Obtaining and Characterization of Vitroceram by Chemical Doped ZnO for Art Mosaic

This paper presents the obtaining and the characterization of ZnO doped vitroceramic, used as photo and termoresistive pigment for art mosaic. The coprecipitation involves two sequential steps, first of ions Zn2+(aq), Cr3+(aq), Co3+(aq) and Mn3+(aq), as oxihydroxides in predetermined molar reports: 98:0,6:0,7:06, followed by maturation, forced filtration and redispersion of the granules in distilled water, after which, by ion exchange is precipitated as intergranular film of Sb3+(aq) and Bi3+(aq) ions. After forced filtration and drying, the material is subjected gradually to a thermal process, according to a curve with three levels: 20-110 °C, 110-360 °C şi 360-950 °C, with a heating rate of 3 °C/min., each level keeping a constant temperature while varying between 4 and 8 h for nanostructures processes of crystalls reform. The vitroceramic was characterized by SEM-EDX, microFTIR and termic derivatography, after treatment at 110 °C and respectively 950 °C, underlining uniformity of grains and revealing their heterojonctional structure in cross-section

Structural and Mechanical Properties of Hot Rolled CuAlBe Non-Spark Alloy Explosion

Explosion protection is of particular importance for safety as explosions also endanger the health of workers due to the uncontrolled effects of flames and pressure, the presence of harmful reaction products and the consumption of oxygen in the ambient air breathed by workers. CuAlBe alloy is proposed as a solution for mechanical actuators such as gears that work in environments with possible explosive atmosphere. Made of CuBe master alloy and pure aluminum in a induction furnace the material present large grains in melted state. After the hot rolling (heated 600s at 900°C) of the ingots small variation of chemical composition was observed based on the oxidation of the material, appearance of small cracks on the edges and a preferential orientation of the grains along the lamination direction. Scanning electron microscopy (SEM) was used to characterize the microstructural states of CuAlBe as laminated and heat treated states

Relationship Between Safety Measures and Human Error in the Construction Industry: Working at Heights.

In recent years, falling from heights (FFH) has been reported as the primary cause of fatalities within the Australian construction industry. While there is substantial literature exploring safety and human error in attempt to decrease the occurrences of accidents through the implementation of organisational and physical hazards related strategies, little attention has been brought towards the impact of psychological distress on the relationship between human error and safety measures. Therefore, this paper is aimed at examining the relationship between safety measures and human error with the objective of identifying the impact of psychological distress among workers working at heights within the construction industry on the relationship. This study found that human error can occur as a result of psychological distress and therefore provides a foundation for future research to explore whether proper implementation of psychological safety measures could decrease the occurrence of human failures and accidents when working at heights

Effects of nanoparticle clustering on the heat transport in nanofluids through fractal theories

Considering that the motion of microphysical object takes place on continuous but non-differentiable curves, i.e. on fractals, effects of nanoparticle clustering on the heat transfer in nanofluids using the scale relativity theory in the topological dimension DT = 3 are analyzed. In the one-dimensional differentiable case, the clustering morphogenesis process is achieved by cnoidal oscillation modes of the speed field and a relation between the radius and growth speed of the cluster is obtained. In the non-differentiable case, the fractal kink spontaneously breaks the vacuum symmetry by tunneling and generates coherent structures. Since all the properties of the speed field are transferred to the thermal one and the fractal potential (fractal soliton) acts as an energy accumulator, for a certain condition of an external load (e.g. for a certain value of thermal gradient) the fractal soliton breaks down (blows up) and releases energy. As result, the thermal conductibility in nanofluids unexpectedly increases