• Title/Summary/Keyword: High Flow Rate

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Effects of Symmetrically Arranged Heat Sources on the Heat Release Performance of Extruded-Type Heat Sinks (열원의 대칭 배열에 따른 압출형 히트싱크의 방열성능 연구)

  • Ku, Min Ye;Shin, Hon Chung;Lee, Gyo Woo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.2
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    • pp.119-126
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    • 2016
  • In this study we investigated the effects of symmetrically arranged heat sources on the heat release performances of extruded-type heat sinks through experiments and thermal fluid simulations. Also, based on the results we suggested a high-efficiency and cost-effective heat sink for a solar inverter cooling system. In this parametric study, the temperatures between heaters on the base plate and the heat release rates were investigated with respect to the arrangements of heat sources and amounts of heat input. Based on the results we believe that the use of both sides of the heat sink is the preferred method for releasing the heat from the heat source to the ambient environment rather than the use of a single side of the heat sink. Also from the results, it is believed that the symmetric arrangement of the heat sources is recommended to achieve a higher rate of heat transfer. From the results of the thermal fluid simulation, it was possible to confirm the qualitative agreement with the experimental results. Finally, quantitative comparison with respect to mass flow rates, heat inputs, and arrangements of the heat source was also performed.

The Effects of Lycium chinese Mill., Morus alba L. and Their Combination on the Asthmatic Murine Model (천식동물모델을 이용한 지골피(地骨皮), 상백피(桑白皮) 및 두 배합약물의 실험적 연구)

  • Seo, Chang-Woo;Lee, Young Cheol;Lee, Jang-Cheon
    • Herbal Formula Science
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    • v.21 no.1
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    • pp.36-50
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    • 2013
  • Objectives : To clarify the possible effect of Lycium chinese Mill (LC)., Morus alba L (MA)., and Lycium chinese Mill. +Morus alba L. (LC+MA), we have examined their influence on the development of pulmonary eosinophilic inflammation in the asthmatic murine model. Methods : Female Balb/c mice (5weeks) were immunized on two different days (21 days and 7 days before inhalational exposure) by intraperitonial injections of 0.2ml alum-precipitated Ag containing $100{\mu}g$ of OVA bound to 4 mg of aluminum hydroxide in PBS. Seven days after the second sensitization, mice were exposed to aerosolized ovalbumin for 30 minutes/day on 3 days/week for 8 weeks (at a flow rate of 250 L/min, 2.5% ovalbumin in normal saline) and, LC, MA, and LC+MA (500 mg/kg) were orally administered 3 times per a week for 8 weeks. Results : The suppressive effect of LC, MA, and LC+MA were demonstrated by the accumulation of eosinophills into airways, with the reduction of eosinophil, total lung leukocytes numbers. These were correlated with the marked reduction of IL-5, IL-13 and IL-4 levels in the BALF and serum. OVA-specific IgE levels were also decreased in serum and BAL from these mice. LC, MA, and LC+MA decreased eosinophil CCR3 expression and CD11b expression in lung cells. Conclusions : These results indicate that LC, MA, and LC+MA have high inhibitory effects on airway inflammation and hyper-responsiveness in the asthmatic murine model. The suppression of IL-5, IgE, eosinophil CCR3 expression and CD11b expression, and the increase of IFN-${\gamma}$ production in BALF seem to contribute to this effect. Hence, the results indicated that LC, MA, and LC+MA could act as a immuno-modulator which possesses anti-inflammatory and anti-asthmatic property by modulating the imbalance between Th1 and Th2 cytokines.

Simultaneous Analysis of Six Compounds in Yijin-tang by HPLC-PDA (HPLC-PDA을 이용한 이진탕 중 6종 성분의 동시분석)

  • Kim, Seong-Sil;Kim, Jung-Hoon;Shin, Hyeun-Kyoo;Seo, Chang-Seob
    • Herbal Formula Science
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    • v.21 no.1
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    • pp.71-79
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    • 2013
  • Objectives : Yijin-tang has been used in the treatment of gastrointestinal diseases such as irritable bowel syndrome, gastritis, and gastric ulcer. In this study, a high-performance liquid chromatography (HPLC) method was established for simultaneous analysis of six compounds, liquiritin, glycyrrhizin, hesperidin, 6-gingerol, homogentisic acid, and 3,4-dihydroxybenzaldehyde in Yijin-tang, a traditional Korean herbal medicinal preparation. Methods : A Gemini C18 column was used for the separation of six constituents at $40^{\circ}C$. The mobile phase using gradient elution consist of two solvent systems, 1.0% acetic acid in water (A) and 1.0% acetic acid in acetonitrile (B). The flow-rate was 1.0 mL/min and injection volume was $10{\mu}g$. The detector was a photodiode array (PDA) detector set at 254 nm and 280 nm. Results : The calibration curves of six compounds showed good linearity in various concentration ranges ($R^2{\geq}0.9997$). The limits of detection (LOD) and limits of quantification (LOQ) were 0.028-$0.192{\mu}g/mL$ and 0.093-$0.540{\mu}g/mL$, respectively. The RSD (%) of the intra and inter day validations were 0.03-0.84% and 0.05 -1.00%, respectively. Recovery was 96.14-01.90% and RSD (%) was less than 1.5%. Conclusions : The established simultaneous analysis methods will help management to improve the quality of Yijin-tang.

