• Title/Summary/Keyword: humidity condition

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Drying and Shrinking Characteristics of Food 2. Influencing Factors in Drying and Shrinking Characteristics of Sea Tange (식품의 건조 및 수축특성에 관한 연구 - 2. 다시마의 건조 및 수축특성에 영향을 미치는 인자 -)

  • CHO Duck-Jae;HUR Jong-Hwa;CHUNG Soo-Yeol
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.1
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    • pp.16-20
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    • 1988
  • Square slices of sea tangle was dried in hot air drier that could be controlled air temperature, relative humidity and air velocity. Under various drying conditions, drying and shrinking characteristics were investigated. 1) During drying sea, tangle, the constant rate period was nonexistant and the falling rate could be devided into a 2 periods, namely, a first falling rate period and a second falling rate period. 2) The tip part was proceeded more shrinkage than base part, and under drying condition of air temperature $50^{\circ}C$, relative humidity $30\%$, air velocity 0.4m/s, when the moisture content was reduced to $20\%$, the shrinking ratio of tip part, middle part and base part were 57.5, 54.0 and $42.7\%$, respectively. 3) The drying shrinking and drying rate increased with decreasing relative humidity, but when the moisture content was reduced to $20\%$, the shrinking ratio increased with increasing relative humidity.

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A Measurement and Evaluation of the Indoor Thermal Conditions in Summer of a Newly-Launched 8,500GT Chemical Carrier (신조 8,500GT 화학물 운반선의 여름철 선실 내 온열환경 실측평가)

  • Hwang, Kwang-Il;Doe, Geun-Young;Cho, Hyo-Jae;Woo, Sang-Woo;Shin, Dong-Keol;Lim, Seong-Taek
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.5
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    • pp.717-723
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    • 2008
  • The purpose of this study is to measure and analyze the indoor thermal conditions of a 8,500GT class chemical carrier which was launched on July 2007. The measurement was operated from 4th June to 4th June 2007, just before handing over to Owner. Followings are the results of this study. (1)The temperature variations of supply air were related to the outdoor temperature variations, but the humidity was stable at $65{\sim}80%$. (2)The temperature variations at the representative position of bridge, restaurant, crew's cabin showed gentle slopes. but that of conference room was very steepy. The humidities of bridge and restaurant were unstable because of outdoor-contact and cooking, respectively. (4)The temperature and humidity of ECR(Engine Control Room) which was designed to supply heating and cooling by PAC(Package Air Conditioner) were directly affected by the operating conditions of PAC. (5)The measured supply air volume from dampers of bridge, crew's cabin and conference room were satisfied with the design supply air volume. (5)For the improvement of the indoor thermal conditions, the temperature of crew's cabin and restaurant and the humidity of conference room, and the temperature and humidity of bridge should be controlled, respectively.

Micrometeorological Factors and Restriction to Azimuth Distribution of Corylopsis coreana Population (히어리 개체군의 선택적 사면분포와 미기상학적 요인)

  • Lee, Eun-Hye;Ryu, Ji-Eun;Lim, Dong-Ok;Choung, Heung-Lak;Lee, Jae-Seok
    • Korean Journal of Environmental Biology
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    • v.25 no.4
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    • pp.363-369
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    • 2007
  • To understand property of distribution restricted at northern slope of Corylopsis coreana, we investigated process of sedentary formation from seed germination to seedling and its micrometeorological factors in Cheongsogol, Suncheon in Korea. The germination tests were carried out in-situ and manipulated condition, respectively. Air and soil temperatures, relative humidity, soil water contents and PPFD were measured in southern and northern slopes for four seasons. The seeds did not shown difference in germination to azimuth slope. However, seedling in the northern slope should have taken advantage on the sedentary stage of seedlings because there was low temperature and high humidity during the spring. At the southern slope, the seedlings seemed to have a disadvantage on high temperature and low humidity in spring season. Accordingly, the formation of Corylopsis coreana population is influenced by microclimatic factors, especially in low temperature and high humidity at the sedentary stage of the germinated seedlings.

A Study on the Physiological Responses and the Microclimate in Girdle (Girdle 착용이 인체생리반응과 의복기후에 미치는 영향)

