• Title/Summary/Keyword: yielding state

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Implications of yield penetration on confinement requirements of r.c. wall elements

  • Tastani, Souzana P.;Pantazopoulou, Stavroula J.
    • Earthquakes and Structures
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    • v.9 no.4
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    • pp.831-849
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    • 2015
  • Seismic-design procedures for walls require that the confinement in the critical (plastic hinge) regions should extend over a length in the compression zone of the cross section at the wall base where concrete strains in the Ultimate Limit State (ULS) exceed the limit of 0.0035. In a performance-based framework, confinement is linked to required curvature ductility so that the drift demand at the performance point of the structure for the design earthquake may be met. However, performance of flexural walls in the recent earthquakes in Chile (2010) and Christchurch (2011) indicates that the actual compression strains in the critical regions of many structural walls were higher than estimated, being responsible for several of the reported failures by toe crushing. In this study, the method of estimating the confined region and magnitude of compression strain demands in slender walls are revisited. The objective is to account for a newly identified kinematic interaction between the normal strains that arise in the compression zone, and the lumped rotations that occur at the other end of the wall base due to penetration of bar tension yielding into the supporting anchorage. Design charts estimating the amount of yield penetration in terms of the resulting lumped rotation at the wall base are used to quantify the increased demands for compression strain in the critical section. The estimated strain increase may exceed by more than 30% the base value estimated from the existing design expressions, which explains the frequently reported occurrence of toe crushing even in well confined slender walls under high drift demands. Example cases are included in the presentation to illustrate the behavioral parametric trends and implications in seismic design of walls.

Nutritional Status of the Long-lived Elderly People in Kyungpook Sung-Ju Area(I) -Estimation of Nutrients Intakes- (경북 성주지역 장수노인의 영양상태(I) -영양섭취상태-)

  • 이혜성
    • Journal of Nutrition and Health
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    • v.33 no.4
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    • pp.438-453
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    • 2000
  • The purposes of this study were to estimate nutritional intakes of the long-lived elderly and to obtain the data for establishing dietary guidelines that may be recommended for the general population for the sake of longevity. The subjects of the study were 300 elederly people of age over 85 years living in Kyungpook Sung-Ju area who had no problem in daily living. Four times of food consumption survey were carried out seasonally by the repeated 24-hr recall method for one year. Mean daily energy intakes and RDA percentage of energy intakes of the male and female subjects were estimated as 1222 kcal(67.9%) and 1047 kcal(65.4%) respectively. Mean daily intakes of nutrients were estimated as 38.3g for protein, 287mg for calcium, 5.8mg for iron, 314R.E. for vitamin A, 0.6mg for vitamin B1 and 0.43mg for vitamin B2 The mean RDA percentages of nutrients intake were 64.4% and 59.8% for protein in male and female, 39.8% for Ca, 48.3% for Fe, 44.9% for vitamin A, 60% for vitamin B1, and 35.8% for B2. The average PFC ratio of energy-yielding nutrients throughout the year in male and female were 15.1 : 15.2 : 69.7 and 13.8 : 13.2 : 73.0 respectively. The mean daily intakes of energy and most of nutreints were significantly high in winter season. The contribution of plant food sources to nutrient intakes were over 60% for protein and fat, 50% for calcium, and 70% for iron. Long-lived elderly people an Sung-Ju, Kyungpook showed considerably smaller physiques compared to the avergae Korean elderly, however their average BMI fell in normal range. The subjects were consuming much less energy and nutrients compared to the present Korean RDA for the elderly over age 75. The subject showed relatively good health state in spite of low intakes of energy and nutrients. Therefore it seems to be necessary to establish a set of new RDA for the elderly over age 8.5.

