Al-Bahir Journal for Engineering and Pure Sciences

This study investigated the impact of high temperatures on dental tissues during the polymerization of optical fillings
using a diode laser and two types of pulsed and continuous LED devices. Three distinct light source units were
employed: a laser diode, an LEDition, and a LED.B. Temperature increases were measured at a distance of 1 mm from the
thermocouple to the tip of the device. To create an experimental model, we fixed the operational voltage of the polymerization device and maintained a 1 mm gap between the terminal and the thermocouple wire. Temperature readings
and thermal background (TO) measurements were taken three times, with 1 h between each measurement, resulting in a
total of 60 readings. The continuous mode of the LED.B produced the highest observed temperature increase of 6
Celsius, while the diode laser recorded the lowest temperature rise of 2 Celsius during each test period. These results
underscore the importance of selecting the appropriate light-activated unit and curing time during basic restorations
with light-activated resin to prevent thermal damage to dental tissues. The study concluded that the diode laser is
preferable for phototherapy, as it consistently records lower temperatures, even with extended treatment times.

Borehole water is a primary drinking water source in Effurun, Delta State, Nigeria, making its quality a critical public health concern. Contaminants such as major ions and trace metals can affect water safety, necessitating comprehensive assessment. This study evaluates the hydrochemical characteristics of borehole water, identifies contamination sources, and assesses compliance with World Health Organization (WHO) and Nigerian Standard for Drinking Water Quality (NSDWQ) guidelines. The study aims to determine the spatial distribution of major ions and trace metals in borehole water, assess water quality variations, and identify contamination patterns due to natural and anthropogenic influences. Water samples were collected from ten boreholes (BH1–BH10) and analyzed for significant cations (Ca²⁺, Mg²⁺, Na⁺, K⁺), anions (Cl⁻, SO₄²⁻, NO₃⁻, HCO₃⁻), and trace metals (Pb, Cu, Zn, Mn). Statistical analysis, spatial mapping using ArcGIS, and hydrogeochemical modeling (Piper and Durov diagrams) were conducted to determine concentration trends and geochemical interactions. Calcium ranged from 29.95 to 64.50 mg/L, showing moderate correlations with sodium and potassium. Magnesium remained stable (9.50–14.20 mg/L), while chloride levels (39.50–52.70 mg/L) suggested seawater intrusion. Sulfate (18.76–31.20 mg/L) and nitrate (16.78–30.70 mg/L) exceeded permissible limits, indicating contamination from agricultural and industrial sources. Lead levels (0.092–0.127 mg/L) exceeded WHO limits (0.01 mg/L) by over tenfold, posing significant health risks. Higher contaminant concentrations in BH7, BH8, and BH9 indicate surface-groundwater interactions, with increased lead (0.127 mg/L in BH8), chloride (49.90 mg/L in BH7), and nitrate (22.40 mg/L in BH9). The spatial analysis identified southeastern Effurun as a contamination hotspot requiring urgent mitigation. Continuous monitoring, pollution control, and water treatment interventions are essential to ensure safe drinking water. This study uniquely integrates hydrogeochemical, statistical, and geospatial approaches to assess borehole water contamination, providing actionable insights for sustainable groundwater management.

Effective mineral exploration in a basement complex necessitates precise delineation of overburden thickness and mineral potential within the Basement Complex terrain. This study examined the subsurface geology and assesses the abundance of prospective mineral deposits within the study area The objective of the study was to outline the overburden thickness and infer mineral potential using integrated ground magnetic and electrical resistivity geophysical methods. The electrical resistivity method unraveled the litho-stratigraphic sequence as surmised from geo-electric layers. Consequently, the mineralization of the basement delineated was characterized by the magnetic method. The acquired data were processed using WINRESIST and Oasis Montaj respectively. The electrical resistivity method provided detailed litho-stratigraphic information, revealing geo-electric layers corresponding to the topsoil (302 – 933 Ωm), weathered layer (48 –181 Ωm), and bedrock (421–1357 Ωm), with overburden thicknesses ranging between 7.62 m and 9.5 m. Ground magnetic data further characterized the basement mineralization, identifying three distinct magnetic anomalies: a null anomaly district (-3 – 3 nT), a weak positive anomaly (7.3–12.4 nT), and a magnetic closure (17.7 – 22 nT). Magnetic source depths varied between 1 m and 14 m, with low magnetic susceptibility indicative of porphyritic granite with quartz phenocrysts. In conclusion, the findings are particularly favorable for quarrying operations in the northern sector of the study area, where granite abundance is estimated at around 68%, indicating strong economic potential. This integrated approach of electrical and magnetic geophysical methods, described the accuracy of subsurface mapping by simultaneously resolving overburden thickness and inferring mineral potential in a Basement Complex terrain.

