• Title/Summary/Keyword: Heating Period

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Analysis on Insulation of Wind Environment and Greenhouse Cover Materials Insulation for Advanced Greenhouse Energy Design in Saemangeum Reclaimed Land (새만금 간척지 첨단온실 에너지 설계를 위한 풍환경 및 온실 피복재의 영향 분석)

  • Hyo-Jae Seo;Il-Hwan Seo;Deuk-ha Noh;Haksung Lee
    • Journal of Bio-Environment Control
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    • v.32 no.1
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    • pp.57-63
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    • 2023
  • The external weather conditions including temperature and wind speed in the Saemangeum reclaimed land is different from that of the inland, affecting the internal environment of the greenhouse. Therefore, it is important to select an appropriate covering material considering the insulation effect according to the type and characteristics of the covering material considering the weather condition in the Saemangeum reclaimed land. A hexahedral insulation chamber was designed to evaluate the insulation efficiency of each glass-clad material in the outside weather condition in reclaimed land. In order to evaluate the insulation effect of each covering material, a radiator was installed and real-time power consumption was monitored. 16-mm PC (polycarbonate), 16-mm PMMA (polymethyl methacrylate), 4-mm greenhouse glass, and 16-mm double-layered glass were used as the covering materials of the chamber. In order to understand the effect of the external wind directions, the windward and downwind insulation properties were evaluated. As a result of comparing the thermal insulation effect of each greenhouse cover material to single-layer glass, the thermal insulation effect of double-layer glass was 16.9% higher, while PMMA and PC were 62.5% and 131.2% higher respectively. On average the wind speed on the windward side was 53.1% higher than that on the lee-wind side, and the temperature difference between the inside and outside of the chamber at the wind ward side was found to be 52.0% larger than that on the lee ward side. During the experiment period, the overall heating operation time for PC was 39.2% lower compared to other insulation materials. Showing highest energy efficiency, and compared to PC, single-layer glass power consumption was 37.4% higher.

A New Temperature Control System by PWM Control Method for Thermal Massage System (PWM 제어방식에 의한 온열치료기의 새로운 온도제어 시스템)

  • Song, Myoung-Gyu;Lee, Jae-Heung
    • Journal of IKEEE
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    • v.18 no.3
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    • pp.409-419
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    • 2014
  • This paper proposes a new temperature control algorithm and system configuration of the pTMS(personal Thermal Massage System). By controlling the pulse width of the PWM(Pulse Width Modulation), the temparature of the heating lamp can be controlled stably, which is indispensable to the massage function. This technology is also adapted to the 'thermal massage', 'thermal acupressure', 'thermal moxibustion' functions of medical equipments. The temperature could be set at between $40^{\circ}C{\sim}70^{\circ}C$ by increments of $5^{\circ}C$, the control could be made in real time by increments of $1^{\circ}C$, and the temperature is displayed on the monitor by triggering every 2 seconds. when the present temperature is equal to the preset temperature, the PWM signal is minimized, and when the present temperature is higher than the preset temperature, overheating is prevented by interrupting the PWM output signal. When the difference of temperature exceeds $4^{\circ}C$, the PWM control is maximized in order for the system to reach the target temperature within a short period of time.

A Study on the Types and Changes of the Urban Houses in the Korean Inland during the Period 1910-1945 (한국(韓國) 근대기(近代期) 내륙지방(內陸地方) 도시주택(都市住宅)의 유형(類型)과 변천(變遷)에 관한 연구(硏究))

  • Kim, Tai-Young
    • Journal of architectural history
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    • v.7 no.3 s.16
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    • pp.53-66
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    • 1998
  • In the meantime, the study of traditional and contemporary house had been produced so many achievements in korea, but modern house is yet to be solved, Accordingly, It is necessary to develop and present the basic research data in order to build up an objective study for urban house in the modern age(1910-1945), Following to a study on the foreigner's house in grid-type settlement of Open Ports, in this research is to investigate and analyze modern houses of urban areas in korean inland, and then clarify types and changes of them. In the first year($1995{\sim}96$), the modern houses of Central Inland Districts(arrounding river Kumgang)-Kunsan kanggyong Puyo Kongju Pugang Chongju were investigated by the layout of room, the construction and materials, the design and style, etc. In the second year($1996{\sim}97$), the modern houses of Open Market(開市場)-Seoul Taegu Kwangju Taejon Chonju were conducted to investigate as above. The traditional house transformed by differentiation and addition of room(kan), the various types were respectively adopted for the korean reforming and western cultural house. In the layout of room, the types of plan were gradually concentrated from the single wings of korean traditional house. The korean traditional house was later improved through the introduction of entrance, corridor, and internal toilet/bathroom. But the korean under-floor heating system(andal) and a series of three rooms had been entirely maintained, composed of master bedroom/living room(daechung)/room. And the traditional town house with shop and storage, being built closely to each other and walled up both sides, it had taken gradually the extensive characteristics in itself. By the displacement of shop/dwelling/ storage. the various types were respectively adopted for the separated, multi-storied, and complex type. The type of them was gradually changed to the narrow and linear form. And so with the stockpile of fundamental datas about modern houses in korean urban areas, we expect these results contribute to the knowledge of the spatial characteristics of urban house at present which are required to the understanding of transition as well as types.

