• 제목/요약/키워드: Protective solution

검색결과 293건 처리시간 0.043초

대한체육회 상임심판제도 운영실태에 관한 사례연구 (A Case Study on Running the Permanent Judge System of the Korean Sport & Olympic Committee)

  • 김미숙;김일광;전상완
    • 디지털융복합연구
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    • 제16권3호
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    • pp.487-495
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    • 2018
  • 본 연구의 목적은 상임심판제도 운영실태에 대한 사례연구를 통하여 제도의 문제점을 진단하며 공정하고 투명한 심판문화 정착을 위한 기초자료를 제공하는데 있다. 본 사례연구 결과를 요약하면 다음과 같다. 첫째, 상임심판제도의 운영에 따른 선발, 배정, 평가, 교육의 애로사항이다. 선발의 문제는 선발규정 미비, 불공정 추천, 적은 선발인원이다. 배정의 문제는 강제배정, 일반심판과의 배정 갈등, 종목 특성이 미반영된 배정규정이다. 평가의 문제는 개인평가와 공정성 한계, 평가규정 미비, 저평가자의 고용불안이다. 둘째, 상임심판제도의 존립에 대한 불안이다. 셋째, 상임심판제도의 환경적 제약이다. 보호장치 미비는 의도적 항의에 대한 구제방안 및 해결책 부재이다. 넷째, 상임심판제도의 낮은 인식도이다. 홍보의 미비는 상임심판에 대한 낮은 인식도와 연맹의 소극적 홍보활동이다.

150℃에서 원전 2차측 배관재료의 Cr함량에 따른 유체가속부식 특성 (Effect of Cr content on the FAC of pipe material at 150℃)

  • 박태준;김홍표
    • Corrosion Science and Technology
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    • 제12권6호
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    • pp.274-279
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    • 2013
  • Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. During the FAC, a protective oxide layer on carbon steel dissolves into flowing water leading to a thinning of the oxide layer and accelerating corrosion of base material. As a result, severe failures may occur in the piping and equipment of NPPs. Effect of alloying elements on FAC of pipe materials was studied with rotating cylinder FAC test facility at $150^{\circ}C$ and at flow velocity of 4m/s. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO) and temperature. Test solution was the demineralized water, and DO concentration was less than 1 ppb. Surface appearance of A 106 Gr. B which is used widely in secondary pipe in NPPs showed orange peel appearance, typical appearance of FAC. The materials with Cr content higher than 0.17wt.% showed pit. The pit is thought to early degradation mode of FAC. The corrosion product within the pit was enriched with Cr, Mo, Cu, Ni and S. But S was not detected in SA336 F22V with 2.25wt.% Cr. The enrichment of Cr and Mo seemed to be related with low, solubility of Cr and Mo compared to Fe. Measured FAC rate was compared with Ducreaux's relationship and showed slightly lower FAC rate than Ducreaux's relationship.

졸-겔 세라믹 코팅에 의한 스테인레스강의 내산화 및 내식성 향상에 관한 연구 (II);$CeO_2$ 안정화 지르코니아 박막의 내산화 및 내식성 효과 (A Study on the Improvement of Oxidation and Corrosion Resistance of Stainless Steel by Sol-Gel Ceramic Coating (II); Effect on Oxidation and Corrosion REsistance of $CeO_2$ Stabilized Zirconia Thin Film)

  • 이재호;우일기;김병호
    • 한국세라믹학회지
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    • 제32권1호
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    • pp.95-105
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    • 1995
  • Ceria(CeO2) stabilized zirconia(CeSZ) sol was synthesized with zirconium n-butoxide Zr(OC4H9)4 and cerium nitrate hexahydrate Ce(NO3)3.6H2O as precursors and ethylacetoacetate(EAcAc) as a chelating agent under atmosphere. CeSZ films were deposited on AISI 304 stainless steel using the prepared polymeric sol by dipcoating and the coating characteristics were investigated by XRD, ellipsometry, scratch test and SEM. The CeSZ film began to crystallize from amorphous to tetragonal phase at 40$0^{\circ}C$ and it was not converted into monoclinic phase up to 100$0^{\circ}C$ by the addition of 16mol% CeO2 as a stabilizer which could suppress phase transformation of zirconia. The CeSZ films were prepared by varying the EAcAc contents and the cncentration of CeSZ sol and measured the thickness and refractive index. From these results, it was found that the EAcAc contents and concentration of CeSZ coating sol evidently affect the densification of CeSZ film. The CeSZ film coated with 0.4M CeSZ sol and heat-treated at $600^{\circ}C$ for 10min had thickness of 50nm and 17% porosity. The CeSZ film on 304 stainless steel effectively acted as a protective layer against oxidation up to 80$0^{\circ}C$ and had superior corrosion resistance in 25% H2SO4 solution for 4.5 hrs.

