• 한국축산식품학회지
• /
• 제38권3호
• /
• pp.487-497
• /
• 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
• /
• 제9권2호
• /
• pp.123-133
• /
• 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.

• 한국주거학회:학술대회논문집
• /
• 한국주거학회 2001년도 학술발표대회논문집
• /
• pp.77-82
• /
• 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
• /
• 제2권3호
• /
• pp.408-412
• /
• 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.

• 한국정밀공학회지
• /
• 제1권2호
• /
• pp.47-57
• /
• 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.

• 한국주거학회논문집
• /
• 제15권3호
• /
• pp.101-108
• /
• 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.

• 한국주거학회:학술대회논문집
• /
• 한국주거학회 2001년도 학술발표대회논문집
• /
• pp.99-104
• /
• 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.

• 한국응용곤충학회지
• /
• 제4권
• /
• pp.11-18
• /
• 1965

Phenylmercuric 8-Oxyquinolinate의 광범위한 식물병원균에 대한 살균작용, 식물의 수분증산억제작용, 식물에 대한 약해작용, Gas작용 및 자외선에 의한 경시변화에 관해 실험을 행하였으며, 그 결과를 요약하면 다음과 같다. (1) 포자발아억제작용은 P.M.A.보다 약간 불량한 결과를 보이며, 균사생장억제작용은 P.M.A. 보다도 양호하였다. (2) 식물의 수분증산억제작용은 초기에는 8-Hydroxyquinoline sulfate가 P.M.Q.보다도 강한 억제작용을 나타내었으나, 끝에 가서는 반대로 P.M.Q가 Oxine sulfate보다도 강한 작용을 나타냈다. (3) 수도종자의 발아, 발근에 미치는 영향은 P.M.A. 보다 약해가 적었고 수도 및 대두의 유식물의 경엽(40ppm 처리)에도 약해가 없었다. (4) 식불병원균에 대한 Gas효과에 의한 살균력은 P.M.A.보다 적었다. (5) 자외선에 의한 영향은 생물학적인 변화와 화학적인 변화가 거의 일치하였으며 P.M.Q.는 P.M.A.보다도 훨씬 자외선에 안정하였다. 이상의 결과로 보아 본약제는 광범위한 식물병원균에 대해 살균작용을 가지고 있고 식물의 수분증산도 억제시키며 이화학적인 안정성을 가진 유망한 살균제가 될 것으로 생각된다.

• 자원ㆍ환경경제연구
• /
• 제26권4호
• /
• pp.549-575
• /
• 2017

앞으로 우리나라의 발전원 구성은 신정부의 에너지 정책에 따라 석탄화력과 원자력이 감소하고 가스복합과 신재생에너지가 증가할 것으로 예상되며, 그러한 변화로 도시가스 산업에도 변화가 있을 것이다. 본 연구에서는 발전원 변경에 따른 영향을 정량적으로 살펴보기 위하여 석탄화력과 원자력을 각각 가스복합과 연료전지로 대체하는 시나리오를 설정하여 시나리오별로 도시가스 산업이 다른 산업에 미치는 경제적 파급효과의 변화를 분석하였다. 이 과정에서 정책의 영향이 나타날 시점을 고려하여 2030년 산업연관표를 추정하여 분석을 실시하였다. 분석 결과 가스복합으로 발전원을 대체하는 경우는 전체 산업에 유발하는 생산이 감소하고 연료전지를 사용하는 경우 증가하는 것으로 나타났으며, 모든 시나리오에서 전체 산업에 유발하는 부가가치는 동일한 것으로 나타났다. 이러한 결과는 발전원 변경 시, 변경 영향이 상대적으로 작게 나타나며 진입장벽이 낮은 가스복합을 단기적으로 활용하고, 장기적으로는 경제적 파급효과가 큰 연료전지를 활용하는 방안이 적절함을 의미한다.

• 한국가스학회지
• /
• 제24권2호
• /
• pp.44-49
• /
• 2020

본 논문에서는 산화주석 기반 반도체식 가스센서의 제조사양을 분석하여 측정회로를 설계하였다. 또한, 실제 가스안전관리 산업현장에서 가스센서를 사용하기 위하여 응답특성시험을 통한 최적 입출력 방정식을 도출하였다. 산화물 반도체 가스센서의 응답특성은 6종의 농도를 가진 표준가스를 제조하여 주입하며 출력전압을 측정을 통해 분석되었다. 각각 농도가 다른 가스의 주입에 대한 센서의 출력 전압의 관계를 룩업 테이블로 생성하였다. 생성된 룩업테이블의 데이터가 등간격이면 근사함수법으로 다항식을 도출할 수 있다. 그래서 5차의 다항식을 정의하고, 그 계수를 최소자승법으로 구하여 센서의 입출력 특성을 대표하는 5차 다항식을 완성하였다. 제안된 5차 다항식이 가스검지기 등에 실제로 적용되기 위해서는 다항식의 역변환이나 사이 값이 추가된 배열형태로 프로그래밍이 다시 생성되어져야 한다. 본 연구에서는 사이 값을 1/5로 세밀하게 구분 및 보간을 계산하여 배열형태로 구현되었다. 제안한 5차 캘리브레이션 교정식의성능은 표준가스를 주입 및 그 농도를 측정했을 때 일차방정식보다 오차가 감소됨을 확인되었다.