• 비파괴검사학회지
• /
• 제22권3호
• /
• pp.267-274
• /
• 2002

본 연구는 Cr-Mo-V강의 다양한 분극특성들을 이용하여 비파괴적으로 재질열화를 평가하는 전기화학적 기법에 대해서 서술한 것이다. 사용된 전기화학적 기법은 스테인레스강의 열 이력에 의해 주로 야기되는 강화원소 결핍 영역에서의 예민화 그리고 부식속도를 평가하기 위해 널리 사용되는 양극분극 시험법이다. 재질열화 평가는 $10{\times}10{\times}0.5mm$ 크기의 시험편을 사용하는 미소역학 시험법으로 잘 알려진 SP시험에 의해 수행되었다. $630^{\circ}C$에서 1,000hrs 시효된 재료가 가장 높은 재질 열화도 ${\Delta}[DBTT]_{SP}$을 보였으나, 2,000hrs 그리고, 3,000hrs 시효된 재료는 시효 시간이 증가함에 따라 ${\Delta}[DBTT]_{SP}$의 감소를 보였다. 전류밀도의 차 $({\Delta}I_{FP},\;{\Delta}I_{SP})$가 1,000hrs 시효시간까지는 증가하였고, 그 이후의 시효시간에서는 시효시간의 증가와 더불어 감소됨이 관찰되었다. 이 같은 결과는 시효재료에 대한 경도의 거동과 일치하였다. 덧붙여, ${\Delta}[DBTT]_{sp}$는 ${\Delta}I_{FP}$ 및 ${\Delta}I_{SP}$와 같은 전기화학적 분극특성들과 좋은 상관관계를 가지고 있음을 알 수 있었다.

• Journal of Welding and Joining
• /
• 제13권1호
• /
• pp.78-88
• /
• 1995

This paper was performed to study the utility of the SP(small punch) test and the AE(acoustic emission) test in the evaluation of SCC(stress corrosion cracking) susceptibility for parent metal and bond line of HT80 steel-weld joint by SAW(submerged arc welding) with the various pH values. The loading rate used was 3*10$^{-4}$ mm/min and the corrosive environment used was synthetic sea water during the SP test and the AE test. According to the test results, the SCC susceptibility of the parent metal was increased in the order of pH6.0, pH8.2 and pH10.0. On the other hand, the bond line showed almost the same high SCC susceptibility in all pH concentrations. Synthetically, from the results of the SCC susceptibility, the macro- and micro-SEM observation, the microfracture behaviors by AE test and the relationship between SCC susceptibility and displacement at incipient failure, .delta.$_{i.f-AE}$, it can be concluded that the SP test and the AE test are the good test methods to evaluate the SCC susceptibility for parent metal and bond line of the weld joint with the change of environmental factors.

• 한국양식학회지
• /
• 제10권1호
• /
• pp.9-15
• /
• 1997

여천군 가막만에서 해산어류의 어병발생은 20^{\circ}C$이상인 시기에 집중적으로 발생하였다. 어종별 병원성생물은 넙치가 Vibrio sp., Edwardsiella sp., Streptococcus sp., Vibrio+Edwardsiella sp., Streptococcus sp.+Microcotyle sp,+Caligus sp. 및 Trichodina sp.에 감염, 조피볼락은 원인 불명 (선회병; 원인생물은 포도상구균으로 1994년에 동정함), 림포시스티스증, , Vibro+Microcotyle sp. 및 Streptococcus sp.+Micrococcus sp.에 감염, 농어는 림포시스티스증, Vibro sp., Vibro+Streptococcus sp. 및 Streptococcus sp.+Microcotyle sp.+Caligus sp.에 감염, 참돔은 Edwardsiella sp.에 각각 감염되었다. 조사지점 7개소 중 1, 5 및 6번 가두리 양식장은 20^{\circ}C$이상인 6월부터 10월까지 연속적으로 어병이 발생하였다. 약제감수성시험에서 Vibrio sp. (KS-9303)는 옥시테트라사이크린, 클로람페니콜, Edwardsiella sp. (KP-9315)는 옥시테트라사이클린, Flaxibacter sp. (KP-9318)는 옥시테트라사이클린, 옥소린산 및 클로람페니콜, 그리고 Streptococcus sp. (KP-9319)는 에리스로마이신, 옥시테트라사이클린 및 클로람페니콜 순으로 감수성이 나타났다.

