• Title/Summary/Keyword: Ground temperature

Search Result 1,599, Processing Time 0.034 seconds

Catch status of the giant pacific octopus, Enterocotpus dofleini, by drift line fishery in the central coast of the East Sea, Korea (동해 중부연안에 서식하는 대문어(Enteroctopus dofleini) 흘림낚시의 어획실태에 관한 연구)

  • Young il, SEO;Soo Jeong, LEE; Jae-Hyeong, YANG
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.58 no.4
    • /
    • pp.310-316
    • /
    • 2022
  • Giant pacific octopus, Enteroctopus dofleini, is a large mollusk distributed in the East Sea of Korea. In this study, the catch status of giant pacific octopus by drift line fishery and the effect of sea temperature on fishing ground were investigated in Goseong-gun, Gangwon-do, which is the central coast of the East Sea. The average catch of giant pacific octopus in Gangwon-do was 1,570 tons over the past ten years, and it accounted for 21% in 2008 and 44% in 2021 compared to the total catch in the East Sea during the same period. Such data indicates that the catch in Gangwon-do has recently increased. In this study area, giant pacific octopus weighing 1.1-5.0 kg dominated accounting for 56% of the total individuals, and followed by those weighing 1 kg or less. However, the ratio of catch of giant pacific octopus over 5.1 kg tended to increase in 2021, which is thought to be related to the sea temperature that affected the fishing ground. The main depth of fishing ground was from 21 m to 50 m in this area and fishing grounds were widely distributed throughout the season except summer. Fishing ground was formed with the conditions of bottom sea temperature under 10℃ and was diminished by moving of giant pacific octopus to deeper depth with conditions of bottom sea temperature over 18℃.

Search of submarine discharge locations with multi-temporal thermal infrared images and ground radar surveys

  • Onishi K.;Sairaiji M.;Rokugawa S.;Tokunaga T.;Sakuno Y.
    • Proceedings of the KSRS Conference
    • /
    • 2004.10a
    • /
    • pp.685-688
    • /
    • 2004
  • Fresh water discharge from the sea floor strongly affects a coastal ecology and the diffusion of contaminants. Much fresh water discharge has been found in the edge of Kurobe alluvial fan, in which annual rainfall is over 4000mm and there is abundant groundwater. However, it is difficult to find the groundwater discharge, thus the search of possible areas with some remote sensing tools is required. Because the temperature of the discharge point is relatively low compared with the surrounding sea water surfaces, there is a possibility to detect the area as an irregular zone of thermal infrared images. Two anomalous temperature zones, which have no surface streams from rivers, are detected by ASTER thermal-infrared images. One of them was verified as the groundwater discharge point by dives. In addition, the distribution of water table under the land side of the two areas is also detected as irregular zones by a ground-penetrating radar

  • PDF

Experimentally Measured Rotational Reorientation Time of Coumarin 6 Laser Dye in Ethanol and Acetonitrile Solvents

  • Renuka, C.G.;Raikar, U.S.
    • Journal of Photoscience
    • /
    • v.12 no.3
    • /
    • pp.119-122
    • /
    • 2005
  • The photophysical properties of coumarin 6 laser dye have been studied in two solvents; ethanol and acetonitrile using steady-state fluorescence depolarization technique. The experimentally measured reorientation time of coumarin 6 is more or less the same in given solvents at particular temperature. It is found that coumarin 6 rotates slower in acetonitrile than in ethanol especially at higher values of viscosity over temperature. We also measure the ground and excited state dipole moments of coumarin 6 by solvent perturbation method. The results found that excited state dipole moment is greater than ground state dipole moment, which indicates that excited state is more polar than the ground state.

  • PDF

The Effects of Burn-out Printing on the Polyester/Cellulosic Fiber Mixed Fabrics (폴리에스테르/셀룰로오스계 교직물의 탄화날염가고에 관한 연구)

  • Kim, Ho-Jung
    • Fashion & Textile Research Journal
    • /
    • v.3 no.4
    • /
    • pp.373-377
    • /
    • 2001
  • When the polyester/cellulosic fiber mixed fabrics were treated with sodium hydrogensulfate for burn-out printing, it is examined how the effects of process conditions as concentration of acid, fixation temperature and fixation time act onto the properties of the polyester ground fabrics. The print paste, indalca solution, was mixed with sodium hydrogensulfate and glycerine, and then screen-printed on the fabrics. The properties of the polyester ground fabrics after removing away the cellulosic fibers were investigated. The yellowness index and the breaking load of polyester ground fabrics affected by the process conditions, especially dry heat fixation temperature.

  • PDF

Heating and Cooling Performance of a Ground Coupled Heat Pump System with Energy-Slab (에너지슬래브 적용 지열원 열펌프 시스템의 성능 특성에 관한 실증 연구)

  • Choi, Jong-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.24 no.2
    • /
    • pp.196-203
    • /
    • 2012
  • Energy foundations and other thermo-active ground structure, energy wells, energy-slab, and pavement heating and cooling represent an innovative technology that contributes to environmental protection and provides substantial long-term cost savings and minimized maintenance. This paper focuses on earth-contact concrete elements that are already required for structural reasons, but which simultaneously work as heat exchangers. Pipes, energy slabs, filled with a heat carrier fluid are installed under conventional structural elements, forming the primary circuit of a geothermal energy system. The natural ground temperature is used as a heat source in winter and a heat sink in summer. The geothermal heat pump system with energy-slab represented very high heating and cooling performance due to the stability of EWT from energy slab. However, the performance of it seemed to be affected by the atmospheric air temperature.

