bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of antibacterial masterbatches selection on the crystal structure and properties of nanosilver composite materials
Authors: Tian Chengcheng , Li Yang , Liu Li‐Zhi , Wang Yuanxia , Shi Ying 
Published: August 2024

AbstractThe distribution of nanosilver in composite materials with two different matrices is related to the selection of antibacterial masterbatches, which has a profound impact on the antibacterial effectiveness of the composite materials. This study utilized ethylene‐vinyl acetate (EVA) and polypropylene (PP) as base materials to fabricate two types of nanosilver composite materials (C1‐EVA/PP and C2‐EVA/PPP) employing varying methods of antimicrobial masterbatches incorporation. Additionally, EVA‐Ag and PP‐Ag nanosilver composite materials were fabricated via melt blending, along with corresponding neat materials and blends (EVA, PP, and C0‐EVA/PP) for comparison. The study results indicate that the addition of nanosilver did not affect the functional groups of either the neat materials and the EVA/PP blends. SEM analysis revealed that nanosilver was dispersed unevenly in the C1‐EVA/PP substrate, while it was more uniformly distributed in the C2‐EVA/PP substrate. In the antibacterial test, the antibacterial rate of C2‐EVA/PP was higher than that of C1‐EVA/PP (56.0% vs. 40.0%). However, all silver‐containing composite materials did not exhibit antibacterial properties in the agar diffusion test. Additionally, nanosilver exhibited an induced crystallization effect on the PP phase of the C2‐EVA/PP composite material, increasing its Tc2 by 0.8°C. Compared with pure PP, the long period of PP‐Ag increased by 0.7 nm, and its impact resistance improved by 13.8%. By comparison, the long period of EVA‐Ag composite materials increased by only 0.2 nm compared to pure EVA. Both C1‐EVA/PP and C2‐EVA/PP composite materials showed 0.3 nm increase in long period compared to C0‐EVA/PP, with their impact resistance improving by 3.1% and 10.3%, respectively, compared to C0‐EVA/PP. The introduction of nanosilver increased the storage modulus, loss modulus, and apparent viscosity of EVA/PP blends. Optical performance analysis shows that nanosilver increases the internal haze of C1‐EVA/PPP by 60% while reducing the transmittance by 0.3%. The effect of nanosilver on the optical properties of C2‐EVA/PPP composites is relatively small. Therefore, this study provides theoretical guidance for the selection of processing methods for dual‐phase antibacterial materials.Highlights
Different antibacterial masterbatch impacts silver distribution in composites.
The addition of nanosilver can improve the impact performance of materials.
Two process methods were used to prepare low‐silver content composite materials.
The antibacterial rate of C2‐EVA/PP is higher than C1‐EVA/PP (56% vs. 40%).
This study guides the processing methods for dual‐phase antibacterial materials.
Comparison of different attract‐and‐kill device densities to control the adult population of Popillia japonica (Coleoptera: Scarabaeidae)
Authors: Paoli Francesco , Barbieri Francesco , Iovinella Immacolata , Sciandra Chiara , Barzanti Gian Paolo , Torrini Giulia , Sabbatini Peverieri Giuseppino , Mazza Giuseppe , Benvenuti Claudia , Sacco Davide , Martinetti Davide , Roversi Pio Federico , Marianelli Leonardo 
Published: August 2024

