• Title/Summary/Keyword: cold stratification

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Coastal Stratification Induced by Oceanographic Conditions of Open Sea in the East Sea on February, 2013 (2013년 2월 동해의 근해 해황에 의한 연안 성층)

  • Choi, Yong-Kyu;Kim, Sang-Woo;Jeong, Hee-Dong;Shim, Jeong-Min;Kwon, Kee-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.4
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    • pp.327-333
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    • 2013
  • In order to see the stratification phenomenon in the coastal area induced by oceanographic conditions of the open sea, we analyzed the CTD (Conductivity-Temperature-Depth) data taken from the oceanographic survey on February 16~28, 2013. The stratification in Jukbyun coast was stronger than those of Sokcho and Gampo coast. Jukbyun line (104 line in the Serial Oceanographic Observation of National Fisheries Research and Development Institute) showed the anticyclonic eddy in the vertical distribution of temperature. The isotherm of $10^{\circ}C$ was concaved to the depth of 200 m in the middle station (station no. 9) of the line 104. It showed above $4^{\circ}C$ in positive temperature anomaly in the depth of 100~200 m in the middle station (station no. 9) of the line 104. This positive temperature anomaly was stretched to the coastal area with shallower depth. It is suggested that the stratification in Jukbyun coast was resulted from the onshoring of the Ulleung warm eddy. The movement of warm eddy may be act as a block to migration of cold water fishes like cod.

Effect of Latent Heat Material Placement on Inside Temperature Uniformity of Insulated Transfer Boxes (단열용기의 잠열재 배치에 따른 내부 온도 균일성에 대한 영향)

  • HyungYong Ji;Dong-Yeol Chung;Seuk Cheun Choi;Joeng-Yeol Kim
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.29 no.1
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    • pp.27-33
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    • 2023
  • An optimized design of the transportation insulated box must be considered to control the thermal damage in order to maintain the fresh condition for temperature-sensitive medicine and frozen food safety. The inside temperature of the insulated box is a natural convection enclosure state, thermal stratification naturally occurs as time passes in case of with outside heat load. The latent heat material (LHM) placement inside the box maintains the target temperature of the product for temperature fluctuations during transport, and LHM application is a common and efficient method. In this work, inside temperature stratification in an insulated box depending on the LHM pack position is numerically simulated and experimented. The insulated box is made up of vacuum insulation panel (VIP), and LHM modules are placed over six faces inside the box, with the same weight. The temperature curves for 72 hrs as experiment results clearly show the temperature stratification in the upper, middle, and lower at the LHM melting time region. However, the temperature stratification state is uniformly changed in accordance with the condition of the upper and lower placement weight of the LHM pack. And also, the temperature uniformity by changed placement weight of LHM has an effect on maintaining time for target air temperature inside the box. These results provide information on the optimized design of the insulated box with LHM.

Germination Characteristics in Seeds of Broussonetia kazinoki Siebold ex Siebold & Zucc (Moraceae) Native to East Asia (동아시아 특산식물 애기닥나무 Broussonetia kazinoki Siebold ex Siebold & Zucc (Moreaceae) 종자의 발아특성)

  • Kim, Gun Mo;Chung, Jae Min;Jung, Ji Young;Choi, Hyeok Jae;Lee, Seung Youn
    • Korean Journal of Plant Resources
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    • v.35 no.1
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    • pp.36-43
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    • 2022
  • This research was conducted to develop a seed propagation protocol for the use of Broussonetia kazinoki Siebold ex Siebold & Zucc, which native to East Asia. Light and temperature conditions, GA3 treatment, and low-temperature stratification were performed to evaluate the germination characteristics. The germination percentage at 4, 15/6, 20/10 and 25/15℃ was 0, 42. 5, 44. 4 and 91.7%, respectively. Thus, the optimal germination temperature of the B. kazinoki seeds was 25/15℃. Although germination was delayed by relatively low temperature conditions, GA3 treatment allowed for increased germination rates even under the low temperature conditions. Cold stratification reduced time to germination. Relatively low germination percentages at 20/10℃ and 15/6℃ indicated that the seeds had been under the state of conditional dormancy. Through this study, B. kazinoki seeds have conditional dormancy because they can be germinated through GA3 treatment even under relatively low temperature conditions and it is judged that it will support the commercial propagation practice in the future.

