• 제목/요약/키워드: Modified rate

검색결과 2,786건 처리시간 0.167초

마이크로파 조사에 따른 금속이 담지 된 활성탄의 특성 연구 (A Study on the Characteristics of Activated Carbons Supported Metal by Microwave Irradiation)

  • 김성욱;김정배;최성우
    • 한국환경과학회지
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    • 제18권5호
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    • pp.501-508
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    • 2009
  • In this study, the characteristics of granular activated carbon (GAC) supported metal was investigated in an area influenced by flame discharge and temperature variation during irradiating microwave. The modified GAC was formulated by impregnating metal hydroxides of nickel (Ni/GAC), barium (Ba/GAC), copper (Cu/GAC), zinc (Zn/GAC), cobalt (Co/GAC) and lanthanum (La/GAC). Ba/GAC was selected as it showed lack of spark discharge and temperature increasing aspects. Comparison of adsorption and desorption amount of GAC and Ba/GAC showed that adsorption and desorption rate of the GAC were higher than those of Ba/GAC. The results show that the presence of barium can decrease adsorption/desorption rate because of plugging pore of GAC. Toluene regeneration rate of Ba/GAC was better than that of GAC due to barium loading. Finally, GAC with barium can be controled a rapid increasing temperature and spark discharge, increased the regeneration rate of toluene during desorption by irradiating microwave.

Fe-18Cr-14Mn-4Ni-0.9N 고질소 내식강의 고온 석출과 변형률 속도에 따른 변형특성 연구 (Deformation behavior of the Fe-18Cr-14Mn-4Ni-0.9N high nitrogen steel under different strain rate conditions)

  • 남승만;김용석
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.421-424
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    • 2006
  • High nitrogen steels (HNS) exhibit both high strength and ductility during tensile deformation. In the present study the Fe-18Cr-14Mn-4Ni-0.9N high nitrogen steel was heat treated at $1000^{\circ}C$ and $1100^{\circ}C$ to produce $Cr_2N$ precipitates in austenite matrix and full austenite microstructures, respectively. Tensile tests of the heat treated specimens were performed at two different strain rates of 0.05/sec and 0.00005/sec. Each tensile curve of the specimens could be well characterized by the the modified Ludwik equation. Plastic deformation of the steel was adequately represented by the four parameters of the modified Ludwik equation. At 0.05/s strain rate, the specimen with the $Cr_2N$ precipitate exhibited higher strength than the full austenite specimen, while the full austenite specimen showed better mechanical properties at 0.00005/s strain rate. It was found that the $Cr_2N$ precipitates influences deformation behavior of the high nitrogen steel significantly.

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복합적층판의 층간파괴에 미치는 충격하중속도의 효과 (Effects of Impact Loading Rate on the Delamination Behavior of Composite Laminates)

  • 최낙삼
    • 대한기계학회논문집A
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    • 제23권11호
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    • pp.1886-1895
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    • 1999
  • The delamination behavior of multidirectional carbon-fiber/epoxy composite laminates under 10NA intermediate and high rates of test, up to rate of about 11.4m s has been investigated using the double cantilever beam specimens. The mode I loading under rates above l.0m/s showed considerable dynamic effects on the load-time curves and thus higher values of the average crack velocity than that expected from a simple proportional relationship with the test rate. The modified beam analysis utilizing only the opening displacement and crack length exhibited an effective means for evaluating the dynamic fracture energy $G_{IC}$. Based on the assumption of constant flexural modulus, values of $G_{IC}$ at the crack initiation and arrest were decreased with an increase of the test rate up to 5.7m/s, but the maximum $G_{IC}$ was increased at 11.4m/s.

A Study on the International Fisher Effect : An Investigation from South Korea and China

  • He, Yugang
    • 산경연구논집
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    • 제9권7호
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    • pp.33-42
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    • 2018
  • Purpose - This paper aims to verify whether the Fisher effect and the international Fisher effect are significant between China and South Korea in the long and short run, respectively. Research design, data, and methodology - The annual and monthly data, respectively, are employed to conduct an empirical estimation under the fully modified ordinary least squares(FMOLS). The nominal interest rate is treated as an independent variable. The inflation rate is treated as a dependent variable. Results - The results exhibit whenever in the long or short run, the Fisher effect exists in China and South Korea. However, the Fisher effect in South Korea is more significant than that of in China. Meanwhile, an empirical analysis is also preformed to investigate the long-run and the short-run international Fisher effect between China and South Korea. The deviation from the equilibrium relationship is that the commodity market and the Financial market have started to integrate in China. But China's integrated level proved to be relatively lower. Conclusions - To exploit that the Fisher effect and the international Fisher effect hold between China and South Korea can help both countries deal with the sufferings from integration of the commodity market and the financial market.

