A CFD-based approach to optimize operating parameters of a flow-through scintillation cell for measurement of 220Rn in indoor environments

Abstract The article presents results of numerical analyzes, which raise a subject of influence of the cooperation the multi-piped impeller with a rationalized flow geometry of annular casing and volute casing for liquid flow through centrifugal pump and their operating parameters in the extremely low specific speed nq<10. The multi-piped impeller (patented by authors) is a major alternative to classic vane impellers. The stator type is responsible for the conversion of the kinetic energy of the liquid by the impeller outlet into potential energy, which determines the overall efficiency of the pump. Also, the article presents qualitative and quantitative verification of results obtained by computer modeling and an attempt to estimate their accuracy. The article focuses mainly on the comparison of the performance parameters of the pump with a multi-piped impeller in cooperation with two stator types with a rationalized flow geometry. Both outlet elements were tested in various configurations of constructional features. The complexity of the construction of the stator can significantly affect the manufacturing costs of pump unit. Knowledge concerning construction of hydraulic elements of centrifugal pumps working in the range of parameters corresponding specific speed (nq<10) is insufficient. As shown in the paper, the annular type casing model pump cooperating with a multi-piped impeller, designed in accordance with literature, reached far poorer operating parameters than the rational annular construction in a configuration with the same impeller.

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A study of disequilibrium between 220Rn and 216Po for 220Rn measurements using a flow-through Lucas scintillation cell

Radiation Protection Dosimetry ◽

10.1093/rpd/nct203 ◽

2013 ◽

Vol 158 (2) ◽

pp. 187-194 ◽

Cited By ~ 1

Author(s):

N. Sathyabama ◽

D. Datta ◽

J. J. Gaware ◽

Y. S. Mayya ◽

R. M. Tripathi

Keyword(s):

Flow Through ◽

Scintillation Cell

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Effect of Silt and Jet Diameter on Performance of Turgo Impulse Hydro Turbine

Volume 1A, Symposia: Keynotes; Advances in Numerical Modeling for Turbomachinery Flow Optimization; Fluid Machinery; Industrial and Environmental Applications of Fluid Mechanics; Pumping Machinery ◽

10.1115/fedsm2017-69527 ◽

2017 ◽

Cited By ~ 1

Author(s):

Sourabh Khurana ◽

Varun Goel ◽

Gurmeet Singh

Keyword(s):

Operating Parameters ◽

Impulse Turbine ◽

Efficiency Loss ◽

Hydro Turbine ◽

Power House ◽

Percentage Efficiency ◽

Flow Through ◽

Jet Velocity ◽

Hydro Turbines

Silt particles flow through hydro turbines cause erosion in turbines and due to silt efficiency of turbine reduces, vibrations produces in hydro turbines components and finally breakdown of hydro turbines take place, which causes immense losses. In the present study experiments were carried out to study the effect of silt size, silt concentration, jet velocity and operating hours on performance of Turgo impulse turbine. Silt was collected from Dehar power house (India). It has been found that erosion strongly depends on silt parameters (silt size, silt concentration) and operating parameters (Jet velocity and operating hours of turbine). A correlation has been developed as a function of jet diameter, silt parameters and operating parameters of percentage efficiency loss in Turgo impulse turbine.

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Microchannel filter for air purification

Open Physics ◽

10.1515/phys-2020-0153 ◽

2020 ◽

Vol 18 (1) ◽

pp. 241-254

Author(s):

Jonathan Rodriguez Andrade ◽

Ernst Kussul ◽

Tetyana Baydyk

Keyword(s):

