• Title/Summary/Keyword: Chemistry I

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The Process of the Quickening and Development of Science-Technology- Society Education in the United Kingdom (II) - During the 2nd Half of the 20th Century - (영국에서의 과학-기술-사회 교육의 태동과 발전 과정 (II) - 20세기 후반을 중심으로 -)

  • Song, Jin-Woong
    • Journal of The Korean Association For Science Education
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    • v.20 no.1
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    • pp.52-76
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    • 2000
  • Following the previous study focused on the period until the middle of the 20th century, this study tried to show how STS-related ideas have been developed historically in British science education, particularly focused on the period of the 2nd half of the 20th century. Like the USA, the UK witnessed the development of numerous academically-oriented programs, such as Nuffield projects, during the 1950-60s. However, during the 1970s, there had been growing criticism against the discipline-centered science education and some new noticeable approaches had been made to compensate the contemporary trend. For example, although its main focus was on the integrated approach in school science, the SCISP was quite successful to illustrate the importance of the relationship between science and society. Following this example, Science in Society and SISCON-in-Schools were more ambitious in developing genuine STS programs. These two projects were developed simultaneously and took the form of modules, rather than of textbooks. Nevertheless, Science in Society was more concerned with the applied and industrial aspects of science while SISCON-in-Schools was more inclined to the historical, philosophical and social aspects of science. During the 1980s, far more ambitious attempts had been made to develop full-scale STS programs, i.e. Salters' Chemistry/Science and SATIS. These two programs have been developed with the active corporation from the ASE and soon became the typical examples of the STS approach across the world. Besides the similarities between them, Salters' approach is more application-oriented, subject-oriented, and textbook-like while SATIS is more socially-oriented, issue-oriented and module-style. In summary, the history of STS approach in school science shows that the STS programs were developed under the different social backgrounds and initiated by different groups of the people who have different views towards the purposes of school science and that the STS approach is certainly not the exclusive characteristic of the last period of the 20th century. Finally, the features of the major STS programs developed in Britain during the 20th century are summarized and compared in relation to the Ziman's criteria of the possible approaches in STS education. And some general conclusion are drown based on the study of the history of the STS approaches in Britain.

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Science Integrated Process Skill of the Students in Science Education Center for the Gifted (과학영재교육원 학생들의 과학 통합 탐구 능력)

  • Jeong, Eunyoung;Kwon, Yi-young;Yang, Joo-sung;Ko, Yu-mi
    • Journal of Science Education
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    • v.37 no.3
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    • pp.525-537
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    • 2013
  • The purpose of this study was to investigate science integrated process skill of the students in science education center for the gifted. In order to do this, 'free-response test for the assessment of science process skills' developed by Yu-Hyang Kim(2013) was administered to 102 students(15 in elementary school science class, 58 in middle school science class I, and 29 in middle school science class II) who attend the program of science education center for the gifted in C university. The assessment tool measured 9 skills ; formulating inquiry questions, recognizing variables, formulating hypotheses, designing experiment, transforming data, interpreting data, drawing conclusions, formulating generalizations, and evaluating the designed experiments. As a result, the students in science education center for the gifted had relatively high scores in the area of 'formulating hypotheses' and 'recognizing variables', but they had relatively low scores in the area of 'transforming data', 'interpreting data', and 'evaluating the designed experiments'. The 2 items' percentage of correct answers were below 40% ; one is about a drawing a line graph in 'transforming data', and the other requires finding improvements of the experimental design in 'evaluation'. There was no significant difference between boys' scores and girls's one, and between the scores of students in the field of biology and those of students in the other fields(physics, chemistry, and earth science) in science integrated process skills. And there was significant difference according to the periods receiving the gifted education in 'formulating generalizations'. The teaching and learning has to focus on improving science integrated process skills in the program of science education center for the gifted and teaching and learning materials needs to be developed.

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Seasonal Variation and Natural Attenuation of Trace Elements in the Stream Water Affected by Mine Drainage from the Abandoned Indae Mine Areas (인대광산 지역 광산배수에 영향을 받은 하천에서 미량원소의 계절적인 수질변화와 자연저감)

