Nonequlibrium Plasma Chemistry for Concept of Sustainable Development

This work is devoted to the exploration of the compatibility of the hybrid plasma-catalytic conversion of liquid hydrocarbons into syngas with the concept of sustainable development. The results of experimental investigations indicate the high efficiency of plasma-catalytic conversion of ethanol to syngas and the small amount of waste (a few percent of feedstock weight). The results of the simulation of the kinetics using ZDPlasKin code for thermochemical and hybrid plasma-catalytic conversion

Перевірка математичної моделі технологічного процесу прокатки на стані Стеккеля заводу Feeriera Valsider SpA

В роботі досліджена математична модель процесу прокатки гарячекатаних рулонів на стані Стеккеля заводу Ferriera Valsider SpA. Виконана перевірка розробленої моделі з метою можливості її використання за для проектування технології прокатки. Враховано вплив «пружини» клітей. Середня похибка при моделюванні температурного режиму прокатки на стані 3170 склала від 8,27% до 9,11%, на стані 1780 від 0,003% до -0,92%. Середня похибка при моделюванні сили прокатки на стані 3170 склала від 0,5% до 5,7%, на стані 1780 від -4,89 до 6,59%. Встановлено вплив на фактичний вимір температури попередньої обробки розкату гідросбивом окалини, що призводить до значних похибок при подальшому порівнянні з результатами розрахунків.    

Перевірка математичної моделі технологічного процесу прокатки на стані Стеккеля заводу Feeriera Valsider SpA

Goal: Mathematic model checking of the technological process of hot-rolled coils rolling at Ferriera Valsider SpA Steckel Mill. Method of doing research: The checking of the developed model was carried out to allow its applying for the rolling process design. The influence of the mill springe was taken into account. It was determined the influence over the actual temperature measuring of the previous transfer bar processing by means of water descaling that results in significant inaccuracies when further comparing to the calculation results. Value: The average inaccuracy when modelling the rolling temperature conditions at mill 3170 is from 8,27% to 9,11%, at mill 1780 is from 0,003% to -0,92%. The average inaccuracy when modelling the rolling force at mill 3170 is from 0,5% to 5,7%, at mill 1780 is from -4,89 to 6,59%.В работе исследована математическая модель процесса прокатки горячекатаных рулонов на стане Стеккеля завода Ferriera Valsider SpA. Выполнена проверка разработанной модели с целью возможности ее использования для проектирования технологии прокатки. Учтено влияние «пружини» клетей. Средняя погрешность при моделировании температурного режима прокатки на стане 3170 составила от 8,27% до 9,11%, на стане 1780 от 0,003% до -0,92%. Средняя погрешность при моделировании силы прокатки на стане 3170 составила от 0,5% до 5,7%, на стане 1780 от -4,89 до 6,59%. Установлено влияние на фактическое измерение температуры предыдущей обработки раската гидросбивом окалины, что приводит к существенным отклонениям при дальнейшем сравнении с результатами расчетов.В роботі досліджена математична модель процесу прокатки гарячекатаних рулонів на стані Стеккеля заводу Ferriera Valsider SpA. Виконана перевірка розробленої моделі з метою можливості її використання за для проектування технології прокатки. Враховано вплив «пружини» клітей. Середня похибка при моделюванні температурного режиму прокатки на стані 3170 склала від 8,27% до 9,11%, на стані 1780 від 0,003% до -0,92%. Середня похибка при моделюванні сили прокатки на стані 3170 склала від 0,5% до 5,7%, на стані 1780 від -4,89 до 6,59%. Встановлено вплив на фактичний вимір температури попередньої обробки розкату гідросбивом окалини, що призводить до значних похибок при подальшому порівнянні з результатами розрахунків.    

