• Title/Summary/Keyword: Base pressure

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Spontaneous Combustion of Various Fuels of Carbonization Rank (탄화도별 발전연료의 자연발화 특성 평가)

  • Kim, Jae-Kwan;Park, Seok-Un;Jeong, Jae-Hyeok;Shin, Dong-Ik;Hong, Jun-Seok;Hong, Jin Pyo
    • Journal of Energy Engineering
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    • v.26 no.3
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    • pp.78-89
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    • 2017
  • Spontaneous combustion propensity of various coals of carbonization grade as a pulverized fuel of coal fired power plant has been tested from an initial temperature of $25^{\circ}C$ to $600^{\circ}C$ by heated in an oven with air to analyze an self oxidation starting temperature. This tests produce a CPT(Cross Point Temperature), IT(Ignition temperature) and CPS(Cross Point Slope) by calculated as the slope of time taken a rapid exothermic oxidation reaction at CPT base. CPS show a carbonization rank dependence, whereby wood pellet has the highest propensity to spontaneous combustion of $20.995^{\circ}C/min$. A subbituminous KIDECO coal shows an CPS values of $15.370^{\circ}C/min$ whereas it of pet coke of the highest carbonization rank has $20.950^{\circ}C/min$. The nature of this trend is most likely a concentration of volatile matter and oxygen functional groups of coal surface that governs the available component for oxidation as well as surface area of fuel char, and constant pressure molar heat.

Development of the Model for Activity Based Costing in the Hospital (의료기관의 활동기준원가 산출 모형)

  • Chun, Ki-Hong;Cho, Woo-Hyun;Kim, Bo-Kyung;Kim, Byung-Cho
    • Korea Journal of Hospital Management
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    • v.6 no.2
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    • pp.37-69
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    • 2001
  • A new cost management system, called Activity Based Costing (ABC) system, has arisen to solve the limitation of a Traditional Cost Accounting (TCA) system until last two decades and ABC has been applied by many companies. TCA systems have limitation in tracing cost because they arbitrarily allocate overhead cost to the cost objects without standard for direct cost distribution. ABC is an accounting system that assigns costs to products or services based on the resources they consume. The costs of all activities are traced to the products for which they are performed. Therefore ABC is a cost management system that provides a matrix to accurately quantify consumed resources triggered by activities and activities triggered by products and services. There is little implementation of ABC in the health services field, one of service industries, due to complicated and many activities, and volatile cost object. However, the necessity for applying reasonable cost accounting system is largely issuing as strategy responding hostile environment, and financial pressure, and it is imperative to implement the Activity Based Costing (ABC) system. Therefore, this study presents the framework to develop ABC system for total health service organizations. Cost objects in this study base on medical service activities per health insurance claim from one general hospital located in Metropolitan Statistical Areas (MSAs). Medical service activities include all health insurance claims in the hospital. The purpose of the study is presenting useful tools and basic frame to develop Activity Based Costing system for health service organizations which want to use ABC system. The steps to develop ABC system for health service organizations are following: 1. Identifying of activity centers; 2. Definition of cost objects and activity by activity center; 3. Analysis of activity and tracing activity contribution; 4. Allocation of direct cost for specific activity; 5. Allocation of indirect cost for specific activity; 6. Allocation of depreciation for facilities, applicants, and consumption goods; 7. Allocation of administration cost; 8. Allocation of cost among activity centers; and 9. Tracing cost of cost objects by activity center. This study identified necessary information from existing reports which hospitals generally made by each step, and defined outcome which had to be produced in each step using this information. The steps of this study had limitation to apply all different size hospitals because the steps were structured ABC system by one hospital, however, this study used similar basic framework and methods with general cases. When a health service organization want to apply Activity Based Costing (ABC) system on all activities of it in future days, this study is very useful to design system structure in the health service organization.

