• Title/Summary/Keyword: Oil pressure

Search Result 1,407, Processing Time 0.025 seconds

Analysis and Antioxidant Activity of Volatile Extracts from Plants Commonly Used in Korean Foods (한국 식품재료로 상용되는 식물로부터 분리한 향기추출물의 항산화능 탐색)

  • Jang, Hae-Won;Lee, Hwa-Jung;Lee, Kwang-Geun
    • Korean Journal of Food Science and Technology
    • /
    • v.37 no.5
    • /
    • pp.723-729
    • /
    • 2005
  • Volatile compounds of dropwort (Oenanthe javanica DC), crown daisy (Chrysanthemum coronarium L. var. spatiosum), and sesame (Sesamum indicum L.) were isolated by steam distillation under reduced pressure (DRP) and liquid-liquid continuous extraction (LLE). Aroma extracts of the plants were identified by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) and their antioxidant activities were evaluated in two different assays. The aroma extracts isolated from dropwort, crown daisy, and sesame inhibited the oxidation of hexanal by 25%, 95%, and 99%, respectively, for one month at the $500{\mu}g/mL$ level. They inhibited malonaldehyde formation from cod liver oil by 48%, 54%, and 29%, respectively, at the $500{\mu}g/mL$ level. Their antioxidant activities were comparable to those of the natural antioxidant, ${\alpha}-tocopherol$.

A Study on Risk Analysis and Acident Prevention Heater Interlock By-pass (Heater interlock by-pass로 인한 위험분석 및 사고방지에 대한 연구)

  • Son Jae-geun;Park Kyo-Shik;Kang Tae-Yeon;Yeo Yeong-Koo
    • Journal of the Korean Institute of Gas
    • /
    • v.7 no.1 s.18
    • /
    • pp.24-27
    • /
    • 2003
  • In this paper it was investigated 15 heaters of CDU plant heater, NCC plant heater, CO plant heater, Aromatic plant heater and so on while running in our country. It was also analysed the standard of operation procedure, the action in alarm, the interlock system, the operating situation of the interlock by-pass and major accident about the heater and so on. This paper presents the installation of the on-line monitoring, the additional installation of the local pressure gauge and temperature gauge, the check in starting operation,'the management of the interlock by-pass, the change of manufacturer causing the disorder of instrument sensor, the management method of DCS alarm for methods of the interlock prevention and facilities improvement. It was few information about the heater interlock in the inside and outside of the country We mainly have studied with reflecting the opinion of the operator and manager on site, the sheet of process trouble and operation procedure and so on. we think that the accident relating to the interlock will significantly reduce if the companies apply the conclusion of this study(i.e. methods of the interlock prevention and facilities improvement).

  • PDF

Evaluation of Electrohydraulic Left Ventricular Assist Device through Animal Experiment (동물실험을 통한 전기유압식 좌심실 보조장치의 성능 평가)

  • Choi, J.S.;Chung, C.I.;Choi, W.W.;Park, S.K.;Jo, Y.H.;Om, K.S.;Lee, J.J.;Won, Y.S.;Kim, H.C.;Kim, W.G.;Min, B.G.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1996 no.05
    • /
    • pp.84-87
    • /
    • 1996
  • We have been developed electrohydraulic left ventricular assist device and done various in vivo evaluation on the device. Through the in vivo experiment conducted from Jan. 23, 1996 to Feb. 8, we could have experience of long-term evaluation fur the first time. The sheep used in this experiment had survived for 16 days. We used new actuator with reduced size and linear motion guide replacing oil box and ball bearings. Also, we used improved blood chamber with reduced size, reduced weight facilitating fixing the chamber to animal's body, and polymer sac having improved folding pattern. Against suction problem, we used absolute pressure limiter only. Motor current for driving this new actuator was not much higher than older one. Effective stroke volume was about 48 cc. Thrombosis was found around top area and peripheral boundary of the sac and valves. There was no sign of damage from suction problem in the atrium observed at autopsy. Main cause of death was presumed to be progressive formation of thrombosis in the cannulae. In this paper, the results of this experiment are documented.

  • PDF

Technical Trends of Hydrogen Manufacture, Storage and Transportation System for Fuel Cell Vehicle (연료전지자동차용 수소제조와 저장·운반기술동향)

  • Kil, Sang-Cheol;Hwang, Young-Gil
    • Resources Recycling
    • /
    • v.25 no.1
    • /
    • pp.48-59
    • /
    • 2016
  • The earth has been warming due to $CO_2$ gas emissions from fossil fuel cars and a ship. So the hydrogen fuel cell vehicle(FCV) using hydrogen as a fossil fuel alternative energy is in the spotlight. Hyundai Motor Company of Korea and a car companies of the US, Japan, Germany is developing a FCV a competitive. Obtained hydrogen as a by-product of the coke plant, oil refineries, chemical plants of steel mill, coal is reacted with steam at high temperatures, methane gas, manufacture of high purity hydrogen Methane Steam Reforming and hydrogen detachable reforming method using the Pressure Swing Adsorption or Membrane Reforming technical or decomposition of water to produce electricity. Hydrogen is the electronic industry, metal and chemical industries, which are used as rocket fuel, etc. are used in factories, hospitals, home of the fuel Ene.Farm system or FCV. And a method of storing hydrogen is to store liquid hydrogen and a method for compressing normal hydrogen to the hydrogen container, by storing the latest hydride or Organic chemical hydride method is used to carry the hydrogen station. Korea is currently 13 hydrogen stations in place and in operation, plans to install a further 43 places.