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Substrate-Perfusion Studies on Coronary Circulation and Myocardial Energy Metabolism in Spontaneously Hypertensive Rat Hearts (발현성 고혈압쥐의 관상순환 기능과 심장근의 에너지 대사에 관한 생체외 에너지원의 관류 연구)

  • 김은지
    • Journal of Nutrition and Health
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    • v.28 no.2
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    • pp.115-126
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    • 1995
  • The effects of energy-yielding substrates on coronary circulation, myocardial oxygen metabolism, and intramyocytic adenylates of perfused Wistar control rat(WC) and spontaneously hypertensive rat(SHR) hearts were examined under basal and $\beta$-adrenergic stimulation conditions. The perfusion medium (1.0mM Ca2+) contained 5mM glucose (+5U/l insulin) in combination with 5mM pyruvate, 5mM lacate, 5mM acetate, or 5mM octanoate as energy substrates. Hearts were perfused with each substrate buffer for 20min under basal conditions. Coronary functinal hyperemia was induced by infusing for 20min isoproterenol (ISO, 1uM), a $\beta$-receptor agonist. Cardiac adenylates, glycolytic intermediates, and coronary venous lactate were measured by using an enzymatic analysis technique. Under basal conditions, acetate and octanoate significantly increased coronary flow(CF) of WC in parallel with myocardial oxygen consumption. However, CF of SHR was partly attenuated by coronary vasoconstriction despite metabolic acidosis. In addition, pyruvate and lactate depressd ISO-induced coronary functional hyperemia in SHR. It should be noted that octanoate exhibited coronary dysfunction under ISO conditions. On the other hand, fat substrates depleted myocardial high energy phosphate pool and accumulated breakdown intermediates. In SHR with coronary vasoconstriction under basal conditions, and with depressed coronary functional hyperemia, high energy phosphates were greatly depleted. These results suggest that energy substrates in the myocardium and coronary smooth muscle alter remarkably coronary circulation, and that coronary circulatory function is associated with a reserve of high energy phosphates and a balance between breakdown and nono synthesis of energy phosphates. These findings could be explained by alterations in the cytosolic redox state manipulated by LDH and hence in the cytosolic phosphorylation potential, which might be involved in hypertension of SHR.

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Antidepressant drug paroxetine blocks the open pore of Kv3.1 potassium channel

  • Lee, Hyang Mi;Chai, Ok Hee;Hahn, Sang June;Choi, Bok Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.1
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    • pp.71-80
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    • 2018
  • In patients with epilepsy, depression is a common comorbidity but difficult to be treated because many antidepressants cause pro-convulsive effects. Thus, it is important to identify the risk of seizures associated with antidepressants. To determine whether paroxetine, a very potent selective serotonin reuptake inhibitor (SSRI), interacts with ion channels that modulate neuronal excitability, we examined the effects of paroxetine on Kv3.1 potassium channels, which contribute to high-frequency firing of interneurons, using the whole-cell patch-clamp technique. Kv3.1 channels were cloned from rat neurons and expressed in Chinese hamster ovary cells. Paroxetine reversibly reduced the amplitude of Kv3.1 current, with an $IC_{50}$ value of $9.43{\mu}M$ and a Hill coefficient of 1.43, and also accelerated the decay of Kv3.1 current. The paroxetine-induced inhibition of Kv3.1 channels was voltage-dependent even when the channels were fully open. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for the paroxetine effect were $4.5{\mu}M^{-1}s^{-1}$ and $35.8s^{-1}$, respectively, yielding a calculated $K_D$ value of $7.9{\mu}M$. The analyses of Kv3.1 tail current indicated that paroxetine did not affect ion selectivity and slowed its deactivation time course, resulting in a tail crossover phenomenon. Paroxetine inhibited Kv3.1 channels in a use-dependent manner. Taken together, these results suggest that paroxetine blocks the open state of Kv3.1 channels. Given the role of Kv3.1 in fast spiking of interneurons, our data imply that the blockade of Kv3.1 by paroxetine might elevate epileptic activity of neural networks by interfering with repetitive firing of inhibitory neurons.

