Hc ≈ 1.5 \\text{T} at 2 K, is observed in TbFeAl which, after an initial increase, shows a subsequent decrease with temperature. The exchange bias field, H eb , shows a slight increase and a subsequent leveling off with temperature. It is argued that the inherent crystallographic disorder among Fe and Al and the high magnetocrystalline anisotropy related to Tb3+ lead to the exchange bias effect. TbFeAl has been recently reported to show the magnetocaloric effect and the present discovery of exchange bias makes this compound a multifunctional one. The result obtained on TbFeAl generalizes the observation of exchange bias in crystallographically disordered materials and gives impetus for the search for materials with exchange bias induced by atomic disorder.

  3. Effective bias and potentials in steady-state quantum transport: A NEGF reverse-engineering study

    Science.gov (United States)

    Karlsson, Daniel; Verdozzi, Claudio

    2016-03-01

    Using non-equilibrium Green's functions combined with many-body perturbation theory, we have calculated steady-state densities and currents through short interacting chains subject to a finite electric bias. By using a steady-state reverse-engineering procedure, the effective potential and bias which reproduce such densities and currents in a non-interacting system have been determined. The role of the effective bias is characterised with the aid of the so-called exchange-correlation bias, recently introduced in a steady-state density-functional- theory formulation for partitioned systems. We find that the effective bias (or, equivalently, the exchange-correlation bias) depends strongly on the interaction strength and the length of the central (chain) region. Moreover, it is rather sensitive to the level of many-body approximation used. Our study shows the importance of the effective/exchange-correlation bias out of equilibrium, thereby offering hints on how to improve the description of density- functional-theory based approaches to quantum transport.

  4. The effect of substrate bias on titanium carbide/amorphous carbon nanocomposite films deposited by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    The titanium carbide/amorphous carbon nanocomposite films have been deposited on silicon substrate by filtered cathodic vacuum arc (FCVA) technology, the effects of substrate bias on composition, structures and mechanical properties of the films are studied by scanning electron spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy and nano-indentation. The results show that the Ti content, deposition rate and hardness at first increase and then decrease with increasing the substrate bias. Maximum hardness of the titanium carbide/amorphous carbon nanocomposite film is 51 Gpa prepared at −400 V. The hardness enhancement may be attributed to the compressive stress and the fraction of crystalline TiC phase due to ion bombardment

  5. Effects of electrode biasing in STOR-M Tokamak

    Science.gov (United States)

    Basu, Debjyoti; Nakajima, Masaru; Rohollahi, Akbar; McColl, David; Adegun, Joseph; Xiao, Chijin; Hirose, Akira

    2015-11-01

    STOR-M is an iron-core, limiter based tokamak with major and minor radii of 46cm and 12 cm, respectively. Recently, electrode biasing experiments have been carried to study the improved confinement. For this purpose we have developed a DC power supply which can be gated by a high power SCR. The rectangular SS electrode has a height of 10 cm, a width of 2 cm and a thickness of 0.2 cm. The radial position of the electrode throughout the experiments is kept around 4mm inside the limiter in the plasma edge region. After application of positive bias with voltages between +90 V to +110 V during the plasma discharge current flat top with slightly higher edge-qa (nearly 5 to 6), noticeable increment of average plasma density and soft x-ray intensity along the central chord have been observed. No distinguishable change in H α emission has been measured. These phenomena may be attributed to improved confinement formed at the inner region but not at the edge. In the upcoming experimental campaign, Ion Doppler spectroscopy will be used to measure possible velocity shear inside the inner plasma region. Edge plasma pressure gradient will also be measured using Langmuir probes. Detailed experimental results will be presented.

  6. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes

    DEFF Research Database (Denmark)

    Wood, Lesley; Egger, Matthias; Gluud, Lise Lotte;

    2008-01-01

    To examine whether the association of inadequate or unclear allocation concealment and lack of blinding with biased estimates of intervention effects varies with the nature of the intervention or outcome....

  7. Effects of frequency of pulsed substrate bias on structure and properties of silicon-doped diamond-like carbon films by plasma deposition

    International Nuclear Information System (INIS)

    We have investigated the effects of the frequency of pulsed substrate bias on the structure and properties of Si-doped diamond-like carbon (Si-DLC) films deposited by radio-frequency plasma-enhanced chemical vapor deposition using CH4, Ar, and monomethylsilane (CH3SiH3) as the Si source. The Si/(Si + C) ratios in the Si-DLC films deposited using pulsed bias were higher than that of the dc-biased Si-DLC film, and the Si fraction increased with decreasing frequency. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that Si–C, Si–Hn, and C–Hn bonds in the Si-DLC films increased with decreasing frequency. The internal stress decreased as the frequency decreased, which is probably due to the increase in Si–C, Si–Hn, and C–Hn bonds in the films. It was found that the wear rate of the pulse-biased Si-DLC film deposited at the highest frequency in this study is comparable to that of the dc-biased, undoped DLC film. Furthermore, the friction coefficient of the former is about one third of that of the latter. - Highlights: • The tribological properties of Si-doped films were improved at higher frequencies. • The internal stress of Si-doped films was lowered at lower frequencies. • The adhesion of pulse-biased films was improved at lower frequencies

  8. Optical selection effects that bias quasar evolution studies

    International Nuclear Information System (INIS)

    This paper gives a study of systematic biases that are redshift-dependent and could influence not only the optical discovery of quasars but also the evolution laws derived from counts of quasars in ''complete'' surveys. A numerical model of the optical biases suggests that the excess of quasars found at z roughly-equal 2.5 when compared to the local density is largely a result of photometric errors and the unrecognized contribution of strong UV emission lines to the blue magnitude of high-redshift quasars. An observational reexamination of the quasars brighter than M/sub B/ = -24 in the Palomar Bright Quasar Survey (BQS) shows that for the brightest quasars in the survey, the data are consistent with no evolution. A comparison of BQS quasars with the brightest quasars from the CTIO Schmidt Telescope Survey (Osmer and Smith 1980) shows that the brightest CTIO survey quasars have much stronger C IV lambda1548 lines than the brightest BQS quasars. If q0 is taken to be near zero, the density of bright quasars in comoving Friedmann cosmology coordinates is about 15 times higher for the CTIO survey quasars (mean z roughly-equal 2.8) than for the BQS quasars (mean z roughly-equal 1.8). In this case, spectral evolution is required, since the high-redshift CTIO quasars have greater C IV lambda1548 equivalent widths than the lower redshift BQS quasars of similar luminosity. Alternatively, if q3] is taken to be near unity, the brightest CTIO survey quasars would all be fainter than the brightest BQS objects. The strong emission lines seen in the CTIO survey quasars could be understood as a consequence of the general correlation between absolute quasar luminosity and C IV lambda1548 equivalent width

  9. Tensile effective stresses in hydrocarbon storage caverns

    CERN Document Server

    Djizanne, Hippolyte; Brouard, Benoît

    2013-01-01

    The "no-tensile effective stress" criterion is discussed. It is proven that effective tensile stresses can be generated at a cavern wall after a rapid increase or decrease in pressure. The Etzel K-102 test, performed in Germany more than 20 years ago, is revisited using the notion of effective tensile stresses.

  10. Tensile effective stresses in hydrocarbon storage caverns

    OpenAIRE

    Djizanne, Hippolyte; Berest, Pierre; Brouard, Benoît

    2013-01-01

    International audience The "no-tensile effective stress" criterion is discussed. It is proven that effective tensile stresses can be generated at a cavern wall after a rapid increase or decrease in pressure. The Etzel K-102 test, performed in Germany more than 20 years ago, is revisited using the notion of effective tensile stresses.

  11. Effective stress coefficient for uniaxial strain condition

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    2012-01-01

    coefficient from one dimensional rock mechanical deformation. We further investigated the effect of boundary condition on the stress dependency of effective stress coefficient and discussed its application in reservoir study. As stress field in the reservoirs are most unlikely to be hydrostatic, effective...

  12. The effects of food-related attentional bias training on appetite and food intake

    Science.gov (United States)

    Hardman, Charlotte A.; Rogers, Peter J.; Etchells, Katie A.; Houstoun, Katie V. E.; Munafò, Marcus R.

    2016-01-01

    Obese and overweight individuals show a marked attentional bias to food cues. Food-related attentional bias may therefore play a causal role in over-eating. To test this possibility, the current study experimentally manipulated attentional bias towards food using a modified version of the visual probe task in which cake-stationery item image pairs were presented for 500 ms each. Participants (N = 60) were either trained to attend to images of cake, trained to avoid images of cake, or assigned to a no-training control group. Hunger was measured before and after the training. Post-training, participants were given the opportunity to consume cake as well as a non-target food (crisps) that was not included in the training. There was weak evidence of an increase in attentional bias towards cake in the attend group only. We found no selective effects of the training on hunger or food intake, and little evidence for any gender differences. Our study suggests that attentional bias for food is particularly ingrained and difficult to modify. It also represents a first step towards elucidating the potential functional significance of food-related attentional biases and the lack of behavioural effects is broadly consistent with single-session attentional training studies from the addiction literature. An alternative hypothesis, that attentional bias represents a noncausal proxy for the motivational impact of appetitive stimuli, is considered. PMID:24025548

  13. Influence of substrate bias voltage on the microstructure and residual stress of CrN films deposited by medium frequency magnetron sputtering

    International Nuclear Information System (INIS)

    Highlights: → The pure CrN films have been successfully prepared by medium frequency magnetron sputtering. → At low substrate bias voltage (-300 V), the compressive stresses are observed in the films. → The texture of the CrN films changes from (1 1 1) to (2 0 0) with increasing substrate bias voltage. → The surface roughness firstly decreases and then increases with increasing bias voltage. - Abstract: In this study, CrN films were deposited on stainless steel and Si (1 1 1) substrates via medium frequency magnetron sputtering under a systematic variation of the substrate bias voltage. The influence of the substrate bias voltage on the structural and the mechanical properties of the films were investigated. It is observed that there are two clear regions: (1) below -300 V, and (2) above -300 V. For the former region, the (1 1 1) texture is dominated as the substrate bias voltage is increased to -200 V. The lattice parameter is smaller than that of CrN reported in the ICSD standard (4.140 A) and the as-deposited films exhibit tensile stress. Meanwhile, the surface roughness decreases and the N concentration show a slow increase. For the latter region, the (2 0 0)-oriented structure is formed. However, the lattice parameter is larger as compared with the value reported in the ICSD standard, and the surface roughness increases and the N concentration decreases obviously. In this case, the compressive stress is obtained.

  14. Bias voltage induced resistance switching effect in single-molecule magnets’ tunneling junction

    International Nuclear Information System (INIS)

    An electric-pulse-induced reversible resistance change effect in a molecular magnetic tunneling junction, consisting of a single-molecule magnet (SMM) sandwiched in one nonmagnetic and one ferromagnetic electrode, is theoretically investigated. By applying a time-varying bias voltage, the SMM's spin orientation can be manipulated with large bias voltage pulses. Moreover, the different magnetic configuration at high-resistance/low-resistance states can be ‘read out’ by utilizing relative low bias voltage. This device scheme can be implemented with current technologies (Khajetoorians et al 2013 Science 339 55) and has potential application in molecular spintronics and high-density nonvolatile memory devices. (paper)

  15. The impact of threat of shock on the framing effect and temporal discounting: executive functions unperturbed by acute stress?

    Directory of Open Access Journals (Sweden)

    Oliver Joe Robinson

    2015-08-01

    Full Text Available Anxiety and stress-related disorders constitute a large global health burden, but are still poorly understood. Prior work has demonstrated clear impacts of stress upon basic cognitive function: biasing attention towards unexpected and potentially threatening information and instantiating a negative affective bias. However, the impact that these changes have on higher-order, executive, decision-making processes is unclear. In this study we examined the impact of a translational within-subjects stress induction (threat of unpredictable shock on two well-established executive decision-making biases: the framing effect (N=83, and temporal discounting (N=36. In both studies, we demonstrate a clear subjective effects of stress, and b clear executive decision-making biases but c no impact of stress on these decision-making biases. Indeed, Bayes factor analyses confirmed substantial preference for decision-making models that did not include stress. We posit that while stress may induce subjective mood change and alter low-level perceptual and action processes (Robinson et al., 2013b, some higher-level executive processes remain unperturbed by these impacts. As such, although stress can induce a transient affective biases and altered mood, these need not result in poor financial decision-making.

  16. Top-gate zinc tin oxide thin-film transistors with high bias and environmental stress stability

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, M.; Theisen, M.; Behrendt, A.; Görrn, P.; Riedl, T. [Institute of Electronic Devices, University of Wuppertal, Wuppertal 42119 (Germany)

    2014-06-23

    Top gated metal-oxide thin-film transistors (TFTs) provide two benefits compared to their conventional bottom-gate counterparts: (i) The gate dielectric may concomitantly serve as encapsulation layer for the TFT channel. (ii) Damage of the dielectric due to high-energetic particles during channel deposition can be avoided. In our work, the top-gate dielectric is prepared by ozone based atomic layer deposition at low temperatures. For ultra-low gas permeation rates, we introduce nano-laminates of Al{sub 2}O{sub 3}/ZrO{sub 2} as dielectrics. The resulting TFTs show a superior environmental stability even at elevated temperatures. Their outstanding stability vs. bias stress is benchmarked against bottom-gate devices with encapsulation.

  17. Top-gate zinc tin oxide thin-film transistors with high bias and environmental stress stability

    Science.gov (United States)

    Fakhri, M.; Theisen, M.; Behrendt, A.; Görrn, P.; Riedl, T.

    2014-06-01

    Top gated metal-oxide thin-film transistors (TFTs) provide two benefits compared to their conventional bottom-gate counterparts: (i) The gate dielectric may concomitantly serve as encapsulation layer for the TFT channel. (ii) Damage of the dielectric due to high-energetic particles during channel deposition can be avoided. In our work, the top-gate dielectric is prepared by ozone based atomic layer deposition at low temperatures. For ultra-low gas permeation rates, we introduce nano-laminates of Al2O3/ZrO2 as dielectrics. The resulting TFTs show a superior environmental stability even at elevated temperatures. Their outstanding stability vs. bias stress is benchmarked against bottom-gate devices with encapsulation.

  18. Top-gate zinc tin oxide thin-film transistors with high bias and environmental stress stability

    International Nuclear Information System (INIS)

    Top gated metal-oxide thin-film transistors (TFTs) provide two benefits compared to their conventional bottom-gate counterparts: (i) The gate dielectric may concomitantly serve as encapsulation layer for the TFT channel. (ii) Damage of the dielectric due to high-energetic particles during channel deposition can be avoided. In our work, the top-gate dielectric is prepared by ozone based atomic layer deposition at low temperatures. For ultra-low gas permeation rates, we introduce nano-laminates of Al2O3/ZrO2 as dielectrics. The resulting TFTs show a superior environmental stability even at elevated temperatures. Their outstanding stability vs. bias stress is benchmarked against bottom-gate devices with encapsulation.

  19. Enhanced stability against bias-stress of metal-oxide thin film transistors deposited at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, M.; Goerrn, P.; Riedl, T. [Institute of Electronic Devices, University of Wuppertal, Rainer-Gruenter-St. 21, 42119 Wuppertal (Germany); Weimann, T.; Hinze, P. [Physikalisch-Technische Bundesanstalt Braunschweig, Bundesallee 100, 38116 Braunschweig (Germany)

    2011-09-19

    Transparent zinc-tin-oxide (ZTO) thin film transistors (TFTs) have been prepared by DC magnetron sputtering. Compared to reference devices with a channel deposited at room temperature and subsequently annealing at 400 deg. C, a substantially enhanced stability against bias stress is evidenced for devices with in-situ substrate heating during deposition (400 deg. C). A reduced density of sub-gap defect states in TFT channels prepared with in-situ substrate heating is found. Concomitantly, a reduced sensitivity to the adsorption of ambient gases is evidenced for the in-situ heated devices. This finding is of particular importance for an application as driver electronics for organic light emitting diode displays.

  20. Enhanced stability against bias-stress of metal-oxide thin film transistors deposited at elevated temperatures

    Science.gov (United States)

    Fakhri, M.; Görrn, P.; Weimann, T.; Hinze, P.; Riedl, T.

    2011-09-01

    Transparent zinc-tin-oxide (ZTO) thin film transistors (TFTs) have been prepared by DC magnetron sputtering. Compared to reference devices with a channel deposited at room temperature and subsequently annealing at 400 °C, a substantially enhanced stability against bias stress is evidenced for devices with in-situ substrate heating during deposition (400 °C). A reduced density of sub-gap defect states in TFT channels prepared with in-situ substrate heating is found. Concomitantly, a reduced sensitivity to the adsorption of ambient gases is evidenced for the in-situ heated devices. This finding is of particular importance for an application as driver electronics for organic light emitting diode displays.

  1. Traumatic stress: effects on the brain

    OpenAIRE

    Bremner, J Douglas

    2006-01-01

    Brain areas implicated in the stress response include the amygdala, hippocampus, and prefrontal cortex. Traumatic stress can be associated with lasting changes in these brain areas. Traumatic stress is associated with increased cortisol and norepinephrine responses to subsequent stressors. Antidepressants have effets on the hippocampus that counteract the effects of stress. Findings from animal studies have been extended to patients with post-traumatic stress disorder (PTSD) showing smaller h...

  2. Social support moderates stress effects on depression

    OpenAIRE

    Wang, Xingmin; Cai, Lin; Qian, Jing; Peng, Jiaxi

    2014-01-01

    This study examined the moderator effect of social support on the relationship between stress and depression of university students. A total of 632 undergraduate students completed the measures of perceived stress, perceived social support, and depression. Hierarchical regression analysis showed that social support moderated the association between stress and depression. Undergraduate students with high stress reported higher scores in depression than those with low stress with low social sup...

  3. Posttraumatic Stress Disorder Symptoms, Intimate Partner Violence Perpetration, and the Mediating Role of Shame Processing Bias

    OpenAIRE

    Sippel, Lauren M.; Marshall, Amy D.

    2011-01-01

    Posttraumatic stress disorder (PTSD) may produce internal “threats to the self,” which generate shame. Shame is theoretically and empirically linked to intimate partner violence (IPV) perpetration. We examined relations among PTSD, cognitive processing of shame-relevant information, and IPV perpetration. Forty-seven community participants completed an emotional Stroop task with shame-relevant and neutral words. Stimuli were presented supraliminally (i.e., until vocal response) and subliminall...

  4. The effect of metacognitive self on confirmation bias revealed in relation to community and competence

    Directory of Open Access Journals (Sweden)

    Brycz Hanna

    2014-09-01

    Full Text Available The main goal of our study was to investigate the role of insight into one’s own biases (metacognitive self in the process of hypothesis validation in accordance to the two fundamental social perception domains (community and competence on the example of confirmation bias. The study was conducted on a group of 593 participants with the use of a confirmation bias procedure, a free recall procedure and the Metacognitive Self scale. We manipulated with the domain and the value of information given to the respondents. We suspected that individuals with a high metacognitive self, in opposition to low metacognitive self ones, would not process the given information according to the two fundamental social perception domains. The results verified the existence of an interaction effect of the metacognitive self (MCS and the domain of the information given about a perceived person on the susceptibility to follow the confirmation bias. Contrary to the low metacognitive self individuals, who show a higher tendency for the confirmation bias within the competence than the community domain, persons with a high insight into their own biases express the same level of confirmation bias in no respect to the domain of the information. The value of the information has no significant influence.

  5. Defending or challenging the status quo : Effects of position on biased perceptions of opponents

    OpenAIRE

    Bäck, Emma; Lindholm, Torun

    2009-01-01

    People want to maintain status quo. Most prior research concern groups with real status differences. Pro/con status quo position may itself carry status information. Three studies explored the effects of pro/con status quo position on biased perceptions of others. Challengers were more biased, regardless of real status differences. Supporting summary The default ideological position is status quo maintaining (Skitka et al. 2002). Most prior research concerns groups with real status difference...

  6. The effect of cognitive bias modification training on memory of emotional words in anxious children

    OpenAIRE

    Wong, Hiu-wing, Sharon.; 黃曉穎.

    2012-01-01

    Previous research had demonstrated cognitive biases towards threatening stimuli in anxious individuals, such as in attention, interpretation and memory. The present study aimed to examine the differences in memory-related information processing between anxious and nonanxious children and the effectiveness of a Cognitive-Bias Modification (CBM) based positive training in altering these differences. The study adopted a directed forgetting paradigm, where children with anxiety disorders (N=12) ...

  7. The Biased Effect of Aggregated and Disaggregated Income Taxation on Investment Decisions

    OpenAIRE

    Martin Fochmann; Dirk Kiesewetter; Abdolkarim Sadrieh

    2010-01-01

    Income taxation may not only affect investment behavior by distorting payoffs, it may also have a more subtle, psychological effect, by biasing investors' perceptions of the financial consequences. In a laboratory experiment that allows us to vary the taxation method, while keeping the financial outcomes constant, we find clear evidence that aggregated income taxation (comparable to profit taxation) with complete loss deduction induces a sustained bias towards more risk-taking, while disaggre...

  8. EFFECTS OF ROCK BEHAVIOR AND STRESS CONDITIONON FIELD STRESS DETERMINATION

    Institute of Scientific and Technical Information of China (English)

    D.H.(Steve)Zou

    1995-01-01

    Non-consistency of stress results is often observed during field measurements. In some cases, even the measurements are made at the same location in a massive rockmass, the results can vary widely. In order to solve the problem, extensive research has been carried out to study the major factors which may affect stress determination. They include the rock behaviour and the stress state. For rocks showing non-isotropic behaviour, the values of Young's modulus and Poisson ratio vary with the orientation of loading and measurement. Stress condition in the rock affects the rock behaviour. Furthermore, the loading condition on rock samples during laboratory tests is different from in the field and therefore the determined elastic constants may not represent the field condition. In general, the Young's modulus may depend on the orientation, the loading path, the stress magnitude and the stress ratio. This paper examines in detail the effects of those factors, especially for rocks showing transversely isotropic behaviour. It is found that the discrepancy of stress results from fieldts in this type of rock is mainly due to over simplification of the rock behavior and inadequate use of elastic constants of the rock during stress calculation. A case study is given, which indicates the significance of these factors and demonstrates the proper procedure for stress calculation from

  9. High-end climate change impact on European water availability and stress: exploring the presence of biases

    Directory of Open Access Journals (Sweden)

    L. V. Papadimitriou

    2015-07-01

    Full Text Available Climate models project a much more substantial warming than the 2 °C target making higher end scenarios increasingly plausible. Freshwater availability under such conditions is a key issue of concern. In this study, an ensemble of Euro-CORDEX projections under RCP8.5 is used to assess the mean and low hydrological states under +4 °C of global warming for the European region. Five major European catchments were analyzed in terms of future drought climatology and the impact of +2 vs. +4 °C global warming was investigated. The effect of bias correction of the climate model outputs and the observations used for this adjustment was also quantified. Projections indicate an intensification of the water cycle at higher levels of warming. Even for areas where the average state may not considerably be affected, low flows are expected to reduce leading to changes in the number of dry days and thus drought climatology. The identified increasing or decreasing runoff trends are substantially intensified when moving from the +2 to the +4 °C of global warming. Bias correction resulted in an improved representation of the historical hydrology. It is also found that the selection of the observational dataset for the application of the bias correction has an impact on the projected signal that could be of the same order of magnitude to the selection of the RCM.

  10. The effect of dc bias on the poled states in PNZST antiferroelectric thin films

    International Nuclear Information System (INIS)

    The effect on the polarization of antiferroelectric (AFE) PNZST ((Pb,Nb)(Zr,Sn,Ti)O3) thin films by ε-E (dc bias field) cycles was studied. It was shown that in these films the AFE ordering is destroyed by the application of a dc electrical field bias along the surface normal direction. After removing the dc bias the film relaxes slowly back to the initial AFE state. This phenomenon is dependent on the film thickness. The relaxation time decreases with increasing film thickness. With increasing storage time of the sample after removing the dc bias at room temperature or heat treatment above the Curie temperature, the AFE ordering can return. From the characteristics of hysteresis loops and ε-E behaviours, we can ascertain that this phenomenon could be attributed to the difference in the poled volume at the interfaces between the electrode and the film

  11. Impurity effects on electrical conductivity of doped bilayer graphene in the presence of a bias voltage

    Institute of Scientific and Technical Information of China (English)

    E Lotfi; H Rezania; B Arghavaninia; M Yarmohammadi

    2016-01-01

    We address the electrical conductivity of bilayer graphene as a function of temperature, impurity concentration, and scattering strength in the presence of a finite bias voltage at finite doping, beginning with a description of the tight-binding model using the linear response theory and Green’s function approach. Our results show a linear behavior at high doping for the case of high bias voltage. The effects of electron doping on the electrical conductivity have been studied via changing the electronic chemical potential. We also discuss and analyze how the bias voltage affects the temperature behavior of the electrical conductivity. Finally, we study the behavior of the electrical conductivity as a function of the impurity concentration and scattering strength for different bias voltages and chemical potentials respectively. The electrical conductivity is found to be monotonically decreasing with impurity scattering strength due to the increased scattering among electrons at higher impurity scattering strength.

  12. Effects of substrate bias on structure and mechanical properties of (AlCrNbSiTiV)N coatings

    International Nuclear Information System (INIS)

    AlCrNbSiTiV nitride films were deposited by reactive radio-frequency magnetron sputtering and the effects of substrate bias on the chemical composition, structure and mechanical properties of the deposited films were investigated. AlCrNbSiTiV nitride films exhibit a single FCC NaCl-type structure and have the stoichiometric nitride ratio of (Al, Cr, Nb, Si, Ti, V)50N50. The deposition rate decreases with increasing substrate bias due to resputtering effects and densification of films, which also leads to less obvious columnar structure, reduced grain size, smaller surface roughness and transition of preferred orientation from the (1 1 1) plane to the (2 0 0) plane. The nitride film deposited at -100 V exhibits the maximum compressive stress around 4.5 GPa and attains a peak hardness and an elastic modulus of 42 GPa and 350 GPa, respectively, which fall in the superhard grade. Moreover, the film keeps its hardness at the superhard grade even after its residual compressive stress was partially released by annealing at 1073 K for 5 h. The structural evolution mechanism and strengthening mechanism are both discussed.

  13. Evolution and the expression of biases: situational value changes the endowment effect in chimpanzees.

    Science.gov (United States)

    Brosnan, Sarah F; Jones, Owen D; Gardner, Molly; Lambeth, Susan P; Schapiro, Steven J

    2012-07-01

    Cognitive and behavioral biases, which are widespread among humans, have recently been demonstrated in other primates, suggesting a common origin. Here we examine whether the expression of one shared bias, the endowment effect, varies as a function of context. We tested whether objects lacking inherent value elicited a stronger endowment effect (or preference for keeping the object) in a context in which the objects had immediate instrumental value for obtaining valuable resources (food). Chimpanzee subjects had opportunities to trade tools when food was not present, visible but unobtainable, and obtainable using the tools. We found that the endowment effect for these tools existed only when they were immediately useful, showing that the effect varies as a function of context-specific utility. Such context-specific variation suggests that the variation seen in some human biases may trace predictably to behaviors that evolved to maximize gains in specific circumstances. PMID:25419111

  14. Effects of substrate bias voltage and target sputtering power on the structural and tribological properties of carbon nitride coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Pengfei, E-mail: wangpf@szu.edu.cn [Institute of Nanosurface Science and Engineering, College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen 518060 (China); Institute of Fluid Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan); Takeno, Takanori [Laboratory of Nanointerface Engineering, Division of Mechanical Engineering, Tohoku University, Aoba 6-6-1, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Fontaine, Julien [Laboratoire de Tribologie et Dynamique des Systèmes, UMR 5513 – CNRS/Ecole Centrale de Lyon, Bâtiment H10, 36 Avenue Guy de Collongue, 69134 Écully Cedex (France); Aono, Masami [Department of Materials Science and Engineering, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239-8686 (Japan); Adachi, Koshi [Laboratory of Nanointerface Engineering, Division of Mechanical Engineering, Tohoku University, Aoba 6-6-1, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Miki, Hiroyuki [Center for Interdisciplinary Research, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Takagi, Toshiyuki [Institute of Fluid Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan)

    2014-06-01

    Effects of substrate bias voltage and target sputtering power on the structural and tribological properties of carbon nitride (CN{sub x}) coatings are investigated. CN{sub x} coatings are fabricated by a hybrid coating process with the combination of radio frequency plasma enhanced chemical vapor deposition (RF PECVD) and DC magnetron sputtering at various substrate bias voltage and target sputtering power in the order of −400 V 200 W, −400 V 100 W, −800 V 200 W, and −800 V 100 W. The deposition rate, N/C atomic ratio, and hardness of CN{sub x} coatings as well as friction coefficient of CN{sub x} coating sliding against AISI 52100 pin in N{sub 2} gas stream decrease, while the residual stress of CN{sub x} coatings increases with the increase of substrate bias voltage and the decrease of target sputtering power. The highest hardness measured under single stiffness mode of 15.0 GPa and lowest residual stress of 3.7 GPa of CN{sub x} coatings are obtained at −400 V 200 W, whereas the lowest friction coefficient of 0.12 of CN{sub x} coatings is achieved at −800 V 100 W. Raman and XPS analysis suggest that sp{sup 3} carbon bonding decreases and sp{sup 2} carbon bonding increases with the variations in substrate bias voltage and target sputtering power. Optical images and Raman characterization of worn surfaces confirm that the friction behavior of CN{sub x} coatings is controlled by the directly sliding between CN{sub x} coating and steel pin. Therefore, the reduction of friction coefficient is attributed to the decrease of sp{sup 3} carbon bonding in the CN{sub x} coating. It is concluded that substrate bias voltage and target sputtering power are effective parameters for tailoring the structural and tribological properties of CN{sub x} coatings. - Highlights: • Various CN{sub x} coatings are produced using a unique hybrid coating process. • Structural and tribological properties of CN{sub x} coatings are investigated. • The lowest friction

  15. The effects of self-focus on attentional biases in social anxiety:An ERP study.

    Science.gov (United States)

    Judah, Matt R; Grant, DeMond M; Carlisle, Nancy B

    2016-06-01

    Cognitive theories of social anxiety disorder suggest that biased attention plays a key role in maintaining symptoms. These biases include self-focus and attention to socially threatening stimuli in the environment. The goal of this study was to utilize ERPs that are elicited by a change detection task to examine biases in selective attention (i.e., N2pc) and working memory maintenance (i.e., contralateral delay activity; CDA). Additionally, the effect of self-focus was examined using false heart rate feedback. In support of the manipulation, self-focus cues resulted in greater self-reported self-consciousness and task interference, enhanced anterior P2 amplitude and reduced SPN amplitude. Moreover, P2 amplitude for self-focus cues was correlated with reduced task performance for socially anxious subjects only. The difference in P2 amplitude between self-focus and standard cues was correlated with social anxiety independent of depression. As hypothesized, socially anxious participants (n = 20) showed early selection and maintenance of disgust faces relative to neutral faces as indicated by the N2pc and CDA components. Nonanxious controls (n = 22) did not show these biases. During self-focus cues, controls showed marginal evidence of biased selection for disgust faces, whereas socially anxious subjects showed no bias in this condition. Controls showed an ipsilateral delay activity after being cued to attend to one hemifield. Overall, this study supports early and persistent attentional bias for social threat in socially anxious individuals. Furthermore, self-focus may disrupt these biases. These findings and supplementary data are discussed in light of cognitive models of social anxiety disorder, recent empirical findings, and treatment. PMID:26676918

  16. Relative Age Effect in Elite Sports: Methodological Bias or Real Discrimination?

    CERN Document Server

    Delorme, Nicolas; Raspaud, Michel; 10.1080/17461390903271584

    2010-01-01

    Sport sciences researchers talk about a relative age effect when they observe a biased distribution of elite athletes' birthdates, with an over-representation of those born at the beginning of the competitive year and an under-representation of those born at the end. Using the whole sample of the French male licensed soccer players (n = 1,831,524), our study suggests that there could be an important bias in the statistical test of this effect. This bias could in turn lead to falsely conclude to a systemic discrimination in the recruitment of professional players. Our findings question the accuracy of past results concerning the existence of this effect at the elite level.

  17. Impact of substrate bias on radiation-inducededge effects in MOSFETs

    Institute of Scientific and Technical Information of China (English)

    Hu Zhi-Yuan; Liu Zhang-Li; Shao-Hua; Zhang Zheng-Xuan; Ning Bing-Xu; Chen Ming; Bi Da-Wei; Zou Shi-Chang

    2011-01-01

    This paper investigates the effects of gamma-ray irradiiation on the Shallow-Trench Isolation (STI) leakage currents in 180-nm complementary metal oxide semiconductor technology.No hump effect in the subthreshold region is observed after irradiation,which is considered to be due to the thin STI corner oxide thickness.A negative substrate bias could effectively suppress the STI leakage,but it also impairs the device characteristics.The three-dimensional simulation is introduced to understand the impact of substrate bias.Moreover,we propose a simple method for extracting the best substrate bias value,which not only eliminates the STI leakage but also has the least impact on the device characteristics.

  18. Effects of Nicotine and Nicotine Expectancy on Attentional Bias for Emotional Stimuli

    Science.gov (United States)

    Adams, Sally; Attwood, Angela S.; Munafò, Marcus R.

    2016-01-01

    Introduction Nicotine’s effects on mood are thought to enhance its addictive potential. However, the mechanisms underlying the effects of nicotine on affect regulation have not been reliably demonstrated in human laboratory studies. We investigated the effects of abstinence (experiment one), and nicotine challenge and expectancy (experiment two) on attentional bias towards facial emotional stimuli differing in emotional valence. Methods In experiment one, 46 nicotine-deprived smokers were randomized to either continue to abstain from smoking or to smoke immediately before testing. In experiment two, 96 nicotine deprived smokers were randomized to smoke a nicotinized or denicotinized cigarette and to be told that the cigarette did or did not contain nicotine. In both experiments participants completed a visual probe task, where positively valenced (happy) and negatively valenced (sad) facial expressions were presented, together with neutral facial expressions. Results In experiment one, there was evidence of an interaction between probe location and abstinence on reaction time, indicating that abstinent smokers showed an attentional bias for neutral stimuli. In experiment two, there was evidence of an interaction between probe location, nicotine challenge and expectation on reaction time, indicating that smokers receiving nicotine, but told that they did not receive nicotine, showed an attentional bias for emotional stimuli. Conclusions Our data suggest that nicotine abstinence appears to disrupt attentional bias towards emotional facial stimuli. These data provide support for nicotine’s modulation of attentional bias as a central mechanism for maintaining affect regulation in cigarette smoking. PMID:25335948

  19. Exchange bias effect in spin glass CoCr{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Changming; Tian, Zhaoming; Wang, Liguang; Yuan, Songliu, E-mail: yuansl@hust.edu.cn

    2015-11-01

    CoCr{sub 2}O{sub 4} nanoparticles are about 5.4 nm in diameter synthesized by a hydrothermal technique. Magnetization measurements reveal that the nanoparticles exhibit a spin glass behavior below glass transition temperature. Signature of memory effect is clear in reheating curve where the step-like shape increasing with the increase of temperature is recovered after cooling process. Magnetic relaxation is performed to prove memory effect. Ageing effect is also detected in CoCr{sub 2}O{sub 4} nanoparticles to verify the spin glass behavior. As temperature decreases to 5 K, which is far below the glass transition temperature, exchange bias effect can be observed clearly accompanied with a shift in field-cooled hysteresis loop. As particle size decreases to 5.4 nm, spin glass behavior appears due to the increased spin disorder effect. The spin glass phase providing a pinning force from some frozen spins to the rotatable spins gives the key to explain the exchange bias effects. - Highlights: • Existence of spin glass phase is verified in CoCr{sub 2}O{sub 4} nanoparticles. • Exchange bias effect with a shift in field-cooled loop is observed at 5 K. • It is proved that exchange bias effect is originated from the spin glass phase.

  20. Photocurrent Effect in Reverse-Biased p-n Silicon Waveguides in Communication Bands

    International Nuclear Information System (INIS)

    The photocurrent effect in reverse biased p-n silicon waveguides at wavelength 1550 nm is experimentally investigated. The photocurrent, which is mainly related to surface-state absorption, defect-state absorption and/or two-photon absorption, is more than 0.08 μA/mm under 8 V reverse biasing and 0.75 mW irradiation. The responsivity of a silicon waveguide with length of 4500 μm achieves 0.5 mA/W. Moreover, the enhancement of the photocurrent effect under the electric field is discussed. (fundamental areas of phenomenology(including applications))

  1. Abnormal Threshold Voltage Shifts in P-Channel Low-Temperature Polycrystalline Silicon Thin Film Transistors Under Negative Bias Temperature Stress.

    Science.gov (United States)

    Kim, Sang Sub; Choi, Pyung Ho; Baek, Do Hyun; Lee, Jae Hyeong; Choi, Byoung Deog

    2015-10-01

    In this research, we have investigated the instability of P-channel low-temperature polycrystalline silicon (poly-Si) thin-film transistors (LTPS TFTs) with double-layer SiO2/SiNx dielectrics. A negative gate bias temperature instability (NBTI) stress was applied and a turn-around behavior phenomenon was observed in the Threshold Voltage Shift (Vth). A positive threshold voltage shift occurs in the first stage, resulting from the negative charge trapping at the SiNx/SiO2 dielectric interface being dominant over the positive charge trapping at dielectric/Poly-Si interface. Following a stress time of 7000 s, the Vth switches to the negative voltage direction, which is "turn-around" behavior. In the second stage, the Vth moves from -1.63 V to -2 V, overwhelming the NBTI effect that results in the trapping of positive charges at the dielectric/Poly-Si interface states and generating grain-boundary trap states and oxide traps. PMID:26726370

  2. Fluency and belief bias in deductive reasoning: new indices for old effects.

    Science.gov (United States)

    Trippas, Dries; Handley, Simon J; Verde, Michael F

    2014-01-01

    Models based on signal detection theory (SDT) have occupied a prominent role in domains such as perception, categorization, and memory. Recent work by Dube et al. (2010) suggests that the framework may also offer important insights in the domain of deductive reasoning. Belief bias in reasoning has traditionally been examined using indices based on raw endorsement rates-indices that critics have claimed are highly problematic. We discuss a new set of SDT indices fit for the investigation belief bias and apply them to new data examining the effect of perceptual disfluency on belief bias in syllogisms. In contrast to the traditional approach, the SDT indices do not violate important statistical assumptions, resulting in a decreased Type 1 error rate. Based on analyses using these novel indices we demonstrate that perceptual disfluency leads to decreased reasoning accuracy, contrary to predictions. Disfluency also appears to eliminate the typical link found between cognitive ability and the effect of beliefs on accuracy. Finally, replicating previous work, we demonstrate that cognitive ability leads to an increase in reasoning accuracy and a decrease in the response bias component of belief bias. PMID:25009515

  3. Fluency and belief bias in deductive reasoning: New indices for old effects

    Directory of Open Access Journals (Sweden)

    Dries eTrippas

    2014-06-01

    Full Text Available Models based on signal detection theory (SDT have occupied a prominent role in domains such as perception, categorisation, and memory. Recent work by Dube et al. (2010 suggests that the framework may also offer important insights in the domain of deductive reasoning. Belief bias in reasoning has traditionally been examined using indices based on raw endorsement rates – indices that critics have claimed are highly problematic. We discuss a new set of SDT indices fit for the investigation belief bias and apply them to new data examining the effect of perceptual disfluency on belief bias in syllogisms. In contrast to the traditional approach, the SDT indices do not violate important statistical assumptions, resulting in a decreased Type 1 error rate. Based on analyses using these novel indices we demonstrate that disfluency leads to decreased reasoning accuracy, contrary to predictions. Disfluency also appears to eliminate the typical link found between cognitive ability and the effect of beliefs on accuracy. Finally, replicating previous work, we demonstrate that cognitive ability leads to an increase in reasoning accuracy and a decrease in the response bias component of belief bias.

  4. Learning effect on survey data: high leverage and estimation bias

    OpenAIRE

    Mazbahul Golam Ahamad

    2010-01-01

    Method of survey data collection, especially at household or personal interview, responders frequently answers extreme, because of their pre-assumption on questionnaire to get financial or food aid. This reduces data consistency and advances leverage that affects estimation procedure and estimated predictors. This study analysis the impact of learning effect on research hypothesis using mailed interview of different cluster of researcher such as expertise, mid-level research assistants and en...

  5. Effect of negative bias voltage on CrN films deposited by arc ion plating. II. Film composition, structure, and properties

    International Nuclear Information System (INIS)

    Chromium nitride (CrN) films were deposited on Si wafers by arc ion plating at various negative bias voltages and several groups of N2/Ar gas flux ratios and chamber gas pressures. The authors systematically investigated the influence of negative bias voltage on the synthesis, composition, microstructure, and properties of the arc ion plating (AIP) CrN films. In this article, the authors investigated the influence of negative bias voltage on the chemical composition, structure, and mechanical properties of the CrN films. The results showed that the chemical composition and phase structure of the AIP CrN films were greatly altered by application of negative bias voltage. Due to the selective resputtering effect, substoichiometric CrN films were obtained. With increase in bias voltages, the main phases in the films transformed from Cr+CrN to Cr2N at low N2/Ar flow ratios, whereas the films at high N2/Ar flow ratios retained the CrN phase structure. The CrN films experienced texture transformation from CrN (200) to CrN (220), and Cr2N (300) to Cr2N(300)+Cr2N(110). Increase in negative bias voltage also resulted in microstructure evolution of coarse columnar grains→fine columnar grains→quasiamorphous microstructure→recrystallized structures. From the experimental results, the authors proposed a new structure zone model based on enhanced bombardment of incident ions by application of negative bias voltage. The influence of negative bias voltage on the microhardness and residual stresses of the films and the inherent mechanisms were also explored

  6. Inelastic effects in molecular transport junctions: The probe technique at high bias

    Science.gov (United States)

    Kilgour, Michael; Segal, Dvira

    2016-03-01

    We extend the Landauer-Büttiker probe formalism for conductances to the high bias regime and study the effects of environmentally induced elastic and inelastic scattering on charge current in single molecule junctions, focusing on high-bias effects. The probe technique phenomenologically incorporates incoherent elastic and inelastic effects to the fully coherent case, mimicking a rich physical environment at trivial cost. We further identify environmentally induced mechanisms which generate an asymmetry in the current, manifested as a weak diode behavior. This rectifying behavior, found in two types of molecular junction models, is absent in the coherent-elastic limit and is only active in the case with incoherent-inelastic scattering. Our work illustrates that in the low bias-linear response regime, the commonly used "dephasing probe" (mimicking only elastic decoherence effects) operates nearly indistinguishably from a "voltage probe" (admitting inelastic-dissipative effects). However, these probes realize fundamentally distinct I-V characteristics at high biases, reflecting the central roles of dissipation and inelastic scattering processes on molecular electronic transport far-from-equilibrium.

  7. Effect of precipitation bias correction on water budget calculation in Upper Yellow River, China

    International Nuclear Information System (INIS)

    This study quantifies the effect of precipitation bias corrections on basin water balance calculations for the Yellow River Source region (YRS). We analyse long-term (1959–2001) monthly and yearly data of precipitation, runoff, and ERA-40 water budget variables and define a water balance regime. Basin precipitation, evapotranspiration and runoff are high in summer and low in winter. The basin water storage change is positive in summer and negative in winter. Monthly precipitation bias corrections, ranging from 2 to 16 mm, do not significantly alter the pattern of the seasonal water budget. The annual bias correction of precipitation is about 98 mm (19%); this increase leads to the same amount of evapotranspiration increase, since yearly runoff remains unchanged and the long-term storage change is assumed to be zero. Annual runoff and evapotranspiration coefficients change, due to precipitation bias corrections, from 0.33 and 0.67 to 0.28 and 0.72, respectively. These changes will impact the parameterization and calibration of land surface and hydrological models. The bias corrections of precipitation data also improve the relationship between annual precipitation and runoff. (letter)

  8. Size-dependent effects in exchange-biased planar Hall effect sensor crosses

    DEFF Research Database (Denmark)

    Donolato, Marco; Dalslet, Bjarke Thomas; Damsgaard, Christian Danvad;

    2011-01-01

    response. For intermediate values of w, the magnetization reversal takes place in two steps, and for small values of w, the magnetization reversal takes place in a single step. Based on electrical measurements, magnetic force microscopy, and micromagnetic simulations, the observations are explained by an......Exchange-biased planar Hall effect magnetic field sensor crosses with arm width w have been studied as function of w. For large values of w, the magnetic behavior is hysteresis-free and follows the single domain Stoner-Wohlfarth model. When w is decreased, hysteresis is observed in the sensor...... increasing magnetic shape anisotropy of the arms of the cross. We propose a simple analytical model that captures the essential physics of the observations and parameterizes the effects of the cross-shape on the central part of the cross. (C) 2011 American Institute of Physics. [doi:10.1063/1.3561364]...

  9. Effect of Barrier Width on Bias-Dependent Tunnelling in Ferromagnetic Junctions

    Institute of Scientific and Technical Information of China (English)

    LI Fei-Fei; XIAO Ming-Wen; LI Zheng-Zhong; HU An; XU Wang

    2004-01-01

    @@ We present a finite temperature theory for bias-dependent tunnelling in ferromagnetic tunnelling junctions. The effects of the barrier width d on the tunnelling magnetoresistance (TMR) and its sign change behaviour are discussed with this theory. Numerical results show that both the zero-bias TMR and the critical voltage Vc at which the TMR changes its sign decrease with the increasing barrier width for a considerably thick barrier junction. Furthermore, it is found that a minimum exists in the curve of Vc versus d if a composite junction is under oxidized.

