• Journal of Korean Society of Environmental Engineers
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• v.39 no.4
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• pp.208-213
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• 2017

In this study, four inorganic pollutants (cadmium, chromium, manganese, lead), that could cause contamination events in drinking water distribution system, were selected and batch tests were carried out to determine the "minimum response concentration (MRC)", a part of Korean Contamination Warning system establishment. As the results, the minimum response concentration of cadmium was found to be 0.05 to 0.08 mg/L (0.005 mg/L : water quality standard) and that of chrome was 0.03 mg/L (0.05 mg/L). And the minimum reaction concentration was 0.005 mg/L for manganese (0.05 mg / L for water quality) and 0.02~0.08 mg/L for lead (0.01 mg/L).

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.538-546
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• 2024

Cinnamaldehyde is a natural compound extracted from cinnamon bark essential oil, acclaimed for its versatile properties in both pharmaceutical and agricultural fields, including antimicrobial, antioxidant, and anticancer activities. Although potential of cinnamaldehyde against plant pathogenic bacteria like Agrobacterium tumefaciens and Pseudomonas syringae pv. actinidiae causative agents of crown gall and bacterial canker diseases, respectively has been documented, in-depth studies into cinnamaldehyde's broader influence on plant pathogenic bacteria are relatively unexplored. Particularly, Pectobacterium spp., gram-negative soil-borne pathogens, notoriously cause soft rot damage across a spectrum of plant families, emphasizing the urgency for effective treatments. Our investigation established that the Minimum Inhibitory Concentrations (MICs) of cinnamaldehyde against strains P. odoriferum JK2, P. carotovorum BP201601, and P. versatile MYP201603 were 250 ㎍/ml, 125 ㎍/ml, and 125 ㎍/ml, respectively. Concurrently, their Minimum Bactericidal Concentrations (MBCs) were found to be 500 ㎍/ml, 250 ㎍/ml, and 500 ㎍/ml, respectively. Using RNA-sequencing analysis, we identified 1,907 differentially expressed genes in P. carotovorum BP201601 treated with 500 ㎍/ml cinnamaldehyde. Notably, our results indicate that cinnamaldehyde upregulated nitrate reductase pathways while downregulating the citrate cycle, suggesting a potential disruption in the aerobic respiration system of P. carotovorum during cinnamaldehyde exposure. This study serves as a pioneering exploration of the transcriptional response of P. carotovorum to cinnamaldehyde, providing insights into the bactericidal mechanisms employed by cinnamaldehyde against this bacterium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.539-547
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• 1997

This study was carried out to identify how soybean seed protein concentration is influenced by climatic factors. Twelve lines selected for seed protein concentration were studied in 13 environments of North Carolina. Sensitivity of seed protein concentration, total seed protein, and seed yield to climatic variables was investigated using a linear regression model. Best response models were determined using two stepwise selection methods, Maximum R-square and Stepwise Selection. There were wide climatic effects in seed protein concentration, total protein and seed yield. The highest protein concentration environment was characterized by the most high temperature days(HTD) and the smallest variance of average daily temperature range (VADTRg), while the lowest protein concentration environment was distinguished by the fewest HTD and the largest VADTRg. For protein concentration, all lines responded positively to average maximum daily temperature(MxDT), HTD, and average daily temperature range(ADTRg) and negatively to ADRa, while they responded positively or negatively to average daily temperature(ADT), variance of average minimum daily temperature (VMnDT), and VADTRg, indicating that genotypes may greatly differ in degrees of sensitivity to each climatic variable. Eleven lines seemed to have best response models with 2 or 3 variables. Exceptionally, NC106 did not show a significant sensitivity to any climatic variable and thus did not have a best response model. This indicates that it may be considered phenotypically more stable. For total seed protein and seed yield, all the lines responded negatively to both ADTRg and VADRa, suggesting that synthesis of seed components may increase with less daily temperature range and less variation in daily rainfall.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.793-801
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• 2011

We examined the quality characteristics of obtaining the optimal curing conditions for black garlic extract (BGE) added mackerel by using response surface methodology (RSM). The condition of RSM was included in 13 experimental points using two dependent variables: concentration of BGE (2.6~12.5 brix, X1) and curing time of BGE (17.58~102.42 min, X2). An assessment was conducted with four replicates on three independent variables: volatile basic amine (VBN, Y1), thiobarbituric acid (TBA, Y2), and shear force (Y3). The minimum content of VBN was 1.625 mg% at 3.17 brix, for 80.5 min. This was obtained when the BGE concentration was lower and the curing time was longer. The content of the TBA was 3.13~12.24 MA mg/kg at experiment range and the stationary point was at saddle point. Therefore, by using ridge analysis, the minimum point of TBA was 2.414 MA mg/kg at 3.5 brix for 84.4 min. The truth coefficient of the BGE concentration and curing time were 2.9 brix and 75.1 min, respectively, with a shear force ($120.764cm/kg^2$) shown at maximum point. The optimum Hunter color range was estimated from the lowest TBA value. The optimum range of the L color was 39.16~40.26, a and b color were 4.40~4.88 and 12.35~13.20, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.415-418
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• 1998

