Hydrologic Data for Urban Studies in The Austin Metropolitan Area, Texas, 1986

The report references Waller Creek and includes data from surrounding watersheds.Waller Creek Working Grou

Multi-parameter scaling of the Kondo effect in quantum dots with an even number of electrons

We address a recent theoretical discrepancy concerning the Kondo effect in quantum dots with an even number of electrons where spin-singlet and -triplet states are nearly degenerate. We show that the discrepancy arises from the fact that the Kondo scaling involves many parameters, which makes the results depend on concrete microscopic models. We illustrate this by the scaling calculations of the Kondo temperature, $T_K$, as a function of the energy difference between the singlet and triplet states $\Delta$. $T_K(\Delta)$ decreases with increasing $\Delta$, showing a crossover from a power law with a universal exponent to that with a nonuniversal exponent. The crossover depends on the initial parameters of the model.Comment: 8 pages, 3 figure

Response of Vegetation to Livestock Grazing at the Texas Experimental Ranch.

40 p

Simple choreographies of the planar Newtonian NN-body Problem

In the $N$-body problem, a simple choreography is a periodic solution, where all masses chase each other on a single loop. In this paper we prove that for the planar Newtonian $N$-body problem with equal masses, $N \ge 3$, there are at least $2^{N-3} + 2^{[(N-3)/2]}$ different main simple choreographies. This confirms a conjecture given by Chenciner and etc. in \cite{CGMS02}.Comment: 31pages, 6 figures. Refinements in notations and proof

Recent advance in high manufacturing readiness level and high temperature CMOS mixed-signal integrated circuits on silicon carbide

A high manufacturing readiness level silicon carbide (SiC) CMOS technology is presented. The unique process flow enables the monolithic integration of pMOS and nMOS transistors with passive circuit elements capable of operation at temperatures of 300 °C and beyond. Critical to this functionality is the behaviour of the gate dielectric and data for high temperature capacitance–voltage measurements are reported for SiO2/4H-SiC (n and p type) MOS structures. In addition, a summary of the long term reliability for a range of structures including contact chains to both n-type and p-type SiC, as well as simple logic circuits is presented, showing function after 2000 h at 300 °C. Circuit data is also presented for the performance of digital logic devices, a 4 to 1 analogue multiplexer and a configurable timer operating over a wide temperature range. A high temperature micro-oven system has been utilised to enable the high temperature testing and stressing of units assembled in ceramic dual in line packages, including a high temperature small form-factor SiC based bridge leg power module prototype, operated for over 1000 h at 300 °C. The data presented show that SiC CMOS is a key enabling technology in high temperature integrated circuit design. In particular it provides the ability to realise sensor interface circuits capable of operating above 300 °C, accommodate shifts in key parameters enabling deployment in applications including automotive, aerospace and deep well drilling

Entanglement Sudden Death in Band Gaps

Using the pseudomode method, we evaluate exactly time-dependent entanglement for two independent qubits, each coupled to a non-Markovian structured environment. Our results suggest a possible way to control entanglement sudden death by modifying the qubit-pseudomode detuning and the spectrum of the reservoirs. Particularly, in environments structured by a model of a density-of-states gap which has two poles, entanglement trapping and prevention of entanglement sudden death occur in the weak-coupling regime

Quantum phase transition in a two-channel-Kondo quantum dot device

We develop a theory of electron transport in a double quantum dot device recently proposed for the observation of the two-channel Kondo effect. Our theory provides a strategy for tuning the device to the non-Fermi-liquid fixed point, which is a quantum critical point in the space of device parameters. We explore the corresponding quantum phase transition, and make explicit predictions for behavior of the differential conductance in the vicinity of the quantum critical point

Fermi Surfaces of Diborides: MgB2 and ZrB2

We provide a comparison of accurate full potential band calculations of the Fermi surfaces areas and masses of MgB2 and ZrB2 with the de Haas-van Alphen date of Yelland et al. and Tanaka et al., respectively. The discrepancies in areas in MgB2 can be removed by a shift of sigma-bands downward with respect to pi-bands by 0.24 eV. Comparison of effective masses lead to orbit averaged electron-phonon coupling constants lambda(sigma)=1.3 (both orbits), lambda(pi)=0.5. The required band shifts, which we interpret as an exchange attraction for sigma states beyond local density band theory, reduces the number of holes from 0.15 to 0.11 holes per cell. This makes the occurrence of superconductivity in MgB2 a somewhat closer call than previously recognized, and increases the likelihood that additional holes can lead to an increased Tc.Comment: 7 pages including 4 figure

Deformation-enhanced recrystallization of titanite drives decoupling between U-Pb and trace elements

Titanite is a common accessory mineral that is useful in determining both age (U-Pb isotopes) and pressure-temperature (P–T) conditions (trace-element composition: Zr, rare earth elements (REE)). However, titanite has a propensity to recrystallize during metamorphism, fluid flow, and deformation, which can result in modifications to its isotopic and trace-element compositions. This modification has implications for the interpretation of titanite dates and the evaluation of pressure–temperature–time paths. The impact of deformation and recrystallization on trace-element mobility in titanite is investigated through microstructural and compositional mapping of titanite crystals from a sheared orthogneiss within an ultrahigh-pressure domain of the Western Gneiss Region (WGR), Norway. Results show that optically coherent titanite single crystals deformed in the dislocation creep regime and recrystallized by the process of grain-boundary migration, forming aggregates of titanite grains. Some of the aggregate grains record Caledonian-exhumation dates, whereas others have an inherited isotopic composition. Individual grains within the aggregate, regardless of their U-Pb isotopic composition, contain patchy zoning that formed during syn- to post-recrystallization fluid alteration and that is characterized by generally decreasing Ca and Ti and increasing Al and Fe from cores to rims. However, Zr and Sr concentrations are broadly zoned with respect to the long axis of the host crystal, without regard for the aggregate grain boundaries. REE do not show any obvious correlation with microstructure or age. These results indicate that many trace elements in titanite are unaffected by multi-stage, deformation-driven recrystallization; in contrast, Pb is variably mobile in these deformed titanite crystals. The combination of microstructural and high-spatial resolution geochemical and isotopic data reveals the potential extent of decoupling between the U-Pb isotopic system and the behavior of trace elements as pressure–temperature conditions change through time

Thermoelectric effects of an Aharonov-Bohm interferometer with an embedded quantum dot in the Kondo regime

Thermoelectric effects are studied in an Aharonov-Bohm (AB) interferometer with an embedded quantum dot in the Kondo regime. The AB flux-dependent transmission probability has an asymmetrical shape arising from the Fano interference between the direct tunneling path and the Kondo-resonant tunneling path through a quantum dot. The sign and magnitude of thermopower can be modulated by the AB flux and the direct tunneling amplitude. In addition, the thermopower is anomalously enhanced by the Kondo correlation in the quantum dot near the Kondo temperature ($T_K$). The Kondo correlation in the quantum dot also leads to crossover behavior in diagonal transport coefficients as a function of temperature. The amplitude of an AB oscillation in electric and thermal conductances is small at temperatures far above $T_K$, but becomes enhanced as the system is cooled below $T_K$. The AB oscillation is strong in the thermopower and Lorenz number within the crossover region near the Kondo temperature.Comment: 16 pages, 10 figure