Development and testing of carbon-bonded alumina foam filters for continuous casting of steel

Carbon-bonded alumina filters with special design for continuous casting were produced by the replication technique using different coating procedures. The filters were investigated regarding filter strut diameter, porosity and cold crushing strength. The potential filter capacity and the mechanical load expected during the immersion in a continuous casting tundish were calculated. The best compromise between mechanical strength and structural features was achieved by combining the advantages of centrifugation, dip coating and spray coating. This filter type was analyzed by computed tomography and withstood the contact with molten steel in a casting test. After melt contact, the filter material exhibited near-surface decarburization and alumina-based in-situ layer formation. The observed layers were more pronounced in zones with potentially lower melt flow velocity. The results of the study indicated that the produced filters are able to withstand the severe conditions in continuous casting.     

Crystallographic Orientation Dependent Reactive Ion Etching in Single Crystal Diamond

Sculpturing desired shapes in single crystal diamond is ever more crucial in the realization of complex devices for nanophotonics, quantum computing, and quantum optics. The crystallographic orientation dependent wet etch of single crystalline silicon in potassium hydroxide (KOH) allows a range of shapes to be formed and has significant impacts on microelectromechanical systems (MEMS), atomic force microscopy (AFM), and microfluidics. Here, a crystal direction dependent dry etching principle in an inductively coupled plasma reactive ion etcher is presented, which selectively reveals desired crystal planes in monocrystalline diamond by controlling the etching conditions. Using this principle, monolithic diamond nanopillars for magnetometry using nitrogen vacancy centers are fabricated. In these nanopillars, a half‐tapering angle up to 21° is achieved, the highest angle reported in the literature, which leads to a high photon efficiency and high mechanical strength of the nanopillar. These results represent the first demonstration of a crystallographic orientation dependent reactive ion etching principle, which opens a new window for shaping specific nanostructures which is at the heart of nanotechnology. It is believed that this principle will prove to be valuable for the structuring and patterning of other single crystal materials as well.     

用于多显示屏背光照明的多用途白光LED驱动器

引言 今年,预计全球将生产超过6亿部蜂窝电话.这些蜂窝电话不仅是人们的通话工具,现今最新型的蜂窝电话还可用来浏览Web、无线传输电子邮件、拍照甚至收看流式视频.消费者对这些"丰富功能"的需求给电话制造商们带来了越来越大的压力,它们必须把这些功能放进越来越小的电话中,同时还要保证电池的使用时间.     

Synthesis of Indium Nanowires by Galvanic Displacement and Their Optical Properties

Single crystalline indium nanowires were prepared on Zn substrate which had been treated in concentrated sulphuric acid by galvanic displacement in the 0.002 mol L⁻¹ In₂(SO₄)₃-0.002 mol L⁻¹ SeO₂-0.02 mol L⁻¹ SDS-0.01 mol L⁻¹ citric acid aqueous solution. The typical diameter of indium nanowires is 30 nm and most of the nanowires are over 30 μm in length. XRD, HRTEM, SAED and structural simulation clearly demonstrate that indium nanowires are single-crystalline with the tetragonal structure, the growth direction of the nanowires is along [100] facet. The UV-Vis absorption spectra showed that indium nanowires display typical transverse resonance of SPR properties. The surfactant (SDS) and the pretreatment of Zn substrate play an important role in the growth process. The mechanism of indium nanowires growth is the synergic effect of treated Zn substrate (hard template) and SDS (soft template).     

Probing young drinking water biofilms with hard and soft particles

The aim of our study was to investigate, through the use of soft (Escherichia coli) and hard (polystyrene microspheres) particles, the distribution and persistence of allochthonous particles inoculated in drinking water flow chambers. Biofilms were allowed to grow for 7-10 months in tap water from Nancy's drinking water network and were composed of bacterial aggregates and filamentous fungi. Both model particles adhered almost exclusively on the biofilms (i.e. on the bacterial aggregates and on the filamentous structures) and not directly on the uncolonized walls (glass or Plexiglas). Biofilm age (i.e. bacterial density and biofilm properties) and convective-diffusion were found to govern particle accumulation: older biofilms and higher wall shear rates both increased the velocity and the amount of particle deposition on the biofilm. Persistence of the polystyrene particles was measured over a two-month period after inoculation. Accumulation amounts were found to be very different between hard and soft particles as only 0.03‰ of the soft particles inoculated accumulated in the biofilm against 0.3-0.8% for hard particles.     

Effects of delayed drying and CO2 application on copper amine fixation in ACQ treated red pine

Fixation of copper and amine in alkaline copper quaternary (ACQ-C) wood preservative was investigated to determine the effects of delayed drying and application of CO₂ gas under pressure. Unlike the fixation of CCA preservative, where the rate of fixation reaction is slowed down by evaporative cooling during drying, delayed drying of ACQ treated wood had no observable effect on the copper fixation rate. However, at 50 °C, delayed drying resulted in a higher degree of copper fixation, while this effect was not observed at 22 °C. Post-treatment of ACQ treated wood with pressurized CO₂ immediately after treatment, reduced the pH of the solution in wood and resulted in rapid fixation of the copper. However, in time, the pH increased as CO₂ dissipated from the solution allowing the copper to re-solubilize.     

Effect of hot air post-treatments on copper leaching resistance in ACQ-D treated Chinese fir

Chinese fir (Cunninghamia lanceolata Hook.) wood cubes (19?×?19?×?19 mm³) were treated with amine copper quat-type D (ACQ-D) solution and fixed with different hot air post-treatments. The effects of temperature, relative humidity, duration, air circulation of post-treatment as well as the copper retention in the treated wood on copper leaching were investigated. With the help of ultraviolet or visible spectroscopy (UV/VIS), the valence conversion of copper in treated wood post-treated with optimal post-treatment conditions was investigated, and its relation with copper leaching was also discussed. The results showed that besides temperature and relative humidity, air circulation during hot air post-treatments also had a significant effect on accelerating copper fixation in ACQ-D treated wood. 70 °C, 80% R.H. with good air circulation provided a suitable condition for complete fixation of copper in a short period. After the applied post-treatments, up to 11.3% cupric copper reduced to cuprous form. A higher copper conversion rate usually corresponds to lower copper leaching, which is consistent with the contribution of lower water solubility cuprous copper.     

Governing GMOs in the USA: science,law and public health

Controversy surrounds the production and consumption of genetically modified organisms (GMOs). Proponents argue that GMO food sources represent the only viable solution to food shortages in an ever‐growing global population. Science reports no harm from GMO use and consumption so far. Opponents fear the potentially negative impact that GMO development and use could have on the environment and consumers, and are concerned about the lack of data on the long‐term effects of GMO use. We discuss the development of GMO food sources, the history of legislation and policy for the labeling requirements of GMO food products, and the health, environmental, and legal rationale for and against GMO food labeling. The Food and Drug Administration regulates food with GMOs within a coordinated framework of federal agencies. Despite mounting scientific evidence that GMO foods are substantially equivalent to traditionally bred food sources, debate remains over the appropriateness of GMO food labeling. In fact, food manufacturers have mounted a First Amendment challenge against Vermont's passage of a law that requires GMO labeling. Mandatory GMO labeling is not supported by science. Compulsory GMO labels may not only hinder the development of agricultural biotechnology, but may also exacerbate the misconception that GMOs endanger people's health. © 2015 Society of Chemical Industry