Microeconomics of the materials and energents consumption in a simulated copper casting process

An analytical model for the optimization of the consumption of materials and energents in a typical coppercasting process based on a standard simulation procedure is presented. The proposed microeconomic analysisin correlation with the virtual manufacture of castings enabled a shortening of the time required to developa product, as well as the fabrication of high quality castings, which could be a crucial contributionto the achievement of increased engineering adequacy and economic competitiveness.In this sense, the article demonstrates the beneficial employment of mathematical programming withina systematic economic analysis. The analyzed casting process is a part of the metallurgical manufacturingoperations of the Copper Smelter and Refinery Bor, Serbia

Multivariate Normal Approximation on the Wiener Space: New Bounds in the Convex Distance

Copyright © The Author(s) 2021. We establish explicit bounds on the convex distance between the distribution of a vector of smooth functionals of a Gaussian field and that of a normal vector with a positive-definite covariance matrix. Our bounds are commensurate to the ones obtained by Nourdin et al. (Ann Inst Henri Poincaré Probab Stat 46(1):45–58, 2010) for the (smoother) 1-Wasserstein distance, and do not involve any additional logarithmic factor. One of the main tools exploited in our work is a recursive estimate on the convex distance recently obtained by Schulte and Yukich (Electron J Probab 24(130):1–42, 2019). We illustrate our abstract results in two different situations: (i) we prove a quantitative multivariate fourth moment theorem for vectors of multiple Wiener–Itô integrals, and (ii) we characterize the rate of convergence for the finite-dimensional distributions in the functional Breuer–Major theorem.FNR grant APOGee (R-AGR-3585-10) at Luxembourg University; FNR grant FoRGES (R-AGR-3376-10) at Luxembourg University; FNR Grant MISSILe (R-AGR-3410-12-Z) at Luxembourg and Singapore Universities

Optimisation of cast pistons made of Al–Si piston alloy

Abstract In this paper, the advantages of applying software packages for the optimisation of the relevant technological parameters of casting and their implementation and control in production processes using the example of a cast piston are presented. The micro- and macrostructural characteristics of two different modes of solidification are given. In previous studies, possible phases in the microstructure of an aluminium alloy piston were identified, and their influences on the physical, chemical and mechanical properties are well known. The aim of this study is to obtain piston alloys with the desired mechanical and physical properties in the appropriate sections by combination of specific phases (share and distribution stages, the optimal size of primary silicon crystals, grain size, etc.) based on modern techniques

Synthesis of ZrO2 Particles Reinforced ZA25 Alloy Composites by Compocasting Process

Microstructures and compressive properties of Zn25Al3Cu/ZrO2 particulate composites were studied. The composites were obtained by compocasting process through infiltration of 1 and 3 wt% ZrO2 particles of different size into the semi-solid melt of the base alloy. The influence of reinforcing particles size and quantity on microstructure and mechanical properties of the composites was examined. The composites have shown significant improvement of mechanical properties with respect to the base alloy. Increase in hardness and compressive yield strength of the composites was more expressed in the composites with coarse ZrO2 particles. (C) Koninklijke Brill NV, Leiden, 201

Biomimetic 3D in vitro model of biofilm triggered osteomyelitis for investigating hematopoiesis during bone marrow infections

In this work, we define the requirements for a human cell-based osteomyelitis model which overcomes the limitations of state of the art animal models. Osteomyelitis is a severe and difficult to treat infection of the bone that develops rapidly, making it difficult to study in humans. We have developed a 3D in vitro model of the bone marrow, comprising a macroporous material, human hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs). Inclusion of biofilms grown on an implant into the model system allowed us to study the effects of postoperative osteomyelitis-inducing bacteria on the bone marrow. The bacteria influenced the myeloid differentiation of HSPCs as well as MSC cytokine expression and the MSC ability to support HSPC maintenance. In conclusion, we provide a new 3D in vitro model which meets all the requirements for investigating the impact of osteomyelitis. Statement of Significance: Implant-associated osteomyelitis is a persistent bacterial infection of the bone which occurs in many implant patients and can result in functional impairments or even entire loss of the extremity. Nevertheless, surprisingly little is known on the triangle interaction between implant material, bacterial biofilm and affected bone tissue. Closing this gap of knowledge would be crucial for the fundamental understanding of the disease and the development of novel treatment strategies. For this purpose, we developed the first biomaterial-based system that is able to mimic implant-associated osteomyelitis outside of the body, thus, opening the avenue to study this fatal disease in the laboratory