bluuebunny/crossref_metadata_2025_split huggingface dataset:
A hybrid mesoscale-continuum approach to understand and predict melting kinetics of Al powders during laser processing
Authors: Chen Ching , Galitskiy Sergey , Ivanov D S , Dongare Avinash M 
Published: September 2024

Abstract
Laser interaction with metallic powders during additive manufacturing (AM) leads to fast heating and cooling rates that can affect the quality of the final products due to the formation of defects. One of the first steps towards predicting microstructures generated during AM, therefore, requires an accurate understanding of the laser energy deposition mechanisms that determine the melting kinetics at the level of individual powders. The critical challenge, however, is the availability of computational methods that can model the laser energy absorption, heat transfer, and the related microstructure evolution in individual metal powders at the length and time scales of AM. This manuscript demonstrates the capability of a novel scale-bridging methodology that combines the mesoscale quasi-coarse-grained dynamics (QCGD) simulations with a continuum two-temperature model (TTM) to account for the atomistic mechanisms of laser energy deposition and microstructure evolution and predict the kinetics of melting of individual powders at the experimental time and length scales. The scale-bridging capability of the hybrid QCGD-TTM simulations is demonstrated here by investigating the laser-induced microstructure evolution in aluminum powders with various sizes ranging from 200 nm to 20 µm. The analysis of the evolution of temperature, pressure, phase fraction, and melt fronts suggests the melting mechanism is heterogeneous due to the interaction with a laser, and the melting time is observed to decrease exponentially as the laser intensity increases. The solid–liquid interface velocity can be quantified to identify correlations with interface temperatures, and the predicted values satisfy the theoretically reported limits of crystal stability of metals against homogeneous melting. In addition, the pre-melting is found at the grain boundaries of 20 µm polycrystalline aluminum powder, while a minute contribution to melting is observed. This manuscript demonstrates the capability of the QCGD-TTM method to capture laser-powder interaction and allow the investigation of the kinetics of laser melting.
Cellular automaton simulation of solid-phase grain growth under conditions involving scanning heat sources and temperature gradients
Authors: Murata Kenji , Chen Ta-Te , Sun Fei , Adachi Yoshitaka 
Published: September 2024

Abstract
A cellular automaton simulation of grain growth in a solid phase was conducted, considering the temperature gradient, heat source movement, and conditions favoring prioritized grain growth. The results reveal that, under optimal conditions, cellular grains elongated in the direction of the heat source movement. Detailed simulations illustrate the dynamics of grain growth and effect of mobility and driving forces on the dynamics, providing valuable insights into cellular grain growth in a solid phase.
Genetic algorithm optimization of langevin thermostat and thermal properties of graphene-aluminum nanocomposites: a molecular dynamics
Authors: Toprak Kasim 
Published: September 2024

Abstract
The thermal properties of a laminated structure of graphene-coated aluminum composite nanomaterial were investigated through non-equilibrium molecular dynamics (NEMD) simulations to address the problem of temperature deviation in the thermostat volume applied. This paper presents a new insight into the best values of timestep and Langevin thermostat damping parameters for each atom in the nanomaterial with different size configurations using the genetic algorithm (GA) method by considering the timestep and thermostat damping parameters for each atom type, as well as the thickness of the nanomaterial, the thermostat, buffer, and heat flow lengths. The initial population results indicate that the thermostat temperature deviation increases with higher thermostat damping coefficients and timestep. However, the deviation decreases significantly with increased heat flow and thermostat lengths. Variations in buffer length and aluminum thickness do not have a significant effect on temperature. The application of a GA for optimization leads to a decrease in thermostat temperature deviation. The optimized parameters resulted in better thermostat temperature deviations when analyzing the temperature, aluminum thickness, and both buffer and thermostat lengths. Additionally, the thermal conductivity of aluminum-graphene nanomaterial decreases with increasing temperature, buffer length, and aluminum thickness, but increases by up to 9.85% with increasing thermostat length.
4D printing of polylactic acid (PLA)/PLA-thermoplastic polyurethane (TPU)-based metastructure: examining the mechanical, thermal, and shape memory properties
Authors: Ladakhan Saiyadali H , Sreesha Rakshith B , Makireddypalli Adinarayanappa Somashekara 
Published: September 2024