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Stabilization of Retinol through Incorporation into Liposomes

  • 이승철;육현균;이동훈;이경은;황용일;Richard D. Ludescher
    • BMB Reports
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    • 제35권4호
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    • pp.358-363
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    • 2002
  • Chemical and photochemical processes during storage and preparation rapidly degrade retinol, the most active form of vitamin A. therefore, the efficacy of incorporation into liposomes in order to modulate the kinetics of retinol degradation was investigated. Retinol was readily incorporated into multilamellar liposomes that were prepared form soybean phosphatidylcholine; the extent of the incorporation was 98.14±0.93% at pH 9.0 at a ratio of 0.01 : 1 (wt:wt) retinol : phospholipid. It was only marginally lower at higher retinol concentrations. The pH of the hydration buffer had a small effect. The incorporation efficiency ranged from 99.25±0.47% at pH 3 to 97.45±1.13% at pH 11. The time course of the retinol degradation in the aqueous solution in liposomes was compared to that of free retinol and free retinol with α-tocopherol under a variety of conditions of pH(3, 7, and 11), temperature(4, 25, 37, and 50℃), and light exposure(dark, visible, and UV). The retinol that was incorporated into the liposomes degraded significantly slower than the free retinol or retinol with α-tocopherol at pH 7 and 11. At pH 3, where the free retinol degrades rapidly, the degradation kinetics were similar in liposomes and the presence of α-tocopherol. At pH 7.0 and 4℃ in the light, for example, free aqueous retinol was completely degraded within 2 days, while only 20% of the retinol in the liposomes were degraded after 8 days. In general, the protective effect of the liposome incorporation was greater at low temperatures, at neutral and high pH, and in the dark. The results suggest that protection is greater in the solid, gel phase than in the fluid liquid crystalline phase lipids. These results indicate that the incorporation into liposomes can extend the shelf-life of retinol under a variety of conditions of temperature, pH, and ambient light conditions.

Pomegranate (Punica granatum) Peel Extract Efficacy as a Dietary Antioxidant against Azoxymethane-Induced Colon Cancer in Rat

  • Waly, Mostafa I.;Ali, Amanat;Guizani, Nejib;Al-Rawahi, Amani S.;Farooq, Sardar A.;Rahman, Mohammad S.
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권8호
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    • pp.4051-4055
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    • 2012
  • Functional foods include antioxidant nutrients which may protect against many human chronic diseases by combating reactive oxygen species (ROS) generation. The purpose of the present study was to investigate the protective effect of pomegranate peel extract (PPE) on azoxymethane (AOM)-induced colon tumors in rats as an in vivo experimental model. Forty Sprague-Dawley rats (4 weeks old) were randomly divided into 4 groups containing 10 rats per group, and were treated with either AOM, PPE, or PPE plus AOM or injected with 0.9% physiological saline solution as a control. At 8 weeks of age, the rats in the AOM and PPE plus AOM groups were injected with 15 mg AOM/kg body weight, once a week for two weeks. After the last AOM injection, the rats were continuously fed ad-libitum their specific diets for another 6 weeks. At the end of the experiment (i.e. at the age of 4 months), all rats were killed and the colon tissues were examined microscopically for lesions suspected of being preneoplastic lesions or tumors as well as for biochemical measurement of oxidative stress indices. The results revealed a lower incidence of aberrant crypt foci in the PPE plus AOM administered group as compared to the AOM group. In addition, PPE blocked the AOM-induced impairment of biochemical indicators of oxidative stress in the examined colonic tissue homogenates. The results suggest that PPE can partially inhibit the development of colonic premalignant lesions in an AOM-induced colorectal carcinogenesis model, by abrogating oxidative stress and improving the redox status of colonic cells.

