• Title, Summary, Keyword: Environmental Condition

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A Study on the Operational Environment of Signalling System (신호시스템 운용환경에 관한 연구)

  • 정의진;이종우;황종규
    • Proceedings of the KSR Conference
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    • pp.164-171
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    • 2000
  • To determine operational requirement, the environmental condition for an equipment must be investigated, and to certify equipment's normalized operation, appropriate test must be carried out under the considered environmental condition. The actual environmental conditions to which equipment is likely to be exposed are normally complex and will comprise a number of environmental factors and corresponding parameters, When defining the environmental conditions for a certain application it is, therefore, necessary to list the factors involved and select the appropriate severity. For the preparation to determine operational requirement, environmental condition of equipment is investigated. The environmental condition is structured in two separate such as requirements, guidance and test specifications. For the first step, environmental requirements are considered

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Development of Ecological Sound Proof Wall by the germination of plant species at different Environmental Condition (생태방음벽에 개발에 사용되는 식물종의 성장에 관한 연구)

  • Bashyal, Sarita;Cho, Hae-Yong;Han, Say-Gwon
    • Proceedings of the KAIS Fall Conference
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    • pp.100-102
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    • 2009
  • Effect of temperature, pH and soil depth on germination of Dianthus chinensis, Dianthus barbatus, and Perennial pennant were investigated in growth chamber and soil condition at the ratio of 7:3 (natural soil and organic soil) in laboratory condition. the optimum temperature for seed germination was recorded for $20^{\circ}C-\;25^{\circ}C$. Maximum germination was observed for Dianthus barbatus (76%) where as in soil condition Perennial pennant (51%) showed maximum germination at 1 cm soil depth. Similarly, optimum pH for seed germination was at pH 6 in all the species. So in lower pH (at pH4) seed germination was inhibited. Germination of these selected species at different environmental condition help to construct the ecological sound proof wall to mitigate the noise especially in urban areas.

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An investigation of air condition in Cheong Ju & Je Cheon City Area (청주.제천시지역 대기실태 조사)

  • 김재용;김창영
    • Journal of environmental and Sanitary engineering
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    • v.17 no.4
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    • pp.19-28
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    • 2002
  • We concluded to analysis the air condition of city area in the Chungbuk province by pollutant concentration and weather survey data to used from the data of Air Pollution Monitoring System until September in 2002 from 1998. The results of this study is to prove out the pollutional phenomena and effects in the each area of Cheong-ju & Je-cheon city and to provide the basic data of comfortable environmental condition in the province. Also, we provide environmental statistical dat for the inhabitants in the province as the present condition analysis of air pollution. We got the conclusion of having air condition as clear state in Chungbuk Province from our analytical results.

Effect of Load Condition on Turning Performance of a VLCC in Adverse Weather Conditions

  • Zaky, Mochammad;Yasukawa, Hironori
    • Journal of Advanced Research in Ocean Engineering
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    • v.4 no.2
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    • pp.53-65
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    • 2018
  • The load condition significantly influences ship maneuverability in calm water. In this research, the effect of the load condition on turning performance of a very large crude oil carrier (VLCC) sailing in adverse weather conditions is investigated by an MMG-based maneuvering simulation method. The relative drift direction of the ship in turning to the wave direction is $20^{\circ}-30^{\circ}$ in ballast load condition (NB) and full load condition (DF) with a rudder angle $35^{\circ}$ and almost constant for any wind (wave) directions. The drifting displacement in turning under NB becomes larger than that under DF at the same environmental condition. Advance $A_d$ and tactical diameter $D_t$ become significantly small with an increasing Beaufort scale in head wind and waves when approaching, although $A_d$ and $D_t$ are almost constant in following wind and waves. In beam wind and waves, the tendency depends on the plus and minus of the rudder angle.

Effects of rock-support and inclined-layer conditions on load carrying behavior of piled rafts

  • Roh, Yanghoon;Kim, Garam;Kim, Incheol;Lee, Junhwan
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.363-371
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    • 2019
  • In this study, the load carrying behavior of piled rafts installed in inclined bearing rock layer was investigated for rock-mounted and -socketed conditions. It was found that settlements induced for an inclined bearing rock layer are larger than for a horizontal layer condition. The load capacity of piled rafts for the rock-mounted condition decreased as rock-layer inclination angle (${\theta}$) increased, while vice versa for the rock-socketed condition. The load capacities of raft and piles both decreased with increasing ${\theta}$ for the rock-mounted condition. When bearing rock layer was inclined, loads carried by uphill-side piles were greater than those by downhill-side piles. The values of differential settlements of rock-mounted and -socketed conditions were not significantly different whereas slightly higher for the rock-socketed condition. The values of load sharing ratio (${\alpha}_p$) and its variation with settlement were not markedly changed by the inclination of bedrock. It was shown that ${\alpha}_p$ for piled rafts installed in rock layer was not affected by ${\theta}$ whereas actual loads carried by raft and piles may vary depending on the pile installation and rock-layer inclination conditions.

Analysis of Construction Condition and Environmental Effect of Deep Soil Mixing (심층혼합처리 공법의 시공조건 및 환경적 영향 분석)

  • Cho, Jin-Woo;Lee, Yong-Soo;Yu, Jun;Shin, Won-Jae
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.1155-1158
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    • 2006
  • This paper presents a study on the construction condition and environmental effect of deep soil mixing. Construction condition means the difference in unconfined compressive strength with respect to the depth and location of samples. Environmental effect means alkalinity diffused from soil stabilizer. The experimental results indicate that the unconfined compressive strength vary with respect to the depth, and doesn't show consistency pattern. So, in field application we must decide a mixing ratio enough to satisfy the least unconfined compressive strength. The difference in unconfined compressive strength with respect to the location of samples is negligible. The generation of alkalinity from soil stabilizer is reduced by permeating in non-improved soil and it is expected that the diffusion of alkalinity has no environmental effect on soil and ground water.