Abstract
In the present day and age, increasing demand concerning the enhancement of the mechanical performance of shape memory polymer (SMP) based structures has paved the way for developing newer metastructures of enhanced load-bearing, damping capacity, and durability. The present study focuses on developing SMP-based metastructures made of commercially available polylactic acid (PLA) and 30% by wt. of thermoplastic polyurethane (TPU) blended PLA. The designed metastructures are initially analyzed using numerical modeling to prevent lateral deformation, acute stress concentration zones, and row-wise collapse. Mechanical tests reveal that blending TPU with PLA enhances the material’s flexibility and ductility, further improving the toughness and fracture resistance of the built metastructures. Loading-unloading and shape recovery tests (under compression mode) of the s-shape metastructure reveal that the PLA/TPU metastructure withstands ≅ 170 N load, less than neat PLA’s ≅ 223 N due to TPU’s flexibility. PLA/TPU endures 30 cycles, while PLA fails after the 9th cycle. In shape recovery plots, PLA/TPU metastructures exhibit a lower standard deviation (∼0.32%) than PLA (∼1.4%), attributed to the entropy decrease and cross-linkage disentanglements of PLA. Furthermore, a dynamic mechanical analyzer (DMA) assesses glass transition temperature, energy storage capability, and dissipation in variation with the temperature. The nephograms of ABAQUS result divulge accurate fracture initiation locations of the metastructure unit cells, which involves implementing ductile damage behavior modeling by employing damage initiation and evolution parameters. Finally, assessing compression tests and shape recovery behavior results elucidates that these SMP-based metastructures are promising for load-bearing pallets in the transporting and packaging industries, providing superior damping and self-repairing capabilities during significant plastic deformations.
A multi attribute decision making framework based on partitioned dual Maclaurin symmetric mean operators under Fermatean fuzzy environment
Authors: Roy Susmita 
Published: September 2024

Abstract
In information aggregation, the Maclaurin symmetric mean (MSM) operator has drawn a lot of interest to the researchers. And, partitioned dual MSM (PDMSM) has a precondition that all attributes are grouped into several partitions and the attributes in the same partition are relevant to other attributes in the same group, while the attributes located in different groups have no relation. The Fermatean fuzzy set (FFS), on the other hand, is a potent mathematical model that effectively manages uncertain data. The existing FFS-based multi attribute decision making (MADM) techniques fail to evaluate the partitions of the relative attributes, the interdependencies between various criteria, and the ability to mitigate the detrimental impacts of irrelevant criteria. Motivated by these issues, this paper proposes novel operators named FFPDMSM and weighted FFPDMSM to handle the scenarios where criteria are divided into distinct parts and there are interconnections among multiple criteria within the same part. The proposed operators deal not only with interrelationships between criteria but also with partitioned relationships among criteria. Some properties of the proposed operators are discussed in detail. Further, an MADM approach is developed based on the proposed operators in the FF environment. A realistic numerical illustration with sensitivity analysis is demonstrated to validate the proposed approach. Finally, the method is compared with different existing techniques to demonstrate the proposed method’s applicability and feasibility.
Exploring Al composition and diameter effect on AlxGa1-xAs nanowire photocathodes via first-principles calculations with DFT+U method
Authors: Diao Yu , Xia Sihao 
Published: September 2024

