• Title/Summary/Keyword: 재료관리

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The efficacy of denture cleansing agents: A scanning electron microscopic study (수종 의치세정제의 세척 효과에 관한 주사전자현미경적 비교 연구)

  • Yun, Bo-Hyeok;Yun, Mi-Jung;Hur, Jung-Bo;Jeon, Young-Chan;Jeong, Chang-Mo
    • The Journal of Korean Academy of Prosthodontics
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    • v.49 no.1
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    • pp.57-64
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    • 2011
  • Purpose: The purpose of this study was to compare the cleansing performance of a distilled water, a diluted solution of sodium hypochlorite as a household bleaching cleanser and three alkaline peroxide cleansers in vivo plaque deposits by using scanning electron microscope. Materials and methods: Five individuals were selected from department of the prosthodontics in Pusan National University Hospital, and each of them was inserted with specimens for plaque accumulation in their temporary dentures for 48 hours. The specimens were removed and cleaned by each cleansing agents for 8 hours. Scanning electron micrographs were made from the specimens at a magnification of ${\times}2,000$. A panel of ten persons with a dental or paradental background, but not directly involved in the study, was selected to analyze the photomicrographs to determine which denture cleanser was more effective in removing plaque. Results: Diluted solution of sodium hypochlorite was the most effective at removing plaque following $Polident^{(R)}$, $Cleadent^{(R)}e$, $Bonyplus^{(R)}$ and distilled water in order. But there was no significant difference of cleansing efficacy between diluted solution of sodium hypochlorite and $Polident^{(R)}$, $Polident^{(R)}$ and $Cleadent^{(R)}e$, $Cleadent^{(R)}e$ and $Bonyplus^{(R)}$, respectively (P > .05). Alkaline peroxide cleansers by themselves cannot adequately remove accumulated plaque deposits, especially if the deposits are heavy. Corrosion could be seen on the surface of non-precious alloy specimens immersed in diluted solution of sodium hypochlorite. Conclusion: It is recommended to use of alkaline peroxide type cleansers with brushing whenever possible, since denture cleanliness is often poor due to the relative inefficiency of these cleansers.

A Study on the Permeability Reduction Methods of the Riverbed Ground during Urban Railway Tunnel construction (도시철도터널공사 시 하저통과구간의 지반투수저하 공법에 대한 연구)

  • Kim, Joon-Jeong;Cho, Kook-Hwan;Lee, Jun-Seok
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.551-557
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    • 2007
  • This paper describes a study on the permeability reduction of the riverbed ground during urban railway tunnel construction. The research is mainly concentrated on the study of the grouting or injection methods among permeability reduction methods which can be adapted in the riverbed ground. Firstly, the various grouting methods are theoretically reviewed and compared based on the previous research papers and case study results. It is also evaluated the grouting methods in view of a safe construction of the river crossing railway tunnel. Baced on the literature review and previous construction data, the design technology of grouting methods considering the long term hydro-geological behaviour in the riverbed, is suggested. Two injection methods namely, Natural Durable Stabilizer(N.D.S) and Space-Multi Injaction Grouting(S.M.I) methods, are introduced as new approach methods which can be adopted to modify the riverbed ground. In order to evaluate the ground that grouted and modified by the N.D.S and S.M.I method, the pilot test programmes including the field and laboratory permeability tests, are carried out in the river crossing tunnel construction sites. The results obtained from pilot test programme, are also reviewed. In conclusion, the grouting efficiency of the S.M.I method using the non-alcalimeter silica sol is better than that of NDS method using cement. In addition, it hopes that the research results are contributed to develop the grouting design technology.

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Engineering Characteristics of Wet-mixing Solidified Soil in Pavement Surfacing (습식 경화교반토 포장의 공학적 특성)

  • Yoo, Ji-Hyeung;Shu, Dong-Hyuk;Lee, Seong-Won
    • International Journal of Highway Engineering
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    • v.6 no.3 s.21
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    • pp.1-7
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    • 2004
  • Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.