  10. Effect of cognitive biases on human-robot interaction: a case study of robot's misattribution

    OpenAIRE

    Biswas, Mriganka; Murray, John

    2014-01-01

    This paper presents a model for developing long-term human-robot interactions and social relationships based on the principle of 'human' cognitive biases applied to a robot. The aim of this work is to study how a robot influenced with human ‘misattribution’ helps to build better human-robot interactions than unbiased robots. The results presented in this paper suggest that it is important to know the effect of cognitive biases in human characteristics and interactions in order to better u...

  11. Effects of divertor plate biasing on radial and poloidal edge fluxes in the TdeV

    International Nuclear Information System (INIS)

    The divertor plates of TdeV, a tokamak with a double-null divertor and closed divertor chambers, have been electrically biased with respect to the walls. The paper discusses the resulting effects on the edge electron density profile, on the neutral pressures and impurity fluxes in the main vacuum chamber and the divertor chambers, and on the plasma flow to the divertors. As a function of the bias voltage, which was varied between - 180 V and + 160 V, the electron density scrape-off width and the wall impurity influxes increase monotonically; the flows to the top and bottom divertors vary strongly, in qualitative agreement with an E-vector x B-vector/B2 rotation, but not symmetrically. With negative biasing, the electrostatic barrier and the rotation combine to give a strong improvement of the divertor efficiency. (author). 30 refs, 10 figs

  12. The effects of assembly bias on cosmological inference from galaxy-galaxy lensing and galaxy clusters

    CERN Document Server

    McEwen, Joseph E

    2016-01-01

    The combination of galaxy-galaxy lensing (GGL) and galaxy clustering is a promising route to measuring the amplitude of matter clustering and testing modified gravity theories of cosmic acceleration. Halo occupation distribution (HOD) modeling can extend the approach down to nonlinear scales, but galaxy assembly bias could introduce systematic errors by causing the HOD to vary with large scale environment at fixed halo mass. We investigate this problem using the mock galaxy catalogs created by Hearin & Watson (2013, HW13), which exhibit significant assembly bias because galaxy luminosity is tied to halo peak circular velocity and galaxy colour is tied to halo formation time. The preferential placement of galaxies (especially red galaxies) in older halos affects the cutoff of the mean occupation function $\\langle N_\\text{cen}(M_\\text{min}) \\rangle$ for central galaxies, with halos in overdense regions more likely to host galaxies. The effect of assembly bias on the satellite galaxy HOD is minimal. We intro...

  13. Towards a de-biased social psychology: The effects of ideological perspective go beyond politics.

    Science.gov (United States)

    Funder, David C

    2015-01-01

    Reasonable conservatives are in short supply and will not arrive to save social psychology any time soon. The field needs to save itself through de-biasing. The effects of a liberal worldview permeate and distort discussion of many topics that are not overtly political, including behavioral genetics and evolutionary psychology, the fundamental attribution error, and the remarkably persistent consistency controversy. PMID:26786293

  14. Scrape-off layer biasing, currents, and electric field effects in tokamaks

    International Nuclear Information System (INIS)

    This is a brief report on a workshop with this title held after the 10th International Plasma-Surface Interaction Conference, that was held 6-8 April, 1992, in Borrego Springs, California. Emphasis was on the effect of biasing the scrape-off layer. Theoretical and experimental work was presented. 1 tab

  15. Temperature effects in exchange-biased planar Hall sensors for bioapplications

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Dalslet, Bjarke Thomas; Freitas, S.C.;

    2009-01-01

    The temperature dependence of exchange biased planar Hall effect sensors is investigated between T = −10 and 70 °C. It is shown that a single domain model describes the system well and that the temperature coefficient of the low-field sensitivity at T = 25 °C is 0.32%/°C. A procedure for...

  16. Exchange-biased planar Hall effect sensor optimized for biosensor applications

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Freitas, S.C.; Freitas, P.P.;

    2008-01-01

    This article presents experimental investigations of exchange-biased Permalloy planar Hall effect sensor crosses with a fixed active area of w x w = 40 x 40 mu m(2) and Permalloy thicknesses of t = 20, 30, and 50 nm. It is shown that a single domain model describes the system well and that the...

  17. A Simulation Study of the Effects of Ability Range Restriction on IRT Item Bias Detection Procedures.

    Science.gov (United States)

    Lautenschlager, Gary J.; Park, Dong-Gun

    The effects of variations in degree of range restriction and different subgroup sample sizes on the validity of several item bias detection procedures based on Item Response Theory (IRT) were investigated in a simulation study. The degree of range restriction for each of two subpopulations was varied by cutting the specified subpopulation ability…

  18. Innovative Liner Concepts: Experiments and Impedance Modeling of Liners Including the Effect of Bias Flow

    Science.gov (United States)

    Kelly, Jeff; Betts, Juan Fernando; Fuller, Chris

    2000-01-01

    The study of normal impedance of perforated plate acoustic liners including the effect of bias flow was studied. Two impedance models were developed by modeling the internal flows of perforate orifices as infinite tubes with the inclusion of end corrections to handle finite length effects. These models assumed incompressible and compressible flows, respectively, between the far field and the perforate orifice. The incompressible model was used to predict impedance results for perforated plates with percent open areas ranging from 5% to 15%. The predicted resistance results showed better agreement with experiments for the higher percent open area samples. The agreement also tended to deteriorate as bias flow was increased. For perforated plates with percent open areas ranging from 1% to 5%, the compressible model was used to predict impedance results. The model predictions were closer to the experimental resistance results for the 2% to 3% open area samples. The predictions tended to deteriorate as bias flow was increased. The reactance results were well predicted by the models for the higher percent open area, but deteriorated as the percent open area was lowered (5%) and bias flow was increased. A fit was done on the incompressible model to the experimental database. The fit was performed using an optimization routine that found the optimal set of multiplication coefficients to the non-dimensional groups that minimized the least squares slope error between predictions and experiments. The result of the fit indicated that terms not associated with bias flow required a greater degree of correction than the terms associated with the bias flow. This model improved agreement with experiments by nearly 15% for the low percent open area (5%) samples when compared to the unfitted model. The fitted model and the unfitted model performed equally well for the higher percent open area (10% and 15%).

  19. Hostile Attributional Bias, Negative Emotional Responding, and Aggression in Adults: Moderating Effects of Gender and Impulsivity

    OpenAIRE

    Chen, Pan; Coccaro, Emil F.; Jacobson, Kristen C

    2012-01-01

    The current study examined the main effects of hostile attributional bias (HAB) and negative emotional responding on a variety of aggressive behaviors in adults, including general aggression, physical aggression, relational aggression, and verbal aggression. Effects of both externalizing (anger) and internalizing (embarrassment/upset) negative emotions were considered. In addition, the moderating roles of gender and impulsivity on the effects of HAB and negative emotional responding were expl...

  20. The effects of reality television on weight bias: an examination of The Biggest Loser.

    Science.gov (United States)

    Domoff, Sarah E; Hinman, Nova G; Koball, Afton M; Storfer-Isser, Amy; Carhart, Victoria L; Baik, Kyoung D; Carels, Robert A

    2012-05-01

    Weight-loss reality shows, a popular form of television programming, portray obese individuals and their struggles to lose weight. While the media is believed to reinforce obesity stereotypes and contribute to weight stigma, it is not yet known whether weight-loss reality shows have any effect on weight bias. The goal of this investigation was to examine how exposure to 40-min of The Biggest Loser impacted participants' levels of weight bias. Fifty-nine participants (majority of whom were white females) were randomly assigned to either an experimental (one episode of The Biggest Loser) or control (one episode of a nature reality show) condition. Levels of weight bias were measured by the Implicit Associations Test (IAT), the Obese Person Trait Survey (OPTS), and the Anti-fat Attitudes scale (AFA) at baseline and following the episode viewing (1 week later). Participants in The Biggest Loser condition had significantly higher levels of dislike of overweight individuals and more strongly believed that weight is controllable after the exposure. No significant condition effects were found for implicit bias or traits associated with obese persons. Exploratory analyses examining moderation of the condition effect by BMI and intention to lose weight indicated that participants who had lower BMIs and were not trying to lose weight had significantly higher levels of dislike of overweight individuals following exposure to The Biggest Loser compared to similar participants in the control condition. These results indicate that anti-fat attitudes increase after brief exposure to weight-loss reality television. PMID:22240725

  1. Phase separation and exchange bias effect in Ca doped EuCrO3

    International Nuclear Information System (INIS)

    The rare-earth chromites have attracted increasing interests in recent years, as a member of a few single-phase multiferroic materials. We studied the structure and magnetic property of a series of Ca-doped EuCrO3 samples by using X-ray powder diffraction and Physical Property Measurement System. Phase separation, rotation of magnetization in M(T) curve and exchange bias effect have been identified. The Eu0.7Ca0.3CrO3 polycrystalline sample may be intrinsically phase-separated, with Cr3+-rich, Cr4+-rich canted antiferromagnetic regions surrounded by spin glass-like frustrated phase, resulting in several magnetic features including: (1) a broad and slow increase of M(T) curve with the decrease of temperature; (2) rotation of magnetization with increasing cooling field; (3) exchange bias and glassy magnetism. The rotation of magnetization is ascribed to the rotation of the moment of Cr4+-rich regions, arising from the competition between exchange coupling energy and magnetostatic energy. The exchange bias effect suggests the formation of weak ferromagnetic unidirectional anisotropy during field cooling, due to the exchange coupling among weak ferromagnetic domains and surrounding spin glass-like regions. This result helps understanding the interaction among different magnetic domains and phases in a complex system. - Highlights: • Exchange bias effect and glassy magnetism were observed in Eu0.7Ca0.3CrO3. • Rotation of the moments of Cr4+-rich regions result in the rotation of magnetization in M(T) curve. • Spin glass-like regions contribute to the observed exchange bias effect

  2. Phase separation and exchange bias effect in Ca doped EuCrO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Dongmei, E-mail: dmdeng@shu.edu.cn [Department of Physics and Materials Genome Institute, Shanghai University, Shanghai 200444 (China); Wang, Xingyu; Zheng, Jiashun; Qian, Xiaolong [Department of Physics and Materials Genome Institute, Shanghai University, Shanghai 200444 (China); Yu, Dehong; Sun, Dehui [Bragg Institute, Australian Nuclear Science and Technology Organization, Kirrawee DC, NSW 2232 (Australia); Jing, Chao [Department of Physics and Materials Genome Institute, Shanghai University, Shanghai 200444 (China); Lu, Bo [Analysis and Measurement Center and Laboratory for Microstructures of Shanghai University, Shanghai 200444 (China); Kang, Baojuan; Cao, Shixun; Zhang, Jincang [Department of Physics and Materials Genome Institute, Shanghai University, Shanghai 200444 (China)

    2015-12-01

    The rare-earth chromites have attracted increasing interests in recent years, as a member of a few single-phase multiferroic materials. We studied the structure and magnetic property of a series of Ca-doped EuCrO{sub 3} samples by using X-ray powder diffraction and Physical Property Measurement System. Phase separation, rotation of magnetization in M(T) curve and exchange bias effect have been identified. The Eu{sub 0.7}Ca{sub 0.3}CrO{sub 3} polycrystalline sample may be intrinsically phase-separated, with Cr{sup 3+}-rich, Cr{sup 4+}-rich canted antiferromagnetic regions surrounded by spin glass-like frustrated phase, resulting in several magnetic features including: (1) a broad and slow increase of M(T) curve with the decrease of temperature; (2) rotation of magnetization with increasing cooling field; (3) exchange bias and glassy magnetism. The rotation of magnetization is ascribed to the rotation of the moment of Cr{sup 4+}-rich regions, arising from the competition between exchange coupling energy and magnetostatic energy. The exchange bias effect suggests the formation of weak ferromagnetic unidirectional anisotropy during field cooling, due to the exchange coupling among weak ferromagnetic domains and surrounding spin glass-like regions. This result helps understanding the interaction among different magnetic domains and phases in a complex system. - Highlights: • Exchange bias effect and glassy magnetism were observed in Eu{sub 0.7}Ca{sub 0.3}CrO{sub 3}. • Rotation of the moments of Cr{sup 4+}-rich regions result in the rotation of magnetization in M(T) curve. • Spin glass-like regions contribute to the observed exchange bias effect.

  3. Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence

    OpenAIRE

    Victoria Braithwaite

    2013-01-01

    Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid “stress” hormone response matures and specific regions in the brain undergo considerable change. ...

  4. Exchange bias effect in BiFeO3-NiO nanocomposite

    Science.gov (United States)

    Chakrabarti, Kaushik; Sarkar, Babusona; Dev Ashok, Vishal; Das, Kajari; Sinha Chaudhuri, Sheli; Mitra, Amitava; De, S. K.

    2014-01-01

    Ferromagnetic BiFeO3 nanocrystals of average size 11 nm were used to form nanocomposites (x)BiFeO3/(100 - x)NiO, x = 0, 20, 40, 50, 60, 80, and 100 by simple solvothermal process. The ferromagnetic BiFeO3 nanocrystals embedded in antiferromagnetic NiO nanostructures were confirmed from X-ray diffraction and transmission electron microscope studies. The modification of cycloidal spin structure of bulk BiFeO3 owing to reduction in particle size compared to its spin spiral wavelength (62 nm) results in ferromagnetic ordering in pure BiFeO3 nanocrystals. High Neel temperature (TN) of NiO leads to significant exchange bias effect across the BiFeO3/NiO interface at room temperature. A maximum exchange bias field of 123.5 Oe at 300 K for x = 50 after field cooling at 7 kOe has been observed. The exchange bias coupling causes an enhancement of coercivity up to 235 Oe at 300 K. The observed exchange bias effect originates from the exchange coupling between the surface uncompensated spins of BiFeO3 nanocrystals and NiO nanostructures.

  5. Exchange bias effect in BiFeO{sub 3}-NiO nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarti, Kaushik; Sarkar, Babusona; Dev Ashok, Vishal; Das, Kajari; De, S. K., E-mail: msskd@iacs.res.in [Department of Materials Science, Indian Association For the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Sinha Chaudhuri, Sheli [Department of Electronics and Telecommunication Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India); Mitra, Amitava [Material Science and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur 7 (India)

    2014-01-07

    Ferromagnetic BiFeO{sub 3} nanocrystals of average size 11 nm were used to form nanocomposites (x)BiFeO{sub 3}/(100 − x)NiO, x = 0, 20, 40, 50, 60, 80, and 100 by simple solvothermal process. The ferromagnetic BiFeO{sub 3} nanocrystals embedded in antiferromagnetic NiO nanostructures were confirmed from X-ray diffraction and transmission electron microscope studies. The modification of cycloidal spin structure of bulk BiFeO{sub 3} owing to reduction in particle size compared to its spin spiral wavelength (62 nm) results in ferromagnetic ordering in pure BiFeO{sub 3} nanocrystals. High Neel temperature (T{sub N}) of NiO leads to significant exchange bias effect across the BiFeO{sub 3}/NiO interface at room temperature. A maximum exchange bias field of 123.5 Oe at 300 K for x = 50 after field cooling at 7 kOe has been observed. The exchange bias coupling causes an enhancement of coercivity up to 235 Oe at 300 K. The observed exchange bias effect originates from the exchange coupling between the surface uncompensated spins of BiFeO{sub 3} nanocrystals and NiO nanostructures.

  6. The effect of beam intensity on the estimation bias of beam position

    International Nuclear Information System (INIS)

    For the signals of the beam position monitor (BPM), the signal-to-noise ratio (SNR) is directly related to the beam intensity. Low beam intensity results in poor SNR. The random noise has a modulation effect on both the amplitude and phase of the BPM signals. Therefore, the beam position measurement has a certain random error. In the currently used BPM, time-averaging and waveform clipping are used to improve the measurement. The nonlinear signal processing results in a biased estimate of beam position. A statistical analysis was made to examine the effect of the SNR, which is determined by the beam intensity, on the estimation bias. The results of the analysis suggest that the estimation bias has a dependence not only on the beam position but also on beam intensity. Specifically, the dependence gets strong as the beam intensity decreases. This property has set a lower limit of the beam intensity range which the BPM's can handle. When the beam intensity is below that limit the estimation bias starts to vary dramatically, resulting in the BPMs failure. According to the analysis, the lowest beam intensity is that at which the SNR of the generated BPM signal is about 15 dB. The limit for NSEP BPM, for instance, is about 6Ell. The analysis may provide the BPM designers with some idea about the potential of the current BPM'S

  7. Exchange bias effect in composites of cuo nanoparticles and nanosilica glass

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan Saha, Dhriti [MLS Professor' s Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India); Kumar Nandi, Arun [Polymer Science Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India); Chakravorty, Dipankar, E-mail: mlsdc@iacs.res.in [MLS Professor' s Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India)

    2014-04-15

    Nanodimensional silica based glass containing iron ions was prepared within the compressed pellet of CuO nanoparicles. The nanocomposite material showed exchange bias effect. This effect arose due to ferromagnetic iron doped CuO phase and antiferromagnetic CuO interface formation within the nanocomposite during the synthesis process. Coercive field as a function of temperature was fitted with Arhenius–Neel equation and extracted blocking temperature was 511 K. The value of effective anisotropy constant for the nanocomposite was found to be 3.64x10{sup 5} erg/cc. - Highlights: • Nanoglass comprising SiO{sub 2} and Fe{sub 2}O{sub 3} was grown with pores of CuO nanoparticle compacts. • CuO (AFM)-core and Fe doped CuO (FM) shell were formed during synthesis. • The nanocomposite material showed exchange bias effect.

  8. Exchange bias effect in composites of cuo nanoparticles and nanosilica glass

    International Nuclear Information System (INIS)

    Nanodimensional silica based glass containing iron ions was prepared within the compressed pellet of CuO nanoparicles. The nanocomposite material showed exchange bias effect. This effect arose due to ferromagnetic iron doped CuO phase and antiferromagnetic CuO interface formation within the nanocomposite during the synthesis process. Coercive field as a function of temperature was fitted with Arhenius–Neel equation and extracted blocking temperature was 511 K. The value of effective anisotropy constant for the nanocomposite was found to be 3.64x105 erg/cc. - Highlights: • Nanoglass comprising SiO2 and Fe2O3 was grown with pores of CuO nanoparticle compacts. • CuO (AFM)-core and Fe doped CuO (FM) shell were formed during synthesis. • The nanocomposite material showed exchange bias effect

  9. Food stress causes sex-specific maternal effects in mites.

    Science.gov (United States)

    Walzer, Andreas; Schausberger, Peter

    2015-08-01

    Life history theory predicts that females should produce few large eggs under food stress and many small eggs when food is abundant. We tested this prediction in three female-biased size-dimorphic predatory mites feeding on herbivorous spider mite prey: Phytoseiulus persimilis, a specialized spider mite predator; Neoseiulus californicus, a generalist preferring spider mites; Amblyseius andersoni, a broad diet generalist. Irrespective of predator species and offspring sex, most females laid only one small egg under severe food stress. Irrespective of predator species, the number of female but not male eggs decreased with increasing maternal food stress. This sex-specific effect was probably due to the higher production costs of large female than small male eggs. The complexity of the response to the varying availability of spider mite prey correlated with the predators' degree of adaptation to this prey. Most A. andersoni females did not oviposit under severe food stress, whereas N. californicus and P. persimilis did oviposit. Under moderate food stress, only P. persimilis increased its investment per offspring, at the expense of egg number, and produced few large female eggs. When prey was abundant, P. persimilis decreased the female egg sizes at the expense of increased egg numbers, resulting in a sex-specific egg size/number trade-off. Maternal effects manifested only in N. californicus and P. persimilis. Small egg size correlated with the body size of daughters but not sons. Overall, our study provides a key example of sex-specific maternal effects, i.e. food stress during egg production more strongly affects the sex of the large than the small offspring. PMID:26089530

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

    Science.gov (United States)

    Niang, K. M.; Barquinha, P. M. C.; Martins, R. F. P.; Cobb, B.; Powell, M. J.; Flewitt, A. J.

    2016-02-01

    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 107 s-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.

  11. Contamination, potential bias and humidity effects on electrical performance and corrosion reliability of electronic devices

    OpenAIRE

    Piotrowska, Kamila; Verdingovas, Vadimas; Jellesen, Morten S.; Ambat, Rajan

    2015-01-01

    This paper describes the interactions between flux contamination, humidity and po-tential bias and their effect on corrosion reliability. Water layer formation on laminate surfaces and behavior of different solder flux chemistries with humid conditions have been studied, together with their influence on electrical performance of electronics. The effect of the type of laminate’s solder mask on the formation of water film and droplets was investigated for two different types: smooth glossy and ...

  12. Are Real Effects of Credit Supply Overestimated? Bias from Firms' Current Situation and Future Expectations

    OpenAIRE

    Kleemann, Michael; Wiegand, Manuel

    2014-01-01

    This paper advocates for incorporating timely measures of firms' current situation and future expectations when disentangling real effects of credit supply from demand-side factors. Identification of supply-side effects in firm-level analyses often relies on balance sheet variables to control for firm heterogeneity. While balance sheets mirror past business, bias from contemporaneous and forward-looking firm-side factors may persist.Using German firm-level survey data from 2003 to 2011, we sh...

  13. Cognitive biases in processing infant emotion by women with depression, anxiety and post-traumatic stress disorder in pregnancy or after birth: A systematic review

    OpenAIRE

    Webb, R; Ayers, S

    2015-01-01

    Perinatal psychological problems such as post-natal depression are associated with poor mother-baby interaction, but the reason for this is not clear. One explanation is that mothers with negative mood have biased processing of infant emotion. This review aimed to synthesise research on processing of infant emotion by pregnant or post-natal women with anxiety, depression or post-traumatic stress disorder (PTSD). Systematic searches were carried out on 11 electronic databases using terms relat...

  14. Prejudice and the Plate: Effects of Weight Bias in Nutrition Judgments.

    Science.gov (United States)

    Schuldt, Jonathon P; Guillory, Jamie E; Gay, Geri K

    2016-01-01

    As millions of people turn to social media for health information, better understanding the factors that guide health-related judgments and perceptions in this context is imperative. We report on two Web experiments (n>400 total) examining the power of society's widespread weight bias and related stereotypes to influence nutrition judgments in social media spaces. In Experiment 1, meals were judged as lower in nutritional quality when the person who recommended them (the source) was depicted as obese rather than of normal weight, an effect mediated by stereotypic beliefs about the source as a generally unhealthy person. Experiment 2 replicated this effect, which--notably--remained significant when controlling for objective nutritional information (calories and fat content). Results highlight spillover effects of weight bias that extend beyond person perception to color impressions of objects (here, food) that are associated with stigmatized attributes. Implications for everyday nutrition judgments and public health are considered. PMID:26327139

  15. The Effect of Response Bias on the Personality Inventory for DSM-5 (PID-5).

    Science.gov (United States)

    McGee Ng, Sarah A; Bagby, R Michael; Goodwin, Brandee E; Burchett, Danielle; Sellbom, Martin; Ayearst, Lindsay E; Dhillon, Sonya; Yiu, Shirley; Ben-Porath, Yossef S; Baker, Spencer

    2016-01-01

    Valid self-report assessment of psychopathology relies on accurate and credible responses to test questions. There are some individuals who, in certain assessment contexts, cannot or choose not to answer in a manner typically representative of their traits or symptoms. This is referred to, most broadly, as test response bias. In this investigation, we explore the effect of response bias on the Personality Inventory for DSM-5 (PID-5; Krueger, Derringer, Markon, Watson, & Skodol, 2013 ), a self-report instrument designed to assess the pathological personality traits used to inform diagnosis of the personality disorders in Section III of DSM-5. A set of Minnesota Multiphasic Personality Inventory Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008 / 2011 ) validity scales, which are used to assess and identify response bias, were employed to identify individuals who engaged in either noncredible overreporting (OR) or underreporting (UR), or who were deemed to be reporting or responding to the items in a "credible" manner-credible responding (CR). A total of 2,022 research participants (1,587 students, 435 psychiatric patients) completed the MMPI-2-RF and PID-5; following protocol screening, these participants were classified into OR, UR, or CR response groups based on MMPI-2-RF validity scale scores. Groups of students and patients in the OR group scored significantly higher on the PID-5 than those students and patients in the CR group, whereas those in the UR group scored significantly lower than those in the CR group. Although future research is needed to explore the effects of response bias on the PID-5, results from this investigation provide initial evidence suggesting that response bias influences scale elevations on this instrument. PMID:26583767

  16. Copper ion diffusion in porous and nonporous SiO2-based dielectrics using bias thermal stress and thermal stress tests

    International Nuclear Information System (INIS)

    The success of future gigascale integrated circuit chip technology depends critically upon the introduction of low dielectric constant (low-k) materials as interlayer dielectrics, and their integration with copper, the low resistivity interconnect metal of choice. Currently the interest is focused on porous silica-based films due to their ultra low-k value and high compatibility to the current silica technology. Nanoporous silica-based films were deposited by surfactant templated self-assembly spin-on deposition (SOD). Other low-density silica-based films were deposited by plasma enhanced chemical vapor deposition (PECVD). A dense thermal SiO2 was used as a reference. The diffusion of Cu into the different dielectrics studied was evaluated by characterizing metal-insulator-semiconductor (MIS) devices subjected to thermal stress (TS) and bias thermal stresses (BTS). The diffusion of Cu ions induced by TS in the temperature range of 300 up to 500 deg. C can be described by an Arrhenius-like dependence. The lowest activation energy value (0.71 ± 0.04 eV) was obtained for the porous SOD film, which can be attributed to the fast Cu ions surface diffusion through the interconnected pore structure of the film. The activation energies increased with increasing film density, and the highest value (1.02 ± 0.12 eV) was obtained for thermal SiO2, which can be attributed to the slow Cu ions bulk diffusion through the dense dielectric. For the PECVD SiO2 film an intermediate activation energy value of 0.84 ± 0.06 eV was obtained. These activation energy values are comparable to the values reported in the literature for similar types of dielectric films. When subjecting these MIS capacitors to BTS up to 2 MV/cm at 300 deg. C, a general Cu-related phenomenon of no inversion layer was found. This phenomenon was not reported previously in the literature for low-k dielectrics, and has only recently been reported by our group for thermal SiO2. This failure mechanism was related to

  17. Low-bias negative differential resistance effect in armchair graphene nanoribbon junctions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Suchun [Department of Physics, Center for Advanced 2D Materials and Graphene Research Center, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore 117456 (Singapore); Gan, Chee Kwan [Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore); Son, Young-Woo [Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of); Feng, Yuan Ping [Department of Physics, Center for Advanced 2D Materials and Graphene Research Center, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore 117456 (Singapore); Quek, Su Ying, E-mail: phyqsy@nus.edu.sg [Department of Physics, Center for Advanced 2D Materials and Graphene Research Center, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore)

    2015-01-05

    Graphene nanoribbons with armchair edges (AGNRs) have bandgaps that can be flexibly tuned via the ribbon width. A junction made of a narrower AGNR sandwiched between two wider AGNR leads was recently reported to possess two perfect transmission channels close to the Fermi level. Here, we report that by using a bias voltage to drive these transmission channels into the gap of the wider AGNR lead, we can obtain a negative differential resistance (NDR) effect. Owing to the intrinsic properties of the AGNR junctions, the on-set bias reaches as low as ∼0.2 V and the valley current almost vanishes. We further show that such NDR effect is robust against details of the atomic structure of the junction, substrate, and whether the junction is made by etching or by hydrogenation.

  18. Low-bias negative differential resistance effect in armchair graphene nanoribbon junctions

    International Nuclear Information System (INIS)

    Graphene nanoribbons with armchair edges (AGNRs) have bandgaps that can be flexibly tuned via the ribbon width. A junction made of a narrower AGNR sandwiched between two wider AGNR leads was recently reported to possess two perfect transmission channels close to the Fermi level. Here, we report that by using a bias voltage to drive these transmission channels into the gap of the wider AGNR lead, we can obtain a negative differential resistance (NDR) effect. Owing to the intrinsic properties of the AGNR junctions, the on-set bias reaches as low as ∼0.2 V and the valley current almost vanishes. We further show that such NDR effect is robust against details of the atomic structure of the junction, substrate, and whether the junction is made by etching or by hydrogenation

  19. The continuous end-state comfort effect: weighted integration of multiple biases.

    Science.gov (United States)

    Herbort, Oliver; Butz, Martin V

    2012-05-01

    The grasp orientation when grasping an object is frequently aligned in anticipation of the intended rotation of the object (end-state comfort effect). We analyzed grasp orientation selection in a continuous task to determine the mechanisms underlying the end-state comfort effect. Participants had to grasp a box by a circular handle-which allowed for arbitrary grasp orientations-and then had to rotate the box by various angles. Experiments 1 and 2 revealed both that the rotation's direction considerably determined grasp orientations and that end-postures varied considerably. Experiments 3 and 4 further showed that visual stimuli and initial arm postures biased grasp orientations if the intended rotation could be easily achieved. The data show that end-state comfort but also other factors determine grasp orientation selection. A simple mechanism that integrates multiple weighted biases can account for the data. PMID:21499901

  20. Gate/drain bias-induced degradation effects in TFTs fabricated in unhydrogenated SPC polycrystalline silicon films

    International Nuclear Information System (INIS)

    The behavior of the parameters of n-channel thin film transistors (TFTs) in unhydrogenated solid phase crystallized polysilicon films under gate and drain direct-current bias stresses was investigated. The density of states in these films was evaluated using ultraviolet-visible spectroscopy and a larger density of localized states below the bottom of the conduction band was correlated with poorer electrical parameters. The TFT threshold voltage exhibited an initial negative shift attributed to hole trapping and turnaround to positive shift under VGS stress, attributed to electron trapping in the oxide and at stress-induced interface states, with logarithmic stressing time dependence. The subthreshold slope and the electron mobility also exhibited logarithmic degradation. Stress-induced trap creation at the interface and in the polysilicon active layer was inferred as the main cause of these shifts. When a VDS stress is combined with the VGS stress bias the Vth turnaround is suppressed and parameter degradation is enhanced, indicating an increase in stress-induced trap creation and electron trapping, in correlation with the increase of stressing current IDS

  1. Contamination, potential bias and humidity effects on electrical performance and corrosion reliability of electronic devices

    DEFF Research Database (Denmark)

    Piotrowska, Kamila; Verdingovas, Vadimas; Jellesen, Morten S.;

    2015-01-01

    This paper describes the interactions between flux contamination, humidity and po-tential bias and their effect on corrosion reliability. Water layer formation on laminate surfaces and behavior of different solder flux chemistries with humid conditions have been studied, together with their......-sponse of electronics is estimated as a function of contamination type under cycling humid conditions. The results show the correlation between the ionic contamination type and water layer formation on surfaces in the presence of the flux residue....

  2. Alcohol Cue Exposure Effects on Craving and Attentional Bias in Underage College Student Drinkers

    OpenAIRE

    Ramirez, Jason J.; Monti, Peter M.; Colwill, Ruth M.

    2014-01-01

    The effect of alcohol cue exposure on eliciting craving has been well documented and numerous theoretical models assert that craving is a clinically significant construct central to the motivation and maintenance of alcohol-seeking behavior. Furthermore, some theories propose a relationship between craving and attention, such that cue-induced increases in craving bias attention towards alcohol cues, which in turn perpetuates craving. This study examined the extent to which alcohol cues induce...

  3. The quantum approach to human reasoning does explain the belief-bias effect

    CERN Document Server

    Vol, E D

    2013-01-01

    Based on the ideas of quantum physics and dual-process theory of human reasoning that takes into account two primary mechanisms of reasoning : 1) deductive rational thinking and 2) intuitive heuristic judgment, we proposed the "quantum" approach to practical human logic that allows one to specify the most distinctive peculiarities in activity of two reasoning systems mentioned above and in addition to describe phenomenologically well-established experimentally belief-bias effect.

  4. Effective population size does not predict codon usage bias in mammals

    OpenAIRE

    Kessler, Michael D; Dean, Matthew D.

    2014-01-01

    Synonymous codons are not used at equal frequency throughout the genome, a phenomenon termed codon usage bias (CUB). It is often assumed that interspecific variation in the intensity of CUB is related to species differences in effective population sizes (N e), with selection on CUB operating less efficiently in species with small N e. Here, we specifically ask whether variation in N e predicts differences in CUB in mammals and report two main findings. First, across 41 mammalian genomes, CUB ...

  5. Skill biased technical change: panel evidence of task orientation, wage effects, and labor dynamics

    OpenAIRE

    Ross, Matthew

    2014-01-01

    Existing empirical analyses of Skill Biased Technical Change focus on examining repeated cross-sections of individuals holding occupational task measures fixed. That approach cannot explore how wages respond to temporal variation in task orientation. This analysis examines wage effects using a synthetic panel of occupational task measures constructed from 17 releases of the O*NET database. This synthetic panel is combined with a panel of individual workers. Cross-occupational estimates that c...

  6. Observation of an atomic exchange bias effect in DyCo4 film

    OpenAIRE

    Kai Chen; Dieter Lott; Florin Radu; Fadi Choueikani; Edwige Otero; Philippe Ohresser

    2015-01-01

    The fundamental important and technologically widely employed exchange bias effect occurs in general in bilayers of magnetic thin films consisting of antiferromagnetic and ferromagnetic layers where the hard magnetization behavior of an antiferromagnetic thin film causes a shift in the magnetization curve of a soft ferromagnetic film. The minimization of the single magnetic grain size to increase the storage density and the subsequent demand for magnetic materials with very high magnetic anis...

  7. Volunteer bias in sex research :effects of variable stimuli content and intrusiveness of measurement

    OpenAIRE

    Lane, Mary Kathleen

    1988-01-01

    Previous studies of volunteer bias in sex research found that volunteers for such studies differed from nonâ volunteers in terms of reporting increased heterosexual experience; more liberal attitudes toward sex; increased exposure to commercialized erotica; and an increase in sexual trauma. The object of this study was to investigate the effects that varying the stimuli content (i.e. heterosexual vs gay male vs lesbian) of films used in sexual arousal studies would have on volunteer rate an...

  8. On a Class of Bias-Amplifying Variables that Endanger Effect Estimates

    OpenAIRE

    Pearl, Judea

    2012-01-01

    This note deals with a class of variables that, if conditioned on, tends to amplify confounding bias in the analysis of causal effects. This class, independently discovered by Bhattacharya and Vogt (2007) and Wooldridge (2009), includes instrumental variables and variables that have greater influence on treatment selection than on the outcome. We offer a simple derivation and an intuitive explanation of this phenomenon and then extend the analysis to non linear models. We show that: 1. the bi...

  9. Thermophysical Property Estimation by Transient Experiments: The Effect of a Biased Initial Temperature Distribution

    Directory of Open Access Journals (Sweden)

    Federico Scarpa

    2015-01-01

    Full Text Available The identification of thermophysical properties of materials in dynamic experiments can be conveniently performed by the inverse solution of the associated heat conduction problem (IHCP. The inverse technique demands the knowledge of the initial temperature distribution within the material. As only a limited number of temperature sensors (or no sensor at all are arranged inside the test specimen, the knowledge of the initial temperature distribution is affected by some uncertainty. This uncertainty, together with other possible sources of bias in the experimental procedure, will propagate in the estimation process and the accuracy of the reconstructed thermophysical property values could deteriorate. In this work the effect on the estimated thermophysical properties due to errors in the initial temperature distribution is investigated along with a practical method to quantify this effect. Furthermore, a technique for compensating this kind of bias is proposed. The method consists in including the initial temperature distribution among the unknown functions to be estimated. In this way the effect of the initial bias is removed and the accuracy of the identified thermophysical property values is highly improved.

  10. Enhanced effects of combined cognitive bias modification and computerised cognitive behaviour therapy on social anxiety

    Directory of Open Access Journals (Sweden)

    Emma Butler

    2015-12-01

    Full Text Available This study examines whether combined cognitive bias modification for interpretative biases (CBM-I and computerised cognitive behaviour therapy (C-CBT can produce enhanced positive effects on interpretation biases and social anxiety. Forty socially anxious students were randomly assigned into two conditions, an intervention group (positive CBM-I + C-CBT or an active control (neutral CBM-I + C-CBT. At pre-test, participants completed measures of social anxiety, interpretative bias, cognitive distortions, and social and work adjustment. They were exposed to 6 × 30 min sessions of web-based interventions including three sessions of either positive or neutral CBM-I and three sessions of C-CBT, one session per day. At post-test and two-week follow-up, participants completed the baseline measures. A combined positive CBM-I + C-CBT produced less negative interpretations of ambiguous situations than neutral CBM-I + C-CBT. The results also showed that both positive CBM-I + C-CBT and neutral CBM-I + C-CBT reduced social anxiety and cognitive distortions as well as improving work and social adjustment. However, greater effect sizes were observed in the positive CBM-I + C-CBT condition than the control. This indicates that adding positive CBM-I to C-CBT enhanced the training effects on social anxiety, cognitive distortions, and social and work adjustment compared to the neutral CBM-I + C-CBT condition.

  11. A study on the degradation mechanism of InGaZnO thin-film transistors under simultaneous gate and drain bias stresses based on the electronic trap characterization

    Science.gov (United States)

    Jeong, Chan-Yong; Lee, Daeun; Song, Sang-Hun; In Kim, Jong; Lee, Jong-Ho; Kwon, Hyuck-In

    2014-04-01

    We discuss the device degradation mechanism of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) under simultaneous gate and drain bias stresses based on the electronic trap characterization results. The transfer curve exhibits an apparent negative shift as the stress time increases, and a formation of hump is observed in the transfer curve after stresses. A notable increase of the frequency dispersion is observed after stresses in both gate-to-drain capacitance-voltage (CGD-VG) and gate-to-source capacitance-voltage (CGS-VG) curves, which implies that the subgap states are generated by simultaneous gate and drain bias stresses, and the damaged location is not limited to the drain side of TFTs. The larger frequency dispersion is observed in CGD-VG curves after stresses in a wider channel device, which implies that the heat is an important factor in the generation of the subgap states under simultaneous gate and drain bias stresses in a-IGZO TFTs. Based on the electronic trap characterization results, we conclude that the impact ionization near the drain side of the device is not a dominant mechanism causing the generation of subgap states and device degradation in a-IGZO TFTs under simultaneous gate and drain bias stresses. The generation of oxygen vacancy-related donor-like traps near the conduction band edge is considered as a possible mechanism causing the device degradation under simultaneous gate and drain bias stresses in a-IGZO TFTs.

  12. The effects of impurity doping on the optical properties of biased bilayer graphene

    Science.gov (United States)

    Rezania, Hamed; Yarmohammadi, Mohsen

    2016-07-01

    We address the optical conductivity of doped AA-stacked bilayer graphene in the presence of a finite bias voltage at finite temperature. The effect of scattering by dilute charged impurities is discussed in terms of the self-consistent Born approximation. Green's function approach has been implemented to find the behavior of optical conductivity of bilayer graphene within linear response theory. We have found the frequency dependence of optical conductivity for different values of concentration and scattering strength of dopant impurity. Also the dependence of optical conductivity on the impurity concentration and bias voltage has been investigated in details. A peak appears in the plot of optical conductivity versus impurity concentration for different values of chemical potential. Furthermore we find optical conductivity reduces with frequency for any impurity concentration and scattering strength.

  13. Study of exchange bias and training effect in NiCr2O4

    Science.gov (United States)

    Barman, Junmoni; Bora, Tribedi; Ravi, S.

    2015-07-01

    Single phase sample of NiCr2O4 crystallized in a tetragonal structure of I41/amd space group was prepared. Ferrimagnetic transition at TC=73 K along with a large irreversibility has been observed from the magnetization measurement. The sample exhibits exchange bias phenomenon and it is explained by considering the anisotropic exchange interaction between the ferrimagnetic and the antiferromagnetic components of magnetic moment. Presence of training effect is also observed. The exchange bias field (HEB) is found to decay exponentially with increase in temperature and however, the coercive field (HCeff) follows the empirical relation HCeff = HCeff [ 1 - T/TC']2 . The maximum experimental values of HEB and HCeff are found to be 313 Oe and 4839 Oe respectively.

  14. The mass-concentration relation in lensing clusters: the role of statistical biases and selection effects

    CERN Document Server

    Sereno, Mauro; Ettori, Stefano; Moscardini, Lauro

    2014-01-01

    The relation between mass and concentration of galaxy clusters traces their formation and evolution. Massive lensing clusters were observed to be over-concentrated and following a steeper scaling in tension with predictions from the standard concordance $\\Lambda$CDM paradigm. We critically revise the relation in the CLASH, the SGAS, the LOCUSS and a high-redshift samples of weak lensing clusters. Measurements of mass and concentration are anti-correlated, which can bias the observed relation towards steeper values. We corrected for this bias and compared the measured relation to theoretical predictions accounting for halo triaxiality, adiabatic contraction of the halo, presence of a dominant BCG and, mostly, selection effects in the observed sample. The normalization, the slope and the scatter of the expected relation are strongly sample-dependent. For the considered samples, the predicted slope is much steeper than that of the underlying relation characterizing dark-matter only clusters. We found that correc...

  15. Observation of an atomic exchange bias effect in DyCo4 film

    Science.gov (United States)

    Chen, Kai; Lott, Dieter; Radu, Florin; Choueikani, Fadi; Otero, Edwige; Ohresser, Philippe

    2015-12-01

    The fundamental important and technologically widely employed exchange bias effect occurs in general in bilayers of magnetic thin films consisting of antiferromagnetic and ferromagnetic layers where the hard magnetization behavior of an antiferromagnetic thin film causes a shift in the magnetization curve of a soft ferromagnetic film. The minimization of the single magnetic grain size to increase the storage density and the subsequent demand for magnetic materials with very high magnetic anisotropy requires a system with high HEB. Here we report an extremely high HEB of 4 Tesla observed in a single amorphous DyCo4 film close to room temperature. The origin of the exchange bias can be associated with the variation of the magnetic behavior from the surface towards the bulk part of the film revealed by X-ray absorption spectroscopy and X-ray magnetic circular dichroism techniques utilizing the bulk sensitive transmission and the surface sensitive total electron yield modes. The competition between the atomic exchange coupling in the single film and the Zeeman interaction lead to an intrinsic exchanged coupled system and the so far highest exchange bias effect HEB = 4 Tesla reported in a single film, which is accommodated by a partial domain wall formation.

  16. Syntactic flexibility and planning scope: The effect of verb bias on advance planning during sentence recall

    Directory of Open Access Journals (Sweden)

    Maartje evan de Velde

    2014-10-01

    Full Text Available In sentence production, grammatical advance planning scope depends on contextual factors (e.g., time pressure, linguistic factors (e.g., ease of structural processing, and cognitive factors (e.g., production speed. The present study tests the influence of the availability of multiple syntactic alternatives (i.e., syntactic flexibility on the scope of advance planning during the recall of Dutch dative phrases. We manipulated syntactic flexibility by using verbs with a strong bias or a weak bias towards one structural alternative in sentence frames accepting both verbs (e.g., strong/weak bias: De ober schotelt/serveert de klant de maaltijd [voor] 'The waiter dishes out/serves the customer the meal'. To assess lexical planning scope, we varied the frequency of the first post-verbal noun (N1, Experiment 1 or the second post-verbal noun (N2, Experiment 2. In each experiment, 36 speakers produced the verb phrases in a Rapid Serial Visual Presentation (RSVP paradigm. On each trial, they read a sentence presented one word at a time, performed a short distractor task, and then saw a sentence preamble (e.g., De ober… which they had to complete to form the presented sentence. Onset latencies were compared using linear mixed effects models. N1 frequency did not produce any effects. N2 frequency only affected sentence onsets in the weak verb bias condition and especially in slow speakers. These findings highlight the dependency of planning scope during sentence recall on the grammatical properties of the verb and the frequency of post-verbal nouns. Implications for utterance planning in everyday speech are discussed.

  17. Temperature evolution of nickel sulphide phases from thiourea complex and their exchange bias effect

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Nitesh [Chemistry and Physics of Materials Unit and International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore-560 064 (India); Raman, N. [Department of Chemistry, VHNSN College, Virudhunagar-626 001 (India); Sundaresan, A., E-mail: sundaresan@jncasr.ac.in [Chemistry and Physics of Materials Unit and International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore-560 064 (India)

    2013-12-15

    Considering the very complex phase diagram of nickel sulphide, it is quite challenging to stabilize pure phases from a single precursor. Here, we obtain nanoparticles of various phases of nickel sulphide by decomposing nickel–thiourea complex at different temperatures. The first phase in the evolution is the one with the maximum sulphur content, namely, NiS{sub 2} nanoparticles obtained at 400 °C. As the temperature is increased, nanoparticles of phases with lesser sulphur content, NiS (600 °C) and Ni{sub 3}S{sub 2} (800 °C) are formed. NiS{sub 2} nanoparticles exhibit weak ferromagnetic transition at 30 K and show a large exchange bias at 2 K. NiS nanoparticles are antiferromagnetic and show relatively smaller exchange bias effect. On the other hand, Ni{sub 3}S{sub 2} nanoparticles exhibit very weak temperature dependent magnetization. Electrical measurements show that both NiS{sub 2} and NiS are semiconductors whereas Ni{sub 3}S{sub 2} is a metal. - Graphical abstract: Pure phases of NiS{sub 2}, NiS and Ni{sub 3}S{sub 2} have been obtained by thermal decomposition of nickel–thiourea complex wherein, NiS{sub 2} nanoparticles exhibit remarkable exchange bias effect at 2 K. - Highlights: • NiS{sub 2}, NiS and Ni{sub 3}S{sub 2} nanoparticles are obtained by thermal decomposition of nickel–thiourea complex at different temperatures. • As the temperature is increased, nickel sulphide phase with lesser sulphur content is obtained. • NiS{sub 2} nanoparticles show good exchange bias property which can be explained by antiferromagnetic core and ferromagnetic shell model. • NiS{sub 2} and NiS are semiconducting while Ni{sub 3}S{sub 2} shows metallic behavior.

