bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Study on Erosion of String Inner Wall in Perforation Interval in Liquid-Solid Two-Phase Flow
Authors: Zhang Kui , Wang Junchao , Yuan Liang , Mu Lingyu , Cheng Jiarui , Wei Wenlan 
Published: March 2022

Abstract
In the process of large displacement fracture injection, high flow velocity sand-carrying fluid causes serious erosion corrosion to the borehole. Based on the high-speed liquid-solid two-phase erosion experiments, the erosion experiments of single-hole set with flow velocity, sand concentration and grain size, and the three-dimensional profile scanning of the eroded orifice were carried out to investigate the erosion and corrosion expansion law of the high-speed jet orifice. The study shows that the erosion rate increases with the increase of discharge volume, sand concentration and particle size, and the change of discharge volume and sand concentration has the most significant effect on the erosion of the hole. The prediction of the hole expansion law of single hole with sand liquid injection shows that the hole diameter expands to 13mm-19mm after 90min of construction of 8 clusters of 24 holes, while the hole diameter expands to 11.7mm-12.8mm after 90min of construction of 3 clusters of 48 holes. 3 clusters of 48 holes have smaller hole diameter after the same construction time, which is better than 8 clusters of 24 densely packed holes.
First-principles study of resistive random access memory based on AlN
Authors: Shao Peng , Dai Yuehua , Li Xing , Yang Bin , Wang Xiaoqing 
Published: March 2022

Abstract
In this article, the properties of AlN-based RRAM and the effect of O doping on device performance were investigated. After determining the size of electrode and resistive layer through the calculation of LDOS and surface energy, the Ti/AlN and Pt/AlN interfaces were established by the calculation of the binding energy. Through the above steps, the RRAM model is finally established. The I-V curve obtained by calculation shows that the AlN-based RRAM has bipolar resistive switching characteristics. The device has a fairly high switch ratio (104). And its turn-on and turn-off threshold voltages are 1.7 V and 0.6 V, respectively. The calculation of DOS and charge density reveals that the resistance switching mechanism of the AlN-based RRAM is that N vacancies form a conductive path. Finally, by studying the influence of O doping on the formation energy of N vacancies, Electron localization function and migration energy, it is found that O doping can promote the conduction of the device and improve the uniformity of the conductive filaments.
Instability Analysis of Fluid-Conveying Functionally Graded Thin-Walled Pipes on Random Elastic Foundations
Authors: Cao Jianhua 
Published: March 2022

Abstract
The aims in this work are to study the effects of random variables and physical parameters on the critical fluid velocity of functionally graded material thin-walled pipes resting on random elastic foundations which carry the axial flow. The variation of the mean of the critical flow velocity with the spatial correlation length are monotonically increased or not monotonic which is conditional on the values of the coefficient of variation. The length of the intervals for purely ceramic or fully metal is shorter than these for other values of volume fraction index in which the mean of critical flow velocity is higher than that of the deterministic foundation stiffness. As the volume fraction index and temperature gradient of FGMs increase, the curves of the mean of critical flow velocity vary greatly for the fixed values of the coefficient of variation. The numerical results have been of practical interest for the design of the functionally graded pipes.
Experiment and simulation of microwave detection using IQ demodulation method for breast tumor screening
Authors: Li C.P. , Yao Y. , Li Z.H. , Cheng L. , Zhang Y. , Liu H.Q. 
Published: March 2022

