• Journal of the Korea Concrete Institute
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• v.11 no.6
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• pp.3-12
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• 1999

The larger, loftier and more highly strengthened the recent structures become, the greater attention is paid to the problem of thermal crack occurrence associate with hydration heat. As one of methods to solve the problem, a care has been taken to the improvement of construction such as the application of pre-cooling or pipe-cooling, adjustment of concrete block size, concrete placement timing, joint arrangement and so on. But it is expected that a proper selection of cement shall additionally contribute to the control of thermal cracks. In this study, thus, we selected 4 types of cements such as Type V for anti-sulphate, blast furnace cements (slag content of 45% and 65% respectively)and ternary blended low heat cement, and carried out mock-up tests. In every assigned time, temperatures and thermal stresses were measured and calculated from raw data. As a result of measurement, it was found that the magnitude of hydration heat is in order of blast furnace slag cement. Type V and ternary blended low heat cement. Results of thermal stresses were same as the order of temperature. In addition, thermal stresses calculated from the data of strain gauges showed almost similar to those measured from effective stress gauges only when strain values were adjusted properly in accordance with initial time of stress appearance. Theoretical results agreed well with the measured values comparatively, but showed slight differences. It is inferred that these differences shall be reduced if more tests capable of evaluating thermal characteristics of concrete are carried out.

• Journal of fish pathology
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• v.15 no.2
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• pp.65-75
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• 2002

This study was performed to know the effects of stress induced by the daily fluctuation of water temperture from 18$^{\circ}C$ to 25$^{\circ}C$ up and down for 30 days on the defence mechanism of olive flounder. Puralichthys olivaceus. To make clear the temperature stress on the defense mechanism of the tested fish. several factors of immune response such as counting of leucocyte appearance in peripheral blood, phagocytic activity in whole blood cells, nitroblue tetrazolium(NBT) reduction, chemiluminescence(CL) response, and lysozyme activity were investigated at 28 days after giving the change of water temperature. The fish was controlled under the none feeding condition during experimental period. Mortality of the tested fish was rapidly increased up to 22% within the first one week of the experimental period without any additional stress factors. The number of neutrophil of peripheral blood in the tested group was significantly higher than the control group at the 2nd week. but the number of lymphocyte was significantly lower than the control group at the 1st and 3rd day of the experimental period. respectively. In the NBT reduction test, the activity of macrophage in the control group fish was the highest on the 7th day while that in the tested group was on the 3rd day. Also. the phagocytosis of tested group against formalin killed cells was retarded compared with the control. CL response of the tested group was significantly lower from 2nd to 5lh day of the experimental period than the control. 'The lysozyme activity of tested group was remained higher during the experimental period than the control. Even though the tested fish showed different results in some non-specific factors of immune respceses between tested and control group fish, olive flounder seems highly adaptable in repealed water temperature change in condition after one week under the given temperature fluctuation range.

• Journal of the Korean institute of surface engineering
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• v.51 no.1
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• pp.62-70
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• 2018

Sulfamate plating solution containing a small amount of chloride bath was fabricated to study the properties of the electrodeposited Ni thin films. Effects of the changes of current density and additive concentration on current efficiency, residual stress, surface morphology and microstructure of Ni thin films electrodeposited from Ni sulfamate-chloride baths were investigated. The current efficiency was measured to be more than about 95%, independent of the changes of current density and saccharin concentration in the baths. Residual stress of Ni thin film was appeared to be the compressive stress modes in the range of $5{\sim}30mA/cm^2$ current density. Maximum compressive stress was observed at the current density of $10mA/cm^2$. Compressive stress values of Ni thin/thick films were increased to be about -85~-100 MPa with increasing saccharin concentration from 0 to 0.0195 M(4 g/L). Surface morphology was changed from smooth to nodule surface appearance with increasing the current density. Smooth surface morphology of Ni thin films electrodeposited from the baths containing saccharin was observed, independent of the saccharin concentration. Ni thin/thick films consist of FCC(111), FCC(200), FCC(220), FCC(311) and FCC(222) peaks. It was revealed that the FCC(200) peak of Ni thin films is the preferred orientation in the range of $5{\sim}30mA/cm^2$ current density. The intensity of FCC(200) peak was gradually decreased and the intensity of FCC(111) peak was increased with increasing saccharin concentration in the baths.

