A revisit to the temperature dependence of electrical resistivity of α - Titanium at low temperatures

Science.gov (United States)

Sharath Chandra, L. S.; Mondal, R.; Thamizhavel, A.; Dhar, S. K.; Roy, S. B.

2017-09-01

The temperature dependence of resistivity ρ(T) of a polycrystalline sample and a single crystal sample (current along the [0001] direction) of α - Titanium (Ti) at low temperatures is revisited to understand the electrical charge transport phenomena in this hexagonal closed pack metal. We show that the ρ(T) in single crystal Ti can be explained by considering the scattering of electrons due to electron-phonon, electron-electron, inter-band s-d and electron-impurity interactions, whereas the ρ(T) of polycrystalline Ti could not be explained by these interactions alone. We observed that the effects of the anisotropy of the hexagonal structure on the electronic band structure and the phonon dispersion need to be taken into account to explain ρ(T) of polycrystalline Ti. Two Debye temperatures corresponding to two different directions for the electron-phonon interactions and inter-band s-d scattering are needed to account the observed ρ(T) in polycrystalline Ti.

Localized description of valence fluctuations

International Nuclear Information System (INIS)

Alascio, B.; Allub, R.; Aligia, A.

1979-07-01

The authors set up a model for intermediate valence equivalent to the ''atomic'' limit of the Anderson Hamiltonian. Detailed analysis of this model shows that most of the essential characteristics of valence fluctuators are already present in this crudely simplified Hamiltonian. The spin-spin and the 4f charge-charge correlation functions are studied and it is shown that it is possible to define a spin fluctuation frequency ωsub(s.f.) and a charge fluctuation frequency ωsub(ch.f.).ωsub(s.f.) and ωsub(ch.f.) can differ considerably for some values of the parameters of the model. The magnetic susceptibility and the specific heat are calculated as functions of temperature and it is shown how the results simulate the behaviour found in valence fluctuators. (author)

Systematic study on intermolecular valence-band dispersion in molecular crystalline films

International Nuclear Information System (INIS)

Yamane, Hiroyuki; Kosugi, Nobuhiro

2015-01-01

Highlights: • Intermolecular valence-band dispersion of crystalline films of phthalocyanines. • Intermolecular transfer integral versus lattice constant. • Site-specific intermolecular interaction and resultant valence-band dispersion. • Band narrowing effect induced by elevated temperature. - Abstract: Functionalities of organic semiconductors are governed not only by individual properties of constituent molecules but also by solid-state electronic states near the Fermi level such as frontier molecular orbitals, depending on weak intermolecular interactions in various conformations. The individual molecular property has been widely investigated in detail; on the other hand, the weak intermolecular interaction is difficult to investigate precisely due to the presence of the structural and thermal energy broadenings in organic solids. Here we show quite small but essential intermolecular valence band dispersions and their temperature dependence of sub-0.1-eV scale in crystalline films of metal phthalocyanines (H_2Pc, ZnPc, CoPc, MnPc, and F_1_6ZnPc) by using angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. The observed bands show intermolecular and site dependent dispersion widths, phases, and periodicities, for different chemical substitution of terminal groups and central metals in the phthalocyanine molecule. The precise and systematic band-dispersion measurement would be a credible approach toward the comprehensive understanding of intermolecular interactions and resultant charge transport properties as well as their tuning by substituents in organic molecular systems.

Evaluative conditioning induces changes in sound valence

Directory of Open Access Journals (Sweden)

Anna C. Bolders

2012-04-01

Full Text Available Evaluative Conditioning (EC has hardly been tested in the auditory domain, but it is a potentially valuable research tool. In Experiment 1 we investigated whether the affective evaluation of short environmental sounds can be changed using affective words as unconditioned stimuli (US. Congruence effects on an affective priming task (APT for conditioned sounds demonstrated successful EC. Subjective ratings for sounds paired with negative words changed accordingly. In Experiment 2 we investigated whether the acquired valence remains stable after repeated presentation of the conditioned sound without the US or whether extinction occurs. The acquired affective value remained present, albeit weaker, even after 40 extinction trials. These results warrant the use of EC to study processing of short environmental sounds with acquired valence, even if this requires repeated stimulus presentations. This paves the way for studying processing of affective environmental sounds while effectively controlling low level-stimulus properties.

Photo-induced valence change of the sulfur atom in an L-cysteine thin film grown on a silver metal substrate in a saliva-emulated aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Tsujibayashi, Toru [Department of Physics, Osaka Dental University, 8-1 Kuzuha-hanazono, Hirakata, Osaka 573-1121 (Japan); Azuma, Junpei; Yamamoto, Isamu; Takahashi, Kazutoshi; Kamada, Masao [Synchrotron Light Application Center, Saga University, 1 Honjo, Saga, Saga 840-8502 (Japan)

2015-04-27

A thin film of L-cysteine (HSCH{sub 2}CH(NH{sub 2})COOH) is grown on a silver substrate in saliva-emulated aqueous solution. X-ray photoemission spectroscopic measurements have revealed that the sulfur atom shows valence change under IR laser irradiation at 825 nm. The valence change maintains for about a minute at room temperature and more than an hour between 110 and 250 K after stopping the laser irradiation. It is not observed at all at temperatures lower than 110 K. This temperature-dependent behavior indicates that the photo-excited electronic change should be accompanied by a conformational change in the L-cysteine molecule. It is strongly suggested that the reversible valence change of the sulfur atom is applicable to a memory used around room temperature.

Levels of valence

Directory of Open Access Journals (Sweden)

Vera eShuman

2013-05-01

Full Text Available The distinction between the positive and the negative is fundamental in our emotional life. In appraisal theories, in particular in the component process model of emotion (Scherer, 1984, 2010, qualitatively different types of valence are proposed based on appraisals of (unpleasantness, goal obstructiveness/conduciveness, low or high power, self- (incongruence, and moral badness/goodness. This multifaceted conceptualization of valence is highly compatible with the frequent observation of mixed feelings in real life. However, it seems to contradict the one-dimensional conceptualization of valence often encountered in psychological theories, and the notion of valence as a common currency used to explain choice behavior. Here, we propose a framework to integrate the seemingly disparate conceptualizations of multifaceted valence and one-dimensional valence by suggesting that valence should be conceived at different levels, micro and macro. Micro-valences correspond to qualitatively different types of evaluations, potentially resulting in mixed feelings, whereas one-dimensional macro-valence corresponds to an integrative common currency to compare alternatives for choices. We propose that conceptualizing levels of valence may focus research attention on the mechanisms that relate valence at one level (micro to valence at another level (macro, leading to new hypotheses and addressing various concerns that have been raised about the valence concept, such as the valence-emotion relation.

Developmental Reversals in False Memory: Effects of Emotional Valence and Arousal

Science.gov (United States)

Brainerd, C. J.; Holliday, R. E.; Reyna, V. F.; Yang, Y.; Toglia, M. P.

2010-01-01

Do the emotional valence and arousal of events distort children's memories? Do valence and arousal modulate counterintuitive age increases in false memory? We investigated those questions in children, adolescents, and adults using the Cornell/Cortland Emotion Lists, a word list pool that induces false memories and in which valence and arousal can…

Levels of Valence

Science.gov (United States)

Shuman, Vera; Sander, David; Scherer, Klaus R.

2013-01-01

The distinction between the positive and the negative is fundamental in our emotional life. In appraisal theories, in particular in the component process model of emotion (Scherer, 1984, 2010), qualitatively different types of valence are proposed based on appraisals of (un)pleasantness, goal obstructiveness/conduciveness, low or high power, self-(in)congruence, and moral badness/goodness. This multifaceted conceptualization of valence is highly compatible with the frequent observation of mixed feelings in real life. However, it seems to contradict the one-dimensional conceptualization of valence often encountered in psychological theories, and the notion of valence as a common currency used to explain choice behavior. Here, we propose a framework to integrate the seemingly disparate conceptualizations of multifaceted valence and one-dimensional valence by suggesting that valence should be conceived at different levels, micro and macro. Micro-valences correspond to qualitatively different types of evaluations, potentially resulting in mixed feelings, whereas one-dimensional macro-valence corresponds to an integrative “common currency” to compare alternatives for choices. We propose that conceptualizing levels of valence may focus research attention on the mechanisms that relate valence at one level (micro) to valence at another level (macro), leading to new hypotheses, and addressing various concerns that have been raised about the valence concept, such as the valence-emotion relation. PMID:23717292

Intersite interactions and susceptibility in mixed valence systems

International Nuclear Information System (INIS)

Xiaoqian Wang; Gao Lin; Bingjian Ni; Fusui Liu.

1985-10-01

This paper considers the effect of intersite processes on the susceptibility in mixed valence system. The method of thermodynamical perturbation used in this paper can also be generalized to study other properties of mixed valence system. The general formula of partition function of two-site interactions for the mixed valence system is given. The numerical calculations show that the intersite interaction is large enough to explain the minimum of susceptibility discovered in experiments. The different types of our theoretical curves predict that the susceptibility should exhibit a rich variety of behaviour at low temperature for various materials. (author)

RKKY interaction in mixed valence system and heavy fermion superconductivity

International Nuclear Information System (INIS)

Fusui Liu; Gao Lin; Lin Zonghan

1985-11-01

The 1-D RKKY interaction of mixed valence system is given by using the thermodynamic perturbation theory. The numerical comparisons of 1-D and 3-D RKKY interaction between systems with localized magnetic moments of mixed valence and non-mixed valence show that the former is much stronger than the latter. From some analyses we propose that the heavy Fermion superconductivity comes from the RKKY interaction between two local f electrons which hop off the impurity site to become two continuum electrons. The source of the two impurity electrons hopping is the Coulomb interaction. It is also emphasized that the RKKY interaction does not disappear for the Kondo lattice, when the temperature is less than the Kondo temperature. (author)

Local valence balance in the structure of a high-temperature superconductor

International Nuclear Information System (INIS)

Nalbandyan, V.B.

1990-01-01

Hitherto superconductivity of complex oxides has been observed only if the metal is present in a mixed (nonintegral) degree of oxidation. It is of interest to verify the statement that in YBa 2 Cu 3 O x there is no copper in a degree of oxidation above 2+; instead of this, part of the oxygen is in the degree of oxidation 1-. Thus, the calculations of the valence forces tell against the presence of copper in a mixed degree of oxidation between 2+ and 3+ in high-temperature superconductors of the stoichiometric composition RBa 2 Cu 3 O 7 . In two-dimensional layers, copper is in the degree of oxidation 2+ (or even lower), while the electron holes are concentrated in one-dimensional chains - either in the form Cu(3+) or in the form O(1-)

Thermal and electron transport studies on the valence fluctuating compound YbNiAl4

Science.gov (United States)

Falkowski, M.; Kowalczyk, A.

2018-05-01

We report the thermoelectric power S and thermal conductivity κ measurements on the valence fluctuating compound YbNiAl4, furthermore taking into account the impact of the applied magnetic field. We discuss our new results with revisiting the magnetic [χ(T)], transport [ρ(T)], and thermodynamic [Cp(T)] properties in order to better understand the phenomenon of thermal and electron transport in this compound. The field dependence of the magnetoresistivity data is also given. The temperature dependence of thermoelectric power S(T) was found to exhibit a similar behaviour as expected for Yb-based compounds with divalent or nearly divalent Yb ions. In addition, the values of total thermal conductivity as a function of temperature κ(T) of YbNiAl4 are fairly low compared to those of pure metals which may be linked to the fact that the conduction band is perturbed by strong hybridization. A deeper analysis of the specific heat revealed the low-T anomaly of the ratio Cp(T)/T3, most likely associated with the localized low-frequency oscillators in this alloy. In addition, the Kadowaki-Woods ratio and the Wilson ratio are discussed with respect to the electronic correlations in YbNiAl4.

Temperature effects in the valence fluctuation of europium intermetallic compounds

International Nuclear Information System (INIS)

Menezes, O.L.T. de; Troper, A.; Gomes, A.A.

1978-03-01

A previously reported model for valence fluctuations in europium compound in order to account for thermal occupation effect. Experimental results are critically discussed and new experiments are suggested

Valence-Dependent Belief Updating: Computational Validation

Directory of Open Access Journals (Sweden)

Bojana Kuzmanovic

2017-06-01

Full Text Available People tend to update beliefs about their future outcomes in a valence-dependent way: they are likely to incorporate good news and to neglect bad news. However, belief formation is a complex process which depends not only on motivational factors such as the desire for favorable conclusions, but also on multiple cognitive variables such as prior beliefs, knowledge about personal vulnerabilities and resources, and the size of the probabilities and estimation errors. Thus, we applied computational modeling in order to test for valence-induced biases in updating while formally controlling for relevant cognitive factors. We compared biased and unbiased Bayesian models of belief updating, and specified alternative models based on reinforcement learning. The experiment consisted of 80 trials with 80 different adverse future life events. In each trial, participants estimated the base rate of one of these events and estimated their own risk of experiencing the event before and after being confronted with the actual base rate. Belief updates corresponded to the difference between the two self-risk estimates. Valence-dependent updating was assessed by comparing trials with good news (better-than-expected base rates with trials with bad news (worse-than-expected base rates. After receiving bad relative to good news, participants' updates were smaller and deviated more strongly from rational Bayesian predictions, indicating a valence-induced bias. Model comparison revealed that the biased (i.e., optimistic Bayesian model of belief updating better accounted for data than the unbiased (i.e., rational Bayesian model, confirming that the valence of the new information influenced the amount of updating. Moreover, alternative computational modeling based on reinforcement learning demonstrated higher learning rates for good than for bad news, as well as a moderating role of personal knowledge. Finally, in this specific experimental context, the approach based on

Developmental Reversals in False Memory: Effects of Emotional Valence and Arousal

OpenAIRE

Brainerd, C. J.; Holliday, R. E.; Reyna, V. F.; Yang, Y.; Toglia, M. P.

2010-01-01

Do the emotional valence and arousal of events distort children’s memories? Do valence and arousal modulate counterintuitive age increases in false memory? We investigated those questions in children, adolescents, and adults using the Cornell/Cortland Emotion Lists, a word list pool that induces false memories and in which valence and arousal can be manipulated factorially. False memories increased with age for unpresented semantic associates of word lists, and net accuracy (the ratio of true...

Micro-Valences: Affective valence in neutral everyday objects

OpenAIRE

Sophie eLebrecht; Moshe eBar; Lisa F Barrett; Michael J Tarr

2012-01-01

Affective valence influences both our cognition and our perception of the world. Indeed, the speed and quality with which we recognize objects in a visual scene can vary dramatically depending on its affective content. However, affective processing of visual objects has been typically studied using only stimuli with strong affective valences (e.g., guns or roses). Here we explore whether affective valence must be strong or obvious to exert an effect on our perception. We conclude that the maj...

Semiempirical search for oxide superconductors based on bond valence sums

International Nuclear Information System (INIS)

Tanaka, S.; Fukushima, N.; Niu, H.; Ando, K.

1992-01-01

Relationships between crystal structures and electronic states of layered transition-metal oxides are analyzed in the light of bond valence sums. Correlations between the superconducting transition temperature T c and the bond-valence-sum parameters are investigated for the high-T c cuprate compounds. Possibility of making nonsuperconducting oxides superconducting is discussed. (orig.)

Characterization of photo-induced valence tautomerism in a cobalt-dioxolene complex by ultrafast spectroscopy

International Nuclear Information System (INIS)

Beni, A; Bogani, L; Bussotti, L; Dei, A; Gentili, P L; Righini, R

2005-01-01

The valence tautomerism of low-spin Co III (Cat-N-BQ)(Cat-N-SQ) was investigated by means of UV-vis pump-probe transient absorption spectroscopy in chloroform. By exciting the CT transition of the complex at 480 nm, an intramolecular electron transfer process is selectively triggered. The photo-induced charge transfer is pursued by a cascade of two main molecular events characterized by the ultrafast transient absorption spectroscopy: the first gives rise to the metastable high-spin Co II (Cat-N-BQ) 2 that, secondly, reaches the chemical equilibrium with the reactant species

Characterization of photo-induced valence tautomerism in a cobalt-dioxolene complex by ultrafast spectroscopy

Science.gov (United States)

Beni, A.; Bogani, L.; Bussotti, L.; Dei, A.; Gentili, P. L.; Righini, R.

2005-01-01

The valence tautomerism of low-spin CoIII(Cat-N-BQ)(Cat-N-SQ) was investigated by means of UV-vis pump-probe transient absorption spectroscopy in chloroform. By exciting the CT transition of the complex at 480 nm, an intramolecular electron transfer process is selectively triggered. The photo-induced charge transfer is pursued by a cascade of two main molecular events characterized by the ultrafast transient absorption spectroscopy: the first gives rise to the metastable high-spin CoII(Cat-N-BQ)2 that, secondly, reaches the chemical equilibrium with the reactant species.

Spin Dynamics and Magnetic Ordering in Mixed Valence Systems

DEFF Research Database (Denmark)

Shapiro, S. M.; Bjerrum Møller, Hans; Axe, J. D.

1978-01-01

. 0 meV at the transition to the alpha phase. The temperature independence of the susceptibility within the gamma phase cannot be simply reconciled with the temperature dependence of the valence within the gamma phase. TmSe is shown to order in a type I antiferromagnetic structure below T//N similar 3....... 2 K. The magnetic phase diagram is understood as a successive domain reorientation and a metamagnetic phase transition for T less than 3 K with increasing field. The mixed valence nature manifests itself in a reduced moment and a markedly altered crystal field. Another sample of TmSe with a lattice...

Valency state changes in lanthanide-contained systems under high pressure

Energy Technology Data Exchange (ETDEWEB)

Jayaraman, A

1980-08-01

Changes in valency state induced by pressure in samarium sulphide SmS remind one of alchemy, as the mat black initial substance shines golden after the electron transition. The alchemist's dream is of course not realized, however the compound does exhibit an unusually interesting behaviour in the new state. The valency state of samarium as newly appeared fluctuated very rapidly between two electron configurations. Manipulation of the valency state by pressure or chemical substitution can basically change the physical properties of systems containing lanthanides. The phenomena are described and discussed in the following survey.

Valence evaluation with approaching or withdrawing cues: directly testing valence-arousal conflict theory.

Science.gov (United States)

Wang, Yan Mei; Li, Ting; Li, Lin

2017-07-19

The valence-arousal conflict theory assumes that both valence and arousal will trigger approaching or withdrawing tendencies. It also predicts that the speed of processing emotional stimuli will depend on whether valence and arousal trigger conflicting or congruent motivational tendencies. However, most previous studies have provided evidence of the interaction between valence and arousal only, and have not provided direct proof of the interactive links between valence, arousal and motivational tendencies. The present study provides direct evidence for the relationship between approach-withdrawal tendencies and the valence-arousal conflict. In an empirical test, participants were instructed to judge the valence of emotional words after visual-spatial cues that appeared to be either approaching or withdrawing from participants. A three-way interaction (valence, arousal, and approach-withdrawal tendency) was observed such that the response time was shorter if participants responded to a negative high-arousal stimulus after a withdrawing cue, or to a positive low-arousal stimulus after an approaching cue. These findings suggest that the approach-withdrawal tendency indeed plays a crucial role in valence-arousal conflict, and that the effect depends on the congruency of valence, arousal and tendency at an early stage of processing.

Characterization of photo-induced valence tautomerism in a cobalt-dioxolene complex by ultrafast spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Beni, A [Dipartimento di Chimica, Universita di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy); Bogani, L [Dipartimento di Chimica, Universita di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy); Bussotti, L [LENS, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence (Italy); Dei, A [Dipartimento di Chimica, Universita di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy); Gentili, P L [LENS, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence (Italy); Righini, R [Dipartimento di Chimica, Universita di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy)

2005-01-01

The valence tautomerism of low-spin Co{sup III}(Cat-N-BQ)(Cat-N-SQ) was investigated by means of UV-vis pump-probe transient absorption spectroscopy in chloroform. By exciting the CT transition of the complex at 480 nm, an intramolecular electron transfer process is selectively triggered. The photo-induced charge transfer is pursued by a cascade of two main molecular events characterized by the ultrafast transient absorption spectroscopy: the first gives rise to the metastable high-spin Co{sup II}(Cat-N-BQ){sub 2} that, secondly, reaches the chemical equilibrium with the reactant species.

Re-visiting the tympanic membrane vicinity as core body temperature measurement site.

Directory of Open Access Journals (Sweden)

Wui Keat Yeoh

Full Text Available Core body temperature (CBT is an important and commonly used indicator of human health and endurance performance. A rise in baseline CBT can be attributed to an onset of flu, infection or even thermoregulatory failure when it becomes excessive. Sites which have been used for measurement of CBT include the pulmonary artery, the esophagus, the rectum and the tympanic membrane. Among them, the tympanic membrane is an attractive measurement site for CBT due to its unobtrusive nature and ease of measurement facilitated, especially when continuous CBT measurements are needed for monitoring such as during military, occupational and sporting settings. However, to-date, there are still polarizing views on the suitability of tympanic membrane as a CBT site. This paper will revisit a number of key unresolved issues in the literature and also presents, for the first time, a benchmark of the middle ear temperature against temperature measurements from other sites. Results from experiments carried out on human and primate subjects will be presented to draw a fresh set of insights against the backdrop of hypotheses and controversies.

Re-visiting the tympanic membrane vicinity as core body temperature measurement site

Science.gov (United States)

Gan, Chee Wee; Liang, Wenyu

2017-01-01

Core body temperature (CBT) is an important and commonly used indicator of human health and endurance performance. A rise in baseline CBT can be attributed to an onset of flu, infection or even thermoregulatory failure when it becomes excessive. Sites which have been used for measurement of CBT include the pulmonary artery, the esophagus, the rectum and the tympanic membrane. Among them, the tympanic membrane is an attractive measurement site for CBT due to its unobtrusive nature and ease of measurement facilitated, especially when continuous CBT measurements are needed for monitoring such as during military, occupational and sporting settings. However, to-date, there are still polarizing views on the suitability of tympanic membrane as a CBT site. This paper will revisit a number of key unresolved issues in the literature and also presents, for the first time, a benchmark of the middle ear temperature against temperature measurements from other sites. Results from experiments carried out on human and primate subjects will be presented to draw a fresh set of insights against the backdrop of hypotheses and controversies. PMID:28414722

Cerium valence change in the solid solutions Ce(Rh1-xRux)Sn

International Nuclear Information System (INIS)

Niehaus, Oliver; Riecken, Jan F.; Winter, Florian; Poettgen, Rainer; Muenster Univ.; Abdala, Paula M.; Chevalier, Bernard

2013-01-01

The solid solutions Ce(Rh 1-x Ru x )Sn were investigated by means of susceptibility measurements, specific heat, electrical resistivity, X-ray absorption spectroscopy (XAS), and 119 Sn Moessbauer spectroscopy. Magnetic measurements as well as XAS data show a cerium valence change in dependence on the ruthenium content. Higher ruthenium content causes an increase from 3.22 to 3.45 at 300 K. Furthermore χ and χ -1 data indicate valence fluctuation for cerium as a function of temperature. For example, Ce(Rh 0.8 Ru 0.2 )Sn exhibits valence fluctuations between 3.42 and 3.32 in the temperature range of 10 to 300 K. This could be proven by using the interconfiguration fluctuation (ICF) model introduced by Sales and Wohlleben. Cerium valence change does not influence the tin atoms as proven by 119 Sn Moessbauer spectroscopy, but it influences the electrical properties. Ce(Rh 0.9 Ru 0.1 )Sn behaves like a typical valence fluctuating compound, and higher ruthenium content causes an increase of the metallic behavior. (orig.)

Time-resolved spectroscopic characterization of photo-induced valence tautomerism for a cobalt dioxolene complex

Science.gov (United States)

Gentili, Pier Luigi; Bussotti, Laura; Righini, Roberto; Beni, Alessandra; Bogani, Lapo; Dei, Andrea

2005-07-01

The valence tautomerism of low-spin Co III(Cat-N-BQ)(Cat-N-SQ) (where Cat-N-BQ is 2-(2-hydroxy-3,5-di- tert-butylphenylimino)-4,6-di- tert-butylcyclohexa-3,5-dienone and Cat-N-SQ is the dianionic radical analogue) was investigated by means of UV-vis pump-probe transient absorption spectroscopy and 1H NMR technique in chloroform and dichloromethane. By exciting the CT transition of the complex at 480 nm, an intramolecular electron transfer process is selectively triggered. The photo-induced charge transfer is pursued by a cascade of two main molecular events characterized by the ultrafast transient absorption spectroscopy: the first gives rise to the metastable high-spin Co II(Cat-N-BQ) 2 that, secondly, reaches the chemical equilibrium with the reactant species. The rate constant of back valence tautomerization estimated by measuring the lifetime of high-spin Co II(Cat-N-BQ) 2 species and the equilibrium constant for the Co III(Cat-N-BQ)(Cat-N-SQ) ⇄ Co II(Cat-N-BQ) 2 interconversion, is significantly large (on the order of 10 9 s -1). It is interpreted under the point of view of the theory formulated by Jortner and Buhks et al. for non-adiabatic radiationless processes.

Time-resolved spectroscopic characterization of photo-induced valence tautomerism for a cobalt-dioxolene complex

International Nuclear Information System (INIS)

Gentili, Pier Luigi; Bussotti, Laura; Righini, Roberto; Beni, Alessandra; Bogani, Lapo; Dei, Andrea

2005-01-01

The valence tautomerism of low-spin Co III (Cat-N-BQ)(Cat-N-SQ) (where Cat-N-BQ is 2-(2-hydroxy-3,5-di-tert-butylphenylimino)-4,6-di-tert-butylcyclohexa-3, 5-dien one and Cat-N-SQ is the dianionic radical analogue) was investigated by means of UV-vis pump-probe transient absorption spectroscopy and 1 H NMR technique in chloroform and dichloromethane. By exciting the CT transition of the complex at 480 nm, an intramolecular electron transfer process is selectively triggered. The photo-induced charge transfer is pursued by a cascade of two main molecular events characterized by the ultrafast transient absorption spectroscopy: the first gives rise to the metastable high-spin Co II (Cat-N-BQ) 2 that, secondly, reaches the chemical equilibrium with the reactant species. The rate constant of back valence tautomerization estimated by measuring the lifetime of high-spin Co II (Cat-N-BQ) 2 species and the equilibrium constant for the Co III (Cat-N-BQ)(Cat-N-SQ) Co II (Cat-N-BQ) 2 interconversion, is significantly large (on the order of 10 9 s -1 ). It is interpreted under the point of view of the theory formulated by Jortner and Buhks et al. for non-adiabatic radiationless processes

Dissociable neural systems underwrite logical reasoning in the context of induced emotions with positive and negative valence.

Science.gov (United States)

Smith, Kathleen W; Vartanian, Oshin; Goel, Vinod

2014-01-01

How emotions influence syllogistic reasoning is not well understood. fMRI was employed to investigate the effects of induced positive or negative emotion on syllogistic reasoning. Specifically, on a trial-by-trial basis participants were exposed to a positive, negative, or neutral picture, immediately prior to engagement in a reasoning task. After viewing and rating the valence and intensity of each picture, participants indicated by keypress whether or not the conclusion of the syllogism followed logically from the premises. The content of all syllogisms was neutral, and the influence of belief-bias was controlled for in the study design. Emotion did not affect reasoning performance, although there was a trend in the expected direction based on accuracy rates for the positive (63%) and negative (64%) versus neutral (70%) condition. Nevertheless, exposure to positive and negative pictures led to dissociable patterns of neural activation during reasoning. Therefore, the neural basis of deductive reasoning differs as a function of the valence of the context.

Dissociable Neural Systems Underwrite Logical Reasoning in the Context of Induced Emotions with Positive and Negative Valence

Science.gov (United States)

Smith, Kathleen W.; Vartanian, Oshin; Goel, Vinod

2014-01-01

How emotions influence syllogistic reasoning is not well understood. fMRI was employed to investigate the effects of induced positive or negative emotion on syllogistic reasoning. Specifically, on a trial-by-trial basis participants were exposed to a positive, negative, or neutral picture, immediately prior to engagement in a reasoning task. After viewing and rating the valence and intensity of each picture, participants indicated by keypress whether or not the conclusion of the syllogism followed logically from the premises. The content of all syllogisms was neutral, and the influence of belief-bias was controlled for in the study design. Emotion did not affect reasoning performance, although there was a trend in the expected direction based on accuracy rates for the positive (63%) and negative (64%) versus neutral (70%) condition. Nevertheless, exposure to positive and negative pictures led to dissociable patterns of neural activation during reasoning. Therefore, the neural basis of deductive reasoning differs as a function of the valence of the context. PMID:25294997

Magnetic-field-induced valence transition in rare-earth systems

Indian Academy of Sciences (India)

In the present work we investigate the scaling behavior observed experimentally based on an electronic model which has not yet been attempted. 2. The model and approximation. The Hamiltonian of the periodic Anderson model (PAM) with Falicov–Kimball term used to describe both continuous and discontinuous valence ...

Action and valence modulate choice and choice-induced preference change.

Directory of Open Access Journals (Sweden)

Raphael Koster

Full Text Available Choices are not only communicated via explicit actions but also passively through inaction. In this study we investigated how active or passive choice impacts upon the choice process itself as well as a preference change induced by choice. Subjects were tasked to select a preference for unfamiliar photographs by action or inaction, before and after they gave valuation ratings for all photographs. We replicate a finding that valuation increases for chosen items and decreases for unchosen items compared to a control condition in which the choice was made post re-evaluation. Whether choice was expressed actively or passively affected the dynamics of revaluation differently for positive and negatively valenced items. Additionally, the choice itself was biased towards action such that subjects tended to choose a photograph obtained by action more often than a photographed obtained through inaction. These results highlight intrinsic biases consistent with a tight coupling of action and reward and add to an emerging understanding of how the mode of action itself, and not just an associated outcome, modulates the decision making process.

Valencies of the lanthanides

OpenAIRE

Johnson, David A.; Nelson, Peter G.

2018-01-01

The valencies of the lanthanides vary more than was once thought. In addition to valencies associated with a half-full shell, there are valencies associated with a quarter- and three-quarter-full shell. This can be explained on the basis of Slater’s theory of many-electron atoms. The same theory explains the variation in complexing constants in the trivalent state (the “tetrad effect”). Valency in metallic and organometallic compounds is also discussed.

Valence effects of sorption: laboratory control of valence state

International Nuclear Information System (INIS)

Meyer, R.E.; Arnold, W.D.; Case, F.I.

1984-01-01

Estimation of the rates of migration of nuclides from nuclear waste repositories required knowledge of the interaction of these nuclides with the components of the geological formations in the path of the migration. These interactions will be dependent upon the valence state and speciation of the nuclide. If the valence state is not known, then there can be little confidence in use of the data for safety analysis. An electrochemical method of valence state control was developed which makes use of a porous electrode in a flow system containing a column of the adsorbent. By use of this method and solvent extraction analyses of the valence states, a number of reactions of interest to HLW repositories were investigated. These include the reduction of Np(V) and Tc(VII) by crushed basalt and other minerals. For the reduction of Np(V) by basalt, the experiments indicate that sorption on basalt increases with pH and that most of the Np is reduced to Np(IV). The adsorbed Np(IV) is very difficult to remove from the basalt. For the experiments with Tc(VII), the results are considerably more complicated. The results of these experiments are used to assess some of the techniques and methods currently used in safety analyses of proposed HLW repositories. Perhaps the most important consideration is that predictive modeling of valence change reactions, such as the reduction of Np(V) and Tc(VII), must be used with considerable caution, and the occurrence of such reactions should be verified as best as possible with experiments using valence state control and analyses. 13 references, 3 figures, 1 table

Influence of variable tungsten valency on optical transmittance and radiation hardness of lead tungstate (PWO) scintillation crystals

CERN Document Server

Burachas, S; Makov, I; Saveliev, Yu; Ippolitov, M S; Man'ko, V; Nikulin, S P; Nyanin, A; Vasilev, A; Apanasenko, A; Tamulaitis, G

2003-01-01

A new approach to interpret the radiation hardness of PbWO//4 (PWO) scintillators is developed by revealing importance of the inclusions of tungsten oxides WO//3//-//x with variable valency. It is demonstrated that the influence of the ionizing radiation on PWO is, in many aspects, similar to the effect of the high-temperature annealing in oxygenless ambient. In both cases, a valency change of the tungsten oxides is initiated and results in induced absorption and, consequently, in crystal coloration. In the PWO crystals doped with L//2O//3 (L = Y, La, Gd), the radiation hardness and the optical properties are mainly affected by inclusions of W//1//-//yL//yO//3//- //x (0 less than x less than 0.3) instead of inclusions of WO//3//- //x prevailing in the undoped samples. It is demonstrated that the radiation-induced bleaching and the photochromic effect of PWO are caused by phase transitions in the inclusions of tungsten oxide. Thermodynamic conditions for the phase transitions are discussed and the optimal oxid...

Time-resolved spectroscopic characterization of photo-induced valence tautomerism for a cobalt-dioxolene complex

Energy Technology Data Exchange (ETDEWEB)

Gentili, Pier Luigi [LENS, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Firenze (Italy)], E-mail: gentili@lens.unifi.it; Bussotti, Laura [LENS, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Firenze (Italy); Righini, Roberto [LENS, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Chimica, Universita di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze (Italy)], E-mail: righini@lens.unifi.it; Beni, Alessandra [Dipartimento di Chimica, Universita di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze (Italy); Bogani, Lapo [Dipartimento di Chimica, Universita di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze (Italy); Dei, Andrea [Dipartimento di Chimica, Universita di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze (Italy)

2005-07-18

The valence tautomerism of low-spin Co{sup III}(Cat-N-BQ)(Cat-N-SQ) (where Cat-N-BQ is 2-(2-hydroxy-3,5-di-tert-butylphenylimino)-4,6-di-tert-butylcyclohexa-3, 5-dien one and Cat-N-SQ is the dianionic radical analogue) was investigated by means of UV-vis pump-probe transient absorption spectroscopy and {sup 1}H NMR technique in chloroform and dichloromethane. By exciting the CT transition of the complex at 480 nm, an intramolecular electron transfer process is selectively triggered. The photo-induced charge transfer is pursued by a cascade of two main molecular events characterized by the ultrafast transient absorption spectroscopy: the first gives rise to the metastable high-spin Co{sup II}(Cat-N-BQ){sub 2} that, secondly, reaches the chemical equilibrium with the reactant species. The rate constant of back valence tautomerization estimated by measuring the lifetime of high-spin Co{sup II}(Cat-N-BQ){sub 2} species and the equilibrium constant for the Co{sup III}(Cat-N-BQ)(Cat-N-SQ) <-> Co{sup II}(Cat-N-BQ){sub 2} interconversion, is significantly large (on the order of 10{sup 9} s{sup -1}). It is interpreted under the point of view of the theory formulated by Jortner and Buhks et al. for non-adiabatic radiationless processes.

Valence instabilities as a source of actinide system inconsistencies

International Nuclear Information System (INIS)

Sandenaw, T.A.

1979-01-01

Light actinide elements alone, and in some of their alloys, may exist as a static or dynamic mixture of two configurations. Such a state can explain both a resistivity maximum and lack of magnetic order observed in so many actinide materials, and still be compatible with the existence of f-electrons in narrow bands. Impurity elements may stabilize slightly different intermediate valence states in U, Np, and Pu, thus contributing to inconsistencies in published results. The physical property behavior of mixed-valence, rare-earth compounds is very much like that observed in development of antiphase (martensitic) structures. Martensitic transformations in U, Np, and Pu, from high-temperature b. c. c. to alpha phase, may be a way of ordering an alloy-like metal of mixed or intermediate valence. The relative stability of each phase structure may depend upon its electron-valence ratio. A Hubbard model for electron correlations in a narrow energy band has been invoked in most recent theories for explaining light actinide behavior. Such a model may also be applicable to crystal symmetry changes in martensitic transformations in actinides

Double-valence-fluctuating molecules and superconductivity

International Nuclear Information System (INIS)

Hirsch, J.E.; Scalapino, D.J.

1985-01-01

We discuss the possibility of ''double-valence-fluctuating'' molecules, having two ground-state configurations differing by two electrons. We propose a possible realization of such a molecule, and experimental ways to look for it. We argue that a weakly coupled array of such molecules should give rise to a strong-coupling Shafroth-Blatt-Butler superconductor, with a high transition temperature

Electroencephalography Based Analysis of Working Memory Load and Affective Valence in an N-back Task with Emotional Stimuli.

Science.gov (United States)

Grissmann, Sebastian; Faller, Josef; Scharinger, Christian; Spüler, Martin; Gerjets, Peter

2017-01-01

Most brain-based measures of the electroencephalogram (EEG) are used in highly controlled lab environments and only focus on narrow mental states (e.g., working memory load). However, we assume that outside the lab complex multidimensional mental states are evoked. This could potentially create interference between EEG signatures used for identification of specific mental states. In this study, we aimed to investigate more realistic conditions and therefore induced a combination of working memory load and affective valence to reveal potential interferences in EEG measures. To induce changes in working memory load and affective valence, we used a paradigm which combines an N-back task (for working memory load manipulation) with a standard method to induce affect (affective pictures taken from the International Affective Picture System (IAPS) database). Subjective ratings showed that the experimental task was successful in inducing working memory load as well as affective valence. Additionally, performance measures were analyzed and it was found that behavioral performance decreased with increasing workload as well as negative valence, showing that affective valence can have an effect on cognitive processing. These findings are supported by changes in frontal theta and parietal alpha power, parameters used for measuring of working memory load in the EEG. However, these EEG measures are influenced by the negative valence condition as well and thereby show that detection of working memory load is sensitive to affective contexts. Unexpectedly, we did not find any effects for EEG measures typically used for affective valence detection (Frontal Alpha Asymmetry (FAA)). Therefore we assume that the FAA measure might not be usable if cognitive workload is induced simultaneously. We conclude that future studies should account for potential context-specifity of EEG measures.

Magneto-optical studies of valence instability in europium and terbium phosphors

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Lucas C.V. [Department of Chemistry, University of Turku, FI-20014 Turku (Finland); Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Hölsä, Jorma [Department of Chemistry, University of Turku, FI-20014 Turku (Finland); Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Turku University Centre for Materials and Surfaces (MatSurf) (Finland); University of the Free State, Department of Physics, Bloemfontein (South Africa); Brito, Hermi F. [Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Maryško, Miroslav [Institute of Physics, The Academy of Sciences of the Czech Republic, Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Matos, Jivaldo R. [Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Paturi, Petriina [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Rodrigues, Rodrigo V. [Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Lastusaari, Mika, E-mail: miklas@utu.fi [Department of Chemistry, University of Turku, FI-20014 Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf) (Finland)

2016-02-15

The impurities and dopants' inappropriate valences may deteriorate the performance of luminescent materials, cause waste of the precious rare earth (R) material and thus incur financial losses. The usual methods to detect the valence of rare earths; XPS, Mössbauer and XANES spectroscopies, are not sensitive enough for low concentrations and the EPR methods are not very suitable for powders. In this work, the comparison between the theoretical and experimental temperature-dependent paramagnetic susceptibilities was used to obtain quantitatively the concentrations of the impurity valence in Eu{sub 2}O{sub 2}S and Tb{sub 2}O{sub 2}SO{sub 4}, both containing nominally only R{sup 3+}. Minute (ppm level) Eu{sup 2+} impurities could be analyzed because of the huge difference in the paramagnetic susceptibility between Eu{sup 2+} and Eu{sup 3+} at low temperatures. However, temperatures below 50 K are then needed whilst the Tb{sup IV} impurity in a Tb{sup 3+} matrix can be observed already at higher temperatures. The latter method based on comparing the slopes of the Tb{sup 3+}/Tb{sup IV} paramagnetic susceptibility vs temperature curves for the Tb{sup 3+}/Tb{sup IV} couple is less sensitive than for the Eu{sup 2+}/Eu{sup 3+} one. Finally, the host independent temperature evolution of the paramagnetic susceptibility was calculated for Gd{sup 3+} (or Eu{sup 2+} or Tb{sup IV}) to yield a simple analytical expression to be used universally. - Highlights: • Wave functions for Eu{sup 3+}/Tb{sup 3+} with crystal field effect calculated for oxysulfide/sulfate. • Paramagnetic susceptibility between 4 and 300 K simulated for 4f{sup 6/7/8} configurations. • Amount of valence impurities (Eu{sup 2+} and Tb{sup IV}) evaluated from susceptibility data. • Waste of raw materials and loss of luminescence intensity of phosphors can be avoided.

A model on valence state evaluation of TRU nuclides in reprocessing solutions

International Nuclear Information System (INIS)

Uchiyama, Gunzo; Fujine, Sachio; Yoshida, Zenko; Maeda, Mitsuru; Motoyama, Satoshi.

1998-02-01

A mathematical model was developed to evaluate the valence state of TRU nuclides in reprocessing process solutions. The model consists of mass balance equations, Nernst equations, reaction rate equations and electrically neutrality equations. The model is applicable for the valence state evaluation of TRU nuclides in both steady state and transient state conditions in redox equilibrium. The valence state which is difficult to measure under high radiation and multi component conditions is calculated by the model using experimentally measured data for the TRU nuclide concentrations, nitric acid and redox reagent concentrations, electrode potential and solution temperature. (author)

Vection Modulates Emotional Valence of Autobiographical Episodic Memories

Science.gov (United States)

Seno, Takeharu; Kawabe, Takahiro; Ito, Hiroyuki; Sunaga, Shoji

2013-01-01

We examined whether illusory self-motion perception ("vection") induced by viewing upward and downward grating motion stimuli can alter the emotional valence of recollected autobiographical episodic memories. We found that participants recollected positive episodes more often while perceiving upward vection. However, when we tested a small moving…

Optical verification of the valence band structure of cadmium arsenide

NARCIS (Netherlands)

Gelten, M.J.; Es, van C.M.; Blom, F.A.P.; Jongeneelen, J.W.F.

1980-01-01

Optical absorption measurements were performed on thin single crystalline samples of Cd3As2 at temperatures of 300 K and 10 K. At low temperature the interband absorption coefficient shows clearly two steps due to direct transitions from the heavy hole and light hole valence bands to the conduction

Arousal-But Not Valence-Reduces False Memories at Retrieval.

Science.gov (United States)

Mirandola, Chiara; Toffalini, Enrico

2016-01-01

Mood affects both memory accuracy and memory distortions. However, some aspects of this relation are still poorly understood: (1) whether valence and arousal equally affect false memory production, and (2) whether retrieval-related processes matter; the extant literature typically shows that mood influences memory performance when it is induced before encoding, leaving unsolved whether mood induced before retrieval also impacts memory. We examined how negative, positive, and neutral mood induced before retrieval affected inferential false memories and related subjective memory experiences. A recognition-memory paradigm for photographs depicting script-like events was employed. Results showed that individuals in both negative and positive moods-similar in arousal levels-correctly recognized more target events and endorsed fewer false memories (and these errors were linked to remember responses less frequently), compared to individuals in neutral mood. This suggests that arousal (but not valence) predicted memory performance; furthermore, we found that arousal ratings provided by participants were more adequate predictors of memory performance than their actual belonging to either positive, negative or neutral mood groups. These findings suggest that arousal has a primary role in affecting memory, and that mood exerts its power on true and false memory even when induced at retrieval.

Spin dynamics and magnetic ordering in mixed valence systems

International Nuclear Information System (INIS)

Shapiro, S.M.; Moller, H.B.; Axe, J.D.; Birgeneau, R.J.; Bucher, E.

1977-01-01

Neutron scattering measurements are reported on the mixed valence compounds Ce/sub 1-x/Th/sub x/ and TmSe. The Chi''(Q,ω) as derived from the inelastic spectra of Ce 0 . 74 Th 0 . 26 shows a peak in the γ phase near 20.0 meV and shifts abruptly to greater than 70.0 meV at the transition to the α phase. The temperature independence of the susceptibility within the γ phase cannot be simply reconciled with the temperature dependence of the valence within the γ phase. TmSe is shown to order in a type I antiferromagnetic structure below T/sub N/ approx. 3.2 K. The magnetic phase diagram is understood as a successive domain reorientation and a metamagnetic phase transition for T 3+ orders in a type II structure but never achieves long range order

Valency stabilization of Polyvalent Iron Ions in Solution By some Organic additives during Gamma Irradiation

International Nuclear Information System (INIS)

Barakat, M.F.; Abdel Hamid, M.M.

2012-01-01

Valency stabilization of polyvalent ions in gamma irradiated aqueous solutions is sometimes necessary for the success of some chemical operations. In some previous publications valency stabilization of some polyvalent ions in solution upon gamma irradiation was achieved by using additives capable of interacting with the oxidizing or reducing species formed by water radiolysis in the medium. The results showed that the duration of valency stabilization depends on the concentration of the additives used.In the present work, a series of some organic additives has been used to investigate their capability in inducing valency stabilization of polyvalent iron ions when subjected to extended gamma irradiation periods. The results showed that the efficiency of valency stabilization depends on the amount and chemical structure of the organic additive used

Effect of temperature on the valency bands of HDO in water in the liquid and solid states. Effects on the analysis of heavy water using infra-red absorption; Effet de temperature sur les bandes de valence de HDO dans l'eau a l'etat liquide et a l'etat solide - consequences pour l'analyse de l'eau lourde par absorption infra-rouge

Energy Technology Data Exchange (ETDEWEB)

Ceccaldi, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

After, a description of the technique used, a qualitative examination is made of the influence of the temperature on the {nu}{sub OH}(3,400 cm{sup -1}) and {nu}{sub OD} (2,500 cm{sup -1}) valence bands of HDO in the liquid state and then during the passage to the solid state. Quantitative examination with two cells of different thickness makes it possible to define the influence of temperature on the residual absorption of the pure liquid (D{sub 2}O or H{sub 2}O and on the valency bands ({nu}{sub OH} and {nu}{sub OD} respectively). It is found that a similar change occurs in the two bands but that the changes in the background are very different. During the passage from the liquid to the solid state the shape of the bands varies considerably but little change occurs in the total intensity. It has been possible to express these results in a simple form which is directly applicable to analytical problems. (authors) [French] Apres un rappel de la technique utilisee, on examine qualitativement l'influence de la temperature sur les bandes de valence {nu}{sub OH} (3400 cm{sup -1}) et {nu}{sub OD} (2500 cm{sup -1}) de HDO a l'etat liquide puis le passage a l'etat solide. L'examen quantitatif, avec deux cuves d'epaisseurs differentes, permet de preciser l'influence de la temperature sur l'absorption residuelle du liquide pur (D{sub 2}O ou H{sub 2}O) et sur les bandes de valence ( {nu}{sub OH} et {nu}{sub OD} respectivement). On constate une evolution parallele de ces bandes mais un comportement tres different du fond continu. Lors du passage de l'etat liquide a l'etat solide, la forme des bandes varie considerablement mais non l'intensite totale. On a pu formuler ces resultats sous une forme simple applicable directement aux problemes analytiques. (auteurs)

Valence Scaling of Dynamic Facial Expressions Is Altered in High-Functioning Subjects with Autism Spectrum Disorders: An FMRI Study

Science.gov (United States)

Rahko, Jukka S.; Paakki, Jyri-Johan; Starck, Tuomo H.; Nikkinen, Juha; Pauls, David L.; Katsyri, Jari V.; Jansson-Verkasalo, Eira M.; Carter, Alice S.; Hurtig, Tuula M.; Mattila, Marja-Leena; Jussila, Katja K.; Remes, Jukka J.; Kuusikko-Gauffin, Sanna A.; Sams, Mikko E.; Bolte, Sven; Ebeling, Hanna E.; Moilanen, Irma K.; Tervonen, Osmo; Kiviniemi, Vesa

2012-01-01

FMRI was performed with the dynamic facial expressions fear and happiness. This was done to detect differences in valence processing between 25 subjects with autism spectrum disorders (ASDs) and 27 typically developing controls. Valence scaling was abnormal in ASDs. Positive valence induces lower deactivation and abnormally strong activity in ASD…

Effects of emotional valence and three-dimensionality of visual stimuli on brain activation: an fMRI study.

Science.gov (United States)

Dores, A R; Almeida, I; Barbosa, F; Castelo-Branco, M; Monteiro, L; Reis, M; de Sousa, L; Caldas, A Castro

2013-01-01

Examining changes in brain activation linked with emotion-inducing stimuli is essential to the study of emotions. Due to the ecological potential of techniques such as virtual reality (VR), inspection of whether brain activation in response to emotional stimuli can be modulated by the three-dimensional (3D) properties of the images is important. The current study sought to test whether the activation of brain areas involved in the emotional processing of scenarios of different valences can be modulated by 3D. Therefore, the focus was made on the interaction effect between emotion-inducing stimuli of different emotional valences (pleasant, unpleasant and neutral valences) and visualization types (2D, 3D). However, main effects were also analyzed. The effect of emotional valence and visualization types and their interaction were analyzed through a 3 × 2 repeated measures ANOVA. Post-hoc t-tests were performed under a ROI-analysis approach. The results show increased brain activation for the 3D affective-inducing stimuli in comparison with the same stimuli in 2D scenarios, mostly in cortical and subcortical regions that are related to emotional processing, in addition to visual processing regions. This study has the potential of clarify brain mechanisms involved in the processing of emotional stimuli (scenarios' valence) and their interaction with three-dimensionality.

Charge reversal and surface charge amplification in asymmetric valence restricted primitive model planar electric double layers in the modified Poisson-Boltzmann theory

Directory of Open Access Journals (Sweden)

L.B. Bhuiyan

2017-12-01

Full Text Available The modified Poisson-Boltzmann theory of the restricted primitive model double layer is revisited and recast in a fresh, slightly broader perspective. Derivation of relevant equations follow the techniques utilized in the earlier MPB4 and MPB5 formulations and clarifies the relationship between these. The MPB4, MPB5, and a new formulation of the theory are employed in an analysis of the structure and charge reversal phenomenon in asymmetric 2:1/1:2 valence electrolytes. Furthermore, polarization induced surface charge amplification is studied in 3:1/1:3 systems. The results are compared to the corresponding Monte Carlo simulations. The theories are seen to predict the "exact" simulation data to varying degrees of accuracy ranging from qualitative to almost quantitative. The results from a new version of the theory are found to be of comparable accuracy as the MPB5 results in many situations. However, in some cases involving low electrolyte concentrations, theoretical artifacts in the form of un-physical "shoulders" in the singlet ionic distribution functions are observed.

Valence, magnetism and conduction in the intermediate valence compounds: the case SmB6

International Nuclear Information System (INIS)

Derr, J.

2006-09-01

In some rare earth based compounds, the 4f level is situated so close to the Fermi level that the valence of the compound can become intermediate between two integer values. The so called 'intermediate valence' compound of Samarium hexaboride (SmB 6 ) is one typical example of the exciting physics which can result from this quantum equilibrium between two valence configurations. The first configuration (Sm 2+ ) corresponds to an insulating and non magnetic state whereas the second one (Sm 3+ ) would theoretically give a magnetic and metallic ground state. This dissertation deals with the influence of pressure on this equilibrium. Specific heat measurements under pressure evidenced a new long range magnetic ordering for pressures higher than p c ∼ 10 GPa. On another hand, transport measurements measured for the first time in good conditions of hydrostatics found a reliable and reproducible critical pressure for the insulator to metal transition equal to p c . The phase diagram of SmB 6 is now well known and the observation for the first time of a magnetic anomaly in the high pressure resistivity curves certifies that the onset of the magnetic phase really coincide with the closure of the gap. This change at the critical pressure p c is discussed in a general frame taking into account the Kondo lattice temperature as a key parameter for the renormalization of the wavefunction from one integer configuration to the other whereas the valence itself is still intermediate. This general idea seems to be valid also for other systems studied in this dissertation like SmS or TmSe and could even be valid for more general cases (Ytterbium, Cerium). In the same time, resistivity measurements under uniaxial stress were undertaken. The result is a strong anisotropy effect observed on the pressure dependence of the residual resistivity in the compound SmB 6 . The comparison with the transport under hydrostatic conditions enables us to consider a new idea for the nature of the gap

Arousal?But Not Valence?Reduces False Memories at Retrieval

OpenAIRE

Mirandola, Chiara; Toffalini, Enrico

2016-01-01

Mood affects both memory accuracy and memory distortions. However, some aspects of this relation are still poorly understood: (1) whether valence and arousal equally affect false memory production, and (2) whether retrieval-related processes matter; the extant literature typically shows that mood influences memory performance when it is induced before encoding, leaving unsolved whether mood induced before retrieval also impacts memory. We examined how negative, positive, and neutral mood indu...

Effect of Pressure on Valence and Structural Properties of YbFe₂Ge₂ Heavy Fermion Compound A Combined Inelastic X-ray Spectroscopy, X-ray Diffraction, and Theoretical Investigation

Energy Technology Data Exchange (ETDEWEB)

Kumar, Ravhi S.; Svane, Axel; Vaitheeswaran; #8741; , Ganapathy; Kanchana, Venkatakrishnan; Antonio, Daniel; Cornelius, Andrew L.; Bauer, Eric D.; Xiao, Yuming; Chow, Paul (Aarhus); (CIW); (Hyderabad - India); (IIT-India); (LANL); (UNLV)

2016-06-03

The crystal structure and the Yb valence of the YbFe₂Ge₂ heavy fermion compound was measured at room temperature and under high pressures using high-pressure powder X-ray diffraction and X-ray absorption spectroscopy via both partial fluorescence yield and resonant inelastic X-ray emission techniques. Furthermore, the measurements are complemented by first-principles density functional theoretical calculations using the self-interaction corrected local spin density approximation investigating in particular the magnetic structure and the Yb valence. While the ThCr₂Si₂-type tetragonal (I4/mmm) structure is stable up to 53 GPa, the X-ray emission results show an increase of the Yb valence from v = 2.72(2) at ambient pressure to v = 2.93(3) at ~9 GPa, where at low temperature a pressure-induced quantum critical state was reported.

Valence of facial cues influences sheep learning in a visual discrimination task

OpenAIRE

Bellegarde, Lucille; Erhard, Hans; Weiss, A.; Boissy, Alain; Haskell, M.J.

2017-01-01

Sheep are one of the most studied farm species in terms of their ability to process information from faces, but little is known about their face-based emotion recognition abilities. We investigated (a) whether sheep could use images of sheep faces taken in situation of varying valence as cues in a simultaneous discrimination task and (b) whether the valence of the situation affects their learning performance. To accomplish this, we photographed faces of sheep in three situations inducing emot...

Valence of Facial Cues Influences Sheep Learning in a Visual Discrimination Task

OpenAIRE

Lucille G. A. Bellegarde; Lucille G. A. Bellegarde; Lucille G. A. Bellegarde; Hans W. Erhard; Alexander Weiss; Alain Boissy; Marie J. Haskell

2017-01-01

Sheep are one of the most studied farm species in terms of their ability to process information from faces, but little is known about their face-based emotion recognition abilities. We investigated (a) whether sheep could use images of sheep faces taken in situation of varying valence as cues in a simultaneous discrimination task and (b) whether the valence of the situation affects their learning performance. To accomplish this, we photographed faces of sheep in three situations inducing emot...

The valence state of Yb metal under high pressure determined by XANES measurement up to 34.6 GPa

International Nuclear Information System (INIS)

Fuse, Akinori; Nakamoto, Go; Kurisu, Makio; Ishimatsu, Naoki; Tanida, Hajime

2004-01-01

The purpose of this study was to accurately determine the valency of Yb at high pressure and room temperature and to clarify the relation between the valence state and the crystal structure of Yb metal. L III -edge X-ray absorption near-edge structure (XANES) spectra were measured to determine the valence state of Yb metal in the pressure range from 0 to 34.6 GPa at room temperature, using a diamond anvil cell (DAC) and synchrotron radiation at SPring-8. In the fcc phase, Yb metal exhibits mixed valence (the mean valence ν-bar >2.1). At the fcc-to-bcc phase transition, a 0.1 jump is found in ν-bar. In the bcc phase, ν-bar(P) is an increasing function of pressure with downward curvature, reaching only 2.55 at 26 GPa. The ν-bar is only 2.65 in the hcp phase at 34.6 GPa. A tendency for saturation in ν-bar(P) to values smaller than 3.0 is found

Arousal-But Not Valence-Reduces False Memories at Retrieval.

Directory of Open Access Journals (Sweden)

Chiara Mirandola

Full Text Available Mood affects both memory accuracy and memory distortions. However, some aspects of this relation are still poorly understood: (1 whether valence and arousal equally affect false memory production, and (2 whether retrieval-related processes matter; the extant literature typically shows that mood influences memory performance when it is induced before encoding, leaving unsolved whether mood induced before retrieval also impacts memory. We examined how negative, positive, and neutral mood induced before retrieval affected inferential false memories and related subjective memory experiences. A recognition-memory paradigm for photographs depicting script-like events was employed. Results showed that individuals in both negative and positive moods-similar in arousal levels-correctly recognized more target events and endorsed fewer false memories (and these errors were linked to remember responses less frequently, compared to individuals in neutral mood. This suggests that arousal (but not valence predicted memory performance; furthermore, we found that arousal ratings provided by participants were more adequate predictors of memory performance than their actual belonging to either positive, negative or neutral mood groups. These findings suggest that arousal has a primary role in affecting memory, and that mood exerts its power on true and false memory even when induced at retrieval.

Revisit to diffraction anomalous fine structure

International Nuclear Information System (INIS)

Kawaguchi, T.; Fukuda, K.; Tokuda, K.; Shimada, K.; Ichitsubo, T.; Oishi, M.; Mizuki, J.; Matsubara, E.

