bluuebunny/crossref_metadata_2025 huggingface dataset:
Geomagnetic anomalies registered in the Iberian Peninsula before a time period of intense seismic activity
Authors: Duque Maria Rosa
Published: December 2020

Geomagnetic data registered by Geomagnetic Observatories of Almeria, Coimbra, San Fernando and Toledo, located in the Iberian Peninsula and Tenerife in the Canary Islands were used to study geomagnetic field anomalies from August 1968 to March 1969. Data used were obtained in Annals of the Observatories as average hourly values of the magnetic declination and horizontal and vertical components of the magnetic field. Magnetic field disturbances were studied using average monthly values, average daily values and average hourly values. The anomalies were quantified using IGRF model values and monthly average hourly values of the Observatories data. During the time period of our study, four earthquakes of magnitude equal or higher than 3 are registered in the seismic catalogue with two epicentres in the Gibraltar Region and two epicentres in the Gulf of Cadis. In the early hours of February 1969, an earthquake of high magnitude (M=8) was felt in Portugal, Spain and North-Western Morocco. Near two hours later, another earthquake of magnitude 6.5 was recorded. In that day, 32 earthquakes were recorded in the region. In the second part of the work, a special attention is given to the earthquake of February 10th,1969, due to the location of this epicentre and the temporal proximity of February 28th. The magnetic field in the region suffered three strong magnetic disturbances during the month of February in 1969. The earthquake of February 10th occurred just before the start of the second interval of intense magnetic perturbations. The third time interval of intense magnetic disturbances occurred before and during the day of February 28th. The analysis made using hourly values to time intervals including the earthquake occurrence (five earthquakes) shows “equal values” of magnetic anomalies occurring in time intervals of three hours. Strong variations of the horizontal field occurred before the earthquakes of February 10th and February 28th.
Effect of Various Factors on the Estimation of T-Year Discharges for Water Management
Authors: Mitková Veronika Bačová
Published: December 2020

The paper deals with the effect of various factors on the estimation of designed discharges. As input data, the series of daily discharges and annual peak discharges on the Topľa River at Hanušovce nad Topľou for the period of 1931-2015 were used. The first, maximum annual discharges (AM) approach was applied with the most widely used Log-Pearson III. probability distribution. The second, we analysed the effect of the time series length and the effect of seasonality (winter, summer) on the accuracy of T-year maximum discharges estimation. As an alternative to this approach (AM), the Peak Over Threshold (POT) method was used. We analysed the effect of the threshold level value selection and using of maximum daily discharges on the accuracy of T-year maximum discharges estimation. Results showed that not only the selection of the distribution function to estimate T-year discharges but also the type of used data series may affect the results of the estimation (length or selection of the period). Results also showed that the estimation of designed maximum discharges using by the POT method did not show significant differences at the selected various threshold levels, but for a relatively fast and large increase of discharges during floods, it would be necessary to have peak values for all waves included in the analysis. Determining the specific value of a 500- or 1000-year flood for engineering practice is extremely complex and in interpreting the results, it should be kept in mind that estimated values with very high return periods are extrapolated values. Each statistical method includes some uncertainty that may be caused by the method but also the data may be affected by certain measurement error, therefore, it is also necessary to specify confidence intervals in which the flow of a given 100-, 500-, or 1000-year flood may occur with probability, for example, 90%.
Analysis of future changes in short-term rainfall characteristics in the High Tatras Region in Slovakia
Authors: Földes Gabriel , Kohnová Silvia , Labat Marija Mihaela
Published: December 2020

The paper focuses on the analysis of future changes in short-term rainfall characteristics in the High Tatras region. The analysis was performed at three climatological stations, namely: Podbanské, Tatranská Lomnica, Javorina. The area is located in the northern part of Slovakia in a mountainous region which belongs to a mountain climate with characteristic long cold winters and short summers with heavy rainfalls (June, July). The future changes were analysed from the predicted short-term rainfall intensities using the Community Land Model. The Community Land Model was a multidisciplinary project between scientists from several working groups in the USA. The model uses ecological climatology concepts, which explains the impacts of changes in vegetation on the climate. The model well relates to the current processes in the atmosphere; it is a semi-pessimistic scenario with a predicted global temperature increase is about 2.9 °C by the year 2100. The focus of the paper was put on the changes in seasonality, trend analysis. The analysed rainfall durations were available from 60 minutes up to 1440 minutes for the future period 2041-2100. The results were compared with the simulated data from the historical period 1961-2020. The analysis is focused on the seasonality changes in extreme rainfall which was analysed by Burn’s vector methodology, then the trend testing provided by the Mann-Kendall trend testing method. Results show that there is a change in the short-term rainfall intensities characteristics for the future period, the seasonality of extreme rainfall intensities shows a shift to an earlier time period of the year, future trends are also showing increasing change compared to the historical period.
Built Environment Challenges Due to Climate Change
Authors: Zięba Zofia , Dąbrowska Jolanta , Marschalko Marian , Pinto Jorge , Mrówczyńska Maria , Leśniak Agnieszka , Petrovski Aleksandar , Kazak Jan K
Published: December 2020

