• Applied Biological Chemistry
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• v.7
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• pp.67-77
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• 1966

For the production of proteolytic enzyme wilth Aspergillus, the examination is made on the culture-time and koji extracting conditions, during producing koji. 1. The highest activity showed up when the culture-time took 50 hours for Aspergillus sojae and 60 hours for Aspergillus flavus. 2. When the cultured koji was extracted by a buffer solution and water, the former gave the product of higher activity until pH 7 through pH 12, and water until pH 3 through pH 7. 3. In the method of crushing and granule extractions, crushing extraction produced the one of higher activity than granule. 4. The highest activity showed up when Aspergillus sojae took 5 hours (Aspergillus flavus 4 hours) in the time of extracting enzyme solution. 5. The highest activity showed up when both Aspergillu sojae and Aspergillus flavus reacted and indicated $37.60^{\circ}C$ in the reaction temperature and activity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.373-374
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• 2005

NaOCl (Sodium hydrochlorite) have similar smell of chloride and solution of straw color. And boiling point is $110^{\circ}C$, specific gravity is 1.0(50g/l)/1.1(100g/l), Value of pH is 12. NaOCl playa role as bleach, a oxidizer, a germicide, a decolorant, a deodorant, treatment of water supply and drainage, food addition agent because strong oxidation, bleaching, sterilization effect is had. When NaOCl is produced in electrolysis of seawater, this system is composed of injection system by directly electrolysis of salt water on the spot and sodium hydrochlorite generate a safe low concentration(0.4~0.8 %).

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.919-926
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• 2006

In this study, environmental impact assessments of wastewater treatment plant (WWTP), sewerage system, and tailrace were performed using LCA methodology. The life cycle stages were divided into 3 categories; construction stage, maintenance stage and demolition & disposal stage. As a tool of impact assessment, Ecoindicator99 containing fate analysis, exposure & effect analysis and damage analysis, was used. As tile results of WWTP LCA, more than 80% of environmental impact was produced from maintenance stage. On the other hand, most of environmental impact was produced from construction stage in the case of tailrace and sewerage system construction.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.5
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• pp.1-8
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• 2022

Hydrogen can be produced by gasification of biomass and other combustible fuels. Depending on oxydant agents, syngas or producer gas compositions become quite different. Since biomass has limited amount of hydrogen including moisture in it, the hydrogen concentration in the syngas is about 15% when air is supplied for oxidant agent. Experiments were conducted to investigate the channges in hydrogen concentrations in syngas with different oxidant agent conditions, fuel conditions, and external heat supply. Allothermal reaction resulted in higher concentrations of hydrogen with the supply of steam over air, reaching over 60%. Hydrogen is produced by water-gas and water-gas shift reactions. These reactions are endothermic and require enough heat. Autothermal reaction occurred in the downdraft gasifier used in the experiment did not provide enough heat in the reactions for hydrogen production. Steam seems a more desirable oxidant agent in producing the syngas with higher concentrations of hydrogen from biomass gasifications since nitrogen is included in syngas when air is used.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.13-14
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• 2012

This study investigates the effect of adhesive type applying to surface-strengthening Ondol floor on level of attachment. Adhesive materials of four types produced in different companies were prepared and their attaching performance was examined. Test results showed that the water-based epoxy type produced in S company was the most effective on attaching the pieces of the surface-strengthening Ondol floor product.

