Mössbauer effect study of mechanically alloyed γ and Γ1 Fe-Zn intermediate phases

The Mössbauer effect measurements of as-ball-milled mechanically alloyed Fe-Zn intermediate phases of Γ (Fe₃Zn₁₀) and Γ₁ (Fe₅Zn₂₁) compositions exhibit characteristic spectra consisting of triplets. Each is characterized with an Fe site with unusually large quadrupole splittings measuring 0.940 mm/s in the cubic Fe-Zn phases and, in addition, three other doublets. In the aged state, both compositions show spectra free of the Fe site with quadrupole splitting of 0.940 mm/s, designated as _MSΓFe₁ and _{MSΓ 1}Fe₁, respectively. This suggests that the metastable states are similar, while their separate transformation paths to stable equilibrium lead to distinct crystal structures. The parameters for the aged states are compared with those reported in the literature for both phases.     

Mergers and Innovation: Declining Commitment to Pharmaceutical Research

Using the work of Michael Porter it is argued that the success of the UK pharmaceutical industry has been the result of ‘vigorous’ domestic competition. It now appears that the UK industry will effectively become a duopoly dominated by Glaxo-Wellcome and SmithKline Beecham. This will reduce the incentive to innovate new products which has been central to the pharmaceutical industry's success in recent years. In addition, the broader implications for the UK economy are also depressing as the pharmaceutical industry makes a disproportionate contribution to industrial expenditure on R&D.     

On-the-Fly Fluorescence Lifetime Determination with Total Emission Detection in HPLC

The entire fluorescence decay profile during HPLC elution has been directly measured on-the-fly in HPLC at higher sensitivity than in previous literature reports. The fluorescence is excited with the fourth harmonic (266 nm) of a pulsed Nd:YAG laser system and detected broadband with a photomultiplier tube and a digital storage oscilloscope. Detection limits in the range 1-10 ppb are found for several individual polycyclic aromatic hydrocarbons (PAHs) when the total time-integrated fluorescence is analyzed. The chromatograms of PAH mixtures containing 8-10 species were lifetime analyzed with a simple phase plane analysis, in which a single lifetime is determined from the fluorescence decay profile for each point on the chromatogram. The determination of lifetimes under coelution conditions is also illustrated and discussed.     

Joint Estimation of Human Pose and Conversational Groups from Social Scenes

Despite many attempts in the last few years, automatic analysis of social scenes captured by wide-angle camera networks remains a very challenging task due to the low resolution of targets, background clutter and frequent and persistent occlusions. In this paper, we present a novel framework for jointly estimating (i) head, body orientations of targets and (ii) conversational groups called F-formations from social scenes. In contrast to prior works that have (a) exploited the limited range of head and body orientations to jointly learn both, or (b) employed the mutual head (but not body) pose of interactors for deducing F-formations, we propose a weakly-supervised learning algorithm for joint inference. Our algorithm employs body pose as the primary cue for F-formation estimation, and an alternating optimization strategy is proposed to iteratively refine F-formation and pose estimates. We demonstrate the increased efficacy of joint inference over the state-of-the-art via extensive experiments on three social datasets.     

Carbon-14 tracer study of the fate of tetralin under simulated SRC-1 coal liquefaction conditions

A 28.4 wt% slurry of Illinois No. 6 coal in Wilsonville recycle solvent containing 0.83% of 1-¹⁴C-tetralin as a tracer for hydroaromatic solvent components has been hydroliquefied in a bench-scale, continuous-flow system under simulated SRC-I conditions (454 °C dissolver outlet; 13.9 MPa H₂). A combination of solvent fractionation, distillation, g.l.p.c. separation, and radio-assay procedures allow determination of the chemical fate of the labelled tetralin. Of the tetralin which is consumed (47 wt% of the feed), only 85% is converted to the ‘ideal’ dehydrogenation product, naphthalene. The remaining 15% is divided in a 1:2 ratio between conversion to structurally altered C₉–C₁₁ hydrocarbons (l-methylindane, indane, methylnaphthalene) and bonding to much heavier coal- and solvent-derived products. These side reactions would be expected to decrease both the solvent donor quality and the inventory. Although the mechanisms for grafting of tetralin-derived fragments to heavy materials cannot yet be described in detail, the chemical processes responsible must be quite indiscriminant towards functional groups because the specific radioactivities of the oils, the asphaltenes, the preasphaltenes, and even the insoluble organic matter are very similar.     