대황(大黃)이 흰쥐의 위점막 손상에 미치는 영향 (Effects of Rhei Rhizoma on Gastric Ulcer in Sprague-Dawley Rats)

  • 김범회
    • 동의생리병리학회지
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    • 제25권1호
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    • pp.71-77
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    • 2011
  • Gastric ulcer has multifactorial etiology, and the development of ulcer is known to be caused by gastric acidity, pepsin secretion, gastric motility and gastric mucosal blood flow. The ulcer results from the tissue necrosis and apoptotic cell death triggered by mucosal ischemia, free radical formation and cessation of nutrient delivery. The gastric mucosa is usually exposed to a wide range of aggressive insults, and has developed efficient mechanisms to repair tissue injury. The apoptotic process of gastric mucosa is triggered by the induction of such proapoptotic gene expression, such as BAX. The Bcl-2 family of proteins plays a pivotal role in the regulation of apoptosis. The maintenance of gastric mucosa integrity depends upon the ratio between cell proliferation and cell death. Stress-inducing factors may affect Bcl-2/BAX ratio and thus the rate of apoptosis through modulation of the expression of both proteins depends upon the experimental model. In addition to the regulation of apoptosis, new vessels have to be generated in order to ensure an adequate supply of oxygen and nutrients to the healing gastric mucosa. This events are regulated by several factors. Among them, such polypeptide growth factors, such as vascular endothelial growth factor (VEGF) regulates essential cell functions involved in tissue healing including cell proliferation and differentiation. The purpose of this study was carried to investigate whether Rhei Rhizoma administration might protect apoptotic cell death and promote angiogenesis in gastric mucosa. Sprague-Dawley rats were randomly divided into 4 groups; normal, saline, cimetidine and Rhei Rhizoma-treated group. The saline, cimetidine and Rhei Rhizoma extracts were orally administrated to each group and gastric ulcer was induced by HCl-EtOH solution. After 1 hour, the stomachs were collected for histological observation and immunohistochemistry. In results, Rhei Rhizoma proves to promote to heal wound in gastric ulcer in conclusion and the significant changes of BAX, Bcl-2 and VEGF quantity in gastric mucosa were observed. These results suggest that Rhei Rhizoma extract may promote incision wound healing and has protective effects on gastric ulcer in rats.

Plasma Electrolytic Oxidation in Surface Modification of Metals for Electronics

  • Sharma, Mukesh Kumar;Jang, Youngjoo;Kim, Jongmin;Kim, Hyungtae;Jung, Jae Pil
    • Journal of Welding and Joining
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    • 제32권3호
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    • pp.27-33
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    • 2014
  • This paper presents a brief summary on a relatively new plasma aided electrolytic surface treatment process for light metals. A brief discussion regarding the advantages, principle, process parameters and applications of this process is discussed. The process owes its origin to Sluginov who discovered an arc discharge phenomenon in electrolysis in 1880. A similar process was studied and developed by Markov and coworkers in 1970s who successfully deposited an oxide film on aluminium. Several investigation thereafter lead to the establishment of suitable process parameters for deposition of a crystalline oxide film of more than $100{\mu}m$ thickness on the surface of light metals such as aluminium, titanium and magnesium. This process nowadays goes by several names such as plasma electrolytic oxidation (PEO), micro-arc oxidation (MOA), anodic spark deposition (ASD) etc. Several startups and surface treatment companies have taken up the process and deployed it successfully in a range of products, from military grade rifles to common off road sprockets. However, there are certain limitations to this technology such as the formation of an outer porous oxide layer, especially in case of magnesium which displays a Piling Bedworth ratio of less than one and thus an inherent non protective oxide. This can be treated further but adds to the cost of the process. Overall, it can be said the PEO process offers a better solution than the conventional coating processes. It offers advantages considering the fact that he electrolyte used in PEO process is environmental friendly and the temperature control is not as strict as in case of other surface treatment processes.

우리나라 경호업의 현황 및 발전방안 (THE SITUATION AND DEVELOPMENT OF SECURITY GUARD WORKS ON OUR COUNTRY)

  • 박주현
    • 시큐리티연구
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    • 제1호
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    • pp.123-134
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    • 1997
  • Our conuntry have come out to the phenomenon to the atrocity crimes, make into a intellecture crims and specialization with them due to various change to the expension of economy growth, drift of population to cities and sense of value is plunged in confution, Now that things have come to this day, since foundation of the security guard law it first begin, ten years, civilian securities guard law was include to the civil service securities law due to amendment fo the civility secuties law newly on Dec. 30, 1995. According to the amendment, the part of the public peace of peoples livelihood were slough of the visual angle in knowledge which function of the civilies security were only be in under the government dimension were put in order to be tointly according to the such state of affairs, should found the consider a counterplan fundamentally regarding to the what to doing efforts foster the civilities securitylaw and qualitalive elevation of presidential guards. To make a long story short by few words, the question resolves itself into the following five points. The first, peoples arrengements for the attitude fo public duty service with devotedly Sustaining publicity work activities for the thire divert of the understanding of civilian security guard. The secondly, Existing security traders and security association should to support to the civilian security works. The third, The government office concerned should strengthen the licensing system in order to improve the quality of existings in order to may establishment newly systems of license and technical institute of regarding to them. The fourth, Should be newly organixed the exclusive organization of personal protective works in the police buroau for the sustaining development of civirity guard works and soundness of the upbringing. The fifth, It is necessary to found the reserch institute for the study on oretical, scholarly, study for the technical reserch and enlargement of effeciveness And try to find a solution to the Universitys function and duty, activity plan, support plan to the Department of security specialist for the come forward in succession it under the national assistance. The finally, I am sure that the Korean security association could be transiormed into the organization which reliable and receive a love from the peoples when doing best utmost to do pursuit of the structure to be a securitys legalism, specialization and total security systems.