  • Kang, Min-Ju;Lee, Pyeong-Koo;Choi, Sang-Hoon
    • Economic and Environmental Geology
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    • v.40 no.3 s.184
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    • pp.277-293
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    • 2007
  • Seasonal and spatial variations in the concentrations of trace elements, pH and Eh were found in a creek watershed affected by mine drainage and leachate from several waste rock dumps within the As-Pb-rich Indae mine site. Because of mining activity dating back to about 40 years ago and rupture of the waste rock dumps, this creek was heavily contaminated. Due to the influx of leachate and mine drainage, the water quality of upstream reach in this creek was characterized by largest seasonal and spatial variations in concentrations of Zn(up to $5.830 mg/{\ell}$), Cu(up to $1.333 mg/{\ell}$), Cd(up to $0.031 mg/{\ell}$) and $SO_4^{2-}$(up to $173 mg/{\ell}$), relatively acidic pH values (3.8-5.1) and highly oxidized condition. The most abundant metals in the leachate samples were in order of Zn($0.045-13.909 mg/{\ell}$), Fe($0.017-8.730mg/{\ell}$), Cu($0.010-4.154mg/{\ell}$) and Cd($n.d.-0.077mg/{\ell}$), with low pH(3.1-6.1), and high $SO_4^{2-}$(up to $310 mg/{\ell}$). The mine drainage also contained high concentrations of Zn, Cu, Cd and $SO_4^{2-}$ and remained constantly near-neutral pH values(6.5-7.0) in all the year. While the leachate and mine drainage might not affect short-term fluctuations in flow, it may significantly influence the concentrations of chemicals in the stream. The abundance and chemistry of Fe-(oxy)hydroxide within this creek indicated that the Fe-(oxy)hydroxide formation could be responsible for some removal of trace elements from the creek waters. Spatial and seasonal variations along down-stream reach of this creek were caused largely by the influx of water from uncontaminated tributaries. In addition, the trace metal concentrations in this creek have been decreased nearly down to the background level at a short distance from the discharge points without any artificial treatments after hydrologic mixing in a tributary. The nonconservative(i.e. precipitation, adsorption, oxidation, dissolution etc.) and conservative(hydrologic mixing) reactions constituted an efficient mechanism of natural attenuation which reduces considerably the transference of trace elements to rivers.

Effect of Microbial Inoculant to Pig Liquid Fertilizer on Germination Index of Chinese Cabbage (돈 분뇨 액비에 미생물 첨가가 배추의 발아지수에 미치는 영향)

  • Kim, T. I.;Yoo, Y. H.;Chung, E. S.;Barroga, Antonio J.;Yang, C. B.;Kim, M. K.
    • Journal of Animal Environmental Science
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    • v.11 no.2
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    • pp.135-146
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    • 2005
  • This study was carried out to investigate the effect of Synechocystis sp. KACC 91007 when added to a pig slurry or pig liquid fertilizer (PLF) on germination index (GI) of Chinese cabbage. The preliminary experiment involved the screening of inoculant levels which were; 0.05, 0.1, 0.2, and $0.3\%$, respectively. The $0.05\%$ level of inoculant was selected based on low phytotoxicity and high GI.. The PLF underwent a 107 day aerobic and anoxic processing conditions. The T-N, T-P, $NH_4$, and $NO_3-N$ concentrations of the untreated pig slurry were; 2,873, 753, 1,441.6, and 16.48 ppm, respectively. Using aerobic processing treatment, the fertilizer value of the PLF was 3,672, 164, 183.87, and 21.97 ppm, respectively. In contrast, the fertilizer value of the PLF processed under anoxic condition was reduced to 1,261, 68, 161, and 16.87 ppm. The GI value of the untreated PLF under aerobic and anoxic processing condition was 83 and $40.4^{*}\%$, respectively. With the addition of the $0.05\%$ microbial inoculant, the GI improved by more than 40 and $50\%$ respectively, when the PLF was processed under anoxic and aerobic conditions. The above findings proved that the aerobic processing of PLF for 107 days was better than anoxic and yielded higher T-N which is a macro-nutrient fertilizer material. Consequently, the addition of $0.05\%$ microbial inoculant resulted to a higher GI of the Chinese cabbage specifically under aerobic processing condition.

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Research of Heavily Selective Emitter Doping for Making Solar Cell by Using the New Atmospheric Plasma Jet (새로운 대기압 플라즈마 제트를 이용한 태양전지용 고농도 선택적 도핑에 관한 연구)

  • Cho, I Hyun;Yun, Myung Soo;Son, Chan Hee;Jo, Tae Hoon;Kim, Dong Hea;Seo, Il Won;Rho, Jun Hyoung;Jeon, Bu Il;Kim, In Tae;Choi, Eun Ha;Cho, Guangsup;Kwon, Gi Chung
    • Journal of the Korean Vacuum Society
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    • v.22 no.5
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    • pp.238-244
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    • 2013
  • Doping process using laser is an important process in fabrication of solar cell for heat treatment. However, the process of using the furnace is difficult to form a selective emitter doping region. The case of using a selective emitter laser doping is required an expensive laser equipment and induce the wafer's structure damage due to high temperature. This study, we fabricated a new costly plasma source. Through this, we research the selective emitter doping. We fabricated that the atmospheric pressure plasma jet injected Ar gas is inputted a low frequency (a few tens kHz). We used shallow doping wafers existing PSG (Phosphorus Silicate Glass) on the shallow doping CZ P-type wafer. Atmospheric plasma treatment time was 15 s and 30 s, and current for making the plasma is 40 mA and 70 mA. We investigated a doping profile by using SIMS (Secondary Ion Mass Spectroscopy) and we grasp the sheet resistance of electrical character by using doping profile. As result of experiment, prolonged doping process time and highly plasma current occur a deeper doping depth, moreover improve sheet resistance. We grasped the wafer's surface damage after atmospheric pressure plasma doping by using SEM (Scanning Electron Microscopy). We check that wafer's surface is not changed after plasma doping and atmospheric pressure doping width is broaden by increase of plasma treatment time and current.

