bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermophysical properties of nanofluids MWCNT (multi-walled carbon nanotubes) in water for emergency coolant from nuclear reactors
Authors: Oliveira Alexandre Melo , Mesquita Amir Zacarias , Bandarra Enio Pedone , Morales Daniel Flórez
Published: May 2021

To evaluate the synthesis and characterization of MWCNT (Multi-walled Carbon Nanotubes) with different degrees of functionalization in distilled water. The thermophysical properties (thermal conductivity and viscosity) of these nanofluids were measured at a temperature range (20-60°C) and concentrations (0.005-0.05%) by volume. Increases in thermal conductivity and viscosity were found 9.3% and 4.7%, respectively, at a volumetric concentration of 0.01% at a temperature of 30°C. The study of new fluids that improve the rate of removal of heat is fundamental to obtain greater efficiency of energy systems. Among the several factors that compromise the efficiency of the energy systems, we can highlight the thermophysical limitations of the conventional fluids, inhibiting in a very significant way some industrial applications. In this work we intend to improve the heat transfer characteristics of fluids commonly used by the addition of nanoparticles, made up of carbon nanotubes, in water which is the most used fluid for the cooling of nuclear reactors in operation today. It is intended to improve the heat transfer characteristics of fluids commonly used by the addition of nanoparticles, made of carbon nanotubes, through the addition of nanoparticles, made up of carbon nanotubes, in water which is the most used fluid for refrigeration of nuclear reactors currently in operation. In order to assess its benefits for the applicability and nuclear systems, ie primary coolant, safety systems, major accident mitigation strategies.
Commercial grade dedication challenges for Brazilian nuclear industry
Authors: MAIA ANA ROSA BALIZA , Morghi Youssef , MESQUITA AMIR ZACARIAS
Published: May 2021

According to NRC, the commercial-grade dedication is a process by which a commercial-grade item (CGI) is designated for use as a basic component. This acceptance process is undertaken to provide reasonable assurance that a CGI to be used as a basic component will perform its intended safety function and, in this respect, is deemed equivalent to an item designed and manufactured under a quality assurance program. This assurance is achieved by identifying the critical characteristics of the item and verifying their acceptability by inspections, tests, or analyses by the purchaser or third-party dedicating entity. In Brazil there are two Nuclear Power Plants in operation, one is American design (Angra 1), other is German design (Angra 2) and one is under construction that is German design (Angra 3). The nuclear safety items are imported and many of them are obsolete and besides the process of purchasing imported items is very complicated. If the nuclear industry in Brazil adopt the Commercial-grade dedication it will improve the internal market and facilitate the process of purchasing items. The Brazilian Quality Assurance Standard (Cnen NN 1.16) shows the 18 Basic requirements of 10 CFR 50 App B, so the Brazilian Industry can be qualified according to this Brazilian standard. The critical characteristics identification and the testing process is an engineering responsibility that Brazilian engineer can perform. This work shows the challenge of commercial-grade dedication in Brazil and discuss the importance of this process to the operation of the nuclear power plants in Brazil, including the long-term operation and others Brazilian nuclear projects..
Knowledge management of research data: an initial analysis of Institute of Radiation Protection and Dosimetry
Authors: Razuck Fernando Barcellos
Published: May 2021

It can be said that scientific community produces research data, as well as uses research data to validate its work. Thus, research data cease to be research products to become informational resources. In this context, digital data repositories play an extremely important role in the scientific research process, since they can be used to share, access, reuse and validate data. In this sense, the informational recognition of research data, in recent years, transformed the view that characterized them as simple by-products of research processes, to the point that researchers, academic institutions and research development agencies begin to understand that these data contribute as a source of informational resources for scientific research and science teaching. Based on this, the objective of this work is to make a preliminary survey of the type of research data generated at the Institute of Radiation Protection and Dosimetry (IRD). For this, an analysis was made of the papers published by the permanent professors of the Post-graduation Program in Radiation Protection and Dosimetry in the last year (2019). It was then generated a table relating the Concentration Areas versus some technical information, regarding the generation of research data. In this sense, the analysis of the data of the IRD consists of a initial stage to assist the creation of the Institute's Digital data repository, which aims to provide the research data in order to be used in other researches.
Decommissioning cost estimation for a multiple reactor site with interdependent plants: case study using a new management tool and top-down approach
Authors: Monteiro Deiglys Borges , Moreira João Manoel Lousada , Maiorino José Rubens
Published: May 2021

