• Title/Summary/Keyword: technical investigation

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An Investigation into Ultrasonic Flotation Separation of Spent MgO-C Refractories Using Acetic Acid (아세트산을 활용한 폐 마그카본(MgO-C) 내화물의 초음파 부상 분리에 관한 연구)

  • Yunki Byeun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.12 no.1
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    • pp.40-46
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    • 2024
  • A novel approach is presented to address issues associated with the use of strong acidic solutions for the leaching of magnesium oxide (MgO) from spent magnesia-carbon refractories. An ultrasonic flotation and separation process is employed, with a mildly acidic solvent, acetic acid, used to selectively chelate MgO from the spent refractories. When using 2 M acetic acid as a solvent, the recovery of the graphite exhibited 99.7 % with high purity of 72.7 %, showing a significant improvement compared to using water as the solvent. Furthermore, the technology presented in this study offers a method for producing magnesium acetate through the reaction of MgO in spent refractory with acetic acid, providing a means for the purification and separation of graphite.

Development and Implementation of Dam Safety Management System (댐 안전관리 시스템의 개발 및 운용)

  • Jeon, Je Sung;Lee, Jong Wook;Shin, Dong Hoon;Park, Han Gyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.2
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    • pp.121-130
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    • 2008
  • Recently, we can see an increasing amount of dam damage or failure due to aging, earthquakes occurrence and unusual changes in weather. For this reason, dam safety is gaining more importance than ever before in terms of disaster management at a national level. Therefore, the government is trying to come up with an array of legal actions to secure consistent dam safety. Other dam management organizations are also taking various institutional and technical measures for the same purpose. In this study, Dam Safety Management System, KDSMS, has developed for consistent and efficient dam safety management. The KDSMS consists of dam and reservoir data, a hydrological information system, a field inspection and data management system, a instrumentation and monitoring system including earthquake monitoring, a field investigation and safety evaluation system, and a collective information system. The KDSMS is a kind of enterprise management system which has been developed to deal with safety management of each field, research center, and headquarter office and their correlation as well as detailed safety information management.

A Study of The Nursing Education Concerning Two Years Associate Degree Nursing Program (간호 교육에 대한 일 연구 -2년제 초급대학 과정 중심으로-)

  • 변창자
    • Journal of Korean Academy of Nursing
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    • v.4 no.3
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    • pp.63-79
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    • 1974
  • 1. The purpose of this study. The purpose of this study is to plan and investigate short-term nursing education of two-years associate degree program to produce middle-level professional nurses which are needed by-society and nation. Current nursing education in Korea is divided into four years degree program, three years diploma program Even (though) there are differences in the aims of their education, the curriculums are not much different between the education for producing leaders which is its basic purpose and training middle-level professional nurses. Therefore the purpose of associate degree program lies in minimizing the waste of time and finance which are invested for long-term education for middle-level professional nurses. And also this coincide with the policy of national technical training and definite supply of nurse manpower according to health policy for effective role and ability of nurse. 2. The method of study. This is based on the study of literature, research on the actual condition and investigation of opinion- through questionnaire. L) The study of literature: Domestic and foreign literatures for two years associate degree program were studied and investigated. 2) Research on the actual condition : Current three years nursing education program was collected and analysed. 3) Investigation of opinion. The problem of curried nursing education system and the possibility of two years associate degree program were investigated through questionnaire. 3. The result of the study. 1) The trend of recent nursing education. a. The aims of nursing in past chiefly taking care of physical disease of patient has recently changed to nursing of character including physical, mental, socio-economic, educational and psychological condition. b. For the performing systematic and effective nurse's duty according to her role, the-change of educational system which is classified as a range of education the period of education and certificate after graduation has been enforced or fulfilled. c. Nursing education also has a trend to become a collage or two years associate degree program which can get same legal protection as other educational institutions whose basic purpose is education. Attached nursing school to hospital is getting disappeared because of disadvantage of educational system. 2) Problems. Depending upon research on actual condition of current 3 years nursing education program. a. There are too many subjects. b. Contents of education could be doubled because major subjects are subdivided in detail. c. The credits for graduation are too heavy comparing to the period of study or the ability of students. (The necessary credits are 150.8 for three years according to actual investigation 4. There is no certain standard in organizing curriculum therefore there are too much differences between schools. 4. Basic Plan. The plan for two years associate degree program in nursing education depending on demand of professional nursing field of society is based on following items. 1) Training middle-level professional nurse lay emphasis on liberal arts and basic major field. 2) Liberal arts are divided into required and optional subjects and students could take courses by choice. 3) Major subjects are compound together by fields and they become the sciences of nursing Ⅰ,Ⅱ,Ⅲ,Ⅳ and every items has its educational purposes and contents major study includes laboratory practice and clinical experience. 4) The required credits for graduation are to which means 17-18 credits a semester. The above has been planned to solve the problems of current three years nursing education program. In conclusion for the achievement of this system, following items are needed. 1) It is necessary to change educational administration and system such as amendment of educational law or order of educational application of law. 2) Qualified professors should be available to understand and develope the idea or purpose of this educational system. 3) Local medical institutions should be opened widely and educational for clinical training. 4) The job after graduation should he secured positively.

