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X Feng, Edward J. Garboczi, Paul E. Stutzman, T Mason
A scanning electron microscope (SEM) point-counting technique was employed to study the hydration of plain portland cement pastes and blended cement pastes containing fly ash or slag. For plain portland cement pastes, the results for the degree of cement
Mark R. VanLandingham, N-K Chang, T-Y Wu, Li Piin Sung, V D. Jardret, S-H Chang
Instrumented indentation and confocal microscopy were used to characterize the surface mechanical response of polymeric materials. Viscoelastic behavior was measured using instrumented indentation. A model based on contact between a rigid probe and a
William M. Pitts, A V. Murthy, J L. de Ris, J R. Filtz, K Nyard, D Smith, I Wetterlund
Total heat flux gauges are widely employed in fire research and fire testing laboratories. Several fire laboratories have developed systems for calibrating these gauges. There are major differences between these calibration facilities, and prior to this
Recently, techniques for acquiring, analyzing, and using 3-D shape information for aggregates (sand, gravel) have been developed and demonstrated. These mathematical techniques, based on spherical harmonic coefficient analysis, have been applied to x-ray
Li Piin Sung, J Jasmin, Xiaohong Gu, Tinh Nguyen, Jonathan W. Martin
Due to its non-destructive properties, laser scanning confocal microscopy (LSCM) has become a powerful tool for monitoring physical changes in polymeric coatings following ultraviolet (UV) radiation exposure. Physical changes caused by UV exposure include
The localization length is calculated for harmonic one-dimensional lattices havingbinary (isotopic) disorder. The results are applicable to classical strongly scattered systems having arbitrary wavelength, impurity cross section, and impurity concentration
Since its initial recognition in 1928 and commercialization in 1936, R-22 has been applied in systems ranging from the smallest window air conditioners to the largest chillers and heat pumps, including those for district cooling and heating. Individual
A life-cycle-cost analysis revealed that the combined GSA regions would save nearly half a billion dollars over 15 years in electricity costs with a hypothetical 30 % increase in chiller efficiency. The largest savings were apparent for GSA regions 2, 4, 7
Li Piin Sung, Silvia Vicini, D L. Ho, L Hedli, C Olmstead, Kurt Wood
This paper presents research results on the relationships between the microstructure and the performance/weatherability of fluoropolymer/acrylic coatings. We studied fluoropolymer/acrylic blends of identical composition, prepared as films using three
In receent years many individuals and organizations have advocated the use of several ventilation-based strategies to protect building occupants from accidental and intentional releases of airborne chemical, biological and radiological (CBR) agents. For
The paper presents a comparable evaluation of isobutane (R600a), propane (R290), R134a, R22, R410A, and R32 in an optimized finned-tube evaporator, and analyzes the impact of evaporator effects on the system coefficient of performance. The study relied on
Rick D. Davis, Jeffrey W. Gilman, Anthony J. Bur, M M. McBrearty, P R. Start, Young J. Lee
Dielectirc spectroscopy was conducted during extrusion processing of polyamide-6 (PA6) and layered silicate/polyamide-6 manocomposites. Dielectric dispersion parameteers were identified that appear sensitive to layered silicate concentration and degree of
Rodney A. Bryant, Thomas J. Ohlemiller, Erik L. Johnsson, Anthony P. Hamins, B S. Grove, William F. Guthrie, Alexander Maranghides, George W. Mulholland
The 3 Megawatt Heat Release Rate Facility was developed at NIST as a first step toward having broad capabilities for making quantitative large scale fire measurements. Such capabilities will be used at NIST to validate fire models and to develop sub-grid
The paper presents a comparable evaluation of isobutane (R600a), propane (R290), R134a, R22, R410A, and R32 in an optimized finned-tube evaporator, and analyzes the impact of evaporator effects on the system coefficient of performance (COP). The study
Francine K. Amon, Anthony P. Hamins, Jungho Kim, Vytenis Benetis
The Building and Fire Research Laboratory (BFRL) at the National Institute of Standards and Technology (NIST) is developing a new bench-scale testing facility and methods to evaluate the performance of thermal imagers used by fire fighters to search for
The impact of a single water droplet upon a polished stainless steel surface was imaged using a Digital High Speed Camera at 500, 1000, and 15,000 frames per second with shutter speed set to 50 s. The camera was fitted with a 60 mm micro lens to obtain the