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This study focuses on the ideal etching of defective MAX phases in a mechanical exfoliation process to produce vanadium-based MXenes. Two-dimensional MXenes exhibit high structural stability and excellent electrical conductivity, and can be applied as electrode materials. Mechanical exfoliation can be facilitated by modifying the vacancy in the V 2 AlC MAX phase, which makes etching challenging. We report the effects of M (vanadium), A (aluminum), and X (carbon) vacancies on the mechanical behavior of V 2 AlC via ab initio calculations. To this end, the anisotropic mechanical properties and strain–stress curves were calculated for MAX phases with different vacancies (x = 0.08, which corresponds to 8.33 at.%). The presence of vanadium vacancies significantly deteriorated the structural and mechanical properties compared to those of aluminum and carbon vacancies. Thus, it was confirmed that vanadium vacancies had a significant effect on the mechanical exfoliation of the MAX phases. These findings provide further insights into the design of MXenes. [ABSTRACT FROM AUTHOR]

The rapid development of technology and science determines the changes in a variety of areas. This change is also inevitable in processes of education and in didactics, creating new hopes and challenges. Modern education especially referring to the improvement of managerial skills requires tools and methods of teaching focused on preparing flexible infrastructures ready for mappings changeable acting conditions and making multivariant business decisions. Especially simulation-based education can be recommended for students who prefer learning by doing and are generally interested in more active knowledge and skills acquisition forms. The critical factor of successful education in many areas is students' attitude towards the content and forms of teaching. The aim of this article was to examine the understanding and analysis of students' attitudes regarding the concepts of business computer simulations and the usefulness of this type of teaching. [ABSTRACT FROM AUTHOR]

In order to solve a time-varying linear matrix equation with periodic noises, an anti-interference dynamic integral neural network (AI-DINN) is proposed. Based on an indefinite unbounded vector/matrix-type error function, the proposed AI-DINN includes an integral structure, a recursive structure, and an adjustment module. It has the excellent ability to overcome the interference of periodic noises. This paper theoretically proves the convergence and robustness of the proposed AI-DINN for solving the time-varying linear matrix equation with the interference of periodic noises. Computer simulation results verify that the proposed AI-DINN method based on different activation functions can achieve convergence within limited time with the interferences of different periodic noises. In addition, the proposed AI-DINN with different activation functions has its own advantages with the interference of different types of periodic noises. Furthermore, comparative simulation experiments verify that the proposed AI-DINN has better convergence and anti-interference performance compared with state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Trapping of multiple hydrogen (H) atoms inside vacancies in aluminum (Al) is related to the formation of H bubbles, which ultimately results in embrittlement of the material. However, the formation mechanisms of H bubbles are still not well known. In this work, we perform systematical ab initio simulations to study the trapping of H atoms inside vacancies, and its influence on the growth of vacancies. It is found that monovacancy can trap as many as 8 H atoms, forming Vac 1 H 8. H atoms prefer the off-center positions close to tetrahedral sites in vacancy. The shortest H–H bond length in vacancy is 2.10 Å among H atoms, which suggests that it is impossible to form H 2 molecule in monovacancy. The accumulation of H atoms reduces the vacancy formation energy closest to Vac 1 H m , promoting the formation of new vacancy. The newly produced vacancy can bind tightly with Vac 1 H m and form Vac 2 H m. With the similar way, the continuous formation of new vacancies and aggregation of H atoms may ultimately result in growth of Vac n H m and formation of superabundant vacancies and H bubbles in Al. [ABSTRACT FROM AUTHOR]

The potentiometric response of ion-selective electrodes (ISEs) with membranes simultaneously containing two ionophores: valinomycin and lithium ionophore Li VIII, as well as the cation exchanger potassium tetrakis(p-Cl-phenyl) borate in different concentrations is studied in KCl, LiCl and KCl + LiCl solutions. It is shown that ISEs with a membrane containing an excess of ionophores over the ion-exchanger provide Nernstian response to K+ and to Li+ ions. However, membranes with an excess of the ion-exchanger over valinomycin show Nernstian response to K+ only in mixed KCl + LiCl solutions with constant ratios of the concentrations of these electrolytes. On the contrary, the response to Li+ is obtained both in mixed and pure LiCl solutions. The results are semi-quantitatively explained using a simple mathematical model and respective computer simulation. [Display omitted] • Potentiometric response of ISEs with two ionophores and excess of ion-exchanger. • Valinomycin and Li VIII: non-Nernstian response in KCl, Nernstian in LiCl. • Nernstian response to K+ and to Li+ in mixed KCl + LiCl solutions. • Response to more strongly complexed ion (K+) is more prone to ion-exchanger excess. • Semi-quantitative explanation by computer simulations. [ABSTRACT FROM AUTHOR]

The structure of micelles of sodium dodecyl sulfate (SDS) is probed via analysis of small-angle x-ray scattering (SAXS) data with the aim to fit the data over an extended wavenumber q range. This provides detailed information on the micelle shape, which can be described as a polydisperse triaxial ellipsoidal core-shell structure according to model form factor fitting. This model was necessary to fit the data over a wide q range, which is not accurately represented by simpler models such as biaxial ellipsoidal core-shell structures. Data for SDS (at fixed concentration) in a NaCl concentration series revealed increasing structure factor effects with decreasing salt concentration. This reflects decreased charge screening on the headgroups. The structure factor could be modelled using a simple hard sphere structure factor. The analysis of form factor was complemented by atomistic molecular dynamics (MD) simulations, starting from an unbiased initial configuration of a defined number of molecules in a box. The MD configurations were used to calculate the form factor using the software CRYSOL (for small-angle scattering analysis of solution scattering, traditionally for proteins, here for micelles) and accounting for the boundary layer hydration effects. Good agreement with experimental data was found for systems with association numbers close to p = 60. This association number is consistent with that obtained from analysis of the form factor (in the case where structure factor effects could be neglected) and from model-free analysis of the forward scattering intensity. It is also in agreement with prior literature and our findings in regard to form factor parameters are also compared to previous reports. [Display omitted] [ABSTRACT FROM AUTHOR]

Adsorption of surfactants to fluid interfaces occurs in numerous technological and daily-life contexts. The coverage at the interface and other properties of the formed adsorption layers determine the performance of a surfactant with regard to the desired application. Given the importance of these applications, there is a great demand for the comprehensive characterization and understanding of surfactant adsorption layers. In this review, we provide an overview of suitable experimental and simulation-based techniques and review the literature in which they were used for the investigation of surfactant adsorption layers. We come to the conclusion that, while these techniques have been successfully applied to investigate Langmuir monolayers of water-insoluble surfactants, their application to the study of Gibbs adsorption layers of water-soluble surfactants has not been fully exploited. Finally, we emphasize the great potential of these methods in providing a deeper understanding of the behavior of soluble surfactants at interfaces, which is crucial for optimizing their performance in various applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The main obligation of higher education is to provide graduates with a set of competencies that will enable them to obtain viable employment. One of the tools which can support this process can be applying business computer simulations which can be the perfect instruments to increase student engagement, but also stimulate creativity or develop communication skills. It turns out that there is a demand for a specific set of skills in the labour market, which is currently in short supply among graduates. That is why there is a need to improve this area. Considering new approaches in education we decided to penetrate usage of business simulation – looking for novelties and contextual implementation. The purpose of the research is to present the important role of business computer simulations in supporting competencies and highlights areas of possible application and specifies key barriers that determine their implementation. [ABSTRACT FROM AUTHOR]

