• Title/Summary/Keyword: 소재특성

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Distribution and Characteristics of Heterotrophic Plate Count Bacteria in Water Samples from Drinking Water Dispensers (냉온수기에서 일반세균의 분포 및 분리한 세균의 특성)

  • Lee, Eun-Hwa;Koh, Ji-Yun;Kim, Jong-Seol
    • Korean Journal of Microbiology
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    • v.44 no.3
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    • pp.244-250
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    • 2008
  • To evaluate bacteriological water quality, samples were taken from drinking water dispensers placed at S company (S-C) and U highschool (U-H) in Ulsan. The medians of heterotrophic plate counts (HPCs) were 53 CFU/ml for the 74 water samples of S-C and 80 CFU/ml for the 36 cold water samples of U-H, and 38% of the S-C and 42% of the U-H samples showed HPC bacterial concentrations higher than 100 CFU/ml. Coliform bacteria were detected from one sample of S-C. To determine the major source of bacterial contamination, water samples were taken daily for $6\sim8$ days from the bottled water containers as well as the faucets of an experimental water dispenser. While the average HPCs in the bottled water containers were 33 CFU/ml for the first and 132 CFU/ml for the 2nd analysis, the HPC concentration in the cold water samples was 1,022 CFU/ml for the 2nd analysis. These results suggest that the majority of bacteria detected in the cold water samples were originated from the biofilms on the surface of water passages within the water dispensers. There was no significant increase in HPC bacterial concentrations within the bottled water container after installation on the water dispenser. We could isolate and tentatively identify 3 genera 6 species of Gram-positive and 7 genera 7 species of Gram-negative bacteria from the plate count agar plates of U-H samples. Among the isolates, 72% were observed as Gram-positive, and Micrococcus spp. was the most abundant with 54% of the total, followed by Sphingomonas paucimobilis with 16%. It appears that most of the HPC bacteria detected in water dispensers originate from indoor airborne bacteria, which may play important roles in the formation of biofilms on the surface of water passages within the water dispensers.

Optimum Conditions for the Culture of Hericium erinaceum in a Jar Fermenter with the Addition of Ginseng Extract in the Liquid Medium (수삼추출물을 이용한 노루궁뎅이버섯 균사체의 jar fermenter에서의 발효조건 최적화)

  • Park, Chang-Kyu;Tu, Qi;Cho, Ju-Hyun;Yu, Kwang-Won;Jeong, Heon-Sang;Lee, Hyeon-Yong;Jeong, Jae-Hyun
    • Korean Journal of Food Science and Technology
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    • v.42 no.1
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    • pp.82-89
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    • 2010
  • To obtain functional materials from a submerged culture of Hericium erinaceum, a suitable basal medium for flask culture was screened and the optimal culture conditions in a jar fermenter were investigated with the addition of ginseng extracts (GE) to the basal liquid medium. Of all tested basal liquid media, the mushroom complete medium (MCM) supplemented with 0.5% of GE produced the highest mycelial dry weight (MDW) of 5.91 g/L in the flask, which reached a plateau at $25^{\circ}C$, pH 5.5 after 10 days. The submerged culture conditions for the mass production of mycelia in a 50 L jar fermenter were also optimal at $25^{\circ}C$, pH 5.5, 120 rpm agitation speed and 0.4 vvm aeration rate. Under these conditions, the maximum MDW was produced, which reached a value of 4.28 g/L within 5 days. When we investigated the effects of the amount of GE in the MCM on the production of MDW in the jar fermenter, the addition of 5% GE (HE-GE-5) under the optimal culture conditions produced the maximum MDW (4.93 g/L). In addition, the crude polysaccharide of HE-GE-5 contained mainly neutral sugars (63.2%) with considerable amounts of uronic acid (19.3%) and a small amount of proteins (8.8%) and it had potent immunostimulation properties.

A Study on Home Economics Teachers' Concern for Performance Assessment and Its Implementation (기술ㆍ가정과 교사의 수행평가에 대한 관심도, 실행수준, 실행실태 및 관련변수)

