• Title/Summary/Keyword: Rate Law

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Catalytic CVD-Kinetics of Pyrolytic Carbon and SiC on the Stainless Steel Stent (Stainless Steel Stent에 Pyrolytic Carbon과 SiC의 촉매적 CVD-Kinetic연구)

  • 이보성;이무용
    • Proceedings of the KAIS Fall Conference
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    • 2000.10a
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    • pp.30-33
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    • 2000
  • 최근 국내에서도 관 동맥 질환 환자의 수가 급증하고 있으며, 관 동맥 질환의 치료 방법인 관 동맥 성형 술은 관 동맥 stent의 도입에 의하여 보편화되어 국내에서 년간 5000개 이상의 stent가 시술되고 있다. 그러나 stent는 고가(1,200천원/개)로 전량 수입에 의존하고 있으며, 시술 후 사망까지 이를 수 있는 혈전에 의한 급성 페쇠와 재 협착이 문제점이다. 이를 위한 한가지 방법이 생체 적합성이 뛰어난 복합 stent의 개발인데 SiC나 Carbon을 coating한 stent는 시술 후 혈전 형성을 억제하는 것으로 알려져 있다. 특히 가장 순수한 Pyrolytic carbon은 hemocompatibility가 탁월하고 기밀 성이기 때문에 본 연구에서 그의 CVB-Kinetics를 연구코저 하는 것이다. methane으로부터 pyrolytic carbon의 CVD는 온도에 따라서 다양한 구조를 가지며 따라서 그의 mechanism도 다양하다는 것은 잘 알려져 있다. 더구나 광간(균질)반응과 표면(불균질)반응의 정량적 관계에 따라서도 다르다는 것도 확인되었다. 그러나 stainless steel 316L로 만든 stent는 12 - 15 %의 Ni과 2%의 Mo을 함유해서 금속성을 잃지 않는 저온(600℃)에서도 pyrolytic carbon의 속매적 CVD가 가능함을 그리고 SiC의 코팅에 적합한 buffer layer 역할을 함을 확인하였다. 그리하여 본 연구는 반응기 설계에 필요한 저온 촉매적 pyrolytic carbon의 CVD-kinetics의 연구결로 그의 mechanism과 함께 rate law 식을 유도, 확인하였으며 600℃, 90kPa에서 P/sub ch4//P/sub H2/=5:1과 체류시간 1.8 sec가 최적임을 발견하였다. 이때 석출속도 11.2 g-mol/g-cat.h 혹은 두께속도로 73 nm/sec를 나타내었다.메타놀-물 (1 : 1) 유출액에서 $(0.80\;{\mu}g)$ 검출되었다. 하면 morey eel내장에서 얻은 독물질도 DEAE-셀루로즈에서 ST-1 과 ST-2로 나누어지며, 이 ST-1의 TLC, HPLC 및 알루미나 컬럼상의 거동이 파랑비늘돔에서 얻은 ST-1의 그것과 같으므로 scaritoxin으로 보고한 ST-1은 ciguatoxin의 형태인 less polar cigutoxin (LPCTX) 으로 생각된다.에서 각각 대조구의 57, 413 및 315% 증진되었다. 거품의 열안정성은 15분 whipping시, pH 4.0(대조구, 30.2%) 및 5.0(대조구, 23.7%)에서 각각 $0{\sim}38.0$$0{\sim}57.0%$이었고 pH 7.0(대조구, 39.6%) 및 8.0(대조구, 43.6%)에서 각각 $0{\sim}59.4$$36.6{\sim}58.4%$이었으며 sodium alginate 첨가시가 가장 양호하였다. 전체적으로 보아 거품안정성이 높은 것은 열안정성도 높은 경향이며, 표면장력이 낮으면 거품형성능이 높아지고, 비점도가 높으면 거품안정성 및 열안정성이 높아지는 경향이 있었다.protocol.eractions between application agents that are developed using different languages. Dynamic agent invocation is accomplished by Java Native Interface(JNI) that links two heterogeneous methods, and by KQML language interface that facilitates the communications between heterogeneous agents. This scheme of dyna

Prediction and Evaluation of Indoors Noise Level of Exhibition Room in Museum by Road Traffic Noise (도로교통소음으로 인한 박물관 전시실의 실내 소음레벨 예측 및 평가)