AbstractBACKGROUNDPopillia japonica Newman is a scarab beetle native to Japan that is considered a serious pest outside its native range. It can feed on more than 400 host plants and spread about 10 km per year in invaded territories, therefore it is considered the second most important quarantine pest in Europe. Both chemical and biological insecticides have been used for control, with variable results. Despite ongoing efforts, P. japonica remains a threat in invaded countries, and it is necessary to test more effective and sustainable solutions in the context of integrated pest management. Here we present a study on long‐lasting insecticide‐treated nets (LLINs) assembled in semiochemical‐baited attract‐and‐kill devices (A&Ks) as a means to control adults of P. japonica with low environmental impact. This study complements previous ones in which we first evaluated the effectiveness of the LLINs in the laboratory and then tested both effectiveness and duration in field‐exposed A&Ks against P. japonica. In the present work we compared the effectiveness of three different densities of A&Ks per hectare in areas where the population of P. japonica was numerically homogeneous.RESULTSThe different densities of A&K (1, 2, 4 A&Ks per ha) resulted in an overall reduction of the population of P. japonica by about two thirds in comparison to the control area.CONCLUSIONSThis study suggests that the use of one A&K per hectare, requiring minimal management effort, is an effective ratio for reducing local populations of P. japonica. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Universal Quantum Fisher Information and Simultaneous Occurrence of Landau‐Class and Topological‐Class Transitions in Non‐Hermitian Jaynes‐Cummings Models
Authors: Ying Zu‐Jian 
Published: August 2024

AbstractLight‐matter interactions provide an ideal testground for interplay of critical phenomena, topological transitions, quantum metrology, and non‐Hermitian physics with high controllability and tunability. The present work considers two fundamental non‐Hermitian Jaynes‐Cummings models in light‐matter interactions that possess real energy spectra in parity‐time (PT) symmetry and anti‐PT symmetry. The quantum Fisher information is shown to be critical around the transitions at the exceptional points and exhibit a super universality, with respect to different parameters, all energy levels, both models, symmetric phases, and symmetry‐broken phases, which guarantees a universally high measurement precision in quantum metrology. In particular, the transitions are found to be both symmetry‐breaking Landau‐class transitions (LCTs) and symmetry‐protected topological‐class transitions (TCTs), thus realizing a simultaneous occurrence of critical LCTs and TCTs that are conventionally incompatible due to contrary symmetry requirements. Besides establishing a paradigmatic case to break the incompatibility of the LCTs and the TCTs in non‐Hermitian systems, the both availabilities of the sensitive critical feature and the robust topological feature can also provide more potential for designing quantum devices or sensors.
Dynamic event‐triggered leader‐following bipartite consensus of second‐order multi‐agent systems under DoS attacks
Authors: Wang Xiao , Liu Jian , Wu Yongbao , Sun Changyin 
Published: August 2024

AbstractThis article investigates the bipartite secure consensus of the second‐order leader‐follower multi‐agent systems (MASs) against aperiodic denial of service (DoS) attacks. First, a new dynamic event‐triggered strategy is proposed for the consensus control. Compared with the static event‐triggered strategy, the dynamic event‐triggered protocol can reduce the trigger times and save resources by introducing an internal dynamic variable. Different from the secure consensus results which only discussed the cooperative links, based on the theory of the structurally balanced graph, this article considers cooperative and antagonistic interactions among agents simultaneously for complex behaviors of them. Besides, the characteristics of the DoS attacks are analyzed in detail and the secure consensus is achieved by utilizing the Lyapunov theory and inductive methods. Finally, the Zeno behavior is excluded and the availability of the designed algorithms is demonstrated by numerical simulations.
Grain Manipulation by Annealing Treatment Realizes High‐Performance N‐Type Bi2Te2.4Se0.6 Thermoelectric Material and Device
Authors: Chen Lidong , Guo Zhe , Wu Gang , Tan Xiaojian , Sun Peng , Wu Jiehua , Liu Guo‐Qiang , Jiang Jun 
Published: August 2024

AbstractBi2Te3‐based materials play a crucial role in solid cooling and power generation, but the rapidly deteriorated ZT with rising temperatures above 450 K severely limits further applications. Here, this paper reports a novel preparation method of annealing treatment for molten ingot, which can enhance the thermoelectric performance of n‐type Bi2Te2.4Se0.6 in a wide temperature range. Instead of conventional halides, copper is adopted to regulate the carrier concentration and grain size to optimal levels. During the process of annealing at 573 K for 4 h, the number of twins significantly increases and the grains of Cu‐doped samples become larger and more oriented. These optimizations lead to higher carrier mobility with similar carrier concentration compared with the sample without heat treatment. The synergistic effects of Cu doping and annealing treatment realize a high average ZT of 0.89 within 300–600 K in n‐type Cu0.02Bi2Te2.4Se0.6. Combined with p‐type (Bi,Sb)2Te3, the fabricated thermoelectric device exhibits a high conversion efficiency of 6.9% at a temperature difference of 300 K. This study suggests that annealing treatment is a simple and effective scheme to promote the applications of n‐type Bi2(Te,Se)3 in a wide temperature range.
Mycobacterium genavense detection in a blood smear from a domestic ferret
Authors: Fonseca Joana , Silveira João , Duarte Vanessa , Canejo‐Teixeira Rute , Patrício Rui , Belas Adriana 
Published: August 2024

