Results of testing of lip plugging devices for geotechnical wells

Knowledge of the geological structure of the selected field allows to form a clear idea of the nature (geological and mineralogical composition and physico-chemical properties) of rocks, about the stability of rocks and their propensity to fracture under the influence of geological or technological reasons, etc. All this, in turn, largely determines the possibility of using rational method of drilling for specific conditions of the field. The possibility and feasibility of using drilling method is also determined by the presence of the aquifers. Aquifers play a very important role in choosing fields that are favorable for drilling by used method. Using of the device simplifies the design and optimize well because of the small drill diameter, reduced quantity of cement slurry and improved quality of cement job. Practically confirmed that the cementing with predetermined regimes there is no slugging, cement slurry evenly fit around columns. During the construction of technological wells with cementing through the interior of casing with collar device the well value changes significantly. The main factors affecting the change in value of the construction of wells, are time-consuming to plugging wells, the tripping and the waiting on cement. It was established experimentally that the use of the device for lip plugging a filter column reduces the time required to carry out mentioned types of technological operations. The calculation of economic efficiency, based on the saving of fixed costs in the implementation of the developed device, showed that the savings in the construction of wells is 177 663 tenge while the construction of a geotechnological well with 290 m depth

Determination of the parameters of the general contractor selection model for the successful implementation of the construction project

The authors examined the organization of interaction between the technical customer and the general contracting organization and revealed that it is at the stage of construction of facilities that difficulties arise in the interaction of construction participants, which were not initially taken into account when signing the construction contract. The implementation of the construction project depends on the effective organization of construction. The construction is characterized by dynamism and a high level of coordination of construction participants, which indicates the appearance of additional costs for both the technical customer and the contractor. To reduce the level of possible risks, the authors proposed at the initial stage of construction to exclude or reduce the impact of risk factors associated with the choice of an inefficient sub-row organization. 6 most important and relevant risk factors in the field of interaction between the technical customer and the contractor have been identified and analyzed. Expert surveys were conducted to determine the weight coefficients of damage and the probability of occurrence of risk factors. The reliability of the results was confirmed by calculating the multiple correlation coefficient

Revisiting the tangential oscillations of the tool to form the microrelief of the workpiece surface

The article is focused on the possibilities of using the tangential oscillations of the tool to form a microrelief of the workpiece surface. The diagram of the cutting tool oscillation trajectory during vibrational turning is presented. The scheme for calculation of the values of two tangential oscillation components is presented. The photos of the surfaces obtained by machining of the workpieces with the use of vibrational turning are provided. The results of the surface microgeometry modeling under the turning with tangential oscillations imposition of the tool are given. The dependence of the surface microgeometry height on the workpiece rotation speed and the tool oscillation frequency is determined. The factors which influence on the workpiece surface microgeometry formation are specified

Относительная высота деревьев в изолированных популяциях сосновых древостоев

Проведено исследование относительной высоты деревьев в сосняках брусничных, черничных и сфагновых на о-ве Большом Соловецком, самом значительном по площади в Соловецком архипелаге и в Белом море. Архипелаг является объектом Всемирного наследия ЮНЕСКО. Относительная высота – важный показатель, характеризующий рост древесных растений и отражающий, на сколько сантиметров прирастает высота на сантиметр диаметра. Заложено 34 пробных площади в наиболее распространенных типах леса – сосняках брусничных, черничных и сфагновых, занимающих 82,0 % от всей территории сосняков. На каждой пробной площади подобраны учетные деревья (по 64 дерева), у которых выполнены измерения высот, диаметров, взяты керны возрастным буравом у шейки корня для определения возраста. Всего в анализе относительной высоты использовано 2176 деревьев. Средняя относительная высота в сосняках брусничных, черничных и сфагновых на о-ве Б. Соловецком составляет соответственно 62,5; 61,5 и 54,7 см/см. Такой показатель заметно меньше, чем в сосняках на материке в Архангельской области. Там значения составляют 84,9; 84,9 и 79,2 см/см для соответствующих типов леса. Применять существующие таблицы хода роста, разработанные по материалам исследования материковых деревьев, для островных сосняков нельзя. Получены уравнения для определения относительной высоты сосняков о-ва Б. Соловецкого. В качестве входного параметра предлагается использовать диаметр деревьев, а не возраст, т. к. определение возраста значительно труднее, чем диаметра на высоте груди. Для цитирования: Соболев А.Н., Феклистов П.А., Неверов Н.А., Макаров С.С. Относительная высота деревьев в изолированных популяциях сосновых древостоев // Изв. вузов. Лесн. журн. 2023. № 6. С. 102–113. https://doi.org/10.37482/0536-1036-2023-6-102-11

ITO-free silicon-integrated perovskite electrochemical cell for light-emission and light-detection

Halide perovskite light-emitting electrochemical cells are a novel type of the perovskite optoelectronic devices that differs from the perovskite light-emitting diodes by a simple monolayered architecture. Here, we develop a perovskite electrochemical cell both for light emission and detection, where the active layer consists of a composite material made of halide perovskite microcrystals, polymer support matrix, and added mobile ions. The perovskite electrochemical cell of CsPbBr3:PEO:LiTFSI composition, emitting light at the wavelength of 523 nm, yields the luminance more than 7000 cd/m2 and electroluminescence efficiency of 1.3×105 lm/W. The device fabricated on a silicon substrate with transparent single-walled carbon nanotube film as a top contact exhibits 40% lower Joule heating compared to the perovskite optoelectronic devices fabricated on conventional ITO/glass substrates. Moreover, the device operates as a photodetector with a sensitivity up to 0.75 A/W, specific detectivity of 8.56×1011 Jones, and linear dynamic range of 48 dB. The technological potential of such a device is proven by demonstration of 24-pixel indicator display as well as by successful device miniaturization by creation of electroluminescent images with the smallest features less than 50 μm

Lignite from Central Watershed of the Yenisei River and Prospects for their use for Manufacture of Germanium

Лигниты среднего течения р. Енисей, локализованные в пределах мезокайнозойских отложений Касской впадины, рассматриваются как новый перспективный источник германиевого сырья в России. Приведены результаты изучения физико-химических свойств и технологических исследований, позволяющие оценить возможность выделения германия из лигнитов в процессе их сжигания для отработки, а в последующем для промышленной технологии его извлеченияLignite from central watershed of the Yenisei river localized within the Meso-Cenozoic cavity deposit considered as a promising new source of germanium raw materials in Russia. Germanium separating possibility from lignite during the combustion process has been studied on the base of physical and chemical properties research in order to develop the industrial technolog