• Title/Summary/Keyword: stress reduce

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Applicability of Partial Post-Tension Method for Deflection Control of Reinforced Concrete Slabs (RC슬래브의 처짐제어를 위한 상향긴장식 부분PT공법의 적용)

  • Lee, Deuck-Hang;Kim, Kang-Su;Kim, Sang-Sik;Kim, Yong-Nam;Lim, Joo-Hyuk
    • Journal of the Korea Concrete Institute
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    • v.21 no.3
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    • pp.347-358
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    • 2009
  • Recently, it is getting into a good situation for the flat-plate slab system to be applied. The flat-plate slab without beam, however, is often too weak to control deflection properly compared to other typical slab-beam structures, for which the post-tension method is generally regarded as one of best solutions. The post-tension (PT) method can effectively control deflection without increase of slab thickness. Despite this good advantage, however, the application of PT method has been very limited due to cost increase, technical problems, and lack of experiences. Therefore, in order to reduce difficulties on applying full PT method under the current domestic circumstances and to enhance constructability of PT system, this research proposed the partial PT method with top jacking anchorage applied in a part of span as need. For the top jacking anchorage system, the efficiency of deflection control shall be considered in detail because it can vary widely depending on the location of anchorage that can be placed anywhere as need, and tensile stresses induced at back of the anchorage zone also shall be examined. Therefore, in this study, analysis were performed on the efficiency of deflection control depending on the location of anchorage and on tensile stresses or forces using finite element method and strut and tie model in the proposed top jacking anchorage system. The proposed jacking system were also applied to the floor slabs at a construction site to investigate its applicability and the analysis results of slab behavior were compared to the measured values obtained from the PT slab constructed by the partial PT method. The result of this study indicates that the partial PT method can be very efficiently applied with little cost increase to control deflection and tensile stresses in the region as a need basis where problem exists.

Effect of Barley Straw Application on Soil Properties, Rice Yield and Plowable Stress with Plowing Methods and Irrigation Rates in Barley- Rice Double Cropping System (이모작 벼 재배시 경운방법 및 관개량에 따른 쌀 수량, 토양특성에 대한 보릿짚 시용효과)

  • Yang, Chang-Hyu;Kim, Byung-Soo;Park, Woo-Kyun;Lee, Deog-Bae;Yoo, Chul-Hyun;Kim, Jae-Duk;Jeong, Kwang-Yong
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.3
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    • pp.201-207
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    • 2007
  • To reduce both the floatation of the seedling of rice and the failure in standing in the paddy field when the barley straw was applied to paddy field before planting the rice, we tested the effect of rice rooting with plowing methods and irrigation rates for 2 years from 2003 to 2004. This study was carried out in paddy field with Fluvio-Marine deposit in Jeonbug series and the operating accuracy and the change of soil physico-chemical properties depending on plowing methods and irrigation rates following the barley straw applying were examined. There was a less floatation of barley straw in the dry-rotaryI+water-rotaryI(DRI+WRI) plot than in the plowing+water-rotary(PL+WRI) plot. The ratio of miss-planted and floating seedling also decreased by 1.7%, 2.6% in the DRI+WRIplot compared with PL+WRI plot. The soil physical property was improved with the decreasing soil hardness, bulk density and increasing soil porosity after the application of barley straw, especially enhanced greatly in the increase of porosity, gaseous phase and with the decrease of soil hardness, bulk density of subsurface soil in DRI+WRI plot. And the change of soil chemical property were increased the content of total carbon$^{\circ}{\S}$nitrogen$^{\circ}{\S}$organic matter and available phosphate while decreased the content of exchangeable cations and available silicate after the application of barley straw. Also the content of organic matter, available phosphate and cation exchangeable capacity were increased, whereas caron/nitrogen ratio was decreased in DRI+WRI plot compared with PL+WRI plot. The number of panicles, spikelets per square meter were increased and 1,000 grains weight of hulled rice was gained more in DRI+WRI plot at irrigation rate of $500ton\;ha^{-1}$, in DRI+WRII plot at irrigation rate of $700ton\;ha^{-1}$. So the rice yields were increased by 7%, in DRI+WRI and 5% in DRI+WRII plot, respectively compared with PL+WRI plot. The result of this study indicated that the most appropriate plowing method with barley straw application on rice cultivation at double cropping in normal paddy field plain land was DRI+WRI.