• The cooperative evolution (CE) model is the model of agent interaction that reveals possible synergetic effects in evolution. • Agents in the CE model are immobile entities with a finite lifespan and a defined life cycle: birth-growth-shrinkage-die. • Agents' cooperation starts immediately after they contact each other in the CE model space: involved agents get the bonus - lifespan extension • Bonus - mutual stimulation of agents brings about a threshold in the evolution of the CE model • The chaotic behavior of the calculated parameters of the CE model is also threshold dependent. We introduce a model of cooperative evolution of agents (CE model) on any lattice or graph with agents that have only one opportunity to evolve or grow during their lifespan, then shrink or shrivel to die. The CE model cooperative rule: growing agents meet in the model space, and each agent involved is granted a bonus lifespan. Such synergy is easy to find in studies of social media, economics, epidemiology, etc. In the current work, the CE model uses the 2D square regular lattice cellular space and the simplest evolution rules. Numerical simulation shows that the bonus lifespan introduces a threshold into the CE model and the agent-occupied space shows chaotic behavior depending on the CE model parameters. The CE model of cooperative evolution is rather simple but opens up many possibilities for further research to understand in depth the effects of cooperation and synergy, and thus on real-life evolution. [ABSTRACT FROM AUTHOR]

Surfactants play an increasingly important role across diverse scientific and industrial domains. Gaining a deeper understanding of their molecular behavior at various interfaces is thus becoming ever more essential. Despite considerable advances in experimental techniques, challenges in capturing the detailed molecular-level behavior of surfactants at interfaces persist. In this work, we discuss the potential of combining various experimental methods with atomistic molecular dynamics (MD) simulations in studies of surfactant interfacial layers. MD simulations have emerged as a powerful tool that provides detailed insights into molecular structures and dynamic properties, some of which are inaccessible through experimental means alone. By re-examining existing MD simulation data and directly comparing them with experiments, we illustrate how MD simulations can be used to validate and support thermodynamic models and interpret spectroscopy and scattering data. While combining scattering experiments on Langmuir layers of insoluble surfactants with simulations seems to be well-established by now, we emphasize the growing capability of scattering techniques to also investigate the more disordered Gibbs layers of soluble surfactants. Here, MD simulations can now connect the pressure and adsorption isotherms with the equation of state. In light of the ongoing parallel developments of computational and experimental methods, their synergistic use can be expected to drive future progress in surfactant research. [Display omitted] [ABSTRACT FROM AUTHOR]

We recently proposed two atomic structures of the Al 2 CuLi (T1) phase using first-principles density functional theory calculations. Here, we find that both the previously proposed T1 phases (Al 6 Cu 4 Li 3 , Al 13 Cu 7 Li 6) are predicted using X-ray absorption fine structure (XAFS) spectroscopy. It is found that the semi-coherent T1/Al interface of two T1 phases shows approximately 0.70 J/m2 with Al-Li termination at interface. Thus, there is a coexistence of both T1 phases in Al-Cu-Li alloys based on our computations. It is also found that the T1 formation is controlled by Ag and Mg solute segregations at interface over Cu/Li ratio based on bulk thermodynamics. • The T1 phase crystal structure in Al-Cu-Li alloy investigated by XAFS spectroscopy. • The interfacial energy and structure predicted using DFT calculations. • The results support the coexistence of previously proposed crystal structures. • T1 phase formation is controlled by Ag and Mg segregation at T1/Al interface. • Interface thermodynamics is more important than bulk thermodynamics. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study investigated metal-doped boron-nitride monolayer nanosheets. • Determined their ability to detect and adsorb specific toxic gases. • Examined their properties and humidity effects on sensing performance. • Investigated the tunability of adsorption using an applied electric field. • Results show that it is possible to design usable gas-sensing devices. The potential application of metallic boron bit-doped hexagonal boron nitride monolayers (h-BN@M, M = Fe, Sn, Cu, Zn) as materials for the detection of hazardous gases (CH 2 O, CH 4 , Cl 2 , HCN, and CNCl) has been investigated based on the first nature principle. h-BN@Fe exhibits chemisorptive properties for the adsorption of HCN and CNCl and h-BN@Sn exhibits chemisorption and appropriate humidity resistance. The recovery time of HCN on the h-BN@Fe surface and CNCl on the h-BN@Sn surface was significantly shortened under the 392 K ultraviolet light attempt frequency. In the presence of an applied electric field, HCN and CNCl on the h-BN@Fe surface and CNCl on the h-BN@Sn surface showed adjustable recovery times. This suggests that it is possible to design gas sensing devices with good adsorption characteristics on metallic boron bit-doped hexagonal boron nitride monolayers. In the future, the performance of these materials for the detection of hazardous gases will be improved by changing their structure and composition. [ABSTRACT FROM AUTHOR]

Controlling the physical properties of interfacial polymerization (IP) plays a crucial role in tailoring the structures and properties of thin-film composite (TFC) membranes. However, due to the instantaneity and complexity of the IP reaction, it is challenging to determine the mechanism of the process and establish the connection between the synthesis-structure-performance. For the first time, novel characterization techniques that researchers have employed to visualize the IP reaction in real-time and several classical theoretical models for computer simulations of the IP process are discussed to reveal the intrinsic mechanisms of the IP process from the microscopic perspective. Furthermore, this paper also illustrates the latest effective strategies of IP technology to regulate the permeability and selectivity of membranes from a macroscopic perspective. The above discussion is vital to illustrate the synthesis-structure-performance relationships of TFC membranes, and is conducive to breaking the trade-off effect between permeability and selectivity. Finally, we highlight the potential and challenges of using the IP technology to synthesize TFC membranes for targeted separation applications. This review addressed the urgent need for comprehensive research on the IP process and provides a strong foundation for the advancement and improvement of polyamide (PA) membranes. [Display omitted] • The application of visualization technologies for observation the interfacial polymerization (IP) proceess are described. • Classical computer theoretical models for the IP process simulation are summarized. • Multidimensional regulation of the IP technology is outlined for properties of thin-film composite (TFC) membranes. • The challenges and prospects in tailoring high-performance TFC membranes with the IP technology is presented. [ABSTRACT FROM AUTHOR]

Innovative scaffolds consisting of a cartesian mesh of interpenetrated composite struts of polycaprolactone (PCL) and β-tricalcium phosphate (β-TCP) in a core/shell configuration are developed. Photocurable slurries with high solid-loading (40 vol% TCP) and reduced viscosity were produced by adding camphor and used to fabricate ceramic preforms with hollow struts through Digital Light Processing (DLP). After sintering the structures were suction-infiltrated by molten PCL, resulting in co-continuous composite scaffolds. Their mechanical performance was evaluated in compressive and bending tests and analyzed under the light of stress fields calculated by finite element numerical simulations. Toughness of the scaffolds was notably increased after incorporating the polymeric core. The new co-continuous architecture facilitates impregnation and improves the isotropy of the reinforcement provided by the polymeric core over other reported alternatives but increases the stresses in the ceramic. This was compensated, however, by the increased intrinsic strength associated to using a more concentrated feedstock. [ABSTRACT FROM AUTHOR]

