Current Issue : January - March Volume : 2014 Issue Number : 1 Articles : 4 Articles
The article is to study the development of computer-aided design of X-ray microtomographyââ?¬â?the device for investigating\r\nthe structure and construction of three-dimensional images of organic and inorganic objects on the basis of shadow\r\nprojections. This article provides basic information regarding CAD of X-ray microtomography and a scheme consisting\r\nof three levels. The article also shows basic relations of X-ray computed tomography, the generalized scheme of an Xray\r\nmicrotomographic scanner. The methods of X-ray imaging of the spatial microstructure and morphometry of\r\nmaterials are described. The main characteristics of an X-ray microtomographic scanner, the X-ray source, X-ray optical\r\nelements and mechanical components of the positioning system are shown. The block scheme and software functional\r\nscheme for intelligent neural network system of analysis of the internal microstructure of objects are presented.\r\nThe method of choice of design parameters of CAD of X-ray microtomography aims at improving the quality of design\r\nand reducing costs of it. It is supposed to reduce the design time and eliminate the growing number of engineers\r\ninvolved in development and construction of X-ray microtomographic scanners....
A new method of material identification has been developed utilising pixellated X-ray diffraction (PixD) to probe the\r\nmolecular structure of hidden items. Since each material has a unique structure, this technique can be used to\r\nââ?¬Å?fingerprintââ?¬Â items and has significant potential for use in security applications such as airport baggage scanning. The\r\npixellated diffraction technique allows two distinct forms of diffraction, angular-dispersive and energy-dispersive X-ray\r\ndiffraction, to be combined, exploiting the benefits of both. Thus, fast acquisition times are possible with a small\r\nsystem which contains no moving parts and can be easily implemented. In this work, the capability of the system to\r\nidentify specific materials within a sample is highlighted. Such an approach would be highly beneficial for detecting\r\nexplosive materials which are concealed amongst or inside other masking items. The technology could easily be\r\nadded to existing baggage scanning equipment and would mean that if a suspicious item is seen in a regular X-ray\r\nimage, the operator of the equipment could analyse the object in detail without opening the bag. The net result\r\nwould be more accurate analysis of baggage content and faster throughput, as manual searching of suspicious\r\nobjects would not be required....
Extensive modeling of the seeding of plasma-based soft X-ray lasers is reported\nin this article. Seminal experiments on amplification in plasmas created from solids have\nbeen studied in detail and explained. Using a transient collisional excitation scheme, we\nshow that a 18 Ã?µJ, 80 fs fully coherent pulse is achievable by using plasmas pumped by a\ncompact 10 Hz laser. We demonstrate that direct seeding of plasmas created by\nnanosecond lasers is not efficient. Therefore, we propose and fully study the transposition\nto soft X-rays of the Chirped Pulse Amplification (CPA) technique. Soft X-ray pulses with\nenergy of 6 mJ and 200 fs duration are reachable by seeding plasmas pumped by\ncompact 100 J, sub-ns, 1 shot/min lasers. These soft X-ray lasers would reach GW power,\ncorresponding to an increase of 100 times as compared to the highest peak power\nachievable nowadays in the soft X-ray region (30 eVââ?¬â??1 keV). X-ray CPA is opening new\nhorizon for soft x-ray ultra-intense sources....
This work describes X-ray imaging of mouse using a colloid solution of silica-coated Au (Au/SiO2) nanoparticles. A\r\ncolloid solution of Au nanoparticles with a size of 16.9 nm was prepared using hydrogen tetrachloroaurate (III)\r\ntrihydrate as Au source and sodium citrate as reducing reagent. Silica coating of the Au nanoparticles was\r\nperformed by modifying the Au nanoparticle surface with (3-aminopropyl)trimethoxysilane and then by depositing\r\nsilica nuclei generated through a solââ?¬â??gel reaction of tetraethyl orthosilicate in water/ethanol initiated with sodium\r\nhydroxide on the surface-modified surface, which produced Au/SiO2 particles with a size of 136.4 nm. A computed\r\ntomography value of the Au/SiO2 colloid solution with an Au concentration of 0.036 M was as high as 1,184.8\r\nHounsfield units, which was quite higher than that of a commercial X-ray contrast agent with the same iodine\r\nconcentration as the Au concentration. Tissues of mouse could be imaged by injecting the Au/SiO2 particle colloid\r\nsolution into them....
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