Climate change has become one of the most significant problems of recent years. It results in a higher incidence of extreme events, such as strong winds, heavy precipitation, floods and droughts. Their consequences have a negative impact not only on the environment, but also on the engineering structures and the safety of the population. In this article, the relationship between the built environment and the effects of climate change is characterised in order to propose systemic changes to improve the adaptation of cities to climate change. Weather- and climate-related hazards for the built environment are analysed, and the possibilities to reduce the risk and mitigate the effect of construction disasters, should they occur. Moreover, a case study conducted in Central Europe has been presented. Based on quantitative data from the Central Office of Building Control in Poland from 2006-2018, the occurrence of construction disasters, their causes and consequences were examined. It was found that the main cause of disasters occurring in Poland during this period were random events (73%), which consisted in particular of extreme weather events such as strong wind or strong wind with accompanying heavy precipitation causing floods and landslides. The highest number of construction disasters (1113) was recorded in 2008, and as many as 95.6% were caused by random events. The conclusion indicates the need to prepare the built environment for climate change and to develop appropriate solutions to reduce the risk of climate-related hazards and to mitigate their effects. Based on the conducted analyses, a conceptual framework of improved climate-resilient built environment management was proposed.
Tectonic Structures of the Mangazeya Ore Cluster (Verkhoyansk Range, NE Asia)
Authors: Prokopiev Andrei V. , Tretyakov Felix F. , Vasiliev Dmitry A.
Published: December 2020

The Mangazeya ore cluster is located in the central part of the West Verkhoyansk sector of the Verkhoyansk fold-and-thrust belt, in the zone of junction of the Kuranakh anticlinorium and the Sartang synclinorium. High-tonnage Ag deposits and occurrences are concentrated here, which are thought to be associated with the zones of longitudinal strike-slip faults and bedding-plane thrusts. Structural studies were conducted in the dome and the eastern limb of the Endybal anticline, in the areas of the Nizhne-Endybalskoe, Verkhne-Endybalskoe, Bezymyannoe, Vertikalnoe, Sterzhnevoe, and Semenovskoe ore deposits. The Endybal asymmetric anticline 10-15 km wide and 60 km long, with a wide gentle dome is the major tectonic structure of the territory. The conducted structural and statistical analyses of tectonic structures in the study area allowed better understanding of their specific features and trends in development. Morphology of the fold structures indicates manifestation of concentric-type folding produced by bending of strata as a result of bedding-plane slipping. The same NS orientation of the cleavage and folds gives unanimous evidence for their genetic relationship and formation in the conditions of EW horizontal compression. It is established that the structural paragenesis represented by fractures, normal faults, and extension structures in the hinge zone of the concentric Endybal anticline, which determines the general tectonic pattern of the Mangazeya ore cluster and controls localization of ore bodies, was formed at the first deformation stage or in course of bedding-plane faulting and fold-and-thrust deformations rather than as a result of strike-slip motions. It is shown that strike-slip motions of the second deformation stage not only produced new structures but also inherited disturbances of the previous stage. It is found that normal faults in the study area formed synchronously with the fold-and-thrust structures. A similar orientation of the major faults and the strike-slip faults suggests that the regional faults have strike-slip kinematics. The occurrence of different types of tectonic deformation is controlled by rock lithology.
Seismic activity induced by exploitation in vicinity of mined-out space, case study from deep copper ore mine in Poland
Authors: Gogolewska Anna Barbara , Kaszycki Bartosz
Published: December 2020

