INFORMATIZATION OF CONSTRUCTION MANAGEMENT AS A BASIS FOR PREVENTING MAN-MADE ACCIDENTS

the article presents the principles and algorithms of the finite element method in solving geotechnical prob-lems taking into account seismic impacts for determining the stress-strain state of structures and slope stabil-ity, implemented in the Midas GTS NX software package. GTS NX allows you to perform calculations of various types of geotechnical problems and solve complex geotechnical problems in a single software envi-ronment. GTS NX covers the entire range of engineering and geotechnical projects, including calculations of the "base-structure" system, deep pits with various mounting options, tunnels of complex shape, consolida-tion and filtration calculations, as well as calculations for dynamic actions and stability calculations. At the same time, all types of calculations in GTS NX can be performed both in 2D and in 3D. The author does not claim to be the author of the finite element method, but he cannot do without pointing out the basic equa-tions, as this affects the definition of the boundaries of use, the formulation of algorithms for constructing calculation schemes and the analysis of calculation results.

ANALYTICAL AND NUMERICAL METHODS FOR DETERMINING THE CARRYING CAPACITY OF A PILE BARETT ON WEAK SOILS IN DEEP PITS

The article provides an analysis of the bearing capacity of barrett piles in difficult geological conditions at a construction site in the city of Hanoi, Vietnam based on the results of analytical calculations according to Russian building codes, mathematical modeling and field full-scale tests. The paper describes a numerical test of a single barrette for Mohr-Coulomb and Hardening Soil models in the Midas GTS NX software package. The bearing capacity of a barrette in soft soils is also proposed to be determined by an analytical solution for calculating the settlement of a single pile, taking into account the unloading of the pit after soil excavation. The results of full-scale tests at the site of future construction, graphs of "load-settlement" of the barrette head from the applied vertical load and the general assessment of the bearing capacity of the barret pile by various methods are shown.

Microbial assemblages and methanogenesis pathways impact methane production and foaming in manure deep-pit storages

Foam accumulation in swine manure deep-pits has been linked to explosions and flash fires that pose devastating threats to humans and livestock. It is clear that methane accumulation within these pits is the fuel for the fire; it is not understood what microbial drivers cause the accumulation and stabilization of methane. Here, we conducted a 13-month field study to survey the physical, chemical, and biological changes of pit-manure across 46 farms in Iowa. Our results showed that an increased methane production rate was associated with less digestible feed ingredients, suggesting that diet influences the storage pit’s microbiome. Targeted sequencing of the bacterial 16S rRNA and archaeal mcrA genes was used to identify microbial communities’ role and influence. We found that microbial communities in foaming and non-foaming manure were significantly different, and that the bacterial communities of foaming manure were more stable than those of non-foaming manure. Foaming manure methanogen communities were enriched with uncharacterized methanogens whose presence strongly correlated with high methane production rates. We also observed strong correlations between feed ration, manure characteristics, and the relative abundance of specific taxa, suggesting that manure foaming is linked to microbial community assemblage driven by efficient free long-chain fatty acid degradation by hydrogenotrophic methanogenesis.

One-Stage Formation of Two-Dimensional Photonic Crystal and Spatially Ordered Arrays of Self-Assembled Ge(Si) Nanoislandson Pit-Patterned Silicon-On-Insulator Substrate

A new approach to improve the light-emitting efficiency of Ge(Si) quantum dots (QDs) by the formation of an ordered array of QDs on a pit-patterned silicon-on-insulator (SOI) substrate is presented. This approach makes it possible to use the same pre-patterned substrate both for the growth of spatially ordered QDs and for the formation of photonic crystal (PhC) in which QDs are embedded. The periodic array of deep pits on the SOI substrate simultaneously serves as a template for spatially ordering of QDs and the basis for two-dimensional PhCs. As a result of theoretical and experimental studies, the main regularities of the QD nucleation on the pre-patterned surface with deep pits were revealed. The parameters of the pit-patterned substrate (the period of the location of the pits, the pit shape, and depth) providing a significant increase of the QD luminescence intensity due to the effective interaction of QD emission with the PhC modes are found.

