• Title/Summary/Keyword: Heating Characteristics

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Monitoring of Formaldehyde Concentration in Exhibition Hall Using Passive Sampler (Passive Sampler를 이용한 유물 전시관내 폼알데하이드 농도 모니터링)

  • Lee, Sun Myung;Lim, Bo A;Kim, Seojin
    • Journal of Conservation Science
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    • v.33 no.5
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    • pp.319-329
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    • 2017
  • In this study, formaldehyde concentrations in two exhibition halls were monitored using a passive sampler from May 2012 to April 2013. Formaldehyde concentrations in the exhibition halls were 5 to 36 times higher than concentrations outdoors. Concentrations inside the exhibition room and showcase varied according to pollutant source, HVAC(heating, ventilation, air conditioning)system and environment management. The formaldehyde concentration levels were corrected according to a standard method prescribed by Indoor Air Quality Management Law of the Ministry of Environment, Korea. As a result, Most concentration levels exceeded the exhibition standard of the Ministry of Environment($100{\mu}g/m^3$) and artifacts conservation standard of Tokyo National Museum($50{\mu}g/m^3$). Seasonal concentrations in the exhibition room and showcase were in the order summer>fall>spring>winter. Formaldehyde emissions increased in summer when air temperature and relative humidity are both high. Formaldehyde concentration distribution according to the temperature and relative humidity showed positive correlation. Air temperature showed good correlation because $R^2$ was in the range of 0.8~0.9. Analysis of formaldehyde emission characteristics in the exhibition hall would be helpful in efforts to improve indoor air quality.

Materials Analysis of Furnace Wall Excavated from Songdu-ri Site in Jincheon, Chungbuk (충북 진천 송두리 유적 출토 노벽의 재료과학적 분석)

  • Jang, Won Jin;Han, Min Su
    • Journal of Conservation Science
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    • v.36 no.5
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    • pp.421-429
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    • 2020
  • This study examined the manufacturing process of a furnace wall excavated from the Songdu-ri Site in Jincheon, and the difference in material composition between the 11 layers of the wall using physicochemical analyses. Based on microstructure observations, these layers could be largely divided into three groups: an undercalcined first layer, calcined second to ninth layer with evidences of partial heat, and non-fired soil layers from the tenth to the eleventh layer. Particle size analyses revealed that the fired layer constituted a relatively higher content of coarse sand than the non-fired layer. This difference was further confirmed by the results of the curvature coefficient analysis. An analysis of the constituent minerals showed similar overall XRD diffraction patterns between the different layers, but variations in the intensity of the low-temperature and high-temperature minerals. This indicates that the degree of heat was different. The thermal analysis results demonstrated that the heating peak of mullite was only reached in the first and second layers of the wall, thus implying these as the layers to be finally used. Consequently, no significant difference could be observed between the materials of the various layers of the wall. Thus, it can be suggested that the furnace wall was constructed using clay, which had a composition similar to that of the soil present in the area. However, the shape and characteristics of the constituent particles between the layers displayed partial variations, and it is possible that some external materials might have been added.

Studies on the Heat Penetration and Pasteurization Conditions of Retort Pouch Kimchi (Retort Pouch 김치의 전열특성(專熱特性)과 살균조건(殺菌條件)에 관한 연구(硏究))

  • Pyun, Yu-Ryang;Shin, Seung-Kyoo;Kim, Ju-Bong;Cho, Eun-Kyung
    • Korean Journal of Food Science and Technology
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    • v.15 no.4
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    • pp.414-420
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    • 1983
  • Heating characteristics for retort pouches of Kimchi heated in hot water were determined as a function of various parameters for processing. Processing conditions in laboratory and commercial retort were also evaluated on the basis of storage test. D values for Lactobacillus plantarum isolated from test sample ranged from $D^{1.08}\;to\;D^{0.18}$ and z value was $10.5^{\circ}C$. Thermal diffusivity of Kimchi increased from 1.15 to $1.44{\times}10^{-3}cm/s$ by blanching for 15 min at $80^{\circ}C$. The rate of heat penetration was significantly decreased with increasing the thickness of the pouch although the decreases was less significant below 1.0cm thickness. Increasing in the ratio of solid to syrup up to 90:10 proportionately decreased $f_h$ value, but above the ratio $f_h$ values were nearly constant.

