• Title/Summary/Keyword: After-cooling

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Physico-chemical Properties of Bracken (Pteridium aquilinum) Root Starch - II. Physical Properties- (고사리(Pteridium aquilinum) 뿌리 전분의 이화학적 특성에 관한 연구 -제2보 : 전분의 물리적 특성-)

  • Jo, Jae-Sun;Kim, Sung-Kon;Lee, Ke-Ho;Kwon, Tai-Wan
    • Korean Journal of Food Science and Technology
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    • v.13 no.2
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    • pp.133-141
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    • 1981
  • The gelatinization phenomena of bracken root starch were examined by means of the loss of birefringence, degree of digestibility by amylase and X-ray diffraction. These results indicated that gelatinization temperature of the starch was $55{\sim}60^{\circ}$ and over 95% of starch were gelatinized at the temperature between 60 and $70^{\circ}C$. The swelling power of the bracken root starch was much less steeper than that of potato or tapioca starch. Amylograph data on the various starch concentrations showed the pasting temperature of $62{\sim}68^{\circ}$, peak height of $80{\sim}840$ Brabender unit (BU) and peak after cooling to $50^{\circ}C$ of $110{\sim}555\;BU.$. According to the information obtained from amylograph data, the bracken root starch showed low set back. The rate of retrogradation of the starch as tested by Texturometer was slower and faster than that of potato and tapioca starches, respectively.

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Sensitivity Analysis of Depletion Parameters for Heat Load Evaluation of PWR Spent Fuel Storage Pool (경수로 사용후핵연료 저장조 열부하 평가를 위한 연소조건 인자 민감도 분석)

  • Kim, In-Young;Lee, Un-Chul
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.9 no.4
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    • pp.237-245
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    • 2011
  • As necessity of safety re-evaluation for spent fuel storage facility has emphasized after the Fukushima accident, accuracy improvement of heat load evaluation has become more important to acquire reliable thermal-hydraulic evaluation results. As groundwork, parametric and sensitivity analyses of various storage conditions for Kori Unit 4 spent fuel storage pool and spent fuel depletion parameters such as axial burnup effect, operation history, and specific heat are conducted using ORIGEN2 code. According to heat load evaluation and parametric sensitivity analyses, decay heat of last discharged fuel comprises maximum 80.42% of total heat load of storage facility and there is a negative correlation between effect of depletion parameters and cooling period. It is determined that specific heat is most influential parameter and operation history is secondly influential parameter. And decay heat of just discharged fuel is varied from 0.34 to 1.66 times of average value and decay heat of 1 year cooled fuel is varied from 0.55 to 1.37 times of average value in accordance with change of specific power. Namely depletion parameters can cause large variation in decay heat calculation of short-term cooled fuel. Therefore application of real operation data instead of user selection value is needed to improve evaluation accuracy. It is expected that these results could be used to improve accuracy of heat load assessment and evaluate uncertainty of calculated heat load.

Mineralogical Characteristics of Tachylite occurring in Basic Dike, Basaltic Agglomerate Formation, Ulleung Island and Its Implications of Volcanic Activity (울릉도의 하부층 현무암질 집괴암 층내 염기성 암맥에서 산출되는 타킬라이트의 광물학적 특성과 화산학적 의미)