  • Kim Hyun Sik;Choi Jeong Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.11 no.2 s.24
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    • pp.57-67
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    • 1987
  • The purpose of this study was to confirm the effects of girdle on the physiological responses and the microclimate in summer. The measuring points were rectal temperature, skin temperature, pulse rate and sweat volume as physiological responses and the inside clothing temperature, relative humidity as microclimate when the subjects wore girdle (girdle A; polyurethan+nylon, girdle B; polyurethan+cotton) for the period of rest and exercise in climate chamber. The enviromental conditions were at $25^{\circ}C$ ($65{\pm}5\%$ RH) and $30^{\circ}C$ ($75{\pm}5\%$ RR). The results were as followings. 1. Mean skin temperature increased in girdle during the exercise at $30^{\circ}C$. 2. The pulse rate decreased in girdle during the rest at $25^{\circ}C$. In the case of girdle A, it was remarkably decreased. Rectal temperature increased in girdle A and B during the exercise at $25^{\circ}C$. But the kinds of girdle didn't affect the pulse rate and rectal temperature. 3. The total sweat volume in girdle was larger than in control. 4. The difference between skin temperature and inside clothing temperature of abdomen had a tendency to increase at all experiment condition. 5. The relative humidity of inside ($RH_1$) and outside ($RH_2$) of girdle increased in girdle during the rest at $25^{\circ}C$ and $30^{\circ}C$. And the relative humidity of wearing girdle B was hig-her than girdle A during the rest at $25^{\circ}C$ and $30^{\circ}C$. The $RH_1$ after stepping at $30^{\circ}C$ was the highest in girdle A and the lowest in control. From this point of view, we concluded that physiological responses and the microclimate were affected by wearing girdle. And mean skin temperature and relative humidity of inside clothing were affected by the materials of girdle.

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Effect of Storage Temperature and Humidity on the Quality of Apples and Pears harvested in Gyeongnam, Korea (경남산 사과 및 배의 저장온습도별 품질변화)

  • 신영희;조성환
    • Food Science and Preservation
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    • v.8 no.3
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    • pp.269-273
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    • 2001
  • Apples and pears for investigating the optimal storage conditions were purchased from the farmhouse located in Hadong-Goon and Geochang-Goon Gyeongnam just before the beginning of this experiment. Apples and pears were, stored under 70%(storage temperature : 25$^{\circ}C$), 80%(10$^{\circ}C$) and 90%(5$^{\circ}C$) of relative humidity, respectively and their qualities in microbial counts, decay ratio, surface color difference and chemical attributes were monitored during the storage period. Apples and pears stored under 70% of relative humidity showed the minimal change in weight lass, decrease ratio of ascorbic acid content, surface color difference and degrees contaminated by putrefactive microorganisms. As the results of this experiment, apples and pears stored under 90% of relative humidity showed the optimal storage conditions for maintaining their freshness.

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A Study on Examination of Indoor Thermal Environment Elements and Thermal Sensation Vote of Log Cabins in Winter Season (통나무집의 동절기 실내 온열환경 요소의 측정과 온열감 평가에 관한 연구)

  • Min, Byeong-Cheol;Jeon, Ji-Hyeon;Kook, Chan
    • Journal of the Korean housing association
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    • v.18 no.2
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    • pp.21-27
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    • 2007
  • Various buildings constructed by environmentally friendly resources are being built in KOREA. Especially as the wood has distinctive ecological merits in comparison with reinforced concrete and brick, the buildings made by the wood are acknowledged with its superiority of ecological value. Enough field studies for their thermal environment, however, haven't been done. In this study, to investigate indoor environmental condition and occupants' response to it of Log Cabin in Gyeongsangnam-do Hamyang Country Jirisan Natural Recreation Forest, examination of indoor thermal environment and field subjective evaluation have been done in that fundamental information of thermal environment characteristics can be suggested. The results are following; 1) Thermal environment of the Log Cabins; Indoor and outdoor mean dry bulb temperature were $21.9^{\circ}C$ and $-3.1^{\circ}C$, and Indoor and outdoor average relative humidity were 25.8% and 52.1%. These results are below ASHRAE; dry bulb temp. $22.0^{\circ}C$, humidity 30%, and above domestic standards; dry bulb temp. $18{\sim}20.0^{\circ}C$, humidity $40{\sim}60%$. 2) Result of subjective evaluation; Thermal sensation and its comfort were evaluated as 'slightly uncomfortable' because of 'slightly warm'. And humid sensation and its comfort were evaluated as 'slightly uncomfortable' because of 'slightly warm'. 3) Result of vertical temperature and humidity; Vertical temperature difference from head to ankle was $0.54^{\circ}C$ which means most occupants may feel comfortable.

