• Title/Summary/Keyword: stress reduction

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A PHOTOELASTIC STUDY ON EFFECTS OF BONE REDUCTION FORCEPS ON MANDIBULAR FRACTURE REDUCTION (골절정복겸자가 하악골 골절정복에 미치는 효과에 관한 광탄성 연구)

  • Park, Jin-Hyoung;Choi, Byung-Ho;Yoo, Tae-Min;Huh, Jin-Young
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.28 no.6
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    • pp.464-471
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    • 2002
  • The purpose of this study was to evaluate the stress patterns within fractured mandibles generated by reduction forceps and to determine the optimal position of the reduction forcep. Twenty-seven mandibular models were fabricated using a photoelastic resin. Each of the three sets of mandible models prepared was osteotomized according to one of three different fracture types(symphysis, parasymphysis and body fractures). After reducing the cut segments, a reduction forcep was placed into different engagement holes to compress the segments. Photoelastic stress analysis was used to visualize the stress patterns within the fractured mandiblular models generated by the reduction forcep. In the case of symphysis or parasymphysis fractures, an optimum distribution of stress over the fracture site was achieved when placing the reduction forcep more than 12.5mm on either side of the fracture line between the midway level bisecting the mandible and 5mm below the level. In the case of body fractures, optimum stress distribution was achieved when the reduction forcep was placed more than 15mm from the fracture line on the midway level. In conclusion, a correct use of reduction forceps helps to provide a precise threedimensional reduction for mandibular fractures.

The Effects of Stress Reduction Programs for Young Children: A Systematic Review and Meta-analysis (유아의 스트레스 감소 프로그램 효과: 체계적 문헌고찰 및 메타분석)

  • Goh, Eun Kyoung;Kyun, Ju Youn;Ha, Ji Min
    • Korean Journal of Childcare and Education
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    • v.11 no.5
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    • pp.1-18
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    • 2015
  • Following the protocols for meta-analysis process, this study aims to determine the current state and effectiveness of stress reduction programs for young children. A population, intervention, comparisons, outcomes, study design strategy was established, and 2,322 pieces of literature from 3 electronic databases of RISS, KISS and DBpia using the key words such as"young children stress"were reviewed. Twenty-seven of these references met inclusion and exclusion criteria for systematic review and 19 references were selected for meta-analysis. Analysis results are as follows. (1) Most of the literature was published around 2010. Many types of stress reduction programs were related to physical activity for 5-year-old children. (2) Stress reduction programs were found to have positive effects on young children's stress reduction and especially, psychological therapy activity programs are more effective than others. The implications of the systematic review findings are discussed in the article.

A Clinical Report about Panic Disorder Patient imporved by Stress Reduction Program (SRP(Stress Reduction Program)을 적용하여 호전된 공황장애 48세 남환 치험 1례)

  • Suh, Jin-Woo;Kim, Jong-Woo;Chung, Sun-Yong;Park, So-Jung
    • Journal of Oriental Neuropsychiatry
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    • v.18 no.3
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    • pp.157-164
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    • 2007
  • The SRP program(stress reduction program) is reported has a good effect to patient to escape from anxiety. To reduce several symptoms due to anxiety, we performed some SRP programs to our patient who had suffered anxiety disorder. The measurement tools of patient's improvement we used are Heart Rate Variability and State-Trait Anxiety Inventory. Through this programs, symptoms and feeling of anxiety were decreased than first time and Autonomic nerve system balance was much improved. this is caused by effort of self-control meditation, mindfullness, breathing instruction and muscle relaxation program.

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A Study on the Reinforcement Effects of Fully-Grouted Rock Bolts (전면접착형 록볼트의 보강효과에 관한 연구)

  • 정해성;문현구
    • Tunnel and Underground Space
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    • v.9 no.3
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    • pp.194-203
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    • 1999
  • The axial stress in rock bolt, the shear stress at the bolt-grout interface and the neutral point are analyzed to understand the mechanical behavior of rook bolt. To analyze the support effects of rock bolt in various geological conditions, numerical analyses are performed with regard to bolt spacing and bolt length in several geological conditions and tunnel sizes. Through the numerical analyses, the distributions of maximum tensile stress and shear stress are determined. And the excavation width of underground opening affects the position of the neutral point. In the circular opening supported by pattern bolting, the increase of confining pressure, the reduction of plastic zone, and that of ground displacement are determined by using the radial stress increase ratio, the plastic zone reduction ratio and the displacement reduction ratio respectively. The results of this study can be applied to a practical tunnel design through understanding of the trends of these support effects.

