Universiti Teknikal Malaysia Melaka

This research study′s primary motivation is to study the practicality and feasibility of energy harvesting or energy scavenging using ambient energy such as heat absorbed by asphalt pavement to provide elec. power for small electronic circuits or devices, making them self-sufficient.Therefore, this project investigates the thermal distribution evaluation of multiple diameters of the aluminum rod as a cooling element and examines the optimum designs for the surface heat absorption method using the aluminum plate in the road thermoelec. energy harvesting system (RTEHs).The RTEHs exptl. setup consisted of an asphalt-filled wooden base box, "sandwiched" thermoelec. module, top aluminum plate, and bottom aluminum rod, which is partially submerged in the asphalt and soil.Using constructed RTEHs setup and several thermocouples, a series of experiments on multiple diameters of an aluminum rod as a cooling element and few aluminum plate designs were conducted to obtain the best configurations that yield maximum temperature difference between cooling and heating sides in asphalt based RTEHs.Based on the testing results, RTEHs with a mounted triple of Rod C, which has the biggest diameter of 31.75 mm (1.25 in.) and combined with 100 mm x 200 mm of a top plate, proved to be the best performing configuration by producing the highest temperature difference (DT) of 15.19°C.Since the triple rod configuration has a higher value of shape factor, this indicates a better heat transfer performance by conduction.These proved the theory of conduction shape factor for multiple geometries.Based on the results, having a bigger top plate as a heating element promotes a higher heat transfer rate and takes in more heat energy, thus producing the largest DT for the system, which confirmed Stephen-Boltzmann′s law on radiation heat transfer.

The burgeoning field of perovskite solar cells (PSCs) continues to attract research interest, particularly with the potential of copper iodide (CuI) as a high-performing hole transport layer (HTL).This review comprehensively examines the intrinsic advantages of solid-state CuI as HTL for PSC applications due to its exceptional p-type conductivity, ambient stability, and ease of synthesis.Moreover, the review explores cutting-edge strategies for mitigating defects to preserve the power conversion efficiency (PCE) and stability of the device including optimization of synthesis, defect engineering through stoichiometry control, interface engineering and doping engineering.Notably, lanthanum (La) doping engineering on CuI demonstrates remarkable potential, offering enhanced structural compatibility due to its ionic size, improved band alignment, and a substantial reduction in deep-level traps contributing to carrier recombination.This groundbreaking doping strategy produces La-doped CuI HTL that addresses the challenges at the perovskite/HTL interface, leading to an elevation in the PCE of the PSCs.As PSC technol. advances toward com. viability, CuI emerges as a linchpin in accelerating progress in the quest for highly efficient and stable solar energy solutions

Abstract: Fused deposition modeling (FDM) is a widely used additive manufacturing technique known for its versatility and cost-effectiveness in producing complex prototypes and parts.However, FDM needs more mech. properties, surface quality issues, and low-dimensional accuracy.This study aims to enhance the dimensional accuracy of FDM-fabricated thermoplastics, specifically acrylonitrile-butadiene-styrene (ABS) and polylactic acid (PLA), by optimizing two process parameters: infill d. (20%, 55%, and 80%) and printing pressure (101.3 kPa atm. pressure and 20 kPa vacuum pressure).The printed samples′ dimensions, including hole diameter, corner diameter, thickness, width, length, and perpendicular, were precisely measured using a coordinate measuring machine.The Response Surface Methodol. was employed to quantify the relationship between process parameters and dimensional accuracy.The results indicated that vacuum-printed samples demonstrated a 23% improvement in overall dimensional accuracy compared to those printed at atm. pressure.For ABS, the optimal process parameters were identified as 55% infill d. and 20 kPa vacuum pressure, while for PLA, the best accuracy was achieved at 80% infill d. and 20 kPa vacuum pressure.Although the material did not reach 100% of the desired dimensional accuracy, these optimized settings significantly enhanced precision, particularly for applications requiring tight tolerances, such as automotive and aerospace components.The findings of this study provide crucial insights for improving dimensional accuracy in FDM-printed parts, contributing to more reliable and precise additive manufacturing processes.