Optical system design of multispectral video camera for 8-14 microns range

To solve the actual problem of determining the composition of a gas mixture in an uncontrolled leak at industrial sites, it is proposed to use a multispectral camera that allows you to simultaneously form several spectral images on a bolometric matrix. This method will provide visualization of the gas cloud in the far infrared range from 8 to 14 micrometers with selection by chemical composition. The article proposes an optical scheme for simultaneous registration of images in eight narrow spectral ranges of wavelengths, as well as the design of its elements for a bolometric matrix with a resolution of 640x480 pixels: a lens, a raster, and light filters using the ZEMAX application software package. As a result of the design, a low F-number three-lens optical system for a necessary field of view and a raster with a block of light filters are obtained, forming sixteen images in different spectral ranges. Thus, we solved an issue of design an optical system with minimal aberrations for a multispectral camera.

A Brief Overview of Electrochromic Materials and Related Devices: A Nanostructured Materials Perspective

Exactly 50 years ago, the first article on electrochromism was published. Today electrochromic materials are highly popular in various devices. Interest in nanostructured electrochromic and nanocomposite organic/inorganic nanostructured electrochromic materials has increased in the last decade. These materials can enhance the electrochemical and electrochromic properties of devices related to them. This article describes electrochromic materials, proposes their classification and systematization for organic inorganic and nanostructured electrochromic materials, identifies their advantages and shortcomings, analyzes current tendencies in the development of nanomaterials used in electrochromic coatings (films) and their practical use in various optical devices for protection from light radiation, in particular, their use as light filters and light modulators for optoelectronic devices, as well as methods for their preparation. The modern technologies of “Smart Windows”, which are based on chromogenic materials and liquid crystals, are analyzed, and their advantages and disadvantages are also given. Various types of chromogenic materials are presented, examples of which include photochromic, thermochromic and gasochromic materials, as well as the main physical effects affecting changes in their optical properties. Additionally, this study describes electrochromic technologies based on WO3 films prepared by different methods, such as electrochemical deposition, magnetron sputtering, spray pyrolysis, sol–gel, etc. An example of an electrochromic “Smart Window” based on WO3 is shown in the article. A modern analysis of electrochromic devices based on nanostructured materials used in various applications is presented. The paper discusses the causes of internal and external size effects in the process of modifying WO3 electrochromic films using nanomaterials, in particular, GO/rGO nanomaterials.

Coloured Light as a Tool for Working with Architectural Form in the Night Environment of the City

For the past decades the light environment of the evening city has become a critical component of the architectural and administrative activities. Today, the lighting systems not only allow making an object or an entire street ‘visible’ in the evening, but also provide for the development of their new architectural image. The opportunities offered by the white artificial light were appreciated to work with the illuminated polychrome objects long ago. The white light with various spectral properties is capable sometimes to influence dramatically the perception of the architectural form, as with its high intensity under the darkness adaptation conditions it has the capability to ‘absorb’ (turn off) the ‘object’ colour of the illuminated facade surface. In particular, the specifics creates an ‘evening’ object image different from the daily one, where the colour scheme used in the material object is often not critical. In contrast, the chromatic light under certain conditions allows not only maintaining the colouristic nature of the environment existing under the natural lighting conditions, but also developing and unifying it in a unique manner, creating a new colour palette. The description of the main areas of the evening environment arrangement with the chromatic light is provided. A significant work experience has been already accumulated in this field by the light design experts. The colour light opportunities and, even more so, the technologies of dealing with it have not been appreciated and adopted by architects to the full extent yet. The article considers the application specifics of the colour light as a fully functional instrument for dealing with the object form under the night urban conditions. The results of an experiment to study the interaction between the colour of material objects and the colour light based on the analysis of Moscow polychrome, which was carried out in the laboratory of the Moscow Architectural Institute (State Academy), are presented. Visual observations enabled to determine the impact of light with the colour light filters selected for the experiment on the colour samples typical for a number of historical periods in the Moscow architecture. The colour samples typical for the facades of buildings erected in a number of historical periods in the capital architecture were illuminated in the darkness with the light of slide projectors with IL and R, G, B glass light filters, and changes in their visual perception were assessed using the NCS atlas, then the identified colour shifts were determined with the use of E. Rabkin’s atlas by three parameters (λ, P, L). A hypothesis was expressed about the possible use of the results of such studies not only in the architectural colour lighting of the modern urban environment, but also in such a new application area as restoration, preservation and interactive integration of the historical and architectural heritage sites into the programmable image-bearing environment.

