• Title/Summary/Keyword: Water improvement

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Gamma irradiation-induced grafting of 2-hydroxyethyl methacrylate (HEMA) onto ePTFE for implant applications

  • Mohd Hidzir, Norsyahidah;Radzali, Nur Ain Mohd;Rahman, Irman Abdul;Shamsudin, Siti Aisyah
    • Nuclear Engineering and Technology
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    • v.52 no.10
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    • pp.2320-2327
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    • 2020
  • The extreme hydrophobicity of expanded polytetrafluoroethylene (ePTFE) hinders bone-tissue integration, thus limiting the use of ePTFE in medical implant applications. To improve the potential of ePTFE as a biomaterial, 2-hydroxyethyl methacrylate (HEMA) was grafted onto the ePTFE surface using the gamma irradiation technique. The characteristics of the grafted ePTFE were successfully evaluated using attenuated total reflectance Fourier transform infrared (ATR-FTIR), field-emission scanning electron microscopy (FESEM)/energy dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). Under the tensile test, the modified ePTFE was found to be more brittle and rigid than the untreated sample. In addition, the grafted ePTFE was less hydrophobic with a higher percentage of water uptake compared to the untreated ePTFE. The protein adsorption test showed that grafted ePTFE could adsorb protein, which was denoted by the presence of N peaks in the XPS analysis. Moreover, the formation of the globular mineral on the grafted ePTFE surface was successfully visualized using the FESEM analysis, with a ratio of 1.94 for Ca:P minerals by the EDX. To summarize, the capability of the modified ePTFE to show protein adsorption and mineralization indicates the improvement of the polymer properties, and it can potentially be used as a biomaterial for implant application.

A Legal Study on Indemnification of Korean Mutual Insurance of Fisheries Cooperatives (수협공제(水協共濟)의 보상제도(補償制度)에 관한 법적(法的) 연구(硏究))

  • Cha, Cheol-Pyo;Park, Yong-Sub
    • Journal of Fisheries and Marine Sciences Education
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    • v.5 no.2
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    • pp.98-109
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    • 1993
  • By the Article 28 of the Korean Fishing Vessels Act and the Article 47-1 of the Enforcement Ordinance of the Act, fishing vessels over 5 gross tone must be insured the fishing vessels mutual insurance or marine insurance. Therefore the distant-water fishing vessels and vessels registered with Classification Society can be insured to the marine insurance, and non-registered vessels and the small fishing vessels can be insured to the fishing vessels mutual insurance of Fisheries Co-operatives. Moreover, the shipowners of fishing vessels over 5 gross tons to be insured a liability insurance for their crew, and it is to compensate effectively the crewman's accidents prescribed in the Seaman's Act. The shipowner's Liability Insurance to be insured the seaman's Compensation Insurance or the seaman's mutual insurance of the Fisheries Co-operatives and the Protection and Indemnity but they still involve lots of problems to cover the crewman's accidents reasonably. The author's views on the improvement way of the fisheries mutual insurance system are as follows. 1. The size of fishing vessels over 5 gross tons prescribed by the Article 28 of the Fishing Vessels Act must be revised into over 1 gross tons. And the regulations concerning penalties against nonfulfilment of the regulation must be strengthened in order to have legal effectiveness. 2. The level of the government subsidy for the fisheries mutual insurance must be raised up from the large point of view for protection of fishermen. It is concluded that the Government have to take charge of the remutual insurance in order to develop the fisheries mutual insurance system. 3. The mutual insurance system of fish catch have to be executed in order to guarantee the stable income for fishermen on the base of the amount of money by fish catch in the previous year.

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Global Health Project for Maternal Child Health in a Developing Country: Case Study in Tigray, Ethiopia (저개발국 모자보건 수준 향상을 위한 국제보건사업 전략 : 에티오피아 티그라이주 사례를 중심으로)

  • Bang, Kyung-Sook;Lee, Insook;Park, Young-Sook;Chae, Sun-Mi;Kang, Hyunju;Yu, Juyoun;Park, Ji-Sun;Oh, Sang-Jun
    • Perspectives in Nursing Science
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    • v.11 no.1
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    • pp.1-9
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    • 2014
  • Purpose: The purpose of this study was to demonstrate a two-year global health project to improve maternal and child health (MCH) in Ethiopia. Methods: This is a descriptive case study. The target area is Kilte Awlaelo Woreda in Tigray Regional State, Ethiopia. A baseline survey was conducted to identify the needs of community residents and health care professionals. A MCH program was developed according to a project design matrix that included: infrastructure renovation of health centers; continuing education for midwives, nurses, and health extension workers (HEWs); and improvement of residents' MCH awareness. Project evaluation will examine the structure, process, and outcomes of the program. Results: The baseline survey showed low rates of family planning (31%) and antenatal and postnatal care use (36.1% and 69%, respectively). The institutional birth rate was 13.5%. Midwives and nurses received 2~4 educational programs about family planning and perinatal care. HEWs were also given practical education. Water and electrical infrastructure of all five health centers in the Kilte Awlaelo Woreda were renovated. Additionally, medical supplies and equipment were provided. Community health education on perinatal care, family planning, and personal hygiene was presented. Conclusion: This study highlights the role of nursing in global health and provides basic information on the development and outcomes of the global health project.

