Emerging Trends in Materials Research and Manufacturing Processes

The influence of the measurement atmosphere, heating and cooling rate on the Curie temperature of Co_0.5Zn_0.5Fe₂O₄ cobalt-zinc ferrite was studied by thermogravimetric analysis in a magnetic field. This technique allowed determining the temperature of ferrimagnet-paramagnet transition at Curie point of magnetic materials. The method of solid-phase synthesis was used to produce the Co–Zn ferrite. Curie temperature control of the ferrite was carried out by using a Netzsch STA 449C Jupiter thermal analyzer. Measurements were performed in the temperature range of 45–400 °C with heating (cooling) rates of 10, 20, and 50 K/min. The cell of analyzer was purged with air or nitrogen. According to thermomagnetometric analysis, the Curie temperature of Co–Zn ferrite are in the range of 171–188 °C, depending on the experimental conditions. It was shown, that the Curie temperature weakly depends on both the heating and cooling rate during thermogravimetric analysis in a magnetic field. However, this parameter depends on the measurement mode.

Publications are known where the problems of technogenic and space safety of the Earth are discussed, due to the possibility of man-made accident and collision with celestial bodies. It has been established that, as a rule, a major man-made or space disaster is accompanied by the occurrence of massive forest fires. In connection with the assessment of the environmental and climatic consequences of strong fires, it is of interest to predict the impact of this process on the state of the surface layer of the atmosphere. Due to the fact that full-scale research in such problems is simply impossible, methods of mathematical modeling are relevant. Below we consider the problem of the initial stage of the impact of a high-altitude source of radiant energy on the underlying surface of the Earth, covered with forest vegetation. The purpose of this study is to determine the size of the ignition zone and study the physical and chemical processes occurring in this case. In addition, on the basis of the results of the impact on the forests of the explosion of a celestial body, called the Tunguska meteorite, known from the scientific literature, its power is estimated.

The paper addressed the study of feasibility of optical methods to measure the diameter of extended products to perform in-process detection of local microdefects in cable products. The analysis of data on through-transmission methods and the power measurement method showed that the power measurement method is most appropriate for implementation of the microdefect detection device since it enables measuring at the desired frequency. The experimental study confirmed the efficiency of the power measurement method, and revealed a significant drawback of the method, namely, an increased error due to the inhomogeneous distribution of optical flow power when the test object moves through the measurement zone.

Currently technogenic gold-bearing raw materials (tailings and dumps of existing or closed mines) are considered by many experts as a promising raw material for the extraction of residual gold. Technogenic raw materials, as a rule, are crushed, have fairly clear boundaries and are located near energy sources, roads and settlements, which minimize capital costs for its processing. A negative factor that hinders the recycling of technogenic raw materials is the presence of substances harmful to human health in this raw material: floating and leaching reagents, mercury, etc. If the content of clay and sludge fractions in the raw material is 20 –30%, there is a structural bonding of particles and sorption of finely dispersed gold on clays, which makes it difficult to extract. The extraction of finely dispersed gold from hard-to-wash clay rocks and technogenic raw materials is an important task.

In this work, the magnetization of lithium ferrite synthesized from a mechanically activated Fe₂O₃–Li₂CO₃ initial reagents mixture via electron-beam heating was studied by thermomagnetometric analysis. Mechanical activation was carried out using the high-energy grinding of powders in an AGO-2S ball mill. The rotation speed of the steel vials and the grinding time were 1290, 2220 rpm and 5, 15, 30, 60, 120 min, respectively. The samples were synthesized using an ILU-6 pulsed electron accelerator with an electron energy of 2.4 meV. Under certain conditions, the electron beam allowed heating samples up to synthesis temperatures of 600–750 °C. For comparison, some of the samples were synthesized via conventional heating in a laboratory furnace under the same temperature and time conditions. Thermomagnetometric measurements based on thermogravimetry in an external magnetic field were performed at temperatures corresponding to magnetic phase transitions at the Curie point of ferrites. It has been established that the magnetization of the samples depends both on the energy intensity of grinding and on the method of heating. The results revealed a higher degree of magnetization of the samples pre-activated at 2220 rpm for 120 min and then synthesized in an electron beam.

The analysis of need to control ground water level in urban settings has been carried out. The exterior view of control (piezometric) wells has been represented. The modern methods of ground water level control have been reviewed. The technical requirements for control equipment and level sensors have been developed. The schematic diagrams of the sensor and microprocessor-based control unit have been developed. The main causes of capacitive converters errors are investigated. The main points of the program, field tests methods and the monitoring results at the operating facility are given.

The purpose of the research is to document the development process of a low-weight seismic shock vibration sensor with an amplitude-modulated sweep signal, and which possess good signal-to-noise ratio characteristics. The development of such a source of seismic signals will make it possible to study the interior of the Earth in difficult terrain geographic regions. To achieve this goal, the designs of seismic sources were analyzed and their “positive” design features were defined; the effect of different law of amplitude-modulated sweep signal on the degree of compactness of the autocorrelation function was studied; theoretical studies were carried out on the oscillatory system seismic source behavior with the simultaneous impact of a force pulse from a falling load, which forms the pressing force of the base plate and a sweep signal from the oscillation generator; the experimental studies were carried out on a vibration bench which is a physical model of the source; the possibility of excitation of a sweep signal with amplitude modulation was studied; the parameters of the excitation process and the operation modes of the vibration mechanism for the formation of a useful vibration load are recommended.

One of the trends of modern economics is informatization is the use of information technologies for the collection, storage, processing of data for further use in professional and other types of human activity. The paper shows the development of an information system with the formulation of the customer’s primary requirements for the information system and the assessment of existing analogues. The implementation of the documented procedure is described in detail. The designed information system is intended for use by users who are directly involved in production processes and the implementation of corrective actions. Measurements of the time of the flow of the stages of the process were carried out for five cycles of the production process, the average time of the process was determined. It has been proved that the informatization of production processes allows reducing the time for auxiliary processes, thereby increasing the efficiency of the main production processes directly related to the manufacturing technology of products.