scholarly journals EXPERIMENTAL STUDIES OF THE INTERACTION OF TRACTOR DRIVE WHEELS WITH THE SOIL IN THE PLOWED FIELD

2021 ◽  
pp. 430-440
Author(s):  
Gennadii Golub ◽  
Viacheslav Chuba ◽  
Yaroslav Yarosh ◽  
Oleksandr Solarov ◽  
Nataliya Tsyvenkova
Keyword(s):  
Mathematical Models ◽  
Experimental Model ◽  
Negative Impact ◽  
Experimental Studies ◽  
Operating Mode ◽  
Operational Parameters ◽  
Effect Of Pressure ◽  
Soil Hardness ◽  
Pneumatic Chamber

The article defines the influence of structural and operational parameters of a machine-tractor unit on changes in the hardness of freshly plowed soil due to deformation and compaction of the soil by wheeled running systems. An experimental model of the effect of pressure in the pneumatic chamber of the wheel, working width and speed of the unit on changes in soil hardness in the area of operation of running systems is obtained. The obtained mathematical models make it possible to predict changes in soil hardness, which makes it possible to reduce the negative impact on the soil of running systems by optimally completing, configuring and selecting the MTU operating mode.

scholarly journals Development and Research of Crosshead-Free Piston Hybrid Power Machine

Machines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 32
Author(s):  
Viktor Shcherba ◽  
Viktor Shalay ◽  
Evgeniy Nosov ◽  
Evgeniy Pavlyuchenko ◽  
Ablai-Khan Tegzhanov
Keyword(s):  
Experimental Studies ◽  
Operational Parameters ◽  
Work Processes ◽  
Free Piston ◽  
Hybrid Power ◽  
Power Machine ◽  
Hybrid Power Machine ◽  
Simplifying Assumptions ◽  
Cylinder Piston ◽  
Groove Seal

This article considers the development and research of a new design of crosshead-free piston hybrid power machine. After verification of a system of simplifying assumptions based on the fundamental laws of energy, mass, and motion conservation, as well as using the equation of state, mathematical models of the work processes of the compressor section, pump section, and liquid flow in a groove seal have been developed. In accordance with the patent for the invention, a prototype of a crosshead-free piston hybrid power machine (PHPM) was developed; it was equipped with the necessary measuring equipment and a stand for studying the prototype. Using the developed mathematical model, the physical picture of the ongoing work processes in the compressor and pump sections is considered, taking into account their interaction through a groove seal. Using the developed plan, a set of experimental studies was carried out with the main operational parameters of the crosshead-free PHPM: operating processes, temperature of the cylinder–piston group and integral parameters (supply coefficient of the compressor section, volumetric efficiency of the pump section, etc.). As a result of numerical and experimental studies, it was determined that this PHPM design has better cooling of the compressor section (decrease in temperature of the valve plate is from 10 to 15 K; decrease in temperature of intake air is from 6 to 8 K, as well as there is increase in compressor and pump section efficiency up to 5%).

Numerical Modeling and Experimental Studies of the Operational Parameters of the Earth-To-Air Heat Exchanger of the Geothermal Ventilation System

2021 ◽  
Vol 23 ◽  
pp. 42-64
Author(s):  
Boris Basok ◽  
Ihor Bozhko ◽  
Maryna Novitska ◽  
Aleksandr Nedbailo ◽  
Myroslav Tkachenko
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Ventilation System ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Operational Parameters ◽  
Cross Sectional ◽  
Distinctive Features ◽  
Sectional Shape ◽  
Experimental Bench

This article is devoted to the analysis of the heat engineering characteristics of the operation of an Earth-to-Air Heat Exchanger, EAHE, with a circular cross-sectional shape, which is a component of the geothermal ventilation system. The authors analyzed literature sources devoted to the research of heat exchangers of the soil-air type of various designs and for working conditions in various soils. Much attention is paid to the issues of modeling the operation of such heat exchangers and the distinctive features of each of these models. Also important are the results of experimental studies carried out on our own experimental bench and with the help of which the numerical model was validated. The results of these studies are the basis for the development of a method for determining the optimal diameter of an EAHE under operating conditions for soil in Kyiv, Ukraine.

