• Title/Summary/Keyword: Ventilating condition

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Effect of Air Controlled Fermentation on Kimchi Quality (밀폐용기에서의 김치숙성에 관한 연구)

  • 김미경;김소연;우철주;김순동
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.2
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    • pp.268-273
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    • 1994
  • The quality of Kimchi was investigated under airtight and ventilating conditions. At 2$0^{\circ}C$ and 4$^{\circ}C$ fermentation, there were no significantly difference in pH, acidity and vitamin C of Kimchi between airtight and ventilating conditions. The contents of $CO_2$ , the number of lactic acid bacteria and the sensory score of carbonated taste under airtight condition were higher than those values under ventilating condition. While , the number of aerobic bacteria under airtight condition was lower than those under ventilating condition.

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Strength Optimization of Ventilating Container(I)-Experimental Analysis (통기성 상자 구조물의 강도적 최적화 연구(I)-실증 분석)

  • Park, Jong-Min
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.7 no.2
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    • pp.19-24
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    • 2001
  • The design criteria of ventilating container is not provided yet in Korea. This caused strength reduction due to the ventilating hole and bad ventilating performance. The purposes of this study were to survey the present situation of ventilating container in Korea, to analyze the strength reduction on the atmosphere condition variation, and to provide the criteria for the optimum design of ventilating container. The ventilating area of container was $1.41{\sim}2.65%$, and strength reduction due to the varied pattern, size and location of ventilating hole was $8.5{\sim}20.2%$. The effect on the strength reduction from the pattern and location of ventilating hole was bigger than that from the ventilating area. Equilibrium arrival time of temperature and relative humidity was shorter as the ventilating area was bigger, and temperature reached to the equilibrium state earlier than the relative humidity. There was no significant difference on the ventilating hole pattern between equilibrium arrival time of temperature and relative humidity and equilibrium arrival temperature and relative humidity if the ventilating area was the same.

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Finite Element Analysis of a Ventilating Box Structure (통기성 상자 구조물에 대한 유한요소 해석)

  • 박종민;권순구
    • Journal of Biosystems Engineering
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    • v.27 no.6
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    • pp.557-564
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    • 2002
  • Corrugated board is an efficient low-cost structure material fur the boxes that are widely used for transporting, storing and distributing goods. Corrugated board is also considered as an orthotropic because the principal material directions are the same as in paperboard. The purpose of this study was to elucidate the principal design parameters of ventilating box through the FEA on the various types of ventilating hole. From the viewpoint of the stress distribution and stress level, the optimum pattern and location of the ventilating hole were vertically oblong, and symmetry position with a short distance to the right and left from the center of front and rear panel. And, the optimum location and pattern of hand hole were a short distance to the top from the center of both side panels, and modified shape to increase the radius of curvature of both side in horizontal oblong. In general, the optimum pattern and location of both the ventilating hole and hand hole based on the FEM analysis were well verified by experimental investigation. It is suggested that decrease in compressive strength of the box could be minimized in the same ventilating hole area under the condition of the length of major axis of ventilating hole is less than 1/4 of box length, the ratio of minor axis/major axis is 113.5∼l/2.5, and number of the ventilating holes is even and symmetrical.

Thermal Environment Analysis of a Room in Accordance with Ventilation Condition with Multi-Heat Sources (다수의 열원을 가지는 공간에서의 환기 조건에 따른 열환경 해석)

  • Kim, Jae-Jung;Son, Young-Gap;Chang, Seog-Weon;Ryu, Dong-Su
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.199-204
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    • 2000
  • This paper reports a thermal environmental analysis of a room in accommodated with multi-heat sources according to ventilation condition. Two case modification have been investigated to obtain the lower temperature distribution in the room. The temperature distribution of the original room were found about $25{\sim}35^{\circ}C$. As a result, the use of, three ventilating fans and two electric fans are useful for room ventilation respectively, and using two electric fan is more recommendable in side of economical efficiency.

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Effects of Ventilation Condition and Ventilating Hole Sizes to Improve Quality Onion(Allium cepu. L) under Room Temperature (양파 간이저장시 통풍조건 및 통풍구 재료의 크기가 저장에 미치는 영향)

  • 이찬중;김희대;정은호;김우일;서전규
    • Food Science and Preservation
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    • v.8 no.4
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    • pp.356-361
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    • 2001
  • This study was conducted to improve the storability of onion bulbs by assembly simple house storage and the reduce the rotteness caused by field open storage. Allium cepa cv. Changnyungdeago, late strain was used for the test at the storage condition of natural ventilation of levels 2, forced ventilation of levels 2, field open storage and 75mm, 100mm, and 125mm ventilating holes. Mean tamperature and relative humidity were not significantly different by ventilation conditions. Mean temperature was lower in forced ventilation than that of in natural ventilation and non-ventilation, and relative humidity was a little higher in ventilation treatment than those of the others. Weight loss of onion bulbs were 2.5%, 2.9%, 3%, 4.3% in field open storage, non ventilation, natural ventilation of levels 2 and forced ventilation of levels 2 respectively. Rotting rate in natural ventilation of levels 2 and farced ventilation of levels 2 were 27.7% and 25.4% respectively but 34.6% and 37.8% in non ventilation and field open storage. Therefore, the treatment of ventilation reduced the rotteness of storage onion bulbs. The smaller the size of a ventilating hole, the lower mean temperature was maintained. The relative humidity was some high in July, but didn’t showed significantly difference in August and September. With small size of a ventilating hole, the strong wind velocity was obtained, and wind velocity by position was weaker in the middle part than both ends. Rutting rates in 75㎜, 100㎜, and 125㎜ ventilating holes were 17.9%, 15.3% and 14.1% respectively.

