Nonextensive Thermostatistical Investigation of The Blackbody Radiation

Thermodynamical quantities of the blackbody radiation, such as free energy, entropy, total radiation energy, specific heat are calculated within the Tsallis thermostatistics where factorization method is incorparated. It is shown that basic thermodynamical relation of the blackbody radiation is form invariant with respect to nonextensivity entropic index q. Furthermore, the nonextensive thermodynamical quantities related to the blackbody radiation is seperately be obtained in terms of q and the standard thermodynamical quantities of the blackbody radiation .It is indicated that the formulation may give a way to determine the q which determines the degree of the nonextensivity that is the one of the aims of the present study.Comment: 16 pages,No figures,to be appear in Chaos,Solitons&Fractal

Microscopic theory of the activated behavior of the quantized Hall effect

The thermally activated behavior of the gate defined narrow Hall bars is studied by analyzing the existence of the incompressible strips within a Hartree-type approximation. We perform self-consistent calculations considering the linear response regime, supported by a local conductivity model. We investigate the variation of the activation energy depending on the width of samples in the range of $2d\sim [1-10] \mu m$. We show that the largest activation energy of high-mobility narrow samples, is at the low field edge of Hall filling factor 2 plateau (exceeding half of the cyclotron energy), whereas for relatively wide samples the higher activation energy is obtained at the high field edge of Hall plateau. In contrast to the single-particle theories based on the localization of electronic states, we found that the activation energy is almost independent of the properties of the density of states.Comment: 8 pages, 4 figure

Tales Of Language Loss And Language Maintenance: Elicited Ancestral Language Use In Lazuri-Turkish And Turkish-German Caregiver-Child Dyads During Structured Play

In language contact situations parents who grew up acquiring their ancestral language (AL) often have to make choices about the fate of AL transmission by negotiating resources and beliefs about what is best for their children\u27s future. Their language practices contribute to AL loss or maintenance, affecting developmental pathways for bilingualism. The situation faced by speakers of Lazuri -- a Grade 2, severely endangered South Caucasian language that is no longer used in child-directed speech illustrates a global phenomenon of rapid language loss within indigenous communities due to linguistic assimilation to a dominant language (DL). AL loss is associated with parental language socialization goals (e.g., to prepare children for formal education in the DL), as well as socio-economic and historical factors. Study 1 examined AL production in Lazuri-Turkish caregiver-child dyads (N=62, M child age=30.0 months, SD= 9.4, range 12-48 months) as a function of caregiver generation (i.e., comparing 30 grandparent-child vs. 32 parent-child dyads). Dyads were recruited from Lazona communities in Findikli and Ardaşen, Turkey. Study 2 compared a subset of the parent-child dyads from Study 1 with age-matched Turkish-German parent-child dyads (N=12, M child age=29 mo, range 16-46) recruited from the Kreuzberg community of Berlin. The Berlin families tend to maintain usage of AL (i.e., Turkish) in child-directed speech, and served as a base of comparison with the Lazuri communities where the DL has replaced the AL in communication with children. All parents completed a short demographic and language use questionnaire. Across studies, dyads were instructed to converse in their AL (i.e., Lazuri in Lazona, Turkish in Berlin) while engaging with animal farm and tea-party toy sets (10 min each). The elicitation task thus provided an assessment of caregiver language fluency in the AL as well as a semi-structured context for examining cultural variation in caregiver-child communication. Utterances were transcribed and coded for language use (i.e., AL, DL, Mixed) and type (i.e., labeling, questioning, commanding, deictic expression, comment, invitation). Deictic gestures (i.e., pointing, showing, offering, requesting) were also coded. In Study 1, the elicitation task indicated AL loss with grandparents and parents interacting similarly with children: Caregivers spoke Lazuri in only 58.5%, while the remainder of the child-directed speech was in Turkish (26.0%) or mixed languages (15.4%). In contrast, children lacked Lazuri fluency and predominantly spoke Turkish (82.8%) with fewer Lazuri (14.8%) or mixed utterances (2.4%): 79.8% of children\u27s Lazuri utterances were imitative, as opposed to spontaneous speech (21.2%). Caregivers combined Lazuri utterances with deictic gestures more often than Turkish utterances to establish a common ground for effective communication. Reflecting parental language practices in AL usage in Study 2, Berlin dyads conversed fluently in AL. Functional coding of utterances showed cultural variation in child-directed speech: Lazuri parents produced more commands whereas Berlin parents used more questions to engage their children. Despite variation in parental speech, children\u27s communication was remarkably alike, yet mediated by the activity context. The findings extend the bilingual literature by including understudied language enclaves and corroborate how practices and beliefs about what to teach and how to talk to children contribute to AL loss or maintenance. Benefits and ways of maintaining AL in socioeconomically disadvantaged contexts are discussed. Lazuri child stories are included as supplemental materials

