Air plasma sprayed thermal barrier coatings on titanium alloy substrates

Titanium alloys as lightweight structure materials have been shown more interest in the use at moderately elevated temperatures. However, their poor oxidation resistance at temperature above 600 °C limits a wide application. Consequently, thermal protection becomes a concern. 8 wt. % yttria partially stabilized zirconia thermal barrier coatings (TBCs) were air plasma sprayed on titanium alloy substrates (Ti–6.6Al–3.61Mo– 1.69Zr–0.28Si in wt.%). The microstructures and mechanical properties of the coating system were studied by using SEM, XRD, MIP, tensile test and Vickers microhardness. The results show that the as-sprayed ceramic coating consists of the non-transformable tetragonal t′ phase of zirconia. The microstructure of the internal substrate keeps unchanged, no reaction and interdiffusion happen obviously at the bond coat/substrate interface during plasma spraying. However, there exists a thin layer of plastic deformation zone in the substrate beneath the bond coat/substrate interface. The surface connected porosity of the as-sprayed ceramic coating shows a typical bimodal pore size distribution. The adhesive strength of the TBCs decreases with increasing the thickness of the as-sprayed ceramic coatings, which is attributed to the residual stresses induced during thermal spraying. The anisotropy in the mechanical properties between the cross section and the top surface of the ceramic coatings is examined. © 2007 Elsevier B.V. All rights reserved

Even Order Explicit Symplectic Geometric Algorithms for Quaternion Kinematical Differential Equation in Guidance Navigation and Control via Diagonal Pad\`{e} Approximation and Cayley Transform

The Quaternion kinematical differential equation (QKDE) plays a key role in navigation, control and guidance systems. Although explicit symplectic geometric algorithms (ESGA) for this problem are available, there is a lack of a unified way for constructing high order symplectic difference schemes with configurable order parameter. We present even order explicit symplectic geometric algorithms to solve the QKDE with diagonal Pad\`{e} approximation and Cayley transform. The maximum absolute error for solving the QKDE is $\mathcal{O}(\tau^{2\ell})$ where $\tau$ is the time step and $\ell$ is the order parameter. The linear time complexity and constant space complexity of computation as well as the simple algorithmic structure show that our algorithms are appropriate for realtime applications in aeronautics, astronautics, robotics, visual-inertial odemetry and so on. The performance of the proposed algorithms are verified and validated by mathematical analysis and numerical simulation

Effect of omega-3 fatty acid supplementation on cancer incidence, non-vascular death, and total mortality: a meta-analysis of randomized controlled trials

BACKGROUND: Omega-3 fatty acids are known to prevent cardiac death. However, previous observational studies have suggested that omega-3 fatty acids are associated with cancer risk in adults. We conducted a meta-analysis based on randomized controlled trials to evaluate the effect of omega-3 fatty acids on the risk of cancer incidence, nonvascular death, and total mortality. METHODS: In February 2013, we performed electronic searches in PubMed, EmBase, and the Cochrane Library to identify randomized controlled trials on cancer incidence, nonvascular death, and total mortality. Relative risk (RR) was used to measure the effect of omega-3 fatty acid supplementation on the risk of cancer incidence, nonvascular death, and total mortality using a random-effect model. The analysis was further stratified by factors that could affect the treatment effects. RESULTS: Of the 8,746 identified articles, we included 19 trials reporting data on 68,954 individuals. These studies reported 1,039 events of cancer, 2,439 events of nonvascular death, and 7,025 events of total mortality. Omega-3 fatty acid supplementation had no effect on cancer incidence (RR, 1.10; 95% CI: 0.97–1.24; P = 0.12), nonvascular death (RR, 1.00; 95% CI: 0.93–1.08; P = 1.00), or total mortality (RR, 0.95; 95% CI: 0.88–1.03; P = 0.24) when compared to a placebo. Subgroup analysis indicated that omega-3 fatty acid supplementation was associated with a reduction in total mortality risk if the proportion of men in the study population was more than 80%, or participants received alpha-linolenic acid. CONCLUSIONS: Omega-3 fatty acid supplementation does not have an effect on cancer incidence, nonvascular death, or total mortality

Screening and verification of late embryogenesis abundant protein interacting with anthocyanidin reductase in grape berries

Anthocyanidin reductase (ANR, EC 1.3.1.77) catalyzes the conversion of anthocyanidins to 2R, 3R-flavan-3-ols in Vitis vinifera grapes. These are basic structural units of proanthocyanidins (PAs). The regulation of PA biosynthesis at protein level is not yet clear. Here, we find a VvANR interaction partner called late embryogenesis abundant protein (LEA), which can interact with VvANR in the yeast two-hybrid (Y2H) system. We verified the interaction between VvANR and Vv-LEA by Y2H and co-immunoprecipitation (CoIP) in yeast in vitro, and using the firefly luciferase complementation imaging (LCI) system in vivo. Additionally, the co-localization of VvANR and VvLEA in Arabidopsis thaliana protoplasts also provids the essential conditions for their interaction. The different expressions of VvANR and VvLEA depended both on the age of the grape berries and on the duration of cold treatment. These findings provide primary evidence for proteinregulation and the potential formation of multi-enzyme complex of VvANR, as well as of the PA biosynthesis.

Poly[4-(dimethyl­amino)pyridinium [(μ6-5-carboxy­benzene-1,2,4-tricarboxy­ato-κ6 O 1:O 1′:O 2:O 4:O 4′:O 5)diargentate(I)]]

In the title compound, {(C7H11N2)[Ag2(C10H3O8)]}n, the polymeric anion consists of two AgI atoms and a Hbtc3− ligand (H4btc = benzene-1,2,4,5-tetra­carboxylic acid). Each AgI atom is coordinated by four O atoms from three different Hbtc3− ligands. The two AgI atoms are bridged by two bidentate carboxyl­ate groups into an Ag2O4 cyclic unit, with an Ag⋯Ag distance of 2.8189 (3) Å. In this way, the Ag atoms are connected by the Hbtc3− ligands into an extended two-dimensional layer structure. A three-dimensional network is accomplished through O—H⋯O hydrogen bonds between the anionic layers. The cationic guest Hdmap+ [dmap = 4-(dimethyl­amino)pyridine] is trapped in the network and adheres to the layer by an N—H⋯O hydrogen bond

5-(1H-Tetra­zol-5-yl)-1H-indole monohydrate

In the title compound, C9H7N5·H2O, the inter­planar angles between the benzene and tetra­zole rings and between the benzene and imidazole rings are 8.71 (3) and 1.32 (2)°, respectively. In the crystal, strong N—H⋯N hydrogen bonds link the organic 5-(1H-tetra­zol-5-yl)-1H-indole mol­ecules into chains extended along the b axis. The chains are further inter­connected into layers parallel to (100) via strong O—H⋯N and N—H⋯O hydrogen bonds. Furthermore, the layers are inter­connected via strong O—H⋯N hydrogen bonds. Moreover, cohesion between the layers is provided by the π–π inter­actions between the imidazole, tetra­zole and benzene rings with centroid–centroid distances of 3.766 (2), 3.832 (2) and 3.733 (2) Å