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Performance Analysis of Cooling Tower-Assisted Hybrid Ground-Coupled Heat Pump (HGCHP) System (냉각탑 병용 하이브리드 지열 히트펌프 시스템의 성능 분석)

  • Sohn, Byonghu;Lee, Doo-Young;Choi, Jae-Ho;Min, Kyong-Chon
    • Transactions of the KSME C: Technology and Education
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    • v.4 no.1
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    • pp.19-26
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    • 2016
  • This paper presents the measurement and analysis results for the performance of HGCHP system using a cooling tower as a supplemental heat rejector. In order to demonstrate the performance of the hybrid approach, we installed the monitoring equipments including sensors for measuring temperature and power consumption, and measured operation parameters from February 1, 2014 to February 28, 2015. Leaving load temperatures to building showed an average value of $11.7^{\circ}C$ for cooling and $39.5^{\circ}C$ for heating, respectively. From the analysis, the daily PF of hybrid GCHP system varied from 2.6 to 6.6 over the measurement period.

In vitro Characterization of Bacteriocin Produced by Lactic Acid Bacteria Isolated from Nem Chua, a Traditional Vietnamese Fermented Pork

  • Pilasombut, Komkhae;Rumjuankiat, Kittaporn;Ngamyeesoon, Nualphan;Duy, Le Nguyen Doan
    • Food Science of Animal Resources
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    • v.35 no.4
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    • pp.473-478
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    • 2015
  • The aim of this study was to screen and In vitro characterize the properties of bacteriocin produced by lactic acid bacteria isolated from Vietnamese fermented pork (Nem chua). One hundred and fifty LAB were isolated from ten samples of Nem chua and screened for bacteriocin-producing lactic acid bacteria. Antimicrobial activity of bacteriocin was carried out by spot on lawn method against both gram positive and gram negative bacteria. One isolate, assigned as KL-1, produced bacteriocin and showed inhibitory activity against Lactobacillus sakei, Leuconostoc mesenteroides and Enterococcus faecalis. To characterize the bacteriocin-producing strain, optimum temperature, incubation period for maximum bacteriocin production and identification of bacteriocin-producing strain were determined. It was found that the optimum cultivation temperature of the strain to produce the maximum bacteriocin activity (12,800 AU/mL) was obtained at 30℃. Meanwhile, bacteriocin production at 6,400 AU/mL was found when culturing the strain at 37℃ and 42℃. The isolate KL-1 was identified as L. plantarum. Antimicrobial activity of cell-free supernatant was completely inhibited by proteolytic enzyme of trypsin, alpha-chymotrypsin and proteinase K. Bacteriocin activity was stable at high temperature up to 100℃ for 10 min and at 4℃ storage for 2 d. However, the longer heating at 100℃ and 4℃ storage, its activity was reduced.

Analysis of Volatile Organic Compounds Emitted from Electronic Parts in PC/Monitor Set (PC/Monitor 구성 전자부품에서 방출되는 휘발성 유기화합물의 분석)

  • Ri, Chang Seop;Choe, Jong Woo;Baek, Kyu Won
    • Journal of the Korean Chemical Society
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    • v.44 no.4
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    • pp.343-349
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    • 2000
  • Volatile Organic Compounds(VOCs) emitted form electronicSince toluene, xylene, cyclohexanone, and benzofuran will bring on the deleterious smell and the health risk, eventhough very small amount of these areexposed to human body, quantitative analysis was achieved by GC-MS system. As a result of these analyses, except PCB(CEM-1) of which is one of the electronic parts, the left of electronic parts represented, imme-diately form 30 minutes to 1 hour after heating, the trends that toluene, xylene, cyclohexanone and phenol were consecuticely emitted very high. and toluene, xylene, phenol, cyclohexanone, and benzofuran from most of the electronic parts were emitted very frequently within the measuring period. Finally, Trans of electronic parts showed the highest concentration of emission, and xylene(550~2482 ${\mu}g/m^2$) was the most noticeably emitting compound of VOCs.

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EFFECT OF HYDROXYLAPATITE SYNTHETIC GRAFT AND GUIDED TISSUE REGENERATION TECHNIQUE ON HEALING OF EXTRACTION SOCKET IN MONGREL DOGS (성견에서 발치 직후 Hydroxylapatite의 축조와 조직 유도 재생술이 발치와의 골조직 치유에 미치는 영향)

