[en] The determination of Al³⁼ in solution using a continuous-wave mode mismatched thermal lens spectrometer is reported and two spectro-photometric procedures are compared. The reagent systems investigated were bromopyrogallol red-tetradecyltrimethylammonium bromide (BPR-TDTA) and chrome azurol S-cetylpyridinium chloride (CAS-CPC). The CAS-CPC system gave a superior detection limit (0.17 μg l^-1) to the BPR-TDTA system (1.15 mg l^-1) owing to the higher reagent blanks and concomitant laser noise in the latter system. (author). 24 refs.; 6 figs.; 2 tabs

[en] A method for the determination of chromium is presented, based on the oxidation of hydroxylamine hydrochloride to nitrous acid by chromium(VI) in acetic acid medium followed by diazotization of the nitrite produced with p-aminophenylmercaptoacetic acid and subsequent coupling of the diazonium salt with N-(1-naphthyl)ethylenediamine di-hydrochloride in acidic medium to form a stable blueish azo dye. The method is suitable for the determination of chromium(VI) from 0.04 to 1.2 mg l^-1 in a 1.0-cm cuvette. The molar absorptivity and Sandell's sensitivity are 3.65x10⁴ l mol^-1 cm^-1 and 0.0014μg cm^-2, respectively. (author). 17 refs.; 3 figs

[en] A method is reported for the spectrofotocolorimetric determination of iridium. This method is mores reproductible than the methods in current use

[en] A flow-injection spectrophotometric method for the determination of palladium involves the measurement of the absorbance of the palladium complex with DCS-arsenazo at 635 nm. The calibration graph is linear over the range 0-8.0 μg ml^-1. The detection limit is 0.05 μg ml^-1. The sample throughput is 90 h^-1 with 100-μl sample injections. The proposed method has been applied to the determination of palladium in metallurgical samples without preliminary simulation. (author). 7 refs.; 2 figs.; 3 tabs

[en] A fiber-optic sensor system is described for the on-line determination of bromide in spent brine. In this method, the bromide is selectively oxidized to bromine in a flow reactor containing a packed bed of chloramine-T; the optical absorption of the resulting bromine is then used for quantification. The technique exhibits a dynamic range from 20 to 5000 mg l^-1 bromide, provides continuous readout, is not affected by the presence of high concentrations of chloride and has a response time of about 2 min. (author). 13 refs.; 8 figs.; 1 tab

[en] Two-dimensional spectrophotometric observations of bipolar planetary nebulae were performed by using a CCD detector mounted at the Cassegrain focus of either 1.54 m Danish Telescope or 2.2 m German Telescope at La Silla (ESO) in Chile. Emission lines have been selected with the help of narrow band-pass interference filters (Δλ∼ 10 - 20 A). Isophotal maps in various lines Hα, [NII] λ 6584, [OIII] λ 5007 and [SII] λλ 6717-6731 are presented. Particular attention has been given to scrutinize the symmetries inside a few bipolar planetary nebulae, in order to subsequently investigate their space structure

[en] Twenty-six lightcurves of Psyche are presented together with UBV photometry and phase functions from 1975 and 1976. Combining photometric data from this opposition with those from previous apparitions resulted in a mean phase coefficient in V of 0.026 + or - 0.002 mag/deg. No significant phase-dependent variation in the U-B color could be determined from the data. The B-V color, however, displayed a reddening with phase of 0.0010 + or - 0.0004 mag/deg. It is concluded that compositional variations over Psyche's surface are minor, and that Psyche's opposition effect is typical of that for other well-observed asteroids. Psyche's behavior is accounted for if, to the first order, its shape is that of a triaxial ellipsoid with axial ratios near 5:4:3

[en] A method for the spectrophotometric determination of cobalt(II) is presented, with a comparison of the binary complexes formed by cobalt (II) with di-2-pyridyl ketone nicotinoylhydrazone (DPKNH), di-2-pyridyl ketone 2-thiophenoylhydrazone (DPKTH) and di-2-pyridyl ketone benzoyl-hydrazone (DPKBH) in 50% (v/v) ethanolic solution. Cobalt(II) forms 1:2 complexes with the three reagents. Maximum absorbance is at 372 nm for Co(II)-DPKNH, at 389 nm for Co(II)-DPKTH and at 370 nm for Co(II)-DPKBH. Ranges of linearity, effects of pH and excess reagent, sensitivity, stability of the complexes and tolerance limits of ions are reported. It was concluded that the system with DPKTH is the best, followed by DPKNH and then DPKBH. The method was applied to the determination of cobalt in different alloys. (author). 17 refs.; 1 fig.; 3 tabs

[en] The working conditions affecting the kinetics of formation of the complex between terephthalmonohydroxamic acid and manganese were studied and optimized and both classical kinetic determination methods and two new methods based on semi-logarithmic fittings of non-linear portions of absorbance-time curves and on theoretical equations describing the kinetics of the process were used for the determination of microgram amounts of manganese. The kinetic methods thus developed and the new equilibrium spectrophotometric method were applied to the determination of manganese in steels. (author). 15 refs.; 4 figs.; 4 tabs

[en] We have determined the B and V magnitudes for 149 central stars of planetary nebulae, 80 of which being given for the first time. The stellar continuum was measured on spectra taken at ESO, Chile, in a range of 400-740 nm with a resolution of about 1 nm