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A Survey on Attitudes Toward Science and Science Teaching Among the Secondary School Science Teachers (과학(科學)과 과학교육(科學敎育)에 대한 중등과학교사(中等科學敎師)의 태도(態度) 조사연구(調査硏究))

  • Pak, Sung-Jae;Lee, Hi-Sung
    • Journal of The Korean Association For Science Education
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    • v.4 no.1
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    • pp.1-14
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    • 1984
  • The student's attitude toward science is generally influenced by their teachers. Therefore, teachers' positive attitudes toward science and science teaching play an important role to change the student's attitude toward science. The purpose of this survey is to investigate the status on attitudes toward science and science teaching among the secondary school science teachers in Korea. The attitudes were surveyed by the questionnaire which was developed by Sung-Jae Pak. The instrument is designed to use Likert type scale and is composed of two kinds of scale: one is the attitudes toward science scale (the AT scale) and the other is the attitudes toward science teaching scale (the AT Kale), which contains 24 questions respectively. Each of them has 6 sub-level areas. The six areas of attitude toward science are as follow: The goals and values, process and method of science, knowledge and the view of nature, social and cultural aspects, scientist and a career in science, the preferences and willingness. The six areas of attitude toward science teaching are as follow: The goals and values, process and method of science teaching, the content and structure, social and cultural aspects, science educator and a career in science teaching, satisfaction and willingness. From 152 teachers' responses, the tendency of total as well as each area and the contrast of their backgrounds at the level of 5% significance were analyzed by SPSS computer program. Some results and conclusion of the study are as follow: 1. The overall attitude of the measured secondary school science teachers shows a positive trend tendency. Also total positive attitude toward science teaching are slightly higher than that of science, which support the fact that the teachers are not scientists but they are directly involved in teaching of science. 2. The attitudes toward science are moderately correlated to the attitudes toward science teaching (r=0.52). 3. The areas of knowledge, nature-view and tile area of social aspects of science show a very negative tendency. Also the two areas are not correlated to some other areal at the level at 5% significance. 4. Female science teachers exhibit just a little more positive attitudes than those of male teachers in science teaching. 5. The science teachers who wanted to have a profession of scholar or educator exhibit a little more positive attitudes than others in science and total attitudes (AS+AT). 6. The more the science teachers have "intellectual delights" the more their attitudes toward science and science teaching are positive. 7. At the level of 5% significance, there are differences which college they graduated from, but there are no differences in multiple comparison at 10% level. 8. The differences in their background dose not appear in such as age; teaching career; academic career; deny the superstition; their onlook for the scientist or educator when they were freshmen; major the basic science; opinions about the U.F.O. and the origin of life. 9. The responses of certain individual statement are quite different from the overall tendencies, which strongly suggest the de1ailed analysis and deeper study. For the continuing study, it is recommendable to revile the measuring tools with the theoretical study for the better validity and reliability, and investigate the status of the attitudes toward science and science teaching among the science teachers with sufficient samples.

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Ecological Evolution by Competitive Exclusion / An Experimental Approach with Cellular Slime Mold , Polysphondylium pallidum (경쟁배타에 의한 생태적 진화: 세포성 점균 Polysphondylium pallidum에 대한 실험적 접근)

  • ;Robert M. Eisenberg
    • The Korean Journal of Ecology
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    • v.17 no.3
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    • pp.299-310
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    • 1994
  • Intraspecific clonal interactions have important influences on a population structure of the cellular slime mold (CSM). This study was to investigate whether or not evolutionary change in a population could be induced by clonal competition, and to elucidate how various clones in a population evolve in a homogeneous environment of laboratory culture. The characteristic clones of Polysphondylium pallidum which had different resource consumption rates (RCR) and mating types I and II were selected for study. Investigation was conducted for 4 experimental time interval $(T_0-T_4)$; one experimental time interval took almost 10-14 days from inoculation to havest of fruiting bodies. Two sets of 50 clones were cultured from 50 clones at To, and RCR variations of the population were compared between $(T_0\;and\;T_4)$ for each set of clones. Each clone of the CSM had a diverse resource consumption rate, or growth rate, in a homogeneous and limited Cerophyl agar plate despite the passage of 48-56 generations from the beginning of the experiment. Diverse clones with different growth rate could coexist in one site of the homogeneous agar plate as well as heterogeneous soil microenvironment. When there was high clonal diversity of RCR, a clone in a population had high chances to encounter other clones with resultant increased clonal competition. In one set, 26 of 37 clones of mating type I were changed to mating type Il for the 4 experimental time intervals, which indicated that the rate of competitive exclusion among clones during total experiment from $(T_0\;to\;T_4)$ was 0.703. In another set, 31 of 37 clones of mating type I were changed to mating type II , having the rate of competitive exclusion 0.838. The frequency of each of mat~ng types changed by 0.93-1.29% in each successive generation. The competitive exclusion among clones occurred by 1.26-1.75% when approximately $2.6{\times}10^8$ bacterial cells were provided as food and thereafter one generation of myxamoebae of CSM elapsed at room temperature. This finding implicated that in the vegetative state of P, pallidurn there was 1.26-1.75% probabil~ty of evolutionary change per generation changing from one clone to another clone.

