• Title/Summary/Keyword: controlled-stress

Search Result 914, Processing Time 0.028 seconds

Changes of Tree Growth and Fruit Quality of "Yumi" Peach under Long-Term Soil Water Deficit

  • Yun, Seok Kyu;Kim, Sung Jong;Nam, Eun Young;Kwon, Jung Hyun;Chung, Kyeong Ho;Choi, In Myung;Kim, Ghiseok;Shin, Hyunsuk
    • Journal of Biosystems Engineering
    • /
    • v.42 no.4
    • /
    • pp.276-282
    • /
    • 2017
  • Purpose: This paper presents the effects of soil drought stress during the growing season and pre-harvest period on tree growth and fruit quality of "Yumi" peach, an early season cultivar. Methods: Soil drought stresses were treated with four levels of -30, -50, -60, and -70 kPa during long term (LT) and short term (ST). For LT treatments, soil water was controlled for nine weeks from May 1 to July 5, which was assumed as the full growing season. For ST treatments, soil water was controlled for four weeks from June 10 to July 5, which was assumed as the pre-harvest season. Tree growth and leaf photosynthesis were measured, and fruit characteristics such as fruit weight and diameter, soluble solid and tannin contents, and harvest date were investigated. Results: Soil water deficit treatments caused a significant reduction in tree growth, leaf photosynthesis, and fruit enlargement. LT water stress over -60 kPa during the full growing season caused significant reduction in tree growth, including shoot length, trunk girth, leaf photosynthesis, and fruit enlargement. ST water stress over -60 kPa during the pre-harvest period also induced significant reduction in leaf photosynthesis and fruit enlargement, while tree growth was not reduced. In terms of fruit quality, water stress over -50 kPa significantly reduced fruit weight, increased soluble solid and tannin contents, and delayed harvest time in both LT and ST treatments. Conclusions: As a result, it is assumed that LT water stress over -60 kPa can reduce both tree growth and fruit enlargement, whereas ST water stress over -50 kPa can reduce fruit enlargement without reducing tree growth. From an agricultural perspective, moderate water deficit like -50 kPa treatments could have positive effects, such increased fruit soluble solid contents along with minimal reduction in fruit size.

Different Responses to Acupuncture in Electroencephalogram according to Stress Level: A Randomized, Placebo-Controlled, Cross-Over Trial (스트레스 정도에 따라 침 치료가 뇌파(EEG)에 미치는 영향: 무작위배정 플라시보 대조군 교차연구)

  • Kim, Song-Yi;Kim, Sang-Woo;Park, Hi-Joon
    • Korean Journal of Acupuncture
    • /
    • v.31 no.3
    • /
    • pp.136-145
    • /
    • 2014
  • Objectives : The purpose of this randomized, placebo-controlled, cross-over trial was to examine how acupuncture treatment at Shinmun(HT7) affects the brain activity and the autonomic nervous system(ANS), using electroencephalograms(EEG) and heart rate variability(HRV). Methods : Eighteen healthy volunteers participated in two separate experiments: in each experiment, either real acupuncture(RA) or non-penetrating sham acupuncture(SA) was applied at HT7 in random sequences to each person. The EEG and HRV measurements were conducted simultaneously before and during the acupuncture stimulation for 5 minutes, respectively. Resulting EEG and HRV parameters were compared between RA and SA groups. To assess differences according to the stress levels for participants, subgroup analysis was performed based on the results of the stress response index questionnaire. Results : In the results, acupuncture stimulation at HT7 increased ${\alpha}$ band in EEG. In the HRV analysis, heart rate was decreased significantly but HF and RMS-SD were increased in the RA group, compared with those of the SA group. In the subgroup analysis by stress level, participants in the RA group with high stress exhibited an increased in ${\alpha}$ band in their EEG while the low stress participants showed decrease or little increase in the band. For the SA group, ${\alpha}$ band reported relatively moderate changes in all channels. Conclusions : Our results showed that acupuncture induces changes in brain activation and the ANS. Acupuncture was related to the activation of the parasympathetic nervous system. The brain activities of the participants were different depending on the stress level.

Cognitive behavior intervention for critical incident stress management in fire fighters in Korea (소방공무원의 위기상황 스트레스 관리를 위한 인지행동 개입과 대책)

  • Lee, Eun-Jung;Kim, Jee-Hee
    • Journal of the Korea Convergence Society
    • /
    • v.6 no.2
    • /
    • pp.13-18
    • /
    • 2015
  • The purpose of the study is to investigate the predisposing factors of posttraumatic stress disorder (PTSD) in fire fighters in Korea and to suggest the program development and solution to the critical incident stress management (CISM) in the future. PTSD is characterized by invasion, withdrawal, negative change of cognition and mood, and hypersensitivity. Trauma memory includes explicit memory and implicit memory. The explicit memory is conscious, cognitive, and descriptive and is controlled by hippocampus. The data of explicit memory have inhibitive and narrative language structure. The implicit memory is inconscious, emotional, and remembered by the body. The implicit memory is controlled by amygdala and has inexpressive language structure. The deletion of implicit memory is the key point to trauma treatment. Critical incident stress management (CISM) is the approach for the solution of PTSD. In conclusion, the essential goal of CISM is the psychological cessation of PTSD. This study tried to suggest the education program development of PTSD.