In the end of operational life, a nuclear power plant should be decommissioned to release its site for a new purpose. The decommissioning cost estimation is part of the decommissioning plan, which also include the decommissioning strategy definition. The cost estimation is performed by management tools, most of them according the bottom-up approach. However, this approach usually requires large quantities of data and detailed knowledge of the site conditions and the project phases, which are often unknown in the project beginning, requiring the adoption of several assumptions. Otherwise, the top-down approach requires less data or assumptions, and the project details is known as it became mature. Due to this, the top-down approach is a better approach for cost estimation during planning phase than the bottom-up. Despite it, most part of management tools found in literature to cost estimation are structured according the bottom-up approach. To suppress this lack, recently a new management tool was developed according the top-down approach, being able to estimate the decommissioning cost of nuclear power plants for budget/bid purposes. This work aims to present the cost estimation to decommissioning a multiple reactor power site with similar characteristics of the Brazilian ones, which would be used as benchmark. The results demonstrated that the interdependencies among the plants are important and affects significantly the cost to decommissioning each plant. This work is part of a research that is under course in which several strategies alternatives would be evaluated.
Neutron angular flux reconstruction in slab geometry using multigroup discrete ordinates transport models
Authors: Balbina F. T. C. S. , Barros R. C. , Alves Filho H.
Published: May 2021

In this article, we present an application of the coarse-mesh Deterministic Spectral Method (SDM) to generate multigroup angular fluxes in one-dimensional spatial domains using the neutron transport stationary equation, in the formulation of discrete ordinates (SN), considering isotropic scattering source. After obtaining the analytical solution of the SN equations, we replace the integral term of the scattering source in the original neutron transport equation. Thus, we obtain analytically two expressions for angular fluxes in the multigroup formulation, considering the neutron propagation in the positive ( ) and negative ( ) directions, presenting a meaningful reduction in the computational time of simulations of typical neutron shielding problems.
Patologizados, fatigados y perdidos
Authors: Grippaldi Esteban
Published: May 2021

El artículo analiza la emergencia de la depresión como la enfermedad mental más frecuente en la modernidad tardía. Desde el existencialismo sociológico de Peters (2017) concibe la depresión como un particular modo de inseguridad ontológica. Sostiene que el incremento de los diagnósticos es comprensible a partir tres amplias claves interpretativas vinculadas a transformaciones en las sociedades tardo-modernas. La primera alude a una creciente patologización de la angustia asociada a la emergencia de modos de conceptualizar el sufrimiento psíquico. La segunda refiere a la profundización de los imperativos de autorrealización que provocan patologías del agotamiento del yo. La tercera destaca la expansión de una multiplicidad de guías de referencia que se manifiesta en una pérdida de sentido de la existencia. La  depresión contemporánea representa, simultáneamente, una patología retórica, de la acción y del sentido correlativa con figuraciones del sujeto patologizado, fatigado y perdido.
Fenomenologia e teoria social
Authors: Alves Paulo Cesar
Published: May 2021

O presente artigo discute o conceito de “mundo da vida cotidiana”, uma das mais importantes contribuições da “sociologia fenomenológica” de A. Schutz para a teoria social contemporânea. Argumentamos que a premissa fundamental desse conceito se refere prioritariamente à questão de ação (fluxo de atividades sempre em vias de transformação e de concretização) e não apenas de significação. Partimos do pressuposto que a sua teoria assume um “caráter ontológico”: a existência humana consiste em ser/estar no mundo e é próprio do ser humano atuar. A ação é sempre circunstancial, requer um “ímpeto inicial” (motivo) e se constitui essencialmente como processo em curso (trajeto), o que difere do “ato” (o resultado desse percurso, a ação realizada). As significações, produzidas no fluxo de atividades, são interpretações de experiências passadas. Tal premissa levanta um desafio para a sociologia: como lidar com uma realidade que em si mesma é temporal, plural, incerta?
Teoria social e sociologia existencial
Authors: Peters Gabriel , Silva Corrêa Diogo , C. M. Rabelo Miriam
Published: May 2021

Com base nos artigos que compõem o dossiê, os organizadores refletem sobre diferentes modos de conceber e levar a efeito uma sociologia existencial.
Object Detection in Aerial Navigation using Wavelet Transform and Convolutional Neural Networks: A first Approach
Authors: Fortuna-Cervantes Juan Manuel , Ramírez-Torres Marco Tulio , Martinez-Carranza Juan , Murguía-Barra José Salomé , Mejía-Carlos Marcela
Published: May 2021

This paper proposes a first approach based on wavelet analysis inside image processing for object detection with a repetitive pattern and binary classification in the image plane, in particular for navigation in simulated environments. To date, it has become common to use algorithms based on convolutional neural networks (CNNs) to process images obtained from the on-board camera of unmanned aerial vehicles (UAVs) in the spatial domain, being useful in detection and classification tasks. CNN architecture can receive images without pre-processing, as input in the training stage. This advantage allows us to extract the characteristic features of the image/ Nevertheless, in this work, we argue that characteristics at different frequencies, low and high, also affect the performance of CNN during training. Thus, we propose a CNN architecture complemented by the 2D discrete wavelet transform, which is a feature extraction method. The information improves the learning capacity, eliminates the overfitting, and achieves a better efficiency in the detection of a target.
Amphibians and reptiles of Wildsumaco Wildlife Sanctuary, Napo Province, Ecuador
Authors: Camper Jeffrey D. , Torres-Carvajal Omar , Ron Santiago R. , Nilsson Jonas , Arteaga Alejandro , Knowles Travis W. , Arbogast Brian S.
Published: May 2021

