Defect and Diffusion Forum Vol. 435

Abstract: More energy-efficient buildings have a significant impact on reducing energy consumption, as they provide thermal comfort to their occupants with lower electricity usage. Aligned with the interpretation of thermal performance, this article analyzes the results of a thermo-energy performance simulation of a residential building located in different bioclimatic zones, Pelotas/RS (BZ2) and Cuiabá (BZ7). For the simulation, the EnergyPlus software was used, varying the configuration of the building's windows, including electrochromic film, double glass, and common glass. The energy consumption results were analyzed, and finally, the thermal comfort of each model was evaluated using the adaptive method of ASHRAE 55 (2017), with the aim of assisting in the design and construction of residential buildings that are truly suitable and adapted to the climate. After conducting the simulations, it was possible to conclude that the use of electrochromic film led to the greatest reduction in energy consumption in both Zones, by 1.8% in BZ2 and 13.9% in BZ7, with an increase in thermal comfort in both simulated cases, showing better results in BZ7, a region with a hot climate.

Abstract: Taking into account the history of problems concerning high-strength low-alloyed (HSLA) steel used for manufacturing of penstocks (partly presented by authors in previous studies), this paper is oriented toward specifics on structural integrity assessment of construction in question. Experimental testing of parent material, i.e. HSLA steel, such as microstructure analysis, impact toughness testing and hardness measuring provide insight into characteristics of parent material properties. Considering geometry of penstock and specific requirements, finite element method (FEM), i.e. ABAQUS, was used to assess the structural integrity of penstock as a whole, specific the longitudinal welded joint under the different internal (working) pressure. It should be emphasized that a slight undermatching effect was investigated by FEM approach in this case. Focus is being put on plastic deformation investigation on aforementioned welded joint under maximum internal pressure of 120 bar.

Abstract: In this work, rectangular sheets of composite materials consisting of epoxy with a single layer of fiberglass were studied with the internal crack at angles (0°, 90°) with the x-axis in the presence of nanomaterial TiO₂ in proportions (1 wt%, 2 wt%, and 3 wt%), the study was experimental and numerical using the ANSYS. The sample mold was made from plastic using a CNC machine. One case was studied in both the experimental and numerical parts, which is clamped-clamped-free-free (CC-FF). After conducting the test, it was found that the crack negatively affects the rectangular composite plate, as it reduces the value of the natural frequency and increases the value of damping. However, in the case of adding the nanomaterial, it was found that the natural frequency increases with the increase in the percentage of nanomaterials, and the maximum value of the natural frequency was at 3% because it works to increase hardness rectangular plate stiffens and reduces damping. The error rate between the experimental and numerical parts did not exceed (9.717%).

Abstract: The injection moulding industry is dynamically developing. The growing demand for more customizable products can be served by low or middle volume production using prototype moulds and inserts. The conventional material of prototype moulds is aluminum because of its excellent machinability, acceptable strength and stiffness and outstanding thermal conductivity. Prototype moulds are gaining ground in the injection moulding industry, yet their operational behavior (including exact mechanical and thermal process parameters) is largely unknown. We created a comprehensive state monitoring system that measures the operational strain, cavity pressure and temperature of different prototype injection moulds. This way, all important process parameters can be measured and the relations between the moulding parameters and the operational pressure loads, deformations and temperatures can be quantified and analysed.

Abstract: Preparing of Sb₂S₃ precursor by sol gel method and the post selenization is a simple and low-cost method for preparing Sb₂(S, Se)₃. In the preparation process of this method, the number of spin-coating of Sb₂S₃ precursor determines the film thickness, structure, and S/Se ratio. In this work, the effects of different spin-coating times (1 to 5) on the structure, optical and electrical properties of the film were studied. The results showed that when the number of spin-coating increased from 1 to 5, the thickness of the film increased from 0.24 μm to 1.17 μm. When spin-coating twice, the strongest diffraction peak of the film changed from (120) to (230); as the spin-coating frequency continued to increase, the film gradually exhibited Sb₂S₃ characteristics, accompanied by a small amount of Sb₂O₃ impurities. In addition, excessive spin-coating cycles can cause large voids to appear on the surface of the film. From the UV-visible spectrum, it can be seen that as the thickness of the film increases, the light absorption also gradually improve, and the band gap increases from 1.34 eV to 1.66 eV. The Mott-Schottky test showed that the prepared thin films were all P-type semiconductor. When spin-coated twice, the carrier concentration of the thin film reached 5.8×10¹⁵cm^-3.

Abstract: Photoconductive antennas based on low-temperature gallium arsenide (LT-GaAs) with a gold plasmonic-gold grating made of nanorods and nanoislands have been developed and fabricated. The antennas were produced using molecular beam epitaxy and electron-beam nanolithography. LT-GaAs samples with a high annealing temperature of 943 K were employed in the fabrication process. It has been demonstrated that plasmonic nanostructures significantly enhance the efficiency of light-to-terahertz radiation conversion by photoconductive antennas.

Abstract: Amino acid lanthanide complexes are a promising class of environmentally friendly and non-toxic optical organic materials that find extensive applications in biomedicine, molecular probes, and optical devices. In this study, three amino acid lanthanide complexes, octanoyl glycine gadolinium (Gd(oct-ala)₃×H₂O), octanoyl serine gadolinium (Gd(oct-ser)₃×H₂O), and octanoyl phenylalanine gadolinium (Gd(oct-phe)₃×H₂O), were synthesized by reacting octanoyl amino acid ligands with gadolinium chloride. The coordination structure of the gadolinium complexes was determined by elemental analysis and infrared spectroscopy. XRD and polarized light microscopy confirmed the amorphous structure of the complexes. DSC and TG-DTA were used to investigate the thermodynamic stability of the gadolinium complexes, and their solubility and UV-visible light absorption properties were also evaluated. Our results demonstrate that all three gadolinium complexes exhibit excellent UV-visible light absorption performance, with the Gd(oct-phe)₃×H₂O containing a phenyl ring showing the highest light absorption efficiency.