  • Lee, Kook-Hyun;Park, Yeong-Ji;Kim, Jae-Soo
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.8
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    • pp.787-794
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    • 2010
  • Recently, with sudden increase of supplying rate of cars and quantity of goods transported, traffic noisy becomes one of important factors obstruct environment of exhibition and view facilities have purpose in calmness and unsatisfaction about this is high now. Therefore, in case of exhibition and view facilities, it has to be grasped that satisfaction degree about the noisy in and out of the exhibition room by performing effect valuation on traffic noisy from design step. However the level of internal noise cannot be measured at the design phrase of the structure due to the noise of traffic. Up until now a walls transmission loss, based on the law of mass, is predicted using this method. However measuring the internal sound level after actual construction reveals that there is a large difference from measurements made at the design stage, and it is very difficult to find a solution after the opening of the structure. From research looking from this perspective the internal sound level was predicted- calculating the internal sound absorption ability, using acoustic simulation and loss prevention of an insulated wall- based on data collected to evaluate the internal sound of an exhibition room at a Folk Museum adjacent to a freeway. The results of this research are considered to provide important data for the prediction of internal sound level at the time of construction of exhibition facilities similar to this.

Fracture and Hygrothermal Effects in Composite Materials (복합재의 파괴와 hygrothermal 효과에 관한 연구)

  • Kook-Chan Ahn;Nam-Kyung Kim
    • Journal of the Korean Society of Safety
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    • v.11 no.4
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    • pp.143-150
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    • 1996
  • This is an explicit-Implicit, finite element analysis for linear as well as nonlinear hygrothermal stress problems. Additional features, such as moisture diffusion equation, crack element and virtual crack extension(VCE ) method for evaluating J-integral are implemented in this program. The Linear Elastic Fracture Mechanics(LEFM) Theory is employed to estimate the crack driving force under the transient condition for and existing crack. Pores in materials are assumed to be saturated with moisture in the liquid form at the room temperature, which may vaporize as the temperature increases. The vaporization effects on the crack driving force are also studied. The Ideal gas equation is employed to estimate the thermodynamic pressure due to vaporization at each time step after solving basic nodal values. A set of field equations governing the time dependent response of porous media are derived from balance laws based on the mixture theory Darcy's law Is assumed for the fluid flow through the porous media. Perzyna's viscoplastic model incorporating the Von-Mises yield criterion are implemented. The Green-Naghdi stress rate is used for the invariant of stress tensor under superposed rigid body motion. Isotropic elements are used for the spatial discretization and an iterative scheme based on the full newton-Raphson method is used for solving the nonlinear governing equations.

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A Study on Factors Affecting Public Health Center Workforce for Health Behavior based on Pender's Health Promotion Model (서울지역 일부 보건소 공무원의 지각된 건강상태와 건강행동과의 관련성 -Pender의 건강증진모델을 이용하여-)

  • Lee, Eun-Jeoung;Lee, Myung-Sun
    • The Journal of Korean Society for School & Community Health Education
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    • v.15 no.1
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    • pp.121-140
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    • 2014
  • Objectives: Recently, the rate of death by chronic disease, is increasing steadily. To prevent this, the public health center will have taken a leading role in the local community medical business through an establish to the national health promotion act and an amendment to the law of public health center in Korea. Results: Accordingly this research, using the Pender's health promotion model which is related with subject health behavior who government employees serve at the public health center have taken important position in the local community health promotion, have comprehended the actual condition of health behavior. For increasing the health behavior practice of subject to comprehend the factor which have effect on health behavior practice, which can be a correct role model in the local community health promotion. A survey was performed on 406 government employees who serve at five public health centers in Seoul. The period of survey was from 25th October, 2010 to 15th November, 2010. The results of this study were summarized as below. 1. Work-related stress, perceptible beneficial obstacle, and self-efficacy were composed by 5 points measure. The results show those work-related stress were $3.06{\pm}0.469$, 74perceptible beneficial obstacle were $3.74{\pm}0.471$, and self-efficacy were $3.49{\pm}0.469$. 2. As for the health behavior by general characteristic, the results have specific differences on age, education level, state of marriage, rank of the position, field of the occupation and employment forms in statics analysis. 3. As for the past health behavior by health behavior characteristic, work-related stress have specific differences on the past frequency of drinking (p<.05) in statics analysis, perceptible beneficial obstacle have specific differences on the past frequency of having breakfast(p<.05), having snacks(p<.05) and doing exercise(p<.05) in statics analysis. Self-efficacy have specific difference on the past frequency drinking(p<.01) in statics analysis. 4. According to the correlation between the factors related with health behavior and health behavior, the health behavior have specific differences on perceptible health condition(p<.01), the past health behavior and perceptible beneficial obstacle(p<.05). Work-related stress and self-efficacy don't have specific relation in health behavior practice. 5. The factors, which effect on health behavior practice have specific differences on the past health behavior, employment forms and field of the occupations. The ability of explanation occupied 54.8% what explained of the health behavior practice by general characteristic, perceptible health condition, employment forms and perceptible beneficial obstacle. Conclusions: According to the correlation between the factors related with health behavior, the health behavior have specific differences on perceptible health condition(p<.01), the past health behavior and perceptible beneficial obstacle(p<.05). The factors, which effect on health behavior practice have specific differences on the past health behavior, employment forms and field of the occupations.