We conducted a long-term inventory of the herpetofauna of Wildsumaco Wildlife Sanctuary in the eastern part of the Napo Province in Ecuador. This private preserve is about 500 ha in size and is located on the southern slopes of Volcán Sumaco. The preserve contains primary forest, secondary forest, and pasture habitats. Based mostly on nocturnal transect sampling we documented 39 species of amphibians including one species of salamander, two species of caecilians, and 36 species of frogs. Rain frogs (Pristimantis Jiminez de la Espada, 1871) were diverse with 14 species documented. A diverse species assemblage of 45 reptile species was also documented on the preserve. Six amphibian species found were listed by the IUCN Red List. At least three species exhibited substantial geographic range extensions and seven species showed elevational range extensions. We discovered several undescribed species including one salamander, three frogs, one lizard, and one snake.
Decomposition of ferronickel slag through alkali fusion in the roasting process
Authors: Mayangsari Wahyu , Avifah Isma Nur , Prasetyo Agus Budi , Febriana Eni , Maksum Ahmad , Ulum Reza Miftahul , Firdiyono Florentinus , Subagja Rudi , Soedarsono Johny Wahyuadi
Published: May 2021

Ferronickel slag is a by-product of the nickel smelting process. Recycling of ferronickel slag is required since it contains valuable elements besides its potency to pollute the environment. In order to take advantage of the valuable materials and reducing the potential hazard, beneficiation of ferronickel slag is essential. Alkali fusion of ferronickel slag using Na2CO3 in the roasting process was carried out. This study aims to determine the decomposition of the mixture of ferronickel slag-Na2CO3 in the roasting process. Roasting temperature and time were 800–1,000 °C and 60‒240 minutes, respectively. Characterizations of the ferronickel slag were conducted by XRF, ICP-OES, XRD and SEM-EDS. Meanwhile, roasted products were characterized using ICP-OES, XRD and SEM-EDS. Characterization of the ferronickel slag indicates that Mg and Si are the main elements followed by Fe, Al and Cr. Moreover, olivine is detected as the main phase. The roasting process caused percent weight loss of the roasted products, which indicates decomposition occurred and affected the elements content, phases and morphology. The roasting process at about 900 °C for 60 minutes is a preferable decomposition base on the process conditions applied and the change of elements content. Aluminum (Al) and chromium (Cr) content in the roasted products upgraded significantly compared to iron (Fe) and magnesium (Mg) content. Olivine phase transforms to some phases, which were bounded with the sodium compound such as Na2MgSiO4, Na4SiO4 and Na2CrO4. The rough layer is observed on the surface of the roasted product as a result of the decomposition process. It indicates that liquid-solid mass transfer is initiated from the surface
Development of electric vehicle (EV)-bus chassis with reverse engineering method using static analysis
Authors: Nazaruddin Nazaruddin , Adhitya Mohammad , Sumarsono Danardono A , Siregar Rolan , Heryana Ghany , Prasetya Sonki , Zainuri Fuad
Published: May 2021

This research aims to simulate structural steel 400 (SS400) material as an alternative material for the electric bus's chassis structure. The kind of the material is low carbon steel. The SS400 material is produced from one of the largest steel mills in Indonesia, considered a local material. The local material used to increase the total domestic content in electric cars in Indonesia could be improved. Generally, the reverse engineering method of the R260 ladder frame type chassis is used to increase the local content in electric vehicles. However, this research used a ladder frame of type SS400 from local material to fulfill the local content of vehicle (EV)-bus chassis with the reverse engineering method. After the model was successfully created using the finite element software, statics analysis was carried out using the von Mises stress and the simulation results' deflection. The meshing process of the chassis structure is carried out in such a way as to assume global contact. Loading was evenly carried out over the two main beam ladder frames totaling 14,200 kg. The elasticity modulus and tensile strength values used for the material are 190 GPa and 480 MPa. Furthermore, the support was placed in the mounting position of the front and rear wheel leaf springs at a front, rear overhang, and wheelbase distance of 2,380 mm, 3,290 mm, and 6,000 mm. The resulting approach was carried out using a beam model with a two-overhang beam model. The simulation results showed that type SS400 from the local material obtained a maximum von Mises stress value of 75.8 MPa, deflection of 2.568 mm, and the lowest safety factor of 3.2. Meanwhile, through theoretical calculations, the obtained stress occurred in 72.33 MPa and deflection of 2.594. There is no significant difference between simulation results and theoretical results
Development of a method to linearize the quadratic assignment problem
Authors: Munapo Elias
Published: May 2021

