scholarly journals OPPORTUNITIES FOR THE USE OF THE SMALL-SIZE ACCELERATOR VGIK-1

2019 ◽  
pp. 115-121
Author(s):  
D.V. Vinnikiov ◽  
I.V. Buravilov ◽  
V.B. Yuferov ◽  
A.N. Ponomarev ◽  
V.I. Tkachev

The experimental data on modification of the surface of metals, alloys and materials coated using the method of irradiation by a heavy-current electron beam with the energy of 300 keV have been given. The specimen surface structure was studied before and after the irradiation using the method of optic microscopy and the surface layer microhardness measurement. The method of electron microscopy was used to analyze the structure and the sizes of dispersed anode material. The films consisting of the crystals with the size of 6 to 8 nm were obtained. The mass transfer processes that occur in the material of metal targets made of Cu, Ti, Mo, Al were studied. The spatial map was compiled for the X-ray field of the plant. The experiments were carried out to define the action of X-ray radiation on the different types of conditionally pathogenic microflora, in particular such bacteria as Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The fields of application of the plant were defined.

Author(s):  
R. M. Anderson

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.


Author(s):  
Ivan Saenko ◽  
O. Fabrichnaya

AbstractThermodynamic parameters were assessed for the MgO–FeOx system and combined with already available descriptions of ZrO2-FeOx and ZrO2-MgO systems to calculate preliminary phase diagrams for planning experimental investigations. Samples of selected compositions were heat treated at 1523, 1673 and 1873 K and characterized using x-ray and scanning electron microscopy combined with energy dispersive x-ray spectroscopy (SEM/EDX). Experiments indicated extension of cubic ZrO2 solid solution into the ternary system at 1873 K (75 mol.% ZrO2, 10 mol.% FeOx and 15 mol.% MgO) and limited solubility of 4 mol.% ZrO2 in spinel phase. Based on the obtained results thermodynamic parameters of C-ZrO2 and spinel phase were optimized.


Author(s):  
Nguyen Ca ◽  
N. D Vinh ◽  
Phan Van Do ◽  
N. T. Hien ◽  
Xuan Hoa Vu ◽  
...  

Tb3+-doped ZnSe quantum dots (QDs) with Tb content in the range of 0.5 - 7% were successfully synthesized by a wet chemical method. X-ray diffraction (XRD) and transmission electron microscopy...


2005 ◽  
Vol 20 (9) ◽  
pp. 2462-2473 ◽  
Author(s):  
Zhaoming Zhang ◽  
Mark G. Blackford ◽  
Gregory R. Lumpkin ◽  
Katherine L. Smith ◽  
Eric R. Vance

We have characterized thermally annealed perovskite (CaTiO3) surfaces, both before and after aqueous dissolution testing, using scanning electron microscopy, cross-sectional transmission electron microscopy, x-ray photoelectron spectroscopy, and atomic force microscopy. It was shown that mechanical damage caused by polishing was essentially removed at the CaTiO3 surface by subsequent annealing; such annealed samples were used to study the intrinsic dissolution behavior of perovskite in deionized water at RT, 90 °C, and 150 °C. Our results indicate that, although mechanical damage caused higher Ca release initially, it did not affect the long-term Ca dissolution rate. However, the removal of surface damage by annealing did lead to the subsequent spatial ordering of the alteration product, which was identified as anatase (TiO2) by both x-ray and electron diffraction, on CaTiO3 surfaces after dissolution testing at150 °C. The effect of Ca2+ in the leachant on the dissolution reaction of perovskite at 150 °C was also investigated, and the results suggest that under repository conditions, the release of Ca from perovskite is likely to be significantly slower if Ca2+ is present in ground water.


1999 ◽  
Vol 590 ◽  
Author(s):  
X. Zhang ◽  
H. Solak ◽  
F. Cerrina ◽  
B. Lai ◽  
Z. Cai ◽  
...  

ABSTRACTWe have used synchrotron radiation x-ray microdiffraction to study the microstructure and strain variation of copper interconnects. Different types of local microstructures have been found in different samples. Our data show that the Ti adhesion layer has a dramatic effect on Cu microstructure. On site electromigration test has been conducted and strain profile along the same interconnect line was measured before and after this electrical stressing. Cu fluorescence scan was used to find the mass variations along the line. Voids and hillocks can be clearly identified in this scan. x-ray micro-diffraction was used to measure the strain change around the interesting regions.


2012 ◽  
Vol 488-489 ◽  
pp. 1501-1505 ◽  
Author(s):  
Mahsa Esfahani ◽  
Yvonne Durandet ◽  
James Wang ◽  
Yat Choy Wong

In this study, effects of laser assisted self-pierce riveting (LSPR) as a mechanical joining technique were investigated on the coatings of self- piercing rivets. Zn-Sn and Al plated rivets were used to join magnesium sheets by LSPR. Microstructure, surface topography and roughness of the rivet’s coatings were characterized by optical microscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and surface profilometry. A comparison of results before and after joining process showed that under joining conditions, Zn-Sn coating was deformed during riveting process and its thickness and microstructure varied along the rivet shank, while Al coating remained unchanged and no effects of riveting process was detected.