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Seasonal Distribution of Wildlife in An Urban Stream -The Case of Gongji Stream in Chuncheon- (도시하천의 계절별 야생동물 서식 연구 - 춘천시 공지천을 대상으로 -)

  • Jo, Hyun-Kil;Han, Gab-Soo;Choi, Jae-Suk;Park, Jeong-Ho;Lee, Joon-Suk
    • Journal of Environmental Science International
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    • v.16 no.3
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    • pp.277-285
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    • 2007
  • The purpose of this study is to analyze seasonal distribution of insects, birds, fishes, and benthos for Gongji stream in Chuncheon and to explore some strategies towards creating a desirable close-to-nature stream. The number of species occurred in the study stream was 23 for butterflies and 149 for other insects, 23 for birds, 15 for fishes, and 47 for benthos. The study stream was dominated by Artogenia rapae, Polygonia caureum, Cyntia cardui for butterflies, and Passer montanus, Anas crecca, Anas platyrhynchos for birds. The dominant species were Rhynchocypris oxycephalus, Zacco plutypus, Carassius auratus for fishes, and Limnodrilus sp. 2, Chiranumus sp. 2, Hydropsyche KUb for benthos. Attracting insect species of higher density requires planting of host plant species and stabilization of plant coverage against disturbances. To enhance species diversify and density of birds, it is desirable to provide diverse habitats including preservation of downstream wetland and natural vegetation, creation of sand bars and islands with sand and gravel, and restriction or traffic passing and parking. Restoring fish and benthos habitats needs improvement of water quality, layout of gravels and stones on sand-dominant streambed, and use of close-to-nature revetment techniques.

The Validation of MOHID Regional Ocean Circulation Model around the East Asian Seas in 2016 (2016년 동아시아 해역의 MOHID 지역 해양 순환 모델 검증)

  • Lee, Jae-Ho;Lim, Byeong-Jun;Kim, Do-Youn;Park, Sang-Hoon;Chang, You-Soon
    • Journal of the Korean earth science society
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    • v.39 no.5
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    • pp.436-457
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    • 2018
  • In this study, we apply a three-dimensional circulation model, MOHID (MOdelo $HIDrodin{\hat{a}}mico$), and reproduce oceanic variation around the East Asian seas including Korea in 2016. Simulation results are verified by using objective analysis fields (EN4, ARMOR3D, AVISO, and SIO products) and in-situ observation data (serial oceanographic and buoy data). Verification results show that general characteristics of the water temperature, sea level anomaly, surface velocity, and mixed layer depths simulated by MOHID are similar with those of the objective analysis fields in the East Asian seas. Especially, when buoy data in the coastal areas are compared, correlation coefficients of sea surface temperature and sea level anomaly are both over 0.8 and normalized standard deviations are between 0.85 and 1.15, respectively. However, it is analyzed that additional improvement would be necessary in the representation of thermocline structure in the East Sea and strong stratification phenomena in the Yellow and South Sea in summer.

Trend Analysis on Facility Monitoring of Korea National Parks (국립공원 시설모니터링 변화추이 분석)

  • Lee, Ju-Hee;Bae, Min-Ki;Sim, Kyu-Won
    • Journal of Korean Society of Forest Science
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    • v.99 no.4
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    • pp.487-500
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    • 2010
  • The purpose of this study was to provide direction for national parks management policies by analyzing national park facility monitoring data collected every 2 years from 2002 to 2006. The results of this study showed the following. Firstly, 16 mountainous national parks showed increasing values in importance and performance in IPA. The trend analysis results showed that the location and capacity of parking lots as well as the number of rest rooms need to be improved. Secondly, two marine national parks indicated increasing values in campground and coastal facilities in IP value. Also, the location, number, and cleanliness of rest rooms, safety and surface condition of trail, guard rail and warning signs, information signs, drinking water fountains and shower facilities were priorities for improvement. The implications of this study will be able to help by providing guidelines for installation and maintenance of park facilities which in turn will improve visitor satisfaction and establish national park facility operation policies.