The paper presents a new powerful technique to linearize the quadratic assignment problem. There are so many techniques available in the literature that are used to linearize the quadratic assignment problem. In all these linear formulations, both the number of variables and the linear constraints significantly increase. The quadratic assignment problem (QAP) is a well-known problem whereby a set of facilities are allocated to a set of locations in such a way that the cost is a function of the distance and flow between the facilities. In this problem, the costs are associated with a facility being placed at a certain location. The objective is to minimize the assignment of each facility to a location. There are three main categories of methods for solving the quadratic assignment problem. These categories are heuristics, bounding techniques and exact algorithms. Heuristics quickly give near-optimal solutions to the quadratic assignment problem. The five main types of heuristics are construction methods, limited enumeration methods, improvement methods, simulated annealing techniques and genetic algorithms. For every formulated QAP, a lower bound can be calculated. We have Gilmore-Lawler bounds, eigenvalue related bounds and bounds based on reformulations as bounding techniques. There are four main classes of methods for solving the quadratic assignment problem exactly, which are dynamic programming, cutting plane techniques, branch and bound procedures and hybrids of the last two. The QAP has application in computer backboard wiring, hospital layout, dartboard design, typewriter keyboard design, production process, scheduling, etc. The technique proposed in this paper has the strength that the number of linear constraints increases by only one after the linearization process.
Development of a method of providing ergonomics of a web-interface for customers of a virtual instrument-making enterprise with limited physical capabilities
Authors: Sobchak Andrii , Kovshar Nataliiе , Lutai Liudmyla , Fedorenko Mykola , Fedorenko Mykola , Dmytriieva Oksana
Published: May 2021

A method has been developed and implemented to ensure the ergonomics of using the Web interface for customers of a virtual instrument-making enterprise with limited capabilities through the use of expert systems. The essence of this method is to supplement the dialog component of the Information and Analytical Portal (IAP) with a specialized shell of the expert system (ES), which, being filled with knowledge about the limited capabilities of users caused by various pathologies, makes it possible to adapt the interface in the dialogue to the capabilities of a particular user. implementations of this solution method are fully consistent with the results obtained using the principles of interface improvement. However, due to the use in this synthesis method of various approaches to the technology of expert systems development, additional opportunities open up in solving the problem of providing the convenience of using the interface for customers with limited capabilities.
When using the proposed method, it becomes possible to simplify the procedure of interaction "man-machine", to solve the problems of people with disabilities, to increase the volume of consumers who have access to advanced information technologies. These facts, confirmed by the results of numerical modeling, showed the effectiveness of the presented method and an individual approach to users with disabilities. The software implementation of the logical-linguistic hierarchical model on the example of “strong myopia” with the help of the production shell ES is proposed and substantiated. As the initial data, information about hardware was used, the use of which, in appropriate cases, will make it possible to increase the ergonomics of the IAP for users with disabilities.
Methods of constructing models and optimizing the operating modes of a chemical engineering system for the production of benzene in a fuzzy environment
Authors: Orazbayev Batyr , Orazbayeva Kulman , Makhatova Valentina , Tuleuova Raigul , Kulmagambetova Zhumazhan , Toleuov Timur , Mukatayev Nurlan , Ospanov Yerbol
Published: May 2021

The study object: the chemical engineering system for production of benzene and optimization of the system operation modes based on modeling. An approach to the effective solution of problems of optimization of operating modes of real chemical engineering systems was proposed. Since such systems are usually multicriterial and characterized by the fuzziness of initial information, an approach to the development of their models and optimization of their operating modes in a fuzzy environment was proposed. The essence of this approach lies in the construction of mathematical models and optimization of system operation modes based on the system analysis methodology using available information of deterministic, statistical, and fuzzy nature. Statements of the problems of optimization by means of chemical engineering systems in a fuzzy environment have been obtained by modifying various principles of optimality for working in a fuzzy environment. Based on a modification of the principles of maximin and Pareto optimality, a heuristic algorithm for solving the formulated optimization problem was proposed based on the use of knowledge and experience of decision-makers. The proposed method of model construction and an optimization algorithm were implemented in practice when constructing models of benzene and rectification columns of a chemical engineering system of production of benzene when formulating and solving the problem of optimizing their operation modes in a fuzzy environment. Analysis and comparison of optimization results allow us to conclude about the effectiveness of the proposed fuzzy approach to solving optimization problems in a fuzzy environment. As a result of optimization of the benzene production process, the benzene yield increased by 1.45 thousand t or by 1.1 %, the raffinate output volume increased by 0.4 thousand t in conditions of upholding constraints on benzene quality. The proposed approach makes it possible to assess the degree of upholding of fuzzy constraints
Effect of shape formation on the accuracy of grinding ends while compensating for machine tool errors
Authors: Rudyk Andrey , Chupryna Volodymyr , Rudyk Vladislav
Published: May 2021