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A Study of Content Analysis on ICU(Intensive Care Unit) Nurses' Knowledge of Basic Nursing Sciences (중환자실 간호사의 기초간호과학 지식의 필요성 분석)

  • Byeon, Young-Soon;Choe, Myoung-Ae;Kim, Hee-Seung;Park, Mi-Jung;Seo, Wha-Sook;Lee, Kyung-Sook;Choi, S-Mi;Hong, Hae-Sook
    • Journal of Korean Biological Nursing Science
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    • v.4 no.1
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    • pp.41-49
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    • 2002
  • The purpose of this study was to identify the knowledge contents of basic nursing sciences needed by nurses in the practices of the intensive care unit(ICU). To attain the goal of this study, the nurses working at 10 hospitals in the areas of Seoul and Kangwon Province were randomly selected. They were primarily interviewed, and the open question was secondarily put to them through the questionnaire. In the process of the 1st interview, the interviewees were asked of the question, "What is the knowledge of basic sciences such as anatomy, pathology, physiology. microbiology, pharmacology and the like thought to be lacking when you communicate with doctors in the ICU and when you carry out your nursing practices in it?" The contents of the interview were tape-recorded. The period of data collection ranged from May 1, 2001 to Sept 30. The interviews were conducted with total of 20 nurses. The open-end questionnaire was secondarily mailed to nurses. 113 questionnaires were returned. 100 questionnaires except 13 ones thought to be poorly completed in content were used for data analysis. Three coders classified data obtained from the interview and the questionnaire research into 5 detailed items relating to such as anatomical physiology, pathology, pharmacology. microbiology and basics of nursing. The three coders had experiences in nursing education of 18 years, 8 years and 6 years, respectively, and of them one coder was professor in basic nursing sciences. Data were statistically treated using frequency analysis and percentage by the SAS program. As a result, the following findings were obtained : It was found that the contents that ICU nurses responded were most needed in the field of Human structure and function were water and electrolytic balance(38%), blood and circulatory system(20%), changer in the patient's skin(12%), the arrangement of the human body(10%) and the endocrine system(10%), nervous system(6%), and assessment of the state of the patient's consciousness(4%). It was found that the contents that ICU nurses responded were most needed in the field of pathology were found to be the process of the progress of the disease(32%), symptoms of the disease(27%), prognosis of the disease(22%), followed by the injury-healing process, clinical pathological examination, and examination by radiation. It was found that the contents that nurses responded were most needed in the field of pharmacology were the effect of drug(25%), the side effect of drug(22%), the relationship between diseases and drug(20%), the relationship between disease-causing bacteria and drug(20%) and chemotherapy(2%). It was found that the contents that ICU nurses responded were most needed in the field of microbiology were the relationship between diseases and disease-causing bacteria(45%), Kinds and characteristics of disease-causing bacteria(18%), infection control(16%), application of the aseptic technique(12%), isolation(9%) and the like. It was found that the basic knowledge that ICU nurses responded were needed were the identification of the patient's current state(36%), understanding of the therapeutic process(22%), the operating principle of medical equipment and instrument(20%), medical terminology(9%), equipment and instrument management(7%), calculation of the dose of injection(2%) and the like.

