• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.911-919
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• 2021

In this paper, the design stress intensity values for the plate-type fuel assembly for research reactor are presented. Through a tensile test, the material properties of the cladding (aluminum alloy 6061) and structural material (aluminum alloy 6061-T6), in this case the yield and ultimate tensile strengths, Young's modulus and the elongation, are measured with the temperatures. The empirical equations of the material properties with respect to the temperature are presented. The cladding undergoes several heat treatments and hardening processes during the fabrication process. Cladding strengths are reduced compared to those of the raw material during annealing. Up to a temperature of 150 ℃, the strengths of the cladding do not significantly decrease due to the dislocations generated from the cold work. However, over 150 ℃, the mechanical strengths begin to decrease, mainly due to recrystallization, dislocation recovery and precipitate growth. Taking into account the uncertainty of the 95% probability and 95% confidence level, the design stress intensities of the cladding and structural materials are established. The presented design stress intensity values become the basis of the stress design criteria for a safety analysis of plate-type fuels.

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.149-158
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• 2009

American sycamore seedlings were grown in chambers with two different ozone concentrations ($O_3$-free air and air with additional $O_3$) for 45 days. Both the control and the $O_3$ chambers included non-fertilized and fertilized plants. After 18 days of $O_3$ fumigation, seedlings were placed in a clean chamber for 27 days. Seedlings under ozone fumigation showed a significant decrease in pigment contents and photosynthetic activity, and a significant increase in lipid peroxidation. Fertilization enhanced physiological damage such as the inhibition of photosynthetic activity and the increase of lipid peroxidation under ozone fumigation. During the recovery phase, the physiological damage level of seedlings increased with ozone fumigation. In addition, physiological damage was observed in the fertilized seedlings. Superoxide dismutase (SOD) and glutathione reductase (GR) activities of $O_3$-treated seedlings increased up to 33.8% and 16.3% in the fertilized plants. The increase of SOD activity was higher in the fertilized plants than in the non-fertilized plants. Negative effects of ozone treatment were observed in the biomass of the leaves and the total dry weight of the fertilized sycamore seedlings. The $O_3$-treated seedlings decreased in stem, root and total dry weight, and the loss of biomass was statistically significant in the fertilized plants. In conclusion, physiological disturbance under normal nutrient conditions has an effect on growth response. In contrast, in conditions of energy shortage, although stress represents a physiological inhibition, it does not seem to affect the growth response.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.215-224
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• 2006

Objectives : In order to apply useful data to clinical practice, we undertook this study and tried to find factors related with sequelae of facial palsy in relation with patients' age and gender distribution, past history with the disease, condition before onset, duration of recovery time, existence of remaining sequelae, types of the sequelae, and duration for sequelae to disappear. Methods : We evaluated patients' condition (fatigue, stress, chills, cold and so on), past history (diabetes mellitus, hypertension, stroke, herpes zoster, cancer and so on), duration of recovery time, types of the sequelae, age and sequelae distribution as to when the treatments were started as we examined 473 patients who were diagnosed with facial palsy, and visited the Out-patient Department of Acupuncture and Moxibustion of Bundang Oriental Medicine Hospital of Dongguk University through 2003 and 2004. Results : The sequelae of facial palsy were not significantly relevant to the signs found before facial palsy occurred(fatigue, stress, chills, and cold), or to patients' past history (hypertension, diabetes mellitus, facial palsy, herpes zoster). The duration of recovery time was within 30 days for 45.3% of the patients examined in this study, and within 90 days for 72.6%. Evaluating the existence of sequelae in relation to age, we found more in the group comprised of patients aged 50 and over than under 50. We found more sequelae in the group which is consisted of patients who had not been treated until 6 days after than within 5 days from the onset. Conclusion: Attention to sequelae will be needed for patients aged 50 and over and who were not treated until 6 days after the onset, as they had more sequelae.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.353-362
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• 2018

