• Title/Summary/Keyword: concrete technology

Search Result 4,660, Processing Time 0.029 seconds

Review on Assessment Methodology for Human Intrusion Into a Repository for Radioactive Waste (방사성폐기물 처분장 인간침입 평가 방법론에 관한 고찰)

  • Cho, Dong-Keun;Kim, Jung-Woo;Jeong, Jong-Tae;Baik, Min-Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.14 no.3
    • /
    • pp.297-305
    • /
    • 2016
  • An approach to assess inadvertent human intrusion into radwaste repository was proposed with the assumption that the intrusion occurs after a loss of knowledge of the hazardous nature of the disposal facility. The essential boundary conditions were derived on the basis of international recommendations, followed by an overall approach to deal with inadvertent human intrusion. The interrelation between societal factors, human intrusion scenarios, and protective measures is described to provide a concrete explanation of the approach, including the detailed procedures to set up the human intrusion scenario. The procedure for deriving protective measures is also explained with four steps, including how to derive a safety framework, general measures, potential measures, and eventual protective measures on the basis of stylized scenarios. It is expected that the approach proposed in this study will be used effectively to reduce the potential for and/or the consequences of human intrusion during the entire process of realizing a disposal facility.

Odor Removal Efficiency of Biofilter Ducting Systems in Indoor Pig House (바이오 필터를 이용한 비육돈사 배기덕트 시설의 악취저감 효과)

  • Song, J.I.;Choi, H.L.;Choi, H.C.;Kwon, D.J.;Yoo, Y.H.;Jeon, J.H.
    • Journal of Animal Environmental Science
    • /
    • v.13 no.3
    • /
    • pp.195-200
    • /
    • 2007
  • Management of odors is essential to swine industry in the Republic of Korea. This study was conducted to evaluate the odor removal efficiency of biofilter ducting systems. Rice straw and auto clave concrete(ALC) were used as filter medium. The ventilation fans(5 units, diameter: 500 mm) at the side wall of a growing pig housing were connected to a biofilter using a duct. The size of a biofilter is $2.5{\times}2{\times}1.2(W{\times}L{\times}H)$. The air velocities at the 300 mm above rice straw and ALC were 0.77 and 0.56 m/s, respectively. Ammonia concentration at the outlet of rice straw and ALC media were 2 and 3 ppm, respectively. Dust concentrations were also measured. The dust concentrations of rice straw and ALC were 93, $32\;mg/m^3$, respectively. There was no significant difference between filter mediums in terms of carbon dioxide concentrations(rice straw: 320, ALC: 270 mg/l). The concentration of hydrogen sulfide was stable over the experimentation. The actual concentrations of hydrogen sulfide were 4, 3 and 3 ppm at the days of 7, 21 and 36, respectively. These results suggest that biofilter ducting systems may remove odors from pig house effectively.

  • PDF

A Study on Developing Education and Training System for Informationalization in Governmental Organization (정부조직의 정보화교육훈련 체계구축에 관한 연구)

  • 정해용;김상훈
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.4 no.1
    • /
    • pp.34-51
    • /
    • 1999
  • The effective use of IT(information technology) will increasingly become one of the key determinants for successful informationalization in govermental organization And the ability of the public officials in using IT or operating information system is essential to the effective use of IT. This study focuses on constructing a theoretical base of developing the education and training system for enhancing the IT ability of the public officials. In order to achieve this research goal, first this study suggests four categories of IT education and training for (1) the basic capability of IT use (2) the skills of operating information system (3) the management competence of performing strategic use of IT, (4) the expert skills for specific IT, and then derives concrete items for each category. With respect to these items, we empirically investigate the degree of necessity and the effective way of education and training according to tasks, positions and ability of the public officials. The data analyses are based on questionnaires responded by 300 public officials who attend the education and training programs held by the Training Institute of Ministry of Information and Communication. The results of this study can provide the theoretical basis for constructing the IT education and training system which is applicable to most of Korean organizations. Also they can be used as a practical guideline in developing and promoting specific IT education and training programs.

  • PDF

Standardization of work environment measurement information for constructing exposure surveillance system (노출감시체계 구축을 위한 작업환경측정 정보 표준화)

