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BIOMASS-DERIVED ACTIVATED CARBONS FOR ELECTRICAL DOUBLE LAYER SUPERCAPACITORS: PERFORMANCE AND STRESS EFFECTCao, Wenxin 01 January 2019 (has links)
The vigorous development of human civilization has significantly increased the energy consumption in recent years. There is a great need to use renewable energy sources to substitute the depleting traditional fossil fuels, such as crude oil, natural gas and coal. The development of low-cost and high-performance energy storage devices (ESDs) and systems have drawn great attention due to their feasibility as backup power supply and their applications in portable electronics and electric vehicles. Supercapacitors are among the most important ESDs because of their long charging-discharging cycle life, high power capability and a large operating temperature range. In this thesis, high-performance activated carbons (ACs)-based SCs have been synthesized from two biomass materials in both “bottom-up” and “top-down” patterns, including high fructose corn syrup and soybean residues, which are economic and environmental friendly.
Firstly, a hydrothermal carbonization (HTC) - physical activation method is presented to synthesize activated carbons from high fructose corn syrup (HFCS). The effect of the activation time on the geometrical and porous characteristics of the ACs is investigated. The electrochemical performance of the supercapacitor cells made from AC treated at 850ºC for 4 hours are found as the best with a specific capacitance of 168 F/g at 0.2 A/g in 6 M KOH aqueous system. Secondly, a two-step HTC process followed by a physical activation to prepare activated carbons from soybean residue is presented. The effect of activation temperature on geometrical and porous characteristics of the ACs is studied. The ACs activated at 850ºC are found partly crystallized and exhibit a specific capacitance of 227 F/g at 2 mV/s.
To understand the effect of mechanical deformation of the electrode materials on the electrochemical performance of electrical double-layer supercapacitors, a series of compression tests of HFCS-based ACs are further conducted in both dry and wet conditions. The nominal stiffness of the compressed ACs is calculated from the unloading curves. For both dry and wet disks the stiffness get increased with increased compression load, where the wet ones get higher stiffness than that of the dry ones. A simple model of porous materials is used to explain the increase in the stiffness of a compressed disk with the increase of pressure.
Lastly, the effect of mechanical deformation on the electrochemical impedance of HFCS-based ACs is studied. When increasing the mechanical pressure from 4 to 81.5 KPa, the system resistance shows a relatively stable trend around 1 ohm, while the charge transfer resistance shows a dramatic dependence on mechanical pressure decreasing from 420 ohms to 1.5 ohms.
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Predictive Modeling for Extremely Scaled CMOS and Post Silicon DevicesJanuary 2011 (has links)
abstract: To extend the lifetime of complementary metal-oxide-semiconductors (CMOS), emerging process techniques are being proposed to conquer the manufacturing difficulties. New structures and materials are proposed with superior electrical properties to traditional CMOS, such as strain technology and feedback field-effect transistor (FB-FET). To continue the design success and make an impact on leading products, advanced circuit design exploration must begin concurrently with early silicon development. Therefore, an accurate and scalable model is desired to correctly capture those effects and flexible to extend to alternative process choices. For example, strain technology has been successfully integrated into CMOS fabrication to improve transistor performance but the stress is non-uniformly distributed in the channel, leading to systematic performance variations. In this dissertation, a new layout-dependent stress model is proposed as a function of layout, temperature, and other device parameters. Furthermore, a method of layout decomposition is developed to partition the layout into a set of simple patterns for model extraction. These solutions significantly reduce the complexity in stress modeling and simulation. On the other hand, semiconductor devices with self-feedback mechanisms are emerging as promising alternatives to CMOS. Fe-FET was proposed to improve the switching by integrating a ferroelectric material as gate insulator in a MOSFET structure. Under particular circumstances, ferroelectric capacitance is effectively negative, due to the negative slope of its polarization-electrical field curve. This property makes the ferroelectric layer a voltage amplifier to boost surface potential, achieving fast transition. A new threshold voltage model for Fe-FET is developed, and is further revealed that the impact of random dopant fluctuation (RDF) can be suppressed. Furthermore, through silicon via (TSV), a key technology that enables the 3D integration of chips, is studied. TSV structure is usually a cylindrical metal-oxide-semiconductors (MOS) capacitor. A piecewise capacitance model is proposed for 3D interconnect simulation. Due to the mismatch in coefficients of thermal expansion (CTE) among materials, thermal stress is observed in TSV process and impacts neighboring devices. The stress impact is investigated to support the interaction between silicon process and IC design at the early stage. / Dissertation/Thesis / Ph.D. Electrical Engineering 2011