  • 정미정;채정현
    • Journal of Korean Home Economics Education Association
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    • v.16 no.1
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    • pp.79-91
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    • 2004
  • The purpose of this study was to examine how much secondary school home economics teachers paid attention to performance assessment, to what extent and in which way they carried it out and how much support was given to that. It's basically meant to help provide more systematic support for performance assessment. The instrument used in this study was an Interest-Based Reform Adoption Model developed by Hall. Hord and et. al. at Texas University Research & Development Center for Teacher Education. and the subjects in this study were home economics teachers from 95 secondary schools in Gyeonggi province. After a survey was conducted by mail. the responses from 157 teachers were chosen for analysis. For data handling. SPSS/WIN program was utilized, and statistical data on mean. standard deviation and percentage were obtained. In addition. t-test and ANOVA were employed. The major findings of this study were as follows: First. as for their type of interest in performance assessment. influential type(35.0%) was most common. followed by confident type (29.3%). indifferent type(20.4%) and task type(15.3%). Second, regarding their implementation. every teacher carried out performance assessment. The largest group of the teachers fulfilled it as part of routine daily schedule(60 teachers. 38.2%). which could be called the level 4. The second largest group tried to integrate performance assessment to education programs(53 teachers. 33.8%). which could be called the level 5. The third largest group implemented it without making careful preparations for that(26 teachers. 16.6%). which could be called the level 3. and the fourth largest group tried to reinvent it(11 teachers. 7.0%), which could be called the level 6. The fifth largest group was in the middle of researching it(5 teachers, 3.2%). which could be called the level 1. And the sixth largest group was in the course of making preparations for that(2 teachers. 1.3%) . which could be named the level 2. Third. concerning how much they found themselves to be supported about performance assessment. they eave three or less marks to that. which showed that they weren't supported sufficiently There was little gap among them in their concern for performance assessment and its implementation levels. and this fact suggested that there wasn't satisfactory backup for their performance assessment.

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Quality Characteristics of Frozen Doraji (Platycodon grandiflorum) according to Various Blanching Treatment Conditions (블랜칭 처리 조건에 따른 동결 도라지의 품질 특성)

  • Lee, Young-Joo;Lee, Hye-Ok;Kim, Ji-Young;Kwon, Ki-Hyun;Cha, Hwan-Soo;Kim, Byeong-Sam
    • Food Science and Preservation
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    • v.18 no.5
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    • pp.661-668
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    • 2011
  • This study was conducted to devise appropriate blanching-process conditions as a means to convert Doraji, which is widely used in Korean food due to its unique fragrance and flavor, into frozen food materials for various uses. For the Hunter L values representing the brightness transformation among the surface color and gloss changes that were observed in Doraji before and after freezing, and after Doraji went through a blanching process, the specimen that went through a blanching process at $80^{\circ}C$ showed a significantly higher value compared to another specimen processed at a higher temperature, and the first specimen's value also rose after freezing. Meanwhile, for the hardness values, they declined more as the blanching temperature became higher and as the processing time became longer. For the number of total counts and the number of coliform groups, the number of total counts at $3.75{\times}10^5$ and $1.25{\times}10^5$ cfu/g before the blanching process was reduced into the approximately 2-3 log scale, and no coliform group was detected after the blanching process. As for the peroxidase activity, its activation was decreased by the blanching process, and more than 89% of the peroxidase became inactivated in all the specimens that went through the blanching process. The sensory characteristics of the frozen-thawed Doraji by test group showed the radish leaves blanched at $90^{\circ}C$ for 1 min to be the most highly evaluated in terms of the overall preference level (p<0.05).

The Factors Associated with Dental Caries Experience and Oral Hygiens Status in Smoking Adolescents (흡연청소년의 치아우식경험도 및 구강위생 관련요인)

  • Shin, Seon-Haeng;Kim, Myung-Seok
    • Journal of dental hygiene science
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    • v.9 no.5
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    • pp.497-506
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    • 2009
  • This study was conducted to estimate the dental caries experience, oral hygiene status and the factors influencing the dental disease in the smoking adolescents and to provide the baseline data for managing smokers efficiently. We recruited 156 smokers(male: 106, female: 50) in middle, high school students in 5 day Non-smoking program in seoul city and 176 non-smokers(male: 64, female: 112) by matching method for considering sex and age from June 1 to August 31 2009. Data on general characteristics, basic oral health care, smoking factors, self-efficiency, control of oral health, oral health promotion behavior, knowledge of oral health were collected by a questionnaire interview. DMFT index, DT index, MT index, FT index, Plaque index, Calculus index were calculated by the oral examination. The results of this study were as follows. 1. Dental clinic visit(p < 0.05), self-perception of oral health status(p < 0.001), oral health concern (p < 0.01) in non-smoker group were significantly higher than that of smoker group. 2. self-efficiency(p<0.05), oral health promotion behavior(p < 0.05) in non-smoker group were significantly higher than that of smoker group. 3. DT index, Plaque index, Calculus index in non-smoker group was significantly lower than that of smoker group(p < 0.0001). 4. The fewer smoke amount, the lower DT index(p < 0.05), Plaque index(p < 0.01), Calculus index(p < 0.001). 5. It was significant correlated among DT index and self-efficiency, oral health promotion behavior, control of oral health. 6. In multiple regression analysis, oral health promotion behavior, Plaque index was proved as a significant factors related with the degree of dental caries experience in smoking adolescents. In other word, the higher oral health promotion behavior, the lower Plaque index, the fewer DT index.