Rock bursts are one of the most difficult to recognize and assess natural hazards in deep copper ore mines in Poland. The occurrence of rock bursts is conditioned by a number of complex geological and mining factors. The impact of each of the factors on the state of seismic hazard is sometimes impossible to be determined. The correct recognition of the rock mass condition and the causes of rock burst threat gives a chance for advance preparation of adequate prevention, and thus for eliminating or reducing the threat to the level of tolerated risk. In Poland’s copper ore mines, continuous observation of seismic activity is carried out, which is expressed in the number of tremors and their energy over a specified period of time. Moreover, the effectiveness of prevention measures and, in particular, of the active ones, which are aimed at provoking seismic energy emissions through properly executed winning blasting works, is calculated and analysed. Reducing the amount of energy accumulated in the rock mass reduces the risk of rock bursts. Exploitation is carried out in a way that avoids parallel approach of the operational front towards the goafs, drifts, and faults with drops greater than the height of the mined deposit. However, over forty years of mining of the copper ore deposit, which has created the large areas of mined-out space mean that mining works are increasingly carried out under restrained conditions. There are unfavourable geological and mining situations in the exploitation fields, disrupting rhythmic development and an even front line. The specific structure of the copper ore deposit in Poland makes it possible to conduct multidirectional cutting and to introduce local changes in the adopted directions of exploitation. Cases of operational fronts approaching goafs occur often in the vicinity of old mining infrastructure and when there is the need to mine remnant parts of the deposit not previously intended for exploitation or not mined yet. Generally, exploitation in the direction of goafs or yielding zones is limited to the cutting and yielding works. The purpose of the study was to analyse the seismic and rock burst hazard in an exploitation field located at a depth of 850 m in a copper ore mine, over a period of 5 years, when mining was carried out towards goafs. Seismic activity and the effectiveness of rock burst prevention measures were assessed and analysed. The active prevention i.e. the group winning blasting works was an inseparable element of the excavation technology. It was found that when the operational front progressed towards adjacent goafs, there were symptoms of an increase in rock mass pressure causing the destruction of roof rocks and, as a consequence, deterioration of roof stability, squeezing of floor, relaxation of the side walls and increase of seismic activity, which posed the potential threat of rock bursts.
About a possible second source of trap magmatism in the east of the Siberian craton
Authors: Vasileva Aleksandra , Kopylova Albina , Tomshin Mikhail
Published: December 2020

There was made a comparison of trap formation of two major tectonic structures of the eastern part of the Siberian craton - north-east of the Tunguska syncline and Olenek uplift. Using the analysis of geological data and isotopic age determination by the methods of 40Ar/39Ar and U-Pb (also outside the researching area), we can conclude, that the traps of the Tunguska syneclise are 264-240 million years Permo-Triassic age, at the same time, the age of the traps of the Olenek uplift defined as Lower Triassic. The traps of the Tunguska syneclise were formed in three independent intrusion phases, each has its petrochemical specifics, but at the Olenek uplift, there was a single impulse that formed the rocks of the same type, with a well-defined pre-chamber stage of the melt crystallization. The magma that formed the dolerites of the Olenek uplift was more magnesian. The REE distribution patterns for the traps of the Olenek uplift are steeper (La/Ybn=2.4-2.8) in comparison with the Tunguska syneclise traps, the total amount of REE (g/t) in them is within 58-63. A well-defined Sr maximum, promoted by the presence of the early-formed basic plagioclase, is mostly shown in the Olenek uplift traps. In the Nb/Th-Zr/Nb and Nb/Y-Zr/Y diagrams of chemical behavior to incompatible elements, dolerites of the Olenek uplift form composition fields, which are isolated from the Tunguska syneclise traps, thus showing their specific nature. So this information gives us the right to talk about two different sources for the trap forming of the Tunguska syneclise and the Olenek uplift. They resulted from independent plume-induced magmatic events.
Numerical simulation of the possibility of seismic event occurrence in hard rock mine
Authors: Adach-Pawelus Karolina , Butra Jan
Published: December 2020

This article presents the problem of seismic and rockburst hazard in underground hard rock mines. Types of rockbursts and their mechanisms as well as the causes of dynamic phenomena are discussed. The possibility of using numerical modeling to simulate the occurrence of a high-energy tremor, as a result of sudden shear rupture, is also shown. Results of numerical simulations are presented for a model mining field in a hard rock mine at high depth, in which the deposit is mined in a room-and-pillar mining system. General geological and mining conditions characteristic for Polish underground copper mines in Legnica-Glogow Copper Mining District belongs to KGHM Polska Miedz S.A. were adopted in the models. The typical lithological cross-section of the polish copper mines is characterized by rigid, high-strength rock layers in the roof, capable of accumulating elastic energy, while layers with much lower strength parameters are present in the floor. In the analyzed mining field, the remaining undisturbed rock, with a width of 40 m, was left. Numerical simulations were conducted in a plane strain state by means of Phase2 v. 8.0 software. An elastic-plastic model with softening was accepted for the rock mass. The results of numerical modeling showed that sudden (one computational step in the model) collapse of roof strata may occur over the excavated space on the edge of the remaining undisturbed rock, as a result of exceedance of shear strength, above all. This may cause a very high-energy tremor, and under the appropriate conditions, may result in the rockburst phenomenon.
Application of Terrestrial Laser Scanning to Determine Deformations - Practical Aspects
Authors: Antova Gergana
Published: December 2020

