The effect of oxygen supply and oxygen distribution on single-head tunnel with different altitudes under mixed ventilation

2022 ◽  
pp. 1420326X2110514
Author(s):  
Zijun Li ◽  
Junjian Wang ◽  
Shuqi Zhao ◽  
Yu Xu
Keyword(s):  
High Altitude ◽  
Mass Fraction ◽  
Oxygen Supply ◽  
Fluid Model ◽  
Ventilation System ◽  
Hypoxic Environment ◽  
Excavation Work ◽  
Effect Of Oxygen ◽  
Supply Mode ◽  
Different Altitudes

Hypoxia plays a major role in limiting the construction of the high-altitude mine. Understanding the effect and the distribution of diffused oxygen supply at different altitudes is the premise for the design of a mine with oxygen supply system and the full utilization of oxygen resources. For the optimal design of an oxygen supply mode and ventilation system, a multi-component fluid model of the diffused oxygen supply of a single-head tunnel was developed. This study reveals the variation law of the average oxygen mass fraction at different altitudes. The relationship between the distance from the heading face and the oxygen mass fraction at each altitude was fitted. The results show that the distribution of oxygen mass fraction in a single head tunnel at different altitudes presents a similar trend of increasing first and then decline. In addition, the change of the average oxygen mass fraction with the increase of altitude is not linear, and the dispersion loss is larger in high-altitude areas. The largest oxygen enrichment area is distributed at the altitudes of 4000–4500 m. This study provides theoretical support for improving the hypoxic environment of high-altitude metal mines excavation work.

scholarly journals Increasing Oxygen Mass Fraction in Blind Headings of a Plateau Metal Mine by Oxygen Supply Duct Design: A CFD Modelling Approach

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zijun Li ◽  
Shuqi Zhao ◽  
Rongrong Li ◽  
Yilong Huang ◽  
Yu Xu ◽  
...  
Keyword(s):  
Mass Fraction ◽  
Oxygen Supply ◽  
Ventilation System ◽  
Western China ◽  
Cfd Modelling ◽  
Supply Effect ◽  
Metal Mine ◽  
Optimum Height ◽  
Fraction Distribution ◽  
Duct Design

Hypoxia problem has always been a difficult point in plateau tunneling projects. To solve this problem, a blind heading face in a plateau metal mine in western China was taken as the physical model, and the computational fluid dynamics was used to analyze the oxygen mass fraction distribution and oxygen-increasing effect in 1 m, 3 m, and 5 m roadway sections from the heading face. The optimal ventilation system was first built to obtain the optimum height and length of the airflow ducts. Then different cases with various oxygen supply duct designs were built in 2 scenarios. The results found that different oxygen supply duct design has significant influence on the oxygen distribution in the heading face. Also, each design has different optimal height of oxygen outlet. The oxygen supply effect is best when some small holes are made in the oxygen supply duct to diffuse oxygen to the working surface. The finding of this paper is helpful for effective and economical oxygen supply in roadway excavation of plateau metal mine and tunnel.

Limitation of theophylline elimination by reduced oxygen availability in mouse hepatocytes and rat isolated livers

1985 ◽  
Vol 63 (8) ◽  
pp. 903-907 ◽  
Author(s):  
Kanji Nakatsu
Keyword(s):  
Oxygen Supply ◽  
Correlation Coefficients ◽  
Oxygen Availability ◽  
Isolated Perfused Rat Liver ◽  
Mouse Hepatocyte ◽  
Mouse Hepatocytes ◽  
Per Se ◽  
Theophylline Metabolism ◽  
Effect Of Oxygen ◽  
Rat Livers

The effect of oxygen availability on theophylline metabolism by mouse hepatocytes and rat isolated livers was examined. The elimination of theophylline by mouse hepatocytes and the metabolism of theophylline to dimethyluric acid by isolated, perfused rat livers was seriously impaired when the gas mixture supplied contained less than 28% oxygen. The correlation coefficients relating oxygen supply and the concentration of theophylline remaining in mouse hepatocyte suspensions were −0.74 to −0.84. In the isolated, perfused rat liver experiments, the correlation coefficient relating oxygen availability and dimethyluric acid production was 0.87. These observations are interpreted as supporting the hypothesis that oxygen availability per se is an important factor in determining the rate of theophylline metabolism.

Differential effect of oxygen supply and lactate concentration on keratan sulphate and glycoseminoglycuronan production in bovine cornea

1991 ◽  
Vol 19 (4) ◽  
pp. 354S-354S ◽  
Author(s):  
CESARE BALDUINI ◽  
GLANCARLO DE LUCA ◽  
ALBERTO PASSI ◽  
SIMONETTA RINDI ◽  
ROBERTA SALVINI ◽  
...  
Keyword(s):  
Differential Effect ◽  
Oxygen Supply ◽  
Lactate Concentration ◽  
Keratan Sulphate ◽  
Effect Of Oxygen

scholarly journals A Probabilistic Target Search Algorithm Based on Hierarchical Collaboration for Improving Rapidity of Drones

