• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.128-137
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• 2004

For the purpose of making a functional drinkable yoghurt, new types of drinkable yoghurts were prepared from skim milk added with 0.25％ chlorella extract powder and 2.5-10.0％ chlorella extract liquid. Quality characteristics of the drinkable yoghurts were evaluated in terms of quality-keeping property(pH, titratable acidity, number of viable cells) and sensory properties. When the drinkable yoghurts containing chlorella extract(0.25％ chlorella powder and 2.5-10.0％ chlorella extract liquid) were kept at 4$^{\circ}C$ and 20$^{\circ}C$ for 15days, the pH(pH 4.13-4.27), titratable acidity(0.66-0.75％) and number of viable cell counts of the lactic acid(8.42-8.89 log CFU/$m\ell$) were not significantly changed for all drinkable yoghurts during the storage at 4$^{\circ}C$ for 15days, but the pH(pH 3.53-3.56) and titratable acidity(1.30-1.37％) and number of viable cell counts(9.15-9.45 log CFU/$m\ell$) were markedly changed for the storage at 20$^{\circ}C$ for 15days. Therefor the keeping quality of the drinkable yoghurts with addition of chlorella extract was relatively good at 4$^{\circ}C$ for 15days. The results of sensory evaluation of the drinkable yoghurts containing chlorella extract indicated that color, chlorella taste, aftertaste and overall acceptability of the drinkable yoghurt with no addition of chlorella extract showed higher preference than others. And also sensory scores of the yoghurt added with 20％ oligosaccharide were significantly higher than other groups in aftertaste and overall acceptability.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.256-261
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• 2000

Effect of gamma irradiation on quality properties of half·cooked noodle was studied. The noodle were treated with lactic acid(0.1%, w/w), heat(10 min in boiling water) or their combination after cooking for 3 min, and irradiated at 0, 5 and 10 kGy. The noodle were stored at 25。C for 5 weeks and microbial population, Aw, pH, and texture profiles were examined. Fungi were completely eliminated by gamma-irradiation with 5 or 10 kGy does. Number of aerobic bacteria were also decreased by 2 and 4 log cycles with dose of 5 and 10 kGy, respectively. The D10 values of aerobic bacteria were 2.34∼2.95 kGy. Growth of the aerobic bacteria that survived even at 10 kGy of irradiation were significantly inhibited during storage. Acidification of half-cooked noodle was suppressed by gamma irradiation but A${_w}$ were not affected. Stickiness was decreased at the beginning of storage by gamma irradiation but was restored after 3 weeks. The results indicated that the gamma irradiation would be useful to improve quality and storage stability of half-cooked noodle.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.31-39
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• 2007

The objective of this study was to investigate the inactivation characteristics of Cryptosporidium oocysts by ozone and UV and to suggest the better, disinfection method. The inactivation CT value of 1 log(90%) and 2 log(99%) in of one disinfection, which is an index of disinfection for inactivation effect by ozone, were respectively 5.77 $mg{\cdot}min/L$ and 21.30 $mg{\cdot}min/L$. The inactivation in UV disinfection was not affected by pHs(5, 7 and 9), low turbidity(5 and below NTU) and UV intensity(0.2 and 0.6 $mWs/cm^2$) but obviously decreased at high turbidity over 20 NTU. Therefore UV disinfection capacity can be obtained when a good turbidity removal in drinking water treatment process is achieved. And if oocysts is exposed by high UV over 0.6 mWs/cm2 during enough time, the better inactivation effect will be obtained.

• Clean Technology
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• v.2 no.1
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• pp.69-79
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• 1996

Sulfur emission control in coal gasification plants implies the removal of $H_2S$ from the fuel gas in the gas clean-up system. In this study, the effects of particle size of sorbents, temperature of sulfidation and sorbent characteristics on the $H_2S$ removal efficiency of manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about $700^{\circ}C$. And that the smaller particle size, the higher the $H_2S$ removal efficiency, but that was not effective very much. As the temperature increases, the reactivity of sorbents has lowered because agglomeration of sorbents increased the intraparticle transport resistance. This phenomenon was confirmed by SEM photographs. The equilibrium ratio ($P_{H_2O}/P_{H_2S}$) obtained by experiments is represented as a ${\log}(P_{H_2O}/P_{H_2S})=5653/T-3.7909$. It was showed that the natural manganese ore could be used as a sorbent because its capacity for $H_2S$ removal is equivalent to the eariler developed sorbents.

