A Low-Cost Process for Fabricating Reinforced 3D Printing Thermoplastic Filaments

Low-cost desktop-sized fused deposition modeling (FDM) printers have been widely embraced by small to large-scale institutions and individuals. To further enhance their utility and increase the range of materials that they can process, this work proposes a low-cost solution that adapts to low-cost desktop-sized extruders and enables them to fabricate filaments comprising a wide range of nonorganic reinforcing particles. This solution will fill a gap in the field, as low-cost fabrication techniques for reinforced filaments have been lacking. In the proposed solution, particles are heated and deposited on thermoplastic pellets to form a coating. Coated pellets are subsequently extruded using a low-cost desktop single-screw extruder. The effectiveness of the process is demonstrated by fabricating polylactic acid (PLA) filaments reinforced with two types of reinforcements, namely, dune sand and silicon carbide. Filaments’ stiffness and strength were measured, and their microstructure along their lateral and longitudinal directions were investigated. Improvements in tensile strength (up to 8%) and stiffness (up to 4.5%) were observed, but at low reinforcement levels (less than 2 wt%). Results showed that the proposed process could be used to fabricate filaments with multiple types of particles. The produced filaments were successfully used to fabricate 3D parts using a commercial desktop FDM printer

Assessment of the Impact of the Human Coronavirus (COVID-19) Lockdown on the Energy Sector: A Case Study of Sharjah, UAE

The recent coronavirus (COVID-19) pandemic has wreaked havoc on the global economy, causing major shifts in energy use and output patterns. For some countries, this has had a significant effect on energy demand and carbon emissions, at least in the short term. Since the United Arab Emirates is currently exerting many efforts towards sustainability, it is important to assess and understand the impacts of the pandemic and the lockdown measurements on the local energy sectors. Data for this analysis were gathered by the Sharjah Electricity Water & Gas Authority (SEWA) for Sharjah City which is the capital of the Emirate of Sharjah. The changes in electricity after the implementation of quarantine and lockdown-like measures were assessed, and the results indicate that the electric power demand in Sharjah City was reduced in the commercial, industrial, and agricultural sectors, whereas the residential and government sectors witnessed a higher power demand. The overall electricity consumption in the year 2020 was reduced by 1.04% in comparison with previous years including 2016 to 2019. The results of this study indicate that the changes in electricity consumption were minimal in Sharjah City as compared to other cities around the world. However, this paper highlights the importance of governmental response during and after a pandemic, and the possible impacts that lockdowns could potentially have in the energy industry worldwide

Infrared Camera Geometric Calibration: A Review and a Precise Thermal Radiation Checkerboard Target

Different infrared (IR) planar geometric calibration targets have been developed over the years that exploit a well-established and flexible optical camera geometric calibration procedure following the pinhole approximation. This geometric calibration is typically neglected in IR cameras, due to the relatively low resolution of thermal images and the complex IR targets needed for the geometric calibration in comparison to the optical targets. In this study, a thorough literature review of numerous IR camera geometric calibration targets, along with their respective outcomes, were summarized and leveraged to deliver a practical checkerboard target for less experienced end users, while offering the lowest reprojection errors. It was concluded that the fabrication of high emissivity contrast and precise square points of intersection within a checkerboard pattern extends the accuracy of capturing these control points in a thermal image for an optimized IR camera geometric calibration. Accordingly, two simple planar checkerboard targets were fabricated using laser engraving and ultraviolet (UV) printing technologies on a polished stainless steel (SS304) plate. The UV-printed checkerboard target on a polished metallic alloy delivered the lowest mean reprojection error (MRE) of 0.057 pixels and the lowest root mean square error (RMSE) of reprojection of 0.063 pixels, with a standard deviation lower than 0.003 pixels. The UV-printed design offers better accuracy than any other checkerboard calibration target, and comparable results to the best prominent circular pattern results reported in the literature