Food safety as a public health issue for developing countries

"This brief reviews the incidence and health consequences of biological pathogens in developing countries, as these are the most important food safety risks in those parts of the world, and provides an overview of possible methods of control." from TextFood safety ,food security ,Public health ,

Kondo effect in three-dimensional Dirac and Weyl systems

Magnetic impurities in three-dimensional Dirac and Weyl systems are shown to exhibit a fascinatingly diverse range of Kondo physics, with distinctive experimental spectroscopic signatures. When the Fermi level is precisely at the Dirac point, Dirac semimetals are in fact unlikely candidates for a Kondo effect due to the pseudogapped density of states. However, the influence of a nearby quantum critical point leads to the unconventional evolution of Kondo physics for even tiny deviations in the chemical potential. Separating the degenerate Dirac nodes produces a Weyl phase: time-reversal symmetry-breaking precludes Kondo due to an effective impurity magnetic field, but different Kondo variants are accessible in time-reversal invariant Weyl systems.Comment: 4+ pages, 2 figure

Quantum phase transitions and thermodynamics of the power-law Kondo model

We revisit the physics of a Kondo impurity coupled to a fermionic host with a diverging power-law density of states near the Fermi level, $\rho(\omega) \sim |\omega|^r$, with exponent $-1<r<0$. Using the analytical understanding of several fixed points, based partially on powerful mappings between models with bath exponents $r$ and $(-r)$, combined with accurate numerical renormalization group calculations, we determine thermodynamic quantities within the stable phases, and also near the various quantum phase transitions. Antiferromagnetic Kondo coupling leads to strong screening with a negative zero-temperature impurity entropy, while ferromagnetic Kondo coupling can induce a stable fractional spin moment. We formulate the quantum field theories for all critical fixed points of the problem, which are fermionic in nature and allow for a perturbative renormalization-group treatment.Comment: 13 pages, 11 figure

Kondo effect on the surface of 3D topological insulators: Signatures in scanning tunneling spectroscopy

We investigate the scattering off dilute magnetic impurities placed on the surface of three-dimensional topological insulators. In the low-temperature limit, the impurity moments are Kondo-screened by the surface-state electrons, despite their exotic locking of spin and momentum. We determine signatures of the Kondo effect appearing in quasiparticle interference (QPI) patterns as recorded by scanning tunneling spectroscopy, taking into account the full energy dependence of the T matrix as well as the hexagonal warping of the surface Dirac cones. We identify a universal energy dependence of the QPI signal at low scanning energies as the fingerprint of Kondo physics, markedly different from the signal due to non-magnetic or static magnetic impurities. Finally, we discuss our results in the context of recent experimental data.Comment: 9 pages, 9 figure

Plan Commission Basics for Engineers

Whether you are a plan commission member (city engineer, county surveyor, extension agent) or you have to work with one, this session is designed for you. Learn how “public health, safety, and welfare” plays into not only what you do, but also the decisions the plan commission and other local government bodies make. This session is based on the popular Nitty Gritty for Plan Commission and Board of Zoning Appeals Training Series. We will allow time for Q&A

Navigating the Local Planning Process for Engineers

Engineers and surveyors involved with development or infrastructure must sometimes interact with a local government’s planning department. In Indiana, state law even requires that city plan commissions include the city engineer and that county plan commissions include the county surveyor. This session provides basic information that engineering professionals need to know to successfully navigate the local planning process and public meetings, including state law requirements