• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 춘계 학술발표회 논문집
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• pp.43-48
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• 1998

A short-cut equation for the calculation of the air ratio in the case of firing gases containing incombustibles has been derived on the basis of mass balances. The new equation requires the oxygen concentration and the amount of carbon dioxide in the combustion gas, theoretical oxygen and air requirements, and the content of incombustibles other than carbon dioxide in the fuel for the air ratio calculation. By using the equation, a theoretically correct calculation of the air ratio has been enabled.

• Journal of Chest Surgery
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• 제6권1호
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• pp.7-14
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• 1973

Ventilatory functions and arterial respiratory gases were studied in 24 patients who underwent resectional surgery for pulmonary tuberculosis. Postoperative measurements were made 24 hours, 72 hours and 7 days after surgery and the results were compared to preoperative values. Twenty-four hours postoperatively, there occurred striking increase in respiratory rate, minute ventilation, dead space ventilation and dead space tidal volume ratio, and the increase in minute ventilation was caused primarily by the increase in respiratory rate. However, alveolar ventilation, oxygen consumption, carbon dioxide elimination and respiratory quotient showed no significant postoperative changes although two of the last values showed slight decreases 24 hours after surgery. The lowest arterial oxygen saturation level was obtained 24 hours postoperatively followed by gradual rises but not to the preoperative levels until 7 days after surgery. A decreased arterial carbon dioxide tension with elevated pit was noted 24 hours after surgery, which returned to the preoperative level on the following measurement.

• Journal of Chest Surgery
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• 제26권11호
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• pp.866-870
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• 1993

Possible enhancement of myocardial protection with oxygenated crystalloid cardioplegia and blood cardioplegia were evaluated in a cardiac enzyme study. The bicarbonate-containing solution equilibrated with 100% oxygen becomes highly alkaline as carbon dioxide is released. 95% oxygen and 5% carbon dioxide was added to the crystalloid cardioplegic solution [St. Thomas` Hospital No. 2 Solution] for prevention of severe alkalinity of oxygenated crystalloid cardioplegia. Heart was arrested and reinfused every 20 minutes throughtout the ischemic period with crystalloid cardioplegia or oxygenated crystalloid cardioplegia or blood cardioplegia. Group I was a patient with crystalloid cardioplegia in 11 patients. Group II was a patient with oxygenated crystalloid cardioplegia in 9 patients. Group III was a patient with blood cardioplegia in 15 patients. The value of CK-MB was evaluated from the patient`s serum at 6 hours, 24 hours, and 48 hours postoperatively. In Group I and II, there was no significant change of CK-MB. In Group I and III, the value of CK-MB at postoperative 6 hours was 114$\pm$83 ng/ml and 56$\pm$22 ng/ml [P < 0.05]. In conclusion, blood cardioplegia was superior to crystalloid cardioplegia.

• Journal of Chest Surgery
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• 제26권12호
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• pp.899-903
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• 1993

Possible enhancement of myocardial protection with oxygenated crystalloid cardioplegia and blood cardioplegia were evaluated in a cardiac enzyme study. The bicarbonate-containing solution equilibrated with 100% oxygen becomes highly alkaline as carbon dioxide is released. 95% oxygen and 5% carbon dioxide was added to the crystalloid cardioplegic solution[St. Thomas` Hospital No. 2 Solution] for prevention of severe alkalinity of oxygenated crystalloid cardioplegia. Heart was arrested and reinfused every 20 minutes throughtout the ischemic period with crystalloid cardioplegia or oxygenated crystalloid cardioplegia or blood cardioplegia. Group I was a patient with crystalloid cardioplegia in 11 patients. Group II was a patient with oxygenated crystalloid cardioplegia in 9 patients. Group III was a patient with blood cardioplegia in 15 patients. The value of CK-MB was evaluated from the patient`s serum at 6 hours, 24 hours, and 48 hours postoperatively.In Group I and II, there was no significant change of CK-MB. In Group I and 11I, the value of CK-MB at postoperative 6 hours was 114 + 83 ng/ml and 56 + 22 ng/ml [P [0.05]. In conclusion, blood cardioplegia was superior to crystalloid cardioplegia.