2014-01-01

The diffraction anomalous fine structure method has been revisited by applying this measurement technique to polycrystalline samples and using an analytical method with the logarithmic dispersion relation. The diffraction anomalous fine structure (DAFS) method that is a spectroscopic analysis combined with resonant X-ray diffraction enables the determination of the valence state and local structure of a selected element at a specific crystalline site and/or phase. This method has been improved by using a polycrystalline sample, channel-cut monochromator optics with an undulator synchrotron radiation source, an area detector and direct determination of resonant terms with a logarithmic dispersion relation. This study makes the DAFS method more convenient and saves a large amount of measurement time in comparison with the conventional DAFS method with a single crystal. The improved DAFS method has been applied to some model samples, Ni foil and Fe 3 O 4 powder, to demonstrate the validity of the measurement and the analysis of the present DAFS method

Segregation of information about emotional arousal and valence in horse whinnies.

Science.gov (United States)

Briefer, Elodie F; Maigrot, Anne-Laure; Mandel, Roi; Freymond, Sabrina Briefer; Bachmann, Iris; Hillmann, Edna

2015-04-21

Studying vocal correlates of emotions is important to provide a better understanding of the evolution of emotion expression through cross-species comparisons. Emotions are composed of two main dimensions: emotional arousal (calm versus excited) and valence (negative versus positive). These two dimensions could be encoded in different vocal parameters (segregation of information) or in the same parameters, inducing a trade-off between cues indicating emotional arousal and valence. We investigated these two hypotheses in horses. We placed horses in five situations eliciting several arousal levels and positive as well as negative valence. Physiological and behavioral measures collected during the tests suggested the presence of different underlying emotions. First, using detailed vocal analyses, we discovered that all whinnies contained two fundamental frequencies ("F0" and "G0"), which were not harmonically related, suggesting biphonation. Second, we found that F0 and the energy spectrum encoded arousal, while G0 and whinny duration encoded valence. Our results show that cues to emotional arousal and valence are segregated in different, relatively independent parameters of horse whinnies. Most of the emotion-related changes to vocalizations that we observed are similar to those observed in humans and other species, suggesting that vocal expression of emotions has been conserved throughout evolution.

Conduction Mechanism of Valence Change Resistive Switching Memory: A Survey

Directory of Open Access Journals (Sweden)

Ee Wah Lim

2015-09-01

Full Text Available Resistive switching effect in transition metal oxide (TMO based material is often associated with the valence change mechanism (VCM. Typical modeling of valence change resistive switching memory consists of three closely related phenomena, i.e., conductive filament (CF geometry evolution, conduction mechanism and temperature dynamic evolution. It is widely agreed that the electrochemical reduction-oxidation (redox process and oxygen vacancies migration plays an essential role in the CF forming and rupture process. However, the conduction mechanism of resistive switching memory varies considerably depending on the material used in the dielectric layer and selection of electrodes. Among the popular observations are the Poole-Frenkel emission, Schottky emission, space-charge-limited conduction (SCLC, trap-assisted tunneling (TAT and hopping conduction. In this article, we will conduct a survey on several published valence change resistive switching memories with a particular interest in the I-V characteristic and the corresponding conduction mechanism.

The Faraday effect revisited: General theory

DEFF Research Database (Denmark)

Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

2006-01-01

This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. At zero temperature and zero frequency...

Systematic thermodynamic properties of actinide metal-oxygen systems at high temperatures: Emphasis on lower valence states

International Nuclear Information System (INIS)

Ackermann, R.J.; Chandrasekharaiah, M.S.

1975-01-01

The thermodynamic data for the actinide metals and oxides (thorium to curium ) have been assessed, examined for consistency, and compared with the lanthanides. Correlations relating the enthalpies of formation of the solid oxides with the corresponding aquo ions make possible the estimation of the thermodynamic properties of AmO 2 (s) and Am 2 O 3 (s) which are in accordance with vaporization data. The known thermodynamic properties of the substoichiometric dioxides MOsub(2-x)(s) at high temperatures demonstrate the relative stabilities of valence states less than 4+ and lead to the examination of stability requirements for the sesquioxides M 2 O 3 (s) and the monoxides MO(s). Sequential trends in the gaseous metals, monoxides and dioxides are examined, compared, and contrasted with the lanthanides. (author)

Crossover and valence band Kβ X-rays of chromium oxides

International Nuclear Information System (INIS)

Fazinic, Stjepko; Mandic, Luka; Kavcic, Matjaz; Bozicevic, Iva

2011-01-01

Kβ X-ray spectra of chromium metal and selected chromium oxides were measured twice using medium resolution flat crystal spectrometer and high resolution spectrometer employing Johansson geometry after excitation with 2 MeV proton beams. The positions and intensities of crossover (Kβ'') and valence (Kβ 2,5 ) band X-rays relative to the primary Kβ X-ray components were extracted in a consistent way. The results were compared with the existing data obtained by proton and photon induced ionization mechanisms and theoretical predictions. The obtained results in peak relative positions and intensities were analyzed in order to study dependence on the chromium oxidation states and chromium-oxygen bond lengths in selected chromium oxides. Our results obtained by both spectrometers confirm that the linear trend observed for the valence peak relative energy shift as a function of chromium oxidation number does not depend on the experimental resolution. Experimental results for normalized intensities (i.e. relative intensities divided with the number of chromium-oxygen pairs) of crossover and valence band X-rays obtained by both spectrometers are in very good agreement, and follow exponential relationship with the average Cr-O bond lengths in corresponding chromium oxides. The observed trends in crossover and valence X-rays normalized intensities could be used to measure the average chromium-oxygen bond length in various chromium oxides, with the sum of both crossover and valence X-ray normalized intensities being the most sensitive measure.

Yb valence state in Yb{sub 5}Rh{sub 4}Ge{sub 10}

Energy Technology Data Exchange (ETDEWEB)

Sato, Hitoshi; Arita, Masashi; Shimada, Kenya; Namatame, Hirofumi; Taniguchi, Masaki [Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima (Japan); Utsumi, Yuki [Synchrotron SOLEIL, L' Orme des Merisiers, Gif-sur-Yvette (France); Katoh, Kenichi [Department of Applied Physics, National Defense Academy, Yokosuka (Japan); Mimura, Kojiro [Graduate School of Engineering, Osaka Prefecture University, Sakai (Japan); Ueda, Shigenori [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Hyogo (Japan); Quantum Beam Unit, National Institute for Materials Science, Tsukuba (Japan); Yamaoka, Hitoshi [RIKEN SPring-8 Center, Hyogo (Japan); Rousuli, Awabaikeli [Graduate School of Science, Hiroshima University, Higashi-Hiroshima (Japan); Umeo, Kazunori [NBARD, Hiroshima University, Higashi-Hiroshima (Japan)

2017-06-15

Temperature- and pressure-dependent Yb valence state in Yb{sub 5}Rh{sub 4}Ge{sub 10} has been investigated by means of Yb 3d hard X-ray photoemission spectroscopy (HAXPES) and Yb L{sub 3} absorption spectroscopy (XAS). The mean Yb valence derived from the Yb 3d HAXPES is estimated to be ∝2.78 at 300 K and decreases to ∝2.74 at 20 K. On the other hand, the Yb valence deduced from the Yb L{sub 3} XAS at 300 K is almost constant with ∝2.81 in the pressure range between 9.2 and 34.7 GPa. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Optoelectronic properties of valence-state-controlled amorphous niobium oxide

Science.gov (United States)

Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

2016-06-01

In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

Bond charge approximation for valence electron density in elemental semiconductors

International Nuclear Information System (INIS)

Bashenov, V.K.; Gorbachov, V.E.; Marvakov, D.I.

1985-07-01

The spatial valence electron distribution in silicon and diamond is calculated in adiabatic bond charge approximation at zero temperature when bond charges have the Gaussian shape and their tensor character is taken into account. An agreement between theory and experiment has been achieved. For this purpose Xia's ionic pseudopotentials and Schulze-Unger's dielectric function are used. By two additional parameters Asub(B) and Zsub(B)sup(') we describe the spatial extent of the bond charge and local-field corrections, respectively. The parameter Zsub(B)sup(') accounts for the ratio between the Coulomb and exchange correlation interactions of the valence electrons and its silicon and diamond values have different signs. (author)

Chromium valences in ureilite olivine and implications for ureilite petrogenesis

Science.gov (United States)

Goodrich, C. A.; Sutton, S. R.; Wirick, S.; Jercinovic, M. J.

2013-12-01

basaltic melt composition), consistent with fO2 values obtained by assuming olivine-silica-iron metal (OSI) equilibrium. For the primary chromite-bearing-ureilites, the corresponding fO2 were estimated (again, assuming basaltic melt composition) to be ∼IW to IW+1.0, i.e., several orders of magnitude more oxidizing than the conditions estimated for the chromite-free ureilites. In terms of Fo and Cr valence properties, ureilites appear to form two groups rather than a single “Cr-valence (or fO2) vs. Fo” trend. The chromite-bearing ureilites show little variation in Fo (∼74-76) but significant variation in Cr valence, while the non-chromite-bearing ureilites show significant variation in Fo (∼77-95) and little variation in Cr valence. These groups are unrelated to petrologic type (i.e., olivine-pigeonite, olivine-orthopyroxene, or augite-bearing). The chromite-bearing ureilites also have lower contents of Cr in olivine than most non-chromite-bearing ureilites, consistent with predictions based on Cr olivine/melt partitioning in spinel saturated vs. non-spinel-saturated systems. Under the assumption that at magmatic temperatures graphite-gas equilibria controlled fO2 at all depths on the ureilite parent body, we conclude: (1) that ureilite precursor materials having the Fo and Cr valence properties now observed in ureilites are unlikely to have been preserved during planetary processing; and (2) that the Fo and Cr valence properties now observed in ureilites are consistent with having been established by high-temperature carbon redox control over a range of depths on a plausible-sized ureilite parent body. The apparent limit on ureilite Fo values around 74-76 suggests that the precursor material(s) had bulk mg# ⩾ that of LL chondrites.

First determination of the valence band dispersion of CH3NH3PbI3 hybrid organic-inorganic perovskite

Science.gov (United States)

Lee, Min-I.; Barragán, Ana; Nair, Maya N.; Jacques, Vincent L. R.; Le Bolloc'h, David; Fertey, Pierre; Jemli, Khaoula; Lédée, Ferdinand; Trippé-Allard, Gaëlle; Deleporte, Emmanuelle; Taleb-Ibrahimi, Amina; Tejeda, Antonio

2017-07-01

The family of hybrid organic-inorganic halide perovskites is in the limelight because of their recently discovered high photovoltaic efficiency. These materials combine photovoltaic energy conversion efficiencies exceeding 22% and low-temperature and low-cost processing in solution; a breakthrough in the panorama of renewable energy. Solar cell operation relies on the excitation of the valence band electrons to the conduction band by solar photons. One factor strongly impacting the absorption efficiency is the band dispersion. The band dispersion has been extensively studied theoretically, but no experimental information was available. Herein, we present the first experimental determination of the valence band dispersion of methylammonium lead halide in the tetragonal phase. Our results pave the way for contrasting the electronic hopping or the electron effective masses in different theories by comparing to our experimental bands. We also show a significant broadening of the electronic states, promoting relaxed conditions for photon absorption, and demonstrate that the tetragonal structure associated to the octahedra network distortion below 50 °C induces only a minor modification of the electronic bands, with respect to the cubic phase at high temperature, thus minimizing the impact of the cubic-tetragonal transition on solar cell efficiencies.

Low-temperature spin dynamics of a valence bond glass in Ba2YMoO6

Science.gov (United States)

de Vries, M. A.; Piatek, J. O.; Misek, M.; Lord, J. S.; Rønnow, H. M.; Bos, J.-W. G.

2013-04-01

We carried out ac magnetic susceptibility measurements and muon spin relaxation spectroscopy on the cubic double perovskite Ba2YMoO6, down to 50 mK. Below ∼1 K the muon relaxation is typical of a magnetic insulator with a spin-liquid type ground state, i.e. without broken symmetries or frozen moments. However, the ac susceptibility revealed a dilute-spin-glass-like transition below ∼1 K. Antiferromagnetically coupled Mo5+ 4d1 electrons in triply degenerate t2g orbitals are in this material arranged in a geometrically frustrated fcc lattice. Bulk magnetic susceptibility data has previously been interpreted in terms of a freezing to a heterogeneous state with non-magnetic sites where 4d1 electrons have paired in spin-singlets dimers, and residual unpaired Mo5+ 4d1 electron spins. Based on the magnetic heat capacity data it has been suggested that this heterogeneity is the result of kinetic constraints intrinsic to the physics of the pure system (possibly due to topological overprotection) leading to a self-induced glass of valence bonds between neighbouring 4d1 electrons. The muon spin relaxation (μSR) unambiguously points to a heterogeneous state with a static arrangement of unpaired electrons in a background of (valence bond) dimers between the majority of Mo5+ 4d electrons. The ac susceptibility data indicate that the residual magnetic moments freeze into a dilute-spin-glass-like state. This is in apparent contradiction with the muon-spin decoupling at 50 mK in fields up to 200 mT, which indicates that, remarkably, the time scale of the field fluctuations from the residual moments is ∼5 ns. Comparable behaviour has been observed in other geometrically frustrated magnets with spin-liquid-like behaviour and the implications of our observations on Ba2YMoO6 are discussed in this context.

Valence control of cobalt oxide thin films by annealing atmosphere

International Nuclear Information System (INIS)

Wang Shijing; Zhang Boping; Zhao Cuihua; Li Songjie; Zhang Meixia; Yan Liping

2011-01-01

The cobalt oxide (CoO and Co 3 O 4 ) thin films were successfully prepared using a spin-coating technique by a chemical solution method with CH 3 OCH 2 CH 2 OH and Co(NO 3 ) 2 .6H 2 O as starting materials. The grayish cobalt oxide films had uniform crystalline grains with less than 50 nm in diameter. The phase structure is able to tailor by controlling the annealing atmosphere and temperature, in which Co 3 O 4 thin film was obtained by annealing in air at 300-600, and N 2 at 300, and transferred to CoO thin film by raising annealing temperature in N 2 . The fitted X-ray photoelectron spectroscopy (XPS) spectra of the Co2p electrons are distinguishable from different valence states of cobalt oxide especially for their satellite structure. The valence control of cobalt oxide thin films by annealing atmosphere contributes to the tailored optical absorption property.

Electric Field Generation and Control of Bipartite Quantum Entanglement between Electronic Spins in Mixed Valence Polyoxovanadate [GeV14O40]8.

Science.gov (United States)

Palii, Andrew; Aldoshin, Sergey; Tsukerblat, Boris; Borràs-Almenar, Juan José; Clemente-Juan, Juan Modesto; Cardona-Serra, Salvador; Coronado, Eugenio

2017-08-21

As part of the search for systems in which control of quantum entanglement can be achieved, here we consider the paramagnetic mixed valence polyoxometalate K 2 Na 6 [GeV 14 O 40 ]·10H 2 O in which two electrons are delocalized over the 14 vanadium ions. Applying a homogeneous electric field can induce an antiferromagnetic coupling between the two delocalized electronic spins that behave independently in the absence of the field. On the basis of the proposed theoretical model, we show that the external field can be used to generate controllable quantum entanglement between the two electronic spins traveling over a vanadium network of mixed valence polyoxoanion [GeV 14 O 40 ] 8- . Within a simplified two-level picture of the energy pattern of the electronic pair based on the previous ab initio analysis, we evaluate the temperature and field dependencies of concurrence and thus indicate that the entanglement can be controlled via the temperature, magnitude, and orientation of the electric field with respect to molecular axes of [GeV 14 O 40 ] 8- .

Intermediate valence spectroscopy

International Nuclear Information System (INIS)

Gunnarsson, O.; Schoenhammer, K.

1987-01-01

Spectroscopic properties of intermediate valence compounds are studied using the Anderson model. Due to the large orbital and spin degeneracy N/sub f/ of the 4f-level, 1/N/sub f/ can be treated as a small parameter. This approach provides exact T = 0 results for the Anderson impurity model in the limit N/sub f/ → ∞, and by adding 1/N/sub f/ corrections some properties can be calculated accurately even for N/sub f/ = 1 or 2. In particular valence photoemission and resonance photoemission spectroscopies are studied. A comparison of theoretical and experimental spectra provides an estimate of the parameters in the model. Core level photoemission spectra provide estimates of the coupling between the f-level and the conduction states and of the f-level occupancy. With these parameters the model gives a fair description of other electron spectroscopies. For typical parameters the model predicts two structures in the f-spectrum, namely one structure at the f-level and one at the Fermi energy. The resonance photoemission calculation gives a photon energy dependence for these two peaks in fair agreement with experiment. The peak at the Fermi energy is partly due to a narrow Kondo resonance, resulting from many-body effects and the presence of a continuous, partly filled conduction band. This resonance is related to a large density of low-lying excitations, which explains the large susceptibility and specific heat observed for these systems at low temperatures. 38 references, 11 figures, 2 tables

Large shift and small broadening of Br2 valence band upon dimer formation with H2O: an ab initio study.

Science.gov (United States)

Franklin-Mergarejo, Ricardo; Rubayo-Soneira, Jesus; Halberstadt, Nadine; Ayed, Tahra; Bernal-Uruchurtu, Margarita I; Hernández-Lamoneda, Ramón; Janda, Kenneth C

2011-06-16

Valence electronic excitation spectra are calculated for the H(2)O···Br(2) complex using highly correlated ab initio potentials for both the ground and the valence electronic excited states and a 2-D approximation for vibrational motion. Due to the strong interaction between the O-Br and the Br-Br stretching motions, inclusion of these vibrations is the minimum necessary for the spectrum calculation. A basis set calculation is performed to determine the vibrational wave functions for the ground electronic state and a wave packet simulation is conducted for the nuclear dynamics on the excited state surfaces. The effects of both the spin-orbit interaction and temperature on the spectra are explored. The interaction of Br(2) with a single water molecule induces nearly as large a shift in the spectrum as is observed for an aqueous solution. In contrast, complex formation has a remarkably small effect on the T = 0 K width of the valence bands due to the fast dissociation of the dihalogen bond upon excitation. We therefore conclude that the widths of the spectra in aqueous solution are mostly due to inhomogeneous broadening. © 2011 American Chemical Society

Simultaneous conditioning of valence and arousal.

Science.gov (United States)

Gawronski, Bertram; Mitchell, Derek G V

2014-01-01

Evaluative conditioning (EC) refers to the change in the valence of a conditioned stimulus (CS) due to its pairing with a positive or negative unconditioned stimulus (US). To the extent that core affect can be characterised by the two dimensions of valence and arousal, EC has important implications for the origin of affective responses. However, the distinction between valence and arousal is rarely considered in research on EC or conditioned responses more generally. Measuring the subjective feelings elicited by a CS, the results from two experiments showed that (1) repeated pairings of a CS with a positive or negative US of either high or low arousal led to corresponding changes in both CS valence and CS arousal, (2) changes in CS arousal, but not changes in CS valence, were significantly related to recollective memory for CS-US pairings, (3) subsequent presentations of the CS without the US reduced the conditioned valence of the CS, with conditioned arousal being less susceptible to extinction and (4) EC effects were stronger for high arousal than low arousal USs. The results indicate that the conditioning of affective responses can occur simultaneously along two independent dimensions, supporting evidence in related areas that calls for a consideration of both valence and arousal. Implications for research on EC and the acquisition of emotional dispositions are discussed.

Ground state and elementary excitations of a model valence-fluctuation system

International Nuclear Information System (INIS)

Brandow, B.H.

1979-01-01

The nature of the valence fluctuation problem is described, and motivations are given for an Anderson-lattice model Hamiltonian. A simple trial wave function is posed for the ground state, and the variational problem is solved. This demonstrates clearly that there is no Kondo-like divergence; the present concentrated Kondo problem is thus more simple mathematically than the sngle-impurity problem. Elementary excitations are studies by the Green's function techniques of Zubarev and Hubbard. Quenching of local moments and a large specific heat are found at low temperatures. The quasi-particle spectrum exhibits a gap, but epsilon/sub F/ does not lie in this gap. The insulation-like feature of SmB 6 , SmS, and TmSe at very low temperatures is explained in terms of a strongly reduced mobility for states near the gap, and reasons are given why this feature is not observed in other valence-fluctuation compounds. 73 references

Valence control of cobalt oxide thin films by annealing atmosphere

Energy Technology Data Exchange (ETDEWEB)

Wang Shijing [School of Materials Science and Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Beijing 100083 (China); Zhang Boping, E-mail: bpzhang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Beijing 100083 (China); Zhao Cuihua; Li Songjie; Zhang Meixia; Yan Liping [School of Materials Science and Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Beijing 100083 (China)

2011-02-01

The cobalt oxide (CoO and Co{sub 3}O{sub 4}) thin films were successfully prepared using a spin-coating technique by a chemical solution method with CH{sub 3}OCH{sub 2}CH{sub 2}OH and Co(NO{sub 3}){sub 2}.6H{sub 2}O as starting materials. The grayish cobalt oxide films had uniform crystalline grains with less than 50 nm in diameter. The phase structure is able to tailor by controlling the annealing atmosphere and temperature, in which Co{sub 3}O{sub 4} thin film was obtained by annealing in air at 300-600, and N{sub 2} at 300, and transferred to CoO thin film by raising annealing temperature in N{sub 2}. The fitted X-ray photoelectron spectroscopy (XPS) spectra of the Co2p electrons are distinguishable from different valence states of cobalt oxide especially for their satellite structure. The valence control of cobalt oxide thin films by annealing atmosphere contributes to the tailored optical absorption property.

Valence effects on adsorption: a preliminary assessment of the effects on valence state control on sorption measurements

International Nuclear Information System (INIS)

Meyer, R.E.; Arnold, W.D.; Case, F.; Shiao, S.Y.; Palmer, D.A.

1983-01-01

Electrochemical arguments are advanced to illustrate that what is usually measured in practice is a mixed potential determined by the kinetics of the electrode processes occurring at the indicator electrode. Valence states can be altered electrochemically or by use of added chemical reagents, including redox couples which can hold the potential to relatively specific potentials. The disadvantage of added chemical reagents is that they may alter the characteristics of the sorption reactions by interaction with the sorbent. Electrochemical methods are versatile and do not add reagents, but in some caes the nuclide can adsorb on the electrode itself. A description is given of the application of the electrochemical method of valence control to determination of sorption of Np(V) on alumina. Valence state control and analysis can be used to study possible redox reactions on materials which might be used as backfill materials. A description is given of survey experiments with a number of sulfides and iron-containing materials. Valence state analysis is used on the initial solutions and leachate from acid leaches of the sorbent after the sorption experiment to help determine whether valence state change is occurring. The preliminary results indicate that on the sulfides tested, sorption occurs both with and without valence state change

Low-temperature spin dynamics of a valence bond glass in Ba2YMoO6

International Nuclear Information System (INIS)

De Vries, M A; Piatek, J O; Rønnow, H M; Misek, M; Lord, J S; Bos, J-W G

2013-01-01

We carried out ac magnetic susceptibility measurements and muon spin relaxation spectroscopy on the cubic double perovskite Ba 2 YMoO 6 , down to 50 mK. Below ∼1 K the muon relaxation is typical of a magnetic insulator with a spin-liquid type ground state, i.e. without broken symmetries or frozen moments. However, the ac susceptibility revealed a dilute-spin-glass-like transition below ∼1 K. Antiferromagnetically coupled Mo 5+ 4d 1 electrons in triply degenerate t 2g orbitals are in this material arranged in a geometrically frustrated fcc lattice. Bulk magnetic susceptibility data has previously been interpreted in terms of a freezing to a heterogeneous state with non-magnetic sites where 4d 1 electrons have paired in spin-singlets dimers, and residual unpaired Mo 5+ 4d 1 electron spins. Based on the magnetic heat capacity data it has been suggested that this heterogeneity is the result of kinetic constraints intrinsic to the physics of the pure system (possibly due to topological overprotection) leading to a self-induced glass of valence bonds between neighbouring 4d 1 electrons. The muon spin relaxation (μSR) unambiguously points to a heterogeneous state with a static arrangement of unpaired electrons in a background of (valence bond) dimers between the majority of Mo 5+ 4d electrons. The ac susceptibility data indicate that the residual magnetic moments freeze into a dilute-spin-glass-like state. This is in apparent contradiction with the muon-spin decoupling at 50 mK in fields up to 200 mT, which indicates that, remarkably, the time scale of the field fluctuations from the residual moments is ∼5 ns. Comparable behaviour has been observed in other geometrically frustrated magnets with spin-liquid-like behaviour and the implications of our observations on Ba 2 YMoO 6 are discussed in this context. (paper)

The effect of an extinction cue on ABA-renewal: Does valence matter?

NARCIS (Netherlands)

Dibbets, P.; Maes, J.H.R.

2011-01-01

The present human fear conditioning study examined whether the valence of an extinction cue has a differential effect on attenuating renewal that is induced by removal of the extinction context. Additionally, the study aimed to assess whether such attenuating effect is based on a modulatory or

Human Amygdala Represents the Complete Spectrum of Subjective Valence

Science.gov (United States)

Jin, Jingwen; Zelano, Christina; Gottfried, Jay A.

2015-01-01

Although the amygdala is a major locus for hedonic processing, how it encodes valence information is poorly understood. Given the hedonic potency of odor stimuli and the amygdala's anatomical proximity to the peripheral olfactory system, we combined high-resolution fMRI with pattern-based multivariate techniques to examine how valence information is encoded in the amygdala. Ten human subjects underwent fMRI scanning while smelling 9 odorants that systematically varied in perceived valence. Representational similarity analyses showed that amygdala codes the entire dimension of valence, ranging from pleasantness to unpleasantness. This unidimensional representation significantly correlated with self-reported valence ratings but not with intensity ratings. Furthermore, within-trial valence representations evolved over time, prioritizing earlier differentiation of unpleasant stimuli. Together, these findings underscore the idea that both spatial and temporal features uniquely encode pleasant and unpleasant odor valence in the amygdala. The availability of a unidimensional valence code in the amygdala, distributed in both space and time, would create greater flexibility in determining the pleasantness or unpleasantness of stimuli, providing a mechanism by which expectation, context, attention, and learning could influence affective boundaries for guiding behavior. SIGNIFICANCE STATEMENT Our findings elucidate the mechanisms of affective processing in the amygdala by demonstrating that this brain region represents the entire valence dimension from pleasant to unpleasant. An important implication of this unidimensional valence code is that pleasant and unpleasant valence cannot coexist in the amygdale because overlap of fMRI ensemble patterns for these two valence extremes obscures their unique content. This functional architecture, whereby subjective valence maps onto a pattern continuum between pleasant and unpleasant poles, offers a robust mechanism by which context

Revisiting the melting temperature of NpO2 and the challenges associated with high temperature actinide compound measurements

NARCIS (Netherlands)

Böhler, R.; Welland, M.J.; De Bruycker, F.; Boboridis, K.; Janssen, A.; Eloirdi, R.; Konings, R.J.M.; Manara, D.

2012-01-01

This work revisits the melting behaviour of neptunium dioxide, an actinide compound which can be produced in the nuclear fuel during operation, and which has an important impact on the nuclear fuel and waste radioactivity especially on the very long term. The present experimental approach employs

The Mechanism of Valence-Space Metaphors: ERP Evidence for Affective Word Processing

Science.gov (United States)

Xie, Jiushu; Wang, Ruiming; Chang, Song

2014-01-01

Embodied cognition contends that the representation and processing of concepts involve perceptual, somatosensory, motoric, and other physical re-experiencing information. In this view, affective concepts are also grounded in physical information. For instance, people often say “feeling down” or “cheer up” in daily life. These phrases use spatial information to understand affective concepts. This process is referred to as valence-space metaphor. Valence-space metaphors refer to the employment of spatial information (lower/higher space) to elaborate affective concepts (negative/positive concepts). Previous studies have demonstrated that processing affective words affects performance on a spatial detection task. However, the mechanism(s) behind this effect remain unclear. In the current study, we hypothesized that processing affective words might produce spatial information. Consequently, spatial information would affect the following spatial cue detection/discrimination task. In Experiment 1, participants were asked to remember an affective word. Then, they completed a spatial cue detection task while event-related potentials were recorded. The results indicated that the top cues induced enhanced amplitude of P200 component while participants kept positive words relative to negative words in mind. On the contrary, the bottom cues induced enhanced P200 amplitudes while participants kept negative words relative to positive words in mind. In Experiment 2, we conducted a behavioral experiment that employed a similar paradigm to Experiment 1, but used arrows instead of dots to test the attentional nature of the valence-space metaphor. We found a similar facilitation effect as found in Experiment 1. Positive words facilitated the discrimination of upper arrows, whereas negative words facilitated the discrimination of lower arrows. In summary, affective words might activate spatial information and cause participants to allocate their attention to corresponding

The mechanism of valence-space metaphors: ERP evidence for affective word processing.

Science.gov (United States)

Xie, Jiushu; Wang, Ruiming; Chang, Song

2014-01-01

Embodied cognition contends that the representation and processing of concepts involve perceptual, somatosensory, motoric, and other physical re-experiencing information. In this view, affective concepts are also grounded in physical information. For instance, people often say "feeling down" or "cheer up" in daily life. These phrases use spatial information to understand affective concepts. This process is referred to as valence-space metaphor. Valence-space metaphors refer to the employment of spatial information (lower/higher space) to elaborate affective concepts (negative/positive concepts). Previous studies have demonstrated that processing affective words affects performance on a spatial detection task. However, the mechanism(s) behind this effect remain unclear. In the current study, we hypothesized that processing affective words might produce spatial information. Consequently, spatial information would affect the following spatial cue detection/discrimination task. In Experiment 1, participants were asked to remember an affective word. Then, they completed a spatial cue detection task while event-related potentials were recorded. The results indicated that the top cues induced enhanced amplitude of P200 component while participants kept positive words relative to negative words in mind. On the contrary, the bottom cues induced enhanced P200 amplitudes while participants kept negative words relative to positive words in mind. In Experiment 2, we conducted a behavioral experiment that employed a similar paradigm to Experiment 1, but used arrows instead of dots to test the attentional nature of the valence-space metaphor. We found a similar facilitation effect as found in Experiment 1. Positive words facilitated the discrimination of upper arrows, whereas negative words facilitated the discrimination of lower arrows. In summary, affective words might activate spatial information and cause participants to allocate their attention to corresponding locations

Emotional valence and the free-energy principle.

Science.gov (United States)

Joffily, Mateus; Coricelli, Giorgio

2013-01-01

The free-energy principle has recently been proposed as a unified Bayesian account of perception, learning and action. Despite the inextricable link between emotion and cognition, emotion has not yet been formulated under this framework. A core concept that permeates many perspectives on emotion is valence, which broadly refers to the positive and negative character of emotion or some of its aspects. In the present paper, we propose a definition of emotional valence in terms of the negative rate of change of free-energy over time. If the second time-derivative of free-energy is taken into account, the dynamics of basic forms of emotion such as happiness, unhappiness, hope, fear, disappointment and relief can be explained. In this formulation, an important function of emotional valence turns out to regulate the learning rate of the causes of sensory inputs. When sensations increasingly violate the agent's expectations, valence is negative and increases the learning rate. Conversely, when sensations increasingly fulfil the agent's expectations, valence is positive and decreases the learning rate. This dynamic interaction between emotional valence and learning rate highlights the crucial role played by emotions in biological agents' adaptation to unexpected changes in their world.

Emotional valence and the free-energy principle.

Directory of Open Access Journals (Sweden)

Mateus Joffily

Full Text Available The free-energy principle has recently been proposed as a unified Bayesian account of perception, learning and action. Despite the inextricable link between emotion and cognition, emotion has not yet been formulated under this framework. A core concept that permeates many perspectives on emotion is valence, which broadly refers to the positive and negative character of emotion or some of its aspects. In the present paper, we propose a definition of emotional valence in terms of the negative rate of change of free-energy over time. If the second time-derivative of free-energy is taken into account, the dynamics of basic forms of emotion such as happiness, unhappiness, hope, fear, disappointment and relief can be explained. In this formulation, an important function of emotional valence turns out to regulate the learning rate of the causes of sensory inputs. When sensations increasingly violate the agent's expectations, valence is negative and increases the learning rate. Conversely, when sensations increasingly fulfil the agent's expectations, valence is positive and decreases the learning rate. This dynamic interaction between emotional valence and learning rate highlights the crucial role played by emotions in biological agents' adaptation to unexpected changes in their world.

Ab initio valence calculations in chemistry

CERN Document Server

Cook, D B

1974-01-01

Ab Initio Valence Calculations in Chemistry describes the theory and practice of ab initio valence calculations in chemistry and applies the ideas to a specific example, linear BeH2. Topics covered include the Schrödinger equation and the orbital approximation to atomic orbitals; molecular orbital and valence bond methods; practical molecular wave functions; and molecular integrals. Open shell systems, molecular symmetry, and localized descriptions of electronic structure are also discussed. This book is comprised of 13 chapters and begins by introducing the reader to the use of the Schrödinge

Valence of Facial Cues Influences Sheep Learning in a Visual Discrimination Task

Directory of Open Access Journals (Sweden)

Lucille G. A. Bellegarde

2017-11-01

Full Text Available Sheep are one of the most studied farm species in terms of their ability to process information from faces, but little is known about their face-based emotion recognition abilities. We investigated (a whether sheep could use images of sheep faces taken in situation of varying valence as cues in a simultaneous discrimination task and (b whether the valence of the situation affects their learning performance. To accomplish this, we photographed faces of sheep in three situations inducing emotional states of neutral (ruminating in the home pen or negative valence (social isolation or aggressive interaction. Sheep (n = 35 first had to learn a discrimination task with colored cards. Animals that reached the learning criterion (n = 16 were then presented with pairs of images of the face of a single individual taken in the neutral situation and in one of the negative situations. Finally, sheep had to generalize what they had learned to new pairs of images of faces taken in the same situation, but of a different conspecific. All sheep that learned the discrimination task with colored cards reached the learning criterion with images of faces. Sheep that had to associate a negative image with a food reward learned faster than sheep that had to associate a neutral image with a reward. With the exception of sheep from the aggression-rewarded group, sheep generalized this discrimination to images of faces of different individuals. Our results suggest that sheep can perceive the emotional valence displayed on faces of conspecifics and that this valence affects learning processes.

Valency and molecular structure

CERN Document Server

Cartmell, E

1977-01-01

Valency and Molecular Structure, Fourth Edition provides a comprehensive historical background and experimental foundations of theories and methods relating to valency and molecular structures. In this edition, the chapter on Bohr theory has been removed while some sections, such as structures of crystalline solids, have been expanded. Details of structures have also been revised and extended using the best available values for bond lengths and bond angles. Recent developments are mostly noted in the chapter on complex compounds, while a new chapter has been added to serve as an introduction t

The localized effect of the Bi level on the valence band in the dilute bismuth GaBixAs1-x alloy

Science.gov (United States)

Zhao, Chuan-Zhen; Zhu, Min-Min; Wang, Jun; Wang, Sha-Sha; Lu, Ke-Qing

2018-05-01

The research on the temperature dependence of the band gap energy of the dilute bismuth GaBixAs1-x alloy has been done. It is found that its temperature insensitiveness is due to the enhanced localized character of the valence band state and the small decrease of the temperature coefficient for the conduction band minimum (CBM). The enhanced localized character of the valence band state is the main factor. In order to describe the localized effect of the Bi levels on the valence band, the localized energy is introduced into the Varshni's equation. It is found that the effect of the localized Bi level on the valence band becomes strong with increasing Bi content. In addition, it is found that the pressure dependence of the band gap energy of GaBixAs1-x does not seem to be influenced by the localized Bi levels. It is due to two factors. One is that the pressure dependence of the band gap energy is mainly determined by the D CBM of GaBixAs1-x. The D CBM of GaBixAs1-x is not influenced by the localized Bi levels. The other is that the small variation of the pressure coefficient for the D valence band maximum (VBM) state of GaBixAs1-x can be cancelled by the variation of the pressure coefficient for the D CBM state of GaBixAs1-x.

[Emotional valence of words in schizophrenia].

Science.gov (United States)

Jalenques, I; Enjolras, J; Izaute, M

2013-06-01

Emotion recognition is a domain in which deficits have been reported in schizophrenia. A number of emotion classification studies have indicated that emotion processing deficits in schizophrenia are more pronounced for negative affects. Given the difficulty of developing material suitable for the study of these emotional deficits, it would be interesting to examine whether patients suffering from schizophrenia are responsive to positively and negatively charged emotion-related words that could be used within the context of remediation strategies. The emotional perception of words was examined in a clinical experiment involving schizophrenia patients. This emotional perception was expressed by the patients in terms of the valence associated with the words. In the present study, we investigated whether schizophrenia patients would assign the same negative and positive valences to words as healthy individuals. Twenty volunteer, clinically stable, outpatients from the Psychiatric Service of the University Hospital of Clermont-Ferrand were recruited. Diagnoses were based on DSM-IV criteria. Global psychiatric symptoms were assessed using the Positive and Negative Symptoms Scale (PANSS). The patients had to evaluate the emotional valence of a set of 300 words on a 5-point scale ranging from "very unpleasant" to "very pleasant". . The collected results were compared with those obtained by Bonin et al. (2003) [13] from 97 University students. Correlational analyses of the two studies revealed that the emotional valences were highly correlated, i.e. the schizophrenia patients estimated very similar emotional valences. More precisely, it was possible to examine three separate sets of 100 words each (positive words, neutral words and negative words). The positive words that were evaluated were the more positive words from the norms collected by Bonin et al. (2003) [13], and the negative words were the more negative examples taken from these norms. The neutral words

Temperature-induced band shift in bulk γ-InSe by angle-resolved photoemission spectroscopy

Science.gov (United States)

Xu, Huanfeng; Wang, Wei; Zhao, Yafei; Zhang, Xiaoqian; Feng, Yue; Tu, Jian; Gu, Chenyi; Sun, Yizhe; Liu, Chang; Nie, Yuefeng; Edmond Turcu, Ion C.; Xu, Yongbing; He, Liang

2018-05-01

Indium selenide (InSe) has recently become popular research topics because of its unique layered crystal structure, direct band gap and high electron mobilities. In this work, we have acquired the electronic structure of bulk γ-InSe at various temperatures using angle-resolved photoemission spectroscopy (ARPES). We have also found that as the temperature decreases, the valence bands of γ-InSe exhibit a monotonic shift to lower binding energies. This band shift is attributed to the change of lattice parameters and has been validated by variable temperature X-ray diffraction measurements and theoretical calculations.

CVD-Based Valence-Mending Passivation for Crystalline-Si Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Tao, Meng [Arizona State Univ., Mesa, AZ (United States)

2015-03-01

The objective of this project is to investigate a new surface passivation technique, valence-mending passivation, for its applications in crystalline-Si solar cells to achieve significant efficiency improvement and cost reduction. As the enabling technique, the project includes the development of chemical vapor deposition recipes to passivate textured Si(100) and multicrystalline-Si surfaces by sulfur and the characterization of the passivated Si surfaces, including thermal stability, Schottky barrier height, contact resistance and surface recombination. One important application is to replace the Ag finger electrode in Si cells with Al to reduce cost, by ~$0.1/Wp, and allow terawatt-scale deployment of crystalline-Si solar cells. These all-Al Si cells require a low-temperature metallization process for the Al electrode, to be compatible with valence-mending passivation and to prevent Al diffusion into n-type Si. Another application is to explore valence-mending passivation of grain boundaries in multicrystalline Si by diffusing sulfur into grain boundaries, to reduce the efficiency gas between monocrystalline-Si solar cells and multicrystalline-Si cells. The major accomplishments of this project include: 1) Demonstration of chemical vapor deposition processes for valence-mending passivation of both monocrystalline Si(100) and multicrystalline Si surfaces. Record Schottky barriers have been demonstrated, with the new record-low barrier of less than 0.08 eV between Al and sulfur-passivated n-type Si(100) and the new record-high barrier of 1.14 eV between Al and sulfur-passivated p-type Si(100). On the textured p-type monocrystalline Si(100) surface, the highest barrier with Al is 0.85 eV by valence-mending passivation. 2) Demonstration of a low-temperature metallization process for Al in crystalline-Si solar cells. The new metallization process is based on electroplating of Al in a room-temperature ionic liquid. The resistivity of the electroplated Al is ~7×10–6

The Effect of an Extinction Cue on ABA-Renewal: Does Valence Matter?

Science.gov (United States)

Dibbets, Pauline; Maes, Joseph H. R.

2011-01-01

The present human fear conditioning study examined whether the valence of an extinction cue has a differential effect on attenuating renewal that is induced by removal of the extinction context. Additionally, the study aimed to assess whether such attenuating effect is based on a modulatory or safety-signal role of the cue. In acquisition,…

Auger electron emission initiated by the creation of valence-band holes in graphene by positron annihilation.

Science.gov (United States)

Chirayath, V A; Callewaert, V; Fairchild, A J; Chrysler, M D; Gladen, R W; Mcdonald, A D; Imam, S K; Shastry, K; Koymen, A R; Saniz, R; Barbiellini, B; Rajeshwar, K; Partoens, B; Weiss, A H

2017-07-13

Auger processes involving the filling of holes in the valence band are thought to make important contributions to the low-energy photoelectron and secondary electron spectrum from many solids. However, measurements of the energy spectrum and the efficiency with which electrons are emitted in this process remain elusive due to a large unrelated background resulting from primary beam-induced secondary electrons. Here, we report the direct measurement of the energy spectra of electrons emitted from single layer graphene as a result of the decay of deep holes in the valence band. These measurements were made possible by eliminating competing backgrounds by employing low-energy positrons (holes by annihilation. Our experimental results, supported by theoretical calculations, indicate that between 80 and 100% of the deep valence-band holes in graphene are filled via an Auger transition.

Negative pressure driven valence instability of Eu in cubic Eu0.4La0.6Pd3

International Nuclear Information System (INIS)

Pandey, Abhishek; Mazumdar, Chandan; Ranganathan, R

2009-01-01

We report the change in the valency of Eu-ions in the binary intermetallic cubic compound EuPd 3 induced by La doping at rare-earth sites. Doping of La generates negative chemical pressure in the lattice, resulting in a significant increase of the lattice parameter without altering the simple-cubic structure of the compound. Results of dc-magnetic measurements suggest that this increase in the lattice parameter is associated with the valence transition of Eu-ions from Eu 3+ to a mixed-valent state. As Eu 2+ -ions possess a large magnetic moment, this valence transition significantly modifies the magnetic behavior of the compound. In contrast to introducing boron at the vacant body center site of the unit cell to change the valency of Eu-ions, as in the case of EuPd 3 B, our results suggest it can also be altered by doping a rare-earth ion of larger size at the lattice site of Eu in EuPd 3 .

Analysis of the valence electronic structures and calculation of the physical properties of Fe,Co,and Ni

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

The valence electronic structures of Fe, Co and Ni have been investigated with Empirical Electron Theory of Solids and Molecules. The magnetic moments, Curie temperature, cohesive energy and melting point have been calculated according to the valence electronic structure. These calculations fit the experimental data very well. Based on the calculations, the magnetic moments are proportional to the number of 3d magnetic electrons. Curie temperatures are related to the magnetic electrons and the bond lengths between magnetic atoms. Cohesive energies increase with the increase of the number of covalent electrons, and the decrease of the number of magnetic and dumb pair electrons. The melting point is mainly related to the number of covalent electron pairs distributed in the strongest bond. The contribution from the lattice electrons is very small, the dumb pair electrons weaken the melting point; however, the contribution to melting point of the magnetic electrons can be neglected. It reveals that the magnetic and thermal properties are closely related to the valence electronic structures, and the changes or transitions between the electrons obviously affect the physical properties.

Positive valence music restores executive control over sustained attention.

Science.gov (United States)

Baldwin, Carryl L; Lewis, Bridget A

2017-01-01

Music sometimes improves performance in sustained attention tasks. But the type of music employed in previous investigations has varied considerably, which can account for equivocal results. Progress has been hampered by lack of a systematic database of music varying in key characteristics like tempo and valence. The aims of this study were to establish a database of popular music varying along the dimensions of tempo and valence and to examine the impact of music varying along these dimensions on restoring attentional resources following performance of a sustained attention to response task (SART) vigil. Sixty-nine participants rated popular musical selections that varied in valence and tempo to establish a database of four musical types: fast tempo positive valence, fast tempo negative valence, slow tempo positive valence, and slow tempo negative valence. A second group of 89 participants performed two blocks of the SART task interspersed with either no break or a rest break consisting of 1 of the 4 types of music or silence. Presenting positive valence music (particularly of slow tempo) during an intermission between two successive blocks of the SART significantly decreased miss rates relative to negative valence music or silence. Results support an attentional restoration theory of the impact of music on sustained attention, rather than arousal theory and demonstrate a means of restoring sustained attention. Further, the results establish the validity of a music database that will facilitate further investigations of the impact of music on performance.

Self-induced temperature gradients in Brownian dynamics

Science.gov (United States)

Devine, Jack; Jack, M. W.

2017-12-01

Brownian systems often surmount energy barriers by absorbing and emitting heat to and from their local environment. Usually, the temperature gradients created by this heat exchange are assumed to dissipate instantaneously. Here we relax this assumption to consider the case where Brownian dynamics on a time-independent potential can lead to self-induced temperature gradients. In the same way that externally imposed temperature gradients can cause directed motion, these self-induced gradients affect the dynamics of the Brownian system. The result is a coupling between the local environment and the Brownian subsystem. We explore the resulting dynamics and thermodynamics of these coupled systems and develop a robust method for numerical simulation. In particular, by focusing on one-dimensional situations, we show that self-induced temperature gradients reduce barrier-crossing rates. We also consider a heat engine and a heat pump based on temperature gradients induced by a Brownian system in a nonequilibrium potential.

Valence band electronic structure of Pd based ternary chalcogenide superconductors

Energy Technology Data Exchange (ETDEWEB)

Lohani, H. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400085 (India); Mishra, P. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Goyal, R.; Awana, V.P.S. [National Physical Laboratory(CSIR), Dr. K. S. Krishnan Road, New Delhi 110012 (India); Sekhar, B.R., E-mail: sekhar@iopb.res.in [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400085 (India)

2016-12-15

Highlights: • VB Photoemission study and DFT calculations on Pd based ternary superconductors are presented. • Nb{sub 2}Pd{sub 0.95}S{sub 5} shows a temperature dependent pseudogap. • VB spectral features of ternary superconductors are correlated to their structural geometry. - Abstract: We present a comparative study of the valence band electronic structure of Pd based ternary chalcogenide superconductors Nb{sub 2}Pd{sub 0.95}S{sub 5}, Ta{sub 2}Pd{sub 0.97}S{sub 6} and Ta{sub 2}Pd{sub 0.97}Te{sub 6} using experimental photoemission spectroscopy and density functional based theoretical calculations. We observe a qualitatively similarity between valence band (VB) spectra of Nb{sub 2}Pd{sub 0.95}S{sub 5} and Ta{sub 2}Pd{sub 0.97}S{sub 6}. Further, we find a pseudogap feature in Nb{sub 2}Pd{sub 0.95}S{sub 5} at low temperature, unlike other two compounds. We have correlated the structural geometry with the differences in VB spectra of these compounds. The different atomic packing in these compounds could vary the strength of inter-orbital hybridization among various atoms which leads to difference in their electronic structure as clearly observed in our DOS calculations.

Architectural Representation of Valence in the Limbic System

Science.gov (United States)

Namburi, Praneeth; Al-Hasani, Ream; Calhoon, Gwendolyn G; Bruchas, Michael R; Tye, Kay M

2016-01-01

In order to thrive, animals must be able to recognize aversive and appetitive stimuli within the environment and subsequently initiate appropriate behavioral responses. This assignment of positive or negative valence to a stimulus is a key feature of emotional processing, the neural substrates of which have been a topic of study for several decades. Until recently, the result of this work has been the identification of specific brain regions, such as the basolateral amygdala (BLA) and nucleus accumbens (NAc), as important to valence encoding. The advent of modern tools in neuroscience has allowed further dissection of these regions to identify specific populations of neurons signaling the valence of environmental stimuli. In this review, we focus upon recent work examining the mechanisms of valence encoding, and provide a model for the systematic investigation of valence within anatomically-, genetically-, and functionally defined populations of neurons. PMID:26647973

On triangle meshes with valence dominant vertices

KAUST Repository

Morvan, Jean-Marie

2018-02-16

We study triangulations $\\\\cal T$ defined on a closed disc $X$ satisfying the following condition: In the interior of $X$, the valence of all vertices of $\\\\cal T$ except one of them (the irregular vertex) is $6$. By using a flat singular Riemannian metric adapted to $\\\\cal T$, we prove a uniqueness theorem when the valence of the irregular vertex is not a multiple of $6$. Moreover, for a given integer $k >1$, we exhibit non isomorphic triangulations on $X$ with the same boundary, and with a unique irregular vertex whose valence is $6k$.

On triangle meshes with valence dominant vertices

KAUST Repository

Morvan, Jean-Marie

2018-01-01

We study triangulations $\\cal T$ defined on a closed disc $X$ satisfying the following condition: In the interior of $X$, the valence of all vertices of $\\cal T$ except one of them (the irregular vertex) is $6$. By using a flat singular Riemannian metric adapted to $\\cal T$, we prove a uniqueness theorem when the valence of the irregular vertex is not a multiple of $6$. Moreover, for a given integer $k >1$, we exhibit non isomorphic triangulations on $X$ with the same boundary, and with a unique irregular vertex whose valence is $6k$.

Neutron scattering studies of mixed-valence semiconductors

Energy Technology Data Exchange (ETDEWEB)

Mignot, J M [Laboratoire Leon Brillouin (LLB) - Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France); Alekseev, P A [Kurchatov Institute, Moscow (Russian Federation)

1994-12-31

Neutron scattering experiments on the mixed-valence (MV) compounds SmB{sub 6} are reported. The inelastic magnetic response of SmB{sub 6} at T = 2 K, measured on a double-isotope single crystal,displays a strongly damped peak at 35 meV corresponding to the inter multiplet transition of Sm{sup 2+}. At lower energies ( h.{omega} {approx_equal} 14 meV), a narrow magnetic excitation is observed, with remarkable scattering-vector and temperature dependences of its intensity. This novel feature is discussed in terms of recent theoretical works describing the formation of an anisotropic local bound state in semiconducting MV materials. If the average samarium valence is decreased by substituting La for Sm, a peak is found to appear at high energies. The elastic magnetic form factor of SmB{sub 6} was determined using polarised neutrons and no significant difference is observed in its Q-dependence with respect to that of pure divalent samarium. This surprising behaviour is constant with previous measurements on the gold (high-pressure) phase of SmS. The above results are compared to those already reported for other MV materials. In particular existing information for TmSe is supplemented by recent inelastic scattering measurements carried out on a large stoichiometric single crystal. (author). 44 refs., 7 figs.

The effects of colour and valence on news evaluation.

Science.gov (United States)

Kaspar, Kai; Grümmer, Melanie; Kießler, Antje; Neuß, Celina; Schröter, Franziska

2017-12-01

Research across different fields of psychology has reported effects of colour cues on a variety of cognitive processes. Especially, the colour red has been shown to have striking influences. In the context of media reception, however, colour effects have been widely neglected so far. This study made a first step in this direction by investigating the effects of the colour red (compared with blue and grey) on the way news articles are evaluated. Two types of news were framed by a coloured border while the valence of the news content additionally varied. Based on 369 participants who read and evaluated the news articles online, we observed effects for colour cues and news valence in the absence of an interaction effect, indicating that the colour red induced approach motivation. However, only the contrast between red and grey reached statistical significance, indicating that chromatic and achromatic colours may differ in their perceived visual saliency. Overall, these results provide an important complement to previous studies and have practical implications for media researchers and producers. © 2015 International Union of Psychological Science.

Social learning modulates the lateralization of emotional valence.

Science.gov (United States)

Shamay-Tsoory, Simone G; Lavidor, Michal; Aharon-Peretz, Judith

2008-08-01

Although neuropsychological studies of lateralization of emotion have emphasized valence (positive vs. negative) or type (basic vs. complex) dimensions, the interaction between the two dimensions has yet to be elucidated. The purpose of the current study was to test the hypothesis that recognition of basic emotions is processed preferentially by the right prefrontal cortex (PFC), whereas recognition of complex social emotions is processed preferentially by the left PFC. Experiment 1 assessed the ability of healthy controls and patients with right and left PFC lesions to recognize basic and complex emotions. Experiment 2 modeled the patient's data of Experiment 1 on healthy participants under lateralized displays of the emotional stimuli. Both experiments support the Type as well as the Valence Hypotheses. However, our findings indicate that the Valence Hypothesis holds for basic but less so for complex emotions. It is suggested that, since social learning overrules the basic preference of valence in the hemispheres, the processing of complex emotions in the hemispheres is less affected by valence.

A remote valency control technique for actinides by external ultrasound irradiation

International Nuclear Information System (INIS)

Toraishi, Takashi; Kimura, Takaumi; Arisaka, Makoto

2006-01-01

We here report the reduction of Np(V) to Np(IV) induced by external ultrasound irradiation to demonstrate the ability of ultrasound for the valency control of actinide elements. High power ultrasound irradiation to water produces cavitation bubbles. The violent collapse of the bubbles generates 'hot spot' with an instantaneous temperature of thousands degrees and a pressure of thousands atmosphere, and produces H radical and OH radical as a result. Therefore, with scavenging H radical or OH radical, ultrasound irradiation provides either oxidizability or reducibility. 2 ml Np(V) solution in 1 M HCl was irradiated by 600 kHz external ultrasound. 10 vol% of 2-propanol and a Pt black catalyst were added to the test solution. The test solution was kept at 293 K, and bubbled by Ar gas saturated by 2-propanol during irradiation. The reduction was confirmed from the growth of characteristic light absorption of Np(IV) at 725 nm and 960 nm, together with the disappearance of the absorption of Np(V) at 980 nm. Finally, the reduction of Np(V) was completed after 180 min irradiation. (author)

Pressure induced valence transitions in the Anderson lattice model

International Nuclear Information System (INIS)

Bernhard, B.H.; Coqblin, B.

2009-01-01

We apply the equation of motion method to the Anderson lattice model, which describes the physical properties of heavy fermion compounds. In particular, we focus here on the variation of the number of f electrons with pressure, associated to the crossover from the Kondo regime to the intermediate valence regime. We treat here the non-magnetic case and introduce an improved approximation, which consists of an alloy analogy based decoupling for the Anderson lattice model. It is implemented by partial incorporation of the spatial correlations contained in higher-order Green's functions involved in the problem that have been formerly neglected. As it has been verified in the framework of the Hubbard model, the alloy analogy avoids the breakdown of sum rules and is more appropriate to explore the asymmetric case of the periodic Anderson Hamiltonian. The densities of states for a simple cubic lattice are calculated for various values of the model parameters V, t, E f , and U.

Valence nucleons in self-consistent fields

International Nuclear Information System (INIS)

Di Toro, M.; Lomnitz-Adler, J.

1978-01-01

An iterative approach to determine directly the best Hartree-Fock one-body density rho is extended by expressing rho in terms of a core and a valence part and allowing for general crossings of occupied and unoccupied levels in the valence part. Results are shown for 152 Sm and a microscopic analysis of the core structure of deformed light nuclei is carried out. (author)

Chemical and valence reconstruction at the surface of SmB6 revealed by means of resonant soft x-ray reflectometry

Science.gov (United States)

Zabolotnyy, V. B.; Fürsich, K.; Green, R. J.; Lutz, P.; Treiber, K.; Min, Chul-Hee; Dukhnenko, A. V.; Shitsevalova, N. Y.; Filipov, V. B.; Kang, B. Y.; Cho, B. K.; Sutarto, R.; He, Feizhou; Reinert, F.; Inosov, D. S.; Hinkov, V.

2018-05-01

Samarium hexaboride (SmB6), a Kondo insulator with mixed valence, has recently attracted much attention as a possible host for correlated topological surface states. Here, we use a combination of x-ray absorption and reflectometry techniques, backed up with a theoretical model for the resonant M4 ,5 absorption edge of Sm and photoemission data, to establish laterally averaged chemical and valence depth profiles at the surface of SmB6. We show that upon cleaving, the highly polar (001) surface of SmB6 undergoes substantial chemical and valence reconstruction, resulting in boron termination and a Sm3 + dominated subsurface region. Whereas at room temperature, the reconstruction occurs on a timescale of less than 2 h, it takes about 24 h below 50 K. The boron termination is eventually established, irrespective of the initial termination. Our findings reconcile earlier depth resolved photoemission and scanning tunneling spectroscopy studies performed at different temperatures and are important for better control of surface states in this system.

Theory for the mixed-valence state

International Nuclear Information System (INIS)

Varma, C.M.

1979-01-01

A theory is presented which explains why mixed-valence compounds behave as two component Fermi liquids, and why TmSe orders magnetically while the other known mixed-valence compounds do not. The variation of Tsub(N) and the field Hsub(T) to obtain ferromagnetic alignment with changing Tm 2+ /Tm 3+ ratio is quantitatively explained. For Tm 2+ concentration > = 0.3, TmSe is predicted to order ferromagnetically

Probing Transient Valence Orbital Changes with Picosecond Valence-to-Core X-ray Emission Spectroscopy

DEFF Research Database (Denmark)

March, Anne Marie; Assefa, Tadesse A.; Boemer, Christina

2017-01-01

We probe the dynamics of valence electrons in photoexcited [Fe(terpy)2]2+ in solution to gain deeper insight into the Fe ligand bond changes. We use hard X-ray emission spectroscopy (XES), which combines element specificity and high penetration with sensitivity to orbital structure, making...... valence orbitals to the nascent core-hole. Vtc-XES offers particular insight into the molecular orbitals directly involved in the light-driven dynamics; a change in the metal ligand orbital overlap results in an intensity reduction and a blue energy shift in agreement with our theoretical calculations...... and more subtle features at the highest energies reflect changes in the frontier orbital populations....