Methanol Extract of Cassia mimosoides var. nomame and Its Ethyl Acetate Fraction Attenuate Brain Damage by Inhibition of Apoptosis in a Rat Model of Ischemia-Reperfusion

  • Kim, Ki-Hong;Lee, Jong-Won
    • Preventive Nutrition and Food Science
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    • v.15 no.4
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    • pp.255-261
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    • 2010
  • Ischemic stroke, a major cause of death and disability worldwide, is caused by occlusion of cerebral arteries that, coupled with or without reperfusion, results in prolonged ischemia (hypoxia and hypoglycemia) and, ultimately, brain damage. In this study, we examined whether methanol extract of the whole plant of Cassia mimosoides var. nomame Makino that grows naturally in Korea, as well as Japan and China, and some of its fractions obtained by partitioning with organic solvents could protect human hepatocellular carcinoma cells (HepG2) under hypoxic condition by inhibiting apoptosis. We also investigated if these extracts could attenuate brain damage in a rat model of 2 hr of ischemia, generated by middle cerebral artery occlusion, and 22 hr of reperfusion. The whole extract ($100{\mu}g$/mL) maintained the cell number at more than half of that initially plated, even after 24 hr of cell culture under hypoxic condition (3% $O_2$). In the absence of the whole extract, almost all of the cells were dead by this time point. This improvement of cell viability came from a delay of apoptosis, which was confirmed by observing the timing of the formation of a DNA ladder when assessed by gel electrophoresis. Of fractions soluble in hexane, ethyl acetate (EA), butanol and water, EA extracts were selected for the animal experiments, as they improved cell viability at the lowest concentration ($10{\mu}g$/mL). The whole extract (200 mg/kg) and EA extract (10 and 20 mg/kg) significantly reduced infarct size, a measure of brain damage, by 34.7, 33.8 and 45.2.0%, respectively, when assessed by 2,3,5-triphenyl tetrazolium chloride staining. The results suggest that intake of Cassia mimosoides var. nomame Makino might be beneficial for preventing ischemic stroke through inhibition of brain cell apoptosis.

Environmental Impact Review and Improvement of Durability of Silicasol-cement Grout Material (실리카졸 약액의 환경영향성 검토 및 내구증진방안)

  • Lee, Byungho;Kim, Younghun;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.12
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    • pp.13-18
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    • 2010
  • This study was made on the fact that the environmental impact and durability of the recently developed alkali silicasol chemical grout material. The grout material used for this study was designed to understand its environmental impact and durability through the SEM, chemical resistance test, leaching test, permeability test. In order to compare with the engineering characteristics regarding alkali silicasol grout material and sodium silicate grout material. As a result of SEM, the surface and internal tissues of alkali silicasol grout material could be identified to be denser than those of sodium silicate. As a result of leaching test the adaptability was identified as grout material as it had proved to be an ecological material owing to the total amount of the element to be leached being extremely little. As a result of permeability test it is judged that it is possible to apply the silicasol to the site in the place requiring the water cut-off as the silicasol.

Ionization Behaviors in Various Soils Subjected to Impulse Currents (임펄스전류에 의한 토양의 종류별 이온화 특성)

  • Lee, Bok-Hee;Kim, Hoe-Gu;Park, Geon-Hun;Baek, Young-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.12
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    • pp.87-94
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    • 2008
  • This parer presents the soil ionization phenomena and parameters associated to characterize the transient performances of grounding system under lightning impulse Currents. Ionization properties in occurring some soil media were experimentally investigated. The cylindrical test cell was employed in order to facilitate the analysis of soil breakdown field intensity and ionized radius. The soil breakdown field intensity, dependence of impedance on the amplitude of impulse current, V-I curves and transient impedances were discussed based on the voltage and current oscillograms. It was found that the ionization process and dynamic behaviors were strongly dependent on the types of soil and two current peaks were not observed in highly water-saturated soils. The results presented in this paper will provide useful information on the improvement of transient performance of a grounding system subjected to lightning impulse Current considering the soil ionization.

Calculation of the Coefficient of Artificial Reef According to the Coefficient of Volume (체적계수에 따른 인공어초 계수산정)

  • Kim, Young Jong;Choi, Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.9
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    • pp.2307-2312
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    • 2014
  • Artificial reef refers to various structures that facility to construction field format and spawning of marine organisms, sea ranch, forest of the sea, and sea jungle artificially in water, Build a production stable base of marine products, thereby contributing to an increase in the income of fishermen. In the management of an artificial reef, the calculation of the number of square reefs may be that it is a method to perform the submersible is an important part of maintenance is correct. However, cost and diving personnel, depending on the diving situation, there is a difficult thing to implement to coast across the country. Therefore, In this study, We calculated the volume using the multi-beam Echo Sounder and side scan sonar for the reefs of the rectangle are the existing installation. And proposes the improvement of the estimation in accordance with the volume coefficient reef.