• Title/Summary/Keyword: Retention ratio

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Fuel-Coolant Interaction Visualization Test for In-Vessel Corium Retention External Reactor Vessel Cooling (IVR-ERVC) Condition

  • Na, Young Su;Hong, Seong-Ho;Song, Jin Ho;Hong, Seong-Wan
    • Nuclear Engineering and Technology
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    • v.48 no.6
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    • pp.1330-1337
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    • 2016
  • A visualization test of the fuel-coolant interaction in the Test for Real cOrium Interaction with water (TROI) test facility was carried out. To experimentally simulate the In-Vessel corium Retention (IVR)- External Reactor Vessel Cooling (ERVC) conditions, prototypic corium was released directly into the coolant water without a free fall in a gas phase before making contact with the coolant. Corium (34.39 kg) consisting of uranium oxide and zirconium oxide with a weight ratio of 8:2 was superheated, and 22.54 kg of the 34.39 kg corium was passed through water contained in a transparent interaction vessel. An image of the corium jet behavior in the coolant was taken by a high-speed camera every millisecond. Thermocouple junctions installed in the vertical direction of the coolant were cut sequentially by the falling corium jet. It was clearly observed that the visualization image of the corium jet taken during the fuel-coolant interaction corresponded with the temperature variations in the direction of the falling melt. The corium penetrated through the coolant, and the jet leading edge velocity was 2.0 m/s. Debris smaller than 1 mm was 15% of the total weight of the debris collected after a fuel-coolant interaction test, and the mass median diameter was 2.9 mm.

The Protein rich Food Mixtures for Korean Infants (유유아(乳幼兒) 및 성장기 아동을 위한 영양식품 개발에 관한 연구 -흰쥐 성장에 미치는 영향-)

  • Ho, Jin-Hee;Kim, Sook-He
    • Journal of Nutrition and Health
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    • v.3 no.2
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    • pp.95-99
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    • 1970
  • Korea is one of the typical rice eating countries where availability of animal protein is limited even for the growing generation. Nutritive food products for infants and children are not available commercially in large scale at the present time, although a limited amount of expensive milk products are produced. The present study deals with a pioneering attempt on a new food mixture to meet this demand. Several food mixtures, possibly produced in the country, consisting of rice, soybean, FPC, vitamin, minerals and other food additives are developed in this work Sixty female and male rats aged $30{\sim}40$ days were divided into five groups, twelve rats each. The rats had been maintained with the six different diets, as follow. Formulation of proposed infant food mixturesComposition F-R-1 F-S-2 F-F-3 F-P-4 S Rice 100% 40% 37% 46% 70% Sugar - 12 13 10 70 Casein - - - - 20 Bean - 40 37 24 - Yeast - 3 2 3 - Mineral Vitamain - 2 4 2 4.3 F.P.C - 3 4 7 - Fat - - 4 8 4 Cod liver Oil - - - - 3 The findings of this study presented in FER, PER, final organ weights, body weights growth, percentage of nitrogen retention in the body. F-P-4 group tended to remain the heaviest and F-R-1 the lightest in the body weight among three groups throughout the experimental period. In terms of FER (Feed Efficiency Ratio) and PER (Prortein E. R.) value, F-P-4 group kept the highest record throughout. F-P-4 group showed the highest value of nitrogen retention in the body. In comparision between F-P-4 groups and casein 20% group (standard) in all respects of this experiment, F-P-4 group which is the most superior among experimental group, revealed statisfically no significant inferior than that of standard group. This fact could be interpreted that most limiting a. a., methionine in the soy protein produced little inferiority of the experimental groups in the study.

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Predictors of Acute Postoperative Urinary Retention after Transvaginal Uterosacral Suspension Surgery

  • Son, Eun-Joo;Joo, Eunwook;Hwang, Woo Yeon;Kang, Mi Hyun;Choi, Hyun Jin;Yoo, Eun-Hee
    • Journal of Menopausal Medicine
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    • v.24 no.3
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    • pp.163-168
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    • 2018
  • Objectives: To investigate the rate of postoperative urinary retention (POUR) and identify the risk factors for this complication in women who underwent transvaginal uterosacral suspension surgery. Methods: A retrospective chart review was conducted for 75 women who underwent transvaginal uterosacral suspension surgery with vaginal hysterectomy, repair of cystocele, and levator myorrhaphy with/without transobturator anti-incontinence surgery. POUR was defined as a need for continuous intermittent catheterization on the third day subsequent to removal of the urethral indwelling catheter. Results: Acute POUR was reported in 18 women (24.0%). Thirty-six of the 75 patients (48.0%) had undergone anti-incontinence surgery. Crude analysis revealed significant association between the following variables and the risk of POUR: hypertension, the lower average flow rate in the pressure-flow study (PFS), greater post-void residual (PVR) urine volume in PFS, and PVR >30% of the total bladder capacity (TBC) in PFS. In the logistic regression analysis, PVR >30% of the TBC in PFS was identified as the only significant predictor of POUR (odds ratio, 15.4; 95% confidence interval, 2.5-90.9; P = 0.003). Conclusions: The PVR >30% of the TBC in PFS was identified as the only predictive factor of acute POUR in women who underwent transvaginal uterosacral suspension surgery.