• 생물환경조절학회지
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• 제17권3호
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• pp.226-230
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• 2008

혼합 싹채소의 MAP에 적합한 포장재를 선발하기 위해 알팔파, 브로콜리, 양배추, 무, 그리고 적무의 혼합 싹채소를 $50{\mu}m$ 두께의 low-density polyethylene 필름(PE 50), $50{\mu}m$ 두께의 polypropylene 필름(PP 50), $50{\mu}m$ 두께의 ceramic 필름(CE 50), $25{\mu}m$ 두께 ceramic 필름(CE 25), $10\sim13{\mu}m$ 두께의 polyethylene film(wrap), 그리고 통기구가 있는 polyethylene terephthalate 박스(box)로 포장하여 $8^{\circ}C$에서 저장 비교하였다. 저장 중 혼합 싹채소의 생체중은 7%의 감소를 보인 box처리구를 제외한 모든 처리구에서 2% 미만의 감소만을 보였다. 포장재 내부 대기는 필름 종류에 따라 차이를 보였다. CE 25는 산소와 이산화탄소 모두 5% 수준이었으나, PE 50과 CE 50은 이보다 높은 이산화탄소와 낮은 산소 농도를 보였는데, 이러한 대기 조성 변화가 이들 처리구에서 가장 이취가 가장 심했던 원인이라 생각된다. 저장 10일째 포장재 내 에틸렌 농도는 box가 가장 낮았고, 다음으로 PP 50, wrap, CE 25의 순서로 높았으며 외관상 품질이 저하가 가장 심하였던 PE 50과 CE 50에서 가장 높았다. 이상의 결과를 종합할 때, 1% 미만의 생체중 감소와 5% 수준의 이산화탄소와 산소 농도, 그리고 4ppm 이하의 에틸렌 농도를 보인 CE 25가 혼합 싹채소에 가장 적합한 포장재인 것으로 나타났다.

• Advances in environmental research
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• 제3권1호
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• pp.87-106
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• 2014

The concern for the global environment ensues researchers from various disciplines to work in collaboration to tackle with the issues of sustainability and environmental conservation for well-being of the people. In this study, we have selected and focused on few basic environment-effecting factors such as temperature, humidity, carbon dioxide and oxygen concentration level and referred them as meteorological data. In this paper, we present the development of our own customized hardware setup, environmental monitoring device (EMD) to obtain the data. Utilizing the relationship among these basic parameters, represented in the form of formulas and equations, we tried to encode them using Matlab programming. Data visualization is achieved by plotting the graphs of basic parameters obtained from EMD as well for the derivatives using Matlab programs.

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.369-373
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• 2002

The liquid phase oxidation of p-xylene has been carried out with oxygen-enriched gas, and the manganese component was precipitated probably via over-oxidation to $Mn^{4+}$. The precipitation increased with rising oxygen concentration in the reaction gas and occurred mainly in the later part of the oxidation. The activity of the reaction decreased, and the blackening of the product and side reactions to carbon dioxide increased with the degree of precipitation. Precipitation can be decreased with the addition of metal ions, such as cerium, chromium and iron.

• Nuclear Engineering and Technology
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• 제45권2호
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• pp.211-218
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• 2013

