• Title/Summary/Keyword: log houses

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Investigation of the shift trends of temperature and humidity in greenhouses for oak mushroom cultivation (최근 국내 표고 재배사의 온도, 습도 변화 성향 조사)

  • Kim, Ji Eun;Kim, Jun Young;Ahn, Hong Seok;Kown, Hyuk Woo;Ko, Han Gyu;Kim, Seong Hwan
    • Journal of Mushroom
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    • v.16 no.4
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    • pp.342-346
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    • 2018
  • The temperature and humidity of 49 greenhouses for oak mushroom cultivation were investigated for 5 years to analyze the trends in the change of these parameters according to the climate change in Korea. The 5-year average temperature and humidity were $24.7^{\circ}C$ and 60.5%, respectively, in sawdust media-based cultivation houses and $24.4^{\circ}C$ and 60.0%, respectively, in log-bed cultivation houses. The average temperature in the summer was $29.8^{\circ}C$ in 2016, $29.1^{\circ}C$ in 2017, and $33.3^{\circ}C$ in 2018 in the log-bed cultivation houses and $26.8^{\circ}C$ in 2016, $20.4^{\circ}C$ in 2017, and $24.2^{\circ}C$ in 2018 in the sawdust media-based cultivation houses. During the investigation, temperatures over $30^{\circ}C$ were detected in one cultivation house in spring and five such houses in summer. When classifying by cultivation type, temperatures over $30^{\circ}C$ were found in five log-bed cultivation houses and temperatures less than $20^{\circ}C$ were found in four log-bed cultivation houses in fall. This study shows that log-bed cultivation houses for oak mushroom need to be modified to cope with the climate change.

A Study on the transformation Pross of Vernacular Houses in Ulleung-Island -Focused on wall, roof, window and ceiling- (울릉도 민가의 변화과정에 관한 연구 -벽체, 지붕, 창호, 천장을 중심으로-)

  • Kim Chan-Yeong
    • Journal of the Korean housing association
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    • v.15 no.5
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    • pp.85-96
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    • 2004
  • The purpose of this study was to (md out the characteristics of the residential house in Ulleung Island in terms of building materials, structure and construction method, structural design by actual field surveys. This study found several facts; First, the house was classified into the log house and mud-wall house according to building material for wall structure. The log house prevailed in the early days of the settlement in the island because of affulent timber materials available around. However, the mud wall house became a popular type in later days because of the depletion of timber materials. Second, the Udeki wall was an unique installation reflecting the severe climate conditions of Ulleung Island. However, many aspects of the Udeki wall was changed according to the change of living style and the introduction of modem heating systems in terms of its function, size, building material, layout position etc. Third, the roofing material also has been changed from materials available locally to slate materials transported from the mainland. Fourth, the bamboo slender-ribbed door as a single-swing door type was popular and later time the single-sliding door or three ribbed door was widely used in rooms installed later instead. Fifth, the roof was placed over the room, kitchen, and Chukdam (outer wall) and this was a resonable way to cope with heavy snowfalls in the winter season in Ulleung Island.

Study Case on the Log Cultivation of Phellinus baumii for It's High Quality and Large Quantity (고품질 다수확 원목 상황버섯 재배 경영사례 조사)

  • Suh, Gyu-Sun;Chang, Hyun-You;Kim, Soon-Geun
    • Journal of Practical Agriculture & Fisheries Research
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    • v.10 no.1
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    • pp.153-167
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    • 2008
  • High temperature and natural sun light are considered as the core conditions for high quality and large quantity of Phellinus baumii production. However still now on there has been a mistake of excessively cutting off the natural light by spreading the closing nets on the mushroom cultivating house. For an example there are many houses where the closing nets under the roofs be extended to cover the sides of the houses, which way prevents the mushrooms in the houses from receiving sufficient natural sun light and getting the temperature sufficiently to grow so that the quantity and quality of the produced mushrooms are lowered even though the mushrooms can grow in those conditions. In order to avoid this mistake, the closing nets must be placed on the roofs of the houses only without dropping them to cover the sides. Further more when the closing nets are placed triply at the beginning stage of Phellinus baumii's growth in the house, the nets restrain the internal temperature of the house going up and intercept the natural bright light flowing into the house so that the growing tardiness occur to the Phellinus baumii. Therefore the roof only must have been covered by the closing net for 65% cutting off the light until May, and then covered by double folded the net for June, triple folded the net for July and August, double folded the net for September, and the single net for October. When the ventilation in the house has been maintained until the house tightly balloon out through controling lifting force of internal air, the Phellinus baumii can grow well while the bed logs themselves aren't dried out. Marketing is also very much important as well as increasing quality and quantity of Phellinus baumii production.

