scholarly journals MODIFICATION OF SURFACE OF DOUBLE WALL CARBON NANO TUBES BY FULLERENE C60

2018 ◽  
Vol 59 (8) ◽  
pp. 12
Author(s):  
Aida R. Karaeva ◽  
Ekaterina A. Zhukova ◽  
Sergei A. Urvanov ◽  
Boris R. Senatulin ◽  
Elena A. Skryleva ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Laser Treatment ◽  
Laser Processing ◽  
Fullerene C60 ◽  
Carbon Nano Tubes ◽  
Fullerene Clusters ◽  
Charging Effect ◽  
Double Wall ◽  
Composite Samples

The composite samples based on double-wall carbon nano tubes and fullerenes followed by laser treatment were prepared. XPS confirmed existence of essential contact between two components of the composite. The differential charging effect disappears after laser processing, which induces photopolymerization of fullerene clusters.  The TEM showed close-packed continuous coating of cross-linked C60 clusters formed on the surface of nano tubes after laser irradiation.

Influence of Er,Cr:YSGG Laser Treatment on Microtensile Bond Strength of Adhesives to Enamel

2008 ◽  
Vol 33 (4) ◽  
pp. 448-455 ◽  
Author(s):  
M. V. Cardoso ◽  
J. De Munck ◽  
E. Coutinho ◽  
R. B. Ermis ◽  
K. Van Landuyt ◽  
...  
Keyword(s):  
Bond Strength ◽  
Laser Irradiation ◽  
Laser Treatment ◽  
Clinical Relevance ◽  
Microtensile Bond Strength ◽  
Morphological Alterations

Clinical Relevance Er,Cr:YSGG laser irradiation produced morphological alterations on enamel, which may adversely influence the bond strength of certain adhesives, depending on their approach and composition.

Laser Modification of Leather and Fur Surface to Improve Its Quality when Conducting Finishing Operations

2020 ◽  
Vol 20 (4) ◽  
pp. 353-360
Author(s):  
Akmal Yusupovich TOSHEV ◽  
Mariya Ivanovna MARKEVICH ◽  
Tulkin Jumayevich KODIROV ◽  
Valentina Illarionovna ZHURAVLEVA
Keyword(s):  
Chemical Modification ◽  
Laser Treatment ◽  
Laser Processing ◽  
Collagen Fibers ◽  
Laser Exposure ◽  
Laser Modification ◽  
Treatment Changes ◽  
Configuration Changes

The article discusses the problems of activation of the surface of the leather tissue by laser exposure, changes in the morphology of the surface of the leather tissue during laser processing, and subsequent covering dyeing of the leather. It is shown that laser treatment changes the structure of the surface of the leather tissue, the bundles of collagen fibers are split, the structure becomes loose, which increases the diffusion of the coating dye reagents, and their reactivity increases without chemical modification. In the process of grinding leather fabric, it is finely cleaned which improves adhesion of the coating paint to the surface of the leather fabric, which improves the quality of leather fabric products. It was shown that laser exposure under the conditions found (pulses with an interval of 3 μs, a duration of 10 ns) does not cause destruction and configuration changes in collagen.

In situ Mineral Loss Inhibition by CO2 Laser and Fluoride

2006 ◽  
Vol 85 (7) ◽  
pp. 617-621 ◽  
Author(s):  
L.K.A. Rodrigues ◽  
M. Nobre dos Santos ◽  
J.D.B. Featherstone
Keyword(s):  
Laser Irradiation ◽  
Laser Treatment ◽  
Co2 Laser ◽  
Sucrose Solution ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Human Enamel ◽  
Fluoride Dentifrice ◽  
Mineral Loss

