AISI 4320 강과 AISI 4340 강의 Tempered Martensite Embrittlement 현상에 관한 연구

權寧逸,林秉洙 成均館大學校 科學技術硏究所 1987 論文集 Vol.38 No.1

The effect of carbon and austenitizing temperature on Tempered Martensite Embrittlement(TME) has been studied using AISI 4320 and AISI 4340 steels. Samples were austenitized at 870℃ and 1170℃ to change the austenite grain sizes and then oil quenched to obtain the martensite structure. Tempering was performed between 200℃ and 500℃ for 1 hour. The change of TME characteristics has been studied by the measurements of mechanical properties and the investigation of microstructures. Some of the conclusions obtained from the study are as follows; (1) As the austenitizing temperature increases, the tempering temperature where \4E occurs also increases. This is believed to be the effect of larger grain size and more homogeneous distribution of carbon at the higher austenitizing temperature. (2) The CVN impact energy values of the samples austenifized at the lower temperature were found to be higher than those of samples austenifized at the higher temperature, indicating the effect of the fine grain structure. (3) When TME occured, fracture was intergranular. This indicates that TME is associated with the combined effects of the cementite precipitation during the tempering process and the impurity segregation during the austenitizing treatment.

강인한 퍼지 디지털 PI+D 제어 시스템의 설계 및 구현

권태익,이재홍,김승철,설재훈,임영도 동아대학교 정보기술연구소 2001 情報通信硏究所論文誌 Vol.9 No.1

In this paper, Fuzzy Digital PI+D Controller plans for load, noise, plant change, Fuzzy Controller makes use of simple four rule and membership function, and plant used three phase Induction Motor. Characteristic of system compared from experimentation respectively the proposed Control System, Digital PID Control and Digital PI+D Control System.

호밀 유식물의 생장과 질산염 흡수에 대한 2,4-Dinitrophenol의 영향

임영선,권오영 충남대학교 자연과학연구소 1993 忠南科學硏究誌 Vol.20 No.2

This work has been accomplished to determine the effect of 2, 4-dinitrophenol on the growth and nitrate uptake in 6 days old rye(Secale cereale L.) seedlings. The shoot length and fresh weight have been increased in the groups as time go on, and the degree in the treated group has been lower than the control group. The dry weight has been decreased in both groups. The optimum pH for the nitrate uptake of the control group was 7.2 in the range of pH 4.5 - 8.5, but pH of the group treated with 0.5 mM 2,4-dinitrophenol has been gradually increased to 8.5. According to the treatment time in the solution of 10 mM KNO_3, the nitrate uptake has been increased for 2 hours in the control group, for 1 hour in the treated group, and then it has been decreased in both groups thereafter. With increasing of the concentration in the solution of KNO_3, the nitrate uptake has been promoted in both groups, and lower in the treated group than the control group. Consequently, it has been suggested that 2,4-dinitrophenol, one of the uncoupling agent in electron transport system, has inhibited the growth and nitrate uptake in the 6 day old rye seedlings.

Are Adolescents with Internet Addiction Prone to Aggressive Behavior? The Mediating Effect of Clinical Comorbidities on the Predictability of Aggression in Adolescents with Internet Addiction

Lim, Jae-A,Gwak, Ah Reum,Park, Su Mi,Kwon, Jun-Gun,Lee, Jun-Young,Jung, Hee Yeon,Sohn, Bo Kyung,Kim, Jae-Won,Kim, Dai Jin,Choi, Jung-Seok Mary Ann Liebert 2015 CYBERPSYCHOLOGY BEHAVIOR AND SOCIAL NETWORKING Vol.18 No.5

<P>Previous studies have reported associations between aggression and Internet addiction disorder (IAD), which has also been linked with anxiety, depression, and impulsiveness. However, the causal relationship between aggression and IAD has thus far not been clearly demonstrated. This study was designed to (a) examine the association between aggression and IAD and (b) investigate the mediating effects of anxiety, depression, and impulsivity in cases in which IAD predicts aggression or aggression predicts IAD. A total of 714 middle school students in Seoul, South Korea, were asked to provide demographic information and complete the Young's Internet Addiction Test (Y-IAT), the Buss-Perry Aggression Questionnaire, the Barratt Impulsiveness Scale-11, the State-Trait Anger Expression Inventory-2, the Beck Anxiety Inventory, the Beck Depression Inventory, and the Conners-Wells Adolescent Self-Report Scale. Three groups were identified based on the Y-IAT: the usual user group (n=487, 68.2%), the high-risk group (n=191, 26.8%), and the Internet addiction group (n=13, 1.8%). The data revealed a linear association between aggression and IAD such that one variable could be predicted by the other. According to the path analysis, the clinical scales (BAI, BDI, and CASS) had partial or full mediating effects on the ability of aggression to predict IAD, but the clinical scales had no mediating effect on the ability of IAD to predict aggression. The current findings suggest that adolescents with IAD seem to have more aggressive dispositions than do normal adolescents. If more aggressive individuals are clinically prone to Internet addiction, early psychiatric intervention may contribute to the prevention of IAD.</P>