Prediction of shiver differentiation by the form alteration on the stable condition

  • Kim, Jeong-lae;Kim, Kyu-dong
    • International Journal of Internet, Broadcasting and Communication
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    • 제9권4호
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    • pp.8-13
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    • 2017
  • Movement technique is comprised of the movement status of the circulation differentiation rate (CDR) and rotation differentiation rate (RDR) on the shiver movement form. Condition of the differentiation rate by the shiver movement form is to be modified the teetering movement system. As to fix the movement of signal on the material of body, we compared a shiver value of the circulation differentiation rate on the circulation state. The concept of rotation differentiation rate was identified the reference of rotation differentiation signal and rotation differentiation signal by the rotation state. For detecting a alteration of the CDR-RDR of the maximum and average in terms of the movement form, and shiver movement value that was a shiver value of the top alteration of the Top-ф$_{MAX-AVG}$ with $12.80{\pm}1.27units$, that was a shiver value of the peripheral alteration of the Per-ф$_{MAX-AVG}$ with $4.38{\pm}1.15units$, that was a shiver value of the limbus alteration of the Lim-ф$_{MAX-AVG}$ with $1.65{\pm}0.25units$, that was a shiver value of the center alteration of the Cen-ф$_{MAX-AVG}$ with $0.25{\pm}0.01units$. The teetering movement will be to assess at the ability of the movement form for the control degree of differentiation rate on the CDR-RDR that was shown the circulation and rotation form by the differentiation rate system. Teetering differentiation system was modified of a form by the special movement and was included a shiver data of teetering movement rate.

등속성 에르고미터 운동을 이용한 수정된 생리적 부담 지수와 산소소비량 변화량과의 상관성 (Relationship Between Modified Physiological Cost Index for Isokinetic Ergometer Exercise Test and Oxygen Consumption)

  • 박호준;조상현;이충휘;박정미
    • 한국전문물리치료학회지
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    • 제7권2호
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    • pp.20-34
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    • 2000
  • The purpose of this study was to establish modified physiological cost index (PCI) for predicting energy consumption by heart rate (HR) at isokinetic ergometer exercise testing. The subjects were twenty-eight healthy men in their twenties. All of them performed upper and lower extremity isokinetic ergometer exercise tests which had six loads (400, 500, 600, 700, 800, and 900 kg-m/min) and five loads (400, 500, 600, 700, and 800 kg-m/min) respectively. The exercise sessions were finished when HR was in plateau. HR and oxygen consumption were determined during the final minute. Resting heart rate and oxygen consumption were used for calculating heart rate, oxygen consumption changes and modified PCI. Regression analysis established the relationship between each variable to work load, HR and oxygen consumption. The results were as follows: 1) In the lower extremity ergometer exercise test, oxygen consumption increased continuously as work load increased, but in the upper extremity ergometer test, oxygen consumption only increased until work load was 700 kg-m/min. 2) HR increased as work load increased in both exercise tests, but in the upper extremity ergometer test, HR decreased from the 700 kg-m/min. 3) The modified PCI increased as work load mcreased until the 700 kg-m/min point in the lower extremity ergometer test and until the 500 kg-m/min point in the upper extremity ergometer test when it started to decrease in both tests. 4) In the lower extremity ergometer exercise test, regression analysis established the relation as $dVO_2$ = -.0215HR - .2141 where $dVO_2$ is given in l/min and HR in beat/min ($R^2$ = .2677, p = .000). ln the upper extremity ergometer exercise test. regression analysis established the relation as $dVO_2$ = -.0115HR + .2746 ($R^2$ = .1308, p = .000). The results of this study were similar to previous studies but were different under high work load conditions. So modified PCI should be used with only low intensity work load testing. Subjects for upper extremity ergometer exercise testing should complete a prescribed training course prior to testing, and only low intensity work load should be used for safety considerations.

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Comparative Analysis of the Physical and Biochemical Properties of Light-cure Resin-modified Pulp Capping Materials

