scholarly journals Portable System for Sampling Liquid Atmospheric Precipitation

2020 ◽  
pp. 71-78
Author(s):  
A. Zdobytskyi ◽  
O. Matviykiv ◽  
M. Lobur ◽  
T. Klymkovych ◽  
N. Bokla
Keyword(s):  
Mass Flow ◽  
Total Mass ◽  
Atmospheric Precipitation ◽  
Portable Device ◽  
Working Capacity ◽  
Design Features ◽  
Time Intervals ◽  
Mechanical Parts ◽  
Sources Of Pollution ◽  
Portable System

The paper considers the possibility of determining the permanent and random sources of pollution of the environment by the level of pollution of liquid atmospheric precipitation. The problems of liquid atmospheric precipitation testing and monitoring of pollution concentration during precipitation are outlined. The expediency of developing of a portable system that allows collecting samples of liquid atmospheric precipitation in autonomous modes at different time intervals and periods of rainfall, regardless of the place of its installation, is substantiated. The design features of the electric and mechanical parts of the device, as well as the algorithm of their work, are described. The results of modeling and checking of the working capacity of the portable device, which determine the total mass flow of water, are described.

Nearly free-molecular slit flow at finite pressure and temperature ratios

1971 ◽  
Vol 50 (3) ◽  
pp. 565-577 ◽  
Author(s):  
P. Y. Wang ◽  
E. Y. Yu
Keyword(s):  
Mass Flow ◽  
Total Mass ◽  
Noble Gas ◽  
Order Correction ◽  
Linear Boltzmann Equation ◽  
Molecular Flow ◽  
First Order ◽  
Slit Flow ◽  
Isothermal Case ◽  
First Order Correction

An analytical study is made of nearly free-molecular flow of a noble gas from one reservoir to another through a two-dimensional slit, with finite pressure and temperature ratios across the slit. The fundamental solution of the linear Boltzmann equation is employed in the study. The total mass flow is calculated to the first-order correction terms, of the order of α ln α and α, where α is the inverse Knudsen number. The coefficients of these terms are in general multiple integrals, but they become explicit functions of the pressure and temperature ratios after the multiple integrations are carried out by using Krook collision model. When the general result is simplified to the isothermal case the first-order correction has a negative value, indicating the reduction of the total mass flow due to intermolecular collisions in the counter flows.

Nonpoint sources of pollution in the Morava River basin

1996 ◽  
Vol 33 (4-5) ◽  
pp. 127-135 ◽  
Author(s):  
D. Beránková ◽  
J. Ungerman
Keyword(s):  
River Basin ◽  
Mass Flow ◽  
Quality Parameters ◽  
Mineral Nitrogen ◽  
Nitrogen Fertilizers ◽  
Large Area ◽  
Nonpoint Sources ◽  
Sources Of Pollution ◽  
Morava River ◽  
Morava River Basin

The diversity of natural conditions as well as the industrial and agricultural character of the landscape are responsible for changes influencing the share of point and nonpoint sources of pollution in the Morava River basin. Nonpoint sources of pollution were specified on the basis of data on agriculture, forestry, erosion, suspended solids, water quality parameters, mass flow of nutrients and atmospheric deposition. The relationship between concentrations of nitrates and application rates of mineral nitrogen fertilizers in the lower part of the Morava River basin was significant. In the longitudinal profile of the Morava River concentrations of mineral nitrogen and total phosphorus were specified and mass flow calculated by characteristic discharge. Changes of political system in 1989 in the Czech Republic initiated dynamic development of the state agricultural policy with consequences for the intensity of nonpoint pollution. Mainly in the field of plant and animal production some influences were evidently reduced. Consumption of industrial fertilizers was minimized to 13 of the former level and livestock population was also significantly decreased. Although privatization in agriculture is practicaly finished, there are not many positive changes in the field of large-area land use and structure of plots. The process of soil erosion still causes damages of land and pollution of surface waters.

STAGES OF VACUUM FISH-PUMP UNIT OPERATION

Fisheries ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. 108-112 ◽  
Author(s):  
Vladimir Naumov ◽  
Nikolay Velikanov
Keyword(s):  
Numerical Method ◽  
Vacuum Pump ◽  
Unit Operation ◽  
Working Capacity ◽  
Pump Unit ◽  
Time Intervals ◽  
Pump Operation ◽  
Water Fish ◽  
Pressure Changes ◽  
Water Ring

The article describes the features of modeling the stages of pumping a water- fish mixture using a water-ring vacuum pump. The dynamics of pressure changes in the working capacity during pump operation for different time intervals is considered. Solutions of the corresponding differential equations are obtained using the numerical method. The results of calculating the characteristics of the process of pumping the water- fish mixture into the receiving container are presented.

CVD of Carbide Multi-Phased Coatings

1999 ◽  
Vol 581 ◽  
Author(s):  
K.E. Versprille ◽  
Hua Xia Ji ◽  
C.C. Amato-Wierda ◽  
P.J. Ramsey ◽  
D.A. Wierda
Keyword(s):  
Mass Flow ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Total Mass ◽  
Fractional Factorial Design ◽  
Chemical Vapor ◽  
Fractional Factorial ◽  
Deposited Film ◽  
Reactor Pressure

ABSTRACTTiC and Ti-W-C films have been produced by chemical vapor deposition (CVD). A fractional factorial design was used to study the effects of deposition temperature, C:Ti input, H:Ti input, reactor pressure, and total mass flow on TiC film composition. Statistical models were developed for both titanium at.% and C:Ti in the film. It was found that the most significant affect on titanium at.% was the interaction of temperature, pressure and total mass flow. The most important affect on the C:Ti in the deposited film was the interaction C:Ti input, H:Ti, and total mass flow. Ti-W-C films have been deposited at 1050°C at various (TiCl4+W(CO)6)/CH4 inlet ratios ranging from 0.53 to 1.01. The characterization of the films revealed that the changes in deposition rate, crystallinity, film orientation, and morphology of various Ti-W-C compositions were affected by (TiCl4+W(CO)6)/CH4 inlet ratios.

