Now showing items 51-60 of 483
A convenient synthesis of substituted [gamma]-pyrones
(Elsevier, 1980)
An efficient and general synthetic method for various 2-mono- and 2,6-disubstituted [gamma]-pyrones has been developed. This utilizes the -acylation (70-85%) of [beta]-methoxy-[alpha],[beta]-enone lithium enolates by acid ...
Exciton transport in naphthalene alloys: A transition from percolation to diffusion
(Elsevier, 1982-12-03)
Steady-state singlet excitation transport in ternary naphthalene crystals (C10H8/C10D8/[beta]-methylnaphthalene) fits diffusion models at 4.2 K, but not at 1.8 K, where it fits a percolation model.
Emulsion stability: Determination from turbidity
(Elsevier, 1981-01)
A novel technique for studying the stability of emulsions has been developed. Owing to the fact that emulsion turbidity is a function of particle concentration and size, the stability of emulsions can be determined by ...
Supercritical fluid jet expansions of polar aromatic carboxylic acids using simple derivatization with detection by resonant two-photon ionization
(Elsevier, 1988)
In this work simple derivatization is used as a means of enhancing the solubility of polar aromatic carboxylic acids in supercritical CO2 and N2O. The supercritical fluid is then expanded from 200 atm and 40[deg]C through ...
Mechanism of cholesterol gallstone dissolution. II. Correlation between the effect of the alkyl amines as cholesterol gallstone dissolution rate accelerators and the degree of binding of the alkyl amines to the bile acid micelles
(Elsevier, 1980-03)
Recent studies have shown that cholesterol monohydrate pellet dissolution rates in real and synthetic bile systems are enhanced dramatically in the presence of small concentrations of amines, quaternary ammonium compounds, ...
Dynamics of growth of silica particles from ammonia-catalyzed hydrolysis of tetra-ethyl-orthosilicate
(Elsevier, 1988-07)
The NH3-catalyzed formation of colloidal silica particles from tetra-ethyl-orthosilicate (TEOS) in methanol and ethanol is studied by means of light scattering and Raman spectroscopy. We find that the growth is characterized ...
Vibrational analysis of peptides, polypeptides, and proteins. XVIII. Conformational sensitivity of the Α-helix spectrum: Α I - and Α II -Poly( L -alanine)
(Wiley Subscription Services, Inc., A Wiley Company, 1984-05)
The Α II -helix (φ = −70.47°, Ψ = −35.75°) is a structure having the same n and h as the (standard) Α I -helix (φ = −57.37°, Ψ = −47.49°). Its conformational angles are commonly found in proteins. Using an improved ...
Thermophysics of metal alkanoates III. Heat capacities and thermodynamic properties of lithium and potassium propanoates
(Elsevier, 1984-01)
At 298.15 K, the values of Cp, m/R, Smo/R, {Hmo - Hmo(0)}/R, and {Gmo - Hmo(0)}/RT ar 15.58, 17.13, 2588.6 K, and -8.445 for CH3CH2CO2Li(cr), and 17.30, 21.16, 3134.0 K, and -10.647 for CH3CH2CO2K(cr). The energetics and ...
Potentiometric ion- and bio-selective electrodes based on asymmetric cellulose acetate membranes
(Elsevier, 1989)
The potentiometric response properties of ammonium-, carbonate-, and proton-selective electrodes prepared by incorporating appropriate neutral carriers within novel asymmetric cellulose acetate membranes are reported. The ...