bluuebunny/crossref_metadata_2025 huggingface dataset:
Re-interpretation of distribution of Lautan Pasir caldera-forming eruption products, Bromo-Tengger Caldera Complex, East Java
Authors: Gunawan R M P P , Ikhwanushova G , Harijoko A , Wibowo H E , Setianto A
Published: October 2021

We present the result of morphostratigraphic analysis and geological field observation to identify the distribution of scoria flow deposit related to the caldera-forming eruption of Lautan Pasir caldera as the youngest caldera in Bromo-Tengger caldera complex. Morphostratigraphic analysis derived from digital elevation model and volcanic stratigraphy shows that products of Lautan Pasir caldera-forming eruption(s) mainly distributed to the north filled up the Sapikerep valley, and further to the north formed Sukapura distal fan. While to the south, it filled the valley between Ijo and Old Semeru. Field observation in the deeply dissected part of Sapikerep valley found two massive pyroclastic flow deposits separated by lava flow. Above the lava flow is scoria rich pyroclastic flow deposit typical of Lautan Pasir caldera-forming eruptions. Below the lava flow is scoria poor pyroclastic deposit of older products, most likely, of Ngadisari caldera. The distribution of Ngadisari caldera-forming eruption products is very limited considering the following massive volcanism of Lautan Pasir caldera. This outcrop might provide the key information to further reconstruct the volcanism stage of Bromo-Tengger caldera complex
Effect of power plant operating conditions on fly ash and bottom ash composition: a case study from power plant in Lampung
Authors: Besari D A A , Anggara F , Petrus H T B M , Astuti W. , Husnah W.A.
Published: October 2021

Fly ash and Bottom ash (FA-BA) are solid waste produced from the coal-generated power plant. FA consists of fine powder particles with diameters varying from 0.5-100 µm, while BA consists of coarser particles with a diameter of 0.125-2 mm. FABA and feed coal samples were collected from the power plant in Lampung to distinguish the effect of power plant operating conditions on FABA composition. Feed coal characteristics were examined by proximate and petrography analysis. Organic and inorganic components of FABA were identified using petrography analysis, while the detailed mineralogical composition of FABA was determined using X-Ray diffraction analysis. Moreover, major oxides of the feed coal and FABA were determined using inductive ICP-AES. From the analysis, it was found that FA composition is mainly organic material in the form of unburned carbon (UC). The abundance of UC content (up to 74.68%) indicates the inefficiency of the coal combustion process. In terms of inorganic, quartz is the most abundant mineral found in the FABA sample, up to 50.15%, in contrast to the glass content that was only 17.41%. A minor amount of spinel (0.03-2.00%) was found associated with Fe-oxide mineral. Kaolinite was only found in the BA sample from a landfill source and interpreted as external input from the dumping ground. The high content of UC and quartz will decrease the compressive strength of the material construction product providing a negative impact on the utilization of FABA.
The potential of lithium enrichment in Lapindo Brantas, Mount Anyar, and Buncitan Mud Volcanoes, Sidoarjo District, East Java Province
Authors: Sari N A , Warmada I W , Anggara F
Published: October 2021

Lithium is an alkaline, metallic element found primarily in the earth’s crust and seawater. Recently, the industry’s need, especially lithium batteries, has been increasing. Lithium exploration is directed to various geological environments that have the potential to contain lithium. Based on previous research, mud products from mud volcanoes can contain lithium. We conducted this research to determine the potential for lithium enrichment found in mud produced by mud volcanoes in Lapindo, Mount Anyar, and Buncitan. Samples were prepared to analyze petrography, X-ray diffraction (XRD), ICP-MS, and ICP-AES. Mineralogically, the mud sample comprises smectite, kaolinite, quartz, plagioclase, clinopyroxene, calcite, pyrite, and dolomite. Lithium in the mud sample has an average concentration of 92.5 ppm with the highest concentration of 130 ppm from the Lapindo Mud volcano. The lowest concentration of 70 ppm comes from the Buncitan Mud Volcano sample. Based on its mineralogy and structure, the dominant of smectite and kaolinite clay minerals can bind the lithium. Lithium in the study area is thought to come from altered rocks below the surface, which migrate and are bound to clay minerals predominantly found in subsurface mud.
Ore characterization of LSE gold deposit in “X” Pit, Toka Tindung Project, North Sulawesi
Authors: Raharjanti N A , Warmada I W , Petrus H T B M
Published: October 2021

