Numerical simulation on the aerodynamic effects of blade icing on small scale Straight-bladed VAWT

AbstractTo invest the effects of blade surface icing on the aerodynamics performance of the straight-bladed vertical-axis wind turbine (SB-VAWT), wind tunnel tests were carried out on a static straight blade using a simple icing wind tunnel. Firstly, the icing situations on blade surface at some kinds of typical attack angle were observed and recorded under different cold water flow fluxes. Then the iced blade airfoils were combined into a SB-VAWT model with two blades. Numerical simulations were carried out on this model, and the static and dynamic torque coefficients of the model with and without icing were computed. Both the static and dynamic torque coefficients were decreased for the icing effects

Knowledge-driven Meta-learning for CSI Feedback

Accurate and effective channel state information (CSI) feedback is a key technology for massive multiple-input and multiple-output systems. Recently, deep learning (DL) has been introduced for CSI feedback enhancement through massive collected training data and lengthy training time, which is quite costly and impractical for realistic deployment. In this article, a knowledge-driven meta-learning approach is proposed, where the DL model initialized by the meta model obtained from meta training phase is able to achieve rapid convergence when facing a new scenario during target retraining phase. Specifically, instead of training with massive data collected from various scenarios, the meta task environment is constructed based on the intrinsic knowledge of spatial-frequency characteristics of CSI for meta training. Moreover, the target task dataset is also augmented by exploiting the knowledge of statistical characteristics of wireless channel, so that the DL model can achieve higher performance with small actually collected dataset and short training time. In addition, we provide analyses of rationale for the improvement yielded by the knowledge in both phases. Simulation results demonstrate the superiority of the proposed approach from the perspective of feedback performance and convergence speed.Comment: arXiv admin note: text overlap with arXiv:2301.1347

Genome-wide gene expression analyses reveal unique cellular characteristics related to the amenability of HPC/HSCs into high-quality induced pluripotent stem cells

is Table S2 presenting characteristics of the SF-iPSCs and TTF-iPSCs. (DOC 28 kb

Generation and characterization of the humoral immune response to DNA immunization with a chimeric beta-amyloid-interleukin-4 minigene

Active immunization with fibrillar beta-amyloid peptide (AB42) as well as passive transfer of anti-AB antibodies significantly reduces AB plaque deposition, neuritic dystrophy, and astrogliosis in the brain of mutant amyloid precursor protein (APP)-transgenic mice. Although the mechanism(s) of clearance of AB from the brain following active or passive immunization remains to be determined, it is clear that anti-AB antibodies are critical for clearance. DNA immunization provides an attractive alternative to direct peptide and adjuvant approaches for inducing a humoral response to AB. We constructed a DNA minigene with AB fused to mouse interleukin-4 (pAB42-IL-4) as a molecular adjuvant to generate anti-AB antibodies and enhance the Th2-type of immune responses. Gene gun immunizations induced primarily IgG1 and IgG2b anti-AB antibodies. Fine epitope analysis with overlapping peptides of the AB42 sequence identified the 1- 15 region as a dominant B cell epitope. The DNA minigeneinduced anti-AB antibodies bound to AB plaques in brain tissue from an Alzheimer's disease patient demonstrating functional activity of the antibodies and the potential for therapeutic efficacy. Originally published European Journal of Immunology, Vol. 33, No. 12, Dec 200

Characteristics of Wild Cherry Beverage Co-fermented by Hanseniaspora uvarum and Saccharomyces cerevisiae

One strain of Hanseniaspora uvarum YT-35 was screened from fermented sediment of wild cherry. Hanseniaspora uvarum YT-35 and commercial Saccharomyces cerevisiae were used as coculture for manufacture of fermented wild cherry beverage. The dynamics of microbial populations, reducing sugars and ethanol were analyzed at different stages of fermentation using single-strain fermentation with 2 strains of bacteria as a control. Meanwhile, the organic acids and volatile aromatic compounds of the fermented beverages were detected by high-performance liquid chromatography (HPLC) and headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). The results showed that H. uvarum YT-35 dominated in the pre-fermentation stage of co-culture. Compared with single fermentation with S. cerevisiae, the coculture fermentation resulted in lower ethanol content (3.51 g/L). Notably, HPLC results revealed that coculture fermented beverage reduced the yield of citric, malic and quinic acids and increased the yield of glacial acetic acid. HS-SPME/GC-MS results revealed that coculture fermented beverage produced more volatile compounds of esters, such as ethyl caproate, methyl benzoate and isoamyl octanoate and showed enhanced contents of ethyl laurate, ethyl octanoate, phenyl ethyl alcohol, benzyl alcohol, octanoic acid and lauric acid. Meanwhile, clustering analysis revealed that coculture fermentation were correlated with the greatest number of volatile aroma compounds in the fermented wild cherry beverage. This study provides scientific basis and theoretical guidance for the research of coculture strains with different metabolic potential in improving the quality of fruit juice fermented beverage

Efficacy of LVIS vs. Enterprise Stent for Endovascular Treatment of Medium-Sized Intracranial Aneurysms: A Hemodynamic Comparison Study

Background: We conducted a computational fluid dynamics (CFD) study and compared the treatment of medium-sized intracranial aneurysms with LVIS and Enterprise stent-assisted coil embolization (SACE) to determine the effects of hemodynamic changes caused by different stent and coil packing densities (PDs) in endovascular treatment.Methods: We enrolled 87 consecutive patients, with 87 medium-sized intracranial aneurysms (≥7, ≤ 12 mm), who underwent LVIS or Enterprise SACE. Aneurysms treated with LVIS SACE were allocated to the LVIS group, and the remainder were allocated to the Enterprise group. CFD were performed to assess hemodynamic alterations between before treatment, after stent deployment, and after SACE.Results: One aneurysm recanalized in the LVIS group (n = 42), and five recanalized in the Enterprise group (n = 45) (recanalization rate: 2.4 vs. 11.1%, respectively; P = 0.108). Higher complete obliteration rate (P = 0.069) was found in the LVIS group. Velocity at the neck plane showed a greater reduction ratio than velocity and WSS of the aneurysm in both groups after stent deployment, while velocity and WSS of the aneurysm showed a greater reduction ratio after coil placement. Further, there was a greater reduction in velocity at the neck plane (59.52 vs. 39.81%), aneurysmal velocity (88.46 vs. 69.45%), and wall shear stress (WSS) (85.45 vs. 69.49%) on the aneurysm in the LVIS group (P < 0.001 for all). Specifically, the reduction ratio of velocity at the neck plane showed significant difference between the groups in the multivariate analysis (P = 0.013).Conclusions : LVIS SACE showed a lower recanalization for endovascular treatment of medium-sized intracranial aneurysms, and the greater hemodynamic alterations might be the key factors