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2535 ◽  
Author(s):  
Il-Kyu Ha ◽  
You-Ze Cho
Keyword(s):  
High Altitude ◽  
Target Detection ◽  
Information Transfer ◽  
Search Algorithm ◽  
Search Time ◽  
Previous Method ◽  
Target Search ◽  
Low Altitude ◽  
Military Facilities ◽  
Different Altitudes

Finding a target quickly is one of the most important tasks in drone operations. In particular, rapid target detection is a critical issue for tasks such as finding rescue victims during the golden period, environmental monitoring, locating military facilities, and monitoring natural disasters. Therefore, in this study, an improved hierarchical probabilistic target search algorithm based on the collaboration of drones at different altitudes is proposed. This is a method for reducing the search time and search distance by improving the information transfer methods between high-altitude and low-altitude drones. Specifically, to improve the speed of target detection, a high-altitude drone first performs a search of a wide area. Then, when the probability of existence of the target is higher than a certain threshold, the search information is transmitted to a low-altitude drone which then performs a more detailed search in the identified area. This method takes full advantage of fast searching capabilities at high altitudes. In other words, it reduces the total time and travel distance required for searching by quickly searching a wide search area. Several drone collaboration scenarios that can be performed by two drones at different altitudes are described and compared to the proposed algorithm. Through simulations, the performances of the proposed algorithm and the cooperation scenarios are analyzed. It is demonstrated that methods utilizing hierarchical searches with drones are comparatively excellent and that the proposed algorithm is approximately 13% more effective than a previous method and much better compared to other scenarios.

scholarly journals Impact of High-Altitude on Truck’s Climbing Speed: Case study in Qinghai-Tibet Plateau Area in China

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Tian Lei ◽  
Jinliang Xu ◽  
Xingli Jia ◽  
Leyu Wei ◽  
Lin Tian
Keyword(s):  
High Altitude ◽  
Traffic Safety ◽  
Field Tests ◽  
Tibet Plateau ◽  
Infrastructure Development ◽  
Plateau Area ◽  
Negative Effect ◽  
High Altitude Area ◽  
The Impact ◽  
Different Altitudes

Truck’s climbing performance is an important consideration in traffic safety, efficiency, and highway geometric design. With the infrastructure development in high-altitude area in China, more attention needs to be paid on truck’s climbing performance in such area. In this article, truck’s climbing speed in high-altitude area was examined through field tests on different grade sections at different altitudes. Truck’s speed-distance curves were built at different altitudes and the impact of altitude on truck’s climbing speed was explored based on the test results. It was shown that, within the altitude range of 3000~5000m, altitude had an obvious influence on test truck’s decelerating and accelerating performance. Truck’s speed decreased faster on steep grades and increased slower on gentle grades with the increase of the altitude. Also, the stable speed that test truck could maintain on a certain grade was lower at a higher altitude. In addition, test truck’s theoretical speed-distance curves at the sea level were estimated through truck’s dynamic model. Compared with the theoretical crawl speed, a negative effect of altitude change (from 0 to the altitude above 3000 m) was found on truck’s climbing performance.

Effect of oxygen supply on energy metabolism in rats

1994 ◽  
Vol 13 ◽  
pp. 39
Author(s):  
Y. Mimura ◽  
K. Furuya ◽  
J. Maeda ◽  
M. Yamakawa ◽  
T. Oohara
Keyword(s):  
Energy Metabolism ◽  
Oxygen Supply ◽  
Effect Of Oxygen

scholarly journals Oxygen Saturation of Hemoglobin in Healthy Children of 2- 14 Years at High Altitude in Nepal

2012 ◽  
Vol 10 (1) ◽  
pp. 30-33
Author(s):  
S Shrestha ◽  
S Shrestha ◽  
L Shrestha ◽  
N Bhandary
Keyword(s):  
Oxygen Saturation ◽  
High Altitude ◽  
Healthy Children ◽  
Older Children ◽  
Contributing Factors ◽  
Lower Altitude ◽  
Value Of Children ◽  
The Mean ◽  
The Difference ◽  
Different Altitudes

Background Individuals residing at higher altitude may have oxygen saturation of hemoglobin different to those living at lower altitude. # Objectives To find out the baseline value of SpO2 in healthy Nepali children (2-14 years) living permanently at high altitude using pulse oximeter and also to study the relation of SpO2 with age, sex and ethnicity. Methods A descriptive observational study was conducted at 4 different altitudes ranging from 2700 to 3800 m in Mustang district. The mean pulse oximery values at different altitudes were calculated and compared. Results One hundred six children were enrolled with the median age of 10 years. The mean SpO2 value of children permanently residing at altitude 2700m was 95.18%, at 2800m was 94.82%, at 3550m was 94.1% and 3800m was 93.1%.The difference in the SpO2 values at different altitude was statistically significant. No sex or age wise differences were noted on the mean SpO2 values in the study group. Conclusions The mean SpO2 values were higher than several other studies done in the altitude above 2500 meters. Enrollment of older children and the different ethnic background could be the contributing factors for the differences. KATHMANDU UNIVERSITY MEDICAL JOURNAL  VOL.10 | NO. 1 | ISSUE 37 | JAN - MAR 2012 | 40-43 DOI: http://dx.doi.org/10.3126/kumj.v10i1.6912

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