• Title/Summary/Keyword: N cycle

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Synthesization and Characterization of Pitch-based Activated Carbon Fiber for Indoor Radon Removal (실내 라돈가스 제거를 위한 Pitch계 활성탄소섬유 제조 및 특성연구)

  • Gwak, Dae-Cheol;Choi, Sang-Sun;Lee, Joon-Huyk;Lee, Soon-Hong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.3
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    • pp.207-218
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    • 2017
  • In this study, pitch-based activated carbon fibers (ACFs) were modified with pyrolysis fuel oil (PFO). Carbonized ACF samples were activated at $850^{\circ}C$, $880^{\circ}C$ and $900^{\circ}C$. A scanning electron microscope (SEM) and a BET surface area apparatus were employed to evaluate the indoor radon removal of each sample. Among three samples, the BET surface area and micropore area of ACF880 recorded the highest value with $1,420m^2{\cdot}g^{-1}$ and $1,270m^2{\cdot}g^{-1}$. Moreover, ACF880 had the lowest external surface area and BJH adsorption cumulative surface area of pores with $151m^2{\cdot}g^{-1}$ and $35.5m^2{\cdot}g^{-1}$. This indicates that satisfactory surface area depends on the appropriate temperature. With the above scope, ACF880 also achieved the highest radon absorption rate and speed in comparison to other samples. Therefore, we suggest that the optimum activation temperature for PFO containing ACFs is $880^{\circ}C$ for effective indoor radon adsorption.

Conservation of an endangered Corylopsis corona Uyeki in and ex situ and Development of cooperative model within local community I. Study for a Characteristic of Distribution Pattern in Corylopsis coreana $U_{YEKI}$ (보호종인 히어리의 자생지내외 보전과 지역사회 협력 모델 개발 I. 히어리 분포지 특성에 관한 연구)

  • 임동옥;황인천;정흥락;유윤미
    • Proceedings of the Korean Society of Environment and Ecology Conference
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    • 2005.04a
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    • pp.85-101
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    • 2005
  • This study was carried out a field survey and review articles to investigate a characteristic of the distribution pattern in Korean endemic Corylopsis coreana. Distribution of Corylopsis coreana was found from Boseung-gun, Gwangyang-si, Suncheon- si, Jeumanl-myeon Goheung-gun, Ganjeon-myeon Gurye-gun, Mt. Cheongwan Jangheung-gun, Nogodan Mt. Jiri in Jeollanam-do, Mt. Cheonhwang Namwon-si and Beamsagol and Banyabong Mt. Jiri, in Jeollabuk-do, Sancheong-gun, hadong-gun and Namhea-gun in Gyeongsangnam-do and Mt. Backun, Pocheon-si in Gyeonggi-do. Total flora in the distribution region of Coryloplsis coreana were recorded as 242 taxa; 70 families, 159 genus, 216 species, 22 varieties, 4 forma. Ratio of taxonomic categories was consisted of Pteridophyte $5.8\%$, Gymnosperm $3.7\%$, Dicotyledon $18.6\%$ and Monocotyledon $71.9\%$. Ratio of Life cycle styles was Annual $1.7\%$ and Perennial $98.3\%$. Ratio of growth habit was appeared to Herb $44.2\%$, Vine $12.4\%$, Shrub $17.8\%$ and Tree $25.6\%$. The distribution region of Corylopsis coreana found to typical type which distribute in N, NE or NE slope. The native Corylopsis coreana of Sinjeonri Sungju-eup in Jellanam-do appeared to a declining tendency which caused by influence of tree lager.

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A STUDY ON THE RESISTANCE OF WEAR AND CYTOTOXICITY OF THE TITANIUM SURFACE AFTER FILM DEPOSITIONS (박막증착시 티타늄 표면의 마손저항도와 세포독성에 관한 연구)

