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Displaying 1351 - 1375 of 3839

Load-Displacement Relations for Nanoindentation of Viscoelastic Materials

August 2, 2006
Author(s)
Chien-Kuo Liu, S H. Lee, Li Piin Sung, Tinh Nguyen
A model based on the Burgers viscoelastic concept has been developed to describe the nanoindentation behaviors of polymeric materials. An analytical solution of displacement at the indenter tip has been derived based on the analog of the governing equation

Addressing Security in the Early Stages of the Project Life Cycle

August 1, 2006
Author(s)
Benjamin Matthews, Jonathan Sylvie, Edd Gibson, Stephen R. Thomas, Robert E. Chapman, Sang-Hoon Lee
This article summarizes the first phase of a three-phase research effort to develop and deploy best practices for project security on industrial projects. It shows how to address security early in the project life cycle and its impacts on the capital

Measurement of 100 nm and 60 nm Particle Standards by Differential Mobility Analysis

August 1, 2006
Author(s)
George W. Mulholland, Michelle K. Donnelly, Robert C. Hagwood, S R. Kukuck, Vincent A. Hackley, D Y. Pui
The peak particle size and expanded uncertainties (95 % confidence interval) for two new particle calibration standards are measured as 101.60 nm ? 1.02 nm and 60.68 nm ? 0.59 nm. The particle samples are polystyrene spheres suspended in filtered

MEMS Sensors for HVAC&R: Small, Fast, Cheap (in Polish)

August 1, 2006
Author(s)
David A. Yashar, Piotr A. Domanski
Microelectronic mechanical systems (MEMS) have revolutionized the market for sensors by providing small, fast-responding measurement devices at low cost. They have been widely accepted in several common products. As an example, today's automobile uses

R-22 Replacement Status (In Spanish)

August 1, 2006
Author(s)
J M. Calm, Piotr A. Domanski
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

Screening Candidates for 30 nm Spheres

August 1, 2006
Author(s)
Michelle K. Donnelly, Jiann C. Yang
This paper describes the preliminary screening process that was conducted to identify potential candidate particles to be used as the NIST Standard Reference Material (SRM) 30 nm spheres. Five different samples were obtained and measured using the NIST

Cement Hydration: Building Bridges and Dams at the Microstructure Level

July 12, 2006
Author(s)
Dale P. Bentz
The concurrent goals of cement hydration are to percolate (bridge) the original cement particles into a load-bearing network and to depercolate (dam) the original water-filled capillary porosity. The initial volume, particle size distribution, and

Certification of SRM 114q: Part I

June 14, 2006
Author(s)
Chiara F. Ferraris, William F. Guthrie, A Aviles, Robin K. Haupt, Bruce S. MacDonald
The standard reference material (SRM) for fineness of cement, SRM 114, is an integral part of the calibration material routinely used in the cement industry to qualify cements. Being a powder, the main physical properties of cement, prior to hydration, are

Certification of SRM 114q: Part II

June 14, 2006
Author(s)
Chiara F. Ferraris, Max A. Peltz, William F. Guthrie, A Aviles, Robin K. Haupt, Bruce S. MacDonald
The standard reference material (SRM) for fineness of cement, SRM 114, is an integral part of the calibration material routinely used in the cement industry to qualify cements. Being a powder, the main physical properties of cement, prior to hydration, are

Feasibility on Using a Concrete Mixing Truck as a Rheometer

June 14, 2006
Author(s)
S Amziane, Chiara C. Ferraris, E Koehler
Fresh concrete properties are crucial for the performance of the concrete in its hardened state. The measurement of workability is usually done using a simple slump test. This test, although widely used for almost 100 years, does not provide a full picture

NIST Station Nightclub Fire Investigation: Physical Simulation of the Fire

June 1, 2006
Author(s)
Daniel M. Madrzykowski, Nelson P. Bryner, Stephen Kerber
A fire occurred on the night of February 20, 2003, at The Station Nightclub located in West Warwick, Rhode Island. A band that was performing that night, during its performance, used pyrotechnics that ignited foam insulation lining the walls and part of
Displaying 1351 - 1375 of 3839