Vulnerability model of an Australian high-set house subjected to cyclonic wind loading

  • Henderson, D.J.;Ginger, J.D.
    • Wind and Structures
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    • v.10 no.3
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    • pp.269-285
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    • 2007
  • This paper assesses the damage to high-set rectangular-plan houses with low-pitch gable roofs (built in the 1960 and 70s in the northern parts of Australia) to wind speeds experienced in tropical cyclones. The study estimates the likely failure mode and percentage of failure for a representative proportion of houses with increasing wind speed. Structural reliability concepts are used to determine the levels of damage. The wind load and the component connection strengths are treated as random variables with log-normal distributions. These variables are derived from experiments, structural analysis, damage investigations and experience. This study also incorporates progressive failures and considers the inter-dependency between the structural components in the house, when estimating the types and percentages of the overall failures in the population of these houses. The progressively increasing percentage of houses being subjected to high internal pressures resulting from damage to the envelope is considered. Results from this study also compare favourably with levels of damage and related modes of failure for high-set houses observed in post-cyclone damage surveys.

A Study on Concentration of Indoor Nitrogen Dioxide in Relation to House Characteristics (주택특성에 관련된 실내 이산화질소 농도에 관한 연구)

  • 양원호;배현주;김현용;정문식;정문호
    • Journal of environmental and Sanitary engineering
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    • v.14 no.4
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    • pp.85-92
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    • 1999
  • Indoor air quality tends to be the dominant contributor to personal exposure because most people spend over 90% of their time indoors. For some contaminants, exposure to indoor air poses a potentially greater health threat than outdoor air exposures. Indoor nitrogen dioxide ($NO_2$) levels are mainly affected gas range, flue gas spillage, kerosene heaters, wood-burning appliances and cigarette smoke. In addition, indoor $NO_2$ levels are influenced by such house characterization as surface reaction and air exchange rate. In this study, the measurements of indoor and outdoor $NO_2$ concentrations were taken using identical protocols, and information was collected on housing characteristics using identical questionnaires in 14 houses out of 15 houses for daily 30 daily 30 days in Brisbane, Australia.The usage of gas range was the most contributing factor in indoor $NO_2$ concentration in relation to house characteristics. Average indoor and outdoor ratios of NO2 concentration in electronic and gas cooking houses were $0.6{\pm}0.1$ and $0.9{\pm}0.2$, respectively. The frequency distributions of $NO_2$ concentration in each house were approximately log-normal Geometric mean of indoor $NO_2$ concentrations of electronic and gas cooking houses for daily 30 days ranged from 2.5 ppm to 11.5 ppm with a mean 6.8 and from 4.7 ppm to 28.6 ppm with a mean 15.6 ppm, respectively. The $NO_2$ concentrations between electronic and gas cooking houses were significantly different (p<0.05). Since each house has different life-style and house characteristics, sampling interval to measure the $NO_2$ levels was recommended above 7 days.

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Unrecorded Fungal Species Isolated from Indoor Air in the Log Bed- and Sawdust Media-based Mushroom Cultivation Houses (원목 및 톱밥배지 버섯 재배사 내 실내 공기서 분리한 미기록 진균 보고)

  • Ahn, Geum Ran;Kim, Ji Eun;Kim, Jun Young;Kim, Seong Hwan
    • The Korean Journal of Mycology
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    • v.46 no.4
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    • pp.495-503
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    • 2018
  • Oak mushroom is cultivated using logs and sawdust media as substrates. In this study, fungi were isolated during a monitoring of indoor air in the oak mushroom cultivation houses located in Cheongyang-gun of Chungnam, Geoje-gun of Gyeongnam, Gumi-si of Gyeongbuk, Jangheung-gun of Jeonnam and Yeoju-si of Gyeongggi-do. Identification of the fungi based on morphology and molecular analysis of the internal transcribed spacer region and 28S rDNA, translation elongation factor translation elongation factor 1 a gene, and ${\beta}-tubulin$ gene revealed that six fungi, Cenangium acuum, Neopestalotiopsis surinamensis, Metarhizium marquandii, Periconia macrospinosa, Trichoderma petersenii, and Trichoderma paratroviride that have not been recorded previously in Korea.

