• Journal of Ginseng Research
• /
• v.17 no.3
• /
• pp.210-218
• /
• 1993

This study was conducted to investigate the effects of Korean ginseng extracts and their fractions on the growth of Saccharomyces cerevsiae and Saccharomyces uvamm, their glucose consumption and alcohol production. The growth of both yeasts were stimulated by ginseng extracts and their water soluble fractions, but were supressed by ether extracts and an n-butanol extracts. Their growth were enhanced considerably by low molecular weight fractions (< 1,000) in water solubles. Similar results were also obtained with glucose consumption by yeasts. Substances increasing the growth and glucose consumption by yeasts proved to be a low molecular weight fractions (<1,000) in water solubles not saponins. The production of n-propyl alcohol by yeast was enhanced by adding ginseng extracts into the media, but that of ism-butyl alcohol was suppressed at same condition.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1998.10a
• /
• pp.1-7
• /
• 1998

To investigate the water balance in a paddy rice field with the pumping station for irrigation water supply, flow measurements and analysis on various components of water balance were carried out. The investigated area is 103.7 ha, and the irrigation water was supplied for 102 days during the total irrigation period starting from June 1. It was found that the consumption rate was increased as the growing stage was progressed. The variation of evapotranspiration rate was shown same tendency as the consumption rate, while no apparent tendency was found in infiltration rate upon different growing stages. And the ground water input to the area was predominant during the early stage of growing period, while ground water output from the study area was predominant at the end of the growing stage. The range of return flow rate, the ratio of total outflow to total inflow in every decad, was 57.6 to 85.7%. These values are slightly higher than reported values from the other investigation projects.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.161-166
• /
• 2009

Condensing gas boiler units may make a big role for the reduction of energy consumption in heating industries. In order to decrease the energy consumption of a boiler unit, the effective operation is necessary. In this study, the supply water temperature algorithm of a condensing gas boiler was developed. This includes the setpoint algorithm and the control algorithm of the supply water temperature. The setpoint algorithm was developed by the fuzzy logic and the control algorithm was developed by the proportional integral algorithm. In order to analyse the performance of the supply water temperature algorithm, the dynamic model of a condensing gas boiler system was used. Simulation results showed that the supply water temperature algorithm developed for this study may be practically applied for the control of the condensing gas boiler.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.1
• /
• pp.56-61
• /
• 1999

Oxygen consumption rate of Far eastern catfish, Silurus asotus, weighing 280g, was measured using continuous flow respirometry chamber linked computer monitoring system. Mean oxygen consumption rates at $15^{\circ}C,\;20^{\circ}C,\;25^{\circ}C$, and $30^{\circ}C$ were ranged in 35.2$\~96.4mg\;O_2/kg$ fish/hr, 78.6$\~127.9mg\;O_2/kg$ fish/hr, 120.1$\~231.7mg\;O_2/kg$ fish/hr, and 197.5$\~352.3mg\;O_2/kg$ fish/hr, respectively. The oxygen consumption rates increased with increasing water temperature (p<0.05). A photoperiod-mediated oxygen consumption rates was higher during the light period than during the darkness (P<0.05). When acclimated with different photoperiods, 24L:0D, 12L:12D, and 0L:24D, the lowest oxygen consumption rate was observed in the continuous darkness (0L:24D). The differences between maximum and minimum oxygen consumption rates oyer 24 hour increased with increasing water temperature and the difference was the highest in 12L:12D. Oxygen consumption rate changed suddenly at dawn and at dusk.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.11 no.3
• /
• pp.7-12
• /
• 2015

Currently water supply system with water storage is generally applied except for small building such as single-family houses, and water supply system on replacing water storage installed system by direct connecting system has been increasing because of sanitary and energy-saving aspects. The purpose of this study is to evaluate energy-saving and environmental efficiency of direct connecting booster pump system in comparison with the water storage installed system. The architectural condition of the evaluation subject is ten-story apartment house in which sixty households live. To calculate the power consumption of the pump, the volume of water supply was determined from existing data and other data, such as head, efficiency of the pump, was the value used for general application in design office. The power consumption of the water supply pump for one day was 8.5 kWh for direct connecting booster pump system, and 22.5 kWh for water storage installed system, and the former system showed energy savings of 62% compared to the latter system. Reduced power consumption also leads to reduction of $CO_2$ emission. According to the criteria presented in the Korea Energy Management Corporation, reducing the 2,410 kg $CO_2$ emission is possible per year.

