• 제목/요약/키워드: Circulating

검색결과 1,832건 처리시간 0.036초

순환식 병류형 곡물건조기 개발(III) - 12톤 용량 건조기 성능평가 - (Development of a Rice Circulating Concurrent-flow Dryer(III) - Performance Evaluation of 12-ton Capacity Dryer -)

  • 한재웅
    • Journal of Biosystems Engineering
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    • 제34권5호
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    • pp.358-362
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    • 2009
  • This study was conducted to evaluate the performance of a 12 tons capacity circulating concurrent flow rice dryer. An actual scale dryer with the capacity of 12 tons was developed to obtain a faster drying rate of 0.8~1.2%(w.b.)/h, while maintaining a lower drying energy consumption of 5,000 kJ/kg-water and achieving a drying quality that was comparable to a conventional cross-flow rice dryer. The Test-1 was conducted at $110^{\circ}C\;-\;20\;cmm/m^2$ and the Test-2 was conducted at $120-110-100-90^{\circ}C\;-\;20\;cmm/m^2$ under the same conditions as Test-1. In Test-1, the drying rate, drying energy consumption and crack ratio were 0.98 %(w.b.)/h, 4,573 kJ/kg-water and 3.2%, respectively. In Test-2, the drying rate, drying energy consumption and crack ratio were 0.74 %(w.b.)/h, 4,790 kJ/kg-water and 4.0%, respectively. The results of these tests demonstrated that this concurrent-flow dryer reached the desired drying rate, drying energy consumption and crack ratio.

어성초(魚腥草) 약침(藥鍼)이 Melanoma B16 피부암(皮膚癌)의 증식억제효과(增殖抑制效果)와 Mononuclear cell subsets에 미치는 영향(影響) (Experimental Studies on the Effect of Houttuyniae herba Aqua-acupuncture on the Growth of Melanoma B16 Tissue and Mononuclear Cell Subsets in Mice)

  • 정승기
    • 대한한방내과학회지
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    • 제21권3호
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    • pp.453-460
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    • 2000
  • Experimental studies were performed to investigate the effect of Houttuyniae herba Aqua-acupuncture on the growth of Melanoma 816 tissue and Mononuclear cell subsets in mice. The results are as follows : 1. In the study of lymphocytes numbers in mice circulating blood, Houttuyniae herba Aqua-acupuncture showed inhibitory effect, but without stastistical significance. 2. In the study of $CD4^+$ T cell percentage in mice circulating blood, Houttuyniae herba Aqua-acupuncture showed inhibitory effect, but without stastistical significance. 3. In the study of $CD8^+$ T cell percentage in mice circulating blood, Houttuyniae herba Aqua-acupuncture showed inhibitory effect, with stastistical significance. 4. in the study of lymphocytes numbers in mice spleen tissue, Houttuyniae herba Aqua-acupuncture showed inhibitory effect, but without stastistical significance. 5. In the study of $CD4^+$ T cell percentage in mice spleen tissue, Houttuyniae herba Aqua-acupuncture showed inhibitory effect, but without stastistical significance. 6. In the study of $CD8^+$ T cell percentage in mice spleen tissue, Houttuyniae herba Aqua-acupuncture showed inhibitory effect, but without stastistical significance. 7. In the measurement of melanoma tissue weight, Houttuyniae herba Aqua-acupuncture showed increasing effect, but without stastistical significance. According to above results, it is concluded that Houttuyniae herba Aqua-acupuncture is effective upon immune responses in Melanoma 816 inoculated mice.

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Planar Motion Mechanism Test of the Mobile Harbor Running in Design Speed in Circulating Water Channel

  • Yoon, Hyeon-Kyu;Kang, Joo-Nyun
    • 한국항해항만학회지
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    • 제34권7호
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    • pp.525-532
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    • 2010
  • Mobile Harbor (MH) is a new transportation platform that can load and unload containers onto and from very large container ships at sea. It could navigate near harbors where several vessels run, or it could navigate through very narrow channels. In the conceptual design phase when the candidate design changes frequently according to the various performance requirements, it is very expensive and time-consuming to carry out model tests using a large model in a large towing tank and a free-running model test in a large maneuvering basin. In this paper, a new Planar Motion Mechanism(PMM) test in a Circulating Water Channel (CWC) was conducted in order to determine the hydrodynamic coefficients of the MH. To do this, PMM devices including three-component load cells and inertia tare device were designed and manufactured, and various tests of the MH such as static drift test, pure sway test, pure yaw test, and drift-and-yaw combined test were carried out. Using those coefficients, course-keeping stability was analyzed. In addition, the PMM tests results carried out for the same KCS (KRISO container ship) were compared with our results in order to confirm the test validity.