Importance-truncated shell model for multi-shell valence spaces

Energy Technology Data Exchange (ETDEWEB)

Stumpf, Christina; Vobig, Klaus; Roth, Robert [Institut fuer Kernphysik, TU Darmstadt (Germany)

2016-07-01

The valence-space shell model is one of the work horses in nuclear structure theory. In traditional applications, shell-model calculations are carried out using effective interactions constructed in a phenomenological framework for rather small valence spaces, typically spanned by one major shell. We improve on this traditional approach addressing two main aspects. First, we use new effective interactions derived in an ab initio approach and, thus, establish a connection to the underlying nuclear interaction providing access to single- and multi-shell valence spaces. Second, we extend the shell model to larger valence spaces by applying an importance-truncation scheme based on a perturbative importance measure. In this way, we reduce the model space to the relevant basis states for the description of a few target eigenstates and solve the eigenvalue problem in this physics-driven truncated model space. In particular multi-shell valence spaces are not tractable otherwise. We combine the importance-truncated shell model with refined extrapolation schemes to approximately recover the exact result. We present first results obtained in the importance-truncated shell model with the newly derived ab initio effective interactions for multi-shell valence spaces, e.g., the sdpf shell.

Liking products by the head of a dog: Perceived orientation of attention induces valence acquisition

NARCIS (Netherlands)

Corneille, O.; Mauduit, S.; Holland, R.W.; Strick, M.A.

2009-01-01

We show that the valence acquired by an object is sensitive to the perceived attention it receives and that this effect occurs in a quite implicit fashion. Participants were exposed to products (i.e., peppermint brands) associated with the head of dogs oriented toward them, looking straight ahead,

Emotion and language: Valence and arousal affect word recognition

Science.gov (United States)

Brysbaert, Marc; Warriner, Amy Beth

2014-01-01

Emotion influences most aspects of cognition and behavior, but emotional factors are conspicuously absent from current models of word recognition. The influence of emotion on word recognition has mostly been reported in prior studies on the automatic vigilance for negative stimuli, but the precise nature of this relationship is unclear. Various models of automatic vigilance have claimed that the effect of valence on response times is categorical, an inverted-U, or interactive with arousal. The present study used a sample of 12,658 words, and included many lexical and semantic control factors, to determine the precise nature of the effects of arousal and valence on word recognition. Converging empirical patterns observed in word-level and trial-level data from lexical decision and naming indicate that valence and arousal exert independent monotonic effects: Negative words are recognized more slowly than positive words, and arousing words are recognized more slowly than calming words. Valence explained about 2% of the variance in word recognition latencies, whereas the effect of arousal was smaller. Valence and arousal do not interact, but both interact with word frequency, such that valence and arousal exert larger effects among low-frequency words than among high-frequency words. These results necessitate a new model of affective word processing whereby the degree of negativity monotonically and independently predicts the speed of responding. This research also demonstrates that incorporating emotional factors, especially valence, improves the performance of models of word recognition. PMID:24490848

Valenced cues and contexts have different effects on event-based prospective memory.

Science.gov (United States)

Graf, Peter; Yu, Martin

2015-01-01

This study examined the separate influence and joint influences on event-based prospective memory task performance due to the valence of cues and the valence of contexts. We manipulated the valence of cues and contexts with pictures from the International Affective Picture System. The participants, undergraduate students, showed higher performance when neutral compared to valenced pictures were used for cueing prospective memory. In addition, neutral pictures were more effective as cues when they occurred in a valenced context than in the context of neutral pictures, but the effectiveness of valenced cues did not vary across contexts that differed in valence. The finding of an interaction between cue and context valence indicates that their respective influence on event-based prospective memory task performance cannot be understood in isolation from each other. Our findings are not consistent with by the prevailing view which holds that the scope of attention is broadened and narrowed, respectively, by positively and negatively valenced stimuli. Instead, our findings are more supportive of the recent proposal that the scope of attention is determined by the motivational intensity associated with valenced stimuli. Consistent with this proposal, we speculate that the motivational intensity associated with different retrieval cues determines the scope of attention, that contexts with different valence values determine participants' task engagement, and that prospective memory task performance is determined jointly by attention scope and task engagement.

Valenced cues and contexts have different effects on event-based prospective memory.

Directory of Open Access Journals (Sweden)

Peter Graf

Full Text Available This study examined the separate influence and joint influences on event-based prospective memory task performance due to the valence of cues and the valence of contexts. We manipulated the valence of cues and contexts with pictures from the International Affective Picture System. The participants, undergraduate students, showed higher performance when neutral compared to valenced pictures were used for cueing prospective memory. In addition, neutral pictures were more effective as cues when they occurred in a valenced context than in the context of neutral pictures, but the effectiveness of valenced cues did not vary across contexts that differed in valence. The finding of an interaction between cue and context valence indicates that their respective influence on event-based prospective memory task performance cannot be understood in isolation from each other. Our findings are not consistent with by the prevailing view which holds that the scope of attention is broadened and narrowed, respectively, by positively and negatively valenced stimuli. Instead, our findings are more supportive of the recent proposal that the scope of attention is determined by the motivational intensity associated with valenced stimuli. Consistent with this proposal, we speculate that the motivational intensity associated with different retrieval cues determines the scope of attention, that contexts with different valence values determine participants' task engagement, and that prospective memory task performance is determined jointly by attention scope and task engagement.

Decoding emotional valence from electroencephalographic rhythmic activity.

Science.gov (United States)

Celikkanat, Hande; Moriya, Hiroki; Ogawa, Takeshi; Kauppi, Jukka-Pekka; Kawanabe, Motoaki; Hyvarinen, Aapo

2017-07-01

We attempt to decode emotional valence from electroencephalographic rhythmic activity in a naturalistic setting. We employ a data-driven method developed in a previous study, Spectral Linear Discriminant Analysis, to discover the relationships between the classification task and independent neuronal sources, optimally utilizing multiple frequency bands. A detailed investigation of the classifier provides insight into the neuronal sources related with emotional valence, and the individual differences of the subjects in processing emotions. Our findings show: (1) sources whose locations are similar across subjects are consistently involved in emotional responses, with the involvement of parietal sources being especially significant, and (2) even though the locations of the involved neuronal sources are consistent, subjects can display highly varying degrees of valence-related EEG activity in the sources.

Virtual Distance and Soundstage, and their Impacts on Experienced Emotional Valence

DEFF Research Database (Denmark)

Christensen, Justin

2015-01-01

stimuli should cause stronger valenced responses in the nearfield than at a distance. Thus, music experienced as being negatively valenced at a distance should be more negatively valenced in nearfield, and music that is experienced as having a positive valence at a distance should be more positively......Research from animal ethology and affective neuroscience suggest that a listener’s perceived distance from a signal source can alter their experienced emotional valence of the music. Furthermore, appraisal theories of emotion suggest that emotionally valenced responses will diverge according...... to the type of emotion presented. For these exploratory investigations, subjects listen to selected musical excerpts on speakers in combination with a tactile transducer attached to their chair. The listening sessions are recorded on EEG supported by subject feedback responses. My hypothesis is that musical...

Space-Valence Priming with Subliminal and Supraliminal Words

Directory of Open Access Journals (Sweden)

Ulrich eAnsorge

2013-02-01

Full Text Available To date it is unclear whether (1 awareness-independent non-evaluative semantic processes influence affective semantics and whether (2 awareness-independent affective semantics influence non-evaluative semantic processing. In the current study, we investigated these questions with the help of subliminal (masked primes and visible targets in a space-valence across-category congruence effect. In line with (1, we found that subliminal space prime words influenced valence classification of supraliminal target words (Experiment 1: Classifications were faster with a congruent prime (e.g., the prime ‘up’ before the target ‘happy’ than with an incongruent prime (e.g., the prime ‘up’ before the target ‘sad’. In contrast to (2, no influence of subliminal valence primes on the classification of supraliminal space targets into up- and down-words was found (Experiment 2. Control conditions showed that standard masked response-priming effects were found with both subliminal prime types, and that an across-category congruence effect was also found with supraliminal valence primes and spatial target words. The final Experiment 3 confirmed that the across-category congruence effect indeed reflected priming of target categorization of a relevant meaning category. Together, the data jointly confirmed prediction (1 that awareness-independent non-evaluative semantic priming influences valence judgments.

Valence, arousal and cognitive control: A voluntary task switching study

Directory of Open Access Journals (Sweden)

Jelle eDemanet

2011-11-01

Full Text Available The present study focused on the interplay between arousal, valence and cognitive control. To this end, we investigated how arousal and valence associated with affective stimuli influenced cognitive flexibility when switching between tasks voluntarily. Three hypotheses were tested. First, a valence hypothesis that states that the positive valence of affective stimuli will facilitate both global and task-switching performance because of increased cognitive flexibility. Second, an arousal hypothesis that states that arousal, and not valence, will specifically impair task-switching performance by strengthening the previously executed task-set. Third, an attention hypothesis that states that both cognitive and emotional control ask for limited attentional resources, and predicts that arousal will impair both global and task-switching performance. The results showed that arousal affected task-switching but not global performance, possibly by phasic modulations of the noradrenergic system that reinforces the previously executed task. In addition, positive valence only affected global performance but not task-switching performance, possibly by phasic modulations of dopamine that stimulates the general ability to perform in a multitasking environment.

Hole energy and momentum distributions in valence bands

International Nuclear Information System (INIS)

Laan, G. van der.

1982-01-01

In order to understand the electrical and magnetic properties of solids, the knowledge of the density of states and the dispersion relation of the valence bands is indispensable. This thesis offers some alternative methods to obtain information about the nature of the valence band. Part A deals with the energy distribution of the photoelectrons. A simple model, which explains the core hole satellite structure in compounds with large correlation effects between the valence band holes and the created photo-hole, is outlined. CuCl, CuX 2 (X = F Cl and Br) are studied, by photoemission and Auger electron spectroscopies in determining the valence band properties. Part B deals with the simultaneous measurement of the energy and the wave vector of the emitted electrons. A practical example is given for the determination of the dispersion relation in copper. The measurements of a surface resonance band and the distribution of the secondary electrons are also reported. (Auth.)

Effect of valence on the electromigration in silver

International Nuclear Information System (INIS)

Nguyen Van Doan

1970-01-01

It is shown that the apparent effective valence Z B ** of a solute deduced from experiments differs from the true effective valence Z B * defined in the atomic models by a corrective term due to the 'vacancy flow effect'. The experimental results suggest that this corrective term is very important and that it is negative for transition elements; this hypothesis is confirmed for the case of iron in a copper matrix. For the elements to the right of silver in the periodic table, where the correction can be neglected, the effective valence of the solute varies linearly with z (z + 1), z being the difference between the valency of the solute and the solvent; in contrast, the further the solute is from the solvent in the periodic table the more nearly the electronic structure of the ion at the saddle point resembles that of the ion at the equilibrium position. (author) [fr

The acoustic correlates of valence depend on emotion family.

Science.gov (United States)

Belyk, Michel; Brown, Steven

2014-07-01

The voice expresses a wide range of emotions through modulations of acoustic parameters such as frequency and amplitude. Although the acoustics of individual emotions are well understood, attempts to describe the acoustic correlates of broad emotional categories such as valence have yielded mixed results. In the present study, we analyzed the acoustics of emotional valence for different families of emotion. We divided emotional vocalizations into "motivational," "moral," and "aesthetic" families as defined by the OCC (Ortony, Clore, and Collins) model of emotion. Subjects viewed emotional scenarios and were cued to vocalize congruent exclamations in response to them, for example, "Yay!" and "Damn!". Positive valence was weakly associated with high-pitched and loud vocalizations. However, valence interacted with emotion family for both pitch and amplitude. A general acoustic code for valence does not hold across families of emotion, whereas family-specific codes provide a more accurate description of vocal emotions. These findings are consolidated into a set of "rules of expression" relating vocal dimensions to emotion dimensions. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Prediction of valence and arousal from music features

NARCIS (Netherlands)

Den Brinker, A.C.; Van Dinther, C.H.B.A.; Skowronek, J.

2011-01-01

Mood is an important attribute of music and knowledge on mood can beused as a basic ingredient in music recommender and retrieval systems. Moods are assumed to be dominantly determined by two dimensions:valence and arousal. An experiment was conducted to attain data forsong-based ratings of valence

Valence photoelectron spectrum of KBr: Effects of electron correlation

International Nuclear Information System (INIS)

Calo, A.; Huttula, M.; Patanen, M.; Aksela, H.; Aksela, S.

2008-01-01

The valence photoelectron spectrum has been measured for molecular KBr. Experimental energies of the main and satellite structures have been compared with the results of ab initio calculations based on molecular orbital theory including configuration and multiconfiguration interaction approaches. Comparison between the experimental KBr spectrum and previously reported Kr valence photoelectron spectrum has also been performed in order to find out if electron correlation is of the same importance in the valence ionized state of KBr as in the corresponding state of Kr

eWOM, Revisit Intention, Destination Trust and Gender

OpenAIRE

Abubakar, Abubakar Mohammed; Ilkan, Mustafa; Al-Tal, Raad Meshall; Eluwole, Kayode

2017-01-01

This article investigates the impact of eWOM on intention to revisit and destination trust, and the moderating role of gender in medical tourism industry. Result from structural equation modeling (n=240) suggests the following: (1) that eWOM influences intention to revisit and destination trust; (2) that destination trust influences intention to revisit; (3) that the impact of eWOM on intention to revisit is about 1.3 times higher in men; (4) that the impact of eWOM on destination trust is ab...

Valence QCD: Connecting QCD to the quark model

International Nuclear Information System (INIS)

Liu, K.F.; Dong, S.J.; Draper, T.; Sloan, J.; Leinweber, D.; Woloshyn, R.M.

1999-01-01

A valence QCD theory is developed to study the valence quark properties of hadrons. To keep only the valence degrees of freedom, the pair creation through the Z graphs is deleted in the connected insertions, whereas the sea quarks are eliminated in the disconnected insertions. This is achieved with a new 'valence QCD' Lagrangian where the action in the time direction is modified so that the particle and antiparticle decouple. It is shown in this valence version of QCD that the ratios of isovector to isoscalar matrix elements (e.g., F A /D A and F S /D S ratios) in the nucleon reproduce the SU(6) quark model predictions in a lattice QCD calculation. We also consider how the hadron masses are affected on the lattice and discover new insights into the origin of dynamical mass generation. It is found that, within statistical errors, the nucleon and the Δ become degenerate for the quark masses we have studied (ranging from 1 to 4 times the strange mass). The π and ρ become nearly degenerate in this range. It is shown that valence QCD has the C, P, T symmetries. The lattice version is reflection positive. It also has the vector and axial symmetries. The latter leads to a modified partially conserved axial Ward identity. As a result, the theory has a U(2N F ) symmetry in the particle-antiparticle space. Through lattice simulation, it appears that this is dynamically broken down to U q (N F )xU bar q (N F ). Furthermore, the lattice simulation reveals spin degeneracy in the hadron masses and various matrix elements. This leads to an approximate U q (2N F )xU bar q (2N F ) symmetry which is the basis for the valence quark model. In addition, we find that the masses of N, Δ,ρ,π,a 1 , and a 0 all drop precipitously compared to their counterparts in the quenched QCD calculation. This is interpreted as due to the disappearance of the 'constituent' quark mass which is dynamically generated through tadpole diagrams. The origin of the hyperfine splitting in the baryon is

Processing negative valence of word pairs that include a positive word.

Science.gov (United States)

Itkes, Oksana; Mashal, Nira

2016-09-01

Previous research has suggested that cognitive performance is interrupted by negative relative to neutral or positive stimuli. We examined whether negative valence affects performance at the word or phrase level. Participants performed a semantic decision task on word pairs that included either a negative or a positive target word. In Experiment 1, the valence of the target word was congruent with the overall valence conveyed by the word pair (e.g., fat kid). As expected, response times were slower in the negative condition relative to the positive condition. Experiment 2 included target words that were incongruent with the overall valence of the word pair (e.g., fat salary). Response times were longer for word pairs whose overall valence was negative relative to positive, even though these word pairs included a positive word. Our findings support the Cognitive Primacy Hypothesis, according to which emotional valence is extracted after conceptual processing is complete.

Reducing the negative valence of stressful memories through emotionally valenced, modality-specific tasks

NARCIS (Netherlands)

Tadmor, Avia; McNally, Richard J; Engelhard, Iris M

2016-01-01

BACKGROUND AND OBJECTIVES: People who perform a cognitively demanding secondary task while recalling a distressing memory often experience the memory as less emotional, vivid, or accurate during subsequent recollections. In this experiment, we tested whether the emotional valence (positive versus

Peripheral temperature drop in response to anticipation and consumption of a signaled palatable reward in laying hens (Gallus domesticus).

Science.gov (United States)

Moe, Randi Oppermann; Stubsjøen, Solveig Marie; Bohlin, Jon; Flø, Andreas; Bakken, Morten

2012-06-25

The present study describes effects of anticipation and consumption of a palatable reward on comb surface temperature. The purpose was to investigate temperature responses as a potential physiological indicator of positive emotional states in laying hens. A rise in body temperature in response to stimuli predictive of or during exposure to unpleasant events has been interpreted as evidence of emotions in mammals and avians. However, this phenomenon has so far only been studied during anticipation of or exposure to negative events; i.e., emotions of a negative valence. Infrared thermography was used to record potential alterations in comb surface temperature to a conditioned cue signaling a reward (mealworms) and during reward delivery. On average, comb temperature dropped 1.5 °C (95% CI: +/-1.2 °C) after exposure to CS and consumption of reward (p~0.0014) when initial comb temperature was above 30 °C. Such temperature drop indicates a peripheral vasoconstriction and has clear resemblances to emotional fever as seen during negative emotional states. Thus, we propose that a drop in peripheral temperature reflects emotional arousal more than emotional valence. Substantial temperature responses due to diet-induced thermogenesis were found, further emphasizing a cautious interpretation of altered comb temperature in studies of animal welfare. Copyright © 2012 Elsevier Inc. All rights reserved.

Explaining the effect of event valence on unrealistic optimism.

Science.gov (United States)

Gold, Ron S; Brown, Mark G

2009-05-01

People typically exhibit 'unrealistic optimism' (UO): they believe they have a lower chance of experiencing negative events and a higher chance of experiencing positive events than does the average person. UO has been found to be greater for negative than positive events. This 'valence effect' has been explained in terms of motivational processes. An alternative explanation is provided by the 'numerosity model', which views the valence effect simply as a by-product of a tendency for likelihood estimates pertaining to the average member of a group to increase with the size of the group. Predictions made by the numerosity model were tested in two studies. In each, UO for a single event was assessed. In Study 1 (n = 115 students), valence was manipulated by framing the event either negatively or positively, and participants estimated their own likelihood and that of the average student at their university. In Study 2 (n = 139 students), valence was again manipulated and participants again estimated their own likelihood; additionally, group size was manipulated by having participants estimate the likelihood of the average student in a small, medium-sized, or large group. In each study, the valence effect was found, but was due to an effect on estimates of own likelihood, not the average person's likelihood. In Study 2, valence did not interact with group size. The findings contradict the numerosity model, but are in accord with the motivational explanation. Implications for health education are discussed.

Determination of the impact of Bi content on the valence band energy of GaAsBi using x-ray photoelectron spectroscopy

Directory of Open Access Journals (Sweden)

K. Collar

2017-07-01

Full Text Available We investigate the change of the valence band energy of GaAs1-xBix (0valence band energy per addition of 1 % Bi is determined for strained and unstrained thin films using a linear approximation applicable to the dilute regime. Spectroscopic ellipsometry (SE was used as a complementary technique to determine the change in GaAsBi bandgap resulting from Bi addition. Analysis of SE and XPS data together supports the conclusion that ∼75% of the reduction in the bandgap is in the valence band for a compressively strained, dilute GaAsBi thin film at room temperature.

Valence bond model potential energy surface for H4

International Nuclear Information System (INIS)

Silver, D.M.; Brown, N.J.

1980-01-01

Potential energy surfaces for the H 4 system are derived using the valence bond procedure. An ab initio evaluation of the valence bond energy expression is described and some of its numerical properties are given. Next, four semiempirical evaluations of the valence bond energy are defined and parametrized to yield reasonable agreement with various ab initio calculations of H 4 energies. Characteristics of these four H 4 surfaces are described by means of tabulated energy minima and equipotential contour maps for selected geometrical arrangements of the four nuclei

Negative pressure driven valence instability of Eu in cubic Eu{sub 0.4}La{sub 0.6}Pd{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Pandey, Abhishek [S N Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata-700098 (India); Mazumdar, Chandan; Ranganathan, R [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata-700064 (India)], E-mail: abhishek.phy@gmail.com, E-mail: chandan.mazumar@saha.ac.in

2009-05-27

We report the change in the valency of Eu-ions in the binary intermetallic cubic compound EuPd{sub 3} induced by La doping at rare-earth sites. Doping of La generates negative chemical pressure in the lattice, resulting in a significant increase of the lattice parameter without altering the simple-cubic structure of the compound. Results of dc-magnetic measurements suggest that this increase in the lattice parameter is associated with the valence transition of Eu-ions from Eu{sup 3+} to a mixed-valent state. As Eu{sup 2+}-ions possess a large magnetic moment, this valence transition significantly modifies the magnetic behavior of the compound. In contrast to introducing boron at the vacant body center site of the unit cell to change the valency of Eu-ions, as in the case of EuPd{sub 3}B, our results suggest it can also be altered by doping a rare-earth ion of larger size at the lattice site of Eu in EuPd{sub 3}.

In-medium pion valence distributions in a light-front model

Energy Technology Data Exchange (ETDEWEB)

Melo, J.P.B.C. de, E-mail: joao.mello@cruzeirodosul.edu.br [Laboratório de Física Teórica e Computacional – LFTC, Universidade Cruzeiro do Sul, 01506-000 São Paulo (Brazil); Tsushima, K. [Laboratório de Física Teórica e Computacional – LFTC, Universidade Cruzeiro do Sul, 01506-000 São Paulo (Brazil); Ahmed, I. [Laboratório de Física Teórica e Computacional – LFTC, Universidade Cruzeiro do Sul, 01506-000 São Paulo (Brazil); National Center for Physics, Quaidi-i-Azam University Campus, Islamabad 45320 (Pakistan)

2017-03-10

Pion valence distributions in nuclear medium and vacuum are studied in a light-front constituent quark model. The in-medium input for studying the pion properties is calculated by the quark-meson coupling model. We find that the in-medium pion valence distribution, as well as the in-medium pion valence wave function, are substantially modified at normal nuclear matter density, due to the reduction in the pion decay constant.

Bond-Valence Constraints on Liquid Water Structure

International Nuclear Information System (INIS)

Bickmore, Barry R.; Rosso, Kevin M.; Brown, I. David; Kerisit, Sebastien N.

2009-01-01

The recent controversy about the structure of liquid water pits a new model involving water molecules in relatively stable rings-and-chains structures against the standard model that posits water molecules in distorted tetrahedral coordination. Molecular dynamics (MD) simulations 'both classical and ab initio' almost uniformly support the standard model, but since none of them can yet reproduce all the anomalous properties of water, they leave room for doubt. We argue that it is possible to evaluate these simulations by testing them against their adherence to the bond-valence model, a well known, and quantitatively accurate, empirical summary of the behavior of atoms in the bonded networks of inorganic solids. Here we use the results of ab initio molecular dynamics simulations of ice, water, and several solvated aqueous species to show that the valence sum rule (the first axiom of the bond-valence model,) is followed in both solid and liquid bond networks. We then test MD simulations of water, employing several popular potential models, against this criterion and the experimental O-O radial distribution function. It appears that most of those tested cannot satisfy both criteria well, except TIP4P and TIP5P. If the valence sum rule really can be applied to simulated liquid structures, then it follows that the bonding behaviors of atoms in liquids are in some ways identical to those in solids. We support this interpretation by showing that the simulations produce O-H-O geometries completely consistent with the range of geometries available in solids, and the distributions of instantaneous valence sums reaching the atoms in both the ice and liquid water simulations are essentially identical. Taken together, this is powerful evidence in favor of the standard distorted tetrahedral model of liquid water structure

Structure of s - p bonded metal clusters with 8, 20 and 40 valence electrons

International Nuclear Information System (INIS)

Kumar, V.

1992-10-01

From studies on some clusters of metals and semiconductors, there appear some similarities in the structure of clusters with a given number of atoms and having the number of valence electrons corresponding to a shell closing. Here we present results of the atomic and electronic structure of a few other clusters with 20 and 40 valence electrons, namely Sb 4 , Sn 5 and Sb 8 using the density functional molecular dynamics method. We suggest that the similarities in the structure and deviation from them may help to understand bonding characteristics in clusters and its evolution to bulk behaviour. Our results on Sb 8 cluster are preliminary but indicate that above room temperature its structure is two weakly interacting tetrahedra which is in general agreement with the observation of predominently antimony tetramers at T > 300 K. (author). 16 refs, 2 figs

Structure and Magnetic Properties of a Mixed-Valence Heptanuclear Manganese Cluster.

Science.gov (United States)

Abbati, Gian Luca; Cornia, Andrea; Fabretti, Antonio C.; Caneschi, Andrea; Gatteschi, Dante

1998-07-27

Two novel polynuclear manganese(II,III) complexes have been synthesized by exploiting controlled methanolysis. A one-pot reaction of MnCl(2), NaOMe, dibenzoylmethane (Hdbm), and O(2) in anhydrous methanol, followed by recrystallization from MeOH/CHCl(3) mixtures, afforded the alkoxomanganese complexes [Mn(7)(OMe)(12)(dbm)(6)].CHCl(3).14MeOH (2) and [Mn(2)(OMe)(2)(dbm)(4)] (3). Complex 2 crystallizes in trigonal space group R&thremacr; with a = 14.439(2) Å, alpha = 86.34(1) degrees, and Z = 1. Complex 3 crystallizes in triclinic space group P&onemacr; with a = 9.612(1) Å, b = 10.740(1) Å, c = 13.168(1) Å, alpha = 80.39(1) degrees, beta = 87.66(1) degrees, gamma = 83.57(1) degrees, and Z = 1. The solid-state structure of 2 comprises a [Mn(6)(OMe)(12)(dbm)(6)] "crown" with crystallographically imposed 6-fold symmetry plus a central manganese ion. The layered Mn/O core mimics a fragment of the manganese oxide mineral lithiophorite. Conductivity measurements confirmed the nonionic character of 2 and suggested a mixed-valence Mn(II)(3)Mn(III)(4) formulation. The metrical parameters of the core were analyzed with the aid of bond-valence sum calculations. The central ion is essentially a valence-trapped Mn(II) ion, whereas the average Mn-O distances for the manganese ions of the "crown" are consistent with the presence of two Mn(II) and four Mn(III) ions. However, (1)H NMR spectra in solution strongly support valence localization and suggest that the observed solid-state structure may be a result of static disorder effects. Magnetic susceptibility vs T and magnetization vs field data at low temperature are consistent with an S = (17)/(2) ground state. Complex 3 is a symmetric alkoxo-bridged dimer. The two high-spin Mn(III) ions are antiferromagnetically coupled with J = 0.28(4) cm(-)(1), g = 1.983(2), and D = -2.5(4) cm(-)(1).

Magnetocaloric properties of the hexagonal HoMnO{sub 3} single crystal revisited

Energy Technology Data Exchange (ETDEWEB)

Balli, M., E-mail: Mohamed.balli@Usherbrooke.ca [Regroupement québécois sur les matériaux de pointe, Département de physique, Université de Sherbrooke, QC, Canada J1K 2R1 (Canada); Roberge, B.; Vermette, J.; Jandl, S. [Regroupement québécois sur les matériaux de pointe, Département de physique, Université de Sherbrooke, QC, Canada J1K 2R1 (Canada); Fournier, P. [Regroupement québécois sur les matériaux de pointe, Département de physique, Université de Sherbrooke, QC, Canada J1K 2R1 (Canada); Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8 (Canada); Gospodinov, M.M. [Institute of Solid State Physics, Bulgarian Academy of Science, Sofia 1184 (Bulgaria)

2015-12-01

Magnetic and magnetocaloric properties of the hexagonal HoMnO{sub 3} single crystal have been revisited. It was found that the magnetocaloric effect shown by HoMnO{sub 3} strongly depends on the crystal orientation in respect to the applied magnetic field. Consequently, a large thermal effect can be induced by spinning the single crystal HoMnO{sub 3} around the a (or b) axis in a constant magnetic field instead of the conventional magnetization–demagnetization process. Under 7 T, the maximum rotating entropy change was evaluated to be about 8 J/kg K. The associated adiabatic temperature change reaches a value of about 5 K. These values are comparable to those of the other oxides exhibiting a large rotating magnetocaloric effect. The presence of both conventional and rotating thermal effects makes the hexagonal HoMnO{sub 3} more interesting from a practical point of view.

Plutonium valence state distributions

International Nuclear Information System (INIS)

Silver, G.L.

1974-01-01

A calculational method for ascertaining equilibrium valence state distributions of plutonium in acid solutions as a function of the plutonium oxidation number and the solution acidity is illustrated with an example. The method may be more practical for manual use than methods based upon polynomial equations. (T.G.)

CzEngVallex: a Bilingual Czech-English Valency Lexicon

Directory of Open Access Journals (Sweden)

Urešová Zdeňka

2016-04-01

Full Text Available This paper introduces a new bilingual Czech-English verbal valency lexicon (called CzEng-Vallex representing a relatively large empirical database. It includes 20,835 aligned valency frame pairs (i.e., verb senses which are translations of each other and their aligned arguments. This new lexicon uses data from the Prague Czech-English Dependency Treebank and also takes advantage of the existing valency lexicons for both languages: the PDT-Vallex for Czech and the EngVallex for English. The CzEngVallex is available for browsing as well as for download in the LINDAT/CLARIN repository.

A crystal chemical approach to superconductivity. I. A bond-valence sum analysis of inorganic compounds

International Nuclear Information System (INIS)

Liebau, Friedrich; Klein, Hans-Joachim; Wang, Xiqu

2011-01-01

A crystal-chemical approach to superconductivity is described that is intended to complement the corresponding physical approach. The former approach takes into account the distinction between the stoichiometric valence ( stoich V) and the structural valence ( struct V) which is represented by the bond-valence sums (BVS). Through calculations of BVS values from crystal-structure data determined at ambient temperature and pressure it has been found that in chalcogenides und pnictides of the transition metals Fe, Co, Ni, Mn, Hf, and Zr the atoms of the potential superconducting units yield values of vertical stroke BVS vertical stroke = vertical stroke struct V vertical stroke ≥ 1.11 x vertical stroke stoich V vertical stroke, whereas the atoms of the charge reservoirs have in general values of vertical stroke struct V vertical stroke stoich V vertical stroke. In corresponding compounds which contain the same elements but are not becoming superconducting, nearly all atoms are found to have vertical stroke struct V vertical stroke stoich V vertical stroke. For atoms of oxocuprates that are not becoming superconducting and for atoms of the charge reservoirs of oxocuprates that become superconducting, the relation vertical stroke struct V vertical stroke stoich V vertical stroke seems also to be fulfilled, with the exception of Ba. However, in several oxocuprates the relation vertical stroke struct V vertical stroke = 1.11 x vertical stroke stoich V vertical stroke for the atoms that become superconducting units is violated. These violations seem to indicate that in oxocuprates it is the local bond-valence distribution rather than the bond-valence sums that is essential for superconductivity. The present analysis can possibly be used to predict, by a simple consideration of ambient-T, P structures, whether a compound can become an unconventional superconductor at low T, under high P and/or by doping, or not. (orig.)

THE VALENCE OF CORPUSCULAR PROTEINS.

Science.gov (United States)

Gorin, M H; Mover, L S

1942-07-20

BY THE USE OF TWO EXTREME MODELS: a hydrated sphere and an unhydrated rod the valence (net charge) of corpuscular proteins can be successfully calculated from electric mobility data by the Debye-Hückel theory (modified to include the effect of the ions in the ion atmosphere) in conjunction with the electrophoretic theory of Henry. As pointed out by Abramson, this permits a comparison with values for the valence from titration data. Electrometric titration measurements of serum albumin B (Kekwick) have been determined at several ionic strengths. These results, together with the available data in the literature for serum albumin B, egg albumin, and beta-lactoglobulin have been used to compare values for the valence calculated from measurements of titration, electrophoresis, and membrane potentials. The results indicate that the usual interpretation of titration curves is open to serious question. By extrapolation of the titration data to zero ionic strength and protein concentration, there results an "intrinsic" net charge curve describing the binding of H(+) (OH(-)) ion alone. This curve agrees closely, in each case, with values of the valence calculated from mobility data (which in turn are in close accord with those estimated from membrane potential measurements). The experimental titration curves in the presence of appreciable quantities of ions and protein deviate widely from the ideal curve. It is suggested that, under these conditions, binding of undissociated acid (base) leads to erroneous values for the net charge. This binding would not affect the electrophoretic mobility. Values of the net charge obtained by the two extreme models from electrophoretic data are in agreement within 15 to 20 per cent. The agreement between the cylindrical model and the titration data is somewhat better in each case than with the sphere; i.e., this comparison enables a choice to be made between asymmetry and hydration in the interpretation of results from sedimentation and

Dynamics of valence-shell electrons and nuclei probed by strong-field holography and rescattering

Science.gov (United States)

Walt, Samuel G.; Bhargava Ram, Niraghatam; Atala, Marcos; Shvetsov-Shilovski, Nikolay I; von Conta, Aaron; Baykusheva, Denitsa; Lein, Manfred; Wörner, Hans Jakob

2017-01-01

Strong-field photoelectron holography and laser-induced electron diffraction (LIED) are two powerful emerging methods for probing the ultrafast dynamics of molecules. However, both of them have remained restricted to static systems and to nuclear dynamics induced by strong-field ionization. Here we extend these promising methods to image purely electronic valence-shell dynamics in molecules using photoelectron holography. In the same experiment, we use LIED and photoelectron holography simultaneously, to observe coupled electronic-rotational dynamics taking place on similar timescales. These results offer perspectives for imaging ultrafast dynamics of molecules on femtosecond to attosecond timescales. PMID:28643771

Valence fluctuations between two magnetic configurations

International Nuclear Information System (INIS)

Mazzaferro, J.O.

1982-01-01

The subject of this work is the study of a microscopic model which describes TmSe through its most important feature, i.e.: the valence fluctuations between two magnetic configurations. Chapter I is a general review of the most important physical properties of rare-earth systems with intermediate valence (I.V.) and a general description of experimental results and theoretical models on Tm compounds. In Chapter II the Hamiltonian model is discussed and the loss of rotational invariance is also analyzed. Chapter III is devoted to the study of non-stoichiometric Tsub(x)Se compounds. It is shown that these compounds can be considered as a mixture of TmSe (I.V. system) and Tm 3+ 0.87Se. Chapter IV is devoted to the calculation of spin-and charge susceptibilities. The results obtained permit to explain the essential features of the neutron scattering spectrum in TmSe. In Chapter V, an exactly solvable periodic Hamiltonian is presented. From the experimental results, some fundamental features are deduced to describe TmSe as an intermediate valence system whose two accessible ionic configurations are magnetic (degenerated fundamental state). (M.E.L) [es

Lying about the valence of affective pictures: an fMRI study.

Directory of Open Access Journals (Sweden)

Tatia M C Lee

Full Text Available The neural correlates of lying about affective information were studied using a functional magnetic resonance imaging (fMRI methodology. Specifically, 13 healthy right-handed Chinese men were instructed to lie about the valence, positive or negative, of pictures selected from the International Affective Picture System (IAPS while their brain activity was scanned by a 3T Philip Achieva scanner. The key finding is that the neural activity associated with deception is valence-related. Comparing to telling the truth, deception about the valence of the affectively positive pictures was associated with activity in the inferior frontal, cingulate, inferior parietal, precuneus, and middle temporal regions. Lying about the valence of the affectively negative pictures, on the other hand, was associated with activity in the orbital and medial frontal regions. While a clear valence-related effect on deception was observed, common neural regions were also recruited for the process of deception about the valence of the affective pictures. These regions included the lateral prefrontal and inferior parietal regions. Activity in these regions has been widely reported in fMRI studies on deception using affectively-neutral stimuli. The findings of this study reveal the effect of valence on the neural activity associated with deception. Furthermore, the data also help to illustrate the complexity of the neural mechanisms underlying deception.

5th International Conference on Valence Fluctuations

CERN Document Server

Malik, S

1987-01-01

During the Koln meeting (August 28-31, 1984), Irdia was chosen as the venue for the next International Conference on Valence Fluctuations. lhis was in recognition ard appreciation of the work done, both experimental ard theoretical, by the Irdian scientists in this area during the last decade. We decided to hold this Conference in the month of January, 1987 at Bangalore. lhe subject of Valence Fluctuations has kept itself alive ard active as it has provided many shocks ard suprises particularly among the Ce- ard U-based intermetallies. lhe richness of many interesting physical phenomena occurring in mixed valent materials, the flexibility of modifying their physical properties (by alloying, for example) ard the possibility of synthesizing a wide variety of new such materials seem to be the key factors in this regard. Barely six months before this Conference, an International Conference on Anomalous Rare Earths and Actinides (ICAREA) had been held at Grenoble (July, 1986) which also focussed on mixed valence a...

Valence electronic properties of porphyrin derivatives.

Science.gov (United States)

Stenuit, G; Castellarin-Cudia, C; Plekan, O; Feyer, V; Prince, K C; Goldoni, A; Umari, P

2010-09-28

We present a combined experimental and theoretical investigation of the valence electronic structure of porphyrin-derived molecules. The valence photoemission spectra of the free-base tetraphenylporphyrin and of the octaethylporphyrin molecule were measured using synchrotron radiation and compared with theoretical spectra calculated using the GW method and the density-functional method within the generalized gradient approximation. Only the GW results could reproduce the experimental data. We found that the contribution to the orbital energies due to electronic correlations has the same linear behavior in both molecules, with larger deviations in the vicinity of the HOMO level. This shows the importance of adequate treatment of electronic correlations in these organic systems.

Valence-to-core-detected X-ray absorption spectroscopy

DEFF Research Database (Denmark)

Hall, Eleanor R.; Pollock, Christopher J.; Bendix, Jesper

2014-01-01

X-ray absorption spectroscopy (XAS) can provide detailed insight into the electronic and geometric structures of transition-metal active sites in metalloproteins and chemical catalysts. However, standard XAS spectra inherently represent an average contribution from the entire coordination...... environment with limited ligand selectivity. To address this limitation, we have investigated the enhancement of XAS features using valence-to-core (VtC)-detected XAS, whereby XAS spectra are measured by monitoring fluorescence from valence-to-core X-ray emission (VtC XES) events. VtC emission corresponds...... to transitions from filled ligand orbitals to the metal 1s core hole, with distinct energetic shifts for ligands of differing ionization potentials. VtC-detected XAS data were obtained from multiple valence emission features for a series of well-characterized Mn model compounds; taken together, these data...

Work Valence as a Predictor of Academic Achievement in the Family Context

Science.gov (United States)

Porfeli, Erik; Ferrari, Lea; Nota, Laura

2013-01-01

This study asserts a theoretical model of academic and work socialization within the family setting. The presumed associations between parents' work valences, children's work valences and valence perceptions, and children's academic interest and achievement are tested. The results suggest that children's perceptions of parents mediate the…

Pressure-induced valence and structure change in some anti-Th3P4 structure rare earth compounds

International Nuclear Information System (INIS)

Werner, A.; Hochheimer, H.D.; Jayaraman, A.; Bucher, E.

1981-01-01

The anti-Th 3 P 4 structure compounds Yb 4 Bi 3 and Yb 4 Sb 3 have been investigated to 350 kbar by high pressure X-ray diffraction, using the diamond anvil cell. From the P-V data it is found that Yb 4 Bi 3 and Yb 4 Sb 3 are much more compressible, compared to Sm 4 Bi 3 before the valence transition. This suggests that a continuous change in the valence state of Yb takes place with pressure in the two compounds and that they may be in the mixed valent state already at ambient pressure. The ''collapsed'' anti-Th 3 P 4 structure becomes unstable in Yb 4 Bi 3 and Yb 4 Sb 3 and new lines appear at high pressure, that fit the NaCl structure. The latter structure change seems to occur also in the electronically collapsed Sm 4 Bi 3 . The results are presented and discussed. (Auth.)

Beam-induced temperature changes in HVEM irradiations

International Nuclear Information System (INIS)

Garner, F.A.; Thomas, L.E.; Gelles, D.S.

1975-01-01

The peak value of the temperature distribution induced by energy loss of 1.0 MeV electrons in traversing a typical HVEM irradiation specimen can be very substantial. The origin and various features of this distribution were analyzed for a variety of specimen geometries. The major parametric dependencies are shown to be relatively independent of specimen geometry, however, and allow the definition of a scaling relationship that can be employed to predict temperature rises in materials that cannot be measured directly. The use of this scaling relationship requires that the experimenter minimize perturbations of the heat flow due to proximity of the central hole in the specimen. An experimental method of determining directly the magnitude and distribution of beam-induced temperature profiles was developed which utilizes the order-disorder transformation in Fe 3 Al and Cu 3 Au. Scaling of experimentally determined temperature changes leads to more realistic estimates of the total temperature rise than are currently available in various literature tabulations. The factors which determine the optimum selection of irradiation parameters for a given experiment are also discussed

Emotions and false memories: valence or arousal?

Science.gov (United States)

Corson, Yves; Verrier, Nadège

2007-03-01

The effects of mood on false memories have not been studied systematically until recently. Some results seem to indicate that negative mood may reduce false recall and thus suggest an influence of emotional valence on false memory. The present research tested the effects of both valence and arousal on recall and recognition and indicates that the effect is actually due to arousal. In fact, whether participants' mood is positive, negative, or neutral, false memories are significantly more frequent under conditions of high arousal than under conditions of low arousal.

Excitations of one-valence-proton, one-valence-neutron nucleus {sup 210}Bi from cold-neutron capture

Energy Technology Data Exchange (ETDEWEB)

Cieplicka-Oryńczak, N. [INFN sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland); Fornal, B.; Szpak, B. [Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland); Leoni, S.; Bottoni, S. [INFN sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Bazzacco, D. [Dipartimento di Fisica e Astronomia dell’Università, I-35131 Padova (Italy); INFN Sezione di Padova, I-35131 Padova (Italy); Blanc, A.; Jentschel, M.; Köster, U.; Mutti, P.; Soldner, T. [Institute Laue-Langevin, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Bocchi, G. [Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); France, G. de [GANIL, Bd. Becquerel, BP 55027, 14076 CAEN Cedex 05 (France); Simpson, G. [LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut National Polytechnique de Grenoble, F-38026 Grenoble Cedex (France); Ur, C. [INFN Sezione di Padova, Via F. Marzolo 8, I-35131 Padova (Italy); Urban, W. [Faculty of Physics, University of Warsaw, ul. Hoża 69, 02-681, Warszawa (Poland)

2015-10-15

The low-spin structure of one-proton, one-neutron {sup 210}Bi nucleus was investigated in cold-neutron capture reaction on {sup 209}Bi. The γ-coincidence measurements were performed with use of EXILL array consisted of 16 HPGe detectors. The experimental results were compared to shell-model calculations involving valence particles excitations. The {sup 210}Bi nucleus offers the potential to test the effective proton-neutron interactions because most of the states should arise from the proton-neutron excitations. Additionally, it was discovered that a few states should come from the couplings of valence particles to the 3{sup −} octupole vibration in {sup 208}Pb which provides also the possibility of testing the calculations involving the core excitations.

Topologically distinct classes of valence-bond solid states with their parent Hamiltonians

International Nuclear Information System (INIS)

Tu Honghao; Zhang Guangming; Xiang Tao; Liu Zhengxin; Ng Taikai

2009-01-01

We present a general method to construct one-dimensional translationally invariant valence-bond solid states with a built-in Lie group G and derive their matrix product representations. The general strategies to find their parent Hamiltonians are provided so that the valence-bond solid states are their unique ground states. For quantum integer-spin-S chains, we discuss two topologically distinct classes of valence-bond solid states: one consists of two virtual SU(2) spin-J variables in each site and another is formed by using two SO(2S+1) spinors. Among them, a spin-1 fermionic valence-bond solid state, its parent Hamiltonian, and its properties are discussed in detail. Moreover, two types of valence-bond solid states with SO(5) symmetries are further generalized and their respective properties are analyzed as well.

Mushroom body output neurons encode valence and guide memory-based action selection in Drosophila

Science.gov (United States)

Aso, Yoshinori; Sitaraman, Divya; Ichinose, Toshiharu; Kaun, Karla R; Vogt, Katrin; Belliart-Guérin, Ghislain; Plaçais, Pierre-Yves; Robie, Alice A; Yamagata, Nobuhiro; Schnaitmann, Christopher; Rowell, William J; Johnston, Rebecca M; Ngo, Teri-T B; Chen, Nan; Korff, Wyatt; Nitabach, Michael N; Heberlein, Ulrike; Preat, Thomas; Branson, Kristin M; Tanimoto, Hiromu; Rubin, Gerald M

2014-01-01

Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by ∼2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types. We studied the role of MBONs in several associative learning tasks and in sleep regulation, revealing the extent to which information flow is segregated into distinct channels and suggesting possible roles for the multi-layered MBON network. We also show that optogenetic activation of MBONs can, depending on cell type, induce repulsion or attraction in flies. The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence. We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli. Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection. DOI: http://dx.doi.org/10.7554/eLife.04580.001 PMID:25535794

Mushroom body output neurons encode valence and guide memory-based action selection in Drosophila.

Science.gov (United States)

Aso, Yoshinori; Sitaraman, Divya; Ichinose, Toshiharu; Kaun, Karla R; Vogt, Katrin; Belliart-Guérin, Ghislain; Plaçais, Pierre-Yves; Robie, Alice A; Yamagata, Nobuhiro; Schnaitmann, Christopher; Rowell, William J; Johnston, Rebecca M; Ngo, Teri-T B; Chen, Nan; Korff, Wyatt; Nitabach, Michael N; Heberlein, Ulrike; Preat, Thomas; Branson, Kristin M; Tanimoto, Hiromu; Rubin, Gerald M

2014-12-23

Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by ∼2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types. We studied the role of MBONs in several associative learning tasks and in sleep regulation, revealing the extent to which information flow is segregated into distinct channels and suggesting possible roles for the multi-layered MBON network. We also show that optogenetic activation of MBONs can, depending on cell type, induce repulsion or attraction in flies. The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence. We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli. Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection.

The valence electron structure and property analysis of TiC

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

The valence electron structure of TiC was calculated by using the empirical electron theory of solids and molecules. The calculated results show that with the increase of temperature the number of common electrons of TiC increases, which indicates that TiC has a good thermal sta-bility; and there exists a close relationship between hardness and brittleness of TiC. According to the number of lattice electrons, the differences among the crystals with different structures can be explained qualitatively. Using the "bond- strengthening factor", the differences of hardness among the crystals with different structures can also be qualitatively explained to some extent.

NEVER forget: negative emotional valence enhances recapitulation.

Science.gov (United States)

Bowen, Holly J; Kark, Sarah M; Kensinger, Elizabeth A

2017-07-10

A hallmark feature of episodic memory is that of "mental time travel," whereby an individual feels they have returned to a prior moment in time. Cognitive and behavioral neuroscience methods have revealed a neurobiological counterpart: Successful retrieval often is associated with reactivation of a prior brain state. We review the emerging literature on memory reactivation and recapitulation, and we describe evidence for the effects of emotion on these processes. Based on this review, we propose a new model: Negative Emotional Valence Enhances Recapitulation (NEVER). This model diverges from existing models of emotional memory in three key ways. First, it underscores the effects of emotion during retrieval. Second, it stresses the importance of sensory processing to emotional memory. Third, it emphasizes how emotional valence - whether an event is negative or positive - affects the way that information is remembered. The model specifically proposes that, as compared to positive events, negative events both trigger increased encoding of sensory detail and elicit a closer resemblance between the sensory encoding signature and the sensory retrieval signature. The model also proposes that negative valence enhances the reactivation and storage of sensory details over offline periods, leading to a greater divergence between the sensory recapitulation of negative and positive memories over time. Importantly, the model proposes that these valence-based differences occur even when events are equated for arousal, thus rendering an exclusively arousal-based theory of emotional memory insufficient. We conclude by discussing implications of the model and suggesting directions for future research to test the tenets of the model.

Optical and electronic properties of polyvinyl alcohol doped with pairs of mixed valence metal ions

International Nuclear Information System (INIS)

Bulinski, Mircea; Kuncser, Victor; Plapcianu, Carmen; Krautwald, Stefan; Franke, Hilmar; Rotaru, P; Filoti, George

2004-01-01

The electronic mechanisms induced by the UV exposure of thin films of polyvinyl alcohol doped with pairs of mixed valence metal ions were studied in relation to their optical behaviour by Moessbauer spectroscopy and optical absorption. The results obtained definitely point to the role of each element from the pair in the electronic mechanism involved, with influence on the optical properties regarding applications in real-time holography and integrated optics

Revisited neoclassical transport theory for steep, collisional plasma edge profiles

International Nuclear Information System (INIS)

Rogister, A.L.

1994-01-01

Published neoclassical results are misleading as concerns the plasma edge for they do not adequately take the peculiar local conditions into account, in particular the fact that the density and temperature variation length-scales are quite small. Coupled novel neoclassical equations obtain, not only for the evolution of the density and temperatures, but also for the radial electric field and the evolution of the parallel ion momentum: gyro-stresses and inertia indeed upset the otherwise de facto ambipolarity of particle transport and a radial electric field necessarily builds up. The increased nonlinear character of these revisited neoclassical equations widens the realm of possible plasma behaviors. (author)

Human Amygdala Tracks a Feature-Based Valence Signal Embedded within the Facial Expression of Surprise.

Science.gov (United States)

Kim, M Justin; Mattek, Alison M; Bennett, Randi H; Solomon, Kimberly M; Shin, Jin; Whalen, Paul J

2017-09-27

Human amygdala function has been traditionally associated with processing the affective valence (negative vs positive) of an emotionally charged event, especially those that signal fear or threat. However, this account of human amygdala function can be explained by alternative views, which posit that the amygdala might be tuned to either (1) general emotional arousal (activation vs deactivation) or (2) specific emotion categories (fear vs happy). Delineating the pure effects of valence independent of arousal or emotion category is a challenging task, given that these variables naturally covary under many circumstances. To circumvent this issue and test the sensitivity of the human amygdala to valence values specifically, we measured the dimension of valence within the single facial expression category of surprise. Given the inherent valence ambiguity of this category, we show that surprised expression exemplars are attributed valence and arousal values that are uniquely and naturally uncorrelated. We then present fMRI data from both sexes, showing that the amygdala tracks these consensus valence values. Finally, we provide evidence that these valence values are linked to specific visual features of the mouth region, isolating the signal by which the amygdala detects this valence information. SIGNIFICANCE STATEMENT There is an open question as to whether human amygdala function tracks the valence value of cues in the environment, as opposed to either a more general emotional arousal value or a more specific emotion category distinction. Here, we demonstrate the utility of surprised facial expressions because exemplars within this emotion category take on valence values spanning the dimension of bipolar valence (positive to negative) at a consistent level of emotional arousal. Functional neuroimaging data showed that amygdala responses tracked the valence of surprised facial expressions, unconfounded by arousal. Furthermore, a machine learning classifier identified

Effects of valence and divided attention on cognitive reappraisal processes.

Science.gov (United States)

Morris, John A; Leclerc, Christina M; Kensinger, Elizabeth A

2014-12-01

Numerous studies have investigated the neural substrates supporting cognitive reappraisal, identifying the importance of cognitive control processes implemented by prefrontal cortex (PFC). This study examined how valence and attention affect the processes used for cognitive reappraisal by asking participants to passively view or to cognitively reappraise positive and negative images with full or divided attention. When participants simply viewed these images, results revealed few effects of valence or attention. However, when participants engaged in reappraisal, there was a robust effect of valence, with the reappraisal of negative relative to positive images associated with more widespread activation, including within regions of medial and lateral PFC. There also was an effect of attention, with more lateral PFC recruitment when regulating with full attention and more medial PFC recruitment when regulating with divided attention. Within two regions of medial PFC and one region of ventrolateral PFC, there was an interaction between valence and attention: in these regions, divided attention reduced activity during reappraisal of positive but not negative images. Critically, participants continued to report reappraisal success even during the Divided Attention condition. These results suggest multiple routes to successful cognitive reappraisal, depending upon image valence and the availability of attentional resources. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Effects of valence and divided attention on cognitive reappraisal processes

Science.gov (United States)

Leclerc, Christina M.; Kensinger, Elizabeth A.

2014-01-01

Numerous studies have investigated the neural substrates supporting cognitive reappraisal, identifying the importance of cognitive control processes implemented by prefrontal cortex (PFC). This study examined how valence and attention affect the processes used for cognitive reappraisal by asking participants to passively view or to cognitively reappraise positive and negative images with full or divided attention. When participants simply viewed these images, results revealed few effects of valence or attention. However, when participants engaged in reappraisal, there was a robust effect of valence, with the reappraisal of negative relative to positive images associated with more widespread activation, including within regions of medial and lateral PFC. There also was an effect of attention, with more lateral PFC recruitment when regulating with full attention and more medial PFC recruitment when regulating with divided attention. Within two regions of medial PFC and one region of ventrolateral PFC, there was an interaction between valence and attention: in these regions, divided attention reduced activity during reappraisal of positive but not negative images. Critically, participants continued to report reappraisal success even during the Divided Attention condition. These results suggest multiple routes to successful cognitive reappraisal, depending upon image valence and the availability of attentional resources. PMID:24493837

Memory effects of sleep, emotional valence, arousal and novelty in children.

Science.gov (United States)

Vermeulen, Marije C M; van der Heijden, Kristiaan B; Benjamins, Jeroen S; Swaab, Hanna; van Someren, Eus J W

2017-06-01

Effectiveness of memory consolidation is determined by multiple factors, including sleep after learning, emotional valence, arousal and novelty. Few studies investigated how the effect of sleep compares with (and interacts with) these other factors, of which virtually none are in children. The present study did so by repeated assessment of declarative memory in 386 children (45% boys) aged 9-11 years through an online word-pair task. Children were randomly assigned to either a morning or evening learning session of 30 unrelated word-pairs with positive, neutral or negative valenced cues and neutral targets. After immediately assessing baseline recognition, delayed recognition was recorded either 12 or 24 h later, resulting in four different assessment schedules. One week later, the procedure was repeated with exactly the same word-pairs to evaluate whether effects differed for relearning versus original novel learning. Mixed-effect logistic regression models were used to evaluate how the probability of correct recognition was affected by sleep, valence, arousal, novelty and their interactions. Both immediate and delayed recognition were worse for pairs with negatively valenced or less arousing cue words. Relearning improved immediate and delayed word-pair recognition. In contrast to these effects, sleep did not affect recognition, nor did sleep moderate the effects of arousal, valence and novelty. The findings suggest a robust inclination of children to specifically forget the pairing of words to negatively valenced cue words. In agreement with a recent meta-analysis, children seem to depend less on sleep for the consolidation of information than has been reported for adults, irrespective of the emotional valence, arousal and novelty of word-pairs. © 2017 European Sleep Research Society.

Investigating Valence and Autonomy in Children's Relationships with Imaginary Companions

Science.gov (United States)

McInnis, Melissa A.; Pierucci, Jillian M.; Gilpin, Ansley Tullos

2013-01-01

Little research has explored valence and autonomy in children's imaginary relationships. In the present study, a new interview (modeled after an existing measure for real relationships) was designed to elicit descriptions of both positive and negative interactions with imaginary companions and to provide a measure of relationship valence and…

Valence configurations in 214Rn

International Nuclear Information System (INIS)

Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.; Bark, R.A.; Poletti, A.R.

1987-01-01

Excited states of 214 Rn, up to spins of ≅ 24 ℎ have been studied using γ-ray and electron spectroscopy following the 208 Pb( 9 Be,3n) 214 Rn reaction. The level scheme (which differs substantially from earlier work) is compared with the results of a semi-empirical shell model calculation. The availability of high-spin orbitals for the four valence protons and two valence neutrons, and the effect of the attractive proton-neutron interaction, leads to the prediction of high-spin states at an unusually low excitation energy. Experimentally, the high level density leads to difficulties in the level scheme assignments at high spin. Nevertheless, configuration assignments, supported by transition strengths deduced from the measured lifetimes (in the nanosecond region) are suggested for the main yrast states. The decay properties also suggest that configuration mixing is important. The possibility of a gradual transition to octupole deformation, implied by the decay properties of the 11 - and 10 + yrast states is also discussed. (orig.)

Disentangling the Effect of Valence and Arousal on Judgments Concerning Moral Transgressions.

Science.gov (United States)

de la Viña, Luis; Garcia-Burgos, David; Okan, Yasmina; Cándido, Antonio; González, Felisa

2015-08-10

An increasing body of research has investigated the effect of emotions on judgments concerning moral transgressions. Yet, few studies have controlled for arousal levels associated with the emotions. High arousal may affect moral processing by triggering attention to salient features of transgressions, independently of valence. Therefore previously documented differences in effects of negative and positive emotions may have been confounded by differences in arousal. We conducted two studies to shed light on this issue. In Study 1 we developed a questionnaire including vignettes selected on the basis of psychometrical properties (i.e., mean ratings of the actions and variability). This questionnaire was administered to participants in Study 2, after presenting them with selected pictures inducing different valence but equivalent levels of arousal. Negative pictures led to more severe moral judgments than neutral (p = .054, d = 0.60) and positive pictures (p = .002, d = 1.02), for vignettes that were not associated with extreme judgments. In contrast, positive pictures did not reliably affect judgments concerning such vignettes. These findings suggest that the observed effects of emotions cannot be accounted for by an increase in attention linked to the arousal which accompanies these emotions.