When using laser scanning for deformation analysis of a given object, there are no pre-signalled points or identical points to compare between two epochs, so we can judge for whether an object deforms only by modelling the surface of the object. There are a number of challenges in this regard presented in the paper. The first challenge is that for the deformation analysis the configuration of the measurement parameters is no longer set by the surveyor-engineer by the number and position of the observed points, but from the laser scanner. Only the location of the scanner and the scanning density could be controlled. The second challenge is to expand the error model, as the surface modelling is included in the deformation process. This unifies both the metrological and the model errors that arise from the insufficient knowledge of the object and the simplification of its surface. All these challenges are oriented to the created 3D surface model. In addition, the metrological aspects of the use of laser scanners should be considered, especially for applications where the determination of the deformation requires high accuracy. A number of conclusions and recommendations are formulated. The influence of the factors influencing the accuracy of ground laser scanning in the deformation study is summarised, and the influence of the external orientation ang georefering of the point cloud on the accuracy of the digital model is established. Preliminary assessment of the accuracy of the TLS results are given. Justification of the reliability of the determined deformations through TLS is presented. Technological scheme and recommendations for determination of deformations with TLS is shown.
Increasing the efficiency of the tem-tdem method while searching for hydrocarbons in conditions of high electric conductivity of sedimentary-terrigenous complexes’ rocks
Authors: Dmitriyev Arkadiy Nikolaevich
Published: December 2020

A possibility to select theoretical signal models for the observed graphs E
obs(t) satisfactorily is shown to be steadily absent while prospecting using the TEM-TDEM method among Western Siberia’s high-electroconductive rocks. Examination of this problem showed Western Siberia’s rocks have a high reactive (inductive) resistance L alongside with ohmic resistance R. At the same time, thin oil and gas beds’ presence in those rocks causes an additional reactive-capacitive resistance Cdep
to appear under the influence of the applied electric field. Therefore, the process of field inducing in RLC-medium is completely different from the “classic” one which is described with only specific resistance ρ. Thereupon, transit process theory, based on process modelling with equivalent loops, was applied. In practice, TEM-TDEM method’s efficiency turned to be very high as the direct search characteristic – anomalous parameter Cdep
appears. All the parameter c’s anomaly contours predicted as hydrocarbon deposits are confirmed as such with deep drilling with the success coefficient almost equal 100%.
Characteristics Evaluation of Fluorescein Sodium as Fluorescent Tracer for Petroleum Wells
Authors: Pataveepaisit Harid , Srisuriyachai Falan
Published: December 2020

Fluorescein sodium (FluNa) is an organic xanthene-derivative fluorochrome appearing as crimson powder. In the form of solution, fluorescein absorbs blue light and emits green-to-yellow fluorescence under the incidence of visible or ultra-violet light. In petroleum industry, it is normally used as fluorescent tracer to determine reservoir connectivity between injection and production wells. In this study, fluorescein concentration at 10 ppm was critical concentration that reversed relationship between fluorescence intensity and fluorescence concentration. Emission wavelength at maximum fluorescence intensity became a function of fluorescein concentration until 512 nm at 1 ppm and there was no longer reduction of emission wavelength beyond this value at lower concentration. Fluorescence of fluorescein could not be observed by naked eyes at concentrations below 100 ppb, whereas its detection limit by fluorescence spectrophotometer could be lowered to 1 ppb. Fluorescence spectra of fluorescein concentrations at 10 ppt and 100 ppt were similar to those of tap water, formation water, and deionized water. Therefore, detection limit of fluorescein was determined to be at 1 ppb. Fluorescence of fluorescein was photodegraded by light up to 30% when stored inside transparent glass bottles and being exposed to light for 7 days and fluorescence of the solution became darker with time. On the other hand, fluorescence intensities of FluNa solution stored inside amber-coloured glass bottles in both all-time concealment and normal room conditions were almost identical. Fluorescence spectra of the solution at pH of 3 had lower fluorescence intensity and shorter emission wavelength at maximum fluorescence intensity than the solutions at pH of 7 and 11 that were mostly identical. Fluorescence of fluorescein was not affected by temperature in the range of 30-70°C for 12 days. Hence, the storage conditions for fluorescein solution were recommended to be stored inside amber-coloured glass bottle to prevent photodegradation with pH 7 or above.
Method for calculating and evaluating the total energy capacity of cotton fiber
Authors: Isakov A , Tukhtamishev B , Choriev R
Published: December 2020

This paper discusses the need to save material and fuel and energy resources, requires a new approach to their accounting, qualitative and quantitative assessment, and, in particular, to their use. The correctness of planning and forecasting the levels of mining, production and distribution of resources, and, as a consequence, the clear functioning of industrial and household consumers, depends on this. As the first stage of the calculation, an analysis of energy consumption was performed for the following groups of their consumption: field work; production of mineral fertilizers used in cotton growing; water supply for cotton fields (pumping stations, vertical drains); preparation points and cotton processing enterprises. According to consumption groups, energy capacity is: field work 41%, mineral fertilizers 14% and irrigation 45%. The analysis of the obtained results shows that cotton production occupies a rather large place in the total energy consumption in the republic and its savings at each stage of agricultural work and in industrial processing can give significant results in increasing the efficiency of saving the country’s fuel and energy resources.
Theoretical basis for the movement of a pulsed current discharge through a plant organism
Authors: Toshpulatov N
Published: December 2020

