This article presents the results of a study on irradiators with a wavelength of 365 nm and the development of an LED-based irradiator with the same wavelength. An analysis of possible irradiator designs, their characteristics, and technical parameters was conducted, based on which the necessary components were selected for designing a prototype ultraviolet LED irradiator. To choose the components for the designed irradiator, LEDs with a wavelength of 365 nm from various manufacturers were analyzed: AMS OSRAM (LZ1–00UV0R‑0000), Lite-on Electronics (LTPL – C034UVH365), Inolux (IN-C33CTNU2), Wurth (15335337AA350), Pro‑Light Opto Technology Corporation (PB2D‑5JLAUS),and Refond (RC35E0-UBE-AR). The electrical and radiative parameters of the designed irradiator were studied and compared with a traditional UV-A irradiator – a low-pressure discharge lamp of the LUFT type. The article includes calculations for the radiator area of the prototype irradiation unit and describes the assembly process. The research showed that the calculated radiation flux of the designed prototype is comparable to that of an LUFT 80‑type lamp. The prototype LED irradiation unit is environmentally safe, as it does not contain toxic mercury or other harmful substances. Recommendations for the application of the developed LED based irradiator are provided.

Numerous methods of light modelling in architecture are classified, which were used in different eras by different authors to solve the problems of figurative presentation of illuminated objects in natural, artificial, and mixed light and (or) determine a number of light composition (lighting engineering) parameters on objects from the scale of the city (light urbanism) to the scale of the object or details of the lighting devices in the exterior or interior (light design). The classifications are illustrated by examples from the domestic and international experience of lighting design and block diagrams.

Preservation of paintings in museum or art galleries, especially of organic materials like paper and textiles, is a great concern. It is crucial to have proper illumination to see an object. Due to urbanization, in most of the place’s daylight is not sufficient. Due to this, usage of electric lighting, with advanced technology, is highly important. The majority of electric lighting release corrosive ultra violet rays (UV). It can be observed that UV ray is also present as a neighbour of visible light. The discoloration effects of UV content, are due to its high energy concentration, leads to day-by-day discolouration of painting. Before using the electric light sources, it is important to check their UV content. For this, a comprehensive analysis and experiment have been carried out. This paper aims to investigate the UV content of various electric light sources and how it affects paintings like water colour and oil paintings. The primary hues red, green, blue, as well as gold and silver, have all been the subject of experiments. To illustrate the nature of the discolouration power of various types of lamps, results have been furnished in the form of tables as well as graphs. In this regard, appropriate light sources can be employed to prevent paintings from discoloration.

Street lighting systems are considered one of the most important pillars necessary for the infrastructure that must be provided in urban cities due to their positive impact on the lives of citizens. Street lighting provides comfort to citizens and makes them feel safe at night. Despite all these advantages, it brings a heavy burden on the energy consumption bill and has negative consequences for the environment. Modern technologies, such as wireless communications and the internet of things (IoT), have enabled the creation of smart street lighting systems that contribute to improving energy saving and preserving the environment compared to traditional systems. In this research, the performance and feasibility of a prototype smart street lighting system based on IoT and wireless communications were studied. This system was implemented and tested at a pilot site with the aim of enhancing energy performance and creating a smart infrastructure on the university campus. Street user data, captured by the passive infrared (PIR) sensor, is exchanged between lighting poles using the ESP-NOW protocol to create adaptive lighting. This ensures that the level of illumination by the LED luminaires around the user is greater than that behind them. The cloud server ThingSpeak was also utilized to collect and store the electrical variable data measured by this system. Additionally, images are captured and stored for street users. From the data obtained from the cloud server and energy measurements, the system has demonstrated its effectiveness in reducing energy consumption.

In this work, a computerized measuring device is developed and created for non-destructive measurement of the concentration distribution of an electrically active impurity in p–n structures. The concentration distribution is measured by recording the parameters of the barrier capacity when a small two-frequency signal is exposed to the structure under the study. The device makes it possible to study the concentration profile of p–n structures in the area of the location of quantum wells with a depth resolution of up to 3–4 atomic layers in the range of changes in the width of the spatial charge region under the influence of a constant bias voltage. The measurement results are processed, and the measuring device is controlled by a microcontroller.

A promising source of radiation for high-speed optical measuring systems are LEDs capable of operating at significantly high currents compared to nominal ones with a short duration of periodic pulse overloads. Recently, it has become possible to replace laser lighting systems with LED ones in some cases, which significantly reduces the cost of physical experiment and simplifies optical measurements. This work is devoted to the development of an infrared illuminator with an LED for high-speed optical studies of gas-liquid flows. An electrical control circuit for an LED, based on an adjustable pulsed voltage source with preliminary automatic power calibration, is described and the results of measuring the main electrical characteristics of the LED are presented. When the illuminator is overloaded by 70 % in power, the illumination from it increases by 48 %. This illuminator has been tested in a number of thermos-physical experiments to study the dispersion composition of particles from a central nozzle, etc., as well as in a tomographic experiment to measure the velocity of particles in the air flowing around the quadcopter. The results obtained confirmed the effectiveness and prospects of using pulsed illuminators with an LED light source in high-speed optical experiments.

This study demonstrates the possibility of growing green walls in normal commercial building environments with lighting designed primarily for aesthetic reasons, rather than the promotion of plant growth. Lighting is a key resource required for the growth and maintenance of robust green walls within interior environments. The study evaluated the appearance and growth of green walls with electric lighting used primarily for aesthetic reasons. Three identical green walls with six different plants were illuminated using three different white LED light sources for a period of five months. Plant health was monitored and documented in terms of successful growth patterns. One hundred and six subjects appraised the appearance of the walls using questionnaires. Findings of this study indicate that it is indeed possible to grow and maintain green walls in normal commercial building environments with lighting designed for aesthetic reasons. Further, key species were identified as appropriate for growing on internal green wall setups.

The retrieval of parameters for a turbid medium presents a challenging and ill-posed inverse problem. In this paper, we investigate the effectiveness of utilizing global optimization algorithms to determine optical properties of the medium such as the optical thickness, the single scattering albedo, the single scattering phase function, and the extinction profile from multi-angle radiance measurements. For this purpose, we consider the application of the Differential Evolution, SHGO, and Dual Annealing solvers. To address the phase function retrieval problem, we introduce an enhanced modification of Differential Evolution capable of handling this complex task. In the context of phase function retrieval, we find that global optimization solvers demonstrate comparable efficiency when compared to the Gauss-Newton method, which requires the computation of Jacobians. In the case of the extinction profile problem, the incorporation of Jacobian estimation, coupled with Tikhonov regularization, leads to significant enhancements in retrieval accuracy.

The article is a continuation of the article “Formation of a new identity of road service objects using lighting design techniques: pre-project analysis” [1]. This article is devoted to the design stages: the design system of the multifunctional zone (MFZ) of road service, the lighting design concept of the MFZ environment, the functional structure, and the lighting scenario of the gas station environment, depending on the typology features, are considered. An imaginative and stylistic concept of the MFZ environment based on lighting design is proposed. The design lighting models of service areas based on functional typology are described and justified. The reliability of the proposed solutions is confirmed by a lighting calculation and a feasibility study of the proposed solution based on the cost of equipment from one of the largest lighting equipment manufacturers in Russia.