Approach for Aerodynamic Gust Load Alleviation by Means of Spanwise-Segmented Flaps

Active gust load alleviation techniques exhibit a high potential in significantly reducing the transient gust loads on aircraft. In this work the aerodynamic potential of trailing-edge flaps and leading-edge flaps is numerically studied with the purpose to significantly reduce the structural gust loads. The utilized spanwise-segmented flaps represent slight modifications of existing devices for high-lift and maneuvering. The investigations based on unsteady Reynolds-averaged Navier-Stokes computations are conducted by employing a generic wing-fuselage aircraft configuration at transonic flow conditions. Idealized discrete "1-cos"-type vertical gusts that are relevant for the certification process are used as representative atmospheric disturbances. The focus of this paper is to introduce a practicable prediction method for required trailing- and leading-edge flap deflections for a significant mitigation of gust-induced wing loads. The three-dimensional flap deflections are determined by parametric two-dimensional simulations at representative wing sections. Different extensions of the estimation approach are investigated to assess the influence of the wing planform, the finite wing span, the aerodynamic phase lags, and the flap scheduling. It is shown that the trailing- and leading-edge flaps are promising in terms of alleviation of gust-induced wing bending and wing torsional moments, respectively. However, at high leading-edge flap deflections that are necessary for a full compensation of the wing torsional moment large-scale flow separation is identified. The introduced gust load alleviation approach indicates a good transferability between two-dimensional airfoil and three-dimensional wing aerodynamics for unsteady flap deflections

SysZNF: the C2H2 zinc finger gene database

C2H2 zinc finger (C2H2-ZNF) genes are one of the largest and most complex gene super-families in metazoan genomes, with hundreds of members in the human and mouse genome. The ongoing investigation of this huge gene family requires computational support to catalog genotype phenotype comparisons of C2H2-ZNF genes between related species and finally to extend the worldwide knowledge on the evolution of C2H2-ZNF genes in general. Here, we systematically collected all the C2H2-ZNF genes in the human and mouse genome and constructed a database named SysZNF to deposit available datasets related to these genes. In the database, each C2H2-ZNF gene entry consists of physical location, gene model (including different transcript forms), Affymetrix gene expression probes, protein domain structures, homologs (and synteny between human and mouse), PubMed references as well as links to relevant public databases. The clustered organization of the C2H2-ZNF genes is highlighted. The database can be searched using text strings or sequence information. The data are also available for batch download from the web site. Moreover, the graphical gene model/protein view system, sequence retrieval system and some other tools embedded in SysZNF facilitate the research on the C2H2 type ZNF genes under an integrative view. The database can be accessed from the URL http://epgd.biosino.org/SysZNF

Revisions of the afrotropical genera of argidae and species of Pampsilota konow, 1899 (Hymenoptera, Tenthredinoidea)

Open Access JournalThe Afrotropical fauna contains five genera of Argidae. These are keyed. New subjective synonyms, followed by the valid name in brackets, are Calarge Enslin, 1911 [Arge Schrank, 1802], Calarge africana Enslin, 1911 [Arge congrua Konow, 1907], Clyparge Pasteels, 1963 [Scobina Lepeletier & Serville, 1828], Clyparge terminalis Pasteels, 1963 [Scobina poecila (Klug, 1834)], and Sterictophora [sic] afra Pasteels, 1963 [Sphacophilus afer comb. n., species inquirenda near S. monjarasi Smith & Morales-Reyes, 2015]. The type material of both C. terminalis and S. afra was probably collected in the New World, but labelled with the wrong locality “Kamerun”. An introduction of both species to Africa, not followed by long-term establishment, seems less likely. The removal of these taxa from the faunal list of the region is recommended. The nine known Afrotropical species of Pampsilota are revised, and an illustrated dichotomous identification key presented, with distribution maps for all species. Four species are here described as new to science: P. dahomeyanus Goergen, Koch & Liston, sp. n., P. nigeriae Liston & Koch, sp. n., P. tsavoensis Liston & Koch, sp. n., and P. zebra Liston & Koch, sp. n. Lectotypes are designated for Pampsilota afer Konow, 1899, and Cipdele africana Mocsáry, 1909. The immature stages and host plant of only one species are known: P. dahomeyanus on Lannea nigritana (Anacardiaceae). Its larval morphology strongly resembles that of European and North American species of Arge. We provisionally retain Pampsilota as a valid genus, although it could justifiably be treated as comprising merely a species group, or groups, within Arge