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The potential of exercise to reverse stress induced abnormalities in the rat brainMarais, Lelanie 03 1900 (has links)
Thesis (PhD (Biomedical Sciences. Medical Physiology.))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Adverse experiences during early life causes alterations in the development of the
central nervous system structures that may result in abnormal functioning of the
brain. It is well known that, in humans, adverse early-life experiences such as social
separation, deprivation, maternal neglect and abuse increase the risk of developing
psychiatric disorders, such as depression, later in life. We used maternal separation
in the rat as a model for early life stress to firstly determine how different brain
systems are dysregulated by this stressful experience and additional chronic or acute
stress during adulthood. Rat pups were separated from their mothers on postnatal
day 2-14 for 3 hours per day while control rats were normally reared. The behavior,
stress response, neurotrophin, apoptotic marker and serotonin levels in the ventral hippocampus, striatum and frontal cortex were measured during adulthood. A
different group of maternally separated rats were allowed chronic voluntary exercise
and similar measurements were done to determine whether exercise was able to
normalize the deficits caused by early life stress. Differentially expressed cytosolic
proteins of the ventral hippocampus of maternally separated rats versus normally
reared rats were also identified. Protein expression levels of maternally separated
rats that received chronic voluntary exercise or escitalopram treatment were
subsequently determined to unravel the mechanism of therapeutic action for these
two interventions. We found that maternal separation increased the baseline
corticosterone response of rats and induced a blunted adrenocorticotropin hormone
after acute restraint stress. Baseline neurotrophin levels were significantly
decreased in the ventral hippocampus. Maternal separation followed by chronic
restraint stress during adulthood resulted in increased depressive-like behavior
compared to control rats. Maternal separation alone or followed by acute restraint stress during adulthood induced changes in apoptotic marker expression in the
striatum and frontal cortex. In rats subjected to maternal separation and chronic
restraint stress during adulthood, we found that chronic voluntary exercise decreased
their depressive-like behavior and increased brain derived neurotrophin levels in the
striatum. Serotonin levels were not affected by maternal separation, but chronic
voluntary exercise increased serotonin in the ventral hippocampus of normally reared
rats. Maternal separation induced a number of changes in the expression of
cytosolic proteins and these stress-induced changes were identified in proteins
relating to cytoskeletal structure, neuroplasticity, oxidative stress, energy metabolism,
protein metabolism, and cell signaling. Chronic voluntary exercise was able to
restore the expression levels of a number of proteins affected by maternal separation
that increased the risk for neuronal death. When comparing the efficacy of exercise
to that of escitalopram treatment it was evident that, in contrast to exercise,
escitalopram targets a different subset of proteins affected by maternal separation,
except for a few involved in energy metabolism pathways and neuroprotection. In
this study we have shown that chronic voluntary exercise has therapeutic effects in
maternally separated rats, decreasing depressive-like behavior, increasing
neurotrophin expression and restoring cytosolic protein expression that were dysregulated by early life stress. / AFRIKAANSE OPSOMMING: Negatiewe stresvolle ervarings gedurende die vroeë stadium van ‘n mens se lewe
veroorsaak veranderinge in die ontwikkeling van breinstrukture en het ‘n nadelige
uitwerking op die funksionering van die brein. Dit is bekend dat stresvolle ervarings
in kinders, byvoorbeeld sosiale afsondering, verwaarlosing en mishandeling, die
risiko vir die ontwikkeling van psigiatriese steurings soos depressie gedurende
volwassenheid kan verhoog. In hierdie studie gebruik ons moederlike skeiding van
neonatale rotte as ‘n model vir vroeë lewensstres om te bepaal hoe dit verskillende
sisteme in die brein negatief beinvloed, en dan ook die effek van addisionele
kroniese of akute stres gedurende volwassenheid. Die neonatale rotte is
weggeneem van hulle moeders af vanaf dag 2 tot 14 vir 3 ure elke dag terwyl
kontrole rotte by hulle moeders gebly het. Die gedrag, stres respons, neurotrofiene,
apoptotiese merkers en serotonien vlakke is gemeet in die ventrale hippokampus,
frontale korteks en striatum gedurende volwassenheid. Rotte wat van hulle moeders
geskei is, is dan toegelaat om vir ses weke in wiele te hardloop om te bepaal of
kroniese vrywillige oefening die negatiewe effekte wat veroorsaak is deur stres kan
ophef. ‘n Bepaling van sitosoliese proteien uitdrukking in die ventrale hippokampus
is ook gedoen om die uitwerking van moederlike skeiding op proteienvlak vas te stel.
