• Title, Summary, Keyword: 가역성

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Porous Glass Electroosmotic Pumps Reduced Bubble Generation Using Reversible Redox Solutions (가역적 산화환원반응 용액을 이용하여 기포 발생을 줄인 다공성 유리막 전기삼투 펌프)

  • Kwon, Kil-Sung;Kim, Dae-Joong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.7
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    • pp.753-757
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    • 2012
  • This paper presents the performance of a porous glass electroosmotic pump using an iodide/triiodide aqueous solution. The porous glass electroosmotic pump is characterized in terms of the flow rate and voltage. The flow rate and voltage increases linearly with current. A point where the voltage significantly increases is observed owing to an excess in redox capacity. The transition time monotonously decreases with current. The normalized flow rate (flow rate per membrane surface area) is used to compare previous results with results obtained in this study. The normalized flow rate of porous glass frits is three times higher than that of Nafion 117.

Irreversible Hemorrhagic Complication of Recurrent Posterior Reversible Encephalopathy Syndrome in a Patient with Systemic Lupus Erythematosus (전신성 홍반성 낭창 환자에서 재발한 가역적 후두부 뇌병증 증후군의 비가역적 출혈성 합병증)

  • Kim, Ho Kyun;Lee, Hui Joong;Shin, Kyung Min
    • Investigative Magnetic Resonance Imaging
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    • v.17 no.2
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    • pp.144-148
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    • 2013
  • Although most cases of posterior reversible encephalopathy syndrome (PRES) are reversible, irreversible lesions as a form of hemorrhage or infarction have been described. PRES as a complication of systemic lupus erythematosus (PRES-SLE) is associated with hypertension or use of immunosuppressive agents. We present a case of recurrent atypical PRES-SLE, which showed restricted diffusion in the first manifestation of SLE, resulted in parenchymal hemorrhagic transformations in the recurrent episode.

Conservation & restoration works for ceramic objects of Hanam Museum of History (하남 역사박물관 소장 도.토기(陶.土器) 보존처리)

  • Mun Seong-Hui;Seo Jeong-Ho;Kim Se-Min
    • 한국문화재보존과학회:학술대회논문집
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    • pp.200-206
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    • 2005
  • 보존 처리된 유물은 경기도 하남시의 발굴현장에서 수습된 도토기로, 박물관의 소장유물로써 지역사(地域史)의 한 단면을 보여줄 수 있는 자료로 활용 가능성이 있을 것으로 판단되었고, 유물의 상태를 고려한 보존처리작업이 계획되었다. 보존처리작업은 가역성(可逆性)과 경제성에 중점을 두어, 박물관에서 이미 책정된 보존처리예산의 한도 내에서 선택할 수 있는 알맞은 약품과 재료를 선택하여, 복원작업이 필요한 부위 역시 추후 재처리작업이 필요할 때 해체가 용이한 기법을 이용하였다.

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Performance Enhancement through Row-Column Cross Scanning in Differential Histogram-based Reversible Watermarking (차이값 히스토그램 기반 가역 워터마킹의 행열 교차 스캐닝을 통한 성능 향상 기법)

  • Yeo, Dong-Gyu;Lee, Hae-Yeoun;Kim, Byeong-Man
    • The KIPS Transactions:PartB
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    • v.18B no.1
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    • pp.1-10
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    • 2011
  • Reversible watermarking inserts watermark into digital media in such a way that visual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. It has various applications, where high capacity and high visual quality are major requirements. This paper presents a new effective multi-round embedding scheme for the differential histogram-based reversible watermarking that satisfies high capacity requirements of the application. The proposed technique exploits the row-column cross scanning to fully utilize the locality of images when multi-round embedding phase to the message inserted image. Through experiments using multiple kinds of test images, we prove that the presented algorithm provides 100% reversibility, effectiveness of multi-round embedding, and higher visual quality, while maintaining the induced-distortion low.

Degradation Evaluation of Mechanical Properties for 12Cr Ferrite Heat Resisting Steel by Reversible Permeability (가역투자율에 의한 12Cr 페라이트 내열강의 역학적 물성의 열화평가)

  • Ryu, Kwon-Sang;Kim, Min-Gi;Nahm, Seung-Hoon;Kim, Chung-Seok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.30 no.5
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    • pp.464-470
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    • 2010
  • The integrity of the industrial equipment in use under high temperature and high pressure must be assessed by regularly measuring the degraded mechanical properties during service time. In order to nondestructively monitor the degraded mechanical properties of industrial equipment, a measuring method of the reversible permeability(RP) using surface type probe is presented. The method for measuring the RP is based on that RP is the differential value of hysteresis loop. The RP is exactly the foundation hatmonics induced in a detecting coil measured by lock-in amplifier tuned to a frequency of the alternating perturbing magnetic field. The peak of RP is measured around the coercive force. Steel material used in this work was 12Cr ferritic heat resisting steel. The eleven kinds of samples aged during different times under same temperature ($700^{\circ}C$) were prepared. Peak interval of reversible permeability(PIRP), Vickers hardness, and tensile strength measured for the aged samples decreased abruptly for short aging time (below 500 h), but the change became small at a long aging time. Vickers hardness and tensile strength linearly decreased as RIRP decreased, so the degraded mechanical properties of 12Cr ferritic heat resisting steel could be nondestructively evaluated by measuring RIRP.

