• Title/Summary/Keyword: Stress- ratio

Search Result 4,009, Processing Time 0.035 seconds

Changes on Initial Growth and Physiological Characteristics of Larix kaempferi and Betula costata Seedlings under Elevated Temperature (온도 증가에 따른 일본잎갈나무와 거제수나무 유묘의 초기 생장과 생리 특성의 변화)

  • Han, Sim-Hee;Kim, Du-Hyun;Kim, Gil-Nam;Lee, Jae-Cheon;Yun, Chung-Weon
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.14 no.2
    • /
    • pp.63-70
    • /
    • 2012
  • Larix kaempferi and Betula costata seedlings were grown under an elevated temperature ($27^{\circ}C$) for four weeks to understand initial changes on physiological characteristics caused by temperature rising in connection with global warming. At the end of the treatment, growth performance, leaf pigment content, antioxidative enzyme activities and malondialdehyde (MDA) content were measured and analyzed. Relative growth rates of the height of two tree species grown under elevated temperature ($27^{\circ}C$) were lower than those of control ($24^{\circ}C$) and dry weights of leaves, stems and roots were also reduced at higher temperature. Particularly, the root growth reduction of two tree species increased markedly at $27^{\circ}C$ over the study period, which increased the ratio of shoot to root. Under higher temperature, leaf pigment contents decreased, whereas anti-oxidative enzyme activities such as ascorbate peroxidase (APX) and catalase (CAT) increased as compared with the control. But MDA content was not affected by elevated temperature. In conclusion, the elevated temperature leads to root growth reduction, restriction of nutrient uptake from soil and the reduction of leaf pigment contents, which can inhibit the aboveground growth. In addition, higher temperature might act as a stress factor that causes growth reduction through the increase of energy consumption during a growth period.

Study on Determination of Proper Pillar Width in Road Tunnel Design Stage (도로터널에서 적정한 필라폭 산정에 관한 연구)

  • Yang, Tae-Seon;Kim, Jae-Kyoung
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.14 no.5
    • /
    • pp.187-194
    • /
    • 2010
  • As the design of the pillar width (PW) of the parallel tunnels in downtown area, in which are located in plains zone with deep alluvium compared with mountain tunnels, is directly related with pre-compensation payment and costs of the underground area, it has to be planned as to keep minimum distance while securing the stability of the parallel tunnels. Although PW of downtown road tunnel in Korea is standardized as 1.5D(D: diameter of the tunnels), PW sometimes has to be reduced within 1.5D to adjust the tunnel lines to the city plan in the cases of the inlet and outlet of the tunnels. In this paper, the design and the analyses of optimum PW of the NATM type road tunnel in the downtown area are introduced. The relationship among the tunnel line planning and underground compensation fee, and ground characteristics are evaluated. In the determination of PW distance, the numerical analyses of underground road tunnels were performed, including the use of the strength decrease method and strength/stress ratio method. In the cases of inlet and outlet part of the tunnels where the stability of the pillars is poor due to contiguous construction of the parallel tunnels, the reinforcement methods are recommended for securing the stability. Numerical verification was performed for the reinforcement proposed.

Clinical Studies on 254 Cases of Patient with Facial Paralysis (구안와사(口眼喎斜) 환자 254명에 대한 감리적(臨床的) 고찰(考察))

  • Ock, Min-Keun;Lim, Woong-Kyoung;Kim, Chang-Hwan;Park, Soo-Eun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.18 no.3
    • /
    • pp.75-83
    • /
    • 2005
  • Objective: The purpose of this study is to investigate the clinical studies on 254 cases of patient with facial paralysis. Methods: We examined the sex, age, region, month, season, physical condition, attened symptoms, the period before admission, the period of treatment the times of treatment, the point of the recovery Results: 1. The distribution of sex was male 119 cases, female 125 cases(1.032:1). The distribution of age was disclosed that fifty was the most in 53 cases(20.9%) 2. In distribution of the region of facial palsy, the ratio of the male-left was 27.6%(70 cases), female-left was 24.4%(62cases), male-right was 23.2%(59 cases), female-right was 24.8%(63 cases). 3. In distribution of contributing frequence in month, January was the most in number(29 cases, 11.4%), In distribution of contributing number in season winter was the most in number(76 cases, 29.9%). 4. In distribution of physical condition, fatigue(99 cases, 40.0%), stress(66 cases 26.0%), cold exposure(43 cases, 16.9%) were investigated highly than other conditions. 5. In distribution of attended symptoms, stylomastoid pain(91 cases, 35.8%), tears(40 cases 15.7%). taste paralysis(29 cases, 11.4%) were investigated highly than other symptoms. 6. In distribution of the period before admission in descending order the first under the third day was the most number in 92 cases(62.2%), over two weeks 22 cases(14.9%) 7. In distribution of the period of treatment, over eight weeks was the most number in 91 cases(35.8%), under a week in 50 cases(19.7%). In distribution of the times of treatment under five times was the most number in 56 cases(14.2%). 8. In distribution of the point of the recovery, under two weeks was the most number in 77 cases(52%).

