• Title/Summary/Keyword: Retention of Fluid

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Effects of Impeller Geometry on the 11α-Hydroxylation of Canrenone in Rushton Turbine-Stirred Tanks

  • Rong, Shaofeng;Tang, Xiaoqing;Guan, Shimin;Zhang, Botao;Li, Qianqian;Cai, Baoguo;Huang, Juan
    • Journal of Microbiology and Biotechnology
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    • v.31 no.6
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    • pp.890-901
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    • 2021
  • The 11α-hydroxylation of canrenone can be catalyzed by Aspergillus ochraceus in bioreactors, where the geometry of the impeller greatly influences the biotransformation. In this study, the effects of the blade number and impeller diameter of a Rushton turbine on the 11α-hydroxylation of canrenone were considered. The results of fermentation experiments using a 50 mm four-blade impeller showed that 3.40% and 11.43% increases in the conversion ratio were achieved by increasing the blade number and impeller diameter, respectively. However, with an impeller diameter of 60 mm, the conversion ratio with a six-blade impeller was 14.42% lower than that with a four-blade impeller. Data from cold model experiments with a large-diameter six-blade impeller indicated that the serious leakage of inclusions and a 22.08% enzyme activity retention led to a low conversion ratio. Numerical simulations suggested that there was good gas distribution and high fluid flow velocity when the fluid was stirred by large-diameter impellers, resulting in a high dissolved oxygen content and good bulk circulation, which positively affected hyphal growth and metabolism. However, a large-diameter six-blade impeller created overly high shear compared to a large-diameter four-blade impeller, thereby decreasing the conversion ratio. The average shear rates of the former and latter cases were 43.25 s-1 and 35.31 s-1, respectively. We therefore concluded that appropriate shear should be applied in the 11α-hydroxylation of canrenone. Overall, this study provides basic data for the scaled-up production of 11α-hydroxycanrenone.

In-depth investigation of natural convection thermal characteristics of BALI experiment through Eulerian computational fluid dynamics code and comparison with Lagrangian code

  • Hyeongi Moon;Sohyun Park;Eungsoo Kim;Jae-Ho Jeong
    • Nuclear Engineering and Technology
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    • v.56 no.1
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    • pp.9-18
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    • 2024
  • In-vessel retention through external reactor vessel cooling (IVR-ERVC) is a severe accident management (SAM) strategy that has been adopted and used in many nuclear reactors such as AP1000, APR1400, and light water reactor etc. Some reactor accidents have raised concerns about nuclear reactors among residents, leading to a decrease in residents' acceptability and many studies on SAM are being conducted. Experiments on IVR-ERVC are almost impossible due to its specificity, so fluid characteristics are analyzed through BALI experiments with similar condition. In this study, computational fluid dynamics (CFD) via Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES) for BALI experiments were performed. Steady-state CFD analysis was performed on three turbulence models, and SST k-ω model was in good agreement with the experimental measurement temperature within the maximum error range of 1.9%. LES CFD analysis was performed based on the RANS analysis results and it was confirmed that the temperature and wall heat flux for depth was consistent within an error range of 1.0% with BALI experiment. The LES CFD analysis results were compared with those of the Lagrangian-based solver. LES matched the temperature distribution better than SOPHIA, but SOPHIA calculated the position of boundary between stratified layer and convective layer more accurately. On the other hand, Lagrangian-based solver predicted several small eddy behaviors of the convective layer and LES predicted large vortex behavior. The vibration characteristics near the cooling part of the BALI experimental device were confirmed through Fast Fourier Transform (FFT) investigation. It was found that the power spectral density for pressure at least 10 times higher near the side cooling than near the top cooling.