• 비파괴검사학회지
• /
• 제15권4호
• /
• pp.549-560
• /
• 1996

본 연구의 목적은 지금까지 적용되지 않은 극소형시험편을 이용한 소형펀치(small punch : SP)시험과 비파괴시험방법(non-destructive test: NDT)으로 알려진 음항방출(acoustic emission : AE)시험에 의해 수소취화된 압력관 재료의 새로운 파괴강도 평가법으로서 SP시험의 적용 가능성을 조사하는데 있다. 시험결과, 300ppm-H까지의 수소농도에서, 수소농도에 따른 Esp의 저하가 상온보다 $-196^{\circ}C$의 경우가 뚜렷하여, 수소취화정도에 따른 Zr-2.5%Nb 압력관 재료의 파괴강도 평가는 상온보다 $-196^{\circ}C$의 저온환경하에서의 평가가 더욱 우수함을 알 수 있었다. 또한 수소농도의 증가에 따라 재료의 파괴과정에서 발생하는 AE신호의 평균에너지의 peak와 누적 평균에너지 그리고 단위 등가파괴변형률(equivalent fracture strain : ${\epsilon}_{qf}$)당 누적 평균에너지의 값이 크게 증가하였다. 그리고 하중-변위거동, Esp 거동, 거시적, 미시적 SEM 관찰 그리고 AE 시험 결과들로부터 미소시험편을 이용한 SP시험법은 수소취화된 CANDU 압력관 재료의 새로운 파괴강도 평가법으로 유용성이 있음을 알 수 있었다.

• International Journal of Safety
• /
• 제6권2호
• /
• pp.1-7
• /
• 2007

In this study mechanical strength of A53B carbon steel was analyzed using several types of test specimens directly machined from oil recycling pipe experienced a failure due to hydrogen attack in chemical plants. High temperature hydrogen attack (HTHA) is the damage process of grain boundary facets due to a chemical reaction of carbides with hydrogen, thus forming cavities with high pressure methane gas. Driven by the methane gas pressure, the cavities grow on grain boundaries forming intergranular micro cracks. Microscopic optical examination, tensile test, Charpy impact test, hardness measurement, and small punch (SP) test were performed. Carbon content of the hydrogen attacked specimens was dramatically reduced compared with that of standard specification of A53B. Traces of decarburization and micro-cracks were observed by optical and scanning electron microscopy. Charpy impact energy in hydrogen attacked part of the pipe exhibited very low values due to the decarburization and micro fissure formation by HTHA, on the other hand, data tested from the sound part of the pipe showed high and scattered impact energy. Maximum reaction forces and ductility in SP test were decreased at hydrogen attacked part of the pipe compared with sound part of the pipe. Finite element analyses for SP test were performed to estimate tensile properties for untested part of the pipe in tensile test. And fracture toughness was calculated using an equivalent strain concept with SP test and finite element analysis results.

• 디지털융복합연구
• /
• 제16권4호
• /
• pp.231-249
• /
• 2018

본 연구 목적은 종합병원 의료종사자 감염관리 표준주의에 대한 지식, 태도, 안전환경 및 인지도가 표준주의 수행도에 미치는 영향요인 분석으로 연구방법은 서술적 조사연구이며 대상은 종합병원 의료종사자 262명으로 표준주의에 대한 지식, 태도, 안전환경, 인지도 및 수행도를 측정하는 설문지를 이용하였다. 자료분석은 SPSS 프로그램을 이용하여 기술통계, t-test, ANOVA, Pearson's correlation coefficient, Multiple regression으로 분석하였다. 연구결과 표준주의에 대한 수행도는 태도(r=.18, p=.003), 안전환경(r=.42, p<.001), 인지도(r=.63, p<.001)와 양의 상관관계로 나타났으며 다중회귀분석 결과, 표준주의 수행도에 영향을 미치는 요인은 인지도(${\beta}=0.57$)와 안전환경(${\beta}=0.31$)이었다. 따라서 표준주의 수행 향상을 위해 인지도와 안전환경을 향상시키고 직종별 특성을 고려한 차별화된 감염관리 교육프로그램과 모니터링이 요구된다.

• Journal of Acupuncture Research
• /
• 제33권3호
• /
• pp.75-87
• /
• 2016

Objectives : The purpose of this study is to investigate the effects of acupuncture and moxibustion treatment at SP6(Sanyinjiao) on the temperature change of feet in healthy adults and evaluate whether SP6 has an effect on cold hypersensitivity of feet. Methods : Subjects of this study were 61 healthy adults consisting of 21 in the acupuncture treatment group, 21 in the moxibustion treatment group and 19 in the control group, selected at random. After starting the experiment, the subjects laid straight on their back and relaxed for 30 minutes. Pictures were then taken of their feet by DITI 3 times before and after treatment. The treatment was carried out by either 15 minutes of acupuncture or 2 pieces of moxibustion at SP6. Whilst the control group rested lying straight. After taking pictures the temperatures of LR2, GB42, ST42, KI1, center of the plantar, and center of the calcaneus were checked and the SPSS for Windows Version 20.0 was used to evaluate the statistical significance by the paired t-test, Wilcoxon signed-ranks test(in group) and the Mann-Whitney U-test(between the groups). Results : Some temperature changes before and after treatment were observed in each of the 12 areas, most of which were not significant. But as a result of comparing the temperature difference of all the samples without dividing the area of each group, the mean temperatures in the acupuncture and moxibustion group were significantly elevated. A comparison between the groups showed the mean temperature of the acupuncture and moxibustion group to be significantly elevated, more so than the control group. Conclusion : The result of this study suggests acupuncture and moxibustion treatment at SP6 has the effect of the rising temperature of feet temporarily.