  • PDF

A study on the Occurrence of the Stroke Patients (뇌졸중 환자의 발생특성에 관한 연구)

  • Kim, Han-Soo
    • The Journal of Korean Physical Therapy
    • /
    • v.2 no.1
    • /
    • pp.21-33
    • /
    • 1990
  • The purpose of this study is to investigated the occurrence properties of the cerebrovascular accidents. Clinical observations were done 252 cases, were carried from June, 1989 to May, 1990 at 4 general hospital in Taegu, Korea. The following results have been obtained ; 1. Among the 252 cases of cerebrovascular accidents, males was noted in $51.6\%$ and females in $48.4\%$. The ratio between males and females was 1.1 : 1 in whole groups of cerebrovascular accidents, and in aging distribution, it was showed variety distribution in age groups, fifties, sixties and forties were in order of frequency, particulary, more than half was shelved from 50 to 69. 2. Among the 252 cases of cerebrovascular accidents, cerebral hemorrhage was rioted in $64.3\%$, cerebral infarction in $25.8\%$, cerebral thrombosis in $6.3\%$, subarachnoid hemorrhage in $2.4\%$ and cerebral embolism in $1.2\%$. 3. In distribution of academic career, high school level was noted in $37.7\%$, elementary school level in $30.5\%$, middle school level in $17.1\%$, elementary school level in $30.5\%$, middle school level in $17.1\%$ arid college level in $14.7\%$. 4. In distribution of occupation, office worker was noted in $21.8\%$, housewife in $20.2\%$, the others in $19.1\%$, physical laborer in $18.3\%$ and inoccupation in $18.3\%$. 5. In seasonal distribution, spring was noted in $34.9\%$, winter in $32.5\%$, autumn in $20.3\%$ and summer in $12.3\%$. 6. Among the preceding diseases at the onset of cerebrovascular accidents, hypertension was noted in $51.6\%$, no preceding disease in $20.2\%$, other disease in $10.3\%$ and diabetes mellitus in $9.5\%$ and cardiovalvular disease in $6.0\%$. 7. In systolic blood pressure on admission, 160-199mmHg was noted in $32.2\%$, 200-239mmHg in $23.4\%$, 140-159mmHg in $19.4\%$, below 140mmHg in $16.3\%$, and above 240mmHg in $8.7\%$, While, in diastolic blood pressure, above 130mmHg noted in $24.6\%$, below 90 mmHg in $17.1\%$, 120-129mmHg in $13.1\%$ and was 90-99mmHg in $11.1\%$. 8. In major predisposing factors of patients, emotional stress was noted in $20.2\%$, physical action in $17.9\%$, rest in $16.9\%$, while sleeping in $10.7\%$, drinking in $9.9\%$ and defecation in $7.9\%$. 9. In distribution of affected side, left was noted in $48.4\%$, right in 42.1 and both $9.5\%$. 10. In rates of recurrent cases, first attach was noted in $79.0\%$, 1st recurrence in $17.0\%$, 2nd recurrence in $3.6\%$ and 3rd recurrence in $0.4\%$.

  • PDF

Exposure of Outdoor Workers to Particulate Matter in Construction Sites (건설업 옥외작업장 근로자의 미세먼지 노출 실태 조사)

