Imaging and image analysis advances are yielding increasingly complete and complicated records of cellular events in tissues and whole embryos. The ability to follow hundreds to thousands of cells at the individual level demands a spatio-temporal data infrastructure: tools to assemble and collate knowledge about development spatially in a manner analogous to geographic information systems (GIS). Just as GIS indexes items or events based on their spatio-temporal or 4D location on the Earth these tools would organize knowledge based on location within the tissues or embryos. Developmental processes are highly context-specific, but the complexity of the 4D environment in which they unfold is a barrier to assembling an understanding of any particular process from diverse sources of information. In the same way that GIS aids the understanding and use of geo-located large data sets, software can, with a proper frame of reference, allow large biological data sets to be understood spatially. Intuitive tools are needed to navigate the spatial structure of complex tissue, collate large data sets and existing knowledge with this spatial structure and help users derive hypotheses about developmental mechanisms. Toward this goal we have developed WormGUIDES, a mobile application that presents a 4D developmental atlas for Caenorhabditis elegans. The WormGUIDES mobile app enables users to navigate a 3D model depicting the nuclear positions of all cells in the developing embryo. The identity of each cell can be queried with a tap, and community databases searched for available information about that cell. Information about ancestry, fate and gene expression can be used to label cells and craft customized visualizations that highlight cells as potential players in an event of interest. Scenes are easily saved, shared and published to other WormGUIDES users. The mobile app is available for Android and iOS platforms. WormGUIDES provides an important tool for examining developmental processes and developing mechanistic hypotheses about their control. Critically, it provides the typical end user with an intuitive interface for developing and sharing custom visualizations of developmental processes. Equally important, because users can select cells based on their position and search for information about them, the app also serves as a spatially organized index into the large body of knowledge available to the C. elegans community online. Moreover, the app can be used to create and publish the result of exploration: interactive content that brings other researchers and students directly to the spatio-temporal point of insight. Ultimately the app will incorporate a detailed time lapse record of cell shape, beginning with neurons. This will add the key ability to navigate and understand the developmental events that result in the coordinated and precise emergence of anatomy, particularly the wiring of the nervous system.
One of the promising ways to increase fuel and modern gas turbine energy efficiency is using cyclic air intercooling between the stages of high- and low-pressure compressors. For intercooling, it is possible to use cooling in the surface heat exchanger and the contact method when water is injected into the compressor air path. In the presented research on the cooling contact method, it is proposed to use a thermopressor that implements the thermo-gas-dynamic compression process, i.e., increasing the airflow pressure by evaporation of the injected liquid in the flow, which moves at near-sonic speed. The thermopressor is a multifunctional contact heat exchanger when using this air-cooling method. This provides efficient high-dispersion liquid spraying after isotherming in the high-pressure compressor, increasing the pressure and decreasing the air temperature in front of the high-pressure compressor, reducing the work on compression. Drops of water injected into the air stream in the thermopressor can significantly affect its characteristics. An increase in the amount of water increases the aerodynamic resistance of the droplets in the stream. Hence, the pressure in the flow parts of the thermopressor can significantly decrease. Therefore, the study aims to experimentally determine the optimal amount of water for water injection in the thermopressor while ensuring a positive increase in the total pressure in the thermopressor under conditions of incomplete evaporation. The experimental results of the low-consumption thermopressor (air consumption up to 0.52 kg/s) characteristics with incomplete liquid evaporation in the flowing part are presented. The research found that the relative water amount to ensure incomplete evaporation in the thermopressor flow part is from 4 to 10% (0.0175–0.0487 kg/s), without significant pressure loss due to the resistance of the dispersed flow. The relative increase in airflow pressure is from 1.01 to 1.03 (5–10 kPa). Based on experimental data, empirical equations were obtained for calculating the relative pressure increase in the thermopressor with evaporation chamber diameters of up to 50 mm (relative flow path length is from 3 to 10 and Mach number is from 0.3 to 0.8).
Higher parameters of centrifugal machines are constantly required, such as the pressure of the medium to be sealed and the speed of rotation of the shaft. However, as the parameters increase, it becomes more and more difficult to ensure the effectiveness of sealing. In addition, sealing systems affect the overall safety of equipment operation, especially vibration. In order to harmonize the sealing functions and increase the dynamic rigidity of the rotors of centrifugal machines, a method for modeling complex sealing systems has been developed. Non-contact seals are considered as hydrostatic–dynamic bearings that can effectively dampen rotor oscillations. A general approach to the analysis of non-contact seals as automatic control systems and an algorithm for constructing their dynamic characteristics at the design stage were proposed for the first time. Models of “rotor-gap seal”, impulse seal and “rotor–hydraulic face” systems, and seal-supports of a shaftless pump have been studied to assess the effect of these seal systems on the oscillatory characteristics of the rotor. Analytical dependencies are obtained for calculating the dynamic characteristics and stability limits of seals as hydromechanical systems. The directions for improving the safety of operation of critical pumping equipment due to a targeted increase in the rigidity of non-contact seals are determined, which leads to an increase in the vibration resistance of the rotor and the environ-mental safety of centrifugal machines. The paper proposes a method for designing sealing systems based on the configuration of sealing components in order to achieve harmonization between sealing and vibration reliability, taking into account oscillatory processes due to hydrodynamic sealing characteristics.
This article is devoted to elaborating the influence mechanism of hub cap shape on the rotor root flow field of axial fan and developing an analytical model for quick design of hub cap. The hub cap of various length ratio and shape was generated using a tested polynomial for an axial fan with Hr = 0.45, and numerical simulations are used to determine the variation of hub cap on axial fan flow field and aero performance. Research found that there exists a critical length ratio for hub cap such that a further reduction of the length ratio will lead to excessive meridional flow angle at the junction plane and inception of rotor root flow separation. The sharper hub cap (decrease in shape coefficient S) makes the hub separation region further expand and migrate toward the rotor pressure surface, resulting in a larger separation vortex. Furthermore, an physical-based analytical model calculating the velocity non-uniformity caused by hub cap is proposed to predict the hub cap critical length ratio for a quick design criterion of hub cap to achieve low loss while keeping short length. The analytical model calculated hub cap critical length ratio LRCr for axial fan of Hr = 0.35–0.65 is 1.29–0.60 and independent of the absolute size of axial fan, which is verified by simulations.