The impact of boron microalloying on the performance of NiMnSn shape memory alloys was investigated using a combination of simulation and experimental methods. The simulation results reveal that B atoms tend to occupy the tetrahedral interstitial positions composed of Ni and Mn. Furthermore, the doping of B atoms not only increases the lattice constant and cell volume of the alloys, but also enhances the phase transition temperature and reduces the thermal hysteresis. The doping of B can enhance the phase stability of austenite and reduce total magnetic moments in the Ni–Mn-Sn alloy. Experimental investigations were conducted on (Ni 43 Mn 47 Sn 10) 100-X B X (X=0,1.5,3) alloys, and findings corroborate the simulations, confirming that B element doping elevates the phase transition temperature, lattice constant, and cell volume, while diminishing the thermal hysteresis. Furthermore, boron microalloying contributes to improved mechanical properties. At a B doping level of 3%at, the annealed alloy compressive strength increases by 125%, reaching 578 MPa, with a fracture strain of 6.7%. However the mechanical properties of the as-cast alloy surpass those of the annealed state, with the compressive strength of the same-component cast alloy reaching 1080 MPa, and a fracture strain of 7.9%, marking an 87% improvement over the annealed state. • B atoms tend to occupy tetrahedral gap positions composed of Ni and Mn. • B atoms doping reduces the stability of austenite phase, increases the phase transition trmperature dna decreases the themal hysteresis. • The magnetic moment of the system decreases due to B atom doping. • Boron microalloying significantly enhances the material's compressive strength. • The as-cast alloy exhibits significantly higher compressive fracture strength compared to the annealed state. [ABSTRACT FROM AUTHOR]

Small amounts of silicon are currently used to partly replace graphite as anode material in lithium-ion batteries to increase their energy density and fast charging capability. Ensuring mechanical integrity during charging and discharging as well as the production of suitable silicon-based materials on a large scale at acceptable costs still remains a challenge. In this work, the formation of silicon nanoparticles from the gas phase is analyzed to understand the process, identify key parameters regarding a suitable process technology, and resolve upscaling issues for transfer to the industrial pilot scale. The experimental findings are supported by simulations of fluid dynamics. Process conditions regarding the formation of pure as well carbon containing nanoparticles are studied and a successful transfer to an industrial pilot plant reactor is demonstrated. [Display omitted] • Si-Nanoparticle properties are tuned in a pilot scale hot-wall reactor. • Fluid dynamics simulations enable deeper understanding of the process. • Geometry changes can reduce detrimental backflows in the reactor. • Comparison with a industry pilot plant show a good transferability of results. [ABSTRACT FROM AUTHOR]

Gd-YBa 2 Cu 3 O 7-δ (Gd-YBCO) thin films with 10 mol% and 20 mol% excess-Gd concentration with respect to Y were investigated at the Gd L 3 and Y K core absorption edges by EXAFS spectroscopy with the aim of determining the local structure of the Gd dopant. To this purpose, EXAFS data were collected also on GdBa 2 Cu 3 O 7-δ (GdBCO) and pristine YBCO films and on Gd 2 O 3 and Y 2 O 3 model compounds for comparison with the YBCO films with Gd excess. The EXAFS analysis was based on Y and Gd oxides as well as on a cluster obtained by Density Functional Theory (DFT) where Gd atoms were inserted substitutional to Y atoms. The EXAFS data clearly reveal the incorporation of Gd in the lattice as substitute of Y and no evidence of segregated Gd oxide was found within the film matrix. • Gd-YBa 2 Cu 3 O 7-δ thin films with excess-Gd concentration were investigated by EXAFS. • For comparison EXAFS was measured on GdBa 2 Cu 3 O 7-δ , YBa 2 Cu 3 O 7-δ , Gd 2 O 3 and Y 2 O 3. • A DFT model with Gd atoms substitutional to Y in the YBCO lattice was calculated. • The model's FFT modulus was compared with the FFT of the Gd-doped thin films. [ABSTRACT FROM AUTHOR]

Zero-thermal-expansion (ZTE) materials are crucial to the fields where the temperature-induced dimension change should be avoided. Here we report a new ZTE composite made of copper foam, negative-thermal-expansion (ZSM) and copper powders. Without changing the volume ratio of ZSM (32 vol%) which ensures that all composites exhibit ZTE around room temperature, we can significantly improve the thermal conductivity (TC) and electrical conductivity (EC) of the composites by increasing the pre-compressing degree of the copper foam. For example, the TC and EC along the direction parallel to the pressurized plane for the composite with 75% copper foam pre-compression reach 83.4 Wm−1K−1 and 9.43 × 106 Ω−1m−1, which are 46% and 71.9% larger than that of the reference composite without copper foam. The improved conductivity is attributable to the oriented three-dimensional interpenetrating metal network derived from copper foam. This work provides an effective way for improving the thermal and electrical conductivities of copper matrix composites. • x Cu n -ZSM/Cu p composites with 3D interpenetrating copper networks prepared using spark plasma sintering process. • 3D interpenetrating networks in x Cu n -ZSM/Cu p composites constructed by commercial copper foam. • xCu n -ZSM/Cu p composites have a high thermal conductivity while achieving near-zero thermal expansion. • Finite element simulation of heat transfer behavior of xCu n -ZSM/Cu p composites was performed. [ABSTRACT FROM AUTHOR]

The progress in developing a C++ module for simulation of channeling radiation in Geant4 using classical description is being discussed. The created module is built into Geant4 as a discrete set of physical processes, which allows combining it with other physical processes of Geant4. The direct simulation of CR in Geant4 allows describing devices such as, e. g. positron sources, without using external programs for CR calculation. In previous version, the module was capable to simulate only planar channeling radiation. In this paper, the implementation of axial channeling radiation in Geant4 is shown. The module now simulates both planar and axial channeling radiation from ultra-relativistic electrons channeled in Si, C, Ge and W single crystals. The simulation results are compared with available experimental data. [ABSTRACT FROM AUTHOR]

Permeability is a very important multiscale parameter providing information of dendritic structures in macroscale simulations of solidification with liquid flow during casting. In our previous study, it was demonstrated that the permeability of liquid flow normal to a columnar dendritic structure can be well approximated by the Kozeny–Carman (KC) equation with a coefficient k c = 9. In this study, the permeability of liquid flow parallel to a columnar dendritic structure is investigated using a method that combines both phase–field and lattice Boltzmann simulations. It is shown that the permeability of parallel flow can also be approximated by the KC equation with k c = 3. A permeability tensor is then proposed for a columnar dendritic structure. Validity of the permeability tensor is confirmed by simulations of liquid flow in arbitrary directions of a columnar dendritic structure. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The optoelectronic industry, which has become a cornerstone, requires a semiconductor compound to function as a sustainable and green energy source. In this connection, the present study provides a systematic approach to examine the electronic and optical properties of α-Ca 3 N 2 using the linear combination of atomic orbitals method. The xc-functional BECKE-PBE gives the best results for electronic properties by describing the band gap correctly. The dispersion curve shows that α-Ca 3 N 2 is a semiconductor with an indirect band gap of 1.33 eV along the H-Γ direction. Effective masses of electrons and holes are calculated at the peak of the lowest conduction band and highest valence band, along the Γ- direction. Calculation for optical properties has been performed using coupled-perturbed Hartree-Fock scheme for static values and phonon spectrum calculations are performed for dynamic dielectric functions. Further, frequency dependent electron loss function and reflectivity are determined from the dielectric functions. The elastic constants are estimated and elastic moduli are determined. Bulk modulus of 80.6 GPa and Poisson's ratio of 0.275 reveals that α-Ca 3 N 2 is a hard and ductile material. The characteristic properties of α-Ca 3 N 2 make it a suitable candidate for optoelectronic applications. • Among various stochiometric forms of Ca x N y like Ca 3 N 2 Ca 2 N, Ca 2 N 3 , and CaN n (where n=1-5), Ca 3 N 2 is stable in the ambient conditions. While the other forms are reported to be in meta-stable or stable form with metallic conductivity. • α-Ca 3 N 2 has optical band gap that resonates with the optimum energy value of the solar spectrum. Electronic band gap energy lies in domain of IR-Visible region , this makes α-Ca 3 N 2 an excellent choice for optoelectronic applications. • Results and data analysis offers critical input for optoelectronic applications owing to high electron mobility and exciton binding energy of conducting carriers in α-Ca 3 N 2. • The mechanical strength and exciton binding energy of α-Ca 3 N 2 fall within the range of commercially developed optoelectronic materials like Si, Ge, CdO CIGS. [ABSTRACT FROM AUTHOR]

