Ventilation Structure Improvement of Air-cooled Induction Motor Using Multiphysics Simulations

 Optimal design of large induction motor is a process that involves electrical and mechanical skills as well as thermal and fluid dynamic skills. For recent machine layouts, one cannot rely on standard analysis methods. In multiphysics simulations which are done by weak coupling finite-element method, rotation boundary values on interface between air gap and rotor cannot be applied directly for fluid-dynamical analysis. A novel multi-component fluid method is proposed to deal with the influence of rotor rotation upon the air convection. This paper investigates a 3-D multi-physics simulation used in simulation of temperature distribution in air-cooled induction motor. The temperature rise in motor is due to Joule’s losses in stator windings and the induced eddy current in squirrel cages, and heat dissipation by air convection and solid conduction. The Joule’s losses calculated by 3-D eddy-current field analysis are used as the input for the thermal field analysis, which deeply depends on accurate air fluid field analysis. Through the coupled-field calculation, we proposed a new ventilation structure of a 15-phase motor to improve the cooling performance

Centralized Coded Caching with User Cooperation

In this paper, we consider the coded-caching broadcast network with user cooperation, where a server connects with multiple users and the users can cooperate with each other through a cooperation network. We propose a centralized coded caching scheme based on a new deterministic placement strategy and a parallel delivery strategy. It is shown that the new scheme optimally allocate the communication loads on the server and users, obtaining cooperation gain and parallel gain that greatly reduces the transmission delay. Furthermore, we show that the number of users who parallelly send information should decrease when the users' caching size increases. In other words, letting more users parallelly send information could be harmful. Finally, we derive a constant multiplicative gap between the lower bound and upper bound on the transmission delay, which proves that our scheme is order optimal.Comment: 9 pages, submitted to ITW201

Numerical Calculation of Transient Thermal Characteristics in Gas-Insulated Transmission Lines

For further knowledge of the thermal characteristics in gas-insulated transmission lines (GILs) installed above ground, a finite-element model of coupling fluid field and thermal field is established, in which the corresponding assumptions and boundary conditions are given.  Transient temperature rise processes of the GIL under the conditions of variable ambient temperature, wind velocity and solar radiation are respectively investigated. Equivalent of surface convective heat transfer coefficient and heat flux boundary conditions are updated in the analysis process. Unlike the traditional finite element method (FEM), the variability of the thermal properties with temperature is considered. The calculation results are validated by the tests results reported in the literature. The conclusion provides method and theory basis for the knowledge of transient temperature rise characteristics of GILs in open environment

A new scoring function for top-down spectral deconvolution

BACKGROUND: Top-down mass spectrometry plays an important role in intact protein identification and characterization. Top-down mass spectra are more complex than bottom-up mass spectra because they often contain many isotopomer envelopes from highly charged ions, which may overlap with one another. As a result, spectral deconvolution, which converts a complex top-down mass spectrum into a monoisotopic mass list, is a key step in top-down spectral interpretation. RESULTS: In this paper, we propose a new scoring function, L-score, for evaluating isotopomer envelopes. By combining L-score with MS-Deconv, a new software tool, MS-Deconv+, was developed for top-down spectral deconvolution. Experimental results showed that MS-Deconv+ outperformed existing software tools in top-down spectral deconvolution. CONCLUSIONS: L-score shows high discriminative ability in identification of isotopomer envelopes. Using L-score, MS-Deconv+ reports many correct monoisotopic masses missed by other software tools, which are valuable for proteoform identification and characterization

Systematic Evaluation of Protein Sequence Filtering Algorithms for Proteoform Identification Using Top-Down Mass Spectrometry

Complex proteoforms contain various primary structural alterations resulting from variations in genes, RNA, and proteins. Top-down mass spectrometry is commonly used for analyzing complex proteoforms because it provides whole sequence information of the proteoforms. Proteoform identification by top-down mass spectral database search is a challenging computational problem because the types and/or locations of some alterations in target proteoforms are in general unknown. Although spectral alignment and mass graph alignment algorithms have been proposed for identifying proteoforms with unknown alterations, they are extremely slow to align millions of spectra against tens of thousands of protein sequences in high throughput proteome level analyses. Many software tools in this area combine efficient protein sequence filtering algorithms and spectral alignment algorithms to speed up database search. As a result, the performance of these tools heavily relies on the sensitivity and efficiency of their filtering algorithms. Here, we propose two efficient approximate spectrum-based filtering algorithms for proteoform identification. We evaluated the performances of the proposed algorithms and four existing ones on simulated and real top-down mass spectrometry data sets. Experiments showed that the proposed algorithms outperformed the existing ones for complex proteoform identification. In addition, combining the proposed filtering algorithms and mass graph alignment algorithms identified many proteoforms missed by ProSightPC in proteome-level proteoform analyses

Effects of caffeoylxanthiazonoside on airway inflammation in an allergic asthma mice model

Purpose: To investigate the inhibitory effects of caffeoylxanthiazonoside (CYT) on airway inflammation in mice and its mechanism of action. Methods: An allergic asthma mice model was established by intraperitoneal injection and aerosol nebulization with ovalbumin (OVA). After treatment with CYT, the blood and bronchoalveolar lavage fluid (BALF) were collected from the mice. The leukocytes were classified and counted with Giemsa solution. Enzyme-linked immunosorbent assay (ELISA) was used to determine the serum levels of IgE, and IL-4, IL-5, IL-13 and IFN-γ in the BALF of mice. Lung tissues were obtained from the mice and MUC5AC protein expression was measured by western blot. Results: CYT significantly decreased the serum level of IgE in asthmatic mice. Inflammatory cells in BALF of mice were markedly reduced (p < 0.05) by CYT treatment at varying doses (10, 20, and 40 mg/kg). Treatment with CYT also significantly suppressed the cytokines of IL-4, IL-5 and IL-13 and increased the IFN-γ in the BLAF of OVA-induced allergic asthma mice (p < 0.05). Western blot results indicate that CYT treatment significantly decreased the expression of MUC5AC protein in the lung tissues of asthmatic mice. In addition, no significant effects on the body weight of the mice were found after CYT treatment. Conclusion: Caffeoylxanthiazonoside inhibits airway inflammation in allergic asthma mice by altering Th1/Th2 via re-balancing of related cytokines and downregulation of lung MUC5AC protein expression. Therefore, this compound can potentially be developed for the therapeutic management of inflammation in allergic asthma

Diurnal Variation of Tropical Ice Cloud Microphysics: Evidence from Global Precipitation Measurement Microwave Imager Polarimetric Measurements

The diurnal variation of tropical ice clouds has been well observed and examined in terms of the occurring frequency and total mass but rarely from the viewpoint of ice microphysical parameters. It accounts for a large portion of uncertainties in evaluating ice cloud's role on global radiation and hydrological budgets. Owing to the advantage of precession orbit design and paired polarized observations at a high-frequency microwave band that is particularly sensitive to ice particle microphysical properties, three years of polarimetric difference (PD) measurements using the 166 GHz channel of Global Precipitation Measurement Microwave Imager (GPM-GMI) are compiled to reveal a strong diurnal cycle over tropical land (30degS-30deg N) with peak amplitude varying up to 38%. Since the PD signal is dominantly determined by ice crystal size, shape, and orientation, the diurnal cycle observed by GMI can be used to infer changes in ice crystal properties. Moreover, PD change is found to lead the diurnal changes of ice cloud occurring frequency and total ice mass by about 2 hours, which strongly implies that understanding ice microphysics is critical to predict, infer, and model ice cloud evolution and precipitation processes