EMTP 기반 지중송전케이블 시뮬레이터 개발 및 적용 (Development and Applicatin of EMTP Based Power Cable Simulator for Underground Transmission Cables)

  • 정채균;박흥석;강지원;이종범;한상옥
    • 전기학회논문지
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    • 제59권8호
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    • pp.1374-1381
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    • 2010
  • This paper discusses the characteristics of sheath circulating current as well as the development and application of new software for underground power cable systems. Generally, in steady state, high sheath circulating current causes the increase of sheath temperature and thermal resistance which leads to the steeply reduction of the power capacity. Therefore, the exact calculation of sheath circulating current is required for analysis about the influence of high sheath current on permissible current. In this paper, Power Cable Simulator is developed for calculation of the sheath current. It can analyse the sheath current by real time. It is also easier to use than conventional software, such as EMTP and CabSim, because all the data for calculating the cable parameters are stored in a database(DB) within Power Cable Simulator. In addition, the accuracy of Power Cable Simulator is also proved through the comparison among the current calculated by Power Cable Simulator, EMTP and Cabsim with measured current.

Effect of Carrier Size on the Performance of a Three-Phase Circulating-Bed Biofilm Reactor for Removing Toluene in Gas Stream

  • Sang, Byoung-In;Yoo, Eui-Sun;Kim, Byung-J.;Rittmann, Bruce E.
    • Journal of Microbiology and Biotechnology
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    • 제18권6호
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    • pp.1121-1129
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    • 2008
  • A series of steady-state and short-term experiments on a three-phase circulating-bed biofilm reactor (CBBR) for removing toluene from gas streams were conducted to investigate the effect of macroporous-carrier size (1-mm cubes versus 4-mm cubes, which have the same total surface area) on CBBR performance. Experimental conditions were identical, except for the carrier size. The CBBR with 1-mm carriers (the 1-mm CBBR) overcame the performance limitation observed with the CBBR with 4-mm carriers (the 4-mm CBBR): oxygen depletion inside the biofilm. The 1-mm CBBR consistently had the superior removal efficiencies of toluene and COD, higher than 93% for all, and the advantage was greatest for the highest toluene loading, $0.12\;M/m^2-day$. The 1-mm carriers achieved superior performance by minimizing the negative effects of oxygen depletion, because they had 4.7 to 6.8 times thinner biofilm depths. The 1-mm carriers continued to provide protection from excess biomass detachment and inhibition from toluene. Finally, the 1-mm CBBR achieved volumetric removal capacities up to 300 times greater than demonstrated by other biofilters treating toluene and related volatile hydrocarbons.

순환식 병류형 곡물건조기 개발(II) - 시뮬레이션모델의 검증 - (Development of a Rice Circulating Concurrent-flow Dryer(II) - Validation of Drying Simulation Model -)

  • 한재웅;금동혁;김훈;홍상진
    • Journal of Biosystems Engineering
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    • 제32권5호
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    • pp.309-315
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    • 2007
  • This study was performed to develop a simulation model of circulating concurrent-flow rice dryer. The simulation model consists of drying model, tempering model and crack prediction model. The drying and tempering models were developed based on mathematical analysis, and the crack prediction model was developed by thin layer drying tests. Rice drying tests were done with three replications by use of a pilot scale dryer of holding capacity of 700 kg. Experimental values for moisture content, rice temperature, rice crack, and drying energy were compared with predicted values by simulation model. The RMSEs of predicted moisture contents were ranged from 0.5807% (d.b.) to 1.1951% (d.b.). and the coefficients of determination were 0.9688 to 0.9812. The RMSEs of predicted rice temperatures at the exit of the drying chamber were 1.83 to $3.81^{\circ}C$ and the coefficients of determination were 0.8834 to 0.9482. The results for moisture contents and rice temperatures showed very good relationships between predicted values and experimental values. The RMSEs of predicted value of crack ratio were 0.4082 to 0.7967% and the coefficients of determination were 0.8742 to 0.9547.

