PM3 and Unrestricted Hartree Fock (UHF) quantum mechanical methods are carried out for the estimation of reaction path for the breakage of (R-O) bond rupture energies, for twelve ampicillin ester prodrugs derivatives, at their calculated equilibrium geometries, in addition to some physical properties such as heat of formation, total energy, dipole moment and the energy difference of EHOMO and ELUMO (ΔEHOMO-LUMO) energy levels, using the Gaussian-03 program. Comparisons were done between the total energies of the reactants, products, activation energies and transition states. The results show non possible use of some substituted organic groups as a carrier linkage for acidic ampicillin drug, whereas others show possible use as a carrier linkage. Density functional theory (DFT) calculations at a B3LYP/6-311G level were carried out for assignment IR vibration frequencies of R-O bond and for some important modes, for all ampicillin derivatives, depending on the pictures of its modes obtained from calculated IR spectra.
When the depth of stressed soil is rather small, Plate Load Test (PLT) becomes the most efficient test to estimate the soil properties for design purposes. Among these properties, modulus of subgrade reaction is the most important one that usually employed in roads and concrete pavement design. Two methods are available to perform PLT: static and dynamic methods. Static PLT is usually adopted due to its simplicity and time saving to be performs in comparison with cyclic (dynamic) method. The two methods are described in ASTM standard.
In this paper the effect of the test method used in PLT in estimation of some mechanical soil properties was distinguished via a series of both test methods applied in a same site. The comparison of
... Show MoreThe present computational work is focused on investigating some properties of Gabor lens. The Gabor lens under consideration consists of two fields, electrostatic and magnetic. The Glaser field model is assumed to represent each field along the optical axis. Under zero magnification condition the trajectory of charged particles along the axis of Gabor lens has been computed. The results have shown that a lens of short focal length and hence high refractive power can be achieved
A good performance of reinforced concrete structures is ensured by the bond between steel and concrete, which makes the materials work together, forming a part of solidarity. The behavior of the bond between the reinforcing bar and the surrounding concrete is significant to evaluate the cracking control in serviceability limit state and load capacity in the ultimate limit state. In this investigation, the bond stresses between reinforcing bar and reactive powder concrete (RPC) was considered to compare it with that of normal strength concrete (NSC). The push-out test with short embedment length is considered in this study to evaluate the bond strength, bond stress-slip relationship, and bond stress-crack width relationsh
... Show MoreThis paper concerns with deriving and estimating the reliability of the multicomponent system in stress-strength model R(s,k), when the stress and strength are identical independent distribution (iid), follows two parameters Exponentiated Pareto Distribution(EPD) with the unknown shape and known scale parameters. Shrinkage estimation method including Maximum likelihood estimator (MLE), has been considered. Comparisons among the proposed estimators were made depending on simulation based on mean squared error (MSE) criteria.
Some mechanical and thermal properties of mullite samples prepared by mixing different phases of alumina and silica powders have been studied according to ASTM methods the cold crushing strength of the sintcred bodies.With different porosity, at room temperature was in the range(18-54)Mpa
In the present work, the possibility of treating many types of radioactive sources was examined practically. Six types of sealed radioactive sources were selected: 137Cs, 133Ba, 90Sr, 152Eu, 226Ra, and 241Am. The sources were exposed to a neutron flux emitted from 241Am/Be source for 33 days. The results showed a measurable reduction of activity for 226Ra, 241Am, and 152Eu, while the other radionuclides, 137Cs, 133Ba, and 90Sr, showed less response to neutron incineration.
This study included preparation for the unsaturated polyester samples before and after reinforced by the Alumina oxide powder of different volume fraction amounting (2%,4%,6%). And this research included the study of some of mechanical properties such as (Hardness,compressive,wear). The results showed that the increase of the hardness and compressive strength after the reinforced and the increase with the volume fraction increase. As the wear test shows that the wear rate increases with applied load increase(5,10,15) from (10.6-18.6) gm/cm befor reninforced and from(5.4-15.2)gm/cm,(4.7-12.9)gm/cm,(48.1)gm/cm,after reinforced from the different volume fraction, and t
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