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Analysis of Church based parish nursing activities in Teagu city (목회간호사의 업무활동분석)

  • Kim, Chung-Nam;Park, Jeong-Sook;Kwon, Young-Sook
    • Research in Community and Public Health Nursing
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    • v.7 no.2
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    • pp.384-399
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    • 1996
  • The concept of parish nursing began in the late 1960s in the United States when increasing numbers of churches employed registered nurses (RNs) to provide holistic, preventive health care to the members of their congregations. Parish nursing role was developed in 1983 by Lutheran chaplain Granger Westberg, and provides care to a variety of church congregation of various denominations. The parish nurse functions as health educator, counselor, group facilitator, client advocate, and liaison to community resources. Since these activities are complementary to the population-focused practice of community health' CNSs, parish nurses either have a strong public health background or work directly with both baccalaureate-prepared public health nurses and CNSs. In a Midwest community in U.S.A., the Healthy People 2000(1991) objectives are being addressed in health ministries through a coalition between public health nurses and parish nurses. Parish nursing is in the beginning state in Korea and up untill now, there has been no research was conducted on concrete role of korean parish nurses. The main purpose of this study was to identify, classify and analyze activities of parish nurses. The other important objective of this study was to establish an effective approach and direction for parish nursing and provide a database for korean parish nursing model through analysis and' classification of the content of the nursing record which included nursing activities. This study was a descriptive survey research. The parish nurses were working in churches where the demonstration project developed on parish nursing. The study was done on all nursing records which were working in churches where the demonstration project developed on parish nursing. The study was done on all nursing records which were documented by parish nurses in three churches from March, 1995 to February, 1996. Namsan, Taegu Jeei and Nedang presbyterian churches in Taegu and Keimyung nursing college incooperated together for the parish nursing demonstration project. The data analysis procedure was as follows: First, a record analysis tool was developed and second, the data was collected, coded and analyzed, the classification for nursing activities was developed through a literature review, from which the basic analysis tool was produced and cotent validity review was also done. The classification of the activities of parish nurses showed 7 activitity categories. 7 activity categories consisted of visitation nursing, health check-ups, health education, referring, attending staff meetings, attending inservices and seminar, volunteers coordinating. The percentage of activities were as follows: Visitation nursing(A: 51.6%, B: 55%, C: 42.6%) Health check-ups(A: 13.5%, B: 12.1%, C: 22.3%) Health education(A: 13.5%, B: 13.2%, C: 18.2%) Referring(A: 1.4%, B: 4.2%, C: 2.4%) Attending staff meeting(A: 18.8%, B: 13.0%, C: 12.2%) Attending inservices and seminar(A: 1.5%, B: 2.2%, C: 2.1%) Volunteers coordinating(A: 0.3%, B: 0.4%, C: 0.0%) To establish and develope parish nursing delivery network in Korea, parish nurses role, activities and boundaries of practice should be continuously monitored and refined every 2 years. Also, It is needed to develope effective nursing recording system based on the need assessment research data of various congregation members. role, activities and boundaries of practice and arrangement of the working structure, continuing education, cooperation with community resources and structuring and organizing parish nursing delivery network. Also, It is needed to develope effective nursing recording system based on the need assessment research data of various congregation members.

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Evaluation of Health Impact of Heat Waves using Bio-Climatic impact Assessment System (BioCAS) at Building scale over the Seoul City Area (생명기후분석시스템(BioCAS)을 이용한 폭염 건강위험의 검증 - 서울시 건물규모를 중심으로 -)

  • Kim, Kyu Rang;Lee, Ji-Sun;Yi, Chaeyeon;Kim, Baek-Jo;Janicke, Britta;Holtmann, Achim;Scherer, Dieter
    • Journal of Environmental Impact Assessment
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    • v.25 no.6
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    • pp.514-524
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    • 2016
  • The Bio-Climatic impact Assessment System, BioCAS was utilized to produce analysis maps of daily maximum perceived temperature ($PT_{max}$) and excess mortality ($r_{EM}$) over the entire Seoul area on a heat wave event. The spatial resolution was 25 m and the Aug. 5, 2012 was the selected heat event date. The analyzed results were evaluated by comparing with observed health impact data - mortality and morbidity - during heat waves in 2004-2013 and 2006-2011,respectively. They were aggregated for 25 districts in Seoul. Spatial resolution of the comparison was equalized to district to match the lower data resolution of mortality and morbidity. Spatial maximum, minimum, average, and total of $PT_{max}$ and $r_{EM}$ were generated and correlated to the health impact data of mortality and morbidity. Correlation results show that the spatial averages of $PT_{max}$ and $r_{EM}$ were not able to explain the observed health impact. Instead, spatial minimum and maximum of $PT_{max}$ were correlated with mortality (r=0.53) and morbidity (r=0.42),respectively. Spatial maximum of $PT_{max}$, determined by building density, affected increasing morbidity at daytime by heat-related diseases such as sunstroke, whereas spatial minimum, determined by vegetation, affected decreasing mortality at nighttime by reducing heat stress. On the other hand, spatial maximum of $r_{EM}$ was correlated with morbidity (r=0.52) but not with mortality. It may have been affected by the limit of district-level irregularity such as difference in base-line heat vulnerability due to the age structure of the population. Areal distribution of the heat impact by local building and vegetation, such as spatial maximum and minimum, was more important than spatial mean. Such high resolution analyses are able to produce quantitative results in health impact and can also be used for economic analyses of localized urban development.

