• Title/Summary/Keyword: weak form

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Mineralogical Characteristics of Hydrothermal Laumontite and Adularia in the Breccia Zone of a Fault, Yangbuk-myeon, Gyeongju and Implications for Fault Activity (경주시 양북면 단층각력대에서 산출하는 로몬타이트와 아듈라리아의 광물학적 특징과 후기 단층활동)

  • Choo, Chang-Oh;Jang, Yun-Deuk;Chang, Chun-Joong
    • Journal of the Mineralogical Society of Korea
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    • v.25 no.1
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    • pp.23-36
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    • 2012
  • Morphological and mineralogical characteristics of laumontite and adularia in the breccia zone in a fault, Yangbuk-myeon, Gyeongju, Korea suggest that they formed by reaction with hydrothermal alteration related to fault activity. Laumontite commonly occurring in the breccia zone is related to the presence of hydrothermal fluids bearing alkaline elements in the zone. Laumonite is characterized by elongated columnar form with aspect ratio varying 5~10. Laumontite and adularia whose characteristic euhedral forms are indicative of the latest product formed as rapid precipitation from fluids or replacements of Ca-plagioclase. Hydrothermal fluids reacted with intensively fractured granite, typical with high permeability, leached alkaline elements such as Ca, K, allowing laumontite and adularia to be precipitated under neutral to weak alkaline conditions. It is noteworthy that the formation process and genesis of low temperature minerals such as laumontite and adularia are very similar to those formed by wallrock alteration or hydrothermal alteration that occurred in epithermal deposits. Taking into account its characteristic morphology and chemistry, authigenic K-feldspar that commonly forms at low temperature in many fault zones must be adularia.

Synthesis of Imogolite by a Hydrothemal Method (이모골라이트의 합성)

  • Jang, Young-Nam;Ryu, Gyoung-Won;Suh, Yong-Jae;Chae, Soo-Chun;Bae, In-Kook
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.3
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    • pp.283-287
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    • 2008
  • The imogolite synthesis wore performed by using tetraethoxysilane (TEOS) and aluminium-sec-butoxide (ASB) at < $100^{\circ}C$. A mixure of TEOS and ASB in a molar ratio of 1:2 was prepared under vigorous stirring and the experiments were performed under the hydrothemal refluxing condition. When the concentration of TEOS and ASB in solution was 0.5 M, a well-crystallized imogolite was synthesized, and the reflections wore shown at d = 22.4, $9.5\;\AA$ etc., after XRD analysis. DTA analysis shows 2 exothemal peaks at 68 and $249^{\circ}C$, suggesting the dehydration and the dehyroxylation reaction, respectively. The result of TG indicates 41% weight loss. And the weak and unsymmetrical peaks by the Si-O-Al stretching vibrations at 953 and $993cm^{-1}$ and by O-Si-O bending vibration at $562cm^{-1}$ were observed after IR analysis. The synthetic imogolite was fibrous and shows a spiders web like network structure.

A Study on the Positive Signals of New Technology-Based Ventures to Entice Venture Capitals in Korea : Exploring Human Capitals and Strategic Endorsements? (벤처캐피탈 투자를 유치하는 신기술기반 벤처기업의 긍정 신호에 관한 연구 : 인적 자본과 전략적 보증효과에 관한 탐구)

  • Lee, Young Min;Choi, Yeounkeun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.6
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    • pp.23-35
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    • 2014
  • In developing countries where many of these institutions exist in relatively weak form, the investment pattern of VCs in developing countries may differ from one of VCs in developed countries. Given this situation, the research question of this study is how venture capitals invest new technology based ventures in developing countries. To address the research question, our study employs insight from signaling theory and examines two ways. First, what are the internal value of new technology based ventures and the identity of endorsing organization signaling to venture capitals' investment in developing countries? Second, Do venture capitals play a pivotal role for the growth of new technology based ventures in developing countries? This study then tests these hypotheses using the new technology based ventures in Korea which is regarded as an example of developing countries in Northeas tern Asia. Entrepreneur's prior work experience in a related industry in the human capital variables and collaboration with business groups and certification of venture company in the endorsement variables result in obtaining venture capital's investment and superior new technology based venture's growth whereas entrepreneur's educational level has no effect on venture capital's investment and firm's growth.

