• Title/Summary/Keyword: Heating System

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Preferences of Stroke Patients for Kitchen Environment in Residential Space (주거공간의 부엌 환경 특성에 대한 뇌졸중 환자의 선호)

  • Baek, Da-Rae;Jung, Yeon-Jin;Kang, Suk-Gu;Kim, Hee-Jung;Lee, Chun-Yeop
    • The Journal of Korean society of community based occupational therapy
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    • v.4 no.2
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    • pp.1-10
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    • 2014
  • Objective : The purpose of this study was to investigate the preferences of kitchen environment for stroke patients. Methods : The subjects of this study were 97 who have experience in rehabilitation therapy at hospitals in Busan. A questionnaire was distributed and collected from February 24th to March 13th, 2014. Descriptive statistics of frequency Study were used to analyze data. Results : First, the subjects demand for improvement that use a chair for work and install non-slip tiles. Second, they preferred the non-slip mat, boilers in heating equipment, drawer storage, L-shaped safety handle, adjustable sink of the height, automatic cutout of gas leak, faucet of touch-sensitive type, ㄷ-shaped kitchen and the ceiling-type hood in ventilation system. Third, they need kitchen items such as the sink self coming down, scissors for slices and knife to avoid hand injury. Conclusion : This study would contribute to kitchen environment for fall prevention and ease in use.

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A Study on the Management Improvement of an Academic Library Using Customer Relationship Management (CRM 기법을 이용한 대학도서관 경영개선에 관한 연구)

  • Park, Il-Jong;Yoo, Kyeong-Jong
    • Journal of the Korean Society for information Management
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    • v.36 no.2
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    • pp.31-56
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    • 2019
  • The user satisfaction and needs of an academic library were caught through a questionnaire survey in this study. The aim of this study is to draw up the CRM based plan for meeting user needs on the study. The users' demographic information, library resources & their use, homepage, services, and facilities/environment of the library were categorized in the questionnaire and analyzed for this study. The major conclusions of this study are: (1) The library resources use was the highest, and its facilities/environment was the lowest in the user satisfaction study. It also revealed that there are much necessities for the quick acquisition and dissemination of the requested material to the library users, and for the inter-library loan (ILL) services among campuses for the subscription books in the library resources use study, too; (2) There are a lot of necessities for the improvement of OPAC retrieval and the subscription books system, and menu rearrangement in the library homepage; (3) There are a lot of necessities for the plans of more frequent library event, more detailed event guidance, and more reinforcement of public relations such as SMS, push services of SDI etc. in the library user services; and (4) There are a lot of necessities for the improved policies to the complaints of library users such as the lack of common study place and lockers, air conditioning and heating problem, complaints about facilities management of restroom (lack of toilet paper), library accessibility on campus, unauthorized user management etc. in the facilities/environment of the library.

Evaluation of thermal stress of poultry according to stocking densities using mumerical BES model (BES 수치모델을 이용한 사육 밀도별 가금류 고온 스트레스 평가)

  • Kwon, Kyeong-seok;Ha, Tahwan;Choi, Hee-chul;Kim, Jong-bok;Lee, Jun-yeob;Jeon, Jung-hwan;Yang, Ka-young;Kim, Rack-woo;Yeo, Uk-hyeon;Lee, Sang-yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.456-463
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    • 2019
  • Micro climatic conditions within the livestock facility are affected by various factors such as ventilation, cooling, heating, insulation and latent and sensible heat generation from animals. In this study, numerical BES method was used to simulate energy flow inside the poultry house. Based on the BES method and THI concept, degree of thermal stress of poultry was evaluated according to the locations in South Korea. Comparison of THI values within the poultry house was also carried out according to the stocking densities to reflect recent animal-welfare issue. Significant decrease in thermal stress of poultry was observed when the stocking density of $30kg/m^2$ was applied in the change of the seasons(p<0.05) however, there was no statistically significant difference in summer season(p>0.05). It meant that installation of proper cooling system is urgently needed. For Iksan city of Jeollabuk-do province, total 252 hours of profit for thermal stress was found according to decrease in the stocking density.