Laser and fluoride treatments have been shown to inhibit enamel demineralization in the laboratory. However, the intra-oral effects of this association have not been tested. This study assessed in situ the effect of a Transversely Excited Atmospheric CO2 laser (λ = 9.6 μm) and the use of pressure fluoridated dentifrice on enamel demineralization. During two 14-day phases, 17 volunteers wore palatal appliances containing human enamel slabs assigned to treatment groups, as follows: (1) non-fluoride dentifrice, (2) CO2 laser irradiation plus non-fluoride dentifrice, (3) fluoride dentifrice, and (4) CO2 laser irradiation plus fluoride dentifrice. A 20% sucrose solution was dripped onto the slabs 8 times per day. The specimens treated with laser and/or fluoridated dentifrice presented a significantly lower mineral loss when compared with those from the non-fluoride dentifrice group. The results suggested that CO2 laser treatment of enamel inhibits demineralization in the human mouth, being more effective when associated with fluoride.

scholarly journals Influence of laser radiation on optical transparent dielectrics

2020 ◽  
Vol 21 (2) ◽  
pp. 279-283
Author(s):  
S. M. Levytskyi
Keyword(s):  
Laser Radiation ◽  
Laser Irradiation ◽  
Pulse Laser ◽  
Laser Processing ◽  
Pulsed Laser ◽  
Radiation Wavelength ◽  
Pulsed Laser Radiation ◽  
Transparent Dielectrics ◽  
Irradiation Energy

This paper deals with the main characteristics of the influence of pulsed laser radiation and its application for the labeling of transparent dielectrics. On the basis of the analysis of the literature data and the study of the possibilities of using laser radiation for marking different materials, it is proposed to investigate the effect of the radiation wavelength on the size of the received defect inside the material. Experimentally shown that the pulse laser processing of samples with laser irradiation energy below 3.4 mJ/cm2 visual tags in the sample are not formed. Thus, you can control the geometric dimensions of the mark.

Investigating oxidation of niobium by laser treatment

2019 ◽  
pp. 61-69
Author(s):  
O. S. Yulmetova
Keyword(s):  
Optical Properties ◽  
Infrared Spectrum ◽  
Oxide Film ◽  
Laser Treatment ◽  
Laser Processing ◽  
Reflection Coefficients ◽  
Optical Contrast ◽  
Blue Shade ◽  
Second Mode ◽  
Composition Structure

Composition, structure, and optical properties of films formed on the surface of niobium during laser processing are presented. Two modes of laser oxidation of niobium are empirically determined. The first mode, using single-pass laser processing, create the blue shade oxide film, the second mode, using multipass laser processing, forms the green shade oxide film. The optical contrast, determined as a difference of reflection coefficients, in the infrared spectrum of the blue oxide film is equal to 0.2 and the green oxide film forms the contrast equal to 0.5. It was found that the niobium blue shade oxide films, obtained after laser processing, has stoichiometry NbO and the green oxide film has stoichiometryNbO2.

Wearability of Non-Smooth Surface with Laser Treatment in the Different Cooling Media

2011 ◽  
Vol 411 ◽  
pp. 542-547 ◽  
Author(s):  
Zhen Wen Yu ◽  
Wen Cui Xiu ◽  
Li Chen
Keyword(s):  
Cast Iron ◽  
Laser Treatment ◽  
Body Surface ◽  
Laser Processing ◽  
Smooth Surface ◽  
Processing Parameters ◽  
The Body ◽  
Water Medium ◽  
Cooling Media ◽  
Better Than

This paper compared wearability of the non-smoothed unit body of the samples treated in water medium with in air, by studying on cast iron intimating the body surface organism at the same laser processing parameters. The research indicated that the size and microhardness of non-smoothed unit body determined the wearability of the samples, and the wearability of the samples treated in water medium was relatively better than in the air.

PRACTICAL USE OF THE SURFACE LAYERS OF LASER MODIFIED WC-Cu COATINGS

Tribologia ◽  
2016 ◽  
Vol 270 (6) ◽  
pp. 121-130
Author(s):  
Izabela PLISZKA ◽  
Norbert RADEK ◽  
Aneta GĄDEK-MOSZCZAK ◽  
Peter FABIAN
Keyword(s):  
Carbon Steel ◽  
Laser Treatment ◽  
Laser Processing ◽  
Resistance Test ◽  
Test Results ◽  
Mechanical Seals ◽  
Surface Layers ◽  
Friction Resistance ◽  
Before And After ◽  
Wear Coatings

The article presents the study of the effect of laser treatment on the microhardness of WC-Cu coatings applied by electro spark deposition. Observations of friction resistance test results allowed the evaluation of the coatings after laser treatment. The studies were conducted using WC-Cu electrodes, produced by sintering of nanostructural powders. The anti-wear coatings were electro-spark deposited over C45 carbon steel by means of EIL-8A, while the laser processing was performed by electro coats applied using a Nd:YAG, BLS720. Model tests were carried on test mechanical seals for rings made of SiC and WC-Cu coatings before and after laser treatment.

