Investigation of genetic structure in mesomorphic bluegrasses, Poa section Stenopoa dum, by using ISSR markers

A morphological and genetic analysis of five mesomorphic bluegrasses populations, Poa section Stenopoa, from a range of geographical locations were performed. We have established that all the populations have different level of the morphological and genetic diversity. A total of 79 DNA bands were obtained from six ISSR primers, including 61 polymorphic bands. Molecular data have shown no clear difference between morphologically homogeneous populations and hybrid populations P. palustris and P. nemoralis. This result may be due to the high genetic diversity of the populations studied

Forced spreading over superhydrophobic and copper surfaces

Dynamic spreading over superhydrophobic and copper surfaces was studied experimentally under the condition of contact line movement with speed greater than 1 mm/sec. Three modes of spreading of distilled water drop over copper surfaces with sufficient typical roughness (0.591, 5.190 and 6.210 μM) were detected. The first one is drop formation when the contact line speed and dynamic contact angle increase sharply. The second mode is spreading of a drop, which is characterized by a monotonic decrease in the contact line speed and dynamic contact angle. The third one is a formation of an equilibrium contact angle at a constant wetted area (the contact line speed tends to zero, and spreading of a drop occurs as long as the driving force is greater than zero). Some features in spreading were detected on superhydrophobic surface with parameter roughness of 0.751μm compared to other substrates. During drop formation after sharp increase in the contact line speed and dynamic contact angle, there is a mode which is accompanied by a decrease in the contact line speed and monotonic increase in the advancing dynamic contact angle

Influence of the Metal Surface Texture on the Possibility of Controlling the Phase Transition of Water Droplets in the Single-Phase Regime

We experimentally studied the influence of the texture of copper and steel surfaces on the possibility of controlling the phase transition of water droplets in the single-phase regime. The texture of metals was formed by polishing and grinding, which corresponded to the finishing treatment of heat transfer surfaces in cooling systems for energy-saturated equipment. The samples were studied by microscopy and profilometry. The texture was estimated by three-dimensional roughness parameters. It was found that, with a 2–2.5-fold increase in roughness, the wetting of copper deteriorates (the contact angle increases from 66° to 93°), whereas the wetting of steel improves (the contact angle decreases from 89° to 71°). It was experimentally proven that, among the two main factors that affect the spreading diameter (wetting and roughness), wetting is the most significant. A hypothesis was formulated regarding the reason for the increase in the contact angle of 7–10° and the drop in the decrease rate of the contact diameter during the transition from the pinning to the mixed stage of droplet evaporation. It was found that an increase in the surface area of 0.1% leads to an increase in the total droplet evaporation rate of 4–6.5%

Critical heat flux in a closed two-phase thermosyphon

A closed two-phase thermosyphon experimental setup with the possibility of recording the coolant and its vapors temperatures was developed. We proved the use of the V. M. Borishansky and S. S. Kutateladze correlations for the determination of the critical heat flux in closed two-phase thermosyphons with the ratio of their internal diameter to the length of the heat supply zone in the range of 1 < dBhym / Lu < 2

Forced spreading over superhydrophobic and copper surfaces

Dynamic spreading over superhydrophobic and copper surfaces was studied experimentally under the condition of contact line movement with speed greater than 1 mm/sec. Three modes of spreading of distilled water drop over copper surfaces with sufficient typical roughness (0.591, 5.190 and 6.210 μM) were detected. The first one is drop formation when the contact line speed and dynamic contact angle increase sharply. The second mode is spreading of a drop, which is characterized by a monotonic decrease in the contact line speed and dynamic contact angle. The third one is a formation of an equilibrium contact angle at a constant wetted area (the contact line speed tends to zero, and spreading of a drop occurs as long as the driving force is greater than zero). Some features in spreading were detected on superhydrophobic surface with parameter roughness of 0.751μm compared to other substrates. During drop formation after sharp increase in the contact line speed and dynamic contact angle, there is a mode which is accompanied by a decrease in the contact line speed and monotonic increase in the advancing dynamic contact angle

CMS Comparative Analysis for the Creation of Electronic Educational Resources

В статье проанализированы наиболее популярные CMS системы, широко используемые веб-разработчиками в настоящее время, подходящие для создания электронных образовательных ресурсов (ЭОР). Рассмотрены наиболее популярные бесплатные системы управления контентом, такие как: WordPress, Joomla!, MODx, Drupal, DataLife Engine, uCoz, Setup.ru, Nethouse. Также, проведен сравнительный анализ бесплатных CMS по выбранным критериям, таким как: открытость исходного кода, знание языка программирования, наличие готовых шаблонов, уровень сложности системы, популярность среди разработчиков, поддержка дополнительных модулей, наличие бесплатного хостинга, наличие дистрибутива, наличие локализации, используемого языка программирования самой системы, используемой базы данных, уровня безопасности.In this article the most popular CMS systems now widely used by web developers were analyzed. These systems are suitable for the creation of electronic educational resources. There were considered the most popular free content management systems, such as: WordPress, Joomla!, MODx, Drupal, DataLife Engine, uCoz, Setup.ru, Nethouse. Also, a comparative analysis of free CMS was carried out according to the selected criteria including open source, programming language knowledge, the availability of ready-made templates, the system complexity level, the popularity among developers, support for additional modules, the presence of free hosting, distribution presence, the presence of localization of the programming language used by the system, databases used, security level

3D Web Technologies Application in Solving Intellectual Tasks

В настоящее время, применение 3D технологий в Web при решении различных интеллектуальных задач, играет важную роль. Данные технологии эффективно используются в таких сферах как: индустрия интерактивных развлечений, современных интеллектуальных обучающих системах, различных научных исследованиях. В данной статье рассмотрена реализация трехмерной графики в Web средствами WebGL. Также, был проведен эксперимент возможностей WebGL, для реализации которого была взята библиотека Three.js, позволяющая отображать интерактивную, анимированную трехмерную графику. С помощью данной библиотеки, написан код для визуализации трехмерного примитивного куба с заданной текстурой, а также задана анимация движения объекта вокруг своей оси. Статья будет полезна не только для проектировщиков электронных образовательных ресурсов, но и для архитекторов Web-интерфейсов в целом.At the present time 3D technologies application on the Web in solving various intellectual tasks plays an important role. These technologies are used efficiently in such areas as: the interactive entertainment industry, modern intelligent tutoring systems and various scientific researches. In this article the implementation of three-dimensional graphics on the Web by means of WebGL is considered. Also, an experiment of WebGL capabilities was carried out. To implement this experiment Three.js library was used allowing us to display interactive, animated three-dimensional graphics. By using this library the code for three-dimensional primitive cube visualization with specified texture was written and the object motion animation around its axis was set. This article will be useful not only for designers of electronic educational resources but also for Web-interfaces architects on the whole

Effect of the Heat Flux Density on the Evaporation Rate of a Distilled Water Drop

This paper presents the experimental dependence of the evaporation rate of a nondeaerated distilled water drop from the heat flux density on the surfaces of non-ferrous metals (copper and brass). A drop was placed on a heated substrate by electronic dosing device. To obtain drop profile we use a shadow optical system; drop symmetry was controlled by a high-speed video camera. It was found that the evaporation rate of a drop on a copper substrate is greater than on a brass. The evaporation rate increases intensively with raising volume of a drop. Calculated values of the heat flux density and the corresponding evaporation rates are presented in this work. The evaporation rate is found to increase intensively on the brass substrate with raising the heat flux density