• 한국물환경학회지
• /
• 제24권1호
• /
• pp.36-43
• /
• 2008

To develop the continuous water quality monitoring system using the daphnid Daphnia sp., the growth of test animal, sensitivity, and behaviour response of toxicants were observed. Growth of test animal significantly increased with increasing the food density under the 90~105 mg/L ($CaCO_3$) hardness, except the concentration of food (Chrollela sp.) was exceeded than optimal food supply. Behaviour responses of test animals were continuously analyzed by changes of fractal dimension value (FDV). The FDV sharply decreased after exposure to the concentrations of 0.13 mg/L copper, 0.06 mg/L lead, and 0.38 mg/L cadmium. In these concentrations, mortality and abnormal behaviour of daphnids exhibited within ca. 1.0-h after exposure. Comparison of 24-h $LC_{50}$ values with other zooplankton species indicated that sensitivity of the Daphnia sp. was higher than most zooplankton for lead, and brain shrimp, rotifer, and water flea (Ceriodaphnia dubia, D. magna) for copper, and brain shrimp, water flea (D. lumholzi), and amphipod for cadmium. Based on the above experimental results, significant relationship between toxicity and behaviour response of Daphnia sp. was supported the high potential of water quality monitoring system. Consequently, behavioural monitoring method in this study suggests a good estimation tool for detection of the discharged toxicants in water body and for ecotoxicological assessment aquatic organisms.

• 여성건강간호학회지
• /
• 제9권2호
• /
• pp.128-137
• /
• 2003

The purpose of this study was to identify effects of the SP-6 acupressure on dysmenorrhea, skin temperature at th e CV2 acupoint. This study was a pretest-post test study design wit h a nonequivalent control group. Data were collected from May 1 to August 31, 2002. A total of 58 female student s from two universities participated in the study. Among them, 30 female students were assigned as the experimental group an d the other 28 students to the control group. Both groups were pretested before the intervention for three variables, the degree of dysmenorrhea, and skin temperature at the CV2 acupoint. Then, the SP-6 acupressure was provided for 20 minutes for students in the experimental group. The instruments used in this study included the Visual Analogue Scale developed by Johnson(1974), skin thermometer by Simson Eectric CO., Menstrual Attitudes Questionnaire Scale developed by Brooks-Gunn & Ruble(1980), and Stress scale developed by Chun and Kim(1990). The data were analyzed with the SAS program using Chi-square test, t-test, and ANCOVA and Bonferroni method were used to determine significant differences between the two groups. The results of this study are as follows ; 1. There was a statistically significant difference in the intensity of dysmenorrhea after the intervention with the experimental group having a lower intensity than the control group. 2. There was a statistically significant difference in skin temperature at the CV2 acupoint 30min (F=4.87, p=0.03) after the intervention with the experimental group having a higher temperature. In conclusion, the SP-6 acupressure has proved to be an effective nursing intervention to reduce dysmenorrhea. Therefore, it is recommended women suffering from dysmenorrhea use the SP-6 acupressure.

• 대한약침학회지
• /
• 제18권2호
• /
• pp.60-66
• /
• 2015

Objectives: This study was carried out in order to find both the single-dose intramuscular injection toxicity and the approximate lethal dose of samjeong pharmacopuncture (SP) in Sprague-Dawley (SD) rats. Methods: The SD rats in this study were divided into four groups, one control group (1.0 mL/animal, normal saline) and three experimental groups (0.25, 0.5, and 1.0 mL/animal, SP). All groups consisted of five male and five female rats. SP was injected as a single-dose intramuscularly at the thigh. After the injection, general symptoms and weight were observed for 14 days. After the observations had ended, hematologic and serum biochemical examinations, necropsy and a local tolerance test at the injection site were performed. The experiments were carried out at the Good Laboratory Practice firm, Biotoxtech Co. (Cheongwon, Chungbuk). Animal experiments were approved by the Ethics Committee (Approval Number: 130379). Results: No deaths occurred in any of the three experimental groups. The injection of SP had no effects on the general symptoms, body weights, results of the hematologic, and serum biochemical examinations, and necropsy findings. In local tolerance tests at the injection sites, mild inflammation was observed in the experimental group, but it did not appear to be a treatment related effect. Conclusion: Under the conditions of this test, the results from the injection of SP suggest that the approximate lethal dose of SP is above 1.0 mL/animal for both male and female SD rats. Therefore, the clinical use of SP is thought to be safe.