  • Bae, Su-Gyeong;Choo, Chang-Oh;Jang, Yun-Deuk
    • Journal of the Mineralogical Society of Korea
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    • v.25 no.2
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    • pp.63-76
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    • 2012
  • Tachylite, black basaltic glass formed by the rapid cooling of molten basalt, locally occurs at the Basaltic Agglomerate Formation (BAF), the lowest formation of Ulleung Island. The purposes of this study are to characterize the occurrence and mineralogy of tachylite and to elucidate its formation condition, with emphasis on its fracture pattern, which can serve as implications for the early volcanic activity of Ulleung Island. To this end, we investigated the occurrence pattern of tachylite in the field and carried out mineralogical analyses using optical microscope, XRD, EPMA, and SEM. Tachylite occurs at the chilled margin of basic dikes which are distributed in Naesujeon, Dodong and Jeodong seasides, Turtle Rock, and Yaerimwon, whose widths vary from several cm to 10 cm. It is evident that the outer surface of tachylite is dense and smooth, whereas the inner surface, if fractured, is characterized by conchoidal fracture. The matrix of tachylite consists of amorphous, glass and some fine-grained phenocrysts present in tachylite include biotite, anorthoclase, sanidine, plagioclase, hornblende, and Fe-Ti oxides. The fracture patterns characteristic of tachylite are subrounded, oval, or less commonly polygonal, bounded by joints to form globule or lump. Taking into account texture and mineralogy, tachylite is interpreted to have undergone little subsequent alteration at low temperature via hydration or hydrolysis that could form clay minerals after it was formed. Because tachylite with peculiar fractures occurs as dikes in a close association with BAF, its presence is considered as reliable evidence that when tachylite formed, the most part of BAF was still under subaqueous conditions, or at least saturated with seawater.

Petrological and Mineralogical Characteristics of Matrix of Pumice in Ulleung Island (울릉도 부석 기질의 암석.광물학적 특성)

  • Im, Ji-Hyeon;Choo, Chang-Oh;Jang, Yun-Deuk
    • Journal of the Mineralogical Society of Korea
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    • v.24 no.3
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    • pp.151-164
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    • 2011
  • Mineralogical and petrological characteristics were investigated on matrix of dense gray, vesiculate gray, brown and black pumice in Ulleung Island by using XRD, FT-IR, XRF, SEM and thermal analysis. According to the analysis, most of pumice matrix are amorphous and include very small amount of sanidine and anorthoclase. Since the adsorption moistures, which commonly observed as O-H peak in FT-IR spectrum, are not identified in thermal analysis, it seems reasonable to conclude that content of the adsorption moisture has very low level. Although pumice has a large specific surface area, with long time elapsed after eruption, pumice matrix shows very low degree of hydration alteration due to the low level of water content. In SEM images, most surfaces of pumice show morphological characteristics such as various shapes of vesicle with wrinkled and thin walls resulted from ductile coalescence. Dense gray pumice formed in the initial stage includes small vesicles less than $15{\mu}m$ in size with subangular to angular shapes, free of ovoid vesicle. These characteristics are interpreted to have related to the hydrous environment derived from phreato-plinian eruption. Submicron particles observed as amorphous alumina silicate assemblages in vesicle surface are considered as particles sticked to the matrix surface through rapidly cooling process during ascent of alkali phonolitic magma. It indicates that these particles coexisted partly with crystallized alkali feldspar.

A study on the development of phthalate plasticizers CRM in ABS resin (ABS 중 phthalates 가소제 CRM 개발에 대한 연구)

  • Jung, Jung-Sul;Park, Jung-Woo;Yoo, Seok;Kweon, Seong-Il;Hong, Sung-Taeg;Sun, Yle-Shik;Park, Cheon-Min;Choi, Chang-Hyoo
    • Analytical Science and Technology
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    • v.25 no.5
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    • pp.273-283
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    • 2012
  • Phthalate plasticizers are regulated by RoHS, REACH and CPSC as hazardous substances. Responding to these international environmental restrictions, we developed ABS certified reference material (CRM) for determination of phthalate plasticizers such as DMP, DEP, DBP, BBP, DEHP and DnOP. The candidate material has been made with ABS resin widely used in electric and electronic products and 6 kinds of phthalate plasticizers. The making of the material involved a series of processes like extruding, cooling, pelletizing, and drying using twin screw extruder. Then it has been certified according to ISO Guide 35. Using isotope dilution-gas chromatography/mass spectrometry (ID-GC/MS), homogeneity, short-term stability, and long-term stability were evaluated. The certified values were determined by using primary reference material (PRM) of KRISS for traceability. From now on, we will provide ABS CRM to national and international companies and research institutes after certification as certified reference material and registering on COMAR (code of reference material).

