Discussion on The Model of Dispersion Oxygen Supply Efficiency in Lhasa: A Typical Cities of Plateau Area

Air distribution of oxygen supply through guardrail slot diffusers in high-altitude hypoxic areas

WE report an oxygen supply tank failure at our institution that occurred during the morning of a busy operating room schedule when medical center oxygen use was maximal.

Effects of different artificial oxygen-supply systems on migrants’ physical and psychological reactions in high-altitude tunnel construction

Problems of low temperature, low pressure, low oxygen, and high carbon dioxide (CO2) concentration in the air-conditioning (AC) trains of the Qinghai-Tibet railway can affect the health and comfort of passengers and cause altitude sickness. When the Qinghai-Tibet railway train runs in high-altitude areas, it is necessary to supply oxygen and introduce fresh air to meet the limited oxygen (O2) and CO2 partial pressures (PPs) in the carriage. In this study, a numerical analysis of the correlation between the CO2 PP and O2 PP in AC trains and the air supply parameters (ASPs), fresh air volume (FAV), and oxygen supply volume (OSV) along the Qinghai-Tibet line in summer was conducted. The results show that the influence of the FAV on the energy consumption of the air-conditioning system (ACS) in different running areas is inconsistent, whereas the influence of the oxygen supply system (OSS) on energy consumption is significant. During the oxygen supply period, the FAV had the opposite effect on energy consumption of ACS and OSS. The energy consumption of the OSS was approximately five times that of the ACS. By studying the correlation between the internal environment and ASP of trains running in different regions, the operation modes of ACS and OSS can be reasonably set, which can effectively reduce energy consumption by 20–50%.

The refuge chamber provides a safe space where people can stay safe when they are trapped by an accident in a coal mine. The refuge chamber includes several systems such as oxygen supply, air purification, cooling, and dehumidifying. The oxygen supply system is the core of the refuge chamber because it is a closed environment. The oxygen supply time is 96 h according to the relevant standards in America and China. If people stay in the refuge chamber for more than 96 h, the oxygen supply may not be enough, and they can be in danger. It is necessary to efficiently use oxygen and extend the oxygen supply time. Based on the experimental platform of the refuge chamber, this paper conducts an in-depth study on the automatic control of the oxygen supply system. The oxygen supply system and the harmful gas removal system can be automatically and efficiently controlled by the programmable logic controller (PLC) according to the personnel number and the oxygen concentration. The experiment has proved that the system is good and reliable.

Wearable oxygen masks play an important role in many fields such as traffic, aviation, medical and health, which is a device worn on the human head. An oxygen supply system (OSS) with a wearable mask is even more essential in aeronautical medicine to ensure the safety of pilots. Because of the complexity of the flight environment, having good control performance for pressure regulation is the key to realize the adaptability of oxygen supply equipment. Based on the application of wearable oxygen mask, an OSS with wearable mask is introduced. A mathematical model of OSS with a voice coil motor drive valve is provided. The improved active disturbance rejection control (ADRC) strategy with feed-forward and two limits is applied to the system according to the dead-zone characteristics of this OSS. The platform is built and mathematical simulations are carried out for the control strategy, comparing with the proportional integral derivative (PID) control algorithm with feed-forward. The results demonstrate that the differential pressure between the mask and the outside can be within ideal boundaries through both improved ADRC and improved PID. And the improved ADRC has better control effect. Meanwhile it can be resistant to disturbances and the changing breathing frequency.

Mon 1445 Comparison of second and third year pediatric residents on critical care transports

An aviation oxygen supply system based on a mechanical ventilation model

Sequential oxygen supply system promotes peripheral nerve regeneration by enhancing Schwann cells survival and angiogenesis

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.

Reliability evaluation of a medical oxygen supply system by FTA based on intuitionistic fuzzy sets

Design and engineering application of medical oxygen supply system in novel coronavirus pneumonia treatment hospital

Second wave of COVID-19 pandemic and the surge of mucormycosis: Lessons learnt and future preparedness: Indian Society of Anaesthesiologists (ISA National) Advisory and Position Statement.

Laboratory experiments were performed to examine flow pattern and oxygen supply by using a micro bubble aeration device in two-layered (densimetrically and anoxically) stratification. The flow pattern is different from two types confirmed previously. This was confirmed from vertical density and DO distributions. Micro bubbles have influenced on the flow pattern. Oxygen supply by using this device consists of gas exchange of micro bubbles and supply of oxygen saturation liquid. The efficiency of oxygen supply with this device that it used this time is twice airation system generating. Oxygen supply through micro bubbles is influenced from changing of height of density surface, increase of DO in the lower layer.

During the first wave of COVID-19, we experienced problems with our hospital oxygen supply system. This study aimed to analyze factors that stressed this system and rethink the design criteria of the gas pipeline system considering the varying oxygen demand. A retrospective study was conducted to describe problems that occurred at different stages in the oxygen supply system at our hospital due to increases in oxygen use in general, and the creation of an intermediate respiratory care unit (IRCU) and use of high-flow nasal cannula (HFNC) in particular. Herein, the characteristics and design criteria of the medical gas pipeline system are analyzed, and the steps taken to avoid future problems are outlined. Increases in oxygen use were observed at times of maximum occupancy, and these created vulnerabilities in the oxygen supply due to insufficient capacity in terms of cryogenic tanks, evaporators, and the piping network. The peak consumption was 3 times higher than the peak in the preceding 4 years. The use of HFNC therapy aggravated the problem; IRCU use accounting for as much as two-fifths of the total across the hospital. Steps taken subsequently prevented the recurrence of vulnerabilities. The design criteria for storage and distribution networks of medical gases in hospitals need to be revised considering new parameters for their implementation and the use of HFNC therapy in an IRCU. In particular, the cryogenic tanks, evaporators, and piping network for hospital wards are critical.