The Trends in Clinical Trials about Effects of Acupuncture on Anxiety, Depression and Mental Stress - In Medline, Pubmedcentral & Oriental Medicine Journal since 2004 - (침치료가 불안, 우울 및 정신적 스트레스에 미치는 효과에 대한 임상시험 연구 경향 - 2004년 이후의 Medline, Pubmedcentral 논문 검색과 국내 한의학 학술지 중심으로 -)

  • Kang, Hee-Chul;Lee, Seung-Gi
    • Journal of Oriental Neuropsychiatry
    • /
    • v.20 no.4
    • /
    • pp.137-148
    • /
    • 2009
  • Objectives : The purpose of this study is to review the recent trends in the clinical trial studies that have been published since 2004. Methods : We reviewed the Medline & Pubmedcentral databases by using searching word of "acupuncture". Then 20 articles were selected within total 803 articles. In oriental medicine journals in Korea, we investigated 6 journals represented Korean Oriental medicine and chose 13 articles. Results & Conclusions : 1. We found 33 articles in journals. 2. The patterns of study were as follows: Randomized Controlled Trials(18), Single case series clinical study(9), Case-Control clinical study(4), Randomized crossover Trial(1) and Prospective Clinical analysis(1). 3. The fields of study were as follows: Combined anxiety, depression & other psychiatic symptoms(18), Stress & heart rate variablity(5), The single study of anxiety(5), The single study of depression(3), Stress & pupil variablity(1), Stress and heart rate & pupil variablity(1). 4. The methods of acupuncture were as follows: Acupuncture on points of 14 meridians(24), Auricular acupuncture(3), Electro acupuncture(2) and Both Auricular & Electro acupuncture(1). 5. Stomach meridian(足陽明胃經) and ST36(足三里) were used mostly.

  • PDF

Joule Heating Effects and Initial Resistance in Electromigration Test (EM시험에서의 Joule Heating 영향 및 초기저항값)

  • Ju, Cheol-Won;Gang, Hyeong-Gon;Han, Byeong-Seong
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.48 no.6
    • /
    • pp.436-441
    • /
    • 1999
  • Joule heating effect in EM(Electromigration) test were performed on a bend test structure. EM test is done under high current densities(1.0-2.5MA/cm2), which leads to joule heating. Since joule heating is added to the controlled oven(stress) temperature, themetal line temperature is higher than the stress temperature. The increase in the stress temperature due to joule heating is important because EM phenomena and metal line failure are related to the stress temperature. In this paper, metal line was stressed with a current density of 1.0 MA/$cm^2$, 1.5MA/$cm^2$, 2.0MA/$cm^2$, 2.5MA/$cm^2$, for 1200 sec and temperature increase due to joule heating was less than $10^{\circ}C$. Also it took 30 minutes for the metal line to equalized with oven temperature. Recommendations are given for the EM test to determine the initial resistance of EM test structure under stress temperature and current density.

  • PDF

Theoretical Study of Design Parameters for the Thermal Stress in Engine Exhaust Manifold (엔진 배기매니폴드의 열응력 발생에 관한 설계 인자들의 이론적 연구)

  • Choi, Bok-Lok
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.6 no.1
    • /
    • pp.50-56
    • /
    • 2007
  • Exhaust manifold is generally subjected to thermal cycle loadings ; at hot condition, large compressive plastic deformations are generated, and at cold condition, tensile stresses are remained in highly deformed critical zones. These phenomena originate from the fact that thermal expansions of the runners are restricted by inlet flange clamped to the cylinder head, because the former is less stiff than the latter and, the temperature of the inlet flange is lower than that of the runners. Since the failure of an exhaust manifold is mainly caused by geometric constraints between the cylinder head and the manifold, the thermal stress can be controlled by geometric factors. The generic geometric factors include the inter distance (2R), the distance from the head to the outlet (L), the tube diameter(d) and the tube thickness (t). This criteria based on elastic analysis up to onset of yield apparently indicate that the pre-stress also reduces the factor; however, high temperature relaxation may reduce this effect at later operation stage.

