Virtual and remote laboratories have improved
learning and training in the academic community. They allow students to acquire methods, skills and experience related to real equipment in an intuitive and cost-effective way. The purpose of this paper is to present…

The analytical approximate technique developed by Wu et al. for conservative oscillators with odd nonlinearity is used to construct approximate frequency-amplitude relations and periodic solutions to the relativistic oscillator. By combining Newton's method with the method of harmonic balance, analytical…

There is no doubt that the population is progressively aging. This study evaluates the relationship between the variables of the level and type of physical activity and the degree of pain, with a series of socio-demographic variables, such as age,…

In their comment, Qing-Yin and Pei derived another analytical approximate expression for the large-angle pendulum period, which they compare with other expressions previously published. Most of these approximate formulas are based on the approximation of the original nonlinear differential equation…

Background The aim of this study was to determine compliance with published good practice guidelines for gender and clinical trials using etoricoxib. The rationale for choosing etoricoxib was that it is widely used by women and there is evidence of…

Congenital hypothyroidism induces developmental abnormalities in the auditory receptor, causing deafness due to a poor development of the outer hair cells (OHCs) and a lack of synaptogenesis between these cells and the olivocochlear axons. This efferent innervation is formed by…

Desalination of seawater has become an important and growing
industry due to the water shortage in some Mediterranean countries. This
activity may result in environmental impacts, mainly generated by the
discharge into the sea of the concentrate (brine) produced. Data…

The methods of differential geometry are used with the assumption that rays of light follow geodesic trajectories in a space whose metric is determined by the refraction index. Keeping this in mind, we show that these hypotheses are equivalent to…

A linearization method of the nonlinear differential equation for conservative nonlinear oscillators is analyzed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force which allows us to obtain a frequency-amplitude relation which is valid…

An approximation scheme to obtain the period for large amplitude oscillations of a simple pendulum is analysed and discussed. The analytical approximate formula for the period is the same as that suggested by Hite (2005 Phys. Teach. 43 290), but…