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Effect of Fe on the High Temperature Oxidation of Ti-Al-Fe Alloys (Ti-Al-Fe계 합금의 고온산화거동에 미치는 Fe의 영향)

  • Yoon, Jang-Won;Hyun, Yong-Taek;Kim, Jeoung-Han;Yeom, Jong-Taek;Yoon, Seog-Young
    • Korean Journal of Materials Research
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    • v.21 no.7
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    • pp.357-363
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    • 2011
  • In this paper, high temperature oxidation behavior of newly developed alloys, Ti-6Al-4Fe and Ti-6Al-1Fe, is examined. To understand the effect of Fe on the air oxidation behavior of the Ti-Al-Fe alloy system, thermal oxidation tests are carried out at $700^{\circ}C$ and $800^{\circ}C$ for 96 hours. Ti-6Al-4V alloy is also prepared and tested under the same conditions for comparison with the developed alloys. The oxidation resistance of the Ti-Al-Fe alloy system is superior to that of Ti-6Al-4V alloy. Ti-6Al-4V shows the worst oxidation resistance for all test conditions. This is not a result of the addition of Fe, but rather it is due to the elimination of V, which has deleterious effects on high temperature oxidation. The oxidation of the Ti-Al-Fe alloy system follows the parabolic rate law. At $700^{\circ}C$, Fe addition does not have a noticeable influence on the amount of weight gain of all specimens. However, at $800^{\circ}C$, Ti-6Al-4Fe alloy shows remarkable degradation compared to Ti-6Al-1Fe and Ti-6Al. It is discovered that the formation of $Al_2O_3$, a diffusion resistance layer, is remarkably hindered by a relative decrease of the ${\alpha}$ volume fraction. This is because Fe addition increases the volume fraction of ${\beta}$ phase within the Ti-6Al-xFe alloy system. Activities of Al, Ti, and Fe with respect to the formation of oxide layers are calculated and analyzed to explore the oxidation mechanism.

Do-not-resuscitation in Terminal Cancer Patient (말기암환자에서 심폐소생술금지)

  • Kwon, Jung Hye
    • Journal of Hospice and Palliative Care
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    • v.18 no.3
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    • pp.179-187
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    • 2015
  • For patients who are near the end of life, an inevitable step is discussion of a do-not-resuscitate (DNR) order, which involves patients, their family members and physicians. To discuss DNR orders, patients and family members should know the meaning of the order and cardiopulmonary resuscitation (CPR) which includes chest compression, defibrillation, medication to restart the heart, artificial ventilation, and tube insertion in the respiratory tract. And the following issues should be considered as well: patients' and their families' autonomy, futility of treatment, and the right for death with dignity. Terminal cancer patients should be informed of what futility of treatment is, such as a low survival rate of CPR, unacceptable quality of life after CPR, and an irremediable disease status. In Korea, two different law suits related to life supporting treatments had been filed, which in turn raised public interest in death with dignity. Since the 1980s, knowledge of and attitude toward DNR among physicians and the public have been improved. However, most patients are still alienated from the decision making process, and the decision is often made less than a week before death. Thus, the DNR discussion process should be improved. Early palliative care should be adopted more widely.

A Study on Improvement of Contract Regulations for Adjusting Contract Amount in Public Construction - Focused on examples of price fluctuation classification - (공공건설 계약금액 조정의 계약예규 개선방안 연구 - 물가변동 분류 사례 중심으로 -)

  • Lee, Wonjei;Shin, Manjoong
    • Korean Journal of Construction Engineering and Management
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    • v.21 no.4
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    • pp.82-89
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    • 2020
  • Article 64 of the Enforcement Decree of the National Contract Act The requirement of the pre-amendment statute related to the adjustment of the contract price was 5% or more of the price fluctuation rate from the date of the contract. However, the meeting requirement was changed from 5% or more to 3% or more from the date of signing of the Presidential Decree No. 19035 to 2005. 9. 8. The method of adjusting the contract amount was also changed to determine the contractor's desired adjustment method at the time of contract. Alleviating these requirements and revising the empowerment of contract partners is intended to prevent difficulties in achieving smooth objectives by applying to public construction contractors without unfairly benefiting or unfavorable to contract partners. Even if the standards are relaxed and the rights are secured as described above, if the existing provisions for the adjustment of price fluctuation are applied, unlike the original purpose of the government system, the Korea Bank's price economic statistics classification method and the contract construction classification criteria applied in public construction work Due to the inconsistency, it can be seen that the amount of adjustment for price fluctuation by construction type is excessive and underestimated. Therefore, the purpose of this study is to analyze problems through cases and to make appropriate construction cost adjustment through improvement measures.

