Estimation of the value of leaks through a through defect of the pipeline when using in-pipe repair elements

The loss of hydrocarbons when using in-pipe repair elements is determined by the nature of the fluid flow in the gap between the pipe and the repair sleeve. An accurate analytical calculation of the flow parameters for a real sleeve, taking into account its length, the asymmetry of the defect and other design features, is very difficult. In this article, the problem of accurate calculation of the radial flow of a viscous incompressible fluid in a thin layer between two annular plates simulating a circular region with a center coincide with a pipeline defect is solved. The area consists of two circles formed by the pipeline wall with a through defect and the surface of the internal repair element. The results obtained will allow us for accurate calculations in the area adjacent to the defect of the pipe and approximate calculations for the whole repair element.

The pacemaker of snake heart is localized near the sinoatrial valve

To provide the first description of the exact location of primary pacemaker of the squamate heart, we used sharp microelectrode impalements and optical mapping of isolated sinus venosus preparations from Burmese pythons. We located the dominant pacemaker site at the base of the right leaflet of the sinoatrial valve (SAV), but latent pacemakers were also identified in a circular region around the SAV. Acetylcholine (10−5M) or noradrenaline (10−6M) induced shifts of the leading pacemaker site to other points near the SAV. The ionic currents of most of the cardiomyocytes isolated enzymatically from the SAV region resembled those of typical working myocytes from the sinus venosus. However, seven cells lacked the background inward rectifier current (IK1) and had a time-dependent hyperpolarization-induced inward current identified as the “funny” current (If). Therefore, region proximal to SAV demonstrates pacemaking activity and contains cells that resemble the electrophysiological properties of mammalian pacemaker myocytes.

Search for smart evaders with sweeping agents

Suppose in a given planar circular region, there are smart mobile evaders and we want to find them using sweeping agents. We assume the sweeping agents are in a line formation whose total length is predetermined. We propose procedures for designing a sweeping process that ensures the successful completion of the task, thereby deriving conditions on the sweeping velocity of the linear formation and its path. Successful completion of the task means that evaders with a given limit on their velocity cannot escape the sweeping agents. We present results on the search time given the initial conditions.

Some Janowski Type Harmonic q-Starlike Functions Associated with Symmetrical Points

The motive behind this article is to apply the notions of q-derivative by introducing some new families of harmonic functions associated with the symmetric circular region. We develop a new criterion for sense preserving and hence the univalency in terms of q-differential operator. The necessary and sufficient conditions are established for univalency for this newly defined class. We also discuss some other interesting properties such as distortion limits, convolution preserving, and convexity conditions. Further, by using sufficient inequality, we establish sharp bounds of the real parts of the ratios of harmonic functions to its sequences of partial sums. Some known consequences of the main results are also obtained by varying the parameters.