• Title/Summary/Keyword: Pressure Key

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A Study on the Changing Roles of Cadastral Organizations to Comply with Environmental Changes (환경변화에 따른 지적기관의 역할 변화에 대한 고찰)

  • Oh, Yi-Kyun;Park, Jong-Cheul
    • Journal of Cadastre & Land InformatiX
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    • v.44 no.2
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    • pp.59-72
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    • 2014
  • In this paper the key drivers change for cadastral organizations have been presented according to the following aspects; Geo-ICT development including positioning technology, government's public organization innovation policy, cadastral market opening pressure and decreasing of cadastral survey work. It was confirmed that the role of cadastral organization has to be changed from the conducting cadastral survey organization to the spatial information provision organization. Eventually it should take a role to realize Spatially Enabled Society(SES) which is fundamental for national development and upgrading quality of life in the society. From the case study of international cadastral organization, cadastral organization should take core responsibility for the Nation Spatial Data Infrastructure(NSDI) and meeting the future costumers requirements through technical developments and organization's innovation efforts.

Ultrahigh Vacuum Technologies Developed for a Large Aluminum Accelerator Vacuum System

  • Hsiung, G.Y.;Chang, C.C.;Yang, Y.C.;Chang, C.H.;Hsueh, H.P.;Hsu, S.N.;Chen, J.R.
    • Applied Science and Convergence Technology
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    • v.23 no.6
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    • pp.309-316
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    • 2014
  • A large particle accelerator requires an ultrahigh vacuum (UHV) system of average pressure under $1{\times}10^{-7}$ Pa for mitigating the impact of beam scattering from the residual gas molecules. The surface inside the beam ducts should be controlled with an extremely low thermal outgassing rate under $1{\times}10^{-9}Pa{\cdot}m^3/(s{\cdot}m^2)$ for the sake of the insufficient pumping speed. To fulfil the requirements, the aluminum alloys were adopted as the materials of the beam ducts for large accelerator that thanks to the good features of higher thermal conductivity, non-radioactivity, non-magnetism, precise machining capability, et al. To put the aluminum into the large accelerator vacuum systems, several key technologies have been developed will be introduced. The concepts contain the precise computer numerical control (CNC) machining process for the large aluminum ducts and parts in pure alcohol and in an oil-free environment, surface cleaning with ozonized water, stringent welding process control manually or automatically to form a large sector of aluminum ducts, ex-situ baking process to reach UHV and sealed for transportation and installation, UHV pumping with the sputtering ion pumps and the non-evaporable getters (NEG), et al. The developed UHV technologies have been applied to the 3 GeV Taiwan Photon Source (TPS) and revealed good results as the expectation. The problems of leakage encountered during the assembling were most associated with the vacuum baking which result in the consequent trouble shootings and more times of baking. Then the installation of the well-sealed UHV systems is recommended.

Fundamentals of Particle Fouling in Membrane Processes

  • Bhattacharjee Subir;Hong Seungkwan
    • Korean Membrane Journal
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    • v.7 no.1
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    • pp.1-18
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    • 2005
  • The permeate flux decline due to membrane fouling can be addressed using a variety of theoretical stand-points. Judicious selection of an appropriate theory is a key toward successful prediction of the permeate flux. The essential criterion f3r such a decision appears to be a detailed characterization of the feed solution and membrane properties. Modem theories are capable of accurately predicting several properties of colloidal systems that are important in membrane separation processes from fundamental information pertaining to the particle size, charge, and solution ionic strength. Based on such information, it is relatively straight-forward to determine the properties of the concentrated colloidal dispersion in a polarized layer or the cake layer properties. Incorporation of such information in the framework of the standard theories of membrane filtration, namely, the convective diffusion equation coupled with an appropriate permeate transport model, can lead to reasonably accurate prediction of the permeate flux due to colloidal fouling. The schematic of the essential approach has been delineated in Figure 5. The modern approaches based on appropriate cell models appear to predict the permeate flux behavior in crossflow membrane filtration processes quite accurately without invoking novel theoretical descriptions of particle back transport mechanisms or depending on adjust-able parameters. Such agreements have been observed for a wide range of particle size ranging from small proteins like BSA (diameter ${\~}$6 nm) to latex suspensions (diameter ${\~}1\;{\mu}m$). There we, however, several areas that need further exploration. Some of these include: 1) A clear mechanistic description of the cake formation mechanisms that clearly identifies the disorder to order transition point in different colloidal systems. 2) Determining the structure of a cake layer based on the interparticle and hydrodynamic interactions instead of assuming a fixed geometrical structure on the basis of cell models. 3) Performing well controlled experiments where the cake deposition mechanism can be observed for small colloidal particles (< $1\;{\mu}m$). 4) A clear mechanistic description of the critical operating conditions (for instance, critical pressure) which can minimize the propensity of colloidal membrane fluting. 5) Developing theoretical approaches to account for polydisperse systems that can render the models capable of handing realistic feed solutions typically encountered in diverse applications of membrane filtration.