Determinants of Dual-earner Wives' Needs for Family-supportive Services: A Comparison of Professional and Blue-collar Models (맞벌이 부인의 가족지원서비스 필요도 결정요인 : 전문직과 생산직 모델 비교)

  • Lee, Myung-Shin
    • Korean Journal of Social Welfare
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    • v.36
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    • pp.199-228
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    • 1998
  • This study is designed to find out the determinants of dual-earner wives' needs for family-supportive services. For this purpose, a hypothetical model which explains the relationships among 6 stressors, role overload, stress and needs for 4 family-supportive services is developed. Using the data collected by purposive sampling from 234 professional women and 208 blue-collar women living in Chinju and Sacheon, the hypothetical model developed in this study was tested. In order to examine occupational class differences, a model for professionals and another model for blue-collars were developed separately and compared. For data analysis, a covariance structure analysis was used. The best-fitting model for professional women (df=141, GFI=0.928, CFI=0.965) and the model for blue collar women (df=141, GFI=0.902, CFI=0.912) were found. As a result of comparing two models, 9 common relationships were found:l)Greater dissatisfaction with child care service increases role overload; 2)Longer work hours increases role overload; 3) Higher level of role overload increases stress; 4)Higher level of stress increase needs for leaves; 5)Older child increases needs for flexible work pattern; 6)Younger child increases needs for finalcial assistance for child care fee; 7)needs for financial assistance for child care increases needs for on-site child care services; 8)needs for on-site child care services increases needs for leaves; 9)needs for leaves increases needs for flexible work pattern. With the exception of these 9 common relationships, the analyses revealed substantial differences between professional and blue-collar dual-earner wives. Based on the common and differential needs between 2 groups of wives, the effective ways to provide family-supportive services according to the needs of individual dual-earner wives who are in different familial, financial, and work conditions were suggested.

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A Study on Fractionation and Characterization of Water-Soluble Natural Fe-Chelates From Garbage Compost and Activated Sewage Sludge (활성오니(活性汚泥) 및 진개퇴비중(塵芥堆肥中) 수용성(水溶性) 철(鐵) 킬레이트의 분리(分離)와 특성(特性)에 관(關)한 연구(硏究))

  • Park, Nae-Joung;Lindsay, W.L.
    • Applied Biological Chemistry
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    • v.18 no.4
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    • pp.194-202
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    • 1975
  • This study was conducted to study the properties of the water-soluble natural chelating agents from garbage compost and activated sewage sludge responsible for Fe chelation, which is closely associated with the effectiveness in correcting iron chlorosis in plant. The water-soluble fraction of these materials was fractionated by menas of Sephadex gel filtration and the fractions of Fe chehates were traced by radioactive $^{59}Fe$. The fractions were examined by ultraviolet and infrared. spectroscopy and stability constants for Fe. The water-soluble fraction from garbage compost was separated by Sephadex G-25 into approximately four fractions. Most of the added $^{59}Fe$ was associated with fraction I, which appeared at the void volume. Further fractionation by Sephadex G-50 indicated that the molecular weight of water-soluble chelating agents is in the approximate range of 5000 to 10,000. The water-soluble fraction from activated sewage sludge gave six fractions by Sephadex G-25. Most of the added $^{59}Fe$ was found in the fraction I,II, and III, The molecular weights of most chelating agents associated with $^{59}Fe$ appeared to be less than 5,000 and those of fraction I that appeared at the void volume was in the range of 5,000 to 1,000. Discrepancy between radio activity count and UV absorption indicated the heterogeneity of the fractions obtained by Sephadex gel filtration. Ultraviolet absorption spectra of all fractions separated by Sephadex G-25 and containing chelating agents showed no differences. Fraction IV and V of sewage extract showed absorption maxima and shifting similar to nucleic acid components suggesting the presence of decomposition products of nucleic acid. Similarity fraction VI contained phenolic type amino acid groups. Fraction I of compost extract contained most of the added $^{59}Fe$ and showed weak but extra definite absorption in the 1230, and $1270cm^{-1}$ region, suggesting that extra oxygen groups in polyphenolic structure were probably involved in Fe chelation. In sewage extract, fraction I,II, and III in which most of the $^{59}Fe$ was found, showed strong definite polypeptide absorption in the region of $1540cm^{-1}$ due to NH deformation and C-N stretching of amide groups in the peptidebond. These extra functional groups in fraction I, II, and III appeared to be associated with Fe chelation. The other fractions, not associated with $^{59}Fe$, still have carboxyl and hydroxyl groups, suggesting that these functional groups in these water extracts may not independently form the Fe chelates. Precipitation of ferric hydroxide precluded measuring the stability constants for Fe-chelates. However, the formation constants for Zn chelates as log K values for compost extract and sewage extract at pH 4.0 from which the strength of chelation with Fe could be presumed, were 8.23, and 9.75, respectively, indicating strong complexation with metals. The chelating capacity of compost extract containing 6.5 g organic matter per liter was 0.82 mM, and that of sewage extract containing 5.3 g per liter was 0. 64 mM.