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Physicochemical Characteristics of Cheonnyuncho Fruit (Opuntia humifusa) Fermented by Leuconostoc mesenteroides SM (Leuconostoc mesenteroides SM을 이용한 천년초(Opuntia humifusa) 열매 발효물의 물리·화학적 특성)

  • Park, Min-Ju;Lee, Sam-Pin
    • Korean Journal of Food Science and Technology
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    • v.45 no.4
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    • pp.434-440
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    • 2013
  • Functional properties of Cheonnyuncho fruit paste (CFP) were enhanced by fermentation, using Leuconostoc mesenteroides SM. The stability of CFP pigment was maintained and microorganisms in crude CFP were sterilized by heating at $80^{\circ}C$ for 30 min. The production of dextran in CFP was increased by increasing the fermentation time and sugar content, resulting in an increase of consistency. The CFP fermented with 20% sucrose contained 4.8% mucilage after fermentation for 2 days. In particular, the production of mucilage was greatly enhanced by fortification with 3% sodium citrate in CFP, resulting in mucilage production of 7%. In addition, the viscous modulus of fermented CFP showed a greater increase than that of the elastic modulus. Thus, it was concluded that CFP fermented by L. mesenteroides SM can be fortified with functional ingredients, such as mucilage and probiotics, with enhanced rheological properties. Therefore fermented CFP can be utilized as the functional ingredients for functional foods.

Growth and Yield of Sedum sarmentosum as Affected by Planting Density in Cultivation System Using a Rice Nursery Tray (벼 육묘상자를 이용한 돌나물 재배에서 삽식밀도에 따른 생육 및 수량)

  • Kim, Hyo-Jin;Lee, Seung-Yeob
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.53 no.2
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    • pp.196-202
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    • 2008
  • To establish a cultivation system of Sedum sarmentosum using a rice nursery tray ($30{\times}60{\times}3\;cm$) in non-heating plastic film house, cuttings of two local strains (Wanju and Keumsan) were prepared and planted at different planting densities (40, 60 and 80 cuttings per tray) on September 7th, and subsequent growth and yield at pre- and post-winter season were investigated. When pre-wintering growth were measured at 60 days after planting, high planting density (80 cuttings/tray) decreased leaf length and lateral shoot number per plant compared to 40 cuttings/tray. When post-wintering growth were measured on April 20th, no significant growth differences as affected by planting density were observed in Keumsan strain, while decreased stem diameter, node number and leaf number were observed in Wanju strain planted at 80 cuttings/tray compared to 40 cuttings/tray. Fresh and dry weights were not significantly different as affected by planting density, but those were significantly increased in Wanju strain compared to Keumsan strain. When regrowth characteristics followed by the first harvest were measured on June 5th, significantly increased stem number was observed at 80 cuttings/tray compared to 40 cuttings/ tray. Fresh and dry weight were significantly increased in Keumsan strain planted at 80 cuttings/tray compared to 40 cuttings/tray, and dry weight were increased in Wanju strain compared to Keumsan strain. Wanju strain showed higher shoot yield, thicker stem, shorter node and larger leaf, and non-succulent stem under high planting density compared to Keumsan strain. Accordingly, the optimum density was 40 cuttings per tray, and Wanju strain was adequate for the cultivation system using a rice nursery tray.

A Study on the Efficient Utilization of Aquaculture Greenhouse by Paralleling Vegetable Nutrient Culture Systems (채소 수경재배체계 도입에 의한 양어시설의 효율적 이용에 관한 연구)

