산소분리막에 의해 상승된 산소농도가 가솔린기관의 성능에 미치는 영향

권병철 大田産業大學校 1993 한밭대학교 논문집 Vol.10 No.1

AbstractThe aim of the study is to improve the performance of the gasoline engine. Recently, the oxygen membrane enriching the oxygen in the air has been developed and used in many engineering field.The engine performance is changed by deeply saturated oxygen concentration supplied to the combustion chamber. According to the oxygen concentration of the fuel air mix- ture, the engine performance is improved as follows.It is shown that the mean effective pressure, output and thermal efficiency is increased, however, fuel consumption rate is decreased as increasing oxygen concen- tration.The oxygen concentration have great effect on the combustion at the poor limit rather than fuel excess state. The aim of the study is to improve the performance of the gasoline engine. Recently, the oxygen membrane enriching the oxygen in the air has been developed and used in many engineering field. The engine performance is changed by deeply saturated oxygen concentration supplied to the combustion chamber. According to the oxygen concentration of the fuel air mixture, the engine performance is improved as follows. It is shown that the mean effective pressure, output and thermal efficiency is increased, however, fuel consumption rate is decreased as increasing oxygen concentration. The oxygen concentration have great effect on the combustion at the poor limit rather than fuel excess state.

Rat를 이용 산소 및 유해가스 노출에 따른 운동성 변화와 치사농도 연구

김현영(Hyeon-Yeong Kim),이성배(Sung-Bae Lee),한정희(Jeong-Hee Han),강민구(Min-Gu Kang),예병진(Byeong-Jin Ye) 환경독성보건학회 2009 환경독성보건학회지 Vol.24 No.3

As an effort to prevent serious accidents involving oxygen deficiency and suffocation in confined spaces and to identify the causes of such accidents, the present study investigated relevant accidents and systems in Korea and other countries. This study also conducted a number of experiments at lethal concentration levels of oxygen deficiency using SD rats and observed the changes of experimental animals with humidity, organic gas (toluene), hydrogen sulfide, carbon monoxide and so on at the oxygen deficient environment. The results of the study are as follows. 1. The results from the experiment conducted using SD rats at lethal concentration levels of oxygen showed that there were no casualties at the 7% oxygen concentration level, but the mortality increase to 20% at 6% oxygen. it was jumped to 90% at 5% oxygen, and it was also dramatically reached 100% at 4% oxygen concentration. Therefore, 5.5% was calculated as the LC?? (rat, 4hr) from these dose-response experiments with oxygen deficiency. 2. When we changed the level of toluene, H₂S, CO, humidity, and so on, in an oxygen deficient environment, it was observed that the small concentrations of H₂S and CO make the highest effect on animals. In case of 350 ppm H₂S, it resulted in 30% mortality, and the 100% mortality was shown in 1,200 ppm CO concentration. The mortality increased as an oxygen deficient condition. However in the case of toluene up to 1,000 ppm, it were not affected with oxygen deficiency, and it did not indicate any significant differences in mortality as 20%, 90% humidities.

The Effects of Combined Stimulation Using Relaxation Scent and High Concentration Oxygen: fNIRS Study

( Kyu-beom Kim ),( Chung-kyo In ),( Eun Heo ),( Yoo-shin Park ),( Geun-ae Park ),( Soon-cheol Chung ),( Byung-chan Min ) 한국감성과학회 2023 한국감성과학회 국제학술대회(ICES) Vol.2023 No.-

The purpose of this study is to explore the effects of combined stimulation consisting of relaxation-inducing scent and high concentration oxygen on psychological/physiological responses. The cerebral blood flow responses and arousal that appear when the oxygen concentration was controlled under the same scent conditions were observed. The scent used in the experiment was lavender oil(relaxing scent), and as for the oxygen concentration, normal concentration oxygen(21%) and high concentration oxygen(30%) were used. The experiment was conducted by repeating a rest period(5 minutes) and a stimulation period(5 minutes) for a total of 12 adult males. In order to observe cerebral blood flow responses, hemoglobin(HbO) concentration was extracted according to the Beer-Lambert law. Arousal was evaluated using a 5-point scale questionnaire. A paired t-test was conducted for comparison between the two stimuli(Lavender_21%, Lavender_30%). As a result, HbO concentration in the frontal lobe increased and arousal decreased at Lavender_30% compared to Lavender_21%. These results suggest that the combined stimulation in which high concentration oxygen is additionally presented to the existing scent stimulation can induce more brain activation and relaxation.

