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Abstract

Preamble

All that surrounds us – atoms gathered in a molecules, which in their turn, form each individual object. For people involved in chemistry and chemical processes, it is important to have an understanding of the interaction of atoms constituting a particular molecule. Before proceeding to the pilot phase of the study of chemical reactions increasingly there is a need imaging particles of chemical elements. Such a task is the goal of this project.

1. Common conceptions

Agglomerates – a collection of particles, held firmly together. The particles in the agglomerates are interconnected stronger interactions than aggregates. The agglomerates can be considered as a "secondary" particles having an inner surface, so in many cases, the internal surface of area is much bigger external. Thus structured agglomerates may have a porous system. Exemplary agglomerates are sandstone, silica gel, etc. Clear distinction between the concepts of "unit" and "agglomerate" does not exist, and sometimes they are used to describe the same objects. In some cases (for example, to describe the technology of pigments, etc.) developed terminology, when the terms "aggregate" and "agglomerate" have values that are contrary to the recommendations of the International Union of Pure and Applied Chemistry (IUPAC). In this regard, the use of the concepts of "aggregate" or "agglomerate" often indicate a strong or weak interactions are present between the primary particles [1].

Each molecule – agglomerate, is an object of indeterminate shape. This means that there are no molecules in the form of ideal spheres, cubes, pyramids, etc. However, for example, known number of atoms of which the agglomerate is active. Question of their porosity and mutual arrangement within the scope of molecules. Program writing which is the end result of this work will allow it to find out and explore before moving on experimental level.

2. Programm's desription

The process of writing of program was conditionally divided into 6 parts:

  1. Reading coordinates of the object from the file.
  2. Create search procedure volume of the object.
  3. Finding the extreme points of the object.
  4. Finding the volume of the parallelepiped with coordinates angles corresponding to the extreme points of the object.
  5. Create Validation procedures falling atom within the object.
  6. Filling volume atoms.

Achieved 5 of 6 points for completing the 3-D object adelomorphous spheres using the programming language C++, and files with the extension. stl.

STL (from the English. stereolithography) – a file format widely [3][4] is used to store three–dimensional models of objects for use in rapid prototyping technology, usually by stereolithography. Information about the object is stored as a list of triangular facets that describe its surface, and their normals. STL-file STL-file can be a text (ASCII) or binary [2].

Face normals – in Binary and ASCII versions of STL, face normal to be a unit vector directed from the object. Most programs can be set to (0,0,0), and the program will automatically calculate based on the normal order of the vertices of a triangle using the right–hand rule. Some STL loaders (eg STL plugin for Art of Illusion), collate the normal file with those calculated from the right hand rule and warn if not coincidence. Other software can be ignored and only use the right–hand rule [2].

    3. Solution of the problem and researchings

  1. Reading coordinates of the object from the file

    Initial data of the program are the coordinates of the triangles forming the agglomerate. File from which they come, has an extension. Stl and has the same normal coordinates for each of the triangles. These normals are read together with the triangles, to which they relate.

    Shape 1, sizes: 364*254, size: 51,2 Kbites
  2. Create search procedure volume of the object

    Omitted from any point to direct each of the triangles, and the volume is calculated and the resulting pyramid depending on the direction of the normal set a positive or negative sign. Then all received values are added and the result is the amount of the entire facility.

  3. Finding the extreme points of the object Here

    Simple sorting triangles coordinates are positive and negative extremes of the three axes X, Y, Z. They are remembered as the extreme points of the object.

  4. Finding the volume of the parallelepiped with coordinates angles corresponding to the extreme points of the object

    Using the data obtained in the preceding paragraph, a box is created. The purpose of this action will be explained further.

  5. Create Validation procedures falling atom within the object

    The smallest atom – an atom of helium having a radius of 32 pm, and the largest – cesium atom (225 pm). These dimensions are thousands of times smaller than the wavelength of visible light (400–700 nm), the atoms can not therefore be seen in the light microscope. Since the atoms are very small, while rendering spheres they are portrayed. For clarity, as for example let's say that the size of the protein molecule is 43*10 –8 cm

    6. Each atom has its own coordinate and radius. From this position in the corners of the parallelepiped are held straight and checked the number of intersections with the triangles forming the object. If the number of intersections of each line with triangles is odd, then the atom is inside the object.

  6. Filling volume of 3D–objects with atoms.

    This step is in development and is for the task at end. However, after various modifications like simulations of movement and collisions of atoms, heating or cooling of sinter and demonstration that entail in consequence of these physical processes.

    Shape 2, sizes: 413*404, size: 79.1 Kbites

    Summation

    When performing work on reference materials used C++, mathematical formulas to calculate the volume of bodies in 3D-space.

In writing this essay master's work is not yet complete. Final completion : December 2014. Full text of the work and materials on the topic can be obtained from the author or his manager after that date.

References

1. Àãëîìåðàò (õèìèÿ). Internet resource. Access mode: http://ru.wikipedia.org/wiki/%D0%90%D0%B3%D0%BB%D0%BE%D0
2. STL (ôîðìàò ôàéëà). Internet resource. Access mode: http://ru.wikipedia.org/wiki/STL
3. Photogrammetry getting more out of the 3x3 rules. Internet resource. Access mode: http://billboyheritagesurvey.wordpress.com/
4. Molecule mass. Internet resource. Access mode:: http://av-physics.narod.ru/molecule/molecule-mass.htm
5. Àòîì. Internet resource. Access mode:http://ru.wikipedia.org/wiki/Àòîì
6. Ïåðåñå÷åíèå ïðÿìîé ñ ïëîñêîñòüþ. Internet resource. Access mode: http://www.gamedev.ru/code/faq/?id=3629 — ïåðåñå÷åíèå ïðÿìîé ñ ïëîñêîñòüþ.
7. A method to calculate the centre of mass. Internet resource. Access mode:http://stackoverflow.com/questions/2083771/a-method-to-calculate-the-centre-of — A method to calculate the centre of mass
8. Determining Whether A Point Is Inside A Complex Polygon. Internet resource. Access mode:http://alienryderflex.com/polygon/ — Determining Whether A Point Is Inside A Complex Polygon.
9. Ïåðåñå÷åíèå ëó÷à è òðåóãîëüíèêà. Internet resource. Access mode:http://www.gamedev.ru/code/forum/?id=64824&page=1 — ïåðåñå÷åíèå ëó÷à è òðåóãîëüíèêà.