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Evaluation of Microbiological Safety of Food Service Environment in Child Care Centers (어린이집 급식환경의 미생물학적 안전성 평가)

  • Lee, Han-Cheol;Jun, Se-Young;Ha, Heon-Ho;Song, Ju-Seok;Lee, Young-Ju;Kim, Jung-Beom
    • Journal of Food Hygiene and Safety
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    • v.35 no.2
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    • pp.146-151
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    • 2020
  • This study investigated microbiological safety of employees' hands, dining tables, and indoor air in cooking areas and lunchrooms in child care centers. Microbiological tests were performed according to the Korea Food Code. Total numbers of aerobic bacteria and coliform bacteria were measured as 5.8±1.9 log CFU/hand and 4.0±2.4 log CFU/hand on employees' hands, and 4.3±3.0 log CFU/100 ㎠ and 2.6±3.3 log CFU/100 ㎠ on dining tables. Bacillus cereus were detected in two cases each of employees' hands and dining tables, respectively. The analysis of microbiological contamination of indoor air in chid care centers showed that the total numbers of aerobic bacteria and coliform bacterial were 28±7.2 CFU/plate and 3.1±2.9 CFU/plate, respectively. Bacillus cereus and Staphylococcus aureus were counted as 1.7±0.2 CFU/plate and 1.6±0.5 CFU/plate from the indoor air in child cate centers. These results indicate that indoor-air in child care centers is considered more safe compared to previous reports. In conclusion, it is necessary to carry out hygienic management using alcohol-based disinfectants before meals to remove microorganism contamination on dining tables and hands. In order to reduce microbial contamination in indoor air, it is also deemed necessary to freshen the sanitary caps, masks, and clothing of the catering staff with periodic ventilation of indoor air.

A Study on Research of Necessity and Practice of Contents of Clothing and Textiles Education (의생활 교육내용의 필요도와 실천도 조사 연구)

  • 박일록;이은희
    • Journal of Korean Home Economics Education Association
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    • v.15 no.3
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    • pp.89-103
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    • 2003
  • The purpose of this study was to investigate to relation of necessity and practice of contents of clothing and textiles education(classify them into four units, choice and dressing of clothes, textile and management of clothes, design and sewing of clothes, knitting and embroidery). Method of posing a questionnaire is adopted to obtain stochastic data required for pertinent analysis. This is the investigation of which 400 (high school students 204, university students 196) girl students located in Choongnam and Junrabookdo province. In this statistical analysis, SPSS 10.0 for Windows Program was utilized to calculate percentage, mean and standard deviation. Also, these materials were verified by t-test, One-way Anova, Pearson's correlation coefficient. The results of this research were as follows. First, girl students' necessity mean point were higher than practice mean point about the contents of clothing and textiles education. And necessity had a positive relationship with practices of contents of clothing and textiles education. Second, there was a significant difference in necessity and practice of contents of clothing and textiles education according to demographic variables. These results should be provide fundamental information for improving students' critical practice in their real life. Since this study has touched only limited research on the topic of clothing and textiles education, it is essential that further research covering a wider array of themes be done in the future. this study has touched only limited research on the topic of clothing and textiles education, it is essential that further research covering a wider array of themes be done in the future.

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Gametogenesis and Reproductive Cycle of the Cockle, Fulvia mutica (Reeve) (새조개, Fulvia mutica (Reeve)의 생식세포형성과정 및 생식주기)