A Study of Spray Characteristics for the Slinger Injector System of Micro Turbo Jet Engine (초소형 터보제트엔진 슬링거 인젝터의 분무특성)

  • Choi, Hyun-Kyung;Choi, Seong-Man;Lee, Dong-Hun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.354-358
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    • 2007
  • An experimental study was performed to understand spray characteristics of the slinger injector. system for the micro turbojet engine. In this fuel injection system, fuel is sprayed and atomized in the combustor by centrifugal forces of engine shaft. This experimental apparatus consist of a high speed rotating Spindle, slinger injector, pressure tank and acrylic case. The droplet size and velocity were measured by PDPA(Phase Doppler Particle Analyzer) and spray was visualized by using Nd-Yag laser-based flash photography. From the test results, the droplet size(SMD) is largely affected to rotational speed, mass flow rate and the number of injection orifice. From the this experimental study, we could understand the spray characteristics of the slinger injection system and obtain the optimum shape of the slinger injector nozzle which is suitable for the micro turbojet engine.

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Combustion Stability Rating Test under Low Pressure Condition of a 75-tonf-class LRE Thrust Chamber (75톤급 액체로켓엔진 연소기의 저압 조건에서 수행된 연소안정성 시험)

  • Lee, Kwang-Jin;Kang, Dong-Hyuk;Kim, Mun-Ki;Ahn, Kyu-Bok;Han, Yeoung-Min;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.14 no.5
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    • pp.92-100
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    • 2010
  • Combustion stability rating tests of 75-tonf-class thrust chamber for technology demonstration were carried out at a low pressure. Two kinds of mixing heads were used in this study. One of them has injectors of 631 and the other has injectors of 721. Mixing head with injectors of 631 showed a self-oscillation instability at the chamber pressure of 30 bar. Mixing head with injectors of 721 showed that a high frequency combustion stability was maintained under the same pressure and the same mass flow rate. But mixing head with injectors of 721 generated a self-oscillation instability at the chamber pressure of 20 bar and it was found that stability boundary region was changed due to the configuration of a mixing head from these results.

EFFECT OF DIFFERENT LEVELS OF ROASTED FULL-FAT SOYBEAN ON THE APPARENT DIGESTIBILITY OF DIETARY COMPONENTS BY CARP (Cyprinus carpio) GROWER

  • Kim, J.D.;Kim, K.S.;Song, J.S.;Woo, Y.B.;Jeong, K.S.;Won, T.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.6
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    • pp.635-639
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    • 1995
  • Digestibility trial was performed with carps weighing 200 g/fish. Fecal collection was made over 7 days using a settling column. The water temperature was in the range of 27 to $30{^{\circ}C}$ during whole experimental period. Fishes were fed 5 diets (Control, $F_{24}S_{13}$, $F_{16}S_{27}$, $F_8S_{40}$ and $F_0S_{56}$) containing both 32%, 24%, 16%, 8% and 0% of fish meal (F) and 0%, 13%, 27%, 40% and 56% of roasted full-fat soybean (S), respectively. Water volume in each recirculated rearing tank was maintained at 130 l with flow rate of 10-12 l/min. Apparent digestibility coefficients (ADCs) of dry matter, protein, lipid, total carbohydrates and energy in diets showed a reduction (p < 0.05) with the increase of dietary full-fat soybean level, although there was no difference in the ADCs between Control and $F_{24}S_{13}$ (p > 0.05). The ADCs of ash, Ca and P in diets significantly increased with the increase of dietary full-fat soybean level, suggesting the high availability of phosphorus in monocalcium phosphate.

Plasma Peptidome as a Source of Biomarkers for Diagnosis of Cholangiocarcinoma

  • Kotawong, Kanawut;Thitapakorn, Veerachai;Roytrakul, Sittiruk;Phaonakrop, Narumon;Viyanant, Vithoon;Na-Bangchang, Kesara
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1163-1168
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    • 2016
  • Cholangiocarcinoma (CCA) is the bile duct cancer which constitutes one of the important public health problems in Thailand with high mortality rate, especially in the Opisthorchis viverrini (a parasite risk factor for CCA) endemic area of the northeastern region of the country. This study aimed to identify potential biomarkers from the plasma peptidome by CCA patients. Peptides were isolated using 10 kDa cut-off filter column and the flow-through was then used as a peptidome for LC-MS/MS analysis. A total of 209 peptides were obtained. Among these, 15 peptides were concerned with signaling pathways and 12 related to metabolic, regulatory, and biosynthesis of secondary metabolite pathways. Five exclusive peptides were identified as potential biomarkers, i.e. ETS domain-containing transcription factor ERF (P50548), KIAA0220 (Q92617), phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit beta isoform isoform 1 (P42338), LP2209 (Q6XYC0), and casein kinase II subunit alpha (P19784). Three of these biomarkers are signaling related molecules. A combination of these biomarkers for CCA diagnosis is proposed.