Hierdie protein data is dan vergelyk met die van gestresde rotte wat kroniese
oefening of escitalopram behandeling ontvang het om die meganisme van werking van beide behandelings te bepaal. Ons het gevind dat moederlike skeiding die
rustende kortikosteroon vlakke van rotte verhoog terwyl dit adrenokortikotropien
vlakke na akute stres inhibeer. Moederlike skeiding het ook die neurotrofien vlakke
in die ventrale hippokampus verlaag en addisionele kroniese stres gedurende
volwassenheid het ‘n verhoging in depressie-agtige gedrag veroorsaak. Moederlike skeiding alleen, sowel as gevolg deur akute stress gedurende volwassenheid het ook
veranderinge in die uitdrukking van apoptotiese merkers in die striatum en frontale
korteks veroorsaak. Kroniese vrywillige oefening na moederlike skeiding en
addisionele stres gedurende volwassenheid kon depressie-agtige gedrag verlaag en
neurotrofienvlakke in die striatum verhoog. Serotonien vlakke was nie beinvloed
deur moederlike skeiding nie, maar oefening in kontrole rotte het serotonien verhoog
in die ventrale hippokampus. Moederlike skeiding het heelwat veranderinge in die
uitdrukking van sitosoliese proteiene van die ventrale hippokampus veroorsaak wat
ingedeel kan word in die volgende funksionele kategorieë: sitoskelet,
neuroplastisiteit, oksidatiewe stres, energiemetabolisme, proteinmetabolisme en
seintransduksie. Oefening kon die uitdrukking van verskeie stres-geïnduseerde
veranderinge in proteiene weer herstel terwyl dit wou bleik asof escitalopram se
meganisme van werking op ‘n ander vlak geskied. Ons bevindinge bewys dat
kroniese vrywillige oefening ‘n goeie behandeling is na vroeë lewenstres en dat dit
depressiewe gedrag verminder, neurotrofien vlakke verhoog en sitosoliese proteien skeiding alleen, sowel as gevolg deur akute stress gedurende volwassenheid het ook
veranderinge in die uitdrukking van apoptotiese merkers in die striatum en frontale
korteks veroorsaak. Kroniese vrywillige oefening na moederlike skeiding en
addisionele stres gedurende volwassenheid kon depressie-agtige gedrag verlaag en
neurotrofienvlakke in die striatum verhoog. Serotonien vlakke was nie beinvloed
deur moederlike skeiding nie, maar oefening in kontrole rotte het serotonien verhoog
in die ventrale hippokampus. Moederlike skeiding het heelwat veranderinge in die
uitdrukking van sitosoliese proteiene van die ventrale hippokampus veroorsaak wat
ingedeel kan word in die volgende funksionele kategorieë: sitoskelet,
neuroplastisiteit, oksidatiewe stres, energiemetabolisme, proteinmetabolisme en
seintransduksie. Oefening kon die uitdrukking van verskeie stres-geïnduseerde
veranderinge in proteiene weer herstel terwyl dit wou bleik asof escitalopram se
meganisme van werking op ‘n ander vlak geskied. Ons bevindinge bewys dat
kroniese vrywillige oefening ‘n goeie behandeling is na vroeë lewenstres en dat dit
depressiewe gedrag verminder, neurotrofien vlakke verhoog en sitosoliese proteien vlakke kan herstel.
