• Title/Summary/Keyword: cold and heat application

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A Study on the Calorific Value of Insulated Gang-form in Winter (동절기 단열갱폼의 발열량 변화 측정에 관한 연구)

  • Kang, In-Seon;Won, Joon-Yuen;Kim, Tae-Hui;Kim, Seong-Deok;Choi, Seok;Nam, Kyung-Yong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.135-136
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    • 2017
  • This paper examines the efficiency of the application of conventional and insulated gang forms for curing and protection of concrete by comparing the amount of electric energy required therefor. In addition, a thermal vision camera was used to identify heat loss from surfaces of the gang forms after each placement of concrete. Experimental results, show that the heat loss at the submerged temperature was large at the submerged surface due to the large calorific value at the surface of the mold. The insulated gang form had some heat loss in the horizontal bars. In the case of adiabatic reforming, the pattern shows a constant calorific value over time. In conclusion, the insulation performance is better than that of general gang form.

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Packaging Design of EPS Cooling Box by Theoretical Heat Flow and Random Vibration Analysis (이론적 열유동 및 랜덤 진동 해석을 적용한 EPS 보냉용기의 포장설계)

  • Kim, Su-Hyun;Park Sang-Hoon;Lee, Min-A;Jung, Hyun-Mo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.27 no.3
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    • pp.175-180
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    • 2021
  • Although it has recently been regulated for use as an eco-friendly policy in Korea, the use of EPS (Expanded Polystyrene) cooling boxes, which are used as cold chain delivery insulation boxes for fresh agricultural and livestock products, is also increasing rapidly as e-commerce logistics such as delivery have increased rapidly due to COVID-19. Studies were conducted to optimize the EPS cooling container through internal air heat flow of CFD (Computational Fluid Dynamics) analysis and FEM (Finite Element Method) random vibration analysis using domestic PSD (Power Spectral Density) profile of the EPS cooling box to which the refrigerant is applied in this study. In the analysis of the internal air heat flow by the refrigerant in the EPS cooling box, the application of vertical protrusions inside was excellent in volume heat flow and internal air temperature distribution. In addition, as a result of random vibration analysis, the internal vertical protrusion gives the rigid effect of the cooling box, so that displacement and stress generation due to vibration during transport are smaller than that of a general cooling container without protrusion. By utilizing the resonance point (frequency) of the EPS cooling box derived by the Model analysis of ANSYS Software, it can be applied to the insulation and cushion packaging design of the EPS product line, which is widely used as insulation and cushion materials.

A Basic Study on the District Cooling System of LNG Cold Thermal Energy (LNG 냉열 에너지의 지역 냉방 시스템에 관한 기반 연구)

  • Kim Chung Kyun
    • Journal of the Korean Institute of Gas
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    • v.7 no.4 s.21
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    • pp.36-43
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    • 2003
  • This paper provides the possibility of the district cooling system by using a LNG cold thermal energy. A liquefied natural gas provides a plenty of cooling source energy during a gasification of a liquefied natural gas. In recent, an ice thermal storage system is used for cooling a building, and a deep water source cooling system has been introduced as a district cooling system in which is used to cool the office towers and other large buildings in old and new downtown. LNG cooling energy refers to the reuse of a large body of naturally cold fluids as a heat sink for process and comfort space cooling as an alternative of conventional, refrigerant based cooling systems. Coincident with significant clean energy and operating cost savings, LNG cold energy cooling system offers radical reductions in air-borne pollutants and the release of environmentally harmful refrigerants in comparison to the conventional air-conditioning system. This study provides useful information on the basic design concepts, environmental considerations and performance related to the application of LNG cold thermal energy.

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Development of Structural Steel and Trend of Welding Technology (건설용 강재개발 및 용접기술동향)

  • Kim, Sung Jin;Jeong, Hong Chul
    • Journal of Welding and Joining
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    • v.34 no.1
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    • pp.7-20
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    • 2016
  • A brief overview is given of the development of various structural steels and their welding application technology. Firstly, the general characteristics and welding performance of structural steels used in architecture and bridge are introduced. For safety against earthquakes or strong wind, and for highly efficient welding in high-rise building constructions, ultra high strength steel with tensile strength over 800 MPa or high HAZ toughness steel plates under high heat input welding have been developed. In particular, efficient welding technology ensuring high resistance to cold and hot cracking of ultra high strength steel is reviewed in the present paper. Secondly, various coated steels used mainly for outer part in construction are briefly discussed. Moreover, a major drawback of coated steel during welding operation, and several solutions to overcome such technical problem are proposed. It is hoped that this review paper can lead to significant academic contributions and provide readers interested in the structural steels with useful welding technology.

