bluuebunny/crossref_metadata_2025_split huggingface dataset:
The driving forces behind the change in energy consumption in developing countries
Authors: Li Shuping , Meng Jing , Zheng Heran , Zhang Ning , Huo Jingwen , Li Yuan , Guan Dabo 
Published: January 2021

Abstract
Economic growth is principally powered by energy fuels. While the potential energy transition pathways in developed countries are clear, they have not been well explored for developing countries. Here, we study the average annual growth rate of energy consumption in 12 aggregated regions during 2001–2017 and the driving factors behind that growth. The countries with high energy consumption growth rates were concentrated in Asia and North Africa and four of the top five regions were in Asia, while the energy consumption in developed countries was stable or even declined in that period. Therefore, based on a comprehensive consideration of factors such as population and economic development, to quantify the role of renewable energy, we analyze the long time series of energy consumption for China, India, Indonesia, Myanmar and Bangladesh since the 1970s. Despite economic development and population growth accelerating energy consumption substantially upward, energy intensity made energy consumption decrease. Coal and oil dominated the energy transition pathway in China and India, while biomass and natural gas dominated in Indonesia, Myanmar and Bangladesh. The amount of CO2 emissions in different countries was closely related to the amount and type of the energy they used. Our research results emphasize the importance of improving energy efficiency and adjusting energy structure to reduce energy consumption and achieve sustainable development.
Integrable hierarchies associated to infinite families of Frobenius manifolds
Authors: Basalaev Alexey , Dunin-Barkowski Petr , Natanzon Sergey 
Published: January 2021

Abstract
We propose a new construction of an integrable hierarchy associated to any infinite series of Frobenius manifolds satisfying a certain stabilization condition. We study these hierarchies for Frobenius manifolds associated to A

N
, D

N
and B

N
singularities. In the case of A

N
Frobenius manifolds our hierarchy turns out to coincide with the dispersionless KP hierarchy; for B

N
Frobenius manifolds it coincides with the dispersionless BKP hierarchy; and for D

N
hierarchy it is a certain reduction of the dispersionless 2-component BKP hierarchy. As a side product to these results we illustrate the enumerative meaning of certain coefficients of A

N
, D

N
and B

N
Frobenius potentials.
Huygens’ principle for the generalized Dirac operator in curved spacetime
Authors: Yagdjian Karen 
Published: January 2021

Abstract
In this article we give sufficient conditions for the generalized Dirac operator to obey the incomplete Huygens principle, as well as necessary and sufficient conditions to obey the Huygens principle by the Dirac operator in the curved spacetime of the Friedmann–Lemaître–Robertson–Walker (FLRW) models of cosmology.
Effects analysis of vertical track irregularities on bogie vibration - method based on bogie modelling and wheelsets accelerations measurement
Authors: Dumitriu M , Fologea D , Cruceanu I C 
Published: January 2021

Abstract
The paper analyzes the effect of the vertical track irregularities upon the vibrations in a two-axle bogie. The method in use implies the bogie modelling and the measurement of the vibrations in wheelsets generated by the track vertical irregularities. The behaviour of vibrations in the bogie is evaluated via the results derived from applications of numerical simulation developed on the basis of the bogie model, where the inputs are the accelerations measured in the two wheelsets. The vibration features in the bogie are pointed out at according to the spectra of accelerations in the bogie frame, to the standard deviation values of accelerations and to the maximum values of the accelerations calculated against the two wheelsets.
Intelligent control of wheel rail contact noise phenomenon in rail transportation
Authors: Chiba E , Abdelkrim M , Belloufi A , Rezgui I 
Published: January 2021

