Mechanism of Formation of Cadmium Oxalate Liesegang Rings

Qualitative and semiquantitative study of the Liesegang rings formed by the reaction of oxalic acid and cadmium chloride in the acidic range of pH in silica hydrogel is made. The behaviour of Jablczynski's space constant and Morce-Pierce's time constant at various temperatures, pH and concentration of outer electrolyte is studied. The possible mechanisms for the above observed behaviour are suggested. The deviations from Isemura's general obserations are interprerted by considering two particular aspects, viz., comparatively larger crystals constituting the rings and the irreversibility of inner and outer electrolytes.     

On the Transfer Matrix for the Two-Dimensional Ising Model

The eigenvalue problem for the transfer matrix of the two-dimensional Ising lattice, with free boundaries perpendicular to the transfer direction, is solved. The mathematical mechanism which produces the asymptotic degeneracy of the eigenvalue spectrum below the bulk transition temperature is different from the case with cyclic boundary conditions. The results are used to calculate the two-spin correlation function between two spins in the same edge of the lattice, and between two spins in opposite edges.     

Thomas rotation and the parametrization of the Lorentz transformation group

Two successive pure Lorentz transformations are equivalent to a pure Lorentz transformation preceded by a 3×3 space rotation, called a Thomas rotation. When applied to the gyration of the rotation axis of a spinning mass, Thomas rotation gives rise to the well-knownThomas precession. A 3×3 parametric, unimodular, orthogonal matrix that represents the Thomas rotation is presented and studied. This matrix representation enables the Lorentz transformation group to be parametrized by two physical observables: the (3-dimensional) relative velocity and orientation between inertial frames. The resulting parametrization of the Lorentz group, in turn, enables the composition of successive Lorentz transformations to be given by parameter composition. This composition is continuously deformed into a corresponding, well-known Galilean transformation composition by letting the speed of light approach infinity. Finally, as an application the Lorentz transformation with given orientation parameter is uniquely expressed in terms of an initial and a final time-like 4-vector.     

The structure and thermodynamics of binary microclusters: A Monte Carlo simulation

The Monte Carlo computer simulation technique of classical statistical mechanics is employed to determine the structure and thermodynamics of binary microclusters of Lennard-Jones atoms as a function of cluster size, composition and temperature. Further, amorphous microclusters are prepared by a Monte Carlo quench, and their structural properties are examined. The properties of interest include the internal energy, instantaneous “snapshot” pictures of the microcluster's atomic configuration, and the single-particle and pair distribution functions. The Lennard-Jones potential parameters are chosen to model Ar₁₃, Ar₇Kr₆, Ar₃₆Kr₁₉ and Ar₁₉Kr₃₆, as well as to crudely model the bimetallic clusters of Cu₁₉Ni₃₆, Cu₁₉Ru₃₆ and Cu₁₉Os₃₆. A large variety of interesting features associated with these systems are described.     

Design and development of a fiber-optic immunosensor utilizing near-infrared fluorophores

The design and application of a fluorescent fiber-optic immunosensor (FFOI) are reported. The FFOI is utilized for the detection of antibody/antigen binding within the near-infrared (NIR) spectral region. The technique is developed through the combined use of fiber-optic, semiconductor laser-excitation, fluorescence detection, NIR dye, and immunochemical techniques. The antibody is immobilized on the FFOI and utilized as a recognition component for trace amounts of specific antigen. The FFOI is constructed to utilize an antibody sandwich technique. The assay involves the immobilization of the capture antibody on the sensing tip of the FFOI followed by the exposure of the immobilized sensing tip to the antigen. The antigen-coated FFOI is then introduced to a second antibody previously labeled with the NIR dye. Typical measurements are performed in about 15 min. A semiconductor laser provides the excitation (780 nm) of the immune complex. The resulting emission is detected by a silicon photodiode detector (820 nm). The intensity of the resulting fluorescence is directly proportional to the concentration of the antigen. The sensitivity of the analysis reaches 10 ng/ml and the response time is 10–15 min.     

Silver halide single-mode strip waveguides for the mid-infrared

We report the demonstration of single-mode AgCl(x)Br(1-x) strip waveguides for the mid-infrared (MIR). The waveguides were made by the deposition of AgCl(x)Br(1-x) layers on top of a Si-SiO(2) substrate, followed by photolithographic and lift-off processing. The propagation losses of 20 dB/cm were measured at λ=10.6 μm using the cut-back method. The development of these waveguides is a crucial step toward realizing AgCl(x)Br(1-x) MIR integrated optical circuits, which would be used for applications such as chemical sensing and stellar interferometry.     

Piecewise finite series solutions of seasonal diseases models using multistage Adomian method

The aim of this paper is to apply the multistage Adomian Decomposition Method MADM to solve systems of nonautonomous nonlinear differential equations that describe several epidemic models with periodic behavior. Here the concept of the MADM is introduced and then it is employed to obtain a piecewise finite series solution. The MADM is used here as a hybrid analytical–numerical technique for approximating the solutions of the epidemic models. In order to show the efficiency of the method, the obtained numerical results are compared with the fourth-order Runge–Kutta method solutions. Numerical comparisons show that the MADM is accurate, easy to apply and the calculated solutions preserve the periodic behavior of the continuous models. Moreover, the method has the advantage of giving a functional form of the solution for any time interval. Furthermore, it is shown that if the truncation order and the time step size are not properly chosen large computational work is required and inaccurate solutions may be obtained.     

Synthesis of glycopeptides from glucosaminic acid

We report on the synthesis of polypeptides with saccharide side chains starting from d ‐glucosaminic acid. The hydroxyl groups were first protected by benzylation, followed by N‐carboxyanhydride formation, which was polymerized by ring opening to form a high molecular weight polyamide. De‐protection of the benzyl groups yields a polypeptide with fully de‐protected saccharide side chains. The resulting new non‐ionic, water soluble, and optically active polymers possessing the properties of both peptides and saccharides have potential use as scaffolds for tissue engineering and drug carriers. The method described here may be extended to any saccharide α‐amino acid. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2657–2662