What is the Valence of Mn in Ga(1-x)Mn(x)N?

Science.gov (United States)

Nelson, Ryky; Berlijn, Tom; Moreno, Juana; Jarrell, Mark; Ku, Wei

2015-11-06

We investigate the current debate on the Mn valence in Ga(1-x)Mn(x)N, a diluted magnetic semiconductor (DMS) with a potentially high Curie temperature. From a first-principles Wannier-function analysis, we unambiguously find the Mn valence to be close to 2+ (d(5)), but in a mixed spin configuration with average magnetic moments of 4μ(B). By integrating out high-energy degrees of freedom differently, we further derive for the first time from first-principles two low-energy pictures that reflect the intrinsic dual nature of the doped holes in the DMS: (1) an effective d(4) picture ideal for local physics, and (2) an effective d(5) picture suitable for extended properties. In the latter, our results further reveal a few novel physical effects, and pave the way for future realistic studies of magnetism. Our study not only resolves one of the outstanding key controversies of the field, but also exemplifies the general need for multiple effective descriptions to account for the rich low-energy physics in many-body systems in general.

Direct double photoionization of the valence shell of Be

International Nuclear Information System (INIS)

Citrini, F.; Malegat, L.; Selles, P.; Kazansky, A.K.

2003-01-01

The hyperspherical R-matrix method with semiclassical outgoing waves is used to study the direct double photoionization (DPI) of the valence shell of the lightest alkaline earth-metal Be. The absolute fully integrated, singly, doubly, and triply differential cross sections obtained are compared with the single set of measurements available and with recent calculations based on the convergent close coupling and time-dependent close coupling methods. The level of agreement between all these data is very encouraging. A comparison is also made between the DPI of He and the direct DPI of the valence shell of Be. It confirms that the electron-electron correlations are stronger in the valence 2s shell of Be than in the 1s shell of He, thus contributing to a desirable clarification

Lakatos Revisited.

Science.gov (United States)

Court, Deborah

1999-01-01

Revisits and reviews Imre Lakatos' ideas on "Falsification and the Methodology of Scientific Research Programmes." Suggests that Lakatos' framework offers an insightful way of looking at the relationship between theory and research that is relevant not only for evaluating research programs in theoretical physics, but in the social…

On the electrical conductivity for the mixed-valence model with d-f correlations

International Nuclear Information System (INIS)

Borgiel, W.; Matlak, M.

1984-08-01

The static electrical conductivity of mixed-valence systems is calculated in the model of Matlak and Nolting [Solid State Commun., 47, 11 (1983); Z. Phys., B55, 103 (1984)]. The method takes into account the atomic properties more exactly than those connected with bands, and hence emphasizes the ionic aspect of the problem in some way; indeed, the calculations overestimate the atomic properties. Some results are presented in a graph. It is found that the electrical conductivity depends strongly on temperature and the electron-hole attraction constant

Flexible temperature and flow sensor from laser-induced graphene

KAUST Repository

Marengo, Marco

2017-12-25

Herein we present a flexible temperature sensor and a flow speed sensor based on laser-induced graphene. The main benefits arise from peculiar electrical, thermal and mechanical performances of the material thus obtained, along with a cheap and simple fabrication process. The temperature sensor is a negative temperature coefficient thermistor with non-linear response typical of semi-metals. The thermistor shows a 4% decrease of the resistance in a temperature range of 20–60 °C. The flow sensor exploits the piezoresistive properties of laser-induced graphene and can be used both in gaseous and liquid media thanks to a protective polydimethylsiloxane coating. Main characteristics are ultra-fast response and versatility in design offered by the laser technology.

Investigation of radiation-enhanced diffusions of non valency impurities in ionic crystals

International Nuclear Information System (INIS)

Surzhikov, A.P.; Pritulov, A.M.; Gyngazov, S.A.; Chernyavskij, A.V.

1999-01-01

Investigations of hetero valency ions Al +3 and Mg +2 diffusion in potassium bromide crystals, under the intensive electron radiation, were conducted. The electron accelerator ELV-6 generating a continuous electron beam of 1.4 MeV in power was used for the investigations. To discover the radiation effects, there was a comparison of outcomes of the heating under the same temperature and annealing duration values. The mass-spectrometer MS-7021M was used to measure the diffusion profiles. The experimental outcomes analysis was carried out by approximation of the experimental concentration profiles, using a relevant solution of Fick's equation. The numerical values of the diffusion factors for the set annealing temperatures were determined according to the approximation outcomes. The investigations were financed by the Russian Fundamental Research Fund

Variable valence of praseodymium in rare-earth oxide solid solutions

International Nuclear Information System (INIS)

Kravchinskaya, M.V.; Merezhinskii, K.Y.; Tikhonov, P.A.

1986-01-01

Solid solutions of elevated praseodymium oxide content have interesting electrical properties, making them the basis for the manufacture of high-temperature electrically conducting materials. Establishment of the composition-structure-valence state relationships enables control of the material properties. The authors performed investigations using a thermogravimetric apparatus with an electronic microbalance of type EM-5-3M, and using x-ray phase analysis of powders (DRON-1 diffractometer, CuK /SUB alpha/ -radiation). The authors also studied the kinetics of praseodymium oxidation with a thermogravimetric apparatus under isothermal conditions. Evaluation of the results with the equation of Kolmogorov, Erofeev, and Avraam indicates that the process is limited by the chemical oxidation of praseodymium and not by diffusion

Oxidative phosphorylation revisited

DEFF Research Database (Denmark)

Nath, Sunil; Villadsen, John

2015-01-01

The fundamentals of oxidative phosphorylation and photophosphorylation are revisited. New experimental data on the involvement of succinate and malate anions respectively in oxidative phosphorylation and photophosphorylation are presented. These new data offer a novel molecular mechanistic...

The random field Blume-Capel model revisited

Science.gov (United States)

Santos, P. V.; da Costa, F. A.; de Araújo, J. M.

2018-04-01

We have revisited the mean-field treatment for the Blume-Capel model under the presence of a discrete random magnetic field as introduced by Kaufman and Kanner (1990). The magnetic field (H) versus temperature (T) phase diagrams for given values of the crystal field D were recovered in accordance to Kaufman and Kanner original work. However, our main goal in the present work was to investigate the distinct structures of the crystal field versus temperature phase diagrams as the random magnetic field is varied because similar models have presented reentrant phenomenon due to randomness. Following previous works we have classified the distinct phase diagrams according to five different topologies. The topological structure of the phase diagrams is maintained for both H - T and D - T cases. Although the phase diagrams exhibit a richness of multicritical phenomena we did not found any reentrant effect as have been seen in similar models.

Increased Risk of Drug-Induced Hyponatremia during High Temperatures

Directory of Open Access Journals (Sweden)

Anna K Jönsson

2017-07-01

Full Text Available Purpose: To investigate the relationship between outdoor temperature in Sweden and the reporting of drug-induced hyponatremia to the Medical Products Agency (MPA. Methods: All individual adverse drug reactions (ADR reported to MPA from 1 January 2010 to 31 October 2013 of suspected drug-induced hyponatremia and random controls were identified. Reports where the ADR had been assessed as having at least a possible relation to the suspected drug were included. Information on administered drugs, onset date, causality assessment, sodium levels, and the geographical origin of the reports was extracted. A case-crossover design was used to ascertain the association between heat exposure and drug-induced hyponatremia at the individual level, while linear regression was used to study its relationship to sodium concentration in blood. Temperature exposure data were obtained from the nearest observation station to the reported cases. Results: During the study period, 280 reports of hyponatremia were identified. More cases of drug-induced hyponatremia were reported in the warmer season, with a peak in June, while other ADRs showed an opposite annual pattern. The distributed lag non-linear model indicated an increasing odds ratio (OR with increasing temperature in the warm season with a highest odds ratio, with delays of 1–5 days after heat exposure. A cumulative OR for a lag time of 1 to 3 days was estimated at 2.21 at an average daily temperature of 20 °C. The change in sodium per 1 °C increase in temperature was estimated to be −0.37 mmol/L (95% CI: −0.02, −0.72. Conclusions: Warm weather appears to increase the risk of drug-induced hyponatremia

Circular revisit orbits design for responsive mission over a single target

Science.gov (United States)

Li, Taibo; Xiang, Junhua; Wang, Zhaokui; Zhang, Yulin

2016-10-01

The responsive orbits play a key role in addressing the mission of Operationally Responsive Space (ORS) because of their capabilities. These capabilities are usually focused on supporting specific targets as opposed to providing global coverage. One subtype of responsive orbits is repeat coverage orbit which is nearly circular in most remote sensing applications. This paper deals with a special kind of repeating ground track orbit, referred to as circular revisit orbit. Different from traditional repeat coverage orbits, a satellite on circular revisit orbit can visit a target site at both the ascending and descending stages in one revisit cycle. This typology of trajectory allows a halving of the traditional revisit time and does a favor to get useful information for responsive applications. However the previous reported numerical methods in some references often cost lots of computation or fail to obtain such orbits. To overcome this difficulty, an analytical method to determine the existence conditions of the solutions to revisit orbits is presented in this paper. To this end, the mathematical model of circular revisit orbit is established under the central gravity model and the J2 perturbation. A constraint function of the circular revisit orbit is introduced, and the monotonicity of that function has been studied. The existent conditions and the number of such orbits are naturally worked out. Taking the launch cost into consideration, optimal design model of circular revisit orbit is established to achieve a best orbit which visits a target twice a day in the morning and in the afternoon respectively for several days. The result shows that it is effective to apply circular revisit orbits in responsive application such as reconnoiter of natural disaster.

Theoretical and experimental study of high-magnetic-field XMCD spectra at the L2,3 absorption edges of mixed-valence rare-earth compounds

International Nuclear Information System (INIS)

Kotani, Akio; Matsuda, Yasuhiro H; Nojiri, Hiroyuki

2009-01-01

X-ray magnetic circular dichroism(XMCD) spectra at the L 2,3 edges of mixed-valence rare-earth compounds in high magnetic fields are studied both theoretically and experimentally. The theoretical study is based on a new framework proposed recently by Kotani. The Zeeman splitting of 4f states, the mixed-valence character of 4f states, and the 4f-5d exchange interaction are incorporated into a single impurity Anderson model. New XMCD experiments in high magnetic fields up to 40 T are carried out for the mixed-valence compounds EuNi 2 (Si 0.18 Ge 0.82 ) 2 and YbInCu 4 by using a miniature pulsed magnet, which was developed recently by Matsuda et al. The XMCD data are taken at 5 K by transmission measurements for incident X-rays with ± helicities at BL39XU in SPring-8. After giving a survey on recent developments in the theory of XMCD spectra for mixed-valence Ce and Yb compounds, we calculate the XMCD spectra of YbInCu 4 at the field-induced valence transition around 32 T by applying the recent theoretical framework and by newly introducing at 32 T a discontinuous change in the Yb 4f level and that in the hybridization strength between the Yb 4f and conduction electrons. The calculated results are compared with the experimental ones.

Valence-Specific Laterality Effects in Vocal Emotion: Interactions with Stimulus Type, Blocking and Sex

Science.gov (United States)

Schepman, Astrid; Rodway, Paul; Geddes, Pauline

2012-01-01

Valence-specific laterality effects have been frequently obtained in facial emotion perception but not in vocal emotion perception. We report a dichotic listening study further examining whether valence-specific laterality effects generalise to vocal emotions. Based on previous literature, we tested whether valence-specific laterality effects were…

Praseodymium valency from crystal structure in Pr-Ba-Cu-O and (Y-Pr)-Ba-Cu-O single crystals

International Nuclear Information System (INIS)

Collin, G.; Albouy, P.A.; Monod, P.; Ribault, M.

1990-01-01

The substitution of Pr to Y leads to materials with a general formula (Y 1-v Pr v ) (Ba 2-x Pr x ) (Cu 3-y vac y ) O 6+x/2-y+z and with a structural transition around v + x' ∼ 0.5. For v + x 0.5 the crystals are tetragonal, La 1.5 Ba 1.5 Cu 3 O 7±z type, with the characteristic tri-twinning of this phase. The Pr valency, in the range 3-3.2 + depending on preparation conditions, is determined from interatomic distances. Orthorhombic crystals of Pr Ba Cu O prepared at high temperatures exhibit a high amount of defects, y ∼ 0.25 on the Cu(1) site and are semiconductors with a T -1/4 activation law attributed to the praseodymium valence fluctuation

The power of emotional valence-from cognitive to affective processes in reading.

Science.gov (United States)

Altmann, Ulrike; Bohrn, Isabel C; Lubrich, Oliver; Menninghaus, Winfried; Jacobs, Arthur M

2012-01-01

The comprehension of stories requires the reader to imagine the cognitive and affective states of the characters. The content of many stories is unpleasant, as they often deal with conflict, disturbance or crisis. Nevertheless, unpleasant stories can be liked and enjoyed. In this fMRI study, we used a parametric approach to examine (1) the capacity of increasing negative valence of story contents to activate the mentalizing network (cognitive and affective theory of mind, ToM), and (2) the neural substrate of liking negatively valenced narratives. A set of 80 short narratives was compiled, ranging from neutral to negative emotional valence. For each story mean rating values on valence and liking were obtained from a group of 32 participants in a prestudy, and later included as parametric regressors in the fMRI analysis. Another group of 24 participants passively read the narratives in a three Tesla MRI scanner. Results revealed a stronger engagement of affective ToM-related brain areas with increasingly negative story valence. Stories that were unpleasant, but simultaneously liked, engaged the medial prefrontal cortex (mPFC), which might reflect the moral exploration of the story content. Further analysis showed that the more the mPFC becomes engaged during the reading of negatively valenced stories, the more coactivation can be observed in other brain areas related to the neural processing of affective ToM and empathy.

Modulation of motor-meaning congruity effects for valenced words

OpenAIRE

Brookshire, Geoffrey; Ivry, Richard; Casasanto, Daniel

2010-01-01

We investigated the extent to which emotionally valenced words automatically cue spatio-motor representations. Participants made speeded button presses, moving their hand upward or downward while viewing words with positive or negative valence. Only the color of the words was relevant to the response; on target trials, there was no requirement to read the words or process their meaning. In Experiment 1, upward responses were faster for positive words, and downward for negative words. This eff...

Topological terms induced by finite temperature and density fluctuations

International Nuclear Information System (INIS)

Niemi, A.J.; Department of Physics, The Ohio State University, Columbus, Ohio 43210)

1986-01-01

In (3+1)-dimensional finite-temperature and -density SU(2) gauge theories with left-handed fermions, the three-dimensional Chern-Simons term (topological mass) can be induced by radiative corrections. This result is derived by use of a family's index theorem which also implies that in many other quantum field theories various additional lower-dimensional topological terms can be induced. In the high-temperature limit these terms dominate the partition function, which suggests applications to early-Universe cosmology

Influence of emotional valence and arousal on the spread of activation in memory.

Science.gov (United States)

Jhean-Larose, Sandra; Leveau, Nicolas; Denhière, Guy

2014-11-01

Controversy still persists on whether emotional valence and arousal influence cognitive activities. Our study sought to compare how these two factors foster the spread of activation within the semantic network. In a lexical decision task, prime words were varied depending on the valence (pleasant or unpleasant) or on the level of emotional arousal (high or low). Target words were carefully selected to avoid semantic priming effects, as well as to avoid arousing specific emotions (neutral). Three SOA durations (220, 420 and 720 ms) were applied across three independent groups. Results indicate that at 220 ms, the effect of arousal is significantly higher than the effect of valence in facilitating spreading activation while at 420 ms, the effect of valence is significantly higher than the effect of arousal in facilitating spreading activation. These findings suggest that affect is a sequential process involving the successive intervention of arousal and valence.

Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS

International Nuclear Information System (INIS)

Kozyukhin, S.; Golovchak, R.; Kovalskiy, A.; Shpotyuk, O.; Jain, H.

2011-01-01

High-resolution X-ray photoelectron spectroscopy (XPS) is used to study regularities in the formation of valence band electronic structure in binary As x Se 100−x , As x S 100−x , Ge x Se 100−x and Ge x S 100−x chalcogenide vitreous semiconductors. It is shown that the highest occupied energetic states in the valence band of these materials are formed by lone pair electrons of chalcogen atoms, which play dominant role in the formation of valence band electronic structure of chalcogen-rich glasses. A well-expressed contribution from chalcogen bonding p electrons and more deep s orbitals are also recorded in the experimental valence band XPS spectra. Compositional dependences of the observed bands are qualitatively analyzed from structural and compositional points of view.

Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS

Energy Technology Data Exchange (ETDEWEB)

Kozyukhin, S., E-mail: sergkoz@igic.ras.ru [Russian Academy of Science, Institute of General and Inorganic Chemistry (Russian Federation); Golovchak, R. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Kovalskiy, A. [Lehigh University, Department of Materials Science and Engineering (United States); Shpotyuk, O. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Jain, H. [Lehigh University, Department of Materials Science and Engineering (United States)

2011-04-15

High-resolution X-ray photoelectron spectroscopy (XPS) is used to study regularities in the formation of valence band electronic structure in binary As{sub x}Se{sub 100-x}, As{sub x}S{sub 100-x}, Ge{sub x}Se{sub 100-x} and Ge{sub x}S{sub 100-x} chalcogenide vitreous semiconductors. It is shown that the highest occupied energetic states in the valence band of these materials are formed by lone pair electrons of chalcogen atoms, which play dominant role in the formation of valence band electronic structure of chalcogen-rich glasses. A well-expressed contribution from chalcogen bonding p electrons and more deep s orbitals are also recorded in the experimental valence band XPS spectra. Compositional dependences of the observed bands are qualitatively analyzed from structural and compositional points of view.

Valence and inner-valence shell dissociative photoionization of CO in the 26-33 eV range. II. Molecular-frame and recoil-frame photoelectron angular distributions

DEFF Research Database (Denmark)

Lebech, M.; Houver, J.C.; Raseev, G.

2012-01-01

Experimental and theoretical results for molecular-frame photoemission are presented for inner-valence shell photoionization of the CO molecule induced by linearly and circularly polarized light. The experimental recoil frame photoelectron angular distributions (RFPADs) obtained from dissociative...... photoionization measurements where the velocities of the ionic fragment and photoelectron were detected in coincidence, are compared to RFPADs computed using the multichannel Schwinger configuration interaction method. The formalism for including a finite lifetime of the predissociative ion state is presented...... for the case of general elliptically polarized light, to obtain the RFPAD rather than the molecular frame photoelectron angular distribution (MFPAD), which would be obtained with the assumption of instantaneous dissociation. We have considered photoionization of CO for the photon energies of 26.0 eV, 29.5 e...

Age-related emotional bias in processing two emotionally valenced tasks.

Science.gov (United States)

Allen, Philip A; Lien, Mei-Ching; Jardin, Elliott

2017-01-01

Previous studies suggest that older adults process positive emotions more efficiently than negative emotions, whereas younger adults show the reverse effect. We examined whether this age-related difference in emotional bias still occurs when attention is engaged in two emotional tasks. We used a psychological refractory period paradigm and varied the emotional valence of Task 1 and Task 2. In both experiments, Task 1 was emotional face discrimination (happy vs. angry faces) and Task 2 was sound discrimination (laugh, punch, vs. cork pop in Experiment 1 and laugh vs. scream in Experiment 2). The backward emotional correspondence effect for positively and negatively valenced Task 2 on Task 1 was measured. In both experiments, younger adults showed a backward correspondence effect from a negatively valenced Task 2, suggesting parallel processing of negatively valenced stimuli. Older adults showed similar negativity bias in Experiment 2 with a more salient negative sound ("scream" relative to "punch"). These results are consistent with an arousal-bias competition model [Mather and Sutherland (Perspectives in Psychological Sciences 6:114-133, 2011)], suggesting that emotional arousal modulates top-down attentional control settings (emotional regulation) with age.

Induced gravity and gauge interactions revisited

International Nuclear Information System (INIS)

Broda, Boguslaw; Szanecki, Michal

2009-01-01

It has been shown that the primary, old-fashioned idea of Sakharov's induced gravity and gauge interactions, in the 'one-loop dominance' version, works astonishingly well yielding phenomenologically reasonable results. As a byproduct, the issue of the role of the UV cutoff in the context of the induced gravity has been reexamined (an idea of self-cutoff induced gravity). As an additional check, the black hole entropy has been used in the place of the action. Finally, it has been explicitly shown that the induced coupling constants of gauge interactions of the standard model assume qualitatively realistic values.

Photoion mass spectroscopy and valence photoionization of hypoxanthine, xanthine and caffeine

Energy Technology Data Exchange (ETDEWEB)

Feyer, Vitaliy, E-mail: vitaliy.feyer@elettra.trieste.it [Sincrotrone Trieste, in Area Science Park, I-34012 Basovizza (Trieste) (Italy); Plekan, Oksana [Sincrotrone Trieste, in Area Science Park, I-34012 Basovizza (Trieste) (Italy)] [Institute of Electron Physics, 21 Universitetska St., 88017 Uzhgorod (Ukraine); Richter, Robert [Sincrotrone Trieste, in Area Science Park, I-34012 Basovizza (Trieste) (Italy); Coreno, Marcello [CNR-IMIP, Area della Ricerca di Roma 1, CP10, I-00016 Monterotondo Scalo (Italy)] [CNR-Laboratorio Nazionale TASC-INFM, I-34012 Basovizza (Trieste) (Italy); Prince, Kevin C. [Sincrotrone Trieste, in Area Science Park, I-34012 Basovizza (Trieste) (Italy)] [CNR-Laboratorio Nazionale TASC-INFM, I-34012 Basovizza (Trieste) (Italy)

2009-03-30

Photoionization mass spectra of hypoxanthine, xanthine and caffeine were measured using the photoelectron-photoion coincidence technique and noble gas resonance radiation at energies from 8.4 to 21.2 eV for ionization. The fragmentation patterns for these compounds show that hydrogen cyanide is the main neutral loss species at higher photon energies, while photoionization below 16.67 eV led predominantly to the parent ion. The valence photoelectron spectra of this family of molecules were measured over an extended energy range, including the inner C, N and O 2s valence orbitals. The observed ion fragments were related to ionization of the valence orbitals.

The processing of inter-item relations as a moderating factor of retrieval-induced forgetting

OpenAIRE

Tempel, Tobias; Wippich, Werner

2012-01-01

We investigated influences of item generation and emotional valence on retrieval-induced forgetting. Drawing on postulates of the three-factor theory of generation effects, generation tasks differentially affecting the processing of inter-item relations were applied. Whereas retrieval-induced forgetting of freely generated items was moderated by the emotional valence as well as retrieval-induced forgetting of read items, even though in the reverse direction (Experiment 1), fragment completion...

An all optical system for studying temperature induced changes in diamond

CSIR Research Space (South Africa)

Masina, B

2010-01-01

Full Text Available .csir.co.za An all optical system for studying temperature induced changes in diamond Bathusile Masina and Andrew Forbes 1 September 2010 © CSIR 2010 Slide 2 It is acknowledged that temperature induces damage in the diamond bits due to friction during the drilling...

Clustering of low-valence particles: structure and kinetics.

Science.gov (United States)

Markova, Olga; Alberts, Jonathan; Munro, Edwin; Lenne, Pierre-François

2014-08-01

We compute the structure and kinetics of two systems of low-valence particles with three or six freely oriented bonds in two dimensions. The structure of clusters formed by trivalent particles is complex with loops and holes, while hexavalent particles self-organize into regular and compact structures. We identify the elementary structures which compose the clusters of trivalent particles. At initial stages of clustering, the clusters of trivalent particles grow with a power-law time dependence. Yet at longer times fusion and fission of clusters equilibrates and clusters form a heterogeneous phase with polydispersed sizes. These results emphasize the role of valence in the kinetics and stability of finite-size clusters.

The bidirectional congruency effect of brightness-valence metaphoric association in the Stroop-like and priming paradigms.

Science.gov (United States)

Huang, Yanli; Tse, Chi-Shing; Xie, Jiushu

2017-11-04

The conceptual metaphor theory (Lakoff & Johnson, 1980, 1999) postulates a unidirectional metaphoric association between abstract and concrete concepts: sensorimotor experience activated by concrete concepts facilitates the processing of abstract concepts, but not the other way around. However, this unidirectional view has been challenged by studies that reported a bidirectional metaphoric association. In three experiments, we tested the directionality of the brightness-valence metaphoric association, using Stroop-like paradigm, priming paradigm, and Stroop-like paradigm with a go/no-go manipulation. Both mean and vincentile analyses of reaction time data were performed. We showed that the directionality of brightness-valence metaphoric congruency effect could be modulated by the activation level of the brightness/valence information. Both brightness-to-valence and valence-to-brightness metaphoric congruency effects occurred in the priming paradigm, which could be attributed to the presentation of prime that pre-activated the brightness or valence information. However, in the Stroop-like paradigm the metaphoric congruency effect was only observed in the brightness-to-valence direction, but not in the valence-to-brightness direction. When the go/no-go manipulation was used to boost the activation of word meaning in the Stroop-like paradigm, the valence-to-brightness metaphoric congruency effect was observed. Vincentile analyses further revealed that valence-to-brightness metaphoric congruency effect approached significance in the Stroop-like paradigm when participants' reaction times were slower (at around 490ms). The implications of the current findings on the conceptual metaphor theory and embodied cognition are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Revisiting Okun's Relationship

NARCIS (Netherlands)

Dixon, R.; Lim, G.C.; van Ours, Jan

2016-01-01

Our paper revisits Okun's relationship between observed unemployment rates and output gaps. We include in the relationship the effect of labour market institutions as well as age and gender effects. Our empirical analysis is based on 20 OECD countries over the period 1985-2013. We find that the

Valence and Magnetic Transitions in YbMn2Ge2-Applied Pressure

International Nuclear Information System (INIS)

Hofmann, M.; Link, P.; Campbell, S.J.; Goncharenko, I.

2005-01-01

Full text: Rare-earth intermetallic compounds containing ytterbium exhibit a wide range of interesting and unusual physical and magnetic properties. This occurs mainly as a result of their mixed valence states (II/III) or changes from one valence state to the other. We have recently determined the magnetic structures of tetragonal YbMn 2 Ge 2 (I4/mmm) by powder neutron diffraction experiments and demonstrated that YbMn 2 Ge 2 has a planar antiferromagnetic structure below T N1 ∼ 510 K with a canted antiferromagnetic structure below T N2 ∼ 185 K. As applied pressure favours changes in the valence character of intermediate valence systems and correspondingly influences the magnetic behaviour, we have investigated the effects of applied pressure on YbMn 2 Ge 2 . Analyses of our in situ neutron diffraction experiments (T=1.5-300 K; p=0-2.7 GPa), reveal a distinct change in magnetic structure and a sharp drop in the a-lattice parameter above ∼ 1.4 GPa with the changes associated with a valence transition. A full account of these effects will be discussed in relation to our current photoelectron spectroscopy measurements of YbMn 2 Ge 2 . (authors)

Transforming from paramagnetism to room temperature ferromagnetism in CuO by ball milling

Directory of Open Access Journals (Sweden)

Daqiang Gao

2011-12-01

Full Text Available In this work, we experimentally demonstrate that it is possible to induce ferromagnetism in CuO by ball milling without any ferromagnetic dopant. The magnetic measurements indicate that paramagnetic CuO is driven to the ferromagnetic state at room temperature by ball milling gradually. The saturation magnetization of the milled powders is found to increase with expanding the milling time and then decrease by annealing under atmosphere. The fitted X-ray photoelectron spectroscopy results indicate that the observed induction and weaken of the ferromagnetism shows close relationship with the valence charged oxygen vacancies (Cu1+-VO in CuO.

Approach and withdrawal tendencies during written word processing: effects of task, emotional valence and emotional arousal

OpenAIRE

Citron, Francesca Maria Marina; Abugaber, David; Herbert, Cornelia

2016-01-01

The affective dimensions of emotional valence and emotional arousal affect processing of verbal and pictorial stimuli. Traditional emotional theories assume a linear relationship between these dimensions, with valence determining the direction of a behaviour (approach vs. withdrawal) and arousal its intensity or strength. In contrast, according to the valence-arousal conflict theory, both dimensions are interactively related: positive valence and low arousal (PL) are associated with an implic...

Vanadium K XANES of synthetic olivine: Valence determinations and crystal orientation effects

International Nuclear Information System (INIS)

Sutton, S.R.; Newville, M.

2005-01-01

Vanadium can exist in a large number of valence states in nature (2+?, 3+, 4+ and 5+) and determinations of V valence is therefore valuable in defining the oxidation states of earth and planetary materials over a large redox range. Synchrotron-based x-ray absorption near edge structure (XANES) spectroscopy is well-suited for measurements of V valence with ∼micrometer spatial resolution and ∼ppm elemental sensitivity. Applications of microXANES have been demonstrated for basaltic glasses. Applications to minerals are feasible but complicated by orientation effects (e.g. due to polarization of the synchrotron x-ray beam) and some results for spinel have been reported. Here we report initial results for olivine from laboratory crystallization ex-periments. The goal is to define the valence partition-ing between olivine and melt and quantify the magnitude of orientation effects, the latter tested by measuring grains at a variety of orientations in the same charge.

Composition-induced structural, electrical, and magnetic phase transitions in AX-type mixed-valence cobalt oxynitride epitaxial thin films

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Jumpei; Oka, Daichi [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu, Kawasaki 213-0012 (Japan); Hirose, Yasushi, E-mail: hirose@chem.s.u-tokyo.ac.jp; Yang, Chang; Fukumura, Tomoteru; Hasegawa, Tetsuya [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu, Kawasaki 213-0012 (Japan); CREST, Japan Science and Technology Agency, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Nakao, Shoichiro [Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu, Kawasaki 213-0012 (Japan); CREST, Japan Science and Technology Agency, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Harayama, Isao; Sekiba, Daiichiro [University of Tsukuba Tandem Accelerator Complex (UTTAC), 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577 (Japan)

2015-12-07

Synthesis of mid- to late-transition metal oxynitrides is generally difficult by conventional thermal ammonolysis because of thermal instability. In this letter, we synthesized epitaxial thin films of AX-type phase-pure cobalt oxynitrides (CoO{sub x}N{sub y}) by using nitrogen-plasma-assisted pulsed laser deposition and investigated their structural, electrical, and magnetic properties. The CoO{sub x}N{sub y} thin films with 0 ≤ y/(x + y) ≤ 0.63 grown on MgO (100) substrates showed a structural phase transition from rock salt (RS) to zinc blend at the nitrogen content y/(x + y) ∼ 0.5. As the nitrogen content increased, the room-temperature electrical resistivity of the CoO{sub x}N{sub y} thin films monotonically decreased from the order of 10{sup 5} Ω cm to 10{sup −4} Ω cm. Furthermore, we observed an insulator-to-metal transition at y/(x + y) ∼ 0.34 in the RS-CoO{sub x}N{sub y} phase, which has not yet been reported in Co{sup 2+}/Co{sup 3+} mixed-valence cobalt oxides with octahedral coordination. The low resistivity in the RS-CoO{sub x}N{sub y} phase, on the 10{sup −3} Ω cm order, may have originated from the intermediate spin state of Co{sup 3+} stabilized by the lowered crystal field symmetry of the CoO{sub 6−n}N{sub n} octahedra (n = 1, 2,…5). Magnetization measurements suggested that a magnetic phase transition occurred in the RS-CoO{sub x}N{sub y} films during the insulator-to-metal transition. These results demonstrate that low-temperature epitaxial growth is a promising approach for exploring novel electronic functionalities in oxynitrides.

Composition-induced structural, electrical, and magnetic phase transitions in AX-type mixed-valence cobalt oxynitride epitaxial thin films

International Nuclear Information System (INIS)

Takahashi, Jumpei; Oka, Daichi; Hirose, Yasushi; Yang, Chang; Fukumura, Tomoteru; Hasegawa, Tetsuya; Nakao, Shoichiro; Harayama, Isao; Sekiba, Daiichiro

2015-01-01

Synthesis of mid- to late-transition metal oxynitrides is generally difficult by conventional thermal ammonolysis because of thermal instability. In this letter, we synthesized epitaxial thin films of AX-type phase-pure cobalt oxynitrides (CoO x N y ) by using nitrogen-plasma-assisted pulsed laser deposition and investigated their structural, electrical, and magnetic properties. The CoO x N y thin films with 0 ≤ y/(x + y) ≤ 0.63 grown on MgO (100) substrates showed a structural phase transition from rock salt (RS) to zinc blend at the nitrogen content y/(x + y) ∼ 0.5. As the nitrogen content increased, the room-temperature electrical resistivity of the CoO x N y thin films monotonically decreased from the order of 10 5  Ω cm to 10 −4  Ω cm. Furthermore, we observed an insulator-to-metal transition at y/(x + y) ∼ 0.34 in the RS-CoO x N y phase, which has not yet been reported in Co 2+ /Co 3+ mixed-valence cobalt oxides with octahedral coordination. The low resistivity in the RS-CoO x N y phase, on the 10 −3  Ω cm order, may have originated from the intermediate spin state of Co 3+ stabilized by the lowered crystal field symmetry of the CoO 6−n N n octahedra (n = 1, 2,…5). Magnetization measurements suggested that a magnetic phase transition occurred in the RS-CoO x N y films during the insulator-to-metal transition. These results demonstrate that low-temperature epitaxial growth is a promising approach for exploring novel electronic functionalities in oxynitrides

Temperature-induced plasticity in egg size and resistance of eggs to temperature stress in a soil arthropod.

NARCIS (Netherlands)

Liefting, M.; Weerenbeck, M.; van Dooremalen, J.A.; Ellers, J.

2010-01-01

Temperature is considered one of the most important mediators of phenotypic plasticity in ectotherms, resulting in predictable changes in egg size. However, the fitness consequences of temperature-induced plasticity in egg size are not well understood and are often assessed at mild temperatures,

Basic features of the pion valence-quark distribution function

Energy Technology Data Exchange (ETDEWEB)

Chang, Lei [CSSM, School of Chemistry and Physics, University of Adelaide, Adelaide, SA 5005 (Australia); Mezrag, Cédric; Moutarde, Hervé [Centre de Saclay, IRFU/Service de Physique Nucléaire, F-91191 Gif-sur-Yvette (France); Roberts, Craig D. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Rodríguez-Quintero, Jose [Departamento de Física Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Huelva E-21071 (Spain); Tandy, Peter C. [Center for Nuclear Research, Department of Physics, Kent State University, Kent, OH 44242 (United States)

2014-10-07

The impulse-approximation expression used hitherto to define the pion's valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression produces the model-independent result that quarks dressed via the rainbow–ladder truncation, or any practical analogue, carry all the pion's light-front momentum at a characteristic hadronic scale. Corrections to the leading contribution may be divided into two classes, responsible for shifting dressed-quark momentum into glue and sea-quarks. Working with available empirical information, we use an algebraic model to express the principal impact of both classes of corrections. This enables a realistic comparison with experiment that allows us to highlight the basic features of the pion's measurable valence-quark distribution, q{sup π}(x); namely, at a characteristic hadronic scale, q{sup π}(x)∼(1−x){sup 2} for x≳0.85; and the valence-quarks carry approximately two-thirds of the pion's light-front momentum.

Spectroscopic determination of valence band parameters in InP

International Nuclear Information System (INIS)

Lewis, R.A.; Lough, B.C.C.

2003-01-01

Full text: The general form of the Hamiltonian for an electron or hole in a semiconductor has been given by Luttinger. The valence band is characterised by three parameters - γ 1 , γ 2 , γ 3 -now commonly known as the Luttinger parameters. Despite many investigations there is still considerable uncertainty regarding the Luttinger parameters of InP. The situation has been reviewed by Hackenberg et al. These authors themselves sought to determine the Luttinger parameters by hot-electron luminescence and discovered that many Luttinger parameter triplets were consistent with their data. We employ a spectroscopic approach to estimating valence-band parameters in InP. Calculations have been made for both the unperturbed energy levels and the energy levels in a magnetic field of acceptor impurities in semiconductors characterised by different Luttinger parameters. We compare our recent experimental data for the transitions associated with the Zn acceptor impurity in InP in magnetic fields up to 30 T to determine the most appropriate set of valence-band parameters for InP

Tourists' perceptions and intention to revisit Norway

OpenAIRE

Lazar, Ana Florina; Komolikova-Blindheim, Galyna

2016-01-01

Purpose - The overall purpose of this study is to explore tourists' perceptions and their intention to revisit Norway. The aim is to find out what are the factors that drive the overall satisfaction, the willingness to recommend and the revisit intention of international tourists that spend their holiday in Norway. Design-Method-Approach - the Theory of Planned Behavior (Ajzen 1991), is used as a framework to investigate tourists' intention and behavior towards Norway as destination. The o...

Temperature-induced viral resistance in Emiliania huxleyi (Prymnesiophyceae).

Science.gov (United States)

Kendrick, B Jacob; DiTullio, Giacomo R; Cyronak, Tyler J; Fulton, James M; Van Mooy, Benjamin A S; Bidle, Kay D

2014-01-01

Annual Emiliania huxleyi blooms (along with other coccolithophorid species) play important roles in the global carbon and sulfur cycles. E. huxleyi blooms are routinely terminated by large, host-specific dsDNA viruses, (Emiliania huxleyi Viruses; EhVs), making these host-virus interactions a driving force behind their potential impact on global biogeochemical cycles. Given projected increases in sea surface temperature due to climate change, it is imperative to understand the effects of temperature on E. huxleyi's susceptibility to viral infection and its production of climatically active dimethylated sulfur species (DSS). Here we demonstrate that a 3°C increase in temperature induces EhV-resistant phenotypes in three E. huxleyi strains and that successful virus infection impacts DSS pool sizes. We also examined cellular polar lipids, given their documented roles in regulating host-virus interactions in this system, and propose that alterations to membrane-bound surface receptors are responsible for the observed temperature-induced resistance. Our findings have potential implications for global biogeochemical cycles in a warming climate and for deciphering the particular mechanism(s) by which some E. huxleyi strains exhibit viral resistance.

A facilitative effect of negative affective valence on working memory.

Science.gov (United States)

Gotoh, Fumiko; Kikuchi, Tadashi; Olofsson, Ulrich

2010-06-01

Previous studies have shown that negatively valenced information impaired working memory performance due to an attention-capturing effect. The present study examined whether negative valence could also facilitate working memory. Affective words (negative, neutral, positive) were used as retro-cues in a working memory task that required participants to remember colors at different spatial locations on a computer screen. Following the cue, a target detection task was used to either shift attention to a different location or keep attention at the same location as the retro-cue. Finally, participants were required to discriminate the cued color from a set of distractors. It was found that negative cues yielded shorter response times (RTs) in the attention-shift condition and longer RTs in the attention-stay condition, compared with neutral and positive cues. The results suggest that negative affective valence may enhance working memory performance (RTs), provided that attention can be disengaged.

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

Science.gov (United States)

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

2017-09-07

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

Temperature-induced transitions in disordered proteins probed by NMR spectroscopy

DEFF Research Database (Denmark)

Kjærgaard, Magnus; Poulsen, Flemming Martin; Kragelund, Birthe Brandt

2012-01-01

Intrinsically disordered proteins are abundant in nature and perform many important physiological functions. Multidimensional NMR spectroscopy has been crucial for the understanding of the conformational properties of disordered proteins and is increasingly used to probe their conformational...... ensembles. Compared to folded proteins, disordered proteins are more malleable and more easily perturbed by environmental factors. Accordingly, the experimental conditions and especially the temperature modify the structural and functional properties of disordered proteins. NMR spectroscopy allows analysis...... of temperature-induced structural changes at residue resolution using secondary chemical shift analysis, paramagnetic relaxation enhancement, and residual dipolar couplings. This chapter discusses practical aspects of NMR studies of temperature-induced structural changes in disordered proteins....

Quantum Zeno subspaces induced by temperature

Energy Technology Data Exchange (ETDEWEB)

Militello, B.; Scala, M.; Messina, A. [Dipartimento di Fisica dell' Universita di Palermo, Via Archirafi 36, I-90123 Palermo (Italy)

2011-08-15

We discuss the partitioning of the Hilbert space of a quantum system induced by the interaction with another system at thermal equilibrium, showing that the higher the temperature the more effective is the formation of Zeno subspaces. We show that our analysis keeps its validity even in the case of interaction with a bosonic reservoir, provided appropriate limitations of the relevant bandwidth.

Valence properties of tellurium in different chemical systems and its determination in refractory environmental samples using hydride generation – Atomic fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Chen, Yu-Wei; Alzahrani, Ali [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada); Deng, Tian-Long [College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin (China); Belzile, Nelson, E-mail: nbelzile@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada); Cooperative Freshwater Ecology Unit, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)

2016-01-28

Using HG – AFS as a powerful tool to study valence transformations of Te, we found that, in presence of HCl and at high temperature, Te can form volatile species and be lost during sample digestion and pre-reduction steps. It was also noticed that the chemical valences of Te can be modified under different chemical and digestion conditions and even by samples themselves with certain matrices. KBr can reduce Te(VI) to Te(IV) in 3.0 M HCl at 100 °C, but when HNO{sub 3} was >5% (v/v) in solution, Br{sub 2} was formed and caused serious interference to Te measurements. HCl alone can also pre-reduce Te(VI) to Te(IV), only when its concentration was ≥6.0 M (100 °C for 15min). Among 10 studied chemical elements, only Cu{sup 2+} caused severe interference. Thiourea is an effective masking agent only when Cu{sup 2+} concentration is equal or lower than 10 mg/L. Chemical reagents, chemical composition of sample, as well as the modes of digestion can greatly affect Te valences, reagent blanks and analytical precisions. A protocol of 2–step–digestion followed by an elimination of HF is proposed to minimize reagent blank and increase the signal/noise ratios. It is important to perform a preliminary test to confirm whether a pre-reduction step is necessary; this is especially true for samples with complex matrices such as those with high sulfide content. The analytical detection limits of this method in a pure solution and a solid sample were 100 ng/L and 0.10 ± 0.02 μg/g, respectively. - Highlights: • HG–AFS is a powerful tool in studies of chemical valences and forms of Te in different conditions. • Te can be lost in form of volatile species in presence of HCl at high temperature. • Metal ions can be classified into 3 categories of interference; thiourea can effectively mask Cu{sup 2+}. • A 2-step digestion allows to eliminate HF, reduce background and improve analytical precision. • Matrix of sample can strongly influence Te chemical valence

The power of emotional valence – From cognitive to affective processes in reading

Directory of Open Access Journals (Sweden)

Ulrike eAltmann

2012-06-01

Full Text Available The comprehension of stories requires the reader to imagine the cognitive and affective states of the characters. The content of many stories is unpleasant, as they often deal with conflict, disturbance or crisis. Nevertheless, unpleasant stories can be liked and enjoyed. In this fMRI study, we used a parametric approach to examine (1 the capacity of increasing negative valence of story contents to activate the mentalizing network (cognitive and affective theory of mind, ToM, and (2 the neural substrate of liking negatively valenced narratives. A set of 80 short narratives was compiled, ranging from neutral to negative emotional valence. For each story mean rating values on valence and liking were obtained from a group of 32 participants in a prestudy, and later included as parametric regressors in the fMRI analysis. Another group of 24 participants passively read the narratives in a 3 Tesla MRI scanner. Results revealed a stronger engagement of affective ToM-related brain areas with increasingly negative story valence. Stories that were unpleasant, but simulatiously liked, selectively engaged the medial prefrontal cortex (mPFC, which might reflect the moral exploration of the story content. Further analysis showed that the more the mPFC becomes engaged during the reading of negatively valenced stories, the more coactivation can be observed in other brain areas related to the neural processing of affective ToM and empathy.

Predictors and Outcomes of Revisits in Older Adults Discharged from the Emergency Department.

Science.gov (United States)

de Gelder, Jelle; Lucke, Jacinta A; de Groot, Bas; Fogteloo, Anne J; Anten, Sander; Heringhaus, Christian; Dekkers, Olaf M; Blauw, Gerard J; Mooijaart, Simon P

2018-04-01

To study predictors of emergency department (ED) revisits and the association between ED revisits and 90-day functional decline or mortality. Multicenter cohort study. One academic and two regional Dutch hospitals. Older adults discharged from the ED (N=1,093). At baseline, data on demographic characteristics, illness severity, and geriatric parameters (cognition, functional capacity) were collected. All participants were prospectively followed for an unplanned revisit within 30 days and for functional decline and mortality 90 days after the initial visit. The median age was 79 (interquartile range 74-84), and 114 participants (10.4%) had an ED revisit within 30 days of discharge. Age (hazard ratio (HR)=0.96, 95% confidence interval (CI)=0.92-0.99), male sex (HR=1.61, 95% CI=1.05-2.45), polypharmacy (HR=2.06, 95% CI=1.34-3.16), and cognitive impairment (HR=1.71, 95% CI=1.02-2.88) were independent predictors of a 30-day ED revisit. The area under the receiver operating characteristic curve to predict an ED revisit was 0.65 (95% CI=0.60-0.70). In a propensity score-matched analysis, individuals with an ED revisit were at higher risk (odds ratio=1.99 95% CI=1.06-3.71) of functional decline or mortality. Age, male sex, polypharmacy, and cognitive impairment were independent predictors of a 30-day ED revisit, but no useful clinical prediction model could be developed. However, an early ED revisit is a strong new predictor of adverse outcomes in older adults. © 2018 The Authors. The Journal of the American Geriatrics Society published by Wiley Periodicals, Inc. on behalf of The American Geriatrics Society.

Sensemaking Revisited

DEFF Research Database (Denmark)

Holt, Robin; Cornelissen, Joep

2014-01-01

We critique and extend theory on organizational sensemaking around three themes. First, we investigate sense arising non-productively and so beyond any instrumental relationship with things; second, we consider how sense is experienced through mood as well as our cognitive skills of manipulation ...... research by revisiting Weick’s seminal reading of Norman Maclean’s book surrounding the tragic events of a 1949 forest fire at Mann Gulch, USA....

Temperature Oscillations in Loop Heat Pipes - A Revisit

Science.gov (United States)

Ku, Jentung

2018-01-01

Three types of temperature oscillation have been observed in the loop heat pipes. The first type is an ultra-high frequency temperature oscillation with a period on the order of seconds or less. This type of temperature oscillation is of little significance in spacecraft thermal control because the amplitude is in the noise level. The second type is a high frequency, low amplitude temperature oscillation with a period on the order of seconds to minutes and an amplitude on the order of one Kelvin. It is caused by the back-and-forth movement of the vapor front near the inlet or outlet of the condenser. The third type is a low frequency, high amplitude oscillation with a period on the order of hours and an amplitude on the order of tens of Kelvin. It is caused by the modulation of the net heat load into the evaporator by the attached large thermal mass which absorbs and releases energy alternately. Several papers on LHP temperature oscillation have been published. This paper presents a further study on the underlying physical processes during the LHP temperature oscillation, with an emphasis on the third type of temperature oscillation. Specifically, equations governing the thermal and hydraulic behaviors of LHP operation will be used to describe interactions among LHP components, heat source, and heat sink. The following sequence of events and their interrelationship will also be explored: 1) maxima and minima of reservoir and thermal mass temperatures; 2) the range of the vapor front movement inside the condenser; 3) rates of change of the reservoir and thermal mass temperatures; 4) the rate of heat absorption and heat release by the thermal mass and the rate of vapor front movement; and 5) inflection points of the reservoir and thermal mass temperatures.

Contribution to the study of higher valency states of americium

International Nuclear Information System (INIS)

Langlet, Jean.

1976-01-01

Study of the chemistry of the higher valencies of americium in aqueous solutions and especially the autoreduction phenomenon. First a purification method of americium solutions is studied by precipitation, solvent extraction and ion exchange chromatography. Studies of higher valency states chemical properties are disturbed by the autoreduction phenomenon changing Am VI and Am V in Am III more stable. Stabilization of higher valency states, characterized by a steady concentration of Am VI in solution, can be done by complexation of Am VI and Am V ions or by a protecting effect of foreign ions. The original medium used has a complexing effect by SO 4 2- ions and a protecting effect by the system S 2 O 8 2- -Ag + consuming H 2 O 2 main reducing agent produced by water radiolysis. These effects are shown by the study of Am VI in acid and basic solutions. A mechanism of the stabilization effect is given [fr

The coordinate coherent states approach revisited

International Nuclear Information System (INIS)

Miao, Yan-Gang; Zhang, Shao-Jun

2013-01-01

We revisit the coordinate coherent states approach through two different quantization procedures in the quantum field theory on the noncommutative Minkowski plane. The first procedure, which is based on the normal commutation relation between an annihilation and creation operators, deduces that a point mass can be described by a Gaussian function instead of the usual Dirac delta function. However, we argue this specific quantization by adopting the canonical one (based on the canonical commutation relation between a field and its conjugate momentum) and show that a point mass should still be described by the Dirac delta function, which implies that the concept of point particles is still valid when we deal with the noncommutativity by following the coordinate coherent states approach. In order to investigate the dependence on quantization procedures, we apply the two quantization procedures to the Unruh effect and Hawking radiation and find that they give rise to significantly different results. Under the first quantization procedure, the Unruh temperature and Unruh spectrum are not deformed by noncommutativity, but the Hawking temperature is deformed by noncommutativity while the radiation specturm is untack. However, under the second quantization procedure, the Unruh temperature and Hawking temperature are untack but the both spectra are modified by an effective greybody (deformed) factor. - Highlights: ► Suggest a canonical quantization in the coordinate coherent states approach. ► Prove the validity of the concept of point particles. ► Apply the canonical quantization to the Unruh effect and Hawking radiation. ► Find no deformations in the Unruh temperature and Hawking temperature. ► Provide the modified spectra of the Unruh effect and Hawking radiation.

Observation of the c-f hybridization effect in valence-transition system EuPtP

Energy Technology Data Exchange (ETDEWEB)

Anzai, Hiroaki; Ichiki, Katsuya [Graduate School of Engineering, Osaka Prefecture University, Sakai (Japan); Schwier, Eike F.; Iwasawa, Hideaki; Arita, Masashi; Sato, Hitoshi; Shimada, Kenya; Namatame, Hirofumi; Taniguchi, Masaki [Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima (Japan); Mitsuda, Akihiro; Wada, Hirofumi [Graduate School of Science, Kyushu University, Fukuoka (Japan); Mimura, Kojiro [Graduate School of Engineering, Osaka Prefecture University, Sakai (Japan); Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima (Japan)

2017-06-15

We study the electronic structure of EuPtP, which exhibits two first-order valence transitions at T{sub 1} = 247 K and T{sub 2} = 201 K, using angle-resolved photoemission spectroscopy. Below T{sub 2}, we observe an energy gap at the crossing point of the bulk Eu 4f and conduction bands. The shape of band dispersions is described by a hybridization-band picture based on the periodic Anderson model. Our results demonstrate the c-f hybridization effect in the low-temperature phase of EuPtP. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Beyond Valence and Magnitude: a Flexible Evaluative Coding System in the Brain

Science.gov (United States)

Gu, Ruolei; Lei, Zhihui; Broster, Lucas; Wu, Tingting; Jiang, Yang; Luo, Yue-jia

2013-01-01

Outcome evaluation is a cognitive process that plays an important role in our daily lives. In most paradigms utilized in the field of experimental psychology, outcome valence and outcome magnitude are the two major features investigated. The classical “independent coding model” suggest that outcome valence and outcome magnitude are evaluated by separate neural mechanisms that may be mapped onto discrete event-related potential (ERP) components: feedback-related negativity (FRN) and the P3, respectively. To examine this model, we presented outcome valence and magnitude sequentially rather than simultaneously. The results reveal that when only outcome valence or magnitude is known, both the FRN and the P3 encode that outcome feature; when both aspects of outcome are known, the cognitive functions of the two components dissociate: the FRN responds to the information available in the current context, while the P3 pattern depends on outcome presentation sequence. The current study indicates that the human evaluative system, indexed in part by the FRN and the P3, is more flexible than previous theories suggested. PMID:22019775

Transfer of chirality from adsorbed chiral molecules to the substrates highlighted by circular dichroism in angle-resolved valence photoelectron spectroscopy

DEFF Research Database (Denmark)

Contini, G.; Turchini, S.; Sanna, Simone

2012-01-01

Studies of self-assembled chiral molecules on achiral metallic surfaces have mostly focused on the determination of the geometry of adsorbates and their electronic structure. The aim of this paper is to provide direct information on the chirality character of the system and on the chirality...... transfer from molecules to substrate by means of circular dichroism in the angular distribution of valence photoelectrons for the extended domain of the chiral self-assembled molecular structure, formed by alaninol adsorbed on Cu(100). We show, by the dichroic behavior of a mixed molecule–copper valence...... state, that the presence of molecular chiral domains induces asymmetry in the interaction with the substrate and locally transfers the chiral character to the underlying metal atoms participating in the adsorption process; combined information related to the asymmetry of the initial electronic state...

2D nanoporous membrane for cation removal from water: Effects of ionic valence, membrane hydrophobicity, and pore size

Science.gov (United States)

Köhler, Mateus Henrique; Bordin, José Rafael; Barbosa, Marcia C.

2018-06-01

Using molecular dynamic simulations, we show that single-layers of molybdenum disulfide (MoS2) and graphene can effectively reject ions and allow high water permeability. Solutions of water and three cations with different valencies (Na+, Zn2+, and Fe3+) were investigated in the presence of the two types of membranes, and the results indicate a high dependence of the ion rejection on the cation charge. The associative characteristic of ferric chloride leads to a high rate of ion rejection by both nanopores, while the monovalent sodium chloride induces lower rejection rates. Particularly, MoS2 shows 100% of Fe3+ rejection for all pore sizes and applied pressures. On the other hand, the water permeation does not vary with the cation valence, having dependence only with the nanopore geometric and chemical characteristics. This study helps us to understand the fluid transport through a nanoporous membrane, essential for the development of new technologies for the removal of pollutants from water.

Electronic structures and valence band splittings of transition metals doped GaNs

International Nuclear Information System (INIS)

Lee, Seung-Cheol; Lee, Kwang-Ryeol; Lee, Kyu-Hwan

2007-01-01

For a practical viewpoint, presence of spin splitting of valence band in host semiconductors by the doping of transition metal (TM) ions is an essential property when designing a diluted magnetic semiconductors (DMS) material. The first principle calculations were performed on the electronic and magnetic structure of 3d transition metal doped GaN. V, Cr, and Mn doped GaNs could not be candidates for DMS materials since most of their magnetic moments is concentrated on the TM ions and the splittings of valence band were negligible. In the cases of Fe, Co, Ni, and Cu doped GaNs, on the contrary, long-ranged spin splitting of valence band was found, which could be candidates for DMS materials

Effect of 7-nitroindazole on body temperature and methamphetamine-induced dopamine toxicity.

Science.gov (United States)

Callahan, B T; Ricaurte, G A

1998-08-24

The present study was undertaken to examine the role of temperature on the ability of 7-nitroindazole (7-NI) to prevent methamphetamine-induced dopamine (DA) neurotoxicity. Male Swiss-Webster mice received methamphetamine alone or in combination with 7-NI at either room temperature (20+/-1 degrees C) or at 28+/-1 degrees C. At 20+/-1 degrees C, 7-NI produced hypothermic effects and afforded total protection against methamphetamine-induced DA depletions in the striatum. At 28+/-1 degrees C, 7-NI produced minimal effects on body temperature and failed to prevent methamphetamine-induced DA reductions. These findings indicate that the neuroprotection afforded by 7-NI is likely related to its ability to produce hypothermia because agents that produce hypothermia and/or prevent hyperthermia are known to attenuate methamphetamine-induced neurotoxicity.

Age effects in emotional prospective memory: cue valence differentially affects the prospective and retrospective component.

Science.gov (United States)

Schnitzspahn, Katharina M; Horn, Sebastian S; Bayen, Ute J; Kliegel, Matthias

2012-06-01

While first studies suggested that emotional task material may enhance prospective memory performance in young and older adults, the extent and mechanisms of this effect are under debate. The authors explored possible differential effects of cue valence on the prospective and retrospective component of prospective memory in young and older adults. Forty-five young and 41 older adults performed a prospective memory task in which emotional valence of the prospective memory cue was manipulated (positive, negative, neutral). The multinomial model of event-based prospective memory was used to analyze effects of valence and age on the two prospective memory components separately. Results revealed an interaction indicating that age differences were smaller in both emotional valence conditions. For older adults positive cues improved the prospective component, while negative cues improved the retrospective component. No main effect of valence was found for younger adults on an overt accuracy measure, but model-based analyses showed that the retrospective component was enhanced in the positive compared with the negative cue condition. The study extends the literature in demonstrating that processes underlying emotional effects on prospective memory may differ depending on valence and age. PsycINFO Database Record (c) 2012 APA, all rights reserved

Mixing positive and negative valence: Affective-semantic integration of bivalent words.