AbstractThe domestic ferret is sensitive to mycobacterial infections, which are likely underdiagnosed. There are limited reports of therapy for mycobacteriosis in ferrets and most have failed. A ferret in poor body condition revealed marked organomegaly on diagnostic imaging. The complete blood count revealed a mild pseudoeosinophilia, which might be attributed to negatively stained bacilli phagocytised by monocytes observed in the blood smear. Ziehl–Neelsen stain was performed and showed acid‐fast bacilli within monocytes. Fine‐needle aspirates of the spleen and liver revealed the same finding. Mycobacterium genavense was identified by PCR and DNA sequencing from peripheral blood. Treatment with rifampicin, clarithromycin and enrofloxacin was initiated. The disseminated mycobacteriosis was suspected from the observation of bacilli on the blood smear. After 16 months, the ferret is still undergoing treatment. To prevent recurrence, continued monitoring of drug toxicity and effective therapy will be maintained even after the resolution of clinical signs (mostly organomegaly).
Analysis of Multiaxial Tensile Stresses in Cold Forging Tools
Authors: Killmann Martin , Merklein Marion 
Published: August 2024

AbstractTools have a key role in cold forging as they directly influence part quality and process economics. High loads from the contact pressure exhibited by the workpiece are a major challenge regarding tool life. In complex geometries, tensile die stresses are concentrated in local areas and oriented both in axial and tangential directions. This superposition of loads leads to fatigue failure at the stress peaks. Since the interactions of multidirectional tensile stresses in cold forging tools have not been investigated in previous investigations, this paper aims to better understand the formation of local stress concentrations in axial and tensile directions as well as the possibilities to influence them. As tool loads in critical areas are difficult to measure during the process, simulation plays an important role in the evaluation of die stresses. Therefore, a model process with multiaxial tool stresses is simulated and the simulation results are compared to experimental values in order to validate the model. The simulation is then used to analyse the die load depending on the prestressing system.
Sensitivity Analysis and Formulation of the Inverse Problem in the Stochastic Approach to Modelling of Phase Transformations in Steels
Authors: Szeliga Danuta , Jażdżewska Natalia , Foryś Jakub , Kusiak Jan , Nadolski Rafał , Oprocha Piotr , Pietrzyk Maciej , Potorski Paweł , Przybyłowicz Paweł 
Published: August 2024

AbstractThe need for a reliable prediction of the distribution of microstructural parameters in metallic materials after processing was the motivation for this work. The model describing phase transformations, which considers the stochastic character of the nucleation of the new phase, was formulated. Numerical tests of the model, including sensitivity analysis, were performed and the optimal parameters such as time step, kind of the random numbers generator (RNG) and the number of the Monte Carlo points were determined. The validation of the model requires an application of proper coefficients corresponding to the considered materials. These coefficients have to be identified through the inverse analysis, which, on the other hand, uses optimization methods and requires the formulation of the appropriate objective function. Since the model involves stochastic parameters, it is a crucial task. Therefore, in the second part of the paper, a specific form of the objective function for the inverse analysis was developed. In the first approach, an objective function based on measurements of the average parameters was used and primary optimization was performed. Various optimization methods were tested. In the second approach, the hybrid objective function, which combined measured average transformation temperatures with a measure based on histograms, was used. Since, at this stage, we do not have measurements of the distribution of microstructural features, the basic histograms were generated by the model with the coefficients obtained in the first step of the optimization. The capability of finding the optimal solution for different starting points was evaluated and various approaches were compared. The elaborated original stochastic approach to modelling the phase transformations occurring during cooling after hot forming was validated on selected carbon steel.
Cold Forging of Hollow Shafts with Variable Wall Thickness by Means of an Adjustable Forming Zone
Authors: Weiß Alexander , Liewald Mathias 
Published: August 2024