Evanescent incompressible strips as origin of the observed Hall resistance overshoot

In this work we provide a systematic explanation to the unusual non-monotonic behavior of the Hall resistance observed at two-dimensional electron systems. We use a semi-analytical model based on the interaction theory of the integer quantized Hall effect to investigate the existence of the anomalous, \emph{i.e} overshoot, Hall resistance $R_{H}$. The observation of the overshoot resistance at low magnetic field edge of the plateaus is elucidated by means of overlapping evanescent incompressible strips, formed due to strong magnetic fields and interactions. Utilizing a self-consistent numerical scheme we also show that, if the magnetic field is decreased the $R_{H}$ decreases to its expected value. The effects of the sample width, temperature, disorder strength and magnetic field on the overshoot peaks are investigated in detail. Based on our findings, we predict a controllable procedure to manipulate the maxima of the peaks, which can be tested experimentally. Our model does not depend on specific and intrinsic properties of the material, provided that a single particle gap exists.Comment: A theoretical follow-up paper of arXiv:1007.258

The Effect of Sleep Quality on Profile of Mood, Physiological Responses, and Athletic Performance

While the extent of an athlete’s physiological adaptations varies due to a range of external factors, sleep deprivation has been proven to negatively affect one’s training and, ultimately, one’s overall athletic success. Sleep deprivation, either for a short or prolonged period of time, also leads to adverse psychological effects, as measured by the alteration of genes in the brain. PURPOSE: This study investigates how both normal sleep and sleep deprivation affect an athlete’s recovery, overall skeletal muscle performance, and mental state. METHODS: Using a randomized-crossover design, 7 healthy individuals, 3 males and 4 females, with at least 1 year of experience in resistance training participated in this study. Exercise testing sessions were identical in nature and took place in the morning following either 3 consecutive nights of 8 hours of sleep (normal) or 3 consecutive nights of 5 hours of sleep (deprivation). Pittsburgh sleep quality index (PSQI) and profile of mood state were collected each morning. Following warm-up, subjects performed the following tests in this order: 1 set of 15 repetitions of a maximal voluntary knee extension/flexion contraction at 300°•s-1, 4 repetitions of 4 seconds of isometric knee extension with EMG data collected, and 1 set of 50 repetitions of a maximal voluntary knee extension/flexion contraction at 60°•s-1. RESULTS: Although some variables in POMS and PSQI were statistically significantly (P\u3c0.05), no statistically significant muscular performance differences were found in normal sleep trials compared with sleep deprivation trials. However, there were trends toward decreased performance during sleep deprivation protocols. In sleep deprivation protocols peak extension and flexion power at 300°•s-1 were decreased 6.8% and 5.5% respectively. Peak torque and average torque during isometric testing decreased 15% and 10% respectively. Similarly, during the 50 repetitions at 60°•s-1, peak torque flexion and extension dropped 4.3% and 4.6% respectively. CONCLUSION: Our hypothesis that sleep deprivation has adverse effects was partially supported in the limited number of subjects, indicating that in an athletic setting, decreased sleep time might be detrimental with various types of athletic performance and one’s psychological well-being

Studies of the metal ion-catalysed oxidation of heterocyclic sulfur compounds.