Science.gov (United States)

Kuhlmann, Michael; Hofmann, Markus J; Briesemeister, Benny B; Jacobs, Arthur M

2016-08-05

Single words have affective and aesthetic properties that influence their processing. Here we investigated the processing of a special case of word stimuli that are extremely difficult to evaluate, bivalent noun-noun-compounds (NNCs), i.e. novel words that mix a positive and negative noun, e.g. 'Bombensex' (bomb-sex). In a functional magnetic resonance imaging (fMRI) experiment we compared their processing with easier-to-evaluate non-bivalent NNCs in a valence decision task (VDT). Bivalent NNCs produced longer reaction times and elicited greater activation in the left inferior frontal gyrus (LIFG) than non-bivalent words, especially in contrast to words of negative valence. We attribute this effect to a LIFG-grounded process of semantic integration that requires greater effort for processing converse information, supporting the notion of a valence representation based on associations in semantic networks.

Exchange Coupling Interactions from the Density Matrix Renormalization Group and N-Electron Valence Perturbation Theory: Application to a Biomimetic Mixed-Valence Manganese Complex.

Science.gov (United States)

Roemelt, Michael; Krewald, Vera; Pantazis, Dimitrios A

2018-01-09

The accurate description of magnetic level energetics in oligonuclear exchange-coupled transition-metal complexes remains a formidable challenge for quantum chemistry. The density matrix renormalization group (DMRG) brings such systems for the first time easily within reach of multireference wave function methods by enabling the use of unprecedentedly large active spaces. But does this guarantee systematic improvement in predictive ability and, if so, under which conditions? We identify operational parameters in the use of DMRG using as a test system an experimentally characterized mixed-valence bis-μ-oxo/μ-acetato Mn(III,IV) dimer, a model for the oxygen-evolving complex of photosystem II. A complete active space of all metal 3d and bridge 2p orbitals proved to be the smallest meaningful starting point; this is readily accessible with DMRG and greatly improves on the unrealistic metal-only configuration interaction or complete active space self-consistent field (CASSCF) values. Orbital optimization is critical for stabilizing the antiferromagnetic state, while a state-averaged approach over all spin states involved is required to avoid artificial deviations from isotropic behavior that are associated with state-specific calculations. Selective inclusion of localized orbital subspaces enables probing the relative contributions of different ligands and distinct superexchange pathways. Overall, however, full-valence DMRG-CASSCF calculations fall short of providing a quantitative description of the exchange coupling owing to insufficient recovery of dynamic correlation. Quantitatively accurate results can be achieved through a DMRG implementation of second order N-electron valence perturbation theory (NEVPT2) in conjunction with a full-valence metal and ligand active space. Perspectives for future applications of DMRG-CASSCF/NEVPT2 to exchange coupling in oligonuclear clusters are discussed.

Approach and Withdrawal Tendencies during Written Word Processing: Effects of Task, Emotional Valence, and Emotional Arousal.

Science.gov (United States)

Citron, Francesca M M; Abugaber, David; Herbert, Cornelia

2015-01-01

The affective dimensions of emotional valence and emotional arousal affect processing of verbal and pictorial stimuli. Traditional emotional theories assume a linear relationship between these dimensions, with valence determining the direction of a behavior (approach vs. withdrawal) and arousal its intensity or strength. In contrast, according to the valence-arousal conflict theory, both dimensions are interactively related: positive valence and low arousal (PL) are associated with an implicit tendency to approach a stimulus, whereas negative valence and high arousal (NH) are associated with withdrawal. Hence, positive, high-arousal (PH) and negative, low-arousal (NL) stimuli elicit conflicting action tendencies. By extending previous research that used several tasks and methods, the present study investigated whether and how emotional valence and arousal affect subjective approach vs. withdrawal tendencies toward emotional words during two novel tasks. In Study 1, participants had to decide whether they would approach or withdraw from concepts expressed by written words. In Studies 2 and 3 participants had to respond to each word by pressing one of two keys labeled with an arrow pointing upward or downward. Across experiments, positive and negative words, high or low in arousal, were presented. In Study 1 (explicit task), in line with the valence-arousal conflict theory, PH and NL words were responded to more slowly than PL and NH words. In addition, participants decided to approach positive words more often than negative words. In Studies 2 and 3, participants responded faster to positive than negative words, irrespective of their level of arousal. Furthermore, positive words were significantly more often associated with "up" responses than negative words, thus supporting the existence of implicit associations between stimulus valence and response coding (positive is up and negative is down). Hence, in contexts in which participants' spontaneous responses are

Pressure and irradiation effects on transport properties of samarium compounds with instable valence

International Nuclear Information System (INIS)

Morillo, J.

1981-01-01

Electron transport properties in samarium compounds with instable valence are studied in this thesis: from SmS in its integer valence phases at common pressure to SmB 6 compound IV at common pressure through SmSsub(1-x)Psub(x) (x 6 is presented [fr

Molecular invariants: atomic group valence

International Nuclear Information System (INIS)

Mundim, K.C.; Giambiagi, M.; Giambiagi, M.S. de.

1988-01-01

Molecular invariants may be deduced in a very compact way through Grassman algebra. In this work, a generalized valence is defined for an atomic group; it reduces to the Known expressions for the case of an atom in a molecule. It is the same of the correlations between the fluctions of the atomic charges qc and qd (C belongs to the group and D does not) around their average values. Numerical results agree with chemical expectation. (author) [pt

Social Annotation Valence: The Impact on Online Informed Consent Beliefs and Behavior.

Science.gov (United States)

Balestra, Martina; Shaer, Orit; Okerlund, Johanna; Westendorf, Lauren; Ball, Madeleine; Nov, Oded

2016-07-20

Social media, mobile and wearable technology, and connected devices have significantly expanded the opportunities for conducting biomedical research online. Electronic consent to collecting such data, however, poses new challenges when contrasted to traditional consent processes. It reduces the participant-researcher dialogue but provides an opportunity for the consent deliberation process to move from solitary to social settings. In this research, we propose that social annotations, embedded in the consent form, can help prospective participants deliberate on the research and the organization behind it in ways that traditional consent forms cannot. Furthermore, we examine the role of the comments' valence on prospective participants' beliefs and behavior. This study focuses specifically on the influence of annotations' valence on participants' perceptions and behaviors surrounding online consent for biomedical research. We hope to shed light on how social annotation can be incorporated into digitally mediated consent forms responsibly and effectively. In this controlled between-subjects experiment, participants were presented with an online consent form for a personal genomics study that contained social annotations embedded in its margins. Individuals were randomly assigned to view the consent form with positive-, negative-, or mixed-valence comments beside the text of the consent form. We compared participants' perceptions of being informed and having understood the material, their trust in the organization seeking the consent, and their actual consent across conditions. We find that comment valence has a marginally significant main effect on participants' perception of being informed (F2=2.40, P=.07); specifically, participants in the positive condition (mean 4.17, SD 0.94) felt less informed than those in the mixed condition (mean 4.50, SD 0.69, P=.09). Comment valence also had a marginal main effect on the extent to which participants reported trusting the

Temperature-touch interaction: Weber's phenomenon revisited.

Science.gov (United States)

Stevens, J C; Green, B G

1978-09-01

The six experiments reported here stemmed from Weber's (E. H. Weber, In R. Wagner (Ed.), Handwnörterbuch der Physiologie, 1846. Vol. 3, pp. 481-588) report that cold objects on the forehead feel heavier than warm ones, implying an effect of temperature on the touch modality. The experiments arrived at first-order answers to how temperature, force of stimulation, areal size of stimulation, and body locus might influence the magnitude of touch sensation. Typically, concomitant cooling greatly intensifies touch magnitude as perceived via the forehead and the forearm. Warning has little or no effect via the forehead but gives a significant intensification (less pronounced than that of cooling) on the forearm. When the areal size of the stimulation becomes very small, the intensification effects cannot be reliably demonstrated. The findings are reviewed in the light of what is known about the physiology of the cutaneous nerves.

A Structural Equation Model of Risk Perception of Rockfall for Revisit Intention

OpenAIRE

Ya-Fen Lee; Yun-Yao Chi

2014-01-01

The study aims to explore the relationship between risk perception of rockfall and revisit intention using a Structural Equation Modeling (SEM) analysis. A total of 573 valid questionnaires are collected from travelers to Taroko National Park, Taiwan. The findings show the majority of travelers have the medium perception of rockfall risk, and are willing to revisit the Taroko National Park. The revisit intention to Taroko National Park is influenced by hazardous preferences, willingness-to-pa...

Verbal instructions targeting valence alter negative conditional stimulus evaluations (but do not affect reinstatement rates).

Science.gov (United States)

Luck, Camilla C; Lipp, Ottmar V

2018-02-01

Negative conditional stimulus (CS) valence acquired during fear conditioning may enhance fear relapse and is difficult to remove as it extinguishes slowly and does not respond to the instruction that unconditional stimulus (US) presentations will cease. We examined whether instructions targeting CS valence would be more effective. In Experiment 1, an image of one person (CS+) was paired with an aversive US, while another (CS-) was presented alone. After acquisition, participants were given positive information about the CS+ poser and negative information about the CS- poser. Instructions reversed the pattern of differential CS valence present during acquisition and eliminated differential electrodermal responding. In Experiment 2, we compared positive and negative CS revaluation by providing positive/negative information about the CS+ and neutral information about CS-. After positive revaluation, differential valence was removed and differential electrodermal responding remained intact. After negative revaluation, differential valence was strengthened and differential electrodermal responding was eliminated. Unexpectedly, the instructions did not affect the reinstatement of differential electrodermal responding.

Thorium valency in molten alkali halides in equilibrium with metallic thorium

International Nuclear Information System (INIS)

Smirnov, M.V.; Kudyakov, V.Ya.

1983-01-01

Metallic thorium is shown to corrode in molten alkali halides even in the absence of external oxidizing agents, alkali cations acting as oxidizing agents. Its corrosion rate grows in the series of alkali chlorides from LiCl to CsCl at constant temperature. Substituting halide anions for one another exerts a smaller influence, the rate rising slightly in going from chlorides to bromides and iodides, having the same alkali cations. Thorium valency is determined coulometrically, the metal being dissolved anodically in molten alkali halides and their mixtures. In fluoride melts it is equal to 4 but in chloride, bromide and iodide ones, as a rule, it has non-integral values between 4 and 2 which diminish as the temperature is raised, as the thorium concentration is lowered, as the radii of alkali cations decrease and those of halide anions increase. The emf of cells Th/N ThHlsub(n) + (1-N) MHl/MHl/C, Hlsub(2(g)) where Hl is Cl, Br or I, M is Li, Na, K, Cs or Na + K, and N < 0.05, is measured as a function of concentration at several temperatures. Expressions are obtained for its concentration dependence. The emf grows in the series of alkali chlorides from LiCl to CsCl, other conditions being equal. (author)

Methanol induces low temperature resilient methanogens and improves methane generation from domestic wastewater at low to moderate temperatures.

Science.gov (United States)

Saha, Shaswati; Badhe, Neha; De Vrieze, Jo; Biswas, Rima; Nandy, Tapas

2015-01-01

Low temperature (methanol is a preferred substrate by methanogens in cold habitats. The study hypothesizes that methanol can induce the growth of low-temperature resilient, methanol utilizing, hydrogenotrophs in UASB reactor. The hypothesis was tested in field conditions to evaluate the impact of seasonal temperature variations on methane yield in the presence and absence of methanol. Results show that 0.04% (v/v) methanol increased methane up to 15 times and its effect was more pronounced at lower temperatures. The qPCR analysis showed the presence of Methanobacteriales along with Methanosetaceae in large numbers. This indicates methanol induced the growth of both the hydrogenotrophic and acetoclastic groups through direct and indirect routes, respectively. This study thus demonstrated that methanol can impart resistance in methanogenic biomass to low temperature and can improve performance of UASB reactor. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fluctuations in Brain Temperature Induced by Lypopolysaccharides: Central and Peripheral Contributions

Directory of Open Access Journals (Sweden)

Jeremy S. Tang

2010-01-01

Full Text Available In this study, we examined changes in central (anterior-preoptic hypothalamus and peripheral (temporal muscle and facial skin temperatures in freely moving rats following intravenous administration of bacterial lipopolysaccharides (LPS at low doses (1 and 10 μg/kg at thermoneutral conditions (28˚C. Recordings were made with high temporal resolution (5-s bin and the effects of LPS were compared with those induced by a tail-pinch, a standard arousing somato-sensory stimulus. At each dose, LPS moderately elevated brain, muscle and skin temperatures. In contrast to rapid, monophasic and relatively short hyperthermic responses induced by a tail-pinch, LPS-induced increases in brain and muscle temperatures occurred with ~40 min onset latencies, showed three not clearly defined phases, were slightly larger with the 10 μm/kg dose and maintained for the entire 4-hour post-injection recording duration. Based on dynamics of brain-muscle and skin-muscle temperature differentials, it appears that the hyperthermic response induced by LPS at the lowest dose originates from enhanced peripheral heat production, with no evidence of brain metabolic activation and skin vasoconstriction. While peripheral heat production also appears to determine the first phase of brain and body temperature elevation with LPS at 10 μg/kg, a further prolonged increase in brain-muscle differentials (onset at ~100 min suggests metabolic brain activation as a factor contributing to brain and body hyperthermia. At this dose, skin temperature increase was weaker than in temporal muscle, suggesting vasoconstriction as another contributor to brain/ body hyperthermia. Therefore, although both LPS at low doses and salient sensory stimuli moderately increase brain and body temperatures, these hyperthermic responses have important qualitative differences, reflecting unique underlying mechanisms.

Fluctuations in brain temperature induced by lipopolysaccharides: central and peripheral contributions.

Science.gov (United States)

Tang, Jeremy S; Kiyatkin, Eugene A

2010-01-01

In this study, we examined changes in central (anterior-preoptic hypothalamus) and peripheral (temporal muscle and facial skin) temperatures in freely moving rats following intravenous administration of bacterial lipopolysaccharides (LPS) at low doses (1 and 10 μg/kg) at thermoneutral conditions (28°C). Recordings were made with high temporal resolution (5-s bin) and the effects of LPS were compared with those induced by a tail-pinch, a standard arousing somato-sensory stimulus. At each dose, LPS moderately elevated brain, muscle, and skin temperatures. In contrast to rapid, monophasic and relatively short hyperthermic responses induced by a tail-pinch, LPS-induced increases in brain and muscle temperatures occurred with ~40 min onset latencies, showed three not clearly defined phases, were slightly larger with the 10 μm/kg dose, and maintained for the entire 4-hour post-injection recording duration. Based on dynamics of brain-muscle and skin-muscle temperature differentials, it appears that the hyperthermic response induced by LPS at the lowest dose originates from enhanced peripheral heat production, with no evidence of brain metabolic activation and skin vasoconstriction. While peripheral heat production also appears to determine the first phase of brain and body temperature elevation with LPS at 10 μg/kg, a further prolonged increase in brain-muscle differentials (onset at ~100 min) suggests metabolic brain activation as a factor contributing to brain and body hyperthermia. At this dose, skin temperature increase was weaker than in temporal muscle, suggesting vasoconstriction as another contributor to brain/body hyperthermia. Therefore, although both LPS at low doses and salient sensory stimuli moderately increase brain and body temperatures, these hyperthermic responses have important qualitative differences, reflecting unique underlying mechanisms.

Dissociable modulation of overt visual attention in valence and arousal revealed by topology of scan path.

Directory of Open Access Journals (Sweden)

Jianguang Ni

Full Text Available Emotional stimuli have evolutionary significance for the survival of organisms; therefore, they are attention-grabbing and are processed preferentially. The neural underpinnings of two principle emotional dimensions in affective space, valence (degree of pleasantness and arousal (intensity of evoked emotion, have been shown to be dissociable in the olfactory, gustatory and memory systems. However, the separable roles of valence and arousal in scene perception are poorly understood. In this study, we asked how these two emotional dimensions modulate overt visual attention. Twenty-two healthy volunteers freely viewed images from the International Affective Picture System (IAPS that were graded for affective levels of valence and arousal (high, medium, and low. Subjects' heads were immobilized and eye movements were recorded by camera to track overt shifts of visual attention. Algebraic graph-based approaches were introduced to model scan paths as weighted undirected path graphs, generating global topology metrics that characterize the algebraic connectivity of scan paths. Our data suggest that human subjects show different scanning patterns to stimuli with different affective ratings. Valence salient stimuli (with neutral arousal elicited faster and larger shifts of attention, while arousal salient stimuli (with neutral valence elicited local scanning, dense attention allocation and deep processing. Furthermore, our model revealed that the modulatory effect of valence was linearly related to the valence level, whereas the relation between the modulatory effect and the level of arousal was nonlinear. Hence, visual attention seems to be modulated by mechanisms that are separate for valence and arousal.

The Faraday effect revisited

DEFF Research Database (Denmark)

Cornean, Horia; Nenciu, Gheorghe

2009-01-01

This paper is the second in a series revisiting the (effect of) Faraday rotation. We formulate and prove the thermodynamic limit for the transverse electric conductivity of Bloch electrons, as well as for the Verdet constant. The main mathematical tool is a regularized magnetic and geometric...

Remembered Experiences and Revisit Intentions

DEFF Research Database (Denmark)

Barnes, Stuart; Mattsson, Jan; Sørensen, Flemming

2016-01-01

Tourism is an experience-intensive sector in which customers seek and pay for experiences above everything else. Remembering past tourism experiences is also crucial for an understanding of the present, including the predicted behaviours of visitors to tourist destinations. We adopt a longitudinal...... approach to memory data collection from psychological science, which has the potential to contribute to our understanding of tourist behaviour. In this study, we examine the impact of remembered tourist experiences in a safari park. In particular, using matched survey data collected longitudinally and PLS...... path modelling, we examine the impact of positive affect tourist experiences on the development of revisit intentions. We find that longer-term remembered experiences have the strongest impact on revisit intentions, more so than predicted or immediate memory after an event. We also find that remembered...

Temperature rise induced by some light emitting diode and quartz-tungsten-halogen curing units.

Science.gov (United States)

Asmussen, Erik; Peutzfeldt, Anne

2005-02-01

Because of the risk of thermal damage to the pulp, the temperature rise induced by light-curing units should not be too high. LED (light emitting diode) curing units have the main part of their irradiation in the blue range and have been reported to generate less heat than QTH (quartz-tungsten-halogen) curing units. This study had two aims: first, to measure the temperature rise induced by ten LED and three QTH curing units; and, second, to relate the measured temperature rise to the power density of the curing units. The light-induced temperature rise was measured by means of a thermocouple embedded in a small cylinder of resin composite. The power density was measured by using a dental radiometer. For LED units, the temperature rise increased with increasing power density, in a statistically significant manner. Two of the three QTH curing units investigated resulted in a higher temperature rise than LED curing units of the same power density. Previous findings, that LED curing units induce less temperature rise than QTH units, does not hold true in general.

Low temperature anomalies in the lattice parameters of rare earth compounds and UPd3

International Nuclear Information System (INIS)

Pluemacher, D.

1980-01-01

Using a low temperature diffractometer, intermediate valence effects and crystal defects can be identified from the temperature dependence of the lattice parameters and the Debye-Waller factor. For polycrystalline powder samples the measuring error are too large. For intermediate valence systems the relative change in the 4f-level population probability can be calculated together with the anisotropic effects on the lattice parameters and on the unit cell colume. Pronounced effects on the lattice parameters can be observed in the case of RE Cu 2 Si 2 compounds with crystal fields. (DG) [de

Convergence of valence bands for high thermoelectric performance for p-type InN

International Nuclear Information System (INIS)

Li, Hai-Zhu; Li, Ruo-Ping; Liu, Jun-Hui; Huang, Ming-Ju

2015-01-01

Band engineering to converge the bands to achieve high valley degeneracy is one of effective approaches for designing ideal thermoelectric materials. Convergence of many valleys in the valence band may lead to a high Seebeck coefficient, and induce promising thermoelectric performance of p-type InN. In the current work, we have systematically investigated the electronic structure and thermoelectric performance of wurtzite InN by using the density functional theory combined with semiclassical Boltzmann transport theory. Form the results, it can be found that intrinsic InN has a large Seebeck coefficient (254 μV/K) and the largest value of Z e T is 0.77. The transport properties of p-type InN are better than that of n-type one at the optimum carrier concentration, which mainly due to the large Seebeck coefficient for p-type InN, although the electrical conductivity of n-type InN is larger than that of p-type one. We found that the larger Seebeck coefficient for p-type InN may originate from the large valley degeneracy in the valence band. Moreover, the low minimum lattice thermal conductivity for InN is one key factor to become a good thermoelectric material. Therefore, p-type InN could be a potential material for further applications in the thermoelectric area.

Event-related brain potential correlates of words' emotional valence irrespective of arousal and type of task.

Science.gov (United States)

Espuny, Javier; Jiménez-Ortega, Laura; Casado, Pilar; Fondevila, Sabela; Muñoz, Francisco; Hernández-Gutiérrez, David; Martín-Loeches, Manuel

2018-03-23

Many Event-Related brain Potential (ERP) experiments have explored how the two main dimensions of emotion, arousal and valence, affect linguistic processing. However, the heterogeneity of experimental paradigms and materials has led to mixed results. In the present study, we aim to clarify words' emotional valence effects on ERP when arousal is controlled, and determine whether these effects may vary as a function of the type of task performed. For these purposes, we designed an ERP experiment with the valence of words manipulated, and arousal equated across valences. The participants performed two types of task: in one, they had to read aloud each word, written in black on a white background; in the other, they had to name the color of the ink in which each word was written. The results showed the main effects of valence irrespective of task, and no interaction between valence and task. The most marked effects of valence were in response to negative words, which elicited an Early Posterior Negativity (EPN) and a Late Positive Complex (LPC). Our results suggest that, when arousal is controlled, the cognitive information in negative words triggers a 'negativity bias', these being the only words able to elicit emotion-related ERP modulations. Moreover, these modulations are largely unaffected by the types of task explored here. Copyright © 2018 Elsevier B.V. All rights reserved.

Lattice QCD with mixed action - Borici-Creutz valence quark on staggered sea

Science.gov (United States)

Basak, Subhasish; Goswami, Jishnu; Chakrabarti, Dipankar

2018-03-01

Mixed action lattice QCD with Borici-Creutz valence quarks on staggered sea is investigated. The counter terms in Borici-Creutz action are fixed nonperturbatively to restore the broken symmetries. On symmetry restoration, the usual signatures of partial quenching / unitarity violation like negative scalar correlator are observed. The size of unitarity violation due to different discretization of valence and sea quark is determined by measuring Δmix.

Revisiting the Okun relationship

NARCIS (Netherlands)

Dixon, R. (Robert); Lim, G.C.; J.C. van Ours (Jan)

2017-01-01

textabstractOur article revisits the Okun relationship between observed unemployment rates and output gaps. We include in the relationship the effect of labour market institutions as well as age and gender effects. Our empirical analysis is based on 20 OECD countries over the period 1985–2013. We

Bounded Intention Planning Revisited

OpenAIRE

Sievers Silvan; Wehrle Martin; Helmert Malte

2014-01-01

Bounded intention planning provides a pruning technique for optimal planning that has been proposed several years ago. In addition partial order reduction techniques based on stubborn sets have recently been investigated for this purpose. In this paper we revisit bounded intention planning in the view of stubborn sets.

A description of phases with induced hybridisation at finite temperatures

Science.gov (United States)

Golosov, D. I.

2018-05-01

In an extended Falicov-Kimball model, an excitonic insulator phase can be stabilised at zero temperature. With increasing temperature, the excitonic order parameter (interaction-induced hybridisation on-site, characterised by the absolute value and phase) eventually becomes disordered, which involves fluctuations of both its phase and (at higher T) its absolute value. In order to build an adequate mean field description, it is important to clarify the nature of degrees of freedom associated with the phase and absolute value of the induced hybridisation, and the corresponding phase space volume. We show that a possible description is provided by the SU(4) parametrisation on-site. In principle, this allows to describe both the lower-temperature regime where phase fluctuations destroy the long-range order, and the higher temperature crossover corresponding to a decrease of absolute value of the hybridisation relative to the fluctuations level. This picture is also expected to be relevant in other contexts, including the Kondo lattice model.

Reply to Isgur's comments on valence QCD

International Nuclear Information System (INIS)

Liu, K.F.

2000-01-01

With the goal of understanding the complexity of QCD and the role of symmetry in dynamics, the authors studied a field theory called Valence QCD (VQCD) in which the Z graphs are forbidden so that the Fock space is limited to the valence quarks. The authors calculated nucleon form factors, matrix elements, and hadron masses both with this theory and with quenched QCD on a set of lattices with the same gauge background. Comparing the results of the lattice calculations in these two theories, the authors drew conclusions regarding the SU(6) valence quark model and chiral symmetry. While recognizing the goal of VQCD, Nathan Isgur disagrees on some of the conclusions the authors have drawn. The foremost objection raised in section 2 is to their suggestion that the major part of the hyperfine splittings in baryons is due to Goldstone boson exchange and not one-gluon-exchange (OGE) interactions. The logic of Isgur's objection is that VQCD yields a spectroscopy vastly different from quenched QCD and therefore the structure of the hadrons (to which hyperfine splittings in a quark model are intimately tied) is also suspect so no definite conclusions are possible. To put this into perspective it should be emphasized at the outset that spectroscopy is only one aspect of hadron physics examined in section 1. The authors have studied the axial and scalar couplings of nucleon in terms of F A /D A and F S /D S , the neutron to proton magnetic moment ratio μn/μp, and various form factors. None of these results reveal any pathologies of hadron structure and turn out to be close to the SU(6) relations, as expected. In fact this is what motivated the study of valence degrees of freedom via VQCD. In section 2 the authors address specific issues related to spectroscopy in VQCD. Isgur also presented more general arguments against the idea of boson exchange as a contributor to hyperfine effects. A cornerstone of his discussion is the unifying aspect of OGE in a quark model picture. The

Measurement of valence band structure in arbitrary dielectric films

International Nuclear Information System (INIS)

Uhm, Han S.; Choi, Eun H.

2012-01-01

A new way of measuring the band structure of various dielectric materials using the secondary electron emission from Auger neutralization of ions is introduced. The first example of this measurement scheme is the magnesium oxide (MgO) films with respect to the application of the films in the display industries. The density of state in the valence bands of MgO film and MgO film with a functional layer (FL) deposited over a dielectric surface reveals that the density peak of film with a FL is considerably less than that of film, thereby indicating a better performance of MgO film with functional layer in display devices. The second example of the measurement is the boron-zinc oxide (BZO) films with respect to the application of the films to the development of solar cells. The measurement of density of state in BZO film suggests that a high concentration of boron impurity in BZO films may enhance the transition of electrons and holes through the band gap from the valence to the conduction band in zinc oxide crystals; thereby improving the conductivity of the film. Secondary electron emission by the Auger neutralization of ions is highly instrumental for the determination of the density of states in the valence band of dielectric materials.

Temperature rise and stress induced by microcracks in accelerating structures

Directory of Open Access Journals (Sweden)

W. Zhu

2010-12-01

Full Text Available The temperature rise and induced stress due to Ohmic heating in the vicinity of microcracks on the walls of high-gradient accelerating structures are considered. The temperature rise and induced stress depend on the orientation of the crack with respect to the rf magnetic field, the shape of the crack, and the power and duration of the rf pulse. Under certain conditions the presence of cracks can double the temperature rise over that of a smooth surface. Stress at the bottom of the cracks can be several times larger than that of the case when there are no cracks. We study these effects both analytically and by computer simulation. It is shown that the stress in cracks is maximal when the crack depth is on the order of the thermal penetration depth.

Size-dependent valence change in small Pr, Nd, and Sm clusters isolated in solid Ar

International Nuclear Information System (INIS)

Luebcke, M.; Sonntag, B.; Niemann, W.; Rabe, P.

1986-01-01

The L/sub III/ absorption thresholds of Pr, Nd, and Sm clusters isolated in solid Ar are marked by prominent white lines. The lines ascribed to divalent and trivalent rare-earth metals are well separated in energy. From the relative intensities of these lines an average valence of the rare-earth atoms in the cluster has been determined. For dimers and trimers the average valence is close to 2, the value for free atoms. For clusters consisting of more than 20 atoms the average valence approaches 3, the value for bulk metals. In between the valence changes abruptly, indicating the existence of a critical cluster size of approximately 5 atoms for Pr and Nd and of 13 atoms for Sm

Approach and withdrawal tendencies during written word processing: effects of task, emotional valence and emotional arousal

Directory of Open Access Journals (Sweden)

Francesca M. M. Citron

2016-01-01

Full Text Available The affective dimensions of emotional valence and emotional arousal affect processing of verbal and pictorial stimuli. Traditional emotional theories assume a linear relationship between these dimensions, with valence determining the direction of a behaviour (approach vs. withdrawal and arousal its intensity or strength. In contrast, according to the valence-arousal conflict theory, both dimensions are interactively related: positive valence and low arousal (PL are associated with an implicit tendency to approach a stimulus, whereas negative valence and high arousal (NH are associated with withdrawal. Hence, positive, high-arousal (PH and negative, low-arousal (NL stimuli elicit conflicting action tendencies. By extending previous research that used several tasks and methods, the present study investigated whether and how emotional valence and arousal affect subjective approach vs. withdrawal tendencies towards emotional words during two novel tasks. In Study 1, participants had to decide whether they would approach or withdraw from concepts expressed by written words. In Studies 2 and 3 participants had to respond to each word by pressing one of two keys labelled with an arrow pointing upward or downward. Across experiments, positive and negative words, high or low in arousal, were presented. In Study 1 (explicit task, in line with the valence-arousal conflict theory, PH and NL words were responded to more slowly than PL and NH words. In addition, participants decided to approach positive words more often than negative words. In Studies 2 and 3, participants responded faster to positive than negative words, irrespective of their level of arousal. Furthermore, positive words were significantly more often associated with up responses than negative words, thus supporting the existence of implicit associations between stimulus valence and response coding (positive is up and negative is down. Hence, in contexts in which participants’ spontaneous

Time-resolved imaging of purely valence-electron dynamics during a chemical reaction

DEFF Research Database (Denmark)

Hockett, Paul; Bisgaard, Christer Z.; Clarkin, Owen J.

2011-01-01

Chemical reactions are manifestations of the dynamics of molecular valence electrons and their couplings to atomic motions. Emerging methods in attosecond science can probe purely electronic dynamics in atomic and molecular systems(1-6). By contrast, time-resolved structural-dynamics methods...... such as electron(7-10) or X-ray diffraction(11) and X-ray absorption(12) yield complementary information about the atomic motions. Time-resolved methods that are directly sensitive to both valence-electron dynamics and atomic motions include photoelectron spectroscopy(13-15) and high-harmonic generation(16......,17): in both cases, this sensitivity derives from the ionization-matrix element(18,19). Here we demonstrate a time-resolved molecular-frame photoelectron-angular-distribution (TRMFPAD) method for imaging the purely valence-electron dynamics during a chemical reaction. Specifically, the TRMFPADs measured during...

fK /f{pi} in Full QCD with Domain Wall Valence Quarks

Energy Technology Data Exchange (ETDEWEB)

Silas Beane; Paulo Bedaque; Konstantinos Orginos; Martin Savage

2007-05-01

We compute the ratio of pseudoscalar decay constants f{sub K}/f{sub {pi}} using domain-wall valence quarks and rooted improved Kogut-Susskind sea quarks. By employing continuum chiral perturbation theory, we extract the Gasser-Leutwyler low-energy constant L{sub 5}, and extrapolate f{sub K}/f{sub {pi}} to the physical point. We find: f{sub K}/f{sub {pi}} = 1.218 {+-} 0.002{sub -0.024}{sup +0.011} where the first error is statistical and the second error is an estimate of the systematic due to chiral extrapolation and fitting procedures. This value agrees within the uncertainties with the determination by the MILC collaboration, calculated using Kogut-Susskind valence quarks, indicating that systematic errors arising from the choice of lattice valence quark are small.

The use of symmetrized valence and relative motion coordinates for crystal potentials

DEFF Research Database (Denmark)

McMurry, H. L.; Hansen, Flemming Yssing

1980-01-01

Symmetrized valence coordinates are linear combinations of conventional valence coordinates which display the symmetry of a set of atoms bound by the valence bonds. Relative motion coordinates are relative translations, or relative rotations, of two or more strongly bonded groups of atoms among...... which relatively weak forces act. They are useful for expressing interactions between molecules in molecular crystals and should be chosen, also, to reflect the symmetry of the interacting groups. Since coordinates defined by these procedures possess elements of symmetry in common with the bonding...... interaction constants coupling coordinates of unlike symmetry with regard to the crystal point group are necessarily zero. They may be small, also, for coordinates which belong to different representations of the local symmetry when this is not the same as for the crystal. Procedures are given for defining...

Intermediate-Valence Tautomerism in Decamethylytterbocene Complexes of Methyl-Substituted Bipyridines

Energy Technology Data Exchange (ETDEWEB)

Booth, Corwin H.; Kazhdan, Daniel; Werkema, Evan L.; Walter, Marc D.; Lukens, Wayne W.; Bauer, Eric D.; Hu, Yung-Jin; Maron, Laurent; Eisenstein, Odile; Head-Gordon, Martin; Andersen, Richard A.

2011-01-25

Multiconfigurational, intermediate valent ground states are established in several methyl-substituted bipyridine complexes of bispentamethylcyclopentadienylytterbium, Cp*{sub 2} Yb(Me{sub x}-bipy). In contrast to Cp*{sub 2} Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state are altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings. In particular, certain substitutions result in multiconfigurational, intermediate valent open-shell singlet states in both the ground state and the first excited state. These conclusions are reached after consideration of single-crystal x-ray diffraction (XRD), the temperature dependence of x-ray absorption near-edge structure (XANES), extended x-ray absorption fine-structure (EXAFS), and magnetic susceptibility data, and are supported by CASSCF-MP2 calculations. These results place the various Cp*{sub 2}Yb(bipy) complexes in a new tautomeric class, that is, intermediate-valence tautomers.

The influence of valence and arousal on reasoning: Affective priming in the semantic verification task

Directory of Open Access Journals (Sweden)

Orlić Ana

2014-01-01

Full Text Available The aim of the present study was to examine the effects of affective valence and arousal on the reasoning process. Reasoning was measured using a semantic verification task and the influence of valence and arousal was tracked using the affective priming paradigm. Primes were photographs varied on two dimensions - emotional valence (positive, neutral, negative and arousal (high, low. Forty-nine psychology students participated in the experiment. Results showed that reaction time needed for semantic verification was significantly faster for positive-high arousing in comparison to positive-low arousing condition and for neutral high arousing in comparison to neutral-low arousing condition, but there were no significant differences in negative low and high arousing conditions. Also, significant differences were found among all three valences in high arousing conditions and there were no such differences in low arousing conditions. These results reveal the importance of both arousal and valence in the research on the influence of emotions on the reasoning process. [Projekat Ministarstva nauke Republike Srbije, br. 179033

Radiation-induced conductivity and high-temperature Q changes in quartz resonators

International Nuclear Information System (INIS)

Koehler, D.R.

1981-01-01

While high temperature electrolysis has proven beneficial as a technique to remove interstitial impurities from quartz, reliable indices to measure the efficacy of such a processing step are still under development. The present work is directed toward providing such an index. Two techniques have been investigated - one involves measurement of the radiation induced conductivity in quartz along the optic axis, and the second involves measurement of high temperature Q changes. Both effects originate when impurity charge compensators are released from their traps, in the first case resulting in ionic conduction and in the second case resulting in increased acoustic losses. Radiation induced conductivity measurements have been carried out with a 200 kV, 14 mA x-ray machine producing 5 rads/s. With electric fields of the order of 10 4 V/cm, the noise level in the current measuring system is equivalent to an ionic current generated by quartz impurities in the 1 ppB range. The accuracy of the high temperature ( 300 to 800 0 K) Q -1 measurement technique will be determined. A number of resonators constructed of quartz material of different impurity contents have been tested and both the radiation induced conductivity and the high temperature Q -1 results compared with earlier radiation induced frequency and resonator resistance changes. 10 figures

Revisiting Nursing Research in Nigeria

African Journals Online (AJOL)

2016-08-18

Aug 18, 2016 ... health care research, it is therefore pertinent to revisit the state of nursing research in the country. .... platforms, updated libraries with electronic resource ... benchmarks for developing countries of 26%, [17] the amount is still ...

Time functions revisited

Science.gov (United States)

Fathi, Albert

2015-07-01

In this paper we revisit our joint work with Antonio Siconolfi on time functions. We will give a brief introduction to the subject. We will then show how to construct a Lipschitz time function in a simplified setting. We will end with a new result showing that the Aubry set is not an artifact of our proof of existence of time functions for stably causal manifolds.

Neurons for hunger and thirst transmit a negative-valence teaching signal

Science.gov (United States)

Gong, Rong; Magnus, Christopher J.; Yu, Yang; Sternson, Scott M.

2015-01-01

Homeostasis is a biological principle for regulation of essential physiological parameters within a set range. Behavioural responses due to deviation from homeostasis are critical for survival, but motivational processes engaged by physiological need states are incompletely understood. We examined motivational characteristics and dynamics of two separate neuron populations that regulate energy and fluid homeostasis by using cell type-specific activity manipulations in mice. We found that starvation-sensitive AGRP neurons exhibit properties consistent with a negative-valence teaching signal. Mice avoided activation of AGRP neurons, indicating that AGRP neuron activity has negative valence. AGRP neuron inhibition conditioned preference for flavours and places. Correspondingly, deep-brain calcium imaging revealed that AGRP neuron activity rapidly reduced in response to food-related cues. Complementary experiments activating thirst-promoting neurons also conditioned avoidance. Therefore, these need-sensing neurons condition preference for environmental cues associated with nutrient or water ingestion, which is learned through reduction of negative-valence signals during restoration of homeostasis. PMID:25915020

The role of valence focus and appraisal overlap in emotion differentiation.

Science.gov (United States)

Erbas, Yasemin; Ceulemans, Eva; Koval, Peter; Kuppens, Peter

2015-06-01

Emotion differentiation refers to the level of specificity with which people distinguish between their emotional states and is considered to play an important role for psychological well-being. Yet, not much is known about what characterizes people high or low in emotion differentiation and what underlies these differences. In 2 studies involving experience sampling (Studies 1-2) and lab based (Study 2) methods, we investigated how emotion differentiation is related to individual differences in valence focus and the overlap in appraisal patterns between emotions. In line with expectations, results showed that high levels of both positive and negative emotion differentiation are related to lower levels of valence focus and lower levels of appraisal overlap between emotions. These findings suggest that individuals who are low in emotion differentiation mainly emphasize the valence aspect of emotions while individuals who are high in emotion differentiation make stronger distinctions between emotions in terms of their underlying appraisal profiles. (c) 2015 APA, all rights reserved).

Interpersonal Valence Dimensions as Discriminators of Communication Contexts: An Empirical Assessment of Dyadic Linkages.

Science.gov (United States)

Garrison, John P.; And Others

The capability of 14 interpersonal dimensions to predict dyadic communication contexts was investigated in this study. Friend, acquaintance, co-worker, and family contexts were examined. The interpersonal valence construct, based on a coactive or mutual-causal paradigm, encompasses traditional source-valence components (credibility, power,…

Iron valence in double-perovskite (Ba,Sr,Ca)2FeMoO6: isovalent substitution effect

International Nuclear Information System (INIS)

Yasukawa, Y.; Linden, J.; Chan, T.S.; Liu, R.S.; Yamauchi, H.; Karppinen, M.

2004-01-01

In the Fe-Mo based B-site ordered double-perovskite, A 2 FeMoO 6.0 , with iron in the mixed-valence II/III state, the valence value of Fe is not precisely fixed at 2.5 but may be fine-tuned by means of applying chemical pressure at the A-cation site. This is shown through a systematic 57 Fe Moessbauer spectroscopy study using a series of A 2 FeMoO 6.0 [A=(Ba,Sr) or (Sr,Ca)] samples with high degree of Fe/Mo order, the same stoichiometric oxygen content and also almost the same grain size. The isomer shift values and other hyperfine parameters obtained from the Moessbauer spectra confirm that Fe remains in the mixed-valence state within the whole range of A constituents. However, upon increasing the average cation size at the A site the precise valence of Fe is found to decrease such that within the A=(Ba,Sr) regime the valence of Fe is closer to II, while within the A=(Sr,Ca) regime it is closer to the actual mixed-valence II/III state. As the valence of Fe approaches II, the difference in charges between Fe and Mo increases, and parallel with this the degree of Fe/Mo order increases. Additionally, for the less-ordered samples an increased tendency of clustering of the antisite Fe atoms is deduced from the Moessbauer data

The Relation Between Valence and Arousal in Subjective Experience Varies With Personality and Culture.

Science.gov (United States)

Kuppens, Peter; Tuerlinckx, Francis; Yik, Michelle; Koval, Peter; Coosemans, Joachim; Zeng, Kevin J; Russell, James A

2017-08-01

While in general arousal increases with positive or negative valence (a so-called V-shaped relation), there are large differences among individuals in how these two fundamental dimensions of affect are related in people's experience. In two studies, we examined two possible sources of this variation: personality and culture. In Study 1, participants (Belgian university students) recalled a recent event that was characterized by high or low valence or arousal and reported on their feelings and their personality in terms of the Five-Factor Model. In Study 2, participants from Canada, China/Hong Kong, Japan, Korea, and Spain reported on their feelings in a thin slice of time and on their personality. In Study 1, we replicated the V-shape as characterizing the relation between valence and arousal, and identified personality correlates of experiencing particular valence-arousal combinations. In Study 2, we documented how the V-shaped relation varied as a function of Western versus Eastern cultural background and personality. The results showed that the steepness of the V-shaped relation between valence and arousal increases with Extraversion within cultures, and with a West-East distinction between cultures. Implications for the personality-emotion link and research on cultural differences in affect are discussed. © 2016 Wiley Periodicals, Inc.

A study of the valence shell electronic states of s-triazine by photoabsorption spectroscopy and ab initio calculations

Energy Technology Data Exchange (ETDEWEB)

Holland, D.M.P., E-mail: david.holland@stfc.ac.uk [Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Shaw, D.A. [Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Stener, M.; Decleva, P. [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri, I-34127 Trieste (Italy); Consorzio Interuniversitario Nazionale per la Scienze e Tecnologia dei Materiali, INSTM, Unità di Trieste (Italy); CNR-IOM, Trieste (Italy); Coriani, S. [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri, I-34127 Trieste (Italy); Consorzio Interuniversitario Nazionale per la Scienze e Tecnologia dei Materiali, INSTM, Unità di Trieste (Italy); Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C (Denmark)

2016-09-30

Highlights: • The valence shell photoabsorption spectrum of s-triazine has been measured. • Electronic structure calculated with TDDFT and coupled cluster approaches. • Assignments proposed for Rydberg and valence states. • Mixing between Rydberg and valence states important. - Abstract: The absolute photoabsorption cross section of s-triazine has been measured between 4 and 40 eV, and is dominated by bands associated with valence states. Structure due to Rydberg excitations is both weak and irregular. Jahn-Teller interactions affect the vibronic structure observed in the Rydberg absorption bands due to excitation from the 1e″ or 6e′ orbitals. The interpretation of the experimental spectrum has been guided by transition energies and oscillator strengths, for Rydberg and valence states, calculated with the time-dependent version of density functional theory and with the coupled cluster linear response approach. The theoretical studies indicate that Rydberg/Rydberg and Rydberg/valence mixing is important.

Music, emotion, and time perception: the influence of subjective emotional valence and arousal?

Science.gov (United States)

Droit-Volet, Sylvie; Ramos, Danilo; Bueno, José L. O.; Bigand, Emmanuel

2013-01-01

The present study used a temporal bisection task with short (2 s) stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow) (Experiment 1) or their instrumentation (orchestral vs. piano pieces). The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant) vs. atonal (unpleasant) versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music. PMID:23882233

Music, Emotion and Time Perception: The influence of subjective emotional valence and arousal?

Directory of Open Access Journals (Sweden)

SYLVIE eDROIT-VOLET

2013-07-01

Full Text Available The present study used a temporal bisection task with short (< 2 s and long (> 2 s stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow (Experiment 1 or their instrumentation (orchestral vs. piano pieces. The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant versus atonal (unpleasant versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music.

Music, emotion, and time perception: the influence of subjective emotional valence and arousal?

Science.gov (United States)

Droit-Volet, Sylvie; Ramos, Danilo; Bueno, José L O; Bigand, Emmanuel

2013-01-01

The present study used a temporal bisection task with short (2 s) stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow) (Experiment 1) or their instrumentation (orchestral vs. piano pieces). The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant) vs. atonal (unpleasant) versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music.

Feedback Valence Affects Auditory Perceptual Learning Independently of Feedback Probability

Science.gov (United States)

Amitay, Sygal; Moore, David R.; Molloy, Katharine; Halliday, Lorna F.

2015-01-01

Previous studies have suggested that negative feedback is more effective in driving learning than positive feedback. We investigated the effect on learning of providing varying amounts of negative and positive feedback while listeners attempted to discriminate between three identical tones; an impossible task that nevertheless produces robust learning. Four feedback conditions were compared during training: 90% positive feedback or 10% negative feedback informed the participants that they were doing equally well, while 10% positive or 90% negative feedback informed them they were doing equally badly. In all conditions the feedback was random in relation to the listeners’ responses (because the task was to discriminate three identical tones), yet both the valence (negative vs. positive) and the probability of feedback (10% vs. 90%) affected learning. Feedback that informed listeners they were doing badly resulted in better post-training performance than feedback that informed them they were doing well, independent of valence. In addition, positive feedback during training resulted in better post-training performance than negative feedback, but only positive feedback indicating listeners were doing badly on the task resulted in learning. As we have previously speculated, feedback that better reflected the difficulty of the task was more effective in driving learning than feedback that suggested performance was better than it should have been given perceived task difficulty. But contrary to expectations, positive feedback was more effective than negative feedback in driving learning. Feedback thus had two separable effects on learning: feedback valence affected motivation on a subjectively difficult task, and learning occurred only when feedback probability reflected the subjective difficulty. To optimize learning, training programs need to take into consideration both feedback valence and probability. PMID:25946173

Overlap valence quarks on a twisted mass sea. A case study for mixed action lattice QCD

International Nuclear Information System (INIS)

Cichy, Krzysztof; Herdoiza, Gregorio; UAM/CSIC Univ. Autonoma de Madrid

2012-11-01

We discuss a Lattice QCD mixed action investigation employing Wilson maximally twisted mass sea and overlap valence fermions. Using four values of the lattice spacing, we demonstrate that the overlap Dirac operator assumes a point-like locality in the continuum limit. We also show that by adopting suitable matching conditions for the sea and valence theories a consistent continuum limit for the pion decay constant and light baryon masses can be obtained. Finally, we confront results for sea-valence mixed meson masses and the valence scalar correlator with corresponding expressions of chiral perturbation theory. This allows us to extract low energy constants of mixed action chiral perturbation which characterize the strength of unitarity violations in our mixed action setup.

Overlap valence quarks on a twisted mass sea. A case study for mixed action lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Cichy, Krzysztof [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics; Drach, Vincent; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Garcia-Ramos, Elena [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany); Herdoiza, Gregorio [UAM/CSIC Univ. Autonoma de Madrid (Spain). Dept. de Fisica Teorica; UAM/CSIC Univ. Autonoma de Madrid (Spain). Inst. de Fisica Teorica; Collaboration: European Twisted Mass Collaboration

2012-11-15

We discuss a Lattice QCD mixed action investigation employing Wilson maximally twisted mass sea and overlap valence fermions. Using four values of the lattice spacing, we demonstrate that the overlap Dirac operator assumes a point-like locality in the continuum limit. We also show that by adopting suitable matching conditions for the sea and valence theories a consistent continuum limit for the pion decay constant and light baryon masses can be obtained. Finally, we confront results for sea-valence mixed meson masses and the valence scalar correlator with corresponding expressions of chiral perturbation theory. This allows us to extract low energy constants of mixed action chiral perturbation which characterize the strength of unitarity violations in our mixed action setup.

The extended variant of the bond valence-bond length correlation curve for boron(III)-oxygen bonds

International Nuclear Information System (INIS)

Sidey, Vasyl

2015-01-01

The extended variant of the bond valence (s)-bond length (r) correlation curve for boron(III)-oxygen bonds has been closely approximated using the three-parameter function s = [k/(r - l)] - m, where s is measured in valence units (vu), r is measured in Aa, k = 0.53 Aa.vu, l = 0.975(1) Aa and m = 0.32 vu. The function s = exp[(r 0 - r)/b] traditionally used in the modern bond valence model requires the separate set of the bond valence parameters (r 0 = 1.362 Aa; b = 0.23 Aa) in order to approximate the above s-r curve for the bonds shorter than ∝1.3 Aa.

Electrical resistivity of YbRh2Si2 and EuT2Ge2 (T=Co,Cu) at extreme conditions of pressure and temperature

International Nuclear Information System (INIS)

Dionicio, G.A.

2006-01-01

This investigation addresses the effect that pressure, p, and temperature, T, have on 4f states of the rare-earth elements in the isostructural YbRh 2 Si 2 , EuCo 2 Ge 2 , and EuCu 2 Ge 2 compounds. Upon applying pressure the volume of the unit cell reduces, enforcing either the enhancement of the hybridization of the 4f localized electrons with the ligand or a change in the valence state of the rare-earth ions. Here, we probe the effect of a pressure-induced lattice contraction on these system by means of electrical-resistivity measurements, ρ(T), from room temperature down to 100 mK. (orig.)

Valence band structure of PDMS surface and a blend with MWCNTs: A UPS and MIES study of an insulating polymer

Energy Technology Data Exchange (ETDEWEB)

Schmerl, Natalya M.; Khodakov, Dmitriy A.; Stapleton, Andrew J.; Ellis, Amanda V.; Andersson, Gunther G., E-mail: gunther.andersson@flinders.edu.au

2015-10-30

Graphical abstract: - Highlights: • Valence electron spectroscopy was performed on an insulating polymer using different charge compensation methods. • MWCNT were embedded in PDMS and found to be the most effective method for reducing the charging of the insulating polymer. • The valence band spectrum of PDMS was obtained via MIES and UPS. • Ion scattering spectroscopy was used to determine the concentration depth profile of the PDMS in the sample. - Abstract: The use of polydimethylsiloxane (PDMS) is increasing with new technologies working toward compact, flexible and transparent devices for use in medical and microfluidic systems. Electronic characterization of PDMS and other insulating materials is difficult due to charging, yet necessary for many applications where the interfacial structure is vital to device function or further modification. The outermost layer in particular is of importance as this is the area where chemical reactions such as surface functionalization will occur. Here, we investigate the valence band structure of the outermost layer and near surface area of PDMS through the use of metastable induced photoelectron spectroscopy (MIES) paired with ultraviolet photoelectron spectroscopy (UPS). The chemical composition of the samples under investigation were measured via X-ray photoelectron spectroscopy (XPS), and the vertical distribution of the polymer was shown with neutral impact collision ion scattering spectroscopy (NICISS). Three separate methods for charge compensation are used for the samples, and their effectiveness is compared.

The Krafft temperature of surfactant solutions

OpenAIRE

Manojlović Jelena Ž.

2012-01-01

Our main motivation to revisit the solution properties of cetyltrimethylammonium bromide is related to the clear requirement for better control of the adsorption parameters to form uniform self-assembled monolayers on muscovite mica substrates. To readily monitor the temporal evolution of structural details in cetyltrimethylammonium bromide solutions, we realized a rather simple conductivity experiment. Conductivity measurements were carried out as a function of temperature, to look clo...

Temperature-reflection I

DEFF Research Database (Denmark)

McGady, David A.

2017-01-01

-temperature path integrals for quantum field theories (QFTs) should be T-reflection invariant. Because multi-particle partition functions are equal to Euclidean path integrals for QFTs, we expect them to be T-reflection invariant. Single-particle partition functions though are often not invariant under T......In this paper, we revisit the claim that many partition functions are invariant under reflecting temperatures to negative values (T-reflection). The goal of this paper is to demarcate which partition functions should be invariant under T-reflection, and why. Our main claim is that finite...... that T-reflection is unrelated to time-reversal. Finally, we study the interplay between T-reflection and perturbation theory in the anharmonic harmonic oscillator in quantum mechanics and in Yang-Mills in four-dimensions. This is the first in a series of papers on temperature-reflections....

Spin--orbit configuration-interaction study of valence and Rydberg states of LiBe

International Nuclear Information System (INIS)

Marino, M.M.; Ermler, W.C.; Kern, C.W.; Bondybey, V.E.

1992-01-01

Ab initio spin--orbit full configuration-interaction calculations in the context of relativistic effective core potentials are reported for the weakly bound metal dimer LiBe, a three-valence-electron system. The effects of basis set on the energies of valence and Rydberg states of the cluster are discussed, as are the effects of configuration space selection on the energy of the latter states. Results at the dissociative limit are compared to the experimental atomic spectra. Potential-energy curves and spectroscopic constants are presented for the ground state and fourteen excited states, which includes the Li and Be 2p valence states, the Li 3s, 3p, 3d, and 4s Rydberg states, as well as three low-lying states of the molecular cation

Not always a matter of context: direct effects of red on arousal but context-dependent moderations on valence

Directory of Open Access Journals (Sweden)

Vanessa L. Buechner

2016-09-01

Full Text Available The arousal theory of color proposes that red is associated with arousal. Research on the color-in-context theory, in turn, states that the context in which red is perceived influences its valence-related meaning and behavioral responses to it. This study faces and integrates these theories by examining the influence of red on both arousal and valence perceptions of test-relevant and neutral stimuli, rendering a color 2 (red vs. blue × context 2 (test vs. neutral between-subjects design. Participants rated different pictures regarding their arousal and valence component, respectively. In line with the assumptions of both theories, red increased arousal perceptions of stimuli irrespective of their valence but a context × color interaction was found for valence perceptions: for participants viewing test-relevant pictures, red increased their perceptions of negativity compared to neutral pictures. The present study shows that both theories are actually compatible when differentiating the arousal and valence component.

Revisiting tourist behavior via destination brand worldness

Directory of Open Access Journals (Sweden)

Murat Kayak

2016-11-01

Full Text Available Taking tourists’ perspective rather than destination offerings as its core concept, this study introduces “perceived destination brand worldness” as a variable. Perceived destination brand worldness is defined as the positive perception that a tourist has of a country that is visited by tourists from all over the world. Then, the relationship between perceived destination brand worldness and intention to revisit is analyzed using partial least squares regression. This empirical study selects Taiwanese tourists as its sample, and the results show that perceived destination brand worldness is a direct predictor of intention to revisit. In light of these empirical findings and observations, practical and theoretical implications are discussed.

Ca-site substitution induced a metal-insulator transition in manganite CaMnO3

International Nuclear Information System (INIS)

Sousa, D.; Nunes, M.R.; Silveira, C.; Matos, I.; Lopes, A.B.; Melo Jorge, M.E.

2008-01-01

A systematic study of the A-site doping in Mn(IV)-rich perovskite manganites Ca 1-x Ho x MnO 3 , over a large homogeneity range (0.1 ≤ x ≤ 0.4), has been performed. A significant increase in the lattice parameters indicated the presence of mixed valence state of Mn: Mn 3+ and Mn 4+ . The substitution of calcium by holmium also induces strong changes in the electrical properties. We found that small Ho concentration produces an important decrease in the electrical resistivity and induces an electrical transition, the temperature corresponding to the metal-insulator transition (T MI ) shifts with the holmium content. This electrical behavior is attributed to the Mn 3+ ions content and a charge order effect

Positron annihilation studies of zirconia doped with metal cations of different valence

Science.gov (United States)

Prochazka, I.; Cizek, J.; Melikhova, O.; Konstantinova, T. E.; Danilenko, I. A.; Yashchishyn, I. A.; Anwand, W.; Brauer, G.

2013-06-01

New results obtained by applying positron annihilation spectroscopy to the investigation of zirconia-based nanomaterials doped with metal cations of different valence are reported. The slow-positron implantation spectroscopy combined with Doppler broadening measurements was employed to study the sintering of pressure-compacted nanopowders of tetragonal yttria-stabilised zirconia (t-YSZ) and t-YSZ with chromia additive. Positronium (Ps) formation in t-YSZ was proven by detecting 3γ-annihilations of ortho-Ps and was found to gradually decrease with increasing sintering temperature. A subsurface layer with enhanced 3γ-annihilations, compared to the deeper regions, could be identified. Addition of chromia was found to inhibit Ps formation. In addition, first results of positron lifetime measurements on nanopowders of zirconia phase-stabilised with MgO and CeO2 are presented.

Investigation of thermal quenching and abnormal thermal quenching in mixed valence Eu co-doped LaAlO{sub 3} phosphor

Energy Technology Data Exchange (ETDEWEB)

Chen, Jingjing [Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Zhao, Yang [China academy of civil aviation science and technology, Beijing 100028 (China); Mao, Zhiyong, E-mail: mzhy1984@163.com [Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Wang, Dajian [Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Bie, Lijian, E-mail: ljbie@tjut.edu.cn [Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China)

2017-06-15

Temperature dependent luminescence of mixed valence Eu co-doped LaAlO{sub 3} phosphors are deeply investigated in this work. Different temperature properties of Eu{sup 2+} and Eu{sup 3+} luminescence are observed as the phosphor excited by different incident light. Eu{sup 3+} luminescence shows normal thermal quenching when excited at 320 nm and abnormal thermal quenching as the excitation light changed into 365 nm, while Eu{sup 2+} luminescence exhibits a normal thermal quenching independent on the incident excitation lights. The origin of these novel normal/abnormal thermal quenching phenomena are analyzed and discussed by the excitation-emission processes in terms of the configuration coordinate model. The presented important experimental and analysis results give insights into the temperature properties of phosphors.

