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# Oscillation of second order neutral delay differential equations of Emden-Fowler type

Acta Mathematica Hungarica
Author: S. Saker

## Abstract

We present new oscillation criteria for the second order nonlinear neutral delay differential equation [y(t)-py(t-τ)]''+ q(t)y λ (g(t)) sgn y(g(t)) = 0, tt 0. Our results solve an open problem posed by James S.W . Wong [24]. The relevance of our results becomes clear due to a carefully selected example.

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# Oscillation theorems for second-order nonlinear delay difference equations

Periodica Mathematica Hungarica
Author: S. Saker

## Abstract

By means of Riccati transformation technique, we establish some new oscillation criteria for second-order nonlinear delay difference equation

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Delta (p_n (\Delta x_n )^\gamma ) + q_n f(x_{n - \sigma } ) = 0,\;\;\;\;n = 0,1,2,...,$$ \end{document}
when
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\sum\limits_{n = 0}^\infty {\left( {\frac{1}{{Pn}}} \right)^{\frac{1}{\gamma }} = \infty }$$ \end{document}
. When
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\sum\limits_{n = 0}^\infty {\left( {\frac{1}{{Pn}}} \right)^{\frac{1}{\gamma }} < \infty }$$ \end{document}
we present some sufficient conditions which guarantee that, every solution oscillates or converges to zero. When
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\sum\limits_{n = 0}^\infty {\left( {\frac{1}{{Pn}}} \right)^{\frac{1}{\gamma }} = \infty }$$ \end{document}
holds, our results do not require the nonlinearity to be nondecreasing and are thus applicable to new classes of equations to which most previously known results are not.

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# Morphological and physiological studies on the effect of salinity and growth promoters on rice plants

Acta Agronomica Hungarica
Authors: M. Afifi, M. Saker, M. Ahmed and S. Khatab

This study aimed to reveal changes in morphological and physiological characters during growth and mature stages of rice plants in response to salinity stress and growth promoters. Salinity stress caused a decrease in vegetative growth, yield and yield components, while growth substances enhanced the leaf area and crop yield of rice plants under salinity stress. It could be concluded that growth promoters can partially alleviate the harmful effect of salinity stress on rice.

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