Study of oriental medical science documentory records of vertigo and dizziness (현훈(眩暈)에 관한 문헌적(文獻的) 고찰(考察))

  • Park, Eun-Sook;Yoon, Il-Ji
    • Journal of Haehwa Medicine
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    • v.17 no.1
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    • pp.157-166
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    • 2008
  • 1. Vertigo and dizziness is also called as Mok-hyun, Hyun-mo, Pung-hyun, Du-pung-hyun-un, Du-sun. 2. Causes and processes of Vertigo and dizziness are mainly divided into external infection and internal damage. Wind, cold, dampness and summer heat are included in the one and in the other, vital energy and blood deficiency, insufficiency of the liver and kidney, retention of phlegm and fluid, emotional disorder and so on. 3. Symptoms of vertigo and dizziness are disequilibrium, nausea, inability of hearing, vomiting, sweating and syncope. 4. Treating of vertigo and dizziness are recovery of vital energy and blood deficiency, strenthening of insufficiency of the liver and kidney, drying of dampness and removing of phlegm.

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Pathophysiology and management of disorders in water metabolism (수분 대사 장애 질환의 병태 생리와 치료)

  • Kim, Dong Un
    • Clinical and Experimental Pediatrics
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    • v.50 no.5
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    • pp.430-435
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    • 2007
  • Even though we drink and excrete water without recognition, the amount and the composition of body fluid remain constant everyday. Maintenance of a normal osmolality is under the control of water balance which is regulated by vasopressin despite sodium concentration is the dominant determinant of plasma osmolality. The increased plasma osmolality (hypernatremia) can be normalized by the concentration of urine, which is the other way of gaining free water than drinking water, while the low plasma osmolality (hyponatremia) can be normalized by the dilution of urine which is the only regulated way of free water excretion. On the other hand, volume status depends on the control of sodium balance which is regulated mainly by renin-angiotensin-aldosterone system, through which volume depletion can be restored by enhancing sodium retention and concomitant water reabsorption. This review focuses on the urine concentration and dilution mechanism mediated by vasopressin and the associated disorders; diabetes insipidus and syndrome of inappropriate antidiuretic hormone secretion.

A Comparison between Questonnaire of Differentiation of Syndromes and QSCC2 (QSCC2검사법과 변증검사설문지(辨證檢査說問紙)의 비교)

  • Shin, Woo-Yong;Park, Un-A;Yoo, Jun-Sang
    • Journal of Sasang Constitutional Medicine
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    • v.17 no.3
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    • pp.69-75
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    • 2005
  • 1. Objectives This study was to investigate relationship between the diagnosis of Sasang Constitutional Medicine(SCM) and the diffrentiation of syndromes according to the state of Qi, Blood, Body Fluid, Phlegm retention and the five viscera. 2. Methods In-patients and students were investigated through questionnaire of the diffrentiation of syndromes and QSCC2. The results were analyzed statiscally by t-test, one-way ANOVA on SPSS 10 3. Results and Conclusions (1) Soeumin has a high grade on Qi-insufficiency than other consititutions. (2) Soyangin has a high grade on blood insufficiency. And Soyangin who have a disease get a high grade on kidney and get a low grade on spleen.

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An Experimental Study of the Airside Performance of Slit Fin-and-Tube Heat Exchangers under Dry and Wet Conditions

  • Chang, Keun-Sun;Long, Phan-Than
    • International Journal of Air-Conditioning and Refrigeration
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    • v.17 no.1
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    • pp.7-14
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    • 2009
  • Water condensate accumulated on the surface of a fin-and-tube heat exchanger significantly affects its thermal and hydraulic performances. The purpose of this study is to investigate the effects of condensate retention on the air-side heat transfer performance and flow friction for various flow and geometric conditions. Total of twelve samples of slit and plate fin-and-tube heat exchangers are tested under dry and wet conditions. The thermal fluid measurements are made using a psychrometric calorimeter. Frontal air velocity varies in the range from 0.7 m/s to 1.5 m/s. Using the experimental data, presented are heat transfer coefficients in terms of Colburn j-factors and friction factors, and these data are compared with the existing correlations.