Some aspects of improving the energy efficiency of a mine centrifugal pumps.

2020 ◽  
Vol 23 (2) ◽  
pp. 48-51
Author(s):  
V. KONDRATENKO ◽  
◽  
V. KALYNYCHENKO ◽  
Keyword(s):  
Energy Efficiency ◽  
Mine Drainage ◽  
Experimental Studies ◽  
Operating Mode ◽  
Centrifugal Pumps ◽  
Pump Unit ◽  
Drainage Systems ◽  
Start Up ◽  
Discharge Unit ◽  
Pumping Units

Mine drainage systems, which are used at the main drainage of mining enterprises, have a drive capacity of up to 1600kW. To reduce non-productive energy losses, as well as for the continuous operation of the mining company, mine pumps must be energy efficient and reliable. Analysis of downtime of drainage systems shows that the weak point is the unloading device. This fact can lead not only to the failure of the pumping unit, but also to possible prolonged downtime of the mine. The main disadvantage of the existing disk unloading devices of mine pumps is their low reliability and low service life, due to the rapid wear of the components of the unloading unit. The most vulnerable elements of the unloading device are the unloading rings. The need for frequent replacement and adjustment of the elements of the discharge unit is associated with disassembly and assembly of the pump directly in the pump chamber. Such actions require significant costs of unproductive manual labor of service personnel, and rapid wear of parts of the unloading device necessitates their constant replenishment. Malfunctions in the unloading device can cause significant pump failures. To increase the reliability and energy efficiency of mine drainage systems, the method of control of the unloading device was used. During the experimental studies it was found that cavitation phenomena during the operation of pumping units are absent and, accordingly, can not be the cause of wear of the elements of the unloading unit. When the pumps are operating in steady state, the displacement of the rotors was monitored for 3-4 hours on each pump unit. After data processing, it was obtained that the wear of the surface of the unloading rings occurs at a rate of 0.05-0.15mm in one hour. To determine the wear of the rings of unloading during start-up - stop of the pump, at first the indicators of measuring devices at the established mode of operation of the pump unit were fixed. Then the pump was turned off and on again. After starting the pump unit, we made sure that the operating mode of the unloading device did not change and compared the readings of the shaft position indicator before stopping and after starting the pump. From the measurements made it followed that stopping and starting the pump does not lead to noticeable wear of the unloading device. Therefore, it can be assumed that mainly the wear of the discharge rings occurs during the steady operation of the pump unit.

New and safe experimental model of radiation-induced neurovascular histological changes for microsurgical research

2016 ◽  
Vol 51 (2) ◽  
pp. 124-137
Author(s):  
Sergi Barrera-Ochoa ◽  
Irene Gallardo-Calero ◽  
Andrea Sallent ◽  
Alba López-Fernández ◽  
Ramona Vergés ◽  
...  
Keyword(s):  
Side Effects ◽  
Experimental Model ◽  
Experimental Studies ◽  
Neurovascular Bundle ◽  
Control Group ◽  
Sprague Dawley ◽  
Histological Changes ◽  
Group I ◽  
Radiation Induced

The aim is to create a new and safe experimental model of radiation-induced neurovascular histological changes with reduced morbidity and mortality for use with experimental microsurgical techniques. Seventy-two Sprague–Dawley rats (250–300 g) were divided as follows: Group I: control group, 24 rats clinically evaluated during six weeks; Group II: evaluation of acute side-effects (two-week follow-up period), 24 irradiated (20 Gy) rats; and Group III: evaluation of subacute side-effects (six-week follow-up period), 24 irradiated (20 Gy) rats. Variables included clinical assessments, weight, vascular permeability (arterial and venous), mortality and histological studies. No significant differences were observed between groups with respect to the variables studied. Significant differences were observed between groups I vs II–III regarding survival rates and histological changes to arteries, veins and nerves. Rat body weights showed progressive increases in all groups, and the mortality rate of the present model is 10.4% compared with 30–40% in the previous models. In conclusion, the designed model induces selective changes by radiotherapy in the neurovascular bundle without histological changes affecting the surrounding tissues. This model allows therapeutic experimental studies to be conducted, including the viability of microvascular and microneural sutures post radiotherapy in the cervical neurovascular bundle.

