• Title/Summary/Keyword: Surface State

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Difference in Muscle Activities According to Stability on Support Surface During Plank Exercise

  • Cho, Yong-Ho;Choi, Jin-Ho
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.3
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    • pp.73-77
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    • 2017
  • PURPOSE: The present study aimed to measure muscle activities in the pectoralis major, the erector spinae, and the quadriceps femoris according to support surface states of arms and legs during plank exercise. METHODS: The subjects of this study were 21 healthy males in their 20s and their muscle activities at three states were measured as follows: The first state was where the support surface of arms and legs was stable. The second state was where only arms were unstable, and the third state was where only legs were unstable. Electromyography (EMG) was used to measure muscle activities. Pectoralis major, quadriceps femoris, and elector spinae were measured for muscle activities. RESULTS: The muscle activities in the pectoralis major were statistically high when arms were unstable. The muscle activities in the quadriceps femoris were statistically high when legs were unstable. The muscle activities in the erector spinae were higher when arms and legs were unstable compared to that at the stable support surface. No significant difference was revealed statistically when arms and legs were unstable. CONCLUSION: If the instability of arms and legs is employed during plank exercise, exercise on the upper and lower bodies or the erector spinae is expected to be more effective.

A Study on the Crevice Corrosion for Ferritic Stainless Steel by Micro Capillary Tube Method

  • Na Eun-Young;Ko Jae-Yong;Baik Shin-Young
    • Journal of the Korean Electrochemical Society
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    • v.7 no.4
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    • pp.179-182
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    • 2004
  • The aim of this study is to investigate the initiation and propagation of crevice corrosion for ferritic stainless steel in artificial crevice based on micro capillary tube method. The 430 stainless steel in artificial crevice is potentiostatically polarized in different sodium chloride solutions. Potentiodynamic and potentiostatic polarization data were measured in situ. The potentials in the crevice were measured by depth profile using the 0.04 mm diameter micro capillary tube inserted in the crevice. The potentials in the crevice ranged from -220 mV to -360 mV vs SCE from opening to bottom of crevice, which are lower than the external surface potential, -200 mV vs SCE. Such a potential drop induced the change of the metal surface state from passive to active. The surface of metal is located in passive state in -200 mV but the inner surface keeps active state below -220 mV, Thus these results show that the It drop mechanism in the crevice was more objective for evaluation and the method was easier to reproduce. Therefore the potential drop is one of the reasons for crevice corrosion by measuring the potentials in narrow crevice with a new micro measuring system.

A First Principles Study of Mn on AlGaP2 Semiconductor Surface (AlGaP2 반도체내와 표면의 Mn에 대한 제일원리 해석)

  • Kang, Byung Sub
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.1
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    • pp.12-17
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    • 2021
  • The electronic and magnetic properties for Mn-adsorbed on the chalcopyrite (CH) AlGaP2 semiconductor are investigated by using first-principles FPLMTO method. The clean CH-AlGaP2 without adsorbed Mn is a p-type semiconductor with a direct band-gap. The Mn-adsorbed CH-AlGaP2 exhibits the ferromagnetic state. It is more energetically stable than the other magnetic ones. The interstitial site on P-terminated surface is more energetically favorable one than the Al/Ga-terminated surface, or the other adsorbing sites. In the case of Mn-adsorbed Al/Ga-terminated surface, it is induced a strong coupling between Mn-3d and neighboring P-3p electrons. The holes of partially unoccupied minority Mn-3d state and majority (or minority) Al-3p or P-3p state are induced. Thus a high magnetic moment of Mn is sustained by holes-mediated double-exchange coupling. It is noticeable that the semiconducting and half-metallic characteristics of CH-AlGaP2:Mn thin film is disappeared.

The Differential Effect of Emotional Labour on Boundary Spanners

  • MUPARANGI, Simbarashe;SIZIBA, Singirai;MAKUDZA, Forbes
    • Journal of Wellbeing Management and Applied Psychology
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    • v.4 no.1
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    • pp.1-10
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    • 2021
  • Purpose: The study sought to uncover the effect of emotional labour strategies (surface acting and deep acting) on job satisfaction and emotional exhaustion. The study also purposed to analyse the moderating effect of organisational support (supervisory support and co-worker support) and the role of gender on emotional labour connotations. Research design, data and methodology: A conceptual framework was developed using extant literature which led to the examination of deep acting and surface acting, which are the two main strategies of emotional labour. The outcome variables were emotional exhaustion and job satisfaction. Data was collected from front line employees of banks and was analysed using SEM-AMOS version 21. Results: It was revealed, in this study, that surface acting is inversely related to job satisfaction and positively related to emotional exhaustion, whereas deep acting was positively related to job satisfaction and inversely related to emotional exhaustion. The roles of gender and organisational support were also confirmed. Conclusions: The study therefore concluded that deep acting is the most ideal strategy of emotional labour as it leads to job satisfaction and reduced emotional exhaustion. Surface acting is a harmful emotional labour strategy.