A coupled crystal plasticity and phase field modeling framework is employed to simulate polycrystalline grain growth via static strain induced grain boundary migration. Specifically, the effect of the average grain size as a microstructural length scale on the development of microstructure and texture in columnar–grained aluminum polycrystal is examined. During annealing, subsequent to plastic tensile straining, a nearly normal grain growth regime is observed for comparatively small microstructural length scales. However, for comparatively large microstructural length scales, abnormal grain growth and development of a specific texture emerge. Hence, grain growth is found to transition from normal to abnormal by enlarging the microstructural length scale. These observations are attributed to the fact that the competing driving forces for grain boundary migration scale differently with the microstructural length scale. In addition, for the case of large microstructural length scale, a transition from abnormal to normal grain growth at later annealing times is observed. This observation is attributed to the weakening of the strain induced boundary migration effects due to the initial rapid reduction of dislocation content. [ABSTRACT FROM AUTHOR]

We study groups of interacting agents who are trying to discover probabilistic truths on the basis of sequentially provided evidence and information about the belief states of other group members. The main research question is which combination of epistemic principles—combinations of an evidential update rule, a rule for determining peerhood, and a rule for aggregating probability functions—such groups should adopt to strike the best balance between being fast and being accurate, where the former is understood by reference to how long it takes before a majority of the group assigns a high probability to the true hypothesis, and the latter by reference to the average Brier penalty incurred by the group. The main methodology to be used is that of agent-based optimization, which is a specific form of evolutionary computing. We implement this methodology in a generalization of the Hegselmann–Krause model. In the end, we are able to identify optimal procedures for taking into account both direct evidence and information about one's peers' beliefs. At the same, we note that optimality for such procedures is dependent on context. [ABSTRACT FROM AUTHOR]

The high-throughput material modeling is helpful tools in the search of discovery new Heusler compounds. In this work the electronic, magnetic, optical and thermodynamic properties of new Ni 2 Mn 1-x Re x Sn and NiMn 1-x Re x Sn Heusler alloys are reported. Ab-initio calculations are based on local density approximation including generalized gradient approximation (GGA and GGA + U). The band structures were computing by means of FPLO, VASP, SPR KKR-CPA and Gibbs2 methods. The calculations have shown the indirect gap (0.8–1.7eV (GGA) and 1.4–2.4 eV (GGA + U)) in Γ point between 3d (5d) states of Mn (Re). The value of the indirect gap depended of the system. The substitution of Mn by Re leads to the increase of the volume of the unit cell and the modification of the band structure. The total magnetic moment in Ni 2 Mn 1-x Re x Sn and NiMn 1-x Re x Sn decreases with the increasing of Re composition. The tetragonal distortion in Ni 2 ReSn leads to the minimum of the total energy at c/a = 1 and the magnetic moment increases with the increasing of c/a. The electronic and magnetic properties of Ni 2 MnSn, NiMnSn, Ni 2 ReSn and NiReSn in the model with vacuum on both sides of the unit cell are different from the bulk materials. In the vacuum model the gap 0.252(0.176) eV is observed in minority spin band in Ni 2 ReSn (NiReSn), respectively and the spin polarization at the Fermi energy P(E F) = 1. The dependence of the total magnetic moment in Ni2Mn1-xRexSn and NiMn1-xRexSn. Image 1 • Electronic and magnetic properties of new Ni 2 (Mn 1-x Re x)Sn and Ni(Mn 1-x Re x)Sn Heusler alloys. • Thermodynamic properties in Debye-Grűneisen approximation. • Effect of surface on the magnetic properties of Ni 2 MnSn, NiMnSn, Ni 2 ReSn and NiReSn. • The gap in minority spin band in Ni 2 ReSn and NiReSn in vacuum model. • Optical properties of Ni 2 MnSn, NiMnSn, Ni 2 ReSn and NiReSn. [ABSTRACT FROM AUTHOR]

Di-phase ferroelectric-ferrite composites with the same composition close to the percolation limit (0.66BaTiO 3 -0.33CoFe 2 O 4) and with different phase arrangements (randomly mixed phases and tri-layer structures) have been consolidated by using spark plasma sintering and their properties were comparatively analyzed. The intrinsic effective dielectric constant has been estimated by using finite element method and a value almost ten times higher was predicted for the randomly mixed composite, as result of different field distributions inside the ferrite and ferroelectric phases. At room temperature, experimental permittivity contains an intrinsic behavior overlapped onto a very strong extrinsic component determined by the interfaces and by local charge inhomogeneity. The extrinsic dielectric behavior has been discussed in terms of thermally activated relaxation mechanisms developed in both types of investigated structures, as revealed by the temperature-dependence impedance spectroscopy. The magnetic properties are derived as "sum property" from the ferrimagnetic character of CoFe 2 O 4 and show the lowest magnetization for the randomly mixed composites and a weak magnetic anisotropy when the magnetic field was applied in-plane or out-of-plane in the layered structure. Due to the different levels of interface doping specific to the different types of interfaces, the magnetic Curie temperature of the two composites ranges from 720 K in the randomly mixed structure to 746 K for the layered one. The ferroelectric P (E) loops and a modest ME coefficient of 14 mVOe−1cm−1 at 100 Hz were determined only for the layered structure, due to the high leakage and to the small grain size (below 200 nm) in the ferroelectric BaTiO 3 component. • Randomly mixed and tri-layered structure composites were comparatively investigated. • Role of the phase arrangement on the dielectric properties was predicted by FEM. • Experimental dielectric data contains a strong influence from extrinsic phenomena. • Magnetic properties slightly depend on the phase arrangement. [ABSTRACT FROM AUTHOR]

An electron impact ion source equipped with a magnet has been designed for enhancing the ionization efficiency of such ion sources with potential applications in Knudsen effusion mass spectrometry or electron impact sources used in gas mass spectrometry. This modernized device utilizes the trapping of electrons in parallel electrical and magnetic fields with the goal of maximizing the probability of impact between an electron and an atom or molecule to be ionized. The influence of magnetic and electrical fields on ions and electron trajectories inside the ion source was studied with numerical simulations. Based on the electron and ion trajectories we have modified the classical Nier-type ion source and found the optimal geometrical and potential parameters to provide better electron ionization and higher ion extraction efficiency. This design has the potential to enhance ionization efficiency by a factor of ∼15–20 compared with existing designs. Image 1 • An electron impact ion source equipped with a magnet has been designed for Knudsen effusion mass spectrometry. • The optimal geometrical parameters, electrical and magnetic fields magnitudes were determined by computer simulations. • The effects of space charge and mass discrimination in the ion source have been analyzed. [ABSTRACT FROM AUTHOR]