  • CHANG Young Jin;LEE Taek Yuil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.3
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    • pp.241-250
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    • 1982
  • The structure of gonads, gametogenesis and reproductive cycle of the cockle, Fulvia mutice, were studied mainly by histological observation. The materials were monthly sampled in the southern area of Yeosu from October 1980 to September 1981. F. mutica was monoecious. The gonads were situated between the liver tissues and the outer fibronuscular layers compacted by the connective tissue fibers and muscle fibers beneath the outermost layer of simple cuboidal epithelium. The gonad was composed of a number of the ovarian sacs and the testicular tubules which form the tubular structure. Testicular tubules in the mature stage sometimes contained 'testis-ova' The undifferentiated mesenchymal tissues and the eosinophilic cells were abundantly distributed on the germinal epithelium in the early development stage. With the further development of the ovary and testis, these tissues and cells gradually disapprared. The undifferentiated mesenchymal tissues and the eosinophilic cells are related to the growing of the oocytes and spermatocytes . Early multiplicating oogonium was about $10{\mu}m$ in diameter. As the oocytes grow to $27-34\times50-58{\mu}m$ by increasing cytoplasm, the oocytes connected to the basement membrane by their egg-stalks. The ripe eggs were about $60{\mu}m$ in diameter and they were surrounded by gelatinous membrane. Most male germ cells in mature stage were transformed into the spermatozoa and they formed the sperm bundles. After spawning, undischarged ripe eggs and spermatozoa remained in the ovarian sac and the testicular tubule respectively for some time, then they finally degenerated. Especially the early spent ovarian sacs in May did not contract significantly and then they took part in the secondary maturation within two or three months during the summer season. The monthly changes of the fatness well agreed with the reproductive cycle. The reproductive cycle of F. mutica could be classified into six successive stages : multiplicative, growing, mature, spent, degenerative and recovery stage. It seems that the spawning season is closely rotated to the water temperature, and the spawning occurs from May to October at about $20^{\circ}C$ in water temperature. The peak spawning seasons appeared twice a year between June and July and in September. Acknowledgement The authors wish to express their gratitude to Dr. Kim, In Bae, Dr. Chun, Seh Kyu and Dr. Yoo, Sung Kyoo of National Fisheries University of Busan and Mr. Min, Byoung Seo of National fisheries Research and Development Agency for their critical reading of the manu script.

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A Survey of Korean Housewives' Perception on the Commercial Korean Basic Side Dishes in Busan Area (시판 밑반찬에 대한 부산지역 주부의 인식조사)

  • Lyu, Eun-Soon;Lee, Dong-Sun;Chung, Sun-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.4
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    • pp.440-447
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    • 2006
  • The perception of Korean housewives was investigated on commercial Korean basic side dishes. The questionnaires were distributed to 464 housewives in Busan area. According to the survey, the housewives preferred discount stores (44.1%) to purchase basic side dishes. The reasons for purchasing them were convenience (54.6%) and readiness in small amount (23.1%). The housewives had high perception scores on saying cooking time (4.90/5.00), the possibility of purchasing when they need (3.93/5.00), and convenient use (3.85/5.00). However, they doubted the propriety of making use of chemical seasoning (2.15/5.00), the original place of raw food materials (2.21/5.00), and shelf life control (2.44/5.00). The satisfaction scores on the commercial basic side dishes were 3.06/5.00 in braised perilla leaves, 2.98/5.00 in braised soybean, 2.96/5.00 in pickled garlic, and 2.96/5.00 in stir-fried/muchim dried fish. The priorities on the improvement demand for the basic side dishes were appeared in order of the sanitary preparation, the consistent tastes, the proper amounts of chemical seasonings, and sanitary distribution systems.

Quality Evaluation of the Home-made Soy-Sauce Jangachi, Korean Traditional Pickle, Prepared by the Head-Families of Andong, Korea (안동지역 종가에서 전통적으로 제조된 간장 장아찌의 품질 특성)

  • Kim, Deok-Jin;Kim, Mi-Sun;Lee, Ye-Seul;Sohn, Ho-Yong
    • Microbiology and Biotechnology Letters
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    • v.41 no.3
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    • pp.311-319
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    • 2013
  • In an effort to characterize the physicochemical properties and microbial risks associated with the soy sauce jangachi (Korean traditional pickle), 15 different home-made products, which were prepared from medicinal plants and wild edible vegetables, from head-families of Andong, Kyungsangbuk-do Province in Korea, and 6 different commercial products sold at supermarket, were investigated. The average pH of the mature soaking solutions and plants soaked in the 21 jangachi were $3.99{\pm}0.38$ and $3.51{\pm}0.41$, and the average acidity of the mature soaking solutions and soaked plants were $1.59{\pm}0.54$ and $1.65{\pm}0.76$, respectively. The average brix of the mature soaking solutions and plants soaked were $27.67{\pm}8.38$ and $25.61{\pm}6.60$, respectively. In salinity, which is a major factor in jangachi industry production, the average salinity of the mature soaking solutions and soaked plants were $7.55{\pm}3.26$ and $5.75{\pm}2.23$, respectively. In particular, the hot-peppers, eusuri, du-rup, kaet-ip, kuji-ppong, myeng-i and sancho jangachi were amongst the home-made products, and the salinity was above 8.8%, which was 2 folds-higher than that of the commercial sterilized products, and 1/3-lower than commercial non-sterilized products. The color difference and turbidity of jangachi were dependent on the plant parts used. In microbial risk assessment, the microorganisms related with food-borne disease, such as Escherichia coli, Salmonella sp, and Shigella sp., were not detected. After some time, total cell count analysis revealed that the commercial products sold at supermarkets were more vulnerable than the home-made products.