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The evaluation of pollution level and release characteristics by inner productivity in the sediment of lake (호소 퇴적물 내부생산성 오염도 영향 평가 및 용출특성에 관한 연구)

  • Lee, Sang Eun;Choi, I Song;Lee, Sang Keun;Lee, In Ho;Oh, Jong Min
    • Journal of Environmental Impact Assessment
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    • v.21 no.1
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    • pp.81-91
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    • 2012
  • In this study, it is grasped the status of nutrients through an investigation of release characteristics and physicochemical properties of sediments on reservoir. And then the effect of sediments is evaluated on the water quality in reservoir. In the results of physicochemical analysis, the pollution level of midstream is the highest, which shows the traits that the water is more deeper and takes place a deposition consistently. Then, the pollution level of upstream is higher than downstream's because inflow has influence on the upstream directly. The downstream is located near tidal gate so that the soil particles can be moved easily and are difficult to be deposited due to the distribution of seawater by control of tidal gate. Therefore, the downstream is showed the lowest pollution level than the others. Also, the concentration of SOD(Sediment Oxygen Demand) in the upstream which is influenced on the effect of inflow is highest than the others. When it analyzes under anaerobic and aerobic condition to understand the release characteristic of sediment, it shows that the release rate is low or negative under the aerobic condition. Whereas the release rate is usually positive under the unaerobic condition relatively. According to these results, it is necessary to maintain the proper environmental factors of water body for decreasing the release rate of sediment. Because the release rate is changeable under the different condition of water body. Therefore, proper strategies are required for increasing the self-purification of water as well as keeping the aerobic condition of sediment and managing a sediment layer directly to control the inner-pollution by the sediment of reservoir.

A Study of Spraying Curing Compound for Concrete Pavement Considering Environmental Condition in Tunnel (터널내 환경을 고려한 콘크리트 포장의 양생제 살포기준 연구)

  • Ryu, SungWoo;Kwon, OhSun;Song, GeoRuemSoo;Lee, MinKyung;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.16 no.3
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    • pp.51-57
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    • 2014
  • PURPOSES : This study is to suggest tunnel length to spray curing compound, based on the field tests. METHODS : At first field test, length from the entrance of tunnel to wet wall was checked by visual survey. The second and third test, various sensors were installed in concrete or in tunnel, such as RH sensor, temperature sensor, portable weather station and etc.. And also, test for bleeding and retaining water of concrete were conducted to evaluate environmental effect on concrete pavement. RESULTS : The result of the field experiment for tunnel length to spray curing compound indicates that length changes depending on tunnel length, season, and location. Environmental condition of a short tunnel was not much different between location near entrance and at center of tunnel. However, in case of a medium and long tunnel, effect of outside environmental condition decreased, when location moved into tunnel center of it. CONCLUSIONS : From the testing results, it can be proposed that optimum tunnel length to spray curing compound is 60m for a medium and long tunnel, and whole length for a short tunnel.

Power Density Enhancement of Anion-Exchange Membrane-Installed Microbial Fuel Cell Under Bicarbonate-Buffered Cathode Condition

  • Piao, Jingmei;An, Junyeong;Ha, Phuc Thi;Kim, Taeyoung;Jang, Jae Kyung;Moon3, Hyunsoo;Chang, In Seop
    • Journal of Microbiology and Biotechnology
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    • v.23 no.1
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    • pp.36-39
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    • 2013
  • We introduce a high-performance microbial fuel cell (MFC) that was operated using a 0.1M bicarbonate buffer as the cathodic electrolyte. The MFC had a 136.42 $mW/m^2$ maximum power density under continuous feeding of 5 mM acetate as fuel. Results of the electrode potential measurements showed that the cathode potential of the bicarbonate-buffered condition was higher than the phosphate-buffered condition, although the phosphate condition had less interfacial resistance between the membrane and electrolyte. Therefore, we posit here that the increased power of the bicarbonate-buffered MFC may be caused by the higher cathode potential rather than by the interfacial membrane-electrolyte resistance.

A Study on the Environmental Improvement in the Interior Construction Fields with the check-list (실내건축의 작업환경 개선을 위한 기본적 관리방안에 관한 연구)

  • 이용의
    • Korean Institute of Interior Design Journal
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    • no.9
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    • pp.10-17
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    • 1996
  • With the ever-increasing important of high-speed information in society as we move towards the 21 st century. Interior design and it's working condition has been changed a great deal included a sort of each special character and make a difference against the others. It used to be find a great poles asunder of worker's safety and project quality according to the environmental dimension of interior construction field as if they should be a pleasantness or poor condition. This research aimed to improvement of environmental construction field of interior with construction engineers and particular interior labors in 4 phases as : ⅠThe preparatory phase : -Secure a Budget, Environmental safety supervisor -Fix of Design quality, Construction period. -Choice of Construction method, Sub constructing Ⅱ. Starting work phase ; -Capacity , Safety of temporary power line. -Carriage, Stock of Material -Safety of Electronic tools, -Personal protector. Ⅲ. Working period ; -Ventilation, I illumination of working place. -Measurement of environmental working condition Ⅳ.Finish working phase ; -Analysis of measurement data. -Evaluation and making up for the weak point. -Keeping data.

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