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- Publications
- Influence

Positive fixed points and fourth-order equations

- J. Cid, D. Franco, Feliz M. Minhós
- Mathematics
- 1 February 2009

This work presents sufficient conditions for the existence of at least one positive solution for a nonlinear fourth-order beam equation under Lidstone boundary conditions. The main tool used is a… Expand

Heteroclinic solutions for non-autonomous boundary value problems withsingular $\Phi$-Laplacian operators

We prove the solvability of the following boundary value problem
on the real line
$\Phi(u'(t))'=f(t,u(t),u'(t))$ on $\mathbb{R}$, $u(-\infty)=-1,$ $u(+\infty)=1,$
with a singular… Expand

Determination of Organophosphorus Compounds in Mediterranean Coastal Waters and Biota Samples Using Gas Chromatography with Nitrogen-Phosphorus and Chemical Ionization Mass Spectrometric Detection

- D. Barceló, C. Porte, J. Cid, J. Albaigés
- Chemistry
- 1 February 1990

Abstract An analytical method is described for the determination of organophosphorus compounds in water and biota samples. This includes solvent extraction, a clean up procedure using silica gel and… Expand

Computation of Green's functions for boundary value problems with Mathematica

- A. Cabada, J. Cid, Beatriz Máquez-Villamarín
- Mathematics, Computer Science
- Appl. Math. Comput.
- 1 November 2012

Abstract This paper is devoted to construct an algorithm that allows us to calculate the explicit expression of the Green’s function related to a n th-order linear ordinary differential equation,… Expand

Positivity and lower and upper solutions for fourth order boundary value problems

- A. Cabada, J. Cid, L. Sánchez
- Mathematics
- 1 September 2007

Abstract This paper is devoted to the study the boundary value problem { u ( 4 ) ( t ) = f ( t , u ( t ) ) for all t ∈ I = [ 0 , 1 ] , u ( 0 ) = u ( 1 ) = u ″ ( 0 ) = u ″ ( 1 ) = 0 . We prove the… Expand

On first-order ordinary differential equations with nonnegative right-hand sides

- J. Cid, R. L. Pouso
- Mathematics
- 8 March 2003

Existence of extremal solutions for scalar initial value problems is investigated. We shall concentrate upon nonlinearities having constant sign, which lead to new existence results.

On uniqueness criteria for systems of ordinary differential equations

- J. Cid
- Mathematics
- 1 May 2003

Abstract We present some new uniqueness criteria for the Cauchy problem x′(t)=f t,x(t) , x(t 0 )=x 0 , based on the local equivalence with another initial value problem.

Green's functions and spectral theory for the Hill's equation

- A. Cabada, J. Cid, Lucía López-Somoza
- Mathematics, Computer Science
- Appl. Math. Comput.
- 3 November 2015

The aim of this paper is to show certain properties of the Green's functions related to the Hill's equation coupled with various two point boundary value conditions. We will obtain the expression of… Expand

Does Lipschitz with Respect to x Imply Uniqueness for the Differential Equation y' = f(x,y)?

- J. Cid, R. L. Pouso
- Computer Science, Mathematics
- Am. Math. Mon.
- 1 January 2009

Of course, the answer to the question posed in the title is no, in general, but, surprisingly enough, yes in a significant situation to be detailed later. This paper aims to bring to the attention of… Expand

Existence of infinitely many solutions for second-order singular initial value problems with an application to nonlinear massive gravity

- José Ángel Cid, Óscar López Pouso, Rodrigo López Pouso
- Mathematics
- 1 October 2011

Abstract We prove the existence of infinitely many solutions for a second-order singular initial value problem between given lower and upper solutions. Our study is motivated by a singular problem… Expand