On Optimal Signal–Filter Pairs

We extend the notion of an optimal signal–filter pair to the case where n-convolution is used instead of cyclic convolution. We construct n-optimal n-adic signals for all n = 2, 3, . . ..     

Acute appendicitis complicated by destruction of the large intestine and septic shock

Access and visualization in the implant-abutment area are often compromised. Tissue impingement and lack of abutment position verification may result in inaccurate fit.     

Analysis of instantaneous cardiac rhythm in a model of multifractal dynamics based on Holter monitoring

For the specific analysis of the variability of RR intervals of the cardiac rhythm, a method for measuring the instantaneous cardiac rhythm (ICR) represented by a multifractal dynamical model (MDM) has been developed. The advantages of this method, compared to the statistical methods of analysis of the RR intervals used, have been demonstrated. The method allows possible catastrophes of the cardiovascular system to be predicted. Using the data of Holter monitoring and the program system developed, we have plotted ICR curves, an ICR piecewise linear trend, and variability charts for three randomly chosen time intervals. The self-similarity (fractality) of the ICR up to an accuracy of 5% has been shown based on the explicit data. The MDM parameters have been calculated based on the ICR data. The analysis of the dynamics of these parameters has been conducted and their compliance with the status of the patient examined has been studied. The relevance of the ICR examination within MDM is closely related to the necessity of recognizing new markers of adverse cardiovascular episodes. The research performed shows that the results obtained could be taken as a basis for developing a new mathematical method of ICR examination based on Holter monitoring.     

Investigation of the iodine component composition in helium for the conditions of a HTGCR

Scientific-Research Physical Chemistry Institute. All-Union Scientific-Research Institute of Automatic Machinery. Institute of Nuclear Reactors, Russian Scientific Center "Kurchatovskii institut." Translated from Atomnaya énergiya, Vol. 76, No. 2, pp. 148–151, February, 1994.     

Broadband Light Absorption and Efficient Charge Separation Using a Light Scattering Layer with Mixed Cavities for High‐Performance Perovskite Photovoltaic Cells with Stability

CH₃NH₃PbI₃ is one of the promising light sensitizers for perovskite photovoltaic cells, but a thick layer is required to enhance light absorption in the long‐wavelength regime ranging from PbI₂ absorption edge (500 nm) to its optical band‐gap edge (780 nm) in visible light. Meanwhile, the thick perovskite layer suppresses visible‐light absorption in the short wavelengths below 500 nm and charge extraction capability of electron–hole pairs produced upon light absorption. Herein, we find that a new light scattering layer with the mixed cavities of sizes in 100 and 200 nm between transparent fluorine‐doped tin oxide and mesoporous titanium dioxide electron transport layer enables full absorption of short‐wavelength photons (λ < 500 nm) to the perovskite along with enhanced absorption of long‐wavelength photons (500 nm < λ < 780 nm). Moreover, the light‐driven electric field is proven to allow efficient charge extraction upon light absorption, thereby leading to the increased photocurrent density as well as the fill factor prompted by the slow recombination rate. Additionally, the photocurrent density of the cell with a light scattering layer of mixed cavities is stabilized due to suppressed charge accumulation. Consequently, this work provides a new route to realize broadband light harvesting of visible light for high‐performance perovskite photovoltaic cells.     

Formation of an iron-containing catalytic nanoparticle during the three-phase Fischer–Tropsch synthesis: Molecular modeling

The effect of a polyacrylonitrile additive on the catalytic behavior of an iron-containing suspension under the conditions of Fischer–Tropsch synthesis in a slurry reactor is studied. Modeling of the formation of a catalytic particle using the molecular dynamics method is performed.     

Improvements in Turbine-Blade Manufacture

Russian Engineering Research - A completely automated manufacturing technology for turbine blades is proposed. The system includes automatic loading and unloading of the workpiece; its automated...