Powder metallurgy is used to obtain high strength and good toughness pistons as an application in aviation, space, and parts. Carbon nanotube CNTs were used with reinforcement ratios of (0,5,10,15,20) wt.% to nickel base, and the device used for piston is a hydraulic piston. The process was carried out at 5 tons for 3 minutes, and the pistons were processed at variable temperatures of (900,950,1000,1050˚C) for 2 hours. XRD of the composites was examined and it was found that the dominant phase of nickel at Miller parameters (111), and of carbon nanotube at (002) with crystalline stability with different sintering temperatures. As for the physical properties, the optimal reinforcement content was found to be 20 wt.% at a sintering temperature of 1050°C, as it yielded the highest density and lowest porosity, Archimedes\' method was used to calculate porosity and density. Which included the apparent density at (8.6g/cm3), the true density (8.75g/cm3), the apparent porosity (10.5%), the true porosity (15.5%), and the water absorption (0.972%). This shows that the percentage of adding nano-carbon has a role in improving the structural and physical properties.

MgO was synthesized using the hydrothermal technique. The autoclave containing material based on magnesium (NO3)2.6H2O was filled and heated to 100°C for three hours. Electrophoretic deposition technique was utilized to deposit MgO powder on a Ti plate. To examine its bioactivity (formation of hydroxyapatite (HAp), coated Ti with MgO was then submerged in concentrated SBF for a month. The formation of pure HAp without additional phases including calcium and phosphorus was confirmed by the XRD test. Scanning electron microscope (SEM) images refer to the formation of semispherical HAp nanoparticles with a diameter ≈ 20 nm. The inhibition zones of MgO were evaluated in order to assess their antibacterial effectiveness against S. aureus , S. epidermidis, Escherichia coli, Klebsiella pneumoniae and Candida albicans. MgO was not shown to have any antibacterial properties against the dangerous bacteria that were identified.

This study discusses photonic crystal fibers (PCFs), a novel type of optical waveguide that performs noticeably better than traditional optical fibers and offers an extraordinary light-guiding mechanism. In this work, a porous core PCF was designed and analyzed. The fiber has a core of 360 μm diameter surrounded by four circular rings of air holes. COMSOL Multiphysics is used to simulate the suggested PCF. By altering two crucial structural components—the pitch spacing, which ranges from 165 to 175 μm, and the diameter (d), which ranges from 140 to 160 μm—the fiber behavior was investigated at frequencies ranging from 0.9 to 1.4 THz. The results demonstrate that dispersion properties exhibit strong dependence on diameter variations, particularly at d=160μm. Analysis of the effective area (Aeff) reveals that it is inversely proportional to frequency, with maximum values observed at d=140, reaching 11.5×10-7 m2. The different effective mode indices of our proposed PCFs are investigated when the diameter d is modified. It can be seen from the results that the effective mode index shows significant sensitivity to the variation of the diameter d, When d=140μm, the effective mode index shows the highest values starting from 1.29 and reaching 1.38, while d=160μm shows the lowest values ranging from 1.23 to 1.35. The medium diameter d=150μm exhibits intermediate values throughout the frequency range. This indicates that the effective mode index changes significantly with diameter variations. the reported design has lower dispersion than the previously reported researches and lower effective area which in turn refer to higher nonlinearity. Hence the suggested design can be used for supercontinuum generation It is possible to fabricate the proposed PCFs by employing the widely utilized sol-gel casting, drilling, and stack and draw techniques. The PCF demonstrates exceptional stability across its operational bandwidth, making it ideal for advanced terahertz sensing and communication applications.