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Behaviors of Glucose Decomposition during Dilute-Acid Hydrolysis of Lignocellulosic Biomass (목질계 바이오매스의 묽은 산 가수분해 공정에서 포도당 분해물 거동)

  • Jeong, Tae-Su;Oh, Kyeong-Keun
    • KSBB Journal
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    • v.24 no.3
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    • pp.267-272
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    • 2009
  • During a dilute acid hydrolysis, degradation products are formed or liberated by pre-treatment of lignocelluloses depend on both the biomass and the pretreatment conditions such as temperature, time, pressure, pH, redox conditions, and addition of catalysts. In lignocellulosic biomass, sugars can be degraded to furfural which is formed from pentoses and 5-hydroxymethulfurfural (HMF) from hexoses. 5-HMF can be further degraded, forming levulinic acid and formic acid. Acetate is liberated from hemicellulose during hydrolysis. Some decomposed compounds hinder the subsequent bioconversion of the solubilized sugars into desired products, reducing conversion yields and rates during fermentation. In the present work, samples of rapeseed strawwere hydrolyzed to study the optimal pretreatment condition by assessing yields of sugars and decomposed products obtained under different reaction conditions ($H_2SO_4$ 0.5-1.25% (w/w), reaction time 0-20 min and temperature range 150-220 C). A careful analytical investigation of acid hydrolyzate of rapeseed straw has not yet been undertaken, and a well-closed mass balance for the hydrolyzate in general is necessary to verify the productivity and economic predictions for this process.

Friction Welding of Ni-Base ODS Alloy Prepared by Mechanical Alloying (기계적 합금법으로 제조된 Ni기 산화물 분산강화 합금의 마찰압접에 관한 연구)

  • 강지훈;박성계;김지순;권영순
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 1994.10b
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    • pp.15-15
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    • 1994
  • M MA ODS 합금의 보다 폭넓용 실용확훌 위해 크게 요구되고 있는 적정 접합기술 개발의 한 방안£로, 마찰압접(Friction Welding) 방법의 가능성옳 조사하기 위하여 마찰압력과 시간, 마 찰 후 접촉압력(Upset Pressure) 풍을 다양하게 변화시켜 접합체톨 제조한 후, 접합체 강도에 대한 인장시험과 접합계연의 결합 및 미세구조에 대한 현미경 관찰, EDS에 의한 원소분석, 접 합이옴부의 경도분포와 파단면 분석 풍율 행하였다. 실험에 사용된 모재는 기계적 합금법으로 제조된 Inca사의 Ni기 MA 754 합금이었으며, 직경 l 10 mm, 길이 50 mm로 가공한 후, 아세통£로 초음파 세척하여 접합에 사용하였다. 접합온 브 레이크식 마찰압접기틀 사용하여 행하였으며, 회전시험편의 회전수는 2400 rpm이었A며, 다른 한쪽의 고정시험편과의 마찰압력 및 마찰시간온 각각 50 - 500 MPa과 1-5초로, 또한 업셋압 력도 50 - 600 MPa로 변화시켰다. 이때 업셋압력은 모든 시편에 대해 일정하게 6초동안 가하 였다. 얻어진 접합체는 각 압접조건 당 2개 이상의 접합시험편에 대해 상온 인장강도톨 측정하 였으며, 파단이 일어난 위치를 확인한 후 파면에 대한 분석율 주사전자현미경(SEM)과 에너지 분산형 분광분석기mDS)릎 사용하여 행하였다. 컵합이옴부의 첩합성올 확인하기 위하여, 접합 체를 접합변에 수직으로 절단, 연마한 후 광학현미경과 SEM, EDS 퉁으로 관찰, 분석하여 접 합부의 형상과 결합형성 여부, 접합계면의 미세조직 퉁옳 조사하였다. 또한 마찰압접에 따론 모재와 접합계연부의 경도분포훌 접합이옴부로부터 모재쪽으로 일정 간격율 두어 마이크로 비 커스 경도기로 측정, 조사하였다. 이상의 설험 결과, 다옴과 같온 결론옳 얻었다. ( (1) 접합체 강도가 모채 강도의 95% 이상이 되는 양호한 렵합체흩 얻기 위한 마찰압력 조건 온, 2400 rpm의 회전속도와 6초의 업셋압력 유지시간에서 마찰압력과 업셋압력, 그리고 마찰시 간이 각각 400 MPa 이상과 500 MPa 이상,2초입율 확인하였다. ( (2) 컵합이옴부의 관찰 결과, 모든 마찰압접 조건에서 컵합이옴부는, 기폰 모재의 texture 조직 을 유지하고 있는 모재부 영역(영역 ill)과 첩합계면부에 인접하여 업셋압력이 주어질 때 단조 효과에 의해 계연 외부로 metal flow가 일어나면서 형성된 영역 II, 매우 미세한 결정립으로 구성된 중앙부의 영역 1 로 이투어져 있옴융 확인하였다. ( (3) 최적접합조건이 충족되지 않온 경우, 접합부의 영역 I 에서 관찰된 void와 균열, 불균일한 접합계면 통의 접합결함에 Al과 Y. Ti 퉁£로 구성된 산화물률이 용집되어 있옴을 확인하였 다-( (4) 접합체의 파단 양상온 크게 접합부 파단과 모재부 파단, 이률의 혼합형 파단i로 나눌수 있었다. 모재부 파단의 경우, 파단면이 매끄럽고 파변상의 결정립도 매우 미세하였으며, 산확물 의 용집도 찾아보기 어려웠 나, 접합부 파단의 경우에는 파변의 굴곡이 비교척 심하고 연성 입계파괴의 형태를 보였£며, 결정립도 모채부 파단의 경우에 비해 조대하였다. 조대하였다.