Separation of $CO_2$ and $N_2$ with a NaY Zeolite Membrane under Various Permeation Test Conditions

  • Cho, Churl-Hee;Yeo, Jeong-Gu;Ahn, Young-Soo;Han, Moon-Hee;Hyun, Sang-Hoon
    • Korean Membrane Journal
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    • v.8 no.1
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    • pp.21-30
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    • 2006
  • A faujasite NaY zeolite membrane was prepared on a tubular ${\alpha}-Al_2O_3$ support by the secondary growth process, and effects of permeation test conditions on the $CO_2/N_2$ separation were investigated. A NaY zeolite membrane with good $CO_2/N_2$ separation was successfully synthesized by using the hydrothermal solution ($Al_2O_3:SiO_2:Na_2O:H_2O$ = 1:6:14:840 in a molar base): at a permeation temperature of $30^{\circ}C$, its $CO_2$ permeance and $CO_2/N_2$ separation factor were $2.5{\times}10^{-7}mol/m^2secPa$ and 34, respectively. The $CO_2$ and $N_2$ permeations were highly dependent on permeation test conditions (feed composition, feeding rate, feed pressure, He sweeping rate and permeation temperature). The results indicated that (i) $CO_2$ and $N_2$ permeations through NaY zeolite membrane are governed by surface and micropore diffusions, respectively, (ii) the preparation of NaY zeolite membrane with a large permeating area is one of the most difficult hurdles for its real applications, and (iii) the retardation of $N_2$ permeation is an effective key to improve $CO_2/N_2$ separation factor in NaY zeolite membrane.

A Study on the Medical Care System using Essential Oil (메디컬피부케어를 위한 에센셜 오일 적용방법에 대한연구)

  • Lee, Ae-Sun
    • Journal of the Korean Society of Fashion and Beauty
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    • v.5 no.3
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    • pp.111-117
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    • 2007
  • Essential oils aims to rejuvenate and beautify medical skin care the body through the use of essential oils, and generally to improve our outward appearance. Much of this section fouses on the different methods by which essential oils can be used to improve the complexion or to treat specific medical care skin conditions. Beauty, however, is not just skin-deep. The condition of the medical care express the overall health of an individual. A relaxed attitude, together with a well-balanced diet, enough exercise, and a daily intake of plenty of spring water or herbal teas, all help to keep the system in top condition. Essential oils is a healing art which has powerful effects on both mind and body. The vital element in essential oils is the pure oils which are extracted from various part of different plants. The key to medical aromatherapy care lies in its dual use of essential oils and medical care massage, thus masking full use of two of our most important senses-smell and touch. Medical aromatherapy care is holistic, working mainly on the nervous system and including the head and body as part of the same treatment. Using pressure points along the spine, Medical aromatherapy care on the autonomic nervous system and has an immediate effect of relexation. In directly it also acts on mood. Many of the medical massage movements help lymphatic drainage. Essential oils have many different qualities; they can be relaxing or invigorating and are generally antisepic and antibacterial. Medical aromatherapy care can have psychological benefits. The power of essences in healing has been recognized in the treatment of insect bites. Clove, thyme, sandalwood, and lavender are a few of the essences that have antiseptic. Essential oils effect the dry skin for small visual pores, dull matte finish, rough sandy feeling, tantskin. Essential oils effect the mature/sun damaged skin for some red or couperose areas, loose saggy skin, exposure to a lot of ultraviolet light. Essential oils effect the medical care nomal skin good elasticity, healthy color(good circulation), smooth terture.

