• Journal of the Korean Ceramic Society
• /
• v.47 no.5
• /
• pp.373-380
• /
• 2010

In this study, we studied on the durability of restorative cement mortar for deteriorated concrete at complex deteriorated conditions as variation of temperature and of humidities. We made a comparison between restorative materials with insulation function and restorative materials without insulation function in items of compressive and bending strength and permeability of water, durability for carbonation, salt damage, diffusion coefficient of salt at complex deterioration conditions like change of temperature, change of humidity, For insulation, we used close-pore type Alumino-Silicate lightweight aggregate and substituted 12 wt% and 15 wt% out of original restorative cement mortar without insulation function. As a result, it was found that original restorative cement mortar without insulation function fail to meet Korean Standard on polymer modified cement mortar for maintenance in concrete structure, but restorative cement mortar with insulation function is in contentment Korean Standard to meet excellent than restorative materials without insulation function for durability at complex deteriorated conditions.

• Journal of Biosystems Engineering
• /
• v.29 no.1
• /
• pp.59-64
• /
• 2004

This study was performed to determine drying equations of sarcodon aspratus. Drying tests for sarcodon aspratus were conducted in an experimental dryer equiped with an air conditioning unit. The drying tests were performed at three air temperatures of 30$^{\circ}C$, 40$^{\circ}C$ and 50$^{\circ}C$, and two relative humidities of 30% and 50%. Measured moisture ratio data were fitted with the selected four drying models(Page, Thompson, Lewis and simplified diffusion models) using stepwise multiple regression analysis. When the coefficients of determination and root mean square errors of moisture ratio were evaluated for four drying models, the Page model was found to fit adequately to all the drying test data with coefficient of determination of 0.9996 and RMSE of 0.00523.

• Korean Journal of Food Science and Technology
• /
• v.19 no.4
• /
• pp.331-337
• /
• 1987

The sorption characteristics of pearled, cutted and pressed barleys stored for 360 hours at $20^{\circ}C$ and various relative humidites were analyzed. The adsorption rate at RH above 57% was the greatest in pearled barley and the lowest in cutted barley. The desorption rate at RH below 44% was in the decreasing order of pearled, pressed and cutted barleys. From the sorption rates an empirical equation was proposed. which can be used for the estimation of moisture content of three barleys at arbitrary storage time and RH.

• Research in Plant Disease
• /
• v.9 no.3
• /
• pp.121-124
• /
• 2003

Occurrence of rust on 2 representative garlic cultivars Daeseo and N므애 in major cultivating regions of Goheung-gun, Jeonnam and Namhae-gun, Gyeongnam was investigated during 1998-1999. Rust disease severities of garlic ranging from 1.2 to 85.8 were quite different according to the investigating years and cultivars. Relatively high rust severities of garlic were observed in 1998 compared with 1999. This might be due to remarkably frequent rainfalls and high humidities during the growing seasons of garlic in 1998. Rust occurred severely on cultivar Daeseo but not on cultivar Namdo. This shows quite different susceptibility or resistance to rust among the cultivars of garlic. Increase of rust severities resulted in remarkable decrease in yields of garlic. It is assumed that rust might cause serious damages in the cultivation of garlic.

• Journal of Environmental Science International
• /
• v.23 no.11
• /
• pp.1851-1862
• /
• 2014

It is well known that urban relative humidity has continuous decreasing trend owing to the influence of urbanization. The change of relative humidity is directly influenced by two factors, namely, temperature effect and water vapor effect in various urban effects. In this study, the temperature and the water vapor effects on the relative humidity change were analyzed by using monthly mean relative humidities for a long period(1961~2013) in Busan and Daegu. The major results obtained in this study can be summarized as follows. Firstly, the urban dryness was caused mainly by water vapor effect in summer. But, for the other seasons, the urban dryness is mainly due to the temperature effect. Secondly, the relative humidity in Busan is on the decrease until now. This phenomenon is similar to another Korean huge cities such as Seoul, Daejeon and Incheon.

• Applied Chemistry for Engineering
• /
• v.19 no.1
• /
• pp.73-79
• /
• 2008

An experimental study was conducted to investigate the effect of a tube row, a fin pitch and an inlet humidity on air-side heat and mass transfer performance of louvered fin-tube heat exchangers under wet conditions. Experimental conditions were varied by three fin pitches, two rows, two inlet relative humidities. Experimental results showed that the heat transfer performance decreased and the friction increased with the decrease of fin pitch, for 2 row heat exchanger. The effect of fin pitch on heat transfer performance was negligible with 3 row heat exchanger. The changes in relative humidity was not affected heat transfer and friction. However, the mass transfer performance was slightly decreased with the increase of relative humidity and with the decrease of fin pitch. The mass transfer performance of the louvered fin-tube heat exchanger decreased with the decrease of the fin pitch and was different according to the number of tube row.

