• Korean journal of food and cookery science
• /
• v.20 no.1
• /
• pp.86-94
• /
• 2004

The purpose of this study was to investigate the changes of hardness and microstructure of Dongchimi cooked with various source of water(distilled water, purified water, Cho Jung Carbonated Natural water). This study was conducted to observe the changes of pH, total acidity, salt content, turbidity, texture and microstructure. Dongchimi cooked with source of water of water was fermented at 10$^{\circ}C$ for 46 days. The changes of pH on Dongchimi cooked with various source of water decreased in all samples during fermentation period, and then showed a slowly decrease after 12 days of fermentation. The total acidity of Dongchimi cooked with Cho Jung Carbonated Natural water was arrived slowly at best tasting condition 0.3 ∼ 0.4 point compared with other conditions. So Dongchimi cooked with Cho Jung Carbonated Natural water was continued to the best tasting condition for end of fermentation. At early stage of fermentation, the changes of turbidity of Dongchimi used Cho Jung Carbonated Natural water showed highly as compared with other test condition for 12th days of fermentation. The maximum cutting force of chinese radish of Dongchimi showed the highest value among all at the 25th day of ripening and then decreased gradually. The maximum cutting force of chinese radish of Dongchimi used Cho Jung Carbonated Natural water was the highest compared with other conditions at 25th day of fermentation. The calcium content of Dongchimi juice used Cho Jung Carbonated Natural water was observed hish at the early stage of fermentation and showed the highest value at 25th day of ripening. The calcium content of chinese radish and Dongchimi juice of Dongchimi cooked with water purifier was lower than that of Dongchimi cooked with Cho Jung Carbonated Natural water, and was higher than that of Dongchimi cooked with Distilled water at the early stage of fermentation. The magnesium content in all samples increased gradually from the early stage of fermentation. The microstructure showed disintegration appearance of middle lamella and cell wall during fermentation period.

• KSBB Journal
• /
• v.7 no.2
• /
• pp.149-153
• /
• 1992

Pseudomanas fluorescens was selected from mushroom and studied in both batch and continuous culture in order to find out optimum conditions for cultivation. P. fluorescens is an aerobic bacterium and antagonistic to Pseudomonas tolaasii which causes blotch disease on the mushroom cap. Cells of P. fluorescens were grown well on medium containing 30g/L of glucose, whereas the growth was inhibited with the glucose concentration at higher than 30g/L. The highest value of specific growth rate and productivity were obtained when using 10g/L of yeast extract. Optimum concentrations of $NH_4Cl$ and $(NH_4)_2SO_4$ for culture were found to be 1.0g/L and 0.1g/L respectively. Optimum concentration of $MgSO_4{\cdot}7H_2O$ used as a sulfur source was 1.0g/L. It was also found that the cell concentrations were at the maximum level when grown on the medium containing 1.0g/L of $KH_2PO_4$ and 0.1g/L of $CaCl_2$. Also, the optimum culture conditions were $30^{\circ}C$ and pH 6.0. Cultivation of P.fluorescens at high initial dissolved oxygen (D.O) value led to a decrease of bacterial productivity in batch culture. Maximum productivity was achieved at 68 for the initial D.O value.

• Applied Chemistry for Engineering
• /
• v.29 no.3
• /
• pp.258-263
• /
• 2018

This study attempted to utilize ultrafine precipitated calcium carbonate for fluoride removal from the wastewater of electronics industries. An average particle size of the calcium carbonate was $0.96{\mu}m$, and pH of the aqueous slurry was 10 with 70% in mass. The suspension solution showed approximately 2 mL/hr of the sedimentation rate. The present calcium carbonate solution could be comparable to the conventional aqueous calcium source, $Ca(OH)_2$, for the neutralization and removal of fluoride ions. Depending on the amount of an additional alkali source, less amounts of test Ca-source slurries were required to reach the solution pH of 7.0 than that of using the aqueous calcium hydroxide. It was also found from XRD analysis that more calcium fluoride precipitates were formed by the addition of calcium carbonate solution rather than that of calcium hydroxide. In addition, Minteq equilibrium modelling estimated various ion complexes of fluoride and calcium in this process.