Sliding Mode Control for Time-delay System using Virtual State (가상 상태를 이용한 시간 지연 시스템의 슬라이딩 모드 제어)

  • 송영삼;권성하;박승규;오도창;정은태
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.341-341
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    • 2000
  • This paper presents a sliding mode control(SMC) design method for single input linear systems with uncertainties and time delay in the state. We define a sliding surface for the augmented system with a virtual state which is defined from the nominal system. We make a virtual state from optimal control input using LOR(Linear Quadratic Regulator) and the states of the nominal system. We construct a controller that combines SMC with optimal controller. The proposed sliding mode controller stabilizes on the overall closed-loop system.

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Direct Observation of Radiative Flux in the Southern Yellow Sea

  • Lu, Lian-Gang;Yu, Fei;Diao, Xinyuan;Guo, Jingsong;Wang, Huiwu;Wei, Chuanjie
    • Ocean Science Journal
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    • v.43 no.2
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    • pp.115-126
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    • 2008
  • Direct measurements of four radiative components at air-sea boundary layer were conducted in the southern Yellow Sea during three cruises (seasons) in 2007. Simultaneous observations of meteorological (cloud cover, air temperature and humidity) and oceanographic (sea surface temperature) parameters were carried out. Observational results of radiative fluxes and meteorological and oceanographic parameters are presented. Mean diurnal cycles of four radiative components, net radiation, and sea surface albedo are calculated to achieve averages in different seasons. Net radiative fluxes in three seasons (winter, spring, autumn) are 8, 146, $60\;W/m^2$, respectively. Comparisons between the observed radiative fluxes and those estimated with formulas are taken.

Heat-induced coarsening of layer-by-layer assembled mixed Au and Pd nanoparticles

  • Shon, Young-Seok;Shon, Dayeon Judy;Truong, Van;Gavia, Diego J.;Torrico, Raul;Abate, Yohannes
    • Advances in nano research
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    • v.2 no.1
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    • pp.57-67
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    • 2014
  • This article shows the coarsening behavior of nanoparticle multilayers during heat treatments which produce larger metallic nanostructures with varying shapes and sizes on glass slides. Nanoparticle multilayer films are initially constructed via the layer-by-layer self-assembly of small and monodispersed gold and/or palladium nanoparticles with different compositions (gold only, palladium only, or both gold and palladium) and assembly orders (compounding layers of gold layers over palladium layers or vice versa). Upon heating the slides at $600^{\circ}C$, the surface nanoparticles undergo coalescence becoming larger nanostructured metallic films. UV-Vis results show a clear reliance of the layering sequence on the optical properties of these metal films, which demonstrates an importance of the outmost (top) layers in each nanoparticle multilayer films. Topographic surface features show that the heat treatments of nanoparticle multilayer films result in the nucleation of nanoparticles and the formation of metallic cluster structures. The results confirm that different composition and layering sequence of nanoparticle multilayer films clearly affect the coalescence behavior of nanoparticles during heat treatments.

Preliminary Study on the Measurement of the Electrostatic Charging State of PM2.5 Collected on Filter Media

  • Okuda, Tomoaki;Yoshida, Tetsuro;Gunji, Yuma;Okahisa, Shunichi;Kusdianto, K.;Gen, Masao;Sato, Seiichi;Lenggoro, I. Wuled
    • Asian Journal of Atmospheric Environment
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    • v.9 no.2
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    • pp.137-145
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    • 2015
  • This study focused on the measurement of the actual charging state of ambient aerosol particles, which is important for understanding the intricate process of adverse health effects caused by particulate matter (PM). The net electrostatic charging state of $PM_{2.5}$ collected on filter media was measured in this study. The Faraday cage method and surface potential measurements were used in this study. The results showed that the polarities of the net charging state measured using these two methods were in agreement for 42 out of 48 samples (87.5%), and 36 samples (75%) were negatively charged. The filters were not significantly charged by friction between the filters and air not containing PM. Charge addition to or leakage from the filters was not observed over a two-month storage period. Net charging state of $PM_{2.5}$ collected on the filters was concluded to be negative in most cases, based on data's support of the assumption that aerosol charging state is not altered by the process of PM collection using filter.