A Study on the Perception of Scattering Ash Facilities in Metropolitan Public Crematorium (수도권 공설화장장의 산골시설 인식에 관한 연구)

  • Nam, Yunju;Lee, Pil-Do
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.4
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    • pp.67-77
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    • 2019
  • Korea, which has changed from burial-oriented culture to cremation culture due to the increase of cremation rate, preferred charnel: however, we have adopted the new processing method of cremated remains, 'natural burial' because of deterioration of charnel facility and the problems with imposed urns. Ashes are absolutely required due to the inefficient use of territory for charnel and natural burial and natural environment pollution, but this is out of legislative system in reality. This study will hold an investigation research on ashes that handles cremated remains which is not mentioned in 'Act on Funeral Services, Etc.' as well as investigate the present-condition of 'facilities for scattering cremated ashes,' as prescribed by law. As a result, there were 42 public crematoriums with a place for scattering cremated ashes, and the name of 40 of them were hill of grave. We conducted a survey to see if the workers at public cremation facilities in the Seoul metropolitan area knew about hill of grave, 'the facilities for scattering cremated ashes.' The result showed 95.9% knew about hill of grave and 88.2% answered some improvement was partially needed. Therefore, this study is to propose improvement measures for the scattering ashes facilities of public crematoriums based on the results of research and present investigation.

The Relative Effectiveness of Various Radiation Sources on the Resistivity Change in n-Type Silicon

  • Jung, Wun
    • Nuclear Engineering and Technology
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    • v.1 no.2
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    • pp.91-101
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    • 1969
  • Resistivity changes of n-type float-zone silicon crystals with 6.4$\times$10$^{14}$ to 1.25$\times$10$^{17}$ phosphorus atoms/㎤ due to irradiation by (1) 1 MeV electrons, (2) two types of research reactors, and (3) $Co^{60}$ ${\gamma}$-ray sources were investigated. The results were analyzed on the basis of a simple exponential formula derived by Buehler. While the formula gave a fair fit in the low fluence range in most cases, the deviation was quite appreciable in the case of 1 MeV electron irradiation, and a linear change gave better fit in some cases. The large change in the carrier removal rate in electron-irradiated samples in the high fluence range was analyzed in detail in terms of the Fermi level cross-over of the defect levels. Based on the damage constants evaluated from the initial portion of data where the formula was applicable, the relative effectiveness of various radiation sources in causing the resistivity change in n-type silicon was compared. The TRIGA Mark II reactor neutrons, for example, were found to be about 40 times more effective than 1 MeV electrons. The dependence of the damage constant on the initial carrier concentration was also examined. The physical basis of the exponential law and the effect of the Fermi level cross-over of the defect levels on the resistivity change in the high fluence ranges are discussed.

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The Study on Applicability of Manufactured Lead(II) Iodide Dosimeter for Dose Measurement in Brachytherapy (방사선근접치료 분야의 선량 측정을 위해 제조된 Lead(II) Iodide 선량계의 적용가능성 연구)

  • Yang, Seung-Woo;Han, Moo-Jae;Park, Sung-Kwang
    • Journal of the Korean Society of Radiology
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    • v.15 no.6
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    • pp.789-794
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    • 2021
  • Brachytherapy is a treatment in which radioactive isotopes are placed inside the body to intensively irradiate the tumor with radiation. Because brachytherapy uses a radioisotope source with a high dose rate, it is very important to know the exact location and dose of the source. However, in clinical practice, it is evaluated inaccurately with the naked eye through rulers and autoradiographs. Therefore, in this study, a dosimeter that can be used for brachytherapy was developed using a lead(II) iodide (PbI2) material, and the applicability was evaluated by analyzing the reproducibility, linearity, and PID items. As a result of reproducibility evaluation, the RSD value was 1.41%, satisfying the evaluation criteria of 1.5%. As a result of the linearity evaluation, the R2 value was 0.9993, which satisfies the evaluation criterion of 0.9990. As a result of PID evaluation, it showed only a difference of 0.06 cm compared with the theoretical value of the inverse square law of distance at the 50% dose reduction point. The dosimeter manufactured in this experiment shows results that satisfy the standard in all evaluations, so it is judged that the possibility of applying the dosimeter in the radiation brachytherapy area is sufficient.