• Journal of Korean Academy of Nursing
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• v.13 no.3
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• pp.75-85
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• 1983

This study was done to research the relationship between general characteristics and stressor, stress situation, Nursing Intervention of pregnant woman. The subjects for this study were 70 pregnant woman from 3 clinics of Obstetrics and Gynecology located in J city. The data was collected through questionaires which was developed by Norman J. Chestnut. The content of the questionaire consist of following 3 categories; (1) stressor (2) stress situation (3) Mental and Physical support of husband. Analysis of data was done by use percentage, x²-test. (through EDPS) The findings of this study are as follows; 1, Stressors of pregnant woman are stresses associated with fetus, socioeconomic problem, herself, delivery, abortion and prematureity, husband, change of appearances, management of home, a woman's parents-in-law. Stress situations of pregnant woman are when she is doing on the heavy management of home, limit of life, socioeconomic discomfort, taking medicine, difficult relationship with a woman's parents-in-law, being sign of abortion and prematurity, her physical discomfort, family desire of delivery of son baby. 2. Husband's mental support that pregnant woman desired are careful husband's role, More love and interest about pregnant, cooperation of child reaing, maintenance of healthy life, understaning of diffical pregnancy, early return home, giving up drinking, positive feeling about changed appearance, unconcern about sex of fetus. And husband's mental supports that pregnant woman desired are cooperating of homework and childrearing, limit of intercouse, release behavior of pregnant woman's physical discern-fort, a walk, behavior with pregnancy together, socioeconomic stability. 3. Stressor of pregnant woman was significant with education, number of son, economic status, personality of husband, dowelling. (P<.05) And stress situation of pregnant woman was significant with personality of husband, dwelling, husband's desired sex .of baby. (P<.05) 4. Husband's mental and physical supports that pregnant woman desired was significant with number of daughter. (P<.05).

• Food Science and Biotechnology
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• v.17 no.4
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• pp.713-717
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• 2008

In the present study, chronic effects of the hot water extracts of walnut seed (Juglans regia L.) (WSE) and Nelumbo nucifera seed (NSE) were investigated in mice exposed to 2 hr of restraint stress each day for 4 weeks. Corticosterone levels in serum were significantly increased in the vehicle-treated stressed group ($25\;{\mu}g/dL$) compared to that in the control group ($13\;{\mu}g/dL$). This stress induced gastric redness and lesions. However, treatment with WSE and/or NSE significantly protected the stomach from this lesion by 50-60% compared to that in the vehicletreated group. In the amygdala, the administration of WSE and/or NSE also reduced the immediate early gene (c-fos) expression by 70-90% vs. the vehicle-treated group. These suggest that WSE and/or NSE may reduce the appearance of symptoms induced by stress and these materials are useful as anti-stress foods, as natural products tend to be relatively safe compared to chemical products.

• Structural Engineering and Mechanics
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• v.47 no.1
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• pp.59-73
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• 2013

The Xiaolan channel super large bridge is unique in style and with greatest span in the world with a total length of 7686.57 m. The main bridge with spans arranged as 100m+220m+100m is a combined structure composed of prestressed concrete V-shape rigid frame and concrete-filled steel tubular flexible arch. First of all, the author compiles APDL command flow program by using the unit birth-death technique and establishes simulation calculation model in the whole construction process. The creep characteristics of concrete are also taken into account. The force ratio of the suspender, arch and beam is discussed. The authors conduct studies on the three-plate webs's rule of shear stress distribution, the box girder's longitudinal bending normal stress on every construction stage, meanwhile the distribution law of longitudinal bending normal stress and transverse bending normal stress of completed bridge's box girder. Results show that, as a new combined bridge, it is featured by: Girder and arch resist forces together; Moment effects of the structure are mainly presented as compressed arch and tensioned girder; The bridge type brings the girder and arch on resisting forces into full play; Great in vertical stiffness and slender in appearance.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.264-271
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• 2019

Currently, teenagers value the beauty of appearance due to the proximity of the media. Therefore, acne on the skin is not a serious disease, but if it is managed incorrectly, it will leave scars and marks on the face, which leads to students' depression, stress and loss of confidence. Therefore, this study analyzed how acne skin afects adolescent's stress, depression and self-esteem and recognized that acne is not a simple skin disease but is closely related to mental health. And three hypotheses were established to be more effective in managing acne skin and to be used as basic data for skin care. As a result, it was found that acne development of junior high school students had an actual effect on stress and depression. Acne skin care is considered to be necessary for mental health, not superficial management.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.447-452
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• 2019

