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Selected Works

1991

Discipline
Institution
Keyword
Publication
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Articles 31 - 35 of 35

Full-Text Articles in Engineering

The Added Mass, Basset, And Viscous Drag Coefficients In Nondilute Bubbly Liquids Undergoing Small-Amplitude Oscillatory Motion, Ashok S. Sangani, D. Z. Zhang, A. Prosperetti Jan 1991

The Added Mass, Basset, And Viscous Drag Coefficients In Nondilute Bubbly Liquids Undergoing Small-Amplitude Oscillatory Motion, Ashok S. Sangani, D. Z. Zhang, A. Prosperetti

Ashok S. Sangani

The motion of bubbles dispersed in a liquid when a small-amplitude oscillatory motion is imposed on the mixture is examined in the limit of small frequency and viscosity. Under these conditions, for bubbles with a stress-free surface, the motion can be described in terms of added mass and viscous force coefficients. For bubbles contaminated with surface-active impurities, the introduction of a further coeflicient to parametrize the Basset force is necessary. These coefficients are calculated numerically for random configurations of bubbles by solving the appropriate multibubble interaction problem exactly using a method of multipole expansion. Results obtained by averaging over several …

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Fluorescent Molecular Probe Technique For Assessing The Interaction Between Sulfonated Polystyrene And Poly(Ethyl Acrylate-Co-4-Vinylpyridine) Ionomers In Tetrahydrofuran, William Macknight, Kirill N. Bakeev Dec 1990

Fluorescent Molecular Probe Technique For Assessing The Interaction Between Sulfonated Polystyrene And Poly(Ethyl Acrylate-Co-4-Vinylpyridine) Ionomers In Tetrahydrofuran, William Macknight, Kirill N. Bakeev

William MacKnight

The interaction between sulfonated polystyrene (SPS) and poly(ethy1 acrylate-eo-4-vinylpyridine)
(EtAc4VP) ionomers was investigated over a wide range of concentrations in the nonpolar solvent,
tetrahydrofuran (THF), using a fluorescent molecular probe technique. The acid-base interaction between
the sulfonate groups of SPS and the pyridine groups of EtAcVP and the miscibility of these ionomers are
evident for pyridine contents of 7.8 and 4.5 mol 5% in EtAc4VP and are not detectable for EtAc4VP with
1.7 mol % pyridine groups. Concentration-dependent excimer fluorescence from SPS and EtAc4VP mixtures
indicates the occurrence of polar interactions as a result of proton transfer from the styrenesulfonic …

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Mechanism Of The Dicyandiamide/Epoxide Reaction, William Macknight, Michael D. Gilbert, Nathan S. Schneider Dec 1990

Mechanism Of The Dicyandiamide/Epoxide Reaction, William Macknight, Michael D. Gilbert, Nathan S. Schneider

William MacKnight

A mechanism is proposed for the dicyandiamide (dicy) cure of epoxy resins based on the
analysis of products formed by the reaction of a monofunctional epoxide with dicy and with cyanamide.
Products were isolated from the uncatalyzed reaction mixtures using preparatory liquid chromatography and
were characterized by FTIR, NMR, mass spectrometry, and elemental analysis. Both linear dicy/epoxide
adducts and cyclical species were identified and the mechanism of the cyclization reaction was delineated.
A mechanism for carbonyl generation during the later stages of cure was also found.

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Thermal, Dielectric, And Mechanical Relaxation In Poly(Benzimidazole)/Poly(Etherimide) Blends, William Macknight, Kuiming Liang, Gyorgy Banhegyi, F. E. Karasz Dec 1990

Thermal, Dielectric, And Mechanical Relaxation In Poly(Benzimidazole)/Poly(Etherimide) Blends, William Macknight, Kuiming Liang, Gyorgy Banhegyi, F. E. Karasz

William MacKnight

Thermal, dielectric, and mechanical relaxation measurements on miscible blends of poly-
benzimidazole(PBI)and a polyetherimide (PEI, Ultem 1000)prepared by solution casting
from dimethylacetamide (DMAc) reveal a number of structurally related features. Annealing
below the glass transition temperature induces an enthalpy relaxation process typical of
single-phase glasses of nonequilibrium structure. Dielectric relaxation experiments on
samples annealed at ambient conditions reveal two relaxation processes below 400°C.At
lower temperatures (50-2OO0C), the desorption of water is observed. Above 200°C in the
first run, a composition-dependent relaxation is seen at the highest frequencies ( 100 kHz)
while a relaxation approximately independent of composition appears in the …

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A Method Of Validating Mw Mvar Values, Venkateswar P. Oruganti Fiete Fie Pmp Dec 1990

A Method Of Validating Mw Mvar Values, Venkateswar P. Oruganti Fiete Fie Pmp

Venkateswar P Oruganti FIETE FIE PMP

A way of quickly validating MW MVAR values. This method helps in reducing number of combinations while trying to ascertain the right connections at the transducers in SCADA systems.

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