Weak Localization and Negative Magnetoresistance in Wurtzite-type Crystals

We have developed a theory of the negative magnetoresistance due to the weak localization in uniaxial wurtzite-type crystals, in which the spin splitting of the conduction band is linear in the wave vector, unlike the cubic ${\rm A_3 B_5}$ crystals. Unlike earlier theories, we take into account the correlation between the electron motion in spin and co-ordinate spaces. It is shown that as a result of this correlation the magnetoresistance depends on the orientation of the magnetic field with respect to the main axis of the crystal even if the effective mass is isotropic. The new theory allows to accurately determine the value of the spin splitting constant in uniaxial crystals.Comment: 5 pages, RevTeX, 2 PostScript figure

Steel Fiber Concrete Mixture Workability

AbstractThe article provides an overview of existing parameters of concrete mixture workability estimates for steel fiber concrete. The study shows that the standard concrete workability parameters such as mobility, stiffness, spread, viscosity may not be used for steel fiber concrete mixtures. We propose evaluation of the steel fiber-concrete mixture workability using the dimensionless coefficient, which is a stress magnitude for the steel fiber concrete mixture at the normal stress unit value. Using of a standard laboratory tool for a single plane shear soil tests with larger rings is recommended for testing. The resulting values for the dimensionless coefficient are approximated by mathematical relations with a high reproducibility. The proposed mathematical model of the dimensionless coefficient provides a clear determination of the steel fiber concrete mixture workability

Systems of Crime and Castigation: A Reevaluation of the Punishment Bureaucracy

Models of reform within the criminal justice system often operate from a top-down perspective, affecting change on surface levels to attempt to better the system. One example of such a reform is Scotland’s Presumption Against Short Sentences. These kinds of changes, as I will illustrate in this paper, both fall short of achieving genuine change and often produce negative side effects. However, a few countries have made deeper changes to the ways their systems both view and handle crime and punishment; one such system is Norway. Through rehabilitation and restorative justice, Norway has greatly decreased rates of recidivism, increased social wellbeing and shifted attitudes around criminality. This paper thus presents an argument as to why top-down models of reform such as Scotland’s are not effective, and why systems must be addressed from the bottom-up to effectuate actual change by examining efficacy and reasoning behind the institution of punishment. Further, I argue that that the United States system of law and order specifically both does not operate objectively and has been wielded as a historical tool of political oppression; I thus posit that small reforms will always fall short when proposed within the context of a system built off of economic and racial oppression. Due to the foundations of injustice within the American criminal justice system, I thus conclude that we must pursue deeper changes instead of peripheral reforms