Mathematical Model for a Three-Phase Fluidized Bed Biofilm Reactor in Wastewater Treatment

Choi, Jeong-Woo,Min, Ju-Hong,Lee, Won-Hong,Lee, Sang-Back The Korean Society for Biotechnology and Bioengine 1999 Biotechnology and Bioprocess Engineering Vol.4 No.1

A mathematical model for a three phase fluidized bed bioreactor (TFBBR) was proposed to describe oxygen utilization rate, biomass concentration and the removal efficiency of Chemical Oxygen Demand (COD) in wastewater treatment. The model consisted of the biofilm model to describe the oxygen uptake rate and the hydraulic model to describe flow characteristics to cause the oxygen distribution in the reactor. The biofilm model represented the oxygen uptake rate by individual bioparticle and the hydrodynamics of fluids presented an axial dispersion flow with back mixing in the liquid phase and a plug flow in the gas phase. The difference of setting velocity along the column height due to the distributions of size and number of bioparticle was considered. The proposed model was able to predict the biomass concentration and the dissolved oxygen concentration along the column height. The removal efficiency of COD was calculated based on the oxygen consumption amounts that were obtained from the dissolved oxygen concentration. The predicted oxygen concentration by the proposed model agreed reasonably well with experimental measurement in a TFBBR. The effects of various operating parameters on the oxygen concentration were simulated based on the proposed model. The media size and media density affected the performance of a TFBBR. The dissolved oxygen concentration was significantly affected by the superficial liquid velocity but the removal efficiency of COD was significantly affected by the superficial gas velocity.

Correlation Between Tunable Oxygen Defects in TiO2 Nanoflower and its Photocatalytic Performance for the Degradation of Organic Waste

Cai Chen,Han Zhang,Arshid M. Ali,Hui Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

Oxygen defects of nanoflower TiO2 photo-catalyst was fabricated at the presence of hydrogen at different temperatures (100–600℃) and the concentrations of oxygen defects were firstly quantitatively analyzed by hydrogen programmed temperature reduction techniques (H2-TPR). Total oxygen defect concentration and surface oxygen defect concentration were consistent with XPS and EPR results, respectively. Even at the hydrogen thermal temperature of 600 ℃, the shape of TiO2 was still kept as nanoflower structure as characterized by SEM. However, the rutile and anatase coexist in the composition of crystal phase when hydrogen reduction temperature of the TiO2 catalyst reached 400 ℃ to 600 ℃ as proved by Raman and XRD results. TiO2 sample with oxygen defects shows excellent photo-catalytic activity for degradation of Direct Blue 78 (DB) regardless of ultraviolet light (the maximum degradation rate achieved within 100 min was 93.27%) or visible light (the maximum degradation rate achieved within 100 min was 88.25%). The photo-catalytic activity seems to be highly correlated with the surface oxygen defects of TiO2 catalyst. With surface oxygen-defect concentrations increase, the degradation ability on DB was significantly enhanced, while bulk oxygen defects had negligible effect on the photo-catalytic activity. The enhanced photo-catalytic performance of TiO2 with a fixed amount of oxygen defects was attributed to the strong capturing capability of the photo-generated electrons. In addition, the surface defects could also improve the photo-catalytic reaction efficiency.