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The antihyperlipidemic effect of alginate-free residue from sea tangle in hyperlipidemic rats

  • Yim, Mi-Jin;Lee, Jeong Min;Choi, Grace;Cho, Soon-Yeong;Lee, Dae-Sung
    • Fisheries and Aquatic Sciences
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    • v.22 no.11
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    • pp.27.1-27.6
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    • 2019
  • Background: In order to assess the high value-added use of the alginate-free residue of sea tangle, an animal study was performed to evaluate the functional activities and key compounds present. In the animal study, sea tangle and the alginate-free residue demonstrated good anti-hyperlipidemic and anti-arteriosclerotic abilities. Results: The functional compounds in the alginate-free residue of the sea tangle were effectively extracted by supercritical fluid extraction (SFE). The optimum extraction temperature and pressure were 40 ℃ and 6500 psi (M1) in the SFE, a better method in comparison to the conditions of 70 ℃ and 4500 psi (M2), respectively. The anti-atherosclerotic effects of the alginate-free residue of sea tangle (M1, M2) were investigated in Sprague-Dawley rats treated with poloxamer 407, Triton WR 1339, corn oil, and a high-fat diet. The M1 fraction reduced the serum lipid levels with greater efficacy than the M2 fraction. In the hyperlipidemic rats, treatment with M1 decreased the serum triglyceride (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) levels when compared to the levels in normal rats. Conclusion: Our results demonstrated that the alginate-free residue of sea tangle reduces serum TC, TG, and LDL-C. These results suggest that the alginate-free residue of sea tangle contains physiologically active components, such as fucosterol, that may exert beneficial effects in the prevention of atherosclerosis.

Factors affecting hand hygiene behavior among health care workers of intensive care units in teaching hospitals in Korea: importance of cultural and situational barriers

  • Jeong, Heon-jae;Jo, Heui-sug;Lee, Hye-jean;Kim, Min-ji;Yoon, Hye-yeon
    • Quality Improvement in Health Care
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    • v.21 no.1
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    • pp.36-49
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    • 2015
  • In Intensive Care Units (ICUs), where severely ill patients are treated, importance of reducing Hospital Acquired Infection (HAI) cannot be overstated. One of the simplest and most effective actions against HAI is proper hand hygiene (HH) behavior of Health Care Workers (HCWs). However, compliance varies across different cultures and different job types of HCWs (physicians, residents and nurses). This study aims to understand determinants of HH behavior by HCWs' job types in Korea. Qualitative analysis was performed based on Reasoned Action Approach style interviews with staff physicians, residents and nurses across 7 teaching hospitals. We found that all HCWs strongly believe HH is important in reducing HAI. There were, however, job type-specific HH behavior modifying factors; staff physicians stated feeling pressure to be HH behavior role model. Residents identified Quality Improvement team that measured compliance as a facilitator; a notable barrier for residents was senior physicians not washing their hands, because they were afraid of appearing impudent to their seniors. Nurses designated their chief nurse as a key referent. All participants mentioned heavy workload and lack of access to alcohol-based sanitizer as situational barriers, and sore and dry hand as deterrents to HH compliance.