Enhancement of Soil Physicochemical Properties by Blending Sand with Super Absorbent Polymers of Different Swelling Capacities (팽윤 능력이 다른 고흡수성수지(Super Absorbent Polymers)의 혼합 비율별 모래 토양의 물리화학성 변화)

  • Young-Sun Kim;Tae-Wooung Kim;Yun-Seob Kim;Yang-Ho Na;Geung-Joo Lee
    • Korean Journal of Environmental Agriculture
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    • v.42 no.1
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    • pp.1-7
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    • 2023
  • Super absorbent polymers (SAPs) are hydrophilic molecules that can absorb large amounts of water. This study was conducted to investigate the enhancement of the physicochemical properties of sand soil blended with three SAPs imbibed with 100, 150, and 200-fold water. Three treatments were applied, namely, 100SAP, 150SAP, and 200SAP. The three SAPs were blended at concentrations of 0% (control), 3%, 5%, 7%, and 10% with sand. The pH, electrical conductivity, and cation exchangeable capacity (CEC) of soil blended with the three SAPs were pH 6.35-6.46, 0.09-0.65 dS/m, and 1.42-1.92 cmolc/kg, respectively, and their capillary porosity, total porosity, and saturated hydraulic conductivity were 21.0-29.3%, 39.2-48.7%, and 272-470 mm/hr. CEC, capillary porosity, total porosity, and saturated hydraulic conductivity of soil were positively correlated with the ratio of the SAPs (p<0.01). These results indicate that blending sand soil with SAPs increased CEC, capillary porosity, and saturated hydraulic conductivity, thus improving the nutrient-retention capacity, water-retention capacity, and permeability of the soil.

Optimal Operation Condition of Livestock Wastewater Treatment Using Shortcut Biological Nitrogen Removal Process (단축질소제거 공정을 이용한 가축분뇨의 적정 처리조건 연구)

  • Jin-Young Kang;Young-Ho Jang;Byeong-Hwan Jeong;Yeon-Jin Kim;Yong-Ho Kim
    • Journal of Korean Society on Water Environment
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    • v.39 no.5
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    • pp.390-395
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    • 2023
  • The feasibility of applying the shortcut nitrogen removal process to treat livestock wastewater on individual farms was examined, and appropriate operating parameters were established. As a result,, it was determined that the nitrification reaction was carried out under 550 mg/L of ammonium nitrogen concentration, but it was less effective under conditions of high ammonia concentration. Consequently, it was confirmed that a partial injection of inflow water was necessary to minimize the effects of ammonia toxicity. Following the sequential batch reactor (SBR) operation results, it was difficult to achieve the effluent quality standard without an external carbon source. Also, selection of the appropriate hydraulic retention time was critical for the optimal SBR operation. Following the livestock farm application, with external carbon source injecting, the total nitrogen concentration in the effluent was 85.1 mg/L. This result revealed that the standard could be accomplished through a single treatment on individual livestock farms. The ratio of nitrite nitrogen to ammonia nitrogen in the effluent was verified to be suitable for implementing the anammox process with a 10 days of hydraulic retention time. This study demonstrated the potential applicability of process in the future. However, in order to apply to livestock farms, managing variations in wastewater load across individual farms and addressing reduced nitrogen oxidation efficiency during the winter season are crucial.

