• KSBB Journal
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• v.14 no.1
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• pp.45-50
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• 1999

This study was focused on investigating the growth properties of a sulfate reducing bacterium Deslfovibrio sp. B5 which has metabolic ability for desulfurization of petroleum. The optimal temperature and pH for growth of Desulfovibiro sp. B5 were $38^{\circ}C$ and 6.6-7.0, respectively. Addition of 10% corn steep liquor to the Postgate medium C resulted in 0.79 g/L cell concentration, corresponding to a 1.8-fold increase in dry cell mass. Acetate concentrations above 10g/$\ell$ inhibited cell growth significantly. $H_2S$ generated from the sulfate reduction also inhibited the growth of Desulfovibrio sp. B5 at a concentration of 10mM total sulfide. But $N_2$ gassing relieved the growth inhibition by $H_2$S and thereby resulted in a 1.75-fold enhancement in specific growth and lactate consumption pattern of Desulfovibrio sp. B5.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.119-125
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• 2007

In recent days, the consumption of stainless steel in the propulsion shafting systems for small-medium class vessel is increased due to its high corrosion protection with wear resistant properties. Unfortunately the small and medium class vessel that operated in the west-south sea area of Korean peninsula experienced heavy wear down due to the role of mud. In the event of wear or broken down, the propeller shaft must be replaced by new one, but the new shaft is very expensive and time-consuming for order made supply. In this case, the methods of built up for wear and broken shaft by welding is one of the most effective cases. In this study, the built up welding for austenitic stainless steel shaft has been accomplished by various pre-surface treatment, welding methods, post heattreatment and inspection. The results confirmed that the built-up welding was one of the effective methods for stainless steel shafting.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.318-326
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• 2016

Two phosphate solubilizing bacteria, Pantoea rodasii PSB-11and Enterobacter aerogenes PSB-12, were isolated from button mushroom compost and employed to assess their synergistic effect in liquid medium and on growth of green gram plants by single and co-inoculation of the strains. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($521{\mu}g\;ml^{-1}$) into the medium, followed by single inoculation of Pantoea strain ($485{\mu}g\;ml^{-1}$) and Enterobacter strain ($470{\mu}g\;ml^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production and glucose consumption was observed in the E. aerogenes PSB-12 single inoculated culture medium rather than those of co-inoculation. According to the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 10.6% and 10.7% higher shoot and root growth respectively compared to the control. Therefore, in concluding, co-inoculation of the strains P. rodasii and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, being short assessment period of the present study, we recommend in engaging further works under field conditions in order to test the suitability of the strains to be used as bio-inoculants.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.1
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• pp.27-31
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• 2000

Characteristics of ethanol production by a xylose-fermenting yeast, Pichia stipitis Y-7124, were studied. The sugar consumption rate and specific growth rate were higher in the glucose-containing medium than in the xylose-containing medium. Specific activities of xylose reductase and xylitol dehydrogenase were higher in the medium with xylose than glucose, suggesting their induction by xylose. Maximum specific growth rate and ethanol yield were achieved at 30 g xylose/L concentration without formation of by-products such as xylitol and acetic acid whereas a maximum ethanol concentration was obtained at 130 g/L xylose. Adding a respiratory inhibitor, rotenone, increased a maximum ethanol concentration by $10\%$ compared with the control experiment. In order to evaluate the pattern of ethanol inhibition on specific growth rate, a kinetic model based on Luong's equations was applied. The relationship between ethanol concentration and specific growth rate was hyperbolic for glucose and parabolic for xylose. A maximum ethanol concentration at which cells did not grow was 33.6 g/L for glucose and 44.7 g/L for xylose.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.880-886
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• 2010

In this paper, we studied the application of low pressure ultra-violet (UV) lamps for the development of an energy saving ship's ballast water treat (BWT) device. We proposed the optimal arrangement of UV lamps by analyzing the energy radiated from medium- and low-pressure UV lamps. Based on the experimental results, we manufactured a disinfection chamber which is composed of low-pressure UV lamps. The rated power and the treatment capacity of the chamber are 216 [W] and 10 [$m^3$/h], respectively. This can replace a disinfection chamber treated by two 2 [kW] medium pressure lamps. The disinfection performance, however the power consumption is about one-eighteen compare to the medium pressure UV lamp, is over 94 [%] for bacteria, 93 [%] for zooplankton, and 94 [%] for phytoplankton. Therefore, it would be possible to develop an energy saving BWT device in a low capacity below 100 [$m^3$/h].

