Study of the Relationships Between Optical and Physical Properties for Nanostructure TiO2 Thin Film

Pulsed Laser Deposition (PLD) technique was performed to deposit the pure Titanium oxide (TiO2) nanoparticles on the glass substrate of temp. (100 - 400°C), using the doubled frequency of Nd: YAG laser wavelength of 532nm at (10) Hz rate, 10 nanosecond duration pulses and a constant laser energy 800 mJ. The optical measurements obtained by UV-Vis transmittance on deposited TiO2 films indicate the highest transparency in the visible wavelength region with an average transmittance of 80%. Estimated the relationship between the refractive index of TiO2 thin films with substrate temperature was n = 2.49 at 400 oC. Moreover, the calculated empirical relation between the energy gap and refractive index have similar to the work results.

Features of Brass Processing with Powerful Ultraviolet Lasers of Nanosecond Duration

We investigated the process of laser heat treatment of polished brass samples (36% zinc, containing a small amount of lead, which does not dissolve in the alloy and is in the form of inclusions, having micron and submicron size) by impacting to a series of 25 - 30 ultraviolet (UV) pulses of a Nd:YAG laser (third harmonic, wavelength λ = 355 nm, duration τ = 10 ns, pulse repetition rate f = 10 Hz, pulse energy density ~ 0.15 - 1.0 J/cm2) in the stationary spot mode. Copper and its alloys absorb up to 90% of the energy of this laser. It is found that the relaxation of the absorbed energy of laser radiation in the metal occurs nonuniformly. Defects in the metal structure such as grain boundaries and lead inclusions are visualized. Traces of crystallographic sliding appear inside some grains. With an increase in the number of impacting impulses, accumulation of damage is observed. A further increase in the radiation energy density leads to an aggravation of the observed phenomena.

Study of conditions of gas- discharge synthesis of Zinc oxide nanostructures under automatic UV-irradiation of the substrate by plasma

The spectroscopic characteristics of a bipolar, overstressed discharge of nanosecond duration between zinc electrodes in oxygen at a pressure p(O2) = 13.3 kPa are presented. In the process of microexplosions of inhomogeneities on the working surfaces of the electrodes in a strong electric field, zinc vapor is introduced into the discharge gap. This creates the prerequisites for the formation of zinc oxide molecules and clusters in the plasma and the synthesis of thin island zinc oxide films, which can be deposited on a dielectric substrate installed near the center of the discharge gap. The spectral characteristics of the discharge were investigated from the central part of the discharge gap 2 mm in size. The main excited components of the plasma of a vapor-gas mixture based on zinc and oxygen were established at high values ​​of the parameter E / N (where E is the electric field strength; N is the total concentration of particles in the plasma), which, when deposited outside the discharge plasma, can lead to the formation of fine nanostructured films based on zinc oxide.

Modification of the Surface of a Reconditioned Cutting Tool via Laser Ablation

The article discusses the possibility of using pulsed laser ablation of nanosecond duration to modify the surface of a cutting tool after regrinding and restoration. Experimental studies of the resistance characteristics of cutting tools with modified surfaces via laser ablation in air and in liquid have been carried out. It was found that after modifying the surface of cutting plates via laser ablation in air, the wear on the trailing surface of the cutting tool at a processing speed of V = 50 m/min is 8 times less than that of the untreated one, the build-up is 20 times less. The wear of the trailing surface of the plates at V = 70 m/min is 2 times less than that of the untreated sample. The resistance studies show surface modification of the cutting tool increases the tool life of the remanufactured tool, overall tool life and savings in tool costs.

Design and Development of Mini-pulsar for Real-Time Bioelectric Experiment

Investigation of the effect of pulsed electric field on eukaryotic cells has been of interestto biomedical scientists and researchers since a few decades. Reversible electroporation (EP) is used for uptake of chemicals, drugs, DNA into the eukaryotic cells under low electric field (100’s V/cm) of millisecond duration to few hundreds of microsecond duration. An electric field of nanosecond duration and a very high electric field (50’s kV/cm) can stress to intracellular organelles of eukaryotic cells and that can trigger apoptotic pathways. In this article experimental setup has been prepared for real-time investigation of the effect of nanosecond electric field on eukaryotic cells. Pulsar producing ~1.5kV, 20ns FWHM, single shot as well as ~10Hz rep-rate with rise-time as fast as ~10ns, has been prepared using blumlein pulse forming line and avalanche transistor switches. A 300µm gap microplate chamber has been prepared to expose the electric fieldtoeukaryotic cells.

Роль добавок графена в стойкости оксида алюминия хрупкому разрушению при импульсных электрофизических воздействиях

The study of the dynamic strength for Al2O3 nanoceramics with different content of five layer graphene under the action of a high-current electron beam and a high-voltage electric discharge of nanosecond duration are presented. It was found that an increase in the graphene content in the composite leads to the embrittlement of the nanocomposite. Key words: .