The maleate copolyrner($C_{18}MA-VE_2$) is used as sensitive materials and deposited on the slide-glass substrates at room temperature using Langmuir-Blodgett(LB) method. The results of current-time(1-t) measurements are performed to investigate the gas-detection characteristics of the sensitive LB films in the presence of organic gases just as chloroform, acetone, ethanol, methanol using the apparatus for the gas-detection measurement. Several interesting responses are observed at room temperature, such as reversible response, sensitivity and response time. Response time and sensitivities are evaluated 160~220[sec], minimum 6[times], maximum 70[times] for each organic gas by adsorption and penetration of the organic gases in the relation concentration of 100[%], respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.810-815
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• 1999

The pectinase treatment conditions for clarification of persimmon vinegar were optimized and monitored by response surface methodology. In clarification of persimmon vinegar by pectinase treatment with variations in temperature, time and concentration, coefficients of determinations(R2) of the models were above 0.91(p<0.05) in turbidity, browning color intensity and tannin content. The turbidity of persimmon vinegar was decreased along with an increase of pectinase treatment temperature. The minimum value of turbidity by pectinase treatment was 0.0021(absorbance at 660nm) in 49.38oC of pectinase treatment temperature, 73.08min of pectinase treatment time and 55.57ppm of pectinase concentration. The minimum value of browning color intensity by pectinase treatment was 0.27(absorbance at 660nm) in 48.39oC, 71.74min and 65.69ppm. The minimum value of total tannin contents by pectinase treatment was 43.72mg/100 ml in 40.05oC, 66.02min and 65.26ppm. The optimum conditions of pectinase treatment that satisfies the least common multiple of turbidity, browning color and tannin content were 40~50oC, 60~70min and 55~70ppm.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.11
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• pp.1564-1570
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• 1998

In-situ particle monitors(ISPMs) are widely used for monitoring contaminant particles in vacuum-based semiconductor manufacturing equipment. In the present research, the performance of a Particle Measuring Systems(PMS) Vaculaz-2 ISPM at subatmospheric pressures has been studied. We created uniform upstream conditions of particle concentration and measured the detection efficiency, the lower detection limit, and the size response of the ISPM using uniform sized methylene blue aerosol particles. The effect of particle size, particle velocity, particle concentration, and system pressure on the detection efficiency was examined. Results show that the detection efficiency of the ISPM decreases with decreasing chamber pressure, and with increasing mass flow rate. The lower detection limit of the ISPM, determined at 50 % of the measured maximum detection efficiency, was found to be about $0.15{\sim}0.2{\mu}m$, which is similar to the minimum detectable size of $0.17{\mu}$ given by the manufacturer.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.99-105
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• 2002

The concentration gradient effects on triple flame have been studied experimentally using a slot burner in order to stabilize stationary triple flame in coflowing stream. By means of contraction we generate the coflowing stream with uniform velocity and linear concentration gradient at the outlet of the slot. In this paper we investigated the response of the triple flame. to the concentration gradient, like the stability, the liftoff height, and the structure of triple flame. Flow velocity is measured with Laser Doppler Velocimetry. As the concentration gradient increases. the flame propagation velocity in immediately upstream triple point increases until the liftoff height of triple flame becomes minimum, and then decreases.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.2
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• pp.109-114
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• 1998

The induction of crassulacean acid metabolism(CAM) characterized by day/night acid fluctuation was investigated in leaves from 10 days exposure to elevated $CO_2$ concentration(1,000 ${\mu}L\;L^{-1}CO_2).$ For Pereskia aculeata, have $C_3-like$ gas exchange pattern in well watered condition and shift into CAM-like in water stress, showed a more typical CAM-like diurnal acid fluctuation. Whereas the massive diurnal fluctuation of acidity in typical CAM of Kalanchoe rosea was declined. The effect of short-term exposure to various concentrations of $CO_2$ on titratable acidity in P. aculeata and K. rosea was also investigated. To investigate the response of various $CO_2$ concentrations, four different $CO_2$ levels(350, 700, 1,000 and 1,500 ${\mu}L\;L^{-1})$ were imposed for 24hr and measured the titratable acidity at 06:00, when the acidity was maximum, and 14:00, when the acidity was minimum. The accumulation of acid in P. aculeata was enhanced markedly by higher concentration of $CO_2,$ while the level of acidity in f rosea did not highly respond to $CO_2.$ A notable difference between P. aculeata and K. rosea was the response of de-acidification to a higher concentration of $CO_2$ Increasing with $CO_2,$ the degree of do-acidification of P. auleata was increased while that of K. rosea was depressed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.304-308
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• 2005

The response of IPTG induction was investigated through the monitoring of the alkali consumption rate and buffer capacity during the cultivation of recombinant E. coli BL21 (DE3) harboring the plasmid pRSET-LacZ under the control of lac promoter. The rate of alkali consumption increased along with cell growth, but declined suddenly after approximately 0.2 h of IPTG induction. The buffer capacity also declined after 0.9 h of IPTG induction. The profile of buffer capacity seems to correlate with the level of acetate production. The IPTG response was monitored only when introduced into the mid-exponential phase of bacterial cell growth. The minimum concentration of IPTG for induction, which was found out to be 0.1 mM, can also be monitored on-line and in-situ. Therefore, the on-line monitoring of alkali consumption rate and buffer capacity can be an indicator of the metabolic shift initiated by IPTG supplement, as well as for the physiological state of cell growth.