Co-firing Characteristics and Slagging Behavior of Sewage Sludge with Coal and Wood Pellet in a Bubbling Fluidized Bed (기포 유동층 반응기를 이용한 하수 슬러지와 석탄 및 우드 펠렛의 혼소 특성 및 슬래깅 성향 연구)

  • Ahn, Hyungjun;Kim, Donghee;Lee, Youngjae
    • Clean Technology
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    • v.24 no.4
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    • pp.323-331
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    • 2018
  • The results of an experimental investigation on the co-firing characteristics and slagging behavior of dried and hydrothermal carbonization sewage sludge, sub-bituminous coal, and wood pellet in a fluidized bed were presented. Combustion tests were conducted in a lab-scale bubbling fluidized bed system at the uniform fuel-air equivalence ratio, air flow rate, and initial bed temperature to measure bed temperature distribution and combustion gas composition. 4 different fuel blending cases were prepared by mixing sewage sludge fuels with coal and wood pellet with the ratio of 50 : 50 by the heating value. $NO_x$ was mostly NO than $NO_2$ and measured in the range of 400 to 600 ppm in all cases. $SO_2$ was considered to be affected mostly by the sulfur content of the sewage sludge fuels. The cases of hydrothermal carbonization sewage sludge mixture showed slightly less $SO_2$ emission but higher fuel-N conversion than the dried sewage sludge mixing cases. The result of fly ash composition analysis implied that the sewage sludge fuels would increase the possibility of slagging/fouling considering the contents of alkali species, such as Na, K, P. Between the two different sewage sludge fuels, dried sewage sludge fuel was expected to have the more severe impact on slagging/fouling behavior than hydrothermal carbonization sewage sludge fuel.

A Study on Heat Transfer and Pressure Drop Characteristics according to Block Size and Turbulence Generator's Placement in a Horizontal Channel (블록 크기 및 난류발생기 배치에 따른 수평채널내의 열전달 및 압력강하 특성에 관한 연구)

  • Seo, Kyu-Won;Lim, Jong-Han;Yoon, Jun-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.639-647
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    • 2019
  • Recently, as the semiconductor integration technology due to miniaturization and high density of electronic equipment have developed, it is importantly recognized the application of thermal control system in order to release inner heat generated from chips, modules, In this study, we considered the heat transfer and pressure drop characteristics in a horizontal channel with four blocks using k-${\omega}$ SST turbulence model During CFD (Computational Fluid Dynamics) analysis, the parameters applied block width, block height, heat source and turbulence generator placement etc. As the boundary conditions of analysis, the channel inlet temperature and flow velocity were respectively 300 K and 3.84 m/s, the heat flux was $358W/m^2$. As a result, the heat transfer performance was decreased as the block width ratio (w/h) was increased, while it was increased as the block height ratio (h/w) was increased. In addition, as the arrangement of heat source size was increased to high heat flux from low heat flux, it was influenced by heat source size and the heat transfer coefficient showed a tendency to increase, When the turbulence generator was installed in the upper part of block No. 1 position the closely to the channel entrance, the heat transfer characteristics was greatly influenced on the whole of four heating blocks. and in oder to consider the pressure drop characteristics, we are able to select the most appropriate turbulence generator's position.

Drying seaweeds using hybrid hot water Goodle dryer (HHGD): comparison with freeze-dryer in chemical composition and antioxidant activity

