Structural correlations in GexSe1-x glasses - a neutron diffraction study

Neutron diffraction measurement is carried out on GexSe1-x glasses, where 0.1 less than or equal to x less than or equal to 0.4, in a Q interval of 0.55-13.8 Angstrom(-1). The first sharp diffraction peak (FSDP) in the structure factor, S(Q), shows a systematic increase in the intensity and shifts to a lower Q with increasing Ge concentration. The coherence length of FSDP increases with x and becomes maximum for 0.33 less than or equal to x less than or equal to 0.4. The Monte-Carlo method, due to Soper, is used to generate S(Q) and also the pair correlation function, g(r). The generated S(Q) is in agreement with the experimental data for all x. Analysis of the first four peaks in the total correlation function, T(r), shows that the short range order in GeSe2 glass is due to Ge(Se-1/2)(4) tetrahedra, in agreement with earlier reports. Se-rich glasses contain Se-chains which are cross-linked with Ge(Se-1/2)(4) tetrahedra. Ge-2(Se-1/2)(6) molecular units are the basic structural units in Ge-rich, x = 0.4, glass. For x = 0.2, 0.33 and 0.4 there is evidence for some of the tetrahedra being in an edge-shared configuration. The number of edge-shared tetrahedra in these glasses increase with increasing Ge content.

The crystal structure of eulytite Pb3BiV3O12

The crystal structure of Pb3BiV3O12 was solved using single-crystal X-ray diffraction technique. The compound crystallizes in the cubic system View the MathML source (No. 220) with eulytite structure with a = 10.7490(7) Å, V = 1241.95(14) Å3 and Z = 4. The final R1 value of 0.0198 (wR2=0.0384) was achieved for 359 independent reflections during the structure refinement. The Pb2+ and Bi3+ cations occupy the special position (16c) while the oxygen anions occupy the general position (48e) in the crystal structure. Unlike many other eulytite compounds, all the crystallographic positions are fully occupied. The structure consists of edge-shared Pb/Bi octahedra linked at the corners to independent [VO4]3− tetrahedra units, generating a eulytite-type network in the crystal lattice.

Remarkable Capacity Retention of Nanostructured Manganese Oxide upon Cycling as an Electrode Material for Supercapacitor

Electrochemical capacity retention of nearly X-ray amorphous nanostructured manganese oxide (nanoMnO2) synthesized by mixing directly KMnO4 with ethylene glycol under ambient conditions for supercapacitor studies is enhanced significantly. Although X-ray diffraction (XRD) pattern of nanoMnO2 shows poor crystallinity, it is found that by Mn K-edge X-ray absorption near edge structure (XANES) measurement that the nanoMnO2 obtained is locally arranged in a δ-MnO2-type layered structure composed of edge-shared network of MnO6 octahedra. Field emission scanning electron microscopy and XANES measurements show that nanoMnO2 contains nearly spherical shaped morphology with δ-MnO2 structure, and 1D nanorods of α-MnO2 type structure (powder XRD) in the annealed (600 °C) sample. Volumetric nitrogen adsorption−desorption isotherms, inductively coupled plasma analysis, and thermal analysis are carried out to obtain physicochemical properties such as surface area (230 m2 g−1), porosity of nanoMnO2 (secondary mesopores of diameter 14.5 nm), water content, composition, etc., which lead to the promising electrochemical properties as an electrode for supercapacitor. The nanoMnO2 shows a very high stability even after 1200 cycles with capacity retention of about 250 F g−1.

