DEVELOPMENT OF AN ADVANCED HIGH PRESSURE RATIO TRANSONIC FAN STAGE. PART-I: DESIGN AND ANALYSIS

A high performance fan stage of pressure ratio 2.0 is being designed and developed under a joint programme between Chinese Aeronautical Establishment (CAE) China and National Aerospace Laboratories (NAL), Bangalore, India.. Special features of the aerodynamic design are i) forward blade sweep and lean to increase the ability to bear intake distortion ii) reverse camber fan tip to reduce losses via pre compression iii) low aspect ratio of the blades to maximize stall margin. The blade will be fabricated using laminates of Carbon/Epoxy composites with tip shroud so as to limit the blade stress and deformation. Stress analysis was carried out using MSC/NASTRAN Finite Element Package. The fan stage has undergone a series of design improvements. Comparison of typical results obtained at NAL and BUAA is shown for the final version of the fan stage TTT98-29

Hydrogen content in doped and undoped BaPrO3 and BaCeO3 by cold neutron prompt-gamma activation analysis

Proton uptake in undoped and Y-doped BaPrO3 has been measured by cold neutron prompt-gamma activation analysis, and compared to the proton uptake in Gd-doped BaCeO3, as determined by the same technique. The conventional proton incorporation model of perovskites in which oxygen ion vacancies, generated by the introduction of the trivalent dopant onto the tetravalent perovskite site, are filled with hydroxyl groups upon exposure of the sample to H2O containing atmospheres, predicts that the proton concentration in such materials should be no greater than the dopant concentration. In contradiction to this model, the proton concentration in BaPr1–xYxO3 after humidification is as much as three times greater than the dopant concentration, and even undoped samples contain a high concentration of protons. Moreover, x-ray photoemission spectra suggest that the Pr oxidation state is lowered upon hydration. In contrast, BaCe0.9Y0.1O3 shows a typical hydrogen concentration, of close to 90% of the yttrium concentration. The results are interpreted in terms of the variable valence of Pr, which can become reduced from the 4+ to the 3+ oxidation state upon exposure to water, and effectively behaves as a self-dopant within the structure

Atoms-to-Circuits Simulation Investigation of CNT Interconnects for Next Generation CMOS Technology

In this study, we suggest a hierarchical model to investigate the electrical performance of carbon nanotube (CNT)- based interconnects. From the density functional theory, we have obtained important physical parameters, which are used in TCAD simulators to obtain the RC netlists. We then use these RC netlists for the circuit-level simulations to optimize interconnect design in VLSI. Also, we have compared various CNT-based interconnects such as single-walled CNTs, multi-walled CNTs, doped CNTs, and Cu-CNT composites in terms of conductivity, ring oscillator delay, and propagation time delay

Similar dissection of sets

In 1994, Martin Gardner stated a set of questions concerning the dissection of a square or an equilateral triangle in three similar parts. Meanwhile, Gardner's questions have been generalized and some of them are already solved. In the present paper, we solve more of his questions and treat them in a much more general context. Let $D\subset \mathbb{R}^d$ be a given set and let $f_1,...,f_k$ be injective continuous mappings. Does there exist a set $X$ such that $D = X \cup f_1(X) \cup ... \cup f_k(X)$ is satisfied with a non-overlapping union? We prove that such a set $X$ exists for certain choices of $D$ and $\{f_1,...,f_k\}$. The solutions $X$ often turn out to be attractors of iterated function systems with condensation in the sense of Barnsley. Coming back to Gardner's setting, we use our theory to prove that an equilateral triangle can be dissected in three similar copies whose areas have ratio $1:1:a$ for $a \ge (3+\sqrt{5})/2$

Confidence Elicitation And Anchoring In The Respondent-Generated Intervals (RGI) Protocol

The Respondent-Generated Intervals protocol (RGI) has been used to have respondents recall the answer to a factual question by giving not only a point estimate but also bounds within which they feel it is almost certain that the true value of the quantity being reported upon falls. The RGI protocol is elaborated in this article with the goal of improving the accuracy of the estimators by introducing cueing mechanisms to direct confident (and thus presumably accurate) respondents to give shorter intervals and less confident (and thus presumably less accurate) respondents to give longer ones

Species-specific control of external superoxide levels by the coral holobiont during a natural bleaching event

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 7 (2016): 13801, doi:10.1038/ncomms13801.The reactive oxygen species superoxide (O2·−) is both beneficial and detrimental to life. Within corals, superoxide may contribute to pathogen resistance but also bleaching, the loss of essential algal symbionts. Yet, the role of superoxide in coral health and physiology is not completely understood owing to a lack of direct in situ observations. By conducting field measurements of superoxide produced by corals during a bleaching event, we show substantial species-specific variation in external superoxide levels, which reflect the balance of production and degradation processes. Extracellular superoxide concentrations are independent of light, algal symbiont abundance and bleaching status, but depend on coral species and bacterial community composition. Furthermore, coral-derived superoxide concentrations ranged from levels below bulk seawater up to ∼120 nM, some of the highest superoxide concentrations observed in marine systems. Overall, these results unveil the ability of corals and/or their microbiomes to regulate superoxide in their immediate surroundings, which suggests species-specific roles of superoxide in coral health and physiology.This work was supported by a Postdoctoral Fellowship from the Ford Foundation (J.M.D.), the National Science Foundation under grants OCE 1225801 (J.M.D.) and OCE 1233612 (A.A.), the Ocean and Climate Change Institute of the Woods Hole Oceanographic Institution (C.M.H.), the Sidney Stern Memorial Trust (C.M.H. and A.A.) and an anonymous donor

Disrupted CXCR2 Signaling in Oligodendroglia Lineage Cells Enhances Myelin Repair in a Viral Model of Multiple Sclerosis.

