scholarly journals Analysis of thermal and gas-dynamic characteristics of different types of propellant in small weapons

2021 ◽  
pp. 138-138
Author(s):  
Abaci Boukera ◽  
Nebojsa Hristov ◽  
Ahmed Ziane ◽  
Damir Jerkovic ◽  
Slobodan Savic
Keyword(s):  
Dynamic Characteristics ◽  
Analytical Approach ◽  
Experimental Tests ◽  
Weapon System ◽  
Model Calculations ◽  
Muzzle Velocity ◽  
Gas Dynamic ◽  
Internal Ballistics ◽  
Different Types

This paper presents a numerical and an analytical approach for calculation of internal ballistics parameters through determination of thermal and gas- dynamic characteristics. The calculated parameters are validated through experimental tests on a real weapon system. The internal ballistic calculations are provided for two types of propellants using an analytical and a numerical model. Calculations and tests are performed for an anti-material rifle 12.7 mm. Weapon and ammunition testing is carried out according to the C.I.P. (Permanent International Commission) standard. Theoretical and experimental results for the gunpowder gases pressure and the muzzle velocity are compared. The good agreements between the calculated and the measured pressures and velocities increase the reliability of the estimated gunpowder gas temperatures in the barrel. The obtained results enable analysis and comparison of the output internal ballistics parameters for different types of propellant applications.

Statistical Description of Isotope Exchange Processes: A Multisite Model for the 18O Exchange

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1161-1169 ◽  
Author(s):  
Paul Rösch
Keyword(s):  
Active Site ◽  
Isotope Exchange ◽  
Analytical Procedure ◽  
Matrix Formalism ◽  
Model Calculations ◽  
Exchange Processes ◽  
Reaction Solution ◽  
Different Types ◽  
Refinement Procedure

Abstract An analytical procedure has been developed for the determination of isotope exchange processes as exemplified by the 18O exchange catalysed by enzyme-nucleotide complexes. The model is able to handle more than one type of active site per reaction solution and is also able to distinguish between different types of inequivalence of the oxygens of enzyme bound Pi. Use of transition matrix formalism and basic statistical considerations lead directly to the simple model. A data refinement procedure is introduced and model calculations are shown.

scholarly journals DETERMINATION OF THE DYNAMIC CHARACTERISTICS OF FREIGHT WAGONS WITH VARIOUS BOGIE

Transport ◽  
2015 ◽  
Vol 30 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Sergey Myamlin ◽  
Leonas Povilas Lingaitis ◽  
Stasys Dailydka ◽  
Gediminas Vaičiūnas ◽  
Marijonas Bogdevičius ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Traffic Safety ◽  
Realistic Potential ◽  
Dynamic Coefficients ◽  
Different Types ◽  
Maintenance Cycle ◽  
The Stability ◽  
Durability Performance ◽  
Dynamic Indicators

In most cases, dynamic characteristics determine the wagon maintenance cycle, traffic safety, reliability and durability performance. The main dynamic indicators include the vertical Kvd and horizontal Khd dynamic coefficients as well as the stability coefficient Ks, which determines the wheel flange resistance to derailment. The article compares dynamic indications for three different types of bogies. There were no tangible differences observed for all the three different types of bogies running at a speed of 40 to 120 km/h on a direct tangent rail section. Nevertheless, there is a realistic potential to improve the dynamic indicators of a freight wagon by rationalising suspension unit parameters.

scholarly journals Gas-dynamic characteristics of the host rocks of Mir pipe mine field deep horizons

2021 ◽  
Vol 44 (3) ◽  
pp. 293-300
Author(s):  
S. A. Yannikova ◽  
A. M. Yannikov
Keyword(s):  
Chemical Composition ◽  
Dynamic Characteristics ◽  
Field Experiments ◽  
Industrial Safety ◽  
Mountain Range ◽  
Mine Field ◽  
Fluid Saturation ◽  
Gas Dynamic ◽  
Under Construction

The purpose of the research is to study the gas-dynamic characteristics of deep horizons of the Mir pipe mine field to ensure industrial safety under construction and production resumption at the field. The study is based on the interval field experiments carried out during drilling and subsequent study of the core. The main gas-dynamic parameters of the deep horizons of the field were studied during the drilling of pilot wells that enabled to perform interval determination of the flow rates of formation gases using packers and complex research equipment, gas sampling for the determination of chemical composition of gases, and gas logging. The conducted works resulted in the formulation of the gas-dynamic characteristic of the Tolbachan formation within the mine field of the Mir pipe. Reservoir intervals were identified and the nature of their fluid saturation was determined. The chemical composition of formation gases was clarified and gas release nature and intensity were studied both under drilling and interval testing. The result of the research carried out was identification of zones with different fluid manifestations, as well as comparison of the field under investigation with the previously studied International pipe. The results of the conducted research works will form the basis for performing design forecast calculations, as well as for making the main design decisions under construction of capital mine workings, especially in terms of advanced degassing of the mountain range. Consideration of the zones identified within the Tolbachan formation, which feature different nature of fluid saturation, will allow to take into account and minimize possible adverse factors.

scholarly journals 1001 - A tool for binary representations of unordered multistate characters (with examples from genomic data)

2015 ◽  
Author(s):  
Evgeny V Mavrodiev
Keyword(s):  
Analytical Approach ◽  
A Priori ◽  
Cladistic Analysis ◽  
Genomic Data ◽  
Molecular Data ◽  
Sequence Alignments ◽  
Different Types ◽  
Binary Matrices ◽  
Historical Basis

In modern molecular systematics, matrices of unordered multistate characters, such as DNA sequence alignments, are used for analysis with no further re-coding procedures nor any a priori determination of character polarity. Here we present 1001, a simple freely available Python-based tool that helps re-code matrices of non-additive characters as different types of binary matrices. Despite to the historical basis, our analytical approach to DNA and protein data has never been properly investigated since the beginning of the molecular age. The polarized matrices produced by 1001 can be used as the proper inputs for Cladistic analysis, as well as used as inputs for future three-taxon permutations. The 1001 binary representations of molecular data (not necessary polarized) may also be used as inputs for different parametric software. This may help to reduce the complicated sets of assumptions that normally precede either Bayesian or Maximum Likelihood analyses.

scholarly journals 1001 - A tool for binary representations of unordered multistate characters (with examples from genomic data)

2015 ◽  
Author(s):  
Evgeny V Mavrodiev
Keyword(s):  
Analytical Approach ◽  
A Priori ◽  
Cladistic Analysis ◽  
Genomic Data ◽  
Molecular Data ◽  
Sequence Alignments ◽  
Different Types ◽  
Binary Matrices ◽  
Historical Basis

In modern molecular systematics, matrices of unordered multistate characters, such as DNA sequence alignments, are used for analysis with no further re-coding procedures nor any a priori determination of character polarity. Here we present 1001, a simple freely available Python-based tool that helps re-code matrices of non-additive characters as different types of binary matrices. Despite to the historical basis, our analytical approach to DNA and protein data has never been properly investigated since the beginning of the molecular age. The polarized matrices produced by 1001 can be used as the proper inputs for Cladistic analysis, as well as used as inputs for future three-taxon permutations. The 1001 binary representations of molecular data (not necessary polarized) may also be used as inputs for different parametric software. This may help to reduce the complicated sets of assumptions that normally precede either Bayesian or Maximum Likelihood analyses.

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