  • Kim, Seung Won;Lee, Ga Hyun;Phee, Young Gyu;Yang, Won-Ho;Ha, Wonchul;Park, Hyunghee
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.27 no.1
    • /
    • pp.46-58
    • /
    • 2017
  • Objectives: Particulate matter (PM) at construction sites mostly originates from either construction activities or the atmospheric environment. This study was conducted to evaluate the exposure level to PM and the contribution ratio of atmosphere sources at construction sites. Methods: We reviewed literature and governmental systems related to PM exposure in occupational settings and summarized them. In the field evaluation, five construction sites and one golf course were selected: two from Gyeonggi-do Province and four from North Gyeongsang-do Province. For each site, personal samples from outdoor construction workers and area samples from the outdoor area around the construction site office were collected according to construction work types. PM concentrations reported from nearby National Ambient Air Monitoring Stations were recorded. Respirable dust concentrations, respirable silica concentrations, and several metal concentrations including Cd, Cr, Pb, and As were monitored over four months. In the end we suggested how to manage particulate matter exposure at construction sites. Results: There was little literature reporting on exposure levels of construction workers to PM. Respirable dust concentrations measured in Gyeonggi-do Province were higher than those measured in North Gyeongsang-do Province. The geometric means of respirable dust concentrations in personal samples and area samples were $37.89{\mu}g/m^3$ and $92.86{\mu}g/m^3$, respectively. The respirable dust concentrations were higher than the PM concentrations reported from nearby National Ambient Air Monitoring Station. The geometric means of respirable silica concentrations of personal samples and area samples were $1.3{\mu}g/m^3$ and $1.1{\mu}g/m^3$, respectively. All metal concentrations were lower than 10% of individual Korean occupational exposure limits. Conclusions: Assuming that personal samples consisted of ambient PM and dust originating from work activities and area samples only collected ambient PM, we concluded that the dust exposure of outdoor construction workers originated 40.8% from the atmosphere and 59.2% from construction activities. PM exposure at construction sites should be controlled by employers, as in the case of outdoor heat stress. The Korean government needs to consider setting an occupational exposure limit for respirable dust.

Enhancement of γ-aminobutyric Acid Production by Combination of Barley Leaf and Corn Silk and Its Fermentation with Lactic Acid Bacteria (보리 잎과 옥수수 수염의 혼합과 유산균 발효를 이용한 γ-aminobutyric acid 생산 증진)

  • Kim, Hyung-Joo;Yoon, Young-Geol
    • Korean Journal of Organic Agriculture
    • /
    • v.25 no.1
    • /
    • pp.171-185
    • /
    • 2017
  • ${\gamma}$-aminobutyric acid (GABA) is a non-proteinogenic amino acid biosynthesized through decarboxylation of L-glutamic acid by glutamic acid decarboxylase. GABA is believed to play a role in defense against stress in plants. In humans, it is known as one of the major inhibitory neurotransmitters in the central nervous system, exerting anti-hypertensive and anti-diabetic effects. In this report, we wanted to enhance the GABA production from the barley leaf and corn silk by culturing them with lactic acid bacteria (LAB). The barley leaf and corn silk were mixed with various weight combinations and were fermented with Lactobacillus plantarum in an incubator at $30^{\circ}C$ for 48 h. After extracting the fermented mixture with hot water, we evaluated the GABA production by thin layer chromatography and GABase assay. We found that the fermented mixture of the barley leaf and corn silk in a nine to one ratio contained a higher level of GABA than other ratios, meaning that the intermixture and fermentation technique was effective in increasing the GABA content. We also tested several biological activities of the fermented extracts and found that the extracts of the fermented mixture showed improved antioxidant activities than the non-fermented extracts and no indication of cytotoxicity. These results suggest that our approach on combining the barley leaf and corn silk and its fermentation with LAB could lead to the possibility of the development of functional foods with high levels of GABA content and improved biological activities.

Physiological and Biochemical Responses of Sedum kamtschaticum and Hosta longipes to Ozone Stress (기린초와 비비추의 오존에 대한 생리·생화학적 반응)

  • Cheng, Hyo Cheng;Woo, Su Young;Lee, Seong Han;Kwak, Myeong Ja;Kim, Kyeong Nam
    • Horticultural Science & Technology
    • /
    • v.31 no.1
    • /
    • pp.1-7
    • /
    • 2013
  • In this study, the resistance to ozone and characteristics of ozone-induced damage were investigated on the perennial ground cover plant species. Sedum kamtschaticum and Hosta longipes were exposed to $200{\mu}g{\cdot}kg^{-1}$ ozone for 8 hours per day (from 08:00 to 16:00) in the naturally irradiated phytotron. The extent of ozone-induced damage was measured through the analysis of physiological parameters, such as water use efficiency (WUE), chlorophyll content (Chl. a, Chl. b, Chl. a + b, and Chl. a/b ratio), carotenoid contents, and the induction of reactive oxygen species (ROS). Ozone exposure significantly reduced the daytime WUE in both species. The contents of chlorophyll and carotenoid were also decreased and ROS, such as hydrogen peroxide ($H_2O_2$) and superoxide radical ($O_2{^-}$) were accumulated after ozone exposure. The above results of this study suggested that S. kamtschaticum is more resistant to atmospheric ozone than Hosta longipes. Considering its fast responses to ozone, it was also assumed that Hosta longipes can be used as an indicator plant of an increase in atmospheric ozone concentration.