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Stress Reduction Protocol for Proper Local Anesthesia of Advanced Infected Teeth in Medically Compromised Patients -Review of Literature & Report of Cases- (전신질환자에서 과도한 감염치아부 국소마취시 스트레스 감소법 : 문헌적 고찰 및 증례보고)

  • Yoo, Jae-Ha;Choi, Byung-Ho;Sul, Sung-Han;Kim, Ha-Rang;Mo, Dong-Yub
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.8 no.1
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    • pp.1-9
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    • 2008
  • Common dental procedures (local anesthesia and dental treatment) are potentially stress-inducing in many patients, especially medically compromised patients. The body response to dental stress involves the cardiovascular system (an increase in cardiovascular workload), the respiratory organ and the endocrine system (change in metabolism). To minimize the stress to the medical risk patient, the stress reduction protocol was established. The obtained contents were as follows: (1) Recognize the patient's degree of medical risk (2) Complete medical consultation before dental therapy (3) Schedule the patient's appointment in the morning (4) Monitor and record preoperative, perioperative and postoperative vital signs (5) Use psychosedation during therapy (6) Use adequate pain control during therapy (7) Short length of appointment: do not exceed the patient's limits of tolerance (8) Follow up with postoperative pain/anxiety control (9) Telephone the higher medical risk patient later on the same day that treatment was given. This protocol is predicated on the belief that the prevention of or reduction of stress ought to begin before the start of an appointment, continue throughout treatment, and, if indicated, into the postoperative period. The authors used the stress reduction protocol in the care of local anesthesia infected teeth in medically compromised patients. The final prognosis was comfortable without any complications.

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Salicylic Acid Counteracts Aluminum Stress-induced Growth and Biomass Yield Reduction in Medicago sativa L.

  • Rahman, Md. Atikur;Lee, Sang-Hoon;Song, Yowook;Ji, Hee Jung;Kim, Ki-Yong;Choi, Gi Jun;Lee, Ki-Won
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.39 no.3
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    • pp.153-157
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    • 2019
  • Salicylic acid (SA) is an essential plant growth regulator that functions as a signaling molecule in plants. The purpose of this study was to clarify how the exogenous application of SA counteracts aluminum stress-induced growth and biomass yield reduction in alfalfa exposed to aluminum (Al) stress. Two-week-old alfalfa seedlings were exposed to a combination of $AlCl_3$ ($0{\mu}M$, $50{\mu}M$ and $100{\mu}M$, respectively) and SA (0.1 mM) for 72 hours. We observed, Al stress-induced plant growth inhibition and forage yield reduction are Al stress-dependent manner. A significant reduction of plant height (42.0-52.9%), leaf relative water content (13.0-21.4%), root length (35.4-48.7%), shoot fresh weight (31.2-25.9%), root fresh weight (15.4-23.3%), shoot dry weight (12.7-22.2%), roots dry weight (47.3-53.5%), were observed in alfalfa. In contrast, SA alleviated the Al-stress and enhanced growth and biomass yield in alfalfa. This study provides useful information concerning the role of SA that counteracts aluminum stress-induced growth and yield reduction in alfalfa.

Study on Fatigue Analysis for the Cutout Panel Structure using the Relation of Max-Min Principal Stress (최대 최소 주응력 관계를 활용한 Cutout Panel 구조물의 피로해석연구)

  • Shin, Insoo;Park, Gyucheul;Moon, Jungwon;Hong, Seunghyun
    • Journal of Aerospace System Engineering
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    • v.9 no.4
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    • pp.31-36
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    • 2015
  • The fatigue analysis for cutout panel used for the weight reduction of aircraft has been conventionally performed through the open hole concept using the reference stress and stress concentration factor (Kt). However, in the actual structure cases, the goal of weight reduction might be less meaningful due to the conservative approach induced by the difficulties of extracting the confident reference stress from FE-Analysis in the complicated loading behavior. Therefore a new approach is proposed in order to secure the effectiveness of weight reduction and validate the confidence of the analysis results using the interaction of max-min principal stress at the critical location of open hole edge line.