Large quantities of irradiated graphite waste from graphite-moderated nuclear reactors exist and are expected to increase in the case of High Temperature Reactor (HTR) deployment [1,2]. This situation indicates the need for a graphite waste management strategy. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 ($^{14}C$), with a half-life of 5730 years. Fachinger et al. [2] have demonstrated that thermal treatment of irradiated graphite removes a significant fraction of the $^{14}C$, which tends to be concentrated on the graphite surface. During thermal treatment, graphite surface carbon atoms interact with naturally adsorbed oxygen complexes to create $CO_x$ gases, i.e. "gasify" graphite. The effectiveness of this process is highly dependent on the availability of adsorbed oxygen compounds. The quantity and form of adsorbed oxygen complexes in pre- and post-irradiated graphite were studied using Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Xray Photoelectron Spectroscopy (XPS) in an effort to better understand the gasification process and to apply that understanding to process optimization. Adsorbed oxygen fragments were detected on both irradiated and unirradiated graphite; however, carbon-oxygen bonds were identified only on the irradiated material. This difference is likely due to a large number of carbon active sites associated with the higher lattice disorder resulting from irradiation. Results of XPS analysis also indicated the potential bonding structures of the oxygen fragments removed during surface impingement. Ester- and carboxyl-like structures were predominant among the identified oxygen-containing fragments. The indicated structures are consistent with those characterized by Fanning and Vannice [3] and later incorporated into an oxidation kinetics model by El-Genk and Tournier [4]. Based on the predicted desorption mechanisms of carbon oxides from the identified compounds, it is expected that a majority of the graphite should gasify as carbon monoxide (CO) rather than carbon dioxide ($CO_2$). Therefore, to optimize the efficiency of thermal treatment the graphite should be heated to temperatures above the surface decomposition temperature increasing the evolution of CO [4].

• 공업화학
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• 제31권3호
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• pp.323-327
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• 2020

이산화탄소 메탄화 공정 적용을 위해 저온에서 우수한 활성을 나타내는 Ni/CeO_2-X의 반응 특성을 조사하였다. 지지체인 CeO_2-X는 Ce(NO₃)₃를 400 ℃에서 열처리하여 획득하였으며, 촉매는 함침법으로 제조되었다. 실험의 운전 변수로써 반응기 내부 압력, 유입가스 중 산소, 메탄, 황화수소의 조성 및 반응 온도에 대하여 수행하였다. Ni/CeO_2-X를 이용한 이산화탄소 메탄화 반응에서 압력이 1 bar에서 3 bar로 증가함에 따라 CO₂ 전환율은 25% 이상 증가하였으며, 낮은 반응 온도에서 증가폭이 크게 나타났다. 유입가스 중 산소와 메탄은 촉매의 CO₂ 전환율을 최대 16, 4%씩 감소시켰으며, 산소와 메탄의 농도가 높아질수록 CO₂ 전환율의 감소율이 증가하는 경향을 나타내었다. 또한 황화수소는 촉매의 CO₂ 전환율을 최대 7% 감소시켰으며 촉매의 비활성화를 야기하였다. 본 연구의 결과들은 이산화탄소의 메탄화 공정 기초 자료로 유용하게 사용될 수 있을 것이다.

• 한국환경과학회지
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• 제7권5호
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• pp.573-580
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• 1998

This study examined the carbon dioxide ($CO_2$) pollution inside vehicles under low ventilation condition and evaluated the Air Quality System (AQS) for in-vehicle air quality using two techniques. The low ventilation condition is not recommended in order to keep oxygen-rich condition inside vehicles. Under the low ventilation condition, the in-vehicle $CO_2$ concentrations exceeded 1,000 ppm, the air qualify guidelines in the United States, Western Europe, and Japan, indicating more oxygen deficiency inside vehicles. On the contrary, with the AQS-on condition, the in-vehicle $CO_2$ concentrations were less than 1,000 ppm fer most of the driving time, indicating that the AQS could solve the problem of $CO_2$ accumulation inside vehicles under the low ventilation condition. The AQS test conducted by comparing carbon monoxide (CO) and volatile organic compound (VOC) concentrations inside two vehicles indicated that the AQS effectively decreased the in-vehicle concentrations by 21 to 36%, as compared to medium ventilation condition with the windows closed, the vent opened, and air conditioning on. In addition, The AQS test conducted by comparing the interior and exterior concentrations indicated that the AQS effectively decreased the in-vehicle concentrations by 18 to 31%, as compared to medium ventilation condition.