Low-flow anaesthesia with a fixed fresh gas flow rate

2018 ◽  
Vol 33 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Seyma Bahar ◽  
Mahmut Arslan ◽  
Aykut Urfalioglu ◽  
Gokce Gisi ◽  
Gozen Oksuz ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Low Flow ◽  
Gas Flow Rate ◽  
Low Flow Anaesthesia

Theoretical Aspects and Design of a Low-Power, Low-Flow-Rate Torch in Inductively Coupled Plasma Atomic Emission Spectroscopy

1984 ◽  
Vol 38 (5) ◽  
pp. 647-653 ◽  
Author(s):  
G Angleys ◽  
J. M. Mermet
Keyword(s):  
Flow Rate ◽  
Inductively Coupled Plasma ◽  
Gas Flow ◽  
Atomic Emission ◽  
Low Flow ◽  
Gas Flow Rate ◽  
Inductively Coupled ◽  
Torch Design ◽  
Practical Design ◽  
Main Influence

Based on a previously published work, calculations of the minimum plasma gas flow rate for torch tubes of various dimensions have been performed Predicted minimum rates have been verified by experiment It is possible to sustain a discharge at 600 W and 6 L/min without reducing drastically the external size of the torch One of the main parameters in torch design is the various flow velocities The main influence on the plasma gas flow rate is provided by the space between the external and the intermediate tube A practical design is proposed and a comparison is made with the literature

Ozone Mass Transfer in a Recirculating Loop Semibatch Reactor Operated at High Pressure

2010 ◽  
Vol 13 (1) ◽  
Author(s):  
Mohammadreza Moslemi ◽  
Simon H. Davies ◽  
Susan J. Masten
Keyword(s):  
Mass Transfer ◽  
High Pressure ◽  
Flow Rate ◽  
Ozone Concentration ◽  
Gas Flow ◽  
Water Flow Rate ◽  
Low Flow ◽  
Ozone Decomposition ◽  
Gas Flow Rate ◽  
Gaseous Ozone

AbstractThe effects of water flow rate, mixing, gaseous ozone concentration, inlet gas flow rate, temperature, and pH on ozone hydrodynamics at high pressure were studied. Varying the cross flow rate had only a slight influence on the ozone mass transfer rates, indicating that sufficient mixing in the reactor was attained at the low flow rates used. The addition of an inline static mixer had a negligible effect on aqueous ozone concentrations in the reactor, suggesting that mixing was sufficient without the mixer. The ozone mass transfer increased with increasing gaseous ozone concentration and with the inlet gas flow rate. The dissolved ozone concentration decreased with increasing pH due to the greater rate of ozone decomposition at higher pH. Increasing the temperature resulted in a decrease in the ozone mass transfer. A model to describe the ozone mass transfer was developed. Good agreement between the model predictions and the experimental data was achieved.

scholarly journals Thermal oxidation improvement in semiconductor wafer fabrication

2019 ◽  
Vol 10 (3) ◽  
pp. 1141
Author(s):  
Christopher Julian Mahandran ◽  
Abdul Yasser Abd Fatah ◽  
Nurul Aini Bani ◽  
Hazilah Mad Kaidi ◽  
Mohd Nabil Bin Muhtazaruddin ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Flow Rate ◽  
Gas Flow ◽  
Elevated Temperatures ◽  
Oxide Thickness ◽  
Oxidation Time ◽  
Low Flow ◽  
Gas Flow Rate ◽  
Semiconductor Wafer ◽  
Location Factor

Thermal oxidation is a process done to grow a layer of oxide on the surface of a silicon wafer at elevated temperatures to form silicon dioxide. Usually, it en- counters instability in oxide growth and results in variation in the oxide thickness formed.  This leads to downtime of furnace and wafer scrap.  This study focuses on the factors leading to this phenomenon and finding the optimum settings of these factors. The factors that cause instability to oxide thickness were narrowed down to location of wafer in furnace, oxidation time, gas flow rate and temperature. Characterization and optimization were done using Design of Experiments. Full factorial design was implemented using 4 factors and 2 levels, resulting in 16 runs. Data analysis was done using Multiple Regression Analysis in JMP software. Actual versus predicted plot is examined to determine whether the model fit is significant. Adjusted <em>R</em><sup>2</sup> value was obtained at 99.8% or 0.998 indicating that there is very minimal variation of the data not explained by the model and thus confirming that the model is good. From the effect test, the factors were narrowed down from 4 factors to 3 factors. Location factor was found to have no impact. Significant factors that have impact are gas flow rate, oxidation time and temperature. Analyzing the leverage plots and least square mean plots, temperature was found to have the highest impact on oxide thickness. The model was further analyzed using prediction profiler in JMP to find the optimum settings for thermal oxidation process to meet the target oxide thickness of 8000A. Optimum setting for temperature was found to be at 958 C, gas flow rate at low flow rate (H<sub>2</sub>:6.5 slm and O<sub>2</sub>:4.5 slm), oxidation time at 280 min and location of wafers at both zone 1 and zone 2.

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

On the Influence of Fluctuating Flow Rate Upon the Performance and Behaviour of Isothermal Reacting Systems

1998 ◽  
Vol 63 (6) ◽  
pp. 881-898
Author(s):  
Otakar Trnka ◽  
Miloslav Hartman
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Fluidized Bed Reactor ◽  
Computational Techniques ◽  
Continuous Stirred Tank Reactor ◽  
Gas Flow Rate ◽  
Solid Reaction ◽  
Continuous Stirred Tank ◽  
And Performance ◽  
Reacting Systems

Three simple computational techniques are proposed and employed to demonstrate the effect of fluctuating flow rate of feed on the behaviour and performance of an isothermal, continuous stirred tank reactor (CSTR). A fluidized bed reactor (FBR), in which a non-catalytic gas-solid reaction occurs, is also considered. The influence of amplitude and frequency of gas flow rate fluctuations on reactant concentrations at the exit of the CSTR is shown in four different situations.

scholarly journals Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Separation Efficiency ◽  
Circulation Rate ◽  
Solid Mass ◽  
Gas Flow Rate ◽  
Gas Leakage ◽  
Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

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