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B N. Hansen, Allan H. Harvey, J P. Coelho, M F. Palavra, Thomas J. Bruno
We measured the solubilities of Β-carotene and capsaicin in supercritical carbon dioxide, and also in difluoromethane (R-32) and 1,1,1,2-tetrafluoroethane (R-134a) in the liquid phase at temperatures near and somewhat below their critical points. Β
A technique is described for the measurement of fluid temperatures in microfluidic systems based on temperature-dependent fluorescence. The technique is easy to implement with a standard fluorescence microscope and CCD camera. In addition, the method can
For a binary mixture of a dilute nonvolatile solute in a volatile solvent, an asymptotic expression is derived for isothermal dew-bubble curves in the region just above the solvent critical point. The expression depends only on the solvent coexistence
A recent workshop at the National Institute of Standards and Technology (NIST) identified research and standards that will benefit users and manufacturers of mass flow controllers and related equipment. The workshop identified problems with flow
We used a novel toroidal cross capacitor to measure accurately the dielectric polarizability e(p) (i.e., the dielectric constant) of helium, argon, nitrogen, methane, and carbon dioxide at T = 50 degrees C. The data extend up to 7 MPa (5 MPa for CO 2) and
Mixing of fluids is a central component to innumerable operations in chemical processing on the plant floor and also in many laboratory operations. Most mixing applications simply require the efficient blending of fluids present in a single phase, such as
We explore the use of evanescent wave cavity ring-down spectroscopy (EW-CRDS) for water detection through a signal-to-noise ratio analysis. Cavity ring-down spectroscopy (CRDS) is an emerging optical absorption technique that employs the mean photon decay
We report measurements and a model of gas flow through a helical duct of rectangular cross section. The measurements on helium, nitrogen, argon, and sulfur hexafluoride yielded molar flow rates from observations of the rate of rise of pressure in a known
On 15-16 May 2000 at NIST, 45 scientists and engineers met to identify research and standards that will benefit users and manufacturers of mass flow controllers (MFCs) and related equipment. Most attendees represented companies closely associated with the
S L. Barker, David J. Ross, Michael J. Tarlov, Michael Gaitan, Laurie E. Locascio
Electroosmotic flow (EOF) is commonly utilized in microfluidics. Because the direction of the EOF can be determined by the substrate surface charge, control of the surface chemical state offers the potential, in addition to voltage control, to direct the
The air flow through a vane-cascade swirl generator is examined both experimentally and numerically to characterize the inlet combustion air flow entering a reference spray combustion facility at NIST. A three-dimensional model is used to simulate the
Vapor-liquid equilibria for the title system indicate azeotropic behavior with the composition of the azeotrope shifting from being benzene-rich at low pressure to isopropanol-rich at high pressure. We attribute this behavior to the nature of the Bancroft
Commonly used primary calibration techniques for the measurement of liquid and gas flows are described. The techniques described include: static gravimetric and dynamic gravimetric methods for both gases and liquids, liquid piston displacement provers