• KSBB Journal
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• v.19 no.4
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• pp.315-320
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• 2004

We examined the culture conditions and degrading characteristics of styrene dimer (endocrine disrupter) using microorganism. The isolated microbe were consisted of 3 kinds of strain. The strains were identified to Pseudomonas sp. and Klebsiella pneumoniae by API 20E kit, but one was not identified. Single strain was not grown on the C-medium containing styrene dimer. However the complex strain YH3 could grow and we confirmed it by the broth color and O.D$_{660nm}$ (optical density 660 nm). The optimal culture conditions of complex strain YH3 were 35$^{\circ}C$, 1,000 ppm (v/v) of styrene dimer and pH 7.0, respectively. In tolerance test against the organic solvents, the complex strain YH3 could grow above log P=3.1, and could degrade ethyl benzene and 2,4-D, one kind of herbicide. As a result of TLC (Thin Layer Chromatography) analysis, we confirmed that the metabolite of styrene dimer was created by YH3 after 5th day, but not at control samples.

• Food Science and Preservation
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• v.19 no.5
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• pp.659-664
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• 2012

The fermentation and quality characteristics of Cheonggukjang with Chinese cabbage, which is produced as a by-product in the kimchi industry, were investigated. Cheonggukjang was prepared with cooked soybean without Chinese cabbage (control), with 10% Chinese cabbage (A10), and with 20% Chinese cabbage (A20), respectively. The A10 and A20 pH values did not show a significant difference compared with the control during fermentation for 72 h. The total aerobes of the Cheonggukjangs reached 8.65 (control), 8.73 (A10), and 9.11 (A20) log CFU/mL after fermentation for 72 h at $37^{\circ}C$, respectively. The numbers of lactic acid bacteria were found to be 5.62 (A10) and 5.87 (A20) log CFU/mL during fermentation for 72 h at $37^{\circ}C$, but lactic acid bacteria were not detected in the control. The amino nitrogen and viscous substance contents of A10 and A20 were lower than those of the control. The total polyphenol contents and DPPH radical scavenging abilities of the tested Cheonggukjang were increased by fermentation. The increasing ratio of polyphenol and the DPPH radical scavenging ability of A10 were higher than those of the control and of A20. The sensory quality of A10 was higher than that of the control and of A20 in taste, color, and overall acceptability.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.792-798
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• 2002

Investigations on the microbiological, physicochemical, and sensory characteristics of seasoned Galbi using various packaging methods during storage at $-1^{\circ}C$ revealed no significant differences in pH values and acidities of seasoned Galbi depending on packaging methods and storage periods. Increments of thiobarbituric acid values of seasoned Galbi with non-evacuated packaging and modified atmosphere packaging were superior to those of vacuum packaging and double-film vacuum packaging during storage. Seasoned Galbi with non-evacuated packaging showed the highest volatile basic nitrogen value, and total plate count significantly increased compared to other packaging methods after 15 days storage. Coliform bacteria showed an average count of 2.35 log CFU/g at the beginning of storage, which increased slightly from 7 to 15 days, and was maintained under 4.0 log CFU/g after 15 days storage. The sensory evaluation revealed that non-evacuated packaging scored relatively lower than other methods in color, flavor, off-odor, and overall acceptability after storage.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.160-171
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• 1995

