140 resultados para Bronzes, Bini


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"Sonderabdruck aus dem XVII. u. XVIII. Jahresbericht des Württ. Vereins für Handelsgeographie."

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Reaction of bismuth metal with WO$_3$ in the absence of oxygen yields interesting bronze-like phases. From analytical electron microscopy and X-ray photoelectron spectroscopy, the product phases are found to have the general composition Bi$_x$ WO$_3$ with bismuth in the 3+ state. Structural investigations made with high resolution electron micrscopy and cognate techniques reveal that when x < 0.02, a perovskite bronze is formed. When x $\geqslant$ 0.02, however, intergrowth tungsten bronzes (i.t.b.) containing varying widths of the WO$_3$ slab are formed, the lattice periodicity being in the range 2.3-5.1 nm in a direction perpendicular to the WO$_3$ slabs. Image-matching studies indicate that the bismuth atoms are in the tunnels of the hexagonal tungsten bronze (h.t.b.) strips and the h.t.b. strips always remain one-tunnel wide. Annealed samples show a satellite structure around the superlattice spots in the electron diffraction patterns, possibly owing to ordering of the bismuth atoms in the tunnels. The i.t.b. phases show recurrent intergrowths extending up to 100 nm in several crystals. The periodicity varies considerably within the same crystal wherever there is disordered intergrowth, but unit cell dimensions can be assigned from X-ray and electron diffraction patterns. The maximum value of x in the i.t.b. phases is ca. 0.07 and there is no evidence for the i.t.b. phase progressively giving way to the h.t.b. phase with increase in x. Hexagonal tungsten bronzes that contain bismuth with x up to 0.02 can be formed by starting from hexagonal WO$_3$, but the h.t.b. phase seems to be metastable. Optical, magnetic and electron transport properties of the i.t.b. phases have been measured and it appears that the electrons become itinerant when x > 0.05.

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A novel low-temperature method of preparing bronzes of tungsten and vanadium and other reduced phases is reported.

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High resolution electron microscopic studies show that bismuth forms intergrowth tungsten bronzes containing varying widths of the WO3 slab and one-tunnel wide HTB strips.

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A new class of layered alkali metal-MoO3 bronzes,AxMoO3 (A =Li, Na, K, Rb), with nearly the same unit cell parameters as the host oxide has been synthesized by the solid-state reaction of MoO3 with alkali metal iodides around 575 K; LixMoO3 absorbs H2O causing an increase in theb parameter of the unit cell. Hexagonal potassium bronzes of W1−xMoxO3 are synthesized for the first time.

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Several vanadium, tungsten, and molybdenum oxide bronzes have been prepared using microwave irradiation. Metal oxides and alkali metal iodides were used as starting materials, Intermittent grinding and inert atmosphere were found to be necessary for the synthesis of most of the bronzes, The reaction temperatures are remarkably lower than those employed for conventional synthetic techniques and the microwave assisted reactions proceed at extremely fast rates. The microwave synthesized bronzes consist of particles having long, rectangular rod-like morphology. (C) 1999 Academic Press.

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[Vente (Art). 1839-12-23. Paris]

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[Vente (Art). 1840-01-18. Paris]

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[Vente (Art). 1841-02-19. Paris]

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Igiogbe cultural heritage has existed since the founding of Bini kingdom without any controversy; however since the Supreme Court decision in Idehen v Idehen the issue of Igiogbe has assumed new dimensions. Igiogbe - the house in which a Benin man