Numerical study of probe parameters on performance of a transonic axial compressor

The paper shows the effect of the probe on the performance of a transonic axial speed compressor. The unobstructed flow case with the experimental data was validated and used as a guide for all subsequent study cases. The aerodynamic performance for different probe parameters were calculated numerically using ANSYS-CFX. This covered the results on compressor output from changing probe axial positions, the radial immersion depths, the size of the probe, and the total number of probes. The findings were evaluated in relation to the total pressure ratio, performance, margin of deflation and stability. The velocity part distributions further showed that the probe block and raises the flow Mach value, which is the explanation why the compressor rotor’s total pressure ratio is lost. In fact, the parameters of the sample will significantly influence the calculation outcomes and affect the standard margin. The range of stability was also affected, which changes the performance trend from the choke to the stall. Consequently, the collection of correct probe parameters with fewer impact on compressor output is addressed.

Catalyst design by scanning probe block copolymer lithography

Scanning probe block copolymer lithography (SPBCL), in combination with density-functional theory (DFT), has been used to design and synthesize hydrogen evolution catalysts. DFT was used to calculate the hydrogen adsorption energy on a series of single-element, bimetallic, and trimetallic (Au, Pt, Ni, and Cu) substrates to provide leads that could be synthesized in the form of alloy or phase-separated particles via SPBCL. PtAuCu (18 nm, ∼1:1:1 stoichiometry) has been identified as a homogeneous alloy phase that behaves as an effective hydrogen evolution catalyst in acidic aqueous media, even when it is made in bulk form via solution phase methods. Significantly, the bulk-prepared PtAuCu/C nanocatalyst discovered via this process exhibits an activity seven times higher than that of the state-of-the-art commercial Pt/C catalyst (based upon Pt content). The advantage of using SPBCL in the discovery process is that one can uniformly make particles, each consisting of a uniform phase combination (e.g., all alloy or all phase-segregated species) at a fixed elemental ratio, an important consideration when working with polyelemental species where multiple phases may exist.

Automated System for Measuring Geometric Parameters of Graphite Masonry and Measuring Deviations of Technological Channels from the Vertical of the Channel Reactor EGP-6

The system solves the problem of controlling the curvature and the diameter of the cells of the graphite masonry of the EGP-6 reactors in two mutually perpendicular planes during the routine preventive and overhaul repairs.Diameter control is carried out by means of 4 sensors of displacement of the resistor type fixed on the sensor probe block. Each of the sensors is mechanically connected to the roller, which is in direct contact with the channel wall. Diameter measurement uses data from sensors connected to two opposite rollers.Curvature control is performed using an ultrasonic inclinometer filled with liquid, which is located in the tail part of the probe. The inclinometer is designed for measuring angles of inclination in 2 mutually perpendicular planes. The data from the inclinometer is transmitted via the interface to an analog-to-digital converter, which is located in the measuring unit and is designed to convert the interface to USB.

On probe 2-clique graphs and probe diamond-free graphs

Graph Theory International audience Given a class G of graphs, probe G graphs are defined as follows. A graph G is probe G if there exists a partition of its vertices into a set of probe vertices and a stable set of nonprobe vertices in such a way that non-edges of G, whose endpoints are nonprobe vertices, can be added so that the resulting graph belongs to G. We investigate probe 2-clique graphs and probe diamond-free graphs. For probe 2-clique graphs, we present a polynomial-time recognition algorithm. Probe diamond-free graphs are characterized by minimal forbidden induced subgraphs. As a by-product, it is proved that the class of probe block graphs is the intersection between the classes of chordal graphs and probe diamond-free graphs.