제약업종 부산물 및 화장품 제조업 폐수처리오니 처리토양에 대한 유기화합물 및 Bioassay 분석 평가

임동규,이상범,이승환,남재작,나영은,권장식,권순익,소규호 한국환경농학회 2004 한국환경농학회지 Vol.23 No.4

본 연구는 퇴비원료로 지정된 제약업종 부산물(공정오니) 및 화장품 제조업 폐수처리오니를 퇴비로서 활용 가능성을 판단하기 위하여 기존의 일반성분이나 중금속 성분 분석 이외 유기성 화합물과 기타 여러 생물검정법 등을 활용하여 시용한 오니에 의한 토양 내 비료의 피해를 밝혀내고 이들의 평가방법을 확립하고자 포장시험을 수행하였다. 오니의 처리에 따른 HEM의 함량은 제약업종 오니2(PS2)와 화장품 오니(CS)처리가 각각 0.51, 1.10 mg/kg로 가장 높았고, PAHs의 함량은 제약업종 오니2(PS2) 처리에서 3,406.8 μg/kg로 가장 높았다. 토양에 서식하는 미소동물의 밀도변화는 생육 중기(7월 23일) 및 수확기(10월 1일) 모두 제약오니2 및 돈분 처리구에서 가장 높았으며, 기타 처리구는 차이가 없이 아주 낮았다. 오니의 처리에 따른 세균 및 사상균의 균수는 제약업종 오니2처리에서 각각 736, 909 cfu/g로 가장 많았고, 화장품 오니도 각각 440, 236 cfu/g으로 다른 처리에 비해 많은 경향을 보였다. 제약오니 및 화장품오니 처리시 우점세균은 무비, 돈분처리에 비해 일정한 경향이 없었으나 3요소 처리보다 다양한 세균이 검출되었다. 오니의 처리에 따른 우점사상균은 무처리에 비해 제약업종 오니3와 화장품 오니처리에서 형태적 특징이 다른 콜로니가 검출되었으나 다른 처리는 비슷한 경향으로 종류 간에 큰 차이는 보이지 않았다. Microcosm test를 통하여 오니 처리 후 3개월이 경과한 토양의 오염정도를 평가한 결과는 제약업종 오니3과 화장품 오니처리는 약간 영향을 받아서 80~90% 생존하였으나, 제약업종 오니1처리는 처리 2주(14일) 이후에는 급격히 생존율이 떨어져서 4주 이후에는 10%만 생존하였다. 그러나 6개월이 경과한 토양에서는 지렁이의 생존율은 제약업종 오니1처리만 약간 영향을 받은 것으로 보였으며 다른 처리들은 전혀 영향을 받지 않았던 것으로 조사되었다. 유기성 오니의 퇴비원료로 활용은 비료관리법의 비료공정 규격 중 퇴비의 비고란에 "퇴비의 원료로 사용 가능한 물질과 사용 불가능한 물질'(별표1)에서 "희비의 원료 중 사전 분석검토 후 사용 가능한 원료에 대한 지정요령'에는 유기물과 중금속(8성분) 함량(건물증)과 제조공정 등을 검토하여 지정하고 있으나, 지정된 원료가 과연 회비원료로 적합한지 잘 알 수 없으며 또한 앞으로 현재의 퇴비원료 규정을 변경할 필요가 있을 경우를 대비하여 희비원료의 적합성 여부를 판별할 수 있는 방법의 개발이 필요하다. 따라서 퇴비원료로 이미 지정('02. 12. 31)된 제약오니 및 화장품 오니를 과량으로 토양에 시용한 후 유해 유기화합물, 미소동물, 미생물 및 생물학적(지렁이) 유해성 검정방법의 도입 가능성을 평가하기 위하여 고추를 재배한 포장에서 비료의 피해시험을 실시한 결과 유해 유기화합물과 생물학적(지렁이) 유해성 검정방법은 앞으로 연구를 통해서 보완할 경우 상당히 활용 가능성이 있는 좋은 평가방법인 것으로 생각된다. This study was conducted to assessment organic compound and bioassay (density of inhabited animal, fluctuation of predominant fungi, and survival ratio of earthworm) for finding damage on red pepper by heavily amount application of sludges in soil, which was treated with 3 pharmaceutical byproducts and a cosmetic industry wastewater sludge as raw materials of compost, and for establishing estimation method. HEM contents in the soil treated with pharmaceutical byproducts sludge2 (PS2) and cosmetic sludge (CS) were 0.51, 1.10 mg/kg respectively. PAHs content of PS2 treatment in the soil was 3406.8 ug/kg on July 8. In abundance of soil faunas, the pharmaceutical byproducts sludge2 treatment was the most highest. The next was decreased in the order of pig manure (PM) and the cosmetic sludge treatment. However the other pharmaceutical sludge treatments were remarkably reduced populations of soil inhabited animals. In upland soil treated with organic sludges, the numbers of bacteria and fungi of the pharmaceutical sludge treatment were 736, 909 cfu/g and those of the cosmetic sludge treatment were 440, 236 cfu/g, respectively. The pharmaceutical sludge treatments and the cosmetic sludge treatment in identification of predominant bacteria were not any tendency to compare with non fertilizer and pig manure treatments, but they had diverse bacteria than NPK treatment. In microcosm tests, the survival of the tiger earthworm in five soil samples was hardly affected against the soil of PSI (20%) after three months treated in the upland. But after six months, survival of PSI was 80%. At present, raw material of compost was authorized by contents of organic matter, heavy metal (8 elements), and product processing according to "The specified gist on possible materials of using after analysis and investigation among raw materials of compost", however, for preparing to change regulation of raw material of compost and for considering to possibility of application, this study was conducted to investigate toxic organic compound and bioassay methods using inhabited animal, fungi, and earthworm without current regulation.

