• Title/Summary/Keyword: reduced pressure

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Studies on Constituents of the Higher Fungi of Korea(XXXVII) - Antitumor Components of Armillariella mellea - (한국산(韓國産) 고등(高等) 균류(菌類)의 성분(成分) 연구(硏究)(제(第)37보(報)) - 뽕나무버섯의 항암(抗癌) 성분(成分) -)

  • Kim, Jin-Sook;Choi, Eung-Chil;Kim, Hye-Ryoung;Lee, Chong-Kil;Lee, Chong-Ock;Chung, Kyeong-Soo;Shim, Mi-Ja;Kim, Byong-Kak
    • The Korean Journal of Mycology
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    • v.11 no.4
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    • pp.151-157
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    • 1983
  • To find antitumor components in Korean basidiomycetes, the carpophores of Armillariella mellea which were collected in Gyeong Gi Province were extracted with distilled water at $90{\sim}100^{\circ}C$ for eight hours. The hot water extract was concentrated under reduced pressure, mixed with three-fold volumes of ethanol and allowed to stand at $4^{\circ}C$ overnight. The precipitate was centrifugated and lyophilized to yield a protein-polysaccharide fraction. It was examined for antitumor activity against sarcoma 180 implanted in ICR mice. The fraction showed 75.7%, 83.9%, and 94.1% of tumor inhibition ratios at the doses of 10, 20 and 50 mg/kg/day, respectively. The chemical analysis of the fraction showed that it contained a polysaccharide(41.3%) and a protein (35.0%). The hydrolyzates of the polysaccharide moiety contained fucose (4.5%), xylose (1.1%), galactose (17.4%), glucose (55.4%), mannose(19.4%), and one unknown monosaccharide. The protein moiety contained seventeen amino acids. The protein-polysaccharide from A. mellea was administered, i.p., to mice and caused an influx of polymorphonuclear leukocytes (PMN) at $5{\sim}24$ hours which was followed by an accumulation of macrophages and disappearance of the PMN at $48{\sim}72$ hours.

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Study on the Development of Reinforced Earth Retaining Wall (보강옹벽개발연구)

  • 유용환
    • Geotechnical Engineering
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    • v.2 no.3
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    • pp.51-66
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    • 1986
  • The design of fabric reinforced retaining wall structure was discussed in this article. It was confirmed that the reinforced retaining earth wall which was designed by new theoretical formulae developed this time was stable structurally and economically. The plastic fabric filter which was placed in layers behind the facing element reduced the lateral earth pressure on the wall elements in comparison with a conventional retaining earth walls. The reinforcing characteristics of earth wall was governed by the spacing of fabric layers, effective length of fabrics, particle distribution and compaction, and thus it is essential that, in the construction field, the reinforcing strips should be selected in order to develop the maximum friction forces bet.eon soil and fabric filters. The maximum tensile stress developed from the reinforcing strips was appeared at a little far distance from the back of skin element and it was not well agreed with the Rankine's theory but distributed well as a symmetrical shape against the point of the maximum tensile stress. The total length of the different layers should be sufficient so that the tension in the fabric strip could be transferred to the backfill material. Also the total stability of reinforced earth wall should be checked with respect to a failure surface which extended blond the different lathers.

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Incidence of Medical Services and Needs for Hospital-based Home Care Nursing in Elder Care Institutions (노인요양시설 내 의료서비스 발생빈도와 병원중심 가정간호 요구도 조사)

  • Kim, Jae-Seung;Lee, Joo-Young;Song, Chong-Rye;Lee, Mi-Gyeong;Hwang, Moon-Sook
    • Journal of Korean Academic Society of Home Health Care Nursing
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    • v.16 no.1
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    • pp.49-58
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    • 2009
  • Purpose: This study aimed to clarify the needs for hospital-based home care nursing medical services in elder care institutions by analyzing the details and frequency of medical services provided by, and the needs for, hospital based home care nursing in select institutions in Korea. Methods: Seventy-seven staffs at elderly care institutions located throughout the country completed self-report questionnaires between February 1 and May 31, 2009. SPSS ver. 14.0 was used for data analysis regarding frequency and percentage, mean and standard deviation. Results: Forty-eight hospital-based home care nursing medical services in eight domains were identified as being needed in elderly care institutions. The most commonly used medical services were providing instruction in oral drug administration, checking drug beneficial/adverse effects, and administering blood glucose test, while the most needed medical services requiring hospital based home care nursing were complex pressure ulcer care, followed by diabetic foot ulcer management and nutrient injection. Conclusion: The present results should provide fundamental data for better healthcare services with hospital based home care nursing at elderly care institutions as part of a 'win-win' strategy through which medical expenses are reduced, insurance costs are kept stable, and safe and high-quality medical services are provided for residents of elder care institutions. Political decisions intended to promote visits by hospital based home care nurses to elder care institutions would be a prudent course.