The article presents the current state of the problem of contamination of cultivated areas with weeds. A tribute to the analysis of scientific and technical information on weed control, their advantages and disadvantages are described. Theoretically substantiated processes are the destructive effects of electric discharges of current on plant tissue.
Study the effect of the design of discharge electrodes on the characteristics of the corona discharge
Authors: Isakov A , Rakhmatov A , Ismailova Z
Published: December 2020

The article discusses the development of electric ionizers for fruit storage. Based on the technological requirements, the design parameters of the electric ionizer were determined, the current source and operating modes were analyzed and appropriate conclusions and solutions were developed. Optimal quantities of basic geometric sizes specific to needle electrodes are recommended.
Problems of integration of the photovoltaic power stations with the grid systems
Authors: Mirzabaev A , Isakov A J , Mirzabekov Sh , Makhkamov T , Kodirov D
Published: December 2020

The analysis of the factors of renewable energy sources (mainly solar ones) integration with the central grid was conducted in the paper. Various problems arising during integration, solved in Uzbekistan through the development and adoption of a modern legislative and regulatory framework were described. Various aspects of solving the problem were considered, including research work intensification in this direction.
Electrotechnological approach for effective storage of fruits and vegetables in farms
Authors: Ibragimov M , Rakhmatov A , Tadjibekova I
Published: December 2020

It is proposed to use the ozonation method in vegetable and fruit storage facilities of farms that are not equipped with refrigerators. Ozone is a strong disinfecting agent against putrefactive microorganisms. The results of the treatment of apples and carrots with various doses of ozone are given. The effectiveness of this processing method has been verified.
Determination the installation efficiency of the evaporative air cooling in the greenhouse by temperature-moisture regime
Authors: Anarbaev A , Tursunov O , Zakhidov R , Kodirov D , Vakhidov U , Bozorov E , Tuhtaeva G , Babaev A
Published: December 2020

The results of theoretical studies and experiments of the developed exhaust ventilation system with direct evaporative air- cooling with using “wet mats” are given. It has shown sufficient efficiency with increasing quality of flower cutting in the summer months. The effect of moisture on the operation of this system was studied. It is established that the heat absorption capacity of air directly depends on its temperature and relative humidity. It is also determined that the temperature of leaves and flowers in summer is usually 2 ÷ 7 °C greater than the air temperature in the greenhouses. In an experimental greenhouse, according to the results of experiments, the effectiveness of the developed installation for evaporative cooling of its operation was determined.
Influence of the ultrasonic irradiation on characteristic of the structures metal-glass-semiconductor
Authors: Kuchkarov B , Mamatkarimov O , Abdulkhayev A
Published: December 2020

The studied influence ultrasonic irradiation on change the rolling charge built-in in structure lead borosilicate glasses PbO - SiO2 - B2O3 - Al2O3 - Ta2O5. It is shown that influenc ultrasonic irradiation brings about reduction of the rolling charge and improvement insulation parameter glass.
Estimation of the error of a magnetic modulation non-contact wide-range device for non-destructive control of high amperage currents
Authors: Plakhtiev A M , Baratov R J , Gaziev G A , Doniyorov O Ch , Norkholboyev D Sh
Published: December 2020

The paper provides information on use of direct current (DC) energy in the electric power supply industry of agriculture and water management, hydraulic engineering construction, metallurgy, irrigation and melioration. The need for non-contact non-destructive control of high amperage DCs of high-capacity electrical installations in irrigation and melioration, hydraulic engineering has been identified. The basic requirements for non-contact transducers and sensors of high amperage DC measurements without circuit breaking are formulated. Identified priority directions in the development of above mentioned transducers. The general construction principles of non-contact ferromagnetic transducers of high amperage DCs and the results of the development of one of the modification of the developed wide-range magneto modulation contactless transducers of high amperage DCs and a device based on it are given. It is shown that the developed transducer and device, as distinct from the known ones, have increased accuracy and sensitivity, technological design and small weight and dimensions with low material consumption and cost. The error estimation of the developed magneto modulation non-contact wide-range device for non-destructive control of high amperage currents is carried out and it’s RMS (root-mean-square) and entropy errors are estimated. It can be widely used in power systems in irrigation and melioration, in water supply system, industry, railway transport, science, technology and for testing power meters at their installation site for contactless control of DC and also ACs (alternative currents).
Study on Ion generators for fruit and vegetable storehouses
Authors: Rakhmatov A , Ibragimov M , Ximmataliev D
Published: December 2020