Abstract
Breast cancer has become the most diagnosed cancer in the world. Microwave detection the breast tumor is attractive due to its high dielectric property contrast between different tissues of tumor. In this paper, we proposed an In-phase-Quadrature (IQ) demodulation-based method to detect the breast tumor with microwave at a frequency of 1.3 GHz. The microwave detection system consists of two signal generators, 12 transmitting/receiving antennas, two talent switches, a phantom and an IQ-Mixer. The amplitude information at the receiving antennas can be obtained by analyzing the difference frequency signals generated with two microwave signal generators. We also use the finite-difference time-domain (FDTD) method for simulation verification, which can simulate the propagation of the electromagnetic wave. Through experiments and simulations of microwave hardware system and FDTD method, it can be proved that the results are consistent. The experimental and simulation results show that when the tumor phantom diameter decreases or its depth from the receiving antenna increases, whether there is a tumor phantom can be clearly distinguished. Moreover, we also explore the effects of different tumor phantom locations on the receiving antennas. The results show that it is feasible to detect the breast tumor with the IQ demodulation method based on microwave.
Graphene oxide encapsulated forsterite scaffolds to improve mechanical properties and antibacterial behavior
Authors: Najafinezhad A , Bakhsheshi-Rad H R , Saberi A , Nourbakhsh A A , Daroonparvar M , Ismail Ahmad Fauzi , Sharif Safian , RamaKrishna Seeram , Dai Yunqian , Berto F 
Published: March 2022

Abstract
It is very desirable to have good antibacterial properties and mechanical properties at the same time for bone scaffolds. Graphene oxide (GO) can increase the mechanical properties and antibacterial performance, while forsterite (Mg2SiO4) as the matrix can increase forsterite/GO scaffolds’ biological activity for bone tissue engineering. Interconnected porous forsterite scaffolds were developed by space holder processes for bone tissue engineering in this research. The forsterite/GO scaffolds had a porosity of 76%–78% with pore size of 300–450 μm. The mechanism of the mechanical strengthening, antibacterial activity, and cellular function of the forsterite/GO scaffold was evaluated. The findings show that the compressive strength of forsterite/1 wt.% GO scaffold (2.4 ± 0.1 MPa) was significantly increased, in comparison to forsterite scaffolds without GO (1.4 ± 0.1 MPa). Validation of the samples’ bioactivity was attained by forming a hydroxyapatite layer on the forsterite/GO surface within in vitro immersion test. The results of cell viability demonstrated that synthesized forsterite scaffolds with low GO did not show cytotoxicity and enhanced cell proliferation. Antibacterial tests showed that the antibacterial influence of forsterite/GO scaffold was strongly correlated with GO concentration from 0.5 to 2 wt.%. The scaffold encapsulated with 2 wt.% GO had the great antibacterial performance with bacterial inhibition rate around 90%. As results show, the produced forsterite/1 wt.% GO can be an attractive option for bone tissue engineering.
Future increases in lightning ignition efficiency and wildfire occurrence expected from drier fuels in boreal forest ecosystems of western North America
Authors: Hessilt Thomas D , Abatzoglou John T , Chen Yang , Randerson James T , Scholten Rebecca C , van der Werf Guido , Veraverbeke Sander 
Published: March 2022

Abstract
Lightning-induced fire is the primary disturbance agent in boreal forests. Recent large fire years have been linked to anomalously high numbers of lightning-caused fire starts, yet the mechanisms regulating the probability of lightning ignition remain uncertain and limit our ability to project future changes. Here, we investigated the influence of lightning properties, landscape characteristics, and fire weather on lightning ignition efficiency—the likelihood that a lightning strike starts a fire—in Alaska, United States of America, and Northwest Territories, Canada, between 2001 and 2018. We found that short-term fuel drying associated with fire weather was the main driver of lightning ignition efficiency. Lightning was also more likely to ignite a wildfire in denser, evergreen forest areas. Under a high greenhouse gas emissions scenario, we predicted that changes in vegetation and fire weather increase lightning ignition efficiency by 14 ± 9% in Alaska and 31 ± 28% in the Northwest Territories per 1 °C warming by end-of-century. The increases in lightning ignition efficiency, together with a projected doubling of lightning strikes, result in a 39%–65% increase in lightning-caused fire occurrence per 1 °C warming. This implies that years with many fires will occur more frequently in the future, thereby accelerating carbon losses from boreal forest ecosystems.
Contribution of Constructed Wetlands for Reclaimed Water Production: A Review
Authors: Pinho Henrique J O , Mateus Dina M R 
Published: April 2022