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.955-963
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• 2009

In this paper, we propose a medium access control(MAC) protocol for reducing the energy efficiency and for improving the transmission efficiency in underwater acoustic sensor networks. In underwater environment, the transmission delay is longer and bandwidth is smaller than terrestrial environment. Considering these points, we propose a new MAC protocol to enhance throughput and to manage efficiently the energy of nodes. The proposed protocol operates as a channel reservation scheme to decrease data collisions, and uses a mechanism to control the hidden node problem and the exposed node problem occurred in ad hoc networks. The proposed protocol consists of the slotted based transmission frame and reduces data collisions between nodes by putting separately the reservation period in the transmission frame. In addition, it is able to solve the hidden node problem and the exposed node problem by reservation information between nodes. We carry out the simulation to evaluate the proposed protocol in terms of the average energy consumption, the ratio of collision, throughput, and the average transmission delay, and compare the proposed protocol to a traditional MAC protocol in the underwater environment. The simulation results show that the proposed protocol outperforms the traditional protocol under a various of network parameters.

• Journal of ILASS-Korea
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• v.25 no.1
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• pp.27-33
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• 2020

NOx, PN and CO emissions from diesel trucks make up a significant portion of domestic air pollutant emissions. Therefore, test vehicles with various emission standards and driving modes were selected to evaluate the emission characteristics of regulated pollutants (NOx, PN, CO) in medium-duty trucks. As a result of test, all test vehicles were satisfied with Euro 5 or 6 regulation. NOx emissions of Euro 6 vehicles with after-treatment of LNT + DPF were lower than those of Euro 5 vehicles with DPF. In WLTC mode, all vehicles have high NOx emissions at section of extra high speeds, which are determined by increased fuel consumption and high combustion temperatures. CO and PN emissions from all vehicles were found to be low at section of low speeds. Also, The NO₂/NOx ratio was analyzed at 7-23% in each mode, and the NO₂/NOx ratio increased as the average vehicle speed increased. In NIER 9 mode, the CO, HC, and PN emissions were higher under cold conditions of engine than hot conditions of engine. In addition, vehicles with after-treatment system of LNT have similar NOx emissions level in this study.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.401-414
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• 2016

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia anthina PSB-15 and Enterobacter aerogenes PSB-16, was assessed in liquid medium and green gram plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($519{\mu}g\;mL^{-1}$) into the medium, followed by single inoculation of Burkholderia strain ($492{\mu}g\;mL^{-1}$) and Enterobacter strain ($483{\mu}g\;mL^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production, and glucose consumption were observed in the culture medium co-inoculated with PSB-15 and PSB-16 strains rather than that of single inoculation. Based on the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 9% and 8% higher shoot and root growth, respectively, compared to the control. Therefore, in conclusion, co-inoculation of the strains B. anthina and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, considering the short assessment period of the present study, we recommend engaging in further work under field conditions in order to test the suitability of these strains as bio-inoculants.

• The Korean Journal of Food And Nutrition
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• v.35 no.2
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• pp.75-87
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• 2022

The purpose of this study was to identify nutrition quotient for elderly (NQ-E) and to investigate factors affecting NQ-E of the elderly using welfare center and senior citizen's center in Changwon city. A self-administered questionnaire was conducted between June 2021 and early August 2021 for 320 elderly (≥65 years, male, n=52, female, n=268). As a result of the survey, the mean NQ-E score was 61.12, which was within the medium-high grade. The scores of balance, moderation, and dietary behavior factors were within the medium-high grade, while diversity factor was within the medium-low grade. According to the results of the Pearson's correlation coefficient analysis, NQ-E showed positive correlations with the 'with family' (p<0.01), 'education level' (p<0.01), 'health functional foods consumption' (p<0.01), 'monthly household income' (p<0.05), 'nutrition education experience' (p<0.05), 'reading nutrition labeling of health functional foods' (p<0.01), 'perception of the efficacy of health functional foods' (p<0.01), and 'the number of times of leisure activities per week' (p<0.01) and negative correlations with the 'gender' (p<0.05), 'age' (p<0.01), 'smoking' (p<0.05), and 'social frailty' (p<0.01). As a result of multiple regression analysis, 'gender' (p<0.05), 'perception of the efficacy of health functional foods' (p<0.05), 'the number of times of leisure activities per week' (p<0.05), and 'social frailty' (p<0.05) were found to be factors affecting NQ-E. Based on the results of this study, customized services by characteristic, nutrition education, and counseling for the elderly should be implemented and the development of various programs and continuous support of the community are necessary so that the elderly can carry out social exchange.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.33-41
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• 1967

