AlGaAs/GaAs Quantum Well Infrared Photodetectors

In this article, we present an overview of a focal plane array (FPA) with 640 × 512 pixels based on the AlGaAs quantum well infrared photodetector (QWIP). The physical principles of the QWIP operation and their parameters for the spectral range of 8–10 μm have been discussed. The technology of the manufacturing FPA based on the QWIP structures with the pixels 384 × 288 and 640 × 512 has been demonstrated. The parameters of the manufactured 640 × 512 FPA with a step of 20 μm have been given. At the operating temperature of 72 K, the temperature resolution of QWIP focal plane arrays is less than 35 mK. The number of defective elements in the matrix does not exceed 0.5%. The stability and uniformity of the FPA have been demonstrated

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Trends in the development of non-invasive technologies for assessing quality of seeds

The article presents studies on the use of non-invasive technologies to determine the quality of seeds of various crops. The authors analyzed patents on this topic. In particular, such laser and optical technologies as IR spectroscopy, hyperspectral spectroscopy, Raman spectroscopy, fluorescence, terahertz spectroscopy were investigated. The conducted patent research showed and confirmed the relevance of the work and the possibility of further implementation of the results into practice, mainly in the field of systems for laser-optical spectroscopy of seeds. Carrying out research on this topic will allow you to design and create new types of devices that will be in demand in many areas of modern agriculture

Experimental studies of combined coulter for direct strip sowing of seeds

In the paper It is presented the results of experimental researches about determination of the main parameters of the seed distributer of the combined coulter for direct sowing of seeds at the installation for high-speed stroboscopic photography of particle movement

Initial requirements for agricultural universal block-modular energy device of traction class 0.6

The state of the tractor industry in Russia is characterized by a deep restructuring of production. This problem is especially acute in the development of modern low-power mobile energy facilities for the mechanization of work in peasant farms. To give a systematic character to the development of this In a promising direction, the initial requirements for an agricultural universal block-modular energy device of traction class 0.6 are proposed

Design features of agricultural transporting technological device equipped with agrophilic wheel mower

Now days there is no a single mass-produced vehicle for agriculture which does not match requirements of the state standard for the maximum allowable impact of movers on the soil. This leads to significant losses and under-harvest of agricultural products. As a promising direction for increasing the efficiency of the transport infrastructure of agricultural production, it is proposed to develop an environmentally friendly transport and technological chassis for agricultural purposes

Complex Spectroscopic Study for Fusarium Genus Fungi Infection Diagnostics of &ldquo;Zalp&rdquo; Cultivar Oat

At present, one of the critical problems in agriculture is the identification of cereals, including oats, infected by Fusarium spp. genus fungi. Timely diagnostics can prevent the further disease spread and help to identify the already stored infected grains. In this regard, the aim of this work is to develop the spectroscopic approaches that determine the infected grains. As an object of the investigation the &ldquo;Zalp&rdquo; cultivar oat, both healthy and infected grains of the 2020 harvest were chosen. The spectroscopic diagnostics included FTIR in the mid-IR region, Raman, and luminescence methods. Combination of chemometric tools with FTIR and Raman spectroscopy allowed obtaining approaches based on identified characteristic spectral features which may be used as infection markers. These approaches make it possible to detect the infection on the grain husk. The carotenoid type fungi pigment was identified within the resonance conditions of Raman scattering excitation. The luminescence study of infected oat husk revealed the presence of characteristic chlorophyll &alpha; peak which is absent in healthy grain husk

DFT Modelling of Molecular Structure, Vibrational and UV-Vis Absorption Spectra of T-2 Toxin and 3-Deacetylcalonectrin

This paper discusses the applicability of optical and vibrational spectroscopies for the identification and characterization of the T-2 mycotoxin. Vibrational states and electronic structure of the T-2 toxin molecules are simulated using a density-functional quantum-mechanical approach. A numerical experiment aimed at comparing the predicted structural, vibrational and electronic properties of the T-2 toxin with analogous characteristics of the structurally similar 3-deacetylcalonectrin is performed, and the characteristic spectral features that can be used as fingerprints of the T-2 toxin are determined. It is shown that theoretical studies of the structure and spectroscopic features of trichothecene molecules facilitate the development of methods for the detection and characterization of the metabolites

Theoretical Investigation of Anhydrofusarubin: Structural and Optical Properties

Anhydrofusarubin is a naphthoquinone pigment synthesized by a number of Fusarium genus fungi. Being a biologically active substance, it demonstrates promising antibiotic properties and rather good hypothetical effectiveness against certain types of cancer. In this regard, an important task arises to study the structural properties and spectral manifestation of Anhydrofusarubin in order to identify and characterize this substance in terms of synthesis and application purposes. In this regard, the aim of the article was to study the structure of the Anhydrofusarubin molecule and its structure-property correlation. The density functional theory was used to investigate the optical properties and stability of the molecular structures. The computational results obtained with B3LYP and wb97XD exchange correlation functionals and the triple zeta basis sets were compared with available experimental data. In addition to the ground state structure, a tautomer with slightly higher energy (by 0.78–0.9 kcal/mol) and a relatively small potential barrier was found. Also, the investigation of flexibility of the pyran ring reveals the presence of two conformational enantiomer forms, being in good agreement with the recent experimental data on the crystal structure. The vibrational and UV-visible absorption spectra were simulated and interpreted

Determination of Main Spectral and Luminescent Characteristics of Winter Wheat Seeds Infected with Pathogenic Microflora

In connection with the constant growth of demand for high-quality food products, there is a need to develop effective methods for storing agricultural products, and the registration and predicting infection in the early stages. The studying of the physical properties of infected plants and seeds has fundamental importance for determining crop losses, conducting a survey of diseases, and assessing the effectiveness of their control (assessment of the resistance of crops and varieties, the effect of fungicides, etc.). Presently, photoluminescent methods for diagnosing seeds in the ultraviolet and visible ranges have not been studied. For research, seeds of winter wheat were selected, and were infected with one of the most common and dangerous diseases for plants—fusarium. The research of luminescence was carried out based on a hardware–software complex consisting of a multifunctional spectrofluorometer “Fluorat-02-Panorama”, a computer with software “Panorama Pro” installed, and an external camera for the samples under study. Spectra were obtained with a diagnostic range of winter wheat seeds of 220–400 nm. Based on the results obtained for winter wheat seeds, it is possible to further develop a method for determining the degree of fusarium infection