Thermal Conductivity Measurement of Insulation Material for Superconducting Application

  • Chol, Y.S.;Kim, D.L.;Shin, D.W.;Hwang, S.D.
    • Progress in Superconductivity and Cryogenics
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    • v.13 no.2
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    • pp.29-32
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    • 2011
  • The thermal properties of insulation material are essential to develop a high-temperature superconducting (HTS) power cable to be operated at around liquid nitrogen temperature. Unlike metallic materials, nonmetallic materials have a high thermal resistance; therefore special attention needs to be paid to estimate heat flow correctly. Thus, we have developed a precise instrument for measuring the thermal conductivity of insulating materials over a temperature range from 40 K to near room temperature using a cryocooler. Firstly, the measurement of thermal conductivity for Teflon is carried out for accuracy confirmation. For a supplied heat flux, the temperature difference between warm and cold side is measured in steady state, from which the thermal conductivity of Teflon is calculated and compared with published result of NIST. In addition, the apparent thermal conductivity of Polypropylene laminated paper (PPLP) is presented and its temperature dependency is discussed.

Effects of Combustion Characteristics of the Burners for Non-Oxidizing Direct Fired Furnaces on the Oxidization of the Surface of Steel Plate (무산화 직화로 버너의 연소특성이 강재표면의 산화에 미치는 영향)

  • Park, Heung Soo;Riu, Kap Jong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.3
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    • pp.330-341
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    • 1999
  • An experimental study for the two types of burners used in the non-oxidizing direct fired furnaces of the heat treatment process for the cold rolled plate has been carried out to investigate the combustion characteristics and the oxidization of the surface of steel plate. A steep temperature gradient and entrainment of residual oxygen were found near the heating surface in the flame of the nozzle mixing burner which has strong swirl velocity component. It was concluded that the elimination of the residual oxygen and the increase of the temperature of combustion gas on the heating surface are needed to enhance the performance of the burners for application to the non-oxidizing direct fired furnaces.

A Literature Study on Surgical Disease of the Four Famous Physicians in JinYuan Period (金元四大家의 外科疾患에 對한 硏究;(癰疽瘍瘡을 中心으로))

  • Kim, Hee-taek;Roh, Sek-seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.1
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    • pp.179-214
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    • 1999
  • The result were as follows: 1. Yu Wan So(劉完素) regarded the cause of surgical disease as the heat(熱). He used the three method to drain(疏通), promoting pus drainage(托裏) and the balance between ying-energy(營氣) and wei-energy(衛氣). 2. Jang Jong Jeung(張從正) only refered to medicines without entire theory. 3. Lee Dong Won(李東垣) regarded the cause of surgical disease as the greasy diet(膏梁厚味), damp air(濕氣), wetness heat(濕熱). For each treatment he used the method of Yu Wan So's treatment and emphasized the balance between ying-energy(營氣) and wei-energy(衛氣), stomach energy(胃氣). 4. Ju Jin Heung(朱震亨) distinguished the cause of surgical disease from enternal(內), external(外) and channel(經). For each treatment he used the method to drain(疏通), promoting pus drainage(托裏) and the balance between ying-energy(營氣) and wei-energy(衛氣). The first stage used the clearing away heat and toxic materials(淸熱解毒) and the last stage used the invigoration and dispersion(補托). 5. Yu Wan So(劉完素) used to be very busy of Moschus(麝香), Alumen(白礬), Olibanum(乳香), Coptidis Rhizoma(黃連), Minium(黃丹) and Scutel1ariae Radix(黃芩) In classification of the medical action, great part of the medicine are activating blood circulation to dissipate blood stasis(活血祛瘀), clearing away heat and toxic materials( 淸熱解毒) and external application(外用). 6. Jang Jong Jeung(張從正) used to be very busy of Olibanum(乳香), Angelicae Gigantis Radix(當歸), Minium(黃丹), Myrrha(沒藥), Calomelas(輕粉), Rhei Radix Et Rhizoma(大黃) and Phellodendri Cortex(黃柏). In classification of the medical action, great part of the medicine arc activating blood circulation to dissipate blood stasis(活血祛瘀), clearing away heat and toxic materials(淸熱解毒) and diverged wind-cold evil(發散風寒). 7. Lee Dong Won(李東垣) used to be very busy of Forsythiae Fructus(連翹), Scuteliariae Radix(黃芩), Angelicae Gigantis Radix(當歸). Astragali Radix(황기), Glycyrrhizae Radix(炙甘草), Bupleuri Radix(紫胡), Phellodendri Cortcx(黃柏), and Coptidis Rhizoma(黃連). In classification of the medical action, great part of the medicine are activating blood circulation to dissipate blood stasis(活血祛瘀), regulating vital energy(理氣) and clearing away heat and toxic materials(淸熱解毒). 8. Ju Jin Heung(朱震亨) used to be very busy of Glycyrrhizae Radix(甘草), Astragali Radix(황기), Angelicae Gigantis Radix(當歸), Phellodendri Cortex(黃柏), Scutellariae Radix(黃芩), Ginseng Radix(人蔘), Qlibanum(乳香). In classification of the medical action, great part of the medicine are clearing away heat and toxic materiaIs(淸熱解毒), activating blood circulation to dissipate blood stasis(活血祛瘀) and diverged wind-cold evil(發散風寒).