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Is BTC Oil Pipeline Good or Bad for Azerbaijan Economy? (BTC 파이프라인이 아제르바이잔 경제에 미치는 영향 분석)

  • Hwang, Yun Seop;Kim, Soo Eun;Choi, Young Jun
    • Environmental and Resource Economics Review
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    • v.19 no.2
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    • pp.413-440
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    • 2010
  • Since 2000, as importance of sourcing energy emphasized caused by instability of international oil price, interests toward Caspian countries as an alternative markets has increased. Especially, Azerbaijan, as middle Asian emerging exporting country, has performed drastic economic boom because of massive amount of foreign capital flowed in and construction of BTC pipeline. However, despite this economic surge, there are unbalanced economy which is merely focusing on energy industry and pressure from increase in real exchange rate and inflation. In order to analyze the sustainability of Azerbaijan economy, the total sample time period of this paper is from January 2001 to December 2007 and the term is divided into before and after BTC line construction. Vector Error-Correction Model has been applied to analysis confirming short-term and long-term effect. As a result, Azerbaijan now face the symptoms of the recession during the time period and this is due to high oil price and increase in export influenced by BTC oil pipeline resulting in decrease in real interest rate. This conclusion is to affect competitiveness of manufacturing industry, base industry for economic proliferation, in a negative way.

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Performance Evaluation to Develop an Engineering Scale Cathode Processor by Multiphase Numerical Analysis (다상유동 전산모사를 통한 공학 규모의 cathode processor의 성능평가)

  • Yoo, Bung Uk;Park, Sung Bin;Kwon, Sang Woon;Kim, Jeong Guck;Lee, Han Soo;Kim, In Tae;Lee, Jong Hyeon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.1
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    • pp.7-17
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    • 2014
  • Molten salt electrorefining process achieves uranium deposits at cathode using an electrochemical processing of spent nuclear fuel. In order to recover pure uranium from cathode deposit containing about 30wt% salt, the adhered salt should be removed by cathode process (CP). The CP has been regarded as one of the bottle-neck of the pyroprocess as the large amount of uranium is treated in this step and the operation parameters are crucial to determine the final purity of the product. Currently, related research activities are mainly based on experiments consequently it is hard to observe processing variables such as temperature, pressure and salt gas behavior during the operation of the cathode process. Hence, in this study operation procedure of cathode process is numerically described by using appropriate mathematical model. The key parameters of this research are the amount of evaporation at the distillation part, diffusion coefficient of gas phase salt in cathode processor and phase change rate at condensation part. Each of these conditions were composed by Hertz-Langmuir equation, Chapman-Enskog theory, and interphase mass flow application in ANSYS-CFX. And physical properties of salt were taken from the data base in HSC Chemistry. In this study, calculation results on the salt gas behavior and optimal operating condition are discussed. The numerical analysis results could be used to closely understand the physical phenomenon during CP and for further scale up to commercial level.

