24,425 research outputs found
Thermoelectric properties of -FeSi
We investigate the thermoelectric properties of -FeSi
using first principles electronic structure and Boltzmann transport
calculations. We report a high thermopower for both \textit{p}- and
\textit{n}-type -FeSi over a wide range of carrier
concentration and in addition find the performance for \textit{n}-type to be
higher than for the \textit{p}-type. Our results indicate that, depending upon
temperature, a doping level of 3 - 2
cm may optimize the thermoelectric performance
Optical properties of cubic and rhombohedral GeTe
Calculations of the optical properties of GeTe in the cubic NaCl and
rhombohedral ferroelectric structures are reported. The rhombohedral
ferroelectric distortion increases the band gap from 0.11 eV to 0.38 eV.
Remarkably, substantial changes in optical properties are found even at high
energies up to 5 eV. The results are discussed in relation to the bonding of
GeTe and to phase change materials based on it
Prediction of Room Temperature High Thermoelectric Performance in n-type La(Ru,Rh)4Sb12
First principles calculations are used to investigate the band structure and
the transport related properties of unfilled and filled 4d skutterudite
antimonides. The calculations show that, while RhSb3 and p-type La(Rh,Ru)4Sb12
are unfavorable for thermoelectric application, n-type La(Rh,Ru)4Sb12 is very
likely a high figure of merit thermoelectric material in the important
temperature range 150-300 K.Comment: 3 pages, 3 figures. To appear, Appl. Phys. Let
A Guide to Solar Power Forecasting using ARMA Models
We describe a simple and succinct methodology to develop hourly
auto-regressive moving average (ARMA) models to forecast power output from a
photovoltaic solar generator. We illustrate how to build an ARMA model, to use
statistical tests to validate it, and construct hourly samples. The resulting
model inherits nice properties for embedding it into more sophisticated
operation and planning models, while at the same time showing relatively good
accuracy. Additionally, it represents a good forecasting tool for sample
generation for stochastic energy optimization models
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