• 제목/요약/키워드: Working Pressure

검색결과 1,329건 처리시간 0.032초

A study for High Efficiency Dewatering of Sludge Contained Fine Particles (미세입자(微細粒子)를 함유(含有)한 슬러지의 고효율(高效率) 탈수(脫水) 연구)

  • Lee, Jung-Eun;Lee, Jae-Keun
    • Resources Recycling
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    • 제15권4호
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    • pp.36-43
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    • 2006
  • There was some difficulty dewatering properties due to small porosity diameter of cake, when pigment sludge contained fine particle was formed by cake under the dewatering. It was difficult to dewater the sludge with fine particles with the conventional mechanical dewatering method. This study was to improve the dewatering rate as discharging the water from porosity of cake easily, supplying the low heat to the cake layer. Thermal dewatering equipment of piston type to keep up constant temperature on the cake was set up and relative experiment was conducted for sludge of 200 g with fine pigment particle. As test results. filtration of 176.8 g, cake weight of 19.4 g, cake thickness of 4.2 mm was measured, and it was analyzed that the water content of cake was 47 wt% and dewatering velocity, which moaned the residual d교 sloid amount per dewatering area, was $2.1DS\;m^{2}{\cdot}cycle$. This results showed that filtration increased, cake weight and thickness decreased and dewatering velocity increased against mechanical dewatering method. And water content of cake decreased about 30%, so the result which dewatering rate improved was drew generally. The reason is that the inner vapor pressure working at the cake porosity increased as applying the low heat to the cake layer, which lead to discharge the water from porosity easily. Therefore, this study was estimated by the useful technology for sludge reduction.

A Study on the Thermal Flow of Waste Heat Recovery Unit (WHRU) for Ship's Organic Rankine Cycle Power Generation System using CFD Method (CFD를 활용한 선박고온도차발전용 WHRU의 열유동 해석에 관한 연구)

  • Whang, Dae-jung;Park, Sang-kyun;Jee, Jae-hoon;Bang, Eun-shin;Oh, Cheol
    • Journal of the Korean Society of Marine Environment & Safety
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    • 제27권5호
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    • pp.647-655
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    • 2021
  • The IMO (International Maritime Organization) is discussing the improvement of energy ef iciency of ships in order to reduce greenhouse gas emissions from ships. Currently, by applying an ORC power generation system using waste heat generated from ships, high energy conversion efficiency can be expected from ships. This technology uses an organic medium based on Freon or hydrocarbons as the working fluid, which evaporates at a lower temperature range than water. Through this, it is possible to generate steam (gas) and generate power at a low and low temperature relatively. In this study, the analysis of heat flow between the refrigerant and waste heat in the ORC power generation system, which is an organic Rankine cycle, is analyzed using 3D simulation techniques to determine the temperature change, velocity change, pressure change, and mass change of the fluid flowing of the WHRU (Waste Heat Recovery Unit) inside and the outside the structure. The purpose of this study is to analyze how the mass change affects the structure, and this study analyzed the heat transfer of the heat exchanger from the refrigerant and the exhaust gas of the ship's main engine in the ORC power generation system using this technique.

A Study on the Financial Structure Effect Factor and Business Analysis of Ocean Shipping Companies (국적외항선사의 경영실태분석과 재무구조 영향요인에 관한 실증연구)

  • Lee, Sung-Yhun;Kim, Young-Dae;Ahn, Ki-Myung
    • Journal of Navigation and Port Research
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    • 제43권4호
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    • pp.264-272
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    • 2019
  • In this study, the rate of return on investment used as a proxy variable for the entity's value and financial structure (liability ratio) is related to positive balance. This is consistent with the Static Tradeoff Theory (STT) that the entity's value and financial structure are related to a positive balance because the capital expense of a debt (tax-saving effects) that is less than its equity cost before it is in financial difficulty. Also, operating profitability (EBITDA/Sales), investment safety, total asset growth, net working capital and depreciation expenses are related to negative (-) with financial structure (liability ratio). This is the result of an analysis consistent with the Pecking Order Theory (POT). Fuel costs, borrowing, total asset turnover, financial costs, and tangible asset ratios have a significant positive relationship with the debt ratio. This is consistent with the agency theory and confirms that excessive chartering expenses, such as the bankrupt H company, are the main factors that pressure the financial structure of Korean ocean carriers.