Toka Tindung Project is a low sulphidation epithermal gold deposit, which is located in North Sulawesi, Indonesia. To be able to maximize the production yield of the Toka Tin-dung Project, it is important to understand the characteristics of the ore along with its mineral associations. This paper discusses the ore characterization and its mineral associations in “X” pit using thin section analysis to define the rock characteristics and hydrothermal alteration, X-Ray Diffraction (XRD) to identify the hydrothermal alteration minerals, and ore microscopy to identify the type of ore minerals. The study area is occupied by three alteration zones, namely silicification, advanced argillic and intermediate argillic alteration. The silicification is characterized by quartz with accessory minerals such as kaolinite, smectite, and celadonite. The advanced argillic alteration is typified by kaolinite, with minor quartz. The intermediate argillic alteration is characterized by clay minerals such as illite, mixed illite/smectite, smectite, and minor quartz minerals. Mineralization in “X” pit is in the form of sheeted vein type quartz with colloform texture, and the ore minerals are found as sulfides such as pyrite and sphalerite.
Ore mineralogy of podiform-type chromite deposit in Tedubara area and its vicinity, Kabaena Island, Indonesia
Authors: Septiana S , Idrus A , Zaccarini F , Garuti G , Setijadji L D
Published: October 2021

Kabaena Island is one of the areas in Southeast Sulawesi that has the potential for chromite deposits. This paper is aimed to provide information on the mineralogical aspects of chromitite from the research area. Back-scattered electron (BSE) imaging and chemical analysis of chromite were performed using an electron microprobe. Chromite deposits in the study area are of podiform-type. Chromite is massive and brecciated. Based on the content of Cr # = Cr/(Cr + Fe3+) of the chromite, comprised between 0.61 and 0.74, the studied chromitite can be classified as Cr-rich. The only PGM (Platinum Group Minerals) found in several chromitite samples is laurite (RuS2). PGM occurs enclosed in chromite crystals and in the contact with microfractures of chromite crystals.
SEM-EDS imaging of multi-stage cleat minerals formation in the South Walker Creek Coals, Bowen Basin
Authors: Permana A K , Ward C R
Published: October 2021

The South Walker Creek coals are moderately to highly developed fracture systems. These fractures can be recognized from the top to the bottom of the seam, with both open and closed apertures. They are filled with several different minerals, occurs either as single-phase infillings (monomineralic), or as mixed mineral deposits (polymineralic). This paper presents scanning electron microscope (SEM) analysis of mineralogical association within coals fractures or cleats, as well as their origin and phase of development. SEM-EDS analysis indicates that the polymineralic cleats seem to be more common in the coal seam compared to monomineralic cleats. The polymineralic cleat infillings are composed of clay minerals, carbonates, and other minerals, such rutile and apatite, with minor occurrences of diaspore. This polymineralic association within the single cleat spaces represents a multi-phase minerals formation, as a result of different stages of epigenetic activity. The hydrothermal fluid circulation are responsible for this epigenetic process, they are re-opened previous minerals filled cleats and transformed pre-existing mineral within the cleats, and/or to remobilization earlier minerals, which then precipitated in the cleat as epigenetic minerals.
The testing of Qp and QsQp equation in Kujung I Formation, East Java, Indonesia
Authors: Sadat A , Haris A , Haryono  , Dharmawan G A
Published: October 2021

Hydrocarbon-bearing reservoir shows attenuation on seismic section, but the use of attenuation in hydrocarbon exploration is less popular than other attributes. This is due to the sophisticated and advanced technology required to measure attenuation. Meanwhile, some studies were designed to estimate attenuation by formulating rock quality factor equations from a wire-line log, although others run on sandstone samples. Therefore, this study aims to estimate rock quality factors in carbonate rock of Kujung Formation using three different methods, discriminate hydrocarbon-bearing reservoir, and identifying the impact of carbonate facies. The results showed the P-wave quality factor method is sensitive to discriminate high gas saturation on facies A. Meanwhile, the QsQp ratio is sensitive to discriminate shale and carbonate. The SQp and SQs methods are sensitive to discriminate hydrocarbon-bearing reservoirs and less affected by carbonate facies. The novelty of this is to estimate the rock quality factor from various methods and identify the impact of facies in hydrocarbon identification, especially for carbonate reservoirs in Northeast Java Basin. Therefore, a new understanding of facies impact on rock quality factor contributes to choosing the best methods in discriminating pore-filling fluid identification.
Method for Assessing the Environmental and Social Risks of Unauthorized Landfill Sites
Authors: Kirilchuk I O , Iordanova A V , Balaban D V
Published: October 2021