The size characteristics of lead particle which is one of the important factors associated with absorption of lead were ignored in establishing lead standard. This study was conducted to investigate distribution of lead particles by operation of industry. Aerodynamic Mass Median Diameters (MMD) of airborne lead particles in the battery and litharge manufacturing industry were $14.1{\mu}m$ and $15.1{\mu}m$, respectively. There was no significant difference between those two values(p>0.05). However, the diameters in radiator manufacturing and secondary smelting industry were $1.3{\mu}m$, $4.9{\mu}m$, respectively. Those were significantly smaller than the particle sizes in other industries(p<0.05). Total lead concentrations in the secondary smelting industry were higher than those in the battery and litharge manufacturing industry. Total lead concentrations in other industries except radiator manufacturing industry exceeded the standard of $50{\mu}g/m^3$. Only radiator manufacturing industry indicated lead concentrations significantly lower than those in other industries(p<0.05). Concentrations of lead particles smaller than $1{\mu}m$ defined as respirable fraction by OSHA's CPA model assumption were $72.4{\mu}g/m^3$ in the secondary smelting industry, exceeding $50{\mu}g/m^3$. The relationship of concentrations between total lead and lead of particles smaller than $1{\mu}m$ was log Y = 0.46 logX + 0.06(n=119, $r^2=0.44$, p=0.0001). Relationship of respirable lead concentrations between OSHA and ACGIH was significantly detected in the litharge and battery manufacturing industry(p=0.0001), but was not significant in the radiator(p=0.2720) and secondary smelting manufacturing industry(p=0.2394). As MMDs of lead particles generated in industry were small, difference of respirable lead concentration between OSHA and ACGIH became smaller. There was a significant difference between concentrations respirable lead defined by two organizations such as OSHA and ACGIH in the battery and litharge manufacturing industry. Average concentration of respirable lead by ACGIH definition was 43.3 % of total lead in secondary smelting and 48.9 % in radiator manufacturing industry, and lower fractions were indicated in battery and litharge manufacturing industry. Relationships of total lead with IPM, TPM, and RPM were significant respectively(p=0.0001) and lead concentrations by particle size could be estimated using this relationship. Linear regression equation between total lead concentration(X) and ACGIH-RPM concentration(Y) was log Y = 0.76 log X - 0.40($r^2=0.89$, p=0.0001).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.401-407
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• 2016

We can consider the following problems for two given points p and q in a simple polygon P. (1) Compute the set of points of P which are visible from both p and q. (2) Compute the set of points of P which are visible from either p or q. They are corresponding to the problems which are to compute the intersection and the union of two visibility polygons. In this paper, we consider algorithms for solving these problems on a reconfigurable mesh(in short, RMESH). The algorithm in [1] can compute the intersection of two general polygons in constant time on an RMESH with size O($n^3$), where n is the total number of vertices of two polygons. In this paper, we construct the planar subdivision graph in constant time on an RMESH with size O($n^2$) using the properties of the visibility polygon for preprocessing. Then we present O($log^2n$) time algorithms for computing the union as well as the intersection of two visibility polygons, which improve the processor-time product from O($n^3$) to O($n^2log^2n$).

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.299-304
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• 2019

Yogurt was prepared with different substitution ratio [10, 20, 30, and 50% (w/w)] of skim milk with enzymatically saccharified Korean rice wine lees powder (eKRWLP) and fermented with commercially available mixed lactic acid bacteria (Bifidobacterium longum, Lactobacillus acidophilus, Streptococcus thermophilus) at $40^{\circ}C$ for 18 h. Fermentation characteristics were evaluated in terms of acid production (pH and titratable acidity) and viable cell counts of lactic acid bacteria. The pH of yogurts decreased with increasing eKRWLP substitution ratio of skim milk. After 12 h fermentation, titratable acidities of eKRWLP substitution and control (yogurt made without eKRWLP) were 0.84~1.04% and 0.93%, respectively. The titratable acidities of yogurts prepared with 10 and 20% substitution ratio increased than that of the control yogurt, but titratable acidities of yogurts of 30 and 50% substitution ratio decreased. After 9 h fermentation, the number of viable lactic acid bacterial cell were increased to 8.18~8.24 log CFU/g in all yogurts. In sensory evaluation, there were similar preference for eKRWLP yogurts prepared with 10 and 20% substitution ratio and the control. When eKRWLP substitution and control yogurts fermented for 9 h were incubated at $4^{\circ}C$, their pHs and titratable acidities were slightly changed but the number of viable lactic acid bacteria were well maintained above $10^7CFU/g$ for 11 days in yogurts prepared with 10 and 20% substitution ratio among eKRWLP substitution yogurts. These results suggest that eKRWLP can be used as substituent of skim milk and the optimum substitution ratio is around 10~20%.