  18. Effect of sputtering pressure on residual stress in Ni films using energy-dispersive x-ray diffraction

    International Nuclear Information System (INIS)

    A procedure for determining the residual stress in thin films using energy dispersive x-ray diffraction was investigated. The effect of the sputtering pressure on the residual stress in dc magnetron sputtered Ni films was studied in greater detail using this approach. The behavior reported suggested the possibility of controlling or influencing the sign and/or magnitude of the residual stress. In addition, the stress variation with increasing negative bias voltage is also presented. In the range studied, between -15 and -150 V, residual stress is always tensile

  19. Comparison of composition and atomic structure of amorphous indium gallium zinc oxide thin film transistor before and after positive bias temperature stress by transmission electron microscopy

    International Nuclear Information System (INIS)

    In this paper high resolution transmission electron microscopy analysis is performed on indium gallium zinc oxide thin film transistors to determine the crystal structure of the material. The relative elemental concentrations of indium, gallium, zinc and oxygen were quantified and analyzed using energy dispersive spectroscopy before and after subjection to positive gate bias temperature stress at 80 °C. Notable changes in the concentration of oxygen in the device channel were observed along with a reduced concentration of the elements indium, gallium and zinc after electrical stressing. We speculate this relative reduction in metal concentration could be attributed to the outdiffusion of metal ions from the channel region into the surrounding thermal oxide and the increase in the oxygen concentration in the stressed device is related to electric field assisted adsorption of oxygen from the ambient. (paper)

  20. Direct testing of the biasing effect of manipulations of endolymphatic pressure on cochlear mechanical function

    Science.gov (United States)

    LePage, Eric; Avan, Paul

    2015-12-01

    The history of cochlear mechanical investigations has been carried out in two largely separate sets of endeavours; those interested in auditory processing in animal models and those interested in the origin of adverse vestibular symptoms in humans. In respect of the first, mechanical vibratory data is considered pathological and not representative of pristine behaviour if it departs from the reigning model of sharp tuning and high hearing sensitivity. Conversely, when the description of the pathological behaviour is the focus, fluid movements responsible for hearing loss and vestibular symptoms dominate. Yet both extensive sets of data possess a common factor now being reconsidered for its potential to shed light on the mechanisms in general. The common factor is a mechanical bias — the departure of cochlear epithelial membranes from their usual resting position. In both cases the bias modulates hearing sensitivity and distorts tuning characteristics. Indeed several early sets of guinea pig mechanical data were dismissed as "pathological" when in hindsight, the primary effect influencing the data was not loss of outer hair cell function per se, but a mechanical bias unknowingly introduced in process of making the measurement. Such biases in the displacement of the basilar membrane from its position are common, and may be caused by low-frequency sounds (topically including infrasound) or by variations in fluid volume in the chambers particularly applying the case of endolymphatic hydrops. Most biases are quantified in terms of visualisation of fluid volume change, electric potential changes and otoacoustic emissions. Notably many previous studies have also searched for raised pressures with negative results. Yet these repeated findings are contrary to the widespread notion that, at least when homeostasis is lost, it is a rise in endolymphatic pressure which is responsible for membrane rupture and Meniere's attacks. This current investigation in Mongolian gerbils

  1. Motional Effect on Wall Shear Stresses

    DEFF Research Database (Denmark)

    Kock, Samuel Alberg; Torben Fründ, Ernst; Yong Kim, Won

    Atherosclerosis is the leading cause of death and severe disability. Wall Shear Stress (WSS), the stress exerted on vessel walls by the flowing blood is a key factor in the development of atherosclerosis. Computational Fluid Dynamics (CFD) is widely used for WSS estimations. Most CFD simulations...... are based on static models to ease computational burden leading to inaccurate estimations. The aim of this work was to estimate the effect of vessel wall deformations (expansion and bending) on WSS levels....

  2. Effective population size does not predict codon usage bias in mammals.

    Science.gov (United States)

    Kessler, Michael D; Dean, Matthew D

    2014-10-01

    Synonymous codons are not used at equal frequency throughout the genome, a phenomenon termed codon usage bias (CUB). It is often assumed that interspecific variation in the intensity of CUB is related to species differences in effective population sizes (N e), with selection on CUB operating less efficiently in species with small N e. Here, we specifically ask whether variation in N e predicts differences in CUB in mammals and report two main findings. First, across 41 mammalian genomes, CUB was not correlated with two indirect proxies of N e (body mass and generation time), even though there was statistically significant evidence of selection shaping CUB across all species. Interestingly, autosomal genes showed higher codon usage bias compared to X-linked genes, and high-recombination genes showed higher codon usage bias compared to low recombination genes, suggesting intraspecific variation in N e predicts variation in CUB. Second, across six mammalian species with genetic estimates of N e (human, chimpanzee, rabbit, and three mouse species: Mus musculus, M. domesticus, and M. castaneus), N e and CUB were weakly and inconsistently correlated. At least in mammals, interspecific divergence in N e does not strongly predict variation in CUB. One hypothesis is that each species responds to a unique distribution of selection coefficients, confounding any straightforward link between N e and CUB. PMID:25505518

  3. Age and response bias: evidence from the strength-based mirror effect.

    Science.gov (United States)

    Criss, Amy H; Aue, William; Kılıç, Aslı

    2014-10-01

    Performance in episodic memory is determined both by accurate retrieval from memory and by decision processes. A substantial body of literature suggests slightly poorer episodic memory accuracy for older than younger adults; however, age-related changes in the decision mechanisms in memory have received much less attention. Response bias, the willingness to endorse an item as remembered, is an important decision factor that contributes to episodic memory performance, and therefore understanding age-related changes in response bias is critical to theoretical development. We manipulate list strength in order to investigate two aspects of response bias. First, we evaluate whether criterion placement in episodic memory differs for older and younger adults. Second, we ask whether older adults have the same degree of flexibility to adjust the criterion in response to task demands as younger adults. Participants were tested on weakly and strongly encoded lists where word frequency (Experiment 1) or similarity between targets and foils (Experiment 2) was manipulated. Both older and younger adults had higher hit rates and lower false-alarm rates for strong lists than for weak lists (i.e., a strength-based mirror effect). Older adults were more conservative (less likely to endorse an item as studied) than younger adults, and we found no evidence that older and younger adults differ in their ability to flexibly adjust their criterion based on the demands of the task. PMID:24386987

  4. Measuring the Deviation from the Linear and Deterministic Bias through Cosmic Gravitational Lensing Effects

    CERN Document Server

    Fan, Z H

    2003-01-01

    Since gravitational lensing effects directly probe inhomogeneities of dark matter, lensing-galaxy cross-correlations can provide us important information on the relation between dark matter and galaxy distributions, i.e., the bias. In this paper, we propose a method to measure the stochasticity/nonlinearity of the galaxy bias through correlation studies of the cosmic shear and galaxy number fluctuations. Specifically, we employ the aperture mass statistics $M_{ap}$ to describe the cosmic shear. We divide the foreground galaxy redshift $z_f^2/$ for each redshift bin. Then the ratio of the summation of $^2/$ over the bins to $$ gives a measure of the nonlinear/stochastic bias. Here $N_g(z_f)$ is the projected surface number density fluctuation of foreground galaxies at redshift $z_f$, and $M_{ap}$ is the aperture mass from the cosmic-shear analysis. We estimate that for a moderately deep weak-lensing survey with $z_s=1$, source galaxy surface number density $n_b=30 \\hbox {gal}/\\hbox {arcmin}^2$ and a survey are...

  5. Effect of Nickel Concentration on Bias Reliability and Thermal Stability of Thin-Film Transistors Fabricated by Ni-Metal-Induced Crystallization

    Science.gov (United States)

    Lai, Ming-Hui; Sermon Wu, YewChung; Huang, Jung-Jie

    2012-01-01

    Ni-metal-induced crystallization (MIC) of amorphous Si (α-Si) has been employed to fabricate low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs). Although the high leakage current is a major issue in the performance of conventional MIC-TFTs since Ni contamination induces deep-level state traps, it can be greatly improved by using well-known technologies to reduce Ni contamination. However, for active-matrix organic light-emitting diode (AMOLED) display applications, the bias reliability and thermal stability are major concerns especially when devices are operated under a hot carrier condition and in a high-temperature environment. It will be interesting to determine how the bias reliability and thermal stability are affected by the reduction of Ni concentration. In the study, the effect of Ni concentration on bias reliability and thermal stability was investigated. We found that a device exhibited high immunity against hot-carrier stress and elevated temperatures. These findings demonstrated that reducing the Ni concentration in MIC films was also beneficial for bias reliability and thermal stability.

  6. Objects in Kepler's Mirror May be Larger Than They Appear: Bias and Selection Effects in Transiting Planet Surveys

    CERN Document Server

    Gaidos, Eric

    2012-01-01

    Statistical analyses of large surveys for transiting planets such as the Kepler mission must account for systematic errors and biases. Transit detection depends not only on the planet's radius and orbital period, but also on host star properties. Thus, a sample of stars with transiting planets may not accurately represent the target population. Moreover, targets are selected using criteria such as a limiting apparent magnitude. These selection effects, combined with uncertainties in stellar radius, lead to biases in the properties of transiting planets and their host stars. We quantify possible biases in the Kepler survey. First, Eddington bias produced by a steep planet radius distribution and uncertainties in stellar radius results in a 15-20% overestimate of planet occurrence. Second, the magnitude limit of the Kepler target catalog induces Malmquist bias towards large, more luminous stars and underestimation of the radii of about one third of candidate planets, especially those larger than Neptune. Third,...

  7. Nonlinear cosmological consistency relations and effective matter stresses

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, Guillermo [Museo Storico della Fisica e Centro Studi e Ricerche ' ' Enrico Fermi' ' , Piazza del Viminale 1, I-00184 Rome (Italy); Hollenstein, Lukas; Jain, Rajeev Kumar; Kunz, Martin, E-mail: guillermo.ballesteros@pd.infn.it, E-mail: lukas.hollenstein@unige.ch, E-mail: rajeev.jain@unige.ch, E-mail: martin.kunz@unige.ch [Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève, Quai E. Ansermet 24, CH-1211 Genève 4 (Switzerland)

    2012-05-01

    We propose a fully nonlinear framework to construct consistency relations for testing generic cosmological scenarios using the evolution of large scale structure. It is based on the covariant approach in combination with a frame that is purely given by the metric, the normal frame. As an example, we apply this framework to the ΛCDM model, by extending the usual first order conditions on the metric potentials to second order, where the two potentials start to differ from each other. We argue that working in the normal frame is not only a practical choice but also helps with the physical interpretation of nonlinear dynamics. In this frame, effective pressures and anisotropic stresses appear at second order in perturbation theory, even for ''pressureless'' dust. We quantify their effect and compare them, for illustration, to the pressure of a generic clustering dark energy fluid and the anisotropic stress in the DGP model. Besides, we also discuss the effect of a mismatch of the potentials on the determination of galaxy bias.

  8. Selection Effects, Biases, and Constraints in the Calan/Tololo Supernova Survey

    International Nuclear Information System (INIS)

    We use Monte Carlo simulations of the Calan/Tololo photographic supernova survey to show that a simple model of the survey close-quote s selection effects accounts for the observed distributions of recession velocity, apparent magnitude, angular offset, and projected radial distance between the supernova and the host galaxy nucleus for this sample of Type Ia supernovae (SNe Ia). The model includes biases due to the flux-limited nature of the survey, the different light-curve morphologies displayed by different SNe Ia, and the difficulty of finding events projected near the central regions of the host galaxies. From these simulations we estimate the bias in the zero point and slope of the absolute magnitude-decline rate relation used in SNe Ia distance measurements. For an assumed intrinsic scatter of 0.15 mag about this relation, these selection effects decrease the zero point by 0.04 mag. The slope of the relation is not significantly biased. We conclude that despite selection effects in the survey, the shape and zero point of the relation determined from the Calan/Tololo sample are quite reliable. We estimate the degree of incompleteness of the survey as a function of decline rate and estimate a corrected luminosity function for SNe Ia in which the frequency of SNe appears to increase with decline rate (the fainter SNe are more common). Finally, we compute the integrated detection efficiency of the survey in order to infer the rate of SNe Ia from the 31 events found. For a value of H0 =65 km s-1 Mpc-1 we obtain a SN Ia rate of 0.21+0.30-0.13 SNu. This is in good agreement with the value 0.16±0.05 SNe recently determined by Capellaro et al. copyright copyright 1999. The American Astronomical Society

  9. Effect of Ta addition of co-sputtered amorphous tantalum indium zinc oxide thin film transistors with bias stability.

    Science.gov (United States)

    Son, Dae-Ho; Kim, Dae-Hwan; Park, Si-Nae; Sung, Shi-Joon; Kang, Jin-Kyu

    2014-11-01

    In this work, we have fabricated thin film transistors (TFTs) using amorphous tantalum indium zinc oxide (a-TaInZnO) channels by the co-sputtering process. The effects of incorporating tantalum on the InZnO material were investigated using Hall-effect measurement results, and electrical characteristics. We also found that the carrier densities of thin films and the transistor on-off currents were greatly influenced by the composition of tantalum addition. Ta ions have strong affinity to oxygen and so suppress the formation of free electron carriers inthin films; they play an important role in enhancing the electrical characteristic due to their high oxygen bonding ability. The electrical characteristics of the optimized TFTs shows a field effect mobility of 3.67 cm2 V(-1) s(-1), a threshold voltage of 1.28 V, an on/off ratio of 1.1 x 10(8), and a subthreshold swing of 480 mV/dec. Under gate bias stress conditions, the TaInZnO TFTs showed lower shift in threshold voltage shifts. PMID:25958492

  10. The effect of thermal bias on the spin-state manipulation in a quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jia, E-mail: jialiu@imust.cn [School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources IMUST, Baotou 014010 (China); Cheng, Jie; Wang, Song [School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science and Technology, Baotou 014010 (China)

    2014-10-01

    The control of the single electronic state in a quantum dot (QD) by magnetic field in the presence of thermal bias was investigated with a master equation method. Results show that the qubits for information processing can be realized by tuning the magnitude and direction of the magnetic field. In addition, the temperature difference between the source (S) and drain (D) leads, a thermal-spin effect, which is inevitable in practical devices, can also be counteracted with magnetic field. Our results have important implications for quantum information processing.

  11. EFFECT OF HALO BIAS AND LYMAN LIMIT SYSTEMS ON THE HISTORY OF COSMIC REIONIZATION

    International Nuclear Information System (INIS)

    We extend the existing analytical model of reionization by Furlanetto et al. to include the biasing of reionization sources and additional absorption by Lyman limit systems. Both effects enhance the original model in non-trivial ways, but do not change its qualitative features. Our model is, by construction, consistent with the observed evolution of the galaxy luminosity function at z ∼ 6 galaxies, the inadequacy of simulations and/or some of the observational constraints, or indicates an additional source of ionizing radiation at z > 8 remains to be seen.

  12. ANSYS Modeling of Hydrostatic Stress Effects

    Science.gov (United States)

    Allen, Phillip A.

    1999-01-01

    Classical metal plasticity theory assumes that hydrostatic pressure has no effect on the yield and postyield behavior of metals. Plasticity textbooks, from the earliest to the most modem, infer that there is no hydrostatic effect on the yielding of metals, and even modem finite element programs direct the user to assume the same. The object of this study is to use the von Mises and Drucker-Prager failure theory constitutive models in the finite element program ANSYS to see how well they model conditions of varying hydrostatic pressure. Data is presented for notched round bar (NRB) and "L" shaped tensile specimens. Similar results from finite element models in ABAQUS are shown for comparison. It is shown that when dealing with geometries having a high hydrostatic stress influence, constitutive models that have a functional dependence on hydrostatic stress are more accurate in predicting material behavior than those that are independent of hydrostatic stress.

  13. Source Credibility and the Biasing Effect of Narrative Information on the Perception of Vaccination Risks.

    Science.gov (United States)

    Haase, Niels; Betsch, Cornelia; Renkewitz, Frank

    2015-08-01

    Immunization rates are below the Global Immunization Vision and Strategy established by the World Health Organization. One reason for this are anti-vaccination activists, who use the Internet to disseminate their agenda, frequently by publishing narrative reports about alleged vaccine adverse events. In health communication, the use of narrative information has been shown to be effectively persuasive. Furthermore, persuasion research indicates that the credibility of an information source may serve as a cue to discount or augment the communicated message. Thus, the present study investigated the effect of source credibility on the biasing effect of narrative information regarding the perception of vaccination risks. 265 participants were provided with statistical information (20%) regarding the occurrence of vaccine adverse events after vaccination against a fictitious disease. This was followed by 20 personalized narratives from an online forum on vaccination experiences. The authors varied the relative frequency of narratives reporting vaccine adverse events (35% vs. 85%), narrative source credibility (anti-vaccination website vs. neutral health forum), and the credibility of the statistical information (reliable data vs. unreliable data vs. control) in a between-subjects design. Results showed a stable narrative bias on risk perception that was not affected by credibility cues. However, narratives from an anti-vaccination website generally led to lower perceptions of vaccination risks. PMID:26065492

  14. Resonance magnetoelectric effect without a bias field in a piezoelectric langatate-hysteretic ferromagnet monolithic structure

    Science.gov (United States)

    Burdin, D. A.; Fetisov, L. Y.; Fetisov, Y. K.; Chashin, D. V.; Ekonomov, N. A.

    2014-09-01

    The frequency, field, temperature, and amplitude characteristics of the direct magnetoelectric effect are studied in a planar monolithic structure consisting of a piezoelectric langatate crystal and a layer of electrolytic nickel. A relation between the magnetic and magnetoelectric properties of the structure is demonstrated, which explains the effects observed in structures with hysteretic layers. At the planar acoustic resonance frequency of the structure (about 70 kHz), the effect amounting to 23 V/(Oe cm) in the absence of a bias field is discovered. In the temperature interval 150-400 K, the amount of the effect changes nearly twofold, the resonance frequency changes by about 1%, and the Q factor on cooling rises to about 8 × 103. The field sensitivity of the structure is on the order of 1 V/Oe, which makes it possible to detect magnetic fields with an amplitude down to ˜10-6 Oe.

  15. Thermoelastic Stress Analysis: The Mean Stress Effect in Metallic Alloys

    Science.gov (United States)

    Gyekenyesi, Andrew L.; Baaklini, George Y.

    1999-01-01

    The primary objective of this study involved the utilization of the thermoelastic stress analysis (TSA) method to demonstrate the mean stress dependence of the thermoelastic constant. Titanium and nickel base alloys, commonly employed in aerospace gas turbines, were the materials of interest. The repeatability of the results was studied through a statistical analysis of the data. Although the mean stress dependence was well established, the ability to confidently quantify it was diminished by the experimental variations. If calibration of the thermoelastic response to mean stress can be successfully implemented, it is feasible to use the relationship to determine a structure's residual stress state.

  16. Social Anxiety-Linked Attention Bias to Threat Is Indirectly Related to Post-Event Processing Via Subjective Emotional Reactivity to Social Stress.

    Science.gov (United States)

    Çek, Demet; Sánchez, Alvaro; Timpano, Kiara R

    2016-05-01

    Attention bias to threat (e.g., disgust faces) is a cognitive vulnerability factor for social anxiety occurring in early stages of information processing. Few studies have investigated the relationship between social anxiety and attention biases, in conjunction with emotional and cognitive responses to a social stressor. Elucidating these links would shed light on maintenance factors of social anxiety and could help identify malleable treatment targets. This study examined the associations between social anxiety level, attention bias to disgust (AB-disgust), subjective emotional and physiological reactivity to a social stressor, and subsequent post-event processing (PEP). We tested a mediational model where social anxiety level indirectly predicted subsequent PEP via its association with AB-disgust and immediate subjective emotional reactivity to social stress. Fifty-five undergraduates (45% female) completed a passive viewing task. Eye movements were tracked during the presentation of social stimuli (e.g., disgust faces) and used to calculate AB-disgust. Next, participants gave an impromptu speech in front of a video camera and watched a neutral video, followed by the completion of a PEP measure. Although there was no association between AB-disgust and physiological reactivity to the stressor, AB-disgust was significantly associated with greater subjective emotional reactivity from baseline to the speech. Analyses supported a partial mediation model where AB-disgust and subjective emotional reactivity to a social stressor partially accounted for the link between social anxiety levels and PEP. PMID:27157031

  17. Effects of work stress and home stress on autonomic nervous function in Japanese male workers

    OpenAIRE

    Maeda, Eri; IWATA, Toyoto; Murata, Katsuyuki

    2014-01-01

    Autonomic imbalance is one of the important pathways through which psychological stress contributes to cardiovascular diseases/sudden death. Although previous studies have focused mainly on stress at work (work stress), the association between autonomic function and stress at home (home stress) is still poorly understood. The purpose was to clarify the effect of work/home stress on autonomic function in 1,809 Japanese male workers. We measured corrected QT (QTc) interval and QT index on the e...

  18. Practical investigation of the gate bias effect on the reverse recovery behavior of the body diode in power MOSFETs

    DEFF Research Database (Denmark)

    Lindberg-Poulsen, Kristian; Petersen, Lars Press; Ouyang, Ziwei; Andersen, Michael A. E.

    reverse recovery at high di=dt. Different bias voltages and dead times are combined, giving a loss map which makes it possible to evaluate the practical efficacy of gate bias on reducing the MOSFET body diode reverse recovery, while comparing it to the well known methods of dead time optimization. A......This work considers an alternative method of reducing the body diode reverse recovery by taking advantage of the MOSFET body effect, and applying a bias voltage to the gate before reverse recovery. A test method is presented, allowing the accurate measurement of voltage and current waveforms during...

  19. Practical investigation of the gate bias effect on the reverse recovery behavior of the body diode in power MOSFETs

    DEFF Research Database (Denmark)

    Lindberg-Poulsen, Kristian; Petersen, Lars Press; Ouyang, Ziwei;

    2014-01-01

    This work considers an alternative method of reducing the body diode reverse recovery by taking advantage of the MOSFET body effect, and applying a bias voltage to the gate before reverse recovery. A test method is presented, allowing the accurate measurement of voltage and current waveforms during...... reverse recovery at high di=dt. Different bias voltages and dead times are combined, giving a loss map which makes it possible to evaluate the practical efficacy of gate bias on reducing the MOSFET body diode reverse recovery, while comparing it to the well known methods of dead time optimization. A...

  20. A Meta-Analysis of the Effect of Cognitive Bias Modification on Anxiety and Depression

    Science.gov (United States)

    Hallion, Lauren S.; Ruscio, Ayelet Meron

    2011-01-01

    Cognitive biases have been theorized to play a critical role in the onset and maintenance of anxiety and depression. Cognitive bias modification (CBM), an experimental paradigm that uses training to induce maladaptive or adaptive cognitive biases, was developed to test these causal models. Although CBM has generated considerable interest in the…

  1. The effect of deadtime and electronic transients on the predelay bias in neutron coincidence counting

    Science.gov (United States)

    Croft, Stephen; Favalli, Andrea; Swinhoe, Martyn T.; Goddard, Braden; Stewart, Scott

    2016-04-01

    In neutron coincidence counting using the shift register autocorrelation technique, a predelay is inserted before the opening of the (R+A)-gate. Operationally the purpose of the predelay is to ensure that the (R+A)- and A-gates have matched effectiveness, otherwise a bias will result when the difference between the gates is used to calculate the accidentals corrected net reals coincidence rate. The necessity for the predelay was established experimentally in the early practical development and deployment of the coincidence counting method. The choice of predelay for a given detection system is usually made experimentally, but even today long standing traditional values (e.g., 4.5 μs) are often used. This, at least in part, reflects the fact that a deep understanding of why a finite predelay setting is needed and how to control the underlying influences has not been fully worked out. In this paper we attempt to gain some insight into the problem. One aspect we consider is the slowing down, thermalization, and diffusion of neutrons in the detector moderator. The other is the influence of deadtime and electronic transients. These may be classified as non-ideal detector behaviors because they are not included in the conventional model used to interpret measurement data. From improved understanding of the effect of deadtime and electronic transients on the predelay bias in neutron coincidence counting, the performance of both future and current coincidence counters may be improved.

  2. Biasing field effects on electronic properties in halogenated phenylene ethynylene oligomers

    International Nuclear Information System (INIS)

    In this paper results from ab initio simulations of the electronic structure properties of a class of halogenated phenylene ethynylene oligomers (OPE) are presented. These molecular species are investigated because of their suitable properties for application as single-molecule switches in the future emerging molecular electronic devices. Combined Hartree-Fock and Density Functional Theory approach is applied to investigate the biasing field effects on the relevant electronic properties, such as potential energy of the ground states, potential barrier height, localization of frontier molecular orbitals and the HOMO-LUMO gap. Special attention is also paid on the effects of substitution of the hydrogen atoms in the central phenyl ene ring of basic OPE molecule with halogen atoms. The analyses of the obtained results undoubtedly show that the biasing field has a strong impact on the potential barrier height, transition probabilities and band gap. Halogenation of the central phenylene ring does not have such a strong influence on the aforementioned properties, but it could be a useful way for fine tuning of some of the properties, especially the potential barrier height, enabling control of the torsional stochastic switching, inherent for the studied species. (Author)

  3. Effect of biased feedback on motor imagery learning in BCI-teleoperation system

    Directory of Open Access Journals (Sweden)

    Maryam eAlimardani

    2014-04-01

    Full Text Available Feedback design is an important issue in motor imagery BCI systems. Regardless, to date it has not been reported how feedback presentation can optimize co-adaptation between a human brain and such systems. This paper assesses the effect of realistic visual feedback on users’ BC performance and motor imagery skills. We previously developed a tele-operation system for a pair of humanlike robotic hands and showed that BCI control of such hands along with first-person perspective visual feedback of movements can arouse a sense of embodiment in the operators. In the first stage of this study, we found that the intensity of this ownership illusion was associated with feedback presentation and subjects’ performance during BCI motion control. In the second stage, we probed the effect of positive and negative feedback bias on subjects’ BCI performance and motor imagery skills. Although the subject specific classifier, which was set up at the beginning of experiment, detected no significant change in the subjects’ online performance, evaluation of brain activity patterns revealed that subjects’ self-regulation of motor imagery features improved due to a positive bias of feedback and a possible occurrence of ownership illusion. Our findings suggest that in general training protocols for BCIs, manipulation of feedback can play an important role in the optimization of subjects’ motor imagery skills.

  4. Implementing a generic method for bias correction in statistical models using random effects, with spatial and population dynamics examples

    DEFF Research Database (Denmark)

    Thorson, James T.; Kristensen, Kasper

    2016-01-01

    Statistical models play an important role in fisheries science when reconciling ecological theory with available data for wild populations or experimental studies. Ecological models increasingly include both fixed and random effects, and are often estimated using maximum likelihood techniques...... is calculated as a nonlinear function of random effects. We therefore describe and evaluate a new "epsilon" estimator as a generic bias-correction estimator for derived quantities. We use simulated data to compare the epsilon-method with an existing bias-correction algorithm for estimating...... recruitment in four configurations of an age-structured population dynamics model. This simulation experiment shows that the epsilon-method and the existing bias-correction method perform equally well in data-rich contexts, but the epsilon-method is slightly less biased in data-poor contexts. We then apply...

  5. Manipulation of perpendicular exchange bias effect in [Co/Ni]N/(Cu, Ta/TbCo multilayer structures

    Directory of Open Access Journals (Sweden)

    Minghong Tang

    2015-08-01

    Full Text Available With the demand for increasing storage density in spintronic applications, extensive work has been devoted to searching for perpendicular magnetic material systems with strong exchange bias effect. In this study we have investigated the exchange bias effect in perpendicular magnetized heterostructures of [Co/Ni]N/(Cu, Ta/TbCo. An interlayer of 0.8 nm Cu is capable of achieving separate magnetization switching, showing a quite large exchange bias field over 2.9 kOe. With increasing the interlayer thickness, both the Co/Ni bias field and TbCo switching field decrease much more rapidly for the samples with a Ta interlayer as compared to the Cu case, due to the better coverage ability of the amorphous nature. The influence of layer thickness and composition of the FM and FI layers has also been investigated and the variation tendencies are well interpreted.

  6. Marijuana's acute effects on cognitive bias for affective and marijuana cues.

    Science.gov (United States)

    Metrik, Jane; Aston, Elizabeth R; Kahler, Christopher W; Rohsenow, Damaris J; McGeary, John E; Knopik, Valerie S

    2015-10-01

    Marijuana produces acute increases in positive subjective effects and decreased reactivity to negative affective stimuli, though may also acutely induce anxiety. Implicit attentional and evaluative processes may explicate marijuana's ability to acutely increase positive and negative emotions. This within-subjects study examined whether smoked marijuana with 2.7-3.0% delta-9-tetrahydrocannabinol (THC), relative to placebo, acutely changed attentional processing of rewarding and negative affective stimuli as well as marijuana-specific stimuli. On 2 separate days, regular marijuana users (N = 89) smoked placebo or active THC cigarette and completed subjective ratings of mood, intoxication, urge to smoke marijuana, and 2 experimental tasks: pleasantness rating (response latency and perceived pleasantness of affective and marijuana-related stimuli) and emotional Stroop (attentional bias to affective stimuli). On the pleasantness rating task, active marijuana increased response latency to negatively valenced and marijuana-related (vs. neutral) visual stimuli, beyond a general slowing of response. Active marijuana also increased pleasantness ratings of marijuana images, although to a lesser extent than placebo due to reduced marijuana urge after smoking. Overall, active marijuana did not acutely change processing of positive emotional stimuli. There was no evidence of attentional bias to affective word stimuli on the emotional Stroop task with the exception of attentional bias to positive word stimuli in the subgroup of marijuana users with cannabis dependence. Marijuana may increase allocation of attentional resources toward marijuana-specific and negatively valenced visual stimuli without altering processing of positively valenced stimuli. Marijuana-specific cues may be more attractive with higher levels of marijuana craving and less wanted with low craving levels. PMID:26167716

  7. Acute Effects of Intoxication and Arousal on Approach/Avoidance Biases Toward Sexual Risk Stimuli in Heterosexual Men.

    Science.gov (United States)

    Simons, Jeffrey S; Maisto, Stephen A; Wray, Tyler B; Emery, Noah N

    2016-01-01

    This study tested the effects of alcohol intoxication and physiological arousal on cognitive biases toward erotic stimuli and condoms. Ninety-seven heterosexual men were randomized to 1 of 6 independent conditions in a 2 (high arousal or control) × 3 (alcohol target BAC = 0.08, placebo, or juice control) design and then completed a variant of the Approach-Avoidance Task (AAT). The AAT assessed reaction times toward approaching and avoiding erotic stimuli and condoms with a joystick. Consistent with hypotheses, the alcohol condition exhibited an approach bias toward erotic stimuli, whereas the control and placebo groups exhibited an approach bias toward condom stimuli. Similarly, the participants in the high arousal condition exhibited an approach bias toward erotic stimuli and the low arousal control condition exhibited an approach bias toward condoms. The results suggest that acute changes in intoxication and physiological arousal independently foster biased responding toward sexual stimuli and these biases are associated with sexual risk intentions. PMID:25808719

  8. Effects of long-term meditation practice on attentional biases towards emotional faces: An eye-tracking study.

    Science.gov (United States)

    Pavlov, S V; Korenyok, V V; Reva, N V; Tumyalis, A V; Loktev, K V; Aftanas, L I

    2015-01-01

    Attentional biases towards affective stimuli reflect an individual balance of appetitive and aversive motivational systems. Vigilance in relation to threatening information reflects emotional imbalance, associated with affective and somatic problems. It is known that meditation practice significantly improves control of attention, which is considered to be a tool for adaptive emotional regulation. In this regard, the main aim of the present study was to evaluate the influence of meditation on attentional bias towards neutral and emotional facial expressions. Eyes were tracked while 21 healthy controls and 23 experienced meditators (all males) viewed displays consisting of four facial expressions (neutral, angry, fearful and happy) for 10 s. Measures of biases in initial orienting and maintenance of attention were assessed. No effects were found for initial orienting biases. Meditators spent significantly less time viewing angry and fearful faces than control subjects. Furthermore, meditators selectively attended to happy faces whereas control subjects showed attentional biases towards both angry and happy faces. In sum we can conclude that long-term meditation practice adaptively affects attentional biases towards motivationally significant stimuli and that these biases reflect positive mood and predominance of appetitive motivation. PMID:25109832

  9. The generalizability of gender bias: Testing the effects of contextual, explicit, and implicit sexism on labor arbitration decisions.

    Science.gov (United States)

    Girvan, Erik J; Deason, Grace; Borgida, Eugene

    2015-10-01

    Decades of social-psychological research show that gender bias can result from features of the social context and from individual-level psychological predispositions. Do these sources of bias impact legal decisions, which are frequently made by people subject to factors that have been proposed to reduce bias (training and accountability)? To answer the question, we examined the potential for 3 major social-psychological theories of gender bias (role-congruity theory, ambivalent sexism, and implicit bias) to predict outcomes of labor arbitration decisions. In the first study, undergraduate students and professional arbitrators made decisions about 2 mock arbitration cases in which the gender of the employee-grievants was experimentally manipulated. Student participants' decisions showed the predicted gender bias, whereas the decisions of experienced professionals did not. Individual-level attitudes did not predict the extent of the observed bias and accountability did not attenuate it. In the second study, arbitrators' explicit and implicit gender attitudes were significant predictors of their decisions in published cases. The laboratory and field results suggest that context, expertise, and implicit and explicit attitudes are relevant to legal decision-making, but that laboratory experiments alone may not fully capture the nature of their effect on legal professionals' decisions in real cases. PMID:26030450

  10. Effect of a direct current bias on the electrohydrodynamic performance of a surface dielectric barrier discharge actuator for airflow control

    Science.gov (United States)

    Yan, Huijie; Yang, Liang; Qi, Xiaohua; Ren, Chunsheng

    2015-02-01

    The effect of a DC bias on the electrohydrodynamics (EHD) force induced by a surface dielectric barrier AC discharge actuator for airflow control at the atmospheric pressure is investigated. The measurement of the surface potential due to charge deposition at different DC biases is carried out by using a special designed corona like discharge potential probe. From the surface potential data, the plasma electromotive force is shown not affected much by the DC biases except for some reduction of the DC bias near the exposed electrode edge for the sheath-like configuration. The total thrust is measured by an analytical balance, and an almost linear relationship to the potential voltage at the exposed electrode edge is found for the direct thrust force. The temporally averaged ionic wind characteristics are investigated by Pitot tube sensor and schlieren visualization system. It is found that the ionic wind velocity profiles with different DC biases are almost the same in the AC discharge plasma area but gradually diversified in the further downstream area as well as the upper space away from the discharge plasma area. Also, the DC bias can significantly modify the topology of the ionic wind produced by the AC discharge actuator. These results can provide an insight into how the DC biases to affect the force generation.

  11. The effects of social stress and cortisol responses on the preconscious selective attention to social threat.

    Science.gov (United States)

    Roelofs, Karin; Bakvis, Patricia; Hermans, Erno J; van Pelt, Johannes; van Honk, Jack

    2007-04-01

    The purpose of the present study was to investigate the effects of social stress and stress-induced cortisol on the preconscious selective attention to social threat. Twenty healthy participants were administered a masked emotional Stroop task (comparing color-naming latencies for angry, neutral and happy faces) in conditions of rest and social stress. Stress was induced by means of the Trier social stress test. Based on the stress-induced increase in cortisol levels, participants were allocated post hoc (median-split) to a high and low responders group. In contrast to low responders, high responders showed a negative or avoidant attentional bias to threat (i.e. shorter latencies for angry than neutral faces) in the rest condition. Most importantly, although low responders became avoidant, the high responders became vigilant to the angry faces after stress induction. There were no such effects for happy faces. Our findings are in line with previous studies in both animals and humans, that associate high glucocorticoid stress-responsiveness with diminished avoidance and prolonged freezing reactions during stress. PMID:17030399

  12. Mental Health on the Go: Effects of a Gamified Attention Bias Modification Mobile Application in Trait Anxious Adults

    OpenAIRE

    Tracy A Dennis; O’Toole, Laura

    2014-01-01

    Interest in the use of mobile technology to deliver mental health services has grown in light of the economic and practical barriers to treatment. Yet, research on alternative delivery strategies that are more affordable, accessible, and engaging is in its infancy. Attention bias modification training (ABMT), has potential to reduce treatment barriers as a mobile intervention for stress and anxiety, but the degree to which ABMT can be embedded in a mobile gaming format and its potential for t...

  13. Determinants and Valuation Effects of the Home Bias in European Banks' Sovereign Debt Portfolios

    OpenAIRE

    Horváth, Bálint; Huizinga, Harry; Ioannidou, Vasso

    2015-01-01

    We document that large European banks hold sovereign debt portfolios heavily biased toward domestic government debt. This bias is stronger if the sovereign is risky and shareholder rights are strong, as evidence of a risk-shifting explanation of the home bias. In addition, the bias is stronger if the sovereign is risky and the government has positive ownership in the bank, as evidence of a government pressure channel. The home bias is positively valued by the stock market, as reflected by a p...

  14. Just like a woman? Effects of gender-biased perceptions of friendship network brokerage on attributions and performance

    OpenAIRE

    Brands, R. A.; Kilduff, M.

    2014-01-01

    Do women face bias in the social realm in which they are purported to excel? Across two different studies (one organizational and one comprising MBA teams), we examined whether the friendship networks around women tend to be systematically misperceived and whether there were effects of these misperceptions on the women themselves and their teammates. Thus, we investigated the possibility (hitherto neglected in the network literature) that biases in friendship networks are triggered not just b...

  15. Expectancy of Stress-Reducing Aromatherapy Effect and Performance on a Stress-Sensitive Cognitive Task

    OpenAIRE

    Irina Chamine; Oken, Barry S.

    2015-01-01

    Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma...

  16. The effects of training in feedback on managers' attributional bias and perceived effectiveness of their work groups

    OpenAIRE

    Lawrence, Harriet Vee

    1992-01-01

    Problematic situations involving managers and employees can be dysfunctional in the work setting. Resolution of these problems often requires giving feedback that is specific, empathic, and in a spirit of inquiry. This research tested the effects of a learning intervention designed to intercept attributional bias and untested inference through training in feedback. An experimental field study was conducted in a large municipal government to address manager-subordinate feedback....

  17. Effect of Bias Correction of Satellite-Rainfall Estimates on Runoff Simulations at the Source of the Upper Blue Nile

    Directory of Open Access Journals (Sweden)

    Emad Habib

    2014-07-01

    Full Text Available Results of numerous evaluation studies indicated that satellite-rainfall products are contaminated with significant systematic and random errors. Therefore, such products may require refinement and correction before being used for hydrologic applications. In the present study, we explore a rainfall-runoff modeling application using the Climate Prediction Center-MORPHing (CMORPH satellite rainfall product. The study area is the Gilgel Abbay catchment situated at the source basin of the Upper Blue Nile basin in Ethiopia, Eastern Africa. Rain gauge networks in such area are typically sparse. We examine different bias correction schemes applied locally to the CMORPH product. These schemes vary in the degree to which spatial and temporal variability in the CMORPH bias fields are accounted for. Three schemes are tested: space and time-invariant, time-variant and spatially invariant, and space and time variant. Bias-corrected CMORPH products were used to calibrate and drive the Hydrologiska Byråns Vattenbalansavdelning (HBV rainfall-runoff model. Applying the space and time-fixed bias correction scheme resulted in slight improvement of the CMORPH-driven runoff simulations, but in some instances caused deterioration. Accounting for temporal variation in the bias reduced the rainfall bias by up to 50%. Additional improvements were observed when both the spatial and temporal variability in the bias was accounted for. The rainfall bias was found to have a pronounced effect on model calibration. The calibrated model parameters changed significantly when using rainfall input from gauges alone, uncorrected, and bias-corrected CMORPH estimates. Changes of up to 81% were obtained for model parameters controlling the stream flow volume.

  18. Stress distribution and effective stress intensity factor of a blunt crack after dislocation emission

    Institute of Scientific and Technical Information of China (English)

    钱才富; 乔利杰; 褚武扬

    2000-01-01

    The stress fields induced by a dislocation and its image dislocations around a narrow elliptic void are formulated. Based on the solution, the stress distribution and effective stress intensity factor of a blunt (elliptic) crack were calculated under mode I constant loading. The results show that a dislocation-free zone (DFZ) is formed after dislocation emission. There exists a second stress peak in the DFZ except a stress peak at the blunt crack tip. With an increase in the applied stress intensity factor Kla or the friction stress T, of the material, the DFZ size and the peak stress at the crack tip decrease, but the peak stress in the DFZ and the effective stress intensity factor Klf presiding at the crack tip increase. Because of dislocation shielding effects, shielding ratio Kla/Klf increases with increasing Kla, but it decreases with increasing Tf.

  19. Stress distribution and effective stress intensity factor of a blunt crack after dislocation emission

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The stress fields induced by a dislocation and its image dislocations around a narrow elliptic void are formulated. Based on the solution, the stress distribution and effective stress intensity factor of a blunt (elliptic) crack were calculated under mode I constant loading. The results show that a dislocation-free zone (DFZ) is formed after dislocation emission. There exists a second stress peak in the DFZ except a stress peak at the blunt crack tip. With an increase in the applied stress intensity factor KIa or the friction stress τf of the material, the DFZ size and the peak stress at the crack tip decrease, but the peak stress in the DFZ and the effective stress intensity factor KIf presiding at the crack tip increase. Because of dislocation shielding effects, shielding ratio KIa/KIf increases with increasing KIa}, but it decreases with increasing τf.

  20. Effect of interfacial iron oxidation on the exchange bias in CoO/Fe bilayers

    International Nuclear Information System (INIS)

    The relation between the interface structure and the exchange bias was studied in the epitaxial CoO/Fe(0 0 1) bilayers that were grown on MgO(0 0 1) using molecular beam epitaxy. Three samples with different interface structures were prepared. The CoO/Fe bilayer, which was prepared using the reactive evaporation of CoO, served as the reference sample. In the other two samples, the CoO/Fe interfaces were modified prior to the CoO growth using either (i) the deposition of a 2 Å thick Co layer or (ii) an exposure to molecular oxygen, which resulted in under- and over-oxidized CoO/Fe interfaces, respectively. The actual structures of the resulting interfaces were revealed using conversion electron Mössbauer spectroscopy. For each sample, an iron oxide was found at the interface, and its amount depended on the sample preparation recipe. The exchange bias effect (EB), as a function of the temperature, was experimentally studied in detail using VSM magnetometry. The coercivity showed a distinct peak near the blocking temperature for all samples; however, the peak's location and its width were diverse. The obtained EB values depended on the interface structure. The largest hysteresis loop shift (HEB = 180 Oe at 4 K) was obtained for the sample with the thickest interfacial iron oxide layer.

  1. Experience of automation failures in training: effects on trust, automation bias, complacency and performance.

    Science.gov (United States)

    Sauer, Juergen; Chavaillaz, Alain; Wastell, David

    2016-06-01

    This work examined the effects of operators' exposure to various types of automation failures in training. Forty-five participants were trained for 3.5 h on a simulated process control environment. During training, participants either experienced a fully reliable, automatic fault repair facility (i.e. faults detected and correctly diagnosed), a misdiagnosis-prone one (i.e. faults detected but not correctly diagnosed) or a miss-prone one (i.e. faults not detected). One week after training, participants were tested for 3 h, experiencing two types of automation failures (misdiagnosis, miss). The results showed that automation bias was very high when operators trained on miss-prone automation encountered a failure of the diagnostic system. Operator errors resulting from automation bias were much higher when automation misdiagnosed a fault than when it missed one. Differences in trust levels that were instilled by the different training experiences disappeared during the testing session. Practitioner Summary: The experience of automation failures during training has some consequences. A greater potential for operator errors may be expected when an automatic system failed to diagnose a fault than when it failed to detect one. PMID:26374396

  2. Exchange bias effect in Fe films deposited on Si(100) substrates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenhong; Takano, Fumiyoshi; Takenaka, Masato; Akinaga, Hiro [Nanotechnology Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Ofuchi, Hironori [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo (Japan)

    2007-12-15

    The crystal structure and exchange bias effect in Fe films deposited on Si(100) substrates have been investigated. X-ray diffraction and fluorescence-extended X-ray absorption fine structure measurements reveal that the as-deoposited Fe films are polycrystalline with a preferred (110) texture. In addition, we observe a shift in the magnetic hysteresis loop of Fe films deposited on Si(100) where there is existance of a thin oxidized layer. By comparison, for Fe film deposited on Si(100) lacking the oxidized layer, it does not exhibit any features of shift in the magnetic hysteresis loop. We postulate the effect results from a coupling between the ferromagnetic Fe film and the antiferromagnetic Fe oxide that forms spontaneously in the interface. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. An age apart: the effects of intergenerational contact and stereotype threat on performance and intergroup bias.