The effect of cerium valence states at cerium oxide nanoparticle surfaces on cell proliferation

KAUST Repository

Naganuma, Tamaki

2014-05-01

Understanding and controlling cell proliferation on biomaterial surfaces is critical for scaffold/artificial-niche design in tissue engineering. The mechanism by which underlying integrin ligates with functionalized biomaterials to induce cell proliferation is still not completely understood. In this study, poly-l-lactide (PL) scaffold surfaces were functionalized using layers of cerium oxide nanoparticles (CNPs), which have recently attracted attention for use in therapeutic application due to their catalytic ability of Ce4+ and Ce3+ sites. To isolate the influence of Ce valance states of CNPs on cell proliferation, human mesenchymal stem cells (hMSCs) and osteoblast-like cells (MG63) were cultured on the PL/CNP surfaces with dominant Ce4+ and Ce3+ regions. Despite cell type (hMSCs and MG63 cells), different surface features of Ce4+ and Ce3+ regions clearly promoted and inhibited cell spreading, migration and adhesion behavior, resulting in rapid and slow cell proliferation, respectively. Cell proliferation results of various modified CNPs with different surface charge and hydrophobicity/hydrophilicity, indicate that Ce valence states closely correlated with the specific cell morphologies and cell-material interactions that trigger cell proliferation. This finding suggests that the cell-material interactions, which influence cell proliferation, may be controlled by introduction of metal elements with different valence states onto the biomaterial surface. © 2014 Elsevier Ltd.

Open-Minded Midwifes, Literate Butchers, and Greedy Hooligans—The Independent Contributions of Stereotype Valence and Consistency on Evaluative Judgments

Science.gov (United States)

Schubert, Lisa; Körner, Anita; Lindau, Berit; Strack, Fritz; Topolinski, Sascha

2017-01-01

Do people evaluate an open-minded midwife less positively than a caring midwife? Both open-minded and caring are generally seen as positive attributes. However, consistency varies—the attribute caring is consistent with the midwife stereotype while open-minded is not. In general, both stimulus valence and consistency can influence evaluations. Six experiments investigated the respective influence of valence and consistency on evaluative judgments in the domain of stereotyping. In an impression formation paradigm, valence and consistency of stereotypic information about target persons were manipulated orthogonally and spontaneous evaluations of these target persons were measured. Valence reliably influenced evaluations. However, for strongly valenced stereotypes, no effect of consistency was observed. Parameters possibly preventing the occurrence of consistency effects were ruled out, specifically, valence of inconsistent attributes, processing priority of category information, and impression formation instructions. However, consistency had subtle effects on evaluative judgments if the information about a target person was not strongly valenced and experimental conditions were optimal. Concluding, in principle, both stereotype valence and consistency can play a role in evaluative judgments of stereotypic target persons. However, the more subtle influence of consistency does not seem to substantially influence evaluations of stereotyped target persons. Implications for fluency research and stereotype disconfirmation are discussed. PMID:29062289

Open-Minded Midwifes, Literate Butchers, and Greedy Hooligans-The Independent Contributions of Stereotype Valence and Consistency on Evaluative Judgments.

Science.gov (United States)

Schubert, Lisa; Körner, Anita; Lindau, Berit; Strack, Fritz; Topolinski, Sascha

2017-01-01

Do people evaluate an open-minded midwife less positively than a caring midwife? Both open-minded and caring are generally seen as positive attributes. However, consistency varies-the attribute caring is consistent with the midwife stereotype while open-minded is not. In general, both stimulus valence and consistency can influence evaluations. Six experiments investigated the respective influence of valence and consistency on evaluative judgments in the domain of stereotyping. In an impression formation paradigm, valence and consistency of stereotypic information about target persons were manipulated orthogonally and spontaneous evaluations of these target persons were measured. Valence reliably influenced evaluations. However, for strongly valenced stereotypes, no effect of consistency was observed. Parameters possibly preventing the occurrence of consistency effects were ruled out, specifically, valence of inconsistent attributes, processing priority of category information, and impression formation instructions. However, consistency had subtle effects on evaluative judgments if the information about a target person was not strongly valenced and experimental conditions were optimal. Concluding, in principle, both stereotype valence and consistency can play a role in evaluative judgments of stereotypic target persons. However, the more subtle influence of consistency does not seem to substantially influence evaluations of stereotyped target persons. Implications for fluency research and stereotype disconfirmation are discussed.

Open-Minded Midwifes, Literate Butchers, and Greedy Hooligans—The Independent Contributions of Stereotype Valence and Consistency on Evaluative Judgments

Directory of Open Access Journals (Sweden)

Lisa Schubert

2017-10-01

Full Text Available Do people evaluate an open-minded midwife less positively than a caring midwife? Both open-minded and caring are generally seen as positive attributes. However, consistency varies—the attribute caring is consistent with the midwife stereotype while open-minded is not. In general, both stimulus valence and consistency can influence evaluations. Six experiments investigated the respective influence of valence and consistency on evaluative judgments in the domain of stereotyping. In an impression formation paradigm, valence and consistency of stereotypic information about target persons were manipulated orthogonally and spontaneous evaluations of these target persons were measured. Valence reliably influenced evaluations. However, for strongly valenced stereotypes, no effect of consistency was observed. Parameters possibly preventing the occurrence of consistency effects were ruled out, specifically, valence of inconsistent attributes, processing priority of category information, and impression formation instructions. However, consistency had subtle effects on evaluative judgments if the information about a target person was not strongly valenced and experimental conditions were optimal. Concluding, in principle, both stereotype valence and consistency can play a role in evaluative judgments of stereotypic target persons. However, the more subtle influence of consistency does not seem to substantially influence evaluations of stereotyped target persons. Implications for fluency research and stereotype disconfirmation are discussed.

Revisiting Inter-Genre Similarity

DEFF Research Database (Denmark)

Sturm, Bob L.; Gouyon, Fabien

2013-01-01

We revisit the idea of ``inter-genre similarity'' (IGS) for machine learning in general, and music genre recognition in particular. We show analytically that the probability of error for IGS is higher than naive Bayes classification with zero-one loss (NB). We show empirically that IGS does...... not perform well, even for data that satisfies all its assumptions....

A Hydrostatic Paradox Revisited

Science.gov (United States)

Ganci, Salvatore

2012-01-01

This paper revisits a well-known hydrostatic paradox, observed when turning upside down a glass partially filled with water and covered with a sheet of light material. The phenomenon is studied in its most general form by including the mass of the cover. A historical survey of this experiment shows that a common misunderstanding of the phenomenon…

THE INFLUENCE OF DESTINATION IMAGE AND TOURIST SATISFACTION TOWARD REVISIT INTENTION OF SETU BABAKAN BETAWI CULTURAL VILLAGE

OpenAIRE

Wibowo, Setyo Ferry; Sazali, Adnan; Kresnamurti R. P., Agung

2016-01-01

The purpose of this research are: 1) To find out the description of destination image, tourist satisfaction, and revisit intention of Betawi cultural village Setu Babakan, 2) test empirically the influence of destination image toward revisit intention of Betawi cultural village Setu Babakan, 3) test empirically the influence of tourist satisfaction toward revisit intention of Betawi cultural village Setu Babakan, 4) test empirically the influence of destination image toward revisit intention ...

Nature of the valence band states in Bi2(Ca, Sr, La)3Cu2O8

International Nuclear Information System (INIS)

Wells, B.O.; Lindberg, P.A.P.; Shen, Z.; Dessau, D.S.; Spicer, W.E.; Lindau, I.; Mitzi, D.B.; Kapitulnik, A.

1990-01-01

We have used photoemission spectroscopy to examine the symmetry of the occupied states of the valence band for the La doped superconductor Bi 2 (Ca, Sr, La) 3 Cu 2 O 8 . While the oxygen states near the bottom of the 7 eV wide valence band exhibit predominantly O 2p z symmetry, the states at the top of the valence band extending to the Fermi level are found to have primarily O 2p x and O 2p y character. We have also examined anomalous intensity enhancements in the valence band feature for photon energies near 18 eV. These enhancements, which occur at photon energies ranging from 15.8 to 18.0 eV for the different valence band features, are not consistent with either simple final state effects or direct O2s transitions to unoccupied O2p states

Looking behaviour and preference for artworks: the role of emotional valence and location.

Science.gov (United States)

Kreplin, Ute; Thoma, Volker; Rodway, Paul

2014-10-01

The position of an item influences its evaluation, with research consistently finding that items occupying central locations are preferred and have a higher subjective value. The current study investigated whether this centre-stage effect (CSE) is a result of bottom-up gaze allocation to the central item, and whether it is affected by item valence. Participants (n=50) were presented with three images of artistic paintings in a row and asked to choose the image they preferred. Eye movements were recorded for a subset of participants (n=22). On each trial the three artworks were either similar but different, or were identical and with positive valence, or were identical and with negative valence. The results showed a centre-stage effect, with artworks in the centre of the row preferred, but only when they were identical and of positive valence. Significantly greater gaze allocation to the central and left artwork was not mirrored by equivalent increases in preference choices. Regression analyses showed that when the artworks were positive and identical the participants' last fixation predicted preference for the central art-work, whereas the fixation duration predicted preference if the images were different. Overall the result showed that item valence, rather than level of gaze allocation, influences the CSE, which is incompatible with the bottom-up gaze explanation. We propose that the centre stage heuristic, which specifies that the best items are in the middle, is able to explain these findings and the centre-stage effect. Copyright © 2014 Elsevier B.V. All rights reserved.

Flexible temperature and flow sensor from laser-induced graphene

KAUST Repository

Marengo, Marco; Marinaro, Giovanni; Kosel, Jü rgen

2017-01-01

Herein we present a flexible temperature sensor and a flow speed sensor based on laser-induced graphene. The main benefits arise from peculiar electrical, thermal and mechanical performances of the material thus obtained, along with a cheap

Two Parallel Pathways Assign Opposing Odor Valences during Drosophila Memory Formation

Directory of Open Access Journals (Sweden)

Daisuke Yamazaki

2018-02-01

Full Text Available During olfactory associative learning in Drosophila, odors activate specific subsets of intrinsic mushroom body (MB neurons. Coincident exposure to either rewards or punishments is thought to activate extrinsic dopaminergic neurons, which modulate synaptic connections between odor-encoding MB neurons and MB output neurons to alter behaviors. However, here we identify two classes of intrinsic MB γ neurons based on cAMP response element (CRE-dependent expression, γCRE-p and γCRE-n, which encode aversive and appetitive valences. γCRE-p and γCRE-n neurons act antagonistically to maintain neutral valences for neutral odors. Activation or inhibition of either cell type upsets this balance, toggling odor preferences to either positive or negative values. The mushroom body output neurons, MBON-γ5β′2a/β′2mp and MBON-γ2α′1, mediate the actions of γCRE-p and γCRE-n neurons. Our data indicate that MB neurons encode valence information, as well as odor information, and this information is integrated through a process involving MBONs to regulate learning and memory.

Organ donation video messaging: differential appeal, emotional valence, and behavioral intention.

Science.gov (United States)

Rodrigue, J R; Fleishman, A; Vishnevsky, T; Fitzpatrick, S; Boger, M

2014-10-01

Video narratives increasingly are used to draw the public's attention to the need for more registered organ donors. We assessed the differential impact of donation messaging videos on appeal, emotional valence, and organ donation intentions in 781 non-registered adults. Participants watched six videos (four personal narratives, one informational video without personal narrative, and one unrelated to donation) with or without sound (subtitled), randomly sequenced to minimize order effects. We assessed appeal, emotional valence, readiness to register as organ donors, and donation information-seeking behavior. Compared to other video types, one featuring a pediatric transplant recipient (with or without sound) showed more favorable appeal (p emotional valence (p emotion (OR = 1.05, 95% CI = 1.03, 1.07, p < 0.001) were significant multivariable predictors of clicking through to the donation website. Brief, one-min videos can have a very dramatic and positive impact on willingness to consider donation and behavioral intentions to register as an organ donor. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Enhanced conflict-driven cognitive control by emotional arousal, not by valence.

Science.gov (United States)

Zeng, Qinghong; Qi, Senqing; Li, Miaoyun; Yao, Shuxia; Ding, Cody; Yang, Dong

2017-09-01

Emotion is widely agreed to have two dimensions, valence and arousal. Few studies have explored the effect of emotion on conflict adaptation by considering both of these, which could have dissociate influence. The present study aimed to fill the gap as to whether emotional valence and arousal would exert dissociable influence on conflict adaptation. In the experiments, we included positive, neutral, and negative conditions, with comparable arousal between positive and negative conditions. Both positive and negative conditions have higher arousal than neutral ones. In Experiment 1, by using a two-colour-word Flanker task, we found that conflict adaptation was enhanced in both positive and negative contexts compared to a neutral context. Furthermore, this effect still existed when controlling stimulus-response repetitions in Experiment 2, which used a four-colour-word Flanker task. The findings suggest emotional arousal enhances conflict adaptation, regardless of emotional valence. Thus, future studies should consider emotional arousal when studying the effect of emotion on conflict adaptation. Moreover, the unique role of the emotional context in conflict-driven cognitive control is emphasised.

Martensitic transition near room temperature and the temperature- and magnetic-field-induced multifunctional properties of Ni49CuMn34In16 alloy

Science.gov (United States)

Sharma, V. K.; Chattopadhyay, M. K.; Khandelwal, A.; Roy, S. B.

2010-11-01

A near room-temperature martensitic transition is observed in the ferromagnetic austenite state of Ni50Mn34In16 alloy with 2% Cu substitution at the Ni site. Application of magnetic field in the martensite state induces a reverse martensitic transition in this alloy. dc magnetization, magnetoresistance and strain measurements in this alloy reveal that associated with this martensitic transition there exist a large magnetocaloric effect, a large magnetoresitance and a magnetic-field temperature-induced strain. This NiMnIn alloy system thus is an example of an emerging class of magnetic materials whose physical properties can be tuned by suitable chemical substitutions, to achieve magnetic-field and temperature-induced multifunctional properties at and around room temperature

Reconstruction of CMB temperature anisotropies with primordial CMB induced polarization in galaxy clusters

Science.gov (United States)

Liu, Guo-Chin; Ichiki, Kiyotomo; Tashiro, Hiroyuki; Sugiyama, Naoshi

2016-07-01

Scattering of cosmic microwave background (CMB) radiation in galaxy clusters induces polarization signals determined by the quadrupole anisotropy in the photon distribution at the location of clusters. This `remote quadrupole' derived from the measurements of the induced polarization in galaxy clusters provides an opportunity to reconstruct local CMB temperature anisotropies. In this Letter, we develop an algorithm of the reconstruction through the estimation of the underlying primordial gravitational potential, which is the origin of the CMB temperature and polarization fluctuations and CMB induced polarization in galaxy clusters. We found a nice reconstruction for the quadrupole and octopole components of the CMB temperature anisotropies with the assistance of the CMB induced polarization signals. The reconstruction can be an important consistency test on the puzzles of CMB anomalies, especially for the low-quadrupole and axis-of-evil problems reported in Wilkinson Microwave Anisotropy Probe and Planck data.

Valence holes observed in nanodiamonds dispersed in water

Science.gov (United States)

Petit, Tristan; Pflüger, Mika; Tolksdorf, Daniel; Xiao, Jie; Aziz, Emad F.

2015-02-01

Colloidal dispersion is essential for most nanodiamond applications, but its influence on nanodiamond electronic properties remains unknown. Here we have probed the electronic structure of oxidized detonation nanodiamonds dispersed in water by using soft X-ray absorption and emission spectroscopies at the carbon and oxygen K edges. Upon dispersion in water, the π* transitions from sp2-hybridized carbon disappear, and holes in the valence band are observed.Colloidal dispersion is essential for most nanodiamond applications, but its influence on nanodiamond electronic properties remains unknown. Here we have probed the electronic structure of oxidized detonation nanodiamonds dispersed in water by using soft X-ray absorption and emission spectroscopies at the carbon and oxygen K edges. Upon dispersion in water, the π* transitions from sp2-hybridized carbon disappear, and holes in the valence band are observed. Electronic supplementary information (ESI) available: Experimental methods, details on XAS/XES normalization and background correction procedures. See DOI: 10.1039/c4nr06639a

Seven Issues, Revisited

OpenAIRE

Whitehead, Jim; De Bra, Paul; Grønbæk, Kaj; Larsen, Deena; Legget, John; schraefel, monica m.c.

2002-01-01

It has been 15 years since the original presentation by Frank Halasz at Hypertext'87 on seven issues for the next generation of hypertext systems. These issues are: Search and Query Composites Virtual Structures Computation in/over hypertext network Versioning Collaborative Work Extensibility and Tailorability Since that time, these issues have formed the nucleus of multiple research agendas within the Hypertext community. Befitting this direction-setting role, the issues have been revisited ...

'Felson Signs' revisited

International Nuclear Information System (INIS)

George, Phiji P.; Irodi, Aparna; Keshava, Shyamkumar N.; Lamont, Anthony C.

2014-01-01

In this article we revisit, with the help of images, those classic signs in chest radiography described by Dr Benjamin Felson himself, or other illustrious radiologists of his time, cited and discussed in 'Chest Roentgenology'. We briefly describe the causes of the signs, their utility and the differential diagnosis to be considered when each sign is seen. Wherever possible, we use CT images to illustrate the basis of some of these classic radiographic signs.

THE INFLUENCE OF DESTINATION IMAGE AND TOURIST SATISFACTION TOWARD REVISIT INTENTION OF SETU BABAKAN BETAWI CULTURAL VILLAGE

Directory of Open Access Journals (Sweden)

Setyo Ferry Wibowo

2016-04-01

Full Text Available The purpose of this research are: 1 To find out the description of destination image, tourist satisfaction, and revisit intention of Betawi cultural village Setu Babakan, 2 test empirically the influence of destination image toward revisit intention of Betawi cultural village Setu Babakan, 3 test empirically the influence of tourist satisfaction toward revisit intention of Betawi cultural village Setu Babakan, 4 test empirically the influence of destination image toward revisit intention of Betawi cultural village Setu Babakan. The object of this research was 200 respondents who have ever visit to Betawi cultural village Setu Babakan at one time. The results of descriptive test explained that the destination image provided is good according to the tourist, so that the tourist is satisfied and want to revisit intention of Betawi cultural village Setu Babakan. The hypothesis test shows: 1 the influence of destination image toward revisit intention by -30%, 2 the influence of tourist satisfaction toward revisit intention by 118%, 3 the influence of destination image toward tourist satisfaction by 92%.

Name-valence and physical attractiveness in Facebook: their compensatory effects on friendship acceptance.

Science.gov (United States)

Greitemeyer, Tobias; Kunz, Irene

2013-01-01

Name-valence and physical attractiveness have been shown to be associated with how people respond toward others, in that people judge and behave more positively toward individuals with positive names and individuals who are physically attractive. The present research examined whether Facebook users are more likely to accept friendship requests from other Facebook users with positive (relative to negative) names and who are physically attractive (relative to being moderately attractive). In fact, both name-valence and physical attractiveness affected friendship acceptance. Moreover, results revealed that name-valence can be compensated by physical attractiveness (and vice versa). Acceptance rates of requests from users with positive names who are moderately attractive, as well as requests from users with negative names who are attractive did not significantly differ from those with positive names who are attractive.

Atomic contributions to the valence band photoelectron spectra of metal-free, iron and manganese phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Bidermane, I., E-mail: ieva.bidermane@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden); Institut des Nanosciences de Paris, UPMC Univ. Paris 06, CNRS UMR 7588, F-75005 Paris (France); Brumboiu, I.E. [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden); Totani, R. [Department of Physical and Chemical Sciences, University of L’Aquila, Via Vetoio, Coppito, I-67010 L’Aquila (Italy); Grazioli, C. [CNR-IOM, Laboratorio TASC, ss. 14 km. 163.5, Basovizza, 34149 Trieste (Italy); Departement of Chemical and Pharmaceutical Sciences, University of Trieste (Italy); Shariati-Nilsson, M.N.; Herper, H.C.; Eriksson, O.; Sanyal, B. [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden); Ressel, B. [University of Nova Gorica, Vipavska Cesta 11c, 5270 Ajdovščina (Slovenia); Simone, M. de [CNR-IOM, Laboratorio TASC, ss. 14 km. 163.5, Basovizza, 34149 Trieste (Italy); Lozzi, L. [Department of Physical and Chemical Sciences, University of L’Aquila, Via Vetoio, Coppito, I-67010 L’Aquila (Italy); Brena, B.; Puglia, C. [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden)

2015-11-15

Highlights: • In detail comparison between the valence band structure of H{sub 2}Pc, FePc and MnPc. • Comparison between the gas phase samples and thin evaporated films on Au (1 1 1). • Detailed analysis of the atomic orbital contributions to the valence band features. • DFT/HSE06 study of the valence band electronic structure of H{sub 2}Pc, FePc and MnPc. - Abstract: The present work reports a photoelectron spectroscopy study of the low-energy region of the valence band of metal-free phthalocyanine (H{sub 2}Pc) compared with those of iron phthalocyanine (FePc) and manganese phthalocyanine (MnPc). We have analysed in detail the atomic orbital composition of the valence band both experimentally, by making use of the variation in photoionization cross-sections with photon energy, and theoretically, by means of density functional theory. The atomic character of the Highest Occupied Molecular Orbital (HOMO), reflected on the outermost valence band binding energy region, is different for MnPc as compared to the other two molecules. The peaks related to the C 2p contributions, result in the HOMO for H{sub 2}Pc and FePc and in the HOMO-1 for MnPc as described by the theoretical predictions, in very good agreement with the experimental results. The DFT simulations, discerning the atomic contribution to the density of states, indicate how the central metal atom interacts with the C and N atoms of the molecule, giving rise to different partial and total density of states for these three Pc molecules.

The chemical bond in inorganic chemistry the bond valence model

CERN Document Server

Brown, I David

2016-01-01

The bond valence model is a version of the ionic model in which the chemical constraints are expressed in terms of localized chemical bonds formed by the valence charge of the atoms. Theorems derived from the properties of the electrostatic flux predict the rules obeyed by both ionic and covalent bonds. They make quantitative predictions of coordination number, crystal structure, bond lengths and bond angles. Bond stability depends on the matching of the bonding strengths of the atoms, while the conflicting requirements of chemistry and space lead to the structural instabilities responsible for the unusual physical properties displayed by some materials. The model has applications in many fields ranging from mineralogy to molecular biology.

Stress-Induced Cubic-to-Hexagonal Phase Transformation in Perovskite Nanothin Films.

Science.gov (United States)

Cao, Shi-Gu; Li, Yunsong; Wu, Hong-Hui; Wang, Jie; Huang, Baoling; Zhang, Tong-Yi

2017-08-09

The strong coupling between crystal structure and mechanical deformation can stabilize low-symmetry phases from high-symmetry phases or induce novel phase transformation in oxide thin films. Stress-induced structural phase transformation in oxide thin films has drawn more and more attention due to its significant influence on the functionalities of the materials. Here, we discovered experimentally a novel stress-induced cubic-to-hexagonal phase transformation in the perovskite nanothin films of barium titanate (BaTiO 3 ) with a special thermomechanical treatment (TMT), where BaTiO 3 nanothin films under various stresses are annealed at temperature of 575 °C. Both high-resolution transmission electron microscopy and Raman spectroscopy show a higher density of hexagonal phase in the perovskite thin film under higher tensile stress. Both X-ray photoelectron spectroscopy and electron energy loss spectroscopy does not detect any change in the valence state of Ti atoms, thereby excluding the mechanism of oxygen vacancy induced cubic-to-hexagonal (c-to-h) phase transformation. First-principles calculations show that the c-to-h phase transformation can be completed by lattice shear at elevated temperature, which is consistent with the experimental observation. The applied bending plus the residual tensile stress produces shear stress in the nanothin film. The thermal energy at the elevated temperature assists the shear stress to overcome the energy barriers during the c-to-h phase transformation. The stress-induced phase transformation in perovskite nanothin films with TMT provides materials scientists and engineers a novel approach to tailor nano/microstructures and properties of ferroelectric materials.

Leadership and Management Theories Revisited

DEFF Research Database (Denmark)

Madsen, Mona Toft

2001-01-01

The goal of the paper is to revisit and analyze key contributions to the understanding of leadership and management. As a part of the discussion a role perspective that allows for additional and/or integrated leader dimensions, including a change-centered, will be outlined. Seemingly, a major...

Photon- and electron-induced surface voltage in electron spectroscopies on ZnSe(0 0 1)

International Nuclear Information System (INIS)

Cantoni, M.; Bertacco, R.; Brambilla, A.; Ciccacci, F.

2009-01-01

The surface band bending in ZnSe(0 0 1), as a function of the temperature, is investigated both in the valence band (by photoemission) and in the conduction band (by inverse photoemission and absorbed current spectroscopies). Two different mechanisms are invoked for interpreting the experimental data: the band bending due to surface states, and the surface voltage induced by the incident beam. While the latter is well known in photoemission (surface photovoltage), we demonstrate the existence of a similar effect in inverse photoemission and absorbed current spectroscopies, induced by the incident electrons instead of photons. These results point to the importance of considering the surface voltage effect even in electron-in techniques for a correct evaluation of the band bending.

Temperature dependent empirical pseudopotential theory for self-assembled quantum dots.

Science.gov (United States)

Wang, Jianping; Gong, Ming; Guo, Guang-Can; He, Lixin

2012-11-28

We develop a temperature dependent empirical pseudopotential theory to study the electronic and optical properties of self-assembled quantum dots (QDs) at finite temperature. The theory takes the effects of both lattice expansion and lattice vibration into account. We apply the theory to InAs/GaAs QDs. For the unstrained InAs/GaAs heterostructure, the conduction band offset increases whereas the valence band offset decreases with increasing temperature, and there is a type-I to type-II transition at approximately 135 K. Yet, for InAs/GaAs QDs, the holes are still localized in the QDs even at room temperature, because the large lattice mismatch between InAs and GaAs greatly enhances the valence band offset. The single-particle energy levels in the QDs show a strong temperature dependence due to the change of confinement potentials. Because of the changes of the band offsets, the electron wavefunctions confined in QDs increase by about 1-5%, whereas the hole wavefunctions decrease by about 30-40% when the temperature increases from 0 to 300 K. The calculated recombination energies of excitons, biexcitons and charged excitons show red shifts with increasing temperature which are in excellent agreement with available experimental data.

NATO Advanced Study Institute on Mixed-Valence Compounds : Theory and Applications in Chemistry, Physics, Geology, and Biology

CERN Document Server

1980-01-01

It has been a decade since two seminal reviews demonstrated that mixed-valence compounds share many unique and fascinating features. The insight pro­ vided by those early works has promoted a great deal of both experimental and theoretical study. As a result of extensive efforts, our understanding of the bonding and properties of mixed-valence compounds has advanced substantially. There has been no compre­ hensive treatment of mixed-valence compounds since 1967, and the meeting convened at Oxford in September, 1979, provided a unique opportunity to examine the subject and its many ramifications. Mixed-valence compounds play an important role in many fields. Although the major impact of the subject has been in chemistry, its importance has become increasingly clear in solid state physics, geology, and biology. Extensive interest and effort in the field of molecular metals has demonstrated that mixed-valency is a prerequisite for high elec­ trical conductivity. The intense colors of many minerals have been s...

Sex, Age, and Emotional Valence: Revealing Possible Biases in the 'Reading the Mind in the Eyes' Task.

Science.gov (United States)

Kynast, Jana; Schroeter, Matthias L

2018-01-01

The 'Reading the Mind in the Eyes' test (RMET) assesses a specific socio-cognitive ability, i.e., the ability to identify mental states from gaze. The development of this ability in a lifespan perspective is of special interest. Whereas former investigations were limited mainly to childhood and adolescence, the focus has been shifted towards aging, and psychiatric and neurodegenerative diseases recently. Although the RMET is frequently applied in developmental psychology and clinical settings, stimulus characteristics have never been investigated with respect to potential effects on test performance. Here, we analyzed the RMET stimulus set with a special focus on interrelations between sex, age and emotional valence. Forty-three persons rated age and emotional valence of the RMET picture set. Differences in emotional valence and age ratings between male and female items were analyzed. The linear relation between age and emotional valence was tested over all items, and separately for male and female items. Male items were rated older and more negative than female stimuli. Regarding male RMET items, age predicted emotional valence: older age was associated with negative emotions. Contrary, age and valence were not linearly related in female pictures. All ratings were independent of rater characteristics. Our results demonstrate a strong confound between sex, age, and emotional valence in the RMET. Male items presented a greater variability in age ratings compared to female items. Age and emotional valence were negatively associated among male items, but no significant association was found among female stimuli. As personal attributes impact social information processing, our results may add a new perspective on the interpretation of previous findings on interindividual differences in RMET accuracy, particularly in the field of developmental psychology, and age-associated neuropsychiatric diseases. A revision of the RMET might be afforded to overcome confounds

Temperature-induced transitions between domain structures of ultrathin magnetic films

International Nuclear Information System (INIS)

Polyakova, T.; Zablotskii, V.

2005-01-01

Full text: Understanding of the influence of temperature on behavior of domain patterns of ultrathin magnetic films is of high significance for the fundamental physics of nanomagnetism as well as for technological applications. A thickness-dependent Curie temperature of ultrathin films may cause many interesting phenomena in the thermal evolution of domain structures (DS): i) nontrivial changes of the anisotropy constants as a function of the film thickness; ii) so-called inverse melting of DSs (processes where a more symmetric domain phase is found at lower temperatures than at higher temperatures - the inverse phase sequence) [1]; iii) temperature-induced transitions between domain structures. The possibility of such transitions is determined by lowering of the potential barriers separating different magnetization states as the film temperature approaches the Curie point. In this case with an increase of temperature, due to a significant decrease of the anisotropy constant, the domain wall energy is low enough and allows the system to reach equilibrium by a change of the domain wall number in the sample. This manifests itself in a transition from a metastable DS to a more stable DS which corresponds to new values of the anisotropy constant and magnetizations saturation. Thus, the temperature-induced transitions are driven by temperature changes of the magnetic parameters of the film. The key parameters controlling the DS geometry and period are the characteristic length, l c =σ/4πM S 2 (the ratio between the domain wall and demagnetization energies), and the quality factor Q =K/2πM S 2 (K is the first anisotropy constant). We show that for films with a pronounced nonmonotonic temperature dependence of l c one can expect a counter thermodynamic behavior: the inverse phase sequence and cooling-induced disordering. On changing temperature the existing domain structure should accommodate itself under new magnitudes of l c and Q. There are the two possible

Nature of the magnetic ground state in the mixed valence compound CeRuSn: a single-crystal study

International Nuclear Information System (INIS)

Fikáček, J; Prokleška, J; Prchal, J; Custers, J; Sechovský, V

2013-01-01

We report on detailed low-temperature measurements of the magnetization, the specific heat and the electrical resistivity on high-quality CeRuSn single crystals. The compound orders antiferromagnetically at T N = 2.8 K with the Ce 3+ ions locked within the a–c plane of the monoclinic structure. Magnetization shows that below T N CeRuSn undergoes a metamagnetic transition when applying a magnetic field of 1.5 and 0.8 T along the a- and c-axis, respectively. This transition manifests in a tremendous negative jump of ∼25% in the magnetoresistance. The value of the saturated magnetization along the easy magnetization direction (c-axis) and the magnetic entropy above T N derived from specific heat data correspond to the scenario of only one third of the Ce ions in the compound being trivalent and carrying a stable Ce 3+ magnetic moment, whereas the other two thirds of the Ce ions are in a nonmagnetic tetravalent and/or mixed valence state. This is consistent with the low-temperature CeRuSn crystal structure i.e., a superstructure consisting of three unit cells of the CeCoAl type piled up along the c-axis, and in which the Ce 3+ ions are characterized by large distances from the Ru ligands while the Ce–Ru distances of the other Ce ions are much shorter causing a strong 4f-ligand hybridization and hence leading to tetravalent and/or mixed valence Ce ions. (paper)

Emotional Valence, Arousal, and Threat Ratings of 160 Chinese Words among Adolescents.

Science.gov (United States)

Ho, Samuel M Y; Mak, Christine W Y; Yeung, Dannii; Duan, Wenjie; Tang, Sandy; Yeung, June C; Ching, Rita

2015-01-01

This study was conducted to provide ratings of valence/pleasantness, arousal/excitement, and threat/potential harm for 160 Chinese words. The emotional valence classification (positive, negative, or neutral) of all of the words corresponded to that of the equivalent English language words. More than 90% of the participants, junior high school students aged between 12 and 17 years, understood the words. The participants were from both mainland China and Hong Kong, thus the words can be applied to adolescents familiar with either simplified (e.g. in mainland China) or traditional Chinese (e.g. in Hong Kong) with a junior secondary school education or higher. We also established eight words with negative valence, high threat, and high arousal ratings to facilitate future research, especially on attentional and memory biases among individuals prone to anxiety. Thus, the new emotional word list provides a useful source of information for affective research in the Chinese language.

Understanding and revisiting the most complex perovskite system via atomistic simulations

Science.gov (United States)

Yang, Yali; Xu, Bin; Xu, Changsong; Ren, Wei; Bellaiche, Laurent

2018-05-01

A first-principles-based effective Hamiltonian is developed and used, along with direct ab initio techniques, to investigate finite-temperature properties of the system commonly coined the most complex perovskite, that is NaNbO3. Such simulations successfully reproduce the existence of seven different phases in its phase diagram. The decomposition of the total energy of this effective Hamiltonian into different terms, altogether with the values of the parameters associated with these terms, also allow us to shed some light into puzzling features of such a compound. Examples include revealing the microscopic reasons of why R 3 c is its ground state and why it solely adopts in-phase tiltings at high temperatures versus complex nanotwins for intermediate temperatures. The results of the computations also call for a revisiting of the so-called P ,R , and S states, in the sense that an unexpected and previously overlooked inhomogeneous electrical polarization is numerically found in the P state while complex tiltings associated with the simultaneous condensation of several k points are predicted for the controversial R and S phases.

Schroedinger's variational method of quantization revisited

International Nuclear Information System (INIS)

Yasue, K.

1980-01-01

Schroedinger's original quantization procedure is revisited in the light of Nelson's stochastic framework of quantum mechanics. It is clarified why Schroedinger's proposal of a variational problem led us to a true description of quantum mechanics. (orig.)

Visible light induced electron transfer process over nitrogen doped TiO2 nanocrystals prepared by oxidation of titanium nitride

International Nuclear Information System (INIS)

Wu Zhongbiao; Dong Fan; Zhao Weirong; Guo Sen

2008-01-01

Nitrogen doped TiO 2 nanocrystals with anatase and rutile mixed phases were prepared by incomplete oxidation of titanium nitride at different temperatures. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), core level X-ray photoelectron spectroscopy (CL XPS), valence band X-ray photoelectron spectroscopy (VB XPS), UV-vis diffuse reflectance spectra (UV-vis DRS), and visible light excited photoluminescence (PL). The photocatalytic activity was evaluated for photocatalytic degradation of toluene in gas phase under visible light irradiation. The visible light absorption and photoactivities of these nitrogen doped TiO 2 nanocrystals can be clearly attributed to the change of the additional electronic (N - ) states above the valence band of TiO 2 modified by N dopant as revealed by the VB XPS and visible light induced PL. A band gap structure model was established to explain the electron transfer process over nitrogen doped TiO 2 nanocrystals under visible light irradiation, which was consistent with the previous theoretical and experimental results. This model can also be applied to understand visible light induced photocatalysis over other nonmetal doped TiO 2

Pion and kaon valence-quark parton quasidistributions

Science.gov (United States)

Xu, Shu-Sheng; Chang, Lei; Roberts, Craig D.; Zong, Hong-Shi

2018-05-01

Algebraic Ansätze for the Poincaré-covariant Bethe-Salpeter wave functions of the pion and kaon are used to calculate their light-front wave functions, parton distribution amplitudes, parton quasidistribution amplitudes, valence parton distribution functions, and parton quasidistribution functions (PqDFs). The light-front wave functions are broad, concave functions, and the scale of flavor-symmetry violation in the kaon is roughly 15%, being set by the ratio of emergent masses in the s - and u -quark sectors. Parton quasidistribution amplitudes computed with longitudinal momentum Pz=1.75 GeV provide a semiquantitatively accurate representation of the objective parton distribution amplitude, but even with Pz=3 GeV , they cannot provide information about this amplitude's end point behavior. On the valence-quark domain, similar outcomes characterize PqDFs. In this connection, however, the ratio of kaon-to-pion u -quark PqDFs is found to provide a good approximation to the true parton distribution function ratio on 0.4 ≲x ≲0.8 , suggesting that with existing resources computations of ratios of parton quasidistributions can yield results that support empirical comparison.

Theory of laser-induced demagnetization at high temperatures

KAUST Repository

Manchon, Aurelien

2012-02-17

Laser-induced demagnetization is theoretically studied by explicitly taking into account interactions among electrons, spins, and lattice. Assuming that the demagnetization processes take place during the thermalization of the subsystems, the temperature dynamics is given by the energy transfer between the thermalized interacting baths. These energy transfers are accounted for explicitly through electron-magnon and electron-phonon interactions, which govern the demagnetization time scale. By properly treating the spin system in a self-consistent random phase approximation, we derive magnetization dynamic equations for a broad range of temperature. The dependence of demagnetization on the temperature and pumping laser intensity is calculated in detail. In particular, we show several salient features for understanding magnetization dynamics near the Curie temperature. While the critical slowdown in dynamics occurs, we find that an external magnetic field can restore the fast dynamics. We discuss the implication of the fast dynamics in the application of heat-assisted magnetic recording.

Theory of laser-induced demagnetization at high temperatures

KAUST Repository

Manchon, Aurelien; Li, Q.; Xu, L.; Zhang, S.

2012-01-01

Laser-induced demagnetization is theoretically studied by explicitly taking into account interactions among electrons, spins, and lattice. Assuming that the demagnetization processes take place during the thermalization of the subsystems, the temperature dynamics is given by the energy transfer between the thermalized interacting baths. These energy transfers are accounted for explicitly through electron-magnon and electron-phonon interactions, which govern the demagnetization time scale. By properly treating the spin system in a self-consistent random phase approximation, we derive magnetization dynamic equations for a broad range of temperature. The dependence of demagnetization on the temperature and pumping laser intensity is calculated in detail. In particular, we show several salient features for understanding magnetization dynamics near the Curie temperature. While the critical slowdown in dynamics occurs, we find that an external magnetic field can restore the fast dynamics. We discuss the implication of the fast dynamics in the application of heat-assisted magnetic recording.

The Synthesis of NiO/TiO2 Heterostructures and Their Valence Band Offset Determination

Directory of Open Access Journals (Sweden)

Z. H. Ibupoto

2014-01-01

Full Text Available In this work, a heterojunction based on p-type NiO/n-type TiO2 nanostructures has been prepared on the fluorine doped tin oxide (FTO glass substrate by hydrothermal method. Scanning electron microscopy (SEM and X-Ray diffraction techniques were used for the morphological and crystalline arrays characterization. The X-ray photoelectron spectroscopy was employed to determine the valence-band offset (VBO of the NiO/TiO2 heterojunction prepared on FTO glass substrate. The core levels of Ni 2p and Ti 2p were utilized to align the valence-band offset of p-type NiO/n-type TiO2 heterojunction. The valence band offset was found to be ∼0.41 eV and the conduction band was calculated about ∼0.91 eV. The ratio of conduction band offset and the valence-band offset was found to be 2.21.

Distinct populations of neurons respond to emotional valence and arousal in the human subthalamic nucleus.

Science.gov (United States)

Sieger, Tomáš; Serranová, Tereza; Růžička, Filip; Vostatek, Pavel; Wild, Jiří; Štastná, Daniela; Bonnet, Cecilia; Novák, Daniel; Růžička, Evžen; Urgošík, Dušan; Jech, Robert

2015-03-10

Both animal studies and studies using deep brain stimulation in humans have demonstrated the involvement of the subthalamic nucleus (STN) in motivational and emotional processes; however, participation of this nucleus in processing human emotion has not been investigated directly at the single-neuron level. We analyzed the relationship between the neuronal firing from intraoperative microrecordings from the STN during affective picture presentation in patients with Parkinson's disease (PD) and the affective ratings of emotional valence and arousal performed subsequently. We observed that 17% of neurons responded to emotional valence and arousal of visual stimuli according to individual ratings. The activity of some neurons was related to emotional valence, whereas different neurons responded to arousal. In addition, 14% of neurons responded to visual stimuli. Our results suggest the existence of neurons involved in processing or transmission of visual and emotional information in the human STN, and provide evidence of separate processing of the affective dimensions of valence and arousal at the level of single neurons as well.

Theoretical calculations of valence states in Fe-Mo compounds

International Nuclear Information System (INIS)

Estrada, F; Navarro, O; Noverola, H; Suárez, J R; Avignon, M

2014-01-01

The half-metallic ferromagnetic double perovskite compound Sr 2 FeMoO 6 is considered as an important material for spintronic applications. It appears to be fundamental to understand the role of electronic parameters controlling the half-metallic ground state. Fe-Mo double perovskites usually present some degree of Fe/Mo disorder which generally increases with doping. In this work, we study the valence states of Fe-Mo cations in the off-stoichiometric system Sr 2 Fe 1+x Mo 1−x O 6 (−1 ≤ x ≤ 1/3) with disorder. Our results for Fe and Mo valence states are obtained using the Green functions and the renormalization perturbation expansion method. The model is based on a correlated electron picture with localized Fe-spins and conduction Mo-electrons interacting with the local spins via a double-exchange-type mechanism

Aluminium doping induced enhancement of p-d coupling in ZnO

International Nuclear Information System (INIS)

Cong, G W; Peng, W Q; Wei, H Y; Liu, X L; Wu, J J; Han, X X; Zhu, Q S; Wang, Z G; Ye, Z Z; Lu, J G; Zhu, L P; Qian, H J; Su, R; Hong, C H; Zhong, J; Ibrahim, K; Hu, T D

2006-01-01

Valence-band type Auger lines in Al doped and undoped ZnO were comparatively studied with the corresponding core level x-ray photoelectron spectrography (XPS) spectra as references. Then the shift trend of energy levels in the valence band was that p and p-s-d states move upwards but e and p-d states downwards with increasing Al concentration. The decreased energy of the Zn 3d state is larger than the increased energy of the O 2p state, indicating the lowering of total energy. This may indicate that Al doping could induce the enhancement of p-d coupling in ZnO, which originates from stronger Al-O hybridization. The shifts of these states and the mechanism were confirmed by valence band XPS spectra and O K-edge x-ray absorption spectrography (XAS) spectra. Finally, some previously reported phenomena are explained based on the Al doping induced enhancement of p-d coupling

Gastrointestinal absorption of large amounts of plutonium. Effect of valency state on transfer

International Nuclear Information System (INIS)

Lataillade, G.; Duserre, C.; Metivier, H.; Madic, C.; CEA Centre d'Etudes Nucleaires de Fontenay-aux-Roses, 92

1989-01-01

The gastrointestinal absorption of Pu, ingested in valency state III, IV, V or VI was studied in baboons. For each state, the absorption of Pu from masses ranging from 1 to 7 mg per kg of body weight was compared with that from masses ranging from 5 to 45 μg per kg of body weight. The mass ingested did not affect the gastrointestinal absorption of Pu(IV) or PU(VI), but for Pu(V) and to a lesser extent Pu(III), absorption clearly increased about 150-fold and 7-fold respectively, when large masses of Pu were ingested. When small masses were ingested, the valency state did not affect absorption. The increased Pu absorption observed after ingestion of large masses of Pu(V) or (III) might be due to the weak hydrolysis of these valency states. (author)

Experimental Constraints on the Partitioning and Valence of V and Cr in Garnet and Coexisting Glass

Science.gov (United States)

Righter, K.; Sutton, S.; Berthet, S.; Newville, M.

2008-01-01

A series of experiments with garnet and coexisting melt have been carried out across a range of oxygen fugacities (near hematite-magnetite (HM) to below the iron-wustite (IW) buffers) at 1.7 GPa to study the partitioning and valence of Cr and V in both phases. Experiments were carried out in a non end loaded piston cylinder apparatus, and the run products were analyzed with electron microprobe and xray absorption near edge structure (XANES) analysis at beamline 13-ID at the Advanced Photon Source of Argonne National Lab. The valence of vanadium and chromium were determined using the position and intensity of the Ka pre-edge peaks, calibrated on a series of Cr and Vbearing standard glasses. This technique has been applied to V and Cr in glasses and V in spinels previously, and in these isotropic phases there are no orientational effects on the XANES spectra (Righter et al., 2006, Amer. Mineral. 91, 1643-1656). We also now demonstrate this to be true for V and Cr in garnet. Also, previous work has shown that V has a higher valence in the glass (or melt) than in the coexisting spinel. This is also true for V in garnet-glass pairs in this study. Vanadium valence in garnets varies from 2.7 below the IW buffer to 3.7 near HM, and for coexisting glass it varies from 3.2 to 4.3. Vanadium valence measured in some natural garnets from mantle localities indicates V in the more reduced range at 2.5. Comparisons will be made between fO2 estimated from V valence and other methods for garnet-bearing mantle samples. In contrast, Cr valence measured in garnet and coexisting glass for all experimental and natural samples is 2.9- 3.0, suggesting that the valence of Cr does not vary within either phase across a large fO2 range. These results demonstrate that while V varies from 2+ to 3+ to 4+ in garnet-melt systems, Cr does not, and this will ultimately affect the partitioning behavior of these two elements in natural systems. Garnet/melt D(Cr) are between 12 and 17 across this range

A practical method of predicting client revisit intention in a hospital setting.

Science.gov (United States)

Lee, Kyun Jick

2005-01-01

Data mining (DM) models are an alternative to traditional statistical methods for examining whether higher customer satisfaction leads to higher revisit intention. This study used a total of 906 outpatients' satisfaction data collected from a nationwide survey interviews conducted by professional interviewers on a face-to-face basis in South Korea, 1998. Analyses showed that the relationship between overall satisfaction with hospital services and outpatients' revisit intention, along with word-of-mouth recommendation as intermediate variables, developed into a nonlinear relationship. The five strongest predictors of revisit intention were overall satisfaction, intention to recommend to others, awareness of hospital promotion, satisfaction with physician's kindness, and satisfaction with treatment level.

The critical catastrophe revisited

International Nuclear Information System (INIS)

De Mulatier, Clélia; Rosso, Alberto; Dumonteil, Eric; Zoia, Andrea

2015-01-01

The neutron population in a prototype model of nuclear reactor can be described in terms of a collection of particles confined in a box and undergoing three key random mechanisms: diffusion, reproduction due to fissions, and death due to absorption events. When the reactor is operated at the critical point, and fissions are exactly compensated by absorptions, the whole neutron population might in principle go to extinction because of the wild fluctuations induced by births and deaths. This phenomenon, which has been named critical catastrophe, is nonetheless never observed in practice: feedback mechanisms acting on the total population, such as human intervention, have a stabilizing effect. In this work, we revisit the critical catastrophe by investigating the spatial behaviour of the fluctuations in a confined geometry. When the system is free to evolve, the neutrons may display a wild patchiness (clustering). On the contrary, imposing a population control on the total population acts also against the local fluctuations, and may thus inhibit the spatial clustering. The effectiveness of population control in quenching spatial fluctuations will be shown to depend on the competition between the mixing time of the neutrons (i.e. the average time taken for a particle to explore the finite viable space) and the extinction time

If You Don't Have Valence, Ask Your Neighbor: Evaluation of Neutral Words as a Function of Affective Semantic Associates.

Science.gov (United States)

Kuhlmann, Michael; Hofmann, Markus J; Jacobs, Arthur M

2017-01-01

How do humans perform difficult forced-choice evaluations, e.g., of words that have been previously rated as being neutral? Here we tested the hypothesis that in this case, the valence of semantic associates is of significant influence. From corpus based co-occurrence statistics as a measure of association strength we computed individual neighborhoods for single neutral words comprised of the 10 words with the largest association strength. We then selected neutral words according to the valence of the associated words included in the neighborhoods, which were either mostly positive, mostly negative, mostly neutral or mixed positive and negative, and tested them using a valence decision task (VDT). The data showed that the valence of semantic neighbors can predict valence judgments to neutral words. However, all but the positive neighborhood items revealed a high tendency to elicit negative responses. For the positive and negative neighborhood categories responses congruent with the neighborhood's valence were faster than incongruent responses. We interpret this effect as a semantic network process that supports the evaluation of neutral words by assessing the valence of the associative semantic neighborhood. In this perspective, valence is considered a semantic super-feature, at least partially represented in associative activation patterns of semantic networks.

Prévalence des dyslipidémies au laboratoire de biochimie du CHU ...

African Journals Online (AJOL)

Le cholestérol total, le cholestérol HDL, le cholestérol LDL ainsi que les triglycérides ont été dosés grâce à des méthodes enzymatiques sur un automate de Biochimie de type Cobas Integra 400 (Roche Diagnostics). Résultats: la prévalence des dyslipidémies dans notre population d'étude est de 39,30%. Les prévalences ...

Dissociable effects of valence and arousal on different subtypes of old/new effect: Evidence from event-related potentials

Directory of Open Access Journals (Sweden)

Huifang eXu

2015-12-01

Full Text Available Here we utilized the study-test paradigm combined with recognition confidence assessment and behavioral and event-related potential (ERP measurements to investigate the effects of valence and arousal on the different subtypes of the old-new effect. We also test the effect of valence and arousal at encoding stage to investigate the underlying mechanism of the effect of the two emotional dimension on different retrieval process. In order to test the effects of valence and arousal on old/new effect precisely, we used the subject-oriented orthogonal design which manipulated valence and arousal independently according to subjects’ verbal reporting to investigate the effects of valence and arousal on old/new effect respectively. Three subtypes of old/new effect were obtained in the test phase, which were FN400, LPC, and late positivity over right frontal. They are supposed to be associated with familiarity, recollection, and post-retrieval processes respectively according to previous studies. For the FN400 component, valence affected mid-frontal negativity from 350 to 500 ms. Pleasant items evoked an enhanced ERP old/new effect relative to unpleasant items. However, arousal only affected LPC amplitude from 500 to 800ms. The old/new effect for high-arousal items was greater than for low-arousal items. Valence also affected the amplitude of a positive-going slow wave at right frontal sites from 800 to 1000 ms, possibly serving as an index of post-retrieval processing. At encoding stage, the valence and arousal also have dissociable effect on the frontal slow wave between 350-800ms and the centro-parietal positivity in 500-800ms. The pleasant items evoked a more positive frontal slow wave relative to unpleasant ones, and the high arousal items evoked a larger centro-parietal positivity relative to low arousal ones. These results suggest that valence and arousal may differentially impact these different memory processes: valence affects familiarity and

Identifying Facial Emotions: Valence Specific Effects and an Exploration of the Effects of Viewer Gender

Science.gov (United States)

Jansari, Ashok; Rodway, Paul; Goncalves, Salvador

2011-01-01

The valence hypothesis suggests that the right hemisphere is specialised for negative emotions and the left hemisphere is specialised for positive emotions (Silberman & Weingartner, 1986). It is unclear to what extent valence-specific effects in facial emotion perception depend upon the gender of the perceiver. To explore this question 46…

Polyploidization mechanisms: temperature environment can induce diploid gamete formation in Rosa sp.

Science.gov (United States)

Pécrix, Yann; Rallo, Géraldine; Folzer, Hélène; Cigna, Mireille; Gudin, Serge; Le Bris, Manuel

2011-06-01

Polyploidy is an important evolutionary phenomenon but the mechanisms by which polyploidy arises still remain underexplored. There may be an environmental component to polyploidization. This study aimed to clarify how temperature may promote diploid gamete formation considered an essential element for sexual polyploidization. First of all, a detailed cytological analysis of microsporogenesis and microgametogenesis was performed to target precisely the key developmental stages which are the most sensitive to temperature. Then, heat-induced modifications in sporad and pollen characteristics were analysed through an exposition of high temperature gradient. Rosa plants are sensitive to high temperatures with a developmental sensitivity window limited to meiosis. Moreover, the range of efficient temperatures is actually narrow. 36 °C at early meiosis led to a decrease in pollen viability, pollen ectexine defects but especially the appearance of numerous diploid pollen grains. They resulted from dyads or triads mainly formed following heat-induced spindle misorientations in telophase II. A high temperature environment has the potential to increase gamete ploidy level. The high frequencies of diplogametes obtained at some extreme temperatures support the hypothesis that polyploidization events could have occurred in adverse conditions and suggest polyploidization facilitating in a global change context.

Leukemia and ionizing radiation revisited

Energy Technology Data Exchange (ETDEWEB)

Cuttler, J.M. [Cuttler & Associates Inc., Vaughan, Ontario (Canada); Welsh, J.S. [Loyola University-Chicago, Dept. or Radiation Oncology, Stritch School of Medicine, Maywood, Illinois (United States)

2016-03-15

A world-wide radiation health scare was created in the late 19508 to stop the testing of atomic bombs and block the development of nuclear energy. In spite of the large amount of evidence that contradicts the cancer predictions, this fear continues. It impairs the use of low radiation doses in medical diagnostic imaging and radiation therapy. This brief article revisits the second of two key studies, which revolutionized radiation protection, and identifies a serious error that was missed. This error in analyzing the leukemia incidence among the 195,000 survivors, in the combined exposed populations of Hiroshima and Nagasaki, invalidates use of the LNT model for assessing the risk of cancer from ionizing radiation. The threshold acute dose for radiation-induced leukemia, based on about 96,800 humans, is identified to be about 50 rem, or 0.5 Sv. It is reasonable to expect that the thresholds for other cancer types are higher than this level. No predictions or hints of excess cancer risk (or any other health risk) should be made for an acute exposure below this value until there is scientific evidence to support the LNT hypothesis. (author)

Affective valence influences participant's susceptibility to false memories and illusory recollection.

Science.gov (United States)

Dehon, Hedwige; Larøi, Frank; Van der Linden, Martial

2010-10-01

This study examined the influence of emotional valence on the production of DRM false memories (Roediger & McDermott, 1995). Participants were presented with neutral, positive, or negative DRM lists for a later recognition (Experiment 1) or recall (Experiment 2) test. In both experiments, confidence and recollective experience (i.e., "Remember-Know" judgments; Tulving, 1985) were also assessed. Results consistently showed that, compared with neutral lists, affective lists induced more false recognition and recall of nonpresented critical lures. Moreover, although confidence ratings did not differ between the false remembering from the different kinds of lists, "Remember" responses were more often associated with negative than positive and neutral false remembering of the critical lures. In contrast, positive false remembering of the critical lures was more often associated with "Know" responses. These results are discussed in light of the Paradoxical Negative Emotion (PNE) hypothesis (Porter, Taylor, & ten Bricke, 2008). (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Voice and Valency in San Luis Potosi Huasteco

Science.gov (United States)

Munoz Ledo Yanez, Veronica

2014-01-01

This thesis presents an analysis of the system of transitivity, voice and valency alternations in Huasteco of San Luis Potosi (Mayan) within a functional-typological framework. The study is based on spoken discourse and elicited data collected in the municipalities of Aquismon and Tancanhuitz de Santos in the state of San Luis Potosi, Mexico. The…

Transfer of newly acquired stimulus valence between identities in dissociative identity disorder (DID).

Science.gov (United States)

Huntjens, Rafaële J C; Peters, Madelon L; Postma, Albert; Woertman, Liesbeth; Effting, Marieke; van der Hart, Onno

2005-02-01

Patients with Dissociative Identity Disorder (DID) frequently report episodes of interidentity amnesia, that is amnesia for events experienced by other identities. The goal of the present experiment was to test the implicit transfer of trauma-related information between identities in DID. We hypothesized that whereas declarative information may transfer from one identity to another, the emotional connotation of the memory may be dissociated, especially in the case of negative, trauma-related emotional valence. An evaluative conditioning procedure was combined with an affective priming procedure, both performed by different identities. In the evaluative conditioning procedure, previously neutral stimuli come to refer to a negative or positive connotation. The affective priming procedure was used to test the transfer of this acquired valence to an identity reporting interidentity amnesia. Results indicated activation of stimulus valence in the affective priming task, that is transfer of emotional material between identities.

On the Reference State for Exergy when Ambient Temperature Fluctuates

OpenAIRE

Michel Pons

2009-01-01

Exergy (availability) is the amount of mechanical work that could be produced by reversible processes. This notion is revisited in the case when ambient temperature fluctuates. Simple examples are first considered, and then a theoretical approach is developed. It results that the most reliable way for combining entropy and total energy into an exergy function is a linear combination where entropy is multiplied by a constant temperature. It results that ambient air has non-zero exergy, but tha...

Response variance in functional maps: neural darwinism revisited.

Directory of Open Access Journals (Sweden)

Hirokazu Takahashi

Full Text Available The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population.

Response variance in functional maps: neural darwinism revisited.

Science.gov (United States)

Takahashi, Hirokazu; Yokota, Ryo; Kanzaki, Ryohei

2013-01-01

The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population.

Automated Construction of Molecular Active Spaces from Atomic Valence Orbitals.

Science.gov (United States)

Sayfutyarova, Elvira R; Sun, Qiming; Chan, Garnet Kin-Lic; Knizia, Gerald

2017-09-12

We introduce the atomic valence active space (AVAS), a simple and well-defined automated technique for constructing active orbital spaces for use in multiconfiguration and multireference (MR) electronic structure calculations. Concretely, the technique constructs active molecular orbitals capable of describing all relevant electronic configurations emerging from a targeted set of atomic valence orbitals (e.g., the metal d orbitals in a coordination complex). This is achieved via a linear transformation of the occupied and unoccupied orbital spaces from an easily obtainable single-reference wave function (such as from a Hartree-Fock or Kohn-Sham calculations) based on projectors to targeted atomic valence orbitals. We discuss the premises, theory, and implementation of the idea, and several of its variations are tested. To investigate the performance and accuracy, we calculate the excitation energies for various transition-metal complexes in typical application scenarios. Additionally, we follow the homolytic bond breaking process of a Fenton reaction along its reaction coordinate. While the described AVAS technique is not a universal solution to the active space problem, its premises are fulfilled in many application scenarios of transition-metal chemistry and bond dissociation processes. In these cases the technique makes MR calculations easier to execute, easier to reproduce by any user, and simplifies the determination of the appropriate size of the active space required for accurate results.

