• Title/Summary/Keyword: earth-work

Search Result 622, Processing Time 0.03 seconds

A study on $CO_2$ absorption of concrete during life cycle of building (건물 생애주기 동안 콘크리트의 이산화탄소 흡수에 관한 연구)

  • Lee, Sang-Hyun;Lee, Han-Seoung;Song, Hoon
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2008.04a
    • /
    • pp.577-580
    • /
    • 2008
  • Concrete absorbs $CO_2$ in the air because of carbonation. according to rising concern for lasting earth environment efforts of reducing greenhouse gas, especially co2, are occurred whole industry throughout the world. In this paper selected one building and computed amount of production and absorbtion of co2 during its lifecycle at concrete. In computing amount of absorbtion of co2 considered amount of absorbtion according to the area of concrete changing senarioes of servicelife(40,60,80 years) and deconstruct preiod(60,40,20 years). As a result, size of concrete and maintenance period of disused concrete work increasement of $CO_2$ as main factors. We came to the conclusion that maintenance period is more important than recycle of unused concrete as a method for reducing environmental load in architectural industry.

  • PDF

Three-dimensional MHD modeling of a CME propagating through a solar wind

  • An, Jun-Mo;Inoue, Satoshi;Magara, Tetsuya;Lee, Hwanhee;Kang, Jihye;Kim, Kap-Sung;Hayashi, Keiji;Tanaka, Takashi
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.39 no.1
    • /
    • pp.70.2-70.2
    • /
    • 2014
  • We developed a three-dimensional (3D) magnetohydrodynamic (MHD) simulation code to reproduce the structure of a solar wind and the propagation of a coronal mass ejection (CME) through it. This code is constructed by a finite volume method based on a total variation diminishing (TVD) scheme using an unstructured grid system (Tanaka 1994). The grid system can avoid the singularity arising in the spherical coordinate system. In this study, we made an improvement of the code focused on the propagation of a CME through a solar wind, which extends a previous work done by Nakamizo et al. (2009). We first reconstructed a solar wind in a steady state from physical values obtained at 50 solar radii away from the Sun via an MHD tomography applied to interplanetary scintillation (IPS) data (Hayashi et al. 2003). We selected CR2057 and inserted a spheromak-type CME (Kataoka et al. 2009) into a reconstructed solar wind. As a result, we found that our simulation well captures the velocity, temperature and density profiles of an observed solar wind. Furthermore, we successfully reproduce the general characteristics of an interplanetary coronal mass ejection (ICME) obtained by the Helios 1/2 spacecraft (R. J. FORSYTH et al. 2006).

  • PDF

A Study on the Utilization of Coal Ash as Construction Materials ln Forcus on the Environmental Analysis (석탄재의 건설재료로서의 활용에 관한 연구-환경적 특성 검토를 중심으로)

  • 천병식;고용일
    • Geotechnical Engineering
    • /
    • v.11 no.2
    • /
    • pp.99-106
    • /
    • 1995
  • Although lots of experimental studies of coal ash have been performed to study the utilization as construction materials, the environmental characteristics of coal ash are still qestionable. In this study, fly ash is examined to be classified according to Korean Environmental Standard and analized whether the batch test results are within the toler trance limit when utilized or treated as reclamation and earth work materials. The batch tests was performed to examine pH and contaminant contents. Consequently, fly ash is classified as non hazardous industrial waste. The pH value shows a strong alkalinity than the tolerance limit, but it is implied that fly ash can be used to neutralize the acid ground. All other items except pH satisfy the tolerance limit, In addition, a small quantity of additives(cement) which used to improve the poor geotechnical properties of coal ash, could decrease the pH value into the tolerance limit as well as improve strengtIL durability and permeability. It is concluded that when coal ash is used properly, there is no enviormental harmfulness as construction materials.

  • PDF

A Study on the Change of Non-Working Days Based on the Rainfall in Incheon Area Using the Climate Change Scenarios (기후변화 시나리오를 활용한 인천지역 강우에 의한 작업불능일 변화 연구)

  • Jang, Junyoung;Lee, Chansik
    • Korean Journal of Construction Engineering and Management
    • /
    • v.19 no.1
    • /
    • pp.103-113
    • /
    • 2018
  • In this study, Construction work is mainly done outdoors, so earth works, reinforced concrete works, etc. are Non-Working Days to rainfall. In particular, changes in rainfall due to global warming have made air calculation more difficult. Therefore, when establishing the process plan, the change of the rainfall in the area should be identified and Non-Working Days should be calculated. In this study, the time of rainfall change point was identified using the meteorological 'observation' data from 1960 to 2016 in Incheon and RCP 4.5, 'weather forecast' data from 2018 to 2074, Year rainfall and seasonal rainfall. The results showed that rainfall changed point in 1972, 1988, 2013, 2038, 2050 and 2069. In particular, it has been found that non-working days due to rainfall has big changed point as of 2013, 2038 and 2069.