Abstract
Railway transport systems play a very important role in the future of transport. They offer sustainable solutions that reduce carbon emissions (environmental requirements) and allow more mobility with better energy efficiency, and they generate advantageous economic benefits in the long term. But the interaction between the wheel and the rail is always very difficult to approach. There are a large number of studies in the literature on this problem. However, there is still no comprehensive approach. On this work we propose to study numerical modelling of contact between wheel-rail systems by using fuzzy logic. For this purpose, the experimental collection data reported in literature are used to predict the resonance noise during wheel-rail contact in rail transport. We found a good agreement between the elaborated model and the results of the literature.
Numerical modeling of pipe parts of agricultural machinery expansion by stepped punches
Authors: Puzyr R H , Shchetynin V T , Arhat R H , Sira Yu B , Muravlov V V , Kravchenko S I 
Published: January 2021

Abstract
The paper presents the research of plastic expansion of a pipe workpiece by punches of various configurations. It is shown that interest in this process is caused by the development of oil production, where there is a need to increase the diameter of well pipes, the automobile industry, where the protection of the driver and passengers in case of accidents comes first. Here, stable plastic deformation plays an important role as a good absorber of kinetic energy, etc. Data on the problems of expanding pipe ends are given, where special attention is paid to the destruction of the end in the form of localization of deformations and appearance of a longitudinal crack. To eliminate this phenomen onvarious technological methods are used. Here the influence of the design and shape of the punch on the localization of deformations along the thickness of the workpiece is researched. Several spatial outlines of the tool are proposed to create an effective reloading of the pipe workpiece in the deformation zone. Based on numerical modeling, the distribution of stresses according to Mises, the displacement of the end of the semi-finished product and logarithmic deformations in the radial direction is shown for each standard size of the punch. Comparative results reveal an increase in the thickness of the workpiece in the dangerous section for all presented punches. The comparison was carried out with a reference tool that has a straight generatrix of a tapered surface. The best results are shown by a punch with an enlarged generatrix at the end of the working stroke. Attention is focused on conducting further research in order to study the possibility of overcritical deformation by the proposed tool.
Automatic positioning methodology and algorithm for modular jigs and fixtures components
Authors: Savu T , Nanu S , Ene I C 
Published: January 2021

Abstract
One of the steps in designing a modular jig or fixture assembly is that of selecting the appropriate components. Among these components, those forming the jig’s body must be chosen for closing the dimensional chains between the other locating, clamping, or indexing components. The methodology starts by defining the components’ virtual connectors, specifying the rules for establishing their coordinates systems, and then is defining the rules to be followed for aligning and assembling two adjacent components. Different cases are described and only some of them are detailed, for clarity reasons. The algorithm is looking to determine a series of components from which the first is in a fixed position, related to other locating or clamping jig’s component. A hierarchical tree is generated, using available components, having in each node a component which is assembled with a previous one using the above-mentioned connectors. Interference criteria is checked for selecting possible solutions only. A stop criterion related to the number of components in a branch is used, Solutions from the different branches are compared using the distances to an end component.
Ways for determining the intermediate dimensions when designing the machining technology
Authors: Slătineanu L , Coteaţă M , Dodun O , Nagîţ G , Hriţuc A , Beşliu-Băncescu I 
Published: January 2021

Abstract
Among other problems to be solved, the design of a technological process of machining by cutting a part involves establishing the dimensions that can be achieved in the pre-final machining of the same surface of the part. There are distinct ways to calculate the so-called intermediate dimensions and, in particular, to define the dimensions for adjusting the position of the cutting tool tip before starting the actual machining process. The paper analyzes some such ways of establishing the intermediate dimensions, highlighting the conditions under which they can be applied, their advantages and limitations of use. Subsequently, the double-entry matrix method was applied to identify one or more methods with wider possibilities of use. It was concluded that the method of tolerance chart and respectively a method that takes into account a statistical processing of the results accumulated over time are methods likely to lead to an efficient solving the problem of determining the intermediate dimensions.
Brief review of methods and techniques used in Learning Factories in the context of Industry 4.0
Authors: Neacsu G C , Pascu I G , Nitu E L , Gavriluta A C 
Published: January 2021

