Higher-Dimensional QCD without the Strong CP Problem

QCD in a five-dimensional sliced bulk with chiral extra-quarks on the boundaries is generically free from the strong CP problem. Accidental axial symmetry is naturally present except for suppressed breaking interactions, which plays a role of the Peccei-Quinn symmetry to make the strong CP phase sufficiently small.Comment: 7 pages, late

The entrepreneurship potential of rural areas: soap production as a side business for Tanzanian rice farmers

Purpose: This study examines soap production’s entrepreneurship potential and profitability as a supplementary business for rural rice farmers in Tanzania to promote their economic independence.Design/ Methodology/ Approach: We randomly sampled and interviewed about ten smallscale soap manufacturers in urban Tanzania gathered from 2019-2021 to develop a soap production business strategy for rural farmers at a similar scale. Considering the Voronoi theory, we calculated the distance from the rural areas to urban centres to determine the transportation costs, which particularly burden rural farmers. Soap production costs and profitability were determined based on transportation costs and raw material prices.Findings: Rural farmers would incur high transportation costs, given the high average distance to the nearest urban centre (sometimes > 100 km). Nevertheless, producing their rice bran oil, valuable raw material for soap production, would give them a competitive advantage over urban producers.Research Limitation: The study’s proposed strategy can be applied to similar contexts to reduce the urban-rural entrepreneurship divide.Practical Implication: Soaps made using rice bran oil help farmers reuse agricultural waste. Their active ingredients also increase their marketability as high-end cosmetic products, providing farmers with additional income.Social Implication: Commercializing agricultural residues such as rice bran increases farmers’ revenues and reduces CO2 emissions by preventing the residues’ incineration; this creates a virtuous cycle in society.Originality/ Value: This study presents a more realistic business strategy for rural Tanzanian farmers, as, unlike previous studies, it considers not only direct costs but also transportation costs

Extension of geodesic acoustic mode theory to helical systems

The present paper extends the theory of geodesic acoustic mode (GAM) oscillation, which so far has been applied to tokamaks, to helical systems. By using drift kinetic equations for three-dimensional equilibriums, a generalized dispersion relation is obtained including Landau damping. The oscillation frequency is obtained in terms of the squared sum of Fourier components of the magnetic field intensity expressed by means of magnetic flux coordinates. An analytic form of the collisionless damping rate of GAM is obtained by solving the dispersion relation perturbatively. It is found that the GAM frequency is higher in helical systems than in tokamaks and that damping rate is enhanced in multi-helicity magnetic configurations. However, damping rates are predicted to be small if the temperature of electrons is higher than that of ions