The problem of production and consumer waste generation is one of the main environmental issues of industrial society. However, the main method of waste disposal in Russia is still its landfilling at waste disposal facilities (landfill deposits, authorized and unauthorized dumps). A separate group of waste disposal facilities consists of illegal unauthorized landfill sites with solid municipal waste. The specificity of these waste disposal facilities is the complexity of monitoring of their formation and the difficulty of assessing their impact on the environment and public health. At present, there is no standard approved methodology for assessing the environmental and social risks of illegal unauthorized landfill sites. For that purpose, the authors have developed a method for assessing the hazards of unauthorized landfill sites, based on comparing the actual characteristics of landfills obtained during field surveys of urban areas with certain tabular values. Initial keeping track of landfill sites is fulfilled with the application of a web portal that implements geoinformational technologies. The use of the web portal for rapid detection of illegal unauthorized landfill sites, as well as the author’s method and soft-ware that implements this method allows for rapid assessment of the environmental and social hazard of landfills based on data from field surveys of urban areas without laboratory measurements. The results obtained are intended for the classification of illegal landfill sites in order to develop plans for their elimination, taking into account the priorities of environmental policy.
Mathematical methods for solving problems of electrodynamics in a layered environment
Authors: Kogay G D , Tyo A L , Drozd V G , Ten T L , Omarova S E , Ivanov V L , Ayazhanov K S
Published: October 2021

The article considers methods for solving applied problems of electrodynamics in the case of layered and vertically inhomogeneous environments. This article suggests the algorithms of primary processing of GPR data. GPR data at a fixed observation point are investigated via the “selecting” method. The analysis of the frequency response of the signal energy distribution by frequency components is being processed. We proposed software implementation for determining the depth of objects and the relative dielectric permittivity of the subsurface environment. To perform this task, we use a module to determine the depth and conductivity of subsurface objects. The computational part was performed by the computationally common method of the approximate solution. As a result of the research, we have developed numerical methods for solving direct electrodynamics problems.
Emission of soot particles from the combustion of various fuels in boilers
Authors: Lyubov V K , Popov A N , Popova E I
Published: October 2021

According to modern estimates, the largest contribution to global warming is made by carbon dioxide, while its share is 60-70%. However, studies of the last decade also indicate a large impact on the planet’s climate of “short-lived climate pollutants”, which mean forcing substances with “lifetimes” in the atmosphere from several days to several years. These pollutants include black carbon. In the Russian Federation, black carbon refers to the substance “carbon (soot)”, which is a dispersed carbon product of incomplete combustion or thermal decomposition of hydrocarbons, consisting of particles of various shapes and having a black color. Soot is a strong carcinogen. It is the 2ndclass harmful substance and carried by winds for thousands of kilometres. It has been found that black carbon retains several hundred times more heat than carbon dioxide does. Therefore, reducing black carbon emissions is one of the most important challenges in the fight against climate change. Therefore, the task arises of a comprehensive study of all aspects related to black carbon emissions. Based on this, experimental studies of the emissions of soot particles formed in the combustion chambers of boilers of various capacities and designs were carried out during the combustion of various solid, liquid and gaseous fuels. The structure, size and quantitative composition of soot particles, as well as their constituent elements, were studied using scanning electron microscopy. The research results made it possible to propose a more extended approach for choosing the values of specific soot emissions from the combustion of various fuels in heat generators, which should be used in the inventory of emissions of this pollutant.
The influence of agroecological factors on diseases development and wheat productivity
Authors: Kolesnikov L E , Kremenevskaya M I , Melnikov S P , Tambulatova E V , Hassan B A , Kolesnikova Yu R
Published: October 2021

In the research, long-term data characterizing the wheat productivity and degree of its affection by diseases were compared with the natural and climatic factors of the NorthWestern region of the Russian Federation. The comparative analysis of the protein growth stimulant (PGS) and organomineral fertilizers’ influence on productivity, yield structure, and disease resistance of the VIR soft wheat was carried out. The greatest influence on the potential (estimated) wheat yield growth was exerted by the preparations “Zerebra agro” and “Edagum”. Foliar spraying with the protein growth stimulant resulted in an increase in wheat yield by 31.5% compared to the control. After applying the protein stimulant, a decrease in the degree of wheat powdery mildew development by 15.7% was revealed compared with the control. Organo-mineral fertilizers had insignificant effects on the disease development. The “Zerebra agro” preparation had high biological effectiveness against wheat leaf diseases (brown rust, powdery mildew).
Experimental studies of the thermal state of heat storage units of electro thermal storage
Authors: Khimenko A V , Tikhomirov D A , Kuzmichev A V , Trunov S S
Published: October 2021

