An Indacenopicene‐based Buckybowl Catcher for Recognition of Fullerenes

A novel buckybowl catcher with an extended π-surface has been synthesized via cross-coupling of two bowl shaped bromoindacenopicene moieties with a tolyl linker. The obtained catcher has been unambiguously characterized by 2D-NMR and mass spectrometry. DFT calculations indicate that the curved shape of the receptor moieties is favourable for binding fullerenes. Effective binding was confirmed for interactions with C$_{60}$ and C$_{70}$ utilizing NMR spectroscopy and isothermal titration calorimetry (ITC). The resulting binding values show a higher affinity of the catcher towards C$_{70}$ over C$_{60}$. The designed catcher demonstrated the fundamental possibility of creating sensors for spherical aromaticity

Investigation of the Technological Possibility of Laser Hardening of Stainless Steel 14Cr17Ni2 to a Deep Depth of the Surface

The article presents the results of a research of the process of laser hardening of steel 14Cr17Ni2 (AISI 431) by radiation of a high-power fiber laser LS-16. Assessment of the theoretically possible maximum depth in laser processing without additional beam transformations, the use of additional coatings and devices were shown. The results of experiments on increasing the depth of the hardened layer during laser processing by using scanning of the laser beam and optimally selected mode parameters without scanning are demonstrated. The influence of the number of passes on the depth of the hardened layer is investigated. The microstructure of hardened samples was studied and quantitative estimation of structural components was carried out. The microhardness of hardened samples at different modes of laser hardening was measured

Determination of the required power for bus hybrid engine

This article presents a methodology for determining the required engine power of hybrid city buses. The vehicle’s driving cycle and its main technical characteristics were used as the initial data. The calculated change in power on the driving wheels is an intermediate result and is used to analyze the chains of energy transfer from gasoline engine to driving wheels. In this approach, a sequential type of circuit in a hybrid drive is used. A bus weighing 4 tons was considered as an example, and the calculations showed that the maximum power of the internal combustion engine should be 15.2 kW

Investigation of the Technological Possibility of Laser Hardening of Stainless Steel 14Cr17Ni2 to a Deep Depth of the Surface

The article presents the results of a research of the process of laser hardening of steel 14Cr17Ni2 (AISI 431) by radiation of a high-power fiber laser LS-16. Assessment of the theoretically possible maximum depth in laser processing without additional beam transformations, the use of additional coatings and devices were shown. The results of experiments on increasing the depth of the hardened layer during laser processing by using scanning of the laser beam and optimally selected mode parameters without scanning are demonstrated. The influence of the number of passes on the depth of the hardened layer is investigated. The microstructure of hardened samples was studied and quantitative estimation of structural components was carried out. The microhardness of hardened samples at different modes of laser hardening was measured

Reliability analysis of the existing reinforced concrete beams with normal cracks by rebar strength criteria

The paper describes the problem of the reliability analysis for individual reinforced concrete (RC) beams by the rebar strength criterion in cross section with a normal crack. It is proposed to evaluate the stress in the rebar by measurements of the crack width at the level of the rebar using the functional dependence of the crack width and the strain (deformation) in the reinforcement. It is also proposed to replace the modulus of elasticity of steel reinforcement on the secant modulus of elasticity, taking into account the increased reinforcement strain in cross section with crack. The work considers two options of the crack width in beam: less and greater than the ultimate crack width. The reliability analysis of RC beams by the rebar strength is based on the possibility theory and fuzzy set theory by the reason of small statistical data from measurements on existing individual RC beams. The use of offered reliability analysis methods will allow preventing the failures of reinforced concrete beams and in some cases to obtain economic benefit from the possibility of further operation of RC beams with cracks, even with a crack width more than ultimate value

Composite Superconductor as a Distributed Trigger System

Composite superconductor with contact electrical resistance between a superconductor proper and a matrix of normal metal is considered as a distributed trigger system described by two coupled diffusion-reaction equations. Analytical expression for the minimum normal zone propagation current in the composite superconductor is derived for the case of a small contact electrical resistance, and the general diagram of resistive states in the coordinates of transport current versus contact resistance is obtained numerically. Comparison of the diagrams for the composite superconductor and a distributed trigger system described by modified FitzhewNagumo type equations is also made. On the diagrams of both systems, regions of stable domains, switching waves propagation and self-organization of domain structures are indicated

See laser testing at different temperatures

The main problem for laser SEE testing at different temperatures is to determine correlation between laser pulse energy and LET. In the first approximation, LET values with the same laser pulse energy and different temperatures are directly proportional to the absorption coefficient of laser light in a semiconductor. Use of tabulated values could lead to errors and absorption coefficient should be determined for each sensitive volume of device under test (DUT). Temperature dependence of absorption coefficient could be determined using ionization response of DUT in power supply circuit under local laser irradiation. Using this approach a satisfactory correlation of ion and laser SEE test result was observed