Analysis of the Stress-Strain State of a Wall of VT6 Titanium Alloy Obtained by Direct Laser Deposition Lasers & Laser Systems DOI: 10.22184/1993-7296.FRos.2019.13.7.634.640
Direct laser deposition is an advanced technology for the production of complex large-sized products from a wide range of alloys, including alloys based on titanium and nickel. During the deposition process an uneven field of residual stresses and strains is formed in manufactured parts, which has a significant effect on long-term strength and performance. The analysis of the stress-strain state of the wall of VT6 titanium alloy obtained by direct laser deposition was carried out. The paper presents the results obtained numerically using finite element method and experimentally using neutron diffraction method. It was found that at the edges of the deposited wall near the substrate, a region is formed where all three components of the stress field are tensile. Moreover, normal plastic strains in this area are also tensile and reach 2.5–3%, and normal stresses exceed the yield strength by 25%. Longitudinal tensile stresses are close to the yield strength along the entire length of the last few layers at the top of the buildup.
Eye-safe Atmospheric Lidar Measurements DOI: 10.22184/1993-7296.FRos.2019.13.7.642.646
Through the use of lidar, various details of atmospheric composition can be discerned. The National Center for Atmospheric Research developed an eye-safe lidar implementation for atmospheric investigation. Using stimulated Raman scattering (a third-order nonlinear process) the instrument output is eye-safe at approximately 1.5 μm. The instrument has a range of up to 9 km. It also has performance and durability advantages over many previously reported eye-safe lidar configurations. Eye-safe operation is necessary to broaden the available locations for measurements, including more populated areas and near airports.
Modern Lidar Systems for Atmosphere Remote Sensing DOI: 10.22184/1993-7296.FRos.2019.13.7.648.657
Remote sensing of the atmosphere in the optical range is currently one of the most effective ways to obtain information about its physicochemical and dynamic properties. Today, lidar technology for atmospheric monitoring is widely used in meteorology, ecology, climatology, in flight safety security, wind energy. The article describes the physical principles of the atmospheric lidars operation, provides measurement results and technical characteristics of lidar meteorological systems and complexes of domestic development.
Hydrophysical Laser-Interference Receiving Systems: Features and Application DOI: 10.22184/1993-7296.FRos.2019.13.7.658.668
Several types of laser-interference instruments for measuring variations of hydrosphere’s pressure are reviewed in this article. Instruments’ frequency range is from conditionally 0 Hz (unbounded in principle) to 1000 Hz with accuracy of 1 mPa. Some of the results of using these laser-interference systems for recording vibrations and waves in the infrasound and sound ranges are briefly discussed.
Research of the Influence of Structural Elements of the IR Lens on the Value of the Thermal Background Flux, Incident at the Focal Plane Array DOI: 10.22184/1993-7296.FRos.2019.13.7.694.699
The sensitivity of thermal imaging and heat-detecting stations used to collect spectral and topological information is limited by background stray light illumination incident at the focal plane array through an IR‑lens. The article discusses the influence of the design of the frames of the optical elements in the IR lens, designed to operate in the range of 8–12 microns, on the value of the internal and external background stray light radiation. Optimization of the design of the frames allows you to minimize stray light and provides high performance characteristics of the optic-electronic system, which includes an infrared lens. In this work, structural elements that make the largest contribution to the total background flux are identified and their structure is optimized using the created digital model. The influence of the cooling process of structural elements on the value of its own background flux is considered.
Metrological Support of Measurements of Temporal Parameters of Pulsed Laser Radiation in The Picosecond Range DOI: 10.22184/1993-7296.FRos.2019.13.7.670.675
Precision material processing, laser ranging and medicine techniques use picosecond pulsed laser systems. This requires the creation of measuring instruments for the temporal characteristics of pulsed laser radiation. Presented in the article are the results of activities of the VNIIOFI in the field of metrological support of measurements of temporal parameters of pulsed laser radiation in the picosecond range.
Features of Optical Reflectometers Metrological Support DOI: 10.22184/1993-7296.FRos.2019.13.7.676.679
The results of optical time domain reflectometer (OTDR) metrological support activities are presented. Metrological and normative standards in the field are described. OTDR metrological standards implementation and exploitation are considered. The results of calibration methods research for optical frequency domain reflectometer (OFDR) are also presented.
Application of Therahertz Technologies in Biophotonics. Part 1: Methods of Terahertz Spectroscopy and Imaging of Tissues DOI: 10.22184/1993-7296.FRos.2019.13.7.680.687
In recent decades, there has been growing interest in the use of terahertz (THz) technology for the early non-invasive, minimally invasive and intraoperative diagnosis of malignant neoplasms featuring different nosologies and localizations. THz diagnostic methods are based on THz spectroscopy and imaging of tissues, using natural (endogenous) neoplasm markers. The abovementioned makes THz diagnostics attractive in comparison with other methods, often including the introduction of exogenous markers into the body. Despite significant progress in the considered branch of science, the THz instruments are far from clinical practice due to the high cost, bulkiness, low ergonomics and lack of an effective THz element base. This two-part paper discusses the current state of research in the diagnosis of malignant neoplasms using THz spectroscopy and imaging. The first part discusses the properties of THz radiation, the specifics of its interaction with biological tissues. Special attention is paid to the THz pulsed spectroscopy, which is increasingly used in THz biophotonics.
Non-Classic Diffraction Gratings at the Exhibition Laser World of Photonics 2019 DOI: 10.22184/1993-7296.FRos.2019.13.7.614.618
The success of laser optics of ultra-high-power and ultra-short pulses has given new breath to technologies for creating diffraction gratings, which are the most important subsystems of delay lines with opposite dispersions. Increasingly, diffraction gratings attract the attention of designers of optoelectronic devices. This is evidenced by the expansion of the diffraction grating product segment at the exposition of the Laser World of Photonics 2019 exhibition (Messe München, Munich, Germany).
Shift Model of Sales: From Product to Functions. Photon and Optical Technologies at the Industrial Fair INNOPROM 2019 DOI: 10.22184/1993-7296.FRos.2019.13.7.620.631
Laser and optical technologies open up new possibilities for creating quality products. But not only knowledge of product manufacturing processes determines the superiority of the company. The ability to provide remote diagnostics and monitoring has led to a more effective monetization of technology. The business model of sales of technological functions replaces the business model of sales of a product that is ahead of its competitors. The review presents technology companies and their integrated solutions based photon technologies that are used in cluster and network models of economic development.
SLS ‑ 3D ‑ Printing Workshop Summary. “Opportunities, Advantages Over FDM and SLA, Examples Of Implementation”
X-Ray Tomography DOI: 10.22184/1993-7296.FRos.2019.13.7.688.692
The article presents the results of research in the development of domestic x-ray tomography. The design of the first serial x-ray tomograph of the MRCT family is described. The results of tomographic studies of various objects are presented.