Experimental data on the behavior of the following thermal parameters of heat storage units made of magnesite and chamotte of electro-thermal storages (ETS) has been obtained: wall temperature change of air channels of heat storage units, temperature change of heated air in channels of heat storage, temperature change in the bulk of thermal insulation, for one cycle of heat charging and heat emission of ETS. After analyzing the obtained temperature distribution in the wall of channels of the heat storage units, it can be concluded that the heating rate of the heat storage units made of chamotte is higher during almost the entire charging mode of ETS compared to the units made of magnesite. In the heat emission mode, the cooling rate is significantly higher for chamotte units compared to a lower cooling rate for magnesite heat storage units.
Study of the antioxidant properties of some aromatic plant extracts
Authors: Suchkova E P , Hussaineh R
Published: October 2021

In this study the effect of extraction conditions (time - temperature-type of aromatic plants-extraction method) on the antioxidant activity, pH extracts was investigated. The extraction process was carried out using water as a solvent, and also through using the ultrasonic treatment. Aromatic plants that have been used are rosemary, a mixture of herbs (black cumin+ oregano). The extracts were prepared by the solvent extraction method, and the ultrasonic treatment was under the following conditions: time - (10-20-30 min), temperature - (40-60-80°C ), then pH extracts were estimated using pH meter, and the antioxidant activity of all extracts was determined by scavenging of DPPH (1,1-diphenyl 2-picrylhydrazyl) radicals. The results have showed that the values of pH extracts increase in the use of ultrasonic treatment. Also it was revealed that the highest value of antioxidant activity (95.43 %) was when extracts were obtained from rosemary using ultrasonic treatment according to the following parameters: (60 °C, 30 min). Therefore, these conditions could be applied for further extraction for their use in the preparation of medicinal products or functional food.
Life cycle assessment of the functional nutrition in the context of the circular economy
Authors: Savoskula V A , Pavlova A S , Plotnikova P A , Daniluk M A
Published: October 2021

In accordance with the principles of sustainable development, all production wastes should be considered as sources of raw materials for other production. Whey in Russia was previously discarded with wastewater, but after studying its properties, it turned out that it has great potential for the production of protein-enriched products. And in order to further reduce the environmental impact, a milk protein life cycle assessment has been carried out. The article presents the results of the study of this assessment. The analysis was carried out for such indicators of the category as global warming potential, total emissions of substances that contribute to ozone formation, total emissions of acidifying compounds, potential for eutrophication, consumption of abiotic resources, consumption of biotic resources, water consumption, air consumption. The categories of impacts that make the greatest contribution to environmental pollution and resource consumption are identified, namely, total emissions of substances that contribute to ozone formation by categories of output flows and water consumption by categories of input flows. Recommendations was given to reduce the impact.
Optimization of the proteolysis process of connective tissue proteins in ostrich meat
Authors: Rogozina E A , Kolodyaznaya V S , Shestopalova I A , Kiprushkina E I , Rumiantceva O N , Broyko Y B
Published: October 2021

A promising area of research for the development of functional food products of mass consumption is the use of non-traditional sources of raw meat of domestic production, including ostrich meat, which has a high nutritional and biological value. However, ostrich meat is characterized by an increased content of connective tissue, which causes its rigidity. The use of proteolytic enzymes will increase the functional and technological properties of meat and the assimilation of hard-to-digest proteins, in particular collagen. The aim of the study is to optimize the technological parameters of biomodification of the properties of ostrich meat raw materials using collagenase The object of the study is the meat of the femoral part of an ostrich grown on the territory of the Leningrad region. To optimize the technological parameters of minced meat fermentation, the fractional replica method was used to study the effect of three factors on the response functions: the mass fraction of collagenase (C, encoded variable X1), the duration (τ, encoded variable X2), and the temperature of minced meat aging (t, encoded variable X3). The response functions are the values of the moisture-holding capacity (Y1) and the content of amine nitrogen (Y2). The regression equations describing the dependence of the response functions on the factors under study have been compiled. The technological parameters of the fermentation of minced meat based on ostrich meat with the use of collagenase have been optimized: the mass fraction of the enzyme is 0.05%, the holding time of the minced meat is 4.5 hours at t=13ºC, allowing one to obtain minced meat with high organoleptic characteristics and functional and technological properties.
The use of solid household waste as fuel in the housing and utilities sector
Authors: Golobokov S V , Lesin I A , Tichomirova A A , Chukareva M M
Published: October 2021