Abstract
Utilizing first-principles calculations with DFT+U method, the structural, electronic and optical behaviors of AlxGa1-xAs nanowire photocathodes modulated by Al composition and diameter are systematically investigated. The findings reveal that the structural stability of AlxGa1-xAs nanowires is progressively enhanced as either the Al composition or the wire diameter increases. Additionally, the charge transfer in nanowires induced by altering the Al composition is significantly greater than that caused by varying wire diameter. Wurtzite AlxGa1-xAs nanowire is a direct bandgap material. Moreover, the continuously reduced bandgap resulting from an increase in diameter confirms the size effect of the nanowire. In addition, the introduction of DFT+U method presents an accurate theoretical bandgap with higher efficiency. The error of the bandgap between predication and experimental results is less than 4% in the case of bulk AlxGa1-xAs. The optical property of AlxGa1-xAs nanowire is more susceptible to the influence of wire diameter compared to that of Al composition. Furthermore, the optical absorption spectrums exhibit a slight blueshift and a redshift with increasing Al composition and wire diameter, respectively. This study is anticipated to provide theoretical support for the design of optoelectronic devices based on AlxGa1-xAs nanowires.
Numerical investigation of saline gravity currents with different water depth and salinity based on the lattice Boltzmann method
Authors: Xu Keqin , Liao Jianghua , Yang Shengfa , Wu Peng , Hu Jiang 
Published: September 2024

Abstract
In this paper, we used Lattice Boltzmann Method (LBM) to simulate the motion of saline gravity currents, considering different cases of water depth and salinity, aiming to evaluate the reliability of the LBM model and investigate the longitudinal properties of the gravity currents. The study in this paper was divided into two phases. The first phase explained the basic principles and the implementation process of the numerical model. By comparing the simulation results with laboratory experimental data, it was found that the simulation results were in good agreement with the laboratory experiments. The second phase of the study simulated the saline gravity currents with different water depths and salinities. It was observed that, due to the increasing density gradient, the front velocity of dense current increased with rising water depth and saltwater salinity, and the intensity of turbulence at the interface was enhanced.
Heat transfer performance of MHD [Ag+Gr+GO/H2O]t ternary nanofluid squeezing flow between two parallel plates in a porous medium with variable viscosity and brownian motion
Authors: Venkateswarlu B , Joo Sang Woo , Narayana P V Satya , Metwally Ahmed Sayed M 
Published: September 2024

Abstract
A novel notion in the realm of research is that ternary nanofluid presents itself as a cutting-edge concept showcasing enhanced heat transfer capabilities when pitted against hybrid nanofluids as well as traditional nanofluids. These ternary nanofluids are employed for boosting thermal conductivity in cooling systems, thereby enhancing energy efficiency in electronics and industrial operations. This research aims to investigate the dynamic viscosity variations within a three-component nanofluid comprising Ag, Gr, and GO nanoparticles suspended in water enclosed between dual parallel plates with entropy generation. The examination encompasses the impact of viscous dissipation, thermophoresis, and Brownian motion occurrences within the energy equation, along with considering chemical reactions in the concentration equation. Techniques of similarity are utilized to transform the complex nonlinear partial differential equations into a collection of ordinary differential equations. The necessary equations that arise are attempted through the utilization of the Runge–Kutta-Fehlberg technique in combination with a shooting method. The research examines graphs and tables to study the effects of new factors on velocity, temperature, concentration, and engineering measures. The outcome of the finding shows that the magnetic field and suction cause a greater decrease in [Ag/H2O]n nanofluid velocity, while an increased squeezing limit elevates [Ag+Gr+GO/H2O]t ternary nanofluid velocity. Increasing thermophoresis and Brownian motion enhance temperature in ternary nanofluid, but [Ag/H2O]n nanofluid concentration diminishes with chemical reaction. Entropy production intensifies in ternary nanofluids due to higher radiation and Brinkman numbers. The magnetic field increases the skin friction of ternary nanofluids by 3.4% at both plates but it decreases by 4.12 more in nanofluids because of alterations in the viscosity factor. Heat transfer decreases by 3.05% at the lower plate but increases by 6.01% at the upper plate in ternary nanofluids due to heat production and thermophoresis. An increase of 3.95% in mass transfer rate is observed in the ternary nanofluid at the lower plate but a decrease of 2.06% is noted at the upper plate due to thermophoresis and Brownian motion. The discoveries illuminate the possibilities of ternary nanofluids to boost thermal conductivity and maximize energy efficiency across a range of industrial applications.
Partial loopholes free device-independent quantum random number generator using IBM’s quantum computers
Authors: Yadav Abhishek , Mishra Sandeep , Pathak Anirban 
Published: September 2024