Circulating levels of vitamin D, vitamin D receptor polymorphisms, and colorectal adenoma: a meta-analysis

  • Lee, Jung-Eun
    • Nutrition Research and Practice
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    • 제5권5호
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    • pp.464-470
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    • 2011
  • Growing evidence suggests an elevated risk for colorectal neoplasia among individuals with low levels of vitamin D, the biological actions of which are mediated by the vitamin D receptor (VDR). To investigate the association among vitamin D status, VDR polymorphisms (FokI, and BsmI), and colorectal adenoma, we conducted a meta-analysis of nine studies of circulating levels of 25-hydroxyvitamin D (25(OH)D) and five studies of FokI or BsmI polymorphisms in relation to colorectal adenomas. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were pooled using a random-effects model. A total of 3398 coloreetal adenomas for 25(OH)D and 1754 colorectal adenomas for VDR were included in the meta-analysis. We identified a significant inverse association between colorectal adenoma (combined RR, 0.93; 95% CI, 0.87-0.98 per 10 ng/mL increase in 25(OH)D levels). When we examined FokI and BsmI polymorphisms in the meta-analysis, we found no association for either FokI (combined RR, 1.00; 95% CI, 0.95-1.06) or BsmI (combined RR, 0.99; 95% CI, 0.93-1.05) in the additive model. These data suggest an inverse association between circulating 25(OH)D levels and colorectal adenoma risk.

Secondary Circulating Tumor Cells (CTCs) but not Primary CTCs are Associated with the Clinico-Pathological Parameters in Chilean Patients With Colo-Rectal Cancer

  • Murray, Nigel P;Albarran, Vidal;Perez, Guillermo;Villalon, Ricardo;Ruiz, Amparo
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권11호
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    • pp.4745-4749
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    • 2015
  • Background: The aim of this study was to assess detection of circulating tumor cells (CTC) using anti-CEA pre and post surgery in Chilean patients with colo-rectal cancer. Materials and Methods: The presence of CTCs was evaluated in 80 colorectal cancer patients pre and post surgery using standard immunocytochemistry and the results were compared with findings for standard clinico-pathological parameters. Results: In patients presurgery CEA (+) CTCs were frequently found, with no relation to tumor size or nodal status. After surgery, the presence of CTCs was associated with such clinico-pathological parameters. The frequency of CTC detection in node positive patients did not change after surgery. In patients with metastasis there was also no change in the frequency of CTC detection, and clusters of 3 or more CTCs were evident. Conclusions: Secondary CTCs are associated with clinico-pathological parameters only after surgical removal of the primary tumor, and might be important in identifying patients at high risk of relapse. Primary CTCs detected before surgical removal are frequently found, are not associated with the clinico-pathological parameters and might have a role in cancer screening. These findings suggest the need for studies with a larger population of patients.

Holdup and Flow Behavior of Fluidized Solid Particles in a Liquid-Solid Circulating Fluidized Bed

  • Lim, Dae Ho;Lim, Ho;Jin, Hae Ryong;Kang, Yong
    • Korean Chemical Engineering Research
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    • 제52권3호
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    • pp.371-377
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    • 2014
  • Characteristics of holdup and flow behavior of fluidized solid particles were investigated in a liquid-solid circulating fluidized bed ($0.102m{\times}3.5m$). Effects of liquid velocity ($U_L$), particle size ($d_P$) and solid circulation rate ($G_S$) on the solid holdup, overall particle rising velocity, slip velocity between liquid and particles and hydrodynamic energy dissipation rate in the riser were examined. The particle holdup increased with increasing $d_P$ or $G_S$ but decreased with increasing $U_L$. The overall particle rising velocity increased with increasing $U_L$ or $G_S$ but decreased with increasing $d_P$. The slip velocity increased with increasing $U_L$ or $d_P$ but did not change considerably with $G_S$. The energy dissipation rate, which was found to be closely related to the contacting frequency of micro eddies, increased with increasing $d_P$, $G_S$ or $U_L$. The solid particle holdup was well correlated with operating variables such as $U_L$, $d_P$ and $G_S$.

전차선로 순환전류 발생원인과 대책에 관한 연구 (A Study on Causes and Measures Against Occurrence of Circulating Current in catenary)

  • 한학수;민경윤
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.816-823
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    • 2007
  • Electric car tract plays the role of supply high electric power to the electric car from the substation by using Pantograph of the electric car. It is always exposed to the external atmosphere, which results in quite substantial fluctuations in current and voltage during operation of electric car. This generates possibility of occurrence of accident at all times. Since range of wiring metallic globe installed on the catenary cannot achieve complete electrical contact, accidents are occurring due to circulating current caused by arc caused by incomplete contact due to occurrence of hairline fracture of Pantograph due to pressure or vibration of wiring. Furthermore, rapid increase in the operational current due to increase in the operational frequency of the electric car is causing erosion and short circuit of the metallic globe at the contact points. This study on arc is generated as current transmitted out of the substation courses through power line or wiring metallic globe other than the main circuit as the current is being collected at the electric car through feeder and feeder divergence device. Accordingly, since heat generated by the arc becomes the cause for generation of circulating current due to melting of metal or softening of metal due to increase in temperature accompanying increase in contact resistance, this research shall describe causes and measures against occurrence of circulation current.

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