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Regulation of Tumor Neceosis Factor-${\alpha}$ Receptors and Signal Transduction Pathways

  • Han, Hyung-Mee
    • Toxicological Research
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    • v.8 no.2
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    • pp.343-357
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    • 1992
  • Tumor necrosis factor-${\alpha}$(TNF), a polypeptide hormone secreted primarily by activated macrophages, was originally identified on the basis of its ability to cause hemorrhagic necrosis and tumor regression in vivo. Subsequently, TNF has been shown to be an important component of the host responses to infection and cancer and may mediate the wasting syndrome known as cachexia. These systemic actions of TNF are reflected in its diverse effects on target cells in vitro. TNF initiates its diverse cellular actions by binding to specific cell surface receptors. Although TNF receptors have been identified on most of animal cells, regulation of these receptors and the mechanisms which transduce TNF receptor binding into cellular responses are not well understood. Therefore, in the present study, the mechanisms how TNF receptors are being regulated and how TNF receptor binding is being transduced into cellular responses were investigated in rat liver plasma membranes (PM) and ME-180 human cervical carcinoma cell lines. $^{125}I$-TNF bound to high ($K_d=1.51{\pm}0.35nM$)affinity receptors in rat liver PM. Solubilization of PM with 1% Triton X-100 increased both high affinity (from $0.33{\pm}0.04\;to\;1.67{\pm}0.05$ pmoles/mg protein) and low affinity (from $1.92{\pm}0.16\;to\;7.57{\pm}0.50$ pmoles/mg protein) TNF binding without affecting the affinities for TNF, suggesting the presence of a large latent pool of TNF receptors. Affinity labeling of receptors whether from PM or solubilized PM resulted in cross-linking of $^{125}I$-TNF into $M_r$ 130 kDa, 90 kDa and 66kDa complexes. Thus, the properties of the latent TNF receptors were similar to those initially accessible to TNF. To determine if exposure of latent receptors is regulated by TNF, $^{125}I$-TNF binding to control and TNF-pretreated membranes were assayed. Specific binding was increased by pretreatment with TNF (P<0.05), demonstrating that hepatic PM contains latent TNF receptors whose exposure is promoted by TNF. Homologous up-regulation of TNF receptors may, in part, be responsible for sustained hepatic responsiveness during chronic exposure to TNF. As a next step, the post-receptor events induced by TNF were examined. Although the signal transduction pathways for TNF have not been delineated clearly, the actions of many other hormones are mediated by the reversible phosphorylation of specific enzymes or target proteins. The present study demonstrated that TNF induces phosphorylation of 28 kDa protein (p28). Two dimensional soidum dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) resolved the 28kDa phosphoprotein into two isoforms having pIs of 6.2 and 6.1. The pIs and relative molecular weight of p28 were consistent with those of a previously characterized mRNA cap binding protein. mRNA cap binding proteins are a class of translation initiation factors that recognize the 7-methylguanosine cap structure found on the 5' end of eukaryotic mRNAs. In vitro, these proteins are defined by their specific elution from affinity columns composed of 7-methylguanosine 5'-triphosphate($m^7$GTP)-Sepharose. Affinity purification of mRNA cap binding proteins from control and TNF treated ME-180 cells proved that TNF rapidly stimulates phosphorylation of an mRNA cap binding protein. Phosphorylation occurred in several cell types that are important in vitro models of TNF action. The mRNA cap binding protein phosphorylated in response to TNF treatment was purifice, sequenced, and identified as the proto-oncogene product eukaryotic initiation factor-4E(eIF-4E). These data show that phosphorylation of a key component of the cellular translational machinery is a common early event in the diverse cellular actions of TNF.