  • Han, Dong-Hoo;Shim, June-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.1
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    • pp.187-200
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    • 1996
  • After loss of tooth, initial healing process is critical to preserve residual alveolar process. This study was conducted to compare the effect of hydroxylapatite particle synthetic graft and guided tissue regeneration procedure on healing of extraction wounds in 5 mongrel dogs. To investigate the maturity of bone and velocity of bone heating, bone-labeled tracers were used. After 16 weeks healing period, dogs were sacrificed. The specimens were treated with Villanueva bone stain. Fluorescence microscopy and polarized microscopy were performed to exam the pattern of bone formation in the extraction socket. The results were following ; 1. Pattern of bone regeneration in the group of hydroxylapatie graft and the group of membrane protection after hydroxylapatite graft was following ; bone regeneration was slow, regenerated bone was immature, and thickness of cortical layer was thin compare to that of untreated control group. 2. Cortical layers in membrane protected group were somewhat thicker but less condense to that of untreated control group. 3. Infiltration of inflammation cells were found in the groups using hydroxylapatite graft and membrane. We concluded that grafting of replamineform hydroxylapatite particles into the extraction socket delayed healing of the wound and disturbed the formation of cortical bone at the roof of extraction socket. The placement of expanded polytetrafluoroethylene membranes on the extraction socket promotes the bone regeneration. But newly formed bone in cortical layer consists of the cortico-cancellous bone in comparison with the cortical bone of the control group.

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여성들의 찜질방 이용 현상에 관한 일상 생활 기술적 연구

  • 전정자;유은광
    • Journal of Korean Academy of Nursing
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    • v.27 no.4
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    • pp.961-974
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    • 1997
  • The ZZimzilbang is a room where many women eagerly go due to the special meaning women give to it related to their health. It is a different type of sauna room which maintains low degree of temperature, consisting of an Ondol room(Korean under-floor heating system, hypocaust) built with mineral stone radiating ultrared rays. Even though many women mention that they utilize it for health, there is no precise evidence of the effects on their health. This ethnographic study sought to define the phenomenon from the perspective of the women who experienced the ZZimzilbang. A convenience sample of 27 women was interviewed during a 15 month period from December 1995 to July 1997 in 12 ZZimzilbangs located in Seoul, Korea. The mean ages of the women 57.3 years ; seventeen women were housekeeper and only eight women had job : twenty women were married and three women among them were widows. The main reasons women patronize the place are : for mitigation and healing of physical signs and symptoms : composure ; safe lodging and boarding : control of outward appearance : control of health ; meeting and fellowship with friends : and custom. The outcomes of the utilization of the place were : mitigation of physical signs and symptoms : psychological tranquility : cosmetic and diet ; good use of spare time : and utilization of services provided there. Most women who visited ZZimzilbang for relief of physical signs and symptoms strongly mentioned a correlation to inadequate Sanhujori, the traditional postpartal and postabortal care for woman. Some of specific kinds of services provided in that place were alternative therapy such as acupuncture, negative cupping, finger-pressure, mugwort steam and various kinds of massage including massage of blood vessels that are influenced by Oriental medicine ; health education of breathing such as abdominal breathing or Danjeon(단전호흡) : and selling of many things including health foods, drugs for osteoporosis, and eutrophics. This study suggests that professional caregivers should further study this phenomenon for the development of adequate care of women with a resulting important in their quality of life.

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Quality Evaluation of Thermal Oxidized Fats and Oils by Spectrophotometer (분광기를 이용한 가열산화 유지의 품질측정)

  • Chang, Young-Sang;Yi, Young-Soo;Cho, Kyung-Ryun;Lee, Chul-Won
    • Korean Journal of Food Science and Technology
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    • v.26 no.6
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    • pp.655-658
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    • 1994
  • This study was designed to investigate the suitability of oxidation matters and physico-chemical characteristics as a quality evaluation for the extent of rancidity development in fats and oils undergoing thermal oxidation. The results showed that acid value rapidly increased during heating time. Soybean oil, especially revealed a faster increase than palm oil and palm olein. Anisidine value and conjugated diene value also increased. Especially, soybean oil increased more rapidly than palm oil and palm olein. Active oxygen method stability was good in the ranks of palm oil, palm olein and soybean oil. Primary oxidation matter (POM) and secondary oxidation matter (SOM) were surveyed as an evaluation method for the extent of rancidity development in fats and oils. POM and SOM showed a sharp increase during the thermal oxidation period.

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Numerical Study on the Thermal Stratification Behavior in Underground Rock Cavern for Thermal Energy Storage (TES) (열에너지 저장을 위한 지하 암반공동 내 열성층화 거동에 대한 수치해석적 연구)

  • Park, Do-Hyun;Kim, Hyung-Mok;Ryu, Dong-Woo;Choi, Byung-Hee;SunWoo, Choon;Han, Kong-Chang
    • Tunnel and Underground Space
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    • v.22 no.3
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    • pp.188-195
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    • 2012
  • Using a computational fluid dynamics (CFD) code, FLUENT, the present study investigated the thermal stratification behavior of Lyckebo storage in Sweden, which is the very first large-scale rock cavern for underground thermal energy storage. Heat transfer analysis was carried out for numerical cases with different temperatures of the surrounding rock mass in order to examine the effect of rock mass heating due to periodic storage and production of thermal energy on thermal stratification and heat loss. The change of thermal stratification with respect to time was quantitatively examined based on an index of the degree of stratification. The results of numerical simulation showed that in the early operational stage where the surrounding rock mass was less heated, the stratification of stored thermal energy was rapidly degraded over time, but the degradation and heat loss tended to reduce as the surrounding rock mass was heated during a long period of operation.