Abstract
Random numbers form an intrinsic part of modern day computing with applications in a wide variety of fields, and quantum systems due to their intrinsic randomness form a suitable candidate for generation of true random numbers that can also be certified. In this work, we have demonstrated the use of cloud based quantum computers to develop a partially loophole free device-independent quantum random number generator (QRNG). The generated random numbers have been tested for their source of origin through experiments based on the testing of Clauser, Horne, Shimony, and Holt (CHSH) inequality through available IBM quantum computers. The performance of each quantum computer against the CHSH test has been plotted and characterized. Further, efforts have been made to close as many loopholes as possible to produce device-independent quantum random number generators. This study will help provide new directions for the development of self-testing and semi-self-testing random number generators using quantum computers.
On sequences of convex records in the plane
Authors: Godrèche Claude , Luck Jean-Marc 
Published: September 2024

Abstract
Convex records have an appealing purely geometric definition. In a sequence of d-dimensional data points, the nth point is a convex record if it lies outside the convex hull of all preceding points. We specifically focus on the bivariate (i.e. two-dimensional) setting. For iid (independent and identically distributed) points, we establish an identity relating the mean number

⟨

R
n

⟩

of convex records up to time n to the mean number

⟨

N
n

⟩

of vertices in the convex hull of the first n points. By combining this identity with extensive numerical simulations, we provide a comprehensive overview of the statistics of convex records for various examples of iid data points in the plane: uniform points in the square and in the disk, Gaussian points and points with an isotropic power-law distribution. In all these cases, the mean values and variances of Nn
and Rn
grow proportionally to each other, resulting in the finite limit Fano factors FN
and FR
. We also consider planar random walks, i.e. sequences of points with iid increments. For both the Pearson walk in the continuum and the Pólya walk on a lattice, we characterise the growth of the mean number

⟨

R
n

⟩

of convex records and demonstrate that the ratio

R
n

/

⟨

R
n

⟩

keeps fluctuating with a universal limit distribution.
AMI water meters deliver end-use water and financial savings in leaky households: experimental evidence from California
Authors: Rupiper Amanda M , Good Robert T , Ackerman Jonathan , Gregory Jack , Jessoe Katrina K , Loge Frank J 
Published: September 2024

Abstract
Advanced metering infrastructure (AMI) for residential water consumption is exploding globally giving water utilities the ability to improve their water tracking, billing, and distribution systems’ leak detection. With AMI, utilities have also gained the opportunity to provide real-time high-resolution water consumption information to their customers to induce conservation. Using a randomized controlled trial we find that on average homes that install AMI and receive conservation based messaging significantly reduce water consumption by 5.24 gallons per household per day beyond savings already obtained from home water reports. Of the estimated water savings we attribute 92.8% to leak reduction. While the payback period from the deployment of AMI meters and treatment in all homes is over 41 years, homes that experience leaks realize financial savings of $60/year and a treatment payback period of four years. This is because treatment did not induce water or financial savings in homes without leaks. These findings indicate that even on top of existing conservation programs, AMI messaging that targets end-user leaks could result in significant water savings, economic benefits to end-users, and advance conservation goals.
Experimental study on tribological properties of PTFE and glass reinforced PTFE-C15 for skid transport of heavy structures
Authors: Gunes Cihan , Makaraci Murat 
Published: September 2024

Abstract
Efficient transportation requires minimal frictional resistance. Skidding has become an alternative method of transporting heavy structures in recent years. The static coefficient of friction plays an important role in determining whether the piston force in the thrust direction is sufficient to counteract the horizontal frictional force caused by the structure’s weight. This study aimed to determine various static coefficient of friction values for PolyTetraFluoroEthylene (PTFE) and glass-reinforced PTFE-C15 materials on steel skids. The research presents the influence of lubrication and the reduction of surface roughness on the static coefficient of friction. We designed six combinations of experiments for 10 repetitions for PTFE and PTFE-C15 under dry, oiled, and oil lubrication with added weight conditions. An inclined plane method was used to investigate and compare the coefficients of friction values of pure PTFE and glass-reinforced PTFE-C15 materials on a steel surface. The steel surface roughness was reduced by grinding to an average Ra value of 2.8 to minimize adhesion, which created a vacuum effect during the test. The application of added weight onto the specimens overcame the vacuum effect. PTFE-C15 in oil lubrication with added weight demonstrated the lowest coefficient of friction. However, it is noteworthy that pure PTFE had better performance than PTFE-C15 when both were oil-lubricated. These results provide essential data for precise engineering calculations to determine the required piston force and total number of pistons for loading heavy structures.
Synthesis of metal powders via reduction of carbonates in self-stirred autoclave
Authors: Bai Liuyang , Qu Linmin , Fu Huitan , Yang Zongxian 
Published: September 2024