• Korean Journal of Microbiology
• /
• v.40 no.2
• /
• pp.139-146
• /
• 2004

A bacterium producing alkaline cellulase was isolated from soil, leaf mold and compost, and was identified as alkalophilic Bacillus sp. HSH-810 by morphological, cultural and biochemical determination. The optimum cul-ture condition of Bacillus sp. HSH-810 for the growth and alkaline cellulase production was $30^{\circ}C$ and pH 10.0. The maximum alkaline cellulase production was obtained when 1.0%(w/v) CMC, 0.5%(w/v) peptone, 0.02%(w/v) $CaCl_2$ and 0.02(w/v) $CoCl_2$ were used as carbon source, nitrogen source and mineral source, respectively. The optimum pH and temperature of the enzyme activity were pH 10.5 and $50^{\circ}C$, respectively. This enzyme was fairly stable in the pH range of 6.0-13.0 and at $50^{\circ}C$. For the effect of surfactants, the activity of alkaline cellulase was stable in the presence of sodium-$\alpha$-olefin sulfonate (AOS), sodium dodecyl sulfonate (SDS), Tween 20 and Tween 80, but inhibited by the presence of 0.1 linear alkyl-benzene sulfonate (LAS) sig-nificantly.

• Asian Journal of Atmospheric Environment
• /
• v.9 no.2
• /
• pp.165-172
• /
• 2015

Under a very tough situation that there has been increasing concern to the air quality in underground subway spaces, this study set sights on the thorough estimation of the chemical properties and source apportionment of particulate matter (PM) collected on an underground subway platform by a cooperative approach of semi-bulk and single particle analyses. The size-resolved PMs were intensively collected on the platform of Miasageori station on the Seoul Subway Line-4, and then, they were semibulkily analyzed by a PIXE and the TOR$^{(R)}$ method, and individually analyzed by a SEM-EDX. Overwhelmingly enriched iron was a notable feature of elemental concentration of $PM_{2.5}$. Source classification of iron in $PM_{10-2.5}$ and $PM_{2.5}$ performed along with their elemental concentrations, indicates that the railway originated iron accounts for 95.71% and 66.39% of total iron in $PM_{10-2.5}$ and $PM_{2.5}$, respectively. Via a stoichiometric categorization, $Fe_2O_3$, $CaAl_2Si_2O_8$, $Al_2O_3$, and $CaCO_3$ show more than 85% abundance ratio in individual coarse particles. The result of theoretical estimation of the subway derived organic carbon ($OC_{Subway}$) suggests that $OC_{Subway}$ in $PM_1$ and $PM_{2.5-1}$ account for 75.86% and 51.88% of total organic carbon, respectively.

• Korean Journal of Environmental Agriculture
• /
• v.18 no.3
• /
• pp.287-291
• /
• 1999

In order to examine the possible use of rock phosphate as P source, tomato seedlings with or without inoculation of arbuscular mycorrhizal fungi were grown in the pots of sterile volcanic ash soil from Cheju island with two levels of phosphorus (100 and 200 mg/kg) supplied either as fused or as rock phosphate. After three months of culture, plant dry weight, P and other nutrient uptake, root colonization and spore density in the soil were determined. Treatments of rock phosphate of both levels resulted in the significantly depressed plant growth in comparison to the treatments of fused phosphate, likely due to lower P availability in soil with rock phosphate. Mycorrhizal fungi inoculation increased the dry weight of plant at 200 mg/kg level of both fused and rock phosphate. Root infection and sporoulation were reduced in rock phosphate treatments. Nitrogen, K, Ca and Mg contents in plants were not significantly different at all treatments. As a P source, rock phosphate in combination with mycorrhizae was not satisfactory for optimum plant growth at $100{\sim}200\;mg/kg$ levels in Cheju volcanic ash soil.