    Science.gov (United States)

    Abrams, Dominic; Eller, Anja; Bryant, Jacqueline

    2006-12-01

    An experimental study examined the effect of intergenerational contact and stereotype threat on older people's cognitive performance, anxiety, intergroup bias, and identification. Participants completed a series of cognitive tasks under high or low stereotype threat (through comparison with younger people). In line with stereotype threat theory, threat resulted in worse performance. However, this did not occur if prior intergenerational contact had been more positive. This moderating effect of contact was mediated by test-related anxiety. In line with intergroup contact theory, more positive contact was associated with reduced prejudice and reduced ingroup identification. However this occurred in the high threat, but not low threat, condition. The findings suggest that positive intergenerational contact can reduce vulnerability to stereotype threat among older people. PMID:17201490

  4. Geometric effects on stress wave propagation.

    Science.gov (United States)

    Johnson, K L; Trim, M W; Horstemeyer, M F; Lee, N; Williams, L N; Liao, J; Rhee, H; Prabhu, R

    2014-02-01

    The present study, through finite element simulations, shows the geometric effects of a bioinspired solid on pressure and impulse mitigation for an elastic, plastic, and viscoelastic material. Because of the bioinspired geometries, stress wave mitigation became apparent in a nonintuitive manner such that potential real-world applications in human protective gear designs are realizable. In nature, there are several toroidal designs that are employed for mitigating stress waves; examples include the hyoid bone on the back of a woodpecker's jaw that extends around the skull to its nose and a ram's horn. This study evaluates four different geometries with the same length and same initial cross-sectional diameter at the impact location in three-dimensional finite element analyses. The geometries in increasing complexity were the following: (1) a round cylinder, (2) a round cylinder that was tapered to a point, (3) a round cylinder that was spiraled in a two dimensional plane, and (4) a round cylinder that was tapered and spiraled in a two-dimensional plane. The results show that the tapered spiral geometry mitigated the greatest amount of pressure and impulse (approximately 98% mitigation) when compared to the cylinder regardless of material type (elastic, plastic, and viscoelastic) and regardless of input pressure signature. The specimen taper effectively mitigated the stress wave as a result of uniaxial deformational processes and an induced shear that arose from its geometry. Due to the decreasing cross-sectional area arising from the taper, the local uniaxial and shear stresses increased along the specimen length. The spiral induced even greater shear stresses that help mitigate the stress wave and also induced transverse displacements at the tip such that minimal wave reflections occurred. This phenomenon arose although only longitudinal waves were introduced as the initial boundary condition (BC). In nature, when shearing occurs within or between materials

  5. Increasing electric vehicle policy efficiency and effectiveness by reducing mainstream market bias

    International Nuclear Information System (INIS)

    Plug-in electric vehicles (PEVs) provide an opportunity for reducing energy use and emissions in the transportation sector. Currently, a number of federal policies are in place to incentivize deployment of PEVs to mainstream consumers with demographics and vehicle attribute preferences most common to today's new vehicle purchasers. This article argues that policies intending to give PEVs a foothold in the market should not focus on mainstream consumers and should instead focus on niche markets—specifically carsharing and postal fleets—and early adopters including green consumers. Two arguments can be made in support of eliminating the mainstream market bias of current policies toward a policy of cultivating niche markets. The first is efficiency: so far PEV policies featuring a mainstream market bias have proven to be inefficient and costly. The second is effectiveness: it is becoming increasingly evident that PEV policies would be more effective in achieving potential societal benefits if they focused on early adopters and niche markets using such approaches as strategic niche management, accessible loans and financing, and appropriately targeted incentives. PEV policies focused on early adopters and niche markets would create complementary system effects that will lead to increased PEV market penetration and realization of intended societal benefits. - Highlights: • We argue that U.S. electric vehicle policies are inefficient and ineffective. • We introduce “mainstream consumer bias” as an explanation for policy deficiencies. • We propose an alternative policy agenda to address some of these policy problems. • Proposed policy options include strategic niche management, targeted R and D and incentives, and loans

  6. Intergroup bias.

    Science.gov (United States)

    Hewstone, Miles; Rubin, Mark; Willis, Hazel

    2002-01-01

    This chapter reviews the extensive literature on bias in favor of in-groups at the expense of out-groups. We focus on five issues and identify areas for future research: (a) measurement and conceptual issues (especially in-group favoritism vs. out-group derogation, and explicit vs. implicit measures of bias); (b) modern theories of bias highlighting motivational explanations (social identity, optimal distinctiveness, uncertainty reduction, social dominance, terror management); (c) key moderators of bias, especially those that exacerbate bias (identification, group size, status and power, threat, positive-negative asymmetry, personality and individual differences); (d) reduction of bias (individual vs. intergroup approaches, especially models of social categorization); and (e) the link between intergroup bias and more corrosive forms of social hostility. PMID:11752497

  7. Stress Effects on Mood, HPA Axis, and Autonomic Response: Comparison of Three Psychosocial Stress Paradigms

    OpenAIRE

    Giles, Grace E.; Mahoney, Caroline R.; Brunyé, Tad T.; Taylor, Holly A.; Kanarek, Robin B.

    2014-01-01

    Extensive experimental psychology research has attempted to parse the complex relationship between psychosocial stress, mood, cognitive performance, and physiological changes. To do so, it is necessary to have effective, validated methods to experimentally induce psychosocial stress. The Trier Social Stress Test (TSST) is the most commonly used method of experimentally inducing psychosocial stress, but it is resource intensive. Less resource intense psychosocial stress tasks include the Socia...

  8. Bootstrap Co-integration Rank Testing: The Effect of Bias-Correcting Parameter Estimates

    OpenAIRE

    Cavaliere, Giuseppe; Taylor, A. M. Robert; Trenkler, Carsten

    2013-01-01

    In this paper we investigate bootstrap-based methods for bias-correcting the first-stage parameter estimates used in some recently developed bootstrap implementations of the co-integration rank tests of Johansen (1996). In order to do so we adapt the framework of Kilian (1998) which estimates the bias in the original parameter estimates using the average bias in the corresponding parameter esti- mates taken across a large number of auxiliary bootstrap replications. A number of possible imp...

  9. Effect of Bias Estimation on Coverage Accuracy of Bootstrap Confidence Intervals for a Probability Density

    OpenAIRE

    Hall, Peter

    1992-01-01

    The bootstrap is a poor estimator of bias in problems of curve estimation, and so bias must be corrected by other means when the bootstrap is used to construct confidence intervals for a probability density. Bias may either be estimated explicitly, or allowed for by undersmoothing the curve estimator. Which of these two approaches is to be preferred? In the present paper we address this question from the viewpoint of coverage accuracy, assuming a given number of derivatives of the unknown den...

  10. Effect of SRAF placement on process window for technology nodes that uses variable etch bias

    Science.gov (United States)

    Seoud, Ahmed M.; Tawfik, Tamer M.

    2009-10-01

    As technology advances to 45 nm node and below, the induced effects of etch process have an increasing contribution to the device critical dimension error budget. Traditionally, original design target shapes are drawn based on the etch target. During mask correction, etch modeling is essential to predict the new resist target that will print on the wafer. This step is known as "Model Based Retargeting" (MBR). During the initial phase of process characterization, the sub-resolution assist features (SRAF) are optimized whether based on the original design target shapes or based on a biased version of the design target (resist target). The goal of the work is to study the different possibilities of SRAF placement to maximize the accuracy and process window immunity of the final resist contour image. We will, statistically, analyze and compare process window simulation results due to various SRAFs placements by changing the reference layer used during placement.

  11. Influence of effective stress coefficient on mechanical failure of chalk

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Hjuler, M.L.;

    2012-01-01

    The Effective stress coefficient is a measure of how chalk grains are connected with each other. The stiffness of chalk may decrease if the amount of contact cements between the grains decreases, which may lead to an increase of the effective stress coefficient. We performed CO2 injection in chalk......, as this process could affect the grain contact cement. If this happens, the effective stress at the grain contacts in a reservoir will change according to the effective stress principle of Biot. In a p′-q space for failure analysis, we observed that a higher effective stress coefficient reduces the...... elastic region and vice versa. However, as the effective stress working on the rock decreases with increased effective stress coefficient, the reduction of elastic region will have less effect on pore collapse strength if we consider the change in the effective stress coefficient. This finding will help...

  12. Stress Management Strategies for Students: The Immediate Effects of Yoga, Humor, and Reading on Stress

    Science.gov (United States)

    Rizzolo, Denise; Zipp, Genevieve Pinto; Stiskal, Doreen; Simpkins, Susan

    2009-01-01

    Background: Health science programs can be demanding and difficult for many students, leading to high levels of stress. High levels of stress can have a negative effect on students and subsequently the practicing clinician. Research suggests that yoga, humor, and reading are simple, effective methods to help reduce stress. To date no research…

  13. When Does Stress Help or Harm? The Effects of Stress Controllability and Subjective Stress Response on Stroop Performance

    OpenAIRE

    Roselinde Kaiser Henderson; Snyder, Hannah R.; Tina eGupta; Banich, Marie T

    2012-01-01

    The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, r...

  14. Tunnel design considering stress release effect

    Directory of Open Access Journals (Sweden)

    Van-hung DAO

    2009-09-01

    Full Text Available In tunnel design, the determination of installation time and the stiffness of supporting structures is very important to the tunnel stability. This study used the convergence-confinement method to determine the stress and displacement of the tunnel while considering the counter-pressure curve of the ground base, the stress release effect, and the interaction between the tunnel lining and the rock surrounding the tunnel chamber. The results allowed for the determination of the installation time, distribution and strength of supporting structures. This method was applied to the intake tunnel in the Ban Ve Hydroelectric Power Plant, in Nghe An Province, Vietnam. The results show that when a suitable displacement u0¬ ranging from 0.086 5 m to 0.091 9 m occurrs, we can install supporting structures that satisfy the stability and economical requirements.

  15. On commercial media bias

    OpenAIRE

    Germano, Fabrizio

    2008-01-01

    Within the spokes model of Chen and Riordan (2007) that allows for non-localized competition among arbitrary numbers of media outlets, we quantify the effect of concentration of ownership on quality and bias of media content. A main result shows that too few commercial outlets, or better, too few separate owners of commercial outlets can lead to substantial bias in equilibrium. Increasing the number of outlets (commercial and non-commercial) tends to bring down this bias; but the strong...

  16. The Accuracy of Metacomprehension Judgments: The Biasing Effect of Text Order

    Science.gov (United States)

    Linderholm, Tracy; Wang, Xuesong; Therriault, David; Zhao, Qin; Jakiel, Laura

    2012-01-01

    Introduction: Two experiments tested the hypothesis that relative metacomprehension accuracy is vulnerable when readers' cognitive efforts are biased by text order. It is proposed that the difficulty level of initial text information biases readers' estimates of text comprehension but is correctable when more cognitive effort is applied. Method:…

  17. Stress vulnerability and the effects of moderate daily stress on sleep polysomnography and subjective sleepiness.

    Science.gov (United States)

    Petersen, Helena; Kecklund, Göran; D'Onofrio, Paolo; Nilsson, Jens; Åkerstedt, Torbjörn

    2013-02-01

    The purpose of this study was to investigate if and how sleep physiology is affected by naturally occurring high work stress and identify individual differences in the response of sleep to stress. Probable upcoming stress levels were estimated through weekly web questionnaire ratings. Based on the modified FIRST-scale (Ford insomnia response to stress) participants were grouped into high (n = 9) or low (n = 19) sensitivity to stress related sleep disturbances (Drake et al., 2004). Sleep was recorded in 28 teachers with polysomnography, sleep diaries and actigraphs during one high stress and one low stress condition in the participants home. EEG showed a decrease in sleep efficiency during the high stress condition. Significant interactions between group and condition were seen for REM sleep, arousals and stage transitions. The sensitive group had an increase in arousals and stage transitions during the high stress condition and a decrease in REM, whereas the opposite was seen in the resilient group. Diary ratings during the high stress condition showed higher bedtime stress and lower ratings on the awakening index (insufficient sleep and difficulties awakening). Ratings also showed lower cognitive function and preoccupation with work thoughts in the evening. KSS ratings of sleepiness increased during stress for the sensitive group. Saliva samples of cortisol showed no effect of stress. It was concluded that moderate daily stress is associated with a moderate negative effect on sleep sleep efficiency and fragmentation. A slightly stronger effect was seen in the sensitive group. PMID:22835074

  18. Proton radiation effect of NPN-input operational amplifier under different bias conditions

    International Nuclear Information System (INIS)

    NPN-input bipolar operational amplifiers LM741 were irradiated with 60Co γ-ray, 3 MeV protons and 10 MeV protons respectively at different biases to investigating the proton radiation response of the NPN-input operational amplifier. The comparison of protons with 60Co γ-rays showed that the proton radiation mainly induced ionization damage in LM741. Under different bias conditions, the radiation sensitivity is different; zero biased devices show more radiation sensitivity in the input biased current than forward biased devices. Supply current (±Icc) is another parameter that is sensitive to proton radiation, 60Co γ-ray, 3 MeV and 10 MeV proton irradiation would induce a different irradiation response in ±Icc, which is caused by different ionization energy deposition and displacement energy deposition of 60Co γ-ray, 3 MeV and 10 MeV proton irradiation. (paper)

  19. Disorder driven robust spontaneous exchange bias effect in Sr doped La2CoMnO6

    International Nuclear Information System (INIS)

    We present a giant spontaneous exchange bias (ZEB) effect (∼0.65 T) in Sr doped La2CoMnO6 sample. Structural and magnetic transitions have been found with Sr doping in La site. A systematic magnetic study has been carried by varying Sr content observed ferromagnetic transition followed by reentrant spin glass behaviour, phase separation to spin glass and ferromagnetic phases and to canted antiferromagnetic transition below 30 K. Giant spontaneous exchange bias effect is found only below the canted antiferromagnetic transition and is attributed to the large unidirectional anisotropy at the interface of isothermally field induced ferromagnetic phase and canted antiferromagnetic background

  20. Stress effects on memory : An update and integration

    NARCIS (Netherlands)

    Schwabe, Lars; Joels, Marian; Roozendaal, Benno; Wolf, Oliver T.; Oitzl, Melly S.

    2012-01-01

    It is well known that stressful experiences may affect learning and memory processes. Less clear is the exact nature of these stress effects on memory: both enhancing and impairing effects have been reported. These opposite effects may be explained if the different time courses of stress hormone, in

  1. Neural correlates of dual-task effect on belief-bias syllogistic reasoning: a near-infrared spectroscopy study.

    Science.gov (United States)

    Tsujii, Takeo; Watanabe, Shigeru

    2009-09-01

    Recent dual-process reasoning theories have explained the belief-bias effect, the tendency for human reasoning to be erroneously biased when logical conclusions are incongruent with beliefs about the world, by proposing a belief-based automatic heuristic system and logic-based demanding analytic system. Although these claims are supported by the behavioral finding that high-load secondary tasks enhance the belief-bias effect, the neural correlates of dual-task reasoning remain unknown. The present study therefore examined the relationship between dual-task effect and activity in the inferior frontal cortex (IFC) during belief-bias reasoning by near-infrared spectroscopy (NIRS). Forty-eight subjects participated in this study (MA=23.46 years). They were required to perform congruent and incongruent reasoning trials while responding to high- and low-load secondary tasks. Behavioral analysis showed that the high-load secondary task impaired only incongruent reasoning performance. NIRS analysis found that the high-load secondary task decreased right IFC activity during incongruent trials. Correlation analysis showed that subjects with enhanced right IFC activity could perform better in the incongruent reasoning trials, though subjects for whom right IFC activity was impaired by the secondary task could not maintain better reasoning performance. These findings suggest that the right IFC may be responsible for the dual-task effect in conflicting reasoning processes. When secondary tasks impair right IFC activity, subjects may rely on the automatic heuristic system, which results in belief-bias responses. We therefore offer the first demonstration of neural correlates of dual-task effect on IFC activity in belief-bias reasoning. PMID:19577547

  2. Hostile attributional bias, negative emotional responding, and aggression in adults: moderating effects of gender and impulsivity.

    Science.gov (United States)

    Chen, Pan; Coccaro, Emil F; Jacobson, Kristen C

    2012-01-01

    The current study examined the main effects of hostile attributional bias (HAB) and negative emotional responding on a variety of aggressive behaviors in adults, including general aggression, physical aggression, relational aggression, and verbal aggression. Effects of both externalizing (anger) and internalizing (embarrassment/upset) negative emotions were considered. In addition, the moderating roles of gender and impulsivity on the effects of HAB and negative emotional responding were explored. Multilevel models were fitted to data from 2,749 adult twins aged 20-55 from the PennTwins cohort. HAB was positively associated with all four forms of aggression. There was also a significant interaction between impulsivity and HAB for general aggression. Specifically, the relationship between HAB and general aggression was only significant for individuals with average or above-average levels of impulsivity. Negative emotional responding was also found to predict all measures of aggression, although in different ways. Anger was positively associated with all forms of aggression, whereas embarrassment/upset predicted decreased levels of general, physical, and verbal aggression but increased levels of relational aggression. The associations between negative emotional responding and aggression were generally stronger for males than females. The current study provides evidence for the utility of HAB and negative emotional responding as predictors of adult aggression and further suggests that gender and impulsivity may moderate their links with aggression. PMID:24833604

  3. OBJECTS IN KEPLER'S MIRROR MAY BE LARGER THAN THEY APPEAR: BIAS AND SELECTION EFFECTS IN TRANSITING PLANET SURVEYS

    International Nuclear Information System (INIS)

    Statistical analyses of large surveys for transiting planets such as the Kepler mission must account for systematic errors and biases. Transit detection depends not only on the planet's radius and orbital period, but also on host star properties. Thus, a sample of stars with transiting planets may not accurately represent the target population. Moreover, targets are selected using criteria such as a limiting apparent magnitude. These selection effects, combined with uncertainties in stellar radius, lead to biases in the properties of transiting planets and their host stars. We quantify possible biases in the Kepler survey. First, Eddington bias produced by a steep planet radius distribution and uncertainties in stellar radius results in a 15%-20% overestimate of planet occurrence. Second, the magnitude limit of the Kepler target catalog induces Malmquist bias toward large, more luminous stars and underestimation of the radii of about one-third of candidate planets, especially those larger than Neptune. Third, because metal-poor stars are smaller, stars with detected planets will be very slightly (<0.02 dex) more metal-poor than the target average. Fourth, uncertainties in stellar radii produce correlated errors in planet radius and stellar irradiation. A previous finding, that highly irradiated giants are more likely to have 'inflated' radii, remains significant, even accounting for this effect. In contrast, transit depth is negatively correlated with stellar metallicity even in the absence of any intrinsic correlation, and a previous claim of a negative correlation between giant planet transit depth and stellar metallicity is probably an artifact.

  4. The effect of bias voltage on the metallic Co and Mo etching rate in CF4/O2 plasma

    International Nuclear Information System (INIS)

    Recently the plasma etching research has been focused on the surface of the metal used in the nuclear industry. In this study, following the surveys on the previous research, experimental research on the surface etching of metallic Co and Mo in R.F. plasma under the D.C. has been conducted. Experimental variables include DC bias voltage and substrate temperature between 300 .deg. C and 400 .deg. C. In this study the ratio, CF4/O2, is maintained to be a value of four, since it is reported to be the optimum in the binary gas mixture system for metallic Co and Mo etching process. Experimental results show that Co and Mo are etched out well enough in the temperature range. Especially the effects of the bias voltage on metallic cobalt are shown to be remarkable. In the previous work, cobalt started to be etched above 350 .deg. C. However in this study it started to be etched at 300 .deg. C by the bias voltage. The Maximum rate of cobalt has reached at 400 .deg. C under 220 W R.F. plasma power and -300 V DC bias voltage is 0.43 μm/min. But for the material of molybdenum, the etching rate was turned to be not much effected by the bias voltage

  5. Experimental observation of the skin effect on plasma uniformity in inductively coupled plasmas with a radio frequency bias

    International Nuclear Information System (INIS)

    Electromagnetic effects such as the skin effect, standing wave effect, and edge effect have been mainly studied in large-area, high-frequency gas discharges. In this study, we show that the skin effect can be a major factor of plasma uniformity in a high-density plasma, even if the discharge regime is in a small electrode area and under moderate excitation frequency. When a radio frequency (RF) bias power was applied to an inductively coupled plasma (ICP), the plasma density near the radial edge was largely increased and the plasma uniformity was significantly enhanced in the high-density plasma regime. This change could be understood by considering the enhanced electric field in the radial edge, the so-called skin effect. The time-dependent behavior of the plasma density and electron temperature by the bias power was also studied. When the RF bias power was applied to the ICP, the electron temperature abruptly increased due to electron heating, while variations of plasma density depending on the radial position were observed with the RF bias power in the high-density plasma of the ICP. (paper)

  6. Selection bias, vote counting, and money-priming effects: A comment on Rohrer, Pashler, and Harris (2015) and Vohs (2015).

    Science.gov (United States)

    Vadillo, Miguel A; Hardwicke, Tom E; Shanks, David R

    2016-05-01

    When a series of studies fails to replicate a well-documented effect, researchers might be tempted to use a "vote counting" approach to decide whether the effect is reliable-that is, simply comparing the number of successful and unsuccessful replications. Vohs's (2015) response to the absence of money priming effects reported by Rohrer, Pashler, and Harris (2015) provides an example of this approach. Unfortunately, vote counting is a poor strategy to assess the reliability of psychological findings because it neglects the impact of selection bias and questionable research practices. In the present comment, we show that a range of meta-analytic tools indicate irregularities in the money priming literature discussed by Rohrer et al. and Vohs, which all point to the conclusion that these effects are distorted by selection bias, reporting biases, or p-hacking. This could help to explain why money-priming effects have proven unreliable in a number of direct replication attempts in which biases have been minimized through preregistration or transparent reporting. Our major conclusion is that the simple proportion of significant findings is a poor guide to the reliability of research and that preregistered replications are an essential means to assess the reliability of money-priming effects. PMID:27077759

  7. Effect of substrate anisotropy on magnetic state and stress state in magnetostrictive multilayers

    International Nuclear Information System (INIS)

    There is a strong interaction of stress and magnetization in magnetostrictive materials which can be traced back to the corresponding elastic energy and magnetoelastic energy terms. In particular, an applied stress or magnetic field can be used to provide a bias which can then ensure large magnetostrictive actuation at minimum coercive field. The use of stress is especially interesting in the case of thin films because it can be conveniently introduced by means of the substrate. In this work, the basic formulations for the elastic, magnetoelastic and potential magnetic energies of an isotropic material, and the assumption that the film is in state of plane stress are combined in a consistent model that is used to study the effect of a stress bias which is created by bending a substrate during deposition of a magnetostrictive multilayer. Using this framework, the biaxial stresses induced in the thin film after the substrate is released and the multilayer total energy are calculated. The effect of energy contributions from strains in the thickness direction is shown to be unimportant, since they provide a constant, orientation-independent contribution which does not affect in-plane magnetization switching. The multilayer total energy, which is shown to vary with magnetic domain orientation, is minimized to find the orientation of the easy axis as well as to estimate the magnetization along various hard axis directions when an external field is applied in those directions. The uniaxial anisotropy energy and the anisotropy field are also calculated and the results are in good agreement with reported data. These calculations are seen to offer significant improvement over the ones obtained with previous models that consider films subjected to uniaxial stresses and to be governed only by variations of the magnetoelastic energy

  8. Chernobyl health effects: radiation or stress?

    International Nuclear Information System (INIS)

    Consideration is given to results of wide-scale examination of human population, subjected to the effect of radiation in result of Chernobyl accident. The examined contingents consisted of liquidators, evacuated from 30-km zone, people still living in contamination territories, children of irradiated parents and children, who received large radiation doses. High levels of respiratory system diseases, digestive system diseases, cardiovascular diseases and nervous system diseases were revealed for these people. It was revealed that stress, socio-economic and chemical factors played sufficient role in disease incidence. It is shown that fair of radiation may damage more, than radiation itself

  9. Judging the implications of a concession: Conversational distance and belief bias effects.

    Science.gov (United States)

    Ricco, Robert B; Sierra, Anthony

    2016-01-01

    An arguer's position at a given point in an argument can be characterized as a set of commitments. The present study considers the perceptions of ordinary language users about the implications of making a concession for the contents of the conceder's commitment set. In particular, we examine two sources of influence on such lay perceptions-conversational distance (i.e., the number of turns separating the concession from commitments incurred earlier in the argument) and an individual's prior beliefs regarding the content of the argument. Across two studies, college students were administered an argument task assessing the extent to which a concession by the protagonist of an argument on the last move indicated changes to other commitments incurred earlier in the argument. Results indicated that participants were more likely to judge a concession as indicating a change in prior commitments if (a) the commitment was incurred later in the argument than earlier, and (b) the participant disagreed with the protagonists' thesis in the argument. In addition, performance on deductive reasoning tasks predicted individual differences in the conversational distance effect, but not the belief bias effect. PMID:26183024

  10. Field-free magnetization reversal by spin-Hall effect and exchange bias

    Science.gov (United States)

    van den Brink, A.; Vermijs, G.; Solignac, A.; Koo, J.; Kohlhepp, J. T.; Swagten, H. J. M.; Koopmans, B.

    2016-03-01

    As the first magnetic random access memories are finding their way onto the market, an important issue remains to be solved: the current density required to write magnetic bits becomes prohibitively high as bit dimensions are reduced. Recently, spin-orbit torques and the spin-Hall effect in particular have attracted significant interest, as they enable magnetization reversal without high current densities running through the tunnel barrier. For perpendicularly magnetized layers, however, the technological implementation of the spin-Hall effect is hampered by the necessity of an in-plane magnetic field for deterministic switching. Here we interface a thin ferromagnetic layer with an anti-ferromagnetic material. An in-plane exchange bias is created and shown to enable field-free S HE-driven magnetization reversal of a perpendicularly magnetized Pt/Co/IrMn structure. Aside from the potential technological implications, our experiment provides additional insight into the local spin structure at the ferromagnetic/anti-ferromagnetic interface.

  11. Quantum Hall effect and semiconductor-to-semimetal transition in biased black phosphorus

    Science.gov (United States)

    Yuan, Shengjun; van Veen, Edo; Katsnelson, Mikhail I.; Roldán, Rafael

    2016-06-01

    We study the quantum Hall effect of two-dimensional electron gas in black phosphorus in the presence of perpendicular electric and magnetic fields. In the absence of a bias voltage, the external magnetic field leads to a quantization of the energy spectrum into equidistant Landau levels, with different cyclotron frequencies for the electron and hole bands. The applied voltage reduces the band gap, and eventually a semiconductor-to-semimetal transition takes place. This nontrivial phase is characterized by the emergence of a pair of Dirac points in the spectrum. As a consequence, the Landau levels are not equidistant anymore but follow the ɛn∝√{n B } characteristic of Dirac crystals as graphene. By using the Kubo-Bastin formula in the context of the kernel polynomial method, we compute the Hall conductivity of the system. We obtain a σx y∝2 n quantization of the Hall conductivity in the gapped phase (standard quantum Hall effect regime) and a σx y∝4 (n +1 /2 ) quantization in the semimetallic phase, characteristic of Dirac systems with nontrivial topology.

  12. Field-free magnetization reversal by spin-Hall effect and exchange bias.

    Science.gov (United States)

    van den Brink, A; Vermijs, G; Solignac, A; Koo, J; Kohlhepp, J T; Swagten, H J M; Koopmans, B

    2016-01-01

    As the first magnetic random access memories are finding their way onto the market, an important issue remains to be solved: the current density required to write magnetic bits becomes prohibitively high as bit dimensions are reduced. Recently, spin-orbit torques and the spin-Hall effect in particular have attracted significant interest, as they enable magnetization reversal without high current densities running through the tunnel barrier. For perpendicularly magnetized layers, however, the technological implementation of the spin-Hall effect is hampered by the necessity of an in-plane magnetic field for deterministic switching. Here we interface a thin ferromagnetic layer with an anti-ferromagnetic material. An in-plane exchange bias is created and shown to enable field-free S HE-driven magnetization reversal of a perpendicularly magnetized Pt/Co/IrMn structure. Aside from the potential technological implications, our experiment provides additional insight into the local spin structure at the ferromagnetic/anti-ferromagnetic interface. PMID:26940861

  13. Effect of thermal cycle on the interfacial antiferromagnetic spin configuration and exchange bias in Ni-Mn-Sb alloy

    Directory of Open Access Journals (Sweden)

    R. L. Wang

    2012-09-01

    Full Text Available Effect of thermal cycle on the interfacial antiferromagnetic (AFM spin configuration and exchange bias in Ni50Mn36Sb14 alloy has been investigated. The results indicate thermal cycle can induce further martensitic transition from part of arrested FM phase to AFM phase, leading to the reconstruction of interfacial antiferromagnetic spin configuration. The shape of hysteresis loops at 5 K after cooling back can be tuned from a single-shifted loop to a nearly symmetric double-shifted loop gradually accompanied with exchange bias field increasing to peak value and then decreasing. The evolutions can be illustrated intuitively by a simple AFM bidomain model.

  14. Substrate bias effects on collector resistance in SiGe heterojunction bipolar transistors on thin film silicon-on-insulator

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Zhang He-Ming; Hu Hui-Yong; Qu Jiang-Tao

    2011-01-01

    An analytical expression for the collector resistance of a novel vertical SiGe heteroj unction bipolar transistor (HBT)on thin film silicon-on-insulator (SOI) is obtained with the substrate bias effects being considered. The resistance is found to decrease slowly and then quickly and to have kinks with the increase of the substrate-collector bias, which is quite different from that of a conventional bulk HBT. The model is consistent with the simulation result and the reported data and is useful to the frequency characteristic design of 0.13 μm millimeter-wave SiGe SOI BiCMOS devices.

  15. Reversible and irreversible temperature-induced changes in exchange-biased planar Hall effect bridge (PHEB) magnetic field sensors

    DEFF Research Database (Denmark)

    Rizzi, G.; Lundtoft, N.C.; Østerberg, F.W.;

    2012-01-01

    We investigate the changes of planar Hall effect bridge magnetic field sensors upon exposure to temperatures between 25° C and 90°C. From analyses of the sensor response vs. magnetic fields we extract the exchange bias field Hex, the uniaxial anisotropy field HK and the anisotropic...... magnetoresistance (AMR) of the exchange biased thin film at a given temperature and by comparing measurements carried out at elevated temperatures T with measurements carried out at 25° C after exposure to T, we can separate the reversible from the irreversible changes of the sensor. The results are not only...

  16. Effects of stress on dietary preference and intake are dependent on access and stress sensitivity

    OpenAIRE

    Teegarden, Sarah L.; Bale, Tracy L.

    2007-01-01

    Recent studies support a link between stress and the increased consumption of palatable foods. However, there has been a noted lack of genetic models to examine predisposing factors of overweight, obesity, and binge eating, particularly the role that stress sensitivity might play in the development of these conditions. We have examined the effects of chronic stress exposure on macronutrient choice preferences in a genetic mouse model of stress sensitivity (corticotropin-releasing factor recep...

  17. The effect of cathode bias (field effect) on the surface leakage current of CdZnTe detectors

    DEFF Research Database (Denmark)

    Bolotnikov, A.E.; Chen, C.M.H.; Cook, W.R.;

    2003-01-01

    Surface resistivity is an important parameter of multi-electrode CZT detectors such as coplanar-grid, strip, or pixel detectors. Low surface resistivity results in a high leakage current and affects the charge collection efficiency in the areas near contacts. Thus, it is always desirable to have...... the surface resistivity of the detector as high as possible. In the past the most significant efforts were concentrated to develop passivation techniques for CZT detectors. However, as we found, the field-effect caused by a bias applied on the cathode can significantly reduce the surface resistivity even...... though the detector surface was carefully passivated. In this paper we illustrate that the field-effect is a common feature of the CZT multi-electrode detectors, and discuss how to take advantage of this effect to improve the surface resistivity of CZT detectors....

  18. Effect of oxygen on the bias-enhanced nucleation of diamond on silicon

    DEFF Research Database (Denmark)

    Schreck, M.; Christensen, Carsten; Stritzker, B.

    The influence of traces of oxygen in the process gas on the bias-enhanced nucleation (BEN) of diamond on silicon has been studied in the present work. CO2 in concentrations ranging from 0 to 3000 ppm was added during the nucleation procedure at U-bias = -200 V in microwave plasma chemical vapour......-covered substrate surface area with increasing CO2 concentration. At 3000 ppm, the nucleation was completely suppressed. An etching of diamond nuclei by the oxygen could be excluded from in-situ growth rate measurements under bias. Instead, optical emission spectra of the IIB Balmer line indicated a decrease in...... electrical field strength in the plasma above the substrate. For all gas compositions allowing diamond nucleation, epitaxially aligned films could be obtained, provided that the duration of the biasing step was chosen appropriately. Thus, traces of oxygen do not completely suppress epitaxy. However, the in...

  19. Modeling the Effects of Stress: An Approach to Training

    Science.gov (United States)

    Cuper, Taryn

    2010-01-01

    Stress is an integral element of the operational conditions experienced by combat medics. The effects of stress can compromise the performance of combat medics who must reach and treat their comrades under often threatening circumstances. Examples of these effects include tunnel vision, loss of motor control, and diminished hearing, which can result in an inability to perceive further danger, satisfactorily treat the casualty, and communicate with others. While many training programs strive to recreate this stress to aid in the experiential learning process, stress inducement may not always be feasible or desired. In addition, live simulations are not always a practical, convenient, and repeatable method of training. Instead, presenting situational training on a personal computer is proposed as an effective training platform in which the effects of stress can be addressed in a different way. We explore the cognitive and motor effects of stress, as well as the benefits of training for mitigating these effects in real life. While many training applications focus on inducing stress in order to "condition" the stress response, the author explores the possibilities of modeling stress to produce a similar effect. Can presenting modeled effects of stress help prepare or inoculate soldiers for stressful situations in which they must perform at a high level? This paper investigates feasibility of modeling stress and describes the preliminary design considerations of a combat medic training system that utilizes this method of battlefield preparation.

  20. The role of attentional bias in the effect of food advertising on actual food intake among children

    NARCIS (Netherlands)

    F. Folkvord; D.J. Anschütz; R.W. Wiers; M. Buijzen

    2015-01-01

    This study examined the potential moderating role of attentional bias (i.e., gaze duration, number of fixations, latency of initial fixation) in the effect of advergames promoting energy-dense snacks on children's snack intake. A randomized between-subject design was conducted with 92 children who p

  1. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study

    DEFF Research Database (Denmark)

    Wood, L.; Egger, M.; Gluud, L.L.;

    2008-01-01

    OBJECTIVE: To examine whether the association of inadequate or unclear allocation concealment and lack of blinding with biased estimates of intervention effects varies with the nature of the intervention or outcome. DESIGN: Combined analysis of data from three meta-epidemiological studies based o...

  2. CONSUMER VALUATION OF GENETICALLY MODIFIED FOODS AND THE EFFECT OF INFORMATION BIAS

    OpenAIRE

    Vanwechel, Tamara; Wachenheim, Cheryl J.; Schuck, Eric C.; Lambert, David K.

    2003-01-01

    Bid prices were elicited for standard-label cookies, muffins, and potato chips and those identified as not including genetically modified (GM) ingredients using an experimental auction. Including a statement that the product did not include GM ingredients increased bids over those offered for standard-label products. Providing negative-biased information about the impact of GM crops on the environment increased the risk participants associated with GM foods, and positive-biased information de...

  3. An Exploration Based Cognitive Bias Test for Mice: Effects of Handling Method and Stereotypic Behaviour

    OpenAIRE

    Novak, Janja; Jeremy D Bailoo; Melotti, Luca; Rommen, Jonas; Würbel, Hanno

    2015-01-01

    Behavioural tests to assess affective states are widely used in human research and have recently been extended to animals. These tests assume that affective state influences cognitive processing, and that animals in a negative affective state interpret ambiguous information as expecting a negative outcome (displaying a negative cognitive bias). Most of these tests however, require long discrimination training. The aim of the study was to validate an exploration based cognitive bias test, usin...

  4. The Effect of Selection Bias in Studies of Fads and Fashions

    OpenAIRE

    Denrell, Jerker; Kovács, Balázs

    2015-01-01

    Most studies of fashion and fads focus on objects and practices that once were popular. We argue that limiting the sample to such trajectories generates a selection bias that obscures the underlying process and generates biased estimates. Through simulations and the analysis of a data set that has previously not been used to analyze the rise and fall of cultural practices, the New York Times text archive, we show that studying a whole range of cultural objects, both popular and less popular, ...

  5. Internal and External Attentional Biases in Social Anxiety: The Effect of Effortful Control

    OpenAIRE

    Whitmore, Maria J

    2006-01-01

    Two cognitive processes have been proposed to play a role in social anxiety: self-focused attention and threat perception bias. Mansell, Clark, and Ehlers (2003) devised a novel dot-probe paradigm to simultaneously measure on-line attention to internal and external events among socially anxious adults. Their results indicated that high speech anxious individuals show an internal attention bias specific to a social threat condition. They did not find any differences between groups in a no-...

  6. Radio frequency bias power effect on surface roughness of silicon carbide plasma etching

    International Nuclear Information System (INIS)

    Control of surface roughness of silicon carbide (SiC) is to maintain or improve the electrical stability of high-power devices. The bias power plays an important role in determining the surface roughness. The surface roughness of SiC films etched in a C2F6 inductively coupled plasma is investigated in two ways: a variation in the bias power at fixed plasma conditions; and a shift in process parameters including radio frequency (rf) source power, pressure, O2 fraction, and gap between the wafer and plasma source. The surface roughness was measured by an atomic force microscopy (AFM). Parameter-induced DC bias was also correlated to the surface roughness. Under high pressure, the surface roughness was strongly correlated to the bias power-induced DC bias for the variation in the source power or the gap. Depending on the pressure, a significant discrepancy in the roughness behavior was observed at fixed or varying plasma conditions. Parameter interactions of practical importance were observed near the plasma source or in the presence of O2 fraction at low pressure. For variations in only the source power, the DC bias was strongly correlated to the surface roughness without regard to the pressure

  7. Radio frequency bias power effect on surface roughness of silicon carbide plasma etching

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byungwhan; Kim, Kunho; Lee, Byung Teak

    2003-07-15

    Control of surface roughness of silicon carbide (SiC) is to maintain or improve the electrical stability of high-power devices. The bias power plays an important role in determining the surface roughness. The surface roughness of SiC films etched in a C{sub 2}F{sub 6} inductively coupled plasma is investigated in two ways: a variation in the bias power at fixed plasma conditions; and a shift in process parameters including radio frequency (rf) source power, pressure, O{sub 2} fraction, and gap between the wafer and plasma source. The surface roughness was measured by an atomic force microscopy (AFM). Parameter-induced DC bias was also correlated to the surface roughness. Under high pressure, the surface roughness was strongly correlated to the bias power-induced DC bias for the variation in the source power or the gap. Depending on the pressure, a significant discrepancy in the roughness behavior was observed at fixed or varying plasma conditions. Parameter interactions of practical importance were observed near the plasma source or in the presence of O{sub 2} fraction at low pressure. For variations in only the source power, the DC bias was strongly correlated to the surface roughness without regard to the pressure.

  8. The effect of bias voltage on the morphology and wettability of plasma deposited titanium oxide films

    Science.gov (United States)

    Liu, Wei; Li, Yan; Guo, Kai; Zhang, Jing

    2008-02-01

    Hydrophobic and hydrophilic films with titanium oxide inside were grown by radio frequency plasma enhanced chemical vapor deposition (RF--PECVD) on glass substrates. Bias voltage was used as an assistant for the deposition process. And a comparison was made between with and without the bias voltage. Titanium tetraisopropoxide (TTIP-Ti (OC 3H 7) 4) was used as the precursor compound. Film wettability was tested by water contact angle measurement (CAM). The water contact angle (WAC) of the film deposited in plasma without biased voltage was greater than 145°, while the WAC of the film deposited in plasma with biased voltage was less than 30°. The morphology of the deposited films was observed by scanning electron microscope (SEM). It is found that the films grown without bias voltage were covered with lots of nano grain and pores, but the surface of the films deposition with bias voltage was much dense. The chemical structure and property of the deposited films were analyzed by Fourier-transformed infrared spectroscopy (FTIR), while the plasma phase was investigated by optical emission spectroscopy (OES).

  9. Effect of percent non-detects on estimation bias in censored distributions

    Science.gov (United States)

    Zhang, Z.; Lennox, W. C.; Panu, U. S.

    2004-09-01

    Uniqueness of the problem surrounding non-detects has been a concern alike to researchers and statisticians dealing with summary statistics while analyzing censored data. To incorporate non-detects in the estimation process, a simple substitution by the MDL (method detection limit) and the maximum likelihood estimation method are routinely implemented as standard methods by US-EPA laboratories. In situations where numerical standards are set at or near the MDL by regulatory agencies, it is prudent and important to closely investigate both the variability in test measurements and the estimation bias, because an inference based on biased estimates could entail significant liabilities. Variability is understood to be not only inevitable but also an inherent and integral part of any chemical analysis or test. In situations where regulatory agencies fail to account for the inherently present variability of test measurements, there is a need for regulated facilities to seek remedial action merely as a consequence of inadequate statistical procedure. This paper utilizes a mathematical approach to derive the bias functions and resulting bias curves are developed to investigate the censored samples from a variety of probability distributions such as normal, log-normal, gamma, and Gumbel distributions. Finally, the bias functions and bias curves are also compared to the results obtained by using Monte Carlo simulations.

  10. Kink effect in AlGaN/GaN high electron mobility transistors by electrical stress

    Institute of Scientific and Technical Information of China (English)

    Ma Xiao-Hua; Ma Ji-Gang; Yang Li-Yuan; He Qiang; Jiao Ying; Ma Ping; Hao Yue

    2011-01-01

    The kink effect is studied in an AlGaN/GaN high electron mobility transistor by measuring DC performance during fresh, short-term stress and recovery cycle with negligible degradation. Vdg plays an assistant role in detrapping electrons and short-term stress results in no creation of new category traps but an increase in number of active traps.A possible mechanism is proposed that electrical stress supplies traps with the electric field for activation and when device is under test field-assisted hot-electrons result in electrons detrapping from traps, thus deteriorating the kink effect. In addition, experiments show that the impact ionization is at a relatively low level, which is not the dominant mechanism compared with trapping effect. We analyse the complicated link between the kink effect and stress bias through groups of electrical stress states: Vds = 0-state, off-state, on-state (on-state with low voltage, high-power state,high field state). Finlly, a conclusion is drawn that electric field brings about more severe kink effect than hot electrons.With the assistance of electric field, hot electrons tend to be possible to modulate the charges in deep-level trap.

  11. Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases.

    Science.gov (United States)

    De Palma, Adriana; Abrahamczyk, Stefan; Aizen, Marcelo A; Albrecht, Matthias; Basset, Yves; Bates, Adam; Blake, Robin J; Boutin, Céline; Bugter, Rob; Connop, Stuart; Cruz-López, Leopoldo; Cunningham, Saul A; Darvill, Ben; Diekötter, Tim; Dorn, Silvia; Downing, Nicola; Entling, Martin H; Farwig, Nina; Felicioli, Antonio; Fonte, Steven J; Fowler, Robert; Franzén, Markus; Goulson, Dave; Grass, Ingo; Hanley, Mick E; Hendrix, Stephen D; Herrmann, Farina; Herzog, Felix; Holzschuh, Andrea; Jauker, Birgit; Kessler, Michael; Knight, M E; Kruess, Andreas; Lavelle, Patrick; Le Féon, Violette; Lentini, Pia; Malone, Louise A; Marshall, Jon; Pachón, Eliana Martínez; McFrederick, Quinn S; Morales, Carolina L; Mudri-Stojnic, Sonja; Nates-Parra, Guiomar; Nilsson, Sven G; Öckinger, Erik; Osgathorpe, Lynne; Parra-H, Alejandro; Peres, Carlos A; Persson, Anna S; Petanidou, Theodora; Poveda, Katja; Power, Eileen F; Quaranta, Marino; Quintero, Carolina; Rader, Romina; Richards, Miriam H; Roulston, T'ai; Rousseau, Laurent; Sadler, Jonathan P; Samnegård, Ulrika; Schellhorn, Nancy A; Schüepp, Christof; Schweiger, Oliver; Smith-Pardo, Allan H; Steffan-Dewenter, Ingolf; Stout, Jane C; Tonietto, Rebecca K; Tscharntke, Teja; Tylianakis, Jason M; Verboven, Hans A F; Vergara, Carlos H; Verhulst, Jort; Westphal, Catrin; Yoon, Hyung Joo; Purvis, Andy

    2016-01-01

    Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises. PMID:27509831

  12. Height bias and scale effect induced by antenna gravitational deformations in geodetic VLBI data analysis

    Science.gov (United States)

    Sarti, Pierguido; Abbondanza, Claudio; Petrov, Leonid; Negusini, Monia

    2011-01-01

    The impact of signal path variations (SPVs) caused by antenna gravitational deformations on geodetic very long baseline interferometry (VLBI) results is evaluated for the first time. Elevation-dependent models of SPV for Medicina and Noto (Italy) telescopes were derived from a combination of terrestrial surveying methods to account for gravitational deformations. After applying these models in geodetic VLBI data analysis, estimates of the antenna reference point positions are shifted upward by 8.9 and 6.7 mm, respectively. The impact on other parameters is negligible. To simulate the impact of antenna gravitational deformations on the entire VLBI network, lacking measurements for other telescopes, we rescaled the SPV models of Medicina and Noto for other antennas according to their size. The effects of the simulations are changes in VLBI heights in the range [-3, 73] mm and a net scale increase of 0.3-0.8 ppb. The height bias is larger than random errors of VLBI position estimates, implying the possibility of significant scale distortions related to antenna gravitational deformations. This demonstrates the need to precisely measure gravitational deformations of other VLBI telescopes, to derive their precise SPV models and to apply them in routine geodetic data analysis.