AbstractHollow shafts are widely used due to their high weight saving potential and only slight reduction of their bending and torsional stiffness compared to solid shafts. Additional weight savings can be achieved by a specific material allocation within the hollow shaft, which can be achieved by varying their wall thickness. The production of such hollow shafts by conventional forming processes and multiple forming stages appears quite costly today. Alternatively, incremental forming processes could be used, but those are very time-consuming. In order to overcome these disadvantages, this paper proposes a special cold forging process characterized by a locally adjustable forming zone, which allows the production of hollow shafts with variable wall thickness within one single press stroke. In previous numerical investigations, the potential of this cold forging process for the production of customized hollow shafts with predefined wall thickness locations or internal splines has already been demonstrated. However, experimental validation has not yet been carried out. In this paper, the first experimental results on hollow shafts produced with wall thickness changes along their longitudinal direction are presented. The experimental setup and the results of the tests carried out so far are described. Furthermore, the experimental results are compared with the numerical calculations of this new forming process.
Numerical and Experimental Analysis of the Influence of Manufacturing Parameters in Additive Manufacturing SLM-PBF on Residual Stress and Thermal Distortion in Parts of Titanium Alloy Ti6Al4V
Authors: Santos M. O. , Maiolini A. S. F. R. , Miranda F. , Farias A. , Seriacopi V. , Bordinassi E. C. , Batalha G. F. 
Published: August 2024

AbstractAdditive manufacturing (AM) has become popular in recent years due to its integration with Industry 4.0 and for enabling the production of complex and optimized geometries. However, the process leads to disadvantages, such as thermal distortions and the generation of residual stresses due to thermal gradients during the parts production. Based on these undesirable characteristics, this work aims to model AM numerically through the Finite Element Method (FEM), besides obtaining experimental results that relate the impact of different process parameters, such as laser power, speed, and hatch distance on the residual stress and distortions distribution, to parts generated by Selective Laser Melting (SLM)—Powder Bed Fusion (PBF)—of titanium alloy Ti6Al4V. The experimental tests, as well as the numerical analyses, followed a factorial design. The results for thermal distortions are excellent with differences below 4.5% between the manufactured and simulated parts. As for the results of residual stresses measured at a single point on the lateral face, for most of the results, the difference was less than 4%; however, there was a large dispersion of results. When the values of average residual stresses were considered in the simulation, the results had statistical relevance and showed greater robustness. It was found that the average diameter of Ti6Al4V titanium parts was greatly influenced by the laser power followed by the hatch distance. The increase in power increased the average diameter of the samples, while the increase in speed and hatch decreased their diameter. In turn, increasing laser power decreased residual stress, while increasing speed and hatch tended to increase the mean residual stress.
Reduced Three-Dimensional Model for Cold Rolling Simulation of Aluminium Alloys
Authors: Pachnek Florian , Simon Peter , Zeman Klaus 
Published: August 2024