The development of civilization is accompanied by a steady increase in the amount of waste and industrial production. Improvement of technology and production technology increases the variety of chemical compounds and their danger to the environment. The problem of processing and disposal of solid household waste (SHW) is becoming more and more urgent not only for megacities, but also for small settlements. The vast majority of solid waste in our country is stored in natural or specially organized landfills. Landfills of solid waste without preliminary processing occupy huge territories, thus removing fertile lands from economic circulation for many decades. Landfills are characterized by a high concentration of carbonaceous materials. For various reasons, fires often occur, as a result of which the products of incomplete combustion pollute the environment. Solid waste landfills are a source of pollution of surface and ground waters due to the drainage of landfills with atmospheric precipitation. In addition, landfills are home to stray animals, rats, mice, birds, insects and parasites. All of them are the cause of the spread of viruses. Because of this, there is a danger of the spread of infectious diseases [1]. In order to reduce the volume of solid waste, harmful emissions into the atmosphere, the number of rodents and birds, and put an effective barrier to the spread of various infections, it is necessary to improve the production and put the project of a mini-plant for processing solid household waste into operation. Thus, the work considers a technological scheme and a set of equipment for processing solid household waste into gas fuel. Calculations of technical and economic indicators are given.
Analysis of the energy efficiency of air conditioning systems based on the outdoor climate statistical model
Authors: Salman A S , Sulin A B , Lysev V I , Nikitina V A
Published: October 2021

The analysis of outdoor climate normative information, given in the form of calculated parameters of outdoor air for warm and cold periods of the year, is given. The requirements to the form of presentation of climatic information and to its content are formulated. The information is presented in the form of tables of recurrence of outdoor parameters in two-dimensional intervals for different cities of the Russian Federation and the capital of Iraq, Baghdad. It is shown that the information in the form of these tables can be used for the tasks indicated in the article at the stage of conceptual design of air conditioning system. The results of approbation of the considered form of climate information implemented at practical tasks are demonstrated. Among these results, we should pay special attention to dependence of installation capacities of subsystems on the time of non-availability of the rated parameters of the air environment in a room. Moreover, it is shown by the example that information about heat, cold, air, and water consumption by heat and humidity treatment in air conditioning systems can be determined for various calculated periods of time. The results were obtained using an applied computer program that executes the recommended form of presentation of climate information for the design of air conditioning systems.
Assessment of heavy metals pollution level in sludge pit
Authors: Avdeeva I I , Romantsov I I , Romanenko S V , Nekhorosheva A V
Published: October 2021

The spatial analysis data of the concentration fields of lead (Pb) and cadmium (Cd) is presented. The depth-areal heterogeneities of the metals distribution in the sludge pit of the well cluster within the territory of the Khanty-Mansi Autonomous Okrug-Yugra are revealed. The highest concentrations of heavy metals were observed in the places where drilling waste was discharged into a sludge pit through a sludge pipeline. The concentrations gradually decreased with distance from the discharge points.
Reduction in heat losses during room heating
Authors: Turkenicheva O A , Turkenicheva L A , Evstratov V A , Makovetskaya A V
Published: October 2021

Today heating devices in most cases are located in window niche in order to save space in a room and improve its interior. However, this leads to unnecessary heat loss. The paper provides a comparative analysis of the dependence of heat losses on the location of heating devices in a room. A comparative analysis of various energy-saving measures for the value of heat losses during heating of buildings is carried out. The influence of heat-reflecting screens and false fronts on heating efficiency is considered. The dependence of heat losses on the temperature difference inside and outside a room is shown.
Kinematics of the transmission gear mechanism for roller machines with different diameters of drive shaft
Authors: Abdukarimov A , Abdullajonov A , Abdukarimov A
Published: October 2021

The article describes the arrangement, principle of operation and kinematic analysis of a ten-link gear-lever differential transmission mechanism with a parallelogram lever contour for roller machines with different diameters of the working shafts. The purpose of the kinematic analysis of the transmission mechanism is to determine the velocities and accelerations of the mechanism links, the gear ratio of the mechanism, and to show the constancy of the gear ratio of the transmission mechanism when the center distance of the driving and driven tooth gears changes. An important condition for the normal operation of roller machines with different diameters of the working shafts is the coincidence of the gear ratio of the working shafts and the gear ratio of the transmission mechanism between these shafts. Initially, the kinematics of the mechanism was performed using the analytical method. In the analytical study of the mechanism, the centroid method was used. Dependencies for determining the kinematic parameters of the ten-link gear-lever transmission mechanism are derived. The advantages and disadvantages of this method are shown. Further, to compare the results of the study, the kinematics of the mechanism is performed by the graphic-analytical method. The method developed by the authors was used in the graphic-analytical study.
Monitoring console using Virtual Reality for automotive industry
Authors: Belu N , Ionescu L M , Nitu E L , Mazare A G
Published: October 2021

