An experiment was conducted to study how SAE 50 engine oil contaminated with diesel fuel affects engine performance. The engine oil was contaminated with diesel fuel at concentrations of 0%, 1%, and 3%. The following performance characteristics were studied: brake-specific fuel consumption, brake thermal efficiency, friction power, and exhaust gas temperature. Each treatment was tested three times. The three treatments (0%, 1%, and 3%) were analyzed statistically with a one-way ANOVA model at the 5% probability level to determine if the three treatments produced significant differences in engine performance. The statistical results showed that there were significant differences in engine performance metrics among the three treatments. The 3

Cracking of soils affects their geotechnical properties and behavior such as soil strength and stability. In this paper, 2D Electrical Resistivity Imaging Method, as a non-invasive technique, was adopted to investigate the effect of soil cracks of a centemetric scale on resistivity of sandy soil. The electrical resistivity measurements were carried out using ABEM SAS 300C Terrameter system at a laboratory scale using Wenner array. The measurements were interpreted using horizontal profiles, forward modeling and 2D inverse resistivity sections. The results showed that soil cracks cause significant changes in soil resistivity. These changes can be attributed to the high resistivity contrast between the highly resistive air-filled cracks an

The current research is a spectroscopic study of Coumarin 334 dissolved in methanol. The range of concentrations of the prepared stock solution was (3.39x10^-9 to 2.03x10^-8) M. Some optical characteristics of this dye were investigated such as absorbance and transmission spectra, absorption coefficient, refractive and extinction coefficients, oscillation and dispersion energies, and energy band gap. The absorbance spectra were recorded at 452 nm using Broad Band Cavity Enhanced Absorption Spectroscopy (BBCEAS) which depends on increasing the path length of the traveling light from the source to the detector. The minimum absorbance amount was 0.07 with a low concentration of 3.39x10^-9 M. As a result, the ot

Purpose Heavy metals are toxic pollutants released into the environment as a result of different industrial activities. Biosorption of heavy metals from aqueous solutions is a new technology for the treatment of industrial wastewater. The aim of the present research is to highlight the basic biosorption theory to heavy metal removal. Materials and methods Heterogeneous cultures mostly dried anaerobic bacteria, yeast (fungi), and protozoa were used as low-cost material to remove metallic cations Pb(II), Cr(III), and Cd(II) from synthetic wastewater. Competitive biosorption of these metals was studied. Results The main biosorption mechanisms were complexation and physical adsorption onto natural active functional groups. It is observed that

The aim of this study is modeling the transport of industrial wastewater in sandy soil by using finite element method. A washing technique was used to remove the industrial wastewater from the soil. The washing technique applied with an efficient hydraulic gradient to help in transport of contaminant mass by advection. Also, the mass transport equation used in modeling the transport of industrial wastewater from soil includes the sorption and chemical reactions. The sandy soil samples obtained from Al-Najaf Governorate/Iraq. The wastewater contaminant was obtained from Al- Musyiebelectricity power plant. The soil samples were synthetically contaminated with four percentages of 10, 20, 30 and 40% of the contaminant and these percentages calc

The isolates were screened according to their capability for pectinase production, screening process identified the best pectinolytic isolate and it was characterized by cultural and biochemical, as Pesudomonas sp. Pectinolytic enzyme producing bacterium Pesudomonas sp. was isolated from the Iraqi soil on nutrient agar plate. Optimiztion of process parameters were carried out by altering some of environmental conditions of chemo-physical environment for the production medium. The highest pectinase production was observed at 48 hrs of incubation at 35 °C with the initial pH of 6.0. Different nutrients and environmental conditions were investigated in terms of their effect on the production of extracellular pectinase using citrus pectin a

The paper establishes explicit representations of the errors and residuals of approximate
solutions of triangular linear systems by Jordan elimination and of general linear algebraic
systems by Gauss-Jordan elimination as functions of the data perturbations and the rounding
errors in arithmetic floating-point operations. From these representations strict optimal
componentwise error and residual bounds are derived. Further, stability estimates for the
solutions are discussed. The error bounds for the solutions of triangular linear systems are
compared to the optimal error bounds for the solutions by back substitution and by Gaussian
elimination with back substitution, respectively. The results confirm in a very

Herein, an efficient inorganic/organic hybrid photocatalyst composed of zeolitic imidazolate framework (ZIF-67) decorated with Cd0.5Zn0.5S solid solution semiconductor was constructed. The properties of prepared ZIF- [email protected] nanocomposite and its components (ZIF-67 and Cd0.5Zn0.5S) were investigated using XRD, FESEM, EDX, TEM, DRS and BET methods. The photocatalytic activity of fabricated [email protected] nanocomposite were measured toward removal of methyl violet (MV) dye as a simulated organic contaminant. Under visible-light and specific conditions (photocatalyst dose 1 g/l, MV dye 10 mg/l, unmodified solution pH 6.7 and reaction time 60 min.), the acquired [email protected] photocatalyst showed advanced photocatalytic activity

The specifications of lubricating oil are fundamentally the final product of materials that have been added for producing the desired properties. In this research, spherical nanoparticles copper oxide (CuO) and titanium oxides (TiO₂) are added to SAE 15W40 engine oil to study the thermal conductivity, stability, viscosity of nano-lubricants, which are prepared at different concentrations of 0.1%, 0.2%, 0.5%, and 1% by weight, and also their pour point, and flash point as five quality parameters. The obtained results show that CuO nanoparticles in all cases, give the best functionality and effect on engine oil with respect to TiO₂. With 0.1 wt. % concentration, the thermal conductivity of CuO/oil and TiO₂/

This paper study the ability of Enterobacter cloacae for degrading crude oil in contaminated water. Six isolates of E. cloacae were isolated from hydrocarbon contaminated soil and water of different sites. The isolate E. cloacae E1 showed the highest emulsification index (E24%) reached 62% thus it was chosen for further study. Biosurfactant produced by E. cloacae E1 reduced the surface tension of the medium from 64 to 36 mN/m. pH range 6.5 – 7 and temperature range 30˚C - 35˚C were the optimal conditions for maximum degradation. After 30 days of incubation, E. cloacae E1 degraded 70.00 ± 0.40% of the crude oil. GC-MS analysis revealed that E. cloacae E1 was able to degrade aromatic compounds. This study proved that E. cloacae E1 con