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Effect of Aralia Cordata Pharmacopuncture on Cartilage Protection and Apoptosis Inhibition In Vitro and in Collagenased-induced Arthritis Rabbit Model

  • Park, Dong-Suk;Baek, Yong-Hyeon
    • 대한한의학회지
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    • 제28권4호
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    • pp.114-123
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    • 2007
  • Osteoarthritis is characterized by cartilage degradation and chondrocytes death. Chondrocyte death is induced by the apotosis through special mechanisms including the activation of caspase-3. On the basis of this background, this study was designed to examine the cartilage protective and anti-apototic effects of Aralia Cordata in in vtro and in collagenase-induced arthritis rabbit model. To conduct in vitro study, chondrocytes culturedfrom rabbit knee joint were treated by 5 ng/ml IL-1a.For in vivo experiment, collagenase-induced arthritis (CIA) rabbit model was made via intraarticular injection with 0.25 ml of collagenase solution. Aralia cordata pharmacopuncture (ACP) was administrated on bilateral Dokbi acupoint (ST35) of rabbits at a dosage of 150 ${\mu}g/kg$ once a day for 28 days after the initiation of the CIA induction. In the study by using CIA rabbit model in vivo, ACP showed the inhibition of cartilage degradation in histological analysis. Aralia cordata also showed anti-apoptotic effect both in vitro and in vivo study. In chondrocytes treated by IL-1a, Aralia cordata inhibited caspase-3 activity and enhanced the proliferation of IL-1a-induced dedifferentiated chondrocytes. ACP showed the inhibition effect on the caspase-3 expression and activity from CIA rabbit model. This study indicates that ACP inhibits the cartilage destruction and the chondrocyte apotosis through downregulation of caspase-3 activity. These data suggest that ACP has a beneficial effect on preventing articular cartilage destruction in osteoarthrtis.

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Carnosic acid protects against acetaminophen-induced hepatotoxicity by potentiating Nrf2-mediated antioxidant capacity in mice

  • Guo, Qi;Shen, Zhiyang;Yu, Hongxia;Lu, Gaofeng;Yu, Yong;Liu, Xia;Zheng, Pengyuan
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권1호
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    • pp.15-23
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    • 2016
  • Acetaminophen (APAP) overdose is one of the most common causes of acute liver failure. The study aimed to investigate the protective effect of carnosic acid (CA) on APAP-induced acute hepatotoxicity and its underlying mechanism in mice. To induce hepatotoxicity, APAP solution (400 mg/kg) was administered into mice by intraperitoneal injection. Histological analysis revealed that CA treatment significantly ameliorated APAP-induced hepatic necrosis. The levels of both alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum were reduced by CA treatment. Moreover, CA treatment significantly inhibited APAP-induced hepatocytes necrosis and lactate dehydrogenase (LDH) releasing. Western blot analysis showed that CA abrogated APAP-induced cleaved caspase-3, Bax and phosphorylated JNK protein expression. Further results showed that CA treatment markedly inhibited APAP-induced pro-inflammatory cytokines TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 mRNA expression and the levels of phosphorylated $I{\kappa}B{\alpha}$ and p65 protein in the liver. In addition, CA treatment reduced APAP- induced hepatic malondialdehyde (MDA) contents and reactive oxygen species (ROS) accumulation. Conversely, hepatic glutathione (GSH) level was increased by administration of CA in APAP-treated mice. Mechanistically, CA facilitated Nrf2 translocation into nuclear through blocking the interaction between Nrf2 and Keap1, which, in turn, upregulated anti-oxidant genes mRNA expression. Taken together, our results indicate that CA facilitates Nrf2 nuclear translocation, causing induction of Nrf2-dependent genes, which contributes to protection from acetaminophen hepatotoxicity.