A Little Algebraic Surface Theory

2012 ◽  
pp. 189-201
Author(s):  
Donu Arapura
Keyword(s):  
Algebraic Surface ◽  
Surface Theory

Topological characterization of C2 via open algebraic surface theory

2020 ◽  
Vol 31 (07) ◽  
pp. 2050055
Author(s):  
R. V. Gurjar ◽  
Sudarshan Gurjar
Keyword(s):  
Algebraic Surface ◽  
Algebraic Surfaces ◽  
Topological Characterization ◽  
Surface Theory ◽  
Affine Line

We will give a new proof of Ramanujam’s topological characterization of the affine [Formula: see text]-space [Formula: see text] using the Abhyankar–Moh–Suzuki theorem on embeddings of the affine line in [Formula: see text] and some ideas from the theory of open algebraic surfaces.

Continuity of lifting surface theory in subsonic and supersonic flow

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 1788-1791
Author(s):  
Tetsuhiko Ueda
Keyword(s):  
Supersonic Flow ◽  
Surface Theory ◽  
Lifting Surface

scholarly journals Isotopic triangulation of a real algebraic surface

2009 ◽  
Vol 44 (9) ◽  
pp. 1291-1310 ◽  
Author(s):  
Lionel Alberti ◽  
Bernard Mourrain ◽  
Jean-Pierre Técourt
Keyword(s):  
Algebraic Surface ◽  
Real Algebraic Surface

scholarly journals On the Reconstruction of the Center of a Projection by Distances and Incidence Relations

2020 ◽  
Author(s):  
András Pongrácz ◽  
Csaba Vincze
Keyword(s):  
Algebraic Surface ◽  
Basic Problem ◽  
Rotational Symmetry ◽  
Image Plane ◽  
Equivalent Condition ◽  
Central Projection ◽  
Profile Curve ◽  
Reconstruction Process ◽  
Restricted Area ◽  
Photographic Images

AbstractUp to an orientation-preserving symmetry, photographic images are produced by a central projection of a restricted area in the space into the image plane. To obtain reliable information about physical objects and the environment through the process of recording is the basic problem of photogrammetry. We present a reconstruction process based on distances from the center of projection and incidence relations among the points to be projected. For any triplet of collinear points in the space, we construct a surface of revolution containing the center of the projection. It is a generalized conic that can be represented as an algebraic surface. The rotational symmetry allows us to restrict the investigations to the defining polynomial of the profile curve in the image plane. An equivalent condition for the boundedness is given in terms of the input parameters, and it is shown that the defining polynomial of the profile curve is irreducible.

scholarly journals An inversion theorem in Fermi surface theory

2000 ◽  
Vol 53 (11) ◽  
pp. 1350-1384 ◽  
Author(s):  
Joel Feldman ◽  
Manfred Salmhofer ◽  
Eugene Trubowitz
Keyword(s):  
Fermi Surface ◽  
Surface Theory ◽  
Inversion Theorem

Unsteady Lifting Surface Theory for a Rotating Cascade of Swept Blades

1989 ◽  
Author(s):  
Hidekazu Kodama ◽  
Masanobu Namba
Keyword(s):  
Three Dimensional ◽  
Acoustic Power ◽  
Aerodynamic Characteristics ◽  
Blade Loading ◽  
Surface Theory ◽  
Numerical Examples ◽  
Lifting Surface ◽  
Blade Flutter ◽  
Annular Cascade ◽  
Remarkable Reduction

A lifting surface theory is developed to predict the unsteady three-dimensional aerodynamic characteristics for a rotating subsonic annular cascade of swept blades. A discrete element method is used to solve the integral equation for the unsteady blade loading. Numerical examples are presented to demonstrate effects of the sweep on the blade flutter and on the acoustic field generated by interaction of rotating blades with a convected sinusoidal gust. It is found that increasing the sweep results in decrease of the aerodynamic work on vibrating blades and also remarkable reduction of the modal acoustic power of lower radial orders for both forward and backward sweeps.

The influence of rectangular shape holes on energy intensity of grinding grain

2021 ◽  
pp. 18-23
Author(s):  
A. V Cherepkov ◽  
I. V. Konoshin
Keyword(s):  
Gastric Juice ◽  
Specific Energy ◽  
Energy Intensity ◽  
Conversion Coefficient ◽  
Grinding Process ◽  
Theoretical Evaluation ◽  
Surface Theory ◽  
Rectangular Shape ◽  
German Scientist ◽  
Circular Shape

Grain before feeding to animals exposed to grinding with the purpose of increasing its digestibility. As a result of this increases the area of interaction of the feed with the gastric juice and decreases the conversion coefficient. Surface theory formulated by German scientist Rittinger, suggests that the work of AR required for the grinding process is directly proportional to newly formed surface. The purpose of this paper is a theoretical evaluation of the intensity of grinding with the use of sieves with rectangular and circular shape holes. When getting groats with the same grinding module by the use of sieves with holes of rectangular shape, one should expect the decrease of specific energy intensity. By reducing the content of dust-like fractions and reduce the total surface feed should be expected to reduce the energy intensity of pneumo transportation.

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