Charge imbalance induced by a temperature gradient in superconducting aluminum

International Nuclear Information System (INIS)

Mamin, H.J.; Clarke, J.; Van Harlingen, D.J.

1984-01-01

The quasiparticle transport current induced in a superconducting aluminum film by a temperature gradient has been measured by means of the spatially decaying charge imbalance generated near the end of the sample where the current is divergent. The magnitude and decay length of the charge imbalance are in good agreement with the predictions of a simple model that takes into account the nonuniformity of the temperature gradient. The inferred value of the thermopower in the superconducting state agrees reasonably well with the value measured in the normal state. Measurements of the decay length of charge imbalance induced by current injection yield a value of the inelastic relaxation time tau/sub E/ of about 2 ns. This value is substantially smaller than that obtained from other measurements for reasons that are not known

Sex, Age, and Emotional Valence: Revealing Possible Biases in the ‘Reading the Mind in the Eyes’ Task

Directory of Open Access Journals (Sweden)

Jana Kynast

2018-04-01

Full Text Available The ‘Reading the Mind in the Eyes’ test (RMET assesses a specific socio-cognitive ability, i.e., the ability to identify mental states from gaze. The development of this ability in a lifespan perspective is of special interest. Whereas former investigations were limited mainly to childhood and adolescence, the focus has been shifted towards aging, and psychiatric and neurodegenerative diseases recently. Although the RMET is frequently applied in developmental psychology and clinical settings, stimulus characteristics have never been investigated with respect to potential effects on test performance. Here, we analyzed the RMET stimulus set with a special focus on interrelations between sex, age and emotional valence. Forty-three persons rated age and emotional valence of the RMET picture set. Differences in emotional valence and age ratings between male and female items were analyzed. The linear relation between age and emotional valence was tested over all items, and separately for male and female items. Male items were rated older and more negative than female stimuli. Regarding male RMET items, age predicted emotional valence: older age was associated with negative emotions. Contrary, age and valence were not linearly related in female pictures. All ratings were independent of rater characteristics. Our results demonstrate a strong confound between sex, age, and emotional valence in the RMET. Male items presented a greater variability in age ratings compared to female items. Age and emotional valence were negatively associated among male items, but no significant association was found among female stimuli. As personal attributes impact social information processing, our results may add a new perspective on the interpretation of previous findings on interindividual differences in RMET accuracy, particularly in the field of developmental psychology, and age-associated neuropsychiatric diseases. A revision of the RMET might be afforded to

Sex, Age, and Emotional Valence: Revealing Possible Biases in the ‘Reading the Mind in the Eyes’ Task

Science.gov (United States)

Kynast, Jana; Schroeter, Matthias L.

2018-01-01

The ‘Reading the Mind in the Eyes’ test (RMET) assesses a specific socio-cognitive ability, i.e., the ability to identify mental states from gaze. The development of this ability in a lifespan perspective is of special interest. Whereas former investigations were limited mainly to childhood and adolescence, the focus has been shifted towards aging, and psychiatric and neurodegenerative diseases recently. Although the RMET is frequently applied in developmental psychology and clinical settings, stimulus characteristics have never been investigated with respect to potential effects on test performance. Here, we analyzed the RMET stimulus set with a special focus on interrelations between sex, age and emotional valence. Forty-three persons rated age and emotional valence of the RMET picture set. Differences in emotional valence and age ratings between male and female items were analyzed. The linear relation between age and emotional valence was tested over all items, and separately for male and female items. Male items were rated older and more negative than female stimuli. Regarding male RMET items, age predicted emotional valence: older age was associated with negative emotions. Contrary, age and valence were not linearly related in female pictures. All ratings were independent of rater characteristics. Our results demonstrate a strong confound between sex, age, and emotional valence in the RMET. Male items presented a greater variability in age ratings compared to female items. Age and emotional valence were negatively associated among male items, but no significant association was found among female stimuli. As personal attributes impact social information processing, our results may add a new perspective on the interpretation of previous findings on interindividual differences in RMET accuracy, particularly in the field of developmental psychology, and age-associated neuropsychiatric diseases. A revision of the RMET might be afforded to overcome confounds

Hysteresis and Power-Law Statistics during temperature induced martensitic transformation

International Nuclear Information System (INIS)

Paul, Arya; Sengupta, Surajit; Rao, Madan

2011-01-01

We study hysteresis in temperature induced martensitic transformation using a 2D model solid exhibiting a square to rhombic structural transition. We find that upon quenching, the high temperature square phase, martensites are nucleated at sites having large non-affineness and ultimately invades the whole of the high temperature square phase. On heating the martensite, the high temperature square phase is restored. The transformation proceeds through avalanches. The amplitude and the time-duration of these avalanches exhibit power-law statistics both during heating and cooling of the system. The exponents corresponding to heating and cooling are different thereby indicating that the nucleation and dissolution of the product phase follows different transformation mechanism.

Nuclear masses and the number of valence nucleons

International Nuclear Information System (INIS)

Mendoza-Temis, J.; Frank, A.; Hirsch, J.G.; Lopez Vieyra, J.C.; Morales, I.; Barea, J.; Van Isacker, P.; Velazquez, V.

2008-01-01

An improved version of the liquid drop model is presented. The addition of two terms, linear and quadratic in the total number of valence nucleons (particles or holes), improves the description of atomic masses, which can be fitted with an r.m.s. error of 1.2 MeV. Predictions are analysed an compared with those of established models

Determination of a natural valence-band offset - The case of HgTe and CdTe

Science.gov (United States)

Shih, C. K.; Spicer, W. E.

1987-01-01

A method to determine a natural valence-band offset (NVBO), i.e., the change in the valence-band maximum energy which is intrinsic to the bulk band structures of semiconductors is proposed. The HgTe-CdTe system is used as an example in which it is found that the valence-band maximum of HgTe lies 0.35 + or - 0.06 eV above that of CdTe. The NVBO of 0.35 eV is in good agreement with the X-ray photoemission spectroscopy measurement of the heterojunction offset. The procedure to determine the NVBO between semiconductors, and its implication on the heterojunction band lineup and the electronic structures of semiconductor alloys, are discussed.

Temperature suppression of STM-induced desorption of hydrogen on Si(100) surfaces

DEFF Research Database (Denmark)

Thirstrup, C.; Sakurai, M.; Nakayama, T.

1999-01-01

The temperature dependence of hydrogen (H) desorption from Si(100) H-terminated surfaces by a scanning tunneling microscope (STM) is reported for negative sample bias. It is found that the STM induced H desorption rate (R) decreases several orders of magnitude when the substrate temperature...

Mixed meson masses with domain-wall valence and staggered sea fermions

International Nuclear Information System (INIS)

Orginos, Kostas; Walker-Loud, Andre

2008-01-01

Mixed action lattice calculations allow for an additive lattice-spacing-dependent mass renormalization of mesons composed of one sea and one valence quark, regardless of the type of fermion discretization methods used in the valence and sea sectors. The value of the mass renormalization depends upon the lattice actions used. This mixed meson mass shift is an important lattice artifact to determine for mixed action calculations; because it modifies the pion mass, it plays a central role in the low-energy dynamics of all hadronic correlation functions. We determine the leading order, O(a 2 ), and next-to-leading order, O(a 2 m π 2 ), additive mass shift of valence-sea mesons for a mixed lattice action with domain-wall valence fermions and rooted staggered sea fermions, relevant to the majority of current large scale mixed action lattice efforts. We find that, on the asqtad-improved coarse MILC lattices, this additive mass shift is well parametrized in lattice units by Δ(am) 2 =0.034(2)-0.06(2)(am π ) 2 , which in physical units, using a=0.125 fm, corresponds to Δ(m) 2 =(291±8 MeV) 2 -0.06(2)m π 2 . In terms of the mixed action effective field theory parameters, the corresponding mass shift is given by a 2 Δ Mix =(316±4 MeV) 2 at leading order plus next-to-leading order corrections including the necessary chiral logarithms for this mixed action calculation, determined in this work. Within the precision of our calculation, one cannot distinguish between the full next-to-leading order effective field theory analysis of this additive mixed meson mass shift and the parametrization given above.

Vitamin K 3 family members - Part II: Single crystal X-ray structures, temperature-induced packing polymorphism, magneto-structural correlations and probable anti-oncogenic candidature

Science.gov (United States)

Rane, Sandhya; Ahmed, Khursheed; Salunke-Gawali, Sunita; Zaware, Santosh B.; Srinivas, D.; Gonnade, Rajesh; Bhadbhade, Mohan

2008-12-01

Temperature-induced packing polymorphism is observed for vitamin K 3 (menadione, 3-methyl-1,4-naphthoquinone, 1). Form 1a crystallizes at 300 K and 1b at 277 K both in the same space group P2 1/ c. Form 1b contains one molecule per asymmetric unit, performing anisotropy in g-factor viz. g z = 2.0082, g y = 2.0055 and g x = 2.0025, whereas form 1a contains two molecules in its asymmetric unit. Vitamin K 3 family members 2, [2-hydroxy vitamin K 3] and 3, [2-hydroxy-1-oximino vitamin K 3] also perform intrinsic neutral active naphthosemiquinone valence tautomers even in dark having spin concentrations due to hydrogen bonding and aromatic stacking interactions which are compared to vitamin K 3. The significant lateral C-H⋯O and O-H⋯π bifurcated or π-π ∗ interactions are discussed for molecular associations and radical formations. X-ray structure of 3 revealed π-π ∗ stack dimers as radicals signatured in EPR as triplet with five hyperfine splits [ Ā( 14N) = 11.9 G]. The centrosymmetric biradicals in 3 show diamagnetism at high temperature but below 10 K it shows paramagnetism with μeff as 0.19 B.M. Vitamin K 3 and its family members inhibit biological activities of acid phosphatase ( APase), which are proportional to their spin concentrations. This may relate to their probable anti-oncogenic candidature in future.

THERMODYNAMICS OF ELECTROLYTES. XI. PROPERTIES OF 3-2, 4-2, AND OTHER HIGH-VALENCE TYPES

Energy Technology Data Exchange (ETDEWEB)

Pitzer, Kenneth S.; Silvester, Leonard F.

1977-12-01

Various thermodynamic properties are considered for very high-valence 3-2 and 4-2 electrolytes in water at room temperature. These solutions show the behavior described by Davies in which ion pairing arises as the concentration increases follow by re-dissociation at still higher concentrations. Heat of dilution data, which extend below 10{sup -4} M, are interpreted with the same form of equation used earlier for 2-2 electrolytes. Activity and osmotic coefficient data do not extend to low enough concentration for independent, interpretation, but they are treated with the aid of conductance data in the more dilute range. Parameters are reported for A{ell}{sub 2}(SO{sub 4}){sub 3}, La{sub 2}(SO{sub 4}){sub 3}, In{sub 2}(SO{sub 4}){sub 3}, and several cyanoferrates. High-valence electrolytes show a special behavior at very low concentrations which was recognized by Bjerrum who showed in 1926 that purely electrostatic forces would yield an ion association. Davies showed that this association commonly reached a maximum at an intermediate concentration above which there was a re-dissociation. From one viewpoint, this ion association is an artifact of the linearization approximation in the Debye-Hueckel theory since a more exact statistical treatment yields agreement with experiment without assuming a separate associated species. If an association equilibrium is assumed for these electrolytes, it is found that the value of the association constant depends on the assumptions about the activity coefficients of the ions. To the extent that these effects are important for 2-2 electrolytes, they are discussed in paper III{sup 6} of this series. While in 3-2 and 4-2 electrolytes the effects are of the same nature as those in the 2-2 solutes, they occur at much lower concentration in the higher-valence solutes; consequently new problems arise in treating experimental data. Indeed, it is only the conductance and heat-of-dilution measurements, which extend down to 10{sup -5} M

The effects of valence and arousal on the neural activity leading to subsequent memory

OpenAIRE

Mickley Steinmetz, Katherine R.; Kensinger, Elizabeth A.

2009-01-01

This study examined how valence and arousal affect the processes linked to subsequent memory for emotional information. While undergoing an fMRI scan, participants viewed neutral pictures and emotional pictures varying by valence and arousal. After the scan, participants performed a recognition test. Subsequent memory for negative or high arousal information was associated with occipital and temporal activity, while memory for positive or low arousal information was associated with frontal ac...

Valence electron momentum distributions in cadmium

International Nuclear Information System (INIS)

Frost, L.; Weigold, E.; Mitroy, J.

1982-08-01

The valence 5s and 4d electron momentum distributions in cadmium have been measured using noncoplanar symmetric (e, 2e) electron coincidence spectroscopy at a total energy of 1200eV. They are in close agreement with Hartree-Fock momentum distributions both in shape and relative magnitudes. Some satellite lines of very low intensity have been detected. A CI calculation of the Cd ground state and several Cd + ion states has been carried out to predict cross reactions for the ground state and various satellite transitions. The predictions are in agreement with the data

Continuum limit of overlap valence quarks on a twisted mass sea

International Nuclear Information System (INIS)

Cichy, Krzysztof; Herdoiza, Gregorio; Univ. Autonoma de Madrid; Jansen, Karl

2010-12-01

We study a lattice QCD mixed action with overlap valence quarks on two flavours of Wilson maximally twisted mass sea quarks. Employing three different matching conditions to relate both actions to each other, we investigate the continuum limit by using three values of the lattice spacing ranging from a∼0.05 fm to 0.08 fm. A particular emphasis is put on the effect on physical observables of the topological zero modes appearing in the valence overlap operator. We estimate the region of parameter space where the contribution from these zero modes is sufficiently small such that their effects can be safely controlled and a restoration of unitarity of the mixed action in the continuum limit is reached. (orig.)

The Faraday effect revisited: General theory

DEFF Research Database (Denmark)

Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. For free electrons, the transverse...

Radio frequency-induced temperature elevations in the human head considering small anatomical structures

International Nuclear Information System (INIS)

Schmid, G.; Ueberbacher, R.; Samaras, T.

2007-01-01

In order to enable a detailed numerical radio frequency (RF) dosimetry and the computations of RF-induced temperature elevations, high-resolution (0.1 mm) numerical models of the human eye, the inner ear organs and the pineal gland were developed and inserted into a commercially available head model. As radiation sources, generic models of handsets at 400, 900 and 1850 MHz operating in close proximity to the head were considered. The results, obtained by finite-difference time domain-based computations, showed a highly heterogeneous specific absorption rate (SAR) distribution and SAR-peaks inside the inner ear structures; however, the corresponding RF-induced temperature elevations were well below 0.1 deg. C, when considering typical output power values of hand-held devices. In case of frontal exposure, with the radiation sources ∼2.5 cm in front of the closed eye, maximum temperature elevations in the eye in the range of ∼0.2-0.6 deg. C were found for typical device output powers. A reduction in tissue perfusion mainly affected the maximum RF-induced temperature elevation of tissues deep inside the head. Similarly, worst-case considerations regarding pulsed irradiation affected temperature elevations in deep tissue significantly more than in superficial tissues. (authors)

Temperature induced alternative splicing is affected in sdg8 and sdg26

OpenAIRE

Pajoro, A.; Severing, E.I.; Immink, G.H.

2017-01-01

Plants developed a plasticity to environmental conditions, such as temperature, that allows their adaptation. A change in ambient temperature leads to changes in the transcriptome in plants, such as the production of different splicing isoforms. Here we study temperature induced alternative splicing events in Arabidopsis thaliana wild-type and two epigenetic mutants, sdg8-2 and sdg26-1 using an RNA-seq approach.

Revisited

DEFF Research Database (Denmark)

Tegtmeier, Silke; Meyer, Verena; Pakura, Stefanie

2017-01-01

were captured when they described entrepreneurs. Therefore, this paper aims to revisit gender role stereotypes among young adults. Design/methodology/approach: To measure stereotyping, participants were asked to describe entrepreneurs in general and either women or men in general. The Schein......Purpose: Entrepreneurship is shaped by a male norm, which has been widely demonstrated in qualitative studies. The authors strive to complement these methods by a quantitative approach. First, gender role stereotypes were measured in entrepreneurship. Second, the explicit notions of participants......: The images of men and entrepreneurs show a high and significant congruence (r = 0.803), mostly in those adjectives that are untypical for men and entrepreneurs. The congruence of women and entrepreneurs was low (r = 0.152) and insignificant. Contrary to the participants’ beliefs, their explicit notions did...

Solvent extraction of irradiated neptunium targets. I. Valence stabilization

International Nuclear Information System (INIS)

Thompson, G.H.; Thompson, M.C.

1977-01-01

Solvent extraction of 237 Np and 238 Pu from irradiated neptunium is being investigated as a possible replacement for the currently used anion exchange process at the Savannah River Plant. Solvent extraction would reduce separations costs and waste volume and increase the production rate. The major difficulty in solvent extraction processing is maintaining neptunium and plutonium in the extractable IV or VI valence states during initial extraction. This study investigated the stability of these states. Results show that: The extractable M(IV) valence states of neptunium and plutonium are mutually unstable in plant dissolver solution (2 g/l 237 Np, 0.4 g/l 238 Pu, 1.2M Al 3+ , 4.6M NO 3 - , and 1M H + ). The reaction rates producing inextractable species from extractable M(IV) or M(VI) are fast enough that greater than or equal to 99.9 percent extractable species in 237 Np-- 238 Pu mixtures cannot be maintained for a practicable processing period

The olfactory tubercle encodes odor valence in behaving mice.

Science.gov (United States)

Gadziola, Marie A; Tylicki, Kate A; Christian, Diana L; Wesson, Daniel W

2015-03-18

Sensory information acquires meaning to adaptively guide behaviors. Despite odors mediating a number of vital behaviors, the components of the olfactory system responsible for assigning meaning to odors remain unclear. The olfactory tubercle (OT), a ventral striatum structure that receives monosynaptic input from the olfactory bulb, is uniquely positioned to transform odor information into behaviorally relevant neural codes. No information is available, however, on the coding of odors among OT neurons in behaving animals. In recordings from mice engaged in an odor discrimination task, we report that the firing rate of OT neurons robustly and flexibly encodes the valence of conditioned odors over identity, with rewarded odors evoking greater firing rates. This coding of rewarded odors occurs before behavioral decisions and represents subsequent behavioral responses. We predict that the OT is an essential region whereby odor valence is encoded in the mammalian brain to guide goal-directed behaviors. Copyright © 2015 the authors 0270-6474/15/354515-13$15.00/0.

Low temperature features of the local structure of Sm1-xYxS

International Nuclear Information System (INIS)

Menushenkov, A. P.; Chernikov, R. V.; Sidorov, V. V.; Klementiev, K. V.; Alekseev, P. A.; Rybina, A. V.

2007-01-01

The particular features of the local electronic and local crystal structures of the mixed-valence compound Sm 1-x Y x S are studied by the XAFS spectroscopy methods in the temperature range 20-300 K for the yttrium concentration x = 0.17, 0.25, 0.33, and 0.45. The temperature behavior of the valence of Sm, as well as of the lengths and the Debye-Waller factors of the bonds Sm-S, Sm-Sm(Y), Y-S, and Y-Sm(Y), has been determined. The violation of the Vegard law has been observed. A model for the estimation of the energy width of the 4f level and of its position with respect to the Fermi level is proposed

Quantum computational capability of a 2D valence bond solid phase

International Nuclear Information System (INIS)

Miyake, Akimasa

2011-01-01

Highlights: → Our model is the 2D valence bond solid phase of a quantum antiferromagnet. → Universal quantum computation is processed by measurements of quantum correlations. → An intrinsic complexity of strongly-correlated quantum systems could be a resource. - Abstract: Quantum phases of naturally-occurring systems exhibit distinctive collective phenomena as manifestation of their many-body correlations, in contrast to our persistent technological challenge to engineer at will such strong correlations artificially. Here we show theoretically that quantum correlations exhibited in the 2D valence bond solid phase of a quantum antiferromagnet, modeled by Affleck, Kennedy, Lieb, and Tasaki (AKLT) as a precursor of spin liquids and topological orders, are sufficiently complex yet structured enough to simulate universal quantum computation when every single spin can be measured individually. This unveils that an intrinsic complexity of naturally-occurring 2D quantum systems-which has been a long-standing challenge for traditional computers-could be tamed as a computationally valuable resource, even if we are limited not to create newly entanglement during computation. Our constructive protocol leverages a novel way to herald the correlations suitable for deterministic quantum computation through a random sampling, and may be extensible to other ground states of various 2D valence bond phases beyond the AKLT state.

Effects of emotional valence and arousal on the voice perception network

Science.gov (United States)

Kotz, Sonja A.; Belin, Pascal

2017-01-01

Abstract Several theories conceptualise emotions along two main dimensions: valence (a continuum from negative to positive) and arousal (a continuum that varies from low to high). These dimensions are typically treated as independent in many neuroimaging experiments, yet recent behavioural findings suggest that they are actually interdependent. This result has impact on neuroimaging design, analysis and theoretical development. We were interested in determining the extent of this interdependence both behaviourally and neuroanatomically, as well as teasing apart any activation that is specific to each dimension. While we found extensive overlap in activation for each dimension in traditional emotion areas (bilateral insulae, orbitofrontal cortex, amygdalae), we also found activation specific to each dimension with characteristic relationships between modulations of these dimensions and BOLD signal change. Increases in arousal ratings were related to increased activations predominantly in voice-sensitive cortices after variance explained by valence had been removed. In contrast, emotions of extreme valence were related to increased activations in bilateral voice-sensitive cortices, hippocampi, anterior and midcingulum and medial orbito- and superior frontal regions after variance explained by arousal had been accounted for. Our results therefore do not support a complete segregation of brain structures underpinning the processing of affective dimensions. PMID:28449127

Band width and multiple-angle valence-state mapping of diamond

International Nuclear Information System (INIS)

Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J.

1997-01-01

The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid's many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of ±1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84 degrees cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space

Band width and multiple-angle valence-state mapping of diamond

Energy Technology Data Exchange (ETDEWEB)

Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid`s many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of {+-}1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84{degrees} cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space.

Revisiting the quasi-particle model of the quark-gluon plasma

International Nuclear Information System (INIS)

Bannur, V.M.

2007-01-01

The quasi-particle model of the quark-gluon plasma (QGP) is revisited here with a new method, different from earlier studies, one without the need of a temperature dependent bag constant and other effects such as confinement, effective degrees of freedom etc. Our model has only one system dependent parameter and shows a surprisingly good fit to the lattice results for the gluon plasma, and for 2-flavor, 3-flavor and (2+1)-flavor QGP. The basic idea is first to evaluate the energy density ε from the grand partition function of quasi-particle QGP, and then derive all other thermodynamic functions from ε. Quasi-particles are assumed to have a temperature dependent mass equal to the plasma frequency. Energy density, pressure and speed of sound at zero chemical potential are evaluated and compared with the available lattice data. We further extend the model to a finite chemical potential, without any new parameters, to obtain the quark density, quark susceptibility etc., and the model fits very well with the lattice results on 2-flavor QGP. (orig.)

Orbital momentum distribution and binding energies for the complete valence shell of molecular bromine

International Nuclear Information System (INIS)

Frost, L.; Grisogono, A.M.; Weigold, E.

1987-08-01

The binding energy spectrum of Br 2 has been recorded in both the outer and inner valence regions using electron momentum spectroscopy. The measurements are compared with the results of several Green's function calculations using different approximations and based on both polarized and unpolarized wave functions. The inner valence region, observed for the first time, is found to exhibit complex structure that is shown to be due to many-body effects, thus indicating a breakdown of the simple MO picture for ionization in this region. Momentum distributions for the three outer valence orbitals are also measured and compared with spherically averaged calculations using the target Hartree-Fock and plane wave impulse approximations. The effect of polarization functions in the basis set is investigated. Orbital density maps in both momentum and position space have been calculated and compared with the experimental measurements

Effects of self-relevant cues and cue valence on autobiographical memory specificity in dysphoria.

Science.gov (United States)

Matsumoto, Noboru; Mochizuki, Satoshi

2017-04-01

Reduced autobiographical memory specificity (rAMS) is a characteristic memory bias observed in depression. To corroborate the capture hypothesis in the CaRFAX (capture and rumination, functional avoidance, executive capacity and control) model, we investigated the effects of self-relevant cues and cue valence on rAMS using an adapted Autobiographical Memory Test conducted with a nonclinical population. Hierarchical linear modelling indicated that the main effects of depression and self-relevant cues elicited rAMS. Moreover, the three-way interaction among valence, self-relevance, and depression scores was significant. A simple slope test revealed that dysphoric participants experienced rAMS in response to highly self-relevant positive cues and low self-relevant negative cues. These results partially supported the capture hypothesis in nonclinical dysphoria. It is important to consider cue valence in future studies examining the capture hypothesis.

Orbital momentum distributions and binding energies for the complete valence shell of molecular iodine

International Nuclear Information System (INIS)

Grisogono, A.M.; Pascual, R.; Weigold, E.

1988-03-01

The complete valence shell binding energy spectrum (8-43eV) of I 2 has been measured by using electron momentum spectroscopy at 1000eV. The complete inner valence region, corresponding to ionization from the 10 σ u and 10 σ g orbitals, has been measured for the first time and shows extensive splitting of the ionization strength due to electron correlation effects in the ion. Many-body calculations using the Green's function method have been carried out and are compared with the data. Momentum distributions, measured in both the outer and inner valence regions, are compared with those given by SCF orbital wave functions calculated with a number of different basis sets. Computed orbital position and momentum density maps for oriented I 2 molecules are discussed in comparison with the measured and calculated spherically averaged momentum distributions

Kalman Filtered MR Temperature Imaging for Laser Induced Thermal Therapies

OpenAIRE

Fuentes, D.; Yung, J.; Hazle, J. D.; Weinberg, J. S.; Stafford, R. J.

2011-01-01

The feasibility of using a stochastic form of Pennes bioheat model within a 3D finite element based Kalman filter (KF) algorithm is critically evaluated for the ability to provide temperature field estimates in the event of magnetic resonance temperature imaging (MRTI) data loss during laser induced thermal therapy (LITT). The ability to recover missing MRTI data was analyzed by systematically removing spatiotemporal information from a clinical MR-guided LITT procedure in human brain and comp...

Who should do the dishes now? Revisiting gender and housework in contemporary urban South Wales

OpenAIRE

Mannay, Dawn

2016-01-01

This chapter revisits Jane Pilcher’s (1994) seminal work ‘Who should do the dishes? Three generations of Welsh women talking about men and housework’, which was originally published in Our Sister’s Land: the changing identities of women in Wales. As discussed in the introductory chapter, I began revisiting classic Welsh studies as part of my doctoral study Mothers and daughters on the margins: gender, generation and education (Mannay, 2012); this lead to the later publication of a revisiting ...

Modulation of cadmium-induced mitochondrial dysfunction and volume changes by temperature in rainbow trout (Oncorhynchus mykiss)

International Nuclear Information System (INIS)

Onukwufor, John O.; Kibenge, Fred; Stevens, Don; Kamunde, Collins

2015-01-01

Highlights: • Interactions of Cd and temperature exacerbate mitochondrial dysfunction and enhance Cd accumulation. • Cd uptake by mitochondria occurs through the Ca uniporter. • Temperature exacerbates Cd-induced mitochondrial volume changes. • Low concentrations of Cd inhibit mitochondrial swelling. - Abstract: We investigated how temperature modulates cadmium (Cd)-induced mitochondrial bioenergetic disturbances, metal accumulation and volume changes in rainbow trout (Oncorhynchus mykiss). In the first set of experiments, rainbow trout liver mitochondrial function and Cd content were measured in the presence of complex I substrates, malate and glutamate, following exposure to Cd (0–100 μM) at three (5, 13 and 25 °C) temperatures. The second set of experiments assessed the effect of temperature on Cd-induced mitochondrial volume changes, including the underlying mechanisms, at 15 and 25 °C. Although temperature stimulated both state 3 and 4 rates of respiration, the coupling efficiency was reduced at temperature extremes due to greater inhibition of state 3 at low temperature and greater stimulation of state 4 at the high temperature. Cadmium exposure reduced the stimulatory effect of temperature on state 3 respiration but increased that on state 4, consequently exacerbating mitochondrial uncoupling. The interaction of Cd and temperature yielded different responses on thermal sensitivity of state 3 and 4 respiration; the Q 10 values for state 3 respiration increased at low temperature (5–13 °C) while those for state 4 increased at high temperature (13–25 °C). Importantly, the mitochondria accumulated more Cd at high temperature suggesting that the observed greater impairment of oxidative phosphorylation with temperature was due, at least in part, to a higher metal burden. Cadmium-induced mitochondrial volume changes were characterized by an early phase of contraction followed by swelling, with temperature changing the kinetics and intensifying

Modulation of cadmium-induced mitochondrial dysfunction and volume changes by temperature in rainbow trout (Oncorhynchus mykiss)

Energy Technology Data Exchange (ETDEWEB)

Onukwufor, John O. [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada); Kibenge, Fred [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada); Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3 (Canada)

2015-01-15

Highlights: • Interactions of Cd and temperature exacerbate mitochondrial dysfunction and enhance Cd accumulation. • Cd uptake by mitochondria occurs through the Ca uniporter. • Temperature exacerbates Cd-induced mitochondrial volume changes. • Low concentrations of Cd inhibit mitochondrial swelling. - Abstract: We investigated how temperature modulates cadmium (Cd)-induced mitochondrial bioenergetic disturbances, metal accumulation and volume changes in rainbow trout (Oncorhynchus mykiss). In the first set of experiments, rainbow trout liver mitochondrial function and Cd content were measured in the presence of complex I substrates, malate and glutamate, following exposure to Cd (0–100 μM) at three (5, 13 and 25 °C) temperatures. The second set of experiments assessed the effect of temperature on Cd-induced mitochondrial volume changes, including the underlying mechanisms, at 15 and 25 °C. Although temperature stimulated both state 3 and 4 rates of respiration, the coupling efficiency was reduced at temperature extremes due to greater inhibition of state 3 at low temperature and greater stimulation of state 4 at the high temperature. Cadmium exposure reduced the stimulatory effect of temperature on state 3 respiration but increased that on state 4, consequently exacerbating mitochondrial uncoupling. The interaction of Cd and temperature yielded different responses on thermal sensitivity of state 3 and 4 respiration; the Q{sub 10} values for state 3 respiration increased at low temperature (5–13 °C) while those for state 4 increased at high temperature (13–25 °C). Importantly, the mitochondria accumulated more Cd at high temperature suggesting that the observed greater impairment of oxidative phosphorylation with temperature was due, at least in part, to a higher metal burden. Cadmium-induced mitochondrial volume changes were characterized by an early phase of contraction followed by swelling, with temperature changing the kinetics and

Stress- and Magnetic Field-Induced Martensitic Transformation at Cryogenic Temperatures in Fe-Mn-Al-Ni Shape Memory Alloys

Science.gov (United States)

Xia, Ji; Xu, Xiao; Miyake, Atsushi; Kimura, Yuta; Omori, Toshihiro; Tokunaga, Masashi; Kainuma, Ryosuke

2017-12-01

Stress-induced and magnetic-field-induced martensitic transformation behaviors at low temperatures were investigated for Fe-Mn-Al-Ni alloys. The magnetic-field-induced reverse martensitic transformation was directly observed by in situ optical microscopy. Magnetization measurements under pulsed magnetic fields up to 50 T were carried out at temperatures between 4.2 and 125 K on a single-crystal sample; full magnetic-field-induced reverse martensitic transformation was confirmed at all tested temperatures. Compression tests from 10 to 100 K were conducted on a single-crystal sample; full shape recovery was obtained at all tested temperatures. It was found that the temperature dependence of both the critical stress and critical magnetic field is small and that the transformation hysteresis is less sensitive to temperature even at cryogenic temperatures. The temperature dependence of entropy change during martensitic transformation up to 100 K was then derived using the Clausius-Clapeyron relation with critical stresses and magnetic fields.

Valence-band splitting energies in wurtzite InP nanowires: Photoluminescence spectroscopy and ab initio calculations

Science.gov (United States)

Gadret, E. G.; Dias, G. O.; Dacal, L. C. O.; de Lima, M. M., Jr.; Ruffo, C. V. R. S.; Iikawa, F.; Brasil, M. J. S. P.; Chiaramonte, T.; Cotta, M. A.; Tizei, L. H. G.; Ugarte, D.; Cantarero, A.

2010-09-01

We investigated experimentally and theoretically the valence-band structure of wurtzite InP nanowires. The wurtzite phase, which usually is not stable for III-V phosphide compounds, has been observed in InP nanowires. We present results on the electronic properties of these nanowires using the photoluminescence excitation technique. Spectra from an ensemble of nanowires show three clear absorption edges separated by 44 meV and 143 meV, respectively. The band edges are attributed to excitonic absorptions involving three distinct valence-bands labeled: A, B, and C. Theoretical results based on “ab initio” calculation gives corresponding valence-band energy separations of 50 meV and 200 meV, respectively, which are in good agreement with the experimental results.

Esterification of jatropha oil via ultrasonic irradiation with auto-induced temperature-rise effect

International Nuclear Information System (INIS)

Andrade-Tacca, Cesar Augusto; Chang, Chia-Chi; Chen, Yi-Hung; Manh, Do-Van; Chang, Ching-Yuan; Ji, Dar-Ren; Tseng, Jyi-Yeong; Shie, Je-Lueng

2014-01-01

Auto-induced temperature-rise effects of ultrasonic irradiation (UI) on the esterification performance of jatropha oil (JO) were studied. Comparisons with other methods of mechanical mixing (MM) and hand shaking mixing were made. Major system parameters examined include: esterification time (t E ), settling time (t S ) after esterification and temperature. Properties of acid value (AV), iodine value (IV), kinematic viscosity (KV) and density of JO and ester product were measured. The esterification conversion efficiencies (η) were determined and assessed. Sulfuric acid was used to catalyze the esterification using methyl alcohol. For esterification without temperature control, η at t E  = 10 and 30 min for UI of 56.73 and 83.23% are much higher than those for MM of 36.76 and 42.48%, respectively. At t E  = 10 min, the jatropha oil esters produced via UI and MM respectively possess AV of 15.82 and 23.12 mg KOH/g, IV of 111.49 and 113.22 g I 2 /100 g, KV of 22.41 and 22.51 mm 2 /s and density of 913.8 and 913.58 kg/m 3 , showing that UI is much better than MM in enhancing the reduction of AV. The t E exhibits more vigorous effect on AV for UI than MM. The UI offers auto-induced temperature-rise, improving the mixing and esterification extents. - Highlights: • Esterification of jatropha oil is pronounced under ultrasonic irradiation (UI). • UI can auto-induce temperature rise. • The induced temperature rise assists the mixing of UI in enhancing esterification. • UI offers better esterification than mechanical mixing with external heating. • An 83.23% reduction of FFA in jatropha-ester is achievable via UI in 30 min

Irradiation-induced creep in fuel compacts for high-temperature reactor applications

Energy Technology Data Exchange (ETDEWEB)

Veringa, H; Blackstone, R [Stichting Energieonderzoek Centrum Nederland, Petten; Loelgen, R

1977-01-01

Restrained shrinkage experiments at neutron fluences up to 3 x 10/sup 21/ n cm/sup -2/ DNE in the temperature range 600 to 1200/sup 0/C were performed on three different dummy coated-particle fuel compacts in the high-flux reactor at Petten. The data were evaluated to obtain the steady-state radiation creep coefficient of the compacts. It was found that, for the materials investigated, the creep coefficient is temperature dependent, but no clear relationship with Young's modulus could be established. Under certain conditions this irradiation-induced plasticity influences the elastic properties, with the concomitant increase of the creep coefficient. This effect coincides with the formation and further opening up of cracks due to stresses caused by irradiation-induced shrinkage of matrix material.

Irradiation-induced creep in fuel compacts for high-temperature reactor applications

International Nuclear Information System (INIS)

Veringa, H.; Blackstone, R.; Loelgen, R.

1977-01-01

Restrained shrinkage experiments at neutron fluences up to 3 x 10 21 n cm -2 DNE in the temperature range 600 to 1200 0 C were performed on three different dummy coated-particle fuel compacts in the high-flux reactor at Petten. The data were evaluated to obtain the steady-state radiation creep coefficient of the compacts. It was found that, for the materials investigated, the creep coefficient is temperature dependent, but no clear relationship with Young's modulus could be established. Under certain conditions this irradiation-induced plasticity influences the elastic properties, with the concomitant increase of the creep coefficient. This effect coincides with the formation and further opening up of cracks due to stresses caused by irradiation-induced shrinkage of matrix material. (author)

Voluntary or Mandatory? The Valence Framing Effect of Attitudes Regarding HPV Vaccination.

Science.gov (United States)

Gesser-Edelsburg, Anat; Walter, Nathan; Shir-Raz, Yaffa; Green, Manfred S

2015-01-01

This study addresses the issue of valence framing effect in the context of immunization, a preventive behavior often addressed by the equation of benefit versus risk. The authors examined how framing (support vs. oppose) the issue of HPV vaccination in Israel's immunization routine affects attitudes regarding vaccine regulations. The study also examined issue involvement as a moderator of valence framing effect. The results demonstrate that participants in the positive framing condition tended to express greater support for voluntary immunization than participants in the negative framing condition (77.5% and 48.5%, respectively). Among those who supported the mandatory HPV immunization policy, the negative framing condition was more prominent than the positive condition (51.5% and 22.5%, respectively). The analysis of interaction between valence framing and issue involvement showed that the latter tends to moderate the direct effect of framing on attitudes towards vaccination. Findings indicate that even attitudes towards such consequential preventive behaviors as vaccination could be affected by different framing of the issue, especially for those who are less involved. Implications of predilection for freedom of choice regarding vaccination are also discussed.

False memory in aging: effects of emotional valence on word recognition accuracy.

Science.gov (United States)

Piguet, Olivier; Connally, Emily; Krendl, Anne C; Huot, Jessica R; Corkin, Suzanne

2008-06-01

Memory is susceptible to distortions. Valence and increasing age are variables known to affect memory accuracy and may increase false alarm production. Interaction between these variables and their impact on false memory was investigated in 36 young (18-28 years) and 36 older (61-83 years) healthy adults. At study, participants viewed lists of neutral words orthographically related to negative, neutral, or positive critical lures (not presented). Memory for these words was subsequently tested with a remember-know procedure. At test, items included the words seen at study and their associated critical lures, as well as sets of orthographically related neutral words not seen at study and their associated unstudied lures. Positive valence was shown to have two opposite effects on older adults' discrimination of the lures: It improved correct rejection of unstudied lures but increased false memory for critical lures (i.e., lures associated with words studied previously). Thus, increased salience triggered by positive valence may disrupt memory accuracy in older adults when discriminating among similar events. These findings likely reflect a source memory deficit due to decreased efficiency in cognitive control processes with aging.

A THIOLATO-BRIDGED OCTANUCLEAR COPPER(I,II MIXED- VALENCE COMPLEX WITH N,N,S-TRIDENTATE LIGAND

Directory of Open Access Journals (Sweden)

Takanori Kotera

2007-06-01

Full Text Available Thiolato-bridged complex [CuI4CuII4(peampt4Cl8]·2H2O (Hpeampt = 1-(2-pyridylethylamino methylpropane-2-thiol has been synthesized and characterized by the elemental analysis, IR and UV-vis spectroscopies and magnetic susceptibility measurement. The X-ray crystal structure analysis of this complex shows a localized mixed-valence octanuclear cage structure made up of four trigonal-bipyramidal CuIIN2SCl2, two trigonal CuIS2Cl, and two tetrahedral CuIS2Cl2 coordination sites. Temperature dependence of magnetic susceptibility (4.5— 300 K shows that a fairly strong antiferromagnetic interaction is operating between the four CuII ions.

Photocatalysts: ambient temperature destruction of VOCs

Energy Technology Data Exchange (ETDEWEB)

Miller, R [IT Corp., Oak Ridge, TN (United States)

1994-12-31

Photocatalysis was a failure as a solar energy driven organic synthesis technique, but as this study indicates, it has undergone a renaissance as a promising treatment method for volatile organic compounds (VOCs) in air streams. Photocatalytic oxidation (PCO) relies upon the ability of certain semiconductors to be stimulated by UV radiation. UV light excites valence band electrons in the semiconductor catalyst to jump to a conductance band leaving holes in the valence band. The electrons and holes can react with compounds such as organic contaminants present in an air stream. Hallmarks of the technology include rapid destruction kinetics for many VOCs at ambient temperature and efficient use energy in the form of UV-A photons. Studies clearly indicate that PCO is competitive on capital cost and offers significant operating cost savings on selected applications. 6 refs., 3 tabs., 2 figs.

Photocatalysts: ambient temperature destruction of VOCs

International Nuclear Information System (INIS)

Miller, R.

1994-01-01

Photocatalysis was a failure as a solar energy driven organic synthesis technique, but as this study indicates, it has undergone a renaissance as a promising treatment method for volatile organic compounds (VOCs) in air streams. Photocatalytic oxidation (PCO) relies upon the ability of certain semiconductors to be stimulated by UV radiation. UV light excites valence band electrons in the semiconductor catalyst to jump to a conductance band leaving holes in the valence band. The electrons and holes can react with compounds such as organic contaminants present in an air stream. Hallmarks of the technology include rapid destruction kinetics for many VOCs at ambient temperature and efficient use energy in the form of UV-A photons. Studies clearly indicate that PCO is competitive on capital cost and offers significant operating cost savings on selected applications. 6 refs., 3 tabs., 2 figs

Continuum limit of overlap valence quarks on a twisted mass sea

Energy Technology Data Exchange (ETDEWEB)

Cichy, Krzysztof [Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Herdoiza, Gregorio [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC; Univ. Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Jansen, Karl [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC

2010-12-15

We study a lattice QCD mixed action with overlap valence quarks on two flavours of Wilson maximally twisted mass sea quarks. Employing three different matching conditions to relate both actions to each other, we investigate the continuum limit by using three values of the lattice spacing ranging from a{approx}0.05 fm to 0.08 fm. A particular emphasis is put on the effect on physical observables of the topological zero modes appearing in the valence overlap operator. We estimate the region of parameter space where the contribution from these zero modes is sufficiently small such that their effects can be safely controlled and a restoration of unitarity of the mixed action in the continuum limit is reached. (orig.)

Equation of states and phonons at high pressure of intermediate valence compound TmTe

International Nuclear Information System (INIS)

Jha, Prafulla K.; Sanyal, Sankar P.

1997-01-01

The study of equation of states and pressure dependence of the phonon frequencies of the compound TmTe have been performed by using a simple interatomic potential approach in the frame work of rigid ion model. The compressibility study confirms that below 2 GPa the valence of the Tm is 2+ while there is a valence transition from Tm 2+ to Tm 3+ above 2 GPa. The phonon frequencies of TmTe increases as pressure is increased. (author)

Generalized oscillator strengths for some higher valence-shell excitations of krypton atom

Institute of Scientific and Technical Information of China (English)

2007-01-01

The valence-shell excitations of krypton atom have been investigated by fast electron impact with an angle-resolved electron-energy-loss spectrometer. The generalized oscillator strengths for some higher mixed valence-shell excitations in 4d, 4f, 5p, 5d, 6s, 6p, 7s ← 4p of krypton atom have been determined. Their profiles are discussed, and the generalized oscillator strengths for the electric monopole and quadrupole excitations in 5p ← 4p are compared with the calculations of Amusia et al. (Phys. Rev. A 67 022703 (2003)). The differences between the experimental results and theoretical calculations show that more studies are needed.

Coincidence Doppler broadening study on hydrocarbons with pi and sigma valence electrons: positronium correction

International Nuclear Information System (INIS)

Djourelov, N.; Suzuki, T.; Yu, R.S.; Ito, Y.

2005-01-01

The coincidence Doppler broadening (CDB) technique was applied to study the electron momentum distribution in anthracene, diphenyl, naphthalene, and polystyrene. A method for separation of the positron and positronium (Ps) components from the Doppler-broadened annihilation line (DBAL) was developed further to be applicable to hydrocarbons with different π and σ valence electron distributions. This method allows extraction of the electron momentum distribution (EMD) from DBAL for samples when Ps formation occurs. The annihilation on π valence electrons was detected as broadening of the EMD compared to that obtained for a polymer sample only with σ valence electrons. The broadening appeared as a significant change in the shape of the CDB ratio of the corresponding positronium-corrected curves: a slight enhancement above the unity line in the low-momentum region and a drop in the momentum region, 10-20x10 -3 m o c

Experimental evaluation of the pressure and temperature dependence of ion-induced nucleation.

Science.gov (United States)

Munir, Muhammad Miftahul; Suhendi, Asep; Ogi, Takashi; Iskandar, Ferry; Okuyama, Kikuo

2010-09-28

An experimental system for the study of ion-induced nucleation in a SO(2)/H(2)O/N(2) gas mixture was developed, employing a soft x-ray at different pressure and temperature levels. The difficulties associated with these experiments included the changes in physical properties of the gas mixture when temperature and pressure were varied. Changes in the relative humidity (RH) as a function of pressure and temperature also had a significant effect on the different behaviors of the mobility distributions of particles. In order to accomplish reliable measurement and minimize uncertainties, an integrated on-line control system was utilized. As the pressure decreased in a range of 500-980 hPa, the peak concentration of both ions and nanometer-sized particles decreased, which suggests that higher pressure tended to enhance the growth of particles nucleated by ion-induced nucleation. Moreover, the modal diameters of the measured particle size distributions showed a systematic shift to larger sizes with increasing pressure. However, in the temperature range of 5-20 °C, temperature increases had no significant effects on the mobility distribution of particles. The effects of residence time, RH (7%-70%), and SO(2) concentration (0.08-6.7 ppm) on ion-induced nucleation were also systematically investigated. The results show that the nucleation and growth were significantly dependent on the residence time, RH, and SO(2) concentration, which is in agreement with both a previous model and previous observations. This research will be inevitable for a better understanding of the role of ions in an atmospheric nucleation mechanism.

Electrical resistivity of YbRh{sub 2}Si{sub 2} and EuT{sub 2}Ge{sub 2} (T=Co,Cu) at extreme conditions of pressure and temperature

Energy Technology Data Exchange (ETDEWEB)

Dionicio, G.A.

2006-07-01

This investigation addresses the effect that pressure, p, and temperature, T, have on 4f states of the rare-earth elements in the isostructural YbRh{sub 2}Si{sub 2}, EuCo{sub 2}Ge{sub 2}, and EuCu{sub 2}Ge{sub 2} compounds. Upon applying pressure the volume of the unit cell reduces, enforcing either the enhancement of the hybridization of the 4f localized electrons with the ligand or a change in the valence state of the rare-earth ions. Here, we probe the effect of a pressure-induced lattice contraction on these system by means of electrical-resistivity measurements, {rho}(T), from room temperature down to 100 mK. (orig.)

Examining Relationships of Destination Image, Service Quality, e-WOM, and Revisit Intention to Sabang Island, Indonesia

Directory of Open Access Journals (Sweden)

Rangga Restu Prayogo

2016-12-01

Full Text Available The purpose of this research is to study the relationship among destination image, service quality, e-WOM, and revisit intentions in the tourism industry. A questionnaire given to tourists who visit one of the farrest island in western part of Indonesia, Sabang Island and using sampling through the convenience sampling. A structural equation model (SEM test with WarpPLS 3.0 was used to test the relationship between research variables. This research gathered from 150 respondents. The empirical results from PLS-SEM showed that; the destination image positive affect e-WOM and revisit intention; service quality affect e-WOM and revisit intention; e-WOM positive affect to revisit intention tourists. The implications and future research issues were discussed.

The dynamics of the laser-induced metal-semiconductor phase transition of samarium sulfide (SmS)

International Nuclear Information System (INIS)

Kaempfer, Tino

2009-01-01

The present thesis is dedicated to the experimental study of the metal-semiconductor phase transition of samarium sulfide (SmS): Temperature- and time-resolved experiments on the characterization of the phase transition of mixed-valence SmS samples (M-SmS) are presented. The measurement of the dynamics of the laser-induced phase transition pursues via time-resolved ultrashort-time microscopy and by X-ray diffraction with sub-picosecond time resolution. The electronic and structural processes, which follow an excitation of M-SmS with infrared femtosecond laser pulses, are physically interpreted on the base of the results obtained in this thesis and model imaginations. [de

I-space: the effects of emotional valence and source of music on interpersonal distance.

Directory of Open Access Journals (Sweden)

Ana Tajadura-Jiménez

Full Text Available BACKGROUND: The ubiquitous use of personal music players in over-crowded public transport alludes to the hypothesis that apart from making the journey more pleasant, listening to music through headphones may also affect representations of our personal space, that is, the emotionally-tinged zone around the human body that people feel is "their space". We evaluated the effects of emotional valence (positive versus negative and source (external, i.e. loudspeakers, versus embedded, i.e. headphones of music on the participant's interpersonal distance when interacting with others. METHODOLOGY/PRINCIPAL FINDINGS: Personal space was evaluated as the comfort interpersonal distance between participant and experimenter during both active and passive approach tasks. Our results show that, during passive approach tasks, listening to positive versus negative emotion-inducing music reduces the representation of personal space, allowing others to come closer to us. With respect to a no-music condition, an embedded source of positive emotion-inducing music reduced personal space, while an external source of negative emotion-inducing music expanded personal space. CONCLUSIONS/SIGNIFICANCE: The results provide the first empirical evidence of the relation between induced emotional state, as a result of listening to positive music through headphones, and personal space when interacting with others. This research might help to understand the benefit that people find in using personal music players in crowded situations, such as when using the public transport in urban settings.

Topological Qubits from Valence Bond Solids

Science.gov (United States)

Wang, Dong-Sheng; Affleck, Ian; Raussendorf, Robert

2018-05-01

Topological qubits based on S U (N )-symmetric valence-bond solid models are constructed. A logical topological qubit is the ground subspace with twofold degeneracy, which is due to the spontaneous breaking of a global parity symmetry. A logical Z rotation by an angle 2 π /N , for any integer N >2 , is provided by a global twist operation, which is of a topological nature and protected by the energy gap. A general concatenation scheme with standard quantum error-correction codes is also proposed, which can lead to better codes. Generic error-correction properties of symmetry-protected topological order are also demonstrated.

verbal extensions: valency decreasing extensions in the basà ...

African Journals Online (AJOL)

Finance

London: Hodder. Education. Imoh, P.M., 2013. Verbal extensions: Valency increasing operations in Basà verbal system. Paper presented at the West African Languages Congress (WALC) and 26th Annual. Conference of the Linguistic Association of Nigeria (26th CLAN), 29th July to 2nd August. 2013, University of Ibadan, ...

Deterministic Graphical Games Revisited

DEFF Research Database (Denmark)

Andersson, Daniel; Hansen, Kristoffer Arnsfelt; Miltersen, Peter Bro

2008-01-01

We revisit the deterministic graphical games of Washburn. A deterministic graphical game can be described as a simple stochastic game (a notion due to Anne Condon), except that we allow arbitrary real payoffs but disallow moves of chance. We study the complexity of solving deterministic graphical...... games and obtain an almost-linear time comparison-based algorithm for computing an equilibrium of such a game. The existence of a linear time comparison-based algorithm remains an open problem....

[Connection between the evaluation of positive or negative valence and verbal responses to a lexical decision making task].

Science.gov (United States)

Brouillet, Thibaut; Syssau, Arielle

2005-12-01

Evaluation of the positive or negative valence of a stimulus is an activity that is part of any emotional experience that has been mostly studied using the affective priming paradigm. When the prime and the target have the same valence (e.g. positive prime and positive target), the target response is facilitated as a function of opposing valence conditions (e.g. negative prime and positive target). These studies show that this evaluation is automatic but depends on the nature of the task's implied response because the priming effects are only observed for positive responses, not for negative responses. This result was explained in automatic judgmental tendency model put forth by Abelson and Rosenberg (1958) and Klauer and Stern (1992). In this model, affective priming assumes there is an overlap between both responses, the first response taking precedence as a function of the prime-target valence, and the second response one that is required by the task. We are assuming that another type of response was not foreseen under this model. In fact, upon activating the valence for each of the prime-target elements, two preliminary responses would be activated before the response on the prime-target valence relationship. These responses are directly linked to the prime and target evaluation independently of the prime-target relationship. This hypothesis can be linked to the larger hypothesis whereby the evaluative process is related to two distinct motivational systems corresponding to approach and avoidance behaviour responses (Lang, Bradley, & Cuthbert, 1990; Neuman & Strack, 2000; Cacciopo, Piester & Bernston, 1993). In this study, we use the hypothesis that when a word leads to a positive valence evaluation, this favours a positive verbal response and inversely, a negative valence word favours a negative response. We are testing this hypothesis outside the affective priming paradigm to study to what extent evaluating a word, even when it is not primed, activates both

Mode-coupling theory predictions for a limited valency attractive square well model

International Nuclear Information System (INIS)

Zaccarelli, E; Saika-Voivod, I; Moreno, A J; Nave, E La; Buldyrev, S V; Sciortino, F; Tartaglia, P

2006-01-01

Recently we have studied, using numerical simulations, a limited valency model, i.e. an attractive square well model with a constraint on the maximum number of bonded neighbours. Studying a large region of temperatures T and packing fractions φ, we have estimated the location of the liquid-gas phase separation spinodal and the loci of dynamic arrest, where the system is trapped in a disordered non-ergodic state. Two distinct arrest lines for the system are present in the system: a (repulsive) glass line at high packing fraction, and a gel line at low φ and T. The former is essentially vertical φ controlled), while the latter is rather horizontal (T controlled) in the φ-T) plane. We here complement the molecular dynamics results with mode coupling theory calculations, using the numerical structure factors as input. We find that the theory predicts a repulsive glass line-in satisfactory agreement with the simulation results-and an attractive glass line, which appears to be unrelated to the gel line

Influence of changes in the valence electronic configuration on the structure of L-X-ray spectra of molybdenum

International Nuclear Information System (INIS)

Polasik, M; Koziol, K; Slabkowska, K; Czarnota, M; Pajek, M

2009-01-01

Extensive multiconfiguration Dirac-Fock (MCDF) calculations with the inclusion of the transverse (Breit) interaction and QED corrections have been carried out on molybdenum to explain the dependence of the structure of Lα 1,2 and Lβ 1 lines on the changes in configurations of the valence electrons belonging to two different configuration types: three open-shell 4d 6-r 5s r (r = 2,1,0) configurations and one closed-shell 4d 4 3/2 5s 2 configuration. It has been found that the MCDF predictions for open-shell valence configurations (4d 4 5s 2 , 4d 5 5s 1 , 4d 6 5s 0 ) much better reproduce observed structure of Lα 1,2 lines in X-ray spectra of molybdenum than closed-shell 4d 4 3/2 5s 2 valence configuration. The influence of changes in the valence electronic configuration on the structure of L-X-ray spectra of molybdenum is noticeable. Moreover, the observation of the shapes of L-X-ray spectra seems to be very good method to investigate the changes of the valence electronic configuration caused by the chemical environment.

Mn valence state and electrode performance of perovskite-type ...

Indian Academy of Sciences (India)

increase in the oxidation state of Mn ions was due to the formation of Mn4+ ions and oxygen vacancies. The addition of Cu ions to LSM systems could lead to enhanced electrode performance for oxygen reduction reactions originating from the change in valence of Mn ions. Keywords. Cu-doped LSM; electrical conductivity; ...

Effective valence as the control parameter of the superconducting ...

African Journals Online (AJOL)

One approach to investigating the superconductivity in the ironbased materials is understanding the chemical and structural parameters that can be used to tune their remarkably high Tc. In this paper, we have demonstrated that the effective valence of iron can be used as the control parameter to tune the Tc of this family of ...

Brain activations to emotional pictures are differentially associated with valence and arousal ratings

Directory of Open Access Journals (Sweden)

Antje B M Gerdes

2010-10-01

Full Text Available Several studies have investigated the neural responses triggered by emotional pictures, but the specificity of the involved structures such as the amygdala or the ventral striatum is still under debate. Furthermore, only few studies examined the association of stimuli’s valence and arousal and the underlying brain responses. Therefore, we investigated brain responses with functional magnetic resonance imaging of 17 healthy subjects to pleasant and unpleasant affective pictures with comparable arousal levels and afterwards assessed ratings of valence and arousal. As expected, unpleasant pictures strongly activated the right and left amygdala, the right hippocampus, and the medial occipital lobe, whereas pleasant pictures elicited significant activations in left occipital regions, and in parts of the medial temporal lobe. The direct comparison of unpleasant and pleasant pictures which were comparable in arousal clearly indicated stronger amygdala activation in response to the unpleasant pictures. Most important, correlational analyses revealed on the one hand that the arousal of unpleasant pictures was significantly associated with activations in the right amygdala and the left caudate body. On the other hand, valence of pleasant pictures was significantly correlated with activations in the right caudate head, extending to the nucleus accumbens (NAcc and the left dorso-lateral prefrontal cortex. These findings support the notion that the amygdala is primarily involved in processing of unpleasant stimuli, and the stronger the more arousing the stimuli are, whereas reward-related structures like the NAcc primarily responds to pleasant stimuli, the stronger the more positive the valence of these stimuli is.

Multilevel analysis of facial expressions of emotion and script: self-report (arousal and valence) and psychophysiological correlates.

