COMPARATIVE ANALYSIS OF THE CALCULATION METHODS OF THE BACKGROUND CONCENTRATIONS OF MAJOR IONS IN THE LEFT TRIBUTARIES OF THE MIDDLE OB RIVER

Using the precision bomb combustion calorimeter B-08-MA, the combustion energies of 5- (2- nitrophenyl) -furan-2-carbaldehyde, 5- (2-nitro-4-methylphenyl) -furan-2-carbaldehyde and 5- ( 2-nitro-4- oxymethylphenyl) -furan-2-carbaldehyde. Based on the obtained data, the values of enthalpies of combustion and formation of substances in the condensed state are calculated. A comparative analysis of experimentally determined values with theoretically calculated values by additive calculation methods is given.

Download Full-text

Determining efficiency of cycloid reducers using different calculation methods

MATEC Web of Conferences ◽

10.1051/matecconf/201929001008 ◽

2019 ◽

Vol 290 ◽

pp. 01008

Author(s):

Milos Matejic ◽

Mirko Blagojevic ◽

Ileana Ioana Cofaru ◽

Nenad Kostic ◽

Nenad Petrovic ◽

...

Keyword(s):

Comparative Analysis ◽

Analytical Methods ◽

Common Property ◽

Experimental Results ◽

Calculation Methods ◽

Wide Range ◽

Pros And Cons ◽

Gear Trains ◽

Central Gear ◽

The Way

Cycloid reducers are gear trains which can be classified as planetary transmissions. These transmissions have a very wide range of uses in industry in transporters, robots, satellites, etc. This research presents a comparative analysis of three analytical methods for determining cycloid drive efficiency. The paper explores every mathematically formulated method and compares them to experimental results from literature. The presented methods for determining efficiency have a common property, in that they all determine losses due to friction on the bearing cam surface of the shaft, the rollers of the central gear and the output rollers. The calculation of efficiency values is done for standard power values. The methods differ primarily in the way they calculate losses. For each method of calculating efficiency there is an analysis of pros and cons. The paper concludes with suggestions as well as possible directions for further research.

Download Full-text

A comparative analysis of the calculation methods of the heat emission during heating water with underheating

Thermal Engineering ◽

10.1134/s0040601513080089 ◽

2014 ◽

Vol 61 (3) ◽

pp. 203-209

Author(s):

O. E. Stepanov ◽

V. E. Karnaukhov ◽

A. M. Khudyakov ◽

Yu. N. Eikhorn ◽

A. V. Bulanov ◽

...

Keyword(s):

Comparative Analysis ◽

Heat Emission ◽

Calculation Methods ◽

Heating Water

Download Full-text

On the Issue of Correction of Calculation Methods and Initial Hydrological and Hydro/chemical Information Input in the Process of Regulation of the Technogenic Impacts on Water Bodies

Water sector of Russia: problems, technologies, management - Методы оценки и механизмы регулирования водопользования в современных условиях ◽

10.35567/1999-4508-2017-1-5 ◽

2017 ◽

Author(s):

Keyword(s):

Water Consumption ◽

Sufficient Conditions ◽

Chemical Information ◽

Background Concentrations ◽

Calculation Methods ◽

Initial Information ◽

One Dimensional ◽

Normal Water ◽

Information Input ◽

Discharge Method

Issues concerning the correctness of the currently used system of admissible discharge norms development, as well as the practice of initial hydrological and hydro/chemical information input have been considered. Required and sufficient conditions of V.A. Frolov – I.D. Rodziller and A.V. Karaushev methods application have been substantiated. The necessity of transfer to the use of combined schemes including one-dimensional, two-dimensional and threedimensional models in calculation of the admissible discharge norms has been demonstrated. The above models enable to calculate the watercourse hydrodynamic parameters in accordance with the normal water consumption morphometry provided the hydrodynamic blocks availability. Within-year and inter-year non-stationarity of the hydrological and hydro/chemical characteristics’ rows used in development of the admissible discharge norms development has been discussed, the necessity of the minimal water consumption correction in these calculations due to climate change has been proved. Assessment of correctness of the currently adopted in the admissible discharge method heterogeneity threshold for background concentrations values both by analytic methods and by the direct statistical methods (Monte-Carlo method) has been carried out. It was proved that application of non-parametric criteria in input of hydro/chemical initial information was effective. Comparative assessment of the median and average arithmetic values use in the hydro/chemical information analyzing was conducted.

Download Full-text

Study on Improving the Empirical Formula of Calculating Francis Turbine’s Axial Hydro-Thrust

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.733.619 ◽

2015 ◽

Vol 733 ◽

pp. 619-622

Author(s):

Xi Zhao ◽

Li Zhu

Keyword(s):

Comparative Analysis ◽

Working Conditions ◽

Empirical Formula ◽

Hydropower Station ◽

Calculation Methods ◽

Operational Parameters ◽

Flow Head

This paper improved the empirical formula so that it can calculate the axial hydro-thrust under different working conditions. Then based on the operational parameters of a hydropower station, two calculation methods were used to calculate axial hydro-thrust and made comparative analysis. The results show that the improved formula is simple in computation and closely combined with parameters like flow, head and speed, and its calculation accuracy satisfies the engineering demand.

Download Full-text