A Case Study of Test Production of Gas from Hydrate Bearing Sediments on Nankai Trough in Japan (일본 난카이 해구 가스하이드레이트 퇴적층으로부터의 가스 시험생산 사례분석)

  • Kim, A-Ram;Lee, Jong-Won;Kim, Hyung-Mok
    • Tunnel and Underground Space
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    • v.25 no.2
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    • pp.133-143
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    • 2015
  • Gas hydrate is a solid substance composed of natural gas constrained in water molecules under low temperature and high pressure conditions. The existence of hydrates has been reported to be world-widely distributed, mainly at permafrost and deep ocean floor. Test productions of small amount of natural gas from the on-shore permafrost have been accomplished in U.S.A and Canada, but, world-first and the only production case from off-shore hydrate bearing sediments was in Nankai trough, Japan. In this study, we introduce key technologies in gas production from hydrates by analyzing the Japanese off-shore gas production project in Nankai trough in terms of depressurization- induced dissociation so as to utilize planned domestic gas production test in Ulleung basin.

A Study on the Flow Path Position Design of Waviness Friction Pad for Drag Torque Reduction in Wet Type DCT (파형 습식클러치의 드래그 토크 저감을 위한 파형내 유로 위치 설정 설계 연구)

  • Cho, Junghee;Han, Juneyeol;Kim, Woojung;Jang, Siyoul
    • Tribology and Lubricants
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    • v.33 no.1
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    • pp.1-8
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    • 2017
  • Drag torque reduction in a wet clutch pack is a key aspect of the design process of the dual clutch transmission (DCT) system. In order to reduce the drag torque caused by lubricant shear resistance, recently developed wet clutch pack systems of DCT, as well as automatic transmission and other four-wheel drive (4WD) couplings, frequently utilize wavy wet clutch pads. Therefore, wavy shape of friction pad are made on the groove patterns like waffle pattern for the reduction of drag torque. Additionally, the groove patterns are designed with larger channels at several locations on the friction pad to facilitate faster outflow of lubricant. However, channel performance is a function of the waviness of the friction pad at the location of the particular channel. This is because the discharge sectional area varies according to the waviness amplitude at the location of the particular channel. The higher location of the additional channel on the friction pad results in a larger cross-sectional area, which allows for a larger flow discharge rate. This results in reduction of the drag torque caused by the shear resistance of DCTF, because of marginal volume fraction of fluid (VOF) in the space between the friction pad and separator. This study computes the VOF in the space between the friction pad and separator, the hydrodynamic pressure developed, and the shear resistance of friction torque, by using CFD software (FLUENT). In addition, the study investigates the dependence of these parameters on the location and waviness amplitude of the channel pattern on the friction pad. The paper presents design guidelines on the proper location of high waviness amplitude on wavy friction pads.

Adventitious Root Cultures of Panax ginseng C.V. Meyer and Ginsenoside Production through Large-Scale Bioreactor System

  • Hahn, Eun-Joo;Kim, Yun-Soo;Yu, Kee-Won;Jeong, Cheol-Seung;Paek, Kee-Yoeup
    • Journal of Plant Biotechnology
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    • v.5 no.1
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    • pp.1-6
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    • 2003
  • The adventitious root of Panax ginseng C.A. Meyer is regarded as an efficient alternative to cell culture or hairy root culture for biomass production due to its fast growth and stable metabolite production. To determine optimal culture conditions for the bioreactor culture of ginseng roots, experiments have been conducted on physical and chemical factors such as bioreactor type, dissolved oxygen, gas supply, aeration, medium type, macro- and micro-elements, medium supplement during culture period, sucrose concentration, osmotic agents, medium pH and light. Elicitation is a key step to increase ginsenoside accumulation in the adventitious roots but biomass growth is severely inhibited by elicitor treatment. To obtain high ginsenoside content with avoiding biomass decrease, we applied two-stage bioreactor culture system. Ginseng adventitious roots were cultured for 40 days to maximize biomass increase followed by elicitation for 7 days to enhance ginsenoside accumulation. We also experimented on types and concentrations of jasmonate to determine optimal elicitation methods. In this paper, we discussed several factors affecting the root propagation and ginsenoside accumulation. Based on the results obtained from previous experiments we have established large-scale bioreactor system (1 ton-10 ton) for the efficient production of ginseng adventitious roots and bioactive compounds including ginsenoside. Still, experiments are on going in our laboratory to determine other bioactive compounds having effects on diet, high blood pressure, DPPH elimination and increasing memories.