Low Cost ◽

Air Flow ◽

Flow Simulation ◽

Air Purification ◽

Indoor Environments ◽

Contaminant Removal ◽

Human Beings ◽

Manufacturing Tests ◽

Triangular Profile ◽

Flow Through

AbstractIn this study, we propose a new design for a microchannel filter. The closed indoor environments with which we interact daily are sources of diseases for the respiratory system of human beings. Recommendations for the design of microchannel filters for indoor air purification are proposed, implementing low-cost microequipment technology (MET) for the manufacture of the elements that constitute a microfiltration system. For the microchannel filter production, we proposed to use MET, which is a miniaturization technology and can reduce manufacturing costs. The microchannel filter was 3.75 cm in radius with a thickness of 3 mm. It had a triangular profile and a helical trajectory. It was designed, manufactured, and tested for two profile dimensions. The main purpose was to reduce the pressure drop of the air flow through the filter. We described the air flow simulation for the microchannel filter using SolidWorks. A prototype microchannel filter was constructed, which underwent manufacturing tests. It is possible to clean the microchannel using water flow, which allows us to maintain the filtration quality within an optimum range of contaminant removal.

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Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072666 ◽

1973 ◽

Vol 31 ◽

pp. 444-445

Author(s):

P.J. Killingworth ◽

M. Warren

Keyword(s):

Electron Beam ◽

Organic Materials ◽

Operating Parameters ◽

Low Density ◽

Beam Diameter ◽

Incident Electron Beam ◽

Specimen Material ◽

Voltage Compensation ◽

Selection Of ◽

Scanning Electron

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

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Development of apical pits in chloride cells of the gills of Pimephales promelas after chronic exposure to acid water

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076044 ◽

1983 ◽

Vol 41 ◽

pp. 462-463

Author(s):

Richard L. Leino ◽

Jon G. Anderson ◽

J. Howard McCormick

Keyword(s):

Confidence Interval ◽

Chronic Exposure ◽

Lake Superior ◽

Pimephales Promelas ◽

Chloride Cells ◽

Fathead Minnows ◽

Secondary Lamellae ◽

Untreated Water ◽

Water Ph ◽

Flow Through

Groups of 12 fathead minnows were exposed for 129 days to Lake Superior water acidified (pH 5.0, 5.5, 6.0 or 6.5) with reagent grade H2SO4 by means of a multichannel toxicant system for flow-through bioassays. Untreated water (pH 7.5) had the following properties: hardness 45.3 ± 0.3 (95% confidence interval) mg/1 as CaCO3; alkalinity 42.6 ± 0.2 mg/1; Cl- 0.03 meq/1; Na+ 0.05 meq/1; K+ 0.01 meq/1; Ca2+ 0.68 meq/1; Mg2+ 0.26 meq/1; dissolved O2 5.8 ± 0.3 mg/1; free CO2 3.2 ± 0.4 mg/1; T= 24.3 ± 0.1°C. The 1st, 2nd and 3rd gills were subsequently processed for LM (methacrylate), TEM and SEM respectively.Three changes involving chloride cells were correlated with increasing acidity: 1) the appearance of apical pits (figs. 2,5 as compared to figs. 1, 3,4) in chloride cells (about 22% of the chloride cells had pits at pH 5.0); 2) increases in their numbers and 3) increases in the % of these cells in the epithelium of the secondary lamellae.

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Electron sources: Past, present, and future

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100149659 ◽

1993 ◽

Vol 51 ◽

pp. 764-765

Author(s):

David C Joy

Keyword(s):

Glass Tube ◽

Source Size ◽

Electron Gun ◽

Operating Parameters ◽

Operational Parameters ◽

Electron Sources ◽

Difficult Decision ◽

Probe Size ◽

Wide Range ◽

Overall Performance

The electron source is the most important component of the Scanning electron microscope (SEM) since it is this which will determine the overall performance of the machine. The gun performance can be described in terms of quantities such as its brightness, its source size, its energy spread, and its stability and, depending on the chosen application, any of these factors may be the most significant one. The task of the electron gun in an SEM is, in fact, particularly difficult because of the very wide range of operational parameters that may be required e.g a variation in probe size of from a few angstroms to a few microns, and a probe current which may go from less than a pico-amp to more than a microamp. This wide range of operating parameters makes the choice of the optimum source for scanning microscopy a difficult decision.Historically, the first step up from the sealed glass tube ‘cathode ray generator’ was the simple, diode, tungsten thermionic emitter.

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