The metabolic patterns of C-1 and C-6-carbon atoms of glucose were observed in the tissue homogenates of the Ehrlich ascites tumor tissue which was incubated for 3 hours in the Dubnuff metabolic shaking incubator. $C^{14}-1-and\;C^{14}-6-glucose$ were used as tracers. The glucose media in which tissue homogenate was incubated was kept at a concentration of 200mg% glucose of carrier and appropriate amount of $C^{14}-1-or\;C^{14}-6-tracer$. At the end of 3 hour incubation, respiratory $CO_2$ samples trapped by alkaline which is placed in the tenter well of incubation flask were analyzed for the total $CO_2$ production rates and their radioactivities. The tissue homogenate samples after incubation were analyzed for their concentrations of glucose, lactate, pyruvate and glycogen and calculations were made on the glucose consumption rate, pyruvate and lactate accumulation rates. The following results were obtained. Data obtained in each group are as follows: 1. In the tissue homogenate, which was incubated with $C^{14}-1-glucose as a substrate, total $CO_2$ production rate averaged $19.0{\pm}5.0{\mu}M/hr/gm$ and the mean specific activity of respiratory $CO_2$ was $840{\pm}296\;cpm/mgC.$ Relative specific activity (RSA) which means the fraction of $CO_2$ derived from medium $C^{14}-1-glucose$ to total $CO_2$ production rate was calculated by ratio of SA of respiratory $CO_2$ and medium $C^{14}-1-glucose.$ RSA was $14.3{\pm}5.0%,$ Accordingly actual $CO_2$ production rate from medium $C^{14}-1-glucose$ showed a mean value of $2.79{\pm}1.35\;{\mu}m$ of which amount was equivalent to the mean value of total glucose consumption rate $(RGDco_2)$, namely, $5.1{\pm}1.3%.$ Lactate and pyruvate appearance rates averaged $7.13{\pm}1.26\;and\;0.21{\pm}0.02{\mu}M/hr/gm,$ respectively. Assuming that these 3 carbon compounds appeared in the medium were derived from glucose, calculations were made that relative glucose disappearance rate into lactate $(RGD_L)$ was $38.0{\pm}5.4%\;and\;RGD_P$ was $1.23{\pm}0.03%.$ Therefore, about 43.3% of the total glucose consumed were accounted for by conversion into the respiratory $CO_2$, lactate and pyruvate. 2. In the second group, which was incubated with $C^{14}-1-glucose$ as a substrate, glucose consumption rate, lactate and pyruvate appearance rates showed almost the same order as the values of the $C^{14}-1-glucose$ substrate group. However, RSA was remarkably decreased showing a mean value of $1.02{\pm}0.13%.$ This fact means that the C-6 carbon of glucose take the minor part in the oxidative metabolism of glucose. The glycogen level in both substrate tissue homogenate showed less than 0.3% of tissue weight. These low value suggested that there was an inhibition of carbohydrate synthesis in the Ehrlich ascites tumor tissue. 3. The catabolic pathway of glucose in the tumor tissue were analyzed on the basis of Bloom's principle from the values of RSA. It was found that in the tumor tissue more than 90% of $CO_2$ derived from glucose were oxidized via the alternate pathway other than principal EMP-TCA cycle such as hexose monophosphate pathway (HMP). From the data described above, it was assumed that in the Ehrlich tumor tissue anaerobic glycolysis proceeds normally although, the oxidation of products of anaerobic glycolysis via the TCA cycle is inhibited resulting in the accumulation of lactate and almost all of oxidative energy from glucose is released by oxidative pathway such as HMP.