The development of food industry and fruit and vegetable production is currently determined not by the amount of production, but by how much of it is preserved. Therefore, the introduction into fruit and vegetable production plan the task of loss reduction of food raw materials at all stages of its transportation, storage and processing was a timely and important step. This paper presents the results from the influence of ionizer structural and operating parameters on the energy performance of the ionized air. The data on optimal modes, that ensure the minimum product losses during long-term storage, are given.
Intellectual system for water flow and water level control in water management
Authors: Djalilov A , Juraeva N , Nazarov O , Chulliyev Ya , Sobirov E , Begmatov M , Urolov S
Published: December 2020

Currently, the shortage of water in our country is growing. This means that we must support every drop of water. At the same time, water management systems in advanced economies are used to measure and monitor water flow and water meters with different designs. Existing measurement and control systems have some drawbacks in energy saving. Therefore, the issue of improving water and energy saving water flow devices and rights management levels was considered.
Mobile installations for electro treatment of soils and plants with the use of photovoltaic systems as power supply
Authors: Anarbaev A , Muxammadiev A , Umarov S , Tursunov O , Kodirov D , Khushiev S , Muhtarov F , Muzafarov Sh , Izzatillaev J
Published: December 2020

The technology of electro processing by UV- radiation for cultivation of cotton is considered. By results of experimental researches optimum parameters for treatment soils with ultraviolet radiation lamps for increasing the accumulation of the most mobile nitrate forms of nitrogen are defined. Prospects of transition of UV-lamps to light-emitting diodes (LED) as way of improving efficiency of processing, and creation of independent power supply by means of photo-electric batteries are shown.
Study on increase of operation efficiency of electrical energy and electrical equipment
Authors: Isakov A J , Abdullaev Z S
Published: December 2020

This article discusses and reveals the problems of the need for proper use of electricity and electrical installations to improve efficiency. Information on the structure of installed capacity at power plants, the structure of fuel consumption and the consumption of electricity by consumers are reviewed and given; as well as information about the increase in efficiency and causes of failure in operation. Agro-industrial complex consumes about 30 percent of all electricity produced in the country (including the rural population), including pumping stations. This figure is expected to reach 45-50% over the next few years. Thus, the choice, design, installation, maintenance and repair of electrical equipment, which have different forms of ownership and management, but are interconnected by consumers in strict accordance with the rules of electricity consumption, Joint modernization, that is an operating efficiency, remains relevant.
Metrobus in separated corridors as an optimal public transport system
Authors: Berdiyorov T
Published: December 2020

One of the factors in the worsening of the quality of transport services is traffic delays which caused by constant and numerous congestion. In this article analyzed need of BRT-Bus Rapid Transit system which is serving in separated corridors for optimizing passenger turnover. Metrobus is a modern type of optimal public transport system, which is developed such cities Berlin, Curitiba, Ahmadabad, Istanbul, Seoul and etc. According to the above researches, the construction of a reliable transport system will allow increasing the level of transport accessibility, reducing the level of transport discrimination of the population, increasing the transport mobility of the population and improving other indicators characterizing the effective work of public transport in the city as a whole.
Reducing the cost of backfill in the Kauldi gold mine
Authors: Mahmadoliev A K , Makhmudov D R , Nurboboev Y T , Pardaev F Sh
Published: December 2020

The Kauldi gold mine uses the backfill to control the mining pressure. Backfill should be able to effectively manage the pressure of the deposit, ensuring safe working conditions, easier preparation process as well as little funds. The cost of backfill directly affects the cost of ore and is important for the indicators of economic development of the mining enterprise. In this article, the method of reducing the costs spared by making changes to the composition of the backfill used in the Kauldi gold mine has been studied. Ore extraction is carried out in the stopes. After the primary stope is extracted and filled with backfill, the secondary backfill is extracted and filled. In the proposed method, 1/3 of the primary stope and 2/3 of the secondary stope are filled with burden. The remaining parts are left unchanged. The reason for such a distribution of the burden in the stopes is that if the backfill in the primary stope is not sufficiently solid, the ore can also be diluted and the backfill is broke-down when extracting the secondary stope. If this happens, the ore will degrade and cause excessive backfill costs for the secondary stope. Filling the stopes with burden is considered cost-effective, and in general, the amount of cement, sand, as well as marble waste purchased for the mining enterprise is reduced twice. As a result, the costs spent on them will also be reduced twice.
Properties of metal-based and nonmetal-based composite materials: A brief review
Authors: Makhkamov N Y , Yusupov G U , Tursunov T , Djalilov Kh
Published: December 2020