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토양 및 지하수 Investigation 과 Remediation에 대한 현장적용

  • Wallner, Heinz
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.44-63
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    • 2000
  • Situated close to Heathrow Airport, and adjacent to the M4 and M25 Motorways, the site at Axis Park is considered a prime location for business in the UK. In consequnce two of the UK's major property development companies, MEPC and Redrew Homes sought the expertise of Intergeo to remediate the contaminated former industrial site prior to its development. Industrial use of the twenty-six hectare site, started in 1936, when Hawker Aircraft commence aircraft manufacture. In 1963 the Firestone Tyre and Rubber Company purchased part of the site. Ford commenced vehicle production at the site in the mid-1970's and production was continued by Iveco Ford from 1986 to the plant's decommissioning in 1997. Geologically the site is underlain by sand and gravel, deposited in prehistory by the River Thames, with London Clay at around 6m depth. The level of groundwater fluctuates seasonally at around 2.5m depth, moving slowly southwest towards local streams and watercourses. A phased investigation of the site was undertaken, which culminated in the extensive site investigation undertaken by Intergeo in 1998. In total 50 boreholes, 90 probeholes and 60 trial pits were used to investigate the site and around 4000 solid and 1300 liquid samples were tested in the laboratory for chemical substances. The investigations identified total petroleum hydrocarbons in the soil up to 25, 000mg/kg. Diesel oil, with some lubricating oil were the main components. Volatile organic compounds were identified in the groundwater in excess of 10mg/l. Specific substances included trichloromethane, trichloromethane and tetrachloroethene. Both the oil and volatile compounds were widely spread across the site, The specific substances identified could be traced back to industrial processes used at one or other dates in the sites history Slightly elevated levels of toxic metals and polycyclic aromatic hydrocarbons were also identified locally. Prior to remediation of the site and throughout its progress, extensive liaison with the regulatory authorities and the client's professional representatives was required. In addition to meetings, numerous technical documents detailing methods and health and safety issues were required in order to comply with UK environmental and safety legislation. After initially considering a range of options to undertake remediation, the following three main techniques were selected: ex-situ bioremediation of hydrocarbon contaminated soils, skimming of free floating hydrocarbon product from the water surface at wells and excavations and air stripping of volatile organic compounds from groundwater recovered from wells. The achievements were as follows: 1) 350, 000m3 of soil was excavated and 112, 000m3 of sand and gravel was processed to remove gravel and cobble sized particles; 2) 53, 000m3 of hydrocarbon contaminated soil was bioremediated in windrows ; 3) 7000m3 of groundwater was processed by skimming to remove free floating Product; 4) 196, 000m3 of groundwater was Processed by air stripping to remove volatile organic compounds. Only 1000m3 of soil left the site for disposal in licensed waste facilities Given the costs of disposal in the UK, the selected methods represented a considerable cost saving to the Clients. All other soil was engineered back into the ground to a precise geotechnical specification. The following objective levels were achieved across the site 1) By a Risk Based Corrective Action (RBCA) methodology it was demonstrated that soil with less that 1000mg/kg total petroleum hydrocarbons did not pose a hazard to health or water resources and therefore, could remain insitu; 2) Soils destined for the residential areas of the site were remediated to 250mg/kg total petroleum hydrocarbons; in the industrial areas 500mg/kg was proven acceptable. 3) Hydrocarbons in groundwater were remediated to below the Dutch Intervegtion Level of 0.6mg/1; 4) Volatile organic compounds/BTEX group substances were reduced to below the Dutch Intervention Levels; 5) Polycyclic aromatic hydrocarbons and metals were below Inter-departmental Committee for the Redevelopment of Contaminated Land guideline levels for intended enduse. In order to verify the qualify of the work 1500 chemical test results were submitted for the purpose of validation. Quality assurance checks were undertaken by independent consultants and at an independent laboratory selected by Intergeo. Long term monitoring of water quality was undertaken for a period of one year after remediation work had been completed. Both the regulatory authorities and Clients representatives endorsed the quality of remediation now completed at the site. Subsequent to completion of the remediation work Redrew Homes constructed a prestige housing development. The properties at "Belvedere Place" retailed at premium prices. On the MEPC site the Post Office, amongst others, has located a major sorting office for the London area. Exceptionally high standards of remediation, control and documentation were a requirement for the work undertaken here.aken here.