Evaluation on Cyclic Flexural Behavior of HSRC (Hybrid H-steel-reinforced Concrete) Beams Connected with Steel Columns (강재 기둥과 하이브리드 강재 보-RC 보 접합부의 반복 휨 거동 평가)

  • Kwon, Hyuck-Jin;Yang, Keun-Hyeok;Hong, Seung-Hyun
    • Journal of the Korea Concrete Institute
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    • v.29 no.3
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    • pp.291-298
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    • 2017
  • The objective of the present study is to evaluate the cyclic flexural behavior of a hybrid H-steel-reinforced concrete (HSRC) beam at the connection with a H-steel column. The test parameter investigated was the configuration of dowel bars at the joint region of the HSRC beam. The HSRC beam was designed to have plastic hinge at the end of the H-steel beam rather than the RC beam section near the joint. All specimens showed a considerable ductile behavior without a sudden drop of th applied load, resulting in the displacement ductility ratio exceeding 4.6, although an unexpected premature welding failure occurred at the flanges of H-steel beams connecting to H-steel column. The crack propagation in the RC beam region, flexural strength, and ductility of HSRC beam system were insignificantly affected by the configuration of dowel bars. The flexural strength of HSRC beam system governed by the yielding of H-steel beam could be conservatively evaluated from the assumption of a perfect plasticity state along the section.

Sol-Gel Encapsulation as Matrix for Potentiometric Nitrite-Selective Membranes Doped with Chloro (5, 10, 15, 20-Tetraphenylporphyrinato) Cobalt (III)

  • Zhou, Hao;Meyerhoff, Mark E.;Bi, Kai-Shun;Park, Sung-Bae
    • Journal of the Korean Electrochemical Society
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    • v.12 no.4
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    • pp.335-341
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    • 2009
  • Organic-inorganic hybrid sol-gel matrices were used as hosts for chloro (5, 10, 15, 20-tetraphenylporphyrinato) cobalt (III) (Co[TPP]Cl), a known ionophore for nitrite. The sol-gel precursor was prepared by the reaction of (3-isocyanopropyl) triethoxysilane with 1,4-butanediol. An appropriate amount of the anion-exchanger, tridodecylmethylammonium chloride (TDMAC) and the plasticizer, tributylphosphate (DBP) were used as membrane additives. On mixing with an acidic catalyst, the sol-state precursors slowly gelled, yielding a membrane in which the active components, Co[TPP]Cl and TDMAC, were encapsulated. The performances of the sol-gel membrane-based electrodes were compared to those of Co[TPP]Cl-based poly(vinyl chloride) (PVC) membrane electrodes. Membranes with a molar ratio of Co[TPP]Cl: TDMAC (1 : 0.1) showed reasonable response slopes toward nitrite. The response slopes were typically 53 mV/decade between $10^{-5.4}$ and $10^{-1.0}\;M$. Selectivities toward nitrite over hydrophilic and small anions such as chloride were somewhat inferior to those observed with PVC-based membranes, but selectivities over lipophilic anions were quite similar. Reduced asymmetry potentials due to protein adsorption were found to occur with the sol-gel matrix relative to PVC-based films when the sensors were employed as a detector in flow-through configuration.

Health Promotion Behavior of Middle-Aged Women (중년여성의 건강증진행위에 관한 연구)

  • Kwon Young-Sook;Lee Myung-Sook
    • Journal of Korean Public Health Nursing
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    • v.12 no.2
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    • pp.89-106
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    • 1998
  • The Health Promotion Model by Pender(l987) was used as the conceptual framework for analyzing the health promotion behaviors. The purposes of this study were to describe health promoting life style behaviors in 245 women between the ages of 35 and 59 living in Seoul and other cities and to find their predictive factors. Data were collected from 1st to 23th. June. 1998. The tool used for this study was structured questionnaire with consisted of 8 items on general characteristics. 5 items on health related characteristics. 43 items on health promoting life style. 28 items on menopausal symptoms. 5 items on family support. and 28 items on self-efficacy. The collected data were analyzed using the SAS. yielding descriptive statistics. ANOVA. Pearson's Correlation. stepwise multiple regression. The findings of this study are as follows. 1) The mean score of health promotion behavior(3.25) is not high. The mean scores of this self actualization (3.73). interpersonal support (3.68). and nutrition (3.57). regulation of stress (3.22) in domains are higher than health responsibility (2.90). exercise (2.63). 2) The results of the comparison between the health promotion behaviors and general variables showed a statistically significant difference in education (P=.0061), domestic economy status(P=.0001). perception of health status(P=.0001) but. age. state of menstruation. perception of weight is not significant difference. 3) The correlation between health promoting life style and self-efficacy(P=.0001). family support(P=.0001) is significant. But. there is no correlation between health promoting life style and age. number of family. perception of weight. 4) In the cognitive-perceptual factors. self-efficacy (P=.0001) is very significant predictor (accounted for $39.7\%$) and in the modifying factors. family support(P=.0001) is very significant (accounted for $9.0\%$). It is same to other research results.