Association of Lifestyle and Stress on Hypertension Among Temporary Employee, Working in Small and Medium Sized Construction Company (일부 중소형 건설업 임시직 근로자의 고혈압 유병실태와 생활습관 및 스트레스와의 관련성)

  • Kim, Soo-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제20권7호
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    • pp.363-371
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    • 2019
  • The purpose of this research is to provide data for the relations between lifestyle, stress and hypertension in a group of construction Temporary employee. The methods taken in this study was to survey the general characteristics and stress in the group, and figure out the relations between lifestyle and hypertension. This study targeted at 301 Temporary employee. in Young-dong for six months (2014~2015). Data analysis used errors and percentages, chi-square tests, one-way ANOVA analysis, independent sample t-test, chi-square test and multivariate logistic regression. The study shows that no relations between age and hypertension, but according to job characteristics, aggravate lifestyle just like smoking(P=0.049), eating habit(P=0.012), physical(p=0.022) & psychological(p=0.011) state there is an effect on hypertension. Based on the results of this study, it is found that temporary workers in small and medium-sized construction companies with high work-related disaster rates need to improve their living habits and physical psychological conditions and manage high blood pressure, as well as research and management of chronic diseases such as obesity, diabetes and dyslipidemia.

North Korea, Apparel Production Networks and UN Sanctions: Resilience through Informality (북한 의류 생산네트워크와 UN 제재)

  • Lee, Jong-Woon;Gray, Kevin
    • Journal of the Economic Geographical Society of Korea
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    • 제23권4호
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    • pp.373-394
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    • 2020
  • The strengthening of multilateral international sanctions against North Korea has raised questions as to how effective they are in exerting pressure on the country's economy. In this paper, we address this question by examining their impact on the country's integration into regional and global apparel production networks. North Korea has in the past decade become an increasingly competitive exporter of apparel on the basis of consignment-based processing arrangements. Official trade data shows a sharp drop in North Korean exports of clothing since the sectoral ban in 2017. There is evidence to suggest, however, that exports have continued on a more informal and clandestine basis. North Korea's integration into apparel production networks has also taken the form of the dispatch of workers to factories in China's northeastern border regions. Yet there is evidence that the recent sanctions imposed on such practices has similarly led to illicit practices such as working on visitors' visas, often with the help of Chinese enterprises and local government. The resilience of North Korea's integration into apparel production networks follows a capitalist logic and is result of the highly profitable nature of apparel production for all actors concerned and a correspondingly strong desire to evade sanctions. As such, the analysis contributes to the literature on sanctions that suggests that the measures may contribute to emergence of growing informal and illicit practices and to the role of the clandestine economy.

Study on the Application of Dry-Ice Blaster for Development of Automatic Stripe-Line Removal (노면표시 제거 장비 개발을 위한 드라이아이스 블래스터 적용에 관한 연구)

  • Koo, Ja Kyung;Moon, Deuk Soo;Bernold, Leonhard E.;Lee, Tai Si
    • KSCE Journal of Civil and Environmental Engineering Research
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    • 제29권2D호
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    • pp.245-253
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    • 2009
  • Road facility is the most fundamental infrastructure for traffic and various information for smooth traffic is included in road surfaces. Various information included in road surfaces should be often removed and reinstalled by partial damage and aging. In addition, the existing road surface information should be removed in order to mark new information as traffic information changes. The existing road surface removal method suing grinders and torches had problems such as dangerous working equipment and workers' direct exposure to cars. In addition, although water-jet system using super high-pressure water was used to remove road surface in order of improvement of traditional method, there are another problems such as limitations according to water-tanks and water frost on the road surfaces after work. Therefore, this study analyzes and suggests systems to develop prototype after analyzing dry ice blaster in order to improve the current road surface removal methods. In addition, the study analyzes the possibility of introduction of dry ice blaster through a test for proposing an automatized equipment for new road surface mark removal considering environment and work efficiency, and compare traditional method with introduced dry ice blaster for operating cost.

A Survey on Physical Complaints Related with Farmers' Syndrome of Vinylhouse and Non-vinylhouse Farmers (비닐하우스 재배농민과 일반농민의 농부증 관련 신체증상 호소율 조사)

