Abstract
High reliability requirements are imposed on the quality of the soldered joints. Typical defects in the soldered joints of heat exchangers are non-soldered. The minimum size of the ...non-penetration area that must be detected is about 1 square millimeter. The existing assessment of the quality of soldering is reduced to destructive tests. These tests include hydraulic and pneumatic tests. There are control technologies that use non-destructive methods. For example, the applicability of the ultrasonic echo method based on thermo-optical (laser) excitation of ultrasonic waves has been proven. However, continuous inspection of the liquid-propellant engine chamber using the traditional echo method is not rational, since the inspection speed is limited by the size of detected defects (1 square millimeter) and amounts to a few millimeters per minute. In order to increase the scanning speed without losing the ability to reliably detect defects such as “non-soldered”, it is proposed to use phased array antennas (PA) as a means of implementing the ultrasonic echo method. The paper considers the issues related to the interpretation of the information obtained when scanning the soldered joint, as well as issues related to modeling the acoustic field in the model of the soldered joint of the heat exchanger.
Lanthanum orthoferrite powders were synthesized via one‐step hydrothermal reactions under mild conditions using microwave and conventional heating. The use of microwave irradiation during the ...synthesis allows one to obtain nanocrystalline LaFeO3 with a higher yield and reduced crystallite and particle size within a 16 times shorter duration (3 hours) at a lower temperature of 220°C as compared to the conventional heating. The catalytic decomposition of nitrous oxide was performed over both samples, it was shown that the sample obtained under microwave conditions demonstrates enhanced activity as a catalyst: N2O decomposes completely at 700°C over the catalyst formed at microwave conditions, while the comparative catalyst prepared by conventional heating reaches a lower conversion of only 60% at the same temperature and catalytic reaction conditions.
The use of microwave irradiation during the hydrothermal synthesis results in smaller LaFeO3 particles with higher amount of oxygen on the surface and, as a consequence, a higher activity in N2O decomposition.
Nowadays, there is a demand in the production of nontoxic multifunctional magnetic materials possessing both high colloidal stability in water solutions and high magnetization. In this work, a series ...of water-dispersible natural humate-polyanion coated superparamagnetic magnetite nanoparticles has been synthesized via microwave-assisted synthesis without the use of inert atmosphere. An impact of a biocompatible humate-anion as a coating agent on the structural and physical properties of nanoparticles has been established. The injection of humate-polyanion at various synthesis stages leads to differences in the physical properties of the obtained nanomaterials. Depending on the synthesis protocol, nanoparticles are characterized by improved monodispersity, smaller crystallite and grain size (up to 8.2 nm), a shift in the point of zero charge (6.4 pH), enhanced colloidal stability in model solutions, and enhanced magnetization (80 emu g−1).
Abstract
Lanthanum orthoferrite powders were synthesized via one‐step hydrothermal reactions under mild conditions using microwave and conventional heating. The use of microwave irradiation during ...the synthesis allows one to obtain nanocrystalline LaFeO
3
with a higher yield and reduced crystallite and particle size within a 16 times shorter duration (3 hours) at a lower temperature of 220°C as compared to the conventional heating. The catalytic decomposition of nitrous oxide was performed over both samples, it was shown that the sample obtained under microwave conditions demonstrates enhanced activity as a catalyst: N
2
O decomposes completely at 700°C over the catalyst formed at microwave conditions, while the comparative catalyst prepared by conventional heating reaches a lower conversion of only 60% at the same temperature and catalytic reaction conditions.
The most important necessary condition for the practical implementation of the results of fundamentally new technical developments is the assessment of economic and commercial efficiency of the ...production of science-intensive products, which would ensure the mutually beneficial interests of both new scientific knowledge developers (i.e. applied scientific organizations) and industrial enterprises implementing these developments. The aim of the study is to develop a methodology for assessing the economic efficiency of the production of high-tech products, highlighting the contribution of research organizations as developers of new scientific knowledge and participants in the production of a new material product. To assess the contribution of scientific researches of the used potential scientific knowledgean income-cost method has been developed.Its essence is that the total economic effect from the production of innovative (scienceintensive) products using new scientific knowledge is distributed in proportion to the cost of each type of work and the participants in their creation: scientific researches, design effort, equipment and costs of an industrial enterprise. This method provides: - full costs compensation of the production of science-intensive products, including the cost of developing new or improved technologies; - obtaining the effect of each cost components, including the cost of knowledge potential creation not lower than the average level of the final efficiency. In this way, the boundary conditions of equal profitability for each participant in the production of high-tech products are ensured. With this methodological approach, it is taken that the relative economic efficiency of the expenditures on scientific researches (the potential of scientific knowledge), as well as other components of high-tech products development and creation, are at the same level. The proposed principle of total income and profit distribution (in proportion to costs) provides the necessary basis for each participant in science-intensive products creation.In any case this principle allows expecting a reimbursement of their outlaysand distribution of profits according to the general level of efficiency. In whole l, it is recommended to value the scientific knowledge potential as a business forming intangible asset at three levels.
This study is aimed at identifying the best values for the parameters of energy efficient digital development of the petroleum and gas sector. Research methods - construction of a production ...function, regression analysis and linear programming. Based on the production function of Cobb-Douglas, the dependence of the sales volumes of the petroleum and gas sector of the economy on the costs of digitalization and labor costs was revealed; the regression analysis method provided the construction of a set of equations describing the impact of the costs of energy resources of petroleum and gas enterprises and the costs of digitalization on the total costs of enterprises for production and sales, the efficiency of using by-products from petroleum production and labor capital; the optimal values of energy-efficient digital resource-saving development of the petroleum and gas sector of the economy have been determined, the achievement of which will ensure a decrease in the energy consumption of processes at the enterprises of the petroleum and gas complex. Thus, connections have been established and the trajectories of energy efficient functioning of the petroleum and gas sector of the economy have been determined. The research results can be applied within the framework of strategies for socio-economic development, sustainable development, as well as digitalization of the petroleum and gas complex and industrial enterprises.
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The effect of the nature of the metal (Fe and Co) deposited on the surface of hydrolysis lignin, as well as the metal content (1, 3, 5 and 7 wt%), on the process of dry catalytic ...lignin reforming has been studied. The use of the catalyst led to a twofold increase in the conversion of carbon dioxide at temperatures of 500–800 °C, while both metals showed similar activity. The maximum specific catalytic effect is achieved when supporting 7 wt% of active metals.
Controlled execution with explicit model Betelin, V. B.; Galatenko, V. A.; Kostyukhin, K. A.
Programming and computer software,
11/2014, Letnik:
40, Številka:
6
Journal Article
Recenzirano
A framework of controlled execution with explicit model is proposed that increases the reliability and fault tolerance of hardware-software complexes with complex architecture. This framework was ...developed at the Scientific Research Institute of System Analysis of Russian Academy of Sciences.
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