• Title/Summary/Keyword: plant parameters

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Round Robin Analysis for Probabilistic Structural Integrity of Reactor Pressure Vessel under Pressurized Thermal Shock

  • Jhung Myung Jo;Jang Changheui;Kim Seok Hun;Choi Young Hwan;Kim Hho Jung;Jung Sunggyu;Kim Jong Min;Sohn Gap Heon;Jin Tae Eun;Choi Taek Sang;Kim Ji Ho;Kim Jong Wook;Park Keun Bae
    • Journal of Mechanical Science and Technology
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    • v.19 no.2
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    • pp.634-648
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    • 2005
  • Performed here is a comparative assessment study for the probabilistic fracture mechanics approach of the pressurized thermal shock of the reactor pressure vessel. A round robin consisting of one prerequisite deterministic study and five cases for probabilistic approaches is proposed, and all organizations interested are invited. The problems are solved by the participants and their results are compared to issue some recommendation of best practices and to assure an understanding of the key parameters in this type of approach, like transient description and frequency, material properties, defect type and distribution, fracture mechanics methodology etc., which will be useful in the justification through a probabilistic approach for the case of a plant over-passing the screening criteria. Six participants from 3 organizations responded to the problem and their results are compiled and analyzed in this study.

Ensiled Banana Wastes with Molasses or Whey for Lactating Buffaloes during Early Lactation

  • Khattab, H.M.;Kholif, A.M.;EI-Alamy, H.A.;Salem, F.A.;EI-Shewy, A.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.5
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    • pp.619-624
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    • 2000
  • Low-quality roughages [banana wastes (B), wheat straw (WS) and dried broiler litter (BL)] were ensiled using either sweet whey (W) or diluted molasses (M) as rehydration media to study their effects on milk yield, milk composition and some parameters of blood plasma. The feeding trial involved 25 lactating buffaloes in five groups (five animals each). Buffaloes as control animals received diets of concentrate feed mixture, rice straw and wastelages (70:30:00). In the other 4 treatments, the wastelages replaced 50% of rice straw in the control diets. The wastelages were BL:B:M(3:2:10) (T1), BL:WS:M (3:2:10) (T2), BL:B:W (3:2:10) (T3) and BL:WS:W (3:2:10) (T4) on a fresh matter basis, during the 1st 17 weeks of lactation period. Results indicated that feeding lactating buffaloes on wastelages resulted in slightly higher (p>0.05) milk yield, 4% fat-corrected-milk yield and feed efficiency, and slightly lowered (p>0.05) contents of milk total solids, fat and protein. Wastelages, especially BL-B-M, increased (p<0.05) milk non-protein-nitrogen and ash contents and plasma urea, GOT and GPT. The results demonstrate that banana plant wastes with some additives in silage form may be good untraditional roughage for lactating buffaloes without any adverse effect on milk production.

Application of Response Surface Methodology (RSM) on Adsorption of Cs Ion in Aqueous Solution with Zeolite X Synthesized from Coal Fly Ash (석탄비산재로 합성한 제올라이트 X에 의한 수중의 Cs 이온 흡착에 반응표면분석법 적용)

  • Lee, Chang-Han;Lee, Min-Gyu
    • Clean Technology
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    • v.23 no.4
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    • pp.413-420
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    • 2017
  • The batch experiments and response surface methodology (RSM) have been applied to the investigation of the Cs adsorption with zeolite X synthesized using coal fly ash generated from the thermal power plant. Regression equation formulated for Cs adsorption was represented as a function of response variables. The model was highly relevant because the decision coefficient ($r^2$) was 0.9630. It was confirmed from the statistical results that the removal efficiency of Cs was affected by the order of experimental factors as pH > Cs concentration > temperature. The adsorption kinetics were more accurately represented by a pseudo second-order model. The maximum adsorption capacity calculated from the Langmuir isotherm model was $151.52mg\;g^{-1}$ at 293 K. Also, according to the thermodynamic parameters calculated from Vant Hoff equation, it could be confirmed that the adsorption reaction was an endothermic reaction and a spontaneous process.

Development of Adsorption Desalination System Utilizing Silica-gel (실리카겔을 이용한 흡착식 담수화 시스템 개발)

  • Hyun, Jun-Ho;Israr, Farrukh;Lee, Yoon-Joon;Chun, Won-Gee
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.364-369
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    • 2012
  • The development of solar thermal energy used adsorption desalination technology have been examined as a viable option for supplying clean energy. In this study, the modelling of the main devices for solar thermal energy used and adsorption desalination system was introduced. Silica gel type adsorption desalination system is considered to be a promising low-temperature heat utilization system. The design is divided into three parts. First, the evaporator for the vaporization of the tap water is designed, and then the reactor for the adsorption and release of the steam is designed, followed by the condenser for the condensation of the fresh water is designed. In addition, new features based on the energy balance are also included to design absorption desalination system. In this basic research, One-bed(reactor) adsorption desalination plant that employ a low-temperature solar thermal energy was proposed and experimentally studied. The specific water yield is measured experimentally with respect to the time controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times. Desalination is processes that permeate our daily lives, but It requires substantial energy input, powered either from electricity or from thermal input. From the environmental and sustainability perspecives, innovative thermodynamic cycles are needed to produce the above-mentioned useful effects at a lower specific energy input. This article describes the development of adsorption cycles for the production of desalting effects. We want that this adsorption system can be driven by low temperature heat sources at 60 to $80^{\circ}C$, such as renewable, solar thermal energy.