At present, the prospects for the progress of structural materials are mainly associated with the development and widespread use of composite materials. The aim to improve the existing designs, to create new materials opens up the opportunities for the implementation of new design solutions and technologies. The article outlines one of the pressing problems - the need to develop new structural materials such as composite ones. Two types of structural materials are considered in the article: composite materials on a metal basis and composites on a non-metal basis. Technical-technological, physical, technological, mechanical and chemical characteristics and properties of composites are given. Based on the analysis, the properties of unidirectional composite materials on a metal and non-metal basis are revealed. As a result of this review, the fields of application of composite materials on a metal and non-metal basis were determined.
An overview on the experimental methods for the evaluation of properties and durability performance of RCA-containing concrete
Authors: Ngenge J P L , Akpinar P
Published: December 2020

The usage of recycled concrete aggregates (RCA) originates from buildings’ demolishing and increased demand in construction. Demolishing could be due to completion of building’s service life or its pre-mature failure as well as due to other reasons such as wars or earthquakes. In such cases, wastes of demolished buildings pose a threat to nature. RCA usage avoids the environmental degradation resulting from excessive extraction of raw materials to produce natural aggregates (NA) and storage of waste materials from devastated structures. Since RCA originates from construction waste, it becomes important to ensure the quality of new structure to be erected using RCA. From this perspective, the examination of general properties and long-term durability of RCA is vital. Hence, an understanding on the critical parameters to be inspected and experimental procedures are essential. This paper aims to provide a compact overview on the crucial parameters defining the quality, properties and the durability of RCA-containing concrete for the civil engineers and researchers aiming to work in this field. The adopted approach for this study implies a systematic literature review that copes with collecting essential information on this topic from existing respected studies from all around the world and the standard codes covering practices for related issues. The found results asserts that, performing tests on each type of waste materials irrespective of theirs sources is vital. For structural usage, the replacement of RCA with respect to the NA shall not be more than 30%. Finally, the usage of finer RCA shall be minimum for the better performance of RCA-concrete containing.
The Influence of ultrasonic strengthening treatment on microhardness of the construction materials surface with different initial structure
Authors: Abdumuminova D T , Lesyuk E A , Erofeev M N , Kravchenko I N , Deryabin A I , Yuldashev Sh U
Published: December 2020

The description of the method of ultrasonic surface hardening treatment (UST), which makes it possible to form gradient structures in structural materials, is given. This paper presents the results of the effect of UST on the surface microhardness of coarse-grained, ultrafine-grained and nanostructured titanium nickelide. The work is devoted to the study of the effect of ultrasonic hardening surface treatment on the surface microhardness of structural materials with different initial structures (coarse-grained, ultrafine-grained, nanostructured).
Determination of reduction of useful volume in water reservoirs due to sedimentation
Authors: Arifjanov A , Gapparov F , Apakxujaeva T , Xoshimov S
Published: December 2020

To develop a work plan for reliable and efficient use of water reservoirs, an accurate information about the volume of water stored in the reservoir for the safe operation of the reservoir facilities is necessary. The useful water storage capacity of reservoirs has been steadily declining over the years due to the sedimentation coming with the stream.

The article presents a method for determining the continuous change of the reservoir volume during operation due to sedimentation. A calculation method estimating the dynamics of the sediment distribution in the reservoir has been scientifically developed. The proposed calculation method was tested and compared in the field conditions. The analysis of the data collected in the Chimkurgan, Tashkent and South Surkhan water reservoirs under field conditions based on mathematical statistical methods showed a relationship between the relative turbidity and the reservoir depth. A new method of determining the decrease in useful water volume due to sedimentation in reservoirs has been proposed.
Types of Contamination in Landfills and Effects on The Environment: A Review Study
Authors: Iravanian A , Ravari Sh O
Published: December 2020

Waste disposal is one of the important problems in the world. In general, wastes are categorized into different groups, and there are some special landfills and methods for disposing of each of these waste materials. However, it should be noted that although there are some rules and regulations that try to reduce the impact of waste disposal, landfills have negative effects on soil, air, water, and natural life. One of the most important sources of pollution in landfills is the leachate that is generated by the decomposition of waste. Leachate can penetrate into the soil and water resources, contaminate them, and can affect human life. Leachate generation has five different phases and each of these phases contains some reactions that have a direct impact on the quality and quantity of leachate. Leachate has four main types of pollution and each of these pollutants can contaminate soil and water resources and be hazardous for aquatic and animals in the soil. In addition, some of these contaminations can enter the food chain and affect the ecosystem and human life. The negative impacts of landfills remain even years after the landfill is closed. Therefore, it is important to consider the short-term and long-term effects of landfills on their surroundings to protect the environment and human health.
Impact of stops for bus delays on routes
Authors: Kutlimuratov K , Mukhitdinov A
Published: December 2020

