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The purpose of this paper is to depict the effect of time and thermal and diffusion phase-lags due to axisymmetric heat supply in a ring. The problem is discussed within the context of dual-phase-lag heat transfer and dual-phase-lag diffusion models. The upper and lower surfaces of the ring are traction free and subjected to an axisymmetric heat supply.

The solution is found by using Laplace and Hankel transform technique and a direct approach without the use of potential functions. The analytical expressions of displacements, stresses and chemical potential, temperature and mass concentration are computed in transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerically simulated results are depicted graphically. The effect of time and diffusion and thermal phase-lags are shown on the various components. Some particular cases of result are also deduced from the present investigation.

It is observed that change in time changes the behaviour of deformations of the various components of stresses, displacements, chemical potential function, temperature change and mass concentration. The authors find that for t=0.2, trends are oscillatory in all the cases whereas for t=0.1, trends are quite different. A sound impact of diffusion and thermal phase-lags on the various quantities is observed. A lot of difference in the trends of single phase lag and dual phase lag is observed. The use of diffusion phase-lags in the equation of mass diffusion gives a more realistic model of thermoelastic diffusion media as it allows a delayed response between the relative mass flux vector and the potential gradient.

This problem is totally new because dual phase lag is applied in heat conduction and diffusion equation while considering the problem of plate in axisymmetric heat supply.

This study aims to evaluate the safety and quality of organic food product versus conventional ones in the Lebanese market.

Selected organic and conventional Lemon and cucumber were assessed for the presence of pesticides residues using LC-MS/MS and GC/MS/MS, also compared at the level of total polyphenols content, flavonoids, tannins and tested for their antiradical and antibacterial activities.

The findings indicate that organic lemons were contaminated by four types of pesticide residues (33.33%), while one pesticide residue (22.22%) was detected in conventional one, which were all below the European Union Maximum Residue Limits. For cucumber, six pesticide residues (66.66%) were detected in organic samples, while in conventional, eight pesticide residues (55.55%) were detected. However, absolutely four samples (44.44%) in each of conventional and organic cucumber samples surpass the maximum residue levels. Both lemon and cucumber, regardless of the farming systems, possess potent antioxidant activity with no significant difference, except for lemon, where total polyphenol was highly significant in conventional. Additionally, this study showed that lemon of conventional origin was slightly more effective in inhibiting the growth of gram-positive and gram-negative bacterial strains compared to organic samples, while both cucumber types did not exert any antibacterial effect.

This is the first paper to assess the polyphenols, pesticide residue and biological activities of organic lemon and cucumber in Lebanese market as well as comparing conventional to organic.