Engineering Headway Vol. 30

Abstract: This study presents a rapid method for synthesizing yttrium oxide nanoparticles (Y₂O₃-NPs) utilizing ethanol and yttrium oxide (Y₂O₃). The Y₂O₃-NPs were analyzed using Fourier transform infrared (FT-IR), ultraviolet spectroscopy (UV-Vis), atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD).The X-ray diffraction (XRD) analysis revealed that the Y₂O₃ exhibited a preferred alignment and possessed a cubic crystal structure with a (111) orientation. The Atomic Force Microscopy (AFM) findings indicated the presence of a nanoscale structure characterized by a spherical surface that exhibits excellent dispersibility. The granules were seen to have a consistent size ranging from 19 to 36 nanometers, and the surface had a roughness ranging from 38 to 78 nanometers. The aim of this paper was to examine the features of (Y₂O_3-NPs) with antifungal and antibacterial activities. Studies on Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella, Escherichia coli, and Candida have shown the effectiveness of NPs as an antibacterial and antifungal agent.

Abstract: The effect of laser energy number of pulses on the compositional, morphological, topographic, and optical properties of selenium oxide nanoparticles SeO2 nanoparticles prepared by pulsed laser ablation of selenium in a target liquid immersed in water with Nd:YAG laser pulses with energy 400 mJ was investigated using a different number of laser pulses 250 and 300. X-ray diffraction (XRD) tests revealed that the SeO2 nanoparticles exhibited a hexagonal crystal structure. Scanning electron microscope (SEM) tests revealed that the form and size of the produced SeO2 NPs are dependent on the number of laser pulses. The dispersion of nanoparticles was proportional to the increase in laser energy generated by the number of pulses. AFM investigations revealed extremely distributed ball-shaped SeO2 particles. The optical energy gap of SeO2 nanoparticles generated was evaluated using optical characteristics and found to be 3.37 to 4.3 eV for SeO2 induced by 250 and 300 pulses, respectively. The biological effectiveness results revealed that employing laser energy with a pulse number of 300P resulted in the greatest inhibition.

Abstract: This study investigates the effect of different joint designs and surface treatments on the flexural strength of a 3D-printed resin denture base. Seventy specimens of 3D-printed resin were used in this study, these specimens were grouped according to the joint design into four groups (positive control group, butt-joint group, bevel-joint group, and round-joint group) except the positive control group each one of these groups is subgroup into another three groups according to the surface treatment material into heat-cured monomer (MMA), sandblast, and 3-D printed resin. The specimens were cut in the middle according to the joint shape, and the cut surfaces were treated with heat-cured MMA monomer, sandblast, and 3D-printed resin (as a negative control group). Then a silicone mold was used to prepare the specimens with 3D printed resin, using a light-emitting diode, and post-cured with a light-cured unit box. An Instron testing machine examines all specimens. The bevel-joint group repaired with 3D printed resin (G7) had the highest mean flexural strength (85.0483) MPa and a significant difference from the control group. For fixing a fractured denture base made of 3D-printed resin, the bevel-joint design is the most recommended design of the joint, and the best material for treatment is 3D-printed resin. Then a round-joint with heat-cured monomer and the butt-joint with 3D-printed resin treatment.

Abstract: AbstractAlthough manufacturers recommend glazing and polishing for CAD/CAM milled restorations, the relative efficacy of either in achieving optimal surface roughness and wear remains ambiguous. This study has been carried out to investigate how polishing and glazing affect the surface characteristics and hardness of milled monolithic zirconia. Thirty cuboid-shaped milled zirconia samples (10 mm length× 10 mm width× 3mm thickness) were cut from a pre-sintered zirconia block (Aconia^®, Besmile Biotechnology Co., Ltd. Chengdu, China). Samples were sintered, cleaned, and divided into two groups according to surface treatment (n = 15). Group P: Polished only, Group PG: Polished and glazed. Each treatment was performed according to the manufacturer’s guidelines. One sample was examined from each group using a Scanning Electron microscope (SEM) to explore the surface morphology. Surface roughness was assessed using a profilometer. Vickers hardness (VHN) was evaluated using a Vickers diamond indenter. All data were calculated, and statistical analysis was performed. There was a significant difference between groups in surface roughness and hardness. The average surface roughness (Ra) value of polished zirconia samples (2.1611 µm) was higher than the Ra value of glazed zirconia samples (1.3273 µm), while the Vickers hardness (VHN) of polished zirconia samples (1.4721) was lower than the VHN of glazed zirconia samples (3.7843). SEM analysis images validated the findings on the surface roughness. The glazing after polishing of monolithic zirconia showed better surface smoothness and higher hardness.

Abstract: The present study aims to provide a solution that could relieve pain through electro-analgesia by design and implementation of a transcutaneous electrical nerve stimulation (TENS) unit, which is electrotherapeutical process in which electrical current is used to excite and stimulate the nervous system of a living body. In this work, an electrical unit that comprises multiple modules is designed and implemented. There is a pulse generation module that uses NE555 oscillators to make continuous, asymmetric biphasic signals, a timing module that uses a microcontroller and a relay to control the length of therapy, a skin-electrode interface module that uses surface electrodes to send the signal to the subject’s skin and a unit case that was created using Design Spark Mechanical 2.0 software. The intended unit allows the user to control signal parameters (frequency, voltage intensity, pulse width and therapy time) and modulate them so that an optimal outcome is achieved for pain management. Twelve cases of acute and chronic pain were tested in medical facilities under doctors’ supervision. The suggested unit offers a frequency range of 2–119 Hz, a stimulation intensity of up to 111 V, a pulse width of 50–210 µs, and a session time of 1–30 min, which was sufficient for many patients. The results showed that the stimulation intensity has higher significance in the process of pain relief, and it varies depending on the condition of each individual patient. The intensity of the tested cases was (50 to 77) V, which is directly proportional to the severity of the pain. The higher intensity of pain required higher intensities of stimulation, and vice versa. Keywords: Design Spark Mechanical, Electrotherapy, Pain Relief, TENS

Abstract: The need for less harmful remedies to olden day inorganic coagulants like alum regarding with health and environment is for a long time pushing for research towards more sustainable options. This has embarked on by researching the capability of pomegranate seeds as an integral component which is environmentally friendly when it comes to treatment process of waste materials. The impacts of pomegranate seed extract at different concentrations were analyzed to find out their abilities in reducing preference ratio, color, and chemical oxygen demand (COD). It’s only at an optimum dose level set at 500 mg/l that a significant decrease in pollutants’ content was achieved such as this case; 78.3% removal efficiency rate was recorded on turbidity followed by 93.5% of TSS removal rate 91.5% color removal efficiency and finally 17.7% COD removal percentage. These findings indicate that pomegranate seed might be considered as an appropriate alternative to traditional coagulants during water treatment processes.