Enhancing Corrosion Resistance of Stainless Steel 304 Using Laser Surface Treatment

2008 ◽  
Vol 384 ◽  
pp. 157-183 ◽  
Author(s):  
Ibrahim M. Ghayad ◽  
Madiha Shoeib ◽  
Taha Mattar ◽  
Huda M. Hussain
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Surface Treatment ◽  
Laser Irradiation ◽  
Laser Treatment ◽  
Surface Composition ◽  
Specific Treatment ◽  
Laser Surface ◽  
Laser Surface Treatment ◽  
Aisi 304

Stainless steel AISI 304 was laser treated to enhance corrosion resistance and improve surface properties. . This alloy has many applications in auto industry (car body,) as well as oil and gas industry. Different conditions were applied in the laser surface treatment, namely: laser power density, scan speed, distance between paths, medium gas (air, argon and nitrogen). After laser treatment, the samples microstructures were investigated using optical microscope to examine micro structural changes due to laser irradiation. Specimen surfaces were investigated using XRD, SEM and EDAX before and after laser treatment to examine the surface composition changes brought by laser irradiation. Results showed that laser irradiation enhances the corrosion resistance of AISI 304 Stainless steel to a large extent. Corrosion rates as low as 0.011 mpy for laser treated samples were obtained in comparison to 0.952 mpy obtained for the untreated samples. Superior pitting corrosion resistance was obtained under specific treatment conditions. The enhancement of corrosion resistance depends on the laser irradiation conditions. The corrosion protection afforded by laser treatment is attributed mainly to the grain refinement of the top surface layer. This layer is found to consist of nano-scale grains.

Effects of Femtosecond Laser Irradiation on the Surfaces of Alumina and Alumina-Zirconia Composites

2012 ◽  
Vol 727-728 ◽  
pp. 603-608
Author(s):  
Amanda Abati Aguiar ◽  
Nelson Batista de Lima ◽  
W. de Rossi ◽  
R.E. Samad ◽  
N.D. Vieira ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Laser Treatment ◽  
Femtosecond Laser Irradiation ◽  
Threshold Fluence ◽  
Zirconia Composites ◽  
Laser Treatments ◽  
Alumina Composite ◽  
Apatite Deposition ◽  
Biomimetic Method

Alumina and zirconia-alumina composite has been micro-structured in air using femtosecond laser. The threshold fluence of 6.2 J.cm-2 found in this work is close to that found published in literature [1]. In the case of Al-Zr, the threshold fluence is 2.2 J.cm-2.Surface femtosecond laser treatment increase the apatite deposition by biomimetic method on alumina and alumina-zirconia composite and depends on the condition of laser treatments.

Silicon Devices Fabricated by Using Laser Irradiation Process

1981 ◽  
Vol 4 ◽  
Author(s):  
M. Tamura ◽  
N. Natsuaki ◽  
M. Miyao ◽  
M. Ohkura ◽  
F. Murai ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Active Layer ◽  
Laser Processing ◽  
Film Formation ◽  
Si Substrates ◽  
Advantages And Disadvantages ◽  
Silicon Devices ◽  
Formation Conditions ◽  
Si Films ◽  
Irradiation Process

ABSTRACTThe advantages and disadvantages of both pulsed and cw scanned laser processing for Si devices are discussed. In particular, adaptions of laser processes for MOSFETs and bipolar structures are described from the viewpoint of active layer annealing. Moreover, MOSFETs fabricated in laser induced grown Si films on Si substrates having SiO2 patterns by bridging epitaxy, are discussed, as a function of sample structures, film formation conditions and laser irradiation conditions.

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