Chemical oxidation by hydrogen peroxide is used for the treatment of hazardous organic materials present at low concentrations in contaminated soil and water. A knowledge of the oxidation of thiophene and its derivatives, with particular reference to oxidative destruction and the identification of intermediate oxidation products would be useful for a deeper understanding of reaction mechanisms in waste treatment and the optimization of conditions. In this thesis, the oxidation of thiophenes, namely thiophene and 2- and 3-methylthiophene, with hydrogen peroxide and catalyst systems, e.g. Fenton's reagent, Gif systems and titanium dioxide-assisted photocatalytic oxidations, all of which may involve the formation of free radicals, e.g. the hydroxyl radical (HO-), has been studied. Fenton-related catalyst systems, mixtures of iron salts (and sometimes also with copper salts) and hydrogen peroxide, have been suggested in the literature and their reactions with thiophenes have been investigated. Additionally, other catalytic systems that have also been suggested in the literature as having potential have been studied. The oxidation of thiophene derivatives with Fenton-like reagents involving a combinations of hydrogen peroxide with other metal salts including vanadium(IV), titanium(III), copper(I) and copper(II) have been explored, since all of these systems appear to form hydroxyl radicals. Further Fenton-related oxidations of reaction intermediates have been carried out in order to help understand whether the oxidation products described are derived directly from the original compound or from further oxidation of a reaction intermediate. The progress of the oxidation reactions was followed by chromatographic analysis, using Gas Chromatography-Mass Spectrometry and High Performance Liquid Chromatography, so as to establish the nature of the oxidation products and the possible reaction pathways. Components of the mixtures were identified by comparison with commercially available products or synthetic standards. Oxidation reactions were monitored over set time intervals and the amounts of residual thiophenes were determined. In all of the oxidation reactions investigated, Fenton-related and Fenton-like, heteroaromatic ring destruction was observed, together with the formation of small amounts of hydroxylated ring products and dimeric structures. The oxidative destruction of thiophenes was successfully achieved with the above catalyst systems in the presence of excess hydrogen peroxide.Recent literature has questioned the formation of hydroxyl radicals in Fenton-related systems, and in order to contribute to the debate regarding the oxidizing species responsible for the destruction of each of the thiophenes, the oxidation reactions have been carried out in the presence of a complexing agent such as ethylenediaminetetraacetic acid (EDTA), and a radical trapping reagent 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), respectively. Evidence of radical trapping was observed. Gif chemistry may involve the formation of high oxidation state iron complexes rather than free radicals. The oxidation of thiophenes was carried out using Fenton's reagent under Gif conditions and the results were compared with those from conventional Fenton and related conditions, to determine whether free radical species are involved in the latter. Radical derived products were again observed.Titanium-catalysed photooxidation has also formed part of this study to determine the nature of intermediate products which might be similar to those from Fenton-catalysed systems. For these reasons, the photocatalytic oxidation of 2-methylthiophene was studied in aqueous solution and the reaction was conducted in the presence and absence of titanium dioxide under an oxygen atmosphere. A similar range of radical derived products was found as in the conventional Fenton and related systems

Exchange-correlation enhancement of the Lande-g* factor in integer quantized Hall plateaus

We study the emergent role of many-body effects on a two dimensional electron gas (2DEG) within the Thomas-Fermi-Poisson approximation, including both the exchange and correlation interactions in the presence of a strong perpendicular magnetic field. It is shown that, the indirect interactions widen the odd-integer incompressible strips spatially, whereas the even-integer filling factors almost remain unaffected.Comment: 8 pages,4 figure

Quantum Hall Resistance Overshoot in 2-Dimensional Electron Gases - Theory and Experiment

We present a systematical experimental investigation of an unusual transport phenomenon observed in two dimensional electron gases in Si/SiGe heterostructures under integer quantum Hall effect (IQHE) conditions. This phenomenon emerges under specific experimental conditions and in different material systems. It is commonly referred to as Hall resistance overshoot, however, lacks a consistent explanation so far. Based on our experimental findings we are able to develop a model that accounts for all of our observations in the framework of a screening theory for the IQHE. Within this model the origin of the overshoot is attributed to a transport regime where current is confined to co-existing evanescent incompressible strips of different filling factors.Comment: 26 pages, 10 figure