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On the Design of Cold Storage for Fruits and Vegetables (1) -Design of Natural Ventilating Type Store for Citrus Furits in Jejudo- (청과물 저온저장고의 설계에 관한 연구 (1) -자연환기를 이용한 제주산밀감저장고의 설계-)

  • Hur Jong-Wha;Kim Hyo-Kyung
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.5 no.4
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    • pp.272-280
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    • 1976
  • A natural ventilating type store was designed for the economic and effective storage of citrus fruits in Jejudo. The material used for the wall is scoria, widely distributed in Jejudo and known for high strength and insulation. Design condition was chosen for the period till March of a year and the dry bulb temperature was taken from TAC $5\%$ base. The temperature of the store can be maintained below the limiting temperature of $8^{\circ}C$ for the time length of $7\frac{1}{2}$ hours under the condition of the atmospheric temp, $15.3^{\circ}C$ and the solar insolation. The limiting temperature can he recovered to the initial temperature $(7^{\circ}C)$ by the natural ventilation for 8 hours in the night.

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A Study on the Actual Conditions of Indoor Air Quality of Underground Dwellings and the Automatic Ventilating Fan Operated by CO2 Controller and Timer (지하주거의 실내공기환경 실태조사와 CO2 조절기 및 타이머에 의한 환기팬 자동운전에 관한 연구)

  • Kwon, Young Cheol;Park, Jin Chul
    • KIEAE Journal
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    • v.8 no.4
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    • pp.3-9
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    • 2008
  • The rapid urbanization after 1970s caused the shortage of dwellings in urban areas. As the result, the underground dwellings were developed to compensate for the insufficient dwelling spaces. While the underground dwellings have some advantage in the respect of thermal and acoustic environment, they usually have the basic problems in the indoor air quality because of the lack of natural ventilation through small window areas. The purpose of this study is to investigate and to improve the indoor air quality of underground dwellings. Thirty Units in Seoul and Gyung-Gi Province were investigated into the indoor environmental conditions. For the purpose of the improvement of their indoor air quality, Automatically-operated ventilating fan was installed in a sample unit which has worst indoor environmental condition. Then the indoor air quality was monitored when it was operated by $CO_2$ control system and timer. Finally economic feasibility study was made considering the effect of the improvement of indoor air quality. The extra cost for installing timer could be paid back only in 10 months, so timer-installed automatic fan is recommended to improve the indoor air quality of underground dwellings.

Foreign bodies in air passage in Children (소아의 기도이물에 관한 통계적 관찰)

  • 유장열;오경균;백만기
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1977.06a
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    • pp.8.5-9
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    • 1977
  • Foreign bodies in food and air passage, especially the latter in infants and children requires emergency treatment. The frequent symptoms are coughing, wheezing, and dyspnea, So may be confused as asthma, pneumonia and acute Laryngitis. The species and incidence of the foregin bodies are variable according to the age, method of life, environment and economic condition. The authors experienced 35 cases of foreign body in air passage during the period of last 3yrs which were treated by ventilating Bronchoscopy, and thoractomy in this hospital. One of them was lead to death. The authors analysed above cases and report with it's literature consideration. Results: 1. The prevalent foreign bodies were peanut, metal, food particles in order of frequency. 2. In frequent symptoms were dyspnea, coughing and wheezing in the order. 3. In the age incidence, 48% of the foreign bodies were 1∼5yrs. 4. In sex distribution, male to female ratio was 2.1: 1 5. In duration of lodgment, 65% of the foreign body were removed within 24hrs. 6. Most prevalent site of the foreign body was Rt. main bronchus Rt. to Lt. ratis was 2 : 1 was 7. Treatment was done; 25 cases were by ventilating bronchoscopy.

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Development of a Ventilating Waterjet Propulsor for Super-High Speed Ships (초고속선을 위한 공기유입 물제트 추진기 개발)

  • J.T. Lee;I.S. Moon;Y.H. Park;K.Y. Kim;K.S. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.3
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    • pp.41-49
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    • 1999
  • A feasibility study is performed for practical application of a Ventilating Water-Jet(VWJ) propulsor which attracts new attention as a candidate propulsor for super-high speed vessels. Super-cavitating foil sections are adopted for the rotor blades since the rotor is operating at ventilating condition. Wedge type and cavitator type foil sections are used for the design of rotor blades. Other geometric characteristics of rotors are selected from the Kaplan type ducted propeller rotors. The test section of KRISO cavitation tunnel is modified to perform open-water tests of the VWJ propulsors. The tests are performed both at fully-submerged and free-jet conditions. Ventilation occurred at the free-jet condition by sucking the air in the downstream side of the rotor, which easily develops as super-cavitation when the rotor operates at lower advance coefficients. Spoilers are attached at the trailing end of the pressure side of the blade section, in order to increase the lift force.

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