This paper is concerned with finding solutions to free-boundary inverse coefficient problems. Mathematically, we handle a one-dimensional non-homogeneous heat equation subject to initial and boundary conditions as well as non-localized integral observations of zeroth and first-order heat momentum. The direct problem is solved for the temperature distribution and the non-localized integral measurements using the Crank–Nicolson finite difference method. The inverse problem is solved by simultaneously finding the temperature distribution, the time-dependent free-boundary function indicating the location of the moving interface, and the time-wise thermal diffusivity or advection velocities. We reformulate the inverse problem as a non-linear optimization problem and use the lsqnonlin non-linear least-square solver from the MATLAB optimization toolbox. Through examples and discussions, we determine the optimal values of the regulation parameters to ensure accurate, convergent, and stable reconstructions. The direct problem is well-posed, and the Crank–Nicolson method provides accurate solutions with relative errors below 0.006% when the discretization elements are M=N=80. The accuracy of the forward solutions helps to obtain sensible solutions for the inverse problem. Although the inverse problem is ill-posed, we determine the optimal regularization parameter values to obtain satisfactory solutions. We also investigate the existence of inverse solutions to the considered problems and verify their uniqueness based on established definitions and theorems.
Susceptibility of thirty seven clinical isolates of Staphylococcus aureus to various antibiotics was tested. 100 % of tested isolates were resistant to ampicillin, while the lowest resistance recorded to amikacin 8.10 %. Four of S. aureus isolates showed resistant to vancomycin. Minimum inhibitory concentration (MIC) of isolates 33 and 56 for vancomycin was ≥ 32 μg/ml.
One hundred thirty - five clinical specimens of urine, blood, teeth root canal and burns were obtained from patients in hospitals of Baghdad. The specimens were cultured on Pfizer Selective Enterococcus agar to purify Enterococci isolates. 20 E. faecalis isolates were identified biochemically by growing in 10Cº, 45Cº, 6.5% NaCl, at pH 9.6 and confirmed by VITEK. Determination of Vancomycin-Resistant E. faecalis isolates were done by the minimum inhibitory concentrations [MICs] using agar dilution method. Seventeen E. faecalis isolates were determined as Vancomycin-Resistant and Intermediate Resistant.
In this work we study the influence of the laser pulse energy and ablation time on the aluminum nanoparticles productivity during nanosecond laser ablation of bulk aluminum immersed in liquid.
Aluminum nanoparticles were synthesized by pulsed laser ablation of Al targets in ethanol for 3-8 minutes using the 1064 nm wavelength of a Nd:YAG laser with energies of 300-500 mJ per pulse.The laser energy was varied between 300 and 500 mJ/pulse, whereas the ablation time was set to 5 minutes. UV-Visible absorption spectra was used for the characterization and comparison of products.
In this study, polymeric coating was developed by incorporating nano graphene in the polymer blend with applications to oil storage tanks. The oil storage tanks samples were brought from the oil Pipeline Company / Doura refinery in Baghdad. The coating polymer was formed with a blend (epoxy resin and repcoat ZR). The proportion of mixing the mixture was 3:1:1 epoxy resin 21.06 gm: repcoat ZR 10.53 gm: hardener 10.53 gm. The blend/graphene was prepared using in stui-polymerization method with different weight percentage 1, 3, 5, and 7 wt % added to blend. The resulting solution was put in a glass tube on a magnetic stirrer for one hour at a temperature of 40 °C. The result of contact angle and water absorption the best ratio of 3wt
... Show MoreABSTRACT Porous silicon has been produced in this work by photochemical etching process (PC). The irradiation has been achieved using ordinary light source (150250 W) power and (875 nm) wavelength. The influence of various irradiation times and HF concentration on porosity of PSi material was investigated by depending on gravimetric measurements. The I-V and C-V characteristics for CdS/PSi structure have been investigated in this work too.
Swabs from two hospitals at Baghdad city were collected from the period 28-October-2013 to 31-March-2014, to found out the prevalence and distribution of fungi. These isolates were collected from hospitals' environment and most of the items used for hospital work in order to detect the nosocomial pathogens persistent. All fungal isolates were identified depending on the morphological and microscopic examinations as well as biochemical tests. Out of 220 environmental samples, 146 fungal isolates was obtained, Aspergillus flavus was more frequency and occurrence 23.29% and 15.45% respectively, followed Aspergillus niger was 15.57% and 10.45% then Penecillium spp. was 13.27% and 8.64%. In Al -Yarmouk Teaching Hospital more places contaminat
... Show MoreThe synthesis of the MBIB ligand by the reaction of the BIB ligand with methionine in 1:1 ratio, and the metal complexes with Ni(II), Cu(II), and Pt(IV) were described. All synthesized compounds were characterized using spectroscopic methods such as FT-IR, 1H NMR, UV-VIS, thermal analysis (TG and DSC), atomic absorption (AAS), elemental microanalysis (C.H.N.S), melting point (m.p.), magnetic susceptibility, molar conductivity measurements, and chloride content. All the complexes were electrolytes, and the suggested geometric shapes for the complexes were octahedral. The magnetic properties of the platinum complex were diamagnetic, while those of the nickel and copper complexes were paramagnetic. All synthes
... Show MoreClimate change is one of the global issues that is receiving wide attention due to its clear impact on all living organisms. This is essential for Iraq since it was classified as the fifth most vulnerable country to climate change. One of the manifestations of these changes in Iraq is the increasing frequency and severity of dust storms. In this study, the Normalized Difference Dust Index (NDDI) spectral index for Moderate Resolution Imaging Spectroradiometer (MODIS) sensor bands was used to measure and track the dust storm that occurred on May 16, 2022, as well as to test the validity of one of the daily products of this sensor, MOD11A1, to measure surface temperature and emissivity before and after the storm. It was found that the MOD0
... Show MoreBuckling analysis of a laminated composite thin plate with different boundary conditions subjected to in-plane uniform load are studied depending on classical laminated plate theory; analytically using (Rayleigh-Ritz method). Equation of motion of the plates was derived using the principle of virtual work and solved using modified Fourier displacement function that satisfies general edge conditions. The eigenvalue problem generated by using Ritz method, the set of linear algebraic equations can be solved using MATLAB for symmetric and anti-symmetric, cross and angle-ply laminated plate considering some design parameters such as aspect ratios, number of layers, lamination type and orthotropic ratio. The results obtained g
... Show MoreIn this paper, a new procedure is introduced to estimate the solution for the three-point boundary value problem which is instituted on the use of Morgan-Voyce polynomial. In the beginning, Morgan-Voyce polynomial along with their important properties is introduced. Next, this polynomial with aid of the collocation method utilized to modify the differential equation with boundary conditions to the algebraic system. Finally, the examples approve the validity and accuracy of the proposed method.