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Reducing energy use and improving engine efficiency is a complex task however to date a continued reduction of lubricant viscosity has proved effective. Reducing viscosity decreases hydrodynamic friction and pumping losses however it can also exacerbate boundary friction losses. Detailed and representative component level experimentation is required to understand the effects of viscosity reduction on friction and opportunity for further optimisation. This paper presents a novel motored reciprocating Tribometer which has been developed to measure the friction between complete cylinder liners and three-piece oil control rings. The system holds individual or multiple rings stationary in a bespoke ring holder and reciprocate the cylinder liner thereby replicates the relative kinematics of the components in service. The new design has many operational advantages to identify and benchmark the individual contribution of oil control ring friction including near total isolation of oil ring-cylinder liner bore conjunction, pure rectilinear motion and use of full components without resorting to split liner/ring geometries. The experimental rig is used to measure friction at the three-piece oil control ring- cylinder liner conjunction when lubricated with two low viscosity lubricants. The results show prevalence of mixed regime lubrication across the speeds, temperatures and lubricants investigated. The oil control ring under investigation is shown to operate in mixed regime lubrication and at cold start the introduction of lower viscosity lubricants such as 0W-8 showed higher level of oil control ring-cylinder liner friction in comparison to the 0W-40. The information and experimental facility are of critical use for engine designers when considering the potential contradictory component efficiency behaviour when moving to ultra-low viscosity lubricants.

Optical and structural properties of float-type soda lime silicate (SLS) glasses doped with 0.2 mol % TiO2, ZrO2, HfO2, Nb2O5, Ta2O5, MoO3 or WO3 have been studied. Under UV excitation all d0 doped glasses exhibit broadband visible emission centred between 19,000 cm-1 and 25,000 cm-1 (400nm – 525nm) due to a transition from the 2p orbital of O2- to the metal d0 orbital. Dopant additions lead to shifts in the UV absorption edge to lower energies, with doped glasses having an absorption edge 2,000 cm-1 (~20nm), and in the case of MoO3, 4,000 cm-1 (~40nm), lower than the corresponding undoped glass. Combined UV-Vis absorption and X-band EPR spectroscopy analyses confirm that dopant cations occur in the studied glasses in the expected oxidation states of Ti4+, Zr4+, Hf4+, Nb5+, Ta5+, Mo6+ and W6+, although very low levels of Mo5+ are also observed, as demonstrated by the EPR resonance at g=1.92 (3.7T). The incorporation of the studied dopants into SLS glasses may find applications as cover glasses in photovoltaic (PV) applications, providing UV protection of polymers and solar cell materials in PV units whilst enhancing solar cell efficiency through downconversion / fluorescence of absorbed UV photons with re-emission as visible photons, available for absorption and conversion by the solar cell material.

The neutron diffraction isotopic substitution technique is employed to investigate the environment of Fe3+/Fe2+ cations in a sodium borosilicate glass matrix of composition 0.210Na2O0.18511B2O30.605SiO2. The neutron diffraction data were obtained using the D4c diffractometer at the Institut Laue-Langevin (ILL; Grenoble, France), and were recorded for three samples; the base glass, the base glass incorporating natural Fe2O3 (12 mol.%) and a similar glass containing Fe2O3 enriched in 57Fe. The data are Fourier transformed to yield the real-space total correlation function, T(r), and the first co-ordination shells of the Fe3+/Fe2+ cations are investigated via a peak fit to the isotopic difference correlation function TFe(r). It is concluded that the iron is mainly present as Fe3+ cations, both tetrahedrally and octahedrally co-ordinated by oxygen atoms, plus a small fraction (0.07 ± 0.01) of Fe2+ cations in octahedral co-ordination. The Fe3+ tetrahedral fraction is 0.45 ± 0.10, and appears to exist as FeO4 structural units incorporated into the network of silicate chemical groupings, with their negative charge being balanced by Na+ network-modifying cations. The remaining Fe3+ cations (fraction 0.48 ± 0.10) are thought to be predominantly octahedrally co-ordinated and associatedwith BO33 orthoborate anions in FeBO3 chemical groupings, which become non-stoichiometric due to the reduction of some of the Fe3+ cations to Fe2+.