  • Choi, Sangjun;Jeong, Jee Yoen;Im, Sungguk;Lim, Daesung;Koh, Dong-Hee;Park, Donguk;Park, YunKyung;Kim, Soyeon;Chung, Eunkyo
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.29 no.3
    • /
    • pp.322-335
    • /
    • 2019
  • Objectives: The goal of this study is to standardize industry, process, and job within work environment measurement information. Methods: We selected 180 work environment measurement reports on 30 industries from a database monitored from 2014 to 2016 by the Korea Industrial Health Association. Ten industrial hygienists, each with over five years of experience in measurement, conducted a primary standardization of 180 reports. Two professional industrial hygienists with more than 20 years of experience each reviewed and revised the results of the primary standardization. We also examined the validity on the usefulness of the standardized database by the two industrial hygienists. Results: The final standardization results were classified into eight major categories, 23 sub-major categories, 39 minor categories, 53 unit categories and 70 sub-unit categories in the Korean Standard Industrial Classification (KSIC) 10th revision. A total of 161 processes were standardized, and there were 148 processes with K2B codes. Standard job was coded into 13 job groups including operator, automobile maintenance, nurse, maintenance, manager, excavating machine operator, forklift driver, radiologist, clinical pathologist, signer, researcher, kitchen assistant, and concrete reinforcement ironworker. Conclusions: Although the standardized information in this study may be only a part of the total information, it can be useful for improvement of the K2B system. Additional research is needed for an ongoing clean-up of data in the K2B and re-calibration and reclassification of standard processes until the future national exposure monitoring system is fully established.

Applicability Estimation of Ballast Non-exchange-type Quick-hardening Track Using a Layer Separation Pouring Method (층 분리주입을 이용한 도상자갈 무교환방식 급속경화궤도의 적용성 평가)

  • Lee, Il Wha;Jung, Young Ho;Lee, Min Soo
    • Journal of the Korean Society for Railway
    • /
    • v.18 no.6
    • /
    • pp.543-551
    • /
    • 2015
  • Quick-hardening track (QHT) is a construction method which is used to change from old ballast track to concrete track. Sufficient time for construction is important, as the construction should be done during operational breaks at night. Most of the time is spent on exchanging the ballast layer. If it is possible to apply the ballast non-exchange type of quick-hardening track, it would be more effective to reduce the construction time and costs. In this paper, pouring materials with high permeability are suggested and a construction method involving a layer separation pouring process considering the void condition is introduced in order to develop ballast non-exchange type of QHT. The separate pouring method can secure the required strength because optimized materials are poured into the upper layer and the lower layer for each void ratio condition. To ensure this process, a rheology analysis was conducted on the design of the pouring materials according to aggregate size, the aggregate distribution, the void ratio, the void size, the tortuosity and the permeability. A polymer series was used as the pouring material of the lower layer to secure the void filling capacity and for adhesion to the fine-grained layer. In addition, magnesium-phosphate ceramic (MPC) was used as the pouring material of the upper layer to secure the void-filling capacity and for adhesion of the coarse-grained layer. As a result of a mechanics test of the materials, satisfactory performance corresponding to existing quick-hardening track was noted.

Electrical Resistivity of ITZ According to the Type of Aggregate (골재 종류별 시멘트 경화체 계면의 전기저항 특성)

  • Kim, Ho-Jin;Bae, Je Hyun;Jung, Young-Hoon;Park, Sun-Gyu
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.9 no.3
    • /
    • pp.268-275
    • /
    • 2021
  • The three factors that determine the strength of concrete are the strength of cement paste, aggregate and ITZ(Interfacial Transition Zone) between aggregate and cement paste. Out of these, the strength of ITZ is the most vulnerable. ITZ is formed in 10~50㎛, the ratio of calcium hydroxide is high, and CSH appears low ratio. A high calcium hydroxide ratio causes a decrease in the bond strength of ITZ. ITZ is due to further weak area. The problem of ITZ appears as a more disadvantageous factor when it used lightweight aggregate. The previous study of ITZ properties have measured interfacial toughness, identified influencing factors ITZ, and it progressed SEM and XRD analysis on cement matrix without using coarse aggregates. also it was identified microstructure using EMPA-BSE equipment. However, in previous studies, it is difficult to understand the microstructure and mechanical properties. Therefore, in this study, a method of measuring electrical resistance using EIS(Electrochemical Impedance Spectroscopy) measuring equipment was adopted to identify the ITZ between natural aggregate and lightweight aggregate, and it was tested the change of ITZ by surface coating of lightweight aggregate with ground granulated blast furnace slag. As a result, the compressive strength of natural aggregate and lightweight aggregate appear high strength of natural aggregate with high density, surface coating lightweight aggregate appear strength higher than natural aggregate. The electrical resistivity of ITZ according to the aggregate appeared difference.

A Study on the Educational Plan of Business Chinese Speaking by Using the Method of Storytelling and Role-play - Focused on Chinese Drama - (스토리텔링과 롤 플레이 기법을 통한 비즈니스 중국어 말하기 교육방안 탐색 - 드라마를 중심으로 -)

  • Li, Xiaohui;Li, Zhangpei;Park, Changun
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
    • /
    • v.9 no.5
    • /
    • pp.273-280
    • /
    • 2019
  • The main purpose of this study is to reveal the educational value of the Chinese drama and present a concrete and feasible Chinese speaking teaching-learning programme targeted at intermediate level Chinese learners through storytelling and role-play. There is some advice for Chinese speaking teaching-learning by using Chinese dramas. Firstly, applying various techniques actively such as storytelling and role play, not only could it help to correct Chinese speaking pronunciation, but it could also help students to make up and express their ideas as free as possible. Secondly, it's necessary to accord with the teaching objectives of Chinese speaking, students' actual level and requirements to select Chinese dramas as Chinese speaking teaching-learning materials. Thirdly, it's noteworthy that teachers should select Chinese dramas with various genres or theme according to social development to promote the fun of class and maximize the educational value of Chinese dramas as teaching-learning materials.