  13. The effect of research-based instruction in introductory physics on a common cognitive bias

    Science.gov (United States)

    Galloway, Ross K.; Bates, Simon P.; Parker, Jonathan; Usoskina, Evguenia

    2013-01-01

    Inspired by a paper at last year's PERC conference, in which Rebello [1] compared students' individual and cohort mean score estimations with their actual assessment scores, we present results of a study in which students in an introductory physics class were asked to predict their scores on two assessments, one delivered at the start of the course (pre-instruction) and one at the end of the course (post-instruction). Our results show that, pre-instruction, the academically strongest students tend to underestimate their score slightly, whereas the weakest overestimate their performance significantly, consistent with the findings of Rebello and demonstrating a well-known cognitive bias (the Dunning-Kruger effect). Post-instruction, we find that the ability of the original weakest quartile cohort to accurately predict their own assessment score has improved significantly, but a flux of students between quartiles from one assessment to the other reveals that the least able students continue to over-estimate their performance, but with a reduced mean discrepancy. We discuss the implications these results have for instruction and for development of enhanced metacognition amongst physics students.

  14. The effect of job stress on smoking and alcohol consumption

    OpenAIRE

    Azagba, Sunday; Sharaf, Mesbah F

    2011-01-01

    This paper examines the effect of job stress on two key health risk-behaviors: smoking and alcohol consumption, using data from the Canadian National Population Health Survey. Findings in the extant literature are inconclusive and are mainly based on standard models which can model differential responses to job stress only by observed characteristics. However, the effect of job stress on smoking and drinking may largely depend on unobserved characteristics such as: self control, stress-coping...

  15. The effect of sea surface temperature bias in the PMIP2 AOGCMs on mid-Holocene Asian monsoon enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Ohgaito, Rumi [Frontier Research Center for Global Change, JAMSTEC, Yokohama (Japan); Abe-Ouchi, A. [Frontier Research Center for Global Change, JAMSTEC, Yokohama (Japan); The University of Tokyo, Center for Climate System Research, Kashiwa (Japan)

    2009-12-15

    The effect of bias on control simulation is a significant issue for climate change modeling studies. We investigated the effect of the sea surface temperature (SST) bias in present day (0 ka) Atmosphere-Ocean Coupled General Circulation Model (AOGCM) simulations on simulations of the mid-Holocene (6 ka, i.e., 6,000 years before present) Asian monsoon enhancement. Because changes in ocean heat transport have a negligible effect on the 6 ka Asian monsoon (Ohgaito and Abe-Ouchi in Clim Dyn 29(1):39-50, 2007), we used an Atmospheric General Circulation Model (AGCM) rather than an AOGCM. Simulations using the AGCM coupled to a mixed layer ocean model (MLM) were conducted for 0 and for 6 ka with different ocean heat transport estimated from the climatological SST of the 0 ka simulations from nine Paleoclimate Modeling Intercomparison Project (PMIP) phase 2 (PMIP2) AOGCMs (henceforth ''MA'' is used to refer to experiments using the AGCM coupled with the MLM). No correlation between MA and the corresponding PMIP2 was seen in the 0 ka precipitation and it was not very strong for the 6 ka precipitation enhancement. Thus, the influences from the different AGCMs play a substantial role on the 0 ka precipitation and the 6 ka precipitation enhancement. The sensitivity experiments indicated that it was the pattern of the 0 ka SST bias which played a dominant role in the 0 ka precipitation and the 6 ka precipitation enhancement, not the difference in the mean value of the SST bias. The distributions of the 6 ka precipitation enhancements for the nine PMIP2 AOGCMs and nine MA experiments were compared. These showed that the effects of SST bias on 6 ka precipitation enhancement among the AOGCMs were not negligible. The effects of biases among the AGCMs were not negligible either, but of comparable size. That is, improvements in both the SST bias and the AGCM contribute to simulate better 6 ka monsoon. (orig.)

  16. 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.

  17. EEG biofeedback improves attentional bias in high trait anxiety individuals

    OpenAIRE

    Wang, Sheng; Zhao, Yan; Chen, Sijuan; Lin, Guiping; Sun, Peng; Wang, Tinghuai

    2013-01-01

    Background Emotion-related attentional bias is implicated in the aetiology and maintenance of anxiety disorders. Electroencephalogram (EEG) biofeedback can obviously improve the anxiety disorders and reduce stress level, and can also enhance attention performance in healthy subjects. The present study examined the effects and mechanisms of EEG biofeedback training on the attentional bias of high trait anxiety (HTA) individuals toward negative stimuli. Results Event-related potentials were rec...

  18. Phosphorus stress effects on assimilation of nitrate

    International Nuclear Information System (INIS)

    An experiment was conducted to investigate alterations in uptake and assimilation of NO3- by phosphorus-stressed plants. Young tobacco plants (Nicotiana tabacum [L.], cv NC 2326) growing in solution culture were derived of an external phosphorus (P) supply for 12 days. On selected days, plants were exposed to 15NO3- during the 12 hour light period to determine changes in NO3- assimilation as the P deficiency progressed. Decreased whole-plant growth was evident after 3 days of P deprivation and became more pronounced with time, but root growth was unaffected until after day 6. Uptake of 15NO3- per gram root dry weight and translocation of absorbed 15NO3- out of the root were noticeably restricted in -P plants by day 3, and effects on both increased in severity with time. Whole-plant reduction of 15NO3- and 15N incorporation into insoluble reduced-N in the shoot decreased after day 3. Although the P limitation was associated with a substantial accumulation of amino acids in the shoot, there was no indication of excessive accumulation of soluble reduced-15N in the shoot during the 12 hour 15NO3- exposure periods. The results indicate that alterations in NO3- transport processes in the root system are the primary initial responses limiting synthesis of shoot protein in P-stressed plants. Elevated amino acid levels evidently are associated with enhanced degradation of protein rather than inhibition of concurrent protein synthesis

  19. Expectancy of Stress-Reducing Aromatherapy Effect and Performance on a Stress-Sensitive Cognitive Task

    Directory of Open Access Journals (Sweden)

    Irina Chamine

    2015-01-01

    Full Text Available Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG task performance and event related potentials (ERP components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime. GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress. Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude. Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention.

  20. Expectancy of stress-reducing aromatherapy effect and performance on a stress-sensitive cognitive task.

    Science.gov (United States)

    Chamine, Irina; Oken, Barry S

    2015-01-01

    Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress. Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude. Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention. PMID:25802539

  1. Using the DC self-bias effect for simultaneous ion-electron beam generation in space thruster applications

    Science.gov (United States)

    Rafalskyi, Dmytro; Aanesland, Ane

    2014-10-01

    In this work we discuss ways to use the self-bias effect for broad ion-electron beam generation and present recent experimental results. In asymmetrical systems the self-bias effect leads to rectification of the applied RF voltage to a DC voltage dropped across the space charge sheath near to the electrode having smaller area. Thus, continuous ion acceleration is possible towards the smaller electrode with periodical electron extraction due to the RF plasma potential oscillations. We propose a new concept of neutralizer-free gridded space thruster called NEPTUNE. In this concept, the RF electrodes in contact with the plasma are replaced by a two-grid system such that ``the smaller electrode'' is now the external grid. The grids are biased with RF power across a capacitor. This allows to locate RF space charge sheath between the acceleration grids while still keeping the possibility of a DC self-bias generation. Here we present first proof-of-concept of the NEPTUNE thruster prototype and give basic parameters spacing for such thruster. Comparison of the main parameters of the beam generated using RF and a classical ``DC with neutralizer'' acceleration method shows several advantages of the NEPTUNE concept. This work was supported by a Marie Curie International Incoming Fellowships within the 7th European Community Framework (NEPTUNE PIIF-GA-2012-326054).

  2. The mechanism of asymmetric pipe-wall thinning behind an orifice by combined effect of swirling flow and orifice bias

    International Nuclear Information System (INIS)

    Highlights: ► The mechanism of asymmetric pipe-wall thinning is clarified. ► Flow fields and pipe-wall thinning are evaluated experimentally for orifice flow. ► We demonstrate combined effects of swirling flows and orifice biases on flows. ► Strong swirling flows and orifice biases cause an asymmetric pipe-wall thinning. - Abstract: In this paper, the mechanism of asymmetric pipe-wall thinning caused by flow accelerated corrosion behind an orifice in a circular pipe is studied by measuring the velocity fields by PIV and the mass transfer coefficients by naphthalene sublimation method. An attention is placed on the variations of the velocity fields and mass flux under the combined effect of swirling flow and orifice bias. The present measurement indicates that the flow field become asymmetric about the pipe axis due to the influence of swirling flow at large swirl intensity S = 0.3 in combination with an allowable orifice bias as small as 0.8% of a pipe diameter of standard steel pipes. This flow phenomenon results in the asymmetric distribution of mass transfer coefficient along the pipe-wall behind the orifice. The position of enhanced mass transfer occurs on the shorter orifice side near the orifice due to the flow reattachment, while the flow on the longer orifice side remains the same distribution of mass transfer coefficient as the case without swirl. These variations of velocity field and mass transfer data suggest that the mechanism of asymmetric pipe-wall thinning behind the orifice is due to the combined effect of swirling flow and orifice bias.

  3. Perceptual decision making and the time-order effect: A neural circuit model of biased vibrotactile discrimination

    OpenAIRE

    Angela Langdon; John Rinzel

    2012-01-01

    Human performance on sequential discrimination tasks displays the 'time-order effect' - a perceptual bias in which the order of stimulus presentation on a given trial critically influences the subjective judgement of relative magnitude. In vibrotactile discrimination, this effect manifests as a relative increase in response accuracy and decrease in reaction times on trials in which the difference in stimulus frequency points away from, rather than towards, the average of all stimulus frequ...

  4. Hindsight Bias.

    Science.gov (United States)

    Roese, Neal J; Vohs, Kathleen D

    2012-09-01

    Hindsight bias occurs when people feel that they "knew it all along," that is, when they believe that an event is more predictable after it becomes known than it was before it became known. Hindsight bias embodies any combination of three aspects: memory distortion, beliefs about events' objective likelihoods, or subjective beliefs about one's own prediction abilities. Hindsight bias stems from (a) cognitive inputs (people selectively recall information consistent with what they now know to be true and engage in sensemaking to impose meaning on their own knowledge), (b) metacognitive inputs (the ease with which a past outcome is understood may be misattributed to its assumed prior likelihood), and (c) motivational inputs (people have a need to see the world as orderly and predictable and to avoid being blamed for problems). Consequences of hindsight bias include myopic attention to a single causal understanding of the past (to the neglect of other reasonable explanations) as well as general overconfidence in the certainty of one's judgments. New technologies for visualizing and understanding data sets may have the unintended consequence of heightening hindsight bias, but an intervention that encourages people to consider alternative causal explanations for a given outcome can reduce hindsight bias. PMID:26168501

  5. Selection bias, demographic effects, and ability effects in common value auction experiments

    OpenAIRE

    Casari, Marco; John C. Ham; John H. Kagel

    2005-01-01

    We find clear demographic and ability effects on bidding in common value auctions: inexperienced women are much more susceptible to the winner's curse than men, controlling for SAT/ACT scores and college major; economics and business majors substantially overbid relative to other majors; and those with superior SAT/ACT scores are much less susceptible to the winner's curse, with the primary effect coming from those with below median scores doing worse, as opposed to those with very high score...

  6. Effect of a Stress Management Class: One Year Later.

    Science.gov (United States)

    Somerville, Addison W.; And Others

    1984-01-01

    Graduate and undergraduate students showed a reduction in anxiety during a 16-week course designed to include information on the causes and effects of stress as well as practical techniques for stress management. A follow-up study showed that the students were still successfully using the stress management techniques a year later. (RM)

  7. An Exploration Based Cognitive Bias Test for Mice: Effects of Handling Method and Stereotypic Behaviour.

    Directory of Open Access Journals (Sweden)

    Janja Novak

    Full Text Available Behavioural tests to assess affective states are widely used in human research and have recently been extended to animals. These tests assume that affective state influences cognitive processing, and that animals in a negative affective state interpret ambiguous information as expecting a negative outcome (displaying a negative cognitive bias. Most of these tests however, require long discrimination training. The aim of the study was to validate an exploration based cognitive bias test, using two different handling methods, as previous studies have shown that standard tail handling of mice increases physiological and behavioural measures of anxiety compared to cupped handling. Therefore, we hypothesised that tail handled mice would display a negative cognitive bias. We handled 28 female CD-1 mice for 16 weeks using either tail handling or cupped handling. The mice were then trained in an eight arm radial maze, where two adjacent arms predicted a positive outcome (darkness and food, while the two opposite arms predicted a negative outcome (no food, white noise and light. After six days of training, the mice were also given access to the four previously unavailable intermediate ambiguous arms of the radial maze and tested for cognitive bias. We were unable to validate this test, as mice from both handling groups displayed a similar pattern of exploration. Furthermore, we examined whether maze exploration is affected by the expression of stereotypic behaviour in the home cage. Mice with higher levels of stereotypic behaviour spent more time in positive arms and avoided ambiguous arms, displaying a negative cognitive bias. While this test needs further validation, our results indicate that it may allow the assessment of affective state in mice with minimal training-a major confound in current cognitive bias paradigms.

  8. An Exploration Based Cognitive Bias Test for Mice: Effects of Handling Method and Stereotypic Behaviour.

    Science.gov (United States)

    Novak, Janja; Bailoo, Jeremy D; Melotti, Luca; Rommen, Jonas; Würbel, Hanno

    2015-01-01

    Behavioural tests to assess affective states are widely used in human research and have recently been extended to animals. These tests assume that affective state influences cognitive processing, and that animals in a negative affective state interpret ambiguous information as expecting a negative outcome (displaying a negative cognitive bias). Most of these tests however, require long discrimination training. The aim of the study was to validate an exploration based cognitive bias test, using two different handling methods, as previous studies have shown that standard tail handling of mice increases physiological and behavioural measures of anxiety compared to cupped handling. Therefore, we hypothesised that tail handled mice would display a negative cognitive bias. We handled 28 female CD-1 mice for 16 weeks using either tail handling or cupped handling. The mice were then trained in an eight arm radial maze, where two adjacent arms predicted a positive outcome (darkness and food), while the two opposite arms predicted a negative outcome (no food, white noise and light). After six days of training, the mice were also given access to the four previously unavailable intermediate ambiguous arms of the radial maze and tested for cognitive bias. We were unable to validate this test, as mice from both handling groups displayed a similar pattern of exploration. Furthermore, we examined whether maze exploration is affected by the expression of stereotypic behaviour in the home cage. Mice with higher levels of stereotypic behaviour spent more time in positive arms and avoided ambiguous arms, displaying a negative cognitive bias. While this test needs further validation, our results indicate that it may allow the assessment of affective state in mice with minimal training-a major confound in current cognitive bias paradigms. PMID:26154309

  9. Is Terzaghi’s effective stress a stress variable under seepage conditions?

    Institute of Scientific and Technical Information of China (English)

    雷国辉; 赵仲辉; 吴宏伟

    2015-01-01

    From the continuum mechanics perspective, an attempt was made to clarify the role of Terzaghi’s effective stress in the theoretical analysis of saturated soil subjected to seepage. The necessity of performing a coupled hydromechanical analysis to solve the seepage−deformation interaction problem was illustrated by examining the equations of static equilibrium among the effective stress, seepage force, pore-water pressure and total stress. The conceptual definition of stress variable that satisfies the principles of continuum mechanics is applied in the coupled hydromechanical analysis. It is shown that Terzaghi’s effective stress is in fact not a stress variable under seepage conditions, and the seepage force acting on the soil skeleton cannot be viewed as a body force. This offers a clue to the underlying cause of a paradox between the real Pascal’s hydrostatic state and the hydrostatic state predicted by a class of continuum hydromechanical theories.

  10. Effect of collector bias current on the linearity of common-emitter BJT amplifiers

    International Nuclear Information System (INIS)

    Using a Volterra series, an explicit formula is derived for the connection between input 3rd-order intercept point and collector bias current (ICQ) in a common-emitter bipolar junction transistor amplifier. The analysis indicates that the larger ICQ is, the more linear the amplifier is. Furthermore, this has been verified by experiment. This study also integrates a method called dynamic bias current for expanding the dynamic range of an LNA (low noise amplifier) as an application of the analysis result obtained above. IMR3 (3rd-order intermodulation rate) is applied to evaluate the LNA's performance with and without adopting this method in this study. (semiconductor devices)

  11. Effects of exchange bias on magnetotransport in permalloy kagome artificial spin ice

    International Nuclear Information System (INIS)

    We investigate the magnetotransport properties of connected kagome artificial spin ice networks composed of permalloy nanowires. Our data show clear evidence of magnetic switching among the wires, both in the longitudinal and transverse magnetoresistance. An unusual asymmetry with field sweep direction appears at temperatures below about 20 K that appears to be associated with exchange bias resulting from surface oxidation of permalloy, and which disappears in alumina-capped samples. These results demonstrate that exchange bias is a phenomenon that must be considered in understanding the physics of such artificial spin ice systems, and that opens up new possibilities for their control. (paper)

  12. Nonlinear excitation kinetics of biased quantum wells. Coherent dynamical screening effect

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Jepsen, Peter Uhd

    2006-01-01

    In this paper we describe a strongly nonlinear process of ultrafast photoexcitation of a biased quantum well. This process is governed by coherent dynamical screening, where the instantaneously polarized photoexcited carriers screen initial bias field. This results in a dynamic modification of the...... bandstructure of the quantum well, which is totally coherent with the temporal intensity distribution of the excitation laser pulse. We developed a time-resolved theoretical model of coherent dynamical screening, which predicts interesting fundamental consequences, such as nonlinear absorption and ultra...

  13. Effects of drought stress on growth and yield of barley

    OpenAIRE

    H. Samarah, Nezar

    2005-01-01

    International audience Barley (Hordeum vulgare) grown in Mediterranean regions undergoes drought stress during the grain-filling period. A greenhouse experiment was conducted to study the effect of drought stress on grain growth and yield of barley. Plants were exposed to three drought treatments at the beginning of grain filling: (1) well-watered at 100% field capacity, (2) mild drought stress at 60% field capacity, and (3) severe drought stress at 20% field capacity until grain maturity....

  14. THE DELAYED EFFECTS OF CHRONIC UNPREDICTABLE STRESS ON ANXIETY MEASURES

    OpenAIRE

    Matuszewich, Leslie; Karney, Jared J.; Carter, Samantha R.; Janasik, Steven P.; O’Brien, Johanna L.; Friedman, Ross D.

    2006-01-01

    Previous research has found that exposure to unpredictable stress can augment anxiety in humans and animals. The appearance of anxiety symptoms in humans frequently develop after stress exposure has terminated, but few rodent studies have systematically examined the delayed anxiogenic effects of unpredictable stress. Therefore, the current study investigated whether anxiety-like behaviors in rats would increase at several time intervals following exposure to chronic unpredictable stress (CUS)...

  15. Hardening rate under reverse loading in 316 L: back stress and effective stress evolutions

    Energy Technology Data Exchange (ETDEWEB)

    Gaudin, C.; Guillemer-Neel, C.; Feaugas, X. [UTC, Compiegne (France). Lab. Roberval

    2001-09-01

    The Bauschinger effect has been investigated in a low stacking fault energy f.c.c. alloy. Reverse hardening rate is discussed in terms of internal stresses evolutions as a function of reverse straining. A distinction is made between short-range (effective stress) and long-range (back stresses) elastic interactions. Moreover the back stress is partitioned into intra-granular and inter-granular components. The evolutions of all stress components are directly related to the modification of dislocation densities and distributions in grains (over 50 grains). Back stress evolution is explained by heterogeneous dislocation patterns dissolution and formation of new ones with opposite polarization. This dissolution is promoted by both components of the back stress which enhance reverse slip and cross-slip under reverse straining. But only the cross-slip can induce plastic strain irreversibility and then permanent softening. The effective stress evolution results from a competition between latent hardening, dislocations emission at wall/channel interface and annihilation process. After stress reversal, the observed transient softening results from the evolution of dislocation distribution and density, in particular from the dissolution of the polarized structures (walls, cells) developed during pre-straining. The permanent softening occurs at reverse plastic strains higher than 2% when the initial heterogeneous dislocation structures are re-established by reverse loading. This permanent softening is mainly associated with the intra-granular back stress. (orig.)

  16. Hardening rate under reverse loading in 316 L: back stress and effective stress evolutions

    International Nuclear Information System (INIS)

    The Bauschinger effect has been investigated in a low stacking fault energy f.c.c. alloy. Reverse hardening rate is discussed in terms of internal stresses evolutions as a function of reverse straining. A distinction is made between short-range (effective stress) and long-range (back stresses) elastic interactions. Moreover the back stress is partitioned into intra-granular and inter-granular components. The evolutions of all stress components are directly related to the modification of dislocation densities and distributions in grains (over 50 grains). Back stress evolution is explained by heterogeneous dislocation patterns dissolution and formation of new ones with opposite polarization. This dissolution is promoted by both components of the back stress which enhance reverse slip and cross-slip under reverse straining. But only the cross-slip can induce plastic strain irreversibility and then permanent softening. The effective stress evolution results from a competition between latent hardening, dislocations emission at wall/channel interface and annihilation process. After stress reversal, the observed transient softening results from the evolution of dislocation distribution and density, in particular from the dissolution of the polarized structures (walls, cells) developed during pre-straining. The permanent softening occurs at reverse plastic strains higher than 2% when the initial heterogeneous dislocation structures are re-established by reverse loading. This permanent softening is mainly associated with the intra-granular back stress. (orig.)

  17. Are hungry sheep more pessimistic? The effects of food restriction on cognitive bias and the involvement of ghrelin in its regulation.

    Science.gov (United States)

    Verbeek, Else; Ferguson, Drewe; Lee, Caroline

    2014-01-17

    Food restriction is considered to be a welfare issue in extensively reared animals. However, the effects of food restriction on the affective state, and its physiological regulation, are unknown. In Experiment 1, we aimed to assess the effects of increased plasma concentrations of acyl-ghrelin on judgement bias (an indicator of affective states) by fasting sheep for 24h or by ghrelin administration. In Experiment 2, we aimed to assess the effects of chronic food restriction on judgement bias and attention bias towards a food-related cue. For the judgement bias test, sheep were trained in an arena to approach a positive location cue associated with conspecifics and not approach a negative location cue associated with a dog. Three non-trained, non-reinforced ambiguous location cues were situated between the positive and negative locations. Attention bias towards a food-related cue was assessed by placing an empty food bucket against the wall of the arena halfway between the entry point and the positive location. In Experiment 1, sheep were divided into three treatments; 24h fast, ghrelin administration or control. Judgement bias, locomotor activity and plasma cortisol concentrations were assessed. The ghrelin treated group tended to express a more pessimistic bias compared to the control group (Pfood-related cue was presented, LF ewes took longer to reach the positive location (Pfood restriction alters judgement bias and attention bias towards a food-related cue which may indicate altered affective states of sheep. PMID:24096007

  18. Stress effects on mood, HPA axis, and autonomic response: comparison of three psychosocial stress paradigms.

    Directory of Open Access Journals (Sweden)

    Grace E Giles

    Full Text Available Extensive experimental psychology research has attempted to parse the complex relationship between psychosocial stress, mood, cognitive performance, and physiological changes. To do so, it is necessary to have effective, validated methods to experimentally induce psychosocial stress. The Trier Social Stress Test (TSST is the most commonly used method of experimentally inducing psychosocial stress, but it is resource intensive. Less resource intense psychosocial stress tasks include the Socially Evaluative Cold Pressor Task (SECPT and a computerized mental arithmetic task (MAT. These tasks effectively produce a physiological and psychological stress response and have the benefits of requiring fewer experimenters and affording data collection from multiple participants simultaneously. The objective of this study was to compare the magnitude and duration of these three experimental psychosocial stress induction paradigms. On each of four separate days, participants completed either a control non-stressful task or one of the three experimental stressors: the TSST, SECPT, or MAT. We measured mood, working memory performance, salivary cortisol and alpha-amylase (AA, and heart rate. The TSST and SECPT exerted the most robust effects on mood and physiological measures. TSST effects were generally evident immediately post-stress as well as 10- and 20-minutes after stress cessation, whereas SECPT effects were generally limited to the duration of the stressor. The stress duration is a key determinant when planning a study that utilizes an experimental stressor, as researchers may be interested in collecting dependent measures prior to stress cessation. In this way, the TSST would allow the investigator a longer window to administer tasks of interest.

  19. EFFECT OF WORKPLACE STRESS ON JOB PERFORMANCE

    OpenAIRE

    Azman Ismail; Noorshafine Saudin; Yusof Ismail; Ainon Jauhariah Abu Samah; Rizal Abu Bakar; Norish Norsiah Aminudin

    2015-01-01

    The study examines the relationship between workplace stress and job performance. A survey method was employed to gather self-administered questionnaires from executive and non-executive employees of a leading private investment bank in Peninsular Malaysia. The outcomes of SmartPLS path model analysis of the data showed two important findings: firstly, physiological stress was positively and significantly correlated with job performance. Secondly, psychological stress was positively and signi...

  20. The Effects of Sample Selection Bias on Racial Differences in Child Abuse Reporting.

    Science.gov (United States)

    Ards, Sheila; Chung, Chanjin; Myers, Samuel L., Jr.

    1998-01-01

    Data from the National Incidence Study (NIS) of Child Abuse and Neglect suggest no racial difference in child maltreatment, although there are more black children within the child welfare population. This study found selection bias in the NIS design caused by the exclusion of family, friends, and neighbors that resulted in differences in NIS cases…

  1. A Phenomenological Case Study: Teacher Bias Effects on Early Education Assessments

    Science.gov (United States)

    Reynolds, Rebecca Jeannine

    2012-01-01

    This qualitative phenomenological case study explored the lived experiences of a purposive sample of 20 current and past early education teachers who have experience in assessing children through observational assessment. The purpose of this study was to determine if bias affects the documentation of observational assessment and the implementation…

  2. A Rational Analysis of the Effects of Memory Biases on Serial Reproduction

    Science.gov (United States)

    Xu, Jing; Griffiths, Thomas L.

    2010-01-01

    Many human interactions involve pieces of information being passed from one person to another, raising the question of how this process of information transmission is affected by the cognitive capacities of the agents involved. Bartlett (1932) explored the influence of memory biases on the "serial reproduction" of information, in which one…

  3. The Effect of Colour and Size on Attentional Bias to Alcohol-Related Pictures

    Science.gov (United States)

    Harrison, Neil R.; McCann, Amy

    2014-01-01

    Attentional bias plays an important role in the development and maintenance of alcohol addiction, and has often been measured with a visual probe task, where reaction times are compared for probes replacing either a substance-related cue or a neutral cue. Systematic low-level differences between image classes are a potential cause of low internal…

  4. EFFECT OF WORKPLACE STRESS ON JOB PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Azman Ismail

    2015-05-01

    Full Text Available The study examines the relationship between workplace stress and job performance. A survey method was employed to gather self-administered questionnaires from executive and non-executive employees of a leading private investment bank in Peninsular Malaysia. The outcomes of SmartPLS path model analysis of the data showed two important findings: firstly, physiological stress was positively and significantly correlated with job performance. Secondly, psychological stress was positively and significantly correlated with job performance. This finding reveals that physiological and psychological stresses act as important predictors of job performance in the studied organization. The paper provides discussion, implications and conclusion.

  5. Controllable substrate bias voltages effectively tailoring nanocomposite Nb–B–Al–O film properties

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Na [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Dong, Lei, E-mail: dlei0008@126.com [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Xifei, E-mail: xfli2011@hotmail.com [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Dejun, E-mail: dejunli@mail.tjnu.edu.cn [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Wan, Rongxin; Gu, Hanqing [Tianjin Institute of Urological Surgery, Tianjin Medical University, Tianjin 300070 (China)

    2015-07-05

    Graphical abstract: Nb–B–Al–O nanocomposite films were synthesized by multi-target magnetron co-sputtering. Different substrate bias voltages can influence properties of obtained nanocomposite films. The maximum hardness at −160 V bias also showed the better thermostability and oxidation resistance properties at 300 °C in the air. More significantly, the TEM images and XRD results of the nanocomposite films at different bias obviously interpreted the change in mechanical properties, which provides a powerful inspiration to better understand the strategies to improve these films’ engineering applications. - Highlights: • The films were prepared by multi-target magnetron co-sputtering. • The structure and properties were influenced obviously by substrate bias voltages. • Maximum hardness and modulus at −160 V were higher than monolithic films. • The film at −160 V also showed better thermostability and oxidation resistance. - Abstract: The nanocomposite Nb–B–Al–O films based on NbB{sub 2} and Al{sub 2}O{sub 3} were successfully deposited on Si substrate via multi-target magnetron co-sputtering method. The influences of substrate bias on microstructure, mechanical, thermostability and oxidation resistance properties of the films were investigated in detail. Transmission Electron Microscopy (TEM), X-ray diffractometry (XRD), Scanning Electron Microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were performed to study the structural properties such as crystallinity, binding energy and chemical composition of as-prepared films. The combination of monocrystalline NbB{sub 2} (1 0 0) texture and Al{sub 2}O{sub 3} (1 1 3) crystal plane affected the mechanical properties of the films at different bias voltages. The best crystallization appeared at −160 V. The maximum hardness (23.4 GPa) and elastic modulus (274.5 GPa) of the films were obtained at optimal substrate bias of −160 V. The hardest film at −160 V also showed the better

  6. Lexical stress, frequency, and stress neighbourhood effects in the early stages of Italian reading development.

    Science.gov (United States)

    Sulpizio, Simone; Colombo, Lucia

    2013-01-01

    We examined the development of stress assignment in reading Italian aloud. We investigated frequency effects as a marker of the use of item-specific lexical knowledge in assigning stress together with stress dominance and stress neighbourhood (the number of words sharing both stress and ending) as markers of distributional information regarding properties of the lexicon extracted from spoken language. We tested second- and fourth-graders in a reading-aloud experiment including high- and low-frequency words and nonwords. Results show that despite the regularity of orthography-phonology mappings in Italian and the predominant use of phonological recoding procedures, item-specific lexical knowledge is also used, even by beginning readers. The frequency effect was significant and did not increase with age, while stress errors on low-frequency words decreased with increasing grade. Stress neighbourhood increasingly affected stress assignment on nonwords with older children. Taken together, our findings show that both item-specific knowledge and general information about stress distribution are relevant in children's reading, suggesting the simultaneous use of both lexical and sublexical information. Moreover, as the reading system develops, and knowledge about the relative distribution of stress neighbourhood increases, larger grain-size units are also exploited. PMID:23590549

  7. When does stress help or harm? The effects of stress controllability and subjective stress response on Stroop performance.

    Directory of Open Access Journals (Sweden)

    Roselinde Kaiser Henderson

    2012-06-01

    Full Text Available The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing to clinical therapy. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual’s response to stressors: moderate responses to stress can lead to improved performance while extreme (high or low responses can lead to impaired performance. The present studies tested the hypothesis that 1 learning to behaviorally control stressors leads to improved performance on a test of general executive functioning, the color-word Stroop, and that 2 this improvement emerges specifically for people who report moderate (subjective responses to stress. Experiment 1: Stroop performance, measured before and after a stress manipulation, was compared across groups of undergraduate participants (n=109. People who learned to control a noise stressor and received accurate performance feedback demonstrated reduced Stroop interference compared with people exposed to uncontrollable noise stress and feedback indicating an exaggerated rate of failure. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest reduction in Stroop interference. In contrast, in the group exposed to uncontrollable events, self-reported stress failed to predict performance. Experiment 2: In a second sample (n=90, we specifically investigated the role of controllability by keeping the rate of failure feedback constant across groups. In the group who learned behavioral control, those who reported moderate levels of stress

  8. Effect of Sample Configuration on Droplet-Particles of TiN Films Deposited by Pulse Biased Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    Yanhui Zhao; Guoqiang Lin; Jinquan Xiao; Chuang Dong; Lishi Wen

    2009-01-01

    Orthogonal experiments are used to design the pulsed bias related parameters, including bias magnitude, duty cycle and pulse frequency, during arc ion deposition of TiN films on stainless steel substrates in the case of samples placing normal to the plasma flux. The effect of these parameters on the amount and the size distribution of droplet-particles are investigated, and the results have provided sufficient evidence for the physical model, in which particles reduction is due to the case that the particles are negatively charged and repulsed from negative pulse electric field. The effect of sample configuration on amount and size distribution of the particles are analyzed. The results of the amount and size distribution of the particles are compared to those in the case of samples placing parallel to the plasma flux.

  9. Memories of an Autopsy: The Effects of Stress Exposure on Suggestibility for a Stressful Event

    OpenAIRE

    Elisa Krackow; Vanessa M. Jacoby; Scotti, Joseph R.

    2013-01-01

    The current study examined the effects of stressful life events on memory for a stressful event. Two groups ofcollege students (N = 61) were formed for analysis based on the presence or absence of particular stressful lifeevents. Participants then viewed a graphic video depicting an autopsy, and received a memory interview fourdays later. Results showed similar group performance on correctly leading questions. However, participants inthe Specific Stressor-Exposed group were less suggestible t...

  10. Resistance to Early-Life Stress in Mice: Effects of Genetic Background and Stress Duration

    OpenAIRE

    Savignac, Hélène M.; Dinan, Timothy G.; Cryan, John F.

    2011-01-01

    Early-life stress can induce marked behavioral and physiological impairments in adulthood including cognitive deficits, depression, anxiety, and gastrointestinal dysfunction. Although robust rat models of early-life stress exist there are few established effective paradigms in the mouse. Genetic background and protocol parameters used are two critical variables in such model development. Thus we investigated the impact of two different early-life stress protocols in two commonly used inbred m...

  11. Low-stress and high-stress singing have contrasting effects on glucocorticoid response

    OpenAIRE

    Fancourt, Daisy; Aufegger, Lisa; Williamon, Aaron

    2015-01-01

    Performing music in public is widely recognized as a potentially stress-inducing activity. However, despite the interest in music performance as an acute psychosocial stressor, there has been relatively little research on the effects of public performance on the endocrine system. This study examined the impact of singing in a low-stress performance situation and a high-stress live concert on levels of glucocorticoids (cortisol and cortisone) in 15 professional singers. The results showed a si...

  12. Different Effects of Workers' Trust on Work Stress, Perceived Stress, Stress Reaction, and Job Satisfaction between Korean and Japanese Workers

    OpenAIRE

    Rhee, Kyung Yong

    2010-01-01

    Objectives This study was conducted to investigate the effect of trust on work stress. Trust can be classified into three dimensions; social trust, institutional trust, and trust in others. The relationship between work stress and trust is regarded as having three components. First, trust has an influence on work stressors as an antecedent variable; secondly, trust modifies the effect of the various stressors, and finally, trust is one of the stressors. Methods Data for this study was collect...

  13. A Comparison of Cognitive Bias Modification for Interpretation and Computerized Cognitive Behavior Therapy: Effects on Anxiety, Depression, Attentional Control, and Interpretive Bias

    Science.gov (United States)

    Bowler, Jennifer O.; Mackintosh, Bundy; Dunn, Barnaby D.; Mathews, Andrew; Dalgleish, Tim; Hoppitt, Laura

    2012-01-01

    Objective: Computerized cognitive behavioral therapy (cCBT) and cognitive bias modification for interpretation (CBM-I) both have demonstrated efficacy in alleviating social anxiety, but how they compare with each other has not been investigated. The present study tested the prediction that both interventions would reduce anxiety relative to a…

  14. Analytical performance specifications for changes in assay biasbias) for data with logarithmic distributions as assessed by effects on reference change values

    DEFF Research Database (Denmark)

    Hyltoft Petersen, Per; Lund, Flemming; Fraser, Callum G;

    2016-01-01

    performance specifications for reference change value, with combination of Δbias and CVA based on log-Gaussian distributions of CVI as natural logarithms. The model was tested using plasma prolactin and glucose as examples. RESULTS: Analytical performance specifications for reference change value generated...

  15. Volunteer Bias in Sex Research: The effect of recruitment material on demographics, personality, impression management, sociosexuality, sexual desire and preoccupation

    OpenAIRE

    Hope, David

    2008-01-01

    The study investigated volunteer bias in sex research across different measures in an online anonymous environment. 108 participants (79 female, 29 male) participated, completing one of two versions. Version A participants were recruited to a personality and sexual research study. Version B participants were recruited to a personality study then asked to continue to a sexual research study. Condition significantly impacted age but the effect was small. Condition did not affect sexual behaviou...

  16. Evaluating treatment effectiveness under model misspecification: a comparison of targeted maximum likelihood estimation with bias-corrected matching

    OpenAIRE

    Kreif, N.; Gruber, S.; Radice, Rosalba; Grieve, R; J S Sekhon

    2014-01-01

    Statistical approaches for estimating treatment effectiveness commonly model the endpoint, or the propensity score, using parametric regressions such as generalised linear models. Misspecification of these models can lead to biased parameter estimates. We compare two approaches that combine the propensity score and the endpoint regression, and can make weaker modelling assumptions, by using machine learning approaches to estimate the regression function and the propensity score. Targeted maxi...

  17. Effects of nuclear radiation on a high-reliability silicon power diode. 4: Analysis of reverse bias characteristics

    Science.gov (United States)

    Been, J. F.

    1973-01-01

    The effects of nuclear radiation on the reverse bias electrical characteristics of one hundred silicon power diodes were investigated. On a percentage basis, the changes in reverse currents were large but, due to very low initial values, this electrical characteristic was not the limiting factor in use of these diodes. These changes were interpreted in terms of decreasing minority carrier lifetimes as related to generation-recombination currents. The magnitudes of reverse voltage breakdown were unaffected by irradiation.

  18. Effect of Vicarious Fear Learning on Children’s Heart Rate Responses and Attentional Bias for Novel Animals

    OpenAIRE

    Reynolds, Gemma; Field, Andy P.; Askew, Chris

    2014-01-01

    Research with children has shown that vicarious learning can result in changes to 2 of Lang’s (1968) 3 anxiety response systems: subjective report and behavioral avoidance. The current study extended this research by exploring the effect of vicarious learning on physiological responses (Lang’s final response system) and attentional bias. The study used Askew and Field’s (2007) vicarious learning procedure and demonstrated fear-related increases in children’s cognitive, behavioral, and physiol...

  19. The Dichotomous Effect of Chronic Stress on Obesity.

    Science.gov (United States)

    Razzoli, Maria; Bartolomucci, Alessandro

    2016-07-01

    Obesity and metabolic diseases are linked to chronic stress and low socioeconomic status. The mechanistic link between stress and obesity has not been clarified, partly due to the inherent complexity exemplified by the bidirectional effect of stress on eating and body weight. Recent studies focusing on adaptive thermogenesis and brown adipose tissue (BAT) function support a dichotomous relation to explain the impact of stress on obesity: stress promotes obesity in the presence of hyperphagia and unchanged BAT function; stress results in weight loss and/or obesity resistance in the presence of hypophagia, or when hyperphagia is associated with BAT recruitment and enhanced thermogenesis. Mechanistically dissecting the bidirectional effects of stress on metabolic outcomes might open new avenues for innovative pharmacotherapies for the treatment of obesity-associated diseases. PMID:27162125

  20. Origin of the exchange bias training effects in magnetically coupled soft/hard synthetic bilayers at low temperature

    International Nuclear Information System (INIS)

    Hysteresis loops of the nanoscale magnetic layer Co90Fe10 and Ni81Fe19 and bilayer Co90Fe10/Ni81Fe19 and Ni81Fe19/Co90Fe10 films were measured as a function of external dc magnetic field and the thickness dependence of these films were plotted as a function of temperature. Time evolution of the minor/middle/major hysteresis loops of 5/5 nm-thick Ni81Fe19/Co90Fe10 monolayer have been observed at 10 K. The spin valve, exchange bias training and Barkhausen effects for magnetic layer and bilayer films have been analysed at various temperatures, thicknesses and different orientations according to the substrate. The exchange-bias training effects have been observed only in positive magnetization region. Origin of the exchange-bias training effects and asymmetric hysteresis loops are related to the relaxation mechanism of a pinning layer in magnetically coupled soft/hard bilayers

  1. Sampling Soil CO2 for Isotopic Flux Partitioning: Non Steady State Effects and Methodological Biases

    Science.gov (United States)

    Snell, H. S. K.; Robinson, D.; Midwood, A. J.

    2014-12-01

    Measurements of δ13C of soil CO2 are used to partition the surface flux into autotrophic and heterotrophic components. Models predict that the δ13CO2 of the soil efflux is perturbed by non-steady state (NSS) diffusive conditions. These could be large enough to render δ13CO2 unsuitable for accurate flux partitioning. Field studies sometimes find correlations between efflux δ13CO2 and flux or temperature, or that efflux δ13CO2 is not correlated as expected with biological drivers. We tested whether NSS effects in semi-natural soil were comparable with those predicted. We compared chamber designs and their sensitivity to changes in efflux δ13CO2. In a natural soil mesocosm, we controlled temperature to generate NSS conditions of CO2 production. We measured the δ13C of soil CO2 using in situ probes to sample the subsurface, and dynamic and forced-diffusion chambers to sample the surface efflux. Over eight hours we raised soil temperature by 4.5 OC to increase microbial respiration. Subsurface CO2 concentration doubled, surface efflux became 13C-depleted by 1 ‰ and subsurface CO2 became 13C-enriched by around 2 ‰. Opposite changes occurred when temperature was lowered and CO2 production was decreasing. Different chamber designs had inherent biases but all detected similar changes in efflux δ13CO2, which were comparable to those predicted. Measurements using dynamic chambers were more 13C-enriched than expected, probably due to advection of CO2 into the chamber. In the mesocosm soil, δ13CO2 of both efflux and subsurface was determined by physical processes of CO2 production and diffusion. Steady state conditions are unlikely to prevail in the field, so spot measurements of δ13CO2 and assumptions based on the theoretical 4.4 ‰ diffusive fractionation will not be accurate for estimating source δ13CO2. Continuous measurements could be integrated over a period suitable to reduce the influence of transient NSS conditions. It will be difficult to disentangle

  2. Experimental Modification of Interpretation Bias about Animal Fear in Young Children: Effects on Cognition, Avoidance Behavior, Anxiety Vulnerability, and Physiological Responding

    Science.gov (United States)

    Lester, Kathryn J.; Field, Andy P.; Muris, Peter

    2011-01-01

    This study investigated the effects of experimentally modifying interpretation biases for children's cognitions, avoidance behavior, anxiety vulnerability, and physiological responding. Sixty-seven children (6-11 years) were randomly assigned to receive a positive or negative interpretation bias modification procedure to induce interpretation…

  3. The effect of anticipatory psychosocial stress on frontal executive functions

    OpenAIRE

    Olga, Wudarczyk

    2010-01-01

    Previous research has found that stress hormone cortisol affects cognition, especially those cognitive abilities associated with the areas of the brain abundant in glucocorticoid receptors (e.g. Lupien & McEwen, 1997). Most studies have shown negative effects of induced stress on the functions associated with the hippocampus. Less research has investigated the effects of stress on executive functions, associated with the frontal lobes, also rich in glucocorticoid receptors. The evidence of th...

  4. Equivalent circuit model of converse magnetoelectric effect for the tri-layer magnetoelectric laminates with thermal and stress loadings

    Science.gov (United States)

    Zhou, Hao-Miao; Li, Meng-Han; Liu, Hui; Cui, Xiao-Le

    2015-12-01

    For the converse magnetoelectric coupling effect of the piezoelectric/magnetostrictive/piezoelectric tri-layer symmetric magnetoelectric laminates, based on the nonlinear thermo-magneto-mechanical constitutive equations of the giant magnetostrictive materials and the thermo-electro-mechanical constitutive equations of the piezoelectric materials, according to Newton's second law and the magnetic circuit theorem, an equivalent circuit is established. Then an expression of the converse magnetoelectric coefficient describing nonlinear thermo-magneto-electro-mechanical coupling is established. The curve of the nonlinear converse magnetoelectric coefficient versus the bias magnetic field, is predicted effectively by the expression, and the predictions are in good agreement with the experimental result both qualitatively and quantitatively. Furthermore, the model can predict the complex influences of the bias magnetic field, the stress and the ambient temperature on the converse magnetoelectric coefficient. It can be found from these predictions that the converse magnetoelectric coefficient decreases with the increasing temperature and increases with the increasing tensile stress. Under the common effect of the ambient temperature and the stress, it is also found that the converse magnetoelectric coefficient changes sharply with the ambient temperature when the tensile stress is applied on the laminates, but it has a good stability of temperature when a large compressive stress is applied. Therefore, this work contributes to the researches on the giant converse magnetoelectric coefficient and the designs of magnetoelectric devices based on the converse magnetoelectric coupling.