Changes of Quality Properties of Pork Loaves with Chemical-free Sweet Persimmon Powder during Chilled Storage at 5℃ (무 농약 단감분말로 제조한 미트로프의 5℃ 냉장 저장 중 품질 변화)

  • Ha, Chang-Ju;Jin, Sang-Keun;Nam, Young-Wook;Yang, Mi-Ra;Ko, Byung-Soon;Kim, Il-Suk
    • Journal of Animal Science and Technology
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    • v.50 no.2
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    • pp.237-246
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    • 2008
  • Four different pork loaves were made with two levels, HP/FP-3% and HP/FP-6%, containing 3.0 and 6.0% HP(hot air dried sweet persimmon powder)/FP(freezer dried sweet persimmon powder), respectively. HP and FP(3% and 6%) were added into ground pork loin separately. A control without persimmon powder were used for comparison. Patties were cooked to 74℃ in electric oven, after cooling, the aerobic packaged meat loaves were stored at 5℃. The moisture and crude ash were higher in the FP-6%, and the crude protein and crude fat were no different among the samples. The pH in control sample was significantly higher(p<0.05) than those of treatment group, however no significant difference was found among the 4 treatments. The TBARS(thiobarbituric reactive substance) values of all samples showed a tendency of increasing value along the storage days. The TBARS and a* value increased(p<0.05) as the addition ratio of HP/FP increased, respectively. With regard to microorganisms, the number of total aerobic bacteria were lower than 3.11 log10 CFU/g. In sensory evaluation, meat loaves containing persimmon powder resulted in a high overall acceptability, although they were not significantly different in overall acceptability.

Design and performance estimation of fish-luring system using the water cooling typed LED lamp (채낚기 어선용 수랭식 LED 집어시스템의 설계 및 성능평가)

  • Bae, Bong-Seong;An, Heui-Chun;Kwon, Ki-Jin;Park, Seong-Wook;Park, Chang-Doo;Lee, Kyoung-Hoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.2
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    • pp.79-87
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    • 2011
  • A fishing lamp is fishing gear to gather fish in the night. But the cost of oil which is used to a light fishing lamp, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnages. This cost has almost taken 30.40% of total fishing costs. As oil price increases, the business condition of the fishery gets worse and worse. Therefore, it is very urgent to develop an economical fishing lamp, to solve the problem of fishery's business difficulty. This research aims at developing a fishing lamp for squid jigging fishery and hairtail angling fishery using the LED, which has excellent efficiency and durability. One fishing lamp has about 160Watt capacity and five fishing lamps are installed one aluminium panel in which sea water flows to emit generated heat from LED to outside. Developed fishing lamp lights to an effective direction of jigging and angling operation. This fishing lamp can be controlled to light the direction of fish shoal because the aluminium panel can be controlled to up and down direction. The wave length of fishing lamp has white and blue color. White color light is to gather fish shoal of horizontal direction and blue color light is to gather fish shoal of vertical direction. After development of this fishing lamp, 60.110 units are established on the boat, and operated fishing. Consequently, in the case of squid jigging, spent energy was reduced to 39%, in the case of hairtail angling, 68% of spent energy was reduced. And the catch was more than another boat.

Physicochemical Properties of Oxidized Waxy Maize Starches with Sodium Hypochlorite (찰옥수수 산화전분의 이화학적 특성)