The Effect of Progressive Muscle Relaxation using Biofeedback on Stress Response and Natural Killer Cell in first Clinical Practice of Nursing Students (바이오휘드백을 이용한 점진적 근육이완훈련이 스트레스반응과 면역반응에 미치는 효과)

  • Kim Keum-Soon
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.7 no.1
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    • pp.109-121
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    • 2000
  • Increasingly nursing science is embracing the concepts and methodology derived from psycho-neuroimmunology. It has been previously shown that stress increases and immune function declines in students undergoing examinations. To date, however, no many studies have been reported on stress levels, immune function and interventions in Korean students undergoing their first clinical nursing rotation. It was proposed that nursing students during their first clinical rotation experience increase in stress because of the novelty of the situation and their lack of clinical knowledge. It was also hypothesized that biofeedback and progressive relaxation, methods of self-regulation of involuntary autonomic nervous system responses, would reduce the stress response. The purpose of this study is to test the effectiveness of progressive muscle laxation using biofeedback The effectiveness of the experimental methods was tested by measuring the degree of symptoms of stress (SOS) and the values of ephinephrine, pulse rate, blood pressure and natural killer cells. The subjects of this study were thirty nursing students divided into two groups: experimental group was progressive muscle relaxation group using biofeedback and control group. This study was conducted for 8 weeks of clinical practice. Biofeedback training was done by software developed by J&J company (1-410 form for progressive muscle training). Progressive muscle relaxation training according to Jacobson's Theory was done by messaged word from biofeedback. The data was analyzed using Chronbach' ${\alpha}$ and t-test of the SPSS program and the significance level of statistics was 5%. The results of the study were : 1) The progressive muscle relaxation training using biofeedback was effective for the reduction of symptoms of stress(t=-4.248, p<.001) under clinical practice stress conditions. 2) The progressive muscle relaxation training using biofeedback was not effective for the values of epinephrine(t=-1.294, p=.206). 3) The progressive muscle relaxation training using biofeedback was effective for the reduction of systolic blood pressure (t=-2.757, p=.01). 4) The progressive muscle relaxation training using biofeedback was effective for the reduction of diastolic blood pressure (p=-2.032, 0=.05). 5) The progressive muscle relaxation training using biofeedback was not effective for the reduction of pulse rate(t=-15, p=.988). 6) The progressive muscle relaxation training using biofeedback was effective for the maintenance of natural killer cells (t=2.381, p=02). The first clinical rotation for student nurses is a stressful experience as seen by the rise in the SOS in the control group. Biofeedback using progressive muscle relaxation were effective in preventing the rise of symptoms of stress and the blood pressure means when comparing the pre to post clinical experience, The mean natural killer cell count was depressed in the control group but not significantly different in the experimental groups, It is proposed here that stress via the hypothalamic - pituitary - adrenal axis suppressed the NK cell count whereas the relaxation methods prevented the rise in stress and the resulting immune depression. We recommend relaxation techniques using biofeedback as a health promotion technique to reduce psychological stress. In summary. the progressive muscle relaxation training using biofeedback was effective for the reduction of symptoms of stress under clinical practice stress conditions.

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A study on Residual Stress Distribution of a Repair Weldment of Casting (주철 보수용접부의 잔류응력 분포에 관한 연구)

  • 김현수;배상득;박윤기
    • Proceedings of the KWS Conference
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    • 2003.11a
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    • pp.207-209
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    • 2003
  • In FE analysis for residual stress of a casting, contact force between mould and casting material and gravity force must be considered for exact simulation. Preheating of a repair weldment had a little effects on the reduction of residual stress. However, preheating with hammer peening had a great deal of effects on the reduction of residual stress. A method for estimation of fatigue life for a repair weldment has been established.

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Stress and Junction Leakage Current Characteristics of CVD-Tungsten (CVD 텅스텐의 응력 및 접합 누설전류 특성)

  • 이종무;최성호;이종길
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.176-182
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    • 1992
  • t-Stress and junction leakage current characteristics of CVD-tungsten have been investigated. Stressversus continuous annealing temperature plot. shows hysteresis curve where the stress level of the cooling curveis higher than that of the heating curve. It is found that the thermal and intrinsic stress of tungsten film depositedby SiH4 reduction is higher than that by Hz reduction.The tungsten film deposited by SiHl reduction is in the tensile stress state below 700"Cnd the stress ofthe film decreses with increasing annealing temperature. The stress state changes into compressive stress atabout 700"Cnd the compressive stress increases rapidly with increasing temperature.Leakage current of the n+/p diode increases rapidly especially in the range of 400-450$^{\circ}$C with increasingdeposition temperature of the CVD-W by SiH4 reduction, which is due to the Si consumption by W encroachment.On the other hand leakage current of the n+/p diode slightly increases with increasing SiH4/WF6 ratio.h increasing SiH4/WF6 ratio.

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