공변량 구조분석을 이용한 국내 간호연구의 동향

임난영,강현숙,이성은,서연옥,권영은 대한간호학회 2001 Journal of Korean Academy of Nursing Vol.31 No.2

This study was conducted by analyzing all 33 articles based on the LISREL, published from January 1991 to March 1999 in Korea. The analyses consisted of the publication date of articles, principal dependent variables, subjects of the research. adequacy of sampling, adequacy of research purposes and results. accordance between theoretical model and hypothetical model. fit measures, theoretical base of model modification, and adequacy of conclusion. The results were as follows : ? The thesis of 33 articles in total were outnumbered as 25 (75.8%) to 8 (24.2%) research articles. As for a sex classification of the subjects, 45.5% of the research were conducted around a female group of subjects. while 54.5% were done for both sex, The range of the sample size was 105 to 803, and the average was 259 subjects. ? A single theoretical variable was measured for each measurement variable, any difference between variables was hardly found in 8 articles (24.2%), and 19 articles (57.6%) did not consider any measurement error. To analyze if the representative has been considered while collecting the data. most data were collected by a convenient sampling. Seven articles (21.2%) were seen with a sign of a representative. Questionnaires were used in a majority (31 articles) of the data collecting process. Only 2 articles (6.1%) were measured with a physiologic index simultaneously. 14 articles (42.2%) were centered on theory development, 10 articles on theory synthesis. and 9 articles on theory test. The research purposes and results were consistent in 25 articles (75.5%) and 8 articles (24.2%) were inconsistent. The quality of life and health promotion behavior were the concepts most frequently studied as a dependent variable. and 7 articles centered on them. In applied theories a health promotion model was used on 4articles (12.1%), while role theory and stress-coping models were in 3 articles respectively. The articles were analyzed to see if the hypothetical model was elaborated and tested by the theoretical model. Twenty-five articles proved to be rationale for the inconsistencies. Also, 56.5% proposed hypotheses were supported among the subject articles. and 30 articles (90.0%) suggested a revised model. Path coefficient (17 articles) and theoretical adequacy (17 articles) were the standards mostly used. In conclusion. the principal factors were obtained from the research are to be considered as the principes of LISREL application. First. a model has to be established on a theoretical base rather than empirical results dependent on the data. The results are also required to be globally interpreted. Secondly. at least 200 samples are necessary to satisfy the need. Third. more than 3 measurement variables are to be adjusted to a single theoretical variable: the measurement errors must be suggested as well. Finally. normal distribution characteristics of the data and the estimation method need to be reported. Based on the research result. the follows are suggested: ? Systematic criteria on the LISREL application and procedure need to be developed ? Agreement form is required to report the results of research using the LISREL

