Transport properties near the Anderson transition

The electronic transport properties in the presence of a temperature gradient in disordered systems near the metal-insulator transition [MIT] are considered. The d.c. conductivity $\sigma$, the thermoelectric power $S$, the thermal conductivity $K$ and the Lorenz number $L_0$ are calculated for the three-dimensional Anderson model of localization using the Chester-Thellung-Kubo-Greenwood formulation of linear response. We show that $\sigma$, S, K and $L_0$ can be scaled to one-parameter scaling curves with a single scaling paramter $k_BT/|{\mu-E_c}/E_c|$.Comment: 4 pages, 4 EPS figures, uses annalen.cls style [included]; presented at Localization 1999, to appear in Annalen der Physik [supplement

Thermoelectric Transport Properties in Disordered Systems Near the Anderson Transition

We study the thermoelectric transport properties in the three-dimensional Anderson model of localization near the metal-insulator transition [MIT]. In particular, we investigate the dependence of the thermoelectric power S, the thermal conductivity K, and the Lorenz number L_0 on temperature T. We first calculate the T dependence of the chemical potential from the number density of electrons at the MIT using averaged density of state obtained by diagonalization. Without any additional approximation, we determine from the chemical potential the behavior of S, K and L_0 at low T as the MIT is approached. We find that the d.c. conductivity and K decrease to zero at the MIT as T -> 0 and show that S does not diverge. Both S and L_0 become temperature independent at the MIT and depend only on the critical behavior of the conductivity.Comment: 11 pages, 10 eps figures, coded with the EPJ macro package, submitted to EPJ

Aharonov-Bohm effect for an exciton in a finite width nano-ring

We study the Aharonov-Bohm effect for an exciton on a nano-ring using a 2D attractive fermionic Hubbard model. We extend previous results obtained for a 1D ring in which only azimuthal motion is considered, to a more general case of 2D annular lattices. In general, we show that the existence of the localization effect, increased by the nonlinearity, makes the phenomenon in the 2D system similar to the 1D case. However, the introduction of radial motion introduces extra frequencies, different from the original isolated frequency corresponding to the excitonic Aharonov- Bohm oscillations. If the circumference of the system becomes large enough, the Aharonov-Bohm effect is suppressed

Archaeological and Historical Investigations in Bastrop and Lee Counties, Texas

This reconnaissance-level cultural resources survey of 1900 acres in northern Bastrop County, including a small area in Lee County, Texas, was accomplished by the Center for Archaeological Research, The University of Texas at San Antonio, in July 1980. City Public Service (CPS) of San Antonio has proposed a lignite mining project in the area, and this represents the first attempt to determine the nature of the cultural resources and the problems they might present in developing the lignite deposits. Prehistoric resources in the primary area were scarce and of limited significance, but three sites on the west side of the area are considered to be of high potential and may fall within the CPS area of interest. Four historic sites were recorded, eventually, and specific recommendations were made for each. Recommendations were made for future investigations in the area. Where possible, comparisons are made between the present survey and an intensive study, conducted by the Texas Archeological Survey, of the nearby Camp Swift area

“DYNAMIC TRACKING”, A METHOD FOR SMOOTHING KINEMATIC DATA

One basic problem in biomechanical modelling is the transfer of a real motion to a model. Here the motion of an ice speed skater should be transferred to the alaska 3D MBS man model DYNAMICUS. To find an optimal description for the motion of the man model Dynamic Tracking has been used and investigated. The results show that this method is a useful possibilty to recieve time histories for the inner co-ordinates close to reality

INFLUENCE OF BODY MASS INDEX ON ROWING KINEMATICS

Rowing meets the criteria for weight loss as defined by the American College of Sport Medicine. Little research exists on the influence of body shape on movement kinematics. Even if rowing is a non weight bearing exercise, the body shape may have an influence on rowing motion and joint reactions. This study investigated rowing movement kinematics between normal weight and overweight subjects. Differences were found for hip abduction and adduction angles. This knowledge can help to understand the influence of body weight and body shape on movement kinematics and can help to avoid overloading the joints

ELITE OUTSIDE HITTERS IN VOLLEYBALL DO NOT MEET THEIR INDIVIDUAL POSSIBLE MAXIMUM IMPACT HEIGHT IN HIGH SPIKE JUMPS

It is assumed that a high impact height is a relevant factor for success in volleyball spikes. The purpose of the study was to investigate whether outside hitters hit the ball at the highest possible impact height. Spikes from position IV were analysed at a tournament of the European League. The posture of the athletes was less extended in the trunk and upper limb with increasing jump height. Regarding the body posture at the moment of impact, there was no effect on the post impact ball speed. It is concluded that there could be enhancement with respect to the impact height as jump height increases even in elite athletes without reducing ball speed. This should be addressed within the training process

A Single-Product Inventory Model for Multiple Demand Classes

We consider a single-product inventory system that serves multiple demand classes, which differ in their shortage costs or service level requirements. We assume a critical-level control policy, and show the equivalence between this inventory system and a serial inventory system. Based on this equivalence, we develop a model for cost evaluation and optimization, under the assumptions of Poisson demand, deterministic replenishment lead-time, and a continuous-review (Q, R) policy with rationing. We propose a computationally-efficient heuristic and develop a bound on its performance. We provide a numerical experiment to show the effectiveness of the heuristic and the value from a rationing policy. Finally, we describe how to extend the model to permit service times, and to embed within a multi-echelon setting