Hydrophilic Modification of Porous Polyvinylidene Fluoride Membrane by Pre-irradiating Electron Beam (전자빔 전조사를 이용한 Polyvinylidene Fluoride 다공막의 친수화 개질)

  • Choi, Yong-Jin;Lee, Sung-Won;Seo, Bong-Kuk;Kim, Min
    • Membrane Journal
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    • v.21 no.2
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    • pp.118-126
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    • 2011
  • A method of light pre-irradiation, one of methods modifying hydrophobic surface to hydrophilic surface in a membrane, was proposed to overcome the drawback of previous methods such as blending, chemical treatment and post-irradiation, Process of membrane preparation in the study was comprised of 4 parts as follows: firstly process of precursor preparation to introduce hydrophilic nature under atmosphere and aqueous vapor by irradiating electron beam (EB), secondly process of dope solution preparation to cast on non-woven fabrics, thirdly process of casting to prepare membrane and finally process of coagulation in non-solvent to form porous structure. The merit of this method might show simple process as well as homogenous modification compared to previous methods. To carry it out, precursor was prepared by irradiating EB to powder PVDF at 75~125 K Gray dose. Precursor prepared was analyzed by FTIR, EDS and DSC to confirm the introduction of hydrophilic function and its mechanism. From their results, it was inferred I conformed that hydrophilic function was hydroxy1 and it was introduced by dehydrozenation. Hydrophilicity of membranes prepared was evaluated by contact angle (pristine PVDF : $62^{\circ}$, 125 K Gray-PVDF$13^{\circ}$). Porosity was evaluated by mercury intrusion method, simultaneously morpholoy and surface pore size were observed by SEM phothographs. The result showed the trend that more dose of EB led to smaller pore size and to lower porosity (pristine PVDF : 82%, 125 K Gray-PVDF : 63%). Trend of water permeability was similar to result above (pristine PVDF : 892 LMH, 125 K Gray-PVDF : 355 LMH).

Comparative Pathology of chickens Experimentally Inoculated with Virulent Viscerotropic Newcastle Disease Viruses isolated in Korea (강병원성 뉴캣슬병 바이러스 한국분리주의 SPF 닭 접종에 따른 병리학적 변화 비교)

  • I. P. Mo;Y. K. Kwon;M. G. Han;H. W. Seong
    • Korean Journal of Poultry Science
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    • v.28 no.2
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    • pp.99-106
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    • 2001
  • Pathologic changes and distribution of viral antigen as determined by immunohistochemistry were compared among 4-wk-old specific-pathogen free (SPF) chickens inoculated intratracheally with velogenic vis-cerotropic Newcastle disease virus isolated in Korea. Although the pattern of organ involvement and severity of lesion was different among chickens infected with different velogenic viscerotropic Newcastle disease (VVND) viruses, the pathological types of lesion was similar among the chickens. Severe lymphocytic necrosis and depletion were main histologic lesions in the immune related organs such as thymus, Fabricius bursa and spleen. The frequency of IP positive staining was variable depends on the types of tissues but not types of the kinds of VVND viruses infected. Brain, Fabricius bursa, thymus, cecal tonsil and trachea were IP positive with fairly high frequency and spleen, lung, proventriculus, intestine, pancreas, liver, kidney, heart and Harderian gland were with relatively low frequency. These results suggest that histologic evaluation and viral antigen specific immunohistochemical staining methods to determine virus distribution will be useful for pathogenic study of velogenic viscerotropic Newcastle disease virus infection in chicken.