고농도 산소 공급량에 따른 20대와 60대의 혈중 산소 포화도의 차이

최미현 ( Mi Hyun Choi ),김지혜 ( Ji Hye Kim ),이수정 ( Su Jeong Lee ),양재웅 ( Jae Woong Yang ),이정한 ( Jeong Han Yi ),전재훈 ( Jae Hoon Jun ),김현준 ( Hyun Jun Kim ),이태수 ( Tae Soo Lee ),정순철 ( Soon Cheol Chung ) 한국감성과학회 2010 감성과학 Vol.13 No.1

본 연구는 93% 고농도 산소의 세 가지 공급량(1L/min, 3L/min, 5L/min)에 대해 20대 및 60대의 혈중산소 포화도의 차이를 규명하고자 하였다. 20대 남자 10명(25.0±1.8세)과 여자 10명(23.7±1.9세), 60대 남자 10명(68.0±2.6세)과 여자 10명(65.5±3.1세)의 피험자를 대상으로 실험을 수행하였다. 1L/min, 3L/min, 그리고 5L/min의 유량 변화가 가능하면서 순도 93%의 산소 농도를 일정하게 유지 할 수 있는 산소 공급 장치(OXUS Co.)를 사용하였다. Pre-hyperoxia(5분), 93%의 Hyperoxia(10분), Post-hyperoxia(10분)의 세 단계의 순서로 실험이 진행되었고, 전 단계에서 혈중 산소 포화도가 측정되었다. 유량이 증가할수록 혈중 산소 포화도는 증가하였고, 60대보다 20대의 혈중 산소 포화도가 더 높았다. 안정 상태(Pre-/Post-hyperoxia)에 비해 고농도 산소를 공급한 Hyperoxia 구간에서 혈중 산소 포화도가 증가하였다. 그러나 고농도 산소 공급으로 20대에 비해 60대의 혈중산소 포화도의 증가량이 더 컸다. The purpose of this study was to examine differences between 20s and 60s in blood oxygen saturation due to 93% oxygen administration of the three levels(1L/min, 3L/min, 5L/min). Ten 20s male(25.0±1.8 years), ten 20s female(23.7±1.9 years), ten 60s male(68.0±2.6 years), and ten 60s female(65.5±3.1 years) were selected as the subjects for this study. The oxygen supply equipment(OXUS Co.) provided oxygen by supply rate(i.e., 1L/min, 3L/min, and 5L/min) at a constant rate of 93% oxygen. The experiment consisted of three phases, i.e., Pre-hyperoxia(5min), Hyperoxia(10min), and Post-hyperoxia(5min). Blood oxygen saturation were measured throughout the three phases. By increasing the amount of highly concentrated oxygen administration, blood oxygen saturation was increased. Blood oxygen saturation of 20s was higher than 60s. Blood oxygen saturation was greater during Hyperoxia than during Pre- and Post-hyperoxia. However, rising rate of blood oxygen saturation of 60s by oxygen administration was higher than 20s.

생쥐 배아의 체외배양시 저농도 산소 환경이 배아 발달에 미치는 영향

유정현(Jong Hyun Woo),황경주(Kyung Joo Hwang),양현원(Hyun Won Yang),이치형(Chi Hyeong Lee),양정인(Jeong In Yang),권혁찬(Hyuck Chan Kwan),오기석(Kie Suk Oh) 대한산부인과학회 1998 Obstetrics & Gynecology Science Vol.41 No.12