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Impact of Communication Competence and Empathy Abilities on Interpersonal Relationship Abilities among Dental Hygiene Students (일부 치위생 전공 대학생의 의사소통능력과 공감능력이 대인관계능력에 미치는 영향)

  • Kim, Sun-Ju;Kim, Han-Hong
    • Journal of dental hygiene science
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    • v.13 no.3
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    • pp.304-313
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    • 2013
  • The purpose of this study was to examine the influence of the communication competence and empathy abilities of dental hygiene students on their interpersonal relationship abilities. The subjects in this study were 578 students who majored in dental hygiene at five randomly selected colleges. Out of the colleges, three were located in North Chungcheong province, and one was located in the city of Daejeon. The other one was located in South Gyeongsang province. Data were gathered using structured questionnaires from April 1 to May 7, 2013. The major findings of the study were as follows: 1. The respondents got a mean of $3.23{\pm}0.49$, $85.80{\pm}10.12$ and $83.27{\pm}8.37$ in interpersonal relationship abilities, communication competence and empathy abilities respectively. 2. As for communication competence, empathy abilities and interpersonal relationship abilities by general characteristics, there were statistically significant differences according to age, academic year, clinical practice experience and satisfaction with major. 3. The relationship of communication competence and empathy abilities to interpersonal relationship abilities was analyzed, and interpersonal relationship abilities were found to have a strong significant positive correlation to communication competence, empathy abilities and the subfactors of the two. 4. As a result of analyzing which variables affected interpersonal relationship abilities, it's found that interpersonal relationship abilities were under the influence of age, clinical practice experience, communication competence, empathy abilities. These variables made a 57.2% prediction of interpersonal relationship abilities. The above-mentioned findings suggest that communication competence and empathy abilities exerted an influence on interpersonal relationship abilities. Therefore curriculums and educational programs should be developed in consideration of these variables to ensure the stable college lives and successful relationship building of dental hygiene students who are on the way to adulthood and will serve as health care personnels in the future.

Preparation of Instant Powdered Soup using Canned Oyster Processing Waste Water and Its Characteristics (굴통조림 부산액을 이용한 인스턴트 분말수프의 제조 및 특성)

  • KIM Jin-Soo;HEU Min-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.3
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    • pp.285-290
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    • 2001
  • To utilize canned oyster processing waste water effectively, this study was carried out to prepare instant powdered soup using the waste water (IPSW), Instant powdered souu from oyster hot-water extracts (IPSE) was prepared by mixing hot-water extracts powder (15 g) with table salt (5 g), cream powder (19 g), milk replacer (12 g), wheat flour (20 g), corn flour (15 g), starch (5 g), glucose (7.5 g) and onion powder (1.5 g). In preparing IPSW, mixed powder from wash water and boiling liquid waste, instead of powder from hot-water extracts and table salt, was added (powder from boiling liquid waste: powder from wash water= 12: 8) and other additives were added in proportion to those in the IPSE, The IPSW consists mainly of carbohydrates (about $72\%$). It was not different from the IPSE. The volatile basic nitrogen, viable cell counts, coliform group of the IPSW contains 33.4 mg/100g, $2.2\times10^4CFU/g$, <180 MPN/100g, respectively, and its water activity has 0.257. So it was a hygienically safe and conservable instant food. The main fatty acids of IPSW were 16: 0 and 18: 1n-9. Its chemical score of protein was $61.4\%$ and its main inorganic matter was iron. According to a sensual evaluation, in contrast to the IPSE, the IPSW had a bit lower aroma but better taste, It was concluded from the above chemical and sensory evaluation that even the boiling liquid waste which had been mostly abandoned because of its high table salt content can be used as a good material for instant powdered soup if it's powdered and mixed adequately with powder from wash water, and its table salt content is properly adjusted.

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Characteristics and Seasonal Variations in the Structure of Coleoptera Communities (갑충군집(甲蟲群集)의 구조적(構造的) 특성(特性)과 계절적(季節的) 발생소장(發生消長))