Protective Effects of Phellinus linteus and Curry-Added Cooked Mixed Grain Rice Extracts on Oxidative Stress-Induced LLC-PK1 Cell Damage (상황버섯 및 카레를 첨가한 잡곡밥 추출물의 LLC-PK1 세포에서의 산화적 스트레스 보호 효과)

  • Lee, Jung-Sook;Song, Jia-Le;Kil, Jeung-Ha;Jeong, Byung-Jin;Jeong, Jong-Sung;Huh, Tae-Gon;Park, Kun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.11
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    • pp.1674-1680
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    • 2014
  • The aim of this study was to investigate the protective effects of methanolic extracts of cooked mixed grain rice samples, including grain rice (sorghum, black bean, proso millet, and Job's tears) mixed with fermented brown rice (GR), GR added with 0.5% water extract of Sanghwang mushroom (GRS) or 0.1% curry (GRK), and traditional five grain mixed rice (TMR, Ohgokbap), on $H_2O_2$-induced oxidative injury in LLC-PK1 pig renal epithelial cells. White rice (WR) was used as a positive control. Cells were first exposed to $H_2O_2$ ($250{\mu}M$) for 4 hr, followed by treatment with $100{\mu}g/mL$ of different GR extracts for 24 hr. $H_2O_2$ significantly induced cell damage (P<0.05). Cellular levels of reactive oxygen species (ROS), lipid peroxidation, and antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px), were measured. In addition, mRNA levels of antioxidant enzymes were determined by RT-PCR assay. Mixed grain rice, particularly GRS and GRK, were able to reduce cellular levels of ROS, decrease lipid peroxidation, and also increase mRNA expression of antioxidant enzymes compared to other samples. These results suggest that mixed grain rice, specifically GRS and GRK, have strong protective effects against $H_2O_2$-induced oxidative injury in LLC-PK1 cells through inhibition of lipid peroxidation, reduction of ROS levels, and elevation of antioxidant enzyme activities.

Effects of Pre-slaughter Fasting and Chiller Ageing on Objective Meat Quality in Longissimus Dorsi, Biceps Femoris, and Triceps Brachii Muscles of Korean Native Black Pigs (도축전 절식과 냉장숙성이 재래돼지 Longissimus Dorsi, Biceps Femoris와 Triceps Brachii의 육질에 미치는 영향)

  • Hwang, I.H.;Park, B.Y.;Cho, S.H.;Kim, M.J.;Lee, J.M.
    • Journal of Animal Science and Technology
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    • v.46 no.3
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    • pp.405-414
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    • 2004
  • This study evaluated the effects of preslaughter feed withdrawal and chiller ageing on objective meat quality traits in longissimus dorsi (LD), biceps femoris(BF), and triceps brachii(TB) muscles of Korean native black pigs. Twenty males were assigned into a 2(pre-slaughter feeding) ${\times}$ 2(pre-slaughter stress) ${\times}$ 4(chiller ageing) factorial. Pre-slaughter fasting for 18 h resulted in significantly(P < 0.05) higher pHs at 1.5 h for both LD and BF. On the other hand, muscle temperature did not differ between the fasted and fed animals. The result implied that pigs with different pre-slaughter feedings experienced different pH-temperature profiles during rigor development. This was reflected by the significan(P < 0.05) increase in cooking loss and hunter $L^*$ for LD of the fed pigs. However, WB-shear force of LD was not affected by the treatment. Furthermore, objective meat quality of BF and TB did not differ between the treatments. Hunter $L^*$ value and cooking loss for LD were constant for 7 d, followed by a significant(P < 0.05) increase at 14 d. BF and TB had significantly(P < 0.05) higher hunter $L^*$ value and cooking loss at 14 d than at 1 d. Significant(P < 0.05) linear reductions in LD WB-shear force took place from 1 to 7 d, while BF and TB WB-shear forces were significantly (P < 0.05) reduced at 14 d. Simple correlation for WB-shear force between LD and BF, and between LD and TB indicated that 6 kg of shear force for LD was equivalent to approximately 3.5 and 6 kg for TB and BF, respectively. On the basis of the current result, feeding until the morning of slaughter appeared to contribute to favourable meat color for LD. However, negative effect on palatability due to increase in cooking loss should be taken into account. A 7-d chiller ageing was likely the best practice for LD, while TB appeared not to require chiller ageing. A 14-d ageing could improve the tenderness of BF, but could likely reduce juiciness.