  • 이병일;이지원;김기덕;이순길;정선부
    • Journal of Bio-Environment Control
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    • v.1 no.2
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    • pp.123-134
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    • 1992
  • In order to verify the usability of the greenhouse for aquaculture with nutrient culture synchronously and to obtain the fundamental data fir the establishment of efficient farming technology, the characteristics of microclimate and the growth of leafy vegetables were examined. Tilapia averaged 428.6 g grew to 784 g(1.83 times) for 147 days from May 29 to Oct. 21 and fingerlings averaged 12.9 g grew by 1.37 times for 61 days from Sep. 13 to Nov. 12. The growth of vegetables such as water dropwort, leaf lettuce, Chinese cabbage, and Welsh onion in the greenhouse was better for aquaculture with nutrient culture than for nutrient culture only. Between above two greenhouses, pH and EC of nutrient solution was same but the temperature different by about 2$^{\circ}C$. Average day temperature, relative humidity, and $CO_2$ concentration were higher by 2.9$^{\circ}C$, 6%, and 200 ppm in the greenhouse for aquaculture with nutrient culture, respectively. Net assimilation rate of vegetables in the greenhouse was a little higher for aquaculture with nutrient culture than for nutrient culture only. Therefore, provided aquaculture and nutrient culture are carried out in the same greenhouse, the saving effect of heating cost as well as the additional promotive effects of vegetable and tilapia growth can be obtained.

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Quality Characteristics of Frozen Welsh Onion (Allium fistulosum L.) according to Various Blanching Treatment Conditions (Blanching 처리 조건에 따른 동결 대파의 품질 특성)

  • Lee, Hye-Ok;Lee, Young-Joo;Kim, Ji-Young;Yoon, Doo-Hyun;Kim, Byeong-Sam
    • Korean Journal of Food Science and Technology
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    • v.43 no.4
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    • pp.426-431
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    • 2011
  • In this study, we set an optimum blanching condition as a pretreatment condition to freeze welsh onion (Allium fistulosum L.) for the purpose of preserving the cooking material for long-term usage. With higher blanching temperature and longer processing time, the Hunter color values and the hardness of welsh onion tended to decrease, which confirmed softening of the tissue. Compared to before blanching, total bacterial counts decreased to near 2 log scale, whereas coliforms were not detected or decreased to a 1-2 log scale. Blanching by heating at 100$^{\circ}C$ for 5 min decreased peroxidase inactivity to more than 94%, whereas only 47% of the inactivity was achieved at 80$^{\circ}C$ for 1 min. The sensory evaluation for the blanched and defrosted welsh onion showed that the group blanched at 80$^{\circ}C$ for 1 min was preferred significantly (p<0.05).

A Study on Various Trans Fatty Acid Contents (Trans지방산의 함량변화에 관한 연구)

  • Ahn, Myung-Soo;Seo, Mi-Sook;Kim, Hyun-Jung
    • Korean journal of food and cookery science
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    • v.24 no.4
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    • pp.542-548
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    • 2008
  • In this study, the degree of rancidity and trans fatty acids formation was assessed in Soybean oil(SBO), Corn germ oil (CGO), Canola oil(CNO) and Olive oil(OLO). All samples treated under various conditions were analyzed in order to determine their physicochemical characteristics(RI: Refractive index, Tocopherol, AV: Acid Value, IV: Iodine Value) and total trans fatty acid contents via GC. The results were as follows: The AV of corn germ oil was the highest (0.49$\pm$0.01 and 0.72$\pm$0.04 respectively) among the 4 kinds of oils at $170{\pm}2^{\circ}C$ and $210{\pm}2^{\circ}C$. The IV of olive oil was the lowest(88.7$\pm$0.6 and 89.2$\pm$0.5) among the 4 kinds of oils at $170{\pm}2^{\circ}C$ and $210{\pm}2^{\circ}C$. The trans fatty acid contents of the soybean oil, corn germ oil, canola oil and olive oil, respectively(in g/100) increased from 0.41, 0.60, 0.44 and 0.11 prior to heating to 0.84, 1.36, 0.94 and 0.81 after 7 hours. Catechin and BHT reduced trans fatty acid formation by 0.5-15.5% under all treatment conditions. In particular, Catechin exerted a more profound inhibitory effect on trans fatty acids formation than that did BHT.

