• Title/Summary/Keyword: Water transfer characteristic

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Production of a Mozzarella Cheese Analogue by Using Raw Milk and Soy Milk Blends (원유를 두유에 첨가한 혼합액으로 Mozzarella Cheese Analogue 제조에 관한 연구)

  • Lee, Joon-Ha;Song, Kwang-Young;Seo, Kun-Ho;Yoon, Yoh-Chang
    • Journal of Dairy Science and Biotechnology
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    • v.31 no.1
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    • pp.9-20
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    • 2013
  • The study was conducted to evaluate the feasibility of Mozzarella cheese analogue generation by using a mixture of soy milk and raw milk and to compare the quality of the resultant cheese with that of Mozzarella cheese manufactured using the traditional method. The mixtures showed increase in protein and decrease in lactose and SNF in a dose-dependent manner with the addition of soy milk. The Mozzarella cheese analogue had lower total solids content than the control cheese product, while the fat content was similar between both. The analogue cheese had lower ash content than the traditionally prepared cheese; the content was proportional to the amount of soy milk in the mixture. Higher soy milk quantities within mixtures also resulted in proportionally higher levels of fat content within analogue cheese. Water-soluble nitrogen content was lower in the analogue cheese than in the control cheese. While the WSN level increased in the control cheese, it was almost constant in the analogue cheese. The control cheese had much higher actual and predicted yield than the analogue cheese, while the analogue cheese had a higher stability level. The control cheese had a higher transfer rate than the analogue cheese, with the exception of lactose. Electrophoresis analysis showed bands for Mozzarella cheese analogues that were present in addition to the normal ${\alpha}$-casein and ${\beta}$-casein bands. Physical characteristic analysis showed that hardness was affected by the addition of soy milk to cheese, while cohesiveness and brittleness were affected by the addition of raw milk, and elasticity was barely affected by milk composition. The meltability of the control cheese was higher than that of the analogue cheese and increased during 30 days of storage at $4^{\circ}C$. Browning, oiling-off, and stretching characteristics were almost identical between the 2 types of cheeses. Sensory evaluation findings showed that the control cheese had much better body texture, appearance, and flavor than the analogue cheese.

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A Study on the Silica Removal in Primary System using the Membrane Process (막 분리 공정을 이용한 1차 계통 실리카 제거에 관한 연구)

  • Kim Bong-Jin;Lee Sang-Jin;Yang Ho-Yeon;Kim Kyung-Duk;Jung Hee-Chul;Jo Hang-Rae
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.06a
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    • pp.137-144
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    • 2005
  • Silica in primary system combines with an alkali grammatical particle metal and forms the zeolite layer which is hindering the heat transfer on the surface of the cladding. Zeolite layer becomes the cause of the damage in this way. The problems of the NPP's primary system have been issued steadily by EPRI. Through a series of experiments of the laboratory scale, we confirmed the applicability of NF membrane for silica removal, as silica rejection rate of NF membrane is about $60\;{\sim}\;70\%$ and boron rejection rate is about $10\;{\sim}\;20\%$. We accomplished a site experiment about four NF membranes manufactured by FilmTec and Osmonics Inc. In experiment using 400L of SFP water, when operation pressure is $10kg_{f}/cm^2$, we confirmed that the silica rejection rate of NF90-2540 manufactured by FilmTec Inc. is about $98\%$, boron rejection rate is about $43\%$. The silica rejection rate of NF270-2540 is about $38\%$, boron rejection rate is about $3.5\%$. Afterward, through additional experiments, such as long term characteristic experiments, we are going to design a optimum NF membrane system for silica removal.

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Intelligent Tuning of the Two Degrees-of-Freedom Proportional-Integral-Derivative Controller On the Distributed Control System for Steam Temperature Control of Thermal Power Plant

  • Dong Hwa Kim;Won Pyo Hong;Seung Hack Lee
    • KIEE International Transaction on Systems and Control
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    • v.2D no.2
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    • pp.78-91
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    • 2002
  • In the thermal power plant, there are six manipulated variables: main steam flow, feedwater flow, fuel flow, air flow, spray flow, and gas recirculation flow. There are five controlled variables: generator output, main steam pressure, main steam temperature, exhaust gas density, and reheater steam temperature. Therefore, the thermal power plant control system is a multinput and output system. In the control system, the main steam temperature is typically regulated by the fuel flow rate and the spray flow rate, and the reheater steam temperature is regulated by the gas recirculation flow rate. However, strict control of the steam temperature must be maintained to avoid thermal stress. Maintaining the steam temperature can be difficult due to heating value variation to the fuel source, time delay changes in the main steam temperature versus changes in fuel flow rate, difficulty of control of the main steam temperature control and the reheater steam temperature control system owing to the dynamic response characteristics of changes in steam temperature and the reheater steam temperature, and the fluctuation of inner fluid water and steam flow rates during the load-following operation. Up to the present time, the Proportional-Integral-Derivative Controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper focuses on the characteristic comparison of the PID controller and the modified 2-DOF PID Controller (Two-Degrees-Freedom Proportional-Integral-Derivative) on the DCS (Distributed Control System). The method is to design an optimal controller that can be operated on the thermal generating plant in Seoul, Korea. The modified 2-DOF PID controller is designed to enable parameters to fit into the thermal plant during disturbances. To attain an optimal control method, transfer function and operating data from start-up, running, and stop procedures of the thermal plant have been acquired. Through this research, the stable range of a 2-DOF parameter for only this system could be found for the start-up procedure and this parameter could be used for the tuning problem. Also, this paper addressed whether an intelligent tuning method based on immune network algorithms can be used effectively in tuning these controllers.

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A experimental Feasibility of Magnetic Resonance Based Monitoring Method for Underground Environment (지하 환경 감시를 위한 자기공명 기반 모니터링 방법의 타당성 연구)

  • Ryu, Dong-Woo;Lee, Ki-Song;Kim, Eun-Hee;Yum, Byung-Woo
    • Tunnel and Underground Space
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    • v.28 no.6
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    • pp.596-608
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    • 2018
  • As urban infrastructure is aging, the possibility of accidents due to the failures or breakdowns of infrastructure increases. Especially, aging underground infrastructures like sewer pipes, waterworks, and subway have a potential to cause an urban ground sink. Urban ground sink is defined just as a local and erratic collapse occurred by underground cavity due to soil erosion or soil loss, which is separated from a sinkhole in soluble bedrock such as limestone. The conventional measurements such as differential settlement gauge, inclinometer or earth pressure gauge have a shortcoming just to provide point measurements with short coverage. Therefore, these methods are not adequate for monitoring of an erratic subsidence caused by underground cavity due to soil erosion or soil loss which occurring at unspecified time and location. Therefore, an alternative technology is required to detect a change of underground physical condition in real time. In this study, the feasibility of a novel magnetic resonance based monitoring method is investigated through laboratory tests, where the changes of path loss (S21) were measured under various testing conditions: media including air, water, and soil, resonant frequency, impedance, and distances between transmitter (TX) and receiver (RX). Theoretically, the transfer characteristic of magnetic field is known to be independent of the density of the medium. However, the results of the test showed the meaningful differences in the path loss (S21) under the different conditions of medium. And it is found that the reflection coefficient showed the more distinct differences over the testing conditions than the path loss. In particular, input reflection coefficient (S11) is more distinguishable than output reflection coefficient (S22).