• Title/Summary/Keyword: Central water

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Effect of Extrusion Processing and Steam Pelleting Diets on Pellet Durability, Water Absorption and Physical Response of Macrobrachium rosenbergii

  • Misra, Chandra Kanta;Sahu, N.P.;Jain, K.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.9
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    • pp.1354-1358
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    • 2002
  • Two hundred and ten post-larvae (PL) of Macrobrachium rosenbergii (14.5-14.9 mg) were equally distributed in two experimental groups and fed with either steam cooked or extruded pellet for a period of 60 days. Physical evaluation and growth promoting effect of both the pellets were assessed. Significantly higher (p<0.05) water stability, absorption and protein efficiency ratio (PER) were recorded in extruded pellet than the steam cooked pellet. Nutrient loss was minimum in the extruded pellet for which lower feed conversion ratio (FCR) (p<0.05) was recorded in this group. However, weight gain, relative growth and specific growth rate (SGR) in both the groups were not significantly different (p>0.05). Although insignificant (p>0.05) but higher amylase activity was recorded in steam pellet fed group. Survival was not affected by feeding either of the diets.

Real Time Near Optimal Control Application Strategy for Heat Source and HVAC System (열원 및 공조설비 통합 최적제어기법 구현에 관한 연구)

  • Song, Jae-Yeob;Ahn, Byung-Cheon;Joo, Yong-Duk;Kim, Jin
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.60-65
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    • 2008
  • The near-optimal control algorithm for central cooling and heating system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled or hot water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling and heating control system.

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Fishing efficiency by vessel capacity of Korean tuna purse seiners operating in the western and central Pacific Ocean (태평양 수역 우리나라 다랑어선망어업의 선박 역량에 따른 조업 효율성 분석)

  • LEE, Mi Kyung;LEE, Sung Il;KIM, Doo Nam;KU, Jeong Eun;KWON, Youjung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.2
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    • pp.169-176
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    • 2017
  • Tuna purse seine fishery in the western and central Pacific Ocean (WCPO) has been rapidly developed since early 1980s due to massive investment of major distant water fishing nations, and catch by purse seine fishery operating in the WCPO accounts for nearly half of the world's tuna total catch. As fishing efficiency is reflected by not only improving of individual vessel's capacity but also increasing number of active vessel, it is essential to understand vessel capacity for reliable assessment result on how fishery affects stock status of target species. In this study, fishing efficiency was analyzed by main factors which are representative of vessel capacity using fishing data and vessel information related to Korean tuna purse seine fishery operating in the western and central Pacific Ocean from 1992 to 2014. It showed that fishing efficiency of vessel tends to be higher when having larger vessel tonnage, higher engine power, lower vessel age and larger length of vessel. As for fishing efficiency by set type, CPUE of associated set with floating objects was generally higher than that of free school set, and CPUE of free school set seemed to have a greater effect on engine power and vessel age compared to other factors.

Numerical Simulation of Tsunamis that Affected the Coastal Zone of East Sea (동해연안에 영향을 미친 지진해일의 수치시뮬레이션)

  • Kim, Do-Sam;Kim, Ji-Min;Lee, Kwang-Ho
    • Journal of Ocean Engineering and Technology
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    • v.21 no.6
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    • pp.72-80
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    • 2007
  • The tsunami that resulted from the Central East sea Earthquake, which registered 7.7 on the Richter scale, that occurred over the entire water region in Akita on May. 26, 1983 and the tsunami that was triggered by the Southwest off Hokkaido Earthquake (7.8 on the Richter scale) that occurred in Southwest off Hokkaido on July 12, 1993 are representative cases that led to considerable damage in life and property, not only in Japan but also in Korea. In this study, multi-grid method was used in order to reproduce sufficiently the shoaling effect that occurs as water depth becomes shallow in the shallow water region and moving boundary condition was introduced to consider the runup in the coastal region. For the tsunamis that exerted considerable effect on the East Sea coast of Korea that were caused by the Central East Sea Earthquake in 1983 and the Southwest off Hokkaido Earthquake in 1993, characteristics like water level rise and propagation in the East Sea coast will be examined using numerical simulations. At the same time, these values will be compared with observed values. In addition, maximum water level rise and change in the water level with respect to time that were caused by the tsunamis were examined at each location along the East sea coast. Usefulness of numerical analysis was verified by comparing with observed values.

Fishing investigation of trawl fisheries in sea mount of central northern Pacific (북태평양 중부 해산어장에 있어서 저층 트롤의 어획실태)

  • Kim, Young-Seuing;On, Taeg-Yun;Cho, Sam-Kwang;Choi, Seuk-Kwan;Kon, Jeong-Lag;Yang, Won-Seuk
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.3
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    • pp.179-187
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    • 2005
  • This study was conducted in order to the experiment of bottom trawl fisheries in the sea mount of central northern pacific($30^{\circ}-40^{\circ}N$, $170^{\circ}-175^{\circ}E$), during the period of July 1 to August 25, 2004 by commercial trawl ship. Fishing experiment was carried out by bottom trawl, with the codend of 110mm mesh size. The number of 101 test fishing was done in the sea mount of central northern pacific during 56 days and the total catches were 198,593kg as 18 fish species, and CPUE/day and catches/day were 8.3 hours towing time and 3,546kg. Catch ratio according to each fishing ground was higher with the order of B, C, and E, and catches for B was 7,171.0kg during the towing time of 13.2 hours. Main target species were Pseudopentaceros richardsoni and Beryx splendens, there was 14.9% of damage ratio for fishing gears on catching the target fishes inhabiting on the rough sea bottom. Catches by water depth was the order of 300m below, 301-350m, 451-500m and 351-400m. It is thought that there was no problem on the mesh size because most of fishes caught from the experimental fishing was 30cm over.

