• Title/Summary/Keyword: specific absorption rate

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An Experimental Study on Method of Packaged Dry Combined Materials for Concrete using Powder Admixture (분말혼화제를 사용한 콘크리트 포장(包裝)화에 관한 실험적 연구)

  • Han Da Hee;Nam jung Min;Park Hee Gon;Cho Sang Young;Lee Young Do;Jung Sang Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.624-627
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    • 2004
  • Most concrete is recently made of an aggregate which is properly absorbed, and carried in it according to its capability at every fields. We have been close to demand new capability of high flowing and enduring for specific concretes. That is difficult to cope with claiming the efficiency on deterioration from lack of a high Quality aggregate. Therefore, For solving the problems we apply to method of packaged dry combined materials for concrete using dried materials. That is to say that it is a kind of making into an instant. In this study, There is a purpose to present fundamental data, comparing and analyzing a phenomenon of aggregate's absorption following the rate of adding water, for using existing materials.

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A Study on a Remedy of Telangiectasia using Electromagnetic Waves (전자파를 이용한 모세혈관 확장증 치료에 관한 연구)

  • Kim, Wang-Hyun;Cho, Jei-Won;Kwon, Do-Sung;Chung, Young-Seek;Cheon, Chang-Yul
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1570_1571
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    • 2009
  • 본 논문에서는 초고주파를 이용하여 하지정맥류(Varicose vein)의 초기증상인 모세혈관 확장증(Telangiectasia)을 치료하는 데에 목적을 두었다. 유전율 차이에 따라 전자파(Electromagnetic waves)를 흡수하는 양이 다르다는 것을 전제하에 다리 모델링에 필요한 피부, 혈관, 혈액, 피하조직의 유전율을 구하였고, 혈관과 피부의 유전율에 비해 혈액의 유전율이 높다는 것을 통해 다른 조직에 비해 혈액의 전자파 흡수율이 높다는 것을 확인하였다. 피부의 구조와 유전율을 이용하여 모델링 한 후, 시뮬레이션을 통해 SAR(Specific Absorption rate)분포를 확인하였다.

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A Fundamental Study on Physical Properties of Concrete with Packaged Dry Combined Materials (혼합건식 포장 콘크리트의 물리적 특성에 관한 기초적 연구)

  • Kim Han Sik;Han Da Hee;Park Moo Young;Kim Woo Jae;Lee Young Do;Jung Sang Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.735-738
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    • 2005
  • Most concrete is recently made of an aggregate which is properly absorbed, and carried in it in order to do capability at every fields. We have been close to demand new capability of high flowing and enduring for specific concretes. That is difficult to cope with claiming the efficiency on deterioration from lack of a high quality aggregate. Therefore, For solving the problems we apply to a packing method for using dried materials. That is to say it is a kind of making into an instant. In this study, There is a purpose to present fundamental data, comparing and analyzing a phenomenon about aggregate's absorption following the rate of adding water, for using existing materials.

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Investigation of Validity of Exposure Limits for Electromagnetic Field in RF Band (RF 대역 전자계 노출기준의 타당성에 관한 연구)

  • 백정기
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.4
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    • pp.520-529
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    • 1999
  • Exposure limits for human protection are determined by converting basic limits for induced current, SAR(specific absorption rate), or power density, which are based upon biological effects, to measurable electric and magnetic field intensities. As a part of studies for the establishment of a domestic guideline for exposure limits, the validity of the exposure limits of five representative guidelines or standards, which are derived from basic limits, are investigated in this paper, using the published results for coupling mechanisms of electromagnetic field into a human body, and problems in each standard are analyzed and compared with each other.

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A Fundamental Study on Method of Packaged Dry Combined Materials for Concrete - based on physical properties of concrete according to adding-water ratio - (건조된 콘크리트 재료의 포장화에 관한 기초적 연구 -가수율에 따른 콘크리트의 기초물성을 중심으로-)

  • 한다희;황병준;김제섭;박희곤;이영도;정상진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.493-496
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    • 2003
  • Most concrete is recently made of an aggregate which is properly absorbed, and carried in it in order to do capability at every fields. We have been close to demand new capability of high flowing and enduring for specific concretes. That is difficult to cope with claiming the efficiency on deterioration from lack of a high quality aggregate. Therefore, for solving the problems we apply to a packing method for using dried materials. That is to say it is a kind of making into an instant. In this study, There is a purpose to present fundamental data, comparing and analyzing a phenomenon about aggregate absorption following the rate of adding water, for using existing materials.