유지시간 변화에 따른 크리프-피로 수명예측 방법에 관한 연구

권영일,김범준,임병수 成均館大學校 科學技術硏究所 2001 論文集 Vol.52 No.2

In this study, creep-fatigue tests were carried out under the various test conditions using AISI 316 stainless steel. Life prediction was made by three different methods which are the modified Coffin-Manson method, the modified Ostergen method and the artificial neural network method with the adaptive learning rate. The predicted lives were compared with the experimental results and following conclusions were obtained within the scope of this study. Creep-fatigue life prediction by the modified Coffin-Manson method and the modified Ostegren method had the average error of 47.3% and 50.8% respectively whereas the artificial neural network method had only 28.8% for compressive and tensile+compressive hold time. From the obtained results, the artificial neural network method with the adaptive learning rate was proved to be more accurate and effective than the other two methods. The validity of artificial neural network method for life prediction checked with 3 verification data points proved also to be very satisfactory.

高眞空下에서 브롬화벤질류와 이소퀴놀린과의 親核性 置換反應에 관한 速度論的 硏究

권병일,임종완,김영철 漢陽大學校 自然科學硏究所 1997 自然科學論文集 Vol.16 No.-

전기전도도법에 의해 아세토니트릴 용매내에서 브롬화벤질류(p-CH₃, p-H, p-NO₂)와 isoquinoline과의 반응을 고진공하에서 온도(15, 20, 25℃)변화에 따라 속도론적으로 연구하였다. 이때 반응속도상수는 온도가 증가함에 따라 증가하였으며, 또한 기질에 전자 주게 치환체(p-CH₃)가 치환된 경우 증가하였다. 이들 반응속도상수로 부터 활성화에너지(Ea), 활성화엔탈피(???), 활성화엔트로피(???), 활성화자유에너지(???) 및 Hammett 반응상수 ρ를 구하였으며, 이러한 속도론적 연구로 부터 전반적인 반응메카니즘은 dissociative ??? 반응으로 진행됨을 알 수 있었다. Rate of reactions of p-substituted benzyl bromides(p-CH₃, p-H, p-NO₂) with isoquinoline have been measured by conductivity method in acetonitrile, which was determined under vapor pressure of the solution obtained by using high vacuum apparatus, by kinetic studies at several temperatures. The rate constants are increased as a function of temperatures and are further increased by introducing the electron donating substituents in substrates. The activation energies (Ea), activation parameters(???,???,???)and Hammett ρ values are calculated from the rate constants and, generally, the results of these studies show a greater degree of bond breaking than bond formation in the transition state.

관상동맥 질환에서 도플러 심초음파도로 측정한 확장기 좌심실기능의 지표와 혈역학적 소견과의 비교 검토

임헌관,기신영,유창범,최태명,김성구,권영주 순천향의학연구소 1995 Journal of Soonchunhyang Medical Science Vol.1 No.1

Background : Left ventricular diastolic dysfunction is now recognized as a significant cause of cardiac symptoms even in patient with normal systolic ventricular function. During the last several years, the use of Doppler echocardiography for assessing left ventricular diastolic function has attracted increased attention. Doppler study have demonstrated that patients with ischemic heart disease have abnormal diastolic filling pattern suggesting impaired relaxation. Methods : This study was designed to correlate Doppler mitral flow velocity patterns and measuared variance with hemodynamic findings in 33 patients: 10 with myocardial infarction(group 1), 10 with angina pectoris(group 2) and 13 with no coronary disease(group 3). Results: 1. E/A ratio (0.87±0.24 m/sec versus 1.09±0.91 m/sec, P<0.05) was lower in group 1 than in group 3. 2. Significant correlation were demonstrated between pulmonary capillary wedge pressure (PCWP) and isovolumic relaxation time(IVRT) (r=-0.58; p<0.001), and E velocity (r=0.61; p<0.005). 3. IVRT was (61±30msec versus 92±35msec, p<0.05) shorter in patients with PCWP>10mmHg than in patients with PCWP≤10mmHg. Conclusion: Doppler mitral flow recordings have partially clinical potentiality in assessing left ventricalar diastolic function in patient with ischmic heart disease.

말초혈액에서 Tg mRNA에 대한 역전사 중합효소 연쇄 반응법의 갑상선 재발암의 분자생물학적 진단

권성일,박기룡,김현영,신채희,임영찬,최영식,박요한,이강대,장희경,이재화,염하용 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.4