Modern people are investing a lot of time and economically in their appearance as a means of expressing their aesthetic desires. They have a lot of hair dyes that make up most of their appearance, but their hair damage is serious. Especially, they use hair dyes which are very popular among the hair cosmetics that make up most of their appearance, but their hair damage is serious. The purpose of this study is to investigate the hair tensile strength of hair with oxidative hair dye to induce styling while minimizing hair damage. The results showed that the Max. load, Max. stress, Max. elongation, break load, break stress, break elongation, maximum modulus and tangential modulus according to evaluation interval were significantly different between control and 8N-10N experimental groups. The maximum modulus and tangential modulus for the strain interval did not show tendency to increase or decrease constantly, although there was a difference between the control and experimental group. Therefore this study was conducted to investigate the correlation between hair loss and hair damage through the treatment of high grade oxidative hair dye, which is widely used in ield of industry. We want to provide application data.

• Korean Journal of Health Education and Promotion
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• v.3 no.1
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• pp.43-55
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• 1985

The recent problems of adolescents are leading us to amphasize school mental health program. Therefore, for the first step of that program, this study was attempted to find out the students' daily life stress, their adaptation beharior to resolve that stress, and their self-concept which has an effect on that beharior, to analyze the relationship among those three variables, and to provide basic data which help maintain and promote students' adaptability and mental health. The subjects were 4 classes each grade, 743 students who were chosen as a sample subject among the total of 3,250 students of a junior girls' school in Seoul by stratified sampling method. The Oquestionnair surrey was done from April 1, 1985 to April 6, 1985. The instruments were (1) a part of Junghoon chois' perceptual Orientation Scale for measuring self-perception of students, (2) Rosenberg's Questionnair for measuring students' evaluation of self-esteem, (3) modified Bell's Adoptive Behavior Questionnair, and (4) the Measuring scale for stress developed by the investigator. The collected data were analyzed by using descriptive statistics, x²-test, t-test, ANOVA, and Pearsons' Correlation. The results are summarized as follows: 1. The range of mean score of self-concept, stress, and adaptation beharior is 1-5 respectively. The mean score of self concept was 3.45. The mean score of stress was 2.53, and the degree of stress was in order of the problem of study and grade marks, girl friend, appearance, and relaxation. The subjects preferred effective long-term adaptation method (Mean=2.81) to ineffective short-term adaptation method. (Mean=2.47) 2. The self-concept had the highest degree when students were 1st grade, in good health condition, taking high grade marks, both parents existing, fathers' educational level being above college, and being in high economic status. The degree of stress was significantly high when students were 3rd grade, in poor health condition, having low grade marks, being in poor economic status, and fathers' educational level being under elimentary school. In relation with adaptation method, 1st grade students used more sbort-term and long-term method, and when students had high grade marks, being in high economic status. they used more long-term adaptation behavior. 3. Two Hypotheses of this research were tested: Hypothesis 1. "The higher the students' self-concept is, the more they use long-term adaptation method." was accepted. (r=.2482, p<.01) (t=-4.99, p<.001) Hypothesis 2. "The higher the students' stress is, the more they use short-term adaptation method." was accepted. (r=.2897, p<.01) (t= -7.51, p<.001) In conclusion, a person in charge of school health can help students to adapt effectively by planning and implementing methods which highten their self-concept and lower their stress. But because the correlation among self-concept, stress and adaptation behavior was at a low level, I think that the study, which confirm the relationship of those three variables, is needed.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1298-1308
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• 2023

This study collected 245 questionnaires from college students in Gyeonggi-do and analyzed them using SPSS statistical packages, with the aim of identifying the status of hair loss perception due to the relationship between stress and hair loss received by college students and analyzing the correlation between stress and hair loss perception by type. As a result of the study, it was analyzed that the biggest problem caused by hair loss was 'loss of confidence', and in particular, people who were stressed about career/employment and studies were analyzed to consider the problem of 'loss of confidence' the most serious. As a result of cross-analysis of the general characteristics of awareness and the 'most recent stress' item, and as a result of correlation analysis between stress by type and hair loss status that constitutes hair loss awareness, it was analyzed that all types of stress affect hair loss in college students. Among them, career/employment stress and academic stress were found to be the most influential stress, and in the event of hair loss, it was analyzed that they were more willing to engage in hair loss treatment for career/employment, study, and appearance before interpersonal relationships or economic problems. Therefore, this study is of great significance in that it classified stress by type and analyzed the correlation through empirical research methods by specifying the contents of hair loss recognition into three categories: hair loss status, hair loss management, and hair loss treatment.