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Performance Analysis of DS/CDMA System Considering Specific Absorption Rate in the Human (인체에서의 전자파 흡수율을 고려한 DS/CDMA 시스템의 성능 분석)

  • 조광윤;강희곡;조성언;조성준
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2000.11a
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    • pp.264-267
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    • 2000
  • 본 논문에서는 이동국의 안테나로부터 방사되는 전파의 일부가 인체에 흡수되므로써 기지국에서 수신되는 E$_{b}$ N$_{t}$의 감소에 대해 조사하였고, 감소된 E$_{b}$ N$_{t}$를 기준으로 하여 전파의 인체 흡수가 DS/CDMA BPSK 시스템의 성능에 미치는 영향을 분석하였다. 분석 결과, 인체에서의 흡수가 30[%]에서 40[%]로 증가할 때 기지국에서의 E$_{b}$ N$_{t}$, 값이 약 0.5 [dB] 정도 감소함을 알 수 있으며, 40 [%]에서 50[%]로 중가할 때에는 약 0.6 [dB] 정도 감소함을 알 수 있었다. 또한 시뮬레이션을 통해 사용자 수가 15 명일 때 약 2.5 [dB]의 E$_{b}$ N$_{t}$ 값에서 음성 서비스가 가능하다는 것을 알 수 있었다. 그리고 이러한 E$_{b}$ N$_{t}$ 값을 만족시키려면, 흡수율이 10 [%] 증가 할 때마다 안테나 방사 전력을 약 20 [mW] 이상 증가시켜야 한다는 것도 알아내었다. 것도 알아내었다.

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Reclamation of Inorganic wastes to Artificial Lightweight Aggregates

  • Chang, Hui-Lan;Liaw, Chin-Tson
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.565-570
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    • 2001
  • Annually, Taiwan generates approximately 2 million tons of inorganic wastes in the form of sludge, fly ash and slug. To increase the added value of waste and maintain the increasingly insufficient supply of natural gravel, large public construction projects account for this large demand each year. future architectural trends are leading towards high-rise buildings. In light of the above, Center for Environmental, Safety and Health Technology Development, Industrial Technology Research Institute has developed the technology of manufacturing cold-bonding, sintering and bloating types of lightweight aggregates with a specific gravity ranging between 0.7~1.7, water absorption rate < 30%. The lightweight aggregate verified by physical property tests can be used as a substitute for the natural aggregate, which generally appears in replacing gravel in concrete, soundproofing and heat insulation materials. Doing so would not only moderate waste disposal problems, but also achieve the goal of resource recovery.

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A Fundamental Study on Producing Concrete for Using Dried Materials (건조된 재료를 사용한 콘크리트 제조에 관한 기초적 연구)

  • 한다희;남정민;박희곤;정근호;이영도;정상진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.769-774
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    • 2003
  • Most concrete is recently made of an aggregate which is properly absorbed, and carried in it in order to do capability at every fields. We have been close to demand new capability of high flowing and enduring for specific concretes. That is difficult to cope with claiming the efficiency on deterioration from lack of a high quality aggregate. Therefore, For solving the problems we apply to a packing method for using dried materials. That is to say it is a kind of making into an instant. In this study, There is a purpose to present fundamental data, comparing and analyzing a phenomenon about aggregate's absorption following the rate of adding water, for using existing materials.

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Electrochemical Behaviors of Chromium Electrodeposition from Chromium(III) Sulfate complexes Aqueous Solutions (황산크륨(III) 착화합물 스용액으로부터의 크롬전착반응의 전기화학적 거동)

  • 고석수;송진태
    • Journal of the Korean institute of surface engineering
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    • v.21 no.4
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    • pp.160-167
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    • 1988
  • Electrochemical behaviors od chromium electrodeposition from 0.05M chromium (III) sulface complexes in aqueous solutions using sodium formate-glycine mixtures as a complexing agent were studied. In the cathodic current-potential cures, it is found that the intial limiting current of Cr(III) is proportional to square root of scan rate and activiation energy from Arrhenius plot is s obtained 3.05Kcal/mol. From this results, the reaction is considered, Cr3++e longrightarrow Cr2+, which is controlled diffusion of Cr (III). It is also found that the chromium is deposited when the potential reaches to hydrogen evolution potential. Effects of NaSCN as a catalyser in the electrolyte were investigated NCS- anion seems to react strongly by specific absorption at the inner HelmholtZ layer, so that, it is considered to suppress the electrodeposition reaction reaction for chromjum, and also it is considered multipe-bridge such as Cr(III)-NCS---M(M;cathode).

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Analysis on Component and Mechanical Characteristics for Crushed Stone of Excavated Rocks(II) (지하굴착암 쇄석의 성분 및 역학적 특성 분석(II))

  • 이상호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.1
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    • pp.83-90
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    • 2003
  • In order to offer some fundamental data for recycling the excavated rocks, the component and mechanical characteristics was investigated for the excavated rocks, by means of X-ray diffraction analysis, strength test, slacking test and abrasion test were performed. It appeared that the unconfined compressive strength and the elastic wave velocity were the highest in the sound rock. The dissipation rate by stability tests was found to be high in the case of the slacking index of 98% because of more bedding and more clay minerals. The apparent specific gravity of some crushed aggregate was decreased because they included easily weathered minerals while both the absorption and the abrasion were increased. The results in this study were expected to be useful for recycling the excavated rocks as a concrete aggregate.