Factors Affecting Health Promotion Behavior of Apheresis Blood-Donors (성분헌혈자의 건강증진행위에 영향을 미치는 요인)

  • Hong Kyong Hee;Park Ho Ran
    • Journal of Korean Public Health Nursing
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    • v.19 no.1
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    • pp.41-52
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    • 2005
  • This study was designed to provide a base for nursing intervention to help apheresis blood-donors to perform health promotion behavior effectively by surveying their health promotion behavior and by analyzing the critical factors. The study subjects were 468 participants in platelet donation at a university hospital apheresis unit in Seoul. The data for this study were collected between May and June. 2002. by questionnaire. Data were analyzed by t-test, ANOVA. Scheffe test, Pearson correlation coefficient. and stepwise multiple regression. The results were as follows. 1. The degree of performance of health promotion behavior of the subjects was a total average score of $152.9\pm21.5$ points and a mean score of 2.7 points. The highest score was 'I have a good relationship with others' in the factor of self-actualization and interpersonal support. The lowest score was 'I have my blood pressure checked regularly' in the factor of health responsibility. 2. Considering the classification according to the subjects' general characteristics. the health promotion behavior score was significantly higher for soldiers than high school students, for religious believers than atheists. and for high class economic status than mid and low class economic status. Also the health promotion behavior score was higher for those who had made more than five blood donations than those who had made zero or one donation. and for those who had made more than four blood donations than for those who had made less than four blood donations in the previous times of apheresis blood donation. The score was also higher for those not having a relationship with recipient than those having a relationship. 3. The self-efficacy related to donation. general self-efficacy and self-esteem had a significant correlation with the performance in health promotion behavior. 4. The critical factors that influenced the health promotion behavior were explained by $35.6\%$ of the general self-efficacy and by $40.2\%$ of the total of self-efficacy related to donation, and previous times of apheresis blood donation. The health promotion behavior score of apheresis blood-donors differed according to job, religion, economic status, previous times of whole blood donation, previous times of apheresis blood donation, and relationship with recipient. The health promotion behavior and self-efficacy related to donation, general self-efficacy, and self-esteem showed significant positive correlation with one another. The general self-efficacy, self-efficacy related to donation, and previous times of apheresis blood donation appeared to be the significant predictive factors of health promotion behavior. Therefore, from these study results, it is necessary to establish more effective and organized nursing intervention strategies for the health promotion behavior of apheresis blood-donors.

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An Analysis of Global Solar Radiation using the GWNU Solar Radiation Model and Automated Total Cloud Cover Instrument in Gangneung Region (강릉 지역에서 자동 전운량 장비와 GWNU 태양 복사 모델을 이용한 지표면 일사량 분석)