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Electrical Analysis and Physical Mechanisms of £\-InGaZnO Thin Film Transistors with different device structuresWu, Chang-Pei 12 July 2012 (has links)
The higher mobility is needed for thin film transistor (TFT) mainly used to be applied in the larger size flat-panel displays (FPDs). The amorphous metal oxide TFT has mobility higher than 10 cm2/V¡Es and can substitute the poor mobility (<1 cm2/V¡Es) of traditional amorphous silicon TFT, which shows a great potential for the next generation. Due to the superior characteristics in amorphous metal oxide TFT, therefore, the amorphous metal oxide TFT has been studied extensively.
Usually, the source/drain with island type device has a large overlapped/contact area that we cannot determine the exact electron path. That the sample of inverted stagger £\-IGZO TFTs with via type device has smaller contact area and can be estimated the electron path. In this thesis, the devices with different M1 overlaps etching stop layer (ESL) via distance, M2 £\-IGZO contact size and the fringe field effect are investigated. Although the characteristics of £\-IGZO TFTs have great performance, the electrical stability under illumination and long term bias stress are still a important issue to study before implement them into display. Thus, the devices with different structures that we mentioned previously are investigated the electrical reliability which are the negative bias stress of gate voltage, hot carrier stress effect and negative bias of illumination.
The electron path of via type is extracted by contact resistance which is greater than the distance between S/D via. Experiment results show that the increased offset between M1 and ESL via generates the resistance-liked effect in electrical characteristics. The hot carrier stress effect is independent of M2 £\-IGZO contact size in short channel length devices and there are close depletion lengths in drain side. The negative bias stress of illumination is proceeded in the fringe field effect devices, which results a negative shift of threshold voltage due to the hole trapping.
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Mittelspannungseinfluss bei dauerfester Auslegung von Wellen und AchsenNeikes, Kai 12 March 2020 (has links)
Geometrie, Werkstoff und Belastung sind die maßgeblichen Faktoren, welche die Dauerfestigkeit beeinflussen. Allgemein bekannt ist, dass die Dauerfestigkeit bei einer Überlagerung von ruhenden und schwingenden Belastungen geringer ist als bei rein schwingenden Belastungen. Dieser Effekt wird Mittelspannungseinfluss genannt.
Die vorliegende Arbeit widmet sich dem Einfluss von Mittelspannungen auf die Dauerfestigkeit. Hierfür wurden Versuche durchgeführt und ergänzt durch die Auswertung von Ver-suchsdaten aus der Literatur. Der Mittelspannungseinfluss wird ermittelt und ein Vorschlag zur Abschätzung im Nennspannungskonzept vorgestellt. Dieser Vorschlag ist einfacher und genauer als bestehende Methoden zur Abschätzung des Mittelspannungseinflusses auf die Dauerfestigkeit.
Unter Berücksichtigung von plastischen Verformungen wird der lokale Spannungszustand für die im Versuch auftretenden Belastungen ermittelt. Der Mittelspannungseinfluss wird für lokale Spannungen bestimmt und eine Methode zur Berechnung der lokalen Dauerfestig-keit entwickelt, die auch mit Festigkeitswerten aus dem Nennspannungskonzept verwen-det werden kann.:1 Einleitung 1
2 Stand des Wissens 3
2.1 Grundlagen 3
2.2 Experimentelle Ermittlung der Dauerfestigkeit 17
2.3 Mittelspannungseinfluss nach dem Nennspannungskonzept 22
2.4 Mittelspannungseinfluss im Kerbgrundkonzept 38
2.5 Zusammenfassung zum Stand des Wissens 42
3 Experimentelle Untersuchungen 45
3.1 Versuchsplanung und Vorbereitung 45
3.2 Werkstoffuntersuchungen 49
3.3 Versuchsbedingungen und Durchführung 52
3.4 Auswertung und Ergebnisse 54
4 Recherche nach experimentellen Untersuchungen 61
4.1 Kriterien 61
4.2 Aufbereitung und Auswertung 62
4.3 Ergebnisse der Versuchsdaten aus der Literatur 62
4.4 Versuche aus der Literatur, die nicht den Kriterien entsprechen 63
5 Auslegungskonzept und Validierung 69
5.1 Numerische Voruntersuchungen 70
5.2 Untersuchungen mit Nennspannungen 83
5.3 Untersuchungen mit lokalen Spannungen 107
6 Zusammenfassung 123
6.1 Nennspannungskonzept 123
6.2 Lokale Spannungen 124
7 Ausblick 125
7.1 Lastwechselzahl, Lastfolge, Lasthöhe 125
7.2 Werkstoff 125
Literatur 127
A Anhang 136 / Geometry, material and load are the main factors influencing fatigue strength. Loads can be static or oscillating. If static and oscillating loads are superimposed, the fatigue strength is lower than with purely oscillating loads. This effect is called mean stress effect.
