scholarly journals THE INFLUENCE OF LASER TREATMENT OF POWDER STEEL PA-ZHGR ON THE GEOMETRIC PARAMETERS OF THE LASER EXPOSURE ZONE

2019 ◽  
Vol 21 (3) ◽  
pp. 68-75
Author(s):  
Evgeny Usynin ◽  
Svetlana Oglezneva ◽  
Evgeny Morozov
Keyword(s):  
Laser Treatment ◽  
Powder Steel ◽  
Geometric Parameters ◽  
Laser Exposure

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.

Laser treatment of plasma-deposited coatings on powder steel

1992 ◽  
Vol 31 (10) ◽  
pp. 839-842
Author(s):  
V. N. Antsiferov ◽  
A. M. Shmakov ◽  
N. N. Ivshina
Keyword(s):  
Laser Treatment ◽  
Powder Steel

RESEARCH INTO THE EFFECT OF TEMPERATURE FIELDS OF HEATING DURING CONTINUOUS LASER TREATMENT ON T15K6 CARBIDE INSERT PERFORMANCE

2018 ◽  
pp. 76-84 ◽  
Author(s):  
S. I. Bogodukhov ◽  
E. S. Kozik ◽  
E. V. Svidenko
Keyword(s):  
Laser Radiation ◽  
Abrasive Wear ◽  
Laser Treatment ◽  
Temperature Fields ◽  
Effect Of Temperature ◽  
Laser Exposure ◽  
Positive Trend ◽  
Continuous Laser ◽  
Carbide Inserts ◽  
Carbide Insert

The paper studies the effect of temperature fields of heating during continuous laser treatment on T15K6 carbide insert performance. A tool with T15K6 indexable carbide inserts was exposed to laser treatment by heating the working surface with continuous laser radiation using the LK 3015ls07 PM industrial laser according to the KV_OSN program along insert contours with the cutting edge distance ~2 mm. Laser exposure time was 2–3 s in nitrogen as a shielding gas. The study used samples in the form of 12,70×12,70×4,76 mm quadrangular plates (GOST 19052-80) with variable radiation power in the range of q = 300±100 W/cm2, and laser radiation moving speed within VL = 20±10 mm/s. Hardness measured in the laser-hardened zone after laser exposure was Hμ = 15500÷21500 N/mm2. The laser impingement point was tested for cutting and abrasive wear with microstructure analysis. Cutting wear along the front and back surfaces of carbide inserts after laser treatment was up to 5 times reduced. It is shown that further laser power density increase to q = 400 W/cm2 provides no positive trend. Diamond abrasive wear with an increased q value indicates wear reduction to 40 wt.%. Microstructural analysis showed a decrease in the tungsten carbide grain size from 5,6 to 4,3 μm in the continuous laser treatment area.

Clinical efficacy of subthreshold laser treatment for focal diabetic macular edema using a navigation system (short-term results)

2021 ◽  
pp. 217-221
Author(s):  
P.L. Volodin ◽  
◽  
E.V. Ivanova ◽  
E. I. Polyakova ◽  
◽  
...  
Keyword(s):  
Macular Edema ◽  
Laser Treatment ◽  
Diabetic Macular Edema ◽  
Clinical Efficacy ◽  
Morphological Changes ◽  
Foveal Avascular Zone ◽  
Laser Exposure ◽  
Retinal Sensitivity ◽  
Subthreshold Laser

Purpose. To evaluate the clinical efficacy of subthreshold laser treatment for focal DME with continuous and micropulse mode based on navigated technology. Methods. We observed 17 patients (17 eyes) with DME at the age from 25 to 71 years (on average 44±1.6 years). After the stage of diagnostic search for morphological changes in the retina and preoperative planning all patients underwent navigational laser treatment in and continuous and micropulse mode. The study evaluated the retinal thickness in the foveal avascular zone and outside it, the area of retinal ischemia, microaneurysms and edema zones at the level of the superficial vascular plexus and deep vascular complex. Follow-up periods were 1 and 3 months. Results. One month after laser treatment, all patients had positive dynamics, expressed in a decrease of edema height. BCVA increased on average to 0.8±0.06; mean central retinal sensitivity – up to 24.65±0.47 dB. After 3 months, a further decrease in the height of the edema was observed. BCVA increased on average for the group to 0.85±0.06, mean central retinal sensitivity – 25.5±0.3 dB. Сonclusion. Our preliminary results indicate the effectiveness of navigational subthreshold laser treatment for DME, based on targeted topographically oriented laser exposure according to OCT-angiography. Keywords: diabetic macular edema, navigational laser treatment, subthreshold laser therapy.