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Assessment of the Chilling Sensitivity of Korean Rice Cultivars by Chlorophyll Fluorescence Analysis (엽녹소 형광 측정에 의한 수도 내냉성 검정 방법)

  • Rho, Yeong-Deok;Park, Suk-Hong;Park, Rae-Kyeong;J.M. Wilson
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.31 no.3
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    • pp.356-360
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    • 1986
  • The potential of the chlorophyll fluorescence technique in screening eleven rice varieties for chill-sensitivity was assessed by measuring the change in the rate of rise of variable fluorescence (FR) and the maximum yield of variable fluorescence, F$\_$VAR/ (F$\_$MAX/-F$\_$0/) after 8 days chilling at 10$^{\circ}C$. The changes in both fluorescence parameters with chilling agreed well with visual assessments of injury carried out at the end of the chilling period. Furthermore, it was found that in the majority of the rice cultivars tested their chilling sensitivity agreed well with the rate of rise of chlorophyll fluorescence (F$\_$R/) measured at 25$^{\circ}C$. The method of chlorophyll fluorescence was rapid, reproducible, sensitive and non-destructive and it should be a valuable new tool in screening large numbers of closely related rice varieties for chilling sensitivity.

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Characteristics of Ion Exchange of Phosphate using Layered Double Hydroxides in Advanced Wastewater Treatment (하수고도처리에서 층상이중수화물을 이용한 인산 이온교환 특성)

  • Song, Ji-Hyun;Shin, Seung-Kyu;Lee, Sang-Hyup;Park, Ki-Young
    • Journal of Korean Society on Water Environment
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    • v.22 no.6
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    • pp.991-995
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    • 2006
  • The layered double hydroxide with the insertion of chloride ions (LDH-Cl), which was synthesized by the co-precipitation method, was applied to investigate the fundamental aspects of the absorptive agent for phosphate removal from wastewater. The adsorption capacity was best described by the Langmuir-FreundIich isotherm, and the estimated isotherm parameters indicate that the LDH-CI capacity for the phosphate removal is much higher than that observed using a natural adsorbent material such iron oxide tailing. The kinetic experiment also showed that the LDH-Cl adsorption reaction rapidly at the adsorptive rate of 0.55 mg-P/g-LDH/min, implying that this adsorbent can be of use in the full-scale applications. The pH had a minimal effect on the LDH adsorption capacity in the range of 5 to 11, although the capacity dropped at the low pHs because of the change in LDH surface properties. Furthermore, other anions such as $Cl^-$ and $NO_3{^-}$ commonly found in the wastewater streams insignificantly affected the phosphate removal efficiencies, while $HCO_3{^-}$ ions had a negative effect on the LDH adsorption capacity due to its high selectivity. The phosphate removal experiment using the actual secondary effluent from a wastewater treatment plant showed the similar decrease in adsorption capacity, indicating that the bicarbonate ions in the wastewater were competing with phosphate for the adsorptive site in the surface of the LDH-Cl. Overall, the synthetic adsorbent material, LDH-Cl, can be a feasible alternative over other conventional chemical agents, since the LDH-Cl exhibits the high phosphate removal capacity with the low sensitivity to other environmental conditions.

State Evaluation of Nutrient Removal in an Intermittent Aeration Process by Monitoring ORP & pH (ORP와 pH 측정에 의한 간헐폭기 고도처리 공정 제어의 평가)

  • Ko, Kwang Baik;Suh, Jun Suk
    • Journal of Korean Society on Water Environment
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    • v.18 no.4
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    • pp.401-409
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    • 2002
  • In this study, to evaluate the applicability of ORP and pH as process control parameters for an intermittent aeration process, a 200L/d bench-scale plant was installed and operated for 90 days. It was fed with synthetic wastewater which contained $COD_{Cr}$ : 400mg/L, TN : 40mg/L and TP : 7mg/L. ORP & pH were measured on-line and compared with the variation of nutrient concentrations. As the results, both of the ORP and pH were able to monitor successfully nitrification and denitrification. Bending-points on the ORP curve and peak points on the pH curve corresponded to the termination of nitrification and denitrification. For P uptake and release, pH was the best indicator for performance evaluation. The aerobic pH apex was appeared when P uptake was accomplished and there was a relationship between the P release and pH variation. But the pH curve needed filtering because there were many noises on it. In this study, the shape of the ORP & pH curves were varied as the operating conditions such as aeration rates and organic loads were changed. It allowed the operating states of biological systems to be effectively evaluated. If it is properly managed to show the bending points and peak points clearly, the on-line monitoring of ORP & pH will be a reliable and effective technique for process control of intermittent aeration processes.

