Soldered joints of piezoelectric products

The paper considers issues related to the use of capillary luminescent flaw detection for monitoring glass-metal soldered joints of piezoelectric products. Standard methods of leakproofness testing of piezoelectric products are analysed; the framework for the applicability of each of them at the stages of the life cycle of piezoelectric products is established. Based on the results of the studies, a capillary luminescent control method was chosen to check the tightness of glass-metal soldered joints in piezoelectric products. The stages of conducting a capillary luminescent method for monitoring glass-metal soldered joints of piezoelectric products are presented. A method for monitoring the tightness of piezoelectric products using the capillary luminescent method has been developed.

RESEARCH AND DEVELOPMENT OF THE TECHNOLOGY FOR RESTORING THE BLADES OF THE GAS TURBINE ENGINE AFTER OPERATION BY LASER SURFACING

The paper presents the research and development of the technology for restoring the blades of a gas turbine engine made of ZhS6U alloy after operation by laser pulse surfacing. Metallographic examination and control by the luminescent method at the places of surfacing were carried out. A technology for eliminating defects that occur on the blades during operation has been developed and tested.

CONTROL OF PIEZOELECTRIC PRODUCTS JUNCTION

The article describes the work on the use of capillary fluorescent flaw detection for the control of metal-glass junction of piezoelectric products. Within the framework of the work, standard methods of testing piezoelectric products for tightness were analyzed, their analysis was carried out, and the scope of applicability of each of them at the stages of the life cycle of piezoelectric products was established. In the course of work, capillary control methods were considered for use in production and their advantages were highlighted. As a result of the work carried out, a capillary luminescent control method was chosen to check the tightness of piezoelectric products in the area of the metal-glass junction. The stages of the capillary luminescent control method are described. Based on the conducted research, a method for controlling the tightness of piezoelectric products was developed, including the use of a capillary luminescent method.

Technological Methods of Assessing the Maturity of Tomatoes

Tomato maturity is one of the most important indicators related to determining its quality. The maturity assessment of tomatoes is necessary to determine the timing of fruit harvesting, optimize storage conditions, forecast storage periods, export, and more. Over the past three decades, researchers have developed a number of methods for evaluating the quality and sorting of tomato fruits. (Research purpose) The research purpose is in providing an overview of the technological methods used to measure the maturity of tomatoes. (Materials and methods) The article presents methods (spectral, hyperspectral imaging, luminescent, laser, technical vision, and others) for non-destructive assessment of the quality of tomato fruits. (Results and discussion) It was found that the main drawback of the described devices is that only a small part of the fetal surface is controlled by photodetectors. It was pointed out that most of the flow reflected from the fruit, and therefore information about the color of its surface is lost, bypassing the photodetectors and being absorbed by the walls of the camera. Authors found that the quality of fraction selection can be improved if several spectral sections are filtered out from the rays reflected from the fruit. It was found that with the three or more sections, designs of photometric systems are significantly complicated, since there is a need to have a large number of optical receivers. (Conclusions) The article proposes a technology for measuring the maturity of tomatoes using the luminescent method, which is less time-consuming and more accurate than methods for determining the maturity of tomatoes by their color. Authors found that this technology allows to separate tomatoes with any color according to the maturity. The article shows that the considered method makes it possible to divide tomatoes more efficiently by maturity, taking into account their internal structure.

Assessment of Uranium Concentrations in Drinking Water Supply Sources Based on the Results of Laboratory Analysis of 238U and 234U Specific Activities and Laboratory Determination of Uranium According to GOST R 54499–2011

Introduction. The cause of toxicity and damaging effects of uranium and its compounds on the body lies in radioactivity of uranium isotopes and their decay products as well as their high chemical activity. In view of the above, we conducted parallel studies of specific activities and concentrations of uranium in household and drinking water supply sources. Materials and methods. We studied specific activities of uranium-234 and uranium-238 in the centralized drinking water supply sources of the Republic of Khakassia exceeding control levels in terms of specific total alpha activity (Aα) and converted them to mass concentrations of uranium. Parallel analyses of uranium concentrations in water using the luminescent method according to GOST R 54499–2011 were performed. Results. Our assessment of the radionuclide composition of centralized drinking water supply sources showed that Aα levels exceeding control levels were largely due to natural radionuclides uranium-238 (contribution up to 25%) and uranium-234 (contribution up to 69%). Based on the specific activities of uranium-234 and uranium-238, we estimated masses (concentrations) of uranium in water ranging from 0.007 to 0.06 mg/L depending on the water source. In the parallel tests of water samples according to GOST R 54499–2011, uranium concentrations ranged from 0.007 to 0.061 mg/L. Conclusions. The uranium concentrations in the republican centralized drinking water supply sources estimated on the basis of uranium-234 and uranium-238 specific activities differed from the concentrations of uranium measured by the luminescent method according to GOST R 54499–2011 within the error of the test method. In some settlements uranium concentrations in water exceeded the hygienic standard of 0.015 mg/L (GN 2.1.5.2280–07).