АЛГОРИТМ ВИЗНАЧЕННЯ ОПТИМАЛЬНОЇ ТОПОЛОГІЇ РОЗПОДІЛЬЧОЇ МЕРЕЖІ

An algorithm for determining optimal electrical network topologies based on the evaluation of improvement options when changing the topology of local areas, as well as the algorithm for determining the main routing.Предложен алгоритм определения оптимальной топологии сети на основе использования оценки улучшения варианта при изменении топологии в локальных зонах, а также алгоритм определения пути прокладки магистрали.Запропоновано алгоритм визначення оптимальної топології мережі на основі використання оцінки поліпшення варіанту при зміні топології в локальних зонах, а також алгоритм визначення шляху прокладання магістралі

Development of Alternative Technology of Dual Forming of Profiled Workpiece Obtained by Buckling

A possibility of application of longitudinal bending (buckling) as an economical way of profiling workpieces, ensuring replacement of pinching impressions and edgers was shown for manufacturing of eye-bolt forgings. For realization of this method of impression-free profiling of blanks, a process of twin forging of eye-bolt forgings was designed as well as the arrangement of the forging facilities. The peculiarity of this process is that the cut-off blank is upset, it loses its stability and thus obtained profiled semi-finished product is turned over on its side and eventually it is put inside the impression for simultaneous forging of two forgings from one blank. It was found that profiled semi-finished items acquired the desired shape at the degree of blank's upsetting equal to 39 %, the central angle between the twin eye-bolts forgings being 54° and it had been taken into account for the dies' design. Experimental forming of eye-bolts forgings according to the proposed and conventional processes on physical lead models of blanks, which helped to find out that the proposed technical solution, can ensure metal saving at 21.7 % level. Comparison of these two methods revealed improved technical and economic indices of the new process; particularly the coefficient of metal consumption at cutting was raised by 1.4 %, the quotient of output of quality forgings by 21.1 % and coefficient of application of forgings metal along the consumption rate by 27.9 %

Silver incorporation on viscose and cotton fibers after air, nitrogen and oxygen DBD plasma pretreatment

Dielectric barrier discharge (DBD) pretreatments in air, nitrogen and oxygen plasma of viscose and cotton fabrics with subsequent immobilization of silver were studied. Surface activation of treated fibers was evaluated through subsequent sorption of silver from aqueous AgNO3 solution, after which changes in the surface morphology were monitored and quantity of silver deposition on fabric was measured. The plasma treatment was done in volume DBD discharge with the gap distance between electrodes of 0.5 and 2 mm. Depending on the gas used in pretreatment, significant difference in the way silver bonds to the textile surface was found. Nitrogen plasma pretreatment with gap distance of 0.5 mm led to the homogeneous fiber coating by silver nanoparticles with average size up to 300 nm estimated by SEM, while fibers treated in oxygen plasma adsorbed silver in a form of ions. The plasma pretreatment in air leads to changes that contain features of fibers treated in both nitrogen and oxygen DBD plasma. Distinct difference of used configuration of the plasma source is a use of gap distance 0.5 mm, which is in order of textile thickness. Observed results allow us to report a new way how to immobilize silver nanoparticles onto textile fibers using plasma pretreatment with subsequent sorption of silver from aqueous solution

Antimicrobial viscose fabric prepared by treatment in DBD and subsequent deposition of silver and copper ions-Investigation of plasma aging effect

In this work, the effect of dielectric barrier discharge (DBD) in ambient air on preparation of antimicrobial viscose fabric was studied. DBD plasma treatment was applied under constant discharge power and different exposure times. Vertical wicking test was used to evaluate optimal conditions for plasma treatment of viscose in order to increase fabrics' wettability and consequently improve sorption properties. Investigation of aging effect of plasma treatment revealed that there was no significant change in wettability of viscose samples 21 days after plasma treatment, which suggests good durability of treatment. After DBD plasma treatment, fabrics were modified with silver and copper ions in order to impart antimicrobial properties on viscose fabric. Viscose samples, modified with Ag (I) and Cu (II) ions immediately and 1, 7, 14 and 21 days after DBD treatment were tested in vitro against microorganisms S. aureus, E. coli and C. albicans using agar diffusion test. Obtained results showed that modification with DBD, prior to sorption of Ag (I) and Cu (II) ions, leads to improvement of antimicrobial activity of viscose samples, with a possibility to provide specific activity against different microorganisms by altering the days after DBD treatment prior ions sorption