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Petrological Characteristics and Deterioration Aspect of the Pohang Chilpori and Shinheungri Petroglyphs (포항 칠포리 I지구와 신흥리 암각화의 암석학적 특징과 훼손양상 분석)

  • Lee, Sang-Hun;Choi, Gi-Ju
    • Journal of Conservation Science
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    • v.25 no.4
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    • pp.347-361
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    • 2009
  • The Pohang Chilpori is the area with abundant petroglyphs in Korea. The form of the shield, female sex organs, and yut board on the outcrops or float rocks which are composed of the rhyolitic rock are engraved on Chilpori and Shinheungri Petroglyphs. The rhyolitic rock is composed of the phenocryst and groundmass with quartz and feldspar. The rock surface shows mostly yellowish brown color and the rock surface is very irregular by serious weathering, and illite and kaolinite, a kind of the clay minerals, are produced. Deterioration aspects are mainly of surface exfoliation, grain peel-off, damages, scribbling. Chilpori Petroglyph (1) plane has been eroded by running water, in (2) plane has been abrased is on the rock surface, in (3) plane shows surface exfoliation and the various part of the rock surface in plane (4) has become the soil. The corrasion and black phenomenon of the Shinheungri Petroglyph (1) plane was formed by running water, and surface exfoliation and scribbling in plane (2) is serious. Deterioration factors are geomorphologic states, plants, rock of weak to weathering, and artificial influence such as a scribbling and a forest fire. For conservation of the these petroglyphs, study for rock surface conservation and the arrangement of around petroglyphs and construction of water wall are necessary.

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Removal Behavior of Biological Nitrogen and Phosphorus and Prediction of Microbial Community Composition with Its Function, in an Anaerobic-Anoxic System form Weak Sewage

  • LEE, JIN WOO;EUI SO CHOI;KYUNG IK GIL;HAN WOONG LEE;SANG HYON LEE;SOO YOOUN LEE;YONG KEUN PARK
    • Journal of Microbiology and Biotechnology
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    • v.11 no.6
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    • pp.994-1001
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    • 2001
  • An easier way of understanding the BNR system was proposed from the study on substrate, nutrient removal tendency, microbial community and its metabolic function by applying the municipal settled sewage. During the anaerobic period, the phosphorus release rate per VFACOD we varied depending on the phosphorus content in the sludge. When the phosphorus content in the sludge was $6\%$ VSS, according to influent VFACOD, the phosphorus release rate and PHA production were $0.35 gPO_4P/gVFACOD$ and 1.0 gPHA/gVFACOD, respectively. The $NO_3N$ requirement for the phosphorus uptake as an electron acceptor was about $0.5 gNO_3N/gPO_4P_{uptake}$ based on the proposed equation with PHA, biomass, production, and the concentration of phosphorus release/uptake. Bacterial-community analysis of the sludge, as determined by FISH and 16SrDNA characterization FISH, revealed that the beta-subclass proteobacteria were the most abundant group ($27.9\%$ of the proteobacteria-specific probe EUB338), and it was likely that representative of the beta-subclass played key roles in activated sludge. The next dominant group found was the gamma-protebacteria ($15.4\%$ of probe EUB338). 16S rDNA clone library analysis showed that the members of${\beta}$- and ${\gamma}$-proteobacteria were also the most abundant groups, and $21.5\%$ (PN2 and PN4) and $15.4\%$ (PN1 and PN5) of total clones were the genera of denitrifying bacteria and PAO, respectively. Prediction of the microbial community composition was made with phosphorus content (Pv, $\%$ P/VSS) in wasted sludge and profiles of COD, PHA, $PO_4P,\;and\;NO_3N$ in an anaerobic-anoxic SBR unit. Generally, the predicted microbial composition based upon metabolic function, i.e., as measured by stoichiometry, is fairly similar to that measure by the unculturable dependent method. In this study, a proposal was made on he microbial community composition that was more easily approached to analyze the reactor behavior.