Investigations on Arthropods Associated with Decay Stages of Buried Animals in Italy

Burial could be used by criminals to conceal the bodies of victims, interfering with the succession of sarcosaprophagous fauna and with the evaluation of post-mortem interval. In Italy, no experimental investigation on arthropods associated with buried remains has been conducted to date. A first experimental study on arthropods associated with buried carcasses was carried out in a rural area of Arcavacata di Rende (Cosenza), Southern Italy, from November 2017 to May 2018. Six pig carcasses (Susscrofa Linnaeus) were used, five of which were buried in 60-cm deep pits, leaving about 25-cm of soil above each carcass, and one was left above ground. One of the buried carcasses was periodically exhumed to evaluate the effects of disturbance on decay processes and on arthropod fauna. The other four carcasses were exhumed only once, respectively after 43, 82, 133, and 171 days. As expected, the decay rate was different among carcasses. Differences in taxa and colonization of arthropod fauna were also detected in the above ground and periodically exhumed carcasses. In carcasses exhumed only once, no arthropod colonization was detected. The results showed that a burial at about 25 cm depth could be sufficient to prevent colonization by sarcosaprophagous taxa and these data could be relevant in forensic cases involving buried corpses.

Effect of Thermal Treatment and Erosion Aggressiveness on Resistance of S235JR Steel to Cavitation and Slurry

S235JR steel is used in many applications, but its resistance to the erosion processes has been poorly studied. To investigate this resistance, cavitation, and slurry erosion tests were conducted. These tests were carried out at different erosion intensities, i.e., different flow rates in the cavitation tunnel with a system of barricades and different rotational speeds in the slurry pot. The steel was tested as-received and after thermal treatment at 930 °C, which lowered the hardness of the steel. To better understand the degradation processes, in addition to mass loss measurements, surface roughness and hardness were measured. Along with increasing erosion intensity, the mass loss increased as well. However, the nature of the increase in mass loss, as well as the effect of steel hardness on this mass loss, was different for each of the erosion processes. In the cavitation erosion tests, the mass loss increased linearly with the increase in flow velocity, while in the slurry tests this relationship was polynomial, indicating a strong increase in mass losses with an increase in rotational speed. Cavitation erosion resulted in stronger and deeper strain hardening than slurry. Surface damage from cavitation erosion tests was mainly deep pits, voids, and cracks during the slurry tests, while flaking was the most significant damage.

Chiral Surface Characterisation and Reactivity Toward H–D Exchange of a Curved Platinum Crystal

Understanding heterogeneous catalysis at the atomic level requires detailed knowledge of the reactivity of different surface sites toward specific bond breaking and bond making events. We illustrate a new method in such investigations. We use a macroscopically curved Pt single crystal containing a large variation in density of highly kinked steps of two different chiralities. Scanning tunneling microscopy maps the entire range of surface structures present on the 31° section surrounding the Pt(111) apex. Whereas most of the surface shows the expected characteristic arrays of parallel steps, hexagonally-shaped, single-atom deep pits remain after cleaning procedures near the apex. Their orientation is indicative of the different chiralities present on the two sides of the crystal’s apex. These unintended defects locally raise the surface defect concentration, but are of little consequence to subsequent reactivity measurements for $$\text {D}_2$$ D 2 dissociation and H–D exchange as probed by supersonic molecular beam techniques. We quantify absolute elementary dissociation and relative isotopic exchange rates across the surface with high spatial resolution. At low incident energies, elementary dissociation of the homonuclear isotoplogues is dominated by the kinked steps. H–D exchange kinetics depend also mostly linearly on step density. The changing ratio of D2 dissociation to H–D formation, however, suggests that anisotropic diffusion of H(D) atoms is of influence to the measured HD production rate.

