Analytical evaluation of materials wear resistance and tribotechnical coupling resource

When predicting the durability of various friction units at the design stage of the machine, an experimental-analytical standard of wear resistance is used. Its definition requires long-term and expensive experimental studies of samples or full-scale analogs. In order to reduce these costs, in this work, the fundamental theoretical dependences are derived for evaluating the wear resistance and the life of tribocoupling operating in stationary conditions of friction and fatigue wear. The basis for building the desired dependencies is a thermodynamic analysis of the steady-state process of friction, as a dual, molecular-mechanical process. The verification of the obtained theoretical dependences was carried out by comparing the calculated and experimental values of the wear resistance of samples abraded by the FCM-1 friction commercial machine according to the standard "steel roller - cast iron pad" under various conditions of friction interaction. The obtained results showed a fairly high adequacy of analytical dependencies. The proposed equations can be used to calculate the expected life of various tribocoupling at the design development stage of machines or their reconstruction. © Published under licence by IOP Publishing Ltd

The study of the complex thread knurling process

The study carried out to research a manufacturing process of long products for mining industry by a method of cold knurling, in particular, on a stud of a self-drilling bolt used for strengthening of mountain rocks. The solution of the task was obtained by mathematical simulation of the knurling process in the FE software package that allows establishing stress-strain state parameters necessary to analyze forming and loading of the process. According to the R&D carried out on a basis of the two-rolled screw thread rolling machine was developed a technological process for which the knurling rollers were design and created. The manufactured pilot batch of items that's meeting the requirements for such type of anchors speaks of capability to maintain low-series production of self-drilling fasteners based on the complex profile cold knurling method of a long billet. © Published under licence by IOP Publishing Ltd

Applying the algorithm computational mathematics in the task of implementing machine vision

В данной работе рассматриваются вопросы, связанные с применением математических методов в инженерных задачах. Поставлена задача реализации системы технического зрения на плате семейства stm32. Модуль выполнен для задач робототехники, где управление роботом непосредственно зависит от полученных видеоданных в режиме реального времени.This paper discusses issues related to the application of mathematical methods in engineering problems. The task of implementing machine vision systems on board stm32 family. Module is adapted for robotics applications where control of the robot is directly dependent on the received video data in real time

An Application of Antifriction Coatings to Increase the Lifetime of Friction Units

This article presents a generalization of the results of theoretical and experimental studies on increasing the reliability of friction units by making antifriction coatings on the working surfaces with a flexible tool. The principle scheme and the essence of the method of cladding with a flexible tool (CFT) - shock-frictional forming of thin films from various materials on the surface of the workpiece with flexible elements of rotating metal brushes are described. Versions of cladding machinery and many parts of movable joints with various forms of friction surfaces, on which various metal, polymer, single and two-layer antifriction coatings are applied, are presented. The modification of the frictional application of polymer coatings is shown. The following is a brief description of the most significant effective results for increasing the durability of the industrial sliding friction and rolling friction units

A combined Thomson-Rayleigh scattering diagnostic using an intensified photodiode array

A combined Thomson-Rayleigh scattering device is discussed. It consists of a Nd:YAG laser as a light source in combination with a multichannel detection technique consisting of a gated light amplifier in combination with an optical multichannel analyzer. Special attention is focused on the analysis of the measured spectra. Including convolution methods and taking into account weak coherent effects increases the dynamic range and the accuracy of the measured electron density n/sub e/ and temperature T/sub e/ and neutral particle density n/sub 0/. Accuracies of 1%-4% for n/sub e/, 2%-6% for T/sub e/, and 10%-50% for n/sub 0/ depending on the plasma condition are obtained. The dynamic range for n/sub e/ is 7*10/sup 17/-10/sup 21/ m/sup -3/, for n/sub 0/ is 10/sup 20/-10/sup 23/ m/sup -3/ and for T/sub e/ is 1000-50000

Information value of ante- And intranatal risk factors for bronchopulmonary dysplasia in preterm newborns

Aim of the study. To identify the leading antenatal and intranatal risk factors for bronchopulmonary dysplasia based on the analysis of their prevalence and information content Materials and methods. We performed a prospective follow-up of 124 infants of gestational age of less than 32 weeks with the classical form of bronchopulmonary dysplasia (study group). The control group included 119 newborns with gestational age of less than 32 weeks without bronchopulmonary dysplasia. The parents of the compared groups were questioned, with the following assessment of the prevalence and informative value of antenatal and intranatal risk factors. Results. The leading antenatal and intranatal risk factors for the development of bronchopulmonary dysplasia are: acute respiratory viral infection in II-III trimester, threatened miscarriage, intrauterine growth retardation, Apgar score at the 1st (3 or less) and 5th minute (5 or less), body weight of less than 1400g at birth, body length less than 36 cm at birth, cesarean section, more then 6-hours waterless period. Conclusion. The combination of these intranatal and antenatal risk factors can be attributed to a group with high risk of bronchopulmonary dysplasia. © 2019 National Academy of Pediatric Science and Innovation. All rights reserved