A Study on Changes in the Space Composition of Each Room in Bukchon Hanok - Focused on Open-Hanoks and Publicly Puhased Hanoks - (북촌한옥 각 실의 용도 및 공간변화 특성에 관한 연구 - 개방한옥과 공공매입한옥을 중심으로 -)

  • Kim, Do-Yeon;Oh, He-Kyung
    • Journal of Families and Better Life
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    • v.26 no.2
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    • pp.115-127
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    • 2008
  • The purpose of this study was to examine the characteristics of change in the composition of indoor spaces in Korean-style houses which have been repaired and improved extensively through the 'Bukchon Improvement Project' and are being utilized for public purposes. For this, we conducted a field survey through visiting the house sites from the 5th to the 26th of May, 2006. Conclusions drawn from this study are as follows. Bukchon Korean-style houses maintain centripetal space composition, in which the rooms surround the court. Centering on the court, the hierarchy of spaces is determined, and the hierarchy of spaces and the composition of internal layout are restructured centering on the court and the main hall without change in direction and position. The main hall is sometimes converted to a room, but it maintains an open space relation with other spaces centering on the court, and therefore, even after its use has been changed, it is still the most Korean-style space. In addition, with floor heating, the common sitting-style life is maintained continuously although the rooms have been converted and standing-style furniture is used. In this way, publicly promoted policies for Korean-style houses are allowed within the limit that the appearance is maintained and the internal spaces do not change the overall structure. However, in order to maintain the tradition of Korean-style houses and utilize them as various spaces, the following supplementations are necessary. First, the main hall and the inner court of a Koreanstyle house should be utilized actively. The court sometimes keeps individuals' privacy or expands the space by extending the view to outdoor spaces, and is sometimes used as an open space through interconnection between the inside and the outside of the house. Second, consideration should be given to vertical spaces. Horizontal expansion causes a change of floor plan. Thus, space should be secured using various cross-sectional changes, such as a kitchen and a loft over the kitchen. Third, structure should be changeable in order to adjust the size of spaces. Thus, through research on traditional windows, we need to develop changeable walls that can be installed and removed easily according to the use of spaces.

Living Conditions of the Rural Elderly: Clothing, Nutrition, Housing, and Psychological Adjustment (농촌지역 노인의 생활실태 조사연구 -의.식.주생활 및 심리적 적응을 중심으로-)

  • 윤복자
    • Journal of the Korean Home Economics Association
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    • v.28 no.4
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    • pp.65-86
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    • 1990
  • Living conditions of the rural elderly were assessed in terms of clothing behavior, health and nutritional status, housing and envioronmental condition, and psychological adjustment. The subjects were eighty individuals over sixty residing in the rural community of Iksan-kun, Chollabukdo. The interview method using questionnaires, direct measurement, and observation was used for this study. Data were compared with those obtained from a previous study of the elderly residing in an urban area. Clothing behavior showed that the elderly residing in the rural community were more concerned about plain and conservative design of clothes than their urban counterparts. Special protective clothes for cropdusting with agricultural chemicals had not been prepared. The following urgent needs were pointed out: development and supply of agricultural chemical protective clothing and development and education of appropriate washing and clothing care methods. The health status of the elderly was generally good, but poor eating habits were found more frequently in the rural elderly than among the urban dwellers. Several dietary nutrient intakes were insufficient. Contrasting the urban elderly with the rural group, it was found that the urban group lacked sufficient vitamin A and vitamin C and the urban women had insufficient calorie whereas the rural group was deficient in protein, vitamin A, calorie, and fat. A significant relationship was found between dietary nutrient intake and health index, food habit points, self recognized health status, meal satisfaction, and economic status. Urgent needs of the development of a nutrition education program for the elderly were pointed out. Most of elderly residing in the surveyed rural communities were living alone or with their spouse only, therefore only one room was used among the three or four available rooms. Most of the rural elderly were living either in a traditional Korean house built with differing floor levels or in a modified Korean style house. Minimal modernization had been made for kitchen facilities such as sink and gas range or for heating facilities with the briquette boiler. However, sanitary space such as lavatory and bathroom had not been remodeled. A housing welfare program for rural communities should be implemented at the national level. The comparison of psychological characteristics of the rural elderly with their city counterparts revealed that the rural elderly have a more stable psychological status and optimistic attitude than those living in a city. However, it was found that most of the elderly did not have any future plan. Community programs for the elderly including hobbies or leisure activities or education programs to generate close interpersonal relationships with their children should be developed and provided.

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