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An Experimental Study on the Distributions of Residual Head and Discharge Rate along Collector Well Laterals of a Model Riverbed Filtration (하상여과의 집수관 모형에서 잔류수두와 유입율 분포에 관한 실험연구)

  • Ahn, Kyu-Hong;Moon, Hyung-Joon;Kim, Kyung-Soo;Kim, Seung-Hyun
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.12
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    • pp.1305-1310
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    • 2005
  • As a way to the optimum design of the collector well lateral in riverbed filtration, experiments were performed using sand tanks which were connected to form a model lateral system. Measured were the residual hydraulic heads along the laterals, the discharge rates at each sand tank and the production rates at the collector well while the model laterals were operated with various scenarios of changing parameters including water level of the collector well, the lateral diameter and length, and the hydraulic conductivity of the sand. Results showed that riverbed filtration could be more efficient when the resistance in the lateral was weak compared with the resistance in the sand, which was indicated by the more flattened distribution of the residual hydraulic heads along the lateral. Results also showed that the discharge rate increased exponentially with the approach to the collector well, and that the exponent increased as the lateral diameter decreased and/or the hydraulic conductivity of the sand increased. It was also seen that the well production increased with the increase in the lateral length and diameter although the marginal productivity decreased. It could be concluded that the axial flow velocity in the lateral was an important factor governing the efficiency of a lateral in riverbed filtration and that the maximum entrance velocity to the collector well, over which the efficiency decreased drastically, was about 1 m/sec under the conditions of this study.

Purification of Band 3 from the Human Erythrocyte Membrane and its Incorporation into Liposome (사람 적혈구막 Band 3의 정제 및 Liposome으로의 도입)

  • Kim, Jae-Ryong;Kim, Jung-Hye;Lee, Ki-Yung
    • Journal of Yeungnam Medical Science
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    • v.3 no.1
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    • pp.41-48
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    • 1986
  • Band 3, the predominent 95,000 dalton anion transport protein, is the major intrinsic glycoprotein of the human erythrocyte membrane. This anion carrier exists as a dimer and binds the cytoskeletons such as spectrin, ankyrin and actin. And the liposomes are vesicular structures which form spontaneouly upon hydration of phospholipids. These artificial lipid vesicles have been investigated as model of the biological membranes and as a mean of improving the delivery of nucleic acids, drugs, proteins and biological substances to specific target tissues and cells. In this study, we were purified Band 3 from the human erythrocyte membrane(ghost) was prepared by hemolysis of intact human erythrocyte with weak alkali-hypotonic solution. Band 6 was removed from ghost by extracting with solution of an ionic strength of 0.15. Band 3 and Band 4 were solubilized selectively by extracting Band 6-depleted ghosts with Triton X-100 under nondenaturing conditions. Band 3 was then purified from Triton X-100 extract treated with p-chloromercuribenzoate by sucrose density gradient ultracentrifugation. This purified Band 3 was incorporated into liposomes prepared by reverse-phase evaporation. Phosphatidyl L-serine and cholesterol(1 : 1 molar ratio) were dissolved in chloroform and then chloroform was removed by rotatory evaporation under reduced pressure. Band 3 solution without Triton X-100 was introduced into a mixture of lipids and diethylether. Diethylether was subsequently removed by evaporation. This purified Band 3 and its incorporation into liposomes were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

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Testicular Cancer and Testicular Self-Examination; Knowledge, Attitudes and Practice in Final Year Medical Students in Nigeria

  • Ugwumba, Fred O;Ekwueme, Osa Eloka C;Okoh, Agharighom D
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.4999-5003
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    • 2016
  • The testicular cancer (TCa) incidence is increasing in many countries, with age-standardized incidence rates up to 7.8/100,000 men in the Western world, although reductions in mortality and increasingly high cure rates are being witnessed at the same time. In Africa, where rates are lower, presentation is often late and morbidity and mortality high. Given this scenario, awareness of testicular cancer and practice of testicular self-examination among future first response doctors is very important. This study was conducted to determine knowledge and attitude to testicular cancer, and practice of testicular self-examination (TSE) among final (6th) year medical students. In addition, the effect of an intervention in the form of a single PowerPoint(R) lecture, lasting 40 minutes with image content on testicular cancer and testicular self examination was assessed. Pre and post intervention administration of a self-administered structured pre tested questionnaire was performed on 151 medical students, 101 of whom returned answers (response rate of 66.8%). In the TC domain, there was a high level of awareness of testicular cancer, but poor knowledge of the age group most affected, with significant improvement post intervention (p<0.001). Notable also was the poor awareness of the potential curability of TC, this also being improved following the intervention (p<0.001). A poor level of awareness and practice of testicular self-examination pre-intervention was found considering the nature of the study group..Respondents had surprisingly weak/poor responses to the question "How important to men's health is regular testicular self-examination?" Answers to the questions "Do you think it is worthwhile to examine your testis regularly?" and "Would you be interested in more information on testicular cancer and testicular self-examination?" were also suboptimal, but improved post intervention p<0.001, p<0.001 and p=0.037. Age, gender and marital status were without specific influence. In conclusion, this study showed poor levels of knowledge regarding epidemiology of TCa and its potential curability when detected early. There was also a poor awareness of, practice of, and poor attitudes to TSE. The significant improvement in these parameters post intervention indicates value in educational intervention. We recommend inclusion of TCa coverage and TSE teaching in the secondary school curriculum (targeting adolescents). Greater emphasis should also be given to testicular cancer in the curricula of medical schools and other training institutions for health care personnel.

