The Flow Field Upstream Of A Horizontal Axis Wind Turbine

A mathematical model is developed for a steady-state axi-symmetric upstream flow of a porous disc, in a uniform flow field . The special case of the upstream flow of a windmill, with and without a nacelle, is treated. First, the windmill is considered as a uniform distribution of sources and then as a linear distribution of sources. Solutions for the blade disc o f the wind field upstream are obtained in the form of stream1 ines and velocity vector components. Sample flow patterns upstream o f the blade disc o f the UMass 25 kW wind turbine are presented for several power levels. Documented computer programs applicable to any wind turbine are appended

Interface induced out-of-plane magnetic anisotropy in magnetoelectric BiFeO3-BaTiO3 superlattices

Room temperature magnetoelectric BiFeO3-BaTiO3 superlattices with strong out-of-plane magnetic anisotropy have been prepared by pulsed laser deposition. We show that the out-ofplane magnetization component increases with the increasing number of double layers. Moreover, the magnetoelectric voltage coefficient can be tuned by varying the number of interfaces, reaching a maximum value of 29 V/cmOe for the20×BiFeO3-BaTiO3 superlattice. This enhancement is accompanied by a high degree of perpendicular magnetic anisotropy, making the latter an ideal candidate for the next generation of data storage devices

Runaway electron energy measurement using hard x-ray spectroscopy in "Damavand" tokamak

Set of experiments has been developed to study existing runaway electrons in "Damavand" tokamak plasma upon characteristics of hard x-ray emissions produced by collision of the runaway electrons with the plasma particles and limiters. As a first step, spatial distribution of hard x-ray emissions on the equatorial plane of the torus was considered. Obtained spectra of hard x-ray emissions for different alignments of shielded detector indicate isotropic emissivity in the equatorial plane. This is in agreement with wide angle cone of bremsstrahlung radiations, deduced from the mean value of energy of the runaway electrons. The mean energy was calculated from the slope of the energy spectrum of hard x-ray photons. In the second stage in order to investigate time evolution of energy of the runaway electrons, similar technique were applied to obtain hard x-ray energy in every 3 ms intervals, from the beginning to the end of plasma. The mean energy of the runaway electrons increases during the ramp up phase and reaches its maximum between 3 and 9 ms after plasma formation. Also considering the time dependence of the counted photons in each energy range shows that energetic photons are emitted during the ramp up phase of the plasma current in Damavand tokamak

A Novel RNA Transcript with Antiapoptotic Function Is Silenced in Fragile X Syndrome

Several genome-wide transcriptomics efforts have shown that a large percentage of the mammalian genome is transcribed into RNAs, however, only a small percentage (1–2%) of these RNAs is translated into proteins. Currently there is an intense interest in characterizing the function of the different classes of noncoding RNAs and their relevance to human disease. Using genomic approaches we discovered FMR4, a primate-specific noncoding RNA transcript (2.4 kb) that resides upstream and likely shares a bidirectional promoter with FMR1. FMR4 is a product of RNA polymerase II and has a similar half-life to FMR1. The CGG expansion in the 5′ UTR of FMR1 appears to affect transcription in both directions as we found FMR4, similar to FMR1, to be silenced in fragile X patients and up-regulated in premutation carriers. Knockdown of FMR4 by several siRNAs did not affect FMR1 expression, nor vice versa, suggesting that FMR4 is not a direct regulatory transcript for FMR1. However, FMR4 markedly affected human cell proliferation in vitro; siRNAs knockdown of FMR4 resulted in alterations in the cell cycle and increased apoptosis, while the overexpression of FMR4 caused an increase in cell proliferation. Collectively, our results demonstrate an antiapoptotic function of FMR4 and provide evidence that a well-studied genomic locus can show unexpected functional complexity. It cannot be excluded that altered FMR4 expression might contribute to aspects of the clinical presentation of fragile X syndrome and/or related disorders

Effective mechanical properties of multilayer nano-heterostructures

Two-dimensional and quasi-two-dimensional materials are important nanostructures because of their exciting electronic, optical, thermal, chemical and mechanical properties. However, a single-layer nanomaterial may not possess a particular property adequately, or multiple desired properties simultaneously. Recently a new trend has emerged to develop nano-heterostructures by assembling multiple monolayers of different nanostructures to achieve various tunable desired properties simultaneously. For example, transition metal dichalcogenides such as MoS2 show promising electronic and piezoelectric properties, but their low mechanical strength is a constraint for practical applications. This barrier can be mitigated by considering graphene-MoS2 heterostructure, as graphene possesses strong mechanical properties. We have developed efficient closed-form expressions for the equivalent elastic properties of such multi-layer hexagonal nano-hetrostructures. Based on these physics-based analytical formulae, mechanical properties are investigated for different heterostructures such as graphene-MoS2, graphene-hBN, graphene-stanene and stanene-MoS2. The proposed formulae will enable efficient characterization of mechanical properties in developing a wide range of application-specific nano-heterostructures

Cell-specific deletion of C1qa identifies microglia as the dominant source of C1q in mouse brain

BACKGROUND: The complement cascade not only provides protection from infection but can also mediate destructive inflammation. Complement is also involved in elimination of neuronal synapses which is essential for proper development, but can be detrimental during aging and disease. C1q, required for several of these complement-mediated activities, is present in the neuropil, microglia, and a subset of interneurons in the brain. METHODS: To identify the source(s) of C1q in the brain, the C1qa gene was selectively inactivated in the microglia or Thy-1(+) neurons in both wild type mice and a mouse model of Alzheimer’s disease (AD), and C1q synthesis assessed by immunohistochemistry, QPCR, and western blot analysis. RESULTS: While C1q expression in the brain was unaffected after inactivation of C1qa in Thy-1(+) neurons, the brains of C1qa (FL/FL) :Cx3cr1 (CreERT2) mice in which C1qa was ablated in microglia were devoid of C1q with the exception of limited C1q in subsets of interneurons. Surprisingly, this loss of C1q occurred even in the absence of tamoxifen by 1 month of age, demonstrating that Cre activity is tamoxifen-independent in microglia in Cx3cr1 (CreERT2/WganJ) mice. C1q expression in C1qa (FL/FL) : Cx3cr1 (CreERT2/WganJ) mice continued to decline and remained almost completely absent through aging and in AD model mice. No difference in C1q was detected in the liver or kidney from C1qa (FL/FL) : Cx3cr1 (CreERT2/WganJ) mice relative to controls, and C1qa (FL/FL) : Cx3cr1 (CreERT2/WganJ) mice had minimal, if any, reduction in plasma C1q. CONCLUSIONS: Thus, microglia, but not neurons or peripheral sources, are the dominant source of C1q in the brain. While demonstrating that the Cx3cr1 (CreERT2/WganJ) deleter cannot be used for adult-induced deletion of genes in microglia, the model described here enables further investigation of physiological roles of C1q in the brain and identification of therapeutic targets for the selective control of complement-mediated activities contributing to neurodegenerative disorders. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12974-017-0814-9) contains supplementary material, which is available to authorized users