Performance Characteristics of a Centrifugal Compressor with Air Injection

1973 ◽  
Vol 187 (1) ◽  
pp. 425-434 ◽  
Author(s):  
J. D. Ledger ◽  
R. S. Benson ◽  
H. Furukawa
Keyword(s):  
Mass Flow ◽  
Centrifugal Compressor ◽  
Total Mass ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Performance Characteristics ◽  
Air Injection ◽  
Delivery Pressure ◽  
Mass Flow Rates ◽  
The Right

The parameters which influence the performance characteristics of centrifugal compressors with air injection through nozzles at the rotor tip are developed using both dimensional analysis and a simple model. Experiments on a small centrifugal compressor show that the injection air pressure is the main influence on the overall performance such as excess torque, increased delivery pressure and increased delivery flow. With air injection the pressure-mass flow characteristics are displaced to the right with surge occurring at increased total mass flow rates and the overall pressure ratio across the compressor is increased for the same total mass flow.

An Enhanced Off-Design Performance Model for Single Stage Fans

2014 ◽  
Author(s):  
Joachim Kurzke
Keyword(s):  
Flow Field ◽  
Mass Flow ◽  
Rotor Blade ◽  
Total Mass ◽  
Pressure Ratio ◽  
Fan Performance ◽  
The Core ◽  
Velocity Triangle ◽  
Tip Radius ◽  
Bypass Ratio

Modern high bypass turbofan engines have single stage fans with a low hub-tip radius ratio. The fan map is a very important element for off-design performance simulations. Such a map consists of tables with corrected mass flow, pressure ratio and efficiency for a range of corrected spool speeds. Applying the data read from a fan map to both the core and the bypass stream is inaccurate because the transonic flow field of the bypass stream is very different to the subsonic flow field of the core stream. A better approximation of reality is to use a hybrid map with total mass flow, bypass pressure ratio and efficiency. Constant factors are employed to derive the core stream pressure ratio and efficiency. For more accurate simulations two maps may be employed, one for the core and another one for the bypass stream. The total mass flow of the fan is the same in these two maps while pressure ratio and efficiency are different for the two streams. The data for each point in this so-called “Split Map” are valid for a pre-defined bypass ratio. This paper describes an alternative to the split map methodology which takes the variability of the bypass ratio into account in a different way. The hypothesis is that the overall fan performance is not affected by variations in bypass ratio. The fan performance map is completed by an additional table with core stream efficiency. This enhanced map is used as follows. When scaling the map, the bypass ratio as well as the pressure ratio and efficiencies for the core and bypass streams are known. Assumed values for fan tip speed, hub-tip radius ratio and fan inlet Mach number yield the core stream velocity triangle. The rotor blade exit flow angle from this triangle remains the same in all other operating conditions. The core flow velocity triangle analysis with known rotor blade exit angle yields the work done on the core stream during off-design. The pressure ratio is calculated from this work and the efficiency read from the core stream efficiency table mentioned above. Finally, the bypass stream pressure ratio and efficiency are calculated from the overall map and the core stream data applying the actual bypass ratio.

scholarly journals Ensuring the environmental safety of residential areas of settlements based on the monitoring of acidic impurities in the atmospheric air кислых примесей в атмосфере

2021 ◽  
Vol 48 (3) ◽  
pp. 93-98
Author(s):  
I. Yu. Glinyanova
Keyword(s):  
Environmental Pollution ◽  
Atmospheric Precipitation ◽  
Environmental Safety ◽  
Prunus Armeniaca ◽  
Environmental Risks ◽  
Residential Areas ◽  
Atmospheric Air ◽  
Sources Of Pollution ◽  
Volgograd Region ◽  
Environmental Measures

Objectives. Purpose Monitoring of acidic impurities in the atmospheric air of residential areas of settlements is one of the areas of ensuring their environmental safety and is officially carried out at 221 stations in the Russian Federation in the study of atmospheric precipitation.Method. In areas where they are minimal, the author proposes an alternative method for assessing environmental pollution based on the preparation of aerosol suspensions. The purpose of this work was to study the acidity index (pH) of aerosol suspensions (washing off aerosols from the leaves of apricot trees (Prunus armeniaca) obtained in the Srednyaya Akhtuba region (Sredneakhtubinsky district of the Volgograd region) in the spring-summer of 2020.Result. The results of the research demonstrated acidic aerosols ( pH = 5.32 + 0.01) in the atmospheric air rp Srednyaya Akhtuba in comparison with the conditionally clean zone (SNT "Oroshenets", "Shelf"), (pH = 6.39 + 0.02) The data indicate environmental pollution and on environmental risks for the population.Conclusion. Acidic impurities in the atmosphere of the middle Akhtuba region in comparison with the conditionally clean zone (SNT "Oroshenets", "Shelf"), which indicates environmental risks for the population. sources of pollution in residential areas of the settlement of Srednyaya Akhtuba and to develop environmental measures to protect the population from acidic impurities contained in aerosols, which requires further study of the territory.

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