  • Chung, Man-Gon;Jeon, Young-Seung;Lee, Sur-Koo;Park, Jong-Moon;Lim, Bun-Sam
    • Korean Journal of Food Science and Technology
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    • v.30 no.1
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    • pp.42-48
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    • 1998
  • Physicochemical properties of waxy maize starch and oxidized waxy maize starch with sodium hypochlorite $(0{\sim}60\;mg\;CL_2/g\;starch,40^{\circ}C,\;pH\;10,\;3.0\;hr)$ were studied. As sodium hypochlorite concentration was increased, the content of crude lipid and crude protein of the oxidized starch were decreased. And crude protein content and whiteness was considered to show negative regression. However, the crude ash content of the oxidized starch increased significantly with oxidation and bore a positive regression to the chlorine content. There was a progressive increase in the carboxyl content with increasing oxidant level. After pasting in hot water and cooling, viscosity of the oxidized starches were drastically lower than that of native starch . As carboxyl contents of the oxidized starch increased, the solubility and swelling power was increased. When waxy maize starch treated with 0, 1.5, 3.0 and 6.0% sodium hypochlorite, temperature of initial gelatinization of oxidized starch was shown to 65, 65, 60 and $50^{\circ}C$, respectively. The oxidized waxy maize starches also form clearer pastes. Water binding capacity of the oxidized starch decreased as the degree of carboxyl group substitution increased. Waxy maize starch has polygonal and some round granules which range from about 3.7 to $20\;{\mu}m$ in diameter. Surface appearance of the waxy maize starch became rough when oxidized with sodium hypochlorite. When homogenate of the oxidized waxy maize starch solution and corn germ oil was stored under room temperature for 24 hours, the emulsion stability was considered to depend on starch concentration and degree of substitution.

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A PRELIMINARY EVALUATION OF UNPROTECTED LOSS-OF-FLOW ACCIDENT FOR A PROTOTYPE FAST-BREEDER REACTOR

  • SUZUKI, TOHRU;TOBITA, YOSHIHARU;KAWADA, KENICHI;TAGAMI, HIROTAKA;SOGABE, JOJI;MATSUBA, KENICHI;ITO, KEI;OHSHIMA, HIROYUKI
    • Nuclear Engineering and Technology
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    • v.47 no.3
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    • pp.240-252
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    • 2015
  • In the original licensing application for the prototype fast-breeder reactor, MONJU, the event progression during an unprotected loss of flow (ULOF), which is one of the technically inconceivable events postulated beyond design basis, was evaluated. Through this evaluation, it was confirmed that radiological consequences could be suitably limited even if mechanical energy was released. Following the Fukushima-Daiichi accident, a new nuclear safety regulation has become effective in Japan. The conformity of MONJU to this new regulation should hence be investigated. The objectives of the present study are to conduct a preliminary evaluation of ULOF for MONJU, reflecting the knowledge obtained after the original licensing application through CABRI experiments and EAGLE projects, and to gain the prospect of in-vessel retention for the conformity of MONJU to the new regulation. The preliminary evaluation in the present study showed that no significant mechanical energy release would take place, and that thermal failure of the reactor vessel could be avoided by the stable cooling of disrupted-core materials. This result suggests that the prospect of in-vessel retention against ULOF, which lies within the bounds of the original licensing evaluation and conforms to the new nuclear safety regulation, will be gained.

Quality Properites of Legumes subjected to Salt Solution and Microwave Heating (가염침지 및 마이크로파 처리 두태류의 품질특성)

  • Park, Jong-Dae;Jeon, Hyang-Mi;Choi, Bong-Kyu;Kum, Jun-Seok;Lee, Hyun-Yu
    • Food Science and Preservation
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    • v.13 no.6
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    • pp.686-690
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    • 2006
  • Quality properties of legumes (Seoritae and red bean) with soaking of 3% NaCl solution and microwave dying were evaluated. The samples were soaking with 3% NaCl at $25^{\circ}C$ for 6 hr(Seoritae) and 12 hr(red bean). Moisture content of Seoritae and red bean after soaking are 35.8%, and 35.1% respectively. The samples were dried with microwave treatment and cooling with microwave treatment combination secondly to $12{\sim}14%$ for moisture content Hardness of Seoritae was decreased from $12,863g_f$ to $3,309g_f$. There was a difference between varieties on color value. Hardness of cooked rice with ratio of milled rice and legumes(7:3) was $3,165g_f$ which is lower value compared to regular cooked mixed rice. Sensory evaluation of cooked mixed rice showed that treated samples have higher scores on color, flavor, taste, texture and overall acceptability values than those of control.