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Lower Extremity Edema in Terminal Cancer Patients (말기 암 환자에서의 하지 부종)

  • Shim, Byoung-Yong;Hong, Seok-In;Park, Ji-Chan;Hong, Sug-Hui;Choi, Gang-Heun;Cho, Hong-Joo;Kim, Seon-Young;Han, Sun-Ae;Lee, Ok-Kyung;Kim, Hoon-Kyo
    • Journal of Hospice and Palliative Care
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    • v.8 no.2
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    • pp.152-155
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    • 2005
  • Purpose: The lower extremity edema (LEE) is a common distressful symptom in advanced cancer patients and is hard to manage. We analyze the characteristics of LEE in patients with advanced cancer to provide the basic information of causes and adequate management. Methods: Physical examination, assessment of the location and severity of edema, blood chemistry (albumin, creatinine), Doppler Sono for patients with suspecting deep vein thrombosis (DVT), and abdomen CT scan for patient with suspecting lymph edema were performed. Severity of edema was classified according to NCI lymph edema scaling and improvement was defined as lowering at least 1 grade of edema after management. Results: Among 154 patient who had been admitted to Hospice Ward from Mar 2003 to Jan 2004, 33 had LEE, and 6 had both upper extremity edema and LEE except generalized edema. Their underlying cancers were stomach (7), lung (6), biliary tract (5), liver (5), colorectal (5), pancreas (2), and others (9). There were 12 patient with grade I, 20 patients with grade II, and 7 patients with grade III edema. The causes were hypoalbuminemia (11), lymph edema (10), DVT (7), obstruction of inferior vena cava (IVC) or portal vein (6), and dependent edema (5). The common managements were including leg elevation and diuretics. Elastic stocking was applied for patients with DVT and leg massage and pneumatic compression was used for lymph edema. The 2/3 patients were improved after management. Conclusion: The incidence of LEE in terminal cancer pts was high (25.3%) and their causes were variable including lymph edema, DVT, hypoalbuminemia and dependent edema. Active noninvasive management according to causes could result in good palliation.

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Molecular Characterization of Cinnamate 4-Hydroxylase gene in Red Hot Pepper (Capsicum annuum L.) (고추에서 분리한 Cinnamate 4-Hydroxylase 유전자의 분자생물학적 특성)

  • Kim Kye-Won;Ha Sun-Hwa;Cho Kang-Jin;Kim Eun-Ju;Lee Min-Kyung;Yu Jae-Ju;Kim Jong-Guk;Lee Shin-Woo
    • Journal of Plant Biotechnology
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    • v.32 no.3
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    • pp.167-173
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    • 2005
  • Three different cDNAS for cinnamate 4-hydroxylase (C4H) which are involved in the second step of the general phenylpropanoid pathway were isolated and designated as pc4h1 (1,755 bp), pc4h2 (1,655 bp), and pc4h3 (1,316 bp), respectively. The nucleotide sequence analysis revealed that both pc4h1 and pc4h2 clones encode polypeptides of 505 amino acids frame but pc4h3 clone was truncated at the 5'-end of coding region. The alignment of the deduced amino acid sequences showed that PC4H1 and PC4H2 are highly homologous (95.8% identical) with each other and contain three conserved domains which are typical in cytochrome P450 monooxygenase: proline-rich region, threonine-containing binding pocket for the oxygen molecule, and heme binding region. In addition, result of the phylogenic tree analysis revealed that both pepper C4Hs belong to Class 1. pc4h2 transcription was strongly induced in wounded fruit (400%) and root (200%) relative to its very low basal level but not in leaf or stem tissue. In case of pc4h1, the basal level of transcription was higher than pc4h2 but induction by wounding was lower in fruit and root while leaf and stem tissues did not respond to wounding. The basal level of pc4h3 transcripts was not, if any, detectable and response to wounding was not observed.

Comparative Analysis of Ecological Health Conditions Before and After Ecological Restoration in Changwon Stream and Nam Stream (창원천.남천에서 생태복원 전.후의 생태건강도 비교평가)

  • Kim, Hyun-Jeong;Lee, Sang-Jae;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.307-318
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    • 2010
  • This study was to analyze the ecological conditions, based on physical habitat, chemical, and biological conditions before (2006, 2007) and after ecological restoration (2009) in five sites of Changwon Stream (CS) and six sites of Nam Stream (NS), respectively, and then to compare ecological health between the two period. The analysis of ecological health was based on the multimetric models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) along with water chemistry in the streams. For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. For the evaluations, the survey was conducted in the period of 2006~2007 before the restoration and in 2009 after the restoration by the city. Chemical conditions, based on conductivity, in both streams showed a typical longitudinal declines along the axis of the upstream-to-downstream. There were no significant differences (p>0.05) in water quality between the two periods. Values of IBI in the CS and NS averaged 21.6 and 19.7, respectively, indicating a C grade in the criteria of Ministry of Environment, Korea, and there was no significant differences in the IBI between the two periods. Values of QHEI after the restoration averaged 29.2 and 63.2 in the CS and NS, respectively and the values decreased markedly especially, in the NS (35.3) after the restoration. The habitat disturbance was mainly attributed to destructions (i.e., the narrower width of riparian vegetation and higher substrate exposure by the air) of artificial materials by massive flood in 2009. Overall, our results suggest that the restoration was not effective in the two streams between the two periods, even if the budget was used a lot and that such ecological restoration, not considered the natural disaster, may not effect for the stream restoration.