Reversible Water Intercalation Accompanied by Coordination and Color Changes in a Layered Metal-Organic Framework

A new two-dimensional 3d-4f mixed-metal mixed dicarboxylate (homocyclic and heterocyclic) of the formula [Gd2(H2O)2Ni(H2O)2(1,2-bdc)2(2,5-pydc)2] 3 8H2O (1; 1,2-H2bdc = 1,2-benzenedicarboxylic acid and 2,5-H2pydc = 2,5- pyridinedicarboxylic acid) has been prepared by employing the hydrothermal method. The structure has infinite onedimensional-Gd-O-Gd- chains formed by the edge-shared GdO9 polyhedral units, resulting exclusively from the connectivity between the Gd3+ ions and the 1,2-bdc units. The chains are connected by the [Ni(H2O)2(2,5-pydc)2]2- metalloligand, forming the two-dimensional layer arrangements. The stacking of the layers creates hydrophilic and hydrophobic spaces in the interlamellar region. A one-dimensional water ladder structure, formed by the extraframework water molecules, occupies the hydrophilic region while the benzene ring of 1,2-bdc occupies the hydrophobic region. To the best of our knowledge, the present compound represents the first example of a 3d-4f mixed-metal carboxylate in which two different aromatic dicarboxylate anions act as the linkers. The stabilization energies of the water clusters have been evaluated using density functional theory calculations. The water molecules in 1 are fully reversible accompanied by a change in color (greenish blue to brown) and coordination around Ni2+ ions (octahedral to distorted tetrahedral).

Origin of the insulating state in NaCuO2

We study the electronic structure of NaCuO2 by analysing experimental core level photoemission and X-ray absorption spectra using a cluster as well as an Anderson impurity Hamiltonian including the band structure of the oxygen sublattice. We show that the X-ray absorption results unambiguously establish a negative value of the charge transfer energy, A. Further, mean-field calculations for the edge-shared one-dimensional CuO2 lattice of NaCuO2 within the multiband Hubbard Hamiltonian show that the origin of the insulating nature lies in the band structure rather than in the correlation effects. LMTO-ASA band structure calculations suggest that NaCuO2 is an insulator with a gap of around 1 eV.

Synthesis and structure of new low dimensional polymeric haloplumbate(II) complexes [Pb4Br12(C40H40N8)] and [Pb4Cl12(C40H40N8)]center dot H2O

New low dimensional polymeric haloplumbate(II) complexes of the dication of (4,4'-bis(imidazolyl-ylmethyl)biphenyl) were synthesised and their crystal structures determined. Complex 1, [Pb4Br12(C40H40N8)], has cis-edge-shared, octahedral, lead bromide double chains. In compound 2 [Pb4Cl12(C40H40N8)]center dot H2O, the inorganic chains are corner-shared, square pyramidal chains of lead chloride. In both compounds the organic ammoniums form regular layers that alternate with the inorganic chains.

Hydrothermal synthesis and structure of [{Mo8V4O36(VO4)(VO)(2)}(n)](7n-) bi-capped alpha-Keggin fragments linked to a chain

The title compound, (H(2)en)(3)H3O {MO8V4O36 (VO4) (VO)(2)} . 4H(2)O, was hydrothermally synthesized and structurally characterized by means of IR, ESR spectrum and single crystal X-ray diffraction. It crystallized in a monoclinic system with space group P2(1)/c, a=1. 980 4(4) nm, b=2. 063 4(4) nm, c=1. 192 0(2) nm, (beta =94. 76(3)degrees and deep black colour. The compound contains V-centered bi-capped alpha -Keggin fragments {Mo8V7O42} that are linked together by edge-shared units (VO5)-O-N via V-O-V bonds, forming a chain.

Syntheses, structures and magnetic properties of two copper(Ii) diphosphonates: [NH3(CH2)2NH3]2[Cu2(hedp)2]·H2O and [NH3CH(CH3)CH2NH3]2[Cu2(hedp)2] (hedp = 1-hydroxyethylidenediphosphonate)

This paper describes the syntheses and characterization of two new copper(II) diphosphonates: [NH3(CH2)2NH3]2[Cu2(hedp)2]·H2O (1) and [NH3CH(CH3)CH2NH3]2[Cu2(hedp)2] (2) (hedp = 1-hydroxyethylidenediphosphonate). Both compounds exhibit similar one-dimensional linear chain structures. The symmetrical {Cu2(hedp)2} dimers are connected by edge-shared {CuO5} square pyramids and form infinite chains. The Cu(II) ions are alternately bridged by O–P–O groups and O atoms. The Cu–O–Cu angles are 95.8(1) and 96.1(1)° for 1 and 2, respectively. Their magnetic properties show moderately strong antiferromagnetic interactions in both compounds.