Acidic pH-activated $Cl^-$ Current and Intracellular $Ca^{2+}$ Response in Human Keratinocytes

  • Park, Su-Jung;Choi, Won-Woo;Kwon, Oh-Sang;Chung, Jin-Ho;Eun, Hee-Chul;Earm, Young-E;Kim, Sung-Joon
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.4
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    • pp.177-183
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    • 2008
  • The layers of keratinocytes form an acid mantle on the surface of the skin. Herein, we investigated the effects of acidic pH on the membrane current and $[Ca^{2+}]_c$ of human primary keratinocytes from foreskins and human keratinocyte cell line (HaCaT). Acidic extracellular pH ($pH_e{\leq}5.5$) activated outwardly rectifying $Cl^-$ current ($I_{Cl,pH}$) with slow kinetics of voltage-dependent activation. $I_{Cl,pH}$ was potently inhibited by an anion channel blocker 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS, 73.5% inhibition at 1${\mu}$M). $I_{Cl,pH}$ became more sensitive to $pH_e$ by raising temperature from $24^{circ}C$ to $37^{circ}C$. HaCaT cells also expressed $Ca^{2+}$-activated $Cl^-$ current ($I_{Cl,Ca}$), and the amplitude of $I_{Cl,Ca}$ was increased by relatively weak acidic $pH_e$ (7.0 and 6.8). Interestingly, the acidic $pH_e$ (5.0) also induced a sharp increase in the intracellular [$Ca^{2+}$] (${\triangle}[Ca^{2+}]_{acid}$) of HaCaT cells. The ${\triangle}[Ca^{2+}]_{acid}$ was independent of extracellular $Ca^{2+}$, and was abolished by the pretreatment with PLC inhibitor, U73122. In primary human keratinocytes, 5 out of 28 tested cells showed ${\triangle}[Ca^{2+}]_{acid}$. In summary, we found $I_{Cl,pH}$ and ${\triangle}[Ca^{2+}]_{acid}$ in human keratinocytes, and these ionic signals might have implication in pathophysiological responses and differentiation of epidermal keratinocytes.

Towards Evolution of Innovation System of Korean IT SoC Industry: Comparing Experiences of Korea and Taiwan (국내 IT SoC산업의 혁신체제 발전방안: 대만과의 비교 관점에서)

  • Min, Wan-Kee;Oh, Wan-Keun;Hwang, Jin-Young
    • Journal of Korea Technology Innovation Society
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    • v.11 no.4
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    • pp.565-591
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    • 2008
  • Using theories of sectoral innovation system and supply chain management, this paper examines the status quo of Korean IT SoC industry's innovation system by comparing it with Taiwanese one. Taiwan IT SoC industry has accomplished a rapid growth on the basis of government policies that foster domestic firms after the establishment of Hsinchu Science Park. Cooperative networks between foundries firms and fablesses have been formed within the supply chain in this process. Therefore, Taiwan industry has possessed the possibility of the coevolution in sectoral innovation system. However, Korean IT SoC industry has failed to form cooperative networks, because of weak networks between related firms. In other words, there exists an interaction failure, which is a kind of the system failure, and it means a lack of linkage between actors as a result of insufficient use of complementarities and interactive learning. Therefore, Korean industry has little possibility of the coevolution in sectoral innovation system. The cooperative networks between actors are prerequisite towards evolution of innovation system of Korean IT SoC industry. Above all, the cooperative networks between fablesses and system companies need to be strengthened within the supply chain.

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