Prevalence and Genotype Distribution of Human Papillomavirus among Women from Henan, China

  • Wang, Xiao-Chuan;Sun, Liang-Qi;Ma, Li;Li, Hua-Xin;Wang, Xiu-Li;Wang, Xin;Yun, Tian;Meng, Nian-Long;Lv, Da-Le
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7333-7336
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    • 2014
  • Human papillomavirus (HPV) infection has been implicated as a causative of cervical cancer. In the present study, a total of 578 samples from females attending the gynecological outpatient clinic in Henan province, China, were collected and the HPV genotypes were detected by gene chip and flow-through hybridization. Overall, 44.5% (257/578) females were found to be HPV DNA positive, and the high risk HPV (HR-HPV) rate was 35.1% (203/578). The first peak of HR-HPV infection appeared in the >60 year-old group (55.0%), and the second was within the 51-55 year-old group (50.0%) (${\chi}^2$=19.497, p<0.05). HPV 16 was the most prevalent genotype (9.2%), followed by HPV 52 (7.8%), HPV 6 (6.9%), HPV 11 (5.9%) and HPV 42 (5.0%). The single type HPV infection was 30.4%, with the five majority prevalent genotype HPV 16 (16.5%), HPV 52 (14.3%), HPV 6 (12.6%), HPV 42 (8.6%), HPV 31 (5.1%). The multiple-type HPV infections were 14.0%, and HPV 16 was the most prevalent type (29.6%), followed by HPV 52 (24.7%), HPV 6 (22.2%), HPV 11 (22.2%), HPV 42 (17.3%) and HPV 39 (17.3%).

Novel Solid Phase Extraction Procedure for Some Trace Elements in Various Samples Prior to Their Determinations by FAAS

  • Sacmaci, Srife;Kartal, Senol;Sacmaci, Mustafa;Soykan, Cengiz
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.444-450
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    • 2011
  • A novel method that utilizes poly(5-methyl-2-thiozyl methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene) [MTMAAm/AMPS/DVB] as a solid-phase extractant was developed for simultaneous preconcentration of trace Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) prior to the measurement by flame atomic absorpiton spectrometry (FAAS). Experimental conditions for effective adsorption of the metal ions were optimized using column procedures. The optimum pH value for the simultaneously separation of the metal ions on the new adsorbent was 2.5. Effects of concentration and volume of elution solution, sample flow rate, sample volume and interfering ions on the recovery of the analytes were investigated. A high preconcentration factor, 100, and low relative standard deviation values, $\leq$1.5% (n = 10), were obtained. The detection limits (${\mu}gL^{-1}$) based on the 3s criterion were 0.18 for Cd(II), 0.11 for Co(II), 0.07 for Cr(III), 0.12 for Cu(II), 0.18 for Fe(III), 0.67 for Mn(II), 0.13 for Ni(II), 0.06 for Pb(II), and 0.09 for Zn(II). The validation of the procedure was performed by the analysis of two certified reference materials. The presented method was applied to the determination of the analytes in various environmental samples with satisfactory results.

A Study on the Performance of the Heat Transfer for the Liquid Filling as the Ratio of Working Fluid Volume to Total Volume of the Thermosyphon with Axial Internal Fins (축방향 내부 핀을 가진 열사이폰의 작동유체 체적변화에 대한 열전달 성능에 관한 연구)

  • Lee, Jung-Han;Lee, Ki-Baik;Cho, Dong-Hyun
    • Journal of the Korean Solar Energy Society
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    • v.22 no.1
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    • pp.23-30
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    • 2002
  • This study concerns the performance of the heat transfer of the thermosyphon having 80 internal fins in which boiling and condensation occur. Water has been used as the working fluid. The Liquid filling as the ratio of working fluid volume to total volume of thermosyphon have been used as the experimental parameters. The heat flux and heat transfer coefficient at the condenser are estimated from the experimental results. The experimental results have been assessed and compared with existing theories. As a result of the experimental investigation we can state that the maximum heat flow rate in the thermosyphon prove to depend upon the liquid fill quantity. The relatively high rates of heat transfer have been achived operating in the thermosyphon with axial internal fins. Also, the thermosyphon with internal micro fins can be used to achieve some inexpensive and compact heat exchangers in low temperature. In addition, it is to obtain the overall heat transfer coefficients and the characteristics as a operating temperature for the practical applications.