• Title/Summary/Keyword: Flow regulation

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A Study on Fire Hazard Analysis and Smoke Flowing for the Semiconductor Manufacturing Process (반도체 제조공정의 연기유동에 관한 연구)

  • Han, Soo-Jin;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.9 no.1
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    • pp.197-211
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    • 2007
  • The power of semiconductor, Korea is continuously constructing semiconductor production line for keeping a front-runner status. however, studies and data about potential risks in semiconductor factory are still short. If fire does not initially suppressed, the fire causes a great damage. To decrease fire risk factors, in addition to fire fighting safety equipment, more important thing is how to design and construct fire protection system. The current fire protection codes about semiconductor factory come under functional law, and this law is short of consideration about particularity of factory. The existing prescriptive fire codes depending on experience compose without evident engineering verifications, thus equipments which is created by the current prescriptive fire code may bring about a variety of problems. For example, the design under the current regulation can not cope with the excessive investments, low efficiencies, and the diversifying construction designs and be applied to the quick changes of new technologies. Ergo, an optimal design for fire protection is to equip fire protection arrangements with condition and environment of production field. Manufacturing factory of semiconductors is a windowless airtight space. And for cleanliness, there exists strong flow of cooperation. Therefore, there is a need for fire safety design that meets the characteristic of a clean room. Accordingly, we are to derive smoke flow according to cooperation process within a clean room and construction plan of an optimal sensor system. In this study, in order to confirm the performance of proposed smoke-exhaust equipment and suggest efficient smoke exhaust device when there is a fire of 1MW of methane in the clean room of company H, we have implemented fire simulation using fluid dynamics computation.

Effect of Majoon Idraare Haiz in Polycystic Ovarian Syndrome - A pilot study

  • Firdose, Kouser fathima;Begum, Wajeeha
    • CELLMED
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    • v.12 no.1
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    • pp.3.1-3.7
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    • 2022
  • Background & Objectives: Polycystic ovarian syndrome (PCOS) is one of the commonest endocrine abnormality in women of reproductive age affecting from 4% - 21% of the reproductive women and is characterized by chronic anovulation and hyperandrogenism. The aim of the study was to evaluate the effect of majoon idraare haiz in menstrual regulation and morphological changes in ovaries in poly cystic ovarian syndrome. Methods: A Pilot study was carried out in the department of Ilmul qabalat wa amraze niswan, National institute of unani medicine, hospital, Bengaluru. Fifteen Patients of PCOS aged 18-35 diagnosed using Rotterdam criteria were included in the study. Patients with insulin sensitizing treatment within 3 months, hormonal treatment and those with h/o diabetes mellitus, hypertension, pregnant and lactating women were excluded.Majoon idraare haiz was administered orally at a dose of 10 g with 20 ml arqbed mushk once daily from fifth day of cycle for 21 days for three consecutive cycles. Primary outcome measure was menstrual regularity while changes in USG pelvis(normal ovarian morphology) was considered as secondary outcome measure. In addition, duration of flow and changes in basal metabolic index (BMI), modified Ferriman Gallwey (mFG) score, acanthosis nigricanswere observed. Data were analyzed using, ANOVA, paired student 't' test, fisher exact test. Results: Changes in duration of cycle, duration and amount of flow was achieved in 93.3% patients with p<0.0001 and 46.6% patients showed normal findings on pelvic ultrasonography with p=0.006. In addition, significant changes were also observed in BMI, hirsutism and acanthosis nigricans with p value of 0.0001, p=0.003 and p=0.009 respectively Conclusion: Majoonidraare haiz can be used as an effective alternative in management of PCOS patients. It has significant effect on menstrual regulation and changes in polycystic ovarian morphology to normal.

Seepage-Advection-Dispersion Numerical Analysis of Barrier System of Offshore Rubble Mound Revetment Landfill Under Steady Flow (정상류 조건에서 경사식호안 해상폐기물매립장의 차수에 대한 침투이류 분산해석)

  • Hwang, Woong-Ki;Kim, Hyang-Eun;Kim, Tae-Hyung
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.4
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    • pp.97-106
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    • 2019
  • This study was conducted to propose a reasonable requirement regulation of barrier system of rubble mound revetment offshore landfill for preventing contaminant leakage. The barrier is composed with bottom layer and side barrier. The bottom layer was assumed as impermeable clay layer and side barrier was composed with HDPE sheet (primary element) and mid-protection layer (supplementary element). Seepage-advection-dispersion numerical analysis has been conducted using SEEP/W and CTRAN/W programs under steady flow. As the results, the minimum required barrier regulations for hydraulic conductivity and thickness of the bottom layer were suggested. For side barrier, the extended length of HDPE sheet and the hydraulic conductivity of mid-protection layer were also suggested.

