The determination of the rate constants for the dissociation and recombination of weak acids by High Level Faradaic Rectification

1964 ◽  
Vol 51 (8) ◽  
pp. 191-192 ◽  
Author(s):  
H. W. N�rnberg ◽  
G. C. Barker
2019 ◽  
Vol 24 (2) ◽  
pp. 145-149
Author(s):  
A. I. Musienko ◽  
K. I. Nesterova

Relevance. Rehabilitation of patients with moderate to severe generalized periodontitis is a leading problem in periodontology. It was the determination of the prospects for immediate implantation in patients with chronic periodontitis, combined with the pathology of the tooth root and maxillary sinus.Materials and methods. A group of 94 people with periodontitis and chronic odontogenic rhinosinus was observed who underwent sinus surgical treatment, tooth extraction and one-stage implantation with FRP growth factor according to the author's technology.Results. The method showed high efciency on the basis of assessing the clinical, aesthetic result and restoration of bone density after surgery.Conclusions. The developed technology is a promising direction, it allows to combine a high level of sanation of alveolar tissue with the advantages of immediate implantation, prevents bone atrophy, helps reduce the duration of treatment and the number of surgical and orthopedic interventions.


2020 ◽  
pp. 160-164
Author(s):  
Leonid Tsubov ◽  
Oresta Shcherban

The set of scientific-methodological tools to secure the mechanism of economic safety management of tourism entrepreneurship is examined as an aggregate of methods, tools, and conceptual activities directed at maintaining the high level of economic safety of tourism entrepreneurship. The features of managing the tourism enterprise and economic safety are analyzed. The basic valuation principles of the reliability and efficiency of the economic safety of the tourism enterprise are determined. The basic tasks of ensuring the economic safety of a small enterprise are outlined. The need to use the integrated approach that secures more opportunities to avoid threats and limits the danger of their emergence is emphasized. The most important principles for securing the economic safety of the tourism enterprise on the microeconomic level are described. Possible practical methods of risk management for the implementation of adopted decisions are proposed. The paper proves the fact that the complex nature of the management of the economic safety of the tourism enterprise and securing the sufficiently efficient management system of detecting and eliminating the threats are provided by the establishment of the management of the economic safety system of the tourism enterprise and its functional components. Research of the methodical approaches to the management of the tourism enterprises’ economic safety allows building and describing the functional structure of the mechanism of management of the tourist enterprise’s economic safety (it is formalized and described by 5 functions: determination of aims; planning; organization and adjusting; motivation and stimulation; control and monitoring).


1983 ◽  
Vol 48 (5) ◽  
pp. 1358-1367 ◽  
Author(s):  
Antonín Tockstein ◽  
František Skopal

A method for constructing curves is proposed that are linear in a wide region and from whose slopes it is possible to determine the rate constant, if a parameter, θ, is calculated numerically from a rapidly converging recurrent formula or from its explicit form. The values of rate constants and parameter θ thus simply found are compared with those found by an optimization algorithm on a computer; the deviations do not exceed ±10%.


1998 ◽  
Vol 63 (7) ◽  
pp. 955-966
Author(s):  
Eva Přibylová ◽  
Miroslav Holík

Four programs for the 1H NMR line shape analysis: two commercial - Winkubo (Bruker) and DNMR5 (QCPE 165) and two written in our laboratory - Newton (in Microsoft Excel) and Simtex (in Matlab) have been tested in order to get highly accurate rate constants of the hindered rotation about a single bond. For this purpose four testing criteria were used, two of them were also developed by us. As supplementary determinations the rate constants obtained for the coalescence temperature and for the thermal racemization of chromatographically separated enantiomers were used which fitted well the temperature dependence of the rate constants determined by the line shape analysis. As a test compound adamantan-1-yl 3-bromo-2,4,6-trimethylphenyl ketone was prepared and studied. It was shown that supermodified simplex method used in our algorithm (Simtex), though time consuming, gives the most accurate values of the rate constants and consequently the calculated thermodynamic parameters Ea, ∆H≠, and ∆S≠ lay in relatively narrow confidence intervals.


1999 ◽  
Vol 64 (11) ◽  
pp. 1770-1779 ◽  
Author(s):  
Herbert Mayr ◽  
Karl-Heinz Müller

The kinetics of the electrophilic additions of four diarylcarbenium ions (4a-4d) to tricarbonyl(η4-cyclohepta-1,3,5-triene)iron (1) have been studied photometrically. The second-order rate constants match the linear Gibbs energy relationship log k20 °C = s(E + N) and yield the nucleophilicity parameter N(1) = 3.69. It is concluded that electrophiles with E ≥ -9 will react with complex 1 at ambient temperature.


Biochemistry ◽  
1991 ◽  
Vol 30 (29) ◽  
pp. 7283-7297 ◽  
Author(s):  
Otto G. Berg ◽  
Bao Zhu Yu ◽  
Joe Rogers ◽  
Mahendra Kumar Jain

Author(s):  
Van-Hao Duong ◽  
Thanh-Duong Nguyen ◽  
Miklos Hegedus ◽  
Erika Kocsis ◽  
Tibor Kovacs

The determination of natural radionuclide concentrations plays an important role for assuring public health and in the estimation of the radiological hazards. This is especially true for high level radiation areas. In this study, 226Ra, 228Ra and 238U concentrations were measured in well waters surrounding eight of the high-level natural radiation areas in northern Vietnam. The 226Ra, 228Ra and 238U activity concentrations vary from <1.2 × 10−3–2.7 (0.46), <2.6 × 10−3–0.43 (0.07) and <38 × 10−3–5.32 Bq/L (0.50 of median), respectively. 226Ra and 238U isotopes in most areas are in equilibrium, except for the DT-Thai Nguyen area. The calculated radiological hazard indices are generally higher than WHO (World Health Organization) recommendations. Average annual effective dose and excess lifetime cancer risk values due to drinking well water range from to 130 to 540 μSv/year and 7.4 × 10−6 to 3.1 × 10−5, respectively.


1969 ◽  
Vol 52 (3) ◽  
pp. 438-441
Author(s):  
Glenn M George ◽  
A C Daftsios ◽  
Joseph L Morrison

Abstract The coccidiostat aklomide is extracted from feed with methanol and assayed colorimetrically by reduction of the nitro group to anamine with titanium trichloride and subsequent color development with t he Bratton-Marshall reaction. Thirteen laboratories studied the method collaboratively on two levels of medicated feed. Overall average recovery was 106.5% of the oretical for the low level and 104.5% of the oretical for the high level. The method is recommended for adoption as official first action


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