bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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%.
The importance of the technical specification of works for the ships repair processes in the maritime shipyards
Authors: Manea M G , Zăgan R , Manea E 
Published: October 2021

Abstract
The technical specification purpose is to include the ship maintenance and improvement works needed to be carried out onboard in a repair shipyard, so that after these works performing to allow for the classification society certification, thus confirming the ship satisfactory technical condition and the relevant requirements of the classification rules were applied, thus confirming the applied management maintenance also. The technical specification has a very important role for the evaluations, done by the shipyard in preparing price and time quotation and the owner / manager, done for the comparison analyzing based on the evidence that the maintenance and improvement workflows performing on board the ship in a shipyard for works depend on the technical specification quality of preparation, which means that had to provide the necessary information in relation to the volume and type of works needed to be carried to the ship hull and structures, machinery, equipment, plants and systems supported by the necessary technical information plans approved by the classification society and the works sheets documentation referring to the followings: work location / equipment thereof number of pieces; types of the works required to be performed on location / equipment; works estimated required to be undertaken on location / equipment. The advantage of a quality technical specification is the limitation of the possibility of ordering additional works during the execution of works for maintenance, upkeeping and improvements on board the shipyard, the costs of the shipyard and the ship being thus maintained at the estimated budgets. The paper purpose is to highlight the advantages of a good quality technical specifications which consists of limiting the possible means of developing additional orders during the execution of maintenance and improvement works on board, thus the shipyard and ship costs being possible to be kept within the original estimated budget margins.
Behavior of Arboblend V2 Nature under AWJ machining
Authors: Marguta D , Herghelegiu E , Tampu C , Mazurchevici S-N , Nedelcu D 
Published: October 2021

Abstract
The harmful effects on the environment caused by the overexploitation of fossil resources and their industrial processing have attracted the attention of researchers worldwide. Their interest is not only in the use of biodegradable materials based on renewable natural resources but also in the use of manufacturing and processing technologies that minimize as much as possible the negative footprint left on the natural ecosystem. In the present paper, the thermoplastic material processed using abrasive water jet cutting technology (AWJ) is Arboblend V2 Nature. Thus, both the processed material and the technology closely follow the interests of the researchers. The study aims to obtain surfaces with higher quality than other synthetic polymers by appropriate variation of process parameters (abrasive material flow, traverse speed and pressure). Two methods for determining the roughness were used, one in accordance with the standard and one adopted by the authors in order to render more accurately the surface roughness value. Other output parameters observed were: the amount of material removed, the width of the machined surface, the deviation from the perpendicularity and the inclination angle of the machined surface. The output parameters result confirms the possibility of using the parts obtained by AWJ in engineering applications and not only because the shape deviations fall within the limitations imposed at the industrial level.
Expanded glass spheres applications for low thermal transfer
Authors: Mocanita O , Chicet D , Istrate B , Raileanu L , Munteanu C 
Published: October 2021

Abstract
This study addresses the possibility of using expanded glass to obtain elements with low thermal transfer and stable from a geometric point of view when exposed to high temperatures, which may later be part of a fire-resistant multi-layer element. For this purpose, three types of recipes were designed and produced, which are composed of expanded foam glass spheres bounded with polymeric resin. Subsequently, 3 sets of each sample were subjected to baking: T1 (heating to 700°C, maintaining for 3 hours, oven cooling); T2 (heating to 600 ° C, maintaining for 3 hours, oven cooling); T3 (heating to 600° C, oven cooling). The 4 sets of samples (1 set in initial state and 3 sets of heat treated samples) were exposed for 1 hour at direct flame. It was found that the samples maintained their structural integrity and all three types of material ensure a temperature difference between the side exposed to temperature and the unexposed side higher than 200°C (considered satisfactory according to SREN 1363-1 / 2001).
Path finding and guidance algorithms for autonomous mobile robots in a tree structure network
Authors: Nanu S , Belgiu G , Dan A-M , Berdich A , Anistoroaei A 
Published: October 2021

Abstract
Considering an autonomous mobile robot that has to navigate indoor and outdoor from a certain point towards another certain point in a tree structure, the paper is giving a solution for finding the path and navigation. The mathematical model is proposed for a number nDP of departure/destination points (DP), a number nIP of intersection points (IP) and connections between them in a tree structure. Based on mathematical model, the problems solved and presented in this paper are i) to find a path from any departure point to any destination point, ii) to generate an algorithm for guidance of an autonomous robot to follow the path. Both algorithms were tested on Matlab Simulink® environment. An implementation of algorithms in a pseudocode is presented. The algorithms were adapted to be implemented on a microcontroller based board. The advantage of algorithms and implementation is simplicity. The outcome is less memory consumption and increased computing and execution speed.
Race car mirror cover production focused on reducing air drag
Authors: Nowak A , Baier A , Kołodziej A , Żur P 
Published: October 2021

Abstract
The paper presents a mirror cover manufacturing process, focused on geometry optimization by reducing air drag for Silesian Greenpower electric car. Silesian Greenpower is a student’s interfaculty project, of which aim is to design, build, and race an electric vehicle. Each car is equipped with the same motor and batteries. Target is to finish as many laps as possible during a set amount of time. Major development takes place in aerodynamics to decrease movement resistance. In the presented development process, computer-aided design software was used to create part concepts and then aerodynamics simulation was carried out to determine quality of each design. The influence of chosen geometric parameters was analysed and discussed in the article. The final concept was manufactured using 3D-printing technology with ABS - acrylonitrile butadiene styrene, because of good mechanical properties but also availability and relatively low cost. 3D˗printed elements were verified experimentally using smoke stream generator.
Application of digital twins in specific manufacturing processes
Authors: Olender-Skóra M 
Published: October 2021

Abstract
Following the requirements of the modern economic environment is a challenge for entrepreneurs. The more, that there is an increasing need to manufacture product for individual customers, the so-called customization approach. As a result, the production is individualized, so that the repeatability of products and stocks is low. This forces companies to apply specific organizational development strategies such as Lean and Agile. It also forces an increase in flexibility of the implementation of individual production tasks of enterprises. Increased production flexibility, at the same time, influences a greater number of decisions made, data generation and the use of enterprise resources. For this purpose, entrepreneurs use various simulations approaches, including applications for simulation of complex production processes, but nowadays they are increasingly leaning towards the so-called digital twins. The article presents the possibility of using a digital twin and the necessary data required to make such a twin in order to reflect the actual activities carried out in production.