There are several general methods for correcting errors related to positioning the machine tool structural units. The task to achieve optimal manufacturing accuracy can be resolved by using a compatible solution to vector equations, a variation of the shape formation function, or applying a matrix of transfer coefficients.
However, there is no mutual relationship between various calculation methods for the case of grinding flat surfaces. The methods should be simplified and tested for the elongated shape formation function while considering the links’ dimensions.
This paper reports a study into the accuracy of grinding flat surfaces, determining and reducing the share of manufacturing errors. The content of variation matrices and transfer coefficients has been substantiated. The comparison of the orientation angles of the grinding machine headstock relative to the machine tool bed has demonstrated close results from all methods. These angles were taken as machine tool errors. The calculation error does not exceed 1.5 %. The experiments are consistent with the calculations.
Different signs of the transfer coefficients in the orientation angles of grinding machine headstocks in the matrix make it possible to mutually compensate for the overall impact. The calculations have shown that the accuracy of the side-end machining is largely affected by a change in the orientation angle in the vertical plane.
The effect exerted on the accuracy of individual mated parts by the machine tool structural units has been estimated. The calculations show that the error of positioning a part in the drum window acquires the highest absolute values and is random in nature, which requires a more accurate base positioning. The findings from both theoretical and experimental studies have been applied. The mathematical model makes it possible to determine the degree of scattering the end surface around the base plane via its variance.
The measured trajectory provides diagnostic information about the sources of error in the machine tool assembly. A task to calculate the accuracy of the end-grinding machine tool can be solved for other models of machine tools in the same way
Development of 3D environmental laser scanner using pinhole projection
Authors: Qudr Lateef Abd Zaid
Published: May 2021

Three-dimensional (3D) information of capturing and reconstructing an object existing in its environment is a big challenge. In this work, we discuss the 3D laser scanning techniques, which can obtain a high density of data points by an accurate and fast method. This work considers the previous developments in this area to propose a developed cost-effective system based on pinhole projection concept and commercial hardware components taking into account the current achieved accuracy. A laser line auto-scanning system was designed to perform close-range 3D reconstructions for home/office objects with high accuracy and resolution. The system changes the laser plane direction with a microcontroller to perform automatic scanning and obtain continuous laser strips for objects’ 3D reconstruction. The system parameters were calibrated with Matlab’s built-in camera calibration toolbox to find camera focal length and optical center constraints. The pinhole projection equation was defined to optimize the prototype rotating axis equation. The developed 3D environmental laser scanner with pinhole projection proved the system’s effectiveness on close-range stationary objects with high resolution and accuracy with a measurement error in the range (0.05–0.25) mm. The 3D point cloud processing of the Matlab computer vision toolbox has been employed to show the 3D object reconstruction and to perform the camera calibration, which improves efficiency and highly simplifies the calibration method. The calibration error is the main error source in the measurements, and the errors of the actual measurement are found to be influenced by several environmental parameters. The presented platform can be equipped with a system of lower power consumption, and compact smaller size
Development of a direct penetrating signal compensator in a distributed reception channel of a surveillance radar
Authors: Khudov Hennadii , Yarosh Serhii , Droban Oleksandr , Lavrut Oleksandr , Hulak Yurii , Porokhnia Ivan , Yarovyi Serhii , Rogulia Alexandr , Yuzova Iryna , Khudov Rostyslav
Published: May 2021

General structure of a compensator of a direct penetrating signal in the diversed reception channel was developed. It is advisable to use the antenna and the receiver of the auxiliary diverted reception channel as an auxiliary antenna and an auxiliary channel. To be able to suppress the penetrating signal in the band of the receiving device of the surveillance radar, distance between the antennas should be up to 6 m. In general, the compensator of the penetrating signals should contain an adder in which the signals received by the main channel are added with the signals received by the auxiliary channel and sent through the amplifier with a corresponding complex transmission coefficient. The direct penetration signal compensator features the obligatory condition of adjusting the value of the complex transmission coefficient of the auxiliary channel signal amplifier.
The direct penetration signal compensator is digital and uses the direct method of forming weighting coefficients without the use of feedback. To reduce the time of formation of weighting coefficients when using direct methods of calculation of the correlation matrix, the technology of parallel computational processes was used.
The quality of operation of the direct penetrating signal suppression system in the diverted reception channel was evaluated. It was established that without the use of suppression of direct penetrating signals, their powerful response at the output of the matched filter mask weak echo signals. When using a direct penetrating signal in the main channel of the compensator, its response at the output of the matched filter is significantly reduced. This makes it possible to observe weak echoes against the background of a strong penetrating signal. The use of the developed direct penetrating signal compensator provides suppression of the direct penetrating signal from 57 dB to 70 dB
Effect of welding sequence and welding current on distortion, mechanical properties and metallurgical observations of orbital pipe welding on SS 316L
Authors: Widyianto Agus , Baskoro Ario Sunar , Kiswanto Gandjar , Ganeswara Muhamad Fathin Ginanjar
Published: May 2021