Development of High Sensitivity Illuminance Meter for Measurements in Lighting Engineering and Photometry

Possible ways of solving the main problems arising in development, manufacture and calibration of high-sensitivity Illuminance meters are considered. Methods of reducing the lower limit of measurement of Illuminance to 10-5 lux are proposed. Errors of correcting light filters of different manufacturing methods are estimated. The calculations of measurement errors of illuminance from modern energy-saving lamps and LEDs are made.

Application of Blue Filters Increases the Usefulness of Moreland Test in Anomaloscopic Color Vision Assessment for Blue–Green Color Range

The effect of blue light filters on the anomaloscopic examination was analyzed. Thirty subjects (18–43 y, 20 female, 10 male) without color vision disorders were examined in 4 filter conditions: no filter (F-0), Blue Control Hoya (F-BC), Med-1 JZO (F-Med1) and 450 Eschenbach (F-450). Both Rayleigh test (red–green axis) and Moreland test (blue–green axis) were performed. Application of F-BC filter shows negligible effect on color vision perception in both tests. Contrary to this, the application of strong F-450 filter causes significant shift in Moreland test towards tritanopy and the decrease in correlations of Moreland parameters with Rayleigh test parameters. The application of medium strong F-Med1 filter causes the slight shift in Moreland test towards the center of the Moreland scale and increases the Spearman correlations between Moreland and Rayleigh test parameters. This observation suggests that the about 15–40% reduction of blue diode intensity in the Moreland test may be beneficial in detecting mild changes in color vision perception in the blue-green axis and may improve its usefulness in evaluating the color vision perception disorders accompanying different illnesses, such as diabetes, glaucoma, neuritis optica, or cataract. The discussion concerning the modifications of Moreland test construction is also presented.

The use of protective red light filter glasses as a m ethod of preventing the development and progression of retinopathy of prematurity, based on the phenomenon of preconditioning photostimulation

Purpose. To study the possible effect of protective red light filter glasses as a method of preventing retinopathy of prematurity, based on the phenomenon of preconditioning photostimulation. Material and methods. For this study, we selected 20 children (40 eyes) from 26.5 to 36 weeks of gestational age and a birth weight of 650 to 2650 grams. All children were divided into 2 groups – the main and control groups of 10 children (20 eyes) each. Results. In the main group of the study, with the use of protective red light filter glasses, the best indicators of the electroretinogram were noted. Conclusions. The use of glasses with red protective light filters-as a method based on the phenomenon of preconditioning photostimulation, is a simple and affordable method of preventing retinopathy of prematurity, which reduces the need for surgical laser treatment and the number of adverse outcomes of this disease. Key words: retinopathy of prematurity, methods of prevention of retinopathy of prematurity.

Theoretical analysis and experimental study of H2S dissociation processes in ultrahigh-frequency plasmotron

Theoretical analysis of aerodynamic conditions in a plasma chemical reactor with tangential gas supply is carried out. It is shown that due to the creation of a swirling flow in the reactor there is a pressure gradient, due to this along the vertical axis there is a vacuum zone, which contributes to the occurrence of plasma discharge. On the basis of the carried-out experimental researches of plasmolysis of hydrogen sulphide in a swirling stream and the analysis of images of the plasma discharge with use of monochromatic light filters the general structure of the plasma discharge is established. The influence of the temperature gradient in the reactor on the possibility of the formation of sulphur clusters as a prerequisite for the formation of a high molecular weight product – polymeric sulphur – was established.