In this paper bus travel time and delay is significant measures in public transportation. This research aims to explore impact of stops for the selected bus route and to find some simple suitable solutions to reduce the travel time and minimize delays for scheduling preferences of travellers. Delays data were collected using automatic vehicle location system (GPS technology) for the bus route #51 in Tashkent. Based on the collected GPS data were proposed the developed a linear and a logistic multivariate regression model. Travel time reliability were estimated regarding to a multivariate regression models and performed. The result shows that very good statistical suitable as expected and thus can be used in the public transportation to determine any travel time using real-time and available offline data. These outcomes, in the future it is expected that will be applicable and more efficient bus public transportation system in Tashkent.
Visualization and analysing the state of hydrotechnical construction via geospatial methods (on the example of Kharshi pumping stations cascade)
Authors: Mamatkulov Z , Rashidov J , Eshchanova G , Berdiev M , Abdurakhmonov Z
Published: December 2020

In the given article the state of Kharshi pumping station, which is considered as one of the huge pumping stations cascade in Central Asia is described through analysing and visualising the geographic information systems (GIS) and remote sensing (RS) methods. As data there were used Shuttle Radar Topographic Mission - SRTM and high-resolution optical images of the area, provided by ESRI. For data processing and visualization, there was used the software of ArcGIS 10.5 by ESRI company and the results were obtained. At the same time the geographical location of pumping stations and water elevating points and the state of water flowing canals were analysed remotely along with the results from the cross-sectional area of cascade were obtained. In assessing, the accuracy of results it was compared with the data based on field search work and the obtained results from the distance showed 86% accuracy.
Frequency analysis of longitudinal-radial vibrations of a cylindrical shell
Authors: Khalmuradov R I , Yalgashev B F
Published: December 2020

The article solves the problem of harmonic longitudinal-radial vibrations of a circular cylindrical shell with freely supported ends. To solve the problem, we used the refined equations of oscillation of such a shell, derived earlier from the exact three-dimensional formulation of the problem and its solution in transformations. An extensive review of works devoted to the study of harmonic and nonstationary processes in elastic bodies on the basis of classical (Kirchhoff-Love, Flyugge) and refined Timoshenko type (Hermann-Mirsky, Filippov-Khudoinazarov) theories is given. Four frequency equations are obtained for the main parts of the longitudinal and radial displacements of the cylindrical shell. These frequency equations admit, as special cases, frequency equations and a thin-walled shell. Based on the solution of the obtained frequency equations, the frequencies of natural vibrations of the shell, including the thin-walled one, are determined. A comparative frequency analysis of longitudinal vibrations of a circular cylindrical elastic shell is carried out on the basis of the classical Kirchhoff-Love theory, refined theories of Hermann-Mirsky and Filippov-Khudoinazarov. On the basis of the results obtained, conclusions were drawn regarding the applicability of the studied oscillation equations, depending on the waveform and shell length. In particular, it was found that all the considered equations are unsuitable for describing wave processes in short shells, the lengths of which are commensurate with the transverse dimensions of the shells.
Contact problems of multilayer slabs interaction on an elastic foundation
Authors: Mirsaidov M , Mamasoliev Q
Published: December 2020

A mathematical model and a method to assess the internal force factors in multilayer strip – slab on elastic foundation under various static loads were developed in the paper. A detailed review of well-known publications on assessing the stress-strain state and dynamic behavior of various structures interacting with the base is given. A closed system of integro-differential equations describing the strain process in multilayer slabs on an elastic foundation was derived. The problem under consideration was reduced (using the Chebyshev polynomial) to the solution of infinite systems of algebraic equations. The regularities of infinite systems of algebraic equations were proved and the corresponding estimates were obtained. A number of terms of the Chebyshev polynomial for obtaining a solution to the problem with the required accuracy was determined. The efficiency of the method was shown on the example of test problems.
A comprehensive impact of Clasterosporiosis and Polistigmosis diseases on almonds plantation: A brief review
Authors: Yuldosheva D , Khodjaev O , Gulmurodova Sh
Published: December 2020

A number of authors have reported on Clasterosporiosis and Polystigmosis diseases of almonds occurring in the Tashkent region. These diseases are common in the CIS in Central Asia, the Caucasus, Moldova, and Ukraine. As well as, these diseases are widespread in all almond growing regions in Uzbekistan. Clasterosporiosis and Polystigmosis are among the most damaging diseases of almonds in Bostanlyk district of the Tashkent region. Red spot disease was first reported in 1970 in the Iranian city of Shiraz and is widespread in the Mediterranean regions and in the Middle East. This disease is one of the most important almond diseases, as it slows down the process of photosynthesis and leads to early defoliation of trees. A drop in fruit production has also been caused by this disease. Polystigmosis (red spot) is caused by the fungus Polystigma rubrum (Po. rubrum). The disease does not quickly destroy the trees, but its damage reduces the quantity and quality of the crop, slows the development of new branches, and consequently weakens the tree. Thus, this brief review paper presents the recent studies focused on the comprehensive impact of Clasterosporiosis and Polistigmosis diseases on almonds plantation.