The Effects of the Installation Conditions of Ground Loop Heat Exchanger to the Thermal Conductivity and Borehole Resistance (지중열교환기 설치 조건이 지중 유효 열전도도와 보어홀 열저항에 미치는 영향)

  • Lim, Hyo-Jae;Kong, Hyoung-Jin;Kang, Sung-Jae;Choi, Jae-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.23 no.2
    • /
    • pp.95-102
    • /
    • 2011
  • A ground loop heat exchanger in a ground source heat pump system is an important unit that determines the thermal performance of a system and its initial cost. A proper design requires certain site specific parameters, most importantly the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. This study was performed to investigate the effect of some parameters such as borehole lengths, various grouting materials and U tube configurations on ground effective thermal conductivity and borehole thermal resistance. In this study, thermal response tests were conducted using a testing device to 9 different ground loop heat exchangers. From the experimental results, the length of ground loop heat exchanger affects to the effective thermal conductivity. The results of this experiment shows that higher thermal conductivity of grouting materials leads to the increase effective thermal conductivity from 22 to 32%. Also, mounting spacers have increased by 14%.

A Study on the Monitoring Methods for Energy Production in Ground Source Heat Pump System (지열원 열펌프 시스템의 에너지 생산량 모니터링 신뢰도 향상 방안 연구)

  • Kang, Shin-Hyung;Lee, Kwang Ho;Do, Sung Lok;Choi, Jong Min
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.15 no.2
    • /
    • pp.10-16
    • /
    • 2019
  • In this study, the present regulation of heat metering for the ground source heat pump was investigated. The ground source heat pump has been adopting the heat metering system used in the district heating system for estimating the heating and cooling energy production amount. The accuracy of the present heat metering systems for a water to water ground source heat pump is low, because the system for district heating has a relatively high temperature range comparing with the ground source heat pump operating conditions. Even though the heat amount for the building side should be measured, the heat absorption and extraction amount from or to the ground was measured for the water to air ground source heat pump due to the difficulty of estimating the air side heating and cooling capacity in the present regulation. It is highly recommended to validate the heat metering system to have reliability for the ground source heat pump and develop the system to be applicable water to air ground source heat pump.

Study on Capacity Alteration of Geothermal Heat Exchanger by Changing Design Condition (설계조건 변화에 따른 지중열교환기 길이 변화 연구)

  • Park, Jong Il;Park, Kyung Soon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.9 no.4
    • /
    • pp.9-14
    • /
    • 2013
  • A ground loop heat exchanger for the ground source heat pump system is the important equipment determining the thermal performance and initial cost of the system. The length and performance of the underground heat exchanger is dependent on ground thermal conductivity, operation hours, ground loop diameter, grout, ground loop arrangement, pipe placement and design temperature. In this study we find out heat exchanger length with various design factor.

Effect of the Design Parameters of Geothermal Heat Exchanger Design Length (설계변수가 수직밀폐형 지중열교환기 설계길이에 미치는 영향)

  • Min, Kyong-Chon;Choi, Jae-Ho
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.7 no.2
    • /
    • pp.10-15
    • /
    • 2011
  • A ground loop heat exchanger for the ground source heat pump system is the core equipment determining the thermal performance and initial cost of the system The length and performance of the heat exchanger is dependent on the ground thermal conductivity, the operation hours, the ground loop diameter, the grout, the ground loop arrangement, the pipe placement and the design temperature. The result of this simulation shows that higher thermal conductivity of grouting materials leads to the decrease length of geothermal heat exchanger from 100.0 to 84.4%.

STUDY ON THERMAL MODELING METHODS OF A CYLINDRICAL GROUND OBJECT CONSIDERING THE SPECTRAL SOLAR RADIATION THROUGH THE ATMOSPHERE

  • Choi Jun-Hyuk;Choi Mi-Na;Gil Tae-Jun;Kim Tae-Kuk
    • Proceedings of the KSRS Conference
    • /
    • 2005.10a
    • /
    • pp.205-208
    • /
    • 2005
  • This research is aimed at the development of a software that predicts the surface temperature profiles of three-dimensional objects on the ground considering the spectral solar radiation through the atmosphere. The thermal modelling is essential for identifying the objects on the scenes obtained from the satellites. And the temperature distribution on the objects is necessary to obtain their infrared images in contrast to the background. We developed a software that could be used to model the thermal problems of the ground objects irradiated by the spectral solar radiation. This software can be used to handle the conduction within the object as a one-dimensional mode into the depth or as a three-dimensional mode through the media. LOWTRAN7 is used to model the spectral solar radiation including the direct and diffuse solar radiances. In this paper, temperature distributions on the objects obtained by using the one-dimensional and the three-dimensional thermal models are compared with each other to examine the applicability of the relatively easy-to-apply one-dimensional model.

  • PDF