  • Kim Hyung-Woo;Kim Chang-Whe;Kim Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.39 no.1
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    • pp.84-95
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    • 2001
  • Titanium is widely used in dentistry for its low density, high strength, fatigue resistance, corrosion resistance, and biocompatibility. But it has a tendency of surface damage under circumstance of friction and impact for its low hardness of the surface. Coating is one of methods fir increasing surface hardness. Its effect is to improve surface physical characteristics without change of titanium. Diamond-like carbon and titanium nitride are known for its high hardness of the surface. So that this study was aimed at the wear test and the cytotoxicity test of the commercially pure titanium and Ti-6Al-4V alloy which were deposited by diamond-like carbon film or titanium nitride film to acertain improvement of the surface hardness and the biocompatibility. A disk (25mm diameter, 2mm thickness) was made of commercially pure titanium and Ti-6Al-4V alloy and these substrates were deposited by diamond-like carbon film or titanium nitride film. Diamond-like carbon film was deposited by the method of radiofrequency plasma assisted chemical vapor deposition and titanium nitride film was deposited by the method of reactive arc ion plating. Then these substrates were tested about wear characteristics by the pin-on-disk type wear tester in which ruby ball was used as a wear causer under the load of 32N, The fracture cycles were measured by rotating the substrates until their films were fractured. The wear volume was measured after 150 cycles and 3,000 cycles using surface profiler. The cytotoxicity test was peformed by the method of the MTT assay. The results were as follows : 1. In the results of the wear volume test, commercially pure titanium and titanium alloy which were coated by diamond-like carbon film or titanium nitride aim had higher resistance against wear than the substrates which were not coated by any films (P<0.05). 2. In the results of the fracture cycle test and the wear volume test, diamond-like carbon film had higher resistance against wear than titanium nitride film (P<0.05). 3. In both coatings of diamond-like carbon aim and titanium nitride film, Ti-6Al-4V alloy had higher resistance against wear than commercially pure titanium (P<0.05) 4. In the results of the cytotoxicity test, diamond-like carbon film and titanium nitride film had little cytotoxicity as like commercially pure titanium or Ti-6Al-4V alloy (P>0.05).

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The Development and Application of Integrating Instruction with Evaluation Materials for Strengthening of Independent Living Competence: Focused on Technology and Home Economics Education (기술·가정과 생활자립역량 함양을 위한 교수학습-평가 연계 자료 개발 및 적용)

  • Lim, Yun Jin;Kim, Eun Jeung
    • Journal of Korean Home Economics Education Association
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    • v.31 no.3
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    • pp.23-39
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    • 2019
  • The purpose of the study was to analyze the home economics education experts' and teachers' perception of ways to align instruction with evaluation, based on the 2015 revised technology and home economics curriculum for the purpose of developing the independent living competencies, and to provide examples of alignment in practice. The analysis is based on the data from a Delphi study (10 experts) and a survey of technology and home economics teachers(n=422). The results of survey indicated that experts and teachers perceived the instruction-assessment alignment to be most appropriate for project learning-project assessment, followed by project learning-portfolio assessment, problem solving learning-portfolio assessment, and problem solving learning-project assessment, in order. Based on the survey results, a model of instruction-assessment alignment and a teaching-learing plan were presented, based on 'Development task of life cycle and Life plan' unit. This was considered to be a proper method of instructional alignment for the purpose of developing 'independent living competence' with project-learning/project-assessment. The model focuses on consistency between instruction and evaluation, unity in methods, and the availablility of feedbacks of assessment for the improvement of independent living competencies. In conclusion, this study contributes as foundational information for teaching and learning-assessment alignment. Diverse methods of instruction-evaluation alignment is expected for future research.

Increased Serum Level of Inhibin in Oligo-amenorrheic Women with Polycystic Ovaries (배란장애를 동반한 다낭성 난소인 여성에서 혈중 Inhibin 농도의 증가)

  • Roh, Jae-Sook;Yoo, Jung-Bae;Moon, Hyung;Hwang, Yoon-Yeong
    • Clinical and Experimental Reproductive Medicine
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    • v.25 no.1
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    • pp.93-102
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    • 1998
  • Normal and abnormal follicular growth and steroidogenesis depend on gonadotropins as well as intraovarian peptides, which may mediate or potentiate gonadotropin action. Inhibin also affect follicular development and steroidogenesis and may play a role in dominant follicle selection and follicular atresia. Therefore, we studied the differences of serum inhibin, gonadotropin and androgen levels in the women with only the ultrasound findings and no disorder, and polycystic ovary (PCO) with ovulatory disturbance. We prospectively analysed forty-three women with PCO. The diagnosis of PCO was based on typical appearance of the ovaries on TVS. Twelve women with regular menstrual cycle and normal ovarian morphology were selected as control. Basal levels of inhibin, luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol $(E_2)$, testosterone (T), androstenedione (ADD), dehydroepiandrosterone-sulfate (DS), prolactin and TSH in serum were determined. There were significant differences in basal LH levels and LH/FSH ratio between the control and the women with PCO. The basal levels of inhibin and $E_2$ in the oligo-amenorrheic PCO (N=34) were significantly higher than those in the control. There was higher negative correlation between the inhibin and T levels in the oligo-amenorrheic PCO, but, not in the regular cycling PCO. Also, there was higher positive correlation between the LH and T levels in the oligo-amenorrheic PCO, but not in the regular cycling PCO. These data presume that the initial event of PCO is elevated pituitary LH secretion. Elevated levels of LH may down-regulate LH receptors on granulosa cells and also cause hypertrophy of the thecal layer. High level of androgen secreted by the hypertrophied thecal layer may stimulate inhibin secretion from granulosa cells and can be converted to estrogen by extraovarian tissues and could serve to augment pituitary sensitivity to GnRH with a resultant secretion of more LH than FSH. Inhibin may inhibit FSH action on granulosa cell in the PCO follicle, impairing follicular development and dominant follicle selection resulted in ovulatory disturbance.