연구배경: 갑상선암은 다른 조직에 발생한 암에 비해 비교적 천천히 자라므로 대부분 예후가 양호하지만, 일부에서는 주위 조직으로 침윤하거나 혹은 원격 전이로 인하여 치명적인 결과를 초래할 수 있다. 갑상선전절제술 및 131^I 제거술 후 경과 관찰시 갑상선암의 재발과 전이의 진단에 있어 131^I 스캔과 혈청 Tg의 측정이 현재 임상에서 가장 많이 이용되고 있으나 이 방법에는 여러 가지의 결점이 있다. 최근 Tg mRNA에 대한 RT-PCR법을 이용한 여러 연구결과는 131^I 스캔과 혈청 Tg 측정의 결점을 보완할 수 있는 좋은 보조적인 진단법으로 이용할 수 있을 가능성을 제시하였다. 이에 말초혈액에서 측정한 Tg mRNA에 대한 RT-PCR법이 갑상선 절제술 및 방사성요드 치료 후 갑상선암의 재발 및 전이 유무의 진단에 유용한가를 알아보고자 이 연구 시행하였다. 방법: 분화된 갑상선암으로 진단된 후 갑상선전절제술을 시행받고 방사성요드 치료를 받은 환자 중 현재까지 한차례에 이상 추적 방사성요드 전신 스캔을 시행하고 추적관찰이 가능했던 유두선암 35예, 여포선암 5예를 대상으로 연구를 시행하였다. 대상군은 131^I 스캔 소견상 음성인 군(Group Ⅰ), 잔여조직이 있는 군(Group Ⅱ), 국소전이가 있는 군(Group Ⅲ), 및 원격전이 군(Group Ⅳ)으로 구분하였다. 정상 대조군은 갑상선질환이 없는 10예의 건강인으로 하였다. 대상환자의 말초혈액을 이용한 Tg mRNA에 대해 특이적인 primer를 이용하여 RT-PCR 및 nested RT-PCR을 시행하였다. 결과: 본 연구 결과는 다음과 같다. 1) 131^I 스캔 소견상 음성인 군 21예 중 1예에서 Tg가 양성소견을 보였다. Anti Tg Ab가 양성인 4예 모두 Tg가 음성을 보였다. 잔여조직이 있거나 국소전이 및 원격전이를 보인 군 19예 중 Tg가 양성인 경우는 4예였으나, Tg mRNA는 전예에서 양성이었다. 2) 131^I 스캔에서 국소 및 원격전이 소견을 보인 8예 중 4예에서 Tg가 음성으로 131^I 스캔과 혈청 Tg 사이에 불일치 소견을 보였다. 3) 말초혈액에서 특이적인 primer를 이용하여 RT-PCR 및 nested RT-PCR을 시행한 결과 대상군 40예 및 정상 대조군 10예 모두에서 Tg mRNA가 양성을 보였다. 결론: 본 연구에서 갑상선 절제술 및 방사성요드 치료 후 갑상선암의 재발 및 전이 유무를 평가함에 있어 역전사 중합효소 연쇄 반응법을 이용한 Tg mRNA 측정의 의의는 재평가되어야 한다고 생각된다. Background: Differentiated thyroid cancer is the most common endocrine malignancy. Despite advances in the treatment of thyroid cancer, disease recurrence and metastasis may occur in as many as 20% of patients, and so continues to pose major problems in its clinical management. Serum thyroglobulin (Tg) measurements, by immunoassay, are used to detect residual or recurrent thyroid cancer following thyriod ablation. However, the usefulness of immunoassay is limited by both the requirement for thyroid hormone withdrawal, to attain optimal test sensitivity, and interference by the antithyroglobulin antibody (Anti-Tg Ab). Recent studies have reported the clinical usefulness of reverse transcription-polymerase chain reaction (RT-PCR) detection of Tg mRNA in the peripheral blood of patients with differentiated thyroid carcinomas. We performed this study to evaluated the usefulness RT-PCR of Tg mRNA in peripheral blood of patients with thyroid carcinoma following a total thyroidectomy and radioiodine ablation therapy. Methods: Forty cases that underwent a total thyroidectomy and radioiodine ablation therapy were included in this study. Of the 40 patients, 35 were papillary carcinomas and 5 were follicular carcinomas. Ten normal control subjects were also studied. Tg mRNA was extracted. Then RT-PCR and nested RT-PCR, were run with specific Tg primers. Concurrently, DNA sequencing of the isolates was carried out to prove the isolates were identical to the nucleotide sequence of the Tg. Results: The Tg was detected in 4 of 19 patients, with either a residual thyroid bed, or metastasis, on a 131^I whole body scan and in 1 of 21 patients with a negative radioiodine scan. Surprisingly, the Tg mRNA was detected in all the patients and normal controls. Conclusion: From our results we can not recommend Tg mRNA, detected by RT-PCR in peripheral blood, as a tumor marker superior to that of the Tg serum level. We consider an intensive re-evaluation of the method is required before considering its clinical applications (J Kor Soc Endocrinol 17:501∼513, 2002).