Abstract
The rapid evolution of science and technology has forced the processes and systems of production, training and learning to adapt to innovation and the digital era of industrial technology. In the case of production processes and systems, innovation and digitalization refer to the transformation of production units into smart factories. In the case of training and learning processes and systems, innovation and digitalization lead to the creation of learning factories. Thus, this process involves the use of modern methods and techniques to develop innovative training, learning and production processes and systems. This paper is an analysis of recent studies and seeks to briefly present the evolution of industrial production processes and systems and Industry 4.0 but also the concept of learning factory. The paper also presents a review of the main methods and techniques used in innovative industrial training, learning and production processes and systems. Finally, some conclusions related to the use of these methods and techniques are summarized.
Improvement of the grain cargo handling technology on the basis of resource-saving
Authors: Kovalov Anton , Prodashchuk Svitlana , Kravets Anna , Mkrtychian Dmytro , Prodashchuk Mikola 
Published: January 2021

Abstract
The article considers the state of grain cargo transportation and related technical and technological problems. As a solution, the possibility of using multiple grain shipping containers and the introduction of a new modern grain cargo handling technology at the station based on inventory management and proper selection of vehicles was considered. The considered measures will contribute to simplifying, improving and reducing the number of cargo operations performed during grain handling, making their implementation more practical and energy-efficient.
Main criteria of complex evaluation of subway train power facility technological productive potential
Authors: Kulbovskyi I I , Aharkov O V , Kharuta V S , Halushko M M 
Published: January 2021

Abstract
Maintaining the train safety and passenger transportation safety is regulated by the technical condition of rolling stock, which meets the requirements of regulatory documentation. Modern conditions of operation of traction rolling stock units (UTRS) are characterized by insufficient use of production and technological potential.
One of the main reasons for this situation is the lack of necessary scientific and methodological developments that describe and improve system methods, models and criteria for the effectiveness of the production processes of UTRS.
Investigation of the Influence of Dynamic Loads of Industrial Equipment on the Occurrence of Prolonged Yielding of their Foundation Soils
Authors: Aleksandrovych V A , Havryliuk O V 
Published: January 2021

Abstract
The parameters of oscillations of the foundations and structures of the dynamic equipment of the new production workshop located in the Kharkiv region were experimentally investigated. For this purpose, appropriate measurements of the amplitude of oscillations in the vertical and orthogonal horizontal directions were performed. To compare the parameters of the amplitudes of forced oscillations and determine the damping properties of the applied rubber spacers placed between the frame and the slides, as well as the quenching effect of the foundation massif, several measurements of oscillation parameters were performed at the locations mentioned above. The amplitude of oscillations of the vertical component of the vibration load on different sides of the rubber dampers was reduced by 2-3 times, the horizontal component was completely attenuated. It was also established that there was no transmission of vibrations to the foundations of the production workshop. The safety of the measured parameters of oscillations from the point of view of long significant unstabilized subsidence of the foundations, both equipment and building, was determined. Recommendations for monitoring are given from the point of view of the possible deterioration of the properties of the used rubber dampers over time.
Environmental assessment of small scale solar thermal electricity generation
Authors: Koltun Paul , Klymenko Vasyl , Soldatenko Valentyn , Kononchuk Serhii , Teliuta Ruslan 
Published: January 2021

Abstract
Solar thermal electricity probably has the greatest potential of any single renewable energy process and it can be economically competitive with other technologies, if environmental costs are accounted for. In spite of the many investigations conducted so far there is no one dominant technology and no single life cycle assessment study conducted to compare different STE technologies. This life cycle study has been undertaken to identify potential materials flow, energy consumption and emissions for small scale STE options. The processes are described by the typical process inputs and outputs including energy, materials, solid wastes and other emissions. The results show sufficient efficiency for Australian conditions of small scale.
Research of Integrity of Fire Insulation Cladding with Mineral Wool of Steel Beam under Fire Impact
Authors: Pozdieiev Serhii , Nuianzin Oleksandr , Borsuk Olena , Nedilko Inna 
Published: January 2021