Statistical Analysis of Killer and Non-Killer Defects in SiC and the Impacts to Device Performance

Multi-channel defect detection in epitaxial SiC layers is used to detect and classify various extended defects. The effects of the killer defect category are analyzed on hundreds of production diode and MOSFET wafers. Invariably, the number of these killer defects sets the yield entitlement for each wafer, and electrically, they fall into a few expected failure bins depending on their position on the die. A variety of non-killer defects like Bar Stacking Faults (BSFs), V-type defects, isolated micro-pipe related bumps, stacking faults, scratches and deep pits are identified in over thousand die each, and their effect on fully fabricated diode and MOSFET products are determined at wafer sort. A very high percentage of the die containing these non-killer defects pass all electrical tests including the rigorous Unclamped Inductive Switching (UIS) testing. Specifically, a population of electrically passing die, containing BSFs, are identified and packaged for High Temperature Reverse Bias (HTRB) tests. Every BSF containing die passes both forward and reverse 1000-hour HTRB drift tests.

Developing the methods of controlling dust and gas conditions when blasting high benches in deep pits

Research aim is to develop a method of reducing dust and gas emissions concentration at bulk explosions in open pits. Research relevance. When drilling and blasting in open pits, a huge amount of dust and toxic gaseous products is released, and the rate of their formation is affected by the blasting method, the range of explosives used, the method of drilling blast holes, type and sort of stemming, massif water content, rock properties, meteorological conditions, etc. It has been established that in an explosion of 1 kg of explosives, 15% from an average of 900 liters of various gases and gaseous products formed are toxic and dangerous to humans and the environment. To prevent dust and gas emissions, various types of tamping are currently used, which affect not only emissions reduction, but also the efficiency and safety of blasting contributing to the fullest use of explosion energy and increasing the exposure time of the products of explosive 120 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 4. 2020 ISSN 0536-1028 transformation. Despite the significant amount of research and successes achieved in this direction, for deep pits it is necessary to determine the rational parameters of stemming in borehole explosive charges, reduce the formation of toxic gases released in bulk explosions, develop a method of producing an absorption solution capable of neutralizing toxic compounds after an explosion, and develop an effective way to reduce dust and gas emissions in bulk explosions. Research methodology. To solve this problem, integrated research methods were used, including theoretical generalizations and experimental studies in laboratory, testing ground and industrial conditions, methods of mathematical modeling of stemming parameters in borehole explosive charges, methods of mathematical programming using modern computer equipment, as well as methods of mathematical statistics and correlation analysis of research results. Results. Detonation products pressure change in the well has been determined taking into account motion processes of sand and absorbing mixture stemming of various lengths. It has been established that when using stemming made of absorbing mixture, detonation products pressure and escape time are higher compared to sand stemming. The effective stemming length in borehole explosive charges has been established depending on well pressure fall time and stemming length in different sections of the well. Mathematical modeling of stemming parameters in the explosion of borehole explosive charges established the change in pressure in the blast chamber as a function of stemming time and length during its escape from the well, as well as the of stemming escape duration and expiration of detonation products during emulsion explosive blast depending on stemming length. A method has been developed of dust and gas atmospheric pollution parameters determination during the production of bulk explosions in deep pits, An absorption mixture has been developed, which makes it possible to intensify the process of dust deposition above the explosion site and reduce pollution of the surrounding quarry, which favorably affects the environmental situation in the mining region. A method has been developed to reduce dust and gas emissions during blasting operations in open pits, which allows to reduce the concentration of dust and gas clouds formed. Scope of the results. A method of suppressing dust and gas emissions has been introduced at the Muruntau open pit of the Navoi Mining and Metallurgical Combinat. As a result, the process of dust deposition above the explosion site has been intensified, pollution of the surrounding open pit area has been reduced, the concentration of nitrogen dioxide has been reduced by 30.1%, carbon monoxide by 28.6% and sulfur dioxide by 20.5%. The results can be used in quarries where rock crushing is carried out using a blasting method