Use of emanation thermal analysis in characterization of the influence of grinding on textural and structural properties of nanosized titania powders

It is shown that emanation thermal analysis (ETA) is a very sensitive method for studying the textural and structural changes undergone during thermal and/or mechanical treatment of TiO2. It is shown that the activation energy for the bulk diffusion of radon into titania samples annealed at 1100 °C dramatically increases by increasing the prior grinding time of the sample at room temperature. These results demonstrate that grinding of TiO2 prior to the annealing treatment considerably improves sintering and densification of the material.     

水乳型涂料最低施工温度对上海地区涂饰质量影响的研究

通过实验发现因对水乳型涂料的最低施工温度控制失当 ,使上海地区涂饰质量受到了影响。阐述了水乳型涂料最低施工温度与乳胶漆用乳液最低成膜温度的根本区别 ,提出必须建立水乳型涂料最低施工温度的标准及施工控制措施的建议。     

泵站声源、振源分析及噪声预防措施

本文对泵站声源、振源其产生原理进行了分析,从源头阐述了噪声的产生、传播过程,介绍了多种降噪措施,进行了多个工程的实际应用,取得了可观的经济和较好的社会效益。     

Iron influences on the Gut-Brain axis and development of type 2 diabetes

Background: Microbiota/neuroendocrine interactions with health and disease are increasingly recognized. Main Body: Aging is associated with progressive iron storage and development of type 2 diabetes, which impacts on brain microstructure and function, mainly in obese subjects. Iron status is also mutually influencing the composition of the gut microbiota, which in turn may affect cognition through the gut-brain axis. Short Conclusion: In this article we update the possible role of iron in all these interactions.     

Nanomagnets with high shape anisotropy and strong crystalline anisotropy: perspectives on magnetic force microscopy

We report on a new approach for magnetic imaging, highly sensitive even in the presence of external, strong magnetic fields. Based on FIB-assisted fabricated high-aspect-ratio rare-earth nanomagnets, we produce groundbreaking magnetic force tips with hard magnetic character where we combine a high aspect ratio (shape anisotropy) together with strong crystalline anisotropy (rare-earth-based alloys). Rare-earth hard nanomagnets are then FIB-integrated to silicon microcantilevers as highly sharpened tips for high-field magnetic imaging applications. Force resolution and domain reversing and recovery capabilities are at least one order of magnitude better than for conventional magnetic tips. This work opens new, pioneering research fields on the surface magnetization process of nanostructures based either on relatively hard magnetic materials-used in magnetic storage media-or on materials like superparamagnetic particles, ferro/antiferromagnetic structures or paramagnetic materials.     

Redox intercalation of alkylammonium ions into VOAO4.nH2O (A=P,As)

The layered, mixed-oxide hydrates, V^VOAsO₄.3H₂O and V^VOPO₄.2H₂O react with alkylammonium iodides to form (RNH₃)_xV^IV_xV^V_1?xOAO₄.H₂O, where R=PhCH₂, or C_nH_2n+1 (n=3 to 8), and x= .4 to .6The intercalate materials exhibit a layered structure derived from the starting solids. After reaction the latter undergo a lamellar swelling which is in agreement with a “pillar” arrangement of alkylchains.     

Thermo-elasto–viscoplastic numerical model for metal casting processes

The finite element method is used to model the thermomechanical behaviour of ductile cast iron using metallic moulds. Heat conduction is assumed for the heat transfer analysis and an elasto-viscoplastic model is employed to predict the development of thermal stresses and strains. Special finite elements with coincident nodes are used to model the heat transfer and the mechanical contact at the metal–mould interface. The local heat transfer coefficient between the casting and the mould may be dependent on the air-gap formation. The latent heat evolution effect is modelled by the use of the enthalpy method. An iterative procedure is required to take into account the material and the contact non-linearity. A real casting has been modelled and numerical results are compared with the experimental measurements.     

Removal of selected pharmaceuticals in waters by photochemical processes

BACKGROUND: Large amounts of pharmaceutical compounds are consumed throughout the world, and after being metabolized in humans are discharged into water streams. Some of them are not completely removed in wastewater treatment plants and, as a result, they are found in some effluents as well as in surface and ground waters. RESULTS: Four pharmaceutical compounds (metoprolol, naproxen, amoxicillin and phenacetin) frequently found in wastewaters were selected to be individually photo‐oxidized in ultra‐pure water by monochromatic UV radiation. The influence of independent variables (pH, temperature, and additional presence of hydrogen peroxide) was established, and first‐order rate constants and quantum yields evaluated. The compounds were also oxidized using Fenton's reagent and, after establishing the influence of the operating conditions (ferrous ions and hydrogen peroxide concentrations, pH and additional presence of UV radiation), the rate constants for the radical reaction between each pharmaceutical and hydroxyl radicals were determined. Finally, the simultaneous photo‐oxidation of mixtures of the selected pharmaceuticals in several types of water (commercial mineral water, groundwater and reservoir water) was performed by means of UV radiation alone and by the combination UV/H₂O₂. The influence of the independent variables in these processes was discussed, and the kinetic study allowed the determination of various rate constants for each compound. CONCLUSION: As the pharmaceutical concentrations theoretically calculated by the proposed kinetic model agree well with the experimental results obtained, this model constitutes an excellent tool to predict the elimination of these compounds when they are present in different natural waters. Copyright © 2009 Society of Chemical Industry