Phase transitions are widely observed in many metal materials including amorphous alloy and high-entropy alloys (HEAs). When HEAs are made in the amorphous form, is it possible for the amorphous phase to transition to simple solid solution? This paper reveals a phase transition from amorphous phase to body-centered cubic (bcc) phase and then to face-centered cubic (fcc) phase in Fe 30 Co 29 Ni 29 Zr 7 B 4 Cu 1 HEA by employing simple heat treatment process. Accordingly, the intrinsic correlation between the microstructure and soft-magnetic properties was established by excluding the composition interference. The explanation of mechanism behind the phase transitions was explored by first-principles density functional theory (DFT) calculations and other methods. This research suggests an approach of designing HEAs with excellent magnetic properties, and provides a prototype to study structure of amorphous alloys. • HEAs with amorphous, bcc or fcc structure were prepared, respectively. • The phase transitions mechanism was investigated by DFT calculations. • The B s of the HEAs is bcc > amorphous ≈ fcc. • The variation of B s was revealed DFT calculations. [ABSTRACT FROM AUTHOR]

We report results of large scale molecular dynamics simulations conducted for diblock copolymer tethered disks in two-dimensional systems. The particles with three and four attached chains are considered. The copolymers consist of the rigid blocks associated with the core and the outer, flexible blocks. We have carried out simulations for nanoparticles with attractive outer (PA) or inner (PB) parts of chains. We analyze the impact of the number of tethers and the length of flexible parts on the self-assembly. The simulations show that the shape of "the rigid skeletons" of the particles determines on the system morphology. The PA particles with short tethers form different ordered networks. The PB-particles form highly ordered crystalline-like structures. For longer flexible tethers the PA particles form disordered networks, while the particles PB assemble into small clusters of various shapes and internal structures. [ABSTRACT FROM AUTHOR]

Abstract In this article, a new approach to directly synthesize drug molecule imbedded in the nanometer sized polymer particles is reported. Molecular imprinting is used to prepare polymers for drug specific for selectively loading of a desired drug. Computer simulations were performed to provide mechanistic insights on the binding modalities of model cancer drug, amygdalin with the polymer precursors. Controlled release of amygdalin from nanoMIPs was studied in vitro cell test and monitoring the absorbance at λ em of 390 nm by fluorescence. The nanoparticles imprinted with amygdalin (nanoMIPs) showed high drug loading (0.98 mg g−1) and also releases drug in a controlled way without burst release. The polymer releases amygdalin 0.095 μg (5 min), 0.120 μg (30 min), 0.180 μg (180 min), 0.205 μg in 300 min in de-ionized water and similar pattern of release was observed in buffer 2 and 7. The sustained release of drug from nanoMIPs follows Fickian diffusion; and uniformity in nanoMIPs size have significant impact on release of drug. Swelling of nanoMIP is one of the dominant factors influencing the drug release patterns. The imprinting procedure and the studies reported in this study would be highly useful in future for cancer drug administration. Highlights • nanoMIPs formulated with VP- co -EGDMA showed high loading of drug, amygdalin (980 μg g- 1 ) • It is possible to tune the drug loading by varying the concentration of amygdalin template during molecular imprinting as per patient requirement • nanoMIPs loaded with amygdalin showed encouraging drug release in vitro experiments [ABSTRACT FROM AUTHOR]

Abstract The size-dependent microstructural evolution behavior has a significant impact on the thermoplastic flow behavior of metallic glass in the supercooled liquid region. In this work, double-cup extrusion tests, corresponding finite element method simulations and nanoindentation measurements of Zr 55 Cu 30 Al 10 Ni 5 metallic glass samples with different sizes, are employed to study the relationship between the size-dependent free volume variations and thermoplastic flowability. Experimental results and theoretical analyses demonstrate that the free volume content increases with increasing sample size. The change tendencies of free volume content and micro-hardness are in a negative correlation. The variation regularity of extruded cup height ratio verifies that the thermoplastic flowability of Zr-based metallic glass is enhanced with rising sample size. Furthermore, the size-dependent free volume variations and distributions induced by internal microstructural evolution behaviors result in the evident variations of micromechanical properties. The results of this study will contribute to a more in-depth understanding of the size-dependent thermoplastic deformation behavior of Zr-based metallic glass. Highlights • Thermoplastic flow ability of Zr-based metallic glass rises with rising sample size. • The ratio of upper and lower cup heights decreases with sample size rising. • The average free volume distribution increases with sample size increasing. • The free volume and micro-hardness change regularities are in a negative correlation. [ABSTRACT FROM AUTHOR]

Abstract Interdiffusion studies in Co-Cr-Fe-Mn-Ni, Co-Fe-Mn-Ni, Co-Cr-Fe-Ni, and Co-Cr-Mn-Ni, as well as a reevaluation of the previous results obtained for Al-Co-Cr-Fe-Ni, were conducted. In the experimental part, diffusion couples were annealed at four different temperatures: 1230, 1270, 1310 and 1350 K for each system. Then, the results were evaluated with use of the optimization-based technique, combined with the Miedema's thermodynamic description, what allowed obtaining of tracer diffusion coefficients for all elements in all considered systems. The correctness of the applied approach was tested on the example of Co-Cr-Fe-Mn-Ni system, showing very good agreement of determined tracer diffusivities with the values obtained by other authors. Obtained values of diffusivities were compared with the available data for a number of conventional binary and ternary systems. No signs of diffusion retardation were observed in the absolute temperature scale. In the case of temperature scale normalized with respect to the melting point, an abnormal behavior, previously attributed to the HEAs' sluggish diffusion effect was observed. However, it occurred only for alloys with prominent manganese content and was completely independent of the number of components, being just as likely to occur in binary systems as in HEAs. Therefore, the alleged sluggishness of diffusion in HEAs should be treated just as a result of specific compositions of the previously studied alloys and cannot be generalized for all high entropy systems. Graphical abstract Image 1 Highlights • Diffusion was studied in Co-Cr-Fe-Mn-Ni, Co-Fe-Mn-Ni, Co-Cr-Fe-Ni, and Co-Cr-Mn-Ni. • Results for Al-Co-Cr-Fe-Ni were reevaluated. • Diffusion couples were evaluated with use of the optimization-based technique. • The observed sluggishness of diffusion was correlated with presence of Mn. • The observed sluggishness was independent of number of components. [ABSTRACT FROM AUTHOR]

Highlights • Molecular recognition between γ-lactone essences and human serum albumin were studied. • The morphology of HSA changed induced by interactions with ligands. • Ligands had weak binding with HSA, causing slight protein second structural changes. • Binding ability and secondary structure changes were positively correlated with side chain length. • Side chain length affected the binding by steric hindrance and hydrophobicity. Abstract The binding properties between γ-lactone essences and HSA were investigated to explore interactional mechanism and influence of ligand side chains on binding via computer simulations, microscopy, and multiple-spectroscopies. Docking and molecular dynamics presented protein recognition mode with low fluctuations. NMR analysis revealed that the lactone ring of ligands was the main group bound to HSA. UV–vis and lifetime results revealed that the combination was static quenching mechanism with binding constants of 102–103 L/mol. FTIR and CD spectra showed conformational changes in the protein secondary structure induced by ligands. Side chains affect the binding process through steric hindrance and hydrophobicity. AFM images showed the four compounds caused different effects on molecular size of HSA. In conclusion, the binding ability and the protein secondary structure changes had a positive correlation with the length of side chain. These studies are beneficial for understanding the safety and biological action of γ-lactone essences. [ABSTRACT FROM AUTHOR]