  5. Effect of pretreatment bias on the nucleation and growth mechanisms of ultrananocrystalline diamond films via bias-enhanced nucleation and growth: An approach to interfacial chemistry analysis via chemical bonding mapping

    International Nuclear Information System (INIS)

    The effect of pretreatment bias on the nucleation and growth mechanisms of the ultrananocrystalline diamond (UNCD) films on the Si substrate via bias-enhanced nucleation and bias-enhanced growth (BEN-BEG) was investigated using cross-sectional high-resolution transmission electron microscopy, chemical bonding mapping, and Raman spectroscopy. The mirror-polished substrate surface showed the formation of a triangular profile produced by a dominant physical sputtering mechanism induced by ion bombardment of ions from the hydrogen plasma accelerated toward the substrate due to biasing and a potential hydrogen-induced chemical reaction component before synthesizing the UNCD films. The BEN-BEG UNCD films grown on the Si substrate with biased and unbiased pretreatments in the hydrogen plasma were compared. In the case of the bias-pretreated substrate, the SiC phases were formed at the peaks of the Si surface triangular profile due to the active unsaturated Si bond and the enhanced local electrical field. The UNCD grains grew preferentially at the peaks of the triangular substrate surface profile and rapidly covered the amorphous carbon (a-C) and oriented graphite phases formed in the valley of the surface profile. In the case of the substrate with unbiased pretreatment, the SiC phases were formed via the reactions between the hydrocarbon species and the active Si atoms released from the substrate with assistance of the hydrogen plasma. The UNCD grains nucleated on the nucleating sites consisting of the SiC, a-C, and graphite phases. Growth mechanisms for the BEN-BEG UNCD films on both Si substrates were proposed to elucidate the different nucleation processes. Applying bias on the Si substrate pretreated in the hydrogen plasma optimized the nucleation sites for growth of UNCD grains, resulting in the low content of the nondiamond phases in UNCD films

  6. Introduction to Unconscious Bias

    Science.gov (United States)

    Schmelz, Joan T.

    2010-05-01

    We all have biases, and we are (for the most part) unaware of them. In general, men and women BOTH unconsciously devalue the contributions of women. This can have a detrimental effect on grant proposals, job applications, and performance reviews. Sociology is way ahead of astronomy in these studies. When evaluating identical application packages, male and female University psychology professors preferred 2:1 to hire "Brian” over "Karen” as an assistant professor. When evaluating a more experienced record (at the point of promotion to tenure), reservations were expressed four times more often when the name was female. This unconscious bias has a repeated negative effect on Karen's career. This talk will introduce the concept of unconscious bias and also give recommendations on how to address it using an example for a faculty search committee. The process of eliminating unconscious bias begins with awareness, then moves to policy and practice, and ends with accountability.

  7. Effective Stress Management: A Model of Emotional Intelligence, Self-Leadership, and Student Stress Coping

    Science.gov (United States)

    Houghton, Jeffery D.; Wu, Jinpei; Godwin, Jeffrey L.; Neck, Christopher P.; Manz, Charles C.

    2012-01-01

    This article develops and presents a model of the relationships among emotional intelligence, self-leadership, and stress coping among management students. In short, the authors' model suggests that effective emotion regulation and self-leadership, as mediated through positive affect and self-efficacy, has the potential to facilitate stress coping…

  8. Low-stress and high-stress singing have contrasting effects on glucocorticoid response

    Directory of Open Access Journals (Sweden)

    Daisy eFancourt

    2015-09-01

    Full Text Available Performing music in public is widely recognised as a potentially stress-inducing activity. However, despite the interest in music performance as an acute psychosocial stressor, there has been relatively little research on the effects of public performance on the endocrine system. This study examined the impact of singing in a low-stress performance situation and a high-stress live concert on levels of glucocorticoids (cortisol and cortisone in 15 professional singers. The results showed a significant decrease in both cortisol and cortisone across the low-stress condition, suggesting that singing in itself is a stress-reducing (and possibly health-promoting activity, but significant increases across the high-stress condition. This is the first study to demonstrate that singing affects glucocorticoid responses and that these responses are modulated by the conditions of performance.

  9. Low-stress and high-stress singing have contrasting effects on glucocorticoid response.

    Science.gov (United States)

    Fancourt, Daisy; Aufegger, Lisa; Williamon, Aaron

    2015-01-01

    Performing music in public is widely recognized as a potentially stress-inducing activity. However, despite the interest in music performance as an acute psychosocial stressor, there has been relatively little research on the effects of public performance on the endocrine system. This study examined the impact of singing in a low-stress performance situation and a high-stress live concert on levels of glucocorticoids (cortisol and cortisone) in 15 professional singers. The results showed a significant decrease in both cortisol and cortisone across the low-stress condition, suggesting that singing in itself is a stress-reducing (and possibly health-promoting) activity, but significant increases across the high-stress condition. This is the first study to demonstrate that singing affects cortisol as well as cortisone responses and that these responses are modulated by the conditions of performance. PMID:26388794

  10. Effects of prism adaptation on motor-intentional spatial bias in neglect

    OpenAIRE

    Fortis, Paola; Chen, Peii; Goedert, Kelly M.; Barrett, Anna M.

    2011-01-01

    Prism adaptation may alleviate some symptoms of spatial neglect. However, the mechanism through which this technique works is still unclear. The current study investigated whether prism adaptation differentially affects dysfunction in perceptual-attentional “where” versus motor-intentional “aiming” bias. Five neglect patients performed a line bisection task in which lines were viewed under both normal and right-left reversed viewing conditions, allowing for the fractionation of “where” and “a...

  11. Effect of Diffusion Limitations on Multianalyte Determination from Biased Biosensor Response

    OpenAIRE

    Romas Baronas; Juozas Kulys; Algirdas Lančinskas; Antanas Žilinskas

    2014-01-01

    The optimization-based quantitative determination of multianalyte concentrations from biased biosensor responses is investigated under internal and external diffusion-limited conditions. A computational model of a biocatalytic amperometric biosensor utilizing a mono-enzyme-catalyzed (nonspecific) competitive conversion of two substrates was used to generate pseudo-experimental responses to mixtures of compounds. The influence of possible perturbations of the biosensor signal, due to a white n...

  12. Fluency and belief bias in deductive reasoning: new indices for old effects

    OpenAIRE

    DriesTrippas

    2014-01-01

    Models based on signal detection theory (SDT) have occupied a prominent role in domains such as perception, categorization, and memory. Recent work by Dube et al. (2010) suggests that the framework may also offer important insights in the domain of deductive reasoning. Belief bias in reasoning has traditionally been examined using indices based on raw endorsement rates—indices that critics have claimed are highly problematic. We discuss a new set of SDT indices fit for the investigation belie...

  13. Genotype effect on regulation of behaviour by vitellogenin supports reproductive origin of honeybee foraging bias

    OpenAIRE

    Ihle, Kate E.; Page, Robert E.; Frederick, Katy; Fondrk, M. Kim; Amdam, Gro V.

    2010-01-01

    In honeybee colonies, food collection is performed by a group of mostly sterile females called workers. After an initial nest phase, workers begin foraging for nectar and pollen, but tend to bias their collection towards one or the other. The foraging choice of honeybees is influenced by vitellogenin (vg), an egg-yolk precursor protein that is expressed although workers typically do not lay eggs. The forager reproductive ground plan hypothesis (RGPH) proposes an evolutionary path in which the...

  14. An Exploration Based Cognitive Bias Test for Mice: Effects of Handling Method and Stereotypic Behaviour

    OpenAIRE

    Novak, Janja; Bailoo, Jeremy Davidson; Melotti, Luca; Rommen, Jonas; Würbel, Hanno

    2015-01-01

    Behavioural tests to assess affective states are widely used in human research and have recently been extended to animals. These tests assume that affective state influences cognitive processing, and that animals in a negative affective state interpret ambiguous information as expecting a negative outcome (displaying a negative cognitive bias). Most of these tests however, require long discrimination training. The aim of the study was to validate an exploration based cognitive ...

  15. Mothers' Body Perception Biased to Obesity and its Effects on Nursing Behaviors

    OpenAIRE

    Yakura,Noriko; Kasagi,Tsunakiyo; Hiroe,Kaori

    1997-01-01

    Many women who have dieted in adolescence seem to become mothers without correcting their obesity-biased perceptions of the body. This study estimated the number of such mothers and analyzed the problems in their nursing: 1496 mothers to 790 babies aged 4 months and 706 children aged 18 months completed questionnaires addressing mothers' images of their own and their children's body, mothers' behaviors to reduce children's weight, their behavior patterns and mothers' experiences to reduce the...

  16. Attentional bias in adults with cannabis use disorders.

    Science.gov (United States)

    Vujanovic, Anka A; Wardle, Margaret C; Liu, Shijing; Dias, Nadeeka R; Lane, Scott D

    2016-01-01

    There has been modest examination of attentional bias in individuals with cannabis use disorders. Clinical implications of this work are directly relevant to better informing extant evidence-based treatment for substance use disorders (e.g., relapse prevention) and/or developing novel interventions. The overarching aim of this investigation was to examine a novel attentional bias task in adults with cannabis use disorders. Participants were comprised of 25 adults (8 women: M age = 31, SD = 6.8; range = 22-45) with cannabis use disorders (n = 12) and controls (n = 13) without any current (past month) psychopathology. Relative to controls, adults with cannabis use disorders had greater attentional bias scores. These differences were present only at the 125-ms probe time, where the cannabis use disorders group showed greater attentional bias to cannabis cues than the control group (adjusted p = .001, cannabis use disorders mean = 59.9, control mean = -24.8, Cohen's d-effect size for 125 ms = 1.03). The cannabis use disorders group also reported significantly greater perceived stress and post-task stress scores than the control group, but stress was not related to attentional bias. This study informs understanding of the influence of cannabis cues on visual detection and reaction time under different cue-target onset times, as attentional bias was most prevalent under time pressure to detect the probe. PMID:26566718

  17. The effects of stress on brain and adrenal stem cells.

    Science.gov (United States)

    de Celis, M F R; Bornstein, S R; Androutsellis-Theotokis, A; Andoniadou, C L; Licinio, J; Wong, M-L; Ehrhart-Bornstein, M

    2016-05-01

    The brain and adrenal are critical control centers that maintain body homeostasis under basal and stress conditions, and orchestrate the body's response to stress. It is noteworthy that patients with stress-related disorders exhibit increased vulnerability to mental illness, even years after the stress experience, which is able to generate long-term changes in the brain's architecture and function. High levels of glucocorticoids produced by the adrenal cortex of the stressed subject reduce neurogenesis, which contributes to the development of depression. In support of the brain-adrenal connection in stress, many (but not all) depressed patients have alterations in the components of the limbic-hypothalamic-pituitary-adrenal (LHPA) axis, with enlarged adrenal cortex and increased glucocorticoid levels. Other psychiatric disorders, such as post-traumatic stress disorder, bipolar disorder and depression, are also associated with abnormalities in hippocampal volume and hippocampal function. In addition, hippocampal lesions impair the regulation of the LHPA axis in stress response. Our knowledge of the functional connection between stress, brain function and adrenal has been further expanded by two recent, independent papers that elucidate the effects of stress on brain and adrenal stem cells, showing similarities in the way that the progenitor populations of these organs behave under stress, and shedding more light into the potential cellular and molecular mechanisms involved in the adaptation of tissues to stress. PMID:26809844

  18. Loving yourself more than your neighbor: ERPs reveal online effects of a self-positivity bias.

    Science.gov (United States)

    Fields, Eric C; Kuperberg, Gina R

    2015-09-01

    A large body of social psychological research suggests that we think quite positively of ourselves, often unrealistically so. Research on this 'self-positivity bias' has relied mainly on self-report and behavioral measures, but these can suffer from a number of problems including confounds that arise from the desire to present oneself well. What has not been clearly assessed is whether the self-positivity bias influences the processing of incoming information as it unfolds in real time. In this study, we used event-related potentials to address this question. Participants read two-sentence social vignettes that were either self- or other-relevant. Pleasant words in self-relevant contexts evoked a smaller negativity between 300 and 500 ms (the N400 time window) than the same words in other-relevant contexts, suggesting that comprehenders were more likely to expect positive information when a scenario referred to themselves. This finding indicates that the self-positivity bias is available online, acting as a general schema that directly influences real-time comprehension. PMID:25605967

  19. Kin-biased distribution in brown trout: an effect of redd location or kin recognition?

    Science.gov (United States)

    Carlsson, J; Carlsson, J E L; Olsén, K H; Hansen, M M; Eriksson, T; Nilsson, J

    2004-02-01

    A wide range of animals have been reported to show kin-biased behaviours, such as reduced aggressiveness and increased food sharing among relatives. However, less is known about whether wild animals also associate with relatives under natural conditions, which is a prerequisite to facilitate kin-biased behaviours and hence kin selection. We tested, by means of microsatellite polymorphism, correlations between pair-wise relatedness and pair-wise metric distance in wild brown trout (Salmo trutta L.) under natural conditions in two streams. Our data show that young-of-the-year as well as older trout found close together also had a higher genetic relatedness in one of the two streams, whereas no relationship was found in the other stream. Very few half and full siblings were found in the second stream and under these conditions it is unlikely that kin-biased behaviours will receive positive selection. We discuss the underlying mechanisms for the observed structure and we specifically address the issue of whether the grouping of related individuals could reflect dispersal from the same spawning redds, or if it reflects active association with relatives, possibly conferring kin-selected advantages. PMID:14666124

  20. Effects of model chemistry and data biases on stratospheric ozone assimilation

    Directory of Open Access Journals (Sweden)

    L. Coy

    2007-06-01

    Full Text Available The innovations or observation minus forecast (O–F residuals produced by a data assimilation system provide a convenient metric of evaluating global analyses. In this study, O–F statistics from the Global Ozone Assimilation Testing System (GOATS are used to examine how ozone assimilation products and their associated O–F statistics depend on input data biases and ozone photochemistry parameterizations (OPP. All the GOATS results shown are based on a 6-h forecast and analysis cycle using observations from SBUV/2 (Solar Backscatter UltraViolet instrument-2 during September–October 2002. Results show that zonal mean ozone analyses are more independent of observation biases and drifts when using an OPP, while the mean ozone O–Fs are more sensitive to observation drifts when using an OPP. In addition, SD O–Fs (standard deviations are reduced in the upper stratosphere when using an OPP due to a reduction of forecast model noise and to increased covariance between the forecast model and the observations. Experiments that changed the OPP reference state to match the observations by using an "adaptive" OPP scheme reduced the mean ozone O–Fs at the expense of zonal mean ozone analyses being more susceptible to data biases and drifts. Additional experiments showed that the upper boundary of the ozone DAS can affect the quality of the ozone analysis and therefore should be placed well above (at least a scale height the region of interest.

  1. Attentional biases to foods: The effects of caloric content and cognitive restraint.

    Science.gov (United States)

    Forestell, Catherine A; Lau, Pia; Gyurovski, Ivo I; Dickter, Cheryl L; Haque, Sabrina S

    2012-12-01

    The goal of the present study was to determine whether female restrained and unrestrained eaters demonstrated differential levels of attentional bias to high calorie foods when they were presented as distractors in a flanker task. This task consisted of four blocks of 68 trials in which three food pictures were briefly presented simultaneously on a computer screen. On each trial a high or low calorie target food was presented in the center of a pair of high or low calorie food flanker pictures and participants' reaction times to answer a basic question about whether they would consume the target food for breakfast were recorded. In Experiment 1, in which all participants were fed a snack prior to engaging in the flanker task, there was no evidence that restrained (n=29) or unrestrained (n=37) eaters had an attentional bias. However, in Experiment 2, when participants completed the flanker task while hungry, restrained eaters (n=27) experienced response conflict only when low calorie targets were flanked by high calorie distractors, whereas unrestrained eaters (n=46) were distracted by high calorie flankers regardless of the caloric content of the target cue. The results from this implicit task indicate that flankers interfere with hungry participants' responses to varying degrees depending on their cognitive restraint. Whether attentional bias to food cues subsequently affects food choices and eating behavior is a topic for further investigation. PMID:22800656

  2. Biological effects of laser-induced stress waves

    International Nuclear Information System (INIS)

    Laser-induced stress waves can be generated by one of the following mechanisms: Optical breakdown, ablation or rapid heating of an absorbing medium. These three modes of laser interaction with matter allow the investigation of cellular and tissue responses to stress waves with different characteristics and under different conditions. The most widely studied phenomena are those of the collateral damage seen in photodisruption in the eye and in 193 run ablation of cornea and skin. On the other hand, the therapeutic application of laser-induced stress waves has been limited to the disruption of noncellular material such as renal stones, atheromatous plaque and vitreous strands. The effects of stress waves to cells and tissues can be quite disparate. Stress waves can fracture tissue, damage cells, and increase the permeability of the plasma membrane. The viability of cell cultures exposed to stress waves increases with the peak stress and the number of pulses applied. The rise time of the stress wave also influences the degree of cell injury. In fact, cell viability, as measured by thymidine incorporation, correlates better with the stress gradient than peak stress. Recent studies have also established that stress waves induce a transient increase of the permeability of the plasma membrane in vitro. In addition, if the stress gradient is below the damage threshhold, the cells remain viable. Thus, stress waves can be useful as a means of drug delivery, increasing the intracellular drug concentration and allowing the use of drugs which are impermeable to the cell membrane. The present studies show that it is important to create controllable stress waves. The wavelength tunability and the micropulse structure of the free electron laser is ideal for generating stress waves with independently adjustable parameters, such as rise time, duration and peak stress

  3. Measuring agricultural policy bias

    DEFF Research Database (Denmark)

    Jensen, Henning Tarp; Robinson, Sherman; Tarp, Finn

    2010-01-01

    that the agricultural price incentive bias generally perceived to exist during the 1980s was largely eliminated during the 1990s. Results also demonstrate that general equilibrium effects and country-specific characteristics are crucial for determining the sign and magnitude of agricultural bias. Our comprehensive...... protection measure is therefore uniquely suited to capture the full impact of trade policies on relative agricultural price incentives....

  4. Synthesis and exchange bias effect of CoFe2O4/CoO composite ceramics

    International Nuclear Information System (INIS)

    Composite ceramics composed of the ferrimagnetic (FM) CoFe2O4 and the antiferromagnetic (AFM) CoO were synthesized by using the chemical combustion method. The characterization measurements including X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis show that CoFe2O4 nano-particles are embedded in CoO matrix. The magnetic measurements show that the hysteresis loops display a small negative exchange bias field (He) of 106 Oe as the ceramic is cooled to 10 K in an applied field of 10,000 Oe. Furthermore, the magnetic parameters including coercivity, remanence, and He show clear dependence on temperature and the applied magnetic field in the cooling procedures. This exchange bias effect is ascribed to the exchange coupling at the FM/AFM interfaces.

  5. Giant spontaneous exchange bias effect in Sm1.5Ca0.5CoMnO6 perovskite

    Science.gov (United States)

    Giri, S. K.; Sahoo, R. C.; Dasgupta, Papri; Poddar, A.; Nath, T. K.

    2016-04-01

    We report here on the enormously large value of the spontaneous exchange bias (SEB) of ~5.1 kOe in the Sm1.5Ca0.5CoMnO6 bulk double perovskite system after zero-field cooling from an unmagnetized state. Depending on the path used for measuring the magnetic hysteresis loop, P-type or N-type, the EB field varies significantly. Dc and ac magnetization reveals a super-spin-glass-like (SSG) state below 19 K. The EB effect has been observed below the glassy transition temperature. The conventional exchange bias (CEB) as well as the SEB increase with a decrease in temperature and show monotonic variation. All these interesting features can be explained through the multimagnetic phase of double perovskite and the onset of unidirectional anisotropy driven by interface exchange coupling between the SSG, turned isothermally into a field-induced superferromagnetic shell and antiferromagnetic core.

  6. Synergistic effect of bias and target currents for magnetron sputtered MoS{sub 2}-Ti composite films

    Energy Technology Data Exchange (ETDEWEB)

    Buelbuel, Ferhat; Efeoglu, Ihsan [Ataturk Univ., Erzurum (Turkey). Dept. of Mechanical Engineering

    2016-07-01

    In terms of modification of the properties of MoS{sub 2}-Ti composite films, especially tribological properties, significant advances have recently been recorded. However, the commercially production of MoS{sub 2}-Ti composite films is still limited, because the production of desirable MoS{sub 2}-Ti composite coating is only possible by using closed field unbalanced magnetron systems and by the selection of convenient deposition parameters. This requirement has focused the researchers' attention on optimization of deposition parameters. This study is concentrating on the effect of the bias voltage and the target currents for MoS{sub 2}-Ti composite films deposited by pulsed magnetron sputtering (PMS). It is found that the bias and the target currents clearly affect the mechanical, structural and tribological properties of MoS{sub 2}-Ti films.

  7. Substrate-bias effect on the breakdown characteristic in a new silicon high-voltage device structure

    Institute of Scientific and Technical Information of China (English)

    Li Qi; Wang Weidong; Zhao Qiuming; Wei Xueming

    2012-01-01

    A novel silicon double-RESURF LDMOS structure with an improved breakdown characteristic by substrate bias technology (SB) is reported.The P-type epitaxial layer is embedded between an N-type drift region and an N-type substrate to block the conduction path in the off-state and change the distributions of the bulk electric field.The substrate bias strengthens the charge share effect of the drift region near the source,and the vertical electric field peak under the drain is decreased,which is especially helpful in improving the vertical breakdown voltage in a lateral power device with a thin drift region.The numerical results by MEDICI indicate that the breakdown voltage of the proposed device is increased by 97% compared with a conventional LDMOS,while maintaining a low on-resistance.

  8. Synergistic effect of bias and target currents for magnetron sputtered MoS2-Ti composite films

    International Nuclear Information System (INIS)

    In terms of modification of the properties of MoS2-Ti composite films, especially tribological properties, significant advances have recently been recorded. However, the commercially production of MoS2-Ti composite films is still limited, because the production of desirable MoS2-Ti composite coating is only possible by using closed field unbalanced magnetron systems and by the selection of convenient deposition parameters. This requirement has focused the researchers' attention on optimization of deposition parameters. This study is concentrating on the effect of the bias voltage and the target currents for MoS2-Ti composite films deposited by pulsed magnetron sputtering (PMS). It is found that the bias and the target currents clearly affect the mechanical, structural and tribological properties of MoS2-Ti films.

  9. Overcoming the effects of stress on reactor operator performance

    Energy Technology Data Exchange (ETDEWEB)

    He Xuhong; Wei Li; Zhao Bingquan [Tsinghua Univ., Nuclear Power Plant Simulation Training Center, Beijing (China)

    2003-03-01

    Reactor operators may be exposed to significant levels of stress during plant emergencies and their performance may be affected by the stress. This paper first identified the potential sources of stress in the nuclear power plant, then discussed the ways in which stress is likely to affect the reactor operators, and finally identified several training approaches for reducing or eliminating stress effects. The challenges for effective stress reducing training may seem daunting, yet the challenges are real and must be addressed. This paper reviewed researches in training design, knowledge and skill acquisition, and training transfer point to a number of strategies that can be used to address these challenges and lead to more effective training and development. (author)

  10. Overcoming the effects of stress on reactor operator performance

    International Nuclear Information System (INIS)

    Reactor operators may be exposed to significant levels of stress during plant emergencies and their performance may be affected by the stress. This paper first identified the potential sources of stress in the nuclear power plant, then discussed the ways in which stress is likely to affect the reactor operators, and finally identified several training approaches for reducing or eliminating stress effects. The challenges for effective stress reducing training may seem daunting, yet the challenges are real and must be addressed. This paper reviewed researches in training design, knowledge and skill acquisition, and training transfer point to a number of strategies that can be used to address these challenges and lead to more effective training and development. (author)

  11. Inverse spin Hall effect of antiferromagnetic MnIr in exchange biased NiFe/MnIr films

    International Nuclear Information System (INIS)

    Antiferromagnetic Mn3Ir, which is widely employed in exchange-biased applications, has attracted much attention recently due to its predicted and subsequently observed large spin Hall effect, therefore increasing its potential for spintronic devices in place of conventional paramagnetic 5d spin Hall metals. (Pt, Ta and W) Via the electrical detection of ferromagnetic resonance, we study a series of exchange biased NiFe/MnIr films for various MnIr thicknesses. In these systems, spin-pumped spin currents from NiFe are converted into dc voltages within MnIr via the inverse spin Hall effect (ISHE), which mixes with spin rectification voltages generated from NiFe. Through angular measurements, we separate these different voltage contributions to qualitatively detect non-zero ISHE in MnIr, which coexists with a non-zero unidirectional anisotropy. We find significant extrinsic damping contributions which prevent the accurate quantification of spin pumping-induced ISHE in MnIr films. The results show that spin currents may propagate and dissipate in MnIr films through ISHE in the presence of exchange bias. (paper)

  12. Exchange bias effect in Au-Fe3O4 dumbbell nanoparticles induced by the charge transfer from gold

    Energy Technology Data Exchange (ETDEWEB)

    Feygenson, Mikhail; Bauer, John C.; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S.; Beyer, Kevin A.; Dai, Sheng

    2015-08-10

    We have studied the origin of the exchange bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron-scattering, synchrotron x-ray diffraction, and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wustite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the exchange bias effect. The strength of the exchange bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into the FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed, presumably across the interface to accommodate an excess of oxygen released during the reduction of magnetite

  13. Contrast-induced nephrotoxicity: possible synergistic effect of stress hyperglycemia.

    LENUS (Irish Health Repository)

    O'Donnell, David H

    2010-07-01

    Oxidative stress on the renal tubules has been implicated as a mechanism of injury in both stress hyperglycemia and contrast-induced nephrotoxicity. The purpose of this study was to determine whether the combination of these effects has a synergistic effect on accentuating renal tubular apoptosis and therefore increasing the risk of contrast-induced nephrotoxicity.

  14. Stress and the social brain: behavioural effects and neurobiological mechanisms.

    Science.gov (United States)

    Sandi, Carmen; Haller, József

    2015-05-01

    Stress often affects our social lives. When undergoing high-level or persistent stress, individuals frequently retract from social interactions and become irritable and hostile. Predisposition to antisocial behaviours - including social detachment and violence - is also modulated by early life adversity; however, the effects of early life stress depend on the timing of exposure and genetic factors. Research in animals and humans has revealed some of the structural, functional and molecular changes in the brain that underlie the effects of stress on social behaviour. Findings in this emerging field will have implications both for the clinic and for society. PMID:25891510

  15. Effect of Pt addition on growth stress and thermal stress of NiSi films

    International Nuclear Information System (INIS)

    We have studied the effect of the addition of Pt on the growth stress and thermal stress of NiSi films. Platinum was added in the form of an interlayer (Ni/Pt/Si), capping layer (Pt/Ni/Si), and as an alloying element within the as-deposited Ni film (Ni-Pt/Si). The evolution of film stress during the solid-state reaction was monitored using in situ curvature measurements. The large transient compressive growth stress observed during the reaction of pure Ni with Si was significantly reduced for samples with a Pt interlayer or alloy. Based on in situ XRD measurements, this reduction in the compressive growth stress could be related to the disappearance of Ni rich phases from the phase sequence and an overall increase in the silicidation temperature during ramp anneals. Pt was also found to affect the buildup of thermal stress while cooling down the sample after Ni1-xPtxSi formation. The presence of Pt as a solute in the monosilicide causes a significant increase in the stress relaxation temperature, and therefore, in the total thermal stress as observed at room temperature. For a Pt interlayer, we observed a faster buildup of thermal stress, which could be related to a preferred epitaxial orientation of the monosilicide grains in this film as revealed by pole figure measurements

  16. High-end climate change impact on European runoff and low flows - exploring the effects of forcing biases

    Science.gov (United States)

    Papadimitriou, Lamprini V.; Koutroulis, Aristeidis G.; Grillakis, Manolis G.; Tsanis, Ioannis K.

    2016-05-01

    Climate models project a much more substantial warming than the 2 °C target under the more probable emission scenarios, making higher-end scenarios increasingly plausible. Freshwater availability under such conditions is a key issue of concern. In this study, an ensemble of Euro-CORDEX projections under RCP8.5 is used to assess the mean and low hydrological states under +4 °C of global warming for the European region. Five major European catchments were analysed in terms of future drought climatology and the impact of +2 °C versus +4 °C global warming was investigated. The effect of bias correction of the climate model outputs and the observations used for this adjustment was also quantified. Projections indicate an intensification of the water cycle at higher levels of warming. Even for areas where the average state may not considerably be affected, low flows are expected to reduce, leading to changes in the number of dry days and thus drought climatology. The identified increasing or decreasing runoff trends are substantially intensified when moving from the +2 to the +4° of global warming. Bias correction resulted in an improved representation of the historical hydrology. It is also found that the selection of the observational data set for the application of the bias correction has an impact on the projected signal that could be of the same order of magnitude to the selection of the Global Climate Model (GCM).

  17. Impact of scale dependent bias and nonlinear structure growth on the integrated Sachs-Wolfe effect: Angular power spectra

    International Nuclear Information System (INIS)

    We investigate the impact of nonlinear evolution of the gravitational potentials in the ΛCDM model on the integrated Sachs-Wolfe (ISW) contribution to the cosmic microwave background (CMB) temperature power spectrum, and on the cross-power spectrum of the CMB and a set of biased tracers of the mass. We use an ensemble of N-body simulations to directly follow the potentials and compare the results to analytic PT methods. The predictions from the PT match the results to high precision for k-1. We compute the nonlinear corrections to the angular power spectrum and find them to be 100 the departures are more significant; however, the CMB signal is more than a factor 103 larger at this scale. Nonlinear ISW effects therefore play no role in shaping the CMB power spectrum for lm(z)<0.3. Numerical results confirm these expectations and we find no sign change in ISW large-scale structure cross power for low redshifts. Corrections due to nonlinearity and scale dependence of the bias are found to be <10% for l<100, and are therefore below the signal to noise of the current and future measurements. Finally, we estimate the cross-correlation coefficient between the CMB and halos and show that it can be made to match that for the dark matter and CMB to within 5% for thin redshift shells, thus mitigating the need to model bias evolution.

  18. The effect of dust on electron heating and dc self-bias in hydrogen diluted silane discharges

    International Nuclear Information System (INIS)

    In capacitive hydrogen diluted silane discharges the formation of dust affects plasma processes used, e.g. for thin film solar cell manufacturing. Thus, a basic understanding of the interaction between plasma and dust is required to optimize such processes. We investigate a highly diluted silane discharge experimentally using phase-resolved optical emission spectroscopy to study the electron dynamics, laser light scattering on the dust particles to relate the electron dynamics with the spatial distribution of dust, and current and voltage measurements to characterize the electrical symmetry of the discharge via the dc self-bias. The measurements are performed in single and dual frequency discharges. A mode transition from the α-mode to a bulk drift mode (Ω-mode) is found, if the amount of silane and, thereby, the amount of dust and negative ions is increased. By controlling the electrode temperatures, the dust can be distributed asymmetrically between the electrodes via the thermophoretic force. This affects both the electron heating and the discharge symmetry, i.e. a dc self-bias develops in a single frequency discharge. Using the Electrical Asymmetry Effect (EAE), the dc self-bias can be controlled in dual frequency discharges via the phase angle between the two applied frequencies. The Ω-mode is observed for all phase angles and is explained by a simple model of the electron power dissipation. The model shows that the mode transition is characterized by a phase shift between the applied voltage and the electron conduction current, and that the plasma density profile can be estimated using the measured phase shift. The control interval of the dc self-bias obtained using the EAE will be shifted, if an asymmetric dust distribution is present. However, the width of the interval remains unchanged, because the dust distribution is hardly affected by the phase angle. (paper)

  19. Embodying an outgroup: the role of racial bias and the effect of multisensory processing in somatosensory remapping

    Directory of Open Access Journals (Sweden)

    Chiara eFini

    2013-11-01

    Full Text Available We come to understand other people’s physical and mental states by re-mapping their bodily states onto our sensorimotor system. This process, also called somatosensory resonance, is an essential ability for social cognition and is stronger when observing ingroup than outgroup members. Here we investigated, first, whether implicit racial bias constrains somatosensory resonance, and second, whether increasing the ingroup/outgroup perceived physical similarity results in an increase in the somatosensory resonance for outgroup members. We used the Visual Remapping of Touch effect as an index of individuals’ ability in resonating with the others, and the Implicit Association Test to measure racial bias. In Experiment 1, participants were asked to detect near-threshold tactile stimuli delivered to their own face while viewing either an ingroup or an outgroup face receiving a similar stimulation. Our results showed that individuals’ tactile accuracy when viewing an outgroup face being touched was negatively correlated to their implicit racial bias. In Experiment 2, participants received the Interpersonal Multisensory Stimulation (IMS while observing an outgroup member. IMS has been found to increase the perceived physical similarity between the observer’s and the observed body. We tested whether such increase in ingroup/outgroup perceived physical similarity increased the remapping ability for outgroup members. We found that after sharing IMS experience with an outgroup member, tactile accuracy when viewing touch on outgroup faces increased. Interestingly, participants with stronger implicit bias against the outgroup showed larger positive change in the remapping. We conclude that shared multisensory experiences might represent one key way to improve our ability to resonate with others by overcoming the boundaries between ingroup and outgroup categories.

  20. Effect of void dependent reactivity modeling bias on BWR axial power tilt - 256

    International Nuclear Information System (INIS)

    Inspired by a Pennsylvania State University study reported in the PHYSOR08 conference related to BWR axial power tilt, an investigation is made as to if there could be any intrinsic deficiency in the conventional nodal diffusion theory leading to a tilt in BWR axial power prediction. It is found that the two-group nodal diffusion theory itself does not cause axial power tilt compared to multigroup deterministic 3D transport calculation. However, the usual practice of flat source approximation in 2D lattice codes based on the Collision Probability (CP) method or the Method of Characteristics (MOC) can cause a void dependent reactivity bias when used to generate the node homogenized cross-sections, if the same geometry meshing modeling is used for all the axial sections over which the void fraction varies severely. The reactivity bias can be removed by using lattice code models based on SN method or MOC method with linear instead of flat source approximation. In absence of the void dependent reactivity bias, there is no axial power tilt between two-group nodal diffusion calculation and multi-group deterministic 3D transport calculation. Therefore there is no intrinsic deficiency in the nodal diffusion theory that causes BWR axial power tilt. But one has to be careful with using the flat source approximation and the generic-meshing modeling in generating homogenized nodal diffusion cross-sections for high void cases. As for any possible axial power tilt between multi-group deterministic 3D transport calculation and continuous energy Monte Carlo 3D simulation, that would be a different issue. (authors)

  1. DC bias effect on alternating current electrical conductivity of poly(ethylene terephthalate)/alumina nanocomposites

    Science.gov (United States)

    Nikam, Pravin N.; Deshpande, Vineeta D.

    2016-05-01

    Polymer nanocomposites based on metal oxide (ceramic) nanoparticles are a new class of materials with unique properties and designed for various applications such as electronic device packaging, insulation, fabrication and automotive industries. Poly(ethylene terephthalate) (PET)/alumina (Al2O3) nanocomposites with filler content between 1 wt% and 5 wt% were prepared by melt compounding method using co-rotating twin screw extruder and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and precision LCR meter techniques. The results revealed that proper uniform dispersion at lower content up to 2 wt% of nano-alumina observed by using TEM. Aggregation of nanoparticles was observed at higher content of alumina examined by using SEM and TEM. The frequency dependences of the alternating current (AC) conductivity (σAC) of PET/alumina nanocomposites on the filler content and DC bias were investigated in the frequency range of 20Hz - 1MHz. The results showed that the AC and direct current (DC) conductivity increases with increasing DC bias and nano-alumina content upto 3 wt%. It follows the Jonscher's universal power law of solids. It revealed that σAC of PET/alumina nanocomposites can be well characterized by the DC conductivity (σDC), critical frequency (ωc), critical exponent of the power law (s). Roll of DC bias potential led to an increase of DC conductivity (σDC) due to the creation of additional conducting paths with the polymer nanocomposites and percolation behavior achieved through co-continuous morphology.

  2. Abnormal positive bias stress instability of In–Ga–Zn–O thin-film transistors with low-temperature Al{sub 2}O{sub 3} gate dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yu-Hong; Yu, Ming-Jiue; Lin, Ruei-Ping; Hsu, Chih-Pin; Hou, Tuo-Hung, E-mail: thhou@mail.nctu.edu.tw [Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu, Taiwan (China)

    2016-01-18

    Low-temperature atomic layer deposition (ALD) was employed to deposit Al{sub 2}O{sub 3} as a gate dielectric in amorphous In–Ga–Zn–O thin-film transistors fabricated at temperatures below 120 °C. The devices exhibited a negligible threshold voltage shift (ΔV{sub T}) during negative bias stress, but a more pronounced ΔV{sub T} under positive bias stress with a characteristic turnaround behavior from a positive ΔV{sub T} to a negative ΔV{sub T}. This abnormal positive bias instability is explained using a two-process model, including both electron trapping and hydrogen release and migration. Electron trapping induces the initial positive ΔV{sub T}, which can be fitted using the stretched exponential function. The breakage of residual AlO-H bonds in low-temperature ALD Al{sub 2}O{sub 3} is triggered by the energetic channel electrons. The hydrogen atoms then diffuse toward the In–Ga–Zn–O channel and induce the negative ΔV{sub T} through electron doping with power-law time dependence. A rapid partial recovery of the negative ΔV{sub T} after stress is also observed during relaxation.

  3. Effects of Stress and MDMA on Hippocampal Gene Expression

    OpenAIRE

    Weber, Georg F.; Johnson, Bethann N.; Yamamoto, Bryan K.; Gudelsky, Gary A.

    2014-01-01

    MDMA (3,4-methylenedioxymethamphetamine) is a substituted amphetamine and popular drug of abuse. Its mood-enhancing short-term effects may prompt its consumption under stress. Clinical studies indicate that MDMA treatment may mitigate the symptoms of stress disorders such as posttraumatic stress syndrome (PTSD). On the other hand, repeated administration of MDMA results in persistent deficits in markers of serotonergic (5-HT) nerve terminals that have been viewed as indicative of 5-HT neuro...

  4. Glucocorticoid Hyper- and Hypofunction: Stress Effects on Cognition and Aggression

    OpenAIRE

    Kim, Jeansok J.; Haller, József

    2007-01-01

    It is now well documented that both increased and decreased stress responses can profoundly affect cognition and behavior. This mini review presents possible neural mechanisms subserving stress effects on memory and aggression, particularly focusing on glucocorticoid (GC) hyper- and hypofunction. First, uncontrollable stress impedes hippocampal memory and long-term potentiation (LTP). Because the hippocampus is important for the stability of long-term memory and because LTP has qualities desi...

  5. Examination of Effects of Stress on Public Officers

    OpenAIRE

    Osman SAHIN

    2015-01-01

    One of the subjects that the science of psychology examines is stress, the problem of our period. Changing structure of society, economic conditions and living conditions caused people to change. Stress, causing people to get sick in terms of physically and psychologically, is defined as pressure emerging in the human body with the effects of some factors. People are living under stress every moment they breathe. In their home, in the streets, in the traffic, when eating in somewhere...

  6. Examination of Effects of Stress on Public Offiers

    OpenAIRE

    Osman SAHIN

    2015-01-01

    One of the subjects that the science of psychology examines is stress, the problem of our period. Changing structure of society, economic conditions and living conditions caused people to change. Stress, causing people to get sick in terms of physically and psychologically, is defied as pressure emerging in the human body with the effects of some factors. People are living under stress every moment they breathe. In their home, in the streets, in the traffi, when eating in somewhere, shortly t...

  7. Effect of Water and Pests Stresses on Cowpea Yield

    OpenAIRE

    J. Abedi Koupai; M. Salehi-Sirzar; S.S. Eslamian; J. Khajeali; Y. Hosseini

    2014-01-01

    In order to investigate the effect of pest and water stresses on different growing stages of cowpea (Vigna sinensis) and pest occurrence, an experiment was conducted in Khazaneh Research station of Isfahan University of Technology. The experiment was carried out in a factorial complete randomized block design, in two different farms, with and without insecticide application. The treatments included severe water stress (50% water requirement), moderate water stress (75% water requirement) in f...

  8. The effects of stress on nuclear power plant operational decision making and training approaches to reduce stress effects

    International Nuclear Information System (INIS)

    Operational personnel may be exposed to significant levels of stress during unexpected changes in plant state an plant emergencies. The decision making that identifies operational actions, which is strongly determined by procedures, may be affected by stress, and performance may be impaired. ER report analyzes potential effects of stress in nuclear power plant (NPP) settings, especially in the context of severe accident management (SAM). First, potential sources of stress in the NPP setting are identified. This analysis is followed by a review of the ways in which stress is likely to affect performance, with an emphasis on performance of cognitive skills that are linked to operational decision making. Finally, potential training approaches for reducing or eliminating stress effects are identified. Several training approaches have the potential to eliminate or mitigate stress effects on cognitive skill performance. First, the use of simulated events for training can reduce the novelty and uncertainty that can lead to stress and performance impairments. Second, training to make cognitive processing more efficient and less reliant on attention and memory resources can offset the reductions in these resources that occur under stressful conditions. Third, training that targets crew communications skills can reduce the likelihood that communications will fail under stress

  9. The effects of stress on nuclear power plant operational decision making and training approaches to reduce stress effects

    Energy Technology Data Exchange (ETDEWEB)

    Mumaw, R.J.

    1994-08-01

    Operational personnel may be exposed to significant levels of stress during unexpected changes in plant state an plant emergencies. The decision making that identifies operational actions, which is strongly determined by procedures, may be affected by stress, and performance may be impaired. ER report analyzes potential effects of stress in nuclear power plant (NPP) settings, especially in the context of severe accident management (SAM). First, potential sources of stress in the NPP setting are identified. This analysis is followed by a review of the ways in which stress is likely to affect performance, with an emphasis on performance of cognitive skills that are linked to operational decision making. Finally, potential training approaches for reducing or eliminating stress effects are identified. Several training approaches have the potential to eliminate or mitigate stress effects on cognitive skill performance. First, the use of simulated events for training can reduce the novelty and uncertainty that can lead to stress and performance impairments. Second, training to make cognitive processing more efficient and less reliant on attention and memory resources can offset the reductions in these resources that occur under stressful conditions. Third, training that targets crew communications skills can reduce the likelihood that communications will fail under stress.

  10. Virtual Cathodes near small electrodes biased near the plasma potential and its effects on Langmuir probes

    Science.gov (United States)

    Yip, Chi-Shung; Hershkowitz, Noah; Severn, Greg

    2015-09-01

    Movable small (3cm x 3.8cm) plates biased near the plasma potential are immersed in a filament discharge in a multi-dipole chamber. The plates are small (Aplate /Achamber collection of an electrode in the presence of the virtual cathode, and was experimentally investigated by comparing I-V characteristics of the small plate and a 0.6cm diameter Langmuir probe. This work is supported by U.S. DOE under the Grant and Contract No. DE-FG02-97ER54437.

  11. Automation bias: a systematic review of frequency, effect mediators, and mitigators

    OpenAIRE

    Goddard, Kate; Roudsari, Abdul; Wyatt, Jeremy C.

    2011-01-01

    Automation bias (AB)—the tendency to over-rely on automation—has been studied in various academic fields. Clinical decision support systems (CDSS) aim to benefit the clinical decision-making process. Although most research shows overall improved performance with use, there is often a failure to recognize the new errors that CDSS can introduce. With a focus on healthcare, a systematic review of the literature from a variety of research fields has been carried out, assessing the frequency and s...

  12. Nature-Based Stress Management Course for Individuals at Risk of Adverse Health Effects from Work-Related Stress

    OpenAIRE

    Sahlin, Eva; Ahlborg Jr., Gunnar; Vega-Matuszczyk, Josefa; Grahn, Patrik

    2014-01-01

    Sick leave due to stress-related disorders is increasing in Sweden after a period of decrease. To avoid that individuals living under heavy stress develop more severe stress-related disorders, different stress management interventions are offered. Self-assessed health, burnout-scores and well-being are commonly used as outcome measures. Few studies have used sick-leave to compare effects of stress interventions. A new approach is to use nature and garden in a multimodal stress management cont...

