Geotourism as a 16-Geosite Empowerment Strategy—For Tourism Sustainability in Toba Caldera Geopark

The study on empowerment strategies for tourism sustainability was carried out in 16 geosites located in seven regencies. These include Karo, Dairi, Simalungun, Samosir, Toba Samosir, North Tapanuli, and Humbang Hasundutan, in Toba Caldera Region (TCA), North Sumatra Province. The empowerment strategies will enhance local and national tourism development policy directives, boost development geared towards community tourism interests, and achieve GGN directives according to the concepts outlined by UNESCO. This geotourism development has been formulated through a synthesis of various investigations including the analyses of government references, potential tourist attractions, and SWOT. Furthermore, the SWOT analysis showed that a travel plan combining the elements of cultural heritage and geosites is an alternative empowerment for sustainable regional development through geotourism, using Pusuk Bukit as a pilot area. Geosites have been mapped as the basis for Toba Caldera’s development.

Spin Symmetry in Dirac-Attractive Radial Problem and Tensor Potential

In this paper,we solve the Dirac equation under spin symmetry limit for attractive radial potential including a Coulomb-like tensor interaction.By using the parametric generalization of the Nikiforov-Uvarov method,the energy eigenvalues equation and the corresponding wave functions have been obtained in closed forms.Some numerical results are given too.

Effective attractive potential between identical dielectric molecules via Lifshitz theory

A general theory of Van der Waals forces developed by Lifshitz based on quantum electrodynamics theory is applied in the range R?λ0( where the Casimir effects may be neglected) to construct Van der Waals attractive potential between identical dielectric molecules in rarefied media in order that the effective attractive potential between the like-molecules (including the repeat units) is offered. A closed form solution for the integral formulation of the attractive potential between like-particles is first obtained based on certain assumptions made in this work. On the basis of the theory of electric polarization, the derived expression in terms of bulk properties is then compared with the well-known London formula, the former differs from the latter only by the fact $\frac{4}{\pi }or\frac{4}{\pi }\left( {\frac{{\varepsilon _\infty + 2}}{3}} \right)^2 $ The validity of the effective potential can be verified by testing cases composed of several types of dielectric materials. The computed results are presented in this paper, and comparisons with the results computed by London dispersion formula, as well as the recommended values in virtue of the experimental and theoretical techniques, are also presented. The effective potential of polyethylene is also computed to demonstrate the effectiveness of the developed model, and it is found that the computed well depth fall within a reasonable range of accuracy.