The purpose of this study is to suggest a professional consensus on the topics that should be dealt with importantly in the movement program for the recovery of cancer patients in Korea. As a result of calculating the importance of the finalized movement program component, First, the opinions about the environment for the promotion of movement were suggested as pleasant facilities, natural lighting, rest room space, facilities aspect of environment friendly space, education about diseases, participation programs, health feedback, information handouts. Second, the opinions on the purpose of the movement program were suggested to promote prevention and early screening of cancer, education, sharing effective treatment methods of cancer patients, cognitive aspect and psychological support for accurate information transmission, stress relief, and improvement of quality of life. Third, the opinions on the consideration of the movement program suggested stress relieving, cancer patient's needs, correct information delivery, quality of life, and participation of cancer patients. Fourth, the problems of the movement program were presented with different physical characteristics, physical inconvenience, the patient side of passive participation, space narrowness and lack, space aspect of program exclusive space etc.

• Korean Journal of Exercise Nutrition
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• v.25 no.1
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• pp.42-55
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• 2021

[Purpose] This study investigated the effects of marine phytoplankton supplementation (Oceanix®, Tetraselmis chuii) on 1) maximal isometric strength and immune function in healthy humans following a oneweek high-intensity resistance-training program and 2) the proinflammatory cytokine response to exercise in a rat model. [Methods] In the human trial, 22 healthy male and female participants were randomly divided into marine phytoplankton and placebo groups. Following baseline testing, participants underwent a 14-day supplement loading phase before completing five consecutive days of intense resistance training. In the rat model, rats were randomly divided into four groups (n=7 per condition): (i) control, (ii) exercise, (iii) exercise + marine phytoplankton (2.55 mg/kg/day), or (iv) exercise + marine phytoplankton (5.1 mg/kg/day). Rats in the exercising groups performed treadmill exercise 5 days per week for 6 weeks. [Results] In the human model, marine phytoplankton prevented significant declines in the isometric peak rate of force development compared to placebo. Additionally, salivary immunoglobulin A concentration was significantly lower following the resistance training protocol in the placebo group but not in the marine phytoplankton group. Marine phytoplankton in exercising rats decreased intramuscular levels and serum concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) and intramuscular concentrations of malondialdehyde. [Conclusion] Marine phytoplankton prevented decrements in indices of functional exercise recovery and immune function. Mechanistically, these outcomes could be prompted by modulating the oxidative stress and proinflammatory cytokine response to exercise.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.59-66
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• 2001

Objectives: This study examined the effect of mood and personality characteristics on psychophysiological responses measured by a biofeedback system in a normal population. Methods: Fifty healthy volunteers without any history of medical or psychiatric illnesses participated in this study. We measured the Spielberger trait anxiety inventory, Beck depression inventory, and Eysenck personality questionnaires in these subjects. Using the J & J biofeedback system, we also measured skin temperature, electrodermal response, forearm and frontal electromyography (EMG)s in 3 experimental conditions of baseline, stress, and recovery phases. Results: Trait anxiety did not show any significant correlation with psychophysiological responses except stress response in forearm EMG levels(r=0.282, p<0.05). Depressed mood was negatively correlated with forearm EMG levels in baseline (r=-0.299, p<0.05) and recovery phases(r=-0.314, p<0.05). Subjects with relatively high levels of depressed mood showed different stress and recovery responses in frontal EMG levels compared with those with relatively low levels of depressed mood (F=4.26, p<0.05). Extroverted subjects showed higher levels of forearm EMG than introverted ones in stress phase. Conclusion: Mood and personality characteristics in healthy subjects are closely related with psychophysiological responses measured by a biofeedback system. We suggest that mood and personality characteristics should be considered as important variables in analyzing abnormal psychophysiological responses in some psychiatric patients.

