• 한국작물학회지
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• 제45권5호
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• pp.300-304
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• 2000

Tuberous roots of yacon (Polymnia sonchifolia Poeppig ＆ Endlicher) were stored in different temperature and relative humidity conditions after curing for 30 days. Non-decadent percentage, moisture contents, brix degree and sugars were investigated. Whether temperature and relative humidity were high or not, most of the tuberous root decayed during storage, and the decayed percentage was increased as long as the storage period. In final, only 13% of tuberous roots remain intact at 4$^{\circ}C$, 85% relative humidity condition to be appeared best storage condition in this experiment and all of the tuberous root decayed in other storage conditions after 6 months. Moisture contents decreased a little in the high relative humidity. Even though tuberous roots decayed when stored at 1$0^{\circ}C$ and 2$0^{\circ}C$, most of brix degree reached about 17.0. Fructose, glucose and sucrose contents were 1.65, 1.15 and 0.35% at early storage period, and 1.6, 1.1 and 0.5% after 6 months at 4$^{\circ}C$, 85% relative humidity, respectively. In 3 temperature conditions, fructose and glucose increased for a month and then decreased successively afterwards, but sucrose increased gradually during 6 months. Also in 4 relative humidity conditions, fructose, glucose and sucrose contents were changed with similar to that of in temperature. Changes of fructose and glucose were the same except on 4$^{\circ}C$, 85% relative humidity, that was lower level than moisture of tuberous root.

• 대한기계학회논문집
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• 제18권10호
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• pp.2597-2605
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• 1994

The wear behavior of two types of $Si_3N_4$ exposed to high and low humidity was examined at various sliding speeds, using bearing steel as disk material under pin-on-disk type sliding conditions. Higher wear rates were obtained at a high humidity than at a low humidity. As the sliding speed was increased, the wear rates were decreased and the effect of humidity on the wear rates of $Si_3N_4$ was reduced. The result that the $Si_3N_4$ pin showed higher wear rate under the high humidity condition was explained by the decrease in microhardness of $Si_3N_4$ due to the chemisorbed moisture on the pin and plowing action by the hard particles of $Fe_2O_3$ from the disk. An increase in the sliding speed is supposed to reduce the effect of humidity on the wear rate of $Si_3N_4$ by raising the average temperature of the disk surface and the local temperature at pin-disk contact point.

• 수산해양기술연구
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• 제13권1호
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• pp.17-25
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• 1977

For four calender years (1971-1974), daily observations of weather conditions (air temperature, humidity, wind speed, wind direction, cloud amount, fog, precipitation etc.) at six stations in the north western Pacific Ocean are used to calculate mean monthly values and to check extra-conditions. At Petropavlosk and Miko'skoe, where indicate the characteristics of modified continental climate, the temperature and humidity are high in summer, and Iow in winter. At A Dak and She Mya, where indicate the characteristics of warm current type maritime climate, humidity is high in all season and annual range of air temperature is nearly negligible. At Simusir and Vasi!' eva, where indicate the characteristics of cold current type maritime climate, humidity is high in all season and annual range of air temperature is $15^{\circ}C.$ As dry cooling power is relatively high in winter, working condition on deck is bad. Most of fogs are advection fog in the area of cold current type climate in summer.

• 한국환경보건학회지
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• 제29권2호
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• pp.87-93
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• 2003

A survey including an inspection was conducted to assess the sanitary condition of kitchens in the school food-service programs and to prepare background data for improving the safety of school meals. The survey was carried out over a two-month period (September-October, 2001). A self-administered questionnaire recommended by the Korea Ministry of Education & Human Resources Development (MOEHRD) was offered to a random sample of dieticians of twenty-five elementary schools in one region of Korea about food, sanitation, and safety inspection of their kitchens. Air temperature, relative humidity, and airborne microbes in the kitchens were monitored during preparation, cooking, and service. The inspection results showed their sanitary rendition met the level B of the recommendation of the Korea MOEHRD. The range of air temperature of the kitchens was 21.4~22.4$^{\circ}C$. and the range of relative humidity was 62.4~69.6%. The microbiological evaluation of kitchen samples indicated aerobic plate count levels from 22..5 to 26.5 CFU/15 minutes. Although the results of inspection show that the levels of sanitary condition of kitchens in the schools were good, they are not satisfactory for safe food-servile because the temperature and humidity levels are high. This study indicates that the school kitchens should be monitored and strict inspection is necessary. The legal standards for school food-service should include standards for kitchen air temperature, relative humidity, and airborne microbes.

• International Journal of Industrial Entomology and Biomaterials
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• 제11권2호
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• pp.139-143
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• 2005

The implications of temperature (25, 30 and $35^{\circ}C$) and relative humidity (RH; 60, 70 and $80\%$) on the hatching rhythmicity and hatching parameters (percentage and duration) were studied in the silkworm, Bombyx mori L. under natural photoperiod (LD 12 : 12). Disease free layings (DFLs) of two pure silkworm breeds, Pure Mysore (PM, a multivoltine breed) and $NB_4D_2$ (a bivoltine breed), and their hybrid, $PM{\times}NB_4D_2$ were introduced into the experimental conditions on the $3^{rd}$ day of oviposition till completion of hatching. The hatching rhythm was predominantly diurnal under all temperature and humidity conditions, with peaks just after 'lights-on' phase (6 hrs). Extreme temperature and humidity conditions did not alter the hatching rhythmicity, but prolonged the hatching durations, extending it to the next day, coupled with reduced hatching percentage in PM and $PM{\times}NB_4D_2{\cdot}In\;NB_4D_2$, on the other hand, hatching did not extend to the next day. Hatching percentage in this breed, however, reduced below the economic level under high temperature and low humidity conditions. The high temperature and low humidity together, though did not alter the rhythmicity, seems to exert synergetic effect on the hatching percentage and its duration in the silkworm, B. mori.