Abstract
In the article, the processes of integrity loss of fire-retardant cladding from mineral wool of a steel I-beam are considered. The relation between fire-retardant cladding integrity and its thermal insulating ability was studied. Computer model of a steel beam with fire-retardant cladding of mineral wool, which takes into account its own weight, current mechanical load and temperature mode of heating under the heat-insulating effect of the cladding, using the computer system LS-DINA, is developed in this article. It is shown that the fire-retardant cladding loses its integrity under the thermal influence of fire long before the onset of the limit state of loss of fire resistance in terms of bearing capacity. The conditions under which fire-retardant cladding loses its integrity and fire-retardant ability are investigated. Having considered the time of fire-retardant cladding integrity loss the fire resistance limit can be significantly clarified and allows to avoid early collapse of building structures cause by fire.
Simulation of the oil film thickness on a friction surface in the presence of fullerene compositions in the lubricant
Authors: Kravtcov A , Gradiskiy Y , Tsymbal B , Borak K 
Published: January 2021

Abstract
The paper contains theoretical studies of the oil film formation on a friction surface in the presence of fullerene solutions in a lubricant. The mathematical model is developed on the basis of the interaction between electrically active heterogeneous finely dispersed systems at the interface between the friction surface and the lubricating medium and is described by the Poisson differential equation. The role of the friction surface on the formation of clusters and micelles in an adsorbed film of the lubricant near the friction surface is established. It is shown that in the stress-strain state of triboelement material surface layers, the friction surface acts as an “electrostatic field generator”. Expressions are obtained for the simulation of the oil film thickness in the presence of fullerenes in the base lubricant. Based on the simulation results, the most significant factors in the formation of the oil film thickness have been established: these are the electric field strengths of the friction surface and the base lubricating medium; the load on the tribosystem; the temperature, and dynamic viscosity of the lubricating medium.
A targeted rheological bioink development guideline and its systematic correlation with printing behavior
Authors: Pössl Axel , Hartzke David , Schmidts Thomas M , Runkel Frank E , Schlupp Peggy 
Published: January 2021

Abstract
Bioprinting for tissue or disease models is a promising but complex process involving biofabrication, cell culture and a carrier material known as bioink. The native extracellular matrix (ECM), which forms the scaffold for cells in vivo, consists of several components including collagen as a gelling agent to confer mechanical stiffness and provide a substrate for cell attachment. Bioprinting therefore needs an artificial ECM that fulfills the same functions as its natural counterpart during and after the printing process. The combination of bioink materials determines the immune response of the host, cell compatibility and adhesion. Here we evaluate multi-material blending with four pre-selected components using a design of experiments approach. Our exemplary designed hydrogel is highly reproducible for the development of artificial ECM and can be expanded to incorporate additional requirements. The bioink displays shear-thinning behavior and a high zero-shear viscosity, which is essential for the printing process. We assessed the printing behavior of our bioink over a wide range of the key process parameters for extrusion-based bioprinting (temperature, pressure, feed rate, and nozzle geometry). Several processing temperatures were linked by rheological measurements directly to the 3D printing process. The printing results were evaluated using a self-developed categoric strand screening process, varying the feed rate and pressure with a fixed nozzle. Accordingly, nozzles differing in size and shape were evaluated and the interactions between printing pressure and feed rate were characterized separately by applying a modified O-R-O test. We tested the short-term cultivation stability of our bioink to mimic the hypothermic and hyperthermic conditions of the human body. As result we present an expandable concept for bioink development and a highly reproducible and well-characterized procedure for printing with the newly developed hydrogel. We provide detailed insights into the relationship between printing parameters, rheological parameters and short-term cultivation stability.
The effect of micro and nano hydroxyapatite powder on biocompatibility and surface integrity of Ti6Al4V (ELI) in powder mixed electrical discharge machining
Authors: Yaşar Hamidullah , Ekmekci Bülent 
Published: January 2021