This paper is dedicated to the mean stress effect on fatigue strength. Tests are carried out on shaft-typical geometries and materials. The tests are supplemented by the evaluation of test data from literature. The mean stress effect is determined for the test and literature data. A proposal for the estimation of the mean stress effect in the nominal stress concept is presented. This proposal is simpler and more accurate than existing methods for estimating the mean stress effect on fatigue strength.
Taking plastic deformations into account, the local stress state for the loads occurring in the test is determined. These are used to determine the mean stress effect and to present a concept for local stresses and a method for calculating the local fatigue strength is de-veloped, which can also be used with strength values from the nominal stress concept.:1 Einleitung 1
2 Stand des Wissens 3
2.1 Grundlagen 3
2.2 Experimentelle Ermittlung der Dauerfestigkeit 17
2.3 Mittelspannungseinfluss nach dem Nennspannungskonzept 22
2.4 Mittelspannungseinfluss im Kerbgrundkonzept 38
2.5 Zusammenfassung zum Stand des Wissens 42
3 Experimentelle Untersuchungen 45
3.1 Versuchsplanung und Vorbereitung 45
3.2 Werkstoffuntersuchungen 49
3.3 Versuchsbedingungen und Durchführung 52
3.4 Auswertung und Ergebnisse 54
4 Recherche nach experimentellen Untersuchungen 61
4.1 Kriterien 61
4.2 Aufbereitung und Auswertung 62
4.3 Ergebnisse der Versuchsdaten aus der Literatur 62
4.4 Versuche aus der Literatur, die nicht den Kriterien entsprechen 63
5 Auslegungskonzept und Validierung 69
5.1 Numerische Voruntersuchungen 70
5.2 Untersuchungen mit Nennspannungen 83
5.3 Untersuchungen mit lokalen Spannungen 107
6 Zusammenfassung 123
6.1 Nennspannungskonzept 123
6.2 Lokale Spannungen 124
7 Ausblick 125
7.1 Lastwechselzahl, Lastfolge, Lasthöhe 125
7.2 Werkstoff 125
Literatur 127
A Anhang 136
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Scale and Stress Effects on Hydro-Mechanical Properties of Fractured Rock MassesBaghbanan, Alireza January 2008 (has links)
In this thesis, the effects of size and stress on permeability, deformability and strength of fractured rock masses are investigated. A comparison study was carried out to examine the effects of considering, or not considering, the correlation between distributions of fracture apertures and fracture trace lengths on the hydro-mechanical behavior of fractured rocks. The basic concepts used are the fundamental principles of the general theory of elasticity, Representative Elementary Volume (REV), the tensor of equivalent permeability, and the strength criteria of the fractured rocks. Due to the size and stress dependence of the hydro-mechanical properties of rock fractures, the overall effective (or equivalent) hydro-mechanical properties of the fractured rocks are also size and stress-dependent. However, such dependence cannot be readily investigated in laboratory using small samples, and so numerical modeling becomes a necessary tool for estimating their impacts. In this study, a closed-form relation is established for representing the correlation between a truncated lognormal distribution of fracture apertures and a truncated power law distribution of trace lengths, as obtained from field mapping. Furthermore, a new nonlinear algorithm is developed for predicting the relationship between normal stress and normal displacement of fractures, based on the Bandis model and the correlation between aperture and length. A large number of stochastic Discrete Fracture Network (DFN) models of varying sizes were extracted from some generated large-sized parent realizations based on a realistic fracture system description from a site investigation programme at Sellafield, UK, for calculating the REV of hydro-mechanical properties of fractured rocks. Rotated DFN models were also generated and used for evaluation