Abstract
Freshwater scarcity is a growing threat to sustainable development, which can be mitigated by adequate management of water resources. Agriculture and related activities consist in the main use of freshwater, but several other human activities present relevant contributions. Because most of the water uses imply the generation of resultant wastewater, the production and use of reclaimed water by appropriate technologies can be part of the solution to that issue. Considering that the use of constructed wetlands (CWs) can be a relevant contribution to the production of reclaimed water, as an eco-friendly alternative to costly advanced water treatment technologies, this work is a review of the last decade of literature on the use of CWs to produce reclaimed water. The results point to a usual focus on the production of reclaimed water for agriculture or urban spaces irrigation. In order to potentiate a broader application of CWs, some directions of future research and use of this green technology are proposed.
Experimental characterisation of physical properties of different PLA filaments used in FFF 3D printing technology
Authors: Lang A 
Published: March 2022

Abstract
In the field of 3D printing, fused filament fabrication (FFF), many PLA filaments are offered by different providers. The physical properties of the filaments from various manufacturers differ significantly from each other. These differences have corresponding effects on the processing of the filaments, as well as on the quality of the final product. This article compares PLA filaments from different manufacturers and additionally gives an overview of their physical properties. The investigated properties were namely the melting point, cold crystallization, glass transition temperature, melt flow index and residual content. The results show the differences between the various manufacturers' specifications in the data sheets and point out others. The melt flow index in particular stands out here, which can have a strong influence on the printing process. The effect especially on the mechanical properties has to be determined in further investigations.
Digital service application for the recalibration of a machine tool through Augmented Reality-supported data acquisition
Authors: Arnold F , Lemme G , Hess M , Witt S , Ihlenfeldt S 
Published: March 2022

Abstract
The effort for checking and correcting the spatial movement accuracy of a processing machine with 5 axes is very high. Calibration and recalibration must be carried out directly on the machine by the machine supplier or a company specializing in this. This is associated with high personnel and long machine downtimes. These constraints can be improved by using modern methods. A consistent approach of an AR-supported measurement procedure for the preparation and execution of a required measurement run and the execution of the calibration itself as a digital service is presented. This enables rapid execution by the machine operator himself using a DoubleBallBar measurement system without the need of the presence of the machine manufacturer. The determination of the calibration parameters on the basis of the measurement data is then carried out by the machine manufacturer and provided as a service. The basis for such a secure and auditable service is a digital service platform. This serves as an intermediary between the user and the machine manufacturer and uses distributed ledger technology. The approach presented is the subject of current development work.
Establishing the machining process for complex aluminum alloy part made from plate raw material
Authors: Moldovan Ş A , Banica M , Năsui V 
Published: March 2022

Abstract
This paper presents a technical solution to establish the machining process for complex structural products made from aluminum alloy plates used in the aerospace industry. Those products have a very tight tolerance for geometrical deviations and positioning characteristics. To achieve a good product and ensure the machining process, repeatability is necessary to solve two issues: first, the temperature dilatation impact, and second the raw material behavior. To solve these problems, several tests were performed for products used in the aerospace industry. For deviations identification, all products were measured using a coordinate measuring machine, and the resulting report data was used for statistical analysis. Using this information, appropriate processing strategies were established. Through several tests and recording all dimensions changes during the milling process, good products were obtained, and it was ensured repeatability of the machining process.
Construction of surface layers with special properties in the hardening of steels
Authors: Volkov O , Knyazev S , Subbotina V , Iancu C , Gutsalenko Yu , Shelkovyi O , Strelchuk R. 
Published: March 2022