Comparison of Ventilation Efficiency in an Enclosed and Conventional Growing-Finishing Pig House (개방형과 무창형 육성비육돈사의 환기효율 비교)

  • Song, J.I.;Choi, D.Y.;Jung, J.W.;Yang, C.B.;Choi, H.L.
    • Journal of Animal Science and Technology
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    • v.46 no.3
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    • pp.459-468
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    • 2004
  • An experiment was conducted to establish comparison of ventulation efficiency in an enclosed and conventional growing-finishing pig house. The main results of the experiment are as follows : In the established temperature was sustained at the level of summer 24.8${\sim}$29.1$^{\circ}C$, winter 17.9${\sim}$23.1$^{\circ}C$ during the experimental period of enclosed growing-finishing pig house, and conventional growing-finishing pig house was at the lovel of summer 24.7${\sim}$32.3$^{\circ}C$, winter 14.5${\sim}$18.2$^{\circ}C$ during the experimental period respectively. As for the results of dertimental gas(ammonia) concentration ratio analysis, while the conventional pig house sustained of summer 9.3${\sim}$16.9 mg/$\ell$ level, enclosed growing-finishing pig house sustained of summer 7.9${\sim}$16.1 mg/$\ell$, and the latter one is lower than that of the conventional growing-finishing pig house. Air flow rate on the floor level which is the low part of pen and the active area of pigs in the enclosed growing and finishing pig house during winter was measured at 0 to 0.87 m/s at the 0.01 to 2.73 m/s at the maximum ventilation efficiency. As for breeding pigs in summer, the pigs from the conventional pig house weighed 100.2kg, on the other hand, the pigs from enclosed growing-finishing pig house weighed 107.3 kg ; the differnce between the two kinds was about 7 kg. This was because the most adequate environment, which was not influenced by the exterior atmosphere, was offered to the pigs from enclosed growing-finishing pig house, and all of this could reduce pigs stress effectively.

The Effect of Polypropylene Mulching Method on Growth of Quercus glauca Thunb. Seedling and Weed Treatments (부직포 멀칭 방식에 따른 종가시나무 묘목의 생장과 제초에 미치는 영향)

  • Sung, Chang-Hyun;Yoon, Jun-Hyuck;Jin, Eon-Ju;Bae, Eun-Ji
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.5
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    • pp.59-66
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    • 2020
  • Recently, cultivation and management technologies have been needed to adapt due to climate change, which is causing abnormal weather conditions. One technique is to increase the utilization of evergreen broad-leaved species with high ornamental value. A total of five treatments were installed (1m×22.5m), including 60g/㎡ and 80g/㎡ using two types mulching material with an overlapping and hole-drilling mulching method and these were compared to un-mulching treatment a total of planted 92㎡ attheWol-aTestSiteForestattheForestforBiomaterialsResearchCenterinJinju-si, Gyeongsangnam-dofor 10monthsusing3-years-oldQuercusglaucaThunb. In comparison with the control site, the 60g/㎡ overlapping method was about 1.9 times higher than the root collar diameter, but there was no statistical significance between the treatments. Healthy seedlings were found to meet these conditions due to high biomass values and below and T/R ratios of 3.0 or lower and H/D ratios of 7.0 or lower. Comparing the values of LWR, SWR, and RWR, which can be evaluated for seedling due to the mulching treatments, as compared to the control, the growth of the ground areas including leaves and stems was enhanced, but the growth of the underground areas containing roots tended to have high control values. Based on this, the SQI value, which can be evaluated for the comprehensive quality of seedlings, was found to be significantly different between the control site and the mulching treatment sites, confirming that the growth and growth improvement effects were achieved with mulching treatments. The chlorophyll content analysis showed that there was a significant difference from the control site, and it was judged that weed generation in the control acted as an environmental stress, causing a decrease in chlorophyll content. It was found that the overlapping 80g/㎡ of polypropylene mulching material generated about 4 times fewer weeds than the control, and the manpower required for the mulching test field and weeding were equal at 3.3 people/100㎡/1 day. Mulching treatments have demonstrated a significant difference in the promotion of growth and quality of the seedlings and are judged as an alternative that can reduce the economic burden incurred by the purchase of the supplies and the manpower required to weed forestry plantations.

