model solutions
Recently Published Documents


TOTAL DOCUMENTS

489
(FIVE YEARS 95)

H-INDEX

44
(FIVE YEARS 5)

2022 ◽  
Vol 56 (3) ◽  
pp. 41-55
Author(s):  
Daria Bręczewska-Kulesza

The article focuses on issues demonstrating the role of architecture in the development of Prussian psychiatry in the nineteenth and the early twentieth century. The Provincial Treatment and Care Institution Allenberg (now Znamensk, Russian Federation) is used as a case study to demonstrate the perception of model solutions used in Prussian asylums located in distant provinces. The asylum discussed in this article met the contemporary requirements, proving that these models and newest trends reached East Prussia very quickly. The asylum complex in Allenberg was a testimony to the development of Prussian and European architectural thought in the service of medicine. Unfortunately, today the former asylum remains in a poor condition and is treated as unwanted legacy rather than a cultural monument.


Author(s):  
Р.Р. Зиннатуллин ◽  
А.И. Искандаров ◽  
Л.А. Ковалева

The dynamics of the interfacial tension coefficient at the interface between water and model solutions of asphaltenes of different concentrations in toluene has been studied. It has been shown that, over time, the interfacial tension decreases due to the adsorption of asphaltene molecules at the interface. With an increase in the concentration of asphaltenes in the solution, the decrease in interfacial tension occurs more intensively. The results of a study of the elongation of a water drop in a solution under the influence of an electric field are presented. It is shown that after the formation of an adsorption film, a higher stress must be applied to stretch the droplet, and the relative elongation depends nonlinearly on the applied stress. The studies were carried out using the suspended drop method.


Author(s):  
Amber L. Puha ◽  
Amy R. Ward

We describe a fluid model with time-varying input that approximates a multiclass many-server queue with general reneging distribution and multiple customer classes (specifically, the multiclass G/GI/N+GI queue). The system dynamics depend on the policy, which is a rule for determining when to serve a given customer class. The class of admissible control policies are those that are head-of-the-line (HL) and nonanticipating. For a sequence of many-server queues operating under admissible HL control policies and satisfying some mild asymptotic conditions, we establish a tightness result for the sequence of fluid scaled queue state descriptors and associated processes and show that limit points of such sequences are fluid model solutions almost surely. The tightness result together with the characterization of distributional limit points as fluid model solutions almost surely provides a foundation for the analysis of particular HL control policies of interest. We leverage these results to analyze a set of admissible HL control policies that we introduce, called weighted random buffer selection (WRBS), and an associated WRBS fluid model that allows multiple classes to be partially served in the fluid limit (which is in contrast to previously analyzed static priority policies).


Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2391
Author(s):  
Lyudmila V. Bel’skaya ◽  
Elena A. Sarf ◽  
Denis V. Solomatin

The aim of this study was to analyze the possibility of simultaneous determination of the concentration of components from the characteristics of FTIR spectra using the example of a model blood serum. To prepare model solutions, a set of freeze-dried control sera based on bovine blood serum was used, certified for approximately 38 parameters. Based on the values of the absorbance and areas of absorption bands in the FTIR spectra of model solutions, a regression equation was constructed by solving a nonlinear problem using the generalized reduced gradient method. By using the absorbance of the absorption bands at 1717 and 3903 cm−1 and the areas of the absorption bands at 616, 3750, and 3903 cm−1, it is possible to simultaneously determine the concentrations of 38 components with an error of less than 0.1%. The results obtained confirm the potential clinical use of FTIR spectroscopy as a reagent-free express method for the analysis of blood serum. However, its practical implementation requires additional research, in particular, analysis of real blood serum samples and validation of the method.


2021 ◽  
Vol 19 (3(75)) ◽  
pp. 40-46
Author(s):  
Olena O. Mamina ◽  
Volodymyr I. Kabachny ◽  
Nataliia Yu. Bondarenko ◽  
Olena V. Lozova

Aim. To develop the unified method of the HPLC analysis of loratadine, which can allow obtaining reliable and reproducible results of the studies of pharmaceuticals and biological matrices for monitoring the treatment effectiveness.Materials and methods. The HPLC analysis was performed on a “Milichrome A-02” microcolumn liquid chromatograph under the following conditions: a reversed-phase variant, 2 × 75 mm column filled with a non-polar sorbent Prontosil 120-5 C18 AQ, 5 μm; the mobile phase in the mode of a linear gradient – from eluent А (5 % of acetonitrile and 95  % of a buffer solution) to eluent B (100 % of acetonitrile) for 40 min. The flow rate of the mobile phase was 100 μL/min; the injection volume was 4 μL. The multichannel detection of the substance was carried out using an UV-detector at 210, 220, 230, 240, 250, 260, 280 and 300 nm; the optimal value of the column temperature was 37 – 40 °С, and the pump pressure was 2.8 – 3.2 MPa.Results and discussion. As a result of the studies performed, the retention parameters of loratadine and spectral relationships were determined using the unified HPLC method. This made it possible to include the results obtained in the database for the identification of antihistamines in the therapeutic monitoring of the treatment with an individual drug or in the complex treatment of allergic reactions. The development of the quantitative determination of loratadine by HPLC on model solutions using various concentrations of the drug was carried out. The content of loratadine was determined by the equation S = 1.14 × 10-3C – 0.50 × 10-4; the correlation coefficient was 0.9998. It was found that the relative standard deviation RSD did not exceed 0.93 % when analyzing loratadine in the model solutions by HPLC.Conclusions. The identification and the quantitative determination of loratadine by the unified HPLC method have been conducted. The method allows obtaining reliable and reproducible research results. The results of the studies can be recommended for implementation in the practice of forensic bureaus, toxicological centers, and clinical laboratories.


2021 ◽  
Vol 39 (2) ◽  
Author(s):  
Osvaldo Osuna ◽  
Jose Geiser Villavicencio Pulido

We analyze the evolution of an infectious disease if infectious individuals are treated or isolated. The analysis of the model shows catastrophic scenarios for the population in which bringing R0 below 1 is not enough to decrease the number of infectious individuals. Finally, we show three scenarios for the behavior of the model solutions in which multiple endemic equilibria exist.


Sign in / Sign up

Export Citation Format

Share Document