Orbital pipe welding was often used to manufacture piping systems. In orbital pipe welding, a major challenge is the welding torch’s position during the welding process, so that additional methods are needed to overcome these challenges. This paper discusses the influence of welding sequence and welding current on distortion, mechanical properties and metallurgical observations in orbital pipe welding with SS 316L pipe square butt joints. The variation of the orbital pipe welding parameters used is welding current and welding sequence. The welding current used is 100 A, 110 A, and 120 A, while the welding sequence used is one sequence, two sequences, three sequences, and four sequences. The welding results will be analyzed from distortion measurement, mechanical properties test and metallurgical observations. Distortion measurements are made on the pipe before welding and after welding. Testing of mechanical properties includes tensile tests and microhardness tests, while metallurgical observations include macrostructure and microstructural observations. The results show that maximum axial distortion, transverse distortion, ovality, and taper occurred at a welding current of 120 A with four sequences of 445 µm, 300 µm, 195 µm, and 275 µm, respectively. The decrease in ultimate tensile strength is 51 % compared to the base metal’s ultimate tensile strength. Horizontal and vertical microhardness tests show that welding with one sequence produces the greatest microhardness value, but there is a decrease in the microhardness value using welding with two to four sequences. Orbital pipe welding results in different depths of penetration at each pipe position. The largest and smallest depth of penetration was 4.11 mm and 1.60 mm, respectively
A procedure to forecast and manage water resources and to redistribute runoff water flow when passing floods
Authors: Olefir Dmytro , Panasenko Anna
Published: May 2021

Economic losses from floods have become catastrophic due to the increase in the number and scale of their propagation. Existing procedures for passing floods and pre-preparing reservoirs for flood water acceptance are ineffective and need to be improved. Therefore, the task to devise a methodology that would eliminate these shortcomings was urgent.
This paper has proposed a procedure for calculating the passage of floods based on the forecasts of water inflow, taking into consideration the characteristics of the flood wave and the mode of reservoir filling, which makes it possible to bring down (reduce) the maximum flow rate through a waterworks by accumulating floodwaters in the reservoir.
The software package Mike 11 (Danish Institute, Denmark) was employed to build a hydrodynamic model of floodwater movement along the examined river section from a hydrological station to a waterworks, which makes it possible to determine the levels of water and the flow rate in a reservoir at any time in the form of free surface curves when passing floods of various range.
Based on the devised methodology, recommendations have been compiled for the forced discharges of water through hydroelectric turbines (in m3/s) when passing floods of various probabilities (which is especially important for floods whose probability is 0.01 %). The constructed hydrodynamic model of floodwater movement through a reservoir has allowed the verification of the devised procedure.
The procedure was devised in order to effectively pass floodwaters and bring down the maximum flow rate through a waterworks.
The introduction of the methodology for calculating the passage of floods could make it possible to avoid idle water discharge through the water drains of waterworks to the lower pool and provide for the most efficient utilization of floodwater resources
Light harvesting enhancement using metal nanoparticles
Authors: Yaseen Mohammad Tariq
Published: May 2021

Metal nanoparticles are very important for their optical properties when they interact with light. Metal nanoparticles have the ability to confine the collective oscillation of electrons, which is called localized surface plasmon resonance (LSPR). In this work, silver nanoparticles have been proposed to enhance light harvesting, which could be useful for different applications. Metal nanoparticles such as gold and silver nanoparticles have the ability to concentrate field in a very small space. In this study, gold and silver nanoparticles optical response was investigated using frequency domain simulation. The resonance wavelength of gold and silver nanoparticles was about 550 nm and 400 nm, respectively.
Silver nanoparticles showed better LSPR performance than gold nanoparticles. Therefore, silver nanoparticles were chosen for optical field enhancement. Here silver nanoparticles were placed on a silicon substrate for optical field enhancement. To study the effect of size on the optical response of silver nanoparticles, the optical properties of this structure with different silver nanoparticles diameter values were investigated. Silver nanoparticles with 40 nm diameters showed a better optical response. To study the effect of the distance between silver nanoparticles on the optical response, different gap values were put between silver nanoparticles. The gap value of 4 nm showed a better optical response. The obtained results showed that the localized field is strongly dependent on the metal type, size, and space between nanoparticles. In addition, the optical field concentration can be controlled by tuning the size and space between silver nanoparticles. This will support localized field enhancement. The enhanced localized field will increase the field absorption near the surface, which can be beneficial for energy harvesting applications such as solar cells and detectors
Theoretical study of the grate-saw-type large-litter cleaner of the mounted type
Authors: Karimov Husnu Kadir , Mustafayeva Esmira , Jafarov Elman , Safarova Terane , Veliev Fazil
Published: May 2021