  • Lee, Ju-Young;Park, Jung-Han;Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • 제27권2호
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    • pp.258-273
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    • 1994
  • To compare the physical complaints of vinylhouse farmers with those of non-vinylhouse farmers, a personal interviews on 250 vinylhouse and 142 non-vinylhouse farmers were conducted in Sungjoo county in Kyungpook province selected by a random sampling from July 5 to July 10, 1993. Blood pressure of the subjects was also measured. Vinylhouse farmers had a higher average age, larger family size, shorter experience of farming, more working hours per day and working days per year and higher annual income than the non-vinylhouse farmers. The frequency of pesticide spray of the vinylhouse farmers was 3.4 times on the average in June 1993 as compared with 2.0 times of non-vinylhouse farmers, and 16.7 times for the vinylhouse farmers during the last one year while it was 8.3 times for the non-vinylhouse farmers in the same period. While 39.6% of vinylhouse farmers experienced pesticide intoxication symptoms such as headache, nausea, vomiting, dizziness, itching, and skin irritation, etc. during the month of June, 25.4% of non-vinylhouse farmers experienced such symptoms. The most frequent symptoms among eight symptoms that constitute the farmers' syndrome were lumbago, numbness of hand or foot, shoulder pain and dizziness regardless of sex and type of farming. Prevalence of the farmers' syndrome in male and female among vinylhouse farmers were 22.1%, 43.4%, respectively, and the prevalence in non-vinylhouse farmers was 23.2% for male and 50.7% for female. There was no statistically significant difference in the prevalence of farmers' syndrome between vinylhouse and non-vinylhouse farmers. However, the prevalence in female was about 2 times higher than that of male. When the effects of other factors were adjusted by multiple logistic regression for farmers' syndrome, the prevalence in female was 3.0 times higher than that of male. The prevalence of farmers' syndrome was increased as the age of farmers increased in both vinylhouse and non-vinylhouse farmers, and adjusted odds ratio of farmers' syndrome increased by 3% as the age increased by 1 year. Adjusted odds ratio for Farmers' syndrome in farmers who experienced pesticide intoxication during the month of June was 3.1 times higher than that of farmers who did not have such experience. While the prevalence of hypertension in male and female non-vinylhouse farmers were 22.4%, 13.7%, respectively, the prevalence in vinylhouse farmers were 13.5% for male and 12.0% for female. However, there was no association between farmers' syndrome and hypertension. It was found in this study that the vinylhouse farmers are at a high risk of pesticide intoxication, which is associated with tile common physical complaints. To reduce such risk it is necessary to develop farming methods which do not require the pesticide or may use less pesticide, a safer method of pesticide spraying, and the protective equipments which can be worn at a high temperature and have a better protective effect. Also education of farmers for the correct methods of ventilation after pesticide spraying in the vinylhouse and wearing the protective equipments may be considered as a supportive method. Since inappropriate posture at work and intensive labor may cause farmers' syndrome, it is recommended to develop farming tools which reduce physical burden and take a rest and exercise periodically during work. It is necessary to strengthen the hypertension management program of the Kyungpook province, because the prevalence of hypertension was as high as about 15%.

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Evaluation on Usefulness of Applying Body-fix to Liver Cancer Patient in Tomotherapy (간암환자의 토모치료시 Body-fix 사용유무에 따른 유용성 평가)

  • Oh, Byeong-Cheon;Choi, Tae-Gu;Kim, Gi-Chul
    • The Journal of Korean Society for Radiation Therapy
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    • 제22권1호
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    • pp.11-18
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    • 2010
  • Purpose: In every time radiation therapy set up errors occur because internal anatomical organs move due to breathing and change of patient's position. These errors may affect the change of dose distribution between target area and normal structure. This study investigates the usefulness of body-fix in clinical treatment. Materials and Methods: Among 55~60 aged male patients who has hepatocellular carcinoma in area of liver's couinaud classification, we chose 10 patients and divided two groups by using body-fix or not. When applying body-fix, we maintained a vacuum of 80 mbar pressure by using vacuum pump (Medical intelligence, Germany). Patients had free breathing with supine position. After working to fuse and consist MV-CT (megavoltage computed tomography) with KV-CT (kilovoltage computed tomography) obtained by 5 times treatments, we compared and analyzed set up errors occurred to (Right to Left, RL) of X axis, (Anterioposterio, AP) of Z axis, (Cranicoudal, CC) of Y axis. Results: Average Set up errors through image fusion showed that group A moved $0.3{\pm}1.1\;mm$ (Cranicoudal, CC), $-1.1{\pm}0.7\;mm$ (Right to Left, RL), $-0.2{\pm}0.7\;mm$ (Anterioposterio, AP) and group B moved $0.62{\pm}1.94\;mm$ (Cranicoudal, CC), $-3.62{\pm}1.5\;mm$ (Right to Left, RL), $-0.22{\pm}1.2\;mm$ (Anterioposterio, AP). Deviations of X, Y and Z axis directions by applying body-fix indicated that maximum X axis was 5.5 mm, Y axis was 19.8 mm and Z axis was 3.2 mm. In relation to analysis of error directions, consistency doesn't exist for every patient but by using body-fix showed that the result of stable aspect in spite of changes of everyday's patient position and breathing. Conclusion: Using body-fix for liver cancer patient is considered effectively for tomotherapy. Because deviations between group A and B exist but they were stable and regular.