Parallel polygon scan conversion algorithms: Performance evaluation on a shared bus architecture

In this paper, three parallel polygon scan conversion algorithms have been proposed, and their performance when executed on a shared bus architecture has been compared. It has been shown that the parallel algorithm that does not use edge coherence performs better than those that use edge coherence. Further, a multiprocessing architecture has been proposed to execute the parallel polygon scan conversion algorithms more efficiently than a single shared bus architecture.

Brain responses to auditory and visual stimulus offset: Shared representations of temporal edges

Edges are crucial for the formation of coherent objects from sequential sensory inputs within a single modality. Moreover, temporally coincident boundaries of perceptual objects across different sensory modalities facilitate crossmodal integration. Here, we used functional magnetic resonance imaging in order to examine the neural basis of temporal edge detection across modalities. Onsets of sensory inputs are not only related to the detection of an edge but also to the processing of novel sensory inputs. Thus, we used transitions from input to rest (offsets) as convenient stimuli for studying the neural underpinnings of visual and acoustic edge detection per se. We found, besides modality-specific patterns, shared visual and auditory offset-related activity in the superior temporal sulcus and insula of the right hemisphere. Our data suggest that right hemispheric regions known to be involved in multisensory processing are crucial for detection of edges in the temporal domain across both visual and auditory modalities. This operation is likely to facilitate cross-modal object feature binding based on temporal coincidence. Hum Brain Mapp, 2008. (c) 2008 Wiley-Liss, Inc.

At-the-edge-of-the-forest

This exhibition was the outcome of a personal arts-based exploration of the meaning of interiority. Through the process it was found that existentially the architectural wall differentiating inside from outside does not exist but operates as a space of overlap, a groundless ground providing for dwelling in the real existential sense of the word.

Assessing the potential of inter-organisational shared services

Shared Services (SS) involves the convergence and streamlining of an organisation’s functions to ensure timely service delivery as effectively and efficiently as possible. As a management structure designed to promote value generation, cost savings and improved service delivery by leveraging on economies of scale, the idea of SS is driven by cost reduction and improvements in quality levels of service and efficiency. Current conventional wisdom is that the potential for SS is increasing due to the increasing costs of changing systems and business requirements for organisations and in implementing and running information systems. In addition, due to commoditisation of large information systems such as enterprise systems, many common, supporting functions across organisations are becoming more similar than not, leading to an increasing overlap in processes and fuelling the notion that it is possible for organisations to derive benefits from collaborating and sharing their common services through an inter-organisational shared services (IOSS) arrangement. While there is some research on traditional SS, very little research has been done on IOSS. In particular, it is unclear what are the potential drivers and inhibitors of IOSS. As the concepts of IOSS and SS are closely related to that of Outsourcing, and their distinction is sometimes blurred, this research has the first objective of seeking a clear conceptual understanding of the differences between SS and Outsourcing (in motivators, arrangements, benefits, disadvantages, etc) and based on this conceptual understanding, the second objective of this research is to develop a decision model (Shared Services Potential model) which would aid organisations in deciding which arrangement would be more appropriate for them to adopt in pursuit of process improvements for their operations. As the context of the study is on universities in higher education sharing administrative services common to or across them and with the assumption that such services were homogenous in nature, this thesis also reports on a case study. The case study involved face to face interviews from representatives of an Australian university to explore the potential for IOSS. Our key findings suggest that it is possible for universities to share services common across them as most of them were currently using the same systems although independently.