This paper reports a theoretical study into the saw-type-grate section of a large litter cleaner in mounted cleaners that operate on a cotton harvester, as well as the theoretical and experimental justifications for its parameters. The effect exerted by a mounted cleaner on the process of cleaning raw cotton when processing in a cotton gin has been studied.
A theoretical model of the impact of grates on weeds in cleaning processes has been developed. A condition for repelling the litter by grates and removing it from a cotton technological flow has been studied. The use of grates with a flat-shaped front edge allows for a steady reduction in the amount of damage in the raw cotton fiber, which improves the fiber quality and leads to a decrease in the number of defects and debris.
The experimental and theoretical studies have produced evidence that enables the efficient operation of mounted-type cleaning machines in the cotton-cleaning industry.
The movements of raw cotton as a viscoelastic body at the free impact of litter with the teeth of the saw against a stationary surface of the grate were investigated; the force schemes between the grates and saws were considered. The effect of a saw-type drum on the technological properties of raw cotton was investigated, namely on seed damage and the formation of the free fiber.
A model of interaction between weed particles and grates was considered; the trajectories of the litter flight were shown in the function of the slope of the grate and the recovery factor.
The issues of the relationship between the physical-mechanical properties of raw cotton, the elastic characteristics of raw cotton, and the impact force of cotton flies against the grate with a flat working face. Solving these issues could make it possible to determine the optimal structure of the raw cotton cleaning mechanisms, which would improve the effectiveness of cleaning raw cotton from weeds.
Based on the identified functional links, it has become possible to construct new or improve existing structures of the saw-type grate section of mounted cleaners. Practical experience shows that the use of the designed structure in large litter cleaners of the mounted type produces a significant increase in the cleaning effect of the machine
Improving energy efficiency of the systems for obtaining water from atmospheric air
Authors: Bilenko Nataliia , Titlov Oleksandr
Published: May 2021

This paper outlines the prospect of obtaining water from atmospheric air by cooling it to the dew point temperature using refrigeration machines in order to partially reduce water scarcity in the arid regions of our planet. To minimize energy costs in the systems for obtaining water from atmospheric air, it is proposed to utilize solar energy with absorption refrigeration units (ARUs) acting as a source of artificial cold.
The characteristic thermodynamic processes have been analyzed in a modernized ARU, capable of working at a lower thermal energy source's temperature than its analogs. The possibility has been studied to reduce the temperature of the heat source by including a solution vaporizer in the ARU scheme. The analysis involved an authentic method based on the balance of specific streams of ARU working body components and actual boundary conditions at characteristic points of the cycle. A limit was shown for the level of a minimum boiling temperature in the ARU generator (from 90 °C) when the systems for obtaining water from atmospheric air are operated under current climatic conditions.
The simulation of heat-and-mass exchange processes during contact interaction between a steam-gas mixture and ammonia water solution was carried out.
Based on variant calculations, it has been shown that the proposed ARU structure with an adiabatic solution vaporizer could work as part of systems to obtain water from atmospheric air at a hot spring temperature above 100 °C and constructively enough fits into the element base of standard models.
It has been proposed to use two types of solar thermal energy sources to operate ARU. In a tropical climate, with vacuum solar collectors or solar energy hubs; in a temperate climate zone, with solar collectors with water as a heat carrier
Software implemented fault diagnosis of natural gas pumping unit based on feedforward neural network
Authors: Kozlenko Mykola , Zamikhovska Olena , Zamikhovskyi Leonid
Published: May 2021

In recent years, more and more attention has been paid to the use of artificial neural networks (ANN) for the diagnostics of gas pumping units (GPU). Usually, ANN training is carried out on GPU workflow models, and generated sets of diagnostic data are used to simulate defect conditions. At the same time, the results obtained do not allow assessing the real state of the GPU. It is proposed to use the characteristics of the acoustic and vibration processes of the GPU as the input data of the ANN.
A descriptive statistical analysis of real vibration and acoustic processes generated by the operation of the GPU type GTK-25-i (Nuovo Pignone, Italy) was carried out. The formation of batches of diagnostic features arriving at the input of the ANN was carried out. Diagnostic features are the five maximum amplitude components of the acoustic and vibration signals, as well as the value of the standard deviation for each sample. Diagnostic features are calculated directly in the ANN input data pipeline in real time for three technical states of the GPU.
Using the frameworks TensorFlow, Keras, NumPy, pandas, in the Python 3 programming language, an architecture was developed for a deep fully connected feedforward ANN, trained on the backpropagation algorithm.
The results of training and testing the developed ANN are presented. During testing, it was found that the signal classification precision for the “nominal” state of all 1,475 signal samples is 1.0000, for the “current” state, precision equals 0.9853, and for the “defective” state, precision is 0.9091.
The use of the developed ANN makes it possible to classify the technical states of the GPU with an accuracy sufficient for practical use, which will prevent the occurrence of GPU failures. ANN can be used to diagnose GPU of any type and power
Improving a method for selecting information technology services
Authors: Рetrychenko Aleksandr , Levykin Ihor , Iuriev Ivan
Published: May 2021