of the distributions of directional permeabilities, such that tensors of equivalent permeability could be established based on stochastically established REVs. The stress-dependence of the permeability and the stress-displacement behaviour were then investigated using models of REV sizes. The Discrete Element Method (DEM) was used for numerical simulation of the fluid flow, deformability properties and mechanical strength behavior of fractured rocks. The results show significant scale-dependency of rock permeability, deformability and strength, and its variation when the correlation between aperture and trace length of fractures are concerned, with the overall permeability and deformability more controlled by dominating fractures with larger apertures and higher transmissivity and deformability, compared with fracture network models having uniform aperture. As the second moment of aperture distribution increases, a fractured rock mass shows more discrete behavior and an REV is established in smaller value of second moment with much larger model size, compared with the models with uniform fracture aperture. When the fracture aperture pattern is more scattered, the overall permeability, Young’s modulus and mechanical strength change significantly. The effect of stress on permeability and fluid flow patterns in fractured rock is significant and can lead to the existence or non-existence of a permeability tensor. Stress changes the fluid flow patterns and can cause significant channeling and the permeability tensor, and REV may be destroyed or re-established at different applied stress conditions. With an increase in the confining stress on the DEM models, the strength is increased. Compared with the Hoek-Brown criterion, the Mohr-Coulomb strength envelope provides a better fit to the results of numerical biaxial compression tests, with significant changes of the strength characteristic parameters occurring when the second moment of the aperture distribution is increased. / QC 20100702
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Streso poveikis sportinių šokių šokėjams ir streso įveikimo būdai / Stress effects of dance sport dancers and stress coping techniquesJasaitis, Nerijus 13 June 2012 (has links)
Darbo objektas. sportinių šokių šokėjų patiriamas stresas, jo įtaka savęs vertinimui ir jo įveikimo būdai.
Darbo problema: kuo ypatingas streso poveikis sportinių šokių šokėjams ir kokie yra galimi jo įveikimo būdai?
Darbo tikslas: nustatyti streso poveikį, jo įtaką savęs vertinimui ir jo įveikimo būdus sportinių šokių šokėjams.
Darbo uždaviniai:
1. Įvertinti streso poveikį sportinių šokių šokėjams.
2. Identifikuoti streso įveikimo būdus.
3. Nustatyti sportinių šokių šokėjų patiriamo streso įtaką jų savęs vertinimui.
Tyrimo metodai:
1. Mokslinės literatūros analizė.
2. Statistinių duomenų analizė. (Taikant SPSS statistinių duomenų apdorojimo programą)
3. Anketinė apklausa.
Tiriamieji klausimai:
- Kuo yra išskirtinis stresas kaip reiškinys?
- Kokie yra šokėjų patiriamo streso teoriniai pagrindai?
- Koks yra streso poveikis sportinių šokių šokėjų savęs vertinimui?
Išvados.
1. Sportinių šokių šokėjos dažniau nei šokėjai patiria stresą (p=0,040). Tiek vyrai, tiek ir moterys dažniausiai stresą patiria profesinėje veikloje – šokiuose (p=0,225). Dauguma sportinių šokių šokėjų šokdami stresą jaučia kartais (p=0,653). Sportinių šokių šokėjams dažniau nei šokėjoms stresą labiausiai kelia integruojančios arba ribinės funkcijos (p=0,002). Tiek vyrams, tiek ir moterims stresą dažniausiai kelia siekis būti geriausiu (p=0,773). Sportinių šokių šokėjoms dažniau nei šokėjams stresą kelia psichiniai stresoriai (p=0,002), o šokėjams vyrams dažniau nei moterims pasireiškia... [toliau žr. visą tekstą] / Object of this paper. Stress experienced by dance sport dancers, its influence to their self assessment and stress coping techniques.