  • Nagahawatta, D.P.;Asanka Sanjeewa, K.K.;Jayawardena, Thilina U.;Kim, Hyun-Soo;Yang, Hye-Won;Jiang, Yunfei;Je, Jun-Geon;Lee, Tae-Ki;Jeon, You-Jin
    • Fisheries and Aquatic Sciences
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    • v.24 no.1
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    • pp.19-31
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    • 2021
  • Seaweeds are a potential source of minerals, essential amino acids, fatty acids, proteins, and various bioactive compounds such as antioxidants. The higher water content of seaweeds reduces the shelf life and this requires the appropriate drying method. The drying conditions play a major role in the conservation of nutrient composition in dried seaweeds. In recent years, the seaweed industry has used many different drying methods with advantages and limitations. Hybrid hot-water Goodle dryer (HHGD) which is a special dryer mixed with hot-water and a Korean traditional heating system (Goodlejang) might be a solution to avoid these limitations. The present study evaluated the effect of drying conditions in HHGD on nutrient composition and bioactivities of brown seaweeds. Moreover, freeze-dryer (FD) and HHGD were employed in this study to compare the dried outputs obtained from four brown seaweed species. The present study aims to evaluate the effect of the hybrid hot-water Goodle drying method (HHGDM) on the nutritional composition and antioxidant activity of dried seaweeds. AOAC standard methods were used to analyze the proximate composition of dried samples and their 70% ethanol extract. The intracellular and extracellular antioxidant activities were evaluated using Vero cells and electron spin resonance (ESR) spectrometer respectively. High performance liquid chromatography, apoptotic body formation, and in-vivo experiments were used for further confirmation of the quality of dried output. The proximate composition results obtained from drying in HHGD and FD did not exhibit any significant difference. Moreover, the seaweed extracts from the dried seaweeds by HHGD and FD dryings were also not different and both significantly down-regulated in-vivo and in-vitro oxidative stress. Furthermore, the high performance liquid chromatography results revealed that the two dryers did not make the major peaks different in the chromatograms. Freeze-drying method (FDM) provides elevated quality for dried output, but there are limitations such as high cost and low capacity. The results from a novel HHGD did not provide any significant difference with the results in FD and expressed a potential to avoid the limitations in FD. Overall, these findings solidified the applicability of HHGD over FD.

A study on the Increase in Construction Cost for Zero Energy Building (제로에너지건축물의 공사비 증가분 산출에 관한 연구)

  • Shim, Hong-Souk;Lee, Sungjoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.603-613
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    • 2021
  • As a core policy for achieving the goal of reducing greenhouse gas emissions in the building sector, Korea has enforced the mandatory certification of zero energy buildings for new public buildings from 2020. This study suggests energy-saving technologies and economic factors that building officials can refer to for decision-making on the implementation of zero energy buildings. For this study, the construction cost for the energy item of a building was analyzed by collecting the building energy efficiency level certification data and detailed construction cost statement data from public institutions for the last three years. Based on the building energy efficiency certification data, each energy item of the baseline building was derived, and the energy performance of the zero energy building was derived through repetitive simulations by gradually increasing the energy performance value of the baseline building. By applying the analyzed construction cost, the construction cost for each energy item of the baseline and zero energy buildings was derived. As a result, the lighting equipment contributed up to 10.5% energy savings, and the increase in construction cost of the cooling and heating system was at least 9.1%.

Thermal Energy Capacity of Concrete Blocks Subjected to High-Temperature Thermal Cycling (열사이클을 적용한 고온 조건 콘크리트 블록의 열용량 특성)

  • Yang, In-Hwan;Park, Ji-Hun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.4
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    • pp.571-580
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    • 2020
  • In this study, an experimental study on storage media for thermal energy storage system was conducted. For thermal energy storage medium, concrete has excellent thermal and mechanical properties and also has various advantages due to its low cost. In addition, the ultra-high strength concrete reinforced by steel fibers exhibits excellent durability against exposure to high temperatures due to its high toughness and high strength characteristics. Moreover, the high thermal conductivity of steel fibers has an advantageous effect on heat storage and heat dissipation. Therefore, to investigate the temperature distribution characteristics of ultra-high-strength concrete, concrete blocks were fabricated and a heating test was performed by applying high-temperature thermal cycles. The heat transfer pipe was buried in the center of the concrete block for heat transfer by heat fluid flow. In order to explore the temperature distribution characteristics according to different shapes of the heat transfer pipe, a round pipe and a longitudinal fin pipe were used. The temperature distribution at the differnent thermal cycles were analyzed, and the thermal energy and the cumulated thermal energy over time were calculated and analyzed for comparison based on test results.