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A Effect of Reaction Conditions on Syngas Yield for the Preparation of Syngas from Landfill Gas (매립지가스(LFG)로부터 합성가스 제조시 반응조건에 따른 수율에 미치는 연구)

  • CHO, WOOKSANG;CHOI, KEONGDON;BAEK, YOUNGSOON
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.5
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    • pp.477-483
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    • 2015
  • LFG (Land-Fill Gas) includes components of $CH_4$, $CO_2$, $O_2$, $N_2$, and water. The preparation of synthesis gas from LFG as a DME (Dimethyl Ether) feedstock was studied by methane reforming of $CO_2$, $O_2$ and steam over $NiO-MgO-CeO_2/Al_2O_3$ catalyst. Our experiments were performed to investigate the effects of methane conversion and syngas yield on the amount of LFG components over $NiO-MgO-CeO_2/Al_2O_3$ catalyst. Results were obtained through the methan reforming experiments at the temperature of $900^{\circ}C$ and GHSV of 8,800. The results were as following; it has generally shown that syngas yield increase with the increase of oxygen and steam amounts and then decrease. Highly methane conversion of above 98% and syngas yield of approximately 60% were obtained in the feed of gas composition flow-rate of 243ml/min of $CH_4$, 241ml/min of $CO_2$, 195ml/min of $O_2$, 48ml/min of $N_2$, and 450ml/min of steam, respectively, under reactor pressure of 1 bar for 200 hrs of reaction time. Also, it was shown that catalyst deactivation by coke formation was reduced by excessively adding oxygen and steam as an oxidizer of the methane reforming.

Effect of Fiber Addition for Improving the Properties of Lightweight Foamed Concrete (경량 기포콘크리트의 성능향상에 대한 섬유혼입의 영향)

  • Lee, Kyung-Ho;Yang, Keun-Hyeok
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.4
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    • pp.383-389
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    • 2015
  • The objective of this study is to develop mixture proportioning approach of crack controlled lightweight foamed concrete without using high-pressure steam curing processes, as an alternative to autoclaved lightweight concrete blocks (class 0.6 specified in KS). To control thermal cracks owing to hydration heat of cementitious materials, 30% ground granulated blast-furnace slag (GGBS) was used as a partial replacement of ordinary portland cement (OPC). Furthermore, polyvinyl alcohol (PVA) and polyamid (PA) fibers were added to improve the crack resistance of foamed concrete. The use of 30% GGBS reduced the peak value of hydration production rate measured from isothermal tests by 28% and the peak temperature of foamed concrete measured from semi-adiabatic hydration tests by 9%. Considering the compressive strength development, internal void structure, and flexural strength of the lightweight foamed concrete, the optimum addition amount of PVA or PA fibers could be recommended to be $0.6kg/m^3$, although PA fiber slightly preferred to PVA fiber in enhancing the flexural strength of foamed concrete.

The Effects of a Low Intensity Excercise Program on Psychosocial Factors of Excercise and Physical Factors in Elderly Women (저강도 운동프로그램이 여성노인의 운동에 대한 사회.심리적 및 신체적 요인에 미치는 효과)

  • Nam, Mi-Ra;Kim, Young-Hee;Ahn, Ok-Hee;Yang, Bok-Sun
    • Research in Community and Public Health Nursing
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    • v.18 no.3
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    • pp.373-381
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    • 2007
  • Purpose: An exercise program, which was composed of motions simple and easy to follow, was developed and applied to aged women as a way to improve their health conditions. Method: To ascertain the effects of the exercise, which was conducted twice a week and 16 times in total for 8 weeks from September 10 to November 5, 2005 in two experimental groups (31 Persons) and a control group (31 persons), this study conducted quasi-experiments of nonequivalent control group pre-post test design. Data were analyzed using SPSS/PC Win 10.0, the reliability of the measuring tools using Cronbach's alpha, the verification of equivalence for general properties and dependent variables using Chi-square test and t-test, and the verification of hypotheses using t-test and ANCOVA. Results: After the exercise program. the aged women showed profitable evaluation of decisional balance, high feeling of self-efficacy as well as improved subjective awareness of health. Their diastolic blood pressure and total cholesterol were also reduced significantly after the exercise. Conclusion: After the conduct of the exercise program for 8 weeks, aged women showed increased profitable decisional balance, self-efficacy and subjective awareness of health. This suggests that continuous and proper exercise is effective as an intervention for health improvement for the aged as well as the prevention of and recovery from geriatric diseases.