• 대한기계학회논문집B
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• 제30권12호
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• pp.1228-1235
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• 2006

PEMFC(Proton Exchange Membrane Fuel Cell) is a low temperature fuel cell and has many probabilities of commercial use. However, water management is one of the serious technical problems for commercialization. It is necessary to understand the relationship between operation conditions and water behavior in PEMFC channel because it affects fuel cell performance. In this paper, the distribution of current density according to inlet humidity condition is mainly observed and discussed. If the anode inlet is well humidified, electro-osmotic drag is very active. For this reason, current density is very high at inlet side and the distribution is non-uniform.

• Journal of the Korean Wood Science and Technology
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• 제27권3호
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• pp.99-116
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• 1999

목재 hollow core 형태의 프러쉬문은 가구과 목공품 산업에서 주요 제품으로 사용중 틀어짐과 좌굴은 매우 중요한 문제이다. 틀어짐은 도아 표면재 간의 물리적 및 기계적 성질의 차이에 기인된다고 알려져 있다. 본 연구는 수치적 모델덜을 사용해 틀어짐과 좌굴을 예측하는데 그 목적이 있다. 여러 환경조건에서 경질섬유판과 합판으로 만들어진 프러쉬문에 대한 각 모델들과 실측치간의 비교를 하였다. 문의 틀어짐과 좌굴을 예측하기 위해 3가지 연속체 모델, 즉 보, 판상 및 판상-좌굴 모델이 채택되었다. 틀어짐은 고습에서보다 저습에서 현저하게 훨씬 현저하게 발생되었으며, 포아송 비를 고려한 판상 모델은 저습에서 보 모델보다 더 정확하게 틀어짐을 예측할 수 있었다. 그러나 고습에서 좌굴이 문의 표면재에 발생하기 때문에 판상-좌굴 모델 이 모든 시험범위에서 가장 적절하였다.

• Journal of Biosystems Engineering
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• 제32권4호
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• pp.247-255
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• 2007

During the winter season in Korea, the relative humidity of greenhouse at night often exceeds 90% because air temperature inside the greenhouse is usually controlled using a heater with all of windows closed to minimize heat loss, thereby requiring the use of a dehumidifier that can maintain optimum humidity levels of $70{\sim}80%$ to provide a good growth condition of crops. Also, such a high humid condition can cause the development of a pest, such as insects, fungi or diseases. However, the use of most conventional dehumidifiers for low temperature dehumidification is limited because their performance is degraded due to frost accumulation on the evaporator coil. This study was carried out to develop a refrigeratory-based dehumidifier suitable for low temperature dehumidification in greenhouse cultivation. The developed dehumidifier consists of a condenser and an evaporator installed separately so that relative and absolute humidity levels can be reduced when air passed through the condenser and evaporator, respectively. The prototype dehumidifier showed a dehumidification capacity of $5{\sim}7kg/h$ when air with a temperature of $15{\sim}25^{\circ}C$ and a relative humidity of $70{\sim}95%$ came into the dehumidifier. Under the condition that either temperature or relative humidity was fixed, the amount of condensed water was proportional to the levels of both temperature and relative humidity.

• 보존과학연구
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• 통권21호
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• pp.145-175
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• 2000

To examine the method for preservation of papers, 9 kinds of papers were purchased and pretreated for 6 months with various artificial conditions which were controlled as 3 temperature classes($20^{\circ}C$, $80^{\circ}C$, $-20^{\circ}C$&$20^{\circ}C$) and 4 humidity classes(40%, 60%, 80%, 100%).Whiteness, acidity and folding endurance were measured to examine the state of papers pretreated under each condition. From the resultexamining the state, all the papers were best condition at low temperature($20^{\circ}C$) and low humidity(40%) and damaged at high temperature($80^{\circ}C$) and high humidity(100%).The values of whiteness, acidity, and folding endurance were measure din relation with deterioration of papers. According to damage of papers caused by the chemical agent, papers became to be acidic, increased color difference and reduced the force of folding endurance. The effect of change of temperature($-20^{\circ}C$&$20^{\circ}C$) on degradation of papers was not well acquired. Because the period of investigation was not long enough to acquire the data. So the more studies are needed to find the cause of damage of papers.

• 대한기계학회논문집A
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• 제26권9호
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• pp.1842-1848
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• 2002

Although DLC coatings have good tribological properties, these are dependant on the deposition method, the property of contact surface, and test condition. Humidity, which has little influence on tribological behavior in macro scale, is an important factor of tribological behavior in small devices like MEMS. The objective of this study is to investigate the tribological behavior of DLC coatings with particular attention to their wettability at various humidities. DLC coatings were deposited on Si substrates and tested using a reciprocating friction tester against Si$_3$N$_4$balls at various humidities. The results showed that the tribological behavior of DLC coatings was dependant on relative humidity and wettablility of DLC coatings. Friction coefficient at high relative humidity was higher thar that at low relative humidity. The tungsten-containing DLC coatings had a good wear resistance at low relative humidity whereas DLC coatings derived from argon(Ar)+cesium(Cs) gases showed a good wear resistance at high relative humidity.