Hydrothermal synthesis is described of layered lithium iron selenide hydroxides Li1-xFex(OH)Fe1-ySe (x ~ 0.2; 0.02 < y < 0.15) with a wide range of iron site vacancy concentrations in the iron selenide layers. This iron vacancy concentration is revealed as the only significant compositional variable and as the key parameter controlling the crystal structure and the electronic properties. Single crystal X-ray diffraction, neutron powder diffraction and X-ray absorption spectroscopy measurements are used to demonstrate that superconductivity at temperatures as high as 40 K is observed in the hydrothermally synthesised samples when the iron vacancy concentration is low (y < 0.05) and when the iron oxidation state is reduced slightly below +2, while samples with a higher vacancy concentration and a correspondingly higher iron oxidation state are not superconducting. The importance of combining a low iron oxidation state with a low vacancy concentration in the iron selenide layers is emphasised by the demonstration that reductive post-synthetic lithiation of the samples turns on superconductivity with critical temperatures exceeding 40 K by displacing iron atoms from the Li1-xFex(OH) reservoir layer to fill vacancies in the selenide layer, 7 pages supplementary material available from Journal, Inorganic Chemistry 2015

Lanthanide orthoferrites have wide-ranging industrial uses including solar, catalytic and electronic applications. Here a series of lanthanide orthoferrite perovskites, LnFeO3 (Ln = La; Nd; Sm; Eu; Gd), prepared through a standard stoichiometric wet ball milling route using oxide precursors, has been studied. Characterisation through X-ray diffraction and X-ray fluorescence confirmed the synthesis of phase-pure or near-pure LnFeO3 compounds. 57Fe Mossbauer spectroscopy was performed over a temperature range of 10 K to 293 K to observe hyperfine structure and to enable calculation of the recoil-free fraction and Debye temperature (θD) of each orthoferrite. Debye temperatures (Ln = La 474 K; Nd 459 K; Sm 457 K; Eu 452 K; Gd 473 K) and recoil-free fractions (Ln = La 0.827; Nd 0.817; Sm 0.816; Eu 0.812; Gd 0.826) were approximated through minimising the difference in the temperature dependent experimental Centre Shift (CS) and theoretical Isomer Shift (IS), by allowing the Debye temperature and Isomer Shift values to vary. This method of minimising the difference between theoretical and actual values yields Debye temperatures consistent with results from other studies determined through thermal analysis methods. This displays the ability of variable-temperature Mossbauer spectroscopy to approximate Debye temperatures and recoil-free fractions, whilst observing temperature induced transitions over the temperature range observed. X-ray diffraction and Rietveld refinement show an inverse relationship between FeO6 octahedral volume and approximated Debye temperatures. Raman spectroscopy show an increase in the band positions attributed to soft modes of Ag symmetry, Ag(3) and Ag(5) from La to GdFeO3 corresponding to octahedral rotations and tilts in the [010] and [101] planes respectively.

The capacity of simulated high-level radioactive waste borosilicate glasses to incorporate sulfate has been studied as a function of glass composition. Combined Raman, 57Fe Mossbauer and literature evidence supports the attribution of coordination numbers and oxidation states of constituent cations for the purposes of modelling, and results confirm the validity of correlating sulfate incorporation in multicomponent borosilicate radioactive waste glasses with different models. A strong compositional dependency is observed and this can be described by an inverse linear relationship between incorporated sulfate (mol% SO42−) and total cation field strength index of the glass, Σ(z/a2), with a high goodness-of-fit (R2 ≈ 0.950). Similar relationships are also obtained if theoretical optical basicity, Λth (R2 ≈ 0.930) or non-bridging oxygen per tetrahedron ratio, NBO/T (R2 ≈ 0.919), are used. Results support the application of these models, and in particular Σ(z/a2), as predictive tools to aid the development of new glass compositions with enhanced sulfate capacities.

Reaction of the Ruddlesden-Popper phases Sr2Fe(0.5)Ru(0.5)O4 and Sr3(Fe(0.5)Ru(0.5))2O7 with CaH2 results in the topochemical deintercalation of oxide ions from these materials and the formation of samples with average compositions of Sr2Fe(0.5)Ru(0.5)O(3.35) and Sr3(Fe(0.5)Ru(0.5))2O(5.68), respectively. Diffraction data reveal that both the n = 1 and n = 2 samples consist of two-phase mixtures of reduced phases with subtly different oxygen contents. The separation of samples into two phases upon reduction is discussed on the basis of a short-range inhomogeneous distribution of iron and ruthenium in the starting materials. X-ray absorption data and Mössbauer spectra reveal the reduced samples contain an Fe(3+) and Ru(2+/3+) oxidation state combination, which is unexpected considering the Fe(3+)/Fe(2+) and Ru(3+)/Ru(2+) redox potentials, suggesting that the local coordination geometry of the transition metal sites helps to stabilize the Ru(2+) centers. Fitted Mössbauer spectra of both the n = 1 and n = 2 samples are consistent with the presence of Fe(3+) cations in square planar coordination sites. Magnetization data of both materials are consistent with spin glass-like behavior.