A Study on the Performance and Dehumidification Load of an HVAC System for Conservation of Ancient Tombs (고분 공조시스템의 운전특성 및 제습부하에 관한 연구)

  • Park, Jin-Yang;Ko, Seok-Bo;Jun, Hee-Ho;Jun, Yong-Du;Lee, Kum-Bae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.3
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    • pp.253-262
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    • 2007
  • Although the importance of good conservation of historical sites including ancient royal tombs is well aware, still not much attention has been paid for facilities to realize it. There are numerous ancient royal tombs spread in Korean peninsula which are opened and some of them are selectively on display for public access. However, the conservation measures of these sites have not been seriously investigated. Even the level of understanding of the underground environment of tombs is not satisfactory. In the present study, we focus on the dehumidification loads to maintain appropriate conservation conditions in terms of temperature and humidity. Two experimental tombs different in size were built in KNU (Kongju National University) campus with the dimensions ($L{\times}W{\times}H$) of $1.0m{\times}2.8m{\times}1.0m\;and\;1.3m{\times}3.0m{\time}1.2m$, respectively, HVAC systems are installed to maintain a suitable condition for conservation, i.e., $22{\pm}2^{\circ}C$ in temperature and $55{\pm}5%$ in relative humidity. The condensed water are measured to estimate the dehumidification loads while the temperature and the humidity inside the tombs were maintained within the specified range.

Characteristics of Proton Exchange Membrane Fuel Cells(PEMFC) Membrane and Electrode Assembly(MEA) Using Sulfonated Poly(ether ether ketone) Membrane (sPEEK 막으로 제조한 고분자전해질 연료전지(PEMFC) 막전극합체(MEA)의 특성)

  • Lee, Hye-Ri;Lee, Se-Hoon;Hwang, Byung-Chan;Na, Il-Chai;Lee, Jung-Hun;Oh, Sung-June;Park, Kwon-Pil
    • Korean Chemical Engineering Research
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    • v.54 no.2
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    • pp.181-186
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    • 2016
  • Recently, there are many efforts focused on development of more economical non-fluorinated membranes for use in PEMFCs (Proton Exchange Membrane Fuel Cells). In this study, characteristics of sulfonated Poly(ether ether ketone) (sPEEK) were compared according to degrees of sulfonation (DS), relative humidity, cell temperatures at PEMFC operation condition. I-V polarization curve, hydrogen crossover, electrochemical surface area, membrane resistance and charge transfer resistance were measured. sPEEK membrane showed high performance at high DS, high temperature and high relative humidity, in particular, performance of sPEEK membrane decreased largely due to low ionic conductivity at low DS and low relative humidity.

Effects of Temperature/Humidity Treatment Conditions on the Peel Strength between Screen-printed Ag and Polyimide Films (고온/고습 조건이 스크린 프린팅 Ag와 Polyimide의 필 강도에 미치는 영향)

  • Lee, Hyeonchul;Bae, Byeong-Hyun;Son, Kirak;Kim, Gahui;Park, Young-Bae
    • Journal of the Microelectronics and Packaging Society
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    • v.29 no.2
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    • pp.43-48
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    • 2022
  • Effect of temperature/humidity (T/H) treatment conditions on the peel strength of screen-printed Ag/polyimide (PI) structures was evaluated by peeling PI films in 90° peel test. Initial peel strength was 25.99±1.47 gf/mm, and then decreased to 6.05±0.54 gf/mm after 500 h at 85℃/85% relative humidity T/H condition. And, the peeled locus was changed from Ag/PI interface to shallow cohesive inside PI near interface. X-ray photoelectron spectroscopy analysis on the peeled surfaces showed that the long-term moisture penetration into the Ag/PI interface during T/H treatment led to hydrolytic degradation of PI to form weak boundary layer inside PI near Ag/PI interface, which are responsible for large decrease in peel strength.

Present Condition of Indoor Thermal and Air Environment by Air-conditioning in School Classrooms (학교교실의 냉방시 실내열.공기 환경 실태)

  • Choi, Yoon-Jung;Kim, Hye-Kyeong;Hwang, Jin-A;Lee, Seon-A;Jeong, Youn-Hong
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.291-296
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    • 2006
  • The purpose of this study were to make clear the present condition of indoor thermal and air environment by air-conditioning in school classrooms and to analyze the relation of the living conditions with indoor environment. The measurements on physical elements and observations on living conditions were carried out in 6 classrooms of 3 middle or high schools. Measuring elements were indoor temperature, relative humidity, $PM_{10}$ and $CO_2$ concentration. As results, the averages of indoor temperature each classrooms were 24.9${\sim}$26.6 . Most of classrooms were lower than the Maintenance standard(26${\sim}$28 ) of School Health Law. The means of relative humidity were 51.3${\sim}$72%, all classrooms were ranged within the standard(30${\sim}$80%). The means of $PM_{10}$ concentration were 3.5${\sim}$23.1 ${\mu}g/m^3$, all classrooms were kept within the standard(100 ${\mu}g/m^3$). The means of $CO_2$ concentration were 1218.7${\sim}$4705.4 ppm, all classrooms were exceed the standard(1,000ppm). The results of analysis on relations of living conditions with the physical elements are as follow; the air conditioner set of temperature, windows and doors opening elapsed time, the number of students in classrooms and activities of students had certain effect on indoor environment.

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