Springback Minimization using Bottoming in Al Can Deep Drawing Process (알루미늄 캔 딥드로잉에서 Bottoming을 이용한 스프링백 최소화)

  • Park, Sang-Min;Lee, Sa-Rang;Hong, Seokmoo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.9
    • /
    • pp.302-307
    • /
    • 2016
  • The technology of multistage deep drawing has been widely applied in the metal forming industry, in order to reduce both the manufacturing cost and time. A battery can used for mobile phone production is a well-known example of multistage deep drawing. It is very difficult to manufacture a battery can, however, because of its large thickness to height aspect ratio. Furthermore, the production of the final parts may result in assembly failure due to springback after multistage deep drawing. In industry, empirical methods such as over bending, corner setting and ironing have been used to reduce springback. In this study, a bottoming approach using the finite element method is proposed as a practical and scientific method of reducing springback. Bottoming induces compression stress in the deformed blank at the final stroke of the punch and, thus, has the effect of reducing springback. Different cases of the bottoming process are studied using the finite element program, DYNAFORM, to determine the optimal die design. The results of the springback simulation after bottoming were found to be in good agreement with the experimental results. In conclusion, the proposed bottoming method is expected to be widely used as a practical method of reducing springback in industry.

The Effects of Individual Patient Behavior and Medical Care Level on Doctor's Diagnosis of Hypertension (개인 건강행태 및 지역보건의료 수준이 고혈압 의사진단에 미치는 영향)

  • Park, Chang-Soo;Kim, Young-Ran;Lee, Tae-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.10
    • /
    • pp.119-130
    • /
    • 2016
  • This study was conducted to investigate the effects of individual patient behavior regarding health and medical care level on doctor's diagnoses of hypertension. A X2-test was used to compare therapeutic compliance in individual characteristics and two-stage multilevel logistic regression to identify community variance of the related index of high blood pressure therapeutic compliance using data from 229,229 adults over the age of 19 in a community health survey conducted in 2010. The experience rate of doctors' diagnoses of hypertension was higher for people of older age, higher level of education, higher BMI, and among heavy drinkers (no recipients of basic living). Furthermore, there was a higher rate for those visiting health and medical institutions, having more frequent checks of blood pressure in a month, having a higher stress level, and having depression. Among paid workers, the ratio was lower for employers and owner/operators with more daily exercise (such as walking), infrequent smokers, and private health insurance holders. Doctor's diagnoses of hypertension was affected by individual health behavior and health and medical care level. Further studies employing multilevel analyses considering regional level data should be conducted in the future.

Bond Behavior of Epoxy Coated Reinforcement Using Direct Pull-out Test and Beam-End Test (직접인발시험과 보-단부 시험을 이용한 에폭시 도막 철근의 부착특성)

  • Kim, Jee-Sang;Kang, Won Hyeak
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.7 no.3
    • /
    • pp.271-278
    • /
    • 2019
  • The corrosion of reinforcements embedded in concrete causes severe deterioration in reinforced concrete structures. As a countermeasure, epoxy coated reinforcements are used to prevent corrosion of reinforcements. When epoxy coated bars are used, the resistance of corrosion is excellent, but epoxy coating on the bars have a disadvantage of reduction in bond capacity comparing to that of normal bars. Therefore, it is necessary to confirm the bond performance of epoxy coated reinforcements through experimental and analytical methods. Bond behaviors of epoxy coated bars for various diameters of 13 and 19mm and thicknesses of cover concrete of 3 types(ratio of cover to bar diameter) are examined. As the diameters of the epoxy coated bars increase, the difference of bond strength between epoxy coated and uncoated bars also increases and damage patterns showed pull out failure. In addition, finite element analysis was performed based on the bond-slip relationship obtained by direct pullout test and compared with the flexural test results. It is considered that flexural member test is more useful than pullout test for simulating the behavior of actual structure.