Polarographic Investigations of Some Metal Monocarhoxylato Complexes. III. Monocarhoxylato Complexes of Cadmium and Copper

The stability constants of cadmium and copper monocarboxylato complexes have been determined by the polarog raphic method in water solutions of a constant ionic strength 2 and a constant monocarboxylic acid concentration of 2 M. The examinations were carried out in the monocarboxylate concentration range up to 2 M. The following values of cumulative stability constants were obtained: Cadmium : formato complexes ~ 1 = 20 ± 2, ; Be = 50 ± 5, p3 = 40 ± 8, p4 = 36 ± 8; acetato complexes P1 = 40±5, B2 = 110±10, p3 = 110 ± 15, p4 = 215 ± 20; propionato complexes P1 = 30 ± 2, B2 = 80 ± 20, Ps = 400 ± 50, p4 = 290 ± 30; butyrato complexes P1 = 17 ±,2, B2 = 160 ± 20 , Bs = 400 ± 50, B4 = 480 ± 60. Copper: formato complexes p1 = 45 ± 5, Bo.= 200 ± 30, ~ 3 = = 200 ± 40 , B4 = 270 ± 40; acetato complexes Bi = 100 ± iO , B2 = 500 + 50, B3 = 1000 + 100 , P4 = 1250 + 200; propionato complexes Bi= l.10 ± 10, B2 = 450 ± 50, Ba = 1100 ± 200 , B4 = 1100 ± 200, B; = 950 ± 200; butyrato complexes B1 = 80 ± 10, P2 = 600 ± 100 , Ba = 2000 ± 300, B4 = 1700 ± 300, Ps = 2000 ± 300

Inhibitory Effect of Amines on Polarographic Processes in Acid. Solution. I. D. C. Polarographic and Oscillopolarographic Investigation

The influence of some amines as capillary active substances and as corrosion inhibitors in acid solution was studied by the conventional d. c. polarographic method and oscillopolarographically. The electrode processes of thallium, cadmium, lead, zinc and bismuth have served as indicators of the inhibitor efficiency. The inhibition of the electrode processes, resulting in a decrease of the limiting current and in the shift of the half-wave potential toward more negative values as well as in a deminution of the corresponding incision on the oscillopolarographic curve, was found to increase, generally, in the order: methylamine < n-butylamine <pyridine< < aniline < quinoline < a-naphthylamine. Since the same sequence was found for the inhibition of corrosion processes, it can be concluded that the cited effects are suited for the evaluation of the inhibiting efficiency of amines in acid solutions

On the Existence of the Logarithmic Correction Term in Black Hole Entropy-Area Relation

In this paper we consider a model universe with large extra dimensions to obtain a modified black hole entropy-area relation. We use the generalized uncertainty principle to find a relation between the number of spacetime dimensions and the presence or vanishing of logarithmic prefactor in the black hole entropy-area relation. Our calculations are restricted to the microcanonical ensembles and we show that in the modified entropy-area relation, the microcanonical logarithmic prefactor appears only when spacetime has an even number of dimensions.Comment: 9 Pages, No Figure

Symmetries at stationary Killing horizons

It has often been suggested (especially by Carlip) that spacetime symmetries in the neighborhood of a black hole horizon may be relevant to a statistical understanding of the Bekenstein-Hawking entropy. A prime candidate for this type of symmetry is that which is exhibited by the Einstein tensor. More precisely, it is now known that this tensor takes on a strongly constrained (block-diagonal) form as it approaches any stationary, non-extremal Killing horizon. Presently, exploiting the geometrical properties of such horizons, we provide a particularly elegant argument that substantiates this highly symmetric form for the Einstein tensor. It is, however, duly noted that, on account of a "loophole", the argument does fall just short of attaining the status of a rigorous proof.Comment: 11 pages, Revte

Double-Layer Effect in the Polarographic Reduction of Vanadate

The effect of inert electrolytes on the polarographic reduction of metavanadate ions is studied in neutral solutions, buffered and unbuffered. The effect of the nature of the cation and anion of the supporting electrolyte, as well as the effect of the ionic and buffer strength on the shape of the polarographic wave is in accordance with modern theories of the mechanism of the reduction of negative ions at the dropping mercury electrode. An accelerating action in the series Li+ < Na• < Cs+, and Na+ < < Ca2+, and of anions: r, SCN- < c1- <No; <ClO~ <SO!- < < F- is found. A combined influence of the cation and anion is established as well. The inhibition, occurring at the beginning of the electrode reaction and observed in the form of a small prewave on the polarographic wave is described

Nontrival Cosmological Constant in Brane Worlds with Unorthodox Lagrangians

In self-tuning brane-world models with extra dimensions, large contributions to the cosmological constant are absorbed into the curvature of extra dimensions and consistent with flat 4d geometry. In models with conventional Lagrangians fine-tuning is needed nevertheless to ensure a finite effective Planck mass. Here, we consider a class of models with non conventional Lagrangian in which known problems can be avoided. Unfortunately these models are found to suffer from tachyonic instabilities. An attempt to cure these instabilities leads to the prediction of a positive cosmological constant, which in turn needs a fine-tuning to be consistent with observations.Comment: 17 pages, 1 figur

Delocalization of brane gravity by a bulk black hole

We investigate the analogue of the Randall-Sundrum brane-world in the case when the bulk contains a black hole. Instead of the static vacuum Minkowski brane of the RS model, we have an Einstein static vacuum brane. We find that the presence of the bulk black hole has a dramatic effect on the gravity that is felt by brane observers. In the RS model, the 5D graviton has a stable localized zero-mode that reproduces 4D gravity on the brane at low energies. With a bulk black hole, there is no such solution -- gravity is delocalized by the 5D horizon. However, the brane does support a discrete spectrum of metastable massive bound states, or quasinormal modes, as was recently shown to be the case in the RS scenario. These states should dominate the high frequency component of the bulk gravity wave spectrum on a cosmological brane. We expect our results to generalize to any bulk spacetime containing a Killing horizon.Comment: 7 pages, 6 figure