Science.gov (United States)

Balconi, Michela; Vanutelli, Maria Elide; Finocchiaro, Roberta

2014-09-26

The paper explored emotion comprehension in children with regard to facial expression of emotion. The effect of valence and arousal evaluation, of context and of psychophysiological measures was monitored. Indeed subjective evaluation of valence (positive vs. negative) and arousal (high vs. low), and contextual (facial expression vs. facial expression and script) variables were supposed to modulate the psychophysiological responses. Self-report measures (in terms of correct recognition, arousal and valence attribution) and psychophysiological correlates (facial electromyography, EMG, skin conductance response, SCR, and heart rate, HR) were observed when children (N = 26; mean age = 8.75 y; range 6-11 y) looked at six facial expressions of emotions (happiness, anger, fear, sadness, surprise, and disgust) and six emotional scripts (contextualized facial expressions). The competencies about the recognition, the evaluation on valence and arousal was tested in concomitance with psychophysiological variations. Specifically, we tested for the congruence of these multiple measures. Log-linear analysis and repeated measure ANOVAs showed different representations across the subjects, as a function of emotion. Specifically, children' recognition and attribution were well developed for some emotions (such as anger, fear, surprise and happiness), whereas some other emotions (mainly disgust and sadness) were less clearly represented. SCR, HR and EMG measures were modulated by the evaluation based on valence and arousal, with increased psychophysiological values mainly in response to anger, fear and happiness. As shown by multiple regression analysis, a significant consonance was found between self-report measures and psychophysiological behavior, mainly for emotions rated as more arousing and negative in valence. The multilevel measures were discussed at light of dimensional attribution model.

Phasic valence and arousal do not influence post-conflict adjustments in the Simon task.

Science.gov (United States)

Dignath, David; Janczyk, Markus; Eder, Andreas B

2017-03-01

According to theoretical accounts of cognitive control, conflict between competing responses is monitored and triggers post conflict behavioural adjustments. Some models proposed that conflict is detected as an affective signal. While the conflict monitoring theory assumed that conflict is registered as a negative valence signal, the adaptation by binding model hypothesized that conflict provides a high arousal signal. The present research induced phasic affect in a Simon task with presentations of pleasant and unpleasant pictures that were high or low in arousal. If conflict is registered as an affective signal, the presentation of a corresponding affective signal should potentiate post conflict adjustments. Results did not support the hypothesis, and Bayesian analyses corroborated the conclusion that phasic affects do not influence post conflict behavioural adjustments in the Simon task. Copyright © 2017 Elsevier B.V. All rights reserved.

In search for an optimal methodology to calculate the valence electron affinities of temporary anions.

Science.gov (United States)

Puiatti, Marcelo; Vera, D Mariano A; Pierini, Adriana B

2009-10-28

Recently, we have proposed an approach for finding the valence anion ground state, based on the stabilization exerted by a polar solvent; the methodology used standard DFT methods and relatively inexpensive basis sets and yielded correct electron affinity (EA) values by gradually decreasing the dielectric constant of the medium. In order to address the overall performance of the new methodology, to find the best conditions for stabilizing the valence state and to evaluate its scope and limitations, we gathered a pool of 60 molecules, 25 of them bearing the conventional valence state as the ground anion and 35 for which the lowest anion state found holds the extra electron in a diffuse orbital around the molecule (non valence state). The results obtained by testing this representative set suggest a very good performance for most species having an experimental EA less negative than -3.0 eV; the correlation at the B3LYP/6-311+G(2df,p) level being y = 1.01x + 0.06, with a correlation index of 0.985. As an alternative, the time dependent DFT (TD-DFT) approach was also tested with both B3LYP and PBE0 functionals. The methodology we proposed shows a comparable or better accuracy with respect to TD-DFT, although the TD-DFT approach with the PBE0 functional is suggested as a suitable estimate for species with the most negative EAs (ca.-2.5 to -3.5 eV), for which stabilization strategies can hardly reach the valence state. As an application, a pool of 8 compounds of key biological interest with EAs which remain unknown or unclear were predicted using the new methodology.

Unusual metal-ligand charge transfer in ferrocene functionalized μ3-O iron carboxylates observed with Mössbauer spectroscopy

International Nuclear Information System (INIS)

Mereacre, Valeriu; Schlageter, Martin; Eichhöfer, Andreas; Bauer, Thomas; Wolny, Juliusz A.; Schünemann, Volker; Powell, Annie K.

2016-01-01

Temperature dependent Mössbauer studies of two ferrocenecarboxylate functionalized {Fe 3 O} complexes in solid state are reported. It was found that conjugation of ferrocene ring orbitals with the π orbitals of the adjacent carboxylic group promotes a shift of electron density from the ferrocene Fe II ion to the cyclopentadienide rings with π-orbital character giving rise to a new type of mixed-valence compound. - Highlights: • In this manuscript we describe a mechanism of electron density shift which stabilizes the trapped mixed-valence state. • The coexistence of ferrocene and ferrocenium in solid state was determined. • A mixed-valence state at room-temperature and a thermally induced electron transfer with gradual interconversion were observed.

Unusual metal-ligand charge transfer in ferrocene functionalized μ{sub 3}-O iron carboxylates observed with Mössbauer spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Mereacre, Valeriu, E-mail: valeriu.mereacre@kit.edu [Institut für Anorganische Chemie, Karlsruher Institut für Technologie, D-76131 Karlsruhe (Germany); Schlageter, Martin; Eichhöfer, Andreas [Institut für Nanotechnologie, Karlsruher Institut für Technologie, D-76344 Eggenstein-Leopoldshafen (Germany); Bauer, Thomas; Wolny, Juliusz A.; Schünemann, Volker [Department of Physics, University of Kaiserslautern, D-67663 Kaiserslautern (Germany); Powell, Annie K., E-mail: annie.powell@kit.edu [Institut für Anorganische Chemie, Karlsruher Institut für Technologie, D-76131 Karlsruhe (Germany); Institut für Nanotechnologie, Karlsruher Institut für Technologie, D-76344 Eggenstein-Leopoldshafen (Germany)

2016-06-01

Temperature dependent Mössbauer studies of two ferrocenecarboxylate functionalized {Fe_3O} complexes in solid state are reported. It was found that conjugation of ferrocene ring orbitals with the π orbitals of the adjacent carboxylic group promotes a shift of electron density from the ferrocene Fe{sup II} ion to the cyclopentadienide rings with π-orbital character giving rise to a new type of mixed-valence compound. - Highlights: • In this manuscript we describe a mechanism of electron density shift which stabilizes the trapped mixed-valence state. • The coexistence of ferrocene and ferrocenium in solid state was determined. • A mixed-valence state at room-temperature and a thermally induced electron transfer with gradual interconversion were observed.

The stabilities and electron structures of Al-Mg clusters with 18 and 20 valence electrons

Science.gov (United States)

Yang, Huihui; Chen, Hongshan

2017-07-01

The spherical jellium model predicts that metal clusters having 18 and 20 valence electrons correspond to the magic numbers and will show specific stabilities. We explore in detail the geometric structures, stabilities and electronic structures of Al-Mg clusters containing 18 and 20 valence electrons by using genetic algorithm combined with density functional theories. The stabilities of the clusters are governed by the electronic configurations and Mg/Al ratios. The clusters with lower Mg/Al ratios are more stable. The molecular orbitals accord with the shell structures predicted by the jellium model but the 2S level interweaves with the 1D levels and the 2S and 1D orbitals form a subgroup. The clusters having 20 valence electrons form closed 1S21P61D102S2 shells and show enhanced stability. The Al-Mg clusters with a valence electron count of 18 do not form closed shells because one 1D orbital is unoccupied. The ionization potential and electron affinity are closely related to the electronic configurations; their values are determined by the subgroups the HOMO or LUMO belong to. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjd/e2017-80042-9

Revisiting Hansen Solubility Parameters by Including Thermodynamics

NARCIS (Netherlands)

Louwerse, Manuel J; Fernández-Maldonado, Ana María; Rousseau, Simon; Moreau-Masselon, Chloe; Roux, Bernard; Rothenberg, Gadi

2017-01-01

The Hansen solubility parameter approach is revisited by implementing the thermodynamics of dissolution and mixing. Hansen's pragmatic approach has earned its spurs in predicting solvents for polymer solutions, but for molecular solutes improvements are needed. By going into the details of entropy

Temperature effects on vaccine induced immunity to viruses in fish

DEFF Research Database (Denmark)

Lorenzen, Niels; Lorenzen, Ellen; Rasmussen, Jesper Skou

a problem in terms of inducing a protective immune response by vaccination in aquaculture, since it is often desirable to vaccinate fish during autumn, winter, or spring. In experimental vaccination trials with rainbow trout (Oncorhynchus mykiss) using a DNA-vaccine encoding the viral glycoprotein of viral...... haemorrhagic septicaemia virus (VHSV), non-specific as well as specific immune mechanisms seemed to be delayed at low temperature. At five weeks post vaccination fish kept at 5C had no detectable response of neutralising antibodies while two thirds of the fish kept at 15C had sero-converted. While protective...... immunity was still established at both temperatures, specificity analysis suggested that protection at the lower temperature was mainly due to non-specific innate antiviral mechanisms, which appeared to last longer at low temperature. This was presumably related to a prolonged persistence of the vaccine...

Objective mapping of temperature field by stochastic inverse method using acoustic tomography experimental data of eastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Murty, T.V.R.; Rao, M.M.M.; Sadhuram, Y.

. The data are revisited for objective mapping of the temperature fields using Stochastic Inverse Method. Hourly reciprocal transmissions were carried with time lag of 30 minutes between each direction. From the multipath arrival patterns, significant peaks...

Bottomonium spectrum revisited

CERN Document Server

Segovia, Jorge; Entem, David R.; Fernández, Francisco

2016-01-01

We revisit the bottomonium spectrum motivated by the recently exciting experimental progress in the observation of new bottomonium states, both conventional and unconventional. Our framework is a nonrelativistic constituent quark model which has been applied to a wide range of hadronic observables from the light to the heavy quark sector and thus the model parameters are completely constrained. Beyond the spectrum, we provide a large number of electromagnetic, strong and hadronic decays in order to discuss the quark content of the bottomonium states and give more insights about the better way to determine their properties experimentally.

Valence band electronic structure of Ho-doped La0.67Ca0.33MnO3 using ultra-violet photoemission spectroscopy

Science.gov (United States)

Rout, S. K.; Mukharjee, R. N.; Mishra, D. K.; Roul, B. K.; Sekhar, B. R.; Dalai, M. K.

2017-05-01

In this manuscript we report the valence band electronic structure of Ho doped La0.67Ca0.33MnO3 using ultraviolet photoemission spectroscopy. We compared the density of states of La0.67Ca0.33MnO3, La0.67Ca0.3Ho0.03MnO3 and La0.64Ho0.03Ca0.33MnO3 near the Fermi level at various temperatures. Significant amount of changes have been observed at higher temperatures (220 K and 300 K) where the near Fermi level density of states increases with Ho doping into La0.67Ca0.33MnO3 indicating the enhancement of magnitude of change in metallicity (conductivity).

Temperature distribution induced by electron beam in a closed cavity

International Nuclear Information System (INIS)

Molhem, A.G.; Soulayman, S.Sh.

2004-01-01

In order to investigate heat transfer phenomena induced by EB in a closed cavity an experimental arrangement, which allows generating and focusing an electron beam in to closed cavity within 1 mm in diameter and measuring temperature all over any perpendicular section to the EB, is used for this purpose. Experimental data show that the radial distribution of current density and temperature is normal with pressure and location dependent parameters. Moreover, there is two distinguishable regions in the EB: one is central while the other surrounds the first one. (orig.)

Valence mixing in YbCuAl: a case study

International Nuclear Information System (INIS)

Mattens, W.

1980-01-01

Results are presented of a study of the valence state of Yb in the intermetallic compound YbCuAl. Both macroscopic physical properties (magnetic susceptibility, heat capacity, thermal expansion, electric resistivity) and microscopic physical properties (neutron inelastic scattering, nuclear magnetic resonance) are determined. The results are compared with a local Fermi liquid theory. (G.T.H.)

Facial and semantic emotional interference: A pilot study on the behavioral and cortical responses to the dual valence association task

Directory of Open Access Journals (Sweden)

Petroni Agustín

2011-04-01

Full Text Available Abstract Background Integration of compatible or incompatible emotional valence and semantic information is an essential aspect of complex social interactions. A modified version of the Implicit Association Test (IAT called Dual Valence Association Task (DVAT was designed in order to measure conflict resolution processing from compatibility/incompatibly of semantic and facial valence. The DVAT involves two emotional valence evaluative tasks which elicits two forms of emotional compatible/incompatible associations (facial and semantic. Methods Behavioural measures and Event Related Potentials were recorded while participants performed the DVAT. Results Behavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT. Conclusions Results suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli.

Hospital revisit rate after a diagnosis of conversion disorder.

Science.gov (United States)

Merkler, Alexander E; Parikh, Neal S; Chaudhry, Simriti; Chait, Alanna; Allen, Nicole C; Navi, Babak B; Kamel, Hooman

2016-04-01

To estimate the hospital revisit rate of patients diagnosed with conversion disorder (CD). Using administrative data, we identified all patients discharged from California, Florida and New York emergency departments (EDs) and acute care hospitals between 2005 and 2011 with a primary discharge diagnosis of CD. Patients discharged with a primary diagnosis of seizure or transient global amnesia (TGA) served as control groups. Our primary outcome was the rate of repeat ED visits and hospital admissions after initial presentation. Poisson regression was used to compare rates between diagnosis groups while adjusting for demographic characteristics. We identified 7946 patients discharged with a primary diagnosis of CD. During a mean follow-up of 3.0 (±1.6) years, patients with CD had a median of three (IQR, 1-9) ED or inpatient revisits, compared with 0 (IQR, 0-2) in patients with TGA and 3 (IQR, 1-7) in those with seizures. Revisit rates were 18.25 (95% CI, 18.10 to 18.40) visits per 100 patients per month in those with CD, 3.90 (95% CI, 3.84 to 3.95) in those with TGA and 17.78 (95% CI, 17.75 to 17.81) in those with seizures. As compared to CD, the incidence rate ratio for repeat ED visits or hospitalisations was 0.89 (95% CI, 0.86 to 0.93) for seizure disorder and 0.32 (95% CI 0.31 to 0.34) for TGA. CD is associated with a substantial hospital revisit rate. Our findings suggest that CD is not an acute, time-limited response to stress, but rather that CD is a manifestation of a broader pattern of chronic neuropsychiatric disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Brillouin-Wigner theory of mixed-valence impurities in BCS superconductor: Tc/TcO and ΔC/ΔCO

International Nuclear Information System (INIS)

Li Jun; Gong Changde.

1986-08-01

The (lowest order) Brillouin-Wigner perturbational expansion theory is adopted to describe the mixed-valence impurities in the BCS superconductor. Two substantial quantities characterizing the superconducting state, i.e. the reduced transition temperature T c /T cO and the reduced specific heat jump ΔC/ΔC O are calculated numerically as a function of the impurity concentration x and the energy level difference E f between two 4f configurations. A comparison with the experimental data of the Th 1-x Ce x and Th 1-x U x alloy is also included with a more reasonable fitting than Kaiser's theory. (author)

Titanium, vanadium and chromium valences in silicates of ungrouped achondrite NWA 7325 and ureilite Y-791538 record highly-reduced origins

Science.gov (United States)

Sutton, S. R.; Goodrich, C. A.; Wirick, S.

2017-05-01

Titanium, Cr, and V valences were determined by applying micro-X-ray Absorption Near Edge Structure (micro-XANES) spectroscopy methods to individual grains of olivine and pyroxene in the ungrouped achondrite NWA 7325 and ureilite Y-791538, as well as to plagioclase in NWA 7325. The advantages of applying multiple, multivalent-element-based oxybarometers to individual grains are (1) the ability to cover the entire oxygen fugacity (fO2) range encountered in nature, and (2) the increased reliability from consistent results for semi-independent fO2 proxies. fO2 values were inferred from each mineral valence determination after correcting with available laboratory-experiment-derived, valence-specific partition coefficients to obtain melt valences and then calibrating with the fO2 values of the relevant equal species proportions points suggested for igneous (primarily basaltic) systems. The resulting olivine and pyroxene valences are highly reduced and similar in the two meteorites with substantial fractions of Cr2+, Ti3+ and V2+. The exception is Cr in NWA 7325 pyroxene which is much more oxidized than the Cr in its olivine. Chromium and Ti in plagioclase in NWA 7325 is relatively oxidized (V valence not determined). The anomalously oxidized Cr in NWA 7325 pyroxene may be due to a secondary reheating event that oxidized Cr in the pyroxene without similarly oxidizing Ti and V. Such a separation of the redox couples may be an effect of re-equilibration kinetics, where the valence of Cr would be more rapidly modified. These valences yielded similar mean fO2s for the two meteorites; IW-3.1 ± 0.2 for NWA 7325 and IW-2.8 ± 0.2 for Y-791538, consistent with an origin of NWA 7325 in either Mercury or an asteroid that experienced redox conditions similar to those on the ureilite parent body.

Zinc Vacancy-Induced Room-Temperature Ferromagnetism in Undoped ZnO Thin Films

Directory of Open Access Journals (Sweden)

Hongtao Ren

2012-01-01

Full Text Available Undoped ZnO thin films are prepared by polymer-assisted deposition (PAD and treated by postannealing at different temperatures in oxygen or forming gases (95%  Ar+5% H2. All the samples exhibit ferromagnetism at room temperature (RT. SQUID and positron annihilation measurements show that post-annealing treatments greatly enhance the magnetizations in undoped ZnO samples, and there is a positive correlation between the magnetization and zinc vacancies in the ZnO thin films. XPS measurements indicate that annealing also induces oxygen vacancies that have no direct relationship with ferromagnetism. Further analysis of the results suggests that the ferromagnetism in undoped ZnO is induced by Zn vacancies.

Running spectral index from large-field inflation with modulations revisited

Energy Technology Data Exchange (ETDEWEB)

Czerny, Michael, E-mail: mczerny@tuhep.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Kobayashi, Takeshi, E-mail: takeshi@cita.utoronto.ca [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 3H8 (Canada); Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Takahashi, Fuminobu, E-mail: fumi@tuhep.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo, Kashiwa 277-8583 (Japan)

2014-07-30

We revisit large field inflation models with modulations in light of the recent discovery of the primordial B-mode polarization by the BICEP2 experiment, which, when combined with the Planck+WP+highL data, gives a strong hint for additional suppression of the CMB temperature fluctuations at small scales. Such a suppression can be explained by a running spectral index. In fact, it was pointed out by two of the present authors (TK and FT) that the existence of both tensor mode perturbations and a sizable running of the spectral index is a natural outcome of large inflation models with modulations such as axion monodromy inflation. We find that this holds also in the recently proposed multi-natural inflation, in which the inflaton potential consists of multiple sinusoidal functions and therefore the modulations are a built-in feature.

The Future of Engineering Education--Revisited

Science.gov (United States)

Wankat, Phillip C.; Bullard, Lisa G.

2016-01-01

This paper revisits the landmark CEE series, "The Future of Engineering Education," published in 2000 (available free in the CEE archives on the internet) to examine the predictions made in the original paper as well as the tools and approaches documented. Most of the advice offered in the original series remains current. Despite new…

Resonating-valence-bond superconductors with fermionic projected entangled pair states

NARCIS (Netherlands)

Poilblanc, D.; Corboz, P.; Schuch, N.; Cirac, J.I.

2014-01-01

We construct a family of simple fermionic projected entangled pair states (fPEPS) on the square lattice with bond dimension D=3 which are exactly hole-doped resonating valence bond (RVB) wave functions with short-range singlet bonds. Under doping the insulating RVB spin liquid evolves immediately

Temperature sensitivity of the penicillin-induced autolysis mechanism in nongrowing cultures of Escherichia coli.

OpenAIRE

Kusser, W; Ishiguro, E E

1987-01-01

The effect of incubation temperature on the ampicillin-induced autolysis of nongrowing Escherichia coli was determined. The autolysis mechanisms in amino acid-deprived relA mutant cells treated with chloramphenicol were temperature sensitive. This temperature-sensitive autolysis was demonstrated in three independent ways: turbidimetric determinations, viable cell counts, and solubilization of radiolabeled peptidoglycan.

Electron momentum distributions and binding energies for the valence orbitals of hydrogen bromide and hydrogen iodide

International Nuclear Information System (INIS)

Brion, C.E.; McCarthy, I.E.; Suzuki, I.H.; Weigold, E.; Williams, G.R.J.; Bedford, K.L.; Kunz, A.B.; Weidman, R.

1981-12-01

The electron binding energy spectra and momentum distributions have been obtained for the valence orbitals of HBr and HI using noncoplanar symmetric electron coincidence spectroscopy at 1200eV. The weakly bonding inner valence ns orbitals, which have not been previously observed, have their spectroscopic (pole) strength severely split among a number of ion states. For HBr the strength of the main inner valence (ns) transition is 0.42 0.03 whereas for HI it is 0.37 0.04, in close agreement with that observed for the valence s orbitals of the corresponding isoelectronic inert gas atoms. The spectroscopic strength for the two outermost orbitals is found to be close to unity, in agreement with many body Green's function calculations. The measured momentum distributions are compared with several spherically averaged MO momentum distributions, as well as (for HBr) with a Green's function calculation of the generalized overlap amplitude (GOA). The GOA momentum distributions are in excellent agreement with the HBr data, both in shape and relative magnitude. Not all of the MO momentum distributions are in reasonable agreement with the data. Comparison is also made with the calculated momentum distributions for Kr, Br, Xe and I

Involvement of prostaglandins and histamine in radiation-induced temperature responses in rats

International Nuclear Information System (INIS)

Kandasamy, S.B.; Hunt, W.A.

1990-01-01

Exposure of rats to 1-15 Gy of gamma radiation induced hyperthermia, whereas exposure to 20-150 Gy produced hypothermia. Since radiation exposure induced the release of prostaglandins (PGs) and histamine, the role of PGs and histamine in radiation-induced temperature changes was examined. Radiation-induced hyper- and hypothermia were antagonized by pretreatment with indomethacin, a cyclooxygenase inhibitor. Intracerebroventricular administration of PGE2 and PGD2 induced hyper- and hypothermia, respectively. Administration of SC-19220, a specific PGE2 antagonist, attenuated PGE2- and radiation-induced hyperthermia, but it did not antagonize PGD2- or radiation-induced hypothermia. Consistent with an apparent role of histamine in hypothermia, administration of disodium cromoglycate (a mast cell stabilizer), mepyramine (H1-receptor antagonist), or cimetidine (H2-receptor antagonist) attenuated PGD2- and radiation-induced hypothermia. These results suggest that radiation-induced hyperthermia is mediated via PGE2 and that radiation-induced hypothermia is mediated by another PG, possibly PGD2, via histamine

Transient dynamics of a quantum-dot: From Kondo regime to mixed valence and to empty orbital regimes

Science.gov (United States)

Cheng, YongXi; Li, ZhenHua; Wei, JianHua; Nie, YiHang; Yan, YiJing

2018-04-01

Based on the hierarchical equations of motion approach, we study the time-dependent transport properties of a strongly correlated quantum dot system in the Kondo regime (KR), mixed valence regime (MVR), and empty orbital regime (EOR). We find that the transient current in KR shows the strongest nonlinear response and the most distinct oscillation behaviors. Both behaviors become weaker in MVR and diminish in EOR. To understand the physical insight, we examine also the corresponding dot occupancies and the spectral functions, with their dependence on the Coulomb interaction, temperature, and applied step bias voltage. The above nonlinear and oscillation behaviors could be understood as the interplay between dynamical Kondo resonance and single electron resonant-tunneling.

Magneto-optical studies of valence instability in europium and terbium phosphors

Czech Academy of Sciences Publication Activity Database

Rodrigues, L.C.v.; Hölsä, J.; Brito, H.F.; Maryško, Miroslav; Matos, J.R.; Paturi, P.; Rodrigues, R.V.; Lastusaari, M.

2016-01-01

Roč. 170, Feb (2016), 701-706 ISSN 0022-2313 Institutional support: RVO:68378271 Keywords : valence * europium * terbium * oxysulfide and -sulfate * phosphors * paramagnetic susceptibility Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.686, year: 2016

Modal analysis of temperature feedback in oscillations induced by xenon

International Nuclear Information System (INIS)

Passos, E.M. dos.

1976-01-01

The flux oscillations induced by Xenon distribution in homogeneous thermal reactors are studied treating the space dependence through the modal expansion technique and the stability limits against power oscillations and spatial oscillations are determined. The effect of the feedbacks due to Xenon and temperature coefficient on the linear stability of the free system is investigated employing several number of terms in the transient expansion, considering the various sizes of the reactor. The heat transfer model considered includes one term due to cooling proportional to the temperature. A PWR model reactor is utilized for numerical calculations. It is found that a slightly higher temperature feedback coefficient is necessary for stability against power oscillations when larger number of terms in the transient modal expansion is maintained. (author)

Accounting for many-body correlation effects in the calculation of the valence band photoelectron emission spectra of ferromagnets

International Nuclear Information System (INIS)

Minar, J.; Chadov, S.; Ebert, H.; Chioncel, L.; Lichtenstein, A.; De Nadai, C.; Brookes, N.B.

2005-01-01

The influence of dynamical correlation effects on the valence band photoelectron emission of ferromagnetic Fe, Co and Ni has been investigated. Angle-resolved as well as angle-integrated valence band photoelectron emission spectra were calculated on the basis of the one-particle Green's function, which was obtained by using the fully relativistic Korringa-Kohn-Rostoker method. The correlation effects have been included in terms of the electronic self-energy which was calculated self-consistently within Dynamical Mean-Field Theory (DMFT). In addition a theoretical approach to calculate high-energy angle-resolved valence band photoelectron emission spectra is presented

Magnetic islands in tokamaks induced by thermal filamentation

International Nuclear Information System (INIS)

Dubois, M.A.; Mohamed-Benkadda, M.S.

1991-11-01

The thermal instability of filamentation is revisited in the fully nonlinear regime of a system of cool magnetic island chains, taking into account: the different transport processes inside and outside island cores, and a realistic temperature dependence of radiative losses. This mechanism is found to be a plausible candidate to explain the anomalous electron energy transport

Is Accessing of Words Affected by Affective Valence Only? A Discrete Emotion View on the Emotional Congruency Effect.

Science.gov (United States)

Chen, Xuqian; Liu, Bo; Lin, Shouwen

2016-01-01

This paper advances the discussion on which emotion information affects word accessing. Emotion information, which is formed as a result of repeated experiences, is primary and necessary in learning and representing word meanings. Previous findings suggested that valence (i.e., positive or negative) denoted by words can be automatically activated and plays a role in many significant cognitive processes. However, there has been a lack of discussion about whether discrete emotion information (i.e., happiness, anger, sadness, and fear) is also involved in these processes. According to the hierarchy model, emotions are considered organized within an abstract-to-concrete hierarchy, in which emotion prototypes are organized following affective valence. By controlling different congruencies of emotion relations (i.e., matches or mismatches between valences and prototypes of emotion), the present study showed both an evaluative congruency effect (Experiment 1) and a discrete emotional congruency effect (Experiment 2). These findings indicate that not only affective valences but also discrete emotions can be activated under the present priming lexical decision task. However, the present findings also suggest that discrete emotions might be activated at the later priming stage as compared to valences. The present work provides evidence that information about discrete emotion could be involved in word processing. This might be a result of subjects' embodied experiences.

Studies on the valence electronic structure of Fe and Ni in FexNi1−x ...

Indian Academy of Sciences (India)

structure of Fe and Ni in various Fex Ni1−x alloys. Since Kβ-to-Kα X-ray intensity ratio has been reported [2–7] to be a sensitive physical parameter to investigate the changes in the valence electronic structure of 3d-transition metals [2], we have undertaken the study of the valence electronic structure of Fe and Ni in the Fex ...

Temperature-induced changes in lecithin model membranes detected by novel covalent spin-labelled phospholipids.

Science.gov (United States)

Stuhne-Sekalec, L; Stanacev, N Z

1977-02-01

Several spin-labelled phospholipids carrying covalently bound 5-doxylstearic acid (2-(3-carboxydecyl)-2-hexyl-4,4-dimethyl-3-oxazolidinoxyl) were intercalated in liposomes of saturated and unsaturated lecithins. Temperature-induced changes of these liposomes, detected by the spin-labelled phospholipids, were found to be in agreement with the previously described transitions of hydrocarbon chains of host lecithins detected by different probes and different techniques, establishing that spin-labelled phosopholipids are sensitive probes for the detection of temperature-induced changes in lecithin model membranes. In addition to the detection of already-known transitions in lecithin liposomes, the coexistence of two distinctly different enviroments was observed above the characteristic transition temperature. This phenomenon was tentatively attributed to the influence of the lecithin polar group on the fluidity of fatty acyl chains near the polar group. Combined with other results from the literature, the coexistence of two environments could be associated with the coexistence of two conformational isomers of lecithin, differing in the orientation of the polar head group with respect to the plane of bilayer. These findings have been discussed in view of the present state of knowledge regarding temperature-induced changes in model membranes.

Kalman filtered MR temperature imaging for laser induced thermal therapies.

Science.gov (United States)

Fuentes, D; Yung, J; Hazle, J D; Weinberg, J S; Stafford, R J

2012-04-01

The feasibility of using a stochastic form of Pennes bioheat model within a 3-D finite element based Kalman filter (KF) algorithm is critically evaluated for the ability to provide temperature field estimates in the event of magnetic resonance temperature imaging (MRTI) data loss during laser induced thermal therapy (LITT). The ability to recover missing MRTI data was analyzed by systematically removing spatiotemporal information from a clinical MR-guided LITT procedure in human brain and comparing predictions in these regions to the original measurements. Performance was quantitatively evaluated in terms of a dimensionless L(2) (RMS) norm of the temperature error weighted by acquisition uncertainty. During periods of no data corruption, observed error histories demonstrate that the Kalman algorithm does not alter the high quality temperature measurement provided by MR thermal imaging. The KF-MRTI implementation considered is seen to predict the bioheat transfer with RMS error 10 sec.

Positive words or negative words: whose valence strength are we more sensitive to?

Science.gov (United States)

Yang, Jiemin; Zeng, Jing; Meng, Xianxin; Zhu, Liping; Yuan, Jiajin; Li, Hong; Yusoff, Nasir

2013-10-02

The present study investigates the human brains' sensitivity to the valence strength of emotionally positive and negative chinese words. Event-Related Potentials were recorded, in two different experimental sessions, for Highly Positive (HP), Mildly Positive (MP) and neutral (NP) words and for Highly Negative (HN), Mildly Negative (MN) and neutral (NN) words, while subjects were required to count the number of words, irrespective of word meanings. The results showed a significant emotion effect in brain potentials for both HP and MP words, and the emotion effect occurred faster for HP words than MP words: HP words elicited more negative deflections than NP words in N2 (250-350 ms) and P3 (350-500 ms) amplitudes, while MP words elicited a significant emotion effect in P3, but not in N2, amplitudes. By contrast, HN words elicited larger amplitudes than NN words in N2 but not in P3 amplitudes, whereas MN words produced no significant emotion effect across N2 and P3 components. Moreover, the size of emotion-neutral differences in P3 amplitudes was significantly larger for MP compared to MN words. Thus, the human brain is reactive to both highly and mildly positive words, and this reactivity increased with the positive valence strength of the words. Conversely, the brain is less reactive to the valence of negative relative to positive words. These results suggest that human brains are equipped with increased sensitivity to the valence strength of positive compared to negative words, a type of emotional stimuli that are well known for reduced arousal. © 2013 Elsevier B.V. All rights reserved.

Valence interacts with the early ERP old/new effect and arousal with the sustained ERP old/new effect for affective pictures.

Science.gov (United States)

Van Strien, Jan W; Langeslag, Sandra J E; Strekalova, Nadja J; Gootjes, Liselotte; Franken, Ingmar H A

2009-01-28

To examine whether valence and arousal influence recognition memory during early automatic or during more sustained processes, event-related brain potentials (ERPs) of 21 women were recorded while they made old/new judgments in a continuous recognition task with pictures from the International Affective Picture System. The pictures were presented twice and differed in emotional valence and arousal. The P1 peak and four time windows were investigated: 200-300 ms, 300-400 ms, 400-600 ms, and 750-1000 ms after stimulus onset. There was a robust old/new effect starting in the 200-300 ms epoch and lasting all time windows. The valence effect was mainly present in the P1 peak and the 200-400 ms epoch, whereas the arousal effect was found in the 300-1000 ms epoch. Exploratory sLORETA analyses dissociated valence-dependent ventromedial prefrontal activity and arousal-dependent occipital activity in the 350-380 ms time window. Valence interacted with the 200-400 ms old/new effect at central and frontal sites. Arousal interacted with the 750-1000 ms old/new effect at posterior sites. It is concluded that valence influences fast recognition memory, while arousal may influence sustained encoding.

A study of the valence shell photoelectron and photoabsorption spectra of CF3SF5

International Nuclear Information System (INIS)

Holland, D M P; Shaw, D A; Walker, I C; McEwen, I J; Apra, E; Guest, M F

2005-01-01

The outer valence shell photoelectron spectrum of CF 3 SF 5 has been studied experimentally and theoretically. Synchrotron radiation has been used to record angle-resolved outer valence shell photoelectron spectra of CF 3 SF 5 in the photon energy range 18-60 eV. These spectra have allowed photoelectron asymmetry parameters and branching ratios to be derived. The Outer Valence Green's Function approach has been employed to calculate the molecular orbital configuration and associated binding energies. A charge distribution analysis has also been obtained. Assignments have been proposed for the peaks observed in the photoelectron spectrum. The absolute photoabsorption cross section of CF 3 SF 5 has been measured from threshold to 40 eV, and strongly resembles that of SF 6 . Assignments, involving intravalence transitions, have been proposed for some of the principal features appearing in the photoabsorption spectrum of CF 3 SF 5

Emotional Valence and Arousal Effects on Memory and Hemispheric Asymmetries

Science.gov (United States)

Mneimne, Malek; Powers, Alice S.; Walton, Kate E.; Kosson, David S.; Fonda, Samantha; Simonetti, Jessica

2010-01-01

This study examined predictions based upon the right hemisphere (RH) model, the valence-arousal model, and a recently proposed integrated model (Killgore & Yurgelun-Todd, 2007) of emotion processing by testing immediate recall and recognition memory for positive, negative, and neutral verbal stimuli among 35 right-handed women. Building upon…

Stabilization of neptunium valence states in nitric media for spent nuclear fuel reprocessing

International Nuclear Information System (INIS)

Feldhaus, P.

1996-12-01

A possibility of standarizing the extraction-behavior of Neptunium during the reprocessing of spent nuclear fuel corresponding to PUREX-Process was investigated. The aim of the work was a qualitative dirigation of the Transuraniumelement (TRUE) into the raffinat of the first extraction cycle by a complete redoxconversion of the Neptunium valence states to unextractable Np(V). In the beginning the theoretical and experimental research focussed on the redoxchemistry of the actinide during the fuel dissolution and the feed preparation. Thereby the nitrous acid, which is produced by a radiological, photochemical and reductive degradation of the nitric acid, revealed an ambivalent influence on the Neptunium valences. By a short-term increase in HNO 2 -concentration the Np(V)-fraction could be obviously risen. The use of some stabilizing reagents inhibited a later reoxidation to Np(VI) also catalyzed by nitrous acid. The urea used for this purpose also led to a further increase in the obtained conversion rates due to a Np(VI)-reduction. The analysis of the valence distribution was performed by an extraction method. This had been compared to chromatographic separation in some preliminary investigations and had turned out to be comparably reliable and easily manageable. (orig.) [de

Valence electron structure and properties of the ZrO2

Institute of Scientific and Technical Information of China (English)

2008-01-01

To reveal the properties of ZrO2 at the atom and electron levels, the valence elec- tron structures of three ZrO2 phases were analyzed on the basis of the empirical electron theory of solids and molecules. The results showed that the hybridization levels of Zr and O atoms in the m-ZrO2 were the same as those in the t-ZrO2, while those in the c-ZrO2 rose markedly. The electron numbers and bond energies on the strongest covalent bonds in the m-ZrO2 phase were the greatest, the values were 0.901106 and 157.5933 kJ/mol, respectively. Those in the t-ZrO2 phase took second place, which were 0.722182 and 123.9304 kJ/mol, and those in the c-ZrO2 phase were the smallest, which were 0.469323 and 79.0289 kJ/mol. According to the product of the bond energy on the strongest covalent bond and equivalent bond number (this value reflected the crystal cohesive energy), the order from the greatness to smallness was the c-ZrO2> t-ZrO2 > m-ZrO2. This showed that the m-phase bonds were the tightest, their energy was the smallest, the crystal cohe- sive energy of the m-phase was the largest, and the m-phase existed most stably at room temperature. So it must need energy or higher temperature to take apart the stronger covalent bonds to form a new phase.

Valence electron structure and properties of the ZrO2

Institute of Scientific and Technical Information of China (English)

LI JinPing; MENG SongHe; HAN JieCai; ZHANG XingHong

2008-01-01

To reveal the properties of ZrO2 at the atom and electron levels, the valence elec-tron structures of three ZrO2 phases were analyzed on the basis of the empirical electron theory of solids and molecules. The results showed that the hybridization levels of Zr and O atoms in the m-ZrO2 were the same as those in the t-ZrO2, while those in the c-ZrO2 rose markedly. The electron numbers and bond energies on the strongest covalent bonds in the m-ZrO2 phase were the greatest, the values were 0.901106 and 157.5933 kJ/mol, respectively. Those in the t-ZrO2 phase took second place, which were 0.722182 and 123.9304 kJ/mol, and those in the c-ZrO2 phase were the smallest, which were 0.469323 and 79.0289 kJ/mol. According to the product of the bond energy on the strongest covalent bond and equivalent bond number (this value reflected the crystal cohesive energy), the order from the greatness to smallness was the c-ZrO2 t-ZrO2 m-ZrO2. This showed that the m-phase bonds were the tightest, their energy was the smallest, the crystal cohe-sive energy of the m-phase was the largest, and the m-phase existed most stably at room temperature. So it must need energy or higher temperature to take apart the stronger covalent bonds to form a new phase.

Revisiting Weak Simulation for Substochastic Markov Chains

DEFF Research Database (Denmark)

Jansen, David N.; Song, Lei; Zhang, Lijun

2013-01-01

of the logic PCTL\\x, and its completeness was conjectured. We revisit this result and show that soundness does not hold in general, but only for Markov chains without divergence. It is refuted for some systems with substochastic distributions. Moreover, we provide a counterexample to completeness...

Effects of Nb and Si on densities of valence electrons in bulk and defects of Fe3Al alloys

Institute of Scientific and Technical Information of China (English)

邓文; 钟夏平; 黄宇阳; 熊良钺; 王淑荷; 郭建亭; 龙期威

1999-01-01

Positron lifetime measurements have been performed in binary Fe3Al and Fe3Al doping with Nb or Si alloys. The densities of valence electrons of the bulk and microdefects in all tested samples have been calculated by using the positron lifetime parameters. Density of valence electron is low in the bulk of Fe3Al alloy. It indicates that, the 3d electrons in a Fe atom have strong-localized properties and tend to form covalent bonds with Al atoms, and the bonding nature in Fe3Al is a mixture of metallic and covalent bonds. The density of valence electron is very low in the defects of Fe3Al grain boundary, which makes the bonding cohesion in grain boundary quite weak. The addition of Si to Fe3Al gives rise to the decrease of the densities of valence electrons in the bulk and the grain boundary thus the metallic bonding cohesion. This makes the alloy more brittle. The addition of Nb to Fe3Al results in the decrease of the ordering energy of the alloy and increases the density of valence electron and th

Re-examining the automaticity and directionality of the activation of the spatial-valence "good is up" metaphoric association.

Directory of Open Access Journals (Sweden)

Yanli Huang

Full Text Available According to the Conceptual Metaphor Theory, people understand abstract concepts depending on the activation of more concrete concepts, but not vice versa. The present research aims to investigate the role of directionality and automaticity regarding the activation of the conceptual metaphor "good is up". Experiment 1 tested the automaticity of the spatial-to-valence metaphoric congruency effect by having participants judge the valence of a positive or negative word that appeared either at the top or at the bottom of the screen. They performed the task concurrently with a 6-digit verbal rehearsal task in the working-memory-load (WML blocks and without this task in the non-WML blocks. The spatial-to-valence metaphoric congruency effect occurred for the positive words in the non-WML blocks (i.e., positive words are judged more quickly when they appeared at the top than at the bottom of the screen, but not in the WML blocks, suggesting that this metaphoric association might not be activated automatically. Experiments 2-6 investigated the valence-to-spatial metaphoric association and its automaticity. Participants processed a positive or negative prime, which appeared at the center of the screen, and then identified a letter (p/q that subsequently appeared at the top or bottom of the screen. The valence-to-spatial metaphoric congruency effect did not occur in the WML (6-digit verbal rehearsal or non-WML blocks, whether response modality to the prime was key-press or vocal, or whether the prime was a word or a picture. The effect only unexpectedly occurred when the task was simultaneously performed with a 4-dot-position visuospatial rehearsal task. Nevertheless, the data collapsed across multiple experiments showed a null valence-to-spatial metaphoric congruency effect, suggesting the absence of the valence-to-spatial metaphoric association in general. The implications of the current findings for the Conceptual Metaphor Theory and its alternatives

Manifesto for the current understanding and management of traumatic brain injury-induced hypopituitarism.

LENUS (Irish Health Repository)

Tanriverdi, F

2011-01-01

Traumatic brain injury (TBI)-induced hypopituitarism remains a relevant medical problem, because it may affect a significant proportion of the population. In the last decade important studies have been published investigating pituitary dysfunction after TBI. Recently, a group of experts gathered and revisited the topic of TBI-induced hypopituitarism. During the 2-day meeting, the main issues of this topic were presented and discussed, and current understanding and management of TBI-induced hypopituitarism are summarized here.

Manifesto for the current understanding and management of traumatic brain injury-induced hypopituitarism

DEFF Research Database (Denmark)

Tanriverdi, F; Agha, A; Aimaretti, G

2011-01-01

Traumatic brain injury (TBI)-induced hypopituitarism remains a relevant medical problem, because it may affect a significant proportion of the population. In the last decade important studies have been published investigating pituitary dysfunction after TBI. Recently, a group of experts gathered...... and revisited the topic of TBI-induced hypopituitarism. During the 2-day meeting, the main issues of this topic were presented and discussed, and current understanding and management of TBI-induced hypopituitarism are summarized here....

Profound and Rapid Reduction in Body Temperature Induced by the Melanocortin Receptor Agonists

Science.gov (United States)

Xu, Yuanzhong; Kim, Eun Ran; Fan, Shengjie; Xia, Yan; Xu, Yong; Huang, Cheng; Tong, Qingchun

2014-01-01

The melanocortin receptor 4 (MC4R) plays a major role in body weight regulation and its agonist MTII has been widely used to study the role of MC4Rs in energy expenditure promotion and feeding reduction. Unexpectedly, we observed that intraperitoneal (i.p.) administration of MTII induced a rapid reduction in both body temperature and energy expenditure, which was independent of its effect on feeding and followed by a prolonged increase in energy expenditure. The rapid reduction was at least partly mediated by brain neurons since intracerebroventricular (icv) administration of alpha melanocyte-stimulating hormone, an endogenous melanocortin receptor agonist, produced a similar response. In addition, the body temperature-lowering effect of MTII was independent of the presence of MC4Rs, but in a similar fashion to the previously shown effect on body temperature by 5′AMP. Moreover, β-adrenergic receptors (β-ARs) were required for the recovery from low body temperature induced by MTII and further pharmacological studies showed that the MTII’s effect on body temperature may be partially mediated by the vasopressin V1a receptors. Collectively, our results reveal a previously unappreciated role for the melanocortin pathway in rapidly lowering body temperature. PMID:25065745

Profound and rapid reduction in body temperature induced by the melanocortin receptor agonists.

Science.gov (United States)

Xu, Yuanzhong; Kim, Eun Ran; Fan, Shengjie; Xia, Yan; Xu, Yong; Huang, Cheng; Tong, Qingchun

2014-08-22

The melanocortin receptor 4 (MC4R) plays a major role in body weight regulation and its agonist MTII has been widely used to study the role of MC4Rs in energy expenditure promotion and feeding reduction. Unexpectedly, we observed that intraperitoneal (i.p.) administration of MTII induced a rapid reduction in both body temperature and energy expenditure, which was independent of its effect on feeding and followed by a prolonged increase in energy expenditure. The rapid reduction was at least partly mediated by brain neurons since intracerebroventricular (icv) administration of alpha melanocyte-stimulating hormone, an endogenous melanocortin receptor agonist, produced a similar response. In addition, the body temperature-lowering effect of MTII was independent of the presence of MC4Rs, but in a similar fashion to the previously shown effect on body temperature by 5'AMP. Moreover, β-adrenergic receptors (β-ARs) were required for the recovery from low body temperature induced by MTII and further pharmacological studies showed that the MTII's effect on body temperature may be partially mediated by the vasopressin V1a receptors. Collectively, our results reveal a previously unappreciated role for the melanocortin pathway in rapidly lowering body temperature. Copyright © 2014 Elsevier Inc. All rights reserved.

Telemetry pill versus rectal and esophageal temperature during extreme rates of exercise-induced core temperature change

International Nuclear Information System (INIS)

Teunissen, L P J; Daanen, H A M; De Haan, A; De Koning, J J

2012-01-01

Core temperature measurement with an ingestible telemetry pill has been scarcely investigated during extreme rates of temperature change, induced by short high-intensity exercise in the heat. Therefore, nine participants performed a protocol of rest, (sub)maximal cycling and recovery at 30 °C. The pill temperature (T pill ) was compared with the rectal temperature (T re ) and esophageal temperature (T es ). T pill corresponded well to T re during the entire trial, but deviated considerably from T es during the exercise and recovery periods. During maximal exercise, the average ΔT pill −T re and ΔT pill −T es were 0.13 ± 0.26 and −0.57 ± 0.53 °C, respectively. The response time from the start of exercise, the rate of change during exercise and the peak temperature were similar for T pill and T re. T es responded 5 min earlier, increased more than twice as fast and its peak value was 0.42 ± 0.46 °C higher than T pill . In conclusion, also during considerable temperature changes at a very high rate, T pill is still a representative of T re . The extent of the deviation in the pattern and peak values between T pill and T es (up to >1 °C) strengthens the assumption that T pill is unsuited to evaluate central blood temperature when body temperatures change rapidly. (paper)

Revisiting the chemical reactivity indices as the state function derivatives. The role of classical chemical hardness

Energy Technology Data Exchange (ETDEWEB)

Malek, Ali; Balawender, Robert, E-mail: rbalawender@ichf.edu.pl [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw (Poland)

2015-02-07

The chemical reactivity indices as the equilibrium state-function derivatives are revisited. They are obtained in terms of the central moments (fluctuation formulas). To analyze the role of the chemical hardness introduced by Pearson [J. Am. Chem. Soc. 105, 7512 (1983)], the relations between the derivatives up to the third-order and the central moments are obtained. As shown, the chemical hardness and the chemical potential are really the principal indices of the chemical reactivity theory. It is clear from the results presented here that the chemical hardness is not the derivative of the Mulliken chemical potential (this means also not the second derivative of the energy at zero-temperature limit). The conventional quadratic dependence of energy, observed at finite temperature, reduces to linear dependence on the electron number at zero-temperature limit. The chemical hardness plays a double role in the admixture of ionic states to the reference neutral state energy: it determines the amplitude of the admixture and regulates the damping of its thermal factor.

Revisiting the chemical reactivity indices as the state function derivatives. The role of classical chemical hardness

International Nuclear Information System (INIS)

Malek, Ali; Balawender, Robert

2015-01-01

The chemical reactivity indices as the equilibrium state-function derivatives are revisited. They are obtained in terms of the central moments (fluctuation formulas). To analyze the role of the chemical hardness introduced by Pearson [J. Am. Chem. Soc. 105, 7512 (1983)], the relations between the derivatives up to the third-order and the central moments are obtained. As shown, the chemical hardness and the chemical potential are really the principal indices of the chemical reactivity theory. It is clear from the results presented here that the chemical hardness is not the derivative of the Mulliken chemical potential (this means also not the second derivative of the energy at zero-temperature limit). The conventional quadratic dependence of energy, observed at finite temperature, reduces to linear dependence on the electron number at zero-temperature limit. The chemical hardness plays a double role in the admixture of ionic states to the reference neutral state energy: it determines the amplitude of the admixture and regulates the damping of its thermal factor

Study of iron valence state and position in sub-site by Moessbauer spectroscopy

International Nuclear Information System (INIS)

Uhm, Young Rang; Lim, Jae Cheong; KIm, Chul Sung; Son, Kwang Jae

2014-01-01

The magnetic ordering temperature and the magnitude of the magnetic fields at the iron sites of YIG can be influenced by substituting, either partially or totally, the Fe 3+ ions at the octahedral and/or the tetrahedral sites with magnetic or diamagnetic ions, and/or by substitution the Y 3+ ions at the dodecahedral sites with magnetic rare earth ions. It has been known for some time that Moessbauer spectroscopy is a powerful method by which iron-containing garnets can be studied. We report here on the synthesis of the compounds with garnet-related structures of composition Y 3 Fe 4.5 Cr 0.5 O 12 and its examination by 57 Fe Moessbauer spectroscopy. The chromium in compounds of the Y 3 Fe 4.5 Cr 0.5 O 12 is distributed at an octahedral site. The Moessbauer spectra can be analyzed using 3 or 4 sets of six Lorentzians with increasing amount of Cr 3+ compounds in this system. It results from the distribution ( 4 C n ) of Fe 3+ and Cr 3+ at an octahedral site. A comparative study of ferrous tablets of Dynabi was carried out using Moessbauer spectroscopy. The obtained results revealed the presence of ferrous (Fe 2+ ) gluconate and ferrous fumarate in a sample. This observation is important to better control the iron state in such medicaments because their pharmaceutical effect in the body is related to the form and valence of iron. The Cr-containing yttrium iron garnet (YIG), and the exchange interactions and site distributions were studied using 57 Fe Moessbauer spectroscopy. The obtained results revealed the presence of ferrous (Fe 2+ ) gluconate and ferrous fumarate in the sample. This observation is important better control the iron state in such medicaments because their pharmaceutical effect in the body is related to the form and valence of iron

Temperature dependent energy levels of methylammonium lead iodide perovskite

Science.gov (United States)

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

2015-06-01

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

Revisiting the formal foundation of Probabilistic Databases

NARCIS (Netherlands)

Wanders, B.; van Keulen, Maurice

2015-01-01

One of the core problems in soft computing is dealing with uncertainty in data. In this paper, we revisit the formal foundation of a class of probabilistic databases with the purpose to (1) obtain data model independence, (2) separate metadata on uncertainty and probabilities from the raw data, (3)

Temperature Effect on Micelle Formation: Molecular Thermodynamic Model Revisited.

Science.gov (United States)

Khoshnood, Atefeh; Lukanov, Boris; Firoozabadi, Abbas

2016-03-08

Temperature affects the aggregation of macromolecules such as surfactants, polymers, and proteins in aqueous solutions. The effect on the critical micelle concentration (CMC) is often nonmonotonic. In this work, the effect of temperature on the micellization of ionic and nonionic surfactants in aqueous solutions is studied using a molecular thermodynamic model. Previous studies based on this technique have predicted monotonic behavior for ionic surfactants. Our investigation shows that the choice of tail transfer energy to describe the hydrophobic effect between the surfactant tails and the polar solvent molecules plays a key role in the predicted CMC. We modify the tail transfer energy by taking into account the effect of the surfactant head on the neighboring methylene group. The modification improves the description of the CMC and the predicted micellar size for aqueous solutions of sodium n-alkyl sulfate, dodecyl trimethylammonium bromide (DTAB), and n-alkyl polyoxyethylene. The new tail transfer energy describes the nonmonotonic behavior of CMC versus temperature. In the DTAB-water system, we redefine the head size by including the methylene group, next to the nitrogen, in the head. The change in the head size along with our modified tail transfer energy improves the CMC and aggregation size prediction significantly. Tail transfer is a dominant energy contribution in micellar and microemulsion systems. It also promotes the adsorption of surfactants at fluid-fluid interfaces and affects the formation of adsorbed layer at fluid-solid interfaces. Our proposed modifications have direct applications in the thermodynamic modeling of the effect of temperature on molecular aggregation, both in the bulk and at the interfaces.

Determination of valence band parameters in ZnTe

Energy Technology Data Exchange (ETDEWEB)

Froehlich, D.; Noethe, A.; Reimann, K. (Duesseldorf Univ. (Germany, F.R.). Physikalisches Inst. - Lehrstuhl 2)

1984-10-01

The fine structure of the 2P exciton in ZnTe is studied by two-photon-absorption. The energy splitting into four states, caused by the envelope-hole coupling, allows the determination of the Luttinger parameters ..gamma../sub 2/ and ..gamma../sub 3/, which describe the complex valence band. ..gamma../sub 2/ = 0.8 and ..gamma../sub 3/ = 1.7 are obtained. These values are compared to results of other experiments mainly on 1S excitons.

Revisiting Mutual Fund Performance Evaluation

OpenAIRE

Angelidis, Timotheos; Giamouridis, Daniel; Tessaromatis, Nikolaos

2012-01-01

Mutual fund manager excess performance should be measured relative to their self-reported benchmark rather than the return of a passive portfolio with the same risk characteristics. Ignoring the self-reported benchmark introduces biases in the measurement of stock selection and timing components of excess performance. We revisit baseline empirical evidence in mutual fund performance evaluation utilizing stock selection and timing measures that address these biases. We introduce a new factor e...

Coexistence of magnetic order and valence fluctuations in a heavy fermion system Ce{sub 2}Rh{sub 3}Sn{sub 5}

Energy Technology Data Exchange (ETDEWEB)

Gamza, Monika [Jeremiah Horrocks Institute, University of Central Lancashire, Preston (United Kingdom); MPI CPfS, Dresden (Germany); Institute of Physics, University of Silesia, Katowice (Poland); Gumeniuk, Roman [Institute of Experimental Physics, Freiberg University of Mining and Technology, Freiberg (Germany); MPI CPfS, Dresden (Germany); Schnelle, Walter; Burkhardt, Ulrich; Rosner, Helge [MPI CPfS, Dresden (Germany); Slebarski, Andrzej [Institute of Physics, University of Silesia, Katowice (Poland)

2016-07-01

While most Ce-based intermetallics contain either trivalent or intermediate-valent Ce ions, only for a few compounds a coexistence of both species has been reported. Here, we present a combined experimental and theoretical study based on thermodynamic measurements and spectroscopic data together with ab-initio electronic structure calculations aiming at exploring magnetic properties of Ce ions in two nonequivalent sites in Ce{sub 2}Rh{sub 3}Sn{sub 5}. Ce L{sub III} XAS spectra give direct evidence for valence fluctuations. Magnetization measurements show an onset of an antiferromagnetic order at T{sub N}∼2.5 K. The electronic structure calculations suggest that the magnetic ordering is related only to one Ce sublattice. This is in-line with a small entropy associated with the magnetic transition S{sub mag}∼0.35 R ln2 per Ce atom as revealed by the specific heat measurement. Furthermore, the temperature dependence of the magnetic susceptibility can be well described assuming that there are fluctuating moments of Ce{sup 3+} ions in one sublattice, whereas Ce atoms from the second sublattice are in a nonmagnetic intermediate valence state.

Embodied simulation as part of affective evaluation processes: task dependence of valence concordant EMG activity.

Science.gov (United States)

Weinreich, André; Funcke, Jakob Maria

2014-01-01

Drawing on recent findings, this study examines whether valence concordant electromyography (EMG) responses can be explained as an unconditional effect of mere stimulus processing or as somatosensory simulation driven by task-dependent processing strategies. While facial EMG over the Corrugator supercilii and the Zygomaticus major was measured, each participant performed two tasks with pictures of album covers. One task was an affective evaluation task and the other was to attribute the album covers to one of five decades. The Embodied Emotion Account predicts that valence concordant EMG is more likely to occur if the task necessitates a somatosensory simulation of the evaluative meaning of stimuli. Results support this prediction with regard to Corrugator supercilii in that valence concordant EMG activity was only present in the affective evaluation task but not in the non-evaluative task. Results for the Zygomaticus major were ambiguous. Our findings are in line with the view that EMG activity is an embodied part of the evaluation process and not a mere physical outcome.

Memory effects of sleep, emotional valence, arousal and novelty in children

NARCIS (Netherlands)

Vermeulen, Marije C M; van der Heijden, Kristiaan B; Benjamins, Jeroen S; Swaab, Hanna; van Someren, Eus J W

Effectiveness of memory consolidation is determined by multiple factors, including sleep after learning, emotional valence, arousal and novelty. Few studies investigated how the effect of sleep compares with (and interacts with) these other factors, of which virtually none are in children. The

Memory effects of sleep, emotional valence, arousal and novelty in children

NARCIS (Netherlands)

Vermeulen, Marije C M; van der Heijden, Kristiaan B; Benjamins, Jeroen S.; Swaab, Hanna; Van Someren, Eus J W

2017-01-01

Effectiveness of memory consolidation is determined by multiple factors, including sleep after learning, emotional valence, arousal and novelty. Few studies investigated how the effect of sleep compares with (and interacts with) these other factors, of which virtually none are in children. The

Deterministic Graphical Games Revisited

DEFF Research Database (Denmark)