One of the technologies used in Industry 4.0 is virtual reality and augmented reality in the industrial applications. These technologies allow: the introduction of the operator in the production process with minimal risk, in the training process (learn manufacturing), the realization of maintenance works with a much more detailed vision of the equipment and the process, the realization of consoles to monitor the manufacturing process and equipment with extended facilities compared to any type of console that has been used before. In this paper we will present an example of a monitoring console using virtual reality. As we will show, the virtual environment accessible through the virtual reality headset can be used as a console with an extended viewing angle in which indicators on the status of the monitored process can be displayed. The indicated values come from IoT equipment with current sensors and temperature sensors. Also, by navigating, using teleport tool, in the virtual environment you can get an overview from several angles of the monitored equipment (in our case a chassis welding workstation) with minimal risk. The environment contains both a modeled image (a 3D sketch of the equipment) and real images of the equipment captured through industrial cameras placed next to the real equipment. In the virtual environment the two “live” video streams are displayed as 2D screens. With this modern monitoring tool, the work standards will be developed that the operator can use in training and in the work process. The system presented in the paper is implemented with an Ocululs Rift kit with headset and touch consoles for capturing the movements of operators and their contacts with virtual objects. The virtual environment is fully implemented using Unity. The system will model workstation for chassis welding. Two IoT devices will be used: one with temperature sensor and the other with current sensor. Two industrial video cameras whit high resolution will also be used to capture images from the workstation. As a result, along with the presentation of the functional system will be presented a model of operational standard made by captures from Unity when exploring the virtual environment.
The possibility of physical implementation of active vibration reduction
Authors: Białas K
Published: October 2021

This work presents non-classical method of design of mechanic systems with subsystem reducing vibrations. The purpose of this paper is also introduces synthesis of mechanic system with reducing vibrations understand as design of this type of systems. This work presents method of reduction unwanted vibration by using mechanical elements, electrical elements, magnetorheological damper ect. The use of such a method enables the analysis and synthesis of mechanical systems irrespective of the type and number of the elements of such a system. The purpose of this paper is also introduces synthesis of mechanical system which is the reverse task of dynamics. The result of synthesis is obtaining system meeting the defined requirements. The system was consisted from mechanical elements and sub-system realized by many types of elements. This subsystem is an active or semiactive subsystem which enables overcoming limitations which occur if passive elements are used. The majority of vibration occurring in devices and machines is harmful and has a disadvantageous effect on their condition. Harmful impact of vibration is caused by the occurrence of increased stresses and the loss of energy, which results in faster wear machinery. Introduced in this work approach adopted makes it possible to undertake actions aiming at the elimination of phenomena resulting in the unwanted operation of machinery or generation of hazardous situations in the machinery environment. Thank to the approach, can be conducted as early as during the designing of future functions of the system as well as during the construction of the system.
Research regarding strip cladding of heat-resistant SA 387 Gr.11Cl.2 steel type
Authors: Bogatu A M , Rontescu C , Diacu R C , Cicic D-T
Published: October 2021

The continuous development of industrial processes in the petrochemical field requires the use of materials with anticorrosive properties, able to withstand working conditions at high temperatures but also in highly corrosive environments. The basic materials with anticorrosive properties have a high cost price which leads to the need to find alternative manufacturing solutions. In such situations, the use of bimetal plates or the option of welding cladding with an anticorrosive layer of the base material is used. The paper analyses the possibility of strip cladding using the submerged arc welding process of a reactor made of SA 387Gr11Cl.2 basic material, a heat-resistant alloy steel. To achieve the deposition of the appropriate anticorrosive layer (stainless steel type AISI 347) it was necessary to use a buffer layer made of austenitic stainless-steel type 309L. In order to eliminate the internal tensions appeared after the cladding process, the sample was subjected to a stress relieving heat treatment. After the heat treatment, the sample was subjected to non-destructive examinations (visual and penetrant testing) but also to destructive examinations specific to the approval tests of cladding technology (Metallographic tests, Vickers hardness test, bend test, ferrite number, chemical composition). Metallographic tests of cross-sectional phase structures were carried out in macroscopic and microscopic terms. In the area of the deposited material can be observed a typical austenitic casting structure resulting from the use of a high linear energy, specific to the automatic submerged arc welding. Following the performance of hardness measurements made in the characteristic areas of the deposition, it can be seen that there was a slight increase in the values obtained in the heat affected zone, without exceeding the prescribed values for the materials used. Following the analysis of the results obtained from the specific examinations and tests to the plated samples, it can be seen that they are within the limits prescribed by the standards in force regarding the approval of the cladding technology used.
Drag Based Wind Turbine Lenz Type Manufacturing and Assembly
Authors: Bucur I O , Malael I , Duran B , Preda D
Published: October 2021

