• Food Science of Animal Resources
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• v.38 no.3
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• pp.487-497
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• 2018

Controlling of microorganisms in the industrial process is important for production and distribution of hatching and table eggs. In the previous study, we reported that chlorine dioxide ($ClO_2$) gas of a proper concentration and humidity can significantly reduce the load of Salmonella spp. on eggshells. In this study, we compared microbial reduction efficacy on egg's surface using hatching eggs and table eggs, internal quality of table eggs, and hatchability after both the conventional method (washing and UV expose, fumigation with formalin) and $ClO_2$ gas disinfection. Application of 40 ppm $ClO_2$ gas to the table and hatching eggs, respectively, reduced the aerobic plate count (APC) with no statistical difference compared with the conventional methods. Additionally, we didn't observed that any significant difference in albumin height, Haugh unit (HU), and yolk color, this result confirms that 40 ppm $ClO_2$ had no effect on the internal quality of the table eggs, when comparing with the UV treatment method. The hatchability of hatching eggs was not statistical different between formaldehyde fumigation and 80 ppm $ClO_2$ gas treatment, though the value was decreased at high concentration of 160 ppm $ClO_2$ gas. From these results, we recommend that $ClO_2$ gas can be used as a safe disinfectant to effectively control egg surface microorganisms without affecting egg quality.

• Advances in environmental research
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• v.9 no.2
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• pp.123-133
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• 2020

A time series dataset was conducted to ascertain the effect of water table on the variability in and emission of CH₄ and CO₂ concentrations at a closed landfill site. An in-situ data of methane/carbon dioxide concentrations and environmental parameters were collected by means of an in-borehole gas monitor, the Gasclam (Ion Science, UK). Linear regression analysis was used to determine the strength of the correlation between ground-gas concentration and water table. The result shows CH₄ and CO₂ concentrations to be variable with strong negative correlations of approximately 0.5 each with water table over the entire monitoring period. The R² was slightly improved by considering their concentration over single periods of increasing and decreasing water table, single periods of increasing water table, and single periods of decreasing water table; their correlations increased significantly at 95% confidence level. The result revealed that fluctuations in groundwater level is the key driving force on the emission of and variability in groundgas concentration and neither barometric pressure nor temperature. This finding further validates the earlier finding that atmospheric pressure - the acclaimed major control on the variability/migration of CH₄ and CO₂ concentrations on contaminated sites, is not always so.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2001.11a
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• pp.77-82
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• 2001

This paper is contents that measure the ventilation rates and temperature by driving condition of exhaust fan, vapor, contaminant occurrence amount of carbon dioxide etc. In kitchen of apartment house. The ventilation rates in the apartment kitchen measured by Tracer Gas Method. And, temperature of when cook by gas table hood lower part 10cm and floor upside 10cm of kitchen central part, 120cm, 210cm heights measure. As ventilation rates measurement result, ventilation number of times was 0.7(number of times/hour) when did not to operate exhaust fan. but we were measured by 2.3(number of times/hour) when drove strongly. As temperature measurement result at cooking by gas table, temperature showed highest in hood lower part 10cm of case that do not operate exhaust fan. Temperature at kitchen central was most low in 10cm height in talc floor, and 210cm were measured highest. Concentration of carbon dioxide is very high by 4,350ppm after measurement time 10 minutes in state who do not operate exhaust fan at cooking by gas table.

• Journal of Electrical Engineering and Technology
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• v.2 no.3
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• pp.408-412
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• 2007

It is almost impossible to secure the reproductibility and stability of a commercial Thick-Film Metal Oxide Semiconductor Gas Sensor since it is very difficult to keep the consistency of the manufacturing environment. Thus it is widely known that the general Semiconductor-Oxide Gas Sensors are not appropriate for precise measurement systems. In this paper, the output characteristic analyzer of the various Thick-Film Metal Oxide Semiconductor Gas Sensors that are used to recognize the air quality within an automobile are proposed and examined. The analyzed output characters in a normal air chamber are grouped by sensor ranks and used to fill out the characteristic table of the Thick-Film Metal Oxide Semiconductor Gas Sensors. The characteristic table is used to determine the rank of the sensor that is equipped in the current air cleaner system of an automobile. The proposed air control system can also adapt the on-demand operation that recognizes the history of the passenger's manual-control.

• Journal of the Korean Society for Precision Engineering
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• v.1 no.2
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• pp.47-57
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• 1984

The porous matterials are used both to control the flow of the compressed gas and to serve as the bearing surface. This porous design offers several advantages over the conventional externally pressurized gas bearings. It can simplify the construction, lower the gas consumption, and make the cleaning of the gas supply less critical. Test apparatus was cinstructed to experi- mentally investigate maximum load capacity of thrust bearing was measured 200 Kg (15Kg/$\mu$m), and radial bearing was 36 Kg/$\mu$m. And a rotation accuracy of face waving was 0.0127$\mu$m, and center waving was measured 0.5 $\mu$m. Finally, the use of this method of design and manufacturing will contribute to many practical application in the field required for precision and high stability.