scholarly journals Determination of the time of ignition of plant raw under the high temperature of the radiation panel

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
V. V. Lomaha ◽  
O. Yu. Tsapko ◽  
Yu. V. Tsapko ◽  
O. P. Bondarenko
Keyword(s):  
High Temperature ◽  
Fire Protection ◽  
Effective Means ◽  
Experimental Studies ◽  
Fire Retardant ◽  
Protective Layer ◽  
Thermal Action ◽  
Environmental Safety ◽  
Wood Products ◽  
Operational Parameters

Reducing the fire prevention of timber is not only an economic task, but also has a social and environmental focus. From economic, technological and environmental perspective, an important problem in ensuring the viability and safe operation of construction sites is the development of fire-retardant coatings for wooden structures. The construction is increasingly looking for new highly effective means of fire protection of wood and wood products which should not only ensure the standardized fire resistance of wood, but also to maintain its operational parameters to solve environmental safety and durability. Studies of the effect of the radiation panel on the ignition of the wood sample have set the parameters of the flame ignition, which makes it possible to influence this process. It is proved that they consist in the formation of a layer of organic material on the surface, which provides heating to a critical temperature, when the intensive decomposition of the material begins with the release of the required amount of combustible gases and their ignition. This makes it possible to determine the effect of fire protection and the properties of protective compositions on the process of slowing down the rate of burning of wood. Experimental studies have confirmed that the untreated sample of wood, under the thermal action of the radiation panel has taken up, the flames spread over the entire surface, which led to its combustion. The application of a fire retardant varnish under the influence of temperature leads to a layer of foam coke and inhibition of heat transfer of high-temperature flame to the material and its ignition. Thanks to this, it became possible to determine the conditions for changing the parameters of combustion and braking during fire protection of wood, by forming a barrier for thermal conductivity. Thus, there is reason to argue for the possibility of directional control of the processes of fire protection of wood by the use of fireproof coatings that can form a protective layer on the surface of the material, which slows down the rate of burning of wood.

Experimental Studies on CO2 Absorption in Immersed Hollow Fiber Membrane Contactor

2012 ◽  
Vol 209-211 ◽  
pp. 1571-1575 ◽  
Author(s):  
Xiao Na Wu ◽  
Liang Wang ◽  
Zhao Hui Zhang ◽  
Wen Yang Li ◽  
Xing Fei Guo
Keyword(s):  
Removal Efficiency ◽  
Hollow Fiber ◽  
Flue Gas ◽  
Polyvinylidene Fluoride ◽  
Hollow Fiber Membrane ◽  
Experimental Studies ◽  
Operating Mode ◽  
Membrane Performance ◽  
Membrane Flux ◽  
Absorption Performance

Carbon dioxide (CO2) absorption performance from flue gas was investigated using monoethanolamine (MEA) solution in porous hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes contactor. The influence of operating parameters on CO2 removal efficiency and flux were studied in the immersion operating mode. The experimental results indicated that the CO2 removal efficiency and flux decreased with the increase of flue gas load and carbonization degrees, but the increase of the absorbent concentration and temperature promoted membrane performance of CO2 capture. An increase of 84 m3•m-2•h-1 in the flue gas load resulted in a 68% decrease in the removal efficiency. Absorbent carbonation degree increased to 0.45 mol CO2•mol-1MEA led to the decrease of active ingredient amounts in the absorption solution, and the corresponding removal efficiency and membrane flux dropped by 50% of the initial amounts, respectively. The increase of concentration and temperature of absorbent also benefited membrane absorption performance of CO2 absorption, so that the concentration and temperature of the solvent increased lead to the CO2 removal efficiency and flux increased.