Abstract
Designing surface layers with special properties at strengthening of steels gives the chance to receive effective tools of a special purpose. The technological process of hardening by boron saturation of the jewellery tool - crimpings for fixing jewellery stones from carbon steel (0.7% C) is offered. Boron saturation of steel crimpings for fixing jewellery stones was performed before traditional hardening and low tempering. The microhardness of the surface layer of boron saturated steel has been more than doubled: at a depth of up to 50 μm – up to more than 16 GPa against 6 GPa for traditional hardening technology. Between the upper hardened layer and the unaltered inner metal, a transitional structure zone with tempering martensite is observed. This zone has a thickness of about 100 μm and an average microhardness in the range from 10 GPa to about 14 GPa.
Computer-aided methods for furniture decoration with traditional motifs of textile heritage
Authors: Lungu A , Gurău L , Georgescu S , Coşereanu C 
Published: March 2022

Abstract
The present paper introduces computer-aided methods for the transposition of ornaments inspired from the textile heritage into the surface furniture decoration. Using digital technology, the furniture industry may bring into modern life the traditional motifs, contributing thus to the preservation of the cultural heritage from the region Ţara Bârsei, located in Transylvania. Two motifs inspired by the traditional costumes from South-Eastern Transylvania were digitized using CorelDraw software. They were imported in AutoCAD and the information was transferred both to CNC router and laser equipment. The CNC routing of ornaments was simulated with two types of tools and two processing methods (engraving and carving) using CAD-CAM-CAE software and the models were afterward processed on wood panels by CNC router and laser equipment and then visually analysed, concluding which method and tool is suitable for each type of ornament, so to transpose better the original motif on furniture wood surface.
FEM-based investigation on machining forces and temperatures induced during AISI-4140 hard turning
Authors: Tzotzis Anastasios , Efkolidis Nikolaos , Tzetzis Dimitrios , Kyratsis Panagiotis 
Published: March 2022

Abstract
Turning is probably one of the most common machining processes used to manufacture parts for the industrial sector. In order to reduce development times and costs during turning, it is necessary to employ methodologies and techniques that enable the precise prediction of the important parameters that relate to the process. Such a methodology is the implementation of Finite Element Method (FEM). In this work, the 3D modelling of AISI-4140 hard turning with ceramic tooling is being presented by utilizing the DEFORM-3D™ Finite Element Analysis (FEA) software system. Nine tests were conducted according to typical cutting conditions as recommended by tool manufacturers; cutting speed of 80 m/min, 115 m/min and 150 m/min and feed of 0.08 mm/rev, 0.11 mm/rev and 0.14 mm/rev, at a constant depth of cut equal to 0.30 mm. The developed friction forces, heat transfer and contact interface stresses between the tool and the workpiece were approximated with the aid of well-established models to simulate the machining mechanisms. Additionally, a validation of the yielded results for the machining components and the temperature distribution was performed by comparing the numerical results with experimental data. Most of the simulations generated results in agreement with the experimental ones. The agreement percentage exceeds 90% in most tests for the investigated components (machining forces and temperature), confirming both the validity and the accuracy of the model.
Finite element analysis for testing safety-belt anchorages
Authors: Manea A M , Iozsa M D , Stan C , Ioniţă A 
Published: March 2022

Abstract
The passive safety of the vehicle is ensured by designing optimized restraint systems to protect the occupants during the accident. The safety-belts have the role of restraining the occupants of the car on the seat during an impact or in the event of a rollover. Their retention prevents or minimizes the impact between the occupants and the interior components of the passenger compartment. Two simplified models of seat structures are proposed to determine the strength of the safety-belts anchorages. The test of the anchorage for safety-belts of the two seat models is performed in accordance with Regulation no. 14 UNECE. For the two seat models, a three-dimensional resistance structure was made. The 3D models of the seats were inserted in the FEA software. The analysis of the models is done by the finite element method with the Static Structural module of the FEA software. A tensile force is applied during the test on the safety-belts anchorages. The traction force shall be applied in the direction corresponding to the seating position, at an angle of 10°±5° above the horizontal, in a plane parallel to the median longitudinal plane of the vehicle. During the tests the safety-belt anchorages shall withstand the entire period of application of the traction force and the upper safety-belt anchorage shall not be displaced during the test forward of a transverse plane passing through the R point of the seat.
Ground penetrating radar for real time surveying of soil as bioremediation precursor
Authors: Iftimie N , Steigmann R , Dobrescu G S 
Published: March 2022