• Korean Journal of Food Science and Technology
• /
• v.29 no.2
• /
• pp.255-260
• /
• 1997

Glucomannan was isolated from konjac (Amorphophallus konjac) flour by precipitating in aqueous alcohol solution. Konjac glucomannan films were prepared at various concentrations up to 1.0% (w/v) in aqueous glycerol solutions. Tensile strength (TS), percent elongation (E), water vapor permeability (WVP) as the barrier property and the solubility of the films were varied with glucomannan concentrations, glycerol contents and storage humidities. TS was decreased as the glucomannan concentration in the film and relative humidity for storage increased, and E was vice versa. WVP showed better barrier properties compared with other polysaccharides films. Glycerol contents in the film significantly affccted TS and E, but did not affect WVP. The glucomannan films were completely dissolved in the water by 150 min stirring at room temperature.

• Korean Journal of Food Science and Technology
• /
• v.15 no.1
• /
• pp.27-31
• /
• 1983

Monolayer moisture contents of white ginseng and white ginseng powder were 6.68g/100g and 7.81g/100g respectively, and the corresponding water activity at that moisture were 0.16 and 0.18 respectively. TBA value increased with an increase in relative humidity and storage period, and the increase of TBA value was the lowest at 23-32% R.H.. The variation of fat soluble and water soluble pigment in white ginseng was similar to that of TBA value.

• Polymer(Korea)
• /
• v.31 no.4
• /
• pp.302-307
• /
• 2007

The resistive-type humidity sensors were prepared from the copolymers of [2-[(methacryloyloxy)ethyl]dimethyl]propylamonium bromide (MEPAB), [2-[(methacryloyloxy)ethyl]-2-hydroxyethyl]dimethylammonium bromide (MEHDAB), 2- [(methacryloyloxy)ethyl]trimethylammonium chloride (METAC), and n-butyl methylacrylate (MBA). Four component copolymers MEPAB/BMA/MEHDAB/METAC=4/4/1/1, 3/5/1/1, 2/6/1/1, 1/7/1/1 crosslinked with blocked-isocyanate on Ag/Pd electrode/alumina substrate showed a good durability at high humidities. The various electrical properties such as frequency dependency, temperature dependency, hysteresis, response time and water durability were examined. In the case of copolymer composed of MEPAB/BMA/MEHDAB/METAC=2/6/1/1, the resistance varied from $1.4\;M{\Omega}$ to $2.9\;k{\Omega}$ at $25^{\circ}C$ in the range of $30{\sim}90\;%RH$ and this copolymers showed a good linearity and low hysteresis.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.9
• /
• pp.1318-1328
• /
• 2011

The tropics is not an ideal location for calf rearing as the high temperatures and humidities introduce many potential disease problems to milk fed calves. In addition, the type of dairy farming (generally poorly resourced small holder farming) and the general lack of awareness of the long term implications of poorly reared stock do not encourage farmers to pay close attention to their calf and heifer rearing systems. Surveys of calf rearing systems in Asia, tropical Africa and South America highlight the high calf and heifer mortalities. A range of 15 to 25% pre-weaning calf mortality is typical on many tropical dairy farms. It is often as high as 50%, indicating very poor calf management. This contrasts with US findings of less than 8% mortality from birth to 6 months while surveys of Australian farmers report only 3% losses. Simple extension programs on farms in Sri Lanka and Kenya have drastically reduced calf mortalities and improved pre-weaning growth rates. Improved management strategies leading to lower calving intervals, higher calving rates, reduced still born and pre-weaned calf mortalities and fewer non pregnant heifers can supply many more dairy herd replacements than currently occurs. Such strategies can increase the number of replacement heifer calves in the herd from 15 to over 35%, thus allowing farmers to increase their herd sizes through natural increases. Simple management procedures such as ensuring adequate intake of good quality colostrum within the first 12 hours of life, housing and good hygiene to minimise disease transfer, providing clean drinking water, developing appropriate feeding protocols to encourage early rumen development and paying closer attention to climate control and animal health can all lead to improved calf vigour and performance. Good record keeping is also important so farmers can more easily identify susceptible calves and quickly treat potential problems.