Search results for " laws"

Generalized Camassa-Holm Equations: Symmetry, Conservation Laws and Regular Pulse and Front Solutions

2021

In this paper, we consider a member of an integrable family of generalized Camassa–Holm (GCH) equations. We make an analysis of the point Lie symmetries of these equations by using the Lie method of infinitesimals. We derive nonclassical symmetries and we find new symmetries via the nonclassical method, which cannot be obtained by Lie symmetry method. We employ the multiplier method to construct conservation laws for this family of GCH equations. Using the conservation laws of the underlying equation, double reduction is also constructed. Finally, we investigate traveling waves of the GCH equations. We derive convergent series solutions both for the homoclinic and heteroclinic orbits of the…

Baltic Journal of English Language, Literature and Culture, N 6

2016

Lagrangian dynamics and possible isochronous behavior in several classes of non-linear second order oscillators via the use of Jacobi last multiplier

2015

Abstract In this paper, we employ the technique of Jacobi Last Multiplier (JLM) to derive Lagrangians for several important and topical classes of non-linear second-order oscillators, including systems with variable and parametric dissipation, a generalized anharmonic oscillator, and a generalized Lane–Emden equation. For several of these systems, it is very difficult to obtain the Lagrangians directly, i.e., by solving the inverse problem of matching the Euler–Lagrange equations to the actual oscillator equation. In order to facilitate the derivation of exact solutions, and also investigate possible isochronous behavior in the analyzed systems, we next invoke some recent theoretical result…

Child Protection in Mediterranean Countries: Italy and Greece

2023

Abstract This chapter explores the child protection systems in Italy and Greece. Both countries have to deal with immigrant children due to the conflict between the rights of minors and immigration laws on control and defense. In Italy, the child protection system is the result of a patchwork of norms and regulations addressing different societal demands and pressures. Family and cash-transfers are fundamental factors in Italy’s child welfare system. Greece, on the other hand, has adopted fragmented measures and policies connected with financial benefits, income support, social security, social care for disabled people, and rehabilitation for children at risk. The chapter also notes how the…

Invariant rotational curves in Sitnikov's Problem

1993

The Sitnikov's Problem is a Restricted Three-Body Problem of Celestial Mechanics depending on a parameter, the eccentricity,e. The Hamiltonian,H(z, v, t, e), does not depend ont ife=0 and we have an integrable system; ife is small the KAM Theory proves the existence of invariant rotational curves, IRC. For larger eccentricities, we show that there exist two complementary sequences of intervals of values ofe that accumulate to the maximum admissible value of the eccentricity, 1, and such that, for one of the sequences IRC around a fixed point persist. Moreover, they shrink to the planez=0 ase tends to 1.

Enjeux fonciers et développement "durable" au Mali

2012

Making the land issue a total economic phenomenon and capital the driving force of development equates to giving free rein to the commodification of the land. Is it really necessary for Mali to sell off its agricultural land and its land resources to access development? For what development? Does development demand that family-run small farming operations and age-old, traditional land management methods be sacrificed? Ever since the country attained national sovereignty in 1960, Mali ‒ a poor country in sub-Saharan Africa ‒ has been seeking in vain to achieve rapid economic, social and industrial development by all the means available, with the exception of the deployment of an endogenous d…

Anomalous tracer diffusion in film forming colloidal dispersions

2000

Film forming colloidal dispersions can be conceived as a material composed of interpenetrating hydrophobic (polymer) and hydrophilic (partially broken interfaces) phases where the transport properties of one phase are influenced by the geometric confinement effect imposed by the other. We studied the transport properties of film forming colloidal dispersions by introducing hydrophobic dye molecules into the colloidal particles and determining their motion with forced Rayleigh Scattering as a function of length scale (grating distance A) and water content. At water contents between 18 and 3 weight percent we find signatures of anomalous tracer diffusion, namely stretched exponential decay cu…

Old Frisian skalk: A ‘Servant’ or a ‘Rogue’?

2017

The Old Frisian wordscalc, scalch, schalcis usually used in the sense of ‘servant, slave’. However, the word evidences a pejoration in meaning, being also attested in the Frisian written tradition in the sense of ‘ill-mannered person, villain, a bad guy’. The investigation of the occurrences ofskalk–along with a comparison of its Germanic cognates–will allow us to draw a picture of the semantic development of this word from medieval times to the Modern stage of the Frisian language. In the author’s opinion, the negative connotation ofskalkas an offensive epithet is the final result of a range of different causes, whose origin should be searched both in Frisian-Scandinavian contacts during t…

Statistical Analysis of Macroseismic Data for a better Evaluation of Earthquakes Attenuation Laws

2020

In this work we propose a statistical approach, based on the joint analysis of macroseismic data of Italian seismic events of the last two centuries, with which we obtain simultaneously maximum likelihood estimates of attenuation laws and coordinates of hypocenters. Our first results encourage us to use in the future more complex models, with a larger number of historical earthquakes.

Recommendations for design and analysis of health examination surveys under selective non-participation

2019

Background The decreasing participation rates and selective non-participation peril the representativeness of health examination surveys (HESs). Methods Finnish HESs conducted in 1972–2012 are used to demonstrate that survey participation rates can be enhanced with well-planned recruitment procedures and auxiliary information about survey non-participants can be used to reduce selection bias. Results Experiments incorporated to pilot surveys and experience from previously conducted surveys lead to practical improvements. For example, SMS reminders were taken as a routine procedure to the Finnish HESs after testing their effect on a pilot study and finding them as a cost-effective way to inc…