Heat Transfer and Friction Characteristics of Slit Fin and Tube Heat Exchangers in Wet Conditions (습표면 조건에서 슬릿 핀-튜브 열교환기의 열전달 및 압력강하 특성)

  • Chang, Keun-Sun;Phan, Thanh-Long
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.1
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    • pp.1-9
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    • 2007
  • Water condensate accumulated on the surface of a fin-and-tube heat exchanger significantly affects its thermal and hydraulic performance. The purpose of this study is to investigate the effect of condensate retention on the air-side heat transfer performance and flow friction. Total 12 samples of slit and plate fin-and-tube heat exchangers with varying fin spacing and number of tube rows are tested under dry and wet conditions. The thermal fluid measurements are made using a psychometric calorimeter. Frontal air velocity varies in the range from 0.7 m/s to 1.5 m/s. Using the experimental data, presented are the heat transfer coefficients in terms of Colburn j-factor and friction factor.

Preparation and Evaluation of Adhesive Hydrogel of Ketoprofen Using Microsphere System (마이크로스피어 시스템을 이용한 케토프로펜 점착성 하이드로겔의 제조 및 평가)

  • Cho, Young-Ho;Lee, Gye-Won
    • KSBB Journal
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    • v.25 no.3
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    • pp.297-302
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    • 2010
  • Ketoprofen is one of the propionic acid class of nonsteroidal anti-inflammatory drug with analgesic and antipyretic effects. The most common side effects from ketoprofen after oral administration are gastrointestinal irritation, diarrhea, abdominal pain and retention of fluid. Ketoprofen was formulated as water-soluble gels to reduce these side effects. To increase the skin permeability of ketoprofen, microsphere containing ketoprofen was prepared with chitosan and ploy-$\varepsilon$-caprolactone. And then prepared microsphere was manufactured as an adhesive hydrogel with polyvinylpyrrolidone K-25, polyethylene glycol 4000, and various permeation enhancers. The flux and permeability of ketoprofen were evaluated. As the concentration of tween 80 and enhancers increased, the flux of ketroprofen was accelerated. Also the permeation rate was facilitated by enhancers, but did not affect the lag time. From these results, the adhesive hydrogel using microsphere could be a good delivery system for ketoprofen to improve the skin permeation.

Thin CNTs nanoliquid film development over a rough rotating disk

  • Swatilekha Nag;Susanta Maity;Sanjeev K. Metya
    • Advances in nano research
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    • v.15 no.2
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    • pp.91-104
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    • 2023
  • Development of thin carbon nanotubes (CNTs) nanoliquid film over the rough surface of a horizontal rotating disk is investigated by considering symmetric roughness either along the azimuthal or radial directions. The disk surface is either heated or cooled axisymmetrically from below. The effects of single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs) are analyzed on the film thinning process with different types of base liquids. Closed form solutions for velocity and temperature field are obtained for small values of Reynolds number whereas the numerical solution is derived for moderate values of Reynolds number. It is found that fluid retention / depletion takes place when the roughness is symmetric along the azimuthal / radial directions. It is also seen that the film thinning rate enhances for MWCNTs compare to SWCNTs. Further it is found that two different heat transfer regions exits within the flow domain depending on the fact that heat is transferred from disk to liquid film and vice-versa.

Hematocolpos, pyocolpos, and pyocolpometra in intact female dogs with imperforate hymen

  • Kim, Hyejin
    • Journal of Animal Reproduction and Biotechnology
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    • v.37 no.2
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    • pp.144-148
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    • 2022
  • Imperforate hymen is a rare congenital disorder that may predispose to retention of fluid in the vagina and uterus, thereby resulting in conditions such as hematocolpos, pyocolpos, and pyocolpometra in female dogs. A 7-year-old intact female shih tzu exhibiting abdominal distension, depression, anorexia, dysuria, dyschezia, and tenesmus was diagnosed with pyocolpos; a 9-year-old intact female Yorkshire terrier with abdominal mass, dysuria, and tenesmus was diagnosed with hematocolpos; and a 7-year-old intact female shih tzu with dysuria, dyschezia, anorexia, and vomiting was diagnosed with pyocolpometra. Ovariohysterectomy and partial vaginectomy were performed, and the blind end of the vaginal stump was omentalized. This clinical report provide diagnostic process and surgical treatment option for congenital vaginal obstruction cases.