Studies on the conditions of homogenization and properties in hot forming of ZK60 cast magnesium alloy

This paper presents a study of temperature conditions for the homogenization of a cast high-strength ZK60 alloy belonging to the Mg-Zn-Zr group of magnesium alloys. On the basis of a literature review, two-stage homogenization conditions were selected to improve the forgeability of the ZK60 casting. The effectiveness of this treatment was evaluated experimentally on the basis of structure and hardness tests and was found to be satisfactory. Plastometric tests were carried out for the samples made from the ingots after homogenization. These tests were performed in a compression test in hot forming conditions at three temperatures (350 ºC, 400 ºC and 450 ºC) and four strain rates (0,01; 0,1; 1,0 and 10 s-1). The determined flow curves will be used to develop a material model of the cast magnesium alloy ZK60 for numerical simulations

Numerical analysis of forging a connector for light vehicles from cast magnesium alloy preforms

The article presents the results of numerical analysis of the new forging process of the connector forging from cast preform on hydraulic press. The high strength ZK60 alloy (belonging to the Mg-Zn-Zr group of Mg alloys) was selected to numerical tests. Currently, this part in the industry is produced by multi-stage forging consisting of operations: bending, preforming, and finishing. The use of the cast preform would enable forging this component in one operation. However, obtaining specific mechanical properties requires inducing a certain level of strain within the forged part. Therefore, the design of the preform, its shape and volume, is of paramount importance. In the work presented in this article, preforms of different shapes were designed and assessed using Finite Element Method (FEM) analysis

Studies on the conditions of homogenization and properties in hot forming of ZK60 cast magnesium alloy

This paper presents a study of temperature conditions for the homogenization of a cast high-strength ZK60 alloy belonging to the Mg-Zn-Zr group of magnesium alloys. On the basis of a literature review, two-stage homogenization conditions were selected to improve the forgeability of the ZK60 casting. The effectiveness of this treatment was evaluated experimentally on the basis of structure and hardness tests and was found to be satisfactory. Plastometric tests were carried out for the samples made from the ingots after homogenization. These tests were performed in a compression test in hot forming conditions at three temperatures (350 ºC, 400 ºC and 450 ºC) and four strain rates (0,01; 0,1; 1,0 and 10 s-1). The determined flow curves will be used to develop a material model of the cast magnesium alloy ZK60 for numerical simulations

Numerical analysis of forging a connector for light vehicles from cast magnesium alloy preforms

The article presents the results of numerical analysis of the new forging process of the connector forging from cast preform on hydraulic press. The high strength ZK60 alloy (belonging to the Mg-Zn-Zr group of Mg alloys) was selected to numerical tests. Currently, this part in the industry is produced by multi-stage forging consisting of operations: bending, preforming, and finishing. The use of the cast preform would enable forging this component in one operation. However, obtaining specific mechanical properties requires inducing a certain level of strain within the forged part. Therefore, the design of the preform, its shape and volume, is of paramount importance. In the work presented in this article, preforms of different shapes were designed and assessed using Finite Element Method (FEM) analysis

Gender in the Making: A Pragmatic Approach to Transgender Experiences in Lowland Tropical America

Based on long-term fieldwork experiences among both the Guna in Panama and the Kakataibo in Peruvian Amazonia, this article proposes to examine the transgender phenomenon in indigenous America. Making use of the notions of performance and status, we argue that (trans)gender should be understood via two complementary dimensions: at the same time that it is manifested in a set of expressive practices, it is also inscribed in a specific system of social organization. Adopting a pragmatic approach that emphasizes the relational, aesthetic and performative dimensions of gender, the article analyses the ways through which two Amerindian peoples negotiate and inhabit gender rules. This relational approach enables the exploration of gender experiences beyond the notions of female and male, and above all in line with local theories of the body and person

Investigation of functions characterizing the flow curves of cast magnesium alloy MgAl9Zn1

The article presents the results of testing the flow curves of cast magnesium alloy MgAl9Zn1. Experimental tests were carried out on a deformation dilatometer in a compression test of cylindrical specimens heated to 380 °C, 400 oC, 420 °C at strain rates of 0,1 s-1, 1 s-1, 10 s-1. The experimental curves were described by functions used in programs for simulating metal forming processes based on the finite element method. The Generalized Reduced Gradient optimization method (GRDM) implemented in Microsoft Excel was used to determine the function coefficients. Based on the results obtained, the best functions characterizing the flow curves were selected for use in describing the material models used in numerical simulations of cast magnesium alloy MgAl9Zn1

Investigation of functions characterizing the flow curves of cast magnesium alloy MgAl9Zn1

The article presents the results of testing the flow curves of cast magnesium alloy MgAl9Zn1. Experimental tests were carried out on a deformation dilatometer in a compression test of cylindrical specimens heated to 380 °C, 400 oC, 420 °C at strain rates of 0,1 s-1, 1 s-1, 10 s-1. The experimental curves were described by functions used in programs for simulating metal forming processes based on the finite element method. The Generalized Reduced Gradient optimization method (GRDM) implemented in Microsoft Excel was used to determine the function coefficients. Based on the results obtained, the best functions characterizing the flow curves were selected for use in describing the material models used in numerical simulations of cast magnesium alloy MgAl9Zn1

DeCAF—Discrimination, Comparison, Alignment Tool for 2D PHarmacophores

Comparison of small molecules is a common component of many cheminformatics workflows, including the design of new compounds and libraries as well as side-effect predictions and drug repurposing. Currently, large-scale comparison methods rely mostly on simple fingerprint representation of molecules, which take into account the structural similarities of compounds. Methods that utilize 3D information depend on multiple conformer generation steps, which are computationally expensive and can greatly influence their results. The aim of this study was to augment molecule representation with spatial and physicochemical properties while simultaneously avoiding conformer generation. To achieve this goal, we describe a molecule as an undirected graph in which the nodes correspond to atoms with pharmacophoric properties and the edges of the graph represent the distances between features. This approach combines the benefits of a conformation-free representation of a molecule with additional spatial information. We implemented our approach as an open-source Python module called DeCAF (Discrimination, Comparison, Alignment tool for 2D PHarmacophores), freely available at http://bitbucket.org/marta-sd/decaf. We show DeCAF’s strengths and weaknesses with usage examples and thorough statistical evaluation. Additionally, we show that our method can be manually tweaked to further improve the results for specific tasks. The full dataset on which DeCAF was evaluated and all scripts used to calculate and analyze the results are also provided