Influence of heat‑treated Al-Si coating on the weldability and microstructural inhomogeneity for hot stamped steel resistance nut projection welds

Eun‑Joon Chun,Sung‑Sang Lim,Young‑Tae Kim,Ki‑Sung Nam,김영민,Young‑Whan Park,Siva Prasad Murugan,Yeong‑Do Park 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.1

Resistance nut projection weldability of Al–Si coated hot stamped steel (HSS) was investigated under the viewpoint of weldablecurrent range and joint strength (pull-out load). The microstructural inhomogeneities in the welds were also studied inorder to elucidate the factors affecting the joint strength of the welds. The weldability of the given Al–Si coated HSS wascompared with the weldability of an identical HSS without the Al–Si coating (Al–Si coating was polished out) and Zn coateddual phase steel. The weldable current range of Al–Si coated HSS was found to be narrower than that of the other materials. Furthermore, the average pull-out load within the weldable current range of the Al–Si coated HSS was the lowest among thethree materials. The reason for poor weld mechanical property of the Al–Si coated hot-stamped steel was attributed to themicrostructural inhomogeneities such as unmixed Al–Si coating layer at the edge of the nugget and the second phase Fe3(Al,Si) intermetallic compound. The formation of Fe3(Al, Si) phase was attributed to the solidification segregation of Al and Siduring the weld solidification and was confirmed with the numerical analysis of solidification segregation.

Skin entrance dose for digital and film radiography in Korean dental schools

Cho, Eun-Sang,Choi, Kun-Ho,Kim, Min-Gyu,Lim, Hoi-Jeong,Yoon, Suk-Ja,,Kang, Byung-Cheol 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.4

Purpose : This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Materials and Methods : Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). Results : The median dose was 491.2 μGy for digital radiography and 1,205.0 μGy for film radiography. The skin entrance dose digital radiography was significantly lower than that of film radiography (p<0.05). Conclusion : Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.

Improved Micropropagation of Root Chicory, Cichorium intybus L. var. sativus.

Lim,Jung-Dae,Yang,Deok-Chun,Lee,Hyeon-Yong,Kim,Jong-Dai,Lee,Jin-Ha,Sung,Eun-Soo,Yu Chang-Yeon 한국자원식물학회 2004 Plant Resources Vol.7 No.1

The establishment of an efficient protocol for plant regeneration and micropropagation from leaf explant cultures of Chicory, Cichorium intybus L. var. sativus. is reported. Callus formation rate appeared 100% from explant in all growth regulators, but calli formed in the prensence of naphthaleneacetic acid (NAA) were appeared very compact and non-embryogenic state. The regenerated shoots were obtained from leaf explant cultures on solid MS medium containing different concentrations of cytokinins and auxin. The highest number of shoots (5.7) per explant and shoot growth (2.8cm) was obtained on MS medium containing 0.1 mg BAP L^-1 and 0.1 mg NAA L^-1. Indole acetic acid was the most suitable auxin for root formation among three auxins tested. 2,4-D had no effect on shoot and root formation.

백서의 실험적 치아이동시 connexin 43의 발현에 관한 연구

임정현,김은철,김상철 원광대학교 생체재료·매식연구소 1998 원광생체재료·매식 Vol.7 No.1

Bone remodeling in response to force requires coordinated actions of osteoblasts, osteoclasts, osteocytes, and periodontal ligament cells. Coordination among these cells may be mediated, in part, by cell-to-cell communication via gap junctions. This study was designed to evaluate the expression of gap junction, connection 43 in periodontal tissue during the experimental movement of rat's incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for connexin 43. Twently seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental group(24 rats) where 75g of force was applied from helical springs across the maxillary incisors. Rats of experimental group were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. And the tissues of a control group and experimental groups were studied immunohistochemically. The results were as follows: 1. In control group, the expression of connexin 43 was rare in gingiva, dentin, cementum, periodontal ligament, and bone cells. 2. In experimental group, the expression of connexin 43 was increased in pulp, periodontal ligament, osteoblasts, and osteoclasts, comparing to that in control. And it was rare in gingiva, dentin, and odontoblasts regardless of the duration of force application, which was not different form that of control group. 3. The expression of connexin 43 in pulp of experimental group began to increase in 4-day after force application and got to the highest degree at 7-day. And it decreased after 14-day to be similar to that of control group at 28-day. 4. The expression of connexin 43 in periodontal ligament was noted in small capillaries adjacent to alveolar bone, showing higher intensity of immunolabelling after 4-day. And it was stronger in the pressure side than in tension side of periodontal ligament. After 7-day, decrease in connexin 43 expression was observed. 5. The expression of connexin 43 in alveolar bone began to increase 1-day, reached to the highest degree at 4-day, and decreased at 7-day. And the expression in osteoclasts was more than that in osteoblasts or osteocyte at 7-day.

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.

잇솔질 압력에 따른 잇솔강모의 탄력손실도 측정

임선아,서은주,강성귀,성진효 조선대학교 구강생물학연구소 2002 Oral Biology Research (Oral Biol Res) Vol.26 No.2