Abstract
The problem of achieving functional surface is receiving substantial attention with the demand for efficient medical devices in biomedical industry. To satisfy both mechanical and biomedical concerns, researchers try to develop appropriate commercial machining techniques. This study analyzes the micro and nano Hydroxyapatite (HAp) powder size effect on surface topography and biocompatibility of Ti-6Al-4V (ELI) biomaterial in Electrical Discharge Machining (EDM). We compare thoroughly the titanium surfaces that EDM’ed with three different HAp powder concentrations in Deionized Water (DW) (0 g l−1, 20 g l−1 Micro HAp, 20 g l−1 Nano HAp) and three pulse current levels (7 A, 12 A, 22 A). The roughness of surfaces varies between 0.38 μm and 6.61 μm. Using micro HAp powder in dielectric liquid lowered the surface roughness and enhanced the wettability whereas the nano HAp effect could be negligible. The Energy Dispersive x-ray Spectrometer results show the Ca and P ion migration from the HAp mixed dielectric to the workpiece surface during EDM. The x-ray Diffraction results affirmed the existence of HAp compounds and oxide phases in the surface structure. Biocompatibility tests employing MG63 osteoblast-like cells revealed that for 24 h culture period all EDM samples showed higher viability than the control in vitro. According to the statistical analyses ANOVA (Tukey), the MTT viability results showed a significant difference especially for those machined in micro HAp mixed DW dielectrics. On the other hand, for 72 h culture period, samples machined in DW with 7 and 12 A currents are more biocompatible and have a proliferative effect on MG63 cells. In conclusion, however the dependency on pulse current, powder additive, and topography of the surface exist; EDM can be employed as an effectual treatment to enhance the biocompatibility.
Structural and magnetodielectric properties of BiFeO3-GdMnO3 multiferroics
Authors: Masso R , Tripathy S N , Aponte F A , Pradhan D K , Martinez R , Palai R 
Published: January 2021

Abstract
We report on structural, microstructural, spectroscopic, dielectric, electrical, ferroelectric, ferromagnetic, and magnetodielectric coupling studies of BiFeO3–GdMnO3[(BFO)1–x
–(GMO)
x
], where x is the concentration of GdMnO3 (x = 0.0, 0.025, 0.05, 0.075, 0.1, 0.15, and 0.2), nanocrystalline ceramic solid solutions by auto-combustion method. The analysis of structural property by Rietveld refinement shows the existence of morphotropic phase boundary (MPB) at x = 0.10, which is in agreement with the Raman spectroscopy and high resolution transmission electron microscopy (HRTEM) studies. The average crystallite size obtained from the transmission electron microscopy (TEM) and x-ray line profile analysis was found to be 20–30 nm. The scanning electron micrographs show the uniform distribution of grains throughout the surface of the sample. The dielectric dispersion behavior fits very well with the Maxwell-Wagner model. The frequency dependent phase angle (θ) study shows the resistive nature of solid solutions at low frequency, whereas it shows capacitive behavior at higher frequencies. The temperature variation of dielectric permittivity shows dielectric anomaly at the magnetic phase transition temperature and shifting of the phase transition towards the lower temperature with increasing GMO concentration. The Nyquist plot showed the conduction mechanism is mostly dominated by grains and grain boundary resistances. The ac conductivity of all the samples follows the modified Jonscher model. The impedance and modulus spectroscopy show a non-Debye type relaxation mechanism which can be modeled using a constant phase element (CPE) in the equivalent circuit. The solid-solutions of BFO-GMO show enhanced ferromagnetic-like behavior at room temperature. The ferroelectric polarization measurement shows lossy ferroelectric behavior. The frequency dependent magnetocapacitance and magnetoimpedance clearly show the existence of intrinsic magnetodielectric coupling. The (BFO)1–x
–(GMO)
x
solid solutions with x = 0.025–0.075 show significantly higher magnetocapacitance and magnetoimpedance compared to the pure BFO.