Abstract Background Understanding the effects of graphene-based nanomaterials on lipid membranes is critical to determine their environmental impact and their efficiency in the biomedical context. Graphene has been reported to favourably interact with biological and model lipid membranes. Methods We report on a systematic coarse-grained molecular dynamics study of the interaction modes of graphene nanometric flakes with POPC/cholesterol liposome membranes. We have simulated graphene layers with a variety of sizes and oxidation degrees, and we have analyzed the trajectories, the interaction modes, and the energetics of the observed phenomena. Results Three interaction modes are reported. Graphene can be transiently adsorbed onto the liposome membrane and/or inserted in its hydrophobic region. Inserted nanosheets prefer a perpendicular orientation, and tilt in order to maximize the contact with phospholipid tails while avoiding the contact with cholesterol molecules. When placed between two liposomes, graphene facilitates their fusion in a single vesicle. Conclusions Graphene can be temporary adsorbed on the liposome before insertion. Bilayer curvature has an influence on the orientation of inserted graphene particles. Cholesterol molecules are depleted from the surrounding of graphene particles. Graphene layers may catalyse membrane fusion by bypassing the energy barrier required in stalk formation. General significance Nanometric graphene layers can be adsorbed/inserted in lipid-based membranes in different manners and affect the cholesterol distribution in the membrane, implying important consequences on the structure and functionality of biological cell membranes, and on the bioaccumulation of graphene in living organisms. The graphene-mediated mechanism opens new possibilities for vesicle fusion in the experimental context. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We used FPCTT to investigate the tensile failure mechanism of the interfaces. • The calculated CDD show that the studied interfaces are dominated by covalent bonds. • Adhesive and cohesive failure occurred for Si-HAP and HAP coatings, respectively. • Si dopants improved the bonding strength of the HAP coating to the substrate. Abstract In this paper we employ first-principles calculations to investigate the effect of substitutional Si doping in the amorphous calcium-phosphate (a-HAP) structure on the work of adhesion, integral charge transfer, charge density difference and theoretical tensile strengths between an a-HAP coating and amorphous titanium dioxide (a-TiO 2) substrate systemically. Our calculations demonstrate that substitution of a P atom by a Si atom in a-HAP (a-Si-HAP) with the creation of OH-vacancies as charge compensation results in a significant increase of the bonding strength of the coating to the substrate. The work of adhesion of the optimized Si-doped interfaces reaches a value of up to −2.52 J m−2, which is significantly higher than for the stoichiometric a-HAP/a-TiO 2. Charge density difference analysis indicates that the dominant interactions at the interface have significant covalent character, and in particular two Ti O and three Ca O bonds are formed for a-Si-HAP/a-TiO 2 and one Ti O and three Ca O bonds for a-HAP/a-TiO 2. From the stress-strain curve, the Young's modulus of a-Si-HAP/a-TiO 2 is calculated to be about 25% higher than that of the a-HAP/a-TiO 2 , and the yielding stress is about 2 times greater than that of the undoped model. Our calculations therefore demonstrate that the presence of Si in the a-HAP structure strongly alters not only the bioactivity and resorption rates, but also the mechanical properties of the a-HAP/a-TiO 2 interface. The results presented here provide an important theoretical insight into the nature of the chemical bonding at the a-HAP/a-TiO 2 interface, and are particularly significant for the practical medical applications of HAP-based biomaterials. [ABSTRACT FROM AUTHOR]

Abstract Computer simulation is the most promising approach for the systematical permeability prediction of liquid flow in the mushy zone for various solidification conditions. In this study, we propose a permeability prediction method by using large–scale simulation of phase–field and lattice Boltzmann methods. Using the proposed method, permeability predictions are performed for the flow normal to the columnar solidification structures with multiple dendrites/cells. In addition, the prediction is also performed for columnar solidification structures with periodically arranged dendrites/cells to evaluate the permeability in the full range of solidification fraction and investigate the effect of primary arm array on the permeability. As a result, it is concluded that the dimensionless permeability using a specific interface area of columnar solidification structures can be well approximated by that of a regular hexagonal array of cylinders. Moreover, it is confirmed that the columnar dendrite/cell structure with a periodic regular hexagonal array provides realistic permeability predictions for columnar solidification structures. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Abstract This study reports the synthesis and characterization of SrSnO 3 :Eu phosphors with various doping concentrations synthesized via a modified sol-gel method. The samples were characterized by powder X-ray diffraction (PXRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. PXRD and Raman spectroscopy showed that the samples crystallized with the orthorhombic perovskite crystal structure, which density functional theory (DFT) calculations suggest is the most energetically stable modification. In addition, Rietveld refinements and XPS analysis indicate that the Eu3+ ion replaces Sr2+ (noncentrosymmetric site) for samples with 1% and 3% Eu3+, while at higher concentrations of dopant, the Eu3+ ions replace both Sr2+ and Sn4+ (centrosymmetric site). Photoluminescence measurements show the characteristic emission spectra of Eu3+, in which the ratio of the intensities of the red/orange PL peaks is a maximum at 3% Eu3+ and then decreases continuously with concentration. This supports the conclusion that Eu3+ ions replace Sr2+ at low concentrations, but Sr2+ and Sn4+ at higher concentrations. Graphical abstract Image 1 Highlights • SrSnO 3 :Eu phosphors with different dopant concentrations were analyzed. • Eu3+ ions replace Sr2+ ions at low concentration. • The orthorhombic perovskite structure is the most energetically stable modification. • At high concentrations Eu3+ replaces both Sr2+ and Sn4+. [ABSTRACT FROM AUTHOR]

Abstract In this work we study the dynamics of opinion formation in the Sznajd model with anticonformity on regular lattices in two and three dimensions. The anticonformity behavior is similar to the introduction of Galam's contrarians in the population. The model was previously studied in fully-connected networks, and it was found an order–disorder transition with the order parameter exponent β = 1 ∕ 2 calculated analytically. However, the other phase transition exponents were not estimated, and no discussion about the possible universality of the phase transition was done. Our target in this work is to estimate numerically the other exponents γ and ν for the fully-connected case, as well as the three exponents for the model defined in square and cubic lattices. Our results suggest that the model belongs to the Ising model universality class in the respective dimensions. Highlights • Impact of anticonformity in the Sznajd model in regular lattices. • Occurrence of order–disorder transitions. • Universality class of the Ising model. [ABSTRACT FROM AUTHOR]

The development of a sense of agency is essential for understanding the causal structure of the world. Previous studies have shown that infants tend to increase the frequency of an action when it is followed by an effect. This was shown, for instance, in the mobile-paradigm, in which infants were in control of moving an overhead mobile by means of a ribbon attached to one of their limbs. These findings have been interpreted as evidence for a sense of agency early in life, as infants were thought to have detected the causal action-movement relation. We argue that solely the increase in action frequency is insufficient as evidence for this claim. Computer simulations are used to demonstrate that systematic, limb-specific increase in movement frequency found in mobile-paradigm studies can be produced by an artificial agent (a 'babybot') implemented with a mechanism that does not represent cause-effect relations at all. Given that a sense of agency requires representing one's actions as the cause of the effect, a behavior that is reproduced with this non-representational babybot can be argued to be, in itself, insufficient as evidence for a sense of agency. However, a behavioral pattern that to date has received little attention in the context of sense of agency, namely an additional increase in movement frequency after the action-effect relation is discontinued, is not produced by the babybot. Future research could benefit from focusing on patterns whose production cannot be reproduced by our babybot as these may require the capacity for causal learning. [ABSTRACT FROM AUTHOR]