  • Tae Gyeom Kim;Jongsoo Kim;Joonhaeng Lee;Jisun Shin;Mi Ran Han;Jongbin Kim;Yujin Kim;Jae Hee Park
    • 대한소아치과학회지
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    • 제51권2호
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    • pp.149-164
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    • 2024
  • This study compared the solubility, water absorption, dimensional stability, release of various ions (hydroxyl, calcium, sulfur, strontium, and silicon), and cytotoxicity of light-cured resin-modified pulp-capping materials. Resin-modified calcium hydroxide (Ultra-blendTM plus, UBP), light-cured resin-modified calcium silicate (TheraCal LCTM, TLC), and dual-cure resin-modified calcium silicate (TheraCal PTTM, TPT) were used. Each material was polymerized; solubility, 24-hour water absorption, and 30- day dimensional stability experiments were conducted to test its physical properties. Solubility was assessed according to the ISO 6876 standard, and 24 hours of water absorption, 30 days of dimensional stability were assessed by referring to the previous protocol respectively. Eluates at 3 and 24 hours and on 7, 14, and 28 days were analyzed according to the ISO 10993-12 standard. And the pH, Ion-releasing ability, cell proliferation rate, and cell viability were assessed using the eluates to evaluate biochemical characteristics. pH was measured with a pH meter and Ion-releasing ability was assessed using inductively coupled plasma atomic emission spectrometry (ICP-AES). Cell proliferation rate and cell viability were assessed using human dental pulp cells (hDPCs). The former was assessed by an absorbance assay using the CCK-8 solution, and the latter was assessed by Live and Dead staining. TPT exhibited lower solubility and water absorption than TLC. UBP and TPT demonstrated higher stability than TLC. The release of sulfur, strontium, calcium, and hydroxyl ions was higher for TLC and TPT than for UBP. The 28-day release of hydroxyl and silicon ions was similar for TLC and TPT. TLC alone exhibited a lower cell proliferation rate compared to the control group at a dilution ratio of 1 : 2 in cell proliferation and dead cells from Live and Dead assay evaluation. Thus, when using light-cure resin-modified pulp-capping materials, calcium silicate-based materials can be considered alternatives to calcium hydroxide-based materials. Moreover, when comparing physical and biochemical properties, TPT could be prioritized over TLC as the first choice.

Modified Multi-Chaotic Systems that are Based on Pixel Shuffle for Image Encryption

  • Verma, Om Prakash;Nizam, Munazza;Ahmad, Musheer
    • Journal of Information Processing Systems
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    • 제9권2호
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    • pp.271-286
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    • 2013
  • Recently, a pixel-chaotic-shuffling (PCS) method has been proposed by Huang et al. for encrypting color images using multiple chaotic systems like the Henon, the Lorenz, the Chua, and the Rossler systems. All of which have great encryption performance. The authors claimed that their pixel-chaotic-shuffle (PCS) encryption method has high confidential security. However, the security analysis of the PCS method against the chosen-plaintext attack (CPA) and known-plaintext attack (KPA) performed by Solak et al. successfully breaks the PCS encryption scheme without knowing the secret key. In this paper we present an improved shuffling pattern for the plaintext image bits to make the cryptosystem proposed by Huang et al. resistant to chosen-plaintext attack and known-plaintext attack. The modifications in the existing PCS encryption method are proposed to improve its security performance against the potential attacks described above. The Number of Pixel Change Rate (NPCR), Unified Average Changed Intensity (UACI), information entropy, and correlation coefficient analysis are performed to evaluate the statistical performance of the modified PCS method. The simulation analysis reveals that the modified PCS method has better statistical features and is more resistant to attacks than Huang et al.'s PCS method.

노치부를 가진 Glass/Epoxy 복합재료의 노치강도 평가와 불안정 파괴조건 (The Notched Strength and Fracture Criterion in Plain Woven Glass/Epoxy Composites With a Crack)

  • 김정규;김도식
    • 한국해양공학회지
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    • 제7권2호
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    • pp.57-67
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    • 1993
  • The fracture behavior of plain woven glass/epoxy composite plates with a crack is investigated under static tensile loading. It is shown in this paper that the characteristic length associated with the point stress criterion depends on the crack length. To predict the not ched tensile strength, the point stress criterion proposed by Whitney and Nuismer are modified. An excellent agreement is found between the experimental results and the analytical prediction of the modified point stress criterion. The condition of unstable crack growth in the presence of a per-existing flaw(machined notch) is examined by means of the maximum stress intensity factor $K_max$ using maximumload P$_max$. The values of $K_max$ evaluated from energy release rate G$_max$(the compliance me thod) indicate a wide difference. Therefore in regard to anisotropy and heterogeneity of the composite materials studied, the modified shape correction factor f(a/W) is obtained. $K_max$evaluated by the compliance method a little or insignificantly depends on the initial crack length a, the specimen thickness B, the crack angle .theta. and the specimen geometry.

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치근피개술의 임상적 효과 비교 (A Comparison of Clinical Effect for Root Coverage)

  • 한종수;홍기석;정진형;임성빈
    • Journal of Periodontal and Implant Science
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    • 제38권3호
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    • pp.483-492
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    • 2008
  • Purpose: The purpose of this study was to compare clinical effect of the Langer & Langer technique, the modified Langer & Langer technique and Bruno technique. Material and Methods: 30 patients who have gingiva recession(Miller class I or class II) were carried root coverage. Langer & Langer technique(14 patients/32 tooth), modified Langer & Langer technique(5 patients/10 tooth) and Bruno technique(11 patients/18 tooth) was carried. At baseline and average 3 months after operation, it was estimated clinical index(Pocket depth, gingiva recession, clinical attachment level, keratinized gingiva, scar tissue, root coverage rate) by Williams style probe. Result: Root coverage rate is indicated Langer & Langer technique(8S%), Modified Langer & Langer technique(86%) and Bruno technique(90%). Conclusion: All three of the procedures were effective in gingival recession and improved clinical parameters.