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Previous plant phenotyping studies have focused on the visible (VIS, 400–700 nm), near-infrared (NIR, 700–1000 nm) and short-wave infrared (SWIR, 1000–2500 nm) range. The ultraviolet range (UV, 200–380 nm) has not yet been used in plant phenotyping even though a number of plant molecules like flavones and phenol feature absorption maxima in this range. In this study an imaging UV line scanner in the range of 250–430 nm is introduced to investigate crop plants for plant phenotyping. Observing plants in the UV-range can provide information about important changes of plant substances. To record reliable and reproducible time series results, measurement conditions were defined that exclude phototoxic effects of UV-illumination in the plant tissue. The measurement quality of the UV-camera has been assessed by comparing it to a non-imaging UV-spectrometer by measuring six different plant-based substances. Given the findings of these preliminary studies, an experiment has been defined and performed monitoring the stress response of barley leaves to salt stress. The aim was to visualize the effects of abiotic stress within the UV-range to provide new insights into the stress response of plants. Our study demonstrated the first use of a hyperspectral sensor in the UV-range for stress detection in plant phenotyping.

The possibility to increase the responsivity of 4 H -SiC p + – n – n + -photodiodes by varying the thickness of the p + -epilayer has been studied. It is shown that the thinning of the upper epilayer by RIE with the use of metal contacts as a mask makes it possible to control both the maximum responsivity and the spectral dependence of the responsivity of photodiodes and does not lead to degradation of dark electrical characteristics.

The main purpose of the article is to study the hardening of steel using non-standard wavelengths of laser radiation. The physical principles of the interaction of laser radiation with matter are also described. Experiments were carried out on hardening steel with a UV laser (wavelength 355 nm). The following experiments and a comparative analysis of volumetric hardening of steel with cooling in water, hardening with a YVO4 laser beam with (λ = 1.06 μm and hardening with a YVO4 laser beam with (λ = 0.355 μm. The studies were carried out on structural steel 45 and tool steels У12 and Р6M5. In the course of the research, new interesting scientific results were obtained: the study of the microstructure of U12 steel samples using an electron microscope showed that the martensite formed during quenching by UV radiation is more dispersed, as a result of which it can be concluded that such processing can lead to the production of surface nanostructures up to 100 nm in size. However, due to the low productivity and low power of UV radiation, the proposed steel hardening can be recommended for measuring and cutting tools.

The interaction of laser radiation with matter is considered. Marking of non-metallic materials requires heating below the softening point, heat treatment requires heating to temperatures above the phase transformation temperature, laser cutting of metals occurs with heating above the melting point, and engraving occurs above the melting or evaporation point. The choice of a laser for a certain type of processing is determined by the specific impact of laser radiation on a given material and the characteristics of the technological task at hand. Laser radiation in the UV range with a wavelength of λ = 355 nm, which can be obtained through third harmonic generation, is increasingly used in industry.Recommendations are provided for the use of low-power pulsed UV lasers for marking, engraving, cutting of metallic and non-metallic materials and surface hardening of steels. The paper presents the results of a study of the effect of laser radiation wavelength on metal engraving. The studies show that engraving with a beam with a radiation wavelength of λ =0.355 μm allows obtaining a high-quality image without melting the surface. Due to the fact that radiation with a wavelength of λ = 0.35 μm is equally well absorbed by metals and dielectrics, UV-lasers can be used for separation operations in microelectronics, for example, for cutting flexible printed circuit boards with high quality. Reducing the diameter of the focus spot of the UV-laser compared to the focus of the CO2-laser makes it possible to reduce the radiation power and perform better cutting. Comparison of thermal strengthening of steels by volume hardening, laser hardening with melting, laser hardening by UV-radiation showed high efficiency of hardening by UV-radiation. Laser processing in the UV-range is rationally used for local surface hardening of fuel equipment parts, cutting tools.

In this contribution, I consider those aspects of the modern star formation theory, which can be substantiated with observations in the UV band, paying special attention to early stages of molecular cloud formation and initial conditions for the chemical evolution of starless cores. I describe the main results of available diffuse cloud observations in the UV band, as well as prospective directions for future studies with the instrumentation of the World Space Observatory project.

The main parameters of spectroscopic experiments in the UV range of the electromagnetic spectrum are estimated. Different spectral devices are compared in terms of their potential quality. Some technical details of current UV experiments and prospects of spectrographs of the WSO-UV project are discussed.

Researchers from the Illinois Institute of Technology discussed their work on the first equivalent circuit model for semiconductor nanoparticles based on charge transport consideration, which can be used to design THz waveguides. They say, both metallic and semiconductor nanoparticles exhibit surface plasmon resonance (SPR) when excited by an EM field at certain frequencies. SPR, the collective oscillation of the conduction band electrons, can be utilised to confine EM energy near a conductor-dielectric interface in sub-wavelength dimensions. Meanwhile, based on a transport formulation, they have obtained analytic and numerical results for the polarisation induced on the particle by a terahertz electric field. The dipole moment derived from the response enables systematic construction of an equivalent circuit capturing the field-carrier interaction in the semiconductor particle. The work was prompted by the observation that complex permittivity functions encompassing bulk conductivity lead to an unrealistic induced dipole moment at low frequency for a nanoparticle containing mobile charges.