N/A Objective: It is known that mouse embryos before implantation develop in a low oxygen environment of 3- 8% concentration and with antioxidant materials such as vitamins, antioxidant enzymes, ferrous binding proteins, and albumin in follicular and tubal fluids. However, the 20% oxygen culture condition with chemically defined media might be produce an abundance of ROS, and leads to developmental delay or developmental block in vitro. In this study, we attempt to elucidate the relationship between intracellular H2O2 production and embryo development in different oxygen culture conditions of mouse embryos. Methods: Prenuclear embryos from C57BL/CBA Fl hybrid and ICR mouse were cultured in incubators which provided 5% carbon dioxide, 20% oxygen and 5% carbon dioxide, 5% oxygen. Measurement of H2O2 level in a embryo was performed with DCHFDA(2,7 -dichlorodihydroflourescein diacetate)and analyzed with Quanti-cell 700, and the number of blastomeres was counted with DAPI( 4, 6'-diamidino-2-phenylindole). Results: Oxygen concentration of the culture medias was significantly higher in the 20% oxygen environment compared to that of 5% oxygen environment. Culture of mice embryos in high oxygen condition leads to high HO concentrations at 2 cell stage and developmental delay or 2-cell block regardless of the strain. But in a 5% oxygen environment, which is similar to in-vivo conditions HO production was suppressed continuously through out culture and development of embryos was definitely improved. Conclusion: These results suggest that there is a difference in the production of ROS or protective mechanism according to the mouse strains and stage of development, and it is thought that in-vitro culture in 5% oxygen environment provides stable in vivo equilibrium but in a 20% oxygen environment there is production of ROS which overcome the protective mechanism which leads to cellular damage and embryo developmental delay.

군발두통에서 가정용 산소발생기를 이용한 산소 치료 효과에 관한 탐색적 연구

홍유하,조수진,배대웅,정필욱,문희수,주민경,김병수,김병건 대한신경과학회 2020 대한신경과학회지 Vol.38 No.1

Cluster headache attacks can be successfully treated with oxygen. We report four patients with episodic cluster headache were treated with oxygen therapy from one or two oxygen concentrators. Oxygen therapy with two oxygen concentrators seems to be effective in reduction or cessation of pain of cluster headaches. Patients expressed excellent satisfaction to oxygen therapy with two oxygen concentrators. Oxygen concentrators can be considered as an effective and safe alternative of oxygen cylinder for patients with cluster headache.

Thermodynamic analysis of oxygen refining during electron-beam additive manufacturing of pure titanium products

Park, Hyung-Ki,Na, Tae-Wook,Yang, Seung-Min,Kim, Gun-Hee,Lee, Byoung-Soo,Kim, Hyung Giun North-Holland 2019 Materials letters Vol.236 No.-

<P><B>Abstract</B></P> <P>Chemical composition of pure titanium, particularly oxygen, severely affects mechanical properties of product. Oxygen refining during electron-beam additive manufacturing (EBAM) of pure titanium products was thermodynamically analyzed. The oxygen concentration of the titanium sample fabricated by EBAM was 0.172%, which was lower than that of the initial titanium powders (0.228%). This was mainly because the TiO<SUB>2</SUB> native oxide layer formed on the initial powders reduced during EBAM, thereby decreasing the oxygen concentration. Analysis of temperature and oxygen partial pressure in the EBAM building chamber confirmed the occurrence of reduction and hence the oxygen refining effect.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Oxygen concentration of CP-Ti product fabricated by EBAM was lower than raw powder. </LI> <LI> Oxygen refining during EBAM of CP-Ti product was thermodynamically analyzed. </LI> <LI> Temperature and oxygen partial pressure induced the reduction from TiO<SUB>2</SUB> to Ti. </LI> </UL> </P>

산소농도 변화에 따른 운동수행능력과 자율신경계의 변화에 관한 연구

이재영(Lee, Jae-Young) 한국체육과학회 2016 한국체육과학회지 Vol.25 No.1

The purpose of this study was to clarify the effects of the administration high concentration oxygen breathing on changes in exercise performance and autonomic nervous system during aerobic exercise. Subjects were 10 male students (23.5±2.8) participated in the experiment twice, one for 21% oxygen and the other for 30% oxygen. Experiment was composed of three sections, which were composure (5 minutes), using cycle during Incremental Load Exercise (for all-out), and recovery (30 minutes). Exercise performance were higher to high concentration oxygen, there was no significant difference. Parasympathetic autonomic nervous system showed stability during aerobic exercise(p<.05). Therefore, the high concentration oxygen environment have a positive impact on exercise performance and stabilization of the autonomic nervous system.