Modeling heat transfer processes in heating systems for surface of highways

В настоящее время обледенение дорожного покрытия оказывает существенное влияние на безопасность движения. Для уменьшения этого негативного воздействия зимой используются фрикционные, химические, физико-химические и комбинированные методы борьбы. Наиболее перспективных способов борьбы с обледенением является использование гидравлической системы таяния снега. Это связано с возможностью прокладки под дорожным покрытием не только индивидуальных систем снеготаяния, но и городских тепловых коммуникаций на участках дорог, подверженных частому обледенению. В связи с этим актуальным является моделирование процессов теплообмена в системах обогрева дорожных покрытий. Разработанная имитационная модель гидросистемы обогрева поверхности автомобильных дорог будет широко использоваться при реконструкции дорожного покрытия, а также для оптимизации систем прокладки тепловых сетей

Adhesiveness of museum and clinical strains of gram-positive microorganisms

Значимість мікроорганізмів у розвитку інфекційних захворювань безпосередньо пов’язана з наявністю факторів патогенності, одним із найвагоміших серед яких є адгезія, запускає каскад імунологічно-опосередкованих реакцій, визначає специфіку інфекційного процесу і є його пусковим механізмом

Design and rationale for parametres of the seed-fertilizer seeder coulter for subsoil broadcast seeding

The article proposes an original design of a seeder for sowing grain crops. В статье предложена оригинальная конструкция сеялки для посева зерновых культур

Research of microdeformation and stress in details of agricultural machines by implementing holography

The article presents theoretical and experimental studies of microstrains and stresses in the details of agricultural machines by the implementation of holography. В статье представлены теоретические и экспериментальные исследования микродеформаций и напряжений в деталях сельскохозяйственных машин с применением голографии

Influence of antiseptic drugs on the adhesive properties of Candida spp.

Представники роду Candida є шостими серед основних госпітальних патогенів та четвертими серед збудників нозокоміальних бактерімій. До недавнього часу в більшості країн переважаючим серед них видом був C. albicans, викликаючи дві-третіх усіх випадків інвазивних кандидозів. Метою дослідження було вивчити адгезивні властивості музейного та клінічних штамів C. albicans та вплив атисептичних препаратів на процес їх адгезі

Application of Cable-Railways for Timber Skidding

The article presents constraining factors of the use of traditional approaches for timber skidding in the winter logging period in the North-West Federal District of the Russian Federation. Based on the study of scientific literature, the classification of cable-railways is given, methods of fastening the platform or cable car to the traction cable, the peculiarities of cable selection are considered. The modes of operation of cable-railways are described (without an engine – as a timber slide, with an engine without a trailing cable, with an engine with a trailing cable), the basic requirements for cable-railways and factors limiting the scope of application of such roads are considered. A methodology for determining the driving forces is proposed. It takes into account the weight of the car moving on the slope, the number of cars, the angle of inclination of the track section, the resistance to car movement, additional resistance to car movement when passing curves, the weight of the cable, its length, the friction of the cable on the ground, sleepers and other obstacles, which depends on the condition of the track structure, the density of sleeper laying, ballast protruding on the surface, cable lubrication and other factors. In addition to the above, power losses from the resistance of track rollers when they are enveloped by the running down branch of the cable, friction losses in the trunnions of the winch drums and friction losses from the cable enveloping the winch drums were considered. The article discusses the conditions under which it is possible to move the car down the slope, as well as prevent slipping and provide cable braking in the grooves of the drums. Limitations for the use of cable-railways, depending on the nature of the track, rolling stock, slope angle of the track, average skidding distance, are determined. A technical solution to improve the existing cable-railways using an articulated carriage that increases the operational properties of cable-railways, is proposed. The proposed design allows to reduce the wear of cables and to organize timber harvesting, including on nonstraight skidding trails with rotation angles up to 45 degrees. At the same time, the design of the articulated carriage can be effectively applied on cable-railways already in operation. For citation: Svoykin F.V., Svoykin V.F., Sokolova V.A., Voinash S.A., Ariko S.Ye. Application of Cable-Railways for Timber Skidding. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 115–125. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-115-12

Mathematical modeling of theim pulse bubbling process of bulk mass by the coolant flow

The main directions of pneumodynamic system usage for storage of bulk agricultural products are bubbling and pneumatic mixing; loading and unloading of technological masses. During pneumodynamic impulse wave formation with alternation of supersonic and subsonic zones, which are limited by shock waves, sound force increasing on the technological mediumabout 150…170 dB, pressure increasing on the product mass due to compressionstretching at the pulse limits to amplitudes of 6…15 barare caused, that promotes implementation of loosening processes during the grain material storage.The developed scheme of the studied process involves the opposite arrangement of pneumatic impulse generators, which allows the formation of a stationary wave, that spreads the pulse energy in both longitudinal and transverse directions, covering the maximum space of the free flowing technological medium. Using the method of D'Alembert for solving the equations, methods of mathematical analysis and their processing in the MathCAD mathematical environment graphical and analytical dependences of force parameters of oscillatory system have been obtained. Choosing an effective mode of pneumodynamic loosening, the force pulse magnitude and the regularities of its change under conditions of the highest mechanical resistance of the free-flow mass have been used as the evaluation criteria the standing wave energy