The evolution of a W, Au-Ag-Te and Au-Ag hydrothermal system, Tinos Island, Cyclades, Greece

At Tinos Island, Greece, the physicochemical evolution of the hydrothermal system and the associated stages of metallic mineralization that are developed in the vicinity of the Tinos granodiorite-leucogranite has been studied, based on fluid inclusion studies and chemical reactions modeling. Early tungsten mineraliozation was related to the metasomatic stage of contact metamorphism and precipitated at ~ 350oC, from moderate saline (10.4 to 14.8 wt% NaCl eq.), CO2- effervescing fluids, that contained variable amounts of CaCl2 and MgCl2. Panormos Bay Au-Ag-Te mineralization, located 16 km away from the intrusive site, was deposited from cooler 200° to 300oC, and low to moderate saline (0.2 to 13.2 wt% NaCl eq.) mineralizing fluids. Au-Ag mineralization at Apigania Bay, which represents a late evolutionary phase, was deposited from even cooler (125o to 235oC) and dilute (0.2 to 6.8 wt % NaCl eq.) fluids. In all, the mineralization stage precipitation was controlled by two principal factors: the exsolution of gaseous phase and an increase in pH from 3.3 to 7.6

Characterization of additively manufactured triply periodic minimal surface structures under compressive loading

Triply periodic minimal surface (TPMS) structures can produce tailored complex structures for various applications and serve as substitutes for polymeric foams. In this study, six different types of TPMS structures (Neovious, gyroid, Schwarz P, Lidinoid, split P, and diamond) were examined under quasi-static compression in terms of their energy absorption capabilities, mechanical properties, and weights, which were compared with those of expanded polystyrene foam and the original printing material Z-Ultra. It was found that the Neovious, diamond, and Lidinoid structures were most suitable for substituting expanded polystyrene foam, especially in safety helmets requiring high specific energy absorption capabilities

Characterization of the Tensile Behavior of Expanded Polystyrene Foam as a Function of Density and Strain Rate

Expanded polystyrene (EPS) foam is a material, frequently used in a range of applications for its good energy absorption, thermal insulation, durability, and acoustic absorption. In this wide range of applications, the material undergoes a variety of loads that can extend from static to dynamic. When it comes to crush applications, these loading profiles create the need of well-defined compression and tensile properties for a range of densities and strain rates. Herein, static and dynamic tension tests are conducted on EPS foam dog-bone samples for material characterization. The target of the study is to obtain stress–strain curves for a range of densities spreading from 60 to 120 g L-1. For the low-strain rates, tensile testing machines are used, whereas for the high-strain rates, a modified drop tower set-up is used. The influence of the strain rate on the stress–strain behavior, the dynamic strength, Young''s modulus, and energy absorption capacities for different foam densities is measured. Furthermore, the experimental results for each density are compared with the predictions of Avalle''s model for crushable foams to evaluate the validity of the model. The quality of fit obtained between experimental and theoretical is between 70% and 97% depending on the strain rate

Characterization of additively manufactured triply periodic minimal surface structures under compressive loading

Triply periodic minimal surface (TPMS) structures can produce tailored complex structures for various applications and serve as substitutes for polymeric foams. In this study, six different types of TPMS structures (Neovious, gyroid, Schwarz P, Lidinoid, split P, and diamond) were examined under quasi-static compression in terms of their energy absorption capabilities, mechanical properties, and weights, which were compared with those of expanded polystyrene foam and the original printing material Z-Ultra. It was found that the Neovious, diamond, and Lidinoid structures were most suitable for substituting expanded polystyrene foam, especially in safety helmets requiring high specific energy absorption capabilities