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Physical properties, released patterns and bio-efficacy of granular mixtures with chlomethoxyfen and butachlor formulated by different methods (제조방식을 달리한 chlomethoxyfen과 butachlor 혼합입제의 물리성, 수중용출도와 생물효과 비교)

  • Chung, Bong-Jin;Yeon, Jae-Heum
    • The Korean Journal of Pesticide Science
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    • v.2 no.3
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    • pp.36-44
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    • 1998
  • To develope cost-effective new granular formulation of mixture with 7.0% chlomethoxyfen and 3.5% butachlor, this study was conducted by investigation of floatability, dispersibility or collapsability and released concentration of active ingredients in water and bio-efficacies of the granules formulated by different formulation methods compared to commercial pellet-extruded granules. They were formulated by coating on or impregnation into extruded pellets, sands and zeolites with two active ingredients, binders, friction reducer, dispersing agents and bentonite. Pellet-coated method showed similar floatability, collapsability and bio-efficacy to the commercial pellet-extruded one or better than that but unstable patterns of released concentration of chlomethoxyfen because of easy isolation of coated technical particles from the surface of granules. Sand-coated methods showed similar physical properties, released pattern of two active ingredients, and bio-efficacy to the commercial one. Liquid binders and/or dispersing agents are more important than powdered ones to control released concentration of active ingredients from the granule mixtures, to improve the floatability and dispersibility, and to show good bio-efficacy. Sand-coated one might be a suitable method if types and amount of liquid binders and dispersing agents are selected.

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Preliminary Review on Function, Needs and Approach of Underground Research Laboratory for Deep Geological Disposal of Spent Nuclear Fuel in Korea (사용후핵연료 심층처분을 위한 지하연구시설(URL)의 필요성 및 접근 방안)

  • Bae, Dae-Seok;Koh, Yong-Kwon;Lee, Sang-Jin;Kim, Hyunjoo;Choi, Byong-Il
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.2
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    • pp.157-178
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    • 2013
  • This study gives a conceptual and basic direction to develop a URL (underground research laboratory) program for establishing the performance and safety of a deep geological disposal system in Korea. The concept of deep geological disposal is one of the preferred methodologies for the final disposal of spent nuclear fuel (SNF). Advanced countries with radioactive waste disposal have developed their own disposal concepts reasonable to their social and environmental conditions and applied to their commercial projects. Deep geological disposal system is a multi-barrier system generally consisting of an engineered barrier and natural barrier. A disposal facility and its host environment can be relied on a necessary containment and isolation over timescales envisaged as several to tens of thousands of years. A disposal system is not allowed in the commercial stage of the disposal program without a validation and demonstration of the performance and safety of the system. All issues confirming performance and safety of a disposal system include investigation, analysis, assessment, design, construction, operation and closure from planning to closure of the deep geological repository. Advanced countries perform RD&D (research, development & demonstration) programs to validate the performance and safety of a disposal system using a URL facility located at the preferred rock area within their own territories. The results and processes from the URL program contribute to construct technical criteria and guidelines for site selection as well as suitability and safety assessment of the final disposal site. Furthermore, the URL program also plays a decisive role in promoting scientific understanding of the deep geological disposal system for stakeholders, such as the public, regulator, and experts.

Resistance Factor and Target Reliability Index Calculation of Static Design Methods for Driven Steel Pipe Pile in Gwangyang (광양지역에 적합한 항타강관말뚝의 목표신뢰성지수 및 저항계수 산정)

  • Kim, Hyeon-Tae;Kim, Daehyeon;Lim, Jae-Choon;Park, Kyung-Ho;Lee, Ik-Hyo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8128-8139
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    • 2015
  • Recently, the necessity of developing the load and resistance factor design(LRFD) for soft ground improvement method has been raised, since the limit state design is requested as international technical standard for the foundation of structures. In this study, to develop LRFD codes for foundation structures in Korea, target reliability index and resistance factor for static bearing capacity of driven steel pipe piles were calibrated in the framework of reliability theory. The 16 data(in Gwangyang) and the 57 data(Korea Institute of Construction Technology, 2008) sets of static load test and soil property tests conducted in the whole domestic area were collected along with available subsurface investigation results. The resistance bias factors were evaluated for the tow static design methods by comparing the representative measured bearing capacities with the expected design values. Reliability analysis was performed by two types of advanced methods : the First Order Reliability Method (FORM), and the Monte Carlo Simulation (MCS) method using resistance bias factor statistics. As a result, when target reliability indices of the driven pipe pile were selected as 2.0, 2.33, 2.5, resistance factor of two design methods for SPT N at pile tip less than 50 were evaluated as 0.611~0.684, 0.537~0.821 respectively, and STP N at pile tip more than 50 were evaluated as 0.545~0.608, 0.643~0.749 respectively. The result from this research will be useful for developing various foundations and soil structures under LRFD.