Appropriate Soil Heat Treatment Promotes Growth and Disease Suppression of Panax notoginseng by Interfering with the Bacterial Community

  • Li, Ying-Bin;Zhang, Zhi-Ping;Yuan, Ye;Huang, Hui-Chuan;Mei, Xin-Yue;Du, Fen;Yang, Min;Liu, Yi-Xiang;Zhu, Shu-Sheng
    • Journal of Microbiology and Biotechnology
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    • v.32 no.3
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    • pp.294-301
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    • 2022
  • In our greenhouse experiment, soil heat treatment groups (50, 80, and 121℃) significantly promoted growth and disease suppression of Panax notoginseng in consecutively cultivated soil (CCS) samples (p < 0.01), and 80℃ worked better than 50℃ and 121℃ (p < 0.01). Furthermore, we found that heat treatment at 80℃ changes the microbial diversity in CCS, and the inhibition ratios of culturable microorganisms, such as fungi and actinomycetes, were nearly 100%. However, the heat-tolerant bacterial community was preserved. The 16S rRNA gene and internal transcribed spacer (ITS) sequencing analyses indicated that the soil heat treatment had a greater effect on the Chao1 index and Shannon's diversity index of bacteria than fungi, and the relative abundances of Firmicutes and Proteobacteria were significantly higher than without heating (80 and 121℃, p < 0.05). Soil probiotic bacteria, such as Bacillus (67%), Sporosarcina (9%), Paenibacillus (6%), Paenisporosarcina (6%), and Cohnella (4%), remained in the soil after the 80℃ and 121℃ heat treatments. Although steam increased the relative abundances of most of the heat-tolerant microbes before sowing, richness and diversity gradually recovered to the level of CCS, regardless of fungi or bacteria, after replanting. Thus, we added heat-tolerant microbes (such as Bacillus) after steaming, which reduced the relative abundance of pathogens, recruited antagonistic bacteria, and provided a long-term protective effect compared to the steaming and Bacillus alone (p < 0.05). Taken together, the current study provides novel insight into sustainable agriculture in a consecutively cultivated system.

Brief Review on Exposure Characteristics, Monitoring Instruments and Threshold Limit Values for Extremely Low Frequency-Magnetic Field (ELF-MF) (직업성 극저주파 자기장 노출평가와 노출 기준에 대한 쟁점 고찰)

  • Dong-Uk, Park;Seunghee, Lee;Kyung Ehi, Zoh
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.32 no.4
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    • pp.381-392
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    • 2022
  • Objectives: Objective of this study is to review briefly exposure characteristics, monitoring instruments and threshold limit values for extremely low frequency-magnetic field (ELF-MF) methods. This study was undertaken through brief literature review. We performed a literature search in PubMed to identify ELF-MF studies conducted in workplaces. Initial search keywords such as 'extremely low frequency-magnetic field (ELF-MF)' and 'electromagnetic fields (EMF)' combined or singly. We limited our review to occupational rather than general nonworkplace environmental exposures. Methods: The contents we reviewed: key industry and occupations generating ELF-MF, several direct-reading instruments monitoring ELF-MF and threshold limit values (TLV) preventing health effects may be caused by the exposure to ELF-MF. Results: The industries related to the generation and supply of electricity, electrolytic installations, welding, and induction heating and more were regarded as high ELF-MF exposure industries. All jobs handling or employed performed in power cable lines, electrical wiring, and electrical equipment are found to be exposed to ELF-MF. Threshold or ceiling limit, 1,000 µT, is established to prevent acute effects of exposure to low-frequency EMFs on the nervous system: the direct stimulation of nerve and muscle tissues and the induction of retinal phosphenes. The International Agency for Research on Cancer (IARC) has classified ELF-MF as possibly carcinogenic to humans chiefly based on epidemiological studies on childhood leukemia. However, a causal relationship between magnetic fields and several types of cancer including childhood leukemia has not been established nor has any other long-term effects. Risk management using precautionary measures, has been initiated by the US and EU to prevent chronic health effects related to ELF-MF exposure in workplaces. Conclusion: This study recommends the implementation of various measures such as theestablishment of occupational exposure limit values for ELF-MF and precautionary principle to prevent potential chronic occupational health effects may be caused by ELF-MF in Korea.