A Capacitorless 1-Transistor DRAM Device using Strained-Silicon-on-Insulator (sSOI) Substrate (Strained-Silicon-on-Insulator (sSOI) 기판을 이용한 Capacitorless 1-Transistor DRAM 소자)

  • Kim, Min-Soo;Oh, Jun-Seok;Jung, Jong-Wan;Lee, Young-Hie;Chung, Hong-Bay;Cho, Won-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.95-96
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    • 2009
  • A fully depleted capacitorless 1-transistor dynamic random access memory (FD 1T-DRAM) based on a sSOI strained-silicon-on-insulator) wafer was investigated. The fabricated device showed excellent electrical characteristics of transistor such as low leakage current, low subthreshold swing, large on/off current ratio, and high electron mobility. The FD sSOI 1T-DRAM can be operated as memory device by the floating body effect when the substrate bias of -15 V is applied, and the FD sSOI 1T-DRAM showed large sensing margin and several milli seconds data retention time.

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Alternative Nutrient Cycles for Terrestrial Plants, Positive Feedbacks through Detrital Processes, and Nutrient Use Efficiency (육상식물 중심의 영양소 순환 경로와 부식과정에 의한 양성 되먹임과정, 그리고 영양소 이용효율)

  • Lee, Dowon;Thomas P. Burns
    • The Korean Journal of Ecology
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    • v.16 no.1
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    • pp.115-131
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    • 1993
  • Six nutrient cycles involving terrestrial plants are identified and characterized. Plants affect biotic and abiotic cycles through their effects on soil properties. They determine their internal nutritional status and nutrient concentrations in their environment via internal and external cycles. Contributions of organic matter to mycorrhizal, trophic, and detrital mediated external cycles and alterations of nutrient concentrations by plants can promote positive feedbacks leading to increased availability and retention of soil nutrients in open systems. Recognizing alternative cycles through plants leads to a definition of nutrient use efficiency for ecosystems: the ratio of system production to nutrient content of organic matter. A simple graph model to predict changes of nutrient use efficiency during primary succession is then presented.

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High speed performance of Pb(Zr,Ti)O$_3$ capacitors through lattice engineering (격자 조정을 통한 PZT커패시터의 고속동작 성능)

  • Yang, B.L.
    • Journal of the Korean institute of surface engineering
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    • v.35 no.3
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    • pp.127-132
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    • 2002
  • High speed performance of ferroelectric Pb(Zr,Ti)$O_3$ (PZT) based capacitors is reported. La substitution up to 10% was performed to systematically lower the coercive and saturation voltages of epitaxial ferroelectric capacitors grown on Si using a ($Ti_{0.9}$ /$Al_{0.1}$ )N/Pt conducting barrier composite. Ferroelectric capacitors substituted with 10% La show significantly lower coercive voltage compared to capacitors with 0% and 3% La. This is attributed to a systematic decrease in the tetragonality (i.e., c/a ratio) of the ferroelectric phase. Furthermore, the samples doped with 10% La showed dramatically better retention and pulse width dependent polarization compared to the capacitors with 0% and 3% La. These capacitors show promise as storage elements in low power high density memory architectures.

A Clinical Study on The Truss Bar-Joint Removable Denture (I) (Truss Bar-Joint denture의 임상적 응용에 관한 연구(I))

  • Chang, Ik-Tae
    • The Journal of Korean Academy of Prosthodontics
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    • v.22 no.1
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    • pp.7-15
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    • 1984
  • A rationale and compendium of treatment for a specific situation of cases have been presented. It consists of a cast metal bar called a truss bar joint removable denture which is soldered to crowns and dowel core on a few remaining teeth, i.e., cuspids or bicuspids. This system gives additional support and retention to the individual teeth and makes possible a more stable removable denture. It is my opinion that the prognosis of the chosen cases may be obtained Successful results when applied on the teeth of less favorable crown-root ratio.

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A Study on the Thermal Decomposition of Carbon Tetrachloride by Pyrolytic Incineration (사염화탄소의 열분해 소각에 관한 연구)

  • 이태호;정홍기
    • Journal of environmental and Sanitary engineering
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    • v.11 no.1
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    • pp.57-61
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    • 1996
  • This study was to decompose carbon tetrachloride and CFC with pyrolytic incineration unit because of prohibition of their usage sooner or later. We have investigated heating value and temperature versus decomposing rate, removal of $Cl_2$ and dust in the flue gas, The results obtained were as follows; 1. In combustion condition to decompose $CCl_4$ heating value was 3,300Kcal/Kg, retention time was 2,0 sec. incinerator exit temperature was $950^{\circ}C$. 2.The removal of HCI and $Cl_2$ in flue gas used NaOH as reagent, then molar ratio o of $Na^+/Cl^-$ was 1.07. 3. NaCI of dust component was more than 90 %, 2 stage venturi scrubber was used to remove dust, then removal rate of dust was 99% over at L/G of $1.7Vm^3$

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