scholarly journals Analysis of mapping of general II degree surfaces in collinear spaces

2010 ◽  
Vol 8 (3) ◽  
pp. 317-327
Author(s):  
Sonja Krasic ◽  
Biserka Markovic
Keyword(s):  
Common Elements ◽  
Characteristic Parameters ◽  
General Surface ◽  
Absolute Conic ◽  
The Common ◽  
Determination Of Parameters ◽  
Associated Pair

Mapping of projective creations which includes the II degree surfaces in the projective, general collinear spaces is complex. In order to simplify it, firstly the characteristic parameters must be constructively determined: vanishing planes, axes and centers of spaces. All II degree surfaces are mapped using the common elements of absolute conic and infinitely distant conic of quadrics in the infinitely distant plane of space, which provide the determination of parameters of any surface of II degree. The common elements of their associated pair of conics in vanishing plane of space are used. The paper analyzed the conditions of choice of general surface of II degree in the first space to be mapped into the respective general surface of II degree in the second collinear space. The mapping is biunivocal. A sphere is chosen in the first space, and it was analyzed how it should be placed in respect to the characteristic parameters of the space, so that it would be mapped in rotating or triaxial general surfaces of II degree in the second space.

scholarly journals Graphic representation of a triaxial ellipsoid by means of a sphere in general collinear spaces

2011 ◽  
Vol 9 (2) ◽  
pp. 269-275
Author(s):  
Sonja Krasic ◽  
Biserka Markovic
Keyword(s):  
General Position ◽  
Graphic Representation ◽  
Triaxial Ellipsoid ◽  
Common Elements ◽  
Characteristic Parameters ◽  
Absolute Conic ◽  
The Common ◽  
The Absolute ◽  
Straight Lines ◽  
Associated Pair

For graphic representation of the projective creations, such as the quadrics (II degree surfaces) in projective, general collinear spaces, it is necessary to firstly determine the characteristic parameters, such as: vanishing planes, axes and centers of space. An absolute conic of a space is an imaginary conic, residing in the infinitely distant plane of that space. The common elements of the absolute conic and infinitely distant conic of a quadric in the infinitely distant plane of that space are the autopolar triangle and two double straight lines which are always real and it is necessary to use the common elements of their associated pair of conics in the vanishing plane of the associated space. The quadric axes are passing through the apices of the autopolar triangle, and they are important for graphic representation of the quadrics. In order to map a sphere in the first space into the triaxial ellipsoid in the second space, it is necessary to select a sphere so that its center is not on the axis of that space and that it intersects the vanishing plane of the second space along the imaginary circumference, which is in general position with the figure of the absolute conic of the second space (the associated pair of conics in the vanishing plane).

scholarly journals Determination of parameters of abnormal wear of brake pads of freight cars

2020 ◽  
Vol 166 ◽  
pp. 07003
Author(s):  
Vasyl Ravlyuk ◽  
İsrail Elyazov ◽  
Ihor Afanasenko ◽  
Mykola Ravliuk
Keyword(s):  
Theoretical Research ◽  
Geometrical Parameters ◽  
Software Environment ◽  
Brake Shoe ◽  
Brake Pads ◽  
Centre Of Gravity ◽  
The Common ◽  
Mathcad Software ◽  
Determination Of Parameters

The complex of operational studies and theoretical research was performed on the occurrence of harmful wear that changes geometrical parameters of the useful contact area of the brake pads of freight cars at various established standard clearance between the pad and the wheel, which significantly impairs the braking efficiency of trains. The inspections of the mechanical part of the brakes attracted attention to the abnormal wear of the brake pads of the freight cars, which occurs because the common centre of gravity of the pad and the brake shoe, which are on the pendular suspension, do not coincide with the centre of the hole in the brake strut for any pad. The results of calculations using the coordinate method performed in the Mathcad software environment and the graphical one performed in AutoCAD to determine the geometrical parameters of the formation of the upper harmful wear of the pad depending on the standard clearance between the wheel and the brake pad were compared to proved theoretically that the error between them does not exceed 5-7%.

scholarly journals Determination of the Origin of Mukdadiya Formation’s Gravels in Al-Teeb Region, East of Maysan Governorate, Southern Iraq, Based on Sedimentological and Paleontological Evidence

2021 ◽  
pp. 2970-2982
Author(s):  
Maher M. Mahdi ◽  
Basim H. Soltan
Keyword(s):  
The Other ◽  
Common Elements ◽  
The Common ◽  
Southern Iraq ◽  
Paleontological Study

      Mukdadiya Formation represents one of the formations that cover a huge area of Iraq. It contains several clastic deposits, such as sandstone, siltstone, and a noticeable amount of gravels. The gravels are considered as the hallmark to differentiate between Injana and Mukdadiya formations. Therefore, the current study focused on these facies to determine the petrography, paleontology , and origin of Mukdadiya deposits. The results of SEM-EDX and XRD analyses showed two types of gravels, namely the siliceous and lime gravels. The highest percentage of gravels belonged to the sedimentary origin (limestone). The elements of Si, Ca, and Fe represented the common elements that formed the studied gravels. The paleontological study displayed numerous fossils that are composed of these gravels, belonging to several groups, including foraminifera, radiolaria, dinoflagellata, echinoida, gastropoda, and calcisphera.  Also, four microfacies were identified in the studied gravels. After comparison of all collected data with selected formations, the results confirmed that the origin of the derived gravels is from the Qulqula Formation, because of their content of radiolaria and the other characterizing fossils.

Determination of parameters of short circuit of power transformer by means of mathematical modeling

2017 ◽  
Vol 26 (102) ◽  
pp. 110-119
Author(s):  
D. S. Yarymbash, ◽  
◽  
S. T. Yarymbash, ◽  
T. E. Divchuk, ◽  
D. A. Litvinov
Keyword(s):  
Mathematical Modeling ◽  
Power Transformer ◽  
Short Circuit ◽  
Determination Of Parameters

Tests of jackhammers (formation of bench techniques)

2020 ◽  
pp. 28-32
Author(s):  
V.S. Vanaev
Keyword(s):  
Impact Energy ◽  
Bench Tests ◽  
Measuring Complex ◽  
Energy Indicators ◽  
Definition Of ◽  
Determination Of Parameters ◽  
Dynamic Indicators

Development of complex determination of parameters of jackhammers at bench tests is studied. The modern support of tests of jackhammers for the purpose of definition of their energy, vibration and noise indicators is considered. Descriptions of the SORP universal bench and UIPU measuring complex are given. Keywords jackhammer, bench, tests, processing object, energy indicators, impact energy, dynamic indicators [email protected]

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