To investigate the elasticity loss of toothbrush according to the strength of pressure. the shape of brushing plane and the duration of use, thirty toothbrushes of five models were used for this examination among the toothbrushes for adults which have been marketed in the Republic of Korea. After 200g/㎠. 300g/㎠, or 400g/㎠ for 1, 2 or 3 month were loaded on toothbrushes, in rolling method the effect of the duration and strength of pressure and the change of the shape of brushing plane on the elasticity loss of toothbrushes was determined using Toothbrush Stroke Testen(CHUMDAN SYSTEM, Korea). The results are as follows; 1. The elasticity loss of toothbrushes according to 200, 300, or 400g/㎠ pressure was 11.11%, 25.21%, 30.84%, respectively. The elasticity loss of toothbrushes was increased with increasing the strength of the pressure (p<0.001) 2. The elasticity loss of the toothbrushes according to 1, 2, or 3months of the duration of use was in 15.60%, 22.09%, 29.47%, respectively. The elasticity loss of the toothbrushes was increased with increasing the duration of the pressure(p<0.001). 3. The elasticity loss of toothbrushes of convex plane according to 1, 2 or 3 month of the durate of use was 10.36% 18.29% and 24.20% respectively, that of toothbrushes of flat brushing plane according to 1, 2 or 3 months of the duration was 20.08%. 25.87% and 34.74%. respectively. The elasticity loss of the toothbrushes or flat brushing plane was higer than that of convex brushing plane(p<0.05). These results show that the property of the KS is optimal according to the pressure of toothbrushing, the shape of toothbrushos and the duration of toothbrushes using must be checked, and the further studies are needed about that.

생물 야외 탐구 학습을 통한 초등 예비교사의 생물 교수 효능감의 변화

임채성,배진호,김은진 부산교육대학교 과학교육연구소 2004 科學敎育硏究 Vol.29 No.-

In this research we took a lesson of the biology outdoor inquiry with preservice elementary teachers and investigated the science and biology teaching efficacy belief of theirs and analyzed it comparing with pre and post-lesson efficacy beliefs, their detailed major in university, their departments in high school, taking a course of applied biology Ⅱ in high school. The following results were obtained. First, preservice elementary teachers' science and biology teaching efficacy belief was changed positively after the lesson of the biology outdoor inquiry. Second, preservice elementary teachers' detailed major in university wasn't related with their science teaching efficacy belief of pre and post-lesson significantly in statistics, but related with their biology teaching efficacy belief of post-lesson significantly in statistics. Third, preservice elementary teachers' departments of high school wasn't related with their science and biology teaching efficacy belief. Fourth, taking a course of applied biology Ⅱ in high school wasn't related with science teaching efficacy belief, but related with biology teaching efficacy belief of pre-lesson significantly in statistics. However, That wasn't related with biology one of post-lesson significantly in statistics. That is, who haven't taken a course of applied biology Ⅱ in high school had not biology teaching efficacy belief before the lesson of the biology outdoor inquiry, but acquired much biology teaching efficacy belief after the lesson.

4.6.9 歲 兒童의 親社會的 行動發達에 關한 硏究

林聖惠,朴銀實 진주여자전문대학 1989 論文集 Vol.11 No.-

The main purpose of the present study was to examine the development of children's prosocial behavior. To achieve this purpose, following problems were put forward. (1) Are there any differences in the level of prosocial behavior according to age? (2) Are thers any differences in the level of prosocial behavior according to sex? (3) Are there any differences in the level of prosocial behavior according to socio-economic leves. Subjects were 60 children(30 boys and 30 girls) in three age groups ; 20 kindergarten children(10 boys and 10 girls) aged 6 ; and 20 third-grade children(10 boys and 10 girls) aged 8. To solve the above problems, 60 subjects were administered a prosocial behavior test by Bar-Tal(l979) and socio-economic level scale. These tools were revised to fit the purpose of this study. The data of the present study were processed with Mean, standard Deviation. ONE-WAY ANOVA, T-test and scheffe'-test by SPSS Program. The findings of this study are summerized as follows : First, there was significant differences in the children's prosocial behavior according to age [F=32.02, P< .01]. That is, children's prosocial behavior increased with age increase. Especially, as result of Scheffe'-test, there were more differences between 6 to 9 years old. second, there was no significant differences in the prosocial behavior according to sex. Third, there was significant differences in the childrens prosocial behavior according to socio-economic levels[t[59]=2.59, p[ .01]. Namely, high socio÷ economic level group was more prosocial than low sociof economic level group.

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

응급환자의 중증도 분류를 위한 지표의 개발 : Triage Score와 Modified Triage Score NEW METHODS TO TRIAGE ALL EMERGENCY PATIENTS

임경수,홍은석,김선만,황성오 대한응급의학회 1996 대한응급의학회지 Vol.7 No.2

Up to now, triage system for all emergent patients, which can be used fast and conviently according to their severity has not been developed yet. For the triage of trauma patient, emergency medical technicians and emergency medical doctors are commonly using R.T.S. (Revised Trauma Score). The R.T.S. consists of GCS(Glasgow coma scale), systolic blood, pressure and respiration rate per minute. But it is difficult for emergency medical technicians to calculate GCS in the prehospital because of its complexity and need for more time. Therefore we develop the Triage Score by remodelling the R.T.S. by replacing GCS with AVPU scale and systolic blood pressure that is under 49 mmHg after adding 1-49 mmHg with 0 mmHg and respiration rate per minute that is under 5/min after adding 1-5/min with 0/min. We stuied the significance and the possible triage application of Triage Score in traumatic emergency patients. For nontraumatic emergency patients, we develop the Modified Triage Score to triage the cardiovascular emergencies by adding the item of chest pain to Triage Score. A prospective study was carried out on 530 patients from March 1 to 31 1996. There were 210 trauma patients and 320 nontraumatic emergency patients and the result shows as follows. For trauma patients, there was linear correlation between R.T.S. and Triage Score(R²=0.965). Comparison analysis between high risk group (admission+death patients) and low risk group(discharge patients) of nontraumatic emergency patients by using Modified Triage Score is statistically significant(P<0,001) The cardiovascular emergencies could not categorized as urgency by Triage Score, but that was possible by application of Modified Triage Score. In conclusion, we can triage the injured patients effectively by Triage Score and the nontraumatic emergency patients including emergency cardiovascular disease can be categorized as urgency by applying the Modified Triage Score.