Reaction of the appropriate Sr3(M(0.5)Ru(0.5))2O7 (M = Ti, Mn, Fe), n = 2, Ruddlesden-Popper oxide with CuF2 under flowing oxygen results in formation of the oxide-fluoride phases Sr3(Ti(0.5)Ru(0.5))2O7F2, Sr3(Mn(0.5)Ru(0.5))2O7F2, and Sr3(Fe(0.5)Ru(0.5))2O(5.5)F(3.5) via a topochemical anion insertion/substitution process. Analysis indicates the titanium and manganese phases have Ti(4+), Ru(6+) and Mn(4+), Ru(6+) oxidation state combinations, respectively, while Mössbauer spectra indicate an Fe(3+), Ru(5.5+) combination for the iron phase. Thus, it can be seen that the soft fluorination conditions employed lead to formation of highly oxidized Ru(6+) centers in all three oxide-fluoride phases, while oxidation states of the other transition metal M cations remain unchanged. Fluorination of Sr3(Ti(0.5)Ru(0.5))2O7 to Sr3(Ti(0.5)Ru(0.5))2O7F2 leads to suppression of magnetic order as the fluorinated material approaches metallic behavior. In contrast, fluorination of Sr3(Mn(0.5)Ru(0.5))2O7 and Sr3(Fe(0.5)Ru(0.5))2O7 lifts the magnetic frustration present in the oxide phases, resulting in observation of long-range antiferromagnetic order at low temperature in Sr3(Mn(0.5)Ru(0.5))2O7F2 and Sr3(Fe(0.5)Ru(0.5))2O(5.5)F(3.5). The influence of the topochemical fluorination on the magnetic behavior of the Sr3(M(0.5)Ru(0.5))2O(x)F(y) phases is discussed on the basis of changes to the ruthenium oxidation state and structural distortions.

Fe Mössbauer spectra have been recorded from the hexagonal (6H)- and trigonal (15R)- modifications of BaFeOF and are compared with those previously recorded from the cubic form of BaFeOF. The spectra, recorded over a temperature range from 15 to 650 K show that all of the iron in all the compounds is in the Fe state. Spectra from the 6H- and 15R-modifications were successfully fitted with components that were related to the Fe(1) and Fe(2) structural sites in the 6H variant and to the Fe(1), Fe(2) and Fe(3) structural sites in the 15R form. The magnetic ordering temperatures were determined as 597 ± 3 K for 6H-BaFeOF and 636 ± 3 K for 15R-BaFeOF. These values are surprisingly close to the value of 645 ± 5 K determined for the cubic form. The magnetic interactions in the three forms are compared with a view to explaining this similarity of magnetic ordering temperature.

We thank EPSRC for funding, STFC for providing neutron facilities and Diamond Light Source for provision of synchrotron facilities. We thank Dr Chiu Tang for assistance at Diamond and Dr A. Kusmartseva (University of Edinburgh) for assistance with the SQUID measurements. FDM thanks the Royal Society for a Research Fellowship. The hexagonal ferrites MFeO3 (M=Y, Yb, In) have been studied using a combination of neutron and X-ray powder diffraction, magnetic susceptibility, dielectric measurements and 57Fe Mössbauer spectroscopy. This study confirms the previously reported crystal structure of InFeO3 (YAlO3 structure type, space group P63/mmc), but YFeO3 and YbFeO3 both show a lowering of symmetry to at most P63cm (ferrielectric YMnO3 structure type). However, Mössbauer spectroscopy shows at least two distinct Fe sites for both YFeO3 and YbFeO3 and we suggest that the best model to rationalise this involves phase separation into more than one similar hexagonal YMnO3-like phase. Rietveld analysis of the neutron diffraction data was carried out using two hexagonal phases as a simplest case scenario. In both YFeO3 and YbFeO3, distinct dielectric anomalies are observed near 130 K and 150 K, respectively. These are tentatively correlated with weak anomalies in magnetic susceptibility and lattice parameters, for YFeO3 and YbFeO3, respectively, which may suggest a weak magnetoelectric effect. Comparison of neutron and X-ray powder diffraction shows evidence of long-range magnetic order in both YFeO3 and YbFeO3 at low temperatures. Due to poor sample crystallinity, the compositional and structural effects underlying the phase separation and possible magnetoelectric phenomena cannot be ascertained. Postprint

