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• An effective method for predicting the magnetocaloric performance of Mn-Fe-P-Si alloys using machine learning is proposed. • Curie temperature, thermal hysteresis, and magnetic entropy change as a function of compositions are clearly displayed. • The composition window suitable for room temperature magnetic refrigeration is optimized to accelerate the alloy design. Magnetocaloric performance is of vital importance for Mn-Fe-P-Si alloys. However, when processes and compositions are considered, designing alloys with large magnetic entropy changes (Δ S m), low thermal hysteresis (Δ T hys), and Curie temperatures (T C) around room temperature become relatively complicated. In this study, we adopt machine learning methods to predict the magnetocaloric performance of Mn-Fe-P-Si compounds for the first time. To achieve this goal, 503, 465, and 660 data points for datasets with T C , Δ T hys , and Δ S m are collected, respectively. The collected datasets contain parameters of compositions, preparations, heat treatment, and magnetic field changes. We search for the optimal configuration using various methods and also compare their mean squared errors (MSE) and allowable errors. Evaluation results show that the performance of neural networks (NNs) is better than other methods. Therefore, we select NN to explore the T C , Δ T hys , and Δ S m values as a function of Mn, Si, metal/non-metal ratios, and B (Boron). We also propose to use the composition window with excellent magnetocaloric performance. These results not only help us gain deep insights into Mn-Fe-P-Si alloys but also accelerate the design process of alloys suitable for magnetocaloric materials. This work has the potential to solve the challenges and boost the research of Mn-Fe-P-Si alloys. [Display omitted] [ABSTRACT FROM AUTHOR]

AlSi10Mg fabricated by selective laser melting (SLM) had a unique network-like silicon-rich structure, and the mechanism for its formation was explained by molecular dynamics (MD) simulations. The effects of the silicon-rich phase and Mg-containing structure on corrosion were studied by first-principles methods. According to the simulations, corrosion resistant materials were designed, samples with laser powers of 150 W, 200 W and 250 W were fabricated. The results indicated that a local thermal gradient during laser printing caused Si segregation, and the rapid cooling rate lead to a large number of subgrains, which assisted precipitation. The difference in potential caused galvanic corrosion, and a structure with low work function in the molten pool caused pitting. The corrosion resistance of materials processed with a high laser power increased. [ABSTRACT FROM AUTHOR]

Numerous ingenious engineering designs and devices have been the product of bio-inspiration. Bone, nacre, and other such stiff structural biological materials (SSBMs) are composites that contain mineral and organic materials interlaid together in layers. In nacre, this lamellar architecture is known to contribute to its fracture toughness, and has been investigated with the goal of discovering new engineering material design principles that can aid the development of synthetic composites that are both strong and tough. The skeletal anchor fibers (spicules) of Euplectella aspergillum (Ea.) also display a lamellar architecture; however, it was recently shown using fracture mechanics experiments and computations that the lamellar structure in them does not significantly contribute to their fracture toughness. An alternate hypothesis—the load carrying capacity (LCC) hypothesis—regarding the lamellar architecture's functional significance in Ea. spicules is that it enhances the spicule's strength, rather than its toughness. From an ecology perspective the LCC hypothesis is certainly plausible, since a higher strength would allow the spicules to more firmly anchor Ea. to the sea floor, which would be beneficial to it since it is a filter feeding animal. In this paper we present support for the LCC hypothesis from a solid and structural mechanics perspective, which, compared to the support from ecology, is far harder to identify but equally, if not more, compelling and valid. We found that when the spicule functions in a knotted configuration a reduced bending stiffness benefits its load carrying capacity and that sectioning a cylindrical tube into an assembly of co-axial tubes can reduce the tube's bending stiffness for a wide class of materials that are consistent with the spicules' axial symmetry. The mechanics theory developed in this paper has applications beyond providing support for the LCC hypothesis. For example, it makes apparent many design strategies for reducing the bending stiffness of large industrial cables (e.g., undersea optical data transmission cables) while maintaining their tensile strength, which has benefits towards the handling, storage, and transportation of such cables. [ABSTRACT FROM AUTHOR]

The features of blast and impact that can damage a delicate target supported by a structure include both the peak pressure and the impulse delivered to the structure. This study examines how layers of elastic and visco-elastic materials may be assembled to mitigate these features. The impedance mismatch between two elastic layers is known to reduce the pressure, but dissipation is required to mitigate the transmitted impulse in light-weight armor. A novel design concept called impact or blast tuning is introduced in which a multi-layered armor is used to tune the stress waves resulting from an impact or blast to specific frequencies that match the damping frequencies of visco-elastic layers. The material and geometrical parameters controlling the viscous dissipation of the energy within the armor are identified for a simplified one-dimensional system, to provide insight into how the optimal design of multi-use armor might be based on this concept. [ABSTRACT FROM AUTHOR]