Laser Treatment of Titanium in Hexane at Various Pressures and the Formation of Periodic Structures

2021 ◽  
Vol 316 ◽  
pp. 765-769
Author(s):  
M.A. Tarasova ◽  
A.I. Ivashchenko ◽  
V.G. Prokoshev
Keyword(s):  
Femtosecond Laser ◽  
Laser Treatment ◽  
Periodic Structures ◽  
Chemical Properties ◽  
Laser Exposure ◽  
Research Activity ◽  
Periodic Surface ◽  
The Past ◽  
Linearly Polarized ◽  
One Step

Laser-induced periodic surface structures are a universal phenomenon that can be observed on almost any material after irradiation with linearly polarized laser beams, especially when using femtosecond laser radiation. Over the past few years, research activity in the field of surface-periodic structures has significantly increased, since their generation in a one-step process provides an easy way to nanostructure and functionalize the surface to control optical, mechanical or chemical properties. The paper presents the results of a femtosecond laser treatment of titanium in a hexane medium at various pressures. The morphology of the treated surfaces was studied under various modes of laser exposure, using optical and scanning electron microscopy.

scholarly journals Laser treatment of chronic central serous chorioretinopathy with a point of leakage in the subfoveolar zone without fluorescein angiography

2019 ◽  
Vol 100 (4) ◽  
pp. 601-605
Author(s):  
A N Samoylov ◽  
A N Korobitsin
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Laser Treatment ◽  
Central Serous Chorioretinopathy ◽  
Central Zone ◽  
Laser Exposure ◽  
Optical Coherence ◽  
Chronic Central Serous Chorioretinopathy ◽  
Corrected Visual Acuity ◽  
Best Corrected Visual Acuity

Aim. Develop a methodology and evaluate the clinical results of laser treatment of patients with chronic central serous chorioretinopathy in the presence of a leakage point in the foveola zone. Methods. The results of patients (32 eyes) with central serous chorioretinopathy after laser exposure in the avascular area were analyzed. The best-corrected visual acuity in these patients before treatment was 0.7 to 1.0 (average 0.78±0.15) with a height of neuroepithelial detachment of 162 to 328 μm according to optical coherence tomography. No signs of choroidal neovascularization was detected in angio mode on optical coherence tomography. The treatment was performed with an Ellex Integre Pro Scan 561 nm. The follow-up examination was performed in 1 and 6 months. Results. In 1 month, positive dynamics of both functional and anatomical parameters was noted in all eyes. According to the optical coherence tomography, a complete attachment of the neuroepithelium in the central zone of the retina occurred, detachment of the neuroepithelium was absent. Best-corrected visual acuity in 1 month after treatment increased to 0.89±0.08, in 6 months to 0.92±0.04. The study revealed a correlation between visual acuity and the central thickness of the retina in the fovea, there were no complaints about the appearance of scotomas after laser treatment in the foveola zone. Conclusion. The developed techniqe of laser exposure on the foveola zone in case of chronic central serous chorioretinopathy with a 561 nm laser demonstrated high clinical efficacy and safety and can be recommended to all patients with central serous chorioretinopathy.

scholarly journals Структура и фазовый состав пленок, полученных методом лазерного спекания из поливинилиденфторида различных марок

2021 ◽  
Vol 47 (23) ◽  
pp. 15
Author(s):  
Е.Ю. Тарасова ◽  
И.И. Журавлева ◽  
И.А. Бакулин ◽  
С.И. Кузнецов ◽  
А.С. Панин
Keyword(s):  
Laser Treatment ◽  
Polyvinylidene Fluoride ◽  
Oxidative Degradation ◽  
Polymer Melt ◽  
Melt Flow Index ◽  
Flow Index ◽  
Laser Exposure ◽  
Β Phase ◽  
Treatment Conditions ◽  
Porosity Coefficient

The processes of laser synthesis of films with a thickness of 80-230 µm from polyvinylidene fluoride of various grades are studied. It is established that the range of synthesis modes does not depend on the grades of PVDF. The content of the piezo active β-phase decreases after laser treatment, but the complete transformation of β→α does not occur. The process of thermos-oxidative degradation after laser treatment is not observed. Under the same treatment conditions, the higher the open porosity coefficient, the lower the polymer melt flow index (MFI). Depending on the MFI of the initial polymer, the selection of laser exposure modes can control the porosity of the films in the range of 26-68 %.