Anionenaustausch in gemischten lösungsmitteln – einwertige anionen am anionenaustauscher wofatit SBK

The equilibrium coefficients and relative affinities of 10 monovalent anions on the strongly basic anion-exchanger resin Wofatit SBK were determined in batches by the conductivity method in water-miscible solvents (H₂O: org. solvent = 20:80) methanol, ethanol, 2-propanol, acetone, dimethylsulfoxide and acetonitrile. The measured values are investigated with respect to their practical applicability and are discussed in relation to values measured in pure aqueous medium.     

A cassette system for systematic cryostorage of low-temperature scanning electron microscopy stubs

A system is described for the storage of cylindrical (10 × 3.5 mm) stubs for low-temperature scanning electron microscopy. The system facilitates rapid retrieval of mounted specimens, maximizes the capacity of the low-temperature (liquid nitrogen) specimen store, locates each stub exactly in a protected well, and eliminates the possibility of specimen damage from conventional hazards during transport between the storage facility and microscope.     

Effect of Carbon‐Based Materials on the Early Hydration of Tricalcium Silicate

Two types of carbon‐based materials, i.e., mesoporous carbon and HNO₃‐oxidized carbon nanotubes, with nearly the same specific surface area and abundant in surface oxygen‐containing functional groups were selected in order to examine their effect on the hydration of tricalcium silicate (C₃S), the main portland cement component, in early stages. Different methods, including XPS and TG‐MS analyses, electrokinetic potential measurements, as well as determination of adsorption capacity for calcium ions from aqueous solutions, were used to investigate the physicochemical surface properties of the selected carbon‐based materials. It was found that the carbon‐based materials with high specific surface area and rich in oxygen‐containing functional groups on their surfaces have a catalytic effect on early C₃S hydration. It was observed that the modification of C₃S paste with the selected materials added in high concentrations (1 wt% and higher) led to an increase in the rate and degree of C₃S hydration in the early stages. The mechanism of early C₃S hydration accelerated by carbon‐based materials rich in surface functional groups was clarified by the example of the mesoporous carbon. It was found that the oxygen‐containing functional groups present on the carbon surface have both an influence on the content of calcium ions in the aqueous phase of the C₃S paste and an indirect positive effect in relation to the specific surface of C₃S.     

Synthesis of SnFe<Subscript>2</Subscript>O<Subscript>4</Subscript> Nanomaterials Via High Energy Ball Milling of SnO (Stannous) and α-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> (Hematite) Solid Precursors

The synthesis of single phase tin-ferrite, SnFe₂O₄, from tin (II) oxide or stannous oxide (SnO), and hematite (α-Fe₂O₃) solid precursors was carried out via high energy ball milling (HEBM) under wet condition involving the addition of controlled amounts of acetone. The stoichiometric amounts of the precursor materials were ball milled continuously for up to 22 h in a Spex-8000D mill using a ball-to-powder ratio of 40:1, with hardened stainless steel balls in WC-lined jars. The time-dependent formation of the SnFe₂O₄ based on combined X-ray diffraction and room temperature Mössbauer spectroscopy (MS) measurements revealed reaction enhancements associated with particles size reduction. The 22 h milled material indicated that synthesized SnFe₂O₄ had a particle size of 10.91 nm, coercivity of 4.44 mT, magnetic saturation/remanent ratio (M _r/M _s) of 0.085, while its superparamagnetic behavior was confirmed based on the combined MS and vibrating sample magnetometer measurements.