CXCR2 is a chemokine receptor expressed on oligodendroglia that has been implicated in the pathogenesis of neuroinflammatory demyelinating diseases as well as enhancement of the migration, proliferation, and myelin production by oligodendroglia. Using an inducible proteolipid protein (Plp) promoter-driven Cre-loxP recombination system, we were able to assess how timed ablation of Cxcr2 in oligodendroglia affected disease following intracranial infection with the neurotropic JHM strain of mouse hepatitis virus (JHMV). Generation of Plp-Cre-ER(T)::Cxcr2flox/flox transgenic mice (termed Cxcr2-CKO mice) allows for Cxcr2 to be silenced in oligodendrocytes in adult mice following treatment with tamoxifen. Ablation of oligodendroglia Cxcr2 did not influence clinical severity in response to intracranial infection with JHMV. Infiltration of activated T cells or myeloid cells into the central nervous system (CNS) was not affected, nor was the ability to control viral infection. In addition, the severity of demyelination was similar between tamoxifen-treated mice and vehicle-treated controls. Notably, deletion of Cxcr2 resulted in increased remyelination, as assessed by g-ratio (the ratio of the inner axonal diameter to the total outer fiber diameter) calculation, compared to that in vehicle-treated control mice. Collectively, our findings argue that CXCR2 signaling in oligodendroglia is dispensable with regard to contributing to neuroinflammation, but its deletion enhances remyelination in a preclinical model of the human demyelinating disease multiple sclerosis (MS).IMPORTANCE Signaling through the chemokine receptor CXCR2 in oligodendroglia is important for developmental myelination in rodents, while chemical inhibition or nonspecific genetic deletion of CXCR2 appears to augment myelin repair in animal models of the human demyelinating disease multiple sclerosis (MS). To better understand the biology of CXCR2 signaling on oligodendroglia, we generated transgenic mice in which Cxcr2 is selectively ablated in oligodendroglia upon treatment with tamoxifen. Using a viral model of neuroinflammation and demyelination, we demonstrate that genetic silencing of CXCR2 on oligodendroglia did not affect clinical disease, neuroinflammation, or demyelination, yet there was increased remyelination. These findings support and extend previous findings suggesting that targeting CXCR2 may offer a therapeutic avenue for enhancing remyelination in patients with demyelinating diseases

Sterilization of lung matrices by supercritical carbon dioxide

Lung engineering is a potential alternative to transplantation for patients with end-stage pulmonary failure. Two challenges critical to the successful development of an engineered lung developed from a decellularized scaffold include (i) the suppression of resident infectious bioburden in the lung matrix, and (ii) the ability to sterilize decellularized tissues while preserving the essential biological and mechanical features intact. To date, the majority of lungs are sterilized using high concentrations of peracetic acid (PAA) resulting in extracellular matrix (ECM) depletion. These mechanically altered tissues have little to no storage potential. In this study, we report a sterilizing technique using supercritical carbon dioxide (ScCO(2)) that can achieve a sterility assurance level 10(−6) in decellularized lung matrix. The effects of ScCO(2) treatment on the histological, mechanical, and biochemical properties of the sterile decellularized lung were evaluated and compared with those of freshly decellularized lung matrix and with PAA-treated acellular lung. Exposure of the decellularized tissue to ScCO(2) did not significantly alter tissue architecture, ECM content or organization (glycosaminoglycans, elastin, collagen, and laminin), observations of cell engraftment, or mechanical integrity of the tissue. Furthermore, these attributes of lung matrix did not change after 6 months in sterile buffer following sterilization with ScCO(2), indicating that ScCO(2) produces a matrix that is stable during storage. The current study's results indicate that ScCO(2) can be used to sterilize acellular lung tissue while simultaneously preserving key biological components required for the function of the scaffold for regenerative medicine purposes

USP13 antagonizes gp78 to maintain functionality of a chaperone in ER-associated degradation

Physiological adaptation to proteotoxic stress in the endoplasmic reticulum (ER) requires retrotranslocation of misfolded proteins into the cytoplasm for ubiquitination and elimination by ER-associated degradation (ERAD). A surprising paradox emerging from recent studies is that ubiquitin ligases (E3s) and deubiquitinases (DUBs), enzymes with opposing activities, can both promote ERAD. Here we demonstrate that the ERAD E3 gp78 can ubiquitinate not only ERAD substrates, but also the machinery protein Ubl4A, a key component of the Bag6 chaperone complex. Remarkably, instead of targeting Ubl4A for degradation, polyubiquitination is associated with irreversible proteolytic processing and inactivation of Bag6. Importantly, we identify USP13 as a gp78-associated DUB that eliminates ubiquitin conjugates from Ubl4A to maintain the functionality of Bag6. Our study reveals an unexpected paradigm in which a DUB prevents undesired ubiquitination to sharpen substrate specificity for an associated ubiquitin ligase partner and to promote ER quality control