AbstractMathematical modelling and computational analyses allow to deepen the understanding of manufacturing processes, to ensure high product quality and to reduce experimental efforts for the optimization of product properties and production processes. In order to predict the evolution of flat rolled aluminium product properties and their interdependence with process parameters, virtual representations of the entire process chain including process models of hot rolling, coiling, and cold rolling operations are highly beneficial. Starting from the solid foundation of a comprehensively validated 3D model of the hot rolling process of various aluminium alloys, the present work presents a 3D thermo-mechanical cold rolling simulation model using the commercial finite element code LS-DYNA. The material behaviour is considered by means of a user defined material model according to a modified dislocation density based flow model. The calculated microstructural and deformation history of the hot rolled strip is considered as input for the developed cold rolling model allowing for seamless prediction of product properties. For numerical studies, a modular modelling approach is pursued, comprising tailor-made simplifications depending on actual applications and research problems. For time efficient multi-pass simulations in an industrial environment, a reduced model with plane strain conditions is derived that extends the predictability of product properties and process parameters from hot rolling over coiling to cold rolling. Simulation results and computational costs are compared with detailed 3D models. Strip tensions can be adjusted showing the expected effects on roll separating forces and minimum rolled thickness. To ensure the desired strip tensions in the numerical model, a sensor-based control of strip tensions is implemented. For validation purposes, measured rolling forces from industrial pass schedules for 6xxx series alloys are compared against simulation results.
Effect of Welding Processes on Microstructure and Mechanical Properties of Laser-Welded Al-Si-Coated 22MnB5 Steel
Authors: He Qi , Hou Zeran , Kong Jie , Deng Lulu , Ma Xiaolong , Min Junying 
Published: August 2024

AbstractTailor welded blank (TWB) has been developed in the automotive industry to improve structural safety and material efficiency. Al-Si-coated 22MnB5 steel is the main material for laser tailor welding due to its resistance to oxidation and decarburization during hot stamping, which can otherwise deteriorate the performance of welded joints. This study investigates the use of partial ablation welding (PAW) and filler wire welding (FWW) as compared to traditional self-fusion welded (SFW) to enhance the mechanical performances of Al-Si-coated 22MnB5 steel welded joints. The effects of welding processes on the microstructure of welded joints as well as the mechanism of performance enhancement were investigated. Tensile testing results showed that PAW and FWW joints consistently fractured at the base material, whereas the SFW joints fractured at the weld seam. The maximum tensile loads of PAW and FWW joints were, respectively, 12.75 and 12.93% higher than that of SFW joints. Additionally, the microhardness distribution of PAW and FWW joints is uniform with no softening zone. Finally, the study discusses the improved mechanical properties of PAW and FWW joints in terms of microstructural evolution and diffusion of Al elements.
Integration of Material Simulation to Extend the Accuracy of FEM Results for Metallic Forming Processes
Authors: Helas Kristin , Biba Nikolay 
Published: August 2024

AbstractNowadays, almost all metallic forming processes can be mapped by FEM simulation. Demands on FEM simulation are becoming increasingly higher with regard to the representation of very fine tolerances, whether in terms of temperature or dimensional accuracy. The combination of a FEM software suitable for the forming process and a connected materials database is a great potential to enlarge these precision figures. In the article, real simulation examples with QForm UK are used to show how this combination positively affects the accuracy of simulation results. For this purpose, several material data—such as flow curves, temperature-dependent properties, or CCT diagrams—and material models—such as the recrystallization or phase transformation model—from the materials database MatILDa® are applied. Hereby, the possibilities of material simulation are demonstrated and practical methods to improve individual simulation projects are given.
Productivity Growth
Authors: Prados de la Escosura Leandro 
Published: August 2024

AbstractThis chapter assesses long-term productivity growth and its immediate determinants in Spain. Over the last 170 years, output per hour worked dominated GDP growth, while hours worked per person shrank by one-quarter and population trebled. Half of labour productivity growth resulted from capital deepening and one-third from efficiency gains (total factor productivity). Labour productivity proceeded steadily, accelerating during the 1920s and from the mid-1950s to the late 1980s, but decelerated thereafter as capital deepening slowed down and TFP stagnated due to the fact that expanding sectors attracted less investment-specific technological progress, largely a result of institutional constraints.
B meson mixing at NNLO: technical aspects
Authors: Reeck Pascal , Shtabovenko Vladyslav , Steinhauser Matthias 
Published: August 2024

Abstract
We provide details to several technical aspects which are important for the calculation of next-to-next-to-leading order corrections to the mixing of neutral B mesons. This includes the computation of the master integrals for finite charm and bottom quark masses, projectors for products of up to 22 γ matrices and tensor integrals with up to rank 11.