Single Oral Dose Toxicity Test of Water Extracts of Radix Araliae Cordatae in ICR Mice

  • Leem, Moon-Jeong;Ryu, Jei-Man;Ku, Sae-Kwang
    • Biomolecules & Therapeutics
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    • v.15 no.2
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    • pp.127-132
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    • 2007
  • The object of this study was to evaluate the acute toxicity of lyophilized water extract of Radix Araliae Cordatae (RA) in male and female mice. The extract was administered to female and male ICR mice as an oral dose of 2000 mg/kg (body wt.) according to the recommendation of KFDA Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy, organ weight and histopathology of 12 principle organs were examined. As results, we could not find any mortality, clinical signs, changes in the body weight and gross findings except for increases of hypertrophy of lymph nodes in male RA extracts-dosing group. In addition, no RA extracts-treatment related abnormal changes in the organ weight and histopathology of principle organs except for some sporadic accidental findings. The results obtained in this study suggest that the RA extracts does not cause any toxicological signs. The LD$_{50}$ and approximate LD of RA extracts in both female and male mice were considered as over 2000 mg/kg.

Study on Increasing High Temperature pH(t) to Reduce Iron Corrosion Products (철부식생성물 저감을 위한 고온 pH(t) 상향 연구)

  • Shin, Dong-Man;Hur, Nam-Yong;Kim, Wang-Bae
    • Corrosion Science and Technology
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    • v.10 no.5
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    • pp.175-179
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    • 2011
  • The transportation and deposition of iron corrosion products are important elements that affect both the steam generator (SG) integrity and secondary system in pressurized water reactor (PWR) nuclear power plants. Most of iron corrosion products are generated on carbon steel materials due to flow accelerated corrosion (FAC). The several parameters like water chemistry, temperature, hydrodynamic, and steel composition affect FAC. It is well established that the at-temperature pH of the deaerated water system has a first order effect on the FAC rate of carbon steels through nuclear industry researches. In order to reduce transportation and deposition of iron corrosion products, increasing pH(t) tests were applied on secondary system of A, B units. Increasing pH(t) successfully reduced flow accelerated corrosion. The effect of increasing pH(t) to inhibit FAC was identified through the experiment and pH(t) evaluation in this paper.

A Simulation Study on Effect Analysis of EMS Combined Control of Central Cooling and Heating System (중앙냉난방시스템의 EMS 복합제어 효과 분석에 관한 시뮬레이션 연구)

  • Jae-Yeob Song;Byung-Cheon Ahn
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.18 no.4
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    • pp.33-44
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    • 2022
  • In this study, we analyze the existing heating and cooling operation method for an office-type complex building with a central heating and cooling system, and examine the effects of applying various EMS that can be applied according to the load size to save energy in the building. For this purpose, simulation analysis was performed. As a control method, reset control of chilled water, hot water, cooling water and supply air temperatures, optimal start/stop of heat source, and number of heat source control were applied according to the load size, and energy consumption was analyzed accordingly. In addition, when all of these control methods were applied, the overlapping energy saving effect was finally confirmed. As a result, it was possible to confirm the energy saving effect when EMS for reset control and heat source control were applied compared to the existing control method of the heating and cooling system, and the effect for the case of using all these control methods in combination was also confirmed.

Effects of High Temperature Heating on the Some Physicochemical Properties of Korean Red Ginseng (Panax ginseng C.A. Meyer) Water Extract (고온 열처리가 홍삼물추출물의 이화학적 특성에 미치는 영향)

  • Kwak, Yi-Seong;Choi, Keum-Hee;Kyung, Jong-Soo;Won, Jun-Yeon;Rhee, Man-Hee;Lee, Jae-Gon;Hwang, Mi-Sun;Kim, Seok-Chang;Park, Chae-Kyu;Song, Kyung-Bin;Han, Gyeong-Ho
    • Journal of Ginseng Research
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    • v.32 no.2
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    • pp.120-126
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    • 2008
  • This study was carried out to investigate the some physicochemical properties of Korean red ginseng (Panax ginseng C.A. Meyer) water extract (RGWE) after heated with high temperatures above $100^{\circ}C$ for 2 hours. RGWEs were heated at 100, 110 and $120^{\circ}C$ for 2 hours by using autoclave. After RGWEs were heated at high temperature for 2 hours without not adjustment of pH, the changes of saponin, free sugars, mineral and color in the RGWEs were investigated. Total ginsenoside content in control was 1.99%, while those of RGWE were 1.65, 1.49 and 1.29% when treated at 100, 110 and $120^{\circ}C$, respectively. The contents of total ginsenoside showed decreased tendency as heating temperatures were increased. The ginsenoside-$Rh_{2}$ and $-Rg_{3}$, which have been reported as very stable red ginseng ginsenosides, showed relatively strong spots on TLC when RGWEs were heated at 110 and $120^{\circ}C$. In case of free sugars in RGWEs, fructose, glucose and maltose showed high contents when compared with control, while Fe, Ca and Mg ions showed very low contents. Value of L in RGWE treated with high temperature was almost the same with control, while values of a and b were increased. Values of a were increased from -0.86 of control to +0.04, +0.05 and +1.14 when treated with 100, 110 and $120^{\circ}C$, respectively. Values of b also were increased from 27.68 of control to 33.61, 33.61 and 37.42 when treated with 100, 110 and $120^{\circ}C$, respectively. Values of total color in RGWEs treated with high temperatures, E, were finally increased by values of a and b.