Abstract
GPR is a non-destructive method based on the emission and reception of electromagnetic waves generated by a bowtie antenna, of 400 MHz, in our case. The soil conductivity influences the propagation of electromagnetic waves, thus any inhomogeneity as water lens, chemical pollution, soil texture, buried objects modify the signal scattered on them and recorded by GPR tools. One of the potential advantages of GPR is that it is able to quickly analyses the presence in the underground of various inhomogeneities without having to come into contact with the ground and measures the time interval between pulse generation and reception, the results being presented in B-scan and linescan representation. Combining and processing the received signals, the results show as a map with emphasized watering regions. This paper presents the results of a case study where it was determined the effectiveness of GPR technology in detecting water content as well as the presence of water holes in airport runway draw. Further investigations will include the use of GPR together with electromagnetic induction method in order to make data fusion and increase the probability of detection.
Desalination by endothermal generators
Authors: Monteiro B , Cavique M 
Published: March 2022

Abstract
Many regions of the planet are under water stress that can create humanitarian disasters. Where available, seawater can undergo a desalination process to produce drinkable water. The desalination processes may use thermal and mechanical energy. Methods based on evaporation and flashing are thermal driven, whether water osmosis uses mechanical energy. An endothermal motor can generate both mechanical and thermal energy. This paper focuses on a Diesel generator able to supply an electrical power of 362 kW. It evaluates the water production of a combined system with a Multi-Effect Evaporator and a Reverse Osmosis system. The Multi-Effect Evaporator uses the thermal energy from the exhaust gases; the Reverse Osmosis uses the generator's electrical power. The generator is typical for marine applications and can be deployed in humanitarian operations. The system can produce 1,011 m3 per day of drinkable water, enough to supply the daily basic needs of a population of about 50,500 persons.
Development of a “Virtual Learning Factory” for learning and applying specific Lean manufacturing methods
Authors: Neacsu G C , Pascu I G , Nitu E L , Ionescu L , Gavriluta A C , Belu N 
Published: March 2022

Abstract
The processes and systems of production and training, influenced by the digital era, are forced to evolve at an accelerated pace to satisfy the need of innovation and digitization. Thus, the development of virtual learning factories within universities, which can adapt to the requirements of innovation and digitalization, is a solution. In this context, the paper presents how to development a virtual learning factory, flexible-reconfigurable to allow easier learning and experimentation of methods, techniques and tools used in Lean manufacturing. To achieve this, specific Lean manufacturing methods will be digitized for integration into the virtual factory, through programming in the Unity platform, using its specific C # language. Thus, at the end of the paper we want to obtain a virtual, mobile and flexible learning factory, which will help the user to understand, learn and experiment easily and in an attractive way the methods and techniques used in Lean manufacturing.
Experimental tests to validate the usage domain for personalised formworks
Authors: Diaconu Raluca , Brindasu Paul Dan 
Published: March 2022

Abstract
Analysing the nowadays tendency for customised products, the personalised formwork is a solution that is worth taking into account. Not only that the concrete mould (due to the composite membrane) can take various shapes, function of the designer’s requirements, but it can be reusable and remodelled at each usage. By using the Product Lifecycle Management (referred as PLM) principles, two directions were analysed: a pushing system without any auxiliary reinforcement of the formwork and a pulling system with additional reinforcement under the formwork membrane. The composite membrane is subjected to multiple tests with different variants. By analysing the resulting values regarding the final shape of the product (concrete element), the proposed solutions were validated by defining the usage domain for each type of personalised formwork.