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Performance Evaluation of K-based Solid Sorbents Depending on the Internal Structure of the Carbonator in the Bench-scale CO2 Capture Process (벤치급 CO2 포집공정에서 흡수반응기의 내부구조에 따른 K-계열 고체흡수제의 성능평가)

  • Kim, Jae-Young;Lim, Ho;Woo, Je Min;Jo, Sung-Ho;Moon, Jong-Ho;Lee, Seung-Yong;Lee, Hyojin;Yi, Chang-Keun;Lee, Jong-Seop;Min, Byoung-Moo;Park, Young Cheol
    • Korean Chemical Engineering Research
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    • 제55권3호
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    • pp.419-425
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    • 2017
  • In this study, the performance characteristics of the K-based sorbents (KEP-CO2P2, KEPCO RI, Korea) has been studied in relation with the heat exchanger structure and shape in a mixing zone of the carbonator in the bench-scale dry $CO_2$ capture process. Two types of heat exchangers (different structure and shape) were used in the carbonator as CASE 1 and CASE 2, in which the experiment has been continuously performed under the same operating conditions. During the continuous operation, working temperature of carbonator was 75 to $80^{\circ}C$, that of regenerator was 190 to $200^{\circ}C$, and $CO_2$ inlet concentration of the feed gas was 12 to 14 vol%. Especially, to compare the dynamic sorption capacity of sorbents, the differential pressure of the mixing zone in the carbonator was maintained around 400 to 500 mm $H_2O$. Also, solid samples from the carbonator and the regenerator were collected and weight variation of those samples was evaluated by TGA. The $CO_2$ removal efficiency and the dynamic sorption capacity were 64.3% and 2.40 wt%, respectively for CASE 1 while they were 81.0% and 4.66 wt%, respectively for CASE 2. Also, the dynamic sorption capacity of the sorbent in CASE 1 and CASE 2 was 2.51 wt% and 4.89 wt%, respectively, based on the weight loss of the TGA measurement results. Therefore, It was concluded that there could be a difference in the performance characteristics of the same sorbents according to the structure and type of heat exchanger inserted in the carbonator under the same operating conditions.

Globalization and Independency of Populist Nations' Welfare Policies: Focusing on the Influences of Multinational Pharmaceutical Companies on the Korean Government's Policy on the Pharmaceutical Industry (세계화와 국민국가의 복지정책 자율성: 다국적 제약자본이 우리나라 제약정책 결정에 미친 영향을 중심으로)

  • Lee, Su-Yun;Kim, Young-Mi
    • Korean Journal of Social Welfare
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    • 제57권3호
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    • pp.5-30
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    • 2005
  • Globalization has conflicting effects on pharmaceutical policies. A change into a 'populist competitive nation' due to globalization strengthens policies to reduce drug manufacturing costs while the WTO's TRIPS Agreement that is affected by multinational pharmaceutical companies increases drug manufacturing costs by bolstering the patent rights on new drugs. Currently, the independency of populist nations' policies to reduce drug manufacturing cost is being compromised because multinational organizations(such as the European Union) which represents the interests of the multinational pharmaceutical companies put restrictions on the pharmaceutical policies of populist nations for purposes of promoting the industrial goals of the multinational companies. Korea is no exception. Up until the late 1990s, the main feature of the pharmaceutical policies in Korea was keeping the drug price at the cost level based on a growth-driven ideology, and this was Korea's unique policy tools as a developing nation. However, the increase in the power of multinational pharmaceutical companies currently infringes on the independency of Korea's pharmaceutical policies. Expensive imported drugs were originally covered by the national health insurance plan, but starting from 1999 such drugs began to be covered by the plan. After separation of medical and pharmaceutical services, the use of expensive drugs was increased, and the Korean government planned to introduce the reference price policy in order to contain the cost of the national health insurance plan. However, due to pressures from the U.S. government as well as multinational pharmaceutical companies, implementation of the policy has been postponed. In addition, due to a pressure from the U.S. government, a working group was created which would affect the health care policy of the Korean government. Discussions so far on globalization was about whether the change into populist competitive nations due to globalization resulted in the reduction of welfare spending. However, this study shows not only the reduction of health care cost through policies to reduce drug manufacturing costs but increase in welfare spending by raising the strengths of multinational pharmaceutical companies that are for-profit providers of welfare service. While focusing on the contradictory effects of globalization on pharmaceutical policies of a nation, this study looked at how these conflicting effects end up promoting the interests of multinational pharmaceutical companies by examining the Korean case.

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