SIMULATION OF THE TISSUE EQUIVALENT PROPORTIONAL COUNTER IN THE INTERNATIONAL SPACE STATION WITH GEANT4 (Geant4를 활용한 국제우주정거장 내의 조직등가비례계수기 모의 실험)

  • Pyo, Jeong-Hyun;Lee, Jae-Jin;Nam, Uk-Won;Kim, Sung-Hwan;Kim, Hyun-Ok;Lim, Chang-Hwy;Park, Kwi-Jong;Lee, Dae-Hee;Park, Young-Sik;Moon, Myung-Kook
    • Publications of The Korean Astronomical Society
    • /
    • v.27 no.3
    • /
    • pp.81-86
    • /
    • 2012
  • The International Space Station (ISS) orbits the Earth within the inner radiation belt, where high-energy protons are produced by collisions of cosmic rays to the upper atmosphere. About 6 astronauts stay in the ISS for a long period, and it should be important to monitor and assess the radiation environment in the ISS. The tissue equivalent proportional counter (TEPC) is an instrument to measure the impact of radiation on the human tissue. KASI is developing a TEPC as a candidate payload of the ISS. Before the detailed design of the TEPC, we performed simulations to test whether our conceptual design of the TEPC will work propertly in the ISS and to predict its performance. The simulations estimated that the TEPC will measure the dose equivalent of about 1:1 mSv during a day in the ISS, which is consistent with previous measurements.

The Effect of Cooperative Learning on the Scientific Preferences of Middle School Girls (협동학습이 여중생들의 과학 선호도에 미치는 효과)

  • Cho, Kyu-Seong;Lee, Koang-Ho;Yang, Su-Mi
    • 한국지구과학회:학술대회논문집
    • /
    • 2005.02a
    • /
    • pp.193-200
    • /
    • 2005
  • I conducted a pretest on the students' preference before I incorporated Cooperative learning in five classes of second grade students, at a girl's middle school which is located in Gimje city. After ten weeks of Cooperative school work, the students took a post test with the same questions as the pretest. The result of this method greatly impacted on the change of students' scientific preference. It means that the students showed their positive awareness of and the participation in the science class in comparison with the classes before they were taught this new style of education. However it is difficult to distinguish the differences of their scientific attitude on the recognition about the scientists and the habit which they think scientifically. This resulted from a short period of ten weeks of learning which is not sufficient to carry out the study strategy effectively. Surveys of the students on Cooperative learning indicates that the middle level students prefer this method unlike the higher or lower level. I am convinced that they can learn from the students of higher level and are able to help the lower level with the interaction through Cooperative learning.

  • PDF

A Study on the Application Possibility of Green Building Design Process based on Building Information Modeling(BIM) for Sustainable Architecture (지속가능한 건축을 위한 BIM기반 친환경건축 설계프로세스 적용가능성에 관한 연구)

  • Kim, Mi-Kyoung;Jang, Won-Jun;Choi, Hyun-Ah;Jun, Han-Jong
    • KIEAE Journal
    • /
    • v.11 no.2
    • /
    • pp.113-122
    • /
    • 2011
  • About 30% of the total annual energy consumption on the earth is used in the architectural activities, including construction, maintenance management, and demonstration of a building. Also, 40% of the natural resource consumption, 50% of $CO_2$ emissions, and 20%~50% of industrial waste emissions are produced from a building. Unfortunately, the percentage of its energy consumption is staidly increasing year by year, about 8% every year, and it recently causes a sustainable architectural concept to come to the fore globally. Indeed, the importance of the sustainable architecture is increasingly becoming a worldwide trend. BIM(Building Information Modeling) is considered a new paradigm and a powerful method in building design, construction and maintenance. BIM has characteristics similar to a building's systems. All of the components in a model have a parametric relationship to each other. Understanding and capitalizing on these interrelationships typically takes numerous iterations that span multiple projects. Optimizing the integrated strategies and technologies for a high-performance, sustainable design requires a continual look at understanding how they work together to deliver the best potential. Throughout all of these concepts, we are going to be using a variety of tools that revolve around a BIM model. Some of the tools will require a heavier use of BIM than others, but all of them will utilize the model geometry you've created as part of your design. This study presents importance and validity of energy performance analyzation in the pre-design phase for the sustainable architecture with the support of Building Information Modeling (BIM) technology.