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Microtubule and Chromatin Organization in Bovine Oocytes following Intracytoplasmic Injection of Spermatozoon, Sperm Head and Tail (소 난자에 있어서 세포질내 정자, 정자두부.미부 주입 후 미세소관과 염색질의 구조변화)

  • Do, J.T.;Jun, S.H.;Choi, J.T.;Kang, Y.S.;Lee, B.Y.;Kim, S.B.;Kim, N.H.;Lee, H.T.;Chung, K.S.
    • Clinical and Experimental Reproductive Medicine
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    • v.24 no.3
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    • pp.301-309
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    • 1997
  • The objective of this study was to determine the microtubule assembly and chromatin configuration during the first cell cycle in bovine oocytes following injection of spermatozoon, sperm head and tail. The microtubule and chromatin configuration was imaged with fluorescent labeled monoclonal ${\alpha}$-tubulin antibody and propidium iodide under laser scanning confocal microscope. Microtubule and chromatin dynamics in bovine oocytes following intracytoplasmic sperm injection (ICSI) were not different from those observed during in vitro fertilization (IVF). Following ICSI, the microtubular aster was observed around sperm midpiece. During pronuclear formation, the sperm aster was enlarged and seen around male and female pronuclei. At mitotic metaphase, the microtubular spindle assemble astral poles and chromosomes were aligned on the spindle equator. At mitosis, asters were concentrated to each spindle pole and they filled the cytoplasm. After injection of the isolated sperm head, the microtubular aster was not seen around sperm head in any cases (0/18). Instead, microtubules were organized from the cytoplasm, which filled the whole cytoplasm during pronuclear apposition. These microtubules seem to move male and female pronuclei. These results suggest that isolated sperm head can develop into normal pronucleus in mature bovine oocytes, and competent to participate syngamy with the ootid chromatin. The functional microtubules following isolated sperm head injection in bovine oocytes appeared to be organized solely from maternal stores.

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Investigation of Oxidation Methods of Organic Radical Polymer for Cathode Material in Lithium Ion Batteries (리튬이차전지 양극재인 유기라디칼 고분자의 산화법에 대한 연구)

  • Lee, Ilbok;Kim, Younghoon;Moon, Ji-Yeon;Lee, Chul Wee;Kim, Daeun;Ha, Kyoung-Su;Lee, Dong Hyun;Son, Hyungbin;Yoon, Songhun
    • Polymer(Korea)
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    • v.38 no.6
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    • pp.827-831
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    • 2014
  • An organic radical polymer (ORP) was prepared by radical polymerization and following oxidation into nitroxyl radical. Two different oxidation methods were employed and their radical concentrations were measured using electroparamagnetic resonance spectroscopy (EPR) and UV-visible absorption (UV-vis) spectroscopy. From these measurements, $H_2O_2-Na_2WO_4$ oxidation method exhibited a complete oxidation, which resulted in 97.6% spin concentration. Also, it was revealed that convenient and cheap UV-vis measurement was useful for preliminary radical concentration comparison. After applied as a cathode material in lithium ion batteries, ORP electrode showed a high initial capacity ($110mAh\;g^{-1}$), a good initial efficiency (96%), a very high rate performance (70% charging during 1.2 min) and stable cycle performance.

A Study on the Emissions Characteristics of a LPG Vehicle According to Various Test Modes and Ambient Conditions (다양한 시험모드와 환경조건에 따른 LPG 차량의 배출특성 연구)

  • Lee, Min-Ho;Ha, Jong-Han
    • Journal of the Korean Institute of Gas
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    • v.19 no.4
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    • pp.1-7
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    • 2015
  • As the interest on the air pollution is gradually rising up at home and abroad, automotive and fuel researchers have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward various main issues : whether PM emissions should be regulated for diesel and gasoline vehicles and whether gasoline and LPG powered vehicles can be further neglected from PM emission inventories. Finally, the greenhouse gas regulation has been discussed including automotive emission regulation. The greenhouse gas and emissions of automotive had many problem that cause of ambient pollution, health effects. Based on various test modes and ambient conditions, this paper discusses the characteristics of LPG on exhaust emissions and greenhouse gases. Also, this paper assessed emission characteristics due to the test temperature. These test temperature were performed by dividing the temperature of the test mode and the lowest local temperature in winter. Through this study, the correlation of vehicle test mode and ambient condition, exhaust emission, greenhouse gas emission was analyzed.