A Study on the Oil/Water Separation Efficiency of Laminated Plate Type Oily water Separator with Inclined Angle (경사각을 갖는 적층판식 유수분리기의 유수분리 효율에 관한 연구)

  • 한원희;김준효;최민선
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.2
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    • pp.365-374
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    • 2001
  • Its a tendency to strengthen related international was as the importance on marine oil pollution recently becomes the issue. According to the regulation of IMO, oil discharge from ships is allowed under 15PPM only and oil filtering equipment is essential. Oily water separator of laminated plate type which is one of gravity type separator can be use as assistant equipment for the oil filtering system to meet the present IMO standard, because it fits well to process large amount of rich oil with high specific gravity. The purpose of this paper is to investigate an efficiency of oil/water separation with the characteristics of laminated plate arrangement. The analyse of oil contents for oil-water mixture were carried out in order to find an efficiency of oil/water separation and an experimental study was simultaneously carried out to investigate internal flow characteristics of separator by visualization method and PIV(Particle Image Velocimetry) measurement at three spaces of plates for 5, 10 and 15 mm with variation of inlet flow rates of $0.25m^3$/h and $0.5m^3$/h. The experimental results showed that the space of the plates acts a significant role in the separating process.

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Increasing the Flow of Protein from Ruminal Fermentation - Review -

  • Wallace, R.J.;Newbold, C.J.;Bequette, B.J.;MacRae, J.C.;Lobley, G.E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.6
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    • pp.885-893
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    • 2001
  • This review summarizes some recent research into ways of improving the productivity of ruminal fermentation by increasing protein flow from the rumen and decreasing the breakdown of protein that results from the action of ruminal microorganisms. Proteinases derived from the plant seem to be of importance to the overall process of proteolysis in grazing animals. Thus, altering the expression of proteinases in grasses may be a way of improving their nutritive value for ruminants. Inhibiting rumen microbial activity in ammonia formation remains an important objective: new ways of inhibiting peptide and amino acid breakdown are described. Rumen protozoa cause much of the bacterial protein turnover which occurs in the rumen. The major impact of defaunation on N recycling in the sheep rumen is described. Alternatively, if the efficiency of microbial protein synthesis can be increased by judicious addition of certain individual amino acids, protein flow from ruminal fermentation may be increased. Proline may be a key amino acid for non-cellulolytic bacteria, while phenylalanine is important for cellulolytic species. Inhibiting rumen wall tissue breakdown appears to be an important mechanism by which the antibiotic, flavomycin, improves N retention in ruminants. A role for Fusobacterium necrophorum seems likely, and alternative methods for its regulation are required, since growth-promoting antibiotics will soon be banned in many countries.

A Study About Grid Impose Method On Real-Time Simulator For Wind-Farm Management System (풍력발전단지 관리·분석 시스템의 Real-Time Simulator 도입을 위한 계통모델 연동방안 연구)

  • Jung, Seungmin;Yoo, Yeuntae;Kim, Hyun-Wook;Jang, Gilsoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.7
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    • pp.28-37
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    • 2015
  • Owing to the variability of large-scaled wind power system, the development of wind farm management technologies and related compensation methods have been receiving attention. To provide an accurate and reliable output power, certain wind farm adopts a specified management system including a wind prediction model and grid expectation solutions for considering grid condition. Those technologies are focused on improving the reliability and stability issues of wind farms, which can affect not only nearby system devices but also a voltage condition of utility grid. Therefore, to adapt the develop management system, an expectation process about voltage condition of Point of Common Coupling should be integrated in operating system for responding system requirements in real-time basis. This paper introduce a grid imposing method for a real-time based wind farm management system. The expected power can be transferred to the power flow section and the required quantity about reactive power can be calculated through the proposed system. For the verification process, the gauss-seidel method is introduced in the Matlab/Simulink for analysing power flow condition. The entire simulation process was designed to interwork with PSCAD for verifying real power system condition.