Efficacy and Safety of Herb Medication According to Cold-heat Tendency of Knee Osteoarthritis Patients (퇴행성 슬관절염 환자의 한열 성향에 따른 한약 제제의 유효성과 안전성 비교)

  • Song, Ji-Yeon;Kim, Min-Jung;Sung, Won-Seok;Kim, Pil-Kun;Goo, Bon-Hyuk;Kwak, Hyun-Young;Kim, Ji-Hye;Kim, Dong-Hyuk;Park, Yeon-Cheol;Seo, Byung-Kwan;Baek, Yong-Hyeon;Choi, Do-Young;Lee, Jae-Dong;Park, Dong-Suk
    • Journal of Acupuncture Research
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    • v.29 no.5
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    • pp.97-108
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    • 2012
  • Objectives : To demonstrate the importance of syndrome differentiation in clinical research of herb medication, through the comparative study on efficacy and safety of herb medication according to cold-heat tendency of OA knee patients. Methods : During December 2010 to July 2011, 138 knee OA patients were randomly assigned to WIN-34B 600mg(300mg, b.i.d.), 1,200mg(600mg, b.i.d.) and placebo b.i.d. for 8 weeks. Patient were re-classified into cold-heat tendency group according to cold-heat questionnaires. To investigate efficacy and safety, we assessed the 100mm pain VAS at baseline and 8 weeks later, and we monitored adverse event of patients during treatment period. Results : 1. Efficacy study : In WIN-34B 1,200mg group, VAS mean changes of heat tendency group showed slightly increase than those of cold tendency, but no significant difference within two groups. In heat tendency group, WIN-34B 1,200mg group showed a significant decrease of VAS compared to placebo group. but there were no significant difference in cold tendency group. 2. Safety study; In WIN-34B 600mg group, incidence of adverse events of cold tendency group was higher than those of heat tendency, but not in WIN-34B 1,200mg group. Conclusions : This study suggests that WIN-34B tend to have more efficacy in heat tendency-knee OA patients and WIN-34B is safe drug relatively, regardless of cold-heat tendency. In further clinical research on efficacy and safety of WIN-34B, stratification using syndrome differentiation is required.

Effects of Several Pre-treatments on Seed Germination or Sophora japonica L. (회화나무 종자발아에 미치는 전처리의 효과)

  • Tak, Woo-Sik;Kim, Tae-Su;Choi, Chung-Ho
    • Korean Journal of Plant Resources
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    • v.19 no.5
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    • pp.580-585
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    • 2006
  • This experiment was conducted to study the effects of sulphuric acid, cutting, cold stratification and hot water on the germination of Sophora japonica seeds, which have difficulty to germinate because they have hard and thick seed coats. The seeds were immersed in 30, 60 and 90% sulphuric acid for 30 minutes as seed scarifications, and cut 1/8, 2/8 and 3/8 of the opposite parts of radicles. As cold stratification the seeds were wrapped in wet towel, and then stored in plastic bags in a refrigerator $(4^{\circ}C)$ for 3, 5 and 10 days. The seeds were immersed in hot water $(90{\sim}95^{\circ}C)$ for 2,5 and 10 minutes. Pretreated seeds represented different germination properties, respectively. After sulphuric acid treatment, the seeds showed an increase in germination (G) and germination index (GI). Compared to the other treatments, 90% sulphuric acid showed the highest G (31.7%) and GI (6.2). The G and GI of cut seeds decreased with the increase of seed cutting lengths. And G and GI of cold stratificated seeds were not significantly different among the days treated (p=0.258). Two minutes treatment of hot water showed lower G and Gl than control, and the seeds were not germinated in 5 and 10 minutes treatments of hot water. At the result of relative growth rate and T/R ratio of seedlings from pretreated seeds, the seedlings from seeds in 90% sulphuric acid treatment represented the highest relative growth rate and T/R ratio.

Characteristics of Water Temperature and Salinity in the Bottol Bada, Yeosu during Summer in 2010 (2010년 하계 보돌바다의 수온과 염분 특성)

  • Cho, Eun-Seob
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.4
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    • pp.301-306
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    • 2011
  • This study was determined to analysis the characteristics of water mass in the Bottol Bada, Yeosu in August, 2010 based on the data from the distribution of water temperature and salinity. Sampling was carried out a total of three times (i.e. July 29, August 13, and August 30, 2010) and performed at three stations. Observation was done during the period of time 10:00-15:00, indicating the decreasing tidal height and turn of tide. In July 29, thermocline was found at 4 m in St. 1, but the stratification did not observe in August 13 and August 30. The remarkable water temperature between surface and bottom was found in St. 2 and St. 3, whereas St. 1 did not find. A particular finding during this study showed a cold water mass at bottom layer from St. 2 and St. 3, which was first occurred in July 29 and persisted in August 30 without any of destruction. Water temperature had a remarkable fluctuation between surface and bottom, whereas salinity had a unique in St. 1. St. 2 and St. 3 showed the increasing salinity according to water depth in August 13 and August 30. Transparency had considerable fluctuations in St. 1 and St. 3 depending to sampling date, but St. 2 did not fluctuate. Consequently, the Bottol Bada had a significantly different water mass between inner and outer waters. Furthermore, strong irradiance and weak wind play an important role in developing the stratification between surface and bottom, in particular the introduction of offshore waters contribute to highly developing the stratification in the Bottol Bada during the period of August in 2010.