Flexible Unit Floor Plan of Off-Site Construction Housing Considering Long-Lasting Housing Certification System (장수명주택 인증을 고려한 OSC공법 주택의 가변형 평면계획 연구)

  • Lee, Ji-Eun;Roh, Jeong-Yeol;Kwon, Soo-Hye;Kim, Seung-Mo
    • Land and Housing Review
    • /
    • v.12 no.4
    • /
    • pp.103-117
    • /
    • 2021
  • With the current rapid changes in population and technology, the long-lastig housing certification system is a means of prolonging the physical and functional lifespan of a building. The certification requires differentiation between the structure and infill elements to allow for variability and ease of repairs. This works well with prefabricated houses so this study investigated the possibility of applying the long-lastig housing certification requirements to apartment construction using off-site construction (OSC) methods focused on the installation of bathrooms (plumbing and toilet) that differ from the traditional wet method. This study examined three different sized floor plans at 22 m2, 46 m2, and a combined one resulting in 69 m2. The larger 69 m2 plan utilized a removeable non-load bearing wall to increase flexibility in the layout of the floorplan. The apartments are constructed of steel reinforced concrete composite columns on a 9 m × 10.5 m grid with integrated slabs. The exterior and interior infill walls are all non-load bearing with some containing plumbing. This separation of the structure and infill walls can help meet some of the criteria in the long-lastig housing certification, particularly with the ease of repairs. Technologies that facilitate the replacement of infill elements that contain plumbing and other building services can benefit the nation by reducing carbon emissions and therefore tax incentives should be introduced to increase the adoption of the proposed construction methods.

A Study of Minimum Reinforcement Ratio of Singly Reinforced Beamy (단철근 보의 최소철근비에 대한 고찰)

  • Choi, Seung-Won
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.22 no.4
    • /
    • pp.396-402
    • /
    • 2021
  • A cross section in RC flexural members must be designed to satisfy flexural strength and ductility requirements simultaneously. In design provisions, ductile behavior is ensured by a sufficient reinforcement ratio or depth of the neutral axis. If the reinforcement ratio is less than the balanced reinforcement ratio, ductile behavior is secured, and this value is theoretically the maximum reinforcement ratio. But for a cross section with less steel, brittle failure can occur regardless of ductile behavior because of unqualifying a cracking moment. Recently, designs with a minimum steel ratio have been increasing along with the use of high-strength material, so in design provisions, a minimum amount of reinforcement is suggested. In the KCI(2012) standard, a minimum amount of reinforcement was suggested in terms of strength of steel and concrete. But in the revised KCI(2017) standard, a minimum amount of reinforcement was suggested by a relationship between the design flexural strength and cracking moment indirectly. This code can reflect the effect of cover thickness, but a material model must be defined. Therefore, the minimum amount of reinforcement in KCI(2012) and KCI(2017) was examined, and a rational review method was studied by parametric analysis.

A Study on Practical Recognition about Rights Advocacy of Social Workers in Disabled Welfare Centers (장애인복지관 사회복지사의 권리옹호에 관한 실천적 인식연구)

  • Lee, Se-Hee;Choi, Yun-young
    • Journal of Convergence for Information Technology
    • /
    • v.8 no.6
    • /
    • pp.265-271
    • /
    • 2018
  • Recently, rights advocacy in disabled welfare centers is one of the most important estimation and also transition of paradigm. However it is difficult to define rights advocacy specifically, so each disabled welfare center goes to conceptualize rights advocacy based on practical experiences. Study of practical recognition of the advocacy rights of social workers in disabled welfare centers provides greater foundation to establishing specific concept and direction of rights advocacy. Method of this research is analysis of metaphors, figuring out concepts and perception of social workers through survey. Analysis of metaphors is a method of analyzing a person's perception in specific context and situation by providing a concrete explanation of new thing, that is, basis of metaphor and analyzing it later. As a result of this research, it is shown that ideological type(necessary thing) and practical type(being together) are the perceptions about rights advocacy of social workers, and rights advocacy is recognized as 'practical concept' which plan and provide direct service at fields. According to these results, policy and environment should be constructed to provide advocacy services at welfare fields, reflecting these perceptions of social workers. Also this should be reflected on practical fields for them to learn appropriately and practice rights advocacy.