Degradation Evaluation of 1Cr-lMo-0.25V Steel by Measuring Reversible Magnetic Permeability (가역 투자율 측정에 의한 1Cr-1Mo-0.25V 강의 열화도 평가)

  • Ryu, Kwon-Sang;Kim, Yong-Il;Nahm, Seung-Hoon;Yu, Kwang-Min;Cho, Youk;Son, De-Rac
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.5
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    • pp.445-450
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    • 2000
  • The integrity of the turbine rotors can be assessed by measuring reversible permeability and Vickers hardness of the aged rotors at service temperature. The measurement system of reversible permeability, which measured by applied alternating perturbing magnetic field, was constructed in order to evaluate material degradation, nondestructively. The test specimen was 1Cr-1Mo-0.25V steel used widely for turbine rotor material, and the specimens were prepared by the isothermal heat treatment at $630\;^{\circ}C$. The reversible permeability of the test materials were measured at room temperature. The peak interval of reversible permeability and Vickers hardness decreased with the increase of degradation. The degradation of test material may be determined nondestructively by the lineality of Vickers hardness and the peak interval of reversible permeability.

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The Complementary Role of FEV6 in Bronchodilator Reversibility Test for the Old Age (노인환자의 기도가역성 검사에서 FEV6의 보완적 지표로서의 역할)

  • Kim, Sae Hee;Lee, Yang Deok;Lee, Jung Yun;Cho, Yong Seon;Na, Dong Jip;Han, Min Soo
    • Tuberculosis and Respiratory Diseases
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    • v.61 no.3
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    • pp.227-232
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    • 2006
  • Background: In the measurement of bronchodilator reversibility, the forced expiratory volume in one second($FEV_{1}$) and the forced vital capacity(FVC) are commonly used parameters and recommended criteria for the reversibility requiring an increase of more than 200ml and 12% above the baseline, respectively. However, aged patients do not often meet the criteria of an increase in volume(>200ml) even though the medical history of that patient is adequate for asthma. This study investigated the role of the forced expiratory volume in six seconds($FEV_{6}$) in the bronchodilator reversibility test in elderly patients. Methods: A total of 236 patients more than 65 years of age with a $FEV_{1}$/FVC ratio<80% were enrolled in this study. The bronchodilator revesibility tests were examined. With the setting $FEV_{1}$ as the baseline, the patients were divided into three groups; Group I : $$FEV_{1}{\geq_-}80%$$ of the predicted value, Group II : 60%<$FEV_{1}$<80% of the predicted value, Group III : $$FEV_{1}{\leq_-}60%$$ of the predicted value. Results: Positive reversibility in the $FEV_{1}$, $FEV_{6}$, and FVC was in 33(14.0%), 49(20.8%) and 55(23.3%). However, Group III presented with reversibility in the $FEV_{1}$, $FEV_{6}$, and FVC in 15(22.4%), 30(44.8%) and 32(47.8%) respectively. Conclusions: The $FEV_{6}$ might be used as a complementary parameter in bronchodilatror reversibility in elderly patients. However, more study will be needed to determine the usefulness of $FEV_{6}$ in bronchodilator reversibility test.

A Study on the Reinforcement of the Damaged Stone Surface by Dismantling of Stone Cultural Heritages - Focusing on the Experiment of a Sublimation(Reversibility) type Consolidant - (석조문화재 해체에 따른 표면 손상부분 보강방안 연구 - 승화성(가역성) 강화처리제 적용실험을 중심으로 -)

  • Lee, Tae Jong;Oh, Hyeon Jung;Cho, Ha Jin;Kim, Sa Dug
    • Journal of Conservation Science
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    • v.31 no.4
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    • pp.351-360
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    • 2015
  • This is the result of the study on the temporary fortifier using sublimation type Consolidate is Cyclododecane to prepare plan for reinforcement of the surface part that can be damaged during the dismantling of stone cultural heritages. To supplement the disadvantages of the existing reinforcement methods using intumescent urethane foam, Cyclododecane was diluted in solvent to reinforce the surface and inside desquamation, and after dismantling the framework, it sublimated by imposing heat of about $60^{\circ}C$. Such method can guarantee the strength needed for reinforcement of the damaged surface with outstanding reversibility of Cyclododecane being entirely sublimated. But, it shows big difference of effect according to the solvent, so it shall be diluted in petroleum ether or heated in a double boiler. Therefore, considering the working conditions at the site, it seems the most appropriate to use petroleum ether double boiler heating method for injection and filling of the desquamation part and temporary reinforcement processing with Cyclododecane diluted in petroleum ether for surface spraying.