Chronic Injuries and Types of Injuries Related to Adolescent Taekwondo Athletes (성장기 태권도 선수의 만성 통증과 손상 유형)

  • Kim, Ha-Kyung;Kim, Chang-Yoon;Shim, Hee-Jong;Park, Sung-Min;Bae, Byung-Jo
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.8 no.1
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    • pp.46-50
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    • 2009
  • Purpose: This study was designed to analyze? the chronic pain of adolescent Taekwondo athletes, to research the understanding about chronic pain of coaches and athletes, to? reduce the development of chronic pain. Materials and Methods: From March. 2006 to June 2007, 210 athletics and 12 coaches of elementary, middle and high school in Kwang-ju city were surveyed. They was evaluated by physical examination, simple radiographs and MRI. Results: In 210 athletics, 162(77.1%) athletes had chronic pain. 19(11.7%) athletes had over three regions of pain, 74(45.7%) athletes had two regions of pain, 69(42.6%) athletes had one region of pain. In 274 cases of 164 athletes, the most common region was foot and ankle(145 cases, 52.9%), followed by hand(47 cases, 17.2%) and knee(38 cases,13.9%), hip(25 cases, 9.1%), and lumbar area(19 cases, 6.9%) The chronic pain was classified by injury type. Contusion of foot was 103 cases(most common), sprain of ankles was 40cases, Contusion of hands and wrists was 28 cases, and so on. The etiologies of injury that causes the chronic pain were match injury in training that is most common, intensive exercise and match injury in competition. Conclusion: The chronic pain was common in adolescent Taekwondo athletes. The ankle and foot were the most common region of chronic pain and the match injury was the most common injury, caused the chronic pain. Although athletes had considerable mental stress about chronic pain, the treatment of chronic pain and rest were insufficient. Therefore the variable effort to prevent injury and to treatment injury must be considered importantly.

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Effect of Probiotics on Risk Factors for Human Disease: A Review (인간 질병의 위험 요인에 대한 Probiotics의 효과: 총설)

  • Chon, Jung-Whan;Kim, Dong-Hyeon;Kim, Hyun-Sook;Kim, Hong-Seok;Hwang, Dae-Geun;Song, Kwang-Young;Yim, Jin-Hyuk;Choi, Dasom;Lim, Jong-Soo;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.32 no.1
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    • pp.17-29
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    • 2014
  • GRAS probiotics can be used to modulate intestinal microbiota and to alleviate various gastrointestinal disorders. In several recent studies, researchers have explored the potential expansion and usability of probiotics to reduce the risk factors associated with diseases, including obesity, hypercholesterolemia, arterial hypertension, hyperhomocysteinemia, and oxidative stress. In this review, our aim was to clarify the mechanism underlying interactions between hosts (animal or human) and probiotics and the beneficial effects of probiotics on human health.

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The Characteristics of Pain Coping Strategies in Patients with Chronic Pain by Using Korean Version-Coping Strategies Questionnaire(K-CSQ) (한국판 대처 전략 질문지 (K-CSQ)를 이용한 만성 통증 환자의 통증대처 특성)