  • Kim, Ho Jun
    • Journal of Korean Society of Forest Science
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    • v.80 no.1
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    • pp.82-96
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    • 1991
  • This study was carried out to investigate the structural characteristics of Coleoptera communities inhabiting the crowns of the Korean pine(Pinus koraiensis S. et Z.). Four plantations of the Korean pine, stand A (11 years old), stand B(21 years old), stand C(31 years old), and stand D(46 years old), were selected in Sudong-myen, Namyangju-gun, Kyeonggi-do. Sampling was done by knock down methods using insectide(DDVP), which was conducted from April, 1986 to September, 1987, except for the winter season. The following major conclusions are drawn from this study : 1. The total number of Coleoptera was 107 species of 85 genera in 35 families : 83 species of 66 genera in 27 families in 1986 and 74 species of 52 genera in 30 families in 1987. 2. The abundant families, based on the number of species, were Staphylinidae (16.8%), Coccinellidae(7.5%), Chrysomlidae(6.5%), Curculionidae(6.5.%), and Cerambycidae(5.6%). These five families occupied 43.0% of the total number of species. 3. The important families, based on the number of individuals, were Cantharidae(28.2%), Catopidae(27.7%), and Coccinellidae(23.0%). These three families occupied 78.9% of the total number of individuals. 4. The important species, based on the number of individuals, were Podabrus sp. (22.6%, C-antharidae), Catnps sp. 1 (21.7%. Catopidae), Anatis halonis (15.2%. Coccinellidae). Dominant species was Podabrus sp. (25.2% in 1986 and Catops sp. 1(24.9%) in 1987. 5. Generally, more spices and individual numbers were found in older stands than in younger ones. 6. The Coleoptera communities decreased in the thinned stand (stand C). Such a phenomenon in the thinned stand was likely to last two or more years. 7. The Coleoptera communities reached their peak of abundance in May, and decreased thereafter.

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Chemical Composition and Antioxidative Activity of Kiwifruit in Different Cultivars and Maturity (제주산 참다래의 품종 및 숙도에 따른 화학성분과 항산화 활성)

  • Oh, Hyun-Jeong;Jeon, Si-Bum;Kang, Hye-Young;Yang, Young-Jun;Kim, Seong-Cheol;Lim, Sang-Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.343-349
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    • 2011
  • The chemical composition and antioxidative activity of kiwifruit varieties in Jeju, such as Jecy Gold (Actinidia chinensis var. 'Jecy Gold'), Halla Gold (A. chinensis var. 'Halla Gold'), Jecy Sweet (A. deliciosa var. 'Jecy Sweet') and Hwabuk 94 (A. deliciosa var. 'Hwabuk 94') were investigated. The crude protein, crude lipid, and pH showed no differences among variety and maturity whereas the moisture contents showed differences among the variety and maturity. Jecy Sweet in mature stage showed the highest values in soluble solid, crude protein, crude lipid, and crude ash. The changes in chemical components of kiwifruit by maturity stage were as follows: during ripening, the glucose and the fructose contents increased considerably with the decrease of sucrose content. Potassium, phosphorus, sodium, and magnesium were estimated as the major minerals in kiwifruit and Jecy Sweet contained the highest amounts of potassium and magnesium. At maturity stage, ascorbic, malic and lactic acid were increased with the decrease of citric acid content. The polyphenol contents were 26.81~56.10 ${\mu}g/g$ and 8.64~26.45 ${\mu}g/g$, respectively, in immature and mature fruits. During ripening, the polyphenol content was decreased. The DPPH radical scavenging activity of methanol extracts were 84.47~89.37% and 43.94~76.96% at 500 ppm, respectively, in immature and mature fruits. The immature varieties of kiwifruit have a high DPPH radical scavenging activity. Therefore the chemical composition and physiological activity of kiwifruit was affected by variety and maturity.

A Study on the Sedimentation of Dredged Soils and Shape Changes of a Transparent Vinyl Tube by Filling Tests - Anti-Crater Formation - (준설토 주입방법에 의한 비닐튜브체의 퇴적 및 변형 특성 - 크레이터 방지 기술을 중심으로 -)

  • Kim, Hyeong-Joo;Sung, Hyun-Jong;Lee, Kwang-Hyung;Lee, Jang-Baek
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.2
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    • pp.1-10
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    • 2014
  • In this study, two different types of dredged fill injection methods are introduced and filling experiments were conducted to analyze the impact of each technique to the distribution and deposition of dredged soil fill and how it influence the final tube shape. Two transparent plastic tubes were fabricated to observe the deposition behavior of the deposited fill material. Both tubes measured 4.0 meters in length (L) and has vinyl tube diameters (D) of 0.5m and 0.7m. T-type and I-type inlet system are also introduced in this paper. The influence of this inlet systems to the distribution and deposition behavior of dredged soil fill inside the vinyl tubes were observed during the experiment. After the sedimentation of the slurry mixture, the water on top of the soil sediments are removed and the slurry mixture was re-injected into the vinyl tube, this process was carried out repeatedly. The shape changes of the vinyl tube, e.g. the changes in both tube height and width, are constantly monitored after each slurry injection and water draining phases. Crater formation was observed in the case of I-Type inlet system and a non-uniform sediment distribution occurred. For the diffusion deposit of soil particles to long distance are minimal shape technique using the T-Type inlet system. Therefore the undrain filling height ratio ($H/D_0$) was found to be around 0.54 to 0.64 and the horizontal strain ratio ($W/D_0$) ranges from 1.45 to 1.54. The filling soil height is proportional to dredged-material filling phases, but, horizontal strain ratio is constant or inversely reduced so that the center of tube body is raised in the upward direction.