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Effect of the Addition of Aluminium Distearate on Manufacturing of $UO_2$ Nuclear Fuel (Aluminium Distearate 첨가가 $UO_2$ 핵연료 제조에 미치는 영향)

  • 박지연;정충환;김영석
    • Journal of the Korean Ceramic Society
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    • v.29 no.8
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    • pp.609-616
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    • 1992
  • This study has been investigated on the milling of Aluminium Distearate (ADS) powder and characteristics of the ADS-doped UO2 pellets. As-received ADS powder of the agglomerated particles has not shown any milling effect because of heat generated during planetary milling. But the use of coolant to effectively remove heat generated during milling has been found an effective way in breaking up the agglomerates of ADS powder. The green density of the UO2 pellet decreases with the amount of ADS powder doped. Therefore, in order to get the sintered density of 95% pellet decreases with the amount of ADS powder doped. Therefore, in order to get the sintered density of 95% theoretical density, the 200 ppm ADS-doped UO2 pellet has to be pressed under higher compacting pressure of 3500~4000 kgf/$\textrm{cm}^2$ compared with the ADS-undoped UO2 pellet pressed under around 3000 kgf/$\textrm{cm}^2$. The ADS-dpoed UO2 pellet with even relatively low sintered density of 10.27 g/㎤ exhibits open porosity of 1% while open porosity of the ADS-undoped UO2 pellet is reduced to around 1% only after its sintered density increases to 10.43g/㎤. It is, therefore, concluded that doping of ADS powder significantly contributes to the decrease in open porosity of the UO2 pellet. The dilatometry of the ADS doped UO2 pellet shows the sintering rate curve with the bimodal mode, which could be attributed to a phase reaction between UO2 and ADS. The X-ray diffraction analysis indicates that there occurs not any new phase formed but the shift of the peaks. It would be expected that a phase reaction resulting in solid solution would happen in the temperature range of 130$0^{\circ}C$ to 150$0^{\circ}C$ between UO2 and ADS.

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Fabrication and Properties of Reaction Bonded SiC Hot Gas Filter Using Si Melt Infiltration Method (용융 Si 침윤방법에 의한 반응소결 탄화규소 고온가스 필터의 제조 및 특성)

  • 황성식;김태우
    • Journal of the Korean Ceramic Society
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    • v.40 no.9
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    • pp.891-896
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    • 2003
  • Novel fabrication technique was developed for high strength Reaction-Bonded SiC (RBSC) hot gas filter for use in IGCC (Integrated Gasification Combined Cycle) system. The room and high temperature fracture strengths for Si-melt infiltrated reaction-bonded SiC were 50-123, and 60-66 MPa, respectively. The average pore size was 60-70 $\mu\textrm{m}$ and the porosity was about 34 vol%. RBSC infiltrated with molten silicon showed improved fracture strength at high temperature, as compared to that of clay-bonded SiC, due to SiC/Si phase present within SiC phase. The thickness for SiC/Si phase was increased with increasing powder particle size of SiC from 10 to 34 $\mu\textrm{m}$. Pressure drop with dust particles showed similar response as compared to that for Schumacher type 20 filter. The filter fabricated in the present study showed good performance in that the filtered powder size was reduced drastically to below 1 $\mu\textrm{m}$ within 4 min.

Study on the Performance of a Spark Ignition Gas Engine for Power Generation fueled by the Methane/Syngas Mixture (메탄/합성가스 혼합물에 의한 발전용 SI 가스엔진의 성능에 관한 연구)

  • Cha, Hyoseok;Hur, Kwang Beom;Song, Soonho
    • Journal of the Korean Institute of Gas
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    • v.19 no.5
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    • pp.7-12
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    • 2015
  • Hydrogen is usually produced by using syngas generated by the fuel reforming for natural gas so far. The further process is needed for increasing the hydrogen yield of syngas. However, the process for upgrading the hydrogen yield is accompanied by additional energy sources and economic costs. Thus related studies on the method for using as a mixture in itself have been conducted in order to utilize more efficiently syngas. The effect on the engine performance for methane/syngas mixture of 30kW spark ignition gas engine for power generation has been investigated in this study. As a result, it was found that the combustion phenomena such as the maximum in-cylinder pressure and crank angle at that time have been improved by methane/syngas mixture. Through these, fuel conversion efficiency could be enhanced by about 98% of methane/hydrogen mixture and $NO_x$ emissions could be reduced by about 12% of methane-hydrogen mixture.

Effects of Curved Pipe Geometry and Inside Fluid Flow on the Vibrational Characteristics of Pipe Systems (배관의 형상 및 내부유체 유동이 배관계의 진동특성에 미치는 영향)

  • Choi, Myung-Jin
    • Journal of the Korean Institute of Gas
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    • v.20 no.6
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    • pp.58-64
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    • 2016
  • Vibrational characteristics of curved pipe structures are investigated with respect to the change of inside flow velocities. Based upon the Hamilton's principle, the equations of motions are derived, and the finite element equation is constructed to solve the frequency equation for curved pipe structures. When the initial tension is neglected in cured pipes, the natural frequencies are reduced as flow velocity increases, and the rapid decreases of the natural frequencies take place. However, when the initial tension is taken into account, the natural frequencies are not changed with the change of the flow velocity. In free vibrational simulation of pipe systems, it is necessary to calculate the initial force due to the velocity and the pressure of the fluid flow from the equilibrium. The force should be included in the equation of motion of the systems to get more accurate natural frequencies. The mechanical properties like stiffness or the location of pipe support need to be changed to avoid resonance. The natural frequencies are to be isolated from the frequency range of dominant vibration modes. The angles of elbows do not affect the change of the fundamental natural frequency, but affect the change of the third or higher natural frequencies.