  13. Temporary amygdala inhibition reduces stress effects in female mice.

    Science.gov (United States)

    Dalooei, Jila Rezaeian; Sahraei, Hedayat; Meftahi, Gholam Hossein; Khosravi, Maryam; Bahari, Zahra; Hatef, Boshra; Mohammadi, Alireza; Nicaeili, Fateme; Eftekhari, Fateme; Ghamari, Fateme; Hadipour, Mohamadmehdi; Kaka, Gholamreza

    2016-09-01

    The current study investigated the effect of temporary inhibition of amygdala in response to metabolic changes caused by stress in female mice. Unilateral and bilateral amygdala cannulation was carried out, and after a week of recovery, 2% lidocaine hydrochloride was injected into the mice amygdalae five minutes before the induction of stress. A communication box was employed to induce stress for four consecutive days and plasma corticosterone, food and water intake, weight changes, and anorexia were measured as stress-induced metabolic changes. Results demonstrated that stress, increases stress, increased plasma corticosterone concentrations, weight, food, and water intake. Temporary inhibition of the amygdala slightly decreased plasma corticosterone concentrations, but did not fully reduce the effect of stress. The bilateral injection of lidocaine hydrochloride to the amygdala reduced the effect of stress and reduced water intake and weight. Unilateral injection of lidocaine hydrochloride into the left and right amygdala reduced food intake. In conclusion, the present study demonstrated that the left side and right side of amygdala nuclei play a different role in metabolic responses in stress. PMID:27489731

  14. Effect of Surface Topography on Stress Concentration Factor

    Institute of Scientific and Technical Information of China (English)

    CHENG Zhengkun; LIAO Ridong

    2015-01-01

    Neuber rule and Arola-Ramulu model are widely used to predict the stress concentration factor of rough specimens. However, the height parameters and effective valley radius used in these two models depend strongly on the resolution of the roughness-measuring instruments and are easily introduce measuring errors. Besides, it is difficult to find a suitable parameter to characterize surface topography to quantitatively describe its effect on stress concentration factor. In order to overcome these disadvantages, profile moments are carried out to characterize surface topography, surface topography is simulated by superposing series of cosine components, the stress concentration factors of different micro cosine-shaped surface topographies are investigated by finite element analysis. In terms of micro cosine-shaped surface topography, an equation using the second profile moment to estimate the stress concentration factor is proposed, predictions for the stress concentration factor using the proposed expression are within 10% error compared with the results of finite element analysis, which are more accurate than other models. Moreover, the proposed equation is applied to the real surface topography machined by turning. Predictions for the stress concentration factor using the proposed expression are within 10% of the maximum stress concentration factors and about 5% of the effective stress concentration factors estimated from the finite element analysis for three levels of turning surface topographies under different simulated scales. The proposed model is feasible in predicting the stress concentration factors of real machined surface topographies.

  15. The Effects of Halo Assembly Bias on Self-Calibration in Galaxy Cluster Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao-Yi; Rozo, Eduardo; Wechsler, Risa H.

    2008-08-07

    Self-calibration techniques for analyzing galaxy cluster counts utilize the abundance and the clustering amplitude of dark matter halos. These properties simultaneously constrain cosmological parameters and the cluster observable-mass relation. It was recently discovered that the clustering amplitude of halos depends not only on the halo mass, but also on various secondary variables, such as the halo formation time and the concentration; these dependences are collectively termed 'assembly bias'. Applying modified Fisher matrix formalism, we explore whether these secondary variables have a significant impact on the study of dark energy properties using the self-calibration technique in current (SDSS) and the near future (DES, SPT, and LSST) cluster surveys. The impact of the secondary dependence is determined by (1) the scatter in the observable-mass relation and (2) the correlation between observable and secondary variables. We find that for optical surveys, the secondary dependence does not significantly influence an SDSS-like survey; however, it may affect a DES-like survey (given the high scatter currently expected from optical clusters) and an LSST-like survey (even for low scatter values and low correlations). For an SZ survey such as SPT, the impact of secondary dependence is insignificant if the scatter is 20% or lower but can be enhanced by the potential high scatter values introduced by a highly-correlated background. Accurate modeling of the assembly bias is necessary for cluster self-calibration in the era of precision cosmology.

  16. Plasma-assisted deposition of lithium phosphorus oxynitride films: Substrate bias effects

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Gu; Wadley, H.N.G. [Department of Material Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, VA 22904 (United States)

    2009-02-15

    Lithium phosphorus oxynitride (Lipon) films have been synthesized by a plasma-assisted directed vapor deposition (PA-DVD) approach. In this approach, a hollow cathode technique was used to create an argon plasma through which was propagated an electron-beam generated Li{sub 3}PO{sub 4} vapor entrained in a N{sub 2}-doped helium gas jet. Without plasma assistance, amorphous, mud cracked and highly porous Li{sub 3}PO{sub 4} films were formed. When plasma-assistance was used, nitrogen was incorporated creating a Lipon film whose composition, morphology, structure, and deposition rate could be manipulated by modifying the substrate bias. Films with spiral or very smooth surfaces could be made in this way. Fully amorphous films or films with locally crystallized regions in an amorphous matrix could be synthesized by varying the bias voltage. The presence of these local regions of crystallinity within a Lipon film decreased the Li-ion conductivities from the 10{sup -7} S cm{sup -1} to 10{sup -10} S cm{sup -1} range. (author)

  17. Simplicity and Specificity in Language: Domain-General Biases Have Domain-Specific Effects.

    Science.gov (United States)

    Culbertson, Jennifer; Kirby, Simon

    2015-01-01

    The extent to which the linguistic system-its architecture, the representations it operates on, the constraints it is subject to-is specific to language has broad implications for cognitive science and its relation to evolutionary biology. Importantly, a given property of the linguistic system can be "specific" to the domain of language in several ways. For example, if the property evolved by natural selection under the pressure of the linguistic function it serves then the property is domain-specific in the sense that its design is tailored for language. Equally though, if that property evolved to serve a different function or if that property is domain-general, it may nevertheless interact with the linguistic system in a way that is unique. This gives a second sense in which a property can be thought of as specific to language. An evolutionary approach to the language faculty might at first blush appear to favor domain-specificity in the first sense, with individual properties of the language faculty being specifically linguistic adaptations. However, we argue that interactions between learning, culture, and biological evolution mean any domain-specific adaptations that evolve will take the form of weak biases rather than hard constraints. Turning to the latter sense of domain-specificity, we highlight a very general bias, simplicity, which operates widely in cognition and yet interacts with linguistic representations in domain-specific ways. PMID:26793132

  18. Simplicity and Specificity in Language: Domain general biases have domain specific effects

    Directory of Open Access Journals (Sweden)

    Jennifer eCulbertson

    2016-01-01

    Full Text Available The extent to which the linguistic system—its architecture, the representations it operates on, the constraints it is subject to—is specific to language has broad implications for cognitive science and its relation to evolutionary biology. Importantly, a given property of the linguistic system can be specific to the domain of language in several ways. For example, if the property evolved by natural selection under the pressure of the linguistic function it serves then the property is domain­-specific in the sense that its design is tailored for language. Equally though, if that property evolved to serve a different function or if that property is domain-general, it may nevertheless interact with the linguistic system in a way that is unique. This gives a second sense in which a property can be thought of as specific to language. An evolutionary approach to the language faculty might at first blush appear to favor domain­-specificity in the first sense, with individual properties of the language faculty being specifically linguistic adaptations. However, we argue that interactions between learning, culture and biological evolution mean any domain-specific adaptations that evolve will take the form of weak biases rather than hard constraints. Turning to the latter sense of domain-specificity, we highlight a very general bias, simplicity, which operates widely in cognition and yet interacts with linguistic representations in a domain-­specific way.

  19. Effect of pulsed bias on TiO2 thin films prepared on silicon by arc ion plating and simulation of pulsed plasma sheath dynamics

    International Nuclear Information System (INIS)

    Dielectric TiO2 thin films were fabricated on p-(100) Si substrates by arc ion plating. A pulsed substrate bias ranging from 0 V to − 900 V was applied to investigate the effect of pulsed bias on phase structure and growth of the films. Phase, microstructure, and growth morphology of TiO2 films prepared at different bias voltages were evaluated with grazing incident x-ray diffraction and atomic force microscopy (AFM). The results show that pulsed bias exerts an evident influence on phase structure and growth morphology. High substrate bias facilitates the formation of rutile phase, a (220) preferred orientation is observed in TiO2 films obtained at − 900 V. AFM images show that pulsed substrate bias exerts a strong influence on the growth of TiO2 films. With increasing bias voltage, the film is initially composed of tiny surface islands separated by shallow boundaries, then of large and spiky surface islands isolated by deep boundaries. Correspondingly, surface roughness increases from 1.1 nm at 0 V to 3.8 nm at − 900 V. To explain the phenomena observed in this study, pulsed plasma sheath model was used to simulate the ion sheath dynamics. By analyzing experimental and simulated results, it can be concluded that film growth and property relate close to ion density and energy in the sheath, which is dominantly governed by negative substrate bias.

  20. Scale effect in fatigue resistance under complex stressed state

    International Nuclear Information System (INIS)

    On the basis the of the fatigue failure statistic theory obtained is the formula for calculated estimation of probabillity of failure under complex stressed state according to partial probabilities of failure under linear stressed state with provision for the scale effect. Also the formula for calculation of equivalent stress is obtained. The verification of both formulae using literary experimental data for plane stressed state torsion has shown that the error of estimations does not exceed 10% for materials with the ultimate strength changing from 61 to 124 kg/mm2

  1. Prenatal stress and its effect on infant development

    NARCIS (Netherlands)

    Huizink, A.C.

    2001-01-01

    In this dissertation the effect of prenatal maternal stress on infant development and behavior is discussed. In a prospective longitudinal study of 170 nulliparous women, data was gatheren on the maternal stress level three times during pregnancy by means of questionnaires and endocrinologic p

  2. NEGATIVE EFFECT OF METALLOID STRESS ON WHEAT

    Directory of Open Access Journals (Sweden)

    Marína Maglovski

    2015-02-01

    Full Text Available Arsenic (As belongs to heavy metals and its accumulation in plants, besides damaging the organism itself, represents a potential health risk to animal and human consumers. Therefore, contamination of soils and waters with this compound is a serious environmental problem. In this work we focused on investigating a negative impact of As on selected parameters of growth of wheat plants (Triticum aestivum L. cv. Genoveva grown in hydropony. In the stage of first assimilation leaves we applied a solution of heavy metal (1 mg.kg-1 As3+ on wheat plants. For plants grown under hydropony conditions we observed different plant parameters such as length, weight, amount of fresh and dry biomass. Further we analyzed accumulation of hydrogen peroxide and products membrane lipid peroxidation as indicators of oxidative stress. In addition to these we also measured the content of photosynthetic pigments, maximal quantum yield and proline in plant tissue. Our data indicate reduction of the biomass of shoots forthcoming as a result of exposure of stressed plants to As. Decline of biomass accumulation was accompanied by increase of hydrogen peroxide in plant tissue. In contrast, level of lipid peroxidation was suppressed in stressed shoots. Contents of photosynthetic pigments soundly decreased. Interestingly, fluorescence (Fp=Fm in stressed wheat shoots increased. Similarly in tested shoots the content of proline was increased. The results indicate that the applied dose of As has a negative impact on the growth and photosynthetic performance of stressed plants. A better understanding of the mechanisms responsible for As resistance and toxicity in plants requires further investigation.

  3. Effects of Stress and MDMA on Hippocampal Gene Expression

    Directory of Open Access Journals (Sweden)

    Georg F. Weber

    2014-01-01

    Full Text Available MDMA (3,4-methylenedioxymethamphetamine is a substituted amphetamine and popular drug of abuse. Its mood-enhancing short-term effects may prompt its consumption under stress. Clinical studies indicate that MDMA treatment may mitigate the symptoms of stress disorders such as posttraumatic stress syndrome (PTSD. On the other hand, repeated administration of MDMA results in persistent deficits in markers of serotonergic (5-HT nerve terminals that have been viewed as indicative of 5-HT neurotoxicity. Exposure to chronic stress has been shown to augment MDMA-induced 5-HT neurotoxicity. Here, we examine the transcriptional responses in the hippocampus to MDMA treatment of control rats and rats exposed to chronic stress. MDMA altered the expression of genes that regulate unfolded protein binding, protein folding, calmodulin-dependent protein kinase activity, and neuropeptide signaling. In stressed rats, the gene expression profile in response to MDMA was altered to affect sensory processing and responses to tissue damage in nerve sheaths. Subsequent treatment with MDMA also markedly altered the genetic responses to stress such that the stress-induced downregulation of genes related to the circadian rhythm was reversed. The data support the view that MDMA-induced transcriptional responses accompany the persistent effects of this drug on neuronal structure/function. In addition, MDMA treatment alters the stress-induced transcriptional signature.

  4. The effect of salinity and moisture stress on pea plant

    International Nuclear Information System (INIS)

    Four experiments were carried out in the green house in Inchas, Atomic Energy Establishment, to study the effect os salinity and moisture stress on pea plants. Salinity experiments were conducted in 1981/1982, 1982/1983 and 1983/1984 seasons to study the effect of NaCl and/or CaCl2 as single or mixed salts and radiation combined with salinity. Water stress studies were conducted in 1983/1984 growing season to investigate the effect of soil moisture stress on growth, yield and water use efficiency

  5. Stress hormones and abiotic stresses have different effects on antioxidants in maize lines with different sensitivity.

    Science.gov (United States)

    Kellos, T; Tímár, I; Szilágyi, V; Szalai, G; Galiba, G; Kocsy, G

    2008-09-01

    The effect of stress hormones and abiotic stress treatments on reactive oxygen species and on antioxidants was compared in two maize (Zea mays L.) lines (Penjalinan and Z7) having different stress tolerance. Following treatment with abscisic acid, salicylic acid or hydrogen peroxide, the amount of hydrogen peroxide and lipid peroxides increased, while after osmotic stress or cultivation in continuous darkness, the levels were unchanged or decreased. The higher amount of lipid peroxides in Penjalinan indicated its greater sensitivity compared to Z7. The level of the examined antioxidants was increased by nearly all treatments. Glutathione and cysteine contents were higher after salicylic acid, hydrogen peroxide and polyethylene glycol treatments and lower after application of abscisic acid, NaCl and growth in darkness in Z7 than in Penjalinan. The activity of glutathione reductase, ascorbate peroxidase, catalase and glutathione S-transferase was higher after almost all treatments in Z7. The expression of the glutathione synthetase (EC 6.3.2.3) gene was not affected by the treatments, while the level of gamma-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione reductase (EC 1.6.4.2) transcripts increased after most treatments. The two stress hormones and the stress treatments resulted in different changes in antioxidant levels in the two maize lines, which indicates the specific, stress tolerance-dependent response of plants to the various growth regulators and adverse environmental effects that were examined. PMID:18761495

  6. Male-Biased Autosomal Effect of 16p13.11 Copy Number Variation in Neurodevelopmental Disorders

    OpenAIRE

    Maria Tropeano; Joo Wook Ahn; Dobson, Richard J. B.; Gerome Breen; James Rucker; Abhishek Dixit; Pal, Deb K; Peter McGuffin; Anne Farmer; White, Peter S.; Joris Andrieux; Evangelos Vassos; Caroline Mackie Ogilvie; Sarah Curran; Collier, David A

    2013-01-01

    Copy number variants (CNVs) at chromosome 16p13.11 have been associated with a range of neurodevelopmental disorders including autism, ADHD, intellectual disability and schizophrenia. Significant sex differences in prevalence, course and severity have been described for a number of these conditions but the biological and environmental factors underlying such sex-specific features remain unclear. We tested the burden and the possible sex-biased effect of CNVs at 16p13.11 in a sample of 10,397 ...

  7. Tunable exchange bias effect in BiGdFeTiO3 mutlferroic nanoparticles

    DEFF Research Database (Denmark)

    Ngo, Duc-The; Abdul Basith, Mohammed; Hung, Tran Quang;

    2014-01-01

    consist of ultrafine monodisperse singlecrystallinenanoparticles and show enhanced ferromagnetism at room temperature. Especially, by cooling the nanoparticles in magnetic field, exchange bias effect, which is manifested by the shift of the magnetic hysteresis loop along the applied field [Fig.1(c)] due...... to the exchange coupling between antiferromagnetism and ferromagnetism, has been established and appears to vary with the cooling field and the temperature.This finding is very crucial for application of multiferroic nanoparticle in spin-electronic technology, and clean-tech energy conversion....

  8. The effect of occupational stress, psychological stress and burnout on employee performance: Evidence from banking industry

    OpenAIRE

    Shahram Hashemnia; Somayeh Abadiyan; Behnam Ghorbani Fard

    2014-01-01

    This paper presents an empirical investigation on the effects of occupational stress, psychological stress as well as job burnout on women’s employee performance in city of Karaj, Iran. The proposed study designs a questionnaire in Likert scale and distributes it among all female employees who worked for Bank Maskan in this city. In our survey, employee performance consists of three parts of interpersonal performance, job performance as well as organizational performance. Cronbach alpha has b...

  9. Effect of surface charge state on the surface stress of a microcantilever.

    Science.gov (United States)

    Zhang, Neng-Hui; Wu, Jun-Zheng; Meng, Wei-Lie; Tan, Zou-Qing

    2016-04-01

    The surface charge state at a liquid-solid interface is important to the variations in the physical/chemical properties of adsorbate film such as surface stress and the ensuing tip deflection of the microcantilever. The well-known Stoney's equation, derived more than 100 years ago, conceals the film electrical properties with the replacement of substrate deformation induced by adsorptions of particles. This implicit expression provides a shortcut to circumvent the difficulty in identifying some film properties, however, it limits the capacity to ascertain the relation between surface stress variation and the surface charge state. In this paper, we present an analytical expression to quantify the cantilever deflection/surface stress and the film potential difference by combining the piezoelectric theory and Poisson-Boltzmann equation for electrolyte solution. This updated version indicates that the two linear correlations between surface stress and surface charge density or the bias voltage are not contradictory, but two aspects of one thing under different conditions. Based on Parsegian's mesoscopic interaction potential, a multiscale prediction for the piezoelectric coefficient of double-stranded DNA (dsDNA) film is done, and the results show that the distinctive size effect with variations in salt concentration and nucleotide number provides us with an opportunity to obtain a more sensitive potential-actuated microcantilever sensor by careful control of packing conditions. PMID:26916422

  10. Stress in photochromic and electrochromic effects on tungsten oxide film

    Energy Technology Data Exchange (ETDEWEB)

    Scarminio, J. [Depto. de Fisica, Universidade Estadual de Londrina, Londrina PR 86051-990 (Brazil)

    2003-09-15

    Optical absorbance at 632.8nm and the stress generated in tungsten oxide film due to photochromic and electrochromic effects were measured. WO{sub 3} thin films were deposited by reactive sputtering and the absorbance was obtained by measuring the optical transmittance of a laser beam through the film. The stress was calculated by measuring the substrate curvature and using the Stoney equation for multilayered films, since two layers are deposited onto a substrate for the electrochromism studies. The optical absorbance and the stress in the tungsten oxide film, as a function of UV irradiation time in photochromism and of inserted charge in electrochromism, are showed and discussed. In both effects the stresses generated were rendered as due to cation insertions into the film: H{sup +} protons in photochromism and Li{sup +} ions in electrochromism. The accuracy of the Stoney equation used for the stress calculation was also discussed.

  11. Dextran's effects on stressed lenses: water, electrolyte, and radioisotope studies

    International Nuclear Information System (INIS)

    To evaluate the beneficial effects of dextran 40 as an additive to infusion solutions, we studied an experimental model of lens stress with use of buffered, low calcium (Ca++)-containing solutions. Incubation in low Ca++ solutions (pCa = 10.7) for ten hours (stress period) resulted in lens swelling and electrolyte imbalances that were irreversible even with reincubation in physiologic, normal Ca++-containing media (pCa = 2.7) (recovery period). The addition of 6% or more of dextran to the media inhibited lens water gain during the stress period. It also rendered the resultant electrolyte imbalances reversible during the recovery period, thus exerting a protective effect. Radioisotope-tracer studies showed that dextran improved the ability of the lens to accumulate rubidium chloride Rb 86 and reduced its efflux during both the stress and recovery periods. Dextran did not markedly decrease sodium chloride Na 22 uptake by lenses under stress

  12. Acute alcohol effects on attentional bias are mediated by subcortical areas associated with arousal and salience attribution.

    Science.gov (United States)

    Nikolaou, Kyriaki; Field, Matt; Critchley, Hugo; Duka, Theodora

    2013-06-01

    Acute alcohol ingestion increases attentional bias to alcohol-related stimuli; however, the underlying cognitive and brain mechanisms remain unknown. We combined functional magnetic resonance imaging (fMRI) with performance of a dual task that probed attentional distraction by alcohol-related stimuli during 'conflict' processing: the Concurrent Flanker/Alcohol-Attentional bias task (CFAAT). In this task, an Eriksen Flanker task is superimposed on task-unrelated background pictures with alcohol-associated or neutral content. Participants respond to the direction of a central 'target' arrow and ignore adjacent congruent (low cognitive load) or incongruent (high cognitive load) 'flanking' arrows. Using a between-subject design, 40 healthy moderate-to-heavy social drinkers received either no alcohol (placebo), 0.4 g/kg (low dose), or 0.8 g/kg (high dose) of alcohol, and underwent fMRI while performing the CFAAT. The low alcohol dose, relative to placebo, increased response latencies on trials with alcohol-associated backgrounds and, under low cognitive load, increased the activity evoked by these pictures within a medial hypothalamic region. Under high cognitive load, the low alcohol dose, relative to placebo, elicited greater activity within a more lateral hypothalamic region, and reduced activity within frontal motor areas. The high alcohol dose, relative to placebo, did not reliably affect response latencies or neural responses to background images, but reduced overall accuracy under high cognitive load. This effect correlated with changes in reactivity within medial and dorsal prefrontal cortices. These data suggest that alcohol at a low dose primes attentional bias to alcohol-associated stimuli, an effect mediated by activation of subcortical hypothalamic areas implicated in arousal and salience attribution. PMID:23361162

  13. Temperature dependence of exchange bias and training effect in Co/CoO film with induced uniaxial anisotropy

    International Nuclear Information System (INIS)

    The exchange bias effect and training effect of the Co/CoO film with induced uniaxial anisotropy were investigated as functions of temperature. It was found that both effects exhibited drastic differences along the easy and the hard axes. Along the easy axis, the magnetization reversal was dominated by domain wall motion throughout the whole temperature range. However, along the hard axis, the magnetization reversal was dominated by domain wall motion and domain rotation at temperatures below and above 150 K, respectively. The crossover of the two reversal modes characterized with significant asymmetry in the hysteresis loop was observed along the hard axis at 150 K due to the interplay between the exchange and uniaxial anisotropies. Significant difference of training effect in the two directions was observed and ascribed to the differences of the duration and intensity of the interaction between ferromagnetic and antiferromagnetic spins in the two magnetization reversal modes. (paper)

  14. Mitochondrial phylogenomics of early land plants: mitigating the effects of saturation, compositional heterogeneity, and codon-usage bias.

    Science.gov (United States)

    Liu, Yang; Cox, Cymon J; Wang, Wei; Goffinet, Bernard

    2014-11-01

    Phylogenetic analyses using concatenation of genomic-scale data have been seen as the panacea for resolving the incongruences among inferences from few or single genes. However, phylogenomics may also suffer from systematic errors, due to the, perhaps cumulative, effects of saturation, among-taxa compositional (GC content) heterogeneity, or codon-usage bias plaguing the individual nucleotide loci that are concatenated. Here, we provide an example of how these factors affect the inferences of the phylogeny of early land plants based on mitochondrial genomic data. Mitochondrial sequences evolve slowly in plants and hence are thought to be suitable for resolving deep relationships. We newly assembled mitochondrial genomes from 20 bryophytes, complemented these with 40 other streptophytes (land plants plus algal outgroups), compiling a data matrix of 60 taxa and 41 mitochondrial genes. Homogeneous analyses of the concatenated nucleotide data resolve mosses as sister-group to the remaining land plants. However, the corresponding translated amino acid data support the liverwort lineage in this position. Both results receive weak to moderate support in maximum-likelihood analyses, but strong support in Bayesian inferences. Tests of alternative hypotheses using either nucleotide or amino acid data provide implicit support for their respective optimal topologies, and clearly reject the hypotheses that bryophytes are monophyletic, liverworts and mosses share a unique common ancestor, or hornworts are sister to the remaining land plants. We determined that land plant lineages differ in their nucleotide composition, and in their usage of synonymous codon variants. Composition heterogeneous Bayesian analyses employing a nonstationary model that accounts for variation in among-lineage composition, and inferences from degenerated nucleotide data that avoid the effects of synonymous substitutions that underlie codon-usage bias, again recovered liverworts being sister to the

  15. Effect of the Mechanical and Thermal Stresses of Rotating Blades

    Directory of Open Access Journals (Sweden)

    Malik M. Ali

    2007-01-01

    Full Text Available Rotating blades are the important parts in gas turbines. Hence, an accurate mathematical estimation (F.E.M of the stresses and deformations characteristics was required in the design applications to avoid failure. In recent year’s there are researchers interest in the effect of temperature on solid bodies has greatly increased, The main of this study investigated the thermal and rotational effects. So, the thermal stresses due to high pressure and temperature are studies, also determine the steady state stresses and deformations of rotating blades due to mechanical effect. Many parameters such as thickness and centre of rotating are investigated in this paper. The study results can ensure good recommendation for the effect of the mechanical and thermal stresses of rotary blades.

  16. Resistance to early-life stress in mice: effects of genetic background and stress duration

    Directory of Open Access Journals (Sweden)

    Helene M. Savignac

    2011-04-01

    Full Text Available Early-life stress can induce marked behavioural and physiological impairments in adulthood including cognitive deficits, depression, anxiety and gastrointestinal dysfunction. Although robust rat models of early-life stress exist there are few established effective paradigms in the mouse. Genetic background and protocol parameters used are two critical variables in such model development.Thus we investigated the impact of two different early-life stress protocols in two commonly used inbred mouse strains. C57BL/6 and innately anxious BALB/c male mice were maternally deprived 3 hrs daily, either from postnatal day 1 to 14 (Protocol 1 or 6 to 10 (Protocol 2. Animals were assessed in adulthood for cognitive performance (spontaneous alternation behaviour test, anxiety (open field, light/dark box and elevated plus maze tests and depression-related behaviours (forced swim test in addition to stress-sensitive physiological changes. Overall, the results showed that early-life stressed mice from both strains displayed good cognitive ability and no elevations in anxiety. However, paradoxical changes occurred in C57BL/6 mice as the longer protocol (protocol 1 decreased anxiety in the light-dark box and increased exploration in the elevated plus maze. In BALB/c mice there were also limited effects of maternal separation with both separation protocols inducing reductions in stress-induced defecation and protocol 1 reducing the colon length. These data suggest that, independent of stress duration, mice from both strains were on the whole resilient to the maladaptive effects of early-life stress. Thus maternal-separation models of brain-gut axis dysfunction should rely on either different stressor protocols or other strains of mice.

  17. Cohesive stresses and size effect in quasi-brittle materials

    Indian Academy of Sciences (India)

    V E Saouma; D Natekar

    2002-08-01

    A novel approach to the derivation of Ba$\\breve{z}$ant’s size effect law is presented. Contrarily to the original Lagrangian derivation which hinged on energetic consideration, a Newtonian approach based on local stress intensity factors is presented. Through this approach, it is shown that Ba$\\breve{z}$ant’s size effect law is the first (and dominant) term in a series expansion for the nominal stress. Furthermore, analytical expressions for are derived for selected specimen geometries.

  18. Cellular effects of swim stress in the dorsal raphe nucleus

    OpenAIRE

    Kirby, Lynn G.; Pan, Yu-Zhen; Freeman-Daniels, Emily; Rani, Shobha; Nunan, John D.; Akanwa, Adaure; Beck, Sheryl G

    2007-01-01

    Swim stress regulates forebrain 5-hydroxytryptamine (5-HT) release in a complex manner and its effects are initiated in the serotonergic dorsal raphe nucleus (DRN). The purpose of this study was to examine the effects of swim stress on the physiology of DRN neurons in conjunction with 5-HT immunohistochemistry. Basic membrane properties, 5-HT1A and 5-HT1B receptor-mediated responses and glutamatergic excitatory postsynaptic currents (EPSCs) were measured using whole-cell patch clamp technique...

  19. Effects of Cadmium Stress on the Quality of Rice Seeds

    Institute of Scientific and Technical Information of China (English)

    Juan; CHEN; Hui; FANG; Ying; ZHANG; Yuanyuan; FAN

    2013-01-01

    Germination and hydroponic experiments are performed on rice seeds growing in soils treated with Cd stress,with rice seeds of the same variety that is not treated with Cd stress as a control,to study the effects of Cd stress on quality of rice seeds.The results have shown that:(1)Cd stress reduces the thousand grain weight of rice seeds,and higher Cd content means lower thousand grain weight;(2)The germination vigor and germination percentage of rice seeds under Cd stress as well as theirα-amylase activity andβ-amylase activity are all lower than those of the control.They decreases as the Cd stress increases;(3)For rice seeds under Cd stress,the height,fresh and dry weight of seedlings,as well as the chlorophyll content,photosynthetic rate and content of soluble protein of their leaves are all lower than those of the control.This indicates that Cd stress has certain effects on the germination and growth of the rice seeds.

  20. Measuring Agricultural Bias

    DEFF Research Database (Denmark)

    Jensen, Henning Tarp; Robinson, Sherman; Tarp, Finn

    The measurement issue is the key issue in the literature on trade policy-induced agri-cultural price incentive bias. This paper introduces a general equilibrium effective rate of protection (GE-ERP) measure, which extends and generalizes earlier partial equilibrium nominal protection measures....... For the 15 sample countries, the results indicate that the agricultural price incentive bias, which was generally perceived to exist during the 1980s, was largely eliminated during the 1990s. The results also demonstrate that general equilibrium effects and country-specific characteristics - including trade...... shares and intersectoral linkages - are crucial for determining the sign and magnitude of trade policy bias. The GE-ERP measure is therefore uniquely suited to capture the full impact of trade policies on agricultural price incentives. A Monte Carlo procedure confirms that the results are robust...

  1. The role of attentional bias in the effect of food advertising on actual food intake among children.

    Science.gov (United States)

    Folkvord, Frans; Anschütz, Doeschka J; Wiers, Reinout W; Buijzen, Moniek

    2015-01-01

    This study examined the potential moderating role of attentional bias (i.e., gaze duration, number of fixations, latency of initial fixation) in the effect of advergames promoting energy-dense snacks on children's snack intake. A randomized between-subject design was conducted with 92 children who played an advergame that promoted either energy-dense snacks or nonfood products. Eye movements and reaction times to food and nonfood cues were recorded to assess attentional bias during playtime using eye-tracking methods. Children could eat freely after playing the game. The results showed that playing an advergame containing food cues increased total intake. Furthermore, children with a higher gaze duration for the food cues ate more of the advertised snacks. In addition, children with a faster latency of initial fixation to the food cues ate more in total and ate more of the advertised snacks. The number of fixations on the food cues did not increase actual snack intake. Food advertisements are designed to grab attention, and this study shows that the extent to which a child's attention is directed to a food cue increases the effect of the advertisement. PMID:25451582

  2. Effects of Referral Bias on Estimates of Anal Intraepithelial Neoplasia Progression and Regression Rates in a 3-State Markov Model

    Science.gov (United States)

    Mathews, William Christopher; Cachay, Edward Rafael; Agmas, Wollelaw; Jackson, Christopher

    2015-01-01

    Abstract The study aim is to compare anal intraepithelial neoplasia (AIN) progression and regression rates in a cytology inception cohort to estimates based on the subcohort referred for ≥1 high-resolution anoscopies (HRAs). A cytology-based retrospective cohort was assembled including the anal cytology histories and invasive anal cancer (IAC) outcomes of all HIV-infected adults under care between 2001 and 2012. A 3-state Markov model (400, and to have HSIL at baseline and thereafter. They also had more anal cytology examinations (median 6 vs 3) and longer follow-up (median 5.5 vs 3.6 years). State transition rates were overestimated in the HRA subcohort relative to inception cohort, but the degree of discordance varied by transition: for effects on the effects of HRA-triage bias may be relevant to estimates of AIN state transitions from other cohorts subject to referral bias. PMID:26334910

  3. Exchange bias effect in polycrystalline NiO/NiMn{sub 2}O{sub 4} composite

    Energy Technology Data Exchange (ETDEWEB)

    Freitas Cabral, A.J. [Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará (UFPA), Belém, PA (Brazil); Peña Serna, J.; Rache Salles, B.; Novak, M.A. [Instituto de Física, Universidade Federal do Rio de janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Pinto, A.L. [Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, RJ (Brazil); Rocha Remédios, C.M. [Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará (UFPA), Belém, PA (Brazil)

    2015-05-05

    Highlights: • Antiferromagnetic NiO/ferrimagnetic NiMn{sub 2}O{sub 4} oxide composites. • Grains are well faceted, indicating that the specimen was well crystallized. • The micrographs suggests that NiO and NiMn{sub 2}O{sub 4} may be stuck to each other. • EB effect in NiO/NiMn{sub 2}O{sub 4} oxide composites. • EB effect increases with the amount of NiO. - Abstract: Calcination of aqueous solutions formed by different molar ratios between the nickel and manganese chlorides led to the formation of antiferromagnetic NiO/ferrimagnetic NiMn{sub 2}O{sub 4} oxide composites, as determined by X-ray powder diffraction technique and Rietveld refinement. Low temperature zero field cooled and field cooled magnetic hysteresis cycles show an exchange bias effect, presumably due to interaction at the interfaces between the antiferromagnetic and ferrimagnetic materials.

  4. Effects of through-thickness stress assumptions on residual stress measurements in welds

    International Nuclear Information System (INIS)

    Full text: The three normal stresses have been measured by neutron diffraction for girth welded rings cut from linepipe in a number of thicknesses. The welds are manual metal arc cellulosic electrode welds made in X70 linepipe, these were measured at 5 through thickness positions at 19 locations (from the center of the weld up to 35 mm away from the weld) with a spatial resolution of 1 mm3. The assumption of zero through thickness stress is a common one in thin walled tubes such as these, however there may be significant local through-thickness stresses depending on the welding technique. These local effects, and the change in measured stresses if these are included, are discussed. (authors)

  5. Effects of acute laboratory stress on executive functions

    Directory of Open Access Journals (Sweden)

    Katrin Starcke

    2016-03-01

    Full Text Available Recent research indicates that stress can affect executive functioning. However, previous results are mixed with respect to the direction and size of effects, especially when considering different subcomponents of executive functions. The current study systematically investigates the effects of stress on the five components of executive functions proposed by Smith and Jonides (1999: Attention and inhibition; task management; planning; monitoring; and coding. Healthy participants (N = 40 were either exposed to the computerized version of the Paced Auditory Serial Addition Test as a stressor (N = 20, or to a rest condition (N = 20. Stress reactions were assessed with heart rate and subjective measures. After the experimental manipulation, all participants performed tasks that measure the different executive functions. The manipulation check indicates that stress induction was successful (i.e., the stress group showed a higher heart rate and higher subjective responses than the control group. The main results demonstrate that stressed participants show a poorer performance compared with unstressed participants in all executive subcomponents, with the exception of monitoring. Effect sizes for the tasks that reveal differences between stressed and unstressed participants are high. We conclude that the laboratory stressor used here overall reduced executive functioning.

  6. Effect of hydrogen on stress corrosion cracking of copper

    Institute of Scientific and Technical Information of China (English)

    Li-jie QIAO

    2008-01-01

    The effects of hydrogen on electrochemical behavior and susceptibility of stress corrosion cracking (SCC) of pure copper were studied. SCC susceptibility of pure copper in a 1 M NaNO2 solution was increased by pre-charged hydrogen. The effect of hydrogen on the sus-ceptibility is more obvious in the low stress region due to the longer fracture time, which resulted in a longer time for more hydrogen to diffuse toward the crack tip. Synergistic effects of hydrogen and stress on corrosion and SCC pro-cesses were discussed. The results showed that an inter-action between stress and hydrogen at the crack tip could increase the anodic dissolution rate remarkably.

  7. Effects of salience-network-node neurofeedback training on affective biases in major depressive disorder.

    Science.gov (United States)

    Hamilton, J Paul; Glover, Gary H; Bagarinao, Epifanio; Chang, Catie; Mackey, Sean; Sacchet, Matthew D; Gotlib, Ian H

    2016-03-30

    Neural models of major depressive disorder (MDD) posit that over-response of components of the brain's salience network (SN) to negative stimuli plays a crucial role in the pathophysiology of MDD. In the present proof-of-concept study, we tested this formulation directly by examining the affective consequences of training depressed persons to down-regulate response of SN nodes to negative material. Ten participants in the real neurofeedback group saw, and attempted to learn to down-regulate, activity from an empirically identified node of the SN. Ten other participants engaged in an equivalent procedure with the exception that they saw SN-node neurofeedback indices from participants in the real neurofeedback group. Before and after scanning, all participants completed tasks assessing emotional responses to negative scenes and to negative and positive self-descriptive adjectives. Compared to participants in the sham-neurofeedback group, from pre- to post-training, participants in the real-neurofeedback group showed a greater decrease in SN-node response to negative stimuli, a greater decrease in self-reported emotional response to negative scenes, and a greater decrease in self-reported emotional response to negative self-descriptive adjectives. Our findings provide support for a neural formulation in which the SN plays a primary role in contributing to negative cognitive biases in MDD. PMID:26862057

  8. Effect of Diffusion Limitations on Multianalyte Determination from Biased Biosensor Response

    Directory of Open Access Journals (Sweden)

    Romas Baronas

    2014-03-01

    Full Text Available The optimization-based quantitative determination of multianalyte concentrations from biased biosensor responses is investigated under internal and external diffusion-limited conditions. A computational model of a biocatalytic amperometric biosensor utilizing a mono-enzyme-catalyzed (nonspecific competitive conversion of two substrates was used to generate pseudo-experimental responses to mixtures of compounds. The influence of possible perturbations of the biosensor signal, due to a white noise- and temperature-induced trend, on the precision of the concentration determination has been investigated for different configurations of the biosensor operation. The optimization method was found to be suitable and accurate enough for the quantitative determination of the concentrations of the compounds from a given biosensor transient response. The computational experiments showed a complex dependence of the precision of the concentration estimation on the relative thickness of the outer diffusion layer, as well as on whether the biosensor operates under diffusion- or kinetics-limited conditions. When the biosensor response is affected by the induced exponential trend, the duration of the biosensor action can be optimized for increasing the accuracy of the quantitative analysis.

  9. The effect of connectives on the selection of arguments: implicit consequentiality bias for the connective "but".

    Science.gov (United States)

    Rigalleau, François; Guerry, Michèle; Granjon, Lionel

    2014-08-01

    Recent studies about the implicit causality of inter-personal verbs showed a symmetric implicit consequentiality bias for psychological verbs. This symmetry is less clear for action verbs because the verbs assigning the implicit cause to the object argument (e.g. "Peter protected John because he was in danger.") tend to assign the implicit consequence to the same argument (e.g. "Peter protected John so he was not hurt."). We replicated this result by comparing continuations of inter-personal events followed by a causal connective "because" or a consequence connective "so". Moreover, we found similar results when the consequence connective was replaced by a contrastive connective "but". This result was confirmed in a second experiment where we measured the time required to imagine a consistent continuation for a fragment finishing with "but s/he ...". The results were consistent with a contrastive connective introducing a denial of a consequence of the previous event. The results were consistent with a model suggesting that thematic roles and connectives can predict preferred co-reference relations. PMID:23982891

  10. The biasing effect of the "sexually violent predator" label on legal decisions.

    Science.gov (United States)

    Scurich, Nicholas; Gongola, Jennifer; Krauss, Daniel A

    2016-01-01

    Public fear has driven legislation designed to identify and exclude sexual offenders from society, culminating in sexually violent predator (SVP) statutes, in which a sex offender who has served his prison sentence is hospitalized indefinitely if a jury determines that he is likely to reoffend as a result of a mental disorder. Jurors rarely vote not to commit a previously-convicted sex offender as an SVP. This study tests whether the mere label of "sexually violent predator" affects these legal decisions. Venire jurors (n=161) were asked to decide whether an individual who had been incarcerated for 16years should be released on parole. The individual was either labeled as a.) a sexually violent predator or b.) a convicted felon, and all other information was identical between the conditions. Jurors were over twice as likely to deny parole to the SVP compared to the felon, even though they did not consider him any more dangerous or any more likely to reoffend. Demographic variables did not moderate this finding. However, jurors' desire to 'get revenge' and to 'make the offender pay', as measured by Gerber and Jackson's (2013) Just Deserts Scale, did significantly relate to decisions to deny parole. These findings suggest that jurors' decisions in SVP hearings are driven by legally impermissible considerations, and that the mere label of "sexually violent predator" induces bias into the decision making process. PMID:27206709

  11. Effects of differential wavefront sensor bias drifts on high contrast imaging

    CERN Document Server

    Sadakuni, Naru; Palmer, David W; Poyneer, Lisa A; Max, Claire E; Savransky, Dmitry; Thomas, Sandrine J; Cardwell, Andrew; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Rantakyrö, Fredrik; Serio, Andrew

    2014-01-01

    The Gemini Planet Imager (GPI) is a new facility, extreme adaptive optics (AO), coronagraphic instrument, currently being integrated onto the 8-meter Gemini South telescope, with the ultimate goal of directly imaging extrasolar planets. To achieve the contrast required for the desired science, it is necessary to quantify and mitigate wavefront error (WFE). A large source of potential static WFE arises from the primary AO wavefront sensor (WFS) detector's use of multiple readout segments with independent signal chains including on-chip preamplifiers and external amplifiers. Temperature changes within GPI's electronics cause drifts in readout segments' bias levels, inducing an RMS WFE of 1.1 nm and 41.9 nm over 4.44 degrees Celsius, for magnitude 4 and 11 stars, respectively. With a goal of $<$2 nm of static WFE, these are significant enough to require remedial action. Simulations imply a requirement to take fresh WFS darks every 2 degrees Celsius of temperature change, for a magnitude 6 star; similarly, for...

  12. Stress Ratio Effect on Ratcheting Behavior of AISI 4340 Steel

    Science.gov (United States)

    Divya Bharathi, K.; Dutta, K.

    2016-02-01

    Ratcheting is known as accumulation of plastic strain during asymmetric cyclic loading of metallic materials under non-zero mean stress. This phenomenon reduces fatigue life of engineering materials and thus limits the life prediction capacity of Coffin-Manson relationship. This study intends to investigate the ratcheting behavior in AISI 4340 steel which is mainly used for designing of railway wheel sets, axles, shafts, aircraft components and other machinery parts. The effect of stress ratio on the ratcheting behaviour in both annealed and normalised conditions were investigated for investigated steel. Ratcheting tests were done at different stress ratios of -0.4, -0.6 and -0.8. The results showed that the material responds to hardening behavior and nature of strain accumulation is dependent on the magnitude of stress ratio. The post ratcheted samples showed increase in tensile strength and hardness which increases with increasing stress ratio and these variations in tensile properties are correlated with the induced cyclic hardening.

  13. Investigation of exchange bias effect in magnetoelectric TbMnO3 and ferromagnetic La2/3Sr1/3MnO3 heterostructures

    International Nuclear Information System (INIS)

    In recent years multiferroic materials in which at least two ferroic or antiferroic orders coexist have drawn significant attention because of their possible applications in spintronics. Moreover the magnetoelectric coupling offers the control of ferroelectric polarization by magnetic field or control of magnetic order parameter by electric field. These materials are suitable for experiencing exchange bias effects. There have been a few reports of observation of exchange bias using a ferroelectric antiferromagnet (AFM) by putting it adjacent to a ferromagnetic material

  14. The effect of winning an Oscar Award on survival: Correcting for healthy performer survivor bias with a rank preserving structural accelerated failure time model

    OpenAIRE

    Han, Xu; Small, Dylan S.; Foster, Dean P.; Patel, Vishal

    2011-01-01

    We study the causal effect of winning an Oscar Award on an actor or actress's survival. Does the increase in social rank from a performer winning an Oscar increase the performer's life expectancy? Previous studies of this issue have suffered from healthy performer survivor bias, that is, candidates who are healthier will be able to act in more films and have more chance to win Oscar Awards. To correct this bias, we adapt Robins' rank preserving structural accelerated failure time model and $g...

  15. Cyclic stress effect on stress corrosion cracking of duplex stainless steel in chloride and caustic solutions

    Science.gov (United States)

    Yang, Di

    Duplex stainless steel (DSS) is a dual-phase material with approximately equal volume amount of austenite and ferrite. It has both great mechanical properties (good ductility and high tensile/fatigue strength) and excellent corrosion resistance due to the mixture of the two phases. Cyclic loadings with high stress level and low frequency are experienced by many structures. However, the existing study on corrosion fatigue (CF) study of various metallic materials has mainly concentrated on relatively high frequency range. No systematic study has been done to understand the ultra-low frequency (˜10-5 Hz) cyclic loading effect on stress corrosion cracking (SCC) of DSSs. In this study, the ultra-low frequency cyclic loading effect on SCC of DSS 2205 was studied in acidified sodium chloride and caustic white liquor (WL) solutions. The research work focused on the environmental effect on SCC of DSS 2205, the cyclic stress effect on strain accumulation behavior of DSS 2205, and the combined environmental and cyclic stress effect on the stress corrosion crack initiation of DSS 2205 in the above environments. Potentiodynamic polarization tests were performed to investigate the electrochemical behavior of DSS 2205 in acidic NaCl solution. Series of slow strain rate tests (SSRTs) at different applied potential values were conducted to reveal the optimum applied potential value for SCC to happen. Room temperature static and cyclic creep tests were performed in air to illustrate the strain accumulation effect of cyclic stresses. Test results showed that cyclic loading could enhance strain accumulation in DSS 2205 compared to static loading. Moreover, the strain accumulation behavior of DSS 2205 was found to be controlled by the two phases of DSS 2205 with different crystal structures. The B.C.C. ferrite phase enhanced strain accumulation due to extensive cross-slips of the dislocations, whereas the F.C.C. austenite phase resisted strain accumulation due to cyclic strain

  16. Effect of yoga on academic performance in relation to stress

    Directory of Open Access Journals (Sweden)

    Kauts Amit

    2009-01-01

    Full Text Available Background: Academic performance is concerned with the quantity and quality of learning attained in a subject or group of subjects after a long period of instruction. Excessive stress hampers students′ performance. Improvement in academic performance and alertness has been reported in several yogic studies. Aims and Objectives: The main objective of the study was to assess the effect of yoga on academic performance in relation to stress. Materials and Methods: The study started with 800 adolescent students; 159 high-stress students and 142 low-stress students were selected on the basis of scores obtained through Stress Battery. Experimental group and control group were given pre test in three subjects, i.e., Mathematics, Science, and Social Studies. A yoga module consisting of yoga asanas, pranayama, meditation, and a value orientation program was administered on experimental group for 7 weeks. The experimental and control groups were post-tested for their performance on the three subjects mentioned above. Results: The results show that the students, who practiced yoga performed better in academics. The study further shows that low-stress students performed better than high-stress students, meaning thereby that stress affects the students′ performance.