A new route to achieve high strength and high ductility compositions in the Cr-Co-Ni medium entropy alloys (MEAs) is proposed, by controlling the solid solution hardening parameter (Mean Square Atomic Displacement, MSAD) and twinning propensity parameter (Stacking Fault Energy, SFE), respectively. The MSAD is calculated to increase with the increase in the Cr content and with the increase in the Ni/Co ratio at high Cr concentrations, while the SFE is calculated to decrease with the increase in the Cr content and with the increase in the Co/Ni ratio at high Cr concentrations. In experiment, the strength at 0 K (derived from the temperature dependence of yield stress) increases as the Cr content increases and/or as the Ni content increases for a given high Cr content, so that a linear correlation is found between the yield strength at 0 K and MSAD. The SFE also decreases as the Cr content increases and as the Co content increases for a given high Cr content. However, while the tensile elongation increases with the decrease in SFE down to SFE values of 10–12 mJ/m2, it abruptly decreases once the SFE decreases below this value due to a change in major deformation mode from deformation twinning to deformation-induced ε-martensite transformation. Based on the established connection between the theoretical calculation and experimental measurement, outstanding combinations of strength and ductility are predicted and experimentally confirmed at high Cr compositions and at a bit Ni-rich side of the Co/Ni equi-composition line. The proposed composition (around 45Cr-20Co-35Ni) exhibits a greater 0 K strength and a superior 77 K tensile ductility by 32 % and 13 %, respectively, compared to those of the equiatomic Cr-Co-Ni alloy. [Display omitted] • A model for strength/ductility prediction is proposed for Cr-Co-Ni MEAs. • Strength and ductility were investigated by experiment and compared with the model prediction. • The model prediction is found to be well correlated with the experimental strength/ductility. • Strong solid-solution hardening as revealed by high MSAD makes the strength higher. • Deformation twinning as revealed by low SFE makes the tensile ductility higher. [ABSTRACT FROM AUTHOR]

Predictive simulations are essential for applications ranging from weather forecasting to material design. The veracity of these simulations hinges on their capacity to capture the effective system dynamics. Massively parallel simulations predict the systems dynamics by resolving all spatiotemporal scales, often at a cost that prevents experimentation. On the other hand, reduced order models are fast but often limited by the linearization of the system dynamics and the adopted heuristic closures. We propose a novel systematic framework that bridges large scale simulations and reduced order models to extract and forecast adaptively the effective dynamics (AdaLED) of multiscale systems. AdaLED employs an autoencoder to identify reduced-order representations of the system dynamics and an ensemble of probabilistic recurrent neural networks (RNNs) as the latent time-stepper. The framework alternates between the computational solver and the surrogate, accelerating learned dynamics while leaving yet-to-be-learned dynamics regimes to the original solver. AdaLED continuously adapts the surrogate to the new dynamics through online training. The transitions between the surrogate and the computational solver are determined by monitoring the prediction accuracy and uncertainty of the surrogate. The effectiveness of AdaLED is demonstrated on three different systems - a Van der Pol oscillator, a 2D reaction–diffusion equation, and a 2D Navier–Stokes flow past a cylinder for varying Reynolds numbers (400 up to 1200), showcasing its ability to learn effective dynamics online, detect unseen dynamics regimes, and provide net speed-ups. To the best of our knowledge, AdaLED is the first framework that couples a surrogate model with a computational solver to achieve online adaptive learning of effective dynamics. It constitutes a potent tool for applications requiring many computationally expensive simulations. • We present a framework for building ML-based online parametric surrogate models. • The model is trained continuously and adapts on the fly to new system dynamics. • The framework balances between speed-up and accuracy using online validation. • The effectiveness is demonstrated on three test dynamical systems. [ABSTRACT FROM AUTHOR]

Double half-Heusler alloys are promising materials for applications as magnetocaloric materials, topological insulators, but especially thermoelectric materials. Four different elements in their composition provide a wide range of possible compositions, which, on the other hand, is difficult to study directly by applying traditional first-principles approaches to large number of compositions. In this work, based on the gradient boosting method, regression models are constructed that allow rapid prediction of the lattice thermal conductivity, as well as a number of other thermal and elastic properties, based on the composition and crystal structure of a compound. This made it possible for the first time to calculate the lattice thermal conductivity, as well as Grüneisen parameter, Debye temperature, and elastic moduli for a number of double half-Heusler compounds. We observe that the predicted thermal conductivity is in better agreement with the experimental data than the results of density functional theory calculations available in the literature. Half-Heusler compounds with thermal conductivity values lower than those previously known have been found. In addition, we have analyzed the importance of various features for predicting each of the studied properties, and the effect of the crystallographic symmetry of the compound on the prediction accuracy. • Regression models predicting thermal conductivity and elastic moduli are built. • Thermal conductivity of 90 novel double half-Heusler alloys is predicted. • Quantitative agreement with available experimental data is obtained. • The double half-Heuslers with thermal conductivity lowest in the class are revealed. • Half Heusler alloys with the lowest thermal conductivity include Mg, Pd or Pt. [ABSTRACT FROM AUTHOR]

Molecular dynamic simulation of the hydrophilic urea and hydrophobic tetramethylurea aqueous solutions using the random network model of liquid water reveals that apolar Me groups induce an increase in the population of water molecules with linear and shorter H-bonds in their first hydration shell, whereas the carbonyl oxygen atom causes an opposite effect with elevation in the population of high angle/distance water molecules pairs. This behavior of water is the major reason for opposite changes in the heat capacity of hydration for apolar and polar species. [ABSTRACT FROM AUTHOR]

Abstract To solve nonlinear and nonconvex optimization problems, a novel finite-time varying-parameter convergent-differential neural network (termed as FT-VP-CDNN) is proposed and analyzed. Compared with finite-time fixed-parameter convergent-differential neural networks (FT-FP-CDNNs), the proposed FT-VP-CDNN has super exponential convergence, finite-time convergence and strong robustness. Finite-time convergence property of the FT-VP-CDNN is proved and various computer simulations are presented. Numerical simulations verify the superiority of the FT-VP-CDNN when solving nonlinear and nonconvex optimization problem. [ABSTRACT FROM AUTHOR]

Abstract Diffusion of interstitial carbon atoms in iron is the rate-limiting phenomenon of a number of phase transitions in body-centered (bcc) and body-centered tetragonal (bct) phases such as ferrite and martensite. These phases being rarely stress-free and undeformed, the influence of stress/strain on the diffusivity of carbon is essential, although scarcely documented. We developed a model of carbon elastodiffusion in bct-iron. We combined anisotropic linear elasticity theory of point defects, the dilute approximation of regular solutions and the multisite model of random walk into a coherent mean-field theory. The model allows predicting the effects of composition, temperature and mechanical loading on the anisotropy of carbon diffusion. Density functional theory calculations have provided most of the materials parameters. The predictions were successfully tested against kinetic Monte Carlo simulations. Our results show that compression of the crystal increases carbon diffusivity, while tension has the opposite effect. Axial straining is accompanied by a large anisotropy of diffusion. This effect could be exploited to produce stress-controlled diffusion channeling for the engineering of anisotropic microstructures during thermal ageing of martensitic Fe-C alloys. Graphical abstract Image 1 Highlights • Carbon diffusion channeling is induced by compression of ferrite. • Carbon diffusion in martensite is transverse to the axis of tetragonality. • Carbon diffusivity is discontinuous at the ferrite – martensite transition. [ABSTRACT FROM AUTHOR]