Design of the Satellite Beacon Receiver Using Array Based Digital Filter (다중배열 디지털필터를 이용한 위성비콘 수신기 설계)

  • Lee, Kyung-Soon;Koo, Kyung-Heon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.27 no.10
    • /
    • pp.909-916
    • /
    • 2016
  • The beacon receiver is an equipment which detects and measures the signal strength of transmitting satellite beacon signal. Beacon signals transmitted by satellites are low power continuous wave(CW) signals without any modulation intended for antenna steering to satellite direction and power control purposes on the earth. The beacon signal detection method using a very narrow band analog filter and RSSI(Received Signal Strength Intensity) has been typically used. However, it requires the implementation to track the frequency at the beacon receiver, thus a beacon frequency variation of the satellite due to temperature changes and long-term operation. Therefore, in this paper, the beacon signal detection receiver is designed by using a very narrow band digital filter array for a faster acquisition and SNR(Signal to Noise Ratio) method detection. For this purpose, by calculating the satellite link budget with the rain attenuation between satellite and ground station, and then extracting the received $C/N_o$ of the beacon signal, this work derives the bandwidth and the array number of the configured digital filter that gives the required C/N.

An Experimental Study of the Effect of the Test-well Arrangement on the Partitioning Interwell Tracer Test for the Estimation of the NAPL Saturation (지하수 유동 방향에 대한 관정배열이 분배추적자 시험에 미치는 영향 분석)

  • Kim, Bo-A;Kim, Yongcheol;Yeo, In Wook;Ko, Kyung-Seok
    • Journal of Soil and Groundwater Environment
    • /
    • v.19 no.3
    • /
    • pp.111-122
    • /
    • 2014
  • Partitioning interwell tracer test (PITT) is a method to quantify and qualify a site contaminated with NAPLs (Non-Aqueous Phase Liquids). Analytical description of PITT assumes that the injection-pumping well pair is on the line of the ambient groundwater flow direction, but the test-well pair could frequently be off the line in a real field site, which could be an erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair on the ambient groundwater flow direction based on the result from PITT. From the experiments, it was found that the obliqueness of the test-well pair to the ambient groundwater flow direction could affect the tracer test resulting in a decreased NAPL estimation efficiency. In case of an oblique arrangement of the test-well pair to the ambient flow direction, it was found that the injection of a chase fluid could enhance the estimation efficiency. An increase of the pumping rate could enhance the recovery rate but it cannot be said that a high pumping rate can increase the test efficiency because a high pumping rate cannot give partitioning tracers enough time to partition into NAPLs. The results have a implication that because the arrangement of the test-well pair is a controlling factor in performing and interpreting PITT in the field in addition to the known factors such as heterogeneity and the source zone architecture, flow direction should be seriously considered in arranging test-well pair.

The Development of a Bag Design Using the Yi Tribe's Traditional Patterns: Focusing on the Fabric Pattern Design (이족의 전통문양을 활용한 가방디자인 개발 연구: 패브릭 패턴 디자인을 중심으로)

  • Lee, Mokgyul;Cho, Jeansuk
    • Journal of Fashion Business
    • /
    • v.19 no.2
    • /
    • pp.149-170
    • /
    • 2015
  • The purpose of this study is to link the Yi tribe's traditional patterns to bag design. Yi tribe is a minor ethic group in China, whose traditional pattern has a high artistic value in that its shapes are diverse and each one has peculiar elegance. Traditional patterns are also indicative of spiritual dept or symbolic stories, rather than being indicative of simple formative beauty. Thus, reorganizing these patterns and applying them artistically to design- in terms of resource utilization- would be significant. Out of all of the Yi tribe's traditional patterns, the cherry blossom_(马樱花), water wave_(水波), sky father and earth mother_(天父地母), pomegranate blossom, triangle, sheep' horn, wisteria vine_(藤条), square and diaper_(四角菱形) and the zigzag_(曲折) patterns were chosen for use during the development of a bag design. This study is based upon document study, including research papers and internet web sites, the point of which was to investigate the form of the traditional patterns, and the creative design process. The design procedure includes these sub-processes: selection, arrangement and color-scheme. In the selection process, the form of the pattern was edited using Adobe Photoshop. The pattern was freely arranged to reflect various emotions. In terms of the color-scheme of the patterns, the colors used by Henri Matisse(1869-1954) in his work were selected and adapted when dyeing the patterns. Subsequently, the final design resulting from these design development processes was applied to the actual production of the bag by using canvas fabric and leather, after which the bag image was proposed using computer simulation. In conclusion, six bag designs were created using traditional patterns from the Yi tribe. Through the processes explained above, this study confirmed that traditional patterns could be widely applied as design motifs and that more sophisticated, modern, and creative designs could be developed based on traditional patterns.