The therapeutic effects of WSY-0702 on benign prostatic hyperplasia in RWPE-1

  • Oh, Hyun-A;Kwon, Eun Bi;Hwang, Yun Gyeong;Park, Soon Eung;Mok, Ji Ye;Hwang, Sung Yeoun
    • CELLMED
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    • v.7 no.2
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    • pp.8.1-8.7
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    • 2017
  • Benign prostatic hyperplasia (BPH) is one of the major diseases of the urinary system in older men. WSY-0702 is the extracted from the traditional medicinal plant; Seoritae, and it has effects of anti-obesity, chronic cervical pain, and anti-oxidant. The present study aimed to investigate the therapeutic potential of WSY-0702 in the prevention and treatment of BPH. Several parameters including inflammatory mediators, hormones, and oxidative stress (OS) have been considered to play a role in the development of BPH. Prostate tissue damage and OS may lead to compensatory cellular proliferation with resulting hyperplastic growth. An in vitro study showed that proliferation inhibited the human prostate epithelial cell line RWPE-1 in a dose-dependent manner. In cell line, the cell cycle at the G2/M and G0/G1 phase and downregulated the expression of CyclineB1 (CCNB1) and CyclineD1 (CCND1). In addition, we measured the $H_2O_2$-induced OS damage using RWPE-1 cells. We examined the relative expression of protein involved in the regulation of prostate apoptosis: transforming growth factor (TGF)-${\beta}$, a negative growth factor able to induced prostate apoptosis under physiological conditions. These results suggest that WSY-0702 that can inhibit the growth of prostate epithelial cell by a mechanism that may involve arresting the cell cycle and downregulating CCNB1 and CCND1 expression. In addition, WSY-0702 exposure resulted in significant protective effects in $H_2O_2$-stressed PWPE-1 cells by reduction in TGF-${\beta}$ levels.

Antioxidant Activity of Medicinal Plant Extracts Used as Folk Remedies by Diabetic Patients

  • Park, Min-Jung;Han, Ji-Sook
    • Preventive Nutrition and Food Science
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    • v.9 no.2
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    • pp.167-173
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    • 2004
  • The aim of this study was to investigate the antioxidant effect of medicinal plants used by diabetic patients. Fourteen medicinal plants were selected and antioxidant activity such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, inhibition effect of linoleic acid autoxidation and low density lipoprotein (LDL) oxidation, thiobarbituric acid (TBA) value were measured. The Cornus officinalis had DPPH radical scavenging activity of 84.79%, which was higher than the 78.79% for $\alpha$-tocopherol. Rosa rugosa Thunberg, Pueraria thundergiana Bentham, Artemisia princeps var. orientalis and Sasamorpha purpurascens Nakai also had high values. Extracts with higher DPPH radical scavenging activities had higher total phenol concentrations, and positive correlations between these parameters were found. Inhibitory activities of linoleic acid autoxidation, LDL oxidation and TBA value, used as indices of oxidative stress, were observed in most of the selected medicinal plants. The highest inhibitory activity for TBA value was observed in the extract of Pueraria thundergiana Bentham. Rosa rugosa Thunberg (75.50 %), Sasamorpha purpurascens Nakai (74.00 %), and Cornus officinalis (73.00 %) all had high antioxidant activity against linoleic acid autoxidation, similar to that of $\alpha$-tocopherol. The same 3 plants also had high in inhibitory activity against LDL oxidation. Therefore, we demonstrated that medicinal plants used as folk remedy by diabetic patients had antioxidant activity. Especially, Rosa rugosa Thunberg, Cornus officinalis, Pueraria thundergiana Bentham, Arlemisia princeps var. orientalis, and Sasamorpha purpurascens Nakai had high phenol concentrations which resulted in high values for DPPH radical scavenging. These same plants exhibited high values for inhibitory activities for TBA value, linoleic acid autoxidation and LDL oxidation, indices associated with lipid peroxidation.

EA-Based Tuning of the PID Controller for a CSTR (CSTR용 PID 제어기의 EA 기반 동조)

  • Jin, Gang-Gyoo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.3
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    • pp.330-336
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    • 2014
  • Many industrial processes such as continuous stirred tank reactors(CSTRs), desalination plant, distillation columns, pH neutralization processes and so on exhibit highly nonlinear characteristic and time-varying behavior during operation. The control of such processes has been challenging to control engineers. Hence, a variety of forms of PID controllers and their tuning rules for industrial processes have been developed to guarantee the best performance. In this paper, a scheme that designs the practical PID controller with an anti-windup strategy incorporating with an evolutionary algorithm(EA) is presented for the concentration control of a nonisothermal CSTR. EA is used to tune the parameters of the overall PID control process with anti-windup by minimizing the integral of absolute error(IAE). Simulation works for reference tracking and disturbance rejecting performances and robustness to parameter changes show the feasibility of using the proposed method.