Transient liquid-phase assisted spark-plasma sintering and dry sliding wear of B4C ceramics fabricated from B4C nanopowders

With the motivation of developing B₄C composites with superior wear resistance for tribological applications, an ultrafine-grained (～200?300 nm) B₄C composite was fabricated, characterized microstructurally, and tested mechanically and tribologically. First, a well-dispersed powder mixture of B₄C nanopowders (～40 nm) with coarse Ti-Al powders (～38 μm) as transient liquid-phase sintering additives was environmentally-friendly prepared by aqueous colloidal processing, optimized by measurements of the zeta potential of dilute suspensions and rheological studies of concentrated suspensions. Second, the powder mixture obtained by freeze-drying was densified by spark-plasma sintering (SPS), identifying the optimal SPS temperature (1850°C) by measurements of density, hardness, and toughness. Third, the dry sliding-wear behaviour of the optimal superhard B₄C composite (～31.5 GPa) was investigated by pin-on-disk tests and observations of the worn surface, determining its specific wear rate (～4.4·10^?8 mm³/(N·m)) as well as wear mode (two-body abrasion) and mechanism (plastic deformation). And lastly, the wear behaviour of the ultrafine-grained B₄C composite was compared with that of a reference fine-grained (～0.7?0.9 μm) B₄C composite, finding that both have the same mode and mechanism of wear but with the former being more resistant than the latter (～2.3·10⁷ vs 1.9·10⁷ (N·m)/mm³). Implications for the fabrication of B₄C tribocomponents with greater superior wear resistance are discussed.     

Study of Protein Adsorption During Sterile Filtration of Protein Formulations by ILC

Protein adsorption is usually regarded as the main reason for filter fouling in sterile filtration of protein formulations. To achieve a better insight into this phenomenon, protein adsorption was studied during filtration of stabilized bovine serum albumin (BSA) and γ-globulin formulations through 0.2-µm microfilter membranes by inverse liquid chromatography (ILC). Adsorption processes can be studied with this method by measurement of breakthrough curves. The change of the concentration in the fluid phase is measured with high accuracy by an inline UV-detector.     

Detecting Vehicles’ Relative Position on Two-Lane Highways Through a Smartphone-Based Video Overtaking Aid Application

Mobile Networks and Applications - In this paper we present a smartphone-based real-time video overtaking architecture for vehicular networks. The developed application aims to prevent head-on...     

Hydrogen storage in the iron series of porous Prussian blue analogues

The hydrogen storage has been studied in several series of porous Prussian blue analogues but not in the iron one, T₃[Fe(CN)₆]₂ with T = Mn, Co, Ni, Cu, Zn, Cd. In this contribution the study of the H₂ adsorption in that series of porous solids is discussed. For comparison, the H₂ adsorption isotherm in Fe₄[Fe(CN)₆]₃ was also recorded. All the samples to be studied were characterized from energy-dispersed spectroscopy, X-ray diffraction, infrared, Mössbauer, and thermogravimetric data. The cavity volume to be occupied by the hydrogen molecule was estimated from the amount of water molecules found within the cavity. The obtained value for the cavity volume was then used to calculate the density for the hydrogen storage within the cavity. The obtained density values remain below the value corresponding to its liquid state (71 g/L).     

From the editor...

Introduces the articles appearing in this issue of the International Journal of Play Therapy. Of the five articles in this issue, three provide a quantitative analysis of the outcomes of play therapy/filial therapy and two present a qualitative approach through case study and model building. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

From the editor...

Introduces this special issue of the International Journal of Play Therapy, which was designed to present a number of the theoretical approaches to play therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of simple sugars,malic acid and total phenolic compounds in apple pomace by infrared spectroscopy and PLSR

The aim of this work was to develop a fast, versatile, inexpensive and environmentally safe analytical method to quantify simple sugars, malic acid and total phenolic compounds in apple pomace, considering its potential use as a raw material with value instead of as an industrial waste. Diffuse reflectance infrared spectroscopy (DRIFTS) measurements of twenty‐six samples of apple pomace were analysed by partial least squares regression (PLSR), using several signal pre‐processing methods. Multivariate models developed with four to five latent variables (LVs) and based in the MIR (mid‐infrared) region had good prediction for the determination of sucrose, fructose, malic acid and total phenolic compounds, with average errors between 3.9% and 6.6%. By contrast, glucose was better determined by models developed in the NIR (near‐infrared) region and using six LVs, yielding an average error lower than 7.4%. These results confirmed the feasibility of the multivariate spectroscopic approach as an alternative for expensive and time‐consuming conventional chemical methods.     

Uranium gastrointestinal absorption: the f1 factor in humans

The present investigation was undertaken by the Department of Health, Canada, to determine the most appropriate value to use for uranium gastrointestinal absorption (f1) in setting the guideline for drinking water. Fifty participants, free from medical problems, were recruited from two communities: a rural area where drinking water, supplied from drilled wells, contained elevated levels of uranium and an urban area where the water supplied by the municipal water system contained < 1 microg l(-1). Uranium intake through food, drinking water and other beverages was monitored using the duplicate diet approach. Intake and excretion were measured by inductively coupled plasma-mass spectrometry (ICP-MS) in samples collected concurrently from the same individuals over a 3 d period. The range of f1 values was between 0.001 and 0.06, with a median of 0.009. These values were independent of gender, age, duration of exposure, daily total uranium intake and allocation of intake between food and water. Consistent with the recommendation of ICRP Publication 69, 78% were below 0.02.     

Recent Progress on Antimonene: A New Bidimensional Material

Antimonene, defined in sensu stricto as a single layer of antimony atoms, is recently the focus of numerous theoretical works predicting a variety of interesting properties and is quickly attracting the attention of the scientific community. However, what places antimonene in a different category from other 2D crystals is its strong spin–orbit coupling and a drastic evolution of its properties from the monolayer to the few‐layer system. The recent isolation of this novel 2D material pushes the interest for antimonene even further. Here, a review of both theoretical predictions and experimental results is compiled. First, an account of the calculations anticipating an electronic band structure suitable for optoelectronics and thermoelectric applications in monolayer form and a topological semimetal in few‐layer form is given. Second, the different approaches to produce antimonene—mechanical and liquid phase exfoliation, and epitaxial growth methods—are reviewed. In addition, this work also reports the main characterization techniques used to study this exotic material. This review provides insights for further exploring the appealing properties of antimonene and puts forward the opportunities and challenges for future applications from (opto)electronic device fabrication to biomedicine.