First-order Studies Research Articles

Диференційований підхід при вивченні лінійних диференціальних рівнянь першого порядку

Диференційований підхід при вивченні лінійних диференціальних рівнянь першого порядку

Correspondence between the first and second order formalism by a metricity constraint

A way to obtain a correspondence between the first order and second order formalism is studied. By introducing a Lagrange multiplier coupled to the covariant derivative of the metric, a metricity constraint is implemented. The new contributions which comes from the variation of the Lagrange multiplier transforms the field equations from the first order to the second order formalism, yet the action is formulated in the first order. In this way all the higher derivatives terms in the second order formalism appear as derivatives of the Lagrange multiplier. Using the same method for breaking metricity condition and building conformal invariant theory is briefly discussed, so the method goes beyond just the study of first order or second formulations of gravity, in fact vast new possible theories of gravity are envisioned this way.

English

English

A detailed comparison study of first order and higher order shear deformation theories in the analysis of laminated composite plate

The primary aim of the present work is to calculate and compare the response of composite plate using first order and higher order shear deformation theories. The present study initially attempts to develop a finite element formulation for handling the analysis of laminated composite plates. The current study elaborately discusses the formulation that makes an easy programming even for a beginner in this field. Presently, mathematical formulation and Matlab coding using First Order Shear Deformation Theory (FSDT) and Higher Order Shear Deformation Theory (HSDT) had done. Results obtained were compared with the available literature. Parametric study also conducted to clearly understand the variation in results obtained from both FSDT and HSDT.

The numerical study of first order wetting transition with two defect lines

Abstract The first order wetting transition with two defect lines, one near a wall and another at a distance N 1 , in the d = 2 Ising model is studied by the bond propagation algorithm. The numerical calculations are carried out on very large lattices with size up to 160 2 × 160 . The finite size effects of the first order transition in that model are discussed. The magnetization profile is also calculated. The numerical results agree with the exact results very well.

Study of first order chemical reaction following charge transfer using the double potential-step chronocoulometric method II. Experimental study of reactions inactivating the product of the charge transfer reaction — derivatives of tetrahydropterins as a model system

Study of first order chemical reaction following charge transfer using the double potential-step chronocoulometric method II. Experimental study of reactions inactivating the product of the charge transfer reaction — derivatives of tetrahydropterins as a model system