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Antiplasmodial and Cytotoxic Activities of Toad Venoms from Southern Amazon, Brazil

  • Banfi, Felipe Finger;Guedes, Karla de Sena;Andrighetti, Carla Regina;Aguiar, Ana Carolina;Debiasi, Bryan Wender;Noronha, Janaina da Costa;Rodrigues, Domingos de Jesus;Vieira, Gerardo Magela Junior;Sanchez, Bruno Antonio Marinho
    • Parasites, Hosts and Diseases
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    • v.54 no.4
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    • pp.415-421
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    • 2016
  • The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower $IC_{50}$ values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.

Seismic Safety Enhancement of Damage-Controlled Reinforced Concrete Frames (손상제어 설계된 철근 콘크리트 프레임의 내진력 향상)

  • ;;Kim, Se Yoll
    • Computational Structural Engineering
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    • v.4 no.3
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    • pp.89-97
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    • 1991
  • Conventional aseismic design methods of R/C frame all but disregard the state of damage over the entire building frame. This paper presents an automated damage-controlled design method for R/C frames which aims at an uniform energy dissipation rate throughout the building frame, so that the resulting damage is uniformly distributed as much as possible over all element. The accuracy of the basic hystertic model and the damage model for R/C members is verified by reproducing the experimental load-deformation curves of one-bay one-story frames. Application of this design method to various frame structures indicate that 1) regardless of the structural properties or input earthquake characteristics, damage-controlled frames generally survive more severe earthquake excitations and suffer less damage than conventionally designed frames, and 2) member yielding strength in the lower stories of damage-controlled frames is larger than that for conventionally designed frames, while the trend is opposite in the upper stories.

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Prospect of new variety breeding of Italian ryegrass in South Korea

  • Ji, Hee Chung;Hwang, Tae Young;Lee, Ki Won
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.108-108
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    • 2017
  • The objective of this study was to know prospect and present state of new variety breeding of Forage and Grassland in South Korea. The industry of forage in Korea is going up to expend through utilization of good quality forage, Italian ryegrass, forage corn and oat rather than rice straw. Especially, since 2007, Italian ryegrass(IRG) had been very important major winter forage crop in South Korea and developed 13 varieties including very early maturity variety (three varieties), early maturity variety (three varieties), medium maturity variety (one variety) and late maturity variety (six varieties). But the disadvantage of Italian ryegrass was weak winter hardness and drought but has good advantage of forage nutritive value, high-yielding and high sugar content, and like livestock as like hanwoo, dairy cattle, goat so on. The Ko-variety (Korea developed variety) of Italian ryegrass has high cold-tolerant and adaptability more than any other country developed variety, and expend to cultivation area from southern area (below Daejeon) to middle-northern area (upper Han river). Although the cultivation area of Italian ryegrass of South Korea was 21,700 ha in 2007, right now, that of Italian ryegrass is about 123,600ha due to expend cultivation area and know famer to good forage crop and have a various maturity varieties (very early, early, medium, late) according to local situation (before-crop harvesting stage or double cropping system). The seed market of Italian ryegrass in South Korea becoming extended to around 100 million Korean won and seed export get nearer to foreign country. We are going to develop of new variety for stress tolerant and high yield and quality forage variety, good adaptability to the Korean environmental conditions including reclaimed area, make self-sufficiency system for forage seed (Italian ryegrass), export our seed to foreign countries.

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