  • Song, Ji-Young;Kim, Tae;Yoon, Hyun-Sang;Kim, Chung-Song;Yeom, Tae-Ho
    • Korean Journal of Psychosomatic Medicine
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    • v.10 no.2
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    • pp.110-119
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    • 2002
  • Objectives : Numbers of patients who have chronic pain seem to be increasing in the psychiatric practice. Many investigators have used models of stress and coping to help explain the differences in adjustment found among persons who experience chronic pain. Coping strategies appear to be associated with adjustment in chronic pain patients. The objectives of this study were to develop a self-report questionnaire which is the most widely used measures of pain coping strategies, Coping Strategies Questionnaire (CSQ) into Korean version and to study the different coping strategies with which chronic pain patients frequently use when their pain reaches a moderate or greater level of intensity. Methods : One hundred twenty-eight individuals with chronic pain conditions and two hundred fifty-two normal controls were administered the Korean version-Coping Strategies Questionnaire(KCSQ) to assess the frequency of use and perceived effectiveness of a variety of cognitive and behavioral pain coping strategies. We also obtained their clinical features in chronic pain patients. Reliability of the questionnaire were analyzed and evaluated differences of coping strategies between two groups. Results : Data analysis revealed that the questionnaire was internally reliable. Chronic pain patients reported frequent use of a variety of pain coping strategies, such as coping self-statements, praying and hoping, catastrophizing, and increase behavior scales which were higher compared to the normal controls. Conclusion: K-CSQ revealed to be a reliable self-report questionnaire which is useful for the assessment of coping strategies in clinical setting on chronic pain. And analysis of pain coping strategies may be helpful in understanding pain for chronic pain patients. The individual K-CSQ may have greater utility in terms of examining coping, appraisals, and pain adjustment. A consideration of pain coping strategies may allow one to design pain coping skills training interventions so as to fit the individual chronic pain patient. Further research is needed to determine whether cognitive-behavioral intervention designed to decrease maladaptive coping strategies can reduce pain and improve the physical and psycho-social functioning of chronic patients.

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The changes of economic though (The trial of supply-side economics) (경제사상의 변화 (공급측면 경제학의 시험))

  • 서홍석
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.8
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    • pp.89-121
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    • 1997
  • Many of the measures and policies advocated by supply-siders, such as lower taxation, less government intervention, more freedom from restrictive legislation and regulation, and the need for increased productivity can be found in writing the classical economist. Nor is supply-side economics a complete divorcement from Keynesian analysis. In both camps the objectives are the same-high level employment, stable prices and healthy economic growth, the means or suggestions for attaining the objectives, however, differ. Consequently, recommended economic policies and measures are different. keynesians rely primarily on the manipulation of effective demand to increase output and employment and to combat inflation. They assume ample resources to be available in order that supply will respond to demand. The supply-siders emphasize the need to increase savings, investment, productivity and output as a means of increasing income. Supply-siders assume that the increase in income will lead to an increase in effective demand. Keynesians suggest that savings, particularly those not invested, dampen economic activity. Supply-siders hold that savings, or at least an increase in after-tax income, stimulates work effort and provides funds for investment. Perhaps keynesians are guilty of assuming that most savings are not going to be invested, whereas supply-siders may erroneously assume that almost all savings will flow into investment and/ or stimulate work effort. In reality, a middle ground is possible. The supply-siders stress the need to increase supply, but Keynes did not preclude the possibility of increasing economic activity by working through the supply side. According to Keynes' aggregate demand-aggregate supply framework, a decrease in supply will increase output and employment. It must be remembered, however, that Keynes' aggregate supply is really a price. Lowering the price or cost of supply would there by result in higher profit and/ or higher output. This coincides with the viewpoint of supply-siders who want to lower the cost of production via various means for the purpose of increasing supply. Then, too, some of the means, such as tax cuts, tax credits and accelerated depreciation, recommended by suply-siders to increase productivity and output would be favored by Keynesians also as a means of increasing investment, curbing costs, and increasing effective demand. In fact, these very measures were used in the early 1960s in the United State during the years when nagging unemployment was plaguing the economy. Keynesians disagree with the supply-siders' proposals to reduce transfer payments and slow down the process of income redistribution, except in full employment inflationary periods. Keynesians likewise disagree with tax measures that favored business as opposed to individuals and the notion of shifting the base of personal taxation away from income and toward spending. A frequent criticism levied at supply-side economics is that it lacks adequate models and thus far has not been quantified to any great extent. But, it should be remembered that Keynesian economics originally was lacking in models and based on a number of unproved assumptions, such as, the stability of the consumption function with its declining marginal propensity to consume. Just as the economic catastrophe of the great depression of the 1930s paved the way for the application of Keynesian or demand-side policies, perhaps the frustrating and restless conditions of the 1970s and 1980s is an open invitation for the application of supply-side policies. If so, the 1980s and 1990s may prove to be the testing era for the supply-side theories. By the end of 1990s we should have better supply-side models and know much more about the effectiveness of supply-side policies. By that time, also, supply-side thinking may be more crystallized and we will learn whether it is something temporary that will fade away, be widely accepted as the new economics replacing Keynesian demand analysis, or something to be continued but melded or fused with demand management.

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