An extensive study of the one-dimensional two-segment Frenkel-Kontorova (FK) model reveals a transition from the counterintuitive existence to the ordinary nonexistence of a negative-differential-thermal-resistance (NDTR) regime, when the system size or the intersegment coupling constant increases to a critical value. A "phase" diagram which depicts the relevant conditions for the exhibition of...

Thermomechanical deformations of a body made of two different materials and undergoing simple shearing deformations are studied with the objectives of finding out when and where adiabatic shear bands will initiate and how they will subsequently grow. Each material is modeled as strain and strain-rate hardening but thermally softening. A shear band is presumed to have formed if the introduction ...

Solid-state thermoelectric technology offers a promising solution for converting waste heat to useful electrical power. Both high operating temperature and high figure of merit zT are desirable for high-efficiency thermoelectric power generation. Here we report a high zT of ∼1.5 at 1,200 K for the p-type FeNbSb heavy-band half-Heusler alloys. High content of heavier Hf dopant simultaneously opt...

0.1016/j.nanoen.2 lsevier Ltd. All rig thor. [email protected] Abstract We propose and demonstrate the beneficial use of minority carrier blocking layers to lessen bipolar conduction at elevated temperatures and increase the Seebeck coefficient in a thermoelectric material. Bipolar conduction, caused by thermally activated intrinsic carriers in semiconductors, causes a detrimental “roll-over” in ...

The objective of this work is to determine the thermal stability and vibrational spectra of datolite CaBSiO4(OH) and relate these properties to the structure of the mineral. The thermal analysis of datolite shows a mass loss of 5.83% over a 700-775°C temperature range. This mass loss corresponds to 1 water (H2O) molecules pfu. A quantitative chemical analysis using electron probe was undertaken...

In this work, we present a method for early forest fire detection from a satellite image using the power spectral density of a Gaussian white noise. To obtain the latter, we have considered each satellite image matrix line as a realization of a non stationary random process in the Thermal Infra-Red (TIR) spectral band, and then divided each line into very small intervals in which any random pro...

Effective May 5, 2003, Landsat-5 (L5) Thematic Mapper (TM) data processed and distributed by the U.S. Geological Survey (USGS) Earth Resources Observation System (EROS) Data Center (EDC) will be radiometrically calibrated using a new procedure and revised calibration parameters. This change will improve absolute calibration accuracy, consistency over time, and consistency with Landsat-7 (L7) En...

Using Raman spectroscopy, we measure the optical phonon energies of suspended graphene before, during, and after thermal cycling between 300 and 700 K. After cycling, we observe large upshifts ( approximately 25 cm(-1)) of the G band frequency in the graphene on the substrate region due to compression induced by the thermal contraction of the underlying substrate, while the G band in the suspen...

We present a general theory of non-Markovian dynamics for open systems of noninteracting fermions (bosons) linearly coupled to thermal environments of noninteracting fermions (bosons). We explore the non-Markovian dynamics by connecting the exact master equations with the nonequilibirum Green's functions. Environmental backactions are fully taken into account. The non-Markovian dynamics consist...