Chasing the Critical Wetting Transition. An Effective Interface Potential Method

Wettablity is one of the important characteristics defining a given surface. Here we show that the effective interface potential method of determining the wetting temperature, originally proposed by MacDowell and Müller for the surfaces exhibiting the first order wetting transition, can also be used to estimate the wetting temperature of the second order (continuous) wetting transition. Some selected other methods of determination of the wetting temperature are also discussed.

Methods of determination and extractants used in the isolation of platinum (review)

There is carried out a systematic review of the literature on methods for determining platinum (IV) ions and extractants used for their extraction in the article. The article considers chemical, physical, and physico-chemical methods of determination. Also, the authors of the article focused on selective and sensitive spectroscopic methods. There are considered several groups of such reagents and extractants as organophosphorus (tributyl phosphate, di-2-ethylhexylphosphoric acid) diphenylthiourea, high-molecular aliphatic alcohols, organic sulfides isolated from high-sulfur oils, binary extractants based on oxygen-containing and sulfur-containing acids, as well as secondary (R_2 〖NН〗_2А), tertiary (R_3NНA) amines, diamines, and quaternary ammonium bases (R_4NA). They were used for the extraction of platinum from multicomponent objects. Practically common to all the extractants used (chloroform, diethyl ether, carbon tetrachloride, etc.) are their rather high solubility in water, toxicity, volatility, fire hazard. Therefore, it is of fundamental importance to select such extraction systems that combine the effectiveness of organic reagents and the use of such extractants that would eliminate the disadvantages of liquid organic solvents. As such extractants, so-called low-melting organic substances can be used, which do not dissolve in water, are non-toxic, fire-safe, have a high extraction capacity, selectivity, and sensitivity to low content of elements. Therefore, it is fundamentally important to select such extraction systems, which would combine the efficiency of organic reagents and the use of such extractants that eliminate the disadvantages of liquid organic solvents. As such extractants can be used so-called fusible organic substances, which are insoluble in water, non-toxic, fire-safe, have a high extraction capacity, selectivity, sensitivity to low element content.

Methods of determination of morphological indicators in hydrological calculations in the design of roads and road structures

In solving the engineering problems in the practice of different specialties, in the design of roads and roads, structures, determining the physiographic conditions of the same regional areas: basin area (F), height (Z), average square difference of basin height (s), slope (J), parameters such as the length of the main channel in the basin (L), the width of the maximum water flow in the basin (V) and its depth (h), that is the determination of the calculated values of morphological indicators, performed using a large-scale map. It allows to estimate the amount of physical-geographical and morphological indicators, analyze their interrelationships, reveal the regions' physical-geographical laws, use them in hydrological calculations in the basin, and determine their values, to apply them in solving engineering problems.

Analysis of the results of microbiological studies of samples of chilled pork and beef meat using traditional and advanced techniques

The article analyzes microbiological studies of meat raw materials obtained using traditional methods of determination and using ready-made test systems. The most promising direction for the development of modern sanitary microbiology at the present time is the use of modern chromogenic medium and ready-made test systems.

Frequency of diagnostic tests in practice

The elaboration concerns methods of determination of term of technical equipment next diagnostication. The purpose of it is presentation of three methods related with determination of time of the next examination of equipment state for needs of devices operating system according to technical state.

Analytical ruled surfaces and their complete classification

The aim of the work - to give the possibility to expand mind of designers and architects projecting structures in the form of traditional and non-canonical ruled surfaces. These surfaces have several unquestionable advantages with a point of view of their forming, designing, and making of factory-made goods and erections in the form of ruled surfaces and analysis methods. Methods. Choosing ruled surfaces for classification, one can use methods of their determination by vector, parametrical, implicit, and in explicit equations. Only analytical ruled surfaces are considered which were examined and presented in scientific-and-technical literature. Results. All known at present time ruled surfaces are given in a graphic form. The determinations of some little known ruled surfaces are presented in a paper. The original sources, where these surfaces are examined or their application in real structures and erections are considered, or methods of determination of stress-strain state in thin-walled shells with ruled middle surfaces are presented, are given in references.