The Yellow Sea Warm Current and the Yellow Sea Cold Bottom Water, Their Impact on the Distribution of Zooplankton in the Southern Yellow Sea

  • Wang, Rong;Zuo, Tao
    • Journal of the korean society of oceanography
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    • v.39 no.1
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    • pp.1-13
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    • 2004
  • The Yellow Sea Warm Current (YSWC) and the Yellow Sea Cold Bottom Water (YSCBW) are two protruding features, which have strong influence on the community structure and distribution of zooplankton in the Yellow Sea. Both of them are seasonal phenomena. In winter, strong north wind drives southward flow at the surface along both Chinese and Korean coasts, which is compensated by a northward flow along the Yellow Sea Trough. That is the YSWC. It advects warmer and saltier water from the East China Sea into the southern Yellow Sea and changes the zooplankton community structure greatly in winter. During a cruise after onset of the winter monsoon in November 2001 in the southern Yellow Sea, 71 zooplankton species were identified, among which 39 species were tropical, accounting for 54.9 %, much more than those found in summer. Many of them were typical for Kuroshio water, e.g. Eucalanus subtenuis, Rhincalanus cornutus, Pareuchaeta russelli, Lucicutia flavicornis, and Euphausia diomedeae etc. 26 species were warm-temperate accounting for 36.6% and 6 temperate 8.5%. The distribution pattern of the warm water species clearly showed the impact of the YSWC and demonstrated that the intrusion of warmer and saltier water happened beneath the surface northwards along the Yellow Sea Trough. The YSCBW is a bottom pool of the remnant Yellow Sea Winter Water resulting from summer stratification and occupy most of the deep area of the Yellow Sea. The temperature of YSCBW temperature remains ${\leq}{\;}10^{\circ}C$ in mid-summer. It is served as an oversummering site for many temperate species, like Calanus sinicus and Euphaisia pacifica. Calanus sinicus is a dominant copepod in the Yellow Sea and East China Sea and can be found throughout the year with the year maximum in May to June. In summer it disappears in the coastal area and in the upper layer of central area due to the high temperature and shrinks its distribution into YSCBW.

Interannual variability of spring bloom in the Gulf of Maine observed by SeaWiFS

  • Son, Seung-Hyun;Thomas, Andrew
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.328-331
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    • 2006
  • Eight years of SeaWiFS data quantify variability in the time/space patterns of spring bloom development in the Gulf of Maine (GOM). Maximum and earliest spring bloom are usually observed over Georges Bank, later on the deep basins from the west to the east GOM, and latest development along the eastern Maine coast in cold, tidally mixed water. Pronounced interannual variability of spring bloom timing, spatial position, and magnitude are shown in the GOM. Strongest negative anomalies are present in April 1998 and 2001 over Georges Bank and the eastern GOM, and in January to April of 2005 over the most of GOM. Positive anomalies are strong in April 2001, 2003 and 2004 in varying locations as well as in February and March 1999. It is suggested that interannaul variability in spring phytoplankton bloom concentrations is strongly associated with changes in water mass and stratification which might be influenced by basin-scale forcing due to large climate change.

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Integral Approximate Solutions to a One-Dimensional Model for Stratified Thermal Storage Tanks (성층화된 축열조의 1차원모델에 대한 적분 근사해)

  • Chung, Jae-Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.7
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    • pp.468-473
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    • 2010
  • This paper deals with approximate integral solutions to the one-dimensional model describing the charging process of stratified thermal storage tanks. Temperature is assumed to be the form of Fermi-Dirac distribution function, which can be separated to two sets of cubic polynomials for each hot and cold side of thermal boundary layers. Proposed approximate integral solutions are compared to the previous works of the approximate analytic solutions and show reasonable agreement. The approach, however, has benefits in mathematical difficulties, complicated solution form and unstable convergence of series solution founded in the previous analytic solutions. Solutions for a semi-infinite region, which have simple closed form solutions, give close agreement to those for a finite region. Thermocline thickness is obtained in closed form and shows proportional behavior to the square root of time and inverse proportional behavior to the square root of flow rate.

Numerical analysis of turbulent natural convection in a cylindrical transformer enclosure (변압기를 모델링한 두 개의 동심 원형 실린더 내에서 난류 자연대류의 수치해석)

  • 오건제;하수석
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.2
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    • pp.157-166
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    • 1999
  • Numerical calculations of turbulent natural convection in an enclosure of the 20 kYA oil-immersed transformer model are presented. The transformer is modelled as two concentric cylinders with different heights and diameters. The thermal boundary layers are well represented in the temperature distributions along the wall of the transformer model. The flow stratification between the hot and cold walls can not be seen in the transformer model. The turbulence eddy viscosity has its maximum at the center of the core and its maximum values at the top of the core are larger than those at the bottom of the core.

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