Effect of Screw Configurations and Process Parameters on Characteristics of Wheat Bran Extrudates (스크류 조합과 공정변수 조절에 따른 밀기울 압출물의 특성)

  • Kim, Chong-Tai;Hwang, Jae-Kwan;Cho, Sung-Ja;Kim, Chul-Jin;Kim, Hae-Sung
    • Korean Journal of Food Science and Technology
    • /
    • v.28 no.1
    • /
    • pp.169-178
    • /
    • 1996
  • Target parameters such as water solubility index (WSI), intrinsic viscosity (IV), water holding capacity (WHC), oil holding capacity (OHC), soluble dietary fiber (SDF) and microstructure were investigated on three different screw configurations during twin-screw extrusion of wheat bran. WSI of raw wheat bran (RWB) was 13.7%, while that of extrudates ranged $16.3{\sim}23.2%$ when extruded using screw configurations with 5 reverse screw elements (RSE). It was found that the moisture content of RWB greatly affected WSI of extrudates. IV of wheat bran extrudates increased from 10.6 ml/g of RWB to $37.86{\sim}44.37\;ml/g$ of extrudates extruded using 3, 4 and 5 RSE, whose trend was highly related to the moisture content of RWB and the extrusion pressure. Multiplication of IV and soluble solid (SS) content exhibited good correlation $(R^2=0.85)$ with specific mechanical energy (SME). The results suggested that SS and molecular size are an important factor governed by the SME in solubilization of wheat bran. WHC increased with increasing feed rate and moisture content, while OHC decreased. SDF increased from 2.68% of RWB to $4.32{\sim}6.48%$ of extruded wheat bran, indicating the significant breakdown of cell wall components. Microstructure of the extrudates showed the distinct patterns of degradation and solubilization of cell wall structure, depending on the moisture content of RWB.

  • PDF

A Study on the Safety Code Development of Gas Engine Micro Combined Heat and Power System (소형 가스엔진 열병합 발전시스템 안전기준 개발)

  • Kwon, Jun-Yeop;Kim, Min-Woo;Lee, Jung-Woon
    • Journal of the Korean Institute of Gas
    • /
    • v.25 no.4
    • /
    • pp.27-35
    • /
    • 2021
  • Recently, as a solution to the sharp drop in "power reserve ratio", it is being converted to a microgrid that enables bi-directional transmission and distribution. A microgrid is composed of a small-scale distributed power supply and a load. As a representative technology of distributed power generation, there is a Micro Combined Heat and Power system applied to homes and buildings. In this study, a safety standard was developed by dividing the power generation system, cooling system, lubrication system, and exhaust system to derive safety standards for a small gas engine power generation system with a gas consumption less than 232.6kW (200,000 kcal/h). In the case of the power generation system, a filter was installed and the system was stopped by detecting gas leakage and abnormalities in engine speed or output and the cooling system is stipulated to stop the system in case of insufficient cooling water or overheating. The lubrication system monitors the pressure and temperature of the lubricating oil and stops the system when an abnormality occurs, and the exhaust gas emission concentration regulation value was specified in accordance with domestic and foreign standards. Through the results of this study, it is judged that the safety of the gas engine power generation system can be improved and it can contribute to the commercialization of products.

Process Risk Assessment for a Batch Condensation Reaction of Polyester Resin using K-PSR Technique (K-PSR 기법을 활용한 회분식 폴리에스터 축합반응에서의 공정 위험성 평가 연구)

  • Park, Kyung-Min;Lee, Dong-Kyu;Lee, Haakil;Lee, Joon-Man;Ahn, Won-Sool
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.3
    • /
    • pp.35-42
    • /
    • 2019
  • Risk assessment and analysis for a medium-to-small sized chemical plant that manufactures a polyester resin by the process of batch-type condensation reaction was conducted using K-PSR technique which is one of the risk assessment methods used to implement the Process Safety Management System (PSM). K-PSR is a risk assessment technique developed by KOSHA to compensate for difficulties caused by the lack of infrastructure of medium-to-small sized chemical plants in the re-evaluation. To apply the K-PSR technique, the entire process of a selected chemical palnt was classified in two review sections, i.e., the condensation reaction process and the dilution/filtration process, and the potential risks of the process about these review sections were identified and classified based on the four guide-words (release, fire.explosion, process trouble, and injury). As the results of the research, refer to recommend of risk rating has been confirmed that non-destructive testing of old facilities and the preparation of LOTO procedures for the electrical equipments are necessary as specific measures to prevent the risk of release and fire.explosion. It was also shown that pressure gauges and thermometers should be installed on the hot-oil supply piping to minimize the process trouble, and exhausting hood should be installed to prevent potential injury.