1987 ◽  
Vol 105 (4) ◽  
pp. 1649-1662 ◽  
Author(s):  
L Sperling ◽  
A Tardieu ◽  
T Gulik-Krzywicki

Paramecium trichocysts are unusual secretory organelles in that: (a) their crystalline contents are built up from a family of low molecular mass acidic proteins; (b) they have a precise, genetically determined shape; and (c) the crystalline trichocyst contents expand rapidly upon exocytosis to give a second, extracellular form which is also an ordered array. We report here the first step of our study of trichocyst structure. We have used a combination of x-ray powder diffraction, freeze-etching, and freeze-fracture electron microscopy of isolated, untreated trichocysts, and density measurements to show that trichocyst contents are indeed protein crystals and to determine the elementary unit cell of both the compact intracellular and the extended extracellular form.


2017 ◽  
Vol 1143 ◽  
pp. 26-31
Author(s):  
Lucica Balint ◽  
Gina Genoveva Istrate

Research has shown the relationship among hardness, usage and corrosion resistance Ni-P-Al2O3 composite coatings on steel support heat treated. The electroless strips were heat treated at 200°C, 300°C, 400°C, 500°C and 600°C. Further studies on corrosion, hardness and usage revealed changes in properties, compared to the initial state, both on the strips coated with Ni-P and the ones coated with Ni-P-Al2O3 composite. The samples have been studied before and after the heat treatment via Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Analysis (EDX) and X-Ray Diffraction (XRD). The results show that untreated Ni-P layers exhibit strong corrosion resistance, while hardness and usage increase with heat treatment temperature, with a peak at 400 °C. Using suspended particles co-deposition, led to new types of layers, some with excellent hardness and usage properties. Corrosion resistance increase with heat treatment. Coating layers can be adjusted to the desired characteristics, by selecting proper parameters for the expected specific results.


2019 ◽  
Vol 9 (14) ◽  
pp. 2837 ◽  
Author(s):  
Antonio Scarano ◽  
Sammy Noumbissi ◽  
Saurabh Gupta ◽  
Francesco Inchingolo ◽  
Pierbiagio Stilla ◽  
...  

Background: Drills are an indispensable tool for dental implant surgery. Today, there are ceramic zirconium dioxide and metal alloy drills available. Osteotomy drills are critical instruments since they come in contact with blood and saliva. Furthermore, they are reusable and should be cleaned and sterilized between uses. Depending on the material, sterilizing agents and protocols can alter the surface and sharpness of implant drills. The hypothesis is that cleaning and sterilization procedures can affect the surface structure of the drills and consequently reduce their cutting efficiency. Methods: Eighteen zirconia ceramic drills and eighteen metal alloy drills were evaluated. Within the scope of this study, the drills were not used to prepare implant sites. They were immersed for 10 min in human blood taken from volunteer subjects and then separately exposed to 50 cycles of cleansing with 6% hydrogen peroxide, cold sterilization with glutaraldehyde 2%, and autoclave heat sterilization. Scanning Electron Microscopy (SEM) and energy dispersion X-ray (EDX) microanalysis were conducted before and after each cycle and was used to evaluate the drill surfaces for alterations. Results: After exposure to the cleansing agents used in this study, alterations were seen in the steel drills compared to zirconia. Conclusions: The chemical sterilization products used in this study cause corrosion of the metal drills and reduce their sharpness. It was observed that the cycles of steam sterilization did not affect any of the drills. Zirconia drill surfaces remained stable.


1987 ◽  
Author(s):  
E B Hunziker ◽  
P W Straub ◽  
A Haeberli

The early stages of fibrin polymerization were investigated by rotatory shadowing and electron microscopy. Individual molecules within initial oligomers were found to be unaligned and contacted neighbouring molecules by single E + D and D + E contacts, suggesting an intermediate phase of activation (des A-fibrin). The interacting molecular domains were separated by a distance of 2 to 3 nm, indicating that (both or at least one) binding sites are located on protruding segments of the polypeptide chains. Upon completion of fibrin activation (des AA-fibrin), molecules within the early oligomers aligned to form single-stranded polymers,o these being characterized by repeating trinodular units of 230 A in length. Based upon these findings, a new interlocking single-stranded model for fibrin polymerization was designed and tested. The model is consistent with previous experimental data on fibrin polymerization such as that obtained by X-ray diffraction and negative staining. Moreover, early branching and lateral association phenomena are easily explained.


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