1,194 research outputs found
From Taub Numbers to the Bondi Mass
Taub numbers are studied on asymptotically flat backgrounds with Killing
symmetries. When the field equations are solved for a background spacetime and
higher order functional derivatives (higher order variational derivatives of
the Hilbert Lagrangean) are solved for perturbations from the background, such
perturbed space-times admit zeroth, first, and second order Taub numbers.
Zeroth order Taub numbers are Komar constants (upto numerical factors) or
Penrose-Goldberg constants of the background. For a Killing symmetry of the
background, first order Taub numbers give the contribution of the linearized
perturbation to the associated backgound quantity, such as the perturbing mass.
Second order Taub numbers give the contribution of second order perturbations
to the background quantity. The Bondi mass is a sum of first and second order
Taubs numbers on a Minkowski background.Comment: To appear in the proceedings of the 8th Marcel Grossmann Conferenc
Radiation effects on silicon Quarterly progress report, 1 Jul. - 30 Sep. 1966
Electrical conductivity and electron spin resonance experiments in study of radiation effects on silico
Ceftazidime: pharmacokinetics in young volunteers versus elderly patients and therapeutic efficacy with complicated urinary tract infections
Thirty-six urological patients (21 male, 15 female) aged 21 to 83 years with complicated and/or hospital-acquired urinary tract infections due to sensitive bacteria were treated with ceftazidime intravenously with a daily dose of 2 g bd over 5 to 17 days. Twenty-seven patients were followed for 1 to 4 weeks after therapy. Cure was observed in 41%, reinfection in 33% and relapse in 26% of the patients. Eradication of the original pathogen occurred in 74%. Five patients showed minor side effects: diarrhoea (2), nausea (1), rash (1), headache (1). No signs of renal, hepatic or haematological toxicity were observed. A pharmacokinetic study was performed in 13 elderly patients aged 63 to 83 years on day 1 of treatment and in 6 volunteers aged 24 to 32 years following administration of 2 g of ceftazidime as short intravenous infusion. The mean serum half life in 12 patients 2.9 h significantly higher than in volunteers (1.75 h). Serum concentrations in patients on day 7 of treatment, however, showed no accumulation when treated with a dosage of 2 g bd
Radiation effects on silicon Sixth quarterly progress report, Apr. 1 - Jun. 30, 1966
Radiation effects on high purity n-type silicon solar cell
Radiation effects on silicon Summary report 1 Nov. 1965 - 20 Apr. 1967
Radiation-induced displacement effects measured in n and p type, low and high resistivity silico
Pharmacokinetics, in-vitro activity, therapeutic efficacy and clinical safety of aztreonam vs. cefotaxime in the treatment of complicated urinary tract infections
The minimal inhibitory concentrations (MICs) of aztreonam and cefotaxime were determined against 400 isolates from urological in-patients with complicated and/or hospital acquired urinary tract infections (UTI). Against the Gram-negative rods the activities of both antibiotics were comparable except for higher activity of aztreonam against Pseudomonas aeruginosa. The pharmacokinetic study in nine elderly patients showed a prolonged plasma half life of aztreonam (2.7 h) as compared to younger volunteers (1.6-1.9 h). In a prospective randomized study 39 urological patients with complicated and/or hospital acquired UTI were treated with 1 g aztreonam or cefotaxime iv twice daily for 4 to 15 days. Cure was obtained in 5 out of 18 patients in the aztreonam and 7 out of 20 patients in the cefotaxime group. There were 3 superinfections, 7 relapses and 3 reinfections in the aztreonam group and 1 failure, 1 superinfection, 6 relapses and 5 reinfections in the cefotaxime group. There was no significant difference in therapeutic efficacy between the two antibiotics. Both antibiotics were tolerated well and seem to be equally effective in the treatment of complicated UTI caused by sensitive organisms
High-performance liquid chromatography analysis of mezlocillin, piperacillin, their degradation products, and of ioxitalamic acid in plasma and urine of healthy volunteers
In plasma and urine of 10 healthy volunteers after intravenous administration of 4 g mezlocillin and piperacillin, respectively, the parent compounds as well as degradation products were assayed by high-performance liquid chromatography. Ioxitalamic acid, a renal contrast medium, was administered simultaneously, in order to measure the glomerular filtration rate, and to control the collection of 24-h urine. As metabolite of mezlocillin the corresponding penicilloic acid only was found, whereas in the case of piperacillin a further degradation product was observed. Half of the doses given was recovered in the urine as unchanged drugs, and in addition 5-10% as metabolites. No differences were found in the pharmacokinetic behaviour of both antibiotics
Time fractional Schrodinger equation
The Schrodinger equation is considered with the first order time derivative
changed to a Caputo fractional derivative, the time fractional Schrodinger
equation. The resulting Hamiltonian is found to be non-Hermitian and non-local
in time. The resulting wave functions are thus not invariant under time
reversal. The time fractional Schrodinger equation is solved for a free
particle and for a potential well. Probability and the resulting energy levels
are found to increase over time to a limiting value depending on the order of
the time derivative. New identities for the Mittag-Leffler function are also
found and presented in an appendix.Comment: 23 page
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