Mathematical Model Simulations Assessing the Effects of Temperature on Residual Chlorine Concentrations in Water Storage Tanks (온도 변화에 따른 수돗물 저장 저수조 내 잔류염소에 관한 수학적 모형 시뮬레이션)

  • Noh, Yoorae;Park, Joonhong
    • Journal of Korean Society on Water Environment
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    • v.33 no.2
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    • pp.187-196
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    • 2017
  • To ensure hygienic safety of drinking water in a water storage tank, the concentrations of residual chlorine should be above a certain regulation level. In this study, we conducted model simulations to investigate the effects of temperature on residual chlorine in water storage tank conditions typically used in Seoul. For this, values of model parameters (decomposition rate constant, sorption coefficient, and evaporation mass transfer coefficient) were experimentally determined from laboratory experiments. The model simulations under continuous flow conditions showed that the residual chlorine concentrations were satisfied the water quality standard level (0.1 mg/L) at all the temperature conditions ($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$ and $25^{\circ}C$). Meanwhile, when the tanks had a no flow condition (i.e., no tap-water influent due to a sudden shut-down), the concentrations became lower than the regulatory level after certain periods. The findings from this modeling works simulating Seoul's water storage tanks suggested disappearance rate of residual chlorine could be reduced through the tanks design optimization with maintenance of low water temperature, minimization of air flow and volume, suppression of dispersion and the use of wall materials with low sorption ability.

Control of Sound Pressure inside a Flow Excited Cavity by Regulation of Vorticity Shedding (와류진동 조절에 의한 유동가진 공동 내부의 음압 제어)

  • Park, Jong-Beom;Hwang, Cheol-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.12
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    • pp.1223-1229
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    • 2007
  • Flow traveling over a cavity opening forms a vortex due to unstable shear layer and induces an aerodynamic pressure excitation from the diffusion of the vortex convecting out of the trailing edge of the opening. The interaction between the excitation force and the cavity response sustains resonance in the resonator(cavity) and locked-in vortex shedding at the leading edge of the opening. The aerodynamic excitation force can be described from the diffusion of the vortex over the trailing edge and the level of its diffusivity is related to the strength of vorticity seeded at the leading edge. In this study, the control scheme of the internal pressure oscillation was proposed from regulating the vorticity at the leading edge by use of an oscillating spoiler. It was found that the relative motion between the spoiler and the air mass at the cavity opening influenced vorticity strength and the control was achieved by direct feedback of the cavity pressure fluctuation to the actuator.

Effect of Nodus Nelumbinis Rhizomatis Extract on the Regulation of Regional Cerebral Blood Flow in Rats (흰쥐에서 우절(藕節) 추출물의 국소 뇌혈류량 조절 효과)

  • Kim, Young-Gyun;Kwon, Mi-Jung;Cho, Su-In
    • The Korea Journal of Herbology
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    • v.20 no.3
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    • pp.75-81
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    • 2005
  • Objectives : In brain disorders such as ischemic stroke, the final outcome depends largely on the duration and the degree of the ischemia as well as the susceptibility of various cell types in the affected brain region. In the present study, the effects of Nodus Nelumbinis Rhizomatis Extract(NNRe) were tested for the anti-oxidative action of rCBF. Methods : Regional cerebral blood flow(rCBF) were determined by LDF methods. LDF allows for real time, noninvasive, continuous recordings of local CBF. The LDF method has been widely used to trace hemodynamic changes in the superficial or the deep brain structures in experimental stroke research. Results : NNRe treatment showed no change on rCBF in methylene blue, ODQ and L-NNA pretreated rats. 120 minutes of MCAO and followed reperfusion, 0.1% concentration of NNR treatment improved the altered cerebral hemodynamics of cerebral ischemic by increasing rCBF. Conclusions : The ischemia/reperfusion induced oxidative stress may have contributed to cerebral damage in rats, and the present study provides clear evidences for the beneficial effect of NNR on ischemia/reperfusion induced brain injury.

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X-ray micro-imaging of the arsenic absorption of sap flow in xylem vessels of a fern brake (X-ray 영상기법을 이용한 비소 흡수가 고사리 내부 수액 거동에 미치는 영향 연구)

  • Lee, Jin-Pyoung;Lee, Sang-Joon
    • 한국가시화정보학회:학술대회논문집
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    • 2006.12a
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    • pp.92-95
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    • 2006
  • The global environment is deteriorating at an alarming rate despite of enhanced international environmental regulation. Many studies have been performed to reduce pollutants. Recently, phytoremediation, plant-based technology for the removal of toxic contaminants from soil, water, and air, has been receiving large attention. Arsenic-contaminated soil is one of the major pollutant sources fur drinking water. The fern brake (Pteris erotica) has been reported as a hyper-accumulate arsenic from soils. In this study, we investigated the arsenic absorption effect on sap flow inside xylem vessels of a fern brake. The synchrotron X-ray micro-imaging technique was employed to monitor flow inside the plant non-invasively. The captured phase-contrast X-ray images show both anatomy and transport of water inside the fern brake. The refilling process of water containing arsenic inside the xylem vessels of fern brake's leaves and stems was clearly observed. These results would provide important information needed fur understanding the mechanisms of accumulation, translocation, and transformation of toxic materials in plants.

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