Due to the current technological evolution trend, the use of renewable energies seems to be the best suited solution for the environment protection against pollution. This paper aims to present the methodology used for the manufacturing and assembling processes of a drag based vertical axis wind turbine, the steps for both processes being addressed broadly. The manufactured vertical axis wind turbine can successfully function in wind conditions with speeds of up to 16m/s and manages to provide up to 5kW of power. The manufacturing materials used for the execution of the blades include metal sheets, mounted on a structural frame for better stiffness. The wind turbine rotor is comprised of three blades, that are installed on a shaft connected to a gear box which will transfer the torque to the permanent magnet generator. The whole process is described in the paper and the result consists of the installed turbine, that is ready to function in real environment operating conditions. The work carried out within this paper is relevant to the general know-how regarding wind turbine manufacturing and installation, as the authors highlight the main impediments they had to overcome when developing, executing and installing the described model.
Study on the Kinetics of the Chemical Vapor Deposition Process for the Coating of Carbon Fibers from the Structure of Composites Materials with Metal and Non-Metal Matrix
Authors: Caliman R
Published: October 2021

In order to keep the fibers intact during processing and to produce the desired surface properties, the process by which the composite material is manufactured almost always comprises a process by which the fiber is coated. The coating protects the fiber during the operation in which the fiber is combined with the matrix. Simultaneously, the wetting and binding of the fiber with the matrix is favored; In some cases, the coating is a sacrificial layer, which is destroyed during processing. In general, the structure, composition and morphology of the coating affect the strength of the composite after manufacture. Thus, the Chemical Vapor Deposition (CVD) process and its variants are used for fiber coating. The reaction products diffuse to the surface, producing surface reactions, which lead to the formation of a deposit on the surface of the fiber. The limiting factor in the deposition process may be the reaction kinetics or the diffusion of vapor species to the surface.
On the long-term hydroelastic global structural response evaluation of a 100000 tdw oil-tanker
Authors: Domnisoru L
Published: October 2021

In this paper, the hydroelastic analysis for a 100000 tdw oil-tanker, with a length of 240 m, operation reference speed of 15 knots, on two loading cases full cargo and ballast, is developed. For a realistic approach of the dynamic response, the oil-tanker is considered under random waves’ loads, requiring several steps in the process of the short-term and long-term global structural analysis. The random waves have Longuet-Higgins formulation, with first-order harmonics by ITTC power density spectrum, with maximum wave significant height 12 m, and second-order interference waves’ harmonics. The short-term hydroelastic analysis includes the linear response by frequency-domain solutions, the non-linear response by time-domain solutions, the global strength significant response by FFT Fast Fourier Transformation spectral approach. The long-term analysis includes the hydroelastic global strength assessment for Word Wide Trade averaged wave’s height histogram, the fatigue hull structure evaluation, over a 25 years exploitation reference time, applying the cumulative damage ratio approach. The stress hot-spot factors, up to 1.5, influence is considered. The oil-tanker model by own program DYN is developed, modules for hydroelastic response and statistical processing, applicable in any ship’s design stage, stressing out to the 100000 tdw oil-tanker long-term operation limits on the two relevant loading cases.
Analysis of defects arising during exploitating of elements of rolling bearings
Authors: Gwiazda A , Topolska S , Rakowska W
Published: October 2021

Bearings are damaged most often as a result of operation under improper lubrication conditions (no correlation between lubricant parameters and operating conditions). this often leads to the operating temperature of the grease being exceeded. Such operating conditions are either the result of the bearing operating under overload conditions (too high load causing the dropping point to be exceeded, leading to lubricant leakage and deterioration of the bearing operating conditions), or the result of improper lubrication of the bearings (application of too little grease and lack of re-lubrication of the bearing or the application of improper grease). The article presents an exemplar analysis of the influence of the exploitation process on their slow degradation.
Determination of Johnson-Cook material constants for Copper using traction tests and inverse identification
Authors: Iordache D M , Oprescu E R , Malea C I , Niţu E L , Crăcănel M O , Bădulescu C
Published: October 2021

Copper and its alloys have specific properties - electrical and thermal conductivity, ductility, mechanical strength, corrosion resistance - which make it a material used in various industrial applications. However, these materials are difficult to weld by conventional processes due to their high thermal conductivity and high rate of oxidation at temperatures close to melting. To be able to join copper-based materials, friction stir welding seems to be a promising possibility. The quality of the assembly obtained strongly depends on the parameters of the process chosen to generate a temperature close to the optimum value. So, to find these parameters, it is necessary to carry out experimental test campaigns which are generally very expensive in terms of time and equipment. An alternative will be to use the numerical simulations of the FSW process to find the optimal parameters. Numerical simulation contributes also to a better understanding of the influence of input parameters on the phenomena in the process and the connections made. To develop a numerical model, it is necessary to use a constitutive equation that defines the behavior of the material throughout the process. The most commonly constitutive equation used for FSW modeling is Johnson-Cook. The paper describes the strategy of identifying the constants of the material, respectively the method of inverse identification of the parameters. The constants of the thermo-mechanical behavior (both elastic and plastic) are identified by coupling the finite element method with Abaqus and Matlab software. This strategy tries to minimize the quadratic deviation between the response of the model and the experimental tests. Tensile tests were carried out on quasi-pure copper CU-DHP samples, at temperatures of 22°C, and 500°C, for speeds of 3 mm/min and 30 mm/min, respectively. The validation of the model thus identified was carried out on tensile tests at a temperature of 300°C, by comparing the curves obtained with the Johnson-Cook model and those obtained experimentally.
Selected methods for material identification on the border of geological layers for the automation of industrial processes of obtaining raw materials
Authors: Kiljan P , Kalinowski K
Published: October 2021