• Journal of Biosystems Engineering
• /
• v.8 no.1
• /
• pp.38-46
• /
• 1983

This study was carried out to investigate the possibility of improving the performance of a kerosene engine with water addition. The engine used in this study was a single-cylinder, four-cycle kerosene engine with the compression ratio of 4.5. Water could be successfully added into the inlet manifold by an extra carburetor for the volumetric ratios of 5, 10, 20, and 30 percents. Variable speed tests at wide-open throttle were performed for five speed levels in the range of 1,000 to 2,200rpm for each fuel type. Volumetric efficiency and brake specific fuel consumption were determined, and brake thermal efficiency based on the lower heats of combustion of kerosene was calculated. To examine variation in fuel consumption, CO concentration, and cooling water temperature, part load tests were also performed. The results obtained are summarized as follow. (1) Brake torque increased almost in proportion to volumetric efficiency. But the ratio of increase in torque was greater than that of volumetric efficiency. Mean torque over the speed range of 1,000 to 2,200rpm increased 1, 3, 7, and 2 percents for 5, 10, 20, and 30 percents water addition, respectively. The increase in brake torque with water addition was greater at lower speeds. (2) Mean brake specific fuel consumption over the speed range of 1,000 to 2,200rpm decreased 1, 2, 3, and 3 percents for 5, 10, 20, and 30 percents water addition, respectively. (3) Mean temperature of cooling water over the speed range of 1,000 to 2,200rpm decreased 2, 4, 8, and 12 percents for 5, 10, 20, and 30 percents water addition, respectively. (4) The effects of decreasing CO concentration in the exhaust emissions with water addition were significant. At the speed range of 1,000 to 2,200rpm, CO concentration in the exhaust emissions decreased 2, 10, 23, percents for 5, 10, and 20 percents water addition, respectively. (5) Deposits were not discovered in the combustion chamber during the experiment. However, a little rust was formed in the water-supply carburetor.

• Journal of Environmental Health Sciences
• /
• v.34 no.1
• /
• pp.95-100
• /
• 2008

An automatic titration system using a PC-camera with a color filter on its lens was used in the $KMnO_4$ consumption test of tap water and distilled water in relation to blank tests. The very faint pink color of titration end point could be effectively detected by using a yellow cellophane paper as a color filter. The average hue value (Havg) of 192 pixels in the image of the sample solution being titrated was computed and followed up at regular time intervals during titration in order to detect the titration end point. The Havg decrease of 2 degrees from the average of first 10 Havgs was regarded as reaching the end point. The volume of 0.01N $KMnO_4$ consumed by a tap water sample was $0.728{\pm}0.022ml$ in manual titration and $0.735{\pm}0.013ml$ in automatic titration (p=0.580). The volume of 0.01N $KMnO_4$ consumed by a distilled water sample was $0.383{\pm}0.015ml$ in manual titration and $0.367{\pm}0.015ml$ in automatic titration (p=0.252). The high p-values for t-test suggested that there were good agreements between manual and automatic titration data and the automatic method proposed in this article was considered to effectively replace the manual titration.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.5
• /
• pp.725-732
• /
• 2020

The sudden drop of water temperature in winter is very threatening factor that affects the productivity of farmed fish and the management in aquafarm. In this study, we investigated the effect of low temperature on the survival, oxygen consumption and stress responses of parrotfish Oplegnathus fasciatus due to acute drop of water temperature. The survival rate of parrotfish Oplegnathus fasciatus was 5% at 6℃, 95% at 8℃ and 100% at 10℃ on the 4^th day of exposure in each experimental temperature. Low-lethal temperature for 4days of parrotfish Oplegnathus fasciatus (4 day-LT₅₀) was 6.99℃ (confidence limit, 6.55-7.42℃). Oxygen consumption rate was significantly decreased with decreasing water temperature. Temperature coefficient (Q₁₀) was found to be 4.0 between 10℃ and 8℃ and 0.39 between 8℃ and 6℃. As a result of investigating the stress response according to the drop in water temperature, the concentration of SOD (Superoxide dismutase), cortisol, glucose, total Ig, AST (Aspartate) and ALT (Alanine aminotransferase) increased with decreasing of water temperature. This study would be useful for the management of temperature about cultured fish.

• Journal of Biosystems Engineering
• /
• v.34 no.5
• /
• pp.358-362
• /
• 2009

This study was conducted to evaluate the performance of a 12 tons capacity circulating concurrent flow rice dryer. An actual scale dryer with the capacity of 12 tons was developed to obtain a faster drying rate of 0.8~1.2%(w.b.)/h, while maintaining a lower drying energy consumption of 5,000 kJ/kg-water and achieving a drying quality that was comparable to a conventional cross-flow rice dryer. The Test-1 was conducted at $110^{\circ}C\;-\;20\;cmm/m^2$ and the Test-2 was conducted at $120-110-100-90^{\circ}C\;-\;20\;cmm/m^2$ under the same conditions as Test-1. In Test-1, the drying rate, drying energy consumption and crack ratio were 0.98 %(w.b.)/h, 4,573 kJ/kg-water and 3.2%, respectively. In Test-2, the drying rate, drying energy consumption and crack ratio were 0.74 %(w.b.)/h, 4,790 kJ/kg-water and 4.0%, respectively. The results of these tests demonstrated that this concurrent-flow dryer reached the desired drying rate, drying energy consumption and crack ratio.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.23 no.2
• /
• pp.207-213
• /
• 2011

The diapause of $Telegryllus$ $emma$, the Emma field cricket, was investigated to study the ecological characteristics of the species. Changes in the volume, oxygen consumption, and water content of T. emma eggs were followed from oviposition. An increase in volume, oxygen consumption and water uptake occurred from 7 to 8 days following oviposition. The oxygen consumption of the eggs increased slowly for 7 days following oviposition, but then decreased until 15 days following oviposition. These results showed that a physiological change at diapause initiation affected the volume, water content, and oxygen consumption of the $T.$ $emma$ eggs. An experimental investigation of egg hatching showed that the eggs could be stocked at $10^{\circ}C$ for 40 days with a 14 day pre-period after laying and yield, 62.1% hatchability under these conditions. Maintaining the temperature at approximately $10^{\circ}C$ was favorable for hatching. Another experiment on egg hatching showed that the storage of eggs at $10^{\circ}C$ from 40 to 180 days would ensure satisfactory, hatching capacity.