Synthesis and characterization of carbon-coated Li0.5Ni0.25TiOPO4 anode material

Li_0.5Ni_0.25TiOPO₄/C composite was synthesized by the co-precipitation method using polyethylene glycol as carbon source. X-ray diffraction study showed that the as-prepared material crystallizes in the monoclinic system (S.G. P2₁/c). This 3D structure exhibits an open framework favourable to intercalation reactions. The morphology and the microstructure characterisation was performed by scanning electron microscopy (SEM). Small particles (∼1 μm) coated by carbon were observed. Raman study confirms the presence of carbon graphite in the Li_0.5Ni_0.25TiOPO₄/C composite. Cyclic voltammetry (CV) and charge-discharge galvanostatic cycling were used to characterize its electrochemical properties. The Li_0.5Ni_0.25TiOPO₄/C composite exhibits excellent electrochemical performances with good capacity retention for 50 cycles. Approximately 200 mAh/g could be reached at C, C/2, C/5 and C/20 rates in the 0.5-3 V potential range. These results clearly evidenced the positive effect of the carbon coating on the electrochemical properties of the studied phosphate.     

Experimental investigation of an industrial scale black liquor gasifier. 1. The effect of reactor operation parameters on product gas composition

A novel technology to mitigate the climate changes and improve energy security is Pressurized Entrained flow High Temperature Black Liquor Gasification (PEHT-BLG) in combination with an efficient fuel synthesis using the resulting syngas. In order to optimise the technology for use in a pulp and paper mill based biorefinery, it is of great importance to understand how the operational parameters of the gasifier affect the product gas composition. The present paper is based on experiments where gas samples were withdrawn from the hot part of a 3 MW entrained flow pressurized black liquor gasifier of semi industrial scale using a high temperature gas sampling system. Specifically, the influence of process conditions on product gas composition (CO₂, CO, H₂, CH₄, H₂S, and COS) were examined by systematically varying the operational parameters: system pressure, oxygen to black liquor equivalence ratio, black liquor flow rate to pressure ratio and black liquor pre-heat temperature. Due to the harsh environment inside the gasification reactor, gas sampling is a challenging task. However, for the purpose of the current study, a specially designed high temperature gas sampling system was successfully developed and used. The results, obtained from two separate experimental campaigns, show that all of the investigated operational parameters have a significant influence on the product gas composition and present valuable information about to the process characteristics.     

Deposition welding of hot forging dies using nanoparticle reinforced weld metal

In the application field of forging, the form-giving tool components are subject to process-related severe environmental conditions, such as high mechanical loads acting simultaneously with high tribological and thermal charges. Due to high machine hour rates as well as increasing environmental requirements in terms of energy consumption, wear protection methods and suitable repair measures for forging tools become more and more important. Laser deposition welding represents an established process for the repair of complex shaped surfaces. A new approach is the addition of nano-sized ceramic particles to improve the mechanical properties. The main idea is to reduce the grain size of the cladded layers by adding nano-sized nuclei. A fine grained microstructure will improve strength as well as ductility and fatigue resistance. Furthermore small hard particles can improve the wear resistance without affecting the friction of the surface. After the cladding process the surface has to be finished usually by turning, milling and grinding operations. Within the presented paper the potential of nanoparticle-reinforced deposition welding with regard to increasing the wear resistance of forging dies will be examined. First, the process of nanoparticle-reinforced deposition welding will be presented. Afterwards it will be shown that yttrium oxide, titanium carbide and tungsten carbide nanoparticles in an AISI H10 matrix material will influence the friction coefficient between forging tool and material as well as the wear properties.     

Automated in-service damage identification

Service damage for mechanical components includes surface delamination, impact damage, crack, wear and corrosion. Automated service damage identification for better analysis of a component remaining life in order to reduce the service cost is increasingly necessary for industrial product-service systems, e.g. power-by-hour contracts. This paper presents a novel approach to apply active thermography and image processing techniques for damage identification and measurement. The study presents experimental results to assess the shape, size and depth of sub-surface damage features on test and real life components. Industrial requirements for the non-destructive inspection for a class of aerospace components are also presented.     

弥散相对铝合金冷轧过程中晶粒分裂和织构演变的影响

制备了2种含有相近合金元素含量但不同的弥散第二相密度的铝锰合金冷轧板材。利用背散射电子衍射和取向成像图技术研究了晶粒分裂和微观织构,使用X射线衍射技术测量了宏观织构。研究发现当应变达到3左右时,高密度的小尺寸弥散相会促进铜型和S型织构的形成,同时增加了大角晶界所占比例。在小应变下,弥散相对织构和大角晶界的影响不显著。研究显示弥散相通过钉扎晶界从而促进织构演化,进而影响晶粒分裂和大角晶界的形成。     

Exposure to diesel exhaust induces changes in EEG in human volunteers

Background  

Ambient particulate matter and nanoparticles have been shown to translocate to the brain, and potentially influence the central nervous system. No data are available whether this may lead to functional changes in the brain.     

Supported binary oxide monolayers as selective oxidation catalysts: Bi2Mo3O12/TiO2

Monolayers of bismuth molybdates supported on low-area TiO₂ (anatase) catalyse the oxidation/isomerisation of 1-butene to butadiene and 2-butenes with combined selectivities of 80–100% and show significantly lower specific rates of deep oxidation than does -Bi₂Mo₃O₁₂. As loadings are increased above 2 wt% (equivalent to one monolayer), selectivities remain high and, although the butadiene yields are generally only moderate, in some cases they exceed that shown by the unsupported -phase. This revised version was published online in July 2006 with corrections to the Cover Date.     

Inhibition of Human DHODH by 4‐Hydroxycoumarins,Fenamic Acids,and N‐(Alkylcarbonyl)anthranilic Acids Identified by Structure‐Guided Fragment Selection

A strategy that combines virtual screening and structure‐guided selection of fragments was used to identify three unexplored classes of human DHODH inhibitor compounds: 4‐hydroxycoumarins, fenamic acids, and N‐(alkylcarbonyl)anthranilic acids. Structure‐guided selection of fragments targeting the inner subsite of the DHODH ubiquinone binding site made these findings possible with screening of fewer than 300 fragments in a DHODH assay. Fragments from the three inhibitor classes identified were subsequently chemically expanded to target an additional subsite of hydrophobic character. All three classes were found to exhibit distinct structure–activity relationships upon expansion. The novel N‐(alkylcarbonyl)anthranilic acid class shows the most promising potency against human DHODH, with IC₅₀ values in the low nanomolar range. The structure of human DHODH in complex with an inhibitor of this class is presented.