Synthesis and Characterization of Interfacial Properties of Sorbitan Laurate Surfactant (Sorbitan Laurate 계면활성제 합성 및 계면 특성에 관한 연구)

  • Lee, Seul;Kim, ByeongJo;Lee, JongGi;Lim, JongChoo
    • Applied Chemistry for Engineering
    • /
    • v.22 no.1
    • /
    • pp.37-44
    • /
    • 2011
  • The critical micelle concentration (CMC) of sorbitan laurate SP 20 surfactant in this paper was near $7.216{\times}10^{-4}mol/L$ and the surface tension at CMC was about 26.0 mN/m, which showed higher CMC and lower surface tension than those of octylphenol ethoxylate octylphenol ethoxylate (OPE) 10 surfactant. Dynamic surface tension measurement using a maximum bubble pressure tensiometer showed that the adsorption rate at the interface between air and surfactant solution was found to be slower with SP 20 surfactant, presumably due to a low mobility of SP 20 surfactant monomer. The contact angle of SP 20 surfactant solution was observed to decrease with an increase in surfactant concentration and showed a larger value than that of OPE 10 surfactant solution. Half-life time for foams generated with 1 wt% surfactant solution was also larger with SP 20 surfactant, which indicated higher foam stability with SP 20 surfactant. Dynamic behavior study reveals that the solubilization of n-decane oil was much lower with SP 20, which is in good agreement with experimental results of foam stability, contact angle and CMC. Dynamic interfacial tension measurement by a spinning drop tensiometer shows that interfacial tensions at equilibrium condition in both systems were almost the same but the time required to reach equilibrium was longer with SP 20.

Numerical study on the foam spraying for AFDSS applicable to initial fire suppression in large underground spaces (지하대공간 초동 화재진압에 적용가능한 자율형 소화체계의 폼 분사 해석 기법 연구)

  • Park, Jinouk;Yoo, Yongho;Kim, Whiseong
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.23 no.6
    • /
    • pp.503-516
    • /
    • 2021
  • Autonomous fire detection and suppression system requires advanced technology for complex detection technology and injection/control technology for accurate hitting by fire location. Also, foam spraying should be included to respond to oil fires. However, when a single spray monitor is used in common, water and foam spray properties appear different, so for accurate fire suppression, research on the spray trajectory and distance will be required. In this study, experimental studies and numerical analysis studies were combined to analyze the foam spray characteristics through the spray monitor developed for the establishment of an autonomous fire extinguishing system. For flow analysis of foam injection, modeling was performed using OpenFOAM analysis software, and the commonly used foaming agent (Aqueous Film-Forming Foam) was applied for foam properties. The injection distance analysis was performed according to the injection pressure and the injection angle according to the form of the foam, and at the same time, the results were verified and presented through the injection experiment.

A Study on Impact of Factors Influencing Maritime Freight Rates Using Poisson and Negative Binomial Regression Analysis on Blank Sailings of Shipping Companies (포아송 및 음이항 회귀분석을 이용한 해상운임 결정요인이 해운선사의 블랭크 세일링에 미치는 영향 분석 연구)

  • Won-Hyeong Ryu;Hyung-Sik Nam
    • Journal of Navigation and Port Research
    • /
    • v.48 no.1
    • /
    • pp.62-77
    • /
    • 2024
  • In the maritime shipping industry, imbalance between supply and demand has persistently increased, leading to the utilization of blank sailings by major shipping companies worldwide as a key means of flexibly adjusting vessel capacity in response to shipping market conditions. Traditionally, blank sailings have been frequently implemented around the Chinese New Year period. However, due to unique circumstances such as the global pandemic starting in 2020 and trade tensions between the United States and China, shipping companies have recently conducted larger-scale blank sailings compared to the past. As blank sailings directly impact freight transport delays, they can have negative repercussions from perspectives of both businesses and consumers. Therefore, this study employed Poisson regression models and negative binomial regression models to analyze the influence of maritime freight rate determinants on shipping companies' decisions regarding blank sailings, aiming to proactively address potential consequences. Results of the analysis indicated that, in Poisson regression analysis for 2M, significant variables included global container shipping volume, container vessel capacity, container ship scrapping volume, container ship newbuilding index, and OECD inflation. In negative binomial regression analysis, ocean alliance showed significance with global container shipping volume and container ship order volume, the alliance with container ship capacity and interest rates, non-alliance with international oil prices, global supply chain pressure index, container ship capacity, OECD inflation, and total alliance with container ship capacity and interest rates.