Highlights • Extinction risk for melanic mosquitofish population was assessed using computer simulations based on data obtained from empirical studies. • Minimal (+4° F), mid-range (+8° F), and maximum (+10° F) climate change scenarios were studied. • Even the most conservative estimates for climate-warming scenarios show a significant impact on the melanic population, which may even go extinct within 100 years. • Despite this, simulations also suggest that if temperature stabilizes before melanic morph goes extinct their population may recover to some degree. • In contrast, the model predicted that the silver morph would be a winner even during the maximum climate-warming scenario as their population would increase and stabilize at the carrying capacity. Abstract Species are typically comprised of a large number of genotypes, some of which are rare. Rare genotypes that are temperature-sensitive will predictably be impacted by climate change more profoundly than common genotypes for which gene expression does not depend on temperature. Computer simulations were used in this study to analyze the impact of changing temperatures on a very rare melanic morph that expresses a temperature-sensitive phenotype and is found in an abundant fish species (Gambusia holbrooki). This numerical model assesses the frequency of the two natural color morphs, silver and black-spotted, over time and iterates in each generation, incorporating survival estimates for different life stages based upon data collected during empirical experiments. Using the current projections for mean surface temperature increase, which are 2.5° F to 10.4° F by the year 2100, the impact of warming environment on the mosquitofish population was analyzed. Three different climate warming scenarios were used to address annual temperature fluctuations and incorporate predicted temperature rise at correspondingly minimal, mid, and maximum levels. Our results indicate that increasing temperatures will seriously affect the rare color morph and in some cases will result in extinction. The minimal climate-warming scenario produced lower extinction risks for the rare morph; however, it still decreased the frequency of the rare genotype to minimal values. The mid-range warming scenario produced a higher risk of extinction, while the maximum warming scenario resulted in the extinction of the rare color morph. The results of this study shed light on the possibility that the effects of climate change may have important ramifications for rare genotypes in nature and will likely drive some rare species genotypes to extinction. [ABSTRACT FROM AUTHOR]

Highlights • Cooling performance of ITER GS thermal anchor is evaluated based on test results. • Contact area between pipe and plate plays an important role in the cooling. • Differences of cooling performance between TIG and copper brazing is slight. Abstract Thermal anchor is a key component of ITER gravity supports and serves to maintain them a temperature for the normal operation of superconducting coils. Two rows of thermal anchor pipes introduced by 80 K helium gas are connected with supports to reduce the heat transferred from pedestal ring to magnet. TIG welding is chosen as the connecting method for the attachment of thermal anchor. A prototype of GS flexible plate with thermal anchor attached is manufactured by TIG welding. And heat exchange efficiency test is done on the prototype with its thermal anchor being introduced by liquid nitrogen under a circumstance similar to ITER. Temperature of the area next to thermal anchor on the plate is about 100 K with only one pipe until temperature variation is not obvious. As helium is a quite expensive coolant for the cooling down of plate, computer simulations with 80 K helium gas being introduced into thermal anchor is performed instead. The finite element model is built and revised as per the test results. And the test results and simulations are discussed and analyzed to make sure the conductive heat from pedestal ring could be dissipated by using helium gas. [ABSTRACT FROM AUTHOR]

In this work, the Smooth Particle Hydrodynamics (SPH) method, a Lagrangian mesh-free numerical scheme, is adapted for the first time to resolve thermal–mechanical–material fields in a range of Laser Fusion Additive Manufacturing processes. The method is capable of simulating large-deformation, free-surface melting, flow, and re-solidification of metallic materials with complex physics and material geometries. A novel SPH formulation for modeling isothermally-incompressible fluids, which allows for the accurate simulation of thermally-driven, liquid-phase metal expansion/contraction, is presented and verified. Fundamental validation of the methodology is performed via comparison with spot laser welding experiments. The methodology is then used to investigate the specific Additive Manufacturing process of the Selective Laser Melting of Metallic, micro-scale particle beds. The physics of a track deposition process is explored through numerical experiments, and the influence of processing parameters on the quality of the finished melt-track is investigated. The unique abilities of using a Lagrangian mesh-free method, as opposed to mesh-based numerical schemes, to model this process are highlighted. The SPH method is found to be a viable and promising numerical tool for simulating laser fusion driven Additive Manufacturing processes. [ABSTRACT FROM AUTHOR]

Highlights • Applied local cooling is proposed as a new method to control cardiac rotors. • Temperature gradients cause rotor drifting due to excitability heterogeneity. • Rotors drift to colder tissue regions having global minimum of excitability. • Local perturbation of 28 °C was found optimal for rotor attraction and anchoring. Abstract Cardiac rotors are believed to be a major driver source of persistent atrial fibrillation (AF), and their spatiotemporal characterization is essential for successful ablation procedures. However, electrograms guided ablation have not been proven to have benefit over empirical ablation thus far, and there is a strong need of improving the localization of cardiac arrhythmogenic targets for ablation. A new approach for characterize rotors is proposed that is based on induced spatial temperature gradients (STGs), and investigated by theoretical study using numerical simulations. We hypothesize that such gradients will cause rotor drifting due to induced spatial heterogeneity in excitability, so that rotors could be driven towards the ablating probe. Numerical simulations were conducted in single cell and 2D atrial models using AF remodeled kinetics. STGs were applied either linearly on the entire tissue or as a small local perturbation, and the major ion channel rate constants were adjusted following Arrhenius equation. In the AF-remodeled single cell, recovery time increased exponentially with decreasing temperatures, despite the marginal effect of temperature on the action potential duration. In 2D models, spiral waves drifted with drifting velocity components affected by both temperature gradient direction and the spiral wave rotation direction. Overall, spiral waves drifted towards the colder tissue region associated with global minimum of excitability. A local perturbation with a temperature of T = 28 °C was found optimal for spiral wave attraction for the studied conditions. This work provides a preliminary proof-of-concept for a potential prospective technique for rotor attraction. We envision that the insights from this study will be utilize in the future in the design of a new methodology for AF characterization and termination during ablation procedures. [ABSTRACT FROM AUTHOR]

Abstract SmCo 5 permanent magnets exhibit enormous uniaxial magnetocrystalline anisotropy energy and have a high Curie temperature. However, their low energy product is a significant deficiency. To increase the energy product in SmCo 5 , we propose substituting cobalt with iron, that has a much larger magnetic moment, in a SmCoNiFe 3 magnet where nickel is used as a thermodynamic stabilizer. Highlights • We study SmFe 3 CoNi magnet with much larger magnetic moment than the SmCo 5 prototype. • We study the role of Ni is stabilization of SmFe 3 CoNi magnet. • We prove that antiparallel spins of Sm and TM is the stable state for SmCo 5 magnet. • We present estimation of the maximum energy product of SmFe 3 CoNi magnet. [ABSTRACT FROM AUTHOR]