Abstract
Commercial carbonates were used as the metal sources for synthesis of metal powders, and a self-stirred autoclave device was proposed to accelerate the complete reduction of carbonates. Fluent software was employed to simulate the system and analyze the distribution of the solution and particles in the autoclave, Ni and Cu powders were synthesized to verify the experiment’s feasibility. Results indicate that sufficient mixing of reactants, solvents, and intermediate products is maintained in the improved self-stirred autoclave throughout the reaction process, facilitating the full reduction of carbonates and enhancing the uniformity of metal powders. Additionally, because basic carbonates can neutralize the hydrogen ions produced by the reduction reaction, and thus Ni powders can be synthesized without NaOH added, which is beneficial for controlling particle morphology and saving reaction time. Well-dispersed Ni and Cu powders were synthesized via the present route, which is possible to promote the reduction preparation of ultrafine metal powders for other insoluble and slightly soluble metal salts.
Comparison of Monte Carlo tally techniques for dosimetry in a transmission-type x-ray tube
Authors: Feng Chen-Ju , Lin Chin-Hsiung , Wu Shu-Wei , Luo Shih-Yong , Yang Ya-Ru , Lee Chao-Hua , Tseng Shao-Chun , Lee Shen-Hao , Hsu Shih-Ming , Wu Chin-Hui 
Published: September 2024

Abstract
This study discussed comparing result accuracy and time cost under different tally methods using MCNP6 for a novel transmission x-ray tube which was designed for the Auger electron yield with specific material (e.g. iodine). The assessment included photon spectrum, percent depth dose, mass-energy absorption coefficient corresponding to air and water, and figure of merit comparison. The mean energy of in-air phantom was from 41.8 keV (0 mm) to 40.9 keV (100 mm), and the mean energy of in-water phantom was from 41.41 keV (0 mm) to 45.2 keV (100 mm). The specific dose conversion factors based mass-energy absorption coefficient corresponding to different materials was established and the difference was less than 2% for the dose conversion of FMESH comparing to measurement data. FMESH had better figure of merit (FOM) than the F6 tally for the dose parameter assessment, which mean the dose calculation that focused on the superficial region could be assessed with more calculation efficiency by FMESH tally for this novel transmission x-ray tube. The results of this study could help develop treatment planning system (TPS) to quickly obtain the calculated data for phase space data establishment and heterogeneous correction under different physical condition settings.
Influence of silver nanoparticles on enhancing performance of optical absorption property in a perovskite solar cell
Authors: Soemphol Chaiyong , Dasri Thananchai 
Published: September 2024

Abstract
This report presents a mostly numerical investigation of solar absorptance enhancement in PSCs through solving partial differential equations. The designed structural device comprised five layers of the transparent conducting contact (ITO), the electron transport layer (TiO2), the active layer (CH3NH3PBI3) embedding with plasmonic silver nanoparticles (AgNPs), the hole transporting layer (NiO), and the back reflectors (Ag). The calculation results showed that the device performance was highly dependent on the particle size of AgNP, structural formation and the location of the AgNPs. Overall, the optimum particle radius was

r
=
10

nm
,

located at the middle of the activated layer

z
=
0

nm

,

a 2-dimensional array of

2
×
2

particles per unit cell and an interparticle distance of

4

nm

were achieved for the AgNPs in the active layer (AL) of the PSCs with the highest optical enhancement of

η
=
1.24
.