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Evaluation of Internal Phosphorus Loading through the Dynamic Monitoring of Dissolved Oxygen in a Shallow Reservoir (수심이 얕은 저수지에서 용존산소 동적 모니터링을 통한 인 내부부하 평가)

  • Park, Hyungseok;Choi, Sunhwa;Chung, Sewoong;Ji, Hyunseo;Oh, Jungkuk;Jun, Hangbae
    • Journal of Environmental Impact Assessment
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    • v.26 no.6
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    • pp.553-562
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    • 2017
  • In these days, agricultural reservoirs are considered as a useful resource for recreational purposes, tour and cultural amenity for vicinity communities as well as irrigation water supply. However, many of the agricultural reservoirs are showing a eutrophic or hyper-eutrophic state and high level of organic contamination. In particular, about 44.7% of the aged agricultural reservoirs that constructed before 1945 exceed the water quality criteria for irrigational water use. In addition to external loading, internal nutrient loading from bottom sediment may play an important role in the nutrient budget of the aged reservoirs. The objectives of this study were to characterize variations of thermal structure of a shallow M reservoir (mean depth 1.7 m) and examine the potential of internal nutrient loading by continuous monitoring of vertical water temperature and dissolved oxygen (DO) concentration profiles in 2015 and 2016. The effect of internal loading on the total loading of the reservoir was evaluated by mass balance analysis. Results showed that a weak thermal stratification and a strong DO stratification were developed in the shallow M Reservoir. And, dynamic temporal variation in DO was observed at the bottom of the reservoir. Persistent hypoxic conditions (DO concentrations less than 2 mg/L) were established for 87 days and 98 days in 2015 and 2016, respectively, during the no-rainy summer periods. The DO concentrations intermittently increased during several events of atmospheric temperature drop and rainfall. According to the mass balance analysis, the amount of internal $PO_4-P$ loading from sediment to the overlying water were 37.9% and 39.7% of total loading during no-rainy season in 2015 and 2016, respectively on August when algae growth is enhanced with increasing water temperature. Consequently, supply of DO to the lower layer of the reservoir could be effective countermeasure to reduce nutrient release under the condition of persistent DO depletion in the bottom of the reservoir.

THE EFFECTS OF SURFACE CONTAMINATION BY HEMOSTATIC AGENTS ON THE SHEAR BOND STRENGTH OF COMPOMER (지혈제 오염이 콤포머의 전단결합강도에 미치는 영향)

  • Heo, Jeong-Moo;Kwak, Ju-Seog;Lee, Hwang;Lee, Su-Jong;Im, Mi-Kyung
    • Restorative Dentistry and Endodontics
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    • v.27 no.2
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    • pp.150-157
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    • 2002
  • One of the latest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not dry but left moist before application of the bonding primer Ideally the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically, contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during cavity preparation. The aim of this study was to evaluate the effect of contamination by hemostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were removed soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive papers on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows : Group 1: Dentin surface was not etched and not contaminated by hemostatic agents. Group 2: Dentin surface was not etched but was contaminated by Astringedent$^{\circledR}$(Ultradent product Inc., Utah, U.S.A.) Group 3: Dentin surface was not etched but was contaminated by Bosmin$^{\circledR}$(Jeil Pharm, Korea.). Group 4: Dentin surface was not etched but was contaminated by Epri-dent$^{\circledR}$(Epr Industries, NJ, U.S.A.). Group 5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6: Dentin sorface was etched and contaminated by Astringedent$^{\circledR}$. Group 7 : Dentin surface was etched and contaminated by Bosmin$^{\circledR}$. Group 8: Dentin surface was etched and contaminated by Epri-dent$^{\circledR}$. Group 9: Dentin surface was contaminated by Astringedent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 10: Dentin surface was contaminated by Bosmin$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 11 : Dentin surface was contaminated by Epri-dent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. After surface conditioning, F2000$^{\circledR}$ was applicated on the conditoned dentin surface The teeth were thermocycled in distilled water at 5$^{\circ}C$ and 55$^{\circ}C$ for 1,000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the knife-edge shearing rod of the Universal Testing Machine(Zwick Z020, Zwick Co., Germany) running at a cross head speed or 1.0 mm/min. Group 2 showed significant decrease in shear bond strength compared with group 1 and group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.