Anomalies in Elastic Scattering at Isobaric Analogue States

Excitation functions for proton elastic scattering on Mn⁵⁵ at proton energies from 1320 KeV to 1480 KeV have been measured at the angles 135° and 150°. Anomalies in the differential elastic scattering were observed at E_p = 1350 ± 4 KeV, 1385 ± 4 KeV and 1445 ± 4 KeV respectively. These resonance states are the isobaric analogues of the ground, first excited and second excited states in Mn⁵⁶ respectively. Analysis of the results showed that these resonance states are best fitted to a J^π = 3⁺, 2⁺ and 1⁺ which is in excellent agreement with the J^π values of the corresponding states in Mn⁵⁶. The total widths and proton widths of these states were determined.     

Milne's problem for anisotropic scattering medium with specular reflecting boundary

The Milne problem is investigated subject to reflecting boundary conditions. The original version of the problem with vacuum boundary condition is generalized assigning, to the surface x=0, a specular reflection coefficient . Linearly anisotropic case is studied. The integral version of the transport equation solved using trial functions based on Case's eigenvalues and exponential integral function. Solution of the Milne problem is formulated in terms of characteristic parameters such as extrapolated end point, emergent angular distribution and total neutron density. Numerical results for the analytically evaluated parameters are then present. Some of our numerical results are compared with the available published results.     

On using the modified variational iteration method for solving the nonlinear coupled equations in the mathematical physics

This paper applied the modified variational iteration method to the nonlinear coupled partial differential equations via the generalized nonlinear Hirota Satsuma coupled KdV equations, the nonlinear coupled Kortewge–de Vries KdV equations and the nonlinear shallow water equations together with the initial conditions. The proposed modification is made by introducing Adomian’s polynomials in the correct functional. The suggested algorithm is quite efficient and is practically well suited for use in such problems. The proposed iterative scheme finds the solution without any discritization, liberalization, perturbation, or restrictive assumptions.     

Study of γ‐Fast Neutron Attenuation and Mechanical Characteristics of Modified Concretes for Shielding and Sheltering Purposes

The study of γ‐neutrons attenuation and mechanical characteristics of modified concrete are vital and crucial parameters for the construction of civilian radiological, nuclear shielding, and/or shelters. In this work, fifteen samples of ordinary concretes with five different additives; steel fibers, polypropylene, silica fume, and fly ash, with variation of cement percentages, were prepared and used for performing the mechanical and radiation attenuation investigations. The compressive strength, tensile strength, slump test, bulk density, and water permeability were also carried out for the prepared concrete mixes. Collimated coherent beams from ⁶⁰Co and Pu‐Be fast neutron sources were used to check the radiation penetrability through the syntheized mixed concrete‐additives. Very sensitive and well calibrated gamma‐neutron pulse shape discriminating spectrometer with its electronic componenets and stilbene organic detector and 3′′ × 3′′ NaI scintillation crystal was used to measure the radiation before and after attenuation and transmission. The integrated fast neutron removal macroscopic cross section (Σ_r) and linear attenuation coefficient of total gamma rays (μ) were calculated for all the analysed concrete mixes. The results of measurements, tests, analyses and calculations are given and explained. The investigated modified concrete mixes show good workability and properties from the view point of mechanical loads and γ‐fast neutrons penetrability and resistance. These results can be used for shielding and sheltering design.     

Novel monofunctional and bifunctional boronic acid‐functionalized squarylium dyes as precolumn and on‐column labels for protein analysis by capillary electrophoresis with laser‐induced fluorescence

This article presents a continuous capillary electrophoresis with laser‐induced fluorescence (CE‐LIF) following spectral studies of the noncovalent interactions between novel Squarylium Boronic Acid 4 (SQ‐BA4) & Squarylium Diboronic Acid 2 (SQ‐DBA2) squarylium dyes and human serum albumin (HSA). Two protocols were used wherein the on‐column‐labeling protocol was found to be more sensitive than the precolumn one by showing a better enhancement in the peak area of the HSA–dye complex besides lower limits of detection (LODs) for HSA. Also, stability studies were conducted with or without HSA using precolumn‐labeling mode over one week exhibiting the superiority of SQ‐BA4 to SQ‐DBA2. Then, a mixture containing three model proteins, HSA, β‐lactoglobulin B, and transferrin, was labeled on‐column with both dyes and completely resolved by CE‐LIF after optimization of several parameters. Both dyes provided lower LODs for HSA than those of β‐lactoglobulin B and transferrin with higher sensitivities. In addition, the SQ‐BA4 dye showed again greater sensitivities with all the three proteins than SQ‐DBA2.     

Negative Charging of Au Nanoparticles during Methanol Synthesis from CO2/H2 on a Au/ZnO Catalyst: Insights from Operando IR and Near‐Ambient‐Pressure XPS and XAS Measurements

The electronic and structural properties of Au/ZnO under industrial and idealized methanol synthesis conditions have been investigated. This was achieved by kinetic measurements in combination with time‐resolved operando infrared (DRIFTS) as well as in situ near‐ambient pressure X‐ray photoelectron spectroscopy (NAP‐XPS) and X‐ray absorption near‐edge spectroscopy (XANES) measurements at the O K‐edge together with high‐resolution electron microscopy. The adsorption of CO during the reaction revealed the presence of negatively charged Au nanoparticles/Au sites during the initial phase of the reaction. Near‐ambient‐pressure XPS and XANES demonstrate the build‐up of O vacancies during the reaction, which goes along with a substantial increase in the rate of methanol formation. The results are discussed in comparison with previous findings for Cu/ZnO and Au/ZnO catalysts.     

Electrochemical behavior of Al2O3/Al composite coated Al electrodes through surface mechanical alloying in alkaline media

The behavior of $A{l}_2{O}_3/Al$ composite coated Al electrodes fabricated by surface mechanical alloying ‘SMA’ was studied. The work was accomplished using Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques in alkaline media $2MKOH$ were done at room temperature. Results show hydroxyl ions accumulate on the surface due to Al deformation micro cavities filling with $A{l}_2{O}_3$ until full charge blockage reached. A barrier cover layer development causing an increase of both resistance and capacitance as it becomes more stable and thinner with exposure time increase. Migrating hydroxyl ion inside micro cavity changed its composition from Al₂O₃ to stable tetrahedral $Al{\left(OH\right)}_4^{?}$ aluminate ions. Therefore future benefits could be reached by developing such surfaces having charge accumulation that enables environmental interaction.     

Utility of 2-furan-2-yl-4-mercapto-6-methylpyrimidine-5-carbonitrile as a precursor for the synthesis of some novel pyrimidines: antibacterial activity

The starting material 2-furan-2-yl-4-mercapto-6-methylpyrimidine-5-carbonitrile 3 was reacted with various reagents resulting in the formation of a group of new pyrimidines and condensed pyrimidines including quinazoline 6 tetrazolopyrimidine 12, pyrazolopyrimidines 14, 18, and 19, triazolopyrimidine 16, and pyrimidopyridazine 20. The antibacterial activity was evaluated for a group of the synthesized compounds against examples of Gram-positive and Gram-negative bacteria.