• Journal of the Korean housing association
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• v.15 no.3
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• pp.101-108
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• 2004

To find more efficient exhaust effect, air curtain of upward or downward trend in gas table and left or right side of range hood were made. As result that film vapor from range hood lower part by digital camera, the air current change by moving existence and nonexistence of exhaust fan and direction of air curtain were known. Under all experiment condition, upward air curtain superior exhaust performance.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2001.11a
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• pp.99-104
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• 2001

This paper is contents that experiment exhaust performance of contaminant by establishment height gas table and hood establishment height. Hood made to control from gas table to 10 centimeters space from 30 centimeters to 70 centimeters. Exhaust fan operated by 110V, 160V, 220V, and gas used propane gas. Center part appeared highest as result that measure wind velocity and temperature from hood lower part. Wind velocity from hood lower part was proved that dominate contaminant exhaust performance. Exhaust performance of carbon dioxide and heat showed that 30 centimeters case overmatches because establishment height of hood compares 80 centimeters. Case of carbon dioxide of exhaust performance by establishment height of hood overmatched more than heat.

• Korean journal of applied entomology
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• v.4
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• pp.11-18
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• 1965

In order to investigate the fungicidal activities against various plant pathogenes, diminishing effect of plant transpiration, phytotoxicities, vapor effect and the rate of reduction by ultraviolet rays of phenylmercuric 8-oxyquinolinate(P.M.Q), this experiments were undertaken under various laboratory conditions. 1. Inhibitory activity on the spore germination of this chemical was shown less effective than that of P.M.A..(Table 2, Table 3, Table 4, Table 5 and Table 6) Also, P.M.Q. was resulted a somewhat higher inhibitory activity on the hyphae growth than P.M.A. (Table 7). 2. In the diminishing effect of plant transpiration, 8-hydroxyquinoline sulfate(oxine sulfate) was more strong inhibitory at first than P.M.Q., while, at last, P.M.Q. was more strong inhibitory in comparison with oxine sulfate(Table 8, Fig. 1 and Table 9). 3. P.M.Q. was shown less injury on the germination of rice plant seeds and the emergence of their roots than P.M. A.(Table 10). Injuries was not observed on the rice seedlings and soy-bean seedlings sprayed with 40 ppm of this chemical. 4. P.M.A. had more inhibitory effects on the mycelial growth of phytopathogenes than P.M.Q. on the vapor effect (Table 11, Fig. 2). 5. Biological activity and chemical decomposition rate of P.M.A. were greatly reduced by exposure of this compound to ultraviolet rays. But, P.M.Q. was only slightly affected by similar treatment(Table 12, Fig. 3, Table 13 and Fig. 4). From the above results, this chemical will be a promising fungicide adding fungitoxicities against various phytopatho genes, diminishing effect of plant transpiration and physico-stability.

• Environmental and Resource Economics Review
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• v.26 no.4
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• pp.549-575
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• 2017

Recently, power mix of Korea is planned to be changed from coal-fired and nuclear to gas-combined and renewables by the energy policy of new government. This change will also affect city-gas industry. This paper analyze the economic impact of city-gas industry by scenario that switching coal-fired and nuclear power generation into gas-combined and fuel cell. 2030 input-output table is estimated to take the transfer period into account. As results, the induced impact by city-gas industry to the others was negative when switching into gas-combined while that was positive when switching into fuel cell. This results imply that the gas-fired can be a feasible alternative for short-run but fuel cell is more helpful for our economy in long-run.

• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.44-49
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• 2020

In this paper, a measuring circuit is designed through analyzing manufacture specification of the sensor based on MOS. And the best input-output polynomial are induced that really gas sensors are used in gas safety management industrial fields. Response characteristics of a MOS gas sensor is analysed by through sensor's output voltages are measured after standard gases with six kinds of concentrations are manufactured and are injected to the sensor. A lookup table is created by relations of sensor's output voltages by injecting gases with other concentrations. Because data of the formed lookup table are equal interval, a polynomial can be induced of method of approximation function. So the 5th polynomial of input-output for a sensor is defined, coefficients are calculated by using least squares method, and the 5th polynomial is completed for representing characteristics of the sensor. If the proposed polynomial is applied to gas leak detectors, an inverse transformation of polynomial and programing of array codes are recreated. In this research, polynomial is implemented with array types that intervals of values of a lookup table are one-fifth sampled and interpolated. The performance of proposed 5th calibration equation is verified that errors are reduced than a linear expression when tests are performed by measurement of concentrations against injection of standard gases.