Comparison of Estradiol Results according to Manufacturer (제조회사에 따른 Estradiol 결과값의 비교)

  • Kim, Dae-Woon;Shin, Hee-Jung;You, Tae-Min;Noh, Gyeong-Woon;Kim, Hyun-Joo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.1
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    • pp.101-105
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    • 2011
  • Purpose: Estradiol in the menstrual cycle and ovulation induction as an important test of currently national nuclear medicine laboratory in the normal patients and patients with infertility tests are being performed. For the diagnosis of menopause is an important test with follicle stimulating hormone (FSH) and Luteinizing hormone (LH). Currently participating in external quality control of the nation's hospitals that is 54 percent of 37 hospitals, 20 hospitals have been using A's reagent. The kit's test results are highly different from other kit comes with the test results of specimens have been found. And for the phenomenon is to study the problem. Materials and Methods: Estraiol test were referred to our hospital which results of samples as more than 100pg/ml 75 specimens measured by radioimmunoassay(RIA) test with company A company B company C company D Kit, Chemiluminescent assay (CMIA) to examine and compare to the results from april to August in 2010. Results: Kit for each manufacturing company as measured by the results obtained using the average value of the correlation coefficient (R2) and A company 0.8906 B 0.9527 C 0.9547 and D company correlation coefficient of 0.873 showed a good correlation that measuring the results of A company high concentrations when Company B Company C Company D with CMIA test concentrations measured low results that the two cases were discovered specimens. Conclusion: Most of the test results of 75 samples came up with a similar trend, but two cases were reported in the patients very differently. A company result reported higher than 700 pg/ml, while the rest of other test results report was approximately 10 pg/ml. The common point of two samples more than 50 years patients are estimated to be diagnosed with cancer in postmenopausal patients receiving treatment and levels of FSH were found to be greater than 50 mIU/ml. Did not identify the exact cause. I suggest if you are using A company kit that need to again check when Estradiol result and follicle stimulating hormone results is higher.

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Studies on the Improvement of the Fishing Efficiency of Purse Seine in the Sea Area of Cheju Island -The Changes of Seine Volume and Tension in the Purseline During Pursing- (제주도 주변해역 선망의 어획성능 향상에 관한 연구 -짐줄 체결 중 선망의 용적과 짐줄의 장력 변화 -)

  • 김석종
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.2
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    • pp.93-101
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    • 1999
  • A simple experimental method was used in an attempt to realize the elevation of the fishing ability of purse seine in the sea area of Cheju Island, the changes of seine volume and tension in the purseline during pursing. Experiments carried out on the six types simplified reduced model seines which were made of knotless nettings. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two-ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cmfor seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. These model purse seines were made of the scale of 1/200 of its full scale, a 120 ton in the near sea of Cheju Island. Designing and testing for the model purse seines were based on the Tauti's law. Experiments were measured in the observation channel of a flume tank at the static conditions set up shooting and pursing equipments. Motion of purse seine during purse line was recorded by the two sets video camera for VTR which were placed in top and front of the model seine. The reading coordinate of seine volume carried out by the video digitization system, disk data for the purseline tension. An analysis were performed on the changes seine volume and tension in the purseline during pursing. The results obtained were as follows: 1. The seine volume during pursing was largest for Ⅵ seine with smallest d/l followed by V, IV, III, II and I seines, and tension in the purseline was small. 2. Seine volume during pursing can be expressed by the following equation; CVt=l-EXP[{2.79 (d/l)+0.35}t-33.37 (d/l) + 0.57] Where CVt is volume ratio, d is twine diameter, l is leg length and t is pursing time (sec). 3. Tension in the purse line during pursing can be expressed by the following equation; T= 1- EXP {0.57t + 13.36 (d/l)+2.97} Where T is tension (kg) in the purseline during pursing.

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