Recovery of Hesperodiaptomus arcticus populations from diapausing eggs following elimination by stocked salmonids

1996 ◽  
Vol 74 (7) ◽  
pp. 1292-1297 ◽  
Author(s):  
Brian R. Parker ◽  
Frank M. Wilhelm ◽  
David W. Schindler
Keyword(s):  
Lake Sediments ◽  
Calanoid Copepod ◽  
Negative Impact ◽  
Experimental Studies ◽  
Fish Population ◽  
Alpine Lakes ◽  
Fish Stocking ◽  
Egg Bank ◽  
Diapausing Eggs ◽  
Gammarus Lacustris

Hesperodiaptomus arcticus, a predatory calanoid copepod, was eliminated from two alpine lakes within 6 years of stocking with salmonids. Using historical and contemporary Zooplankton and fish data, sediment analysis for diapausing eggs, and experiments on predation of Gammarus lacustris on diapausing eggs of H. arcticus, we assess the fate of these populations 35 years after fish stocking. In Pipit Lake, in which the trout introduction failed within 21 years, we propose that H. arcticus recovered as a result of hatching of diapausing eggs held in the sediments. In Snowflake Lake the diapausing egg bank was exhausted prior to the loss of the fish population 25 years after first stocking and H. arcticus recovery did not occur. Experimental studies indicate that G. lacustris predation on diapausing eggs probably occurs within the sediments. Combined with a 10-fold difference in G. lacustris density between Snowflake and Pipit lakes the results of the predation experiments imply that G. lacustris had a strong negative impact on the abundance of diapausing eggs held in Snowflake Lake sediments and therefore reduced the ability of the population to recover following perturbation.

Calculation of the fire resistance of steel hollow structural section columns filled with plain concrete

1994 ◽  
Vol 21 (3) ◽  
pp. 382-385 ◽  
Author(s):  
T. T. Lie ◽  
D. C. Stringer
Keyword(s):  
Mathematical Models ◽  
Key Words ◽  
Fire Resistance ◽  
Experimental Studies ◽  
Plain Concrete ◽  
Building Codes ◽  
Aggregate Concrete ◽  
Parametric Studies ◽  
Hollow Structural Section ◽  
Hollow Structural Sections

Experimental studies were conducted to determine the fire resistance of circular and square hollow structural section columns filled with plain concrete. Mathematical models were developed and used to investigate the influence of important parameters that determine the fire resistance of these columns. The experimental and parametric studies provide information for the development of formulas for the calculation of the fire resistance of circular and square concentrically loaded columns filled with plain carbonate or siliceous aggregate concrete. Such formulas are suitable for incorporation into building codes. Key words: calculation, fire resistance, columns, concrete-filled, steel, hollow structural sections.

REDUCING THE ADVERSE EFFECTS OF THE OPERATION OF GAS FIRED MELTING FURNACES ON THE ENVIRONMENT

2021 ◽  
Author(s):  
Luboslav Straka ◽  
Tibor Krenicky
Keyword(s):  
Fossil Fuels ◽  
Negative Impact ◽  
Combustion Process ◽  
Melting Furnace ◽  
Operating Mode ◽  
Global Scale ◽  
Pollutant Emissions ◽  
Experimental Measurements ◽  
Global Concern ◽  
Overall Efficiency

Due to the growing production on a global scale, the use of fossil fuels is also increasing. Therefore, the control of pollutant emissions produced in the industrial sphere has become a global concern. In general, an imperfect combustion process has a negative impact on the overall efficiency and economy of plant operation, but at the same time increases the share of total emissions in the environment. We also encounter this problem when operating gas fired melting furnaces. Therefore, the paper aimed to describe the results of experimental measurements of the number of emissions produced during the operation of a gas fired melting furnace, which in practice is mainly used for melting alloys. Experimental measurements were oriented to find the most suitable variant of the operating mode of the gas fired melting furnace with regard to minimizing the total amount of emissions produced.

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