We systematically design materials using topology optimization to achieve prescribed nonlinear properties under finite deformation. Instead of a formal homogenization procedure, a numerical experiment is proposed to evaluate the material performance in longitudinal and transverse tensile tests under finite deformation, i.e. stress-strain relations and Poisson?s ratio. By minimizing errors between actual and prescribed properties, materials are tailored to achieve the target. Both two dimensional (2D) truss-based and continuum materials are designed with various prescribed nonlinear properties. The numerical examples illustrate optimized materials with rubber-like behavior and also optimized materials with extreme strain-independent Poisson?s ratio for axial strain intervals of ϵ i ∈ [0.00, 0.30]. [ABSTRACT FROM AUTHOR]

Abstract: We describe a systematic approach to design material microstructures to achieve desired energy propagation in a two-phase composite plate. To generate a well-posed topology optimization problem we use the relaxation approach which requires homogenization theory to relate the macroscopic material properties to the microstructure, here a sequentially ranked laminate. We introduce an algorithm whereby the laminate layer volume fractions and orientations are optimized at each material point. To resolve numerical instabilities associated with the dynamic simulation and constrained optimization problem, we filter the laminate parameters. This also has the effect of generating smoothly varying microstructures which are easier to manufacture. To demonstrate our algorithm we design microstructure layouts for tailored energy propagation, i.e. energy focus, energy redirection, energy dispersion and energy spread. [Copyright &y& Elsevier]

The geometry of atomic arrangement underpins the structural understanding of molecules in many fields. However, no general framework of mathematical/computational theory for the geometry of atomic arrangement exists. Here we present "Molecular Geometry (MG)" as a theoretical framework accompanied by "MG Operating System (MGOS)" which consists of callable functions implementing the MG theory. MG allows researchers to model complicated molecular structure problems in terms of elementary yet standard notions of volume, area, etc. and MGOS frees them from the hard and tedious task of developing/implementing geometric algorithms so that they can focus more on their primary research issues. MG facilitates simpler modeling of molecular structure problems; MGOS functions can be conveniently embedded in application programs for the efficient and accurate solution of geometric queries involving atomic arrangements. The use of MGOS in problems involving spherical entities is akin to the use of math libraries in general purpose programming languages in science and engineering. Program Title: Molecular Geometry Operating System (MGOS) Program Files doi: http://dx.doi.org/10.17632/hp2wmvxsfz.1 Licensing provisions: CC By 4.0 Programming language: C++ Supplementary material: (1) Supplementary Video 1, (2) Supplementary Video 2, (3) Supplementary Video 3, (4) Supplementary Video 4, (5) MGOS manual, and (6) 300 test PDB structure files Nature of problem: For both organic and inorganic molecules, structure determines molecular function and molecular structure is highly correlated with molecular shape or geometry. Hence, many studies were conducted for the analysis and evaluation of the geometry of atomic arrangement. However, most studies were based on Monte Carlo, grid-counting, or approximation methods and a high-quality solution requires heavy computational resources, not to mention its dependency on computation environment. In this paper, we introduce a unified framework of computational library, Molecular Geometry Operating System (MGOS), based on an analytic method for the molecular geometry of atomic arrangements. We believe that the powerful MGOS application programming interface (API) functions will free scientists from developing and implementing complicated geometric algorithms and let them focus on more important scientific problems. Solution method: Molecular Geometry (MG) is a general framework of mathematical/computational methods for solving molecular structure problems using a geometry-priority philosophy and is implemented by MGOS which is a library of callable C++ API functions. MGOS is developed based on the Voronoi diagram of three-dimensional spheres and its two derivative constructs called the quasi-triangulation and beta-complex. Note that this Voronoi diagram is different from the ordinary Voronoi diagram of points where the points are atom centers. Being an analytic method, the solutions of many geometric queries on atomic arrangement, if not all, are obtained correctly and quickly. The MGOS architecture is carefully designed in a three-tier architecture so that future modifications and/or improvements can be reflected in the application programs with no additional programming by users. [ABSTRACT FROM AUTHOR]

The article focuses on the introduction of Material Design guidelines at the Google I/O, an annual software developer-focused conference. It mentions the Material Design was intended to help Google software developers in making ideal Android application (app) user interface. It adds that Francesco Azzola, an indie developer is an early adopters of Material Design, who created an Android app based on the principles. It discusses the 2015 Google I/O.