Chronic Laser Exposure Effects on Rabbit Retina

1972 ◽  
Vol 30 ◽  
pp. 54-55
Author(s):  
Burton B. Silver ◽  
Theodore Lawwill
Keyword(s):  
Laser Irradiation ◽  
Laser Light ◽  
Broad Band ◽  
Argon Laser ◽  
Atropine Sulfate ◽  
Ultrastructural Changes ◽  
Laser Exposure ◽  
Rabbit Retina ◽  
Histological Changes ◽  
Threshold Doses

Dutch-belted 1 to 2.5 kg anesthetized rabbits were exposed to either xenon or argon laser light administered in a broad band, designed to cover large areas of the retina. For laser exposure, the pupil was dilated with atropine sulfate 1% and pheny lephrine 10%. All of the laser generated power was within a band centered at 5145.0 Anstroms. Established threshold for 4 hour exposures to laser irradiation are in the order of 25-35 microwatts/cm2. Animals examined for ultrastructural changes received 4 hour threshold doses. These animals exhibited ERG, opthalmascopic, and histological changes consistent with threshold damage.One month following exposure the rabbits were killed with pentobarbitol. The eyes were immediately enucleated and dissected while bathed in 3% phosphate buffered gluteraldehyde.

Fading of the diaminobenzidine reaction product in the confocal scanning laser microscope

1989 ◽  
Vol 47 ◽  
pp. 146-147
Author(s):  
JS Deitch ◽  
KL Smith ◽  
JW Swann ◽  
JN Turner
Keyword(s):  
Pyramidal Neurons ◽  
Light And Electron Microscopy ◽  
Scanning Laser ◽  
Laser Exposure ◽  
Confocal Scanning Laser Microscope ◽  
Fluorescent Markers ◽  
Before And After ◽  
Staining Protocol ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

Neurons labeled with horseradish peroxidase and reacted with diaminobenzidine (DAB) can be imaged using a confocal scanning laser microscope (CSLM) in the reflection mode. In contrast to fluorescent markers, the DAB reaction product is thought to be stable and can be observed by both light and electron microscopy. We have investigated the sensitivity of the DAB reaction product to laser irradiation, and present the spectrophotometric properties of DAB before and after exposure in the CSLM.Pyramidal neurons in slices of rat hippocampus were injected with biocytin (a biotin-lysine complex), fixed overnight in 4% paraformaldehyde, and vibratome sectioned at 75 μm. Biocytin was detected with avidin-HRP (1:200) in 0.5% Triton X-100, incubated in DAB (0.5 mg/ml) with or without 0.04% nickel ammonium sulfate (Ni), dehydrated, and imaged in a Bio Rad MRC-500 CSLM with an argon ion laser (488 and 514 nm). Spectrophotometric measurements of the soma were made on a Zeiss microspectrophotometer, as a function of laser exposure (100-1000 scans) and staining protocol.

Lectin-Induced RBC Agglutination: Chemical vs. Cryofixation

1980 ◽  
Vol 38 ◽  
pp. 664-665
Author(s):  
Dean A. Handley ◽  
Lanping A. Sung ◽  
Shu Chien
Keyword(s):  
Lectin Binding ◽  
Freeze Substitution ◽  
Electrostatic Charge ◽  
Geometric Parameters ◽  
Comparative Approach ◽  
Chemical Fixation ◽  
Cell Surfaces ◽  
Minimal Cell ◽  
Membrane Stiffness ◽  
Cell Contour

RBC agglutination by lectins represents an interactive balance between the attractive (bridging) force due to lectin binding on cell surfaces and disaggregating forces, such as membrane stiffness and electrostatic charge repulsion (1). During agglutination, critical geometric parameters of cell contour and intercellular distance reflect the magnitude of these interactive forces and the size of the bridging macromolecule (2). Valid ultrastructural measurements of these geometric parameters from agglutinated RBC's require preservation with minimal cell distortion. As chemical fixation may adversely influence RBC geometric properties (3), we used chemical fixation and cryofixation (rapid freezing followed by freeze-substitution) as a comparative approach to examine these parameters from RBC agglutinated with Ulex I lectin.

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