The main purpose of modern information systems (IS) is to support the procedures of controlling many business processes (BP) of an enterprise. At the same time, due to a weak formalization of BP, processes of development, reengineering of various service-oriented IS and IT services are a complex problem.
To address this problem, the task to improve the method for choosing IT services that meet an assigned set of functional and non-functional limitations was stated. The specific features of the original method for choosing IT services were analyzed, its main shortcomings were identified. The model of the BP precedent was modified to establish the relationship between descriptions of the precedent, functional requirements, and the used IT services. The method for selecting IT services for the IS was improved by adding the functions of requirements analysis and searching for descriptions of IT services that partially meet the stated functional requirements. In the method, the adaptive linear associator of the mADALIN neuron was used to quantify the degree of match of the functional requirement and the description of the function of the IT service. These proposals were the basis for the improved method for selecting the IT service that best fits the set of constraints that are formed.
Based on the result of the conducted research, an experimental test of the improved method for selecting an IT service to solve the problem of automation of the activities of sale force of the electronic policy OSAGO was carried out. The information technology implementing the original method for choosing IT services was compared to the improved method. It was shown that the improved method makes it possible to identify situations of a match of functional requirements of a customer and the descriptions of IT services. This makes it possible to select those IT services that match the functional requirements to a degree above the assigned minimum limit
Development of the design and determination of mode characteristics of block cryoconcentrators for pomegranate juice
Authors: Burdo Oleg , Bezbakh Igor , Zykov Aleksandr , Fatieieva Yana , Pour Davar Rostami , Osadchuk Petr , Mazurenko Igor , Zhengzheng Shao , Phylipova Lyudmila
Published: May 2021

The designs of cryoconcentrators of block type BV-2 and BL-20 have been developed. The influence of design and operating parameters on the kinetics of freezing of pomegranate juice was investigated.
A decrease in the operating temperature of the refrigeration unit contributes to a more intensive growth of the ice block. When the temperature of the coolant decreases by 1.2 times, the productivity of the BV-2 unit increases by 27 %, and of the BL-20 unit by 12 %. For BL-20, an increase in the initial concentration by 3 times leads to a decrease in productivity by 2.5...1.5 times.
The influence of the temperature of the coolant and the initial concentration of the juice on the rate of concentration change has been determined. At low initial concentrations of solutions (10...15 %), a sharp increase in concentration is observed at the final stage of freezing. The dry matter content of the juice is increased by 16 % at high concentrations, only 4 %.
The kinetics of the ice block separation process has been studied. At the first stage (duration 10...15 minutes), the concentration of effluents is 2...3 % higher than the concentration of the solution. On the second, increases by 6...10 %. In the third stage, there is a monotonous decrease in effluent concentration (2.5 % / hour).
The results of experimental modeling are generalized. The obtained equation in similarity numbers allows calculating the mass transfer coefficients with an error of no more than 20 %.
The developed designs of the BL-20 and BV-2 cryoconcentrators are semi-industrial units. With block cryoconcentration, a concentration of pomegranate juice of 47° Brix was achieved, which is higher than in traditional devices. The results obtained can be applied for further development and creation of industrial plants with optimal improved product parameters.
Development of iron-containing sorption materials for water purification from arsenic compounds
Authors: Litynska Marta , Dontsova Tetiana , Yanushevska Olena , Tarabaka Volodymyr
Published: May 2021

The paper is devoted to the development of a method for obtaining and using iron-containing sorption materials for the effective removal of arsenic compounds of different oxidation states from an aqueous medium. It is known that arsenic compounds have a harmful effect on biota due to high toxicity. The paper theoretically and experimentally substantiates the choice of iron-containing materials as the main sorbent material for arsenic compounds removal from the aqueous medium. A series of iron-containing adsorbents, including powder, activated carbon-based granular and suspension sorbents, was synthesized by different methods (heterogeneous and homogeneous precipitation). Experimental studies have confirmed that the adsorption of arsenate ions on iron-containing sorption materials corresponds to the pseudo-second order of the reaction (R2=0.999), which is inherent in adsorption processes. It was determined that oxyhydroxide sorption materials obtained by the homogeneous precipitation demonstrate higher sorption activity (up to 70 mg/g for As(III) and over 70 mg/g for As(V)). It was found that activated carbon-based iron-containing sorption materials showed approximately 2 times lower efficiency than powder iron(III) oxide, iron(III) oxyhydroxide and amorphous iron(III) hydroxide. It was shown that the use of microfiltration membranes is promising for the removal of spent suspension iron-containing sorption materials. Experimental studies have confirmed that the use of the combination “fine-particle iron(III) oxyhydroxide/membrane” allows removing arsenic compounds from contaminated water to the sanitary requirements level (less than 10 μg As/l) and separating effectively the spent fine-particle sorbent from water