Production plants wishing to become competitive on the local and global market should offer their products at the lowest possible price and, at the same time, in the highest possible quality. One of the key tasks for the engineering and technical staff working on them is improving the organization of work and the degree of use of means of production, allowing to increase work efficiency. The latest technological achievements focused on the concept of the Industry 4.0 create new opportunities for further improvement of production processes, their optimization, reduction of costs, or reduction of the nuisance of physical work and mental effort of employees. Many industries use both renewable and nonrenewable natural resources available on earth. Acquiring some of them requires considerable resources and is very burdensome for people. Especially regarding resources deep underground. In the near future, we will also use material resources obtained from outside the Earth, which is an additional challenge. Therefore, the integration of the latest technologies, especially in the field of automation and autonomous robots, IoT and Big data is becoming an essential research area.

The paper presents an overview of technological methods and solutions of material identification that can be used in the processes of automated sourcing of materials on an industrial scale. Particular attention was paid to techniques that can be used by specialized, autonomous robots working in conditions that are hard and unsafe for humans. Discussed recognition systems can use advanced methods and the latest technologies. They are most often implemented using special sensors installed on or close to the executive element of a machine. The differences in rocks hardness and compressive strength allowed for the development of methods using acoustic waves and also methods using the measurement of vibration of the cutting tools and machine parts on which they are installed. Another method uses the natural features of rocks adjacent to the seam being extracted - it measures differences in the level of radioactivity. On this basis, a method was developed based on the recognition of low gamma radiation activity. Methods based on the use of radars or thermal imaging cameras testing the temperature of cutting knives installed on the cutting body were also proposed. Another interesting solution is the optical touch sensor that recognizes different types of rock layers. Difficult working conditions, also for machines, in which there is a high concentration of stone dust limiting visibility, the presence of water, and high noise generated by working devices, reveals a number of advantages and disadvantages in the above methods to use them in autonomous, robotic solutions.
Partially autonomous two wheel vehicle for transport of persons at industrial plants – concept of solution
Authors: Malaka J , Gorol A , Nowicki J
Published: October 2021

Within the research, the needs and problems occurring in the movement of the workers at industrial plants were specified and characterised. There were developed concepts of systems necessary for the automatic operation of the vehicle in the manner under consideration. The authors carried out the review and preliminary selection of technical means, used in both manually controlled vehicles and the autonomous ones, possible to adapt in order to implement the proposed solution. The paper considers the principles of the development in transport of persons at industrial plants. The results of the analysis performed are observations and assumptions about the possibility of integrating well-known mobile platform, navigation and power supply in an innovative way. It states the fundamentals for the plan of the future work which leads to actualising the device, including designing, constructing and programming of it.
The effect of appendages on ship resistance
Authors: Mandru A , Pacuraru F
Published: October 2021

The availability of the robust commercial computational fluid dynamics (CFD) software and the increasing power of high-performance computers (HPC) boosts the use of CFD techniques for numerical investigations of ship hydrodynamimcs performaces. Nowadays, CFD tools provide a rather accurate solution for complex physical phenomena, such as wave braking, turbulence, flow detachment and overturning. Consequently, the ability to capture this fenomena allows a detailed insight into the flow mechanism that trigger and sustain them.

The paper focuses on a numerical investigation of flow around hull a fully appended ONR Tumblehome model 5613. Due to special operation conditions, naval ships are equipted with a large number of appendages such as sonar domes, brackets, twin propeller shafts and twin rudders. Position and alignment of these appendages are essential in order to avoid the increased resistance, decreased propulsive efficiency and cavitation. NUMECA/FineMarine commercial code has been used to evaluate the flow field around ONRT (Office of Naval Research Tumblehome) hull and to estimate the effect of the appendages on ship hydrodynamics performances. Comparison with experimental towing tank results showed good agreement with a difference of up to 2%.