Redox Regulation of Stem and Progenitor Cells

The field of stem and progenitor cell biology is expanding. Much of the enthusiasm is based on the potential of using stem and progenitor cells as a cellular therapy for the treatment of human disease. Although the concept of using human embryonic stem cells for therapeutic indications is intriguing, significant challenges face investigators pursuing research in this area. Therefore, renewed scientific energy is focusing on the molecular pathways that differentiate a pluripotent embryonic stem cell from more-committed tissue-specific cells. Molecular mechanisms that govern tissue-specific stem and progenitor cell function are also topics of intense investigation, given that altered function of these cells may promote a variety of human pathologies including aging, vascular disease, and cancer. Considerable progress has been made, but a clear identification of the molecular signatures of stem and progenitor cells remains elusive. A growing body of literature demonstrates that distinct functional characteristics of stem and progenitor cells are under redox regulation. In this Forum Issue, evidence for redox regulation of tissue-specific stem and progenitor cells involved in hematopoiesis and vasculogenesis/angiogenesis is presented. Antioxid. Redox Signal. 10, 1849–1852

Experimental and Numerical Analysis of a Streamwise Vortex Downstream of a Delta Wing

The present paper analyzes the vortical flow downstream of a delta wing. The delta wing is designed to generate a vortex that resembles the vortex of a nacelle strake. The experimental results of stereoscopic particle image velocimetry measurements performed at different positions downstream of the delta wing display the streamwise development of the vortex. Details of the postprocessing of the measurement data and a quantification of the uncertainties are presented. The evaluation of the mean axial and tangential velocity components and Reynolds stresses provides insights to the vortex characteristics and their development in the streamwise direction. In addition, results of numerical simulations with the DLR TAU-code applying the Menter-Shear Stress Transport (SST) eddy viscosity model and the Speziale-Sarkar-Gatski/Launder-Reece-Rodi (SSG/LRR)-omega Reynolds stress model show the ability of the turbulence models to capture the vortex development. The experimental results indicate a preservation of the vortex strength and structure downstream of the delta wing. The Menter-SST model does not predict this preservation; rather it computes a rapid decay of vortex strength and an increase in vortex size. In contrast, the results of the SSG/LRR-omega model are in good agreement with the experiments concerning the mean flow development. However, both turbulence models underpredict the turbulence in the vortex core

Actuator Concepts for Active Gust Alleviation on Transport Aircraft at Transonic Speeds

This paper investigates different concepts for active gust alleviation (GLA) on a generic transport aircraft configuration at transonic speed by means of viscous and inviscid CFD simulations. Four types of dynamic actuator concepts are presented including a fuselage flap, a wing tip flap, a trailing edge flap and a leading edge flap. The wing tip flap is investigated on a forward swept wing configuration being specifically designed for this purpose. The overall aerodynamic effect of the fuselage flap on the lift distribution is relatively small and has significant Phase angles relative to the flap motion. The wing tip flap instead, seems to be a promising approach to alleviate gusts, affecting the lift distribution on the complete wing. The dynamic trailing edge flap and leading edge flap are investigated on a representative 2.5D setup to derive the most effective actuator setup. The 2.5D simulations confirm the potential of the trailing edge flap allowing a compensation of about 95% of gust induced lift increase at moderate incidence angles, while the effect of the droop nose –in the way implemented so far– is much lower. Despite the rather small potential of the leading edge flap regarding lift force preservation, the time history of the pitching moment reveals its favourable effect on eliminating about 50% of the nose up moment induced by the upward deflected flap without significantly affecting the lift Response

Metabolic response to epigallocatechin-3-gallate in relapsing-remitting multiple sclerosis: a randomized clinical trial

BACKGROUND: Muscle weakness and fatigue are common symptoms in multiple sclerosis (MS). Green tea catechins such as (-)epigallocatechin-3-gallate (EGCG) are known to improve energy metabolism at rest and during exercise. OBJECTIVE: We tested the hypothesis that EGCG improves energy metabolism and substrate utilization in patients with MS. DESIGN: Eighteen patients (8 men) with relapsing-remitting MS (expanded disability status scale score women). After placebo, exercise EE was mainly fueled by FAOx in both men and women. After EGCG, there was a shift to a higher and more stable CHOx during exercise in men but not in women. CONCLUSIONS: Our data indicate that EGCG given to patients with MS over 12 wk improves muscle metabolism during moderate exercise to a greater extent in men than in women, possibly because of sex-specific effects on autonomic and endocrine control. This trial was registered at clinicaltrials.gov as NCT01417312