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Displaying 276 - 300 of 384

Measuring order in regioregular poly(3-hexylthiophene) with solid-state 13C CPMAS NMR

January 10, 2014
Author(s)
Ryan C. Nieuwendaal, Chad R. Snyder, Dean M. DeLongchamp
We report on details of molecular packing in high molar mass poly(3-hexylthiophene) (P3HT) by solid-state 13C {1H} cross-polarization magic angle spinning (CPMAS) NMR measurements. The degree of polymer order was estimated for two films of varied drying

Fast and Reliable Spectral Response Measurements of PV Cells Using Light Emitting Diodes

January 1, 2014
Author(s)
Behrang H. Hamadani, John F. Roller, Brian P. Dougherty, Howard W. Yoon
We present a measurement system for absolute differential spectral responsivity of solar cells based on high-powered LED arrays coupled to an optical light guide capable of large area illumination. Two different measurement techniques were developed and

Mapping the Local Photo-Electronic Properties of Polycrystalline Solar Cells through High Resolution Laser-Beam-Induced Current Microscopy

January 1, 2014
Author(s)
Marina S. Leite, Maxim Abashin, Henri J. Lezec, Anthony G. Gianfrancesco, Albert A. Talin, Nikolai B. Zhitenev
To boost the efficiency of thin film polycrystalline solar cells that are microscopically inhomogeneous, it is imperative to understand how the grain cores (GCs) and grain boundaries (GBs) within these materials affect its overall electronic properties. By

FATIGUE CRACK GROWTH OF TWO PIPELINE STEELS IN A PRESSURIZED HYDROGEN ENVIRONMENT

October 22, 2013
Author(s)
Andrew J. Slifka, Elizabeth S. Drexler, Nicholas Nanninga, Yaakov Levy, Joseph D. McColskey, Robert L. Amaro
Fatigue crack growth tests were conducted on two pipeline steel alloys, API 5L X52 and X100. Baseline tests were conducted in air, and those results were compared with tests conducted in pressurized hydrogen gas. All tests were run at (load ratio) R = 0.5

Local electrical characterizations of cadmium telluride solar cells using low energy electron beam

October 1, 2013
Author(s)
Heayoung Yoon, Paul M. Haney, Dmitry A. Ruzmetov, Hua Xu, Marina S. Leite, Behrang H. Hamadani, Albert A. Talin
We investigate local electronic properties of cadmium telluride solar cells using electron beam induced current (EBIC) measurements with current-collecting patterned contacts. EBIC measurements are performed with a spatial resolution as high as ≈20 nm both

Correlating Photovoltaic Clear-Sky and Actual Output to Sky Cover Measurements

September 1, 2013
Author(s)
David R. Daily, David Holmberg, John Baras
As distributed energy resources are added to existing building systems, and variable priced electricity tariffs are introduced, facility owners may profit from understanding the expected performance of their building systems. Hourly, forecast energy

Photocurrent Mapping of 3D CdSe/CdTe Windowless Solar Cells

August 22, 2013
Author(s)
Carlos M. Hangarter, Ratan K. Debnath, Jong Y. Ha, M. E. Sahiner, C. J. Reehil, W. A. Manners, Daniel Josell
This paper details the use of scanning photocurrent microscopy to examine localized current collection efficiency of thin film photovoltaic devices with in-plane patterning at a submicrometer length scale. The devices are based upon two interdigitated comb

Absolute spectral responsivity measurements of solar cells by a hybrid optical technique

July 15, 2013
Author(s)
Behrang H. Hamadani, John F. Roller, Brian P. Dougherty, Fiona Persaud, Howard W. Yoon
An irradiance mode, absolute differential spectral response measurement system for solar cells is presented. The system is based on combining the monochromator-based approach of determining the power mode spectral responsivity of cells with an LED-based

THE EFFECT OF MICROSTRUCTURE ON THE HYDROGEN-ASSISTED FATIGUE OF PIPELINE STEELS

July 14, 2013
Author(s)
Andrew J. Slifka, Elizabeth S. Drexler, Robert L. Amaro, Damian S. Lauria, April Stevenson, Douglas G. Stalheim, Louis E. Hayden
Tests on the fatigue crack growth rate were conducted on four pipeline steels, two of grade API 5L- X52 and two API 5L-X70. One X52 material was from the mid 1960s and the other was manufactured in 2011. The two X70 materials had a similar vintage and

Modulated photocurrent spectroscopy of CdTe/CdS solar cells-equivalent circuit analysis

May 20, 2013
Author(s)
Behrang H. Hamadani, John F. Roller, Kounavis Panagiotis, Nikolai B. Zhitenev, David J. Gundlach
We have used the technique of photocurrent modulated spectroscopy to investigate the dynamic response of charge carrier transport in thin film CdTe/CdS solar cells as a function of light bias and temperature over a broad excitation frequency range. The

Correlation for the Viscosity of Hydrogen obtained from Symbolic Regression

March 27, 2013
Author(s)
Chris D. Muzny, Marcia L. Huber, Andrei F. Kazakov
We report the results of a symbolic regression methodology to obtain both the functional form and the coefficients for a wide-ranging correlation for the viscosity of normal hydrogen. The correlation covers the temperature range from the triple point

A Humidity Generator for Temperatures to 200 degC and Pressures to 1.6 MPa

November 30, 2012
Author(s)
D Vega-Maza, W. Wyatt Miller, Dean C. Ripple, Gregory E. Scace
We have constructed a new humidity generator that produces gas streams of known moisture content at temperatures from 85 °C to 200 °C, absolute pressures from 0.2 MPa to 1.6 MPa, and relative humidities from 10 % to 90 %. The generator produces a moist gas

Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis - 2012

November 26, 2012
Author(s)
Amy S. Rushing, Joshua D. Kneifel, Barbara C. Lippiatt
This is the 2012 edition of energy price indices and discount factors for performing life-cycle cost analyses of energy and water conservation and renewable energy projects in federal facilities. It will be effective from April 1, 2012 to March 31, 2013
Displaying 276 - 300 of 384
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