• The KIPS Transactions:PartC
• /
• v.16C no.1
• /
• pp.21-26
• /
• 2009

Presently, the demand for IPTV, to satisfy a variety of goals, is exploding. IPTV is coming into the spotlight as a killer application in upcoming IP convergence networks such as triple play which is the delivery of voice, internet, and video service to a subscriber. IPTV utilizes CAS, which controls the subscriber access to content for a profit. Although the current CAS scheme provides access control via subscriber authentication, there is no authentication scheme for the content transmitted from service providers. Thus, there is a vulnerability of security, through which an adversary can forge content between the service provider and subscribers and distribute malicious content to subscribers. In this paper, based on a hash tree scheme, we proposed efficient and strong source authentication protocols which remove the vulnerability of the current IPTV system. We also evaluate our protocol from a view of IPTV requirements.

• Korean Journal of Microbiology
• /
• v.32 no.4
• /
• pp.291-296
• /
• 1994

A bacterial strain NO. AM-28, showing proteolytic activity against defatted soybean was isolated from domestic soil. The isolated strain was identified as Aeromonas hydrophila by both the biochemical tests using API kit and the analysis of cellular fatty acid profile with MIDI system. The protease production from A. hydrophila AM-28 was highly enhanced when it was cultivated in the medium containing glycerol as a carbon source, tryptone or $(NH_4)_2HPO_4$ as a nitrogen source, and $CaCl_2$ as a mineral source. The optimal pH and temperature for the enzyme was 8.0 and $65^{\circ}C$, respectively. The enzyme was stable up to $55^{\circ}C$ and at pH values ranging from 7.0 to 13.0. The enzyme activity was inhibited by phenylmethylsulfonyl fluoride and EDTA, indicating that serine residue and metal ions be involved in enzyme activity.

• Applied Biological Chemistry
• /
• v.26 no.2
• /
• pp.110-118
• /
• 1983

A slimy non-spore-forming bacterium strain SAF-C isolated from bean stem and root was motile with flagella and identified to one of Agrobacterium radiobacter. Studies were made on the conditions necessary for maximal production of this acidic succinoglucan polysaccharide by this strain in shaken culture. Much production was observed with yeast extract,$(NH_4)_2\;HPO_4$, distillers' dried solubles(D.D.S.), as nitrogen source in the medium composed of 4% glucose, 0.5% nitrogen source, 0.3% $CaCO_3$. The yield was greatest with yeast extract and decreased in order with the above nitrogen source from 22.9% to 9.6 percent. A polysaccharide was produced in a yield of about 25% in a medium composed of 3% glucose, 0.4% D.D.S., 0.5% $K_2\;HPO_4$, 0.01% $MgSO_4{\cdot}7H_2O$.

• Journal of Korean Society on Water Environment
• /
• v.37 no.6
• /
• pp.520-530
• /
• 2021

Multivariate statistical analysis and an environmental hydrological model were applied for investigating the causes of water pollution and providing best management practices for water quality improvement in urban and agricultural watersheds. Principal component analysis (PCA) and cluster analysis (CA) for water quality time series data show that chemical oxygen demand (COD), total organic carbon (TOC), suspended solids (SS) and total phosphorus (T-P) are classified as non-point source pollutants that are highly correlated with river discharge. Total nitrogen (T-N), which has no correlation with river discharge and inverse relationship with water temperature, behaves like a point source with slow and consistent release. Biochemical oxygen demand (BOD) shows intermediate characteristics between point and non-point source pollutants. The results of the PCA and CA for the spatial water quality data indicate that the cluster 1 of the watersheds was characterized as upstream watersheds with good water quality and high proportion of forest. The cluster 3 shows however indicates the most polluted watersheds with substantial discharge of BOD and nutrients from urban sewage, agricultural and industrial activities. The cluster 2 shows intermediate characteristics between the clusters 1 and 3. The results of hydrological simulation program-Fortran (HSPF) model simulation indicated that the seasonal patterns of BOD, T-N and T-P are affected substantially by agricultural and livestock farming activities, untreated wastewater, and environmental flow. The spatial analysis on the model results indicates that the highly-populated watersheds are the prior contributors to the water quality degradation of the river.