Investigation of the hydrodynamic impact of a planing small vessel on a water body

Рассмотрен экологический аспект использования маломерных глиссирующих судов. В статье представлен способ оценки характеристик потока, возмущённого движением глиссирующего судна. Способ основан на использовании численного метода гидродинамики. Выбраны параметры и зоны исследования потока вокруг корпуса рассмотренного судна, и разработана последовательность действий их определения. Проанализированы качественные картины изменения потока с ростом скорости глиссирующего судна с заданной геометрией, и выделены составляющие наиболее значимые составляющие. Оценены количественные характеристики возмущённого потока: вызванные скорости, расстояние от транца до точки зарождения системы волн, волновые характеристики. Оценка гидродинамического воздействия на водоём была проведена для двух притоков Волги – р.Керженец и р.Сура. Выполнено определение придонных касательных напряжений в выбранных водных объектах в их естественном и возмущённом присутствием судна состоянии. Проведено сравнение рассчитанных касательных напряжений с пороговыми значениями, что позволило оценить влияние движения маломерного судна на донный грунт. The ecological aspect of the use of small-sized planing vessels is considered. The article presents a method for assessing the characteristics of a flow disturbed by the movement of a planing vessel. The method is based on the use of the numerical method of hydrodynamics. The parameters and zones of the flow study around the hull of the vessel under consideration are selected, and a sequence of actions for their determination is developed. Qualitative patterns of flow changes with an increase in the speed of a planing vessel with a given geometry are analyzed, and the most significant components are identified. Quantitative characteristics of the perturbed flow are estimated: induced velocities, distance from the transom to the point of origin of the wave system, wave characteristics. The assessment of the hydrodynamic impact on the reservoir was carried out for two tributaries of the Volga - the Kerzhenets River and the Sura River. The determination of bottom tangential stresses in selected water bodies in their natural and disturbed state by the presence of the vessel was performed. The calculated tangential stresses were compared with threshold values, which made it possible to assess the impact of the movement of a small vessel on the bottom soil.

Dimeric cyclobutane formation under continuous flow conditions using organophotoredox catalysed [2+2]-cycloaddition

Radical cation-initiated dimerization of electron rich alkenes is an expedient method for the synthesis of cyclobutanes. By merging organophotoredox catalysis and continuous flow technology a batch versus continuous flow study has been performed providing a convenient synthetic route to an important carbazole cyclobutane material dimer t-DCzCB using less only 0.1 mol% of an organophotoredox catalyst. The scope of this methodology was explored giving a new class of functional materials, as well as an improved synthetic route to styrene based lignan dimeric natural products. The cyclobutane dimers could be isolated in higher chemical yields under continuous flow conditions and reaction times were reduced significantly compared to traditional batch reaction conditions.

Techno-Economic Analysis of the placement of the Capacitor in the Integrated Nepal Power System

With the increasing load demand, Integrated Nepal Power System (INPS) is facing a stiff challenge to maintain voltage profile within the standards and reduce system loss. Among the loss reduction strategies, an immediate solution would be installation of reactive power compensators at the grid substations. The power flow study of existing system is performed and a genetic algorithm is used to find optimum placement of suitable size of the capacitor banks to be added in system. 6 substations with a total reactive power supply of 80 MVAR was determined as optimal size and location and the installation is also financially feasible. Moreover, the analysis of capacitors placed at the varying voltage levels implied that the most suitable voltage level for the capacitor installation is 11kV.