Universal algebra [5, 9, 4] is the theory of equalities t = u. It is a simple framework within which we can study mathematical structures, for example groups, rings, and fields. It has also been applied to study the mathematical properties of mathematical truth and computability. For example boolean algebras correspond to classical truth, heyting algebras correspond to intuitionistic truth, cyl...

Messenger RNA extracted from the erythroleukemic cell line K562 was translated in vitro and the translation products reacted with an antiserum raised against human erythrocyte ghosts. Polypeptides immunoprecipitated by the antiserum were characterized by SDS-polyacrylamide gel electrophoresis and fluorography. The antiserum immunoprecipitated polypeptides with nominal molecular weights of 37,00...

Nominal unification is a generalisation of first-order unification that takes α-equivalence into account. In this paper, we study nominal unification in the context of equational theories. We introduce nominal narrowing and design a general nominal E-unification procedure, which is sound and complete for a wide class of equational theories. We give examples of application. 1998 ACM Subject Clas...

Robust performance controller design for duty-cycle controlled series resonant converter (SRC) is proposed in this paper. The uncertainties of the converter are analyzed with load variation and power circuit components tolerances are taken into consideration. Additionally, a nominal performance (NP) controller is designed. Closed-loop system is simulated with Orcad and simulation results of r...

The aim of this study was to device in house a suitable absorption filter for colorimetric analyses. An absorption filter was so constructed using 40% CuSO4.5H2O solution in 8M HCl (w/v) in glass support of 2mm internal diameter. The filter was found to have a nominal wavelength of 540±0.92nm, spectral bandwidth of 41±0.82nm and a peak transmittance of 36±0.40%. The filter offered a sensitivity...

The photocatalytic behaviour of a series of ammonium fluoride (NH(4)F)-doped titania (TiO(2)) photocatalysts was investigated in the decomposition of acetic acid in aqueous suspensions and in the gas phase mineralization of acetaldehyde. Very similar photocatalytic activity trends, usually increasing with increasing the calcination temperature for a given nominal dopant amount, were obtained fo...

Individual fluid inclusions in quartz were investigated by synchrotron radiation X-ray fluorescence (SXRF) microprobe to develop protocols for major-element microanalysis. Studies were conducted of synthetic fluid inclusions in Brazilian quartz that contain fluids of known NaC1-CaC12-H20 and KCI-H20 compositions. Inclusions were irradiated by synchrotron X-rays and the resulting energy-dispersi...