• Physical Therapy Rehabilitation Science
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• v.7 no.4
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• pp.191-196
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• 2018

Objective: The purpose of this study was to investigate the effects of 5 different personalities on job stress in physical therapists. Design: Descriptive cross-sectional study. Methods: Structured self-report questionnaires consisted of demographic items, 5 types of personalities, and occupational stress. A questionnaire was distributed to 420 physical therapists working in Seoul and Incheon who had voluntarily agreed to participate in the study after the purpose of the study was explained. Of the 420 questionnaires, 405 questionnaires were collected and showed a recovery rate of 96.4%, of which 28 cases were excluded, leaving a total of 377 questionnaires being used for analyses. Pearson correlation analysis was performed to investigate the correlation of job stress and five personalities types. In addition, multiple regression analysis was performed to investigate the effect of general and occupational characteristics of physical therapist on job stress and the effect of personality type on occupational stress. All statistical significance levels were set at p<0.05. Results: The highest number of subjects, which were the physical therapists, showed the tendency to have a sincere personality, followed by affinity, openness, extroversion, and neuroticism. Physical therapists reported to be the most stressed in the order of professional role conflict, overload of work, work relation with a physician and supervisor, interpersonal relationship with patient and caregiver. The higher the level of affinity and sincerity, the lower the amount of stress received by the therapist from the interpersonal relationships between the patient and caregivers. On the other hand, the greater the level of openness and sincerity, the lower the stress levels related to professional role conflict. Conclusions: This study showed that the personality type and job stress of physiotherapists had a statistically significant effect. It is very important for physiotherapists to find their own way of coping with stress, which is satisfactory and appropriate for their job, because it is related not only to individual problems but also to the quality of patient care and medical services. Therefore, it is necessary to continue conducting research on how to relieve the stress levels of physical therapists according to their personality characteristics.

• Structural Engineering and Mechanics
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• v.23 no.4
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• pp.339-352
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• 2006

Observing the unique stress-strain curves of the superelastic shape memory alloy (SMA) in tension and compression, the primary intention of this study is to investigate the behavior of the shafts made of the same material, under torsional loading-unloading cycles for large angle of twist. Experiments have been performed for the superelastic SMA shafts with different unsupported lengths and angles of twist and the results are compared with those of stainless steel (SUS304) shafts under similar test conditions. As expected for the superelastic SMA, the residual strains are small enough after each cycle and consequently, the hysteresis under loading-reverse loading is much narrower than that for the SUS304. For large angle of twists, the torsional strength of the superelastic SMA increases nonlinearly and exceeds that of SUS304. Most interestingly, the slender solid superelastic SMA shafts are found to buckle when acted upon torsion for large angle of twist.

• Journal of the Korean Home Economics Association
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• v.48 no.3
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• pp.55-69
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• 2010

A college student who exhibited several post traumatic stress disorder (PTSD) symptoms was used as a case study in order to investigate the therapeutic effects of sandplay therapy for PTSD sufferers. In total, 27 sessions of the sandplay treatment program were used to conduct psychological tests before and after the sessions. Any changes in the manner of expressions on the sand box during the treatment, and the results of pre and post psychological tests on aspects of depression, anxiety and interrelationships were analyzed. Overall results showed that the subject exhibited progressive behavioral improvement and signs of recovery. Psychological tests revealed reduced levels of depression and anxiety, and improved interrelationship scores. In conclusion, sandplay therapy does exhibit positive benefits as an effective treatment modality for PTSD in adolescents and young adults.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.93-98
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• 2001

A chilling-tolerant japonica-type and a chilling-susceptible indica-type of rice (Oryza sativa L.) plants were compared with respect to various physiological parameters during chilling and subsequent recovery. The japonica-type and the indica-type of rice cultivars used were Ilpumbyeo and Taebaekbyeo, respectively. The two rice cultivars exhibited little or no differences in the changes of leaf fresh weight and chlorophyll content during chilling at $5^{\circ}C$ for 3 days. During subsequent recovery at $25^{\circ}C$, however, Ilpumbyeo restored its growth more rapidly than Taebaekbyeo. Since the changes of relative water content, malondialdehyde production, an estimate of lipid peroxidation, and chlorophyll fluorescence were significantly different in the two rice cultivars during the chilling and subsequent recovery, they were found to be more sensitive physiological parameters than fresh weight and chlorophyll content. However, the differences in relation to water content, malondialdehyde production, and chlorophyll fluorescence between the two rice cultivars were smaller during chilling than those during subsequent recovery. These results suggest that relative water content, malondialdehyde production, and chlorophyll fluorescence could widely be used as important physiological parameters for screening chilling-tolerant plants.