  17. Cognitive biases to healthy and unhealthy food words predict change in BMI

    OpenAIRE

    Calitri, R.; Pothos, E. M.; Tapper, K; Brunstrom, J M; Rogers, P J

    2010-01-01

    The current study explored the predictive value of cognitive biases to food cues (assessed by emotional Stroop and dot probe tasks) on weight change over a 1-year period. This was a longitudinal study with undergraduate students (N = 102) living in shared student accommodation. After controlling for the effects of variables associated with weight (e.g., physical activity, stress, restrained eating, external eating, and emotional eating), no effects of cognitive bias were found with the dot pr...

  18. Effects of multiple electrode pairs on the performance of a micromixer using dc-biased ac electro-osmosis

    International Nuclear Information System (INIS)

    Recently, ac electro-osmosis (ACEO) has attracted intensive attention due to its capabilities of pumping and mixing enhancement with relatively low voltages. In this paper, we report the effects of electrode arrangement on the performance of a micromixer using dc-biased ACEO with respect to flow rate and ac frequency. The mixer consists of two inlet channels and a straight main microchannel with gold electrode pairs deposited on its bottom, and utilizes asymmetric vortex flows generated by dc-biased ACEO for mixing. The results indicate that there is significant dependence of mixing performance on the number of electrode pairs, especially for different flow rates. For example, the single electrode pair resulted in the best mixing performance at the highest flow rate of 9 µL min−1 (average velocity of 2.5 cm s−1) while three or four electrode pairs provided the maximum mixing performance for the flow rate lower than 4 µL min−1 (4.11 cm s−1). Also, we found that a mixing index of 95% can be achieved by using three electrode pairs while a single electrode pair leads to a mixing index of 85% for a given condition. (paper)

  19. Substrate biasing effect on the physical properties of reactive RF-magnetron-sputtered aluminum oxide dielectric films on ITO glasses.

    Science.gov (United States)

    Liang, Ling Yan; Cao, Hong Tao; Liu, Quan; Jiang, Ke Min; Liu, Zhi Min; Zhuge, Fei; Deng, Fu Ling

    2014-02-26

    High dielectric constant (high-k) Al2O3 thin films were prepared on ITO glasses by reactive RF-magnetron sputtering at room temperature. The effect of substrate bias on the subband structural, morphological, electrode/Al2O3 interfacial and electrical properties of the Al2O3 films is systematically investigated. An optical method based on spectroscopic ellipsometry measurement and modeling is adopted to probe the subband electronic structure, which facilitates us to vividly understand the band-tail and deep-level (4.8-5.0 eV above the valence band maximum) trap states. Well-selected substrate biases can suppress both the trap states due to promoted migration of sputtered particles, which optimizes the leakage current density, breakdown strength, and quadratic voltage coefficient of capacitance. Moreover, high porosity in the unbiased Al2O3 film is considered to induce the absorption of atmospheric moisture and the consequent occurrence of electrolysis reactions at electrode/Al2O3 interface, as a result ruining the electrical properties. PMID:24490685

  20. Tip-contact related low-bias negative differential resistance and rectifying effects in benzene–porphyrin–benzene molecular junctions

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jue-Fei [College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); School of Electronics and Information Engineering, Suzhou Vocational University, Suzhou 215104 (China); Zhou, Liping, E-mail: zhoulp@suda.edu.cn, E-mail: leigao@suda.edu.cn; Liu, Man; Yan, Qiang; Han, Qin; Gao, Lei, E-mail: zhoulp@suda.edu.cn, E-mail: leigao@suda.edu.cn [College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China)

    2014-11-07

    The electronic transport properties of benzene–porphyrin–benzene (BPB) molecules coupled to gold (Au) electrodes were investigated. By successively removing the front-end Au atoms, several BPB junctions with different molecule-electrode contact symmetries were constructed. The calculated current–voltage (I–V) curves depended strongly on the contact configurations between the BPB molecules and the Au electrodes. In particular, a significant low-voltage negative differential resistance effect appeared at −0.3 V in the junctions with pyramidal electrodes on both sides. Along with the breaking of this tip-contact symmetry, the low-bias negative differential resistance effect gradually disappeared. This tip-contact may be ideal for use in the design of future molecular devices because of its similarity with experimental processes.

  1. Tip-contact related low-bias negative differential resistance and rectifying effects in benzene–porphyrin–benzene molecular junctions

    International Nuclear Information System (INIS)

    The electronic transport properties of benzene–porphyrin–benzene (BPB) molecules coupled to gold (Au) electrodes were investigated. By successively removing the front-end Au atoms, several BPB junctions with different molecule-electrode contact symmetries were constructed. The calculated current–voltage (I–V) curves depended strongly on the contact configurations between the BPB molecules and the Au electrodes. In particular, a significant low-voltage negative differential resistance effect appeared at −0.3 V in the junctions with pyramidal electrodes on both sides. Along with the breaking of this tip-contact symmetry, the low-bias negative differential resistance effect gradually disappeared. This tip-contact may be ideal for use in the design of future molecular devices because of its similarity with experimental processes

  2. Metastable magnetic state and exchange bias training effect in Mn-rich YMnO3 thin films

    International Nuclear Information System (INIS)

    The magnetic nature of stoichiometric and Mn rich hexagonal YMnO3 films grown at different oxygen partial pressures is investigated. The stoichiometric YMnO3 thin film showed antiferromagnetic ordering below 72 K; while the film having excess Mn content revealed metastable magnetic behaviour at a temperature of less than 42 K. The metastable magnetic behaviour in this sample is attributed to the competing anti-ferromagnetic and ferromagnetic phase fractions (caused by Mn2+ ions that originated due to excess Mn content). Also, in the metastable regime the exchange bias effect is observed, which is further supported by the training effect. Both the samples reveal room temperature ferroelectric behaviour. (paper)

  3. Effect of Stress on Transformer Insulation

    Directory of Open Access Journals (Sweden)

    Kapil Gandhi

    2012-06-01

    Full Text Available Power transformers use Kraft paper as insulation in the electrical windings present in the core, which is immersed in oil. In service, the temperature of the windings of core will go to 750C to 850C. If the transformer is over loaded, then the temperature can exceed upto 100°C causing the cellulose chains in the paper to cleave at an accelerated rate, which results in the degradation of mechanical strength and performance of the insulation. The Degree of Polymerization (DP will also decrease. If proper action will not take, this can lead to failure of the transformer and disruption to electricity supply and large economic losses to the operating utility. Transformer condition should be maintained because of its importance to electricity network. The life of transformer depends on the life of the oil impregnated paper insulation system to greater extent. Degradation of the cellulose insulation is an irreversible process. After thermal degradation of the paper winding, Furfuraldehyde (FFA is the chemical compound, which is released into the oil from paper. The concentration of FFA has been directly related to the condition of the paper insulation. In the present paper an experimental investigation has been made to evaluate the degradation of transformer oil contaminated by nano-particles of pine wood under accelerated thermal and electrical stress and results are correlated with breakdown strength, density & interfacial tension of the pure oil. The contaminated oil samples are tested at electric stress of 2.0 kV, 3.0 kV, 4.0 kV & 5.0 kV for 24, 48, 72 & 96 hours simultaneously.

  4. Quantum Peierls stress of straight and kinked dislocations and effect of non-glide stresses

    International Nuclear Information System (INIS)

    It was recently shown (Proville et al 2012 Nature Mater. 11 845) that to predict reliable Peierls stresses from atomistic simulations, one has to correct the Peierls barrier by the zero-point energy difference between the initial and activated states of the dislocation. The corresponding quantum Peierls stresses are studied here in α-Fe modeled with two embedded atom method potentials. First, we show that the quantum correction arises from modes localized near the dislocation core, such that partial Hessian matrices built on small cylinders centered on the dislocation core can be used to compute the zero-point energy difference. Second, we compute quantum Peierls stresses for straight and kinked dislocations and show that the former is smaller than the latter with both α-Fe models. Finally, we compare quantum Peierls stresses obtained in simple shear and in traction along two orientations considered experimentally by Kuramoto et al (1979 Phil. Mag. 39 717), evidencing a strong effect of non-glide stresses on the quantum Peierls stress. (paper)

  5. Effect of repeated restraint stress on memory in different tasks

    Directory of Open Access Journals (Sweden)

    Gamaro G.D.

    1999-01-01

    Full Text Available The present study investigated the effect of repeated stress applied to female rats on memory evaluated by three behavioral tasks: two-way shuttle avoidance, inhibitory avoidance and habituation to an open field. Repeated stress had different effects on rat behavior when different tasks were considered. In the two-way active avoidance test the stressed animals presented memory of the task, but their memory scores were impaired when compared to all other groups. In the habituation to the open field, only the control group showed a significant difference in the number of rearings between training and testing sessions, which is interpreted as an adequate memory of the task. In the handled and chronically stressed animals, on the other hand, no memory was observed, suggesting that even a very mild repeated stress would be enough to alter habituation to this task. The performance in the inhibitory avoidance task presented no significant differences between groups. The findings suggest that repeated restraint stress might induce cognitive impairments that are dependent on the task and on stress intensity.

  6. Effect of ground stress on hydraulic fracturing of methane well

    Institute of Scientific and Technical Information of China (English)

    DU Chun-zhi; MAO Xian-biao; MIAO Xie-xing; WANG Peng

    2008-01-01

    Most of the coal reservoirs in China are of low-permeability, so hydraulic fracturing is widely used to improve the permeability in the extraction of gas by ground drilling. The ground stress around the well was analyzed by using theory of elasticity. The pressure when the well fractured is formulated and the effect of ground stress on pressure is discussed. The effect of ground-stress-differences on hydraulic fracturing was analyzed by using the numerical software RFPA2D-Flow in reference to the tectonic stress in Jincheng coal area. The results show that: 1) the position where initial fracture appears is random and fracture branches emerge when the fractures expand if ground stresses in any two directions within a horizontal plane are equal; 2) otherwise, the fractures expand in general along the direction of maximum ground stress and the critical pressure decreases with increasing ground-stress-differences and 3) the preferred well-disposition pattern is diamond shaped. The preferred well spacing is 250 m×300 m. This study can provide a reference for the design of wells.

  7. Effects of the Intake of Sesame Seeds (Sesamum indicum L.) and Derivatives on Oxidative Stress: A Systematic Review.

    Science.gov (United States)

    Vittori Gouveia, Luciana de Almeida; Cardoso, Carolina Alves; de Oliveira, Glaucia Maria Moraes; Rosa, Glorimar; Moreira, Annie Seixas Bello

    2016-04-01

    This study is aimed at assessing the scientific evidence on the effect of the intake of sesame seeds and derivatives on oxidative stress of individuals with systemic hypertension, dyslipidemia, and type 2 diabetes mellitus. A systematic review was conducted in seven databases (Lilacs, PubMed, ISI Web of Knowledge, Cochrane Library, Scopus, Trip Database, and Scielo) from September 2013 to January 2014. Clinical trials on the intake of sesame seeds and derivatives assessing the outcomes related to oxidative stress were retrieved. The risk of bias in the results of the studies selected was assessed according to the criteria of the Cochrane Handbook for Systematic Reviews of Interventions. This review included seven clinical trials showing that the intake of sesame resulted in the increase in enzymatic and nonenzymatic antioxidants, as well as in a reduction in oxidative stress markers. This was mainly observed with the use of sesame oil for hypertensive individuals during 2 months and black sesame meal capsules for prehypertensive individuals during four weeks. Most studies involved a small number of participants, sample size being considered a limiting factor for this review. In addition, a significant heterogeneity was observed in the type of population studied and the type of sesame and derivatives used, as well as their amount. The follow-up time was considered a limiting factor, because it varied in the different studies. The high risk of randomization and blinding biases found in the studies assessed determines lower scientific evidence of the results. Despite the limitations and biases identified in this systematic review, sesame showed relevant effects on oxidative stress, suggesting it could increase the antioxidant capacity. PMID:27074618

  8. Effect of supply voltage and body-biasing on single-event transient pulse quenching in bulk fin field-effect-transistor process

    Science.gov (United States)

    Jun-Ting, Yu; Shu-Ming, Chen; Jian-Jun, Chen; Peng-Cheng, Huang; Rui-Qiang, Song

    2016-04-01

    Charge sharing is becoming an important topic as the feature size scales down in fin field-effect-transistor (FinFET) technology. However, the studies of charge sharing induced single-event transient (SET) pulse quenching with bulk FinFET are reported seldomly. Using three-dimensional technology computer aided design (3DTCAD) mixed-mode simulations, the effects of supply voltage and body-biasing on SET pulse quenching are investigated for the first time in bulk FinFET process. Research results indicate that due to an enhanced charge sharing effect, the propagating SET pulse width decreases with reducing supply voltage. Moreover, compared with reverse body-biasing (RBB), the circuit with forward body-biasing (FBB) is vulnerable to charge sharing and can effectively mitigate the propagating SET pulse width up to 53% at least. This can provide guidance for radiation-hardened bulk FinFET technology especially in low power and high performance applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 61376109, 61434007, and 61176030).

  9. Study on the bias-dependent effects of proton-induced damage in CdZnTe radiation detectors using ion beam induced charge microscopy.

    Science.gov (United States)

    Gu, Yaxu; Jie, Wanqi; Rong, Caicai; Xu, Lingyan; Xu, Yadong; Lv, Haoyan; Shen, Hao; Du, Guanghua; Guo, Na; Guo, Rongrong; Zha, Gangqiang; Wang, Tao; Xi, Shouzhi

    2016-09-01

    The influence of damage induced by 2MeV protons on CdZnTe radiation detectors is investigated using ion beam induced charge (IBIC) microscopy. Charge collection efficiency (CCE) in irradiated region is found to be degraded above a fluence of 3.3×10(11)p/cm(2) and the energy spectrum is severely deteriorated with increasing fluence. Moreover, CCE maps obtained under the applied biases from 50V to 400V suggests that local radiation damage results in significant degradation of CCE uniformity, especially under low bias, i. e., 50V and 100V. The CCE nonuniformity induced by local radiation damage, however, can be greatly improved by increasing the detector applied bias. This bias-dependent effect of 2MeV proton-induced radiation damage in CdZnTe detectors is attributed to the interaction of electron cloud and radiation-induced displacement defects. PMID:27399802

  10. Study on glow discharge effects on catalyst films for growing aligned carbon nanofibers in negative bias-enhanced hot filament chemical vapor deposition system

    International Nuclear Information System (INIS)

    Aligned carbon nanofibers (ACNFs) were grown on silicon substrates coated with NiFe catalyst films by negative bias-enhanced hot filament chemical vapor deposition (CVD). The growth and structure of the aligned carbon nanofibers were investigated by scanning electron microscopy (SEM). The results indicate that the aligned carbon nanofibers could be synthesized after the glow discharge appears when the negative bias is higher than a certain value, while they are bent if the glow discharge does not appear. Furthermore, the diameters of the aligned carbon nanofibers are reduced and their lengths are increased with increasing the negative bias. It is shown that the glow discharge resulting from the negative bias plays an important role in the growth of aligned carbon nanofibers. Here, the effects of the glow discharge on the growth and structure of the aligned carbon nanofibers are discussed

  11. Therapeutic effects of stress-programmed lymphocytes transferred to chronically stressed mice.

    Science.gov (United States)

    Scheinert, Rachel B; Haeri, Mitra H; Lehmann, Michael L; Herkenham, Miles

    2016-10-01

    Our group has recently provided novel insights into a poorly understood component of intercommunication between the brain and the immune system by showing that psychological stress can modify lymphocytes in a manner that may boost resilience to psychological stress. To demonstrate the influence of the adaptive immune system on mood states, we previously showed that cells from lymph nodes of socially defeated mice, but not from unstressed mice, conferred anxiolytic and antidepressant-like effects and elevated hippocampal cell proliferation when transferred into naïve lymphopenic Rag2(-/-) mice. In the present study, we asked whether similar transfer could be anxiolytic and antidepressant when done in animals that had been rendered anxious and depressed by chronic psychological stress. First, we demonstrated that lymphopenic Rag2(-/-) mice and their wild-type C57BL/6 mouse counterparts had similar levels of affect normally. Second, we found that following chronic (14days) restraint stress, both groups displayed an anxious and depressive-like phenotype and decreased hippocampal cell proliferation. Third, we showed that behavior in the open field test and light/dark box was normalized in the restraint-stressed Rag2(-/-) mice following adoptive transfer of lymph node cells from green fluorescent protein (GFP) expressing donor mice previously exposed to chronic (14days) of social defeat stress. Cells transferred from unstressed donor mice had no effect on behavior. Immunolabeling of GFP+ cells confirmed that tissue engraftment had occurred at 14days after transfer. We found GFP+ lymphocytes in the spleen, lymph nodes, blood, choroid plexus, and meninges of the recipient Rag2(-/-) mice. The findings suggest that the adaptive immune system may play a key role in promoting recovery from chronic stress. The data support using lymphocytes as a novel therapeutic target for anxiety states. PMID:27109071

  12. Behavioural and Neuroendocrine Effects of Stress in Salmonid Fish

    OpenAIRE

    Øverli, Øyvind

    2001-01-01

    Stress can affect several behavioural patterns, such as food intake and the general activity level of an animal. The central monoamine neurotransmitters serotonin, dopamine, and norepinephrine are important in the mediation of both behavioural and neuroendocrine stress effects. This thesis describes studies of two salmonid fish model systems: Fish that become socially dominant or subordinate when reared in pairs, and rainbow trout (Oncorhynchus mykiss) genetically selected for high (HR) and l...

  13. Effect of yoga on academic performance in relation to stress

    OpenAIRE

    Kauts Amit; Sharma Neelam

    2009-01-01

    Background: Academic performance is concerned with the quantity and quality of learning attained in a subject or group of subjects after a long period of instruction. Excessive stress hampers students′ performance. Improvement in academic performance and alertness has been reported in several yogic studies. Aims and Objectives: The main objective of the study was to assess the effect of yoga on academic performance in relation to stress. Materials and Methods: The study started ...

  14. Effect of Examination Stress on The Plasma Cortisol Level

    OpenAIRE

    Rachit M Joshi; Saurin J Sanghavi; Devanshi P Upadhyaya; Ashutosh Chauhan; Shital Halvadia

    2012-01-01

    Background: Medical profession has been always a noble and prestigious path but the endeavour behind it has been truly known by the persons who undergone the training of becoming a doctor. Medical students face many stresses in their academic life. This study is carried out to provide data and re-establish the effect of academic examination stress on the plasma cortisol levels. Methods: A longitudinal follow up study was carried out on the first MBBS medical students who were appearing for th...

  15. Epigenetic Effect of Chronic Stress on Dopamine Signaling and Depression

    OpenAIRE

    Sofia Moriam; Mahbub E. Sobhani

    2013-01-01

    Because of the complex causal factors leading to depression, epigenetics is of considerable interest for the understanding effect of stress in depression. Dopamine is a key neurotransmitter important in many physiological functions, including motor control, mood, and the reward pathway. These factors lead many drugs to target Dopamine receptors in treating depressive disorders. In this review, we try to portray how chronic stress as an epigenetic factor changes the gene regulation pattern by ...

  16. Occupational stress and effective coping strategies in nursing

    OpenAIRE

    Akangbe, Ifeoluwa; Tetteh, Isaac

    2015-01-01

    Nursing has been characterized as a high health risk profession due to the very heavy stressors common to the job. The study aimed at producing a descriptive information on occupational stress among nurses and effective coping strategies used in handling work-related stress. Research questions were formulated to assist the writers in meeting their objective during the research process. Narrative literature review methodology was used to answer the set research questions. The study was co...

  17. Investigating The Effect Of Job Stress On Performance Of Employees

    OpenAIRE

    Oyungerel Altangerel; Wang Ruimei; Ehsan Elahi; Bayandalai Dash

    2015-01-01

    Abstract This study is conducted to investigate the effect of job stress on job performance. A random sampling technique is used to collect primary data of 120 employees of four telecommunication companies of Mongolia i.e. Mobicom Unitel Skytel and G-mobile. A well-structured questionnaire is utilized to collect relevant data descriptive and logistic analysis is used to estimate and describe the findings of results. It is found that work overload is major reason of stress among employees and ...

  18. Effects of d-amphetamine upon psychosocial stress responses.

    Science.gov (United States)

    Childs, Emma; Bershad, Anya K; de Wit, Harriet

    2016-07-01

    Psychostimulant drugs alter the salience of stimuli in both laboratory animals and humans. In animals, stimulants increase rates of responding to conditioned incentive stimuli, and in humans, amphetamine increases positive ratings of emotional images. However, the effects of stimulants on real-life emotional events have not been studied in humans. In this study, we examined the effect of d-amphetamine on responses to acute psychosocial stress using a public speaking task. Healthy volunteers (N=56) participated in two experimental sessions, one with a psychosocial stressor (the Trier Social Stress Test) and one with a non-stressful control task. They were randomly assigned to receive d-amphetamine (5 mg n=18, 10 mg n=20) or placebo (n=18) on both sessions under double blind conditions. Salivary cortisol, subjective mood, and vital signs were measured at regular intervals during the session. Subjects also provided cognitive appraisals of the tasks before and after their performances. Amphetamine produced its expected mood and physiological effects, and the Trier Social Stress Test produced its expected effects on cortisol and mood. Although neither dose of amphetamine altered cardiovascular or hormonal responses to stress, amphetamine (10 mg) increased participants' pre-task appraisals of how challenging the task would be, and it increased post-task ratings of self-efficacy. Paradoxically, it also increased ratings of how stressful the task was, and prolonged aversive emotional responses. These findings suggest that amphetamine differentially affects stress response components: it may increase participants' appraisals of self-efficacy without dampening the direct emotional or physiological responses to the stress. PMID:27235381

  19. Prenatal stress and its effect on infant development

    OpenAIRE

    Huizink, A.C.

    2001-01-01

    In this dissertation the effect of prenatal maternal stress on infant development and behavior is discussed. In a prospective longitudinal study of 170 nulliparous women, data was gatheren on the maternal stress level three times during pregnancy by means of questionnaires and endocrinologic parameters (Cortisol, ACTH). After birth, the infants were examined up to the age of 8 months with the Bayley Scales of Infant Development and their behavior was rated by observation and by maternal repor...

  20. Trans-generational effects of prenatal stress in quail

    OpenAIRE

    Guibert, Floriane; Lumineau, Sophie; Kotrschal, Kurt; Möstl, Erich; Richard-Yris, Marie-Annick; Houdelier, Cécilia

    2013-01-01

    The prenatal environment is a source of phenotypic variability influencing the animal's characteristics. Prenatal stress affects not only the development of offspring, but also that of the following generation. Such effects have been best documented in mammals but can also be observed in birds, suggesting common processes across phylogenetic orders. We found previously that Japanese quail females stressed during laying produced offspring with higher fearfulness, probably related to modulation...

  1. The nondiscriminating heart: lovingkindness meditation training decreases implicit intergroup bias.

    Science.gov (United States)

    Kang, Yoona; Gray, Jeremy R; Dovidio, John F

    2014-06-01

    Although meditation is increasingly accepted as having personal benefits, less is known about the broader impact of meditation on social and intergroup relations. We tested the effect of lovingkindness meditation training on improving implicit attitudes toward members of 2 stigmatized social outgroups: Blacks and homeless people. Healthy non-Black, nonhomeless adults (N = 101) were randomly assigned to 1 of 3 conditions: 6-week lovingkindness practice, 6-week lovingkindness discussion (a closely matched active control), or waitlist control. Decreases in implicit bias against stigmatized outgroups (as measured by Implicit Association Test) were observed only in the lovingkindness practice condition. Reduced psychological stress mediated the effect of lovingkindness practice on implicit bias against homeless people, but it did not mediate the reduced bias against Black people. These results suggest that lovingkindness meditation can improve automatically activated, implicit attitudes toward stigmatized social groups and that this effect occurs through distinctive mechanisms for different stigmatized social groups. PMID:23957283

  2. Bias in clinical intervention research

    DEFF Research Database (Denmark)

    Gluud, Lise Lotte

    2006-01-01

    Research on bias in clinical trials may help identify some of the reasons why investigators sometimes reach the wrong conclusions about intervention effects. Several quality components for the assessment of bias control have been suggested, but although they seem intrinsically valid, empirical...

  3. Tunable exchange bias-like effect in patterned hard-soft two-dimensional lateral composites with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Hierro-Rodriguez, A., E-mail: ahierro@fc.up.pt; Alvarez-Prado, L. M.; Martín, J. I.; Alameda, J. M. [Departamento de Física, Universidad de Oviedo, C/Calvo Sotelo S/N, 33007 Oviedo (Spain); Centro de Investigación en Nanomateriales y Nanotecnología—CINN (CSIC—Universidad de Oviedo—Principado de Asturias), Parque Tecnológico de Asturias, 33428 Llanera (Spain); Teixeira, J. M. [IN-IFIMUP, Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua Campo Alegre 687, 4169-007 Porto (Portugal); Vélez, M. [Departamento de Física, Universidad de Oviedo, C/Calvo Sotelo S/N, 33007 Oviedo (Spain)

    2014-09-08

    Patterned hard-soft 2D magnetic lateral composites have been fabricated by e-beam lithography plus dry etching techniques on sputter-deposited NdCo{sub 5} thin films with perpendicular magnetic anisotropy. Their magnetic behavior is strongly thickness dependent due to the interplay between out-of-plane anisotropy and magnetostatic energy. Thus, the spatial modulation of thicknesses leads to an exchange coupled system with hard/soft magnetic regions in which rotatable anisotropy of the thicker elements provides an extra tool to design the global magnetic behavior of the patterned lateral composite. Kerr microscopy studies (domain imaging and magneto-optical Kerr effect magnetometry) reveal that the resulting hysteresis loops exhibit a tunable exchange bias-like shift that can be switched on/off by the applied magnetic field.

  4. Tunable exchange bias-like effect in patterned hard-soft two-dimensional lateral composites with perpendicular magnetic anisotropy

    International Nuclear Information System (INIS)

    Patterned hard-soft 2D magnetic lateral composites have been fabricated by e-beam lithography plus dry etching techniques on sputter-deposited NdCo5 thin films with perpendicular magnetic anisotropy. Their magnetic behavior is strongly thickness dependent due to the interplay between out-of-plane anisotropy and magnetostatic energy. Thus, the spatial modulation of thicknesses leads to an exchange coupled system with hard/soft magnetic regions in which rotatable anisotropy of the thicker elements provides an extra tool to design the global magnetic behavior of the patterned lateral composite. Kerr microscopy studies (domain imaging and magneto-optical Kerr effect magnetometry) reveal that the resulting hysteresis loops exhibit a tunable exchange bias-like shift that can be switched on/off by the applied magnetic field.

  5. Antidepressant and anti-stress effects of curcumin inmice

    Institute of Scientific and Technical Information of China (English)

    YingXU; Bao-shanKU; Hai-yanYAO; Yong-heZHANG; Xue-junLI

    2004-01-01

    Curcumin (diferuloylmethane), a yellow colouring agent contained in the rhizome of Curcuma Longa (turmeric), has a wide array of pharmacological and biological activities, such as antioxidant, anti-inflammatory, immunomodulating and anticarcinogenic effects. In this study, curcumin was examined for the antidepressant and anti-stress effects in forced swimming,

  6. Effects of RSA Feedback on Posttraumatic Stress Disorder Symptomatology

    Science.gov (United States)

    Fourie, Phillip

    2006-01-01

    Posttraumatic stress disorder (PTSD) is one of the anxiety disorders with particularly debilitating effects due to flashbacks and hypervigilance in daily life. Treatments commonly focus upon either pharmacological or psychotherapeutic modalities, but there is often a need to merge both of these approaches to deal effectively with the somatic, as…

  7. The impact of stress on tumor growth: peripheral CRF mediates tumor-promoting effects of stress

    Directory of Open Access Journals (Sweden)

    Stathopoulos Efstathios N

    2010-09-01

    effect. Moreover, antalarmin suppressed neoangiogenesis in 4T1 tumors in vivo. Conclusion This is the first report demonstrating that peripheral CRF, at least in part, mediates the tumor-promoting effects of stress and implicates CRF in SMAD2 and β-catenin expression.

  8. Effect of substrate bias on the micro- structure and properties of nanocom- posite titanium nitride – based films

    Directory of Open Access Journals (Sweden)

    M. Dudek

    2009-12-01

    Full Text Available Purpose: Hard nanocomposite nc-TiN/a-SiN films exhibit very attractive mechanical, tribological, optical and electronic properties related to their microstructure and chemical bonding.Design/methodology/approach: In the present work, we investigate ternary thin film TiSiN systems deposited by plasma assisted reactive pulsed magnetron sputtering (PARPMS from titanium and silicon targets. PARPMS allows one to effectively control ion bombardment by reactive species (e.g., N2 +, N+ on the surface of the growing film by varying the bias voltage (VB induced by a radiofrequency (RF power applied to the substrate.Findings: RF biasing without additional heating of the substrate promotes formation of crystals within the nc films. Specifically, (111 crystal orientation at low VB (- 50 V changed into (200 when VB was increased above - 600 V. At the same time, hardness (H and reduced Young’s modulus (Er of the films changed fromH ~ 10 GPa and Er ~ 135 GPa to their maximum values of H ~ 25 GPa and Er ~ 248 GPa at VB = - 600 V. For comparison, for films deposited at 300ºC and VB = - 200 V, the maximum values of H and Er of ~ 35 GPa and ~ 350 GPa were observed.Practical implications: The use of the PARPMS to effectively control the mechanical properties and microstructure of transition metal nitride systems films.Originality/value: Discussion of evolution of the film microstructure (crystal size and orientation at constant film composition and relate it with the energetic aspects of the film growth and film characteristics.

  9. Stress effects in two modified lead zirconate titanate ferroelectric ceramics

    International Nuclear Information System (INIS)

    Mechanical properties of ferroelectric ceramics with compositions Pb/sub 0.99/Nb/sub 0.02/(Zr/sub 0.95/Ti/sub 0.05/)/sub 0.98/O3 and Pb/sub 0.97/La/sub 0.02/(Zr/sub 0.92/Ti/sub 0.08/)O3 have been studied as functions of both hydrostatic pressure and uniaxial stress. Measurements of ultrasonic velocity and sample strains have been made in order to characterize unpoled samples. Both materials have pressure-induced ferroelectric (FE) to antiferroelectric (AFE) phase transitions at approx.0.2 GPa of hydrostatic pressure. Under uniaxial-stress conditions two effects are observed: rotation of FE domains and the FE--AFE phase transition. These effects are separately resolved by the measurements, even though they occur in overlapping stress regions. The domain reorientation responses of the two materials appear to be nearly identical, but the FE--AFE transition begins at lower stress levels for the Nb-doped material. This is presumably due to that material transforming into the orthorhombic (PbZrO3) phase, whereas the La-doped material transforms into the tetragonal AFE phase. The phase transition is spread over a broad range of uniaxial stress for each material and is not nearly complete by 0.6 GPa, the highest stress level attainable. Possible implications of the results for shock-wave studies of FE ceramics are briefly discussed

  10. Effects of Substrate Bias on the Hardness and Resistivity of Reactively Sputtered TaN and TiN Thin Films

    Science.gov (United States)

    Lu, Junqing; Arshi, Nishat

    2016-06-01

    TaN and TiN films are being widely used as conductive layers in electronic devices or protective coatings on metal surfaces. Among various deposition methods, reactive magnetron sputtering is preferred partly due to its ability to control the energy of the depositing ions by applying different substrate bias voltages. In this study, TaN and TiN films were deposited on Si/SiO2 substrates by using direct current magnetron sputtering technique with 370 W target power at 1.9 mTorr and under different substrate biases. The effects of the substrate bias on both the resistivity and the hardness of the deposited TaN and TiN films were investigated. The phase and composition of the deposited films were investigated by x-ray diffraction, the resistivity was measured by a four-point probe, and the hardness was obtained by nano-indentation. For TaN films, the use of substrate bias not only increased the hardness but also increased the resistivity. Moreover, the formation of the Ta3N5 phase at the -300 V substrate bias significantly increased the TaN film resistivity. For TiN films, the optimum resistivity (minimum) of 19.5 µΩ-cm and the hardness (maximum) of 31.5 GPa were achieved at the -100 V substrate bias. Since the phase changes occurred in both the TaN and the TiN films at higher substrate biases and these phase changes negatively affected the resistivity or hardness property of the films, the substrate bias should not significantly exceed -100 V.

  11. Effect of bias voltage on tunneling mechanism in Co40Fe40B20/MgO/Co40Fe40B20 pseudo-spin valve

    International Nuclear Information System (INIS)

    Bias voltage dependence of tunneling mechanism has been systematically investigated in Co40Fe40B20 (2.1 nm)/MgO (2 nm)/Co40Fe40B20 (1.7 nm) pseudo-spin valve magnetic tunnel junction deposited using the combination of the pulsed DC unbalanced magnetron and RF magnetron sputtering techniques. Structural investigations revealed polycrystalline and partially (001) oriented growth of CoFeB/MgO(001) MTJ with similar low interface roughness on both side of the MgO barrier. The junction with a 25×25 µm2 area indicates a giant tunnel magnetoresistance in the order of 505% at room temperature. The magnetoresistance ratio decreases with increasing applied bias voltage ranging from 0.5 to 1.8 V. Reasonable values for barrier thickness and heights were obtained using the combination of Brinkman and Gundlach models, including average barrier height and symmetry. Both barrier parameters and the tunneling mechanism vary in dependence of applied bias voltage. The tunneling mechanism indicates a change from direct to the FN tunneling, especially when reaching high bias voltages. Effect of the tunneling mechanism on the bias dependence of the magnetoresistance was also discussed. - Highlights: • Polycrystalline and partially (001) oriented CoFeB/MgO MTJ with similar interface roughness was produced. • TMR ratio of 505% was obtained at room temperature, decreasing with increasing bias. • Similar interface roughness with low barrier asymmetry results in high TMR ratio. • Tunneling mechanism changes from direct to Fowler–Nordheim for applied biases >0.8 V. • Bias dependence of TMR is correlated with change of the tunneling mechanism

  12. Transverse stress effects in Nb3Sn cables

    International Nuclear Information System (INIS)

    The effect of transverse compressive stress on the critical current of solder-filled and unfilled Nb3Sn cables is reported. The conductor used in this study is a Nb3Sn Rutherford cable manufactured with a bronze-process wire of 0.92 mm diameter. Like epoxy-impregnated cables, solder-filled cables exhibit much less degradation than wire samples when subjected to the same stresses. On the other hand, unfilled specimens are irreversibly damaged at the thin edge when loaded to 160 MPa, and show significantly higher degradation than similar specimens of the solder-filled cable. A finite-element calculation of the stress state inside a particular composite superconductor indicates that more compressive stress is developed in the virgin wire than in a straight wire segment in a real cable environment

  13. Quantum Stress Tensor Fluctuations and their Physical Effects

    CERN Document Server

    Ford, L H

    2007-01-01

    We summarize several aspects of recent work on quantum stress tensor fluctuations and their role in driving fluctuations of the gravitational field. The role of correlations and anticorrelations is emphasized. We begin with a review of the properties of the stress tensor correlation function. We next consider some illuminating examples of non-gravitational effects of stress tensors fluctuations, specifically fluctuations of the Casimir force and radiation pressure fluctuations. We next discuss passive fluctuations of spacetime geometry and some of their operational signatures. These include luminosity fluctuations, line broadening, and angular blurring of a source viewed through a fluctuating gravitational field. Finally, we discuss the possible role of quantum stress tensor fluctuations in the early universe, especially in inflation. The fluctuations of the expansion of a congruence of comoving geodesics grows during the inflationary era, due to non-cancellation of anticorrelations that would have occurred i...

  14. [The effect of stressor experiences and optimism upon stress responses].

    Science.gov (United States)

    Tonan, K; Sonoda, A

    1994-10-01

    The present studies investigated whether or not optimism/pessimism is a cognitive mediator of future depression for people who have experienced many negative life events. Subjects were administered optimism scales, stress response scales at Time 1. They then completed the stressor scale and stress response scales at Time 2, about six weeks later. The results showed the interaction of stressor experiences and optimistic diathesis: Subjects who have higher stressor experiences and higher stable and global explanatory style for negative events showed higher depressive responses. Other indices of optimistic diathesis--Life Orientation, Cognitive Style, and Internality dimension of Attributional Style--did not produce this interaction effect. Moreover, this interaction did not appear in the psychological stress response other than depression. These results were consistent with diathesis-stress model of depression. PMID:7861687

  15. The effects of stress intensity and stress type on inbreeding depression in Silene vulgaris.

    Science.gov (United States)

    Sandner, Tobias Michael; Matthies, Diethart

    2016-06-01

    Inbreeding depression (ID) is generally assumed to increase under stressful conditions, but a number of studies have found the opposite pattern, that is that crossed offspring were more capable of exploiting benign conditions. Alternatively, the phenotypic variation hypothesis predicts that not stress intensity, but enhanced phenotypic variation in an environment leads to increased ID. We subjected inbred and crossed offspring of Silene vulgaris to drought, simulated herbivory, copper contamination, and two levels of nutrient deficiency and shade. In contrast to the predominant expectation, most stress treatments decreased inbreeding depression. With increasing nutrient limitation, ID decreased strongly, whereas under increasing shade ID did not change. These differences may be due to purging in the population of origin where conditions are nutrient-poor and dry, but not shaded. In contrast to the greenhouse experiment, ID was higher in a field site than in a more benign common garden. However, the predictions of the phenotypic variation hypothesis were met in both the greenhouse and the field versus garden experiment. The results suggest that there may be no general relationship between ID and stress intensity, but specific effects of stress type and the novelty and variability of the environment. PMID:27110935

  16. Effect of reporting bias on meta-analyses of drug trials

    DEFF Research Database (Denmark)

    Hart, Beth; Lundh, Andreas; Bero, Lisa

    2012-01-01

    To investigate the effect of including unpublished trial outcome data obtained from the Food and Drug Administration (FDA) on the results of meta-analyses of drug trials.......To investigate the effect of including unpublished trial outcome data obtained from the Food and Drug Administration (FDA) on the results of meta-analyses of drug trials....

  17. Effects of atosiban on stress-related neuroendocrine factors.

    Science.gov (United States)

    Babic, S; Pokusa, M; Danevova, V; Ding, S T; Jezova, D

    2015-04-01

    Atosiban, an oxytocin/vasopressin receptor antagonist, is used to decrease preterm uterine activity. The risk of preterm delivery is undoubtedly associated with stress, but potential side effects of atosiban on neuroendocrine functions and stress-related pathways are mostly unknown. These studies were designed to test the hypothesis that the chronic treatment of rats with atosiban modulates neuroendocrine functions under stress conditions. Male rats were treated (osmotic minipumps) with atosiban (600 μg/kg per day) or vehicle and were restrained for 120 min/day for 14 days. All animals were treated with a marker of cell proliferation 5-bromo-2-deoxyuridine. Anxiety-like behavior was measured using an elevated plus-maze. Treatment with atosiban failed to modify plasma concentrations of the stress hormones ACTH and corticosterone, but led to a rise in circulating copeptin. Atosiban increased prolactin levels in the non-stressed group. Oxytocin receptor mRNA levels were increased in rats exposed to stress. Treatment with atosiban, in both control and stressed animals, resulted in a decrease in oxytocin receptor gene expression in the hypothalamus. No changes were observed in vasopressin receptor 1A and 1B gene expression. The decrease in hippocampal cell proliferation induced by stress exposure was not modified by atosiban treatment. This study provides the first data, to our knowledge, revealing the effect of atosiban on gene expression of oxytocin receptors in the brain. Atosiban-induced enhancement of plasma copeptin indicates an elevation in vasopressinergic tone with potential influence on water-electrolyte balance. PMID:25609735

  18. Opposite Effects of Early-Life Competition and Developmental Telomere Attrition on Cognitive Biases in Juvenile European Starlings.

    Directory of Open Access Journals (Sweden)

    Melissa Bateson

    Full Text Available Moods are enduring affective states that we hypothesise should be affected by an individual's developmental experience and its current somatic state. We tested whether early-life adversity, induced by manipulating brood size, subsequently altered juvenile European starlings' (Sturnus vulgaris decisions in a judgment bias task designed to provide a cognitive measure of mood. We predicted that starlings from larger broods, specifically those that had experienced more nest competitors larger than themselves would exhibit reduced expectation of reward, indicative of a 'pessimistic', depression-like mood. We used a go/no-go task, in which 30 starlings were trained to probe a grey card disc associated with a palatable mealworm hidden underneath and avoid a different shade of grey card disc associated with a noxious quinine-injected mealworm hidden underneath. Birds' response latencies to the trained stimuli and also to novel, ambiguous stimuli intermediate between these were subsequently tested. Birds that had experienced greater competition in the nest were faster to probe trained stimuli, and it was therefore necessary to control statistically for this difference in subsequent analyses of the birds' responses to the ambiguous stimuli. As predicted, birds with more, larger nest competitors showed relatively longer latencies to probe ambiguous stimuli, suggesting reduced expectation of reward and a 'pessimistic', depression-like mood. However, birds with greater developmental telomere attrition--a measure of cellular aging associated with increased morbidity and reduced life-expectancy that we argue could be used as a measure of somatic state--showed shorter latencies to probe ambiguous stimuli. This would usually be interpreted as evidence for a more positive or 'optimistic' affective state. Thus, increased competition in the nest and poor current somatic state appear to have opposite effects on cognitive biases. Our results lead us to question

  19. Opposite Effects of Early-Life Competition and Developmental Telomere Attrition on Cognitive Biases in Juvenile European Starlings.

    Science.gov (United States)

    Bateson, Melissa; Emmerson, Michael; Ergün, Gökçe; Monaghan, Pat; Nettle, Daniel

    2015-01-01

    Moods are enduring affective states that we hypothesise should be affected by an individual's developmental experience and its current somatic state. We tested whether early-life adversity, induced by manipulating brood size, subsequently altered juvenile European starlings' (Sturnus vulgaris) decisions in a judgment bias task designed to provide a cognitive measure of mood. We predicted that starlings from larger broods, specifically those that had experienced more nest competitors larger than themselves would exhibit reduced expectation of reward, indicative of a 'pessimistic', depression-like mood. We used a go/no-go task, in which 30 starlings were trained to probe a grey card disc associated with a palatable mealworm hidden underneath and avoid a different shade of grey card disc associated with a noxious quinine-injected mealworm hidden underneath. Birds' response latencies to the trained stimuli and also to novel, ambiguous stimuli intermediate between these were subsequently tested. Birds that had experienced greater competition in the nest were faster to probe trained stimuli, and it was therefore necessary to control statistically for this difference in subsequent analyses of the birds' responses to the ambiguous stimuli. As predicted, birds with more, larger nest competitors showed relatively longer latencies to probe ambiguous stimuli, suggesting reduced expectation of reward and a 'pessimistic', depression-like mood. However, birds with greater developmental telomere attrition--a measure of cellular aging associated with increased morbidity and reduced life-expectancy that we argue could be used as a measure of somatic state--showed shorter latencies to probe ambiguous stimuli. This would usually be interpreted as evidence for a more positive or 'optimistic' affective state. Thus, increased competition in the nest and poor current somatic state appear to have opposite effects on cognitive biases. Our results lead us to question whether increased

  20. Body-bias effect in a GaN Schottky barrier MOSFET fabricated on a silicon (111) substrate with an ITO source/drain

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Ju; Kim, Dong-Seok; Yun, Jun-Yeon; Lee, Jung-Hee; Hahm, Sung-Ho; Sung, Sang-Yun; Heo, Young-Woo [Kyungpook National University, Daegu (Korea, Republic of)

    2011-08-15

    We fabricated a GaN Schottky barrier metal-oxide-semiconductor field-effect transistor (SB-MOSFET) by using indium tin oxide (ITO) films as the source/drain and the gate electrodes, and we checked for the body bias effect after forming an Ohmic contact to the substrate. The body bias results exhibit an abnormal effect; i.e., the threshold voltage was decreased by a reverse body bias. In order to find the mechanism for that, we characterized the UV photo response of no-gated MOSFET used as a metal-semiconductor-metal (MSM) diode with and without annealing for the passivation oxide between the source and the drain regions. The leakage current of the back-to-back Schottky diode was significantly improved after passivation annealing, but the UV/visible rejection characteristics were worse.