Abstract We extend the Eruguin result exposed in the paper ”Construction of the whole set of ordinary differential equations with a given integral curve” published in 1952 and construct a differential system in R which admits a given set of the partial integrals, in particular we study the case when theses functions are polynomials. We construct a non-Darboux integrable planar polynomial system...

Most physical processes are modeled by differential equations. First order ordinary differential equations, also known as dynamical systems, arise in a wide range of applications, including population dynamics, mechanical systems, planetary motion, ecology, chemical diffusion, etc., etc. See [19, 72,ODES] for additional material and applications. The goal of this chapter is to study and solve i...

The stress – strength model is one of the models that are used to compute reliability. In this paper, we derived mathematical formulas for reliability follows Rayleigh Pareto (Rayl. Par) distribution. Here, has a single component, where Y subjected X, represented by moment, function, restricted behavior, and ordering statistics. Some estimation methods were used, which maximum likelihood, ordin...

Significance This article reports the discovery of a heretofore unknown icosahedral quasicrystal created by detonation first nuclear device at Alamogordo, NM, on 16 July 1945 (the Trinity test). Like all quasicrystals, new example violates crystallographic symmetry rules that apply to ordinary (periodic) crystals. It was found in sample red trinitite, combination glass fused from natural sand a...

We study the dynamics of a rigid card falling in air using direct numerical simulations of the two-dimensional Navier–Stokes equation and a fluid force model based on ordinary differential equations derived from recent experiments and simulations. The system depends on three non-dimensional parameters, i.e. the thickness-to-width ratio, the dimensionless moment of inertia, and the Reynolds numb...

Recent measurements of the spin-down rates of soft gamma ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) have been interpreted as evidence that these objects are “magnetars”: neutron stars spinning down by magnetic dipole radiation, but with a magnetic field two orders of magnitude larger than that of ordinary neutron stars. We discuss the evidence disfavouring this interpretation. We a...

The (ordinary) Sachs–Wolfe effect relates primordial matter perturbations to the temperature variations δT/T in the cosmic microwave background radiation; δT/T can be observed in all directions around us. A standard but idealised model of this effect leads to an infinite set of moment-like equations: the integral of P (k) j2 ` (ky) with respect to k (0 < k < ∞) is equal to a given constant, C`,...

A comparison is made between conventional Michaelis-Menten kinetics and two models that take into account the duration of the conformational changes that take place at the molecular level during the catalytic cycle of a monomer. The models consider the time that elapses from the moment an enzyme-substrate complex forms until the moment a product molecule is released, as well as the recovery tim...

The aim of this report is threefold: First we generalize to 3D a long ago known fast algorithm for the computation of ordinary geometrical moments of 2D elds starting from what could be named cumulative moments. This is done by rst reformulating the 2D algorithm in terms of matrix operations and subsequently extending the result straightforwardly to 3D. Second, guided by the results of much res...

This paper presents the findings of an experimental investigation on a reinforced concrete frame structure (ordinary moment resistant frame). The test model was subjected to lateral excitation employing 1994 Northridge earthquake accelerogram. fabricated in 1:3 reduced scale acquiring dimensional similarities. utilized ingredient mix ratio 1:1.65:1.75 and water binder 0.47. dynamic characterist...