Problem of this paper: what is the speciality of stress experienced by dance sport dancers and what are possible its coping techniques.
Aim of this paper: to identify effect of stress, its influence to self assessment and stress coping techniques to dance sport dancers.
Tasks of this paper:
1st – to assess stress effect to dance sport dancers.
2nd – to identify stress coping techniques.
3rd – to identify influence of stress effect to dance sport dancers self assessment.
Research methods:
1. Analytical Review of Literature .
2. Analysis of Statistical Data. (Using SPSS statistical data processing program)
3. Questionnaire survey.
Research questions:
- What is an exclusivity of stress phenomenon?
- What are theoretical frameworks of dancers experienced stress?
- What is the effect of stress to dance sport dancers self-assessment?
Conclusions.
1. Sport dance dancers female more often than male feel stress (p = 0.040). Both male and female tend to suffer stress in their profession activities - dancing (p = 0.225). Most of dance sport dancers sometimes feel stress (p = 0.653). Dance sport dancers male more often then female integrative functions cause stress (p = 0.002). Often stress is caused by aspiration to be the best to both dance sport dancers female and male (p = 0.773). Stress is caused by mental stressors more often to dance sport... [to full text]
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Ação de bioestimulantes na mitigação do estresse por deficiência hídrica em soja /Rosa, Vanessa do Rosário January 2020 (has links)
Orientador: Marcelo de Almeida Silva / Resumo: A soja possui grande importância no mercado mundial, e para atender a sua crescente demanda é preciso aumentar a produtividade, que tem se tornado um desafio em condições de ausência de chuva. Para contornar os efeitos negativos do déficit hídrico, tem-se adotado práticas agrícolas com a aplicação de bioestimulantes como os compostos por ácidos fúlvicos e extrato da alga marinha Ascophyllum nodosum (L.), que atuam na melhoria do desenvolvimento das plantas em condições estressantes. Neste estudo, objetivou-se compreender como ácidos fúlvicos e extrato da alga marinha Ascophyllum nodosum (L.) atuam em conjunto nos mecanismos fisiológicos e bioquímicos das plantas e possibilitando a mitigação dos efeitos negativos gerados pelo estresse, e ainda determinar qual formulação e dose do bioestimulante tem melhor efeito sobre o desenvolvimento de plantas de soja submetidas ao déficit hídrico. O experimento foi conduzido em casa de vegetação, em vasos contendo 10 kg de solo sob delineamento experimental de blocos casualizados em fatorial duplo com dois fatores adicionais, com cinco repetições e 11 tratamentos constituídos por três formulações do bioestimulante e três doses (0,25; 0,50 e 1,0 kg ha-1), controle com déficit hídrico e controle sem déficit hídrico. As plantas foram submetidas a 50% da capacidade de campo por três dias, em seguida foram reidratadas e receberam a aplicação do bioestimulante, com exceção dos controles. Foram avaliados parâmetros de crescimento, fisiológicos, b... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Soy has great importance in the world market, and to meet its growing demand it is necessary to increase productivity, which has become a challenge in conditions of absence of rain. To circumvent the negative effects of the water deficit, agricultural practices have been adopted with the application of biostimulants such as those composed of fulvic acids and extract from the seaweed Ascophyllum nodosum (L.), which act in improving the development of plants in stressful conditions. In this study, the objective was to understand how fulvic acids and extract of the seaweed Ascophyllum nodosum (L.) act together in the physiological and biochemical mechanisms of plants and enabling the mitigation of the negative effects generated by stress, and also determine which formulation and dose of biostimulant has a better effect on the development of soybean plants submitted to water deficit. The experiment was carried out in a greenhouse, in pots containing 10 kg of soil under a randomized double-block design with two additional factors, with five replications and 11 treatments consisting of three biostimulant formulations and three doses (0.25; 0.50 and 1.0 kg ha-1), control with water deficit and control without water deficit. The plants were submitted to 50% of the field capacity for three days, then they were rehydrated and received the application of the biostimulant, with the exception of the controls. Growth, physiological, biochemical parameters and productivity components were e... (Complete abstract click electronic access below) / Doutor
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