• International Journal of Concrete Structures and Materials
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• v.7 no.4
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• pp.287-293
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• 2013

Strength and some durability properties of concrete containing rice husk ash (RHA) predominantly composed of amorphous silica at a specific surface of 235 $m^2/kg$ produced using a charcoal incinerator were determined. The maximum ordinary Portland cement (OPC) replacement with the RHA increased with increase in water/binder (w/b) ratio of the concrete mixes. The results show that 15 % OPC could be substituted by the RHAwithout strength loss at w/b ratio of 0.50. The split tensile strength generally increased with increase in RHA content for the mixes.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.357-360
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• 2007

Water retaining pavement is a pavement to lower the surface temperature by using evaporation of the water that the pavement contains when the pavement is heated by the sun in the daytime. The objective of this study is to develop water retaining materials. In this study we evaluated the practical application of a sepiolite and a charcoal as a water retaining material. We produced dense grade asphalt pavement, porous asphalt pavement, semi-rigid Pavement, semi-rigid pavement included a charcoal and semi-rigid pavement included a sepiolite, and then tested surface temperature characteristics. The test result says that water retaining pavements using a sepiolite and a charcoal lower surface temperature more than $10^{\circ}C$ compared to dense grade asphalt pavement. We confirm the practical application of a sepiolite and a charcoal as a water retaining material according to the test results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.4
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• pp.269-277
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• 2002

Dynamic characteristics of water hammer arresters installed in a building water supply system have been investigated numerically by utilizing a commercial rode that employs the method of characteristics. Some preliminary results with those arresters produced in this study agree well with the previously reported. Then, the arresters have been incorporated into a water supply pipe system of a $59m^2$ apartment unit constructed by a leading construction company, and their dynamic characteristics, especially on the reduction in the water hammer pressure, are investigated. It is found that the setting of the arresters in the pipe system, which is recommended by the company, may not be proper for reducing the pressure to less than 1082.0 kPa when buick-closure valves in the pipe system are closed within 30 ms at the static pressure of 542.6 kPa. More arresters in the system may be required to meet a pressure criteria.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.467-473
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• 2001

The internal humoral factors in the central regulation of dry feed intake during water deprivation in sheep were investigated by measurement of cerebrospinal fluid (CSF) constituents. Five animals were fed dried alfalfa chaff for 2 hours once a day. Sheep in the water deprivation treatment were deprived of water for 28 hours, while the sheep in the control treatment were given free access to water. During the first hour of the 2 hour feeding period, a rapid reduction in blood volume occured in both treatments (water deprivation and free access to water). The CSF concentrations of Na, Cl and osmolality during the second hour of the 2 hour feeding period in both treatments were greater (p<0.01) than those during the first hour. The drinking behaviors in sheep were concentrated during the second hour of the 2 hour feeding period in periods of free access to water. Water intake during feeding in periods of free access to water was 1110 ml/2 h. The levels of increase in CSF osmolality with feeding during water deprivation were greater (p<0.01) than during periods of free access to water. The changes in CSF osmolality with feeding during water deprivation produced more vigorous thirst sensations in the brain compared to during periods of free access to water. The eating rates for the first hour of the allotted 2 hour feeding period were the same under both treatments. However, the eating rates for the second hour during water deprivation periods decreased significantly (p<0.05) compared to those during periods of free access to water. The decreased eating rates for the second hour during water deprivation may be due to the vigorous thirst sensations produced in the brain. The results suggest that the increase in CSF osmolality with feeding during water deprivation acts as a thirst and satiety factor in brain mechanisms controlling feeding to decrease dry feed intake in water-deprived sheep.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.4
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• pp.473-479
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• 2005

Applying enhanced coagulation is not uncommon not only to improve water quality but also to obtain economical advantages in water treatment. In this study, the economical evaluation was investigated with considering dosage of coagulant, produced sludges and usage of activated carbon with two different water sources. To simulate the granular activated carbon(GAC) adsorber mini-column test was adapted. Even if there were some variation according to the source waters, the life time of GAC was extended 60 to 110days with adding 2.5 to 3 times of coagulant in enhanced coagulation. With assumption of changing GAC adsorber at 50% of breakthrough the total treatment cost can be reduced to range from 25% to 44% with adapting the enhanced coagulation. The obtained value can not be generalized because the value can be varied by water quality and cost of the GAC or coagulant. However, the evaluation can be basis starting point to find optimum operation methods for the drinking water treatment which has plan to adapt GAC adsorber.