The Drinfel'd twisted XYZ model

We construct a factorizing Drinfel'd twist for a face type model equivalent to the XYZ model. Completely symmetric expressions for the operators of the monodromy matrix are obtained.Comment: 15 pages, 4 figures, second preprint no. added, reference [14] added, typos correcte

Electric Motorcycle Lithium-Ion Battery System

This project entails the processes of design, construction, implementation, and testing of a lithium-ion battery system, including a battery management system, dedicated to converting a 1999 Honda XR100R motorcycle into a fully functional electric motorcycle. The battery system powers the motorcycle with enough voltage and amperage to sustain the needed power capability for a reasonable range. Providing an estimate of the voltage needed, the two largest loads, the DC motor and controller, draw about 48 to 60 volts from the battery for proper operation. Additionally, different aspects of the design also ensure safe operation, correct sizing, and maximum lifetime of the lithium-ion cells. With the large industry movement towards fully electric vehicles, this project provides valuable knowledge, experience, and insight to the future: a world driven by electric power

Spin effects in single-electron tunneling in magnetic junctions

Spin dependent single electron tunneling in ferromagnetic double junctions is analysed theoretically in the limit of sequential tunneling. The influence of discrete energy spectrum of the central electrode (island)on the spin accumulation, spin fluctuations and tunnel magnetoresistance is analysed numerically in the case of a nonmagnetic island. It is shown that spin fluctuations are significant in magnetic as well as in nonmagnetic junctions.Comment: 14 pages, 3 eps-figures include

Theoretical analysis of quantum dynamics in 1D lattices: Wannier-Stark description

This papers presents a formalism describing the dynamics of a quantum particle in a one-dimensional tilted time-dependent lattice. The description uses the Wannier-Stark states, which are localized in each site of the lattice and provides a simple framework leading to fully-analytical developments. Particular attention is devoted to the case of a time-dependent potential, which results in a rich variety of quantum coherent dynamics is found.Comment: 8 pages, 6 figures, submitted to PR

Population Density and Seasonality Effects on Sin Nombre Virus Transmission in North American Deermice (Peromyscus maniculatus) in Outdoor Enclosures

Surveys of wildlife host-pathogen systems often document clear seasonal variation in transmission; conclusions concerning the relationship between host population density and transmission vary. In the field, effects of seasonality and population density on natural disease cycles are challenging to measure independently, but laboratory experiments may poorly reflect what happens in nature. Outdoor manipulative experiments are an alternative that controls for some variables in a relatively natural environment. Using outdoor enclosures, we tested effects of North American deermouse (Peromyscus maniculatus) population density and season on transmission dynamics of Sin Nombre hantavirus. In early summer, mid-summer, late summer, and fall 2007–2008, predetermined numbers of infected and uninfected adult wild deermice were released into enclosures and trapped weekly or bi-weekly. We documented 18 transmission events and observed significant seasonal effects on transmission, wounding frequency, and host breeding condition. Apparent differences in transmission incidence or wounding frequency between high- and low-density treatments were not statistically significant. However, high host density was associated with a lower proportion of males with scrotal testes. Seasonality may have a stronger influence on disease transmission dynamics than host population density, and density effects cannot be considered independent of seasonality

Electron transport uniformity characterization of CdZnTe using alpha particles

Novel electrode configurations, such as coplanar grids, have been successful in mitigating the effects of poor hole transport in CdZnTe gamma-ray detectors. However, poor material uniformity remains a major problem preventing the widespread application of such detectors in gamma-ray spectroscopy. Uniform electron transport is critical for achieving good gamma-ray detection performance in the coplanar-grid configuration. The authors have investigated the use of alpha-particle response as a quick and simple electron transport uniformity screening technique for material selection, and as a method to study other spectral broadening mechanisms in coplanar-grid detectors. The method consists of uniformly illuminating, with an alpha-particle source, the cathode side of the CdZnTe crystal in either a planar or a coplanar-grid detector configuration. In the planar geometry, the variation in the measured pulse heights is dictated in large part by the uniformity of the electron transport. An alpha-particle spectrum that has a single sharp peak with little background indicates uniform electron transport and, consequently, that the CdZnTe crystal should result in a coplanar-grid detector with good gamma-ray detection performance. In the coplanar geometry, the measured pulse-height variation provides information on additional sources of spectral broadening. In this paper the authors present the results of their study to measure the correlation between these simple alpha-particle measurements and the coplanar-grid gamma-ray detector response

Thermo-Coulomb effects in mesoscopic tunnel junctions

We present a study of the thermoelectric effect in tunnel junctions. In particular we calculate the thermopower coefficient S and the Peltier coefficient π. For macroscopic junctions we demonstrate the sensitivity of S and π to the structure of the density of states. For mesoscopic junctions we show that Coulomb effects modify the ordinary Onsager picture and the relation π= TS . The coefficients S and π are found to be very sensitive to the coupling of the junctions to the external world. We analyze measurements of the thermopower in granular films in terms of the thermo-Coulomb effects. We comment on the relevance of these effects to scanning tunneling microscope measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43892/1/10051_2005_Article_BF01307637.pd

Thermoelectric and thermo-Coulomb effects in tunnel junctions

We present a study of the thermoelectric effects in tunnel junctions. In particular we calculate the thermoelectric power coefficient S and the Peltier coefficient P. For macroscopic junctions we demonstrate the sensitivity of S and P to the structure of the density of states. For mesoscopic junctions we show that Coulomb effects modify the ordinary Onsager picture and the relation P=-TS. The coefficients S and P are found to be very sensitive to the coupling of the junctions to the external world. We comment on the relevance of these effects to scanning tunneling microscope measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29684/1/0000011.pd

Interplay between Coulomb Blockade and Resonant Tunneling studied by the Keldysh Green's Function Method

A theory of tunneling through a quantum dot is presented which enables us to study combined effects of Coulomb blockade and discrete energy spectrum of the dot. The expression of tunneling current is derived from the Keldysh Green's function method, and is shown to automatically satisfy the conservation at DC current of both junctions.Comment: 4 pages, 3 figures(mail if you need), use revtex.sty, error corrected, changed titl