Sanitation Assessment and Microbiological Analysis of the Domestic Kitchen Utensils (가정 내 주방용품 및 기구의 위생실태 및 미생물학적 분석)

  • Kang, Myong-Suk;Chang, Yun-Hee
    • Korean journal of food and cookery science
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    • v.24 no.5
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    • pp.706-712
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    • 2008
  • This study was conducted to evaluate the sanitation level and use of dish cloths, chopping board, and drawer in the refrigerator in 50 university students' houses located in Seoul and Kyonggido. The survey questionnaire evaluated general information, frequency of the washing, cleaning method, drying method and the associated factors. The highest percentage of the cleaning and drying methods of dish cloths were “boiling(76.0%)”, and “dry in the kitchen or on the sink(78.0%)”, respectively. For the chopping board and drawer in the refrigerator, the highest percentage of cleaning method was “use detergent” and drying method was “dry in the kitchen”. The mean of coliforms for dish cloths, chopping board, and drawer in the refrigerator was 4.46${\pm}$1.95 log CFU/100 $cm^2$, 3.92${\pm}$1.64 log CFU/100 $cm^2$, 3.48${\pm}$2.01 log CFU/ 100 $cm^2$, respectively. Salmonella spp. were not detected from all samples. But E. coli were detected from dish cloths(4.0%) and S. aureus were detected from dish cloths(16.0%), chopping board(12.0%), and drawer in the refrigerator(8.0%). The results of microbiological test of kitchen utensils indicated that the sanitary conditions of dish cloths, chopping board, drawer in the refrigerator should be improve promptly.

Identification of fungal species in oak mushroom cultivation houses during the rainy season (장마철 표고(Lentinula edodes) 재배사내 발생 유해 진균류의 동정)

  • Jeong, Sang-Wook;Jang, Eun-Gyeong;Choi, Sun-Gyu;Lee, Won-Ho;Ban, Seung-Eon
    • Journal of Mushroom
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    • v.19 no.1
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    • pp.66-70
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    • 2021
  • We monitored the occurrence of fungal species on bed-logs inoculated with oak mushroom (Lentinula edodes) and the environmental conditions of temperature and humidity in the cultivation houses during monsoon. Six fungal species, viz., Cladosporium sp., C. cladosporioides, C. anthropophilum, Pleosporales sp., Trichoderma harzianum, and Acremonium sp., wereidentified from the cultivation houses located in Jangheung, Jeonnam province. This identification was confirmed by performing nucleotide sequence analysis of the internal transcribed spacer and 28S rDNA regions. Our study presents significant findings that can help in preventing fungal damage induced by inappropriate temperature and humidity in oak mushroom cultivation houses.

Air Tightness Performance of Residential Timber Frame Buildings

  • Kim, Hyun-Bae;Park, Joo-Saeng;Hong, Jung-Pyo;Oh, Jung-Kwon;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.2
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    • pp.89-100
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    • 2014
  • Energy consumption statistics in 2005 from the Korea Energy Management Corporation show that building energy usage was about 24.2% of total domestic energy consumption, and 64% of total building energy usage was consumed by residential buildings. Thus, about 10% of total domestic energy consumption is due to the heating of residential buildings. Building energy can be calculated by the configuration of the building envelope and the rate of infiltration (the volume of the infiltration of outdoor air and the leakage of indoor air), and by doing so, the annual energy usage for heating and cooling. Therefore, air-tightness is an important factor in building energy conservation. This investigate air infiltration and various factors that decrease it in timber frame buildings and suggest ways to improve air-tightness for several structural types. Timber frame buildings can be classified into light frame, post and beam, and log house. Post and beam includes Han-ok (a Korean traditional building). Six light frame buildings, three post and beam buildings, one Korean traditional Han-ok and a log house were selected as specimens. Blower door tests were performed following ASTM E779-03. The light frame buildings showed the highest air-tightness, followed by post and beam structures, and last, log houses.