Modified iron phosphate glasses have been prepared with nominal molar compositions [(1�x)�(0.6P2O5–\ud 0.4Fe2O3)]�xRySO4, where x = 0–0.5 in increments of 0.1 and R = Li, Na, K, Mg, Ca, Ba, or Pb and y = 1 or 2. In\ud most cases the vast majority or all of the sulfate volatalizes and quarternary P2O5–Fe2O3–FeO–RyOz\ud glasses or partially crystalline materials are formed. Here we have characterized the structure, thermal\ud properties, chemical durability and redox state of these materials. Raman spectroscopy indicates that\ud increasing modifier oxide additions result in depolymerization of the phosphate network such that the\ud average value of i, the number of bridging oxygens per –(PO4)– tetrahedron, and expressed as Qi,\ud decreases. Differences have been observed between the structural effects of different modifier types\ud but these are secondary to the amount of modifier added. Alkali additions have little effect on density;\ud slightly increasing Tg and Td; increasing a and Tliq; and promoting bulk crystallization at temperatures\ud of 600–700 �C. Additions of divalent cations increase density, a, Tg, Td, Tliq and promote bulk crystallization\ud at temperatures of 700–800 �C. Overall the addition of divalent cations has a less deleterious effect\ud on glass stability than alkali additions. 57Fe Mössbauer spectroscopy confirms that iron is present as Fe2+\ud and Fe3+ ions which primarily occupy distorted octahedral sites. This is consistent with accepted structural\ud models for iron phosphate glasses. The iron redox ratio, Fe2+/RFe, has a value of 0.13–0.29 for the\ud glasses studied. The base glass exhibits a very low aqueous leach rate when measured by Product Consistency\ud Test B, a standard durability test for nuclear waste glasses. The addition of high quantities of\ud alkali oxide (30–40 mol% R2O) to the base glass increases leach rates, but only to levels comparable with\ud those measured for a commercial soda-lime-silica glass and for a surrogate nuclear waste-loaded borosilicate\ud glass. Divalent cation additions decrease aqueous leach rates and large additions (30–50 mol%\ud RO) provide exceptionally low leach rates that are 2–3 orders of magnitude lower than have been measured\ud for the surrogate waste-loaded borosilicate glass. The P2O5–Fe2O3–FeO–BaO glasses reported here\ud show particular promise as they are ultra-durable, thermally stable, low-melting glasses with a large\ud glass-forming compositional range.

The structural changes that occur in a FeOx/γ-Al2O3 catalyst during the dehydrogenation of ethylbenzene in a fluidized CREC Riser Simulator have been investigated. Chemical and morphological changes are observed to take place as a result of reaction. Electron microscopy reveals the formation of needle-like alumina structures apparently enclosing iron oxide particles. The formation of such structures at relatively low temperatures is unexpected and has not previously been reported. Additionally, X-ray diffraction and Mössbauer spectroscopy confirmed the reduction of the oxidation state of iron, from Fe2O3 (haematite) to Fe3O4 (magnetite). Iron carbides, Fe3C and ɛ-Fe2C, were detected by electron microscopy through electron diffraction and lattice fringes analysis. Carbon deposition (coking) on the catalyst surface also occurs. The observed structural changes are likely to be closely correlated with the catalytic properties of the materials, in particular with catalyst deactivation, and thereby provide important avenues for future study of this industrially important reaction. Fe2O3/Al2O3 catalyst undergoes chemical and morphological changes during ethylbenzene dehydrogenation forming Al2O3 needles which appear to contain reduced Fe3O4 particles. Fe3C also forms during reaction.

