The νGeN is new experiment at the Kalinin Nuclear Power Plant (KNPP) for detection of coherent Neutrino-Ge Nucleus elastic scattering. Recent neutrino and Dark Matter search experiments have revolutionized the detection of rear events, and rear events with low energies, in particular. Experiments have achieved sensitivities on the level of several events per hundred kg of detector material per day with energy thresholds from few hundred eV. This opens up a new unique possibility for experimental detection of neutrino-nucleus coherent scattering that has been considered to be impossible so far. The νGeN project uses low threshold high-purity Ge-detectors (HPGe) developed by JINR (Dubna, Russia) in collaboration with BSI (Baltic Scientific Instruments, Riga, Latvia) for creation of a setup designated for first observation of neutrino coherent scattering on Ge. As a powerful neutrino source the experiment will use electron antineutrinos from one of the power-generating units (reactor unit #3) of the KNPP. The coherent neutrino scattering will be observed using a differential method that compares 1) the spectra measured at the reactor operation and shut-down periods; 2) the spectra measured at different distances from the reactor core during the reactor operation. For a setup placed at a 10 m distance from the center of reactor core and with an energy threshold of 350 eV up to tens of events corresponding to neutrino coherent scattering on Ge are expected to be detected per day in the constructed setup with four HPGe low-energythreshold detectors (∼400 grams each). The setup sensitivity will be even more increased by using new detectors with total mass up to 5 kg.
Efficacy of existing designs grinding wheels is relatively low and one of the main reasons for this situation is the lack of control over the shape of grains included in the composition of these tools and their employees cutting elements. Standard wheels are composed of grains with an arbitrary, varying in the range from isometric to the needle-like species. When only part of the grain has a favorable geometry for cutting and participates fully in aggregate nom cutting process. Arranging grain shape and as a consequence, their geometry can increase the efficiency of each individual grain and thus improve the performance of grinding wheels as a whole. The study on the establishment of the variety of forms of grains for abrasives Russian and German production made standard way - by ebb abrasive ingots, their crushing and screening a number of particle size fractions. Studies have shown that each has its abrasive distribution pattern in the manner that depends on the brand of abrasive characteristics of technology and the manufacture of abrasive grit. The interrelation of grain shape to their geometry as derivation of mathematical models. A pilot batch of grinding wheels with controlled grain shape, are prepared by separating the initial mass of abrasive on a number of fractions with the same shape of grains using the vibratory separator. Experimental wheels were tested on the operating processing bearing rings, and as compared with the following instruments used an arbitrary shape of grains. Found that a differentiated approach to the choice of grain shape allows for a increase resistance grinding wheels in 1,5-3,9 times , reduce roughness of machined surfaces in 1.2 - 3.2 times, roundness - 1.3 times, waviness - 2.3 times the wear sized - 2.0 - 3.0 times.
Severe operating conditions of mining equipment have a negative impact on the operating life of the rolling contact bearings used in such equipment. The main reasons for the premature failure of rolling contact bearings include, first of all, poor quality of the bearing steel as delivered and the defects of their subsequent heat treatment. The abovementioned reasons result in splitting of bearings, metal shelling and appearance of potholes on their tracks, as well as intense abrasive wear. Nevertheless, despite the importance of this issue, the quality of bearing steel, either as delivered or in finished bearings, is usually not under control.To solve this problem, the quality of bearing steel was studied, exemplified by the bearings of the Russian, Swedish (SKF) and Japanese (NSK) manufacturers, i.e., main suppliers of rolling contact bearings for mining equipment in Russia. The problem of bearing steel quality control was solved by developing a quality control methodology that took into account the state of the metal after metallurgical treatment and at the stage of bearing production. Based on this methodology, the main types of bearing steel defects affecting the mechanism of bearing failure are identified.It is found that the bearing steel quality of domestic manufacturers is highly competitive with foreign counterparts. A method of nondestructive control is also proposed for detecting possible microstructure defects in bearings, either as delivered or while in operation.
Abstract. After a period of operation imported mining equipment starts failing. As a rule, breakages and critical wear of parts do not involve the entire product, but its individual parts. Despite this, manufacturers of this equipment do not provide repair kits, but offer to change the units and assemblies entirely. As a result, the repair and maintenance of imported equipment imposes significant financial costs. This paper proposes ways to eliminate or reduce the additional costs. The problem solution is based on the determination of the chemical composition and structure of worn out or out-of-order parts, reproduction of their manufacturing technology and production of analogues of these parts in single quantities. The work is performed on the example of high-pressure pump parts and large-sized gears used in mining equipment. For high-pressure pumps, analogues of end sealing gaskets and bearing bushings were made. The obtained experience can be used in the manufacturing and restoration of mining equipment in the Kuzbass enterprises, which allows reducing financial costs and implementing import substitution. The research part of the work was performed in the metallurgical laboratories of KuzSTU, and the reproduction of worn out and out-of-order parts was carried out at enterprises which requested this study.
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