  • PDF

Cyclic Creep Properties of Nicoseal(Fe-29Ni-17Co) Alloy (Nicoseal(Fe-29Ni-17Co) 합금의 Cyclic 크리프 특성)

  • Park, Yong-Gwon;Choi, Jae-Ha
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.18 no.3
    • /
    • pp.177-182
    • /
    • 2005
  • The steady state cyclic mechanism, and the behaviour of Nicoseal(Fe-29Ni-17Co) have been examined under the condition of square wave stress cyclic tension creep test at the temperature, stress and frequency range of $430{\sim}470^{\circ}C$($0.41{\sim}0.43T_m$), 353~383 MPa, and 3 cpm, respectively. Also, the relationship between cyclic creep and static creep have been examined. The stress exponents(n) for the static creep deformation of this alloy were 11.6, 10.0, 8.4 and 7.9 at the temperature of 430, 445, 460 and $470^{\circ}C$, respectively. The apparent activation energies (Q) for the static creep deformation were 54.2, 51.8, 49.7 and 46.8 kcal/mole for the stress of 353, 363, 373 and 383 MPa, From the above results, it could be considered that the cyclic creep accelaration phenomena was obtained and that the cyclic deformation for Nicoseal seemed to be controlled by dislocation climb over the range of experimental conditions. Nicoseal alloy under the cyclic creep conditions was obtained as P=(T+460)(logt+17). The failure plane observed by SEM showed up transgranular fracture at all range.

Rescue of Oxidative Stress by Molecular Chaperones in Yeast

  • Ueom Jeonghoon;Kang Sooim;Lee Kyunghee
    • Proceedings of the Microbiological Society of Korea Conference
    • /
    • 2002.10a
    • /
    • pp.76-78
    • /
    • 2002
  • Heat shock proteins (HSPs) are induced in most living cells by mild heat treatment, ethanol, heavy metal ions and hypoxia. In yeast Saccharomyces cerevisiae, mild heat pretreatment strongly induces Hsp104 and thus provide acquired thermotolerance. The ability of hsp104 deleted mutant $({\triangle}hsp104)$ to acquire tolerance to extreme temperature is severely impaired. In providing thermotolerance, two ATP binding domains are indispensible, as demonstrated in ClpA and ClpB proteases of E. coli. The mechanisms by which Hsp104 protects cells from severe heat stress are not yet completely elucidated. We have investigated regulation of mitochondrial metabolic pathways controlled by the functional Hsp104 protein using $^{13}C_NMR$ spectroscopy and observed that the turnover rate of TCA cycle was enhanced in the absence of Hsp104. Production of ROS, which are toxic to kill cells radiply via oxidative stress, was also examined by fluorescence assay. Mitochondrial dysfunction was manifested in increased ROS levels and higher sensitivity for oxidative stress in the absence of Hsp104 protein expressed. Finally, we have identified mitochondrial complex I and Ferritin as binding protein(s) of Hsp104 by yeast two hybrid experiment. Based on these observations, we suggest that Hsp104 protein functions as a protector of oxidative stress via either keeping mitochondrial integrity, direct binding to mitochonrial components or regulating metal-catalyzed redox chemistry.

  • PDF

A Case Report of Conservative Treatment of Femoral Neck Stress Fracture Developed in Avascular Necrosis of the Femoral Head (대퇴골두 무혈성 괴사에 속발한 대퇴경부 피로골절 환자에서의 보존적 치료 치험 1례)

  • Ro, Hae-Rin;Park, So-Hyun;Kim, Jeong-Won;Cho, Tae-Young
    • The Journal of Churna Manual Medicine for Spine and Nerves
    • /
    • v.6 no.2
    • /
    • pp.79-85
    • /
    • 2011
  • Objectives : The Purpose of this study is to investigate the clinical application of conservative treatment for femoral neck stress fracture developed in avascular necrosis of the femoral head. Methods : Patient is hospitalized at Dept. of Oriental Rehabilitation Medicine, Bu-Chun Jaseng Oriental Medicine Hospital, diagnosed as femoral neck stress fracture developed in avascular necrosis of the femoral head and treated by herbal medicine, acupuncture and moxibustion. This study was measured by Visual Analogue Scale(VAS) score, range of motion and walking time. Results : After conservative treatment, the patient's pain was controlled and VAS score was decreased. Range of motion and walking time were improved. Conclusions : As seen in this one case, Oriental conservative treatment has a positive effect to control pain with femoral neck stress fracture developed in avascular necrosis of the femoral head.

  • PDF

Maximization in Reliability Design when Stress/Strength has Time Dependent Model of Deterministic Cycle Times

  • Oh, Chung-Hwan
    • Journal of Korean Society for Quality Management
    • /
    • v.18 no.1
    • /
    • pp.129-147
    • /
    • 1990
  • This study is to refer to the optimization problems when the stress and strength follow the time dependent model, considering a decision making process in the design methodology from reliability viewpoint. Reliability of a component can be expressed and computed if the probability distributions for the stress and strength in the time dependent case are known. The factors which determine the parameters of the distributions for stress and strength random variables can be controlled in design problems. This leads to the problem of finding the optimal values of these parameters subject to resources and design constraints. This paper is to present techniques for solving the optimization problems at the design stage like as minimizing the total cost to be spent on controlling the stress and strength parameters for random variables subject to the constraint that the component must have a specified reliability, alternatively, maximizing the component reliability subject to certain constraints on amount of resources available to control the parameters. The derived expressions and computations of reliability in the time dependent case and some optimization models of these cases are discussed. The special structure of these models is exploited to develop the optimization techniques which are illustrated by design examples.

  • PDF