Association of a Methanol Extract of Rheum undulatum L. Mediated Cell Death in AGS Cells with an Intrinsic Apoptotic Pathway

  • Hong, Noo Ri;Park, Hyun Soo;Ahn, Tae Seok;Jung, Myeong Ho;Kim, Byung Joo
    • Journal of Pharmacopuncture
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    • v.18 no.2
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    • pp.26-32
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    • 2015
  • Objectives: Rheum undulatum L. has traditionally been used for the treatment of many diseases in Asia. However, its anti-proliferative activity in cancer has still not been studied. In the present study, we investigated the anti-cancer effects of methanol extract of Rheum undulatum L. (MERL) on human adenocarcinoma gastric cell lines (AGS). Methods: To investigate the anti-cancer effect of MERL on AGS cells, we treated the AGS cells with varying concentrations of MERL and performed 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays. Cell cycle analyses, measurements of the mitochondrial membrane potential (MMP), caspase activity assays and Western blots were conducted to determine whether AGS cell death occurred by apoptosis. Results: Treatment with MERL significantly inhibited growth of AGS cells in a concentration dependent manner. MERL treatment in AGS cells leaded to increased accumulation of apoptotic sub G1 phase cells in a concentration dependent manner. In control cultures, 5.38% of the cells were in the sub G1 phase. In MERL treated cells, however, this percentage was significantly increased (9.95% at $70{\mu}g/mL$, 15.94% at $140{\mu}g/mL$, 26.56% at $210{\mu}g/mL$ and 38.08% at $280{\mu}g/mL$). MERL treatment induced the decreased expression of pro-caspase-8 and -9 in a concentration dependent manner, whereas the expression of the active form of caspase-3 was increased. A subsequent Western blot analysis revealed increased cleaved levels of poly (ADP-ribose) polymerase (PARP) protein. Also, treatment with MERL increased the activities of caspase-3 and -9 compared with the control. MERL treatment increased the levels of the pro-apoptotic truncated Bid (tBid) and Bcl2 Antagonist X (Bax) proteins and decreased the levels of the anti-apoptotic B-cell lymphoma 2 (Bcl-2) protein, whose is the stabilization of mitochondria. However, inhibitions of p38, extracellular signal regulated kinases (ERKs) and C-Jun N-terminal kinases (JNK) by MERL treatment did not affect cell death. Conclusion: These results suggest that MERL mediated cell death is associated with an intrinsic apoptotic pathway in AGS cells.

Hormonal Changes of Serum Progesterone and Estradiol-$17{\beta}$ on Flushing Feed before Estrus during Estrous Cycle in Sows of Landrace, Yorkshire and $F_1$ (Landrace ${\times}$ Yorkshire)

  • Lee, Mi-Jin;Choi, Sun-Ho;Sa, Soo-Jin;Lee, Kyoung-Mi;Lee, So-Young;Cho, Kyu-Ho;Hong, Jun-Ki;Kim, Du-Wan;Kim, Ki-Hyun;Park, Jun-Cheol
    • Journal of Embryo Transfer
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    • v.28 no.4
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    • pp.315-318
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    • 2013
  • This study was conducted to investigate the changes of hormone levels of serum progesterone (P4) and estradiol-$17{\beta}$ (E2) in sows of Landrace (L), Yorkshire (Y) and F1 (L ${\times}$ Y) (respectively n=3) with excellent ability, and to provide a baseline data for improving reproductive performance. In this experiment, the sows at the age of 12 months or more were used. The sows were fed by two way methods, one is conventional methods and the other is 3 days-flushing feed before estrus. Each pig's blood was collected in 3, 6, 9, 12, 15 and 18 days after the estrus for the analyses of P4 and E2. Serum was separated by centrifugation for 15 min. with 3,000 rpm. Progesterone and estradiol-$17{\beta}$ were measured by immunochemical assay (ELIZA test). In conventional feeding, serum progesterone levels were significantly (p<0.01) higher in F1 than in L and Y. No significant differences in P4 concentrations were seen between the L and Y of sows. Serum E2 levels were similar the serum progesterone levels. In the case of flushing feed, the tendency of hormonal changes were similar to conventional methods. But almost of hormonal levels were a little higher than that of conventional methods. P4 level of L and Y in flushing feed were significantly different (p<0.01). Serum E2 level of Y in flushing feed was significantly different among the breeds (p<0.01). These results were similar to the tendency of hormonal changes in general sows and moreover, flushing feed is known to develop the swine production, these results proved the fact of the methods. And these results suggested that more studies about hormonal changes in sows according to seasonal and nutritional factors should be needed.