Investigation of Pyroprocessing Concept and Its Applicability as an Alternative Technology for Conventional Fuel Cycle (고온전해분리 기술의 개요 및 기존 핵연료주기 대체 기술로서의 적합성 검토)

  • Yoo, Jae-Hyung;Lee, Byung-Jik;Lee, Han-Soo;Kim, Eung-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.4
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    • pp.283-295
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    • 2007
  • The technical feasibility of a pyroprocessing of PWR spent fuels to recover nuclear fuel materials, uranium and transuranic elements group(TRU), was examined in this study. Also its applicability as a new fuel cycle technology in terms of non-proliferation was investigated. First, various unit processes were combined to a pyroprocess. Then the flow aspects of such materials of issue as uranium, transuraniums, rare earth, noble metals and heat generating elements were examined on the flowsheet, which was obtained by the assumptions on the basis of various experimental results in this work or separation data collected from literatures. Consequently, the calculated results of the material balance for the whole process showed that uranium and TRU could be recovered as products by 98.0 % and 97.0 %, respectively, from a PWR spent fuel while removing the other elemental groups into radioactive wastes. On the one hand, the TRU product was found to emit a considerable amount of ${\gamma}$-ray as well as neutrons favorably contributing to the strategy of proliferation resistance.

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A Study on the Change of Carex ferruginea Community by Fertilization and Grazing (시비 및 방목에 의한 Carex ferruginea 군락의 변화에 관한 연구)

  • ;G. Spatz
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.6 no.2
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    • pp.97-102
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    • 1986
  • This investigation was carried out to find out the succession of Carex ferruginea community by PK-fertilization and sheep grazing. The area covered with Caricetum ferrugineae and located at the Bavarian Alps in the southern part of Germany. 1. By the experimental conditions was changed the plant community of Caricetum ferrugineae, however, the influence of PK-fertilization was much more effective than that of sheep grazing. 2. As the species of Carex ferruginea, Melica nutans, Brachypodium sylvaticum, Calamagrostis varia were weak the absorptive ability of nutritive subatance, they almost disappeared due to PK-fertilization. On the other hand, grasses and legumes (Festuca rubra, Agrostis tenuis, Poa trivialis, Trifolium repens) increased by PK-fertilization distinctly. 3. The life forms of plant community at the experimental area covered with Hemicrytophytes of 55% and Geophytes of 40%. But by the PK-fertilization with sheep grazing increased their life forms Hemicryptophytes by 19% and Geophytes decreased by 31%, but in case the sheep grazing without fertilization increased Geophytes by 11% and Hemicryptophytes decreased by 12%. 4. The plant community of Caricetum ferrugineae before the experiment was successived into Festuco-Cynosuretum by PK-fertilization with sheep grazing.

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Clinical Efficacy of Repetitive Transcranial Magnetic Stimulation for Treatment of Depression and Latest Trends in TMS Techniques (반복 경두개자기자극술의 우울증 치료효과 및 최신동향에 대한 고찰)

  • Kim, Shin Tae;Kim, Hae Won;Kim, Se Joo;Kang, Jee In
    • Korean Journal of Biological Psychiatry
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    • v.24 no.3
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    • pp.95-109
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    • 2017
  • Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation technique which can change cortical excitability in targeted area by producing magnetic field pulses with an electromagnetic coil. rTMS treatment has been used to treat various neuropsychiatric disorders including depression. In this review, we evaluate the literature on rTMS for depression by assessing its efficacy on different subtypes of depression and different technical parameters. In particular, we focus on the results of randomized clinical trials and meta-analyses for depression after the US Food and Drug Administration approval in 2008, which acknowledged its efficacy and acceptability. We also review the new forms of rTMS therapy including deep TMS, theta-burst stimulation, and magnetic seizure therapy (MST) that have been under recent investigation. High frequency rTMS over left dorsolateral prefrontal cortex (DLPFC), low frequency rTMS over right DLPFC, or bilateral rTMS is shown to be effective and acceptable in treatment for patients with non-psychotic, unipolar depression either as monotherapy or adjuvant. Deep TMS, theta-burst stimulation and MST are promising new TMS techniques which warrant further research.