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Application of BIPV System Functioned as Solar Collector (태양열 집열기 기능을 갖는 BIPV 시스템의 응용)

  • Min, Sung-Hye;Suh, Seung-Jik
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.953-958
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    • 2006
  • Perimeter zone has been reinforced by active systems, such as fan-coil units, because it causes an increase in heating and cooling loads, dew condensation in winter, or discomfort with cold-draft to residents in buildings, through poor insulation by light-weighed skin due to progressing multi-storied buildings and skyscrapers. However, because these active systems raise Its capacity so that fossil fuel is used as much as they are added, and ultimately, greenhouse effect is urged, we proposed BIPV system functioned as solar collector which can substitute active system. As an early stage, heat balance equation in steady-state by Fortran was used not only for pre-heating effect and electric power capacity during the day in winter, but also for electric power capacity during day in slimmer and sky radiation effect during night in summer. Especially, we should have considered shading on PV, since even a little bit of it makes the efficiency too low for the PV to work. Still, when the flux of pre-heated air was increased to make air-barrier, its temperature was not enough to make it because the speed of heat exchange was too fast to warm up the air, thus the capacity to meet the condition was evaluated, and electric power from PV was made used for it.

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A Fundamental Study of BIPV System Functioned as Solar Collector for Building Application (건물 적용을 위한 태양열 집열기 기능을 갖는 BIPV 시스템의 기초적 연구)

  • Min, Sung-Hye;Suh, Seung-Jik
    • Journal of the Korean Solar Energy Society
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    • v.27 no.1
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    • pp.91-98
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    • 2007
  • Perimeter zone is one of the weakest area in buildings and it makes an increase of heating and cooling loads, in addition to condensation or discomfort with cold-draft to residents in winter. Because of this, it needs to be reinforced by active systems. However, they use fossil fuel, and ultimately greenhouse effect is urged. Thus, we proposed BIPV system functioned as solar collector which can substitute active system. As an fundamental stage, heat balance equation in steady-state by Fortran was used not only, in winter for pre-heating effect and electric power capacity during the day, but also in summer, for the latter during the day and sky radiation effect during the night. Especially, we should have considered shading on PV by IES Suncast, since even a little bit of it makes the efficiency too low for the PV modules to work. As a result, in summer day, the PV panel should be tiled in 70 degrees to gain the most electric power. Moreover, we could verify that this model makes higher temperature and heat flux under 0.02 m/s. On the other hand, the PV had the high efficiency with high velocity because of cooling effect behind the PV. Therefore, we should regard the air current distribution later on.

Development of Mobile Application for Preventive Management based on Korean Medicine: Mibyeongbogam (한의학 기반 예방관리를 위한 모바일 어플리케이션 개발: 미병보감)

  • Lee, Young Seop;Jin, Hee Jeong;Park, Dae Il;Lee, Si Woo
    • Journal of Sasang Constitutional Medicine
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    • v.30 no.1
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    • pp.66-73
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    • 2018
  • Objectives The purpose of this study was to develop mobile a application that evaluate the Mibyeong(deterioration of the health) in daily life and provide optimal Yangseng(養生) interventions according to the Korean medicine types. Methods The evaluation of Mibyeong utilized questionnaire or objective informations including Facial photographs and hemodynamic information. The Korean medicine type classification was reconstructed based on the concept of Sasang constitution and cold-heat pattern identification. Yangseng interventions were recommended based on Mibyeong symptoms, Korean medicine types, and demographic information. And we have developed tracking and ranking functions for user motivations. We used a Korean medicine database that focused on healthy people as a reference data, and used Yangseng interventions database that reinterpreted classical Yangseng in a modern way. Results and Conclusions We have developed a mobile application that evaluates the user's Mibyeong state and provides optimal Yangseng interventions based on Korean medicine types. This study are expected to improve the quality of health and contribute to the prevention of diseases.