Brazes with increased viscosity are needed for brazing of abrasive diamond tools with working surface of complex contoured shape. It’s known that high viscosity is a property of composite brazes consisting of fusible matrix and refractory filler that is not melting during brazing. Goal of the work is to research the influence of refractory fillers on the process of composite brazing of diamond-abrasive tools and on that basis discover the optimal composition of braze. Composite brazes Sn-Cu-Co were researched in the work. It is determined that at least 26-28% (by mass) of cobalt powder should be included in brazes for giving the braze Sn-Cu-Co necessary viscosity and for creation of uniform diamond-comprising layers with thickness up to 2.5 mm on the vertical layers and sharp edges of tools. It is determined that solid-state sintering of powders on the initial stage of heating the composite braze leads to emerging of internal stresses and forming cracks. Inert additions that prevent solid-state sintering should be include in braze to prevent cracking. Optimal inert addition for brazes Sn-Cu-Co is the tungsten powder. Minimum content of tungsten needed to prevent cracking is 6% (by mass). Optimal content of components in composition braze for brazing shaped diamond-abrasive tools is (% by mass): 30 Co, 20 Sn, 43 Cu, 7 W
The article explains the importance of the transport process when performing repair jobs of asphalt roads. The scheme of the technological process was drawn up; job steps were identified, while the latter may be characterized by non-productive downtime of transport as well as that one of technological machines. We have analyzed the following steps of the flowchart of the road concrete mix transportation: the preparation of the road concrete mix for transportation, loading, transportation, unloading, laying and packing. The transportation of goods starts at the working site of their production and ends at the site of their consumption. The transportation process is a multistep and multioperational process having the greater diversity of technological, operational and economic operations, which must be correctly organized. It is extremely important to deliver the road concrete mix of coating plant (OP) just in time, while avoiding the unproductive idle standing of the equipment, the deterioration of the mixture, as well as performing the job steps at minimum transportation cost savings. The successful combining of the steps of the concept organization of the road concrete mix transportation (coating plant, asphalt laying step, transportation step) will improve the performance and will provide the reduction of the job cost. One must perform the coordination of job steps on different road sections using information technologies and communication facility
We’ve illustrated assessment of energy-loading of disk-pad brakes of the bus A172 in the preliminary stages of tests type I and II according to regulated standards of UNECE and we’ve established regularities of heat exchange processes in the interaction surfaces of solid and self-ventilated brake discs with high-speed currents of washing air
Based on the previous investigations we have underlined the need to increase fruit and vegetables preservation quality while transporting them from the producer to the consumer at the expense of improving the road transport operation for its intended purpose. We have made a conclusion about the need to develop strategies for maintenance and repair as for the actual technical state at the expense of developing the diagnosis system based on the development of a math model of changing the technical state of the diagnosis object, developing a method of rational set of objects to be diagnosed and determining the technical state optimal control frequency. We have confirmed that the above mentioned is possible when considering the system of technical operation of road transport as an organization-production system and applying the engineering-cybernetic approach to improve this system. We have considered the basic requirements for the efficiency indexes when investigating and improving the operation system that will allow achieving the aim we have had and can be described mathematically. We have made a conclusion about the urgency of the issue we studied and the possibility to develop the efficient operation system of road transport based on the provided criteria
The article covers the basics of thermodynamics and the possibility of the application of its provisions to the basic biological entity - the cell under the influence of external electromagnetic fields. Thus, we consider a system whose properties do not change in time, if it does not occur on the external influences. If the system is subjected to such (mechanical, thermal, electrical, magnetic and other effects), then all its properties, or some of them are changing. If at least one property of the system changes, we will talk about changing the status of the system due to the fact that there was some process. From the point of view of external electromagnetic fields on the thermodynamic system - a cell of a living organism or plant is very important essence of the concept of work. Unlike conventional concepts of the work of expansion (pdV), which is not considered to be useful, we have introduced the concept of "useful" work dA /, which means the operation of the electric current, magnetic field or other physical fields in the design of various electrical devices and appliances used in livestock and crop. The impact of electromagnetic fields on biological objects also leads to a slight increase in temperature of the biological system and, as a consequence, it increases the rate of chemical and biochemical reactions and phase transitions, which is reflected in the increased activity of the biochemical processes in these objects. This, to some extent can explain numerous experimental results of scholars and practitioners concerned with stimulating crops, for example, during preplant treatments