Four new phases of general formula, Li11RE18M4O39−δ: REM = NdAl, NdCo, SmCo, SmFe, have been synthesised\ud and characterised. The NdAl phase, and probably the others, is isostructural with the NdFe analogue,\ud but some cation disorder and partial site occupancies prevent full structural refinement of powder\ud neutron diffraction data. The NdCo phase also forms a solid solution with variable Li content (and charge\ud compensation by either oxygen vacancies or variable transition metal oxidation state). The NdAl phase is a\ud modest conductor of Li+ ions whereas the other three phases are electronic conductors, attributed to\ud mixed valence of the transition metal ions. Subsolidus phase diagrams for the systems Li2O–Nd2O3–\ud Al2O3, ‘CoO’ have been determined and an additional new phase, LiCoNd4O8, which appears to have a\ud K2NiF4-related superstructure, identified.

Poland), being the large Ediacaran continental igneous province, that covers an area of 200 000 km 2 in the western margin of East European Craton. The series is underlain by the Cryogenian terrigenous Polesie Series with doleritic sills and dikes. The Volhynian Series consists of the rock beds belonging to the three volcanic cycles with dierent ratios of flood basalts to pyroclastics. The aim of the study was recognition of primary and secondary Fe-bearing minerals, particularly Fe- and Fe-Ti oxides as well as determination of iron oxidation state, that is an important tool in the search for native copper deposits in these rocks. For Mossbauer studies the following rock samples were chosen: the Polesie Series dolerites, the Volhynian Series basalts from the Ukrainian quarries

The main aim of this work is to develop a simple electrochemical sensor for detection of γ-radiation and heavy metals using bacteria. A series of DC and AC electrical measurements were carried out on samples of two types of bacteria, namely Escherichia coli and Deinococcus radiodurans. As a first step, a correlation between DC and AC electrical conductivity and bacteria concentration in solution was established. The study of the effect of γ-radiation and heavy metal ions (Cd2+) on DC and AC electrical characteristics of bacteria revealed a possibility of pattern recognition of the above inhibition factors.

It is an established methodology to use crystallographically well-defined standard materials for understanding site geometries in glasses. Here we discuss the benefits and the limitations of this approach for the investigation by Mossbauer and EXAFS of Fe2+ Fe3+ in aluminosilicate glasses. As a case study we specifically consider [5]Fe2+ [5]Fe3+ sites and whether these exist in our glasses; and if so, whether they have defined site geometries or occur simply as a consequence of the site distortions and Fe-O bond length distributions. Results are consistent with the existence of [5]Fe2+ and [5]Fe3+ but do not prove this because site distortion and a mixture of 4- and 6-coordinated sites can produce comparable results. This exemplifies the need for caution when interpreting glass data based on standards.

A primary mucosa-associated lymphoid tissue lymphoma of the lung in a 27-year-old man was found. The tumor was composed mainly of centrocyte-like cells and plasma cells. These two components were demarcated sharply from each other, resulting in a zoning or biphasic pattern. This characteristic pattern also was present in the involved regional lymph nodes. Monoclonality of tumor cells was shown immunohistochemically and by in situ hybridization techniques. This article also highlights the use of in situ hybridization in detecting light chain mRNA in paraffin sections.

Fifty sections showing cervical intra-epithelial neoplasia grade III were stained with mucicarmine and periodic acid-Schiff reagents to demonstrate mucin production. Seven of these showed mucin within the neoplastic cells (14%); these cases were considered to be a form of adenosquamous carcinoma in situ and lend support to the hypothesis that invasive adenosquamous carcinomas arise from an indifferent reserve cell.

The structural changes that occur in a FeOx/γ-Al2O3 catalyst during the dehydrogenation of ethylbenzene in a fluidized CREC Riser Simulator have been investigated. Chemical and morphological changes are observed to take place as a result of reaction. Electron microscopy reveals the formation of needle-like alumina structures apparently enclosing iron oxide particles. The formation of such structures at relatively low temperatures is unexpected and has not previously been reported. Additionally, X-ray diffraction and Mössbauer spectroscopy confirmed the reduction of the oxidation state of iron, from Fe2O3 (haematite) to Fe3O4 (magnetite). Iron carbides, Fe3C and ɛ-Fe2C, were detected by electron microscopy through electron diffraction and lattice fringes analysis. Carbon deposition (coking) on the catalyst surface also occurs. The observed structural changes are likely to be closely correlated with the catalytic properties of the materials, in particular with catalyst deactivation, and thereby provide important avenues for future study of this industrially important reaction. Fe2O3/Al2O3 catalyst undergoes chemical and morphological changes during ethylbenzene dehydrogenation forming Al2O3 needles which appear to contain reduced Fe3O4 particles. Fe3C also forms during reaction.