  • Park, Hye-In;Zo, Il-Sung;Kim, Bu-Yo;Jee, Joon-Bum;Lee, Kyu-Tae
    • Journal of the Korean earth science society
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    • v.38 no.2
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    • pp.129-140
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    • 2017
  • Global solar radiation was calculated in this research using ground-base measurement data, meteorological satellite data, and GWNU (Gangneung-Wonju National University) solar radiation model. We also analyzed the accuracy of the GWNU model by comparing the observed solar radiation according to the total cloud cover. Our research was based on the global solar radiation of the GWNU radiation site in 2012, observation data such as temperature and pressure, humidity, aerosol, total ozone amount data from the Ozone Monitoring Instrument (OMI) sensor, and Skyview data used for evaluation of cloud mask and total cloud cover. On a clear day when the total cloud cover was 0 tenth, the calculated global solar radiations using the GWNU model had a high correlation coefficient of 0.98 compared with the observed solar radiation, but root mean square error (RMSE) was relatively high, i.e., $36.62Wm^{-2}$. The Skyview equipment was unable to determine the meteorological condition such as thin clouds, mist, and haze. On a cloudy day, regression equations were used for the radiation model to correct the effect of clouds. The correlation coefficient was 0.92, but the RMSE was high, i.e., $99.50Wm^{-2}$. For more accurate analysis, additional analysis of various elements including shielding of the direct radiation component and cloud optical thickness is required. The results of this study can be useful in the area where the global solar radiation is not observed by calculating the global solar radiation per minute or time.

Selection of Postweld Heat Treatment Condition of a High-Temperature and High-Pressure Forged Valve (고온고압용 단조밸브의 용접후열처리 조건 선정)

  • Park, Jae-Seong;Heo, Ki-Moo;Yoon, Sung-Hoon;Moon, Yoon-Jae;Lee, Jae-Heon
    • Plant Journal
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    • v.10 no.2
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    • pp.48-59
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    • 2014
  • Coupons which have same figure as weld joint of the forged steel valves and 1 inch nominal weld thickness were manufactured using ASTM A182 F92 material. After welding with GTAW method, the welded specimens have been post-weld heat treated at $705^{\circ}C$, $735^{\circ}C$, $750^{\circ}C$, $765^{\circ}C$, $795^{\circ}C$ and $825^{\circ}C$ for 1 hour per 1 inch nominal weld thickness each (Group 1) to evaluate characteristics of welds based on various holding temperature. Indeed, 3 welded specimens were post-weld heat treated for 30 minutes, 1 hour and 2 hour (Group 2) at $735^{\circ}C$ to evaluate characteristics of welds based on various holding time. Hardness values were measured at the weld metal, heat affected zone and base metal to observe hardness change depending on the condition. As a result of the evaluation, appropriate holding temperature for PWHT is proved as $750^{\circ}C$ and $765^{\circ}C$ for 1hour per 1 inch nominal weld thickness. Indeed, holding for 1 hour per 1 inch nominal weld thickness was insufficient for PWHT effect when the holding temperature was at $735^{\circ}C$. The microstructure of post-weld heat treated weld metal was determined as tempered-martensite structure.

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Fabrication of mandibular suction denture for complete edentulous patient: A case report (하악 흡착식 의치를 이용한 완전 무치악 환자의 총의치 수복 증례)

  • Park, Minhyuk;Park, Sang-Won;Lim, Hyun-Pil;Park, Chan;Yun, Kwi-Dug
    • The Journal of Korean Academy of Prosthodontics
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    • v.58 no.3
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    • pp.257-267
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    • 2020
  • The goal of suction denture is to enhance retention of dentures by the formation of negative pressure between the denture base and the underlying tissue and sealing around the denture by the mucosa. This patient has been converted to a completely edentulous state after the extraction of residual teeth. Fabrication of suction denture was planned because it was estimated that the conventional compete would be hard to achieve retention due to the absorption of residual ridge and lack of sublingual fold. Through appropriate clinical and laboratory technique such as preliminary impression on the mandibular rest position, provisional vertical dimension determination with Centric Tray® (Ivoclar Vivadent AG, Schaan, Liechtenstein), closed mouth definitive impression and jaw relation record using individual tray with Gnathometer M® (Ivoclar Vivadent AG, Schaan, Liechtenstein), artificial teeth arrangement considering stability of the denture, and proper polymerization technique that minimizes polymerization shrinkage, restoring the patient with suction denture resulted in satisfaction throughout the function and asesthetics.