The article deals with one of the promising areas belonging to energy-saving technologies; it is the introduction of biogasoline stations into agricultural production. The analysis of the application in the world has been shown. To determine the cost-effectiveness of biogasoline stations we have shown the data for the calculation of the potential of biomass: organic waste settlements; animal waste; waste of poultry; crop residues; waste processing industry. We have obtained graphic dependences of electricity generated in the day from livestock and poultry, as well as the number of sunflower, rice, and sugar beets. The table also shows the thermal properties of organic agricultural wastes, allowing increasing the efficiency of calculations to determine the biomass resources. We have considered the schemes of biogasoline stations, a gas turbine power plant and a steam turbine power plant and disclosed the features of their work. To improve the operating and technical specifications of the stations intended for power generation we have proposed using non-contact generators and stabilization of parameters of electric power in their designs to carry out direct frequency converter. We have disclosed the advantages and disadvantages of biogas, as well as the direction of its effective use. It is shown that the use of all the possibilities in the complex of biogasoline stationns (production of fertilizers and motor oil, production of heat and electricity) would improve the efficiency and the payback of investment would be from 3 to 5 years, which is mainly determined by the volumes of biomass
Protective forest plantations, shelter belts and plantings along the highways of Central - Black Earth region and southern Russia are badly damaged, and in some areas destroyed. Therefore, they can not perform their functions and require major reconstruction or restoration. The most resistant and applicable trees and shrubs to create protective forest plantings are: maple, ash, elm species and three-thorned acacia, honey-locust, white and yellow acacia, and other legumes breeds with high drought tolerance, disease resistance, technogenic pollution and pest damage. For the creation and restoration of protective forest plantations we require seeds of these species containing pericarp. In Voronezh State Forestry Academy we have carried out a scientific research for creation of a machine for extracting seeds from the legumes. Analysis of the results of scientific research of prototyping machines showed that they were made without considered technological and mechanical properties of the legumes theoretical researches workflow machines for extracting seeds from the legumes and scientific basis of design parameters and operating modes. In this article we have a presentation of the experimental sample of the machine for extracting seeds from the legumes and theoretical investigation of the workflow in the batch hopper. According to the results of the study, we have obtained a mathematical expression, which allows you to define the parameters and modes of operation of a brush-grater device
The level of technical development today requires the creation of highly effective, including reliable, uninter-rupted power supply systems. We have shown modern requirements and design features of modern systems of uninterruptible power supply, which should be built on a modular principle. It is shown that the problem of synthesis of systems in a modular approach is addressing three issues: development of the structure of the system subject to the requirements of consumers to quality of power and the allowable time of power outage; determining the required level redundancy of major functional units (blocks, elements) to ensure the required reliability of the system; - ensuring the most effective interconnection of modules, including electromagnetic compatibility, and the rational use during normal and emergency operation of the system. We have proposed new structural solution of the main functional units and uninterrupted power supply systems in modular design. To reduce EMI and improve efficiency uninterruptible power supply systems in the design of static converters we need to use a transformer with a rotating magnetic field. In addition, the prospective current is to be used as a source of renewable energy. Another promising approach is the use of direct frequency converters as voltage stabilizers and frequency of the current
Promising is the direction and, above all, in matters of energy saving and energy efficiency of Autonomous systems of power supply, the use of renewable sources-newable energy as a major source of energy for consumers in remote areas. Here priority is given to solar energy. Since solar radiation can be change place not only in heat and electrical. The article contains three main structural schematics of electricity supply with solar power plants. The features of their work are disclosed, as well as an algorithm for calculating solar energy systems, the sequence of which is to define the required parameters, the daily energy consumption by consumers of electric power, the calculation capacity of the battery, the choice of the inverter and determining the area of solar batteries. The article reveals the conditions that affect the calculation of the PV system. It is shown that the greatest efficiency, including economic and reliability we have at combined (hybrid) Autonomous system, which was carried out with both solar power and wind power and gas stations. The important matters of improving the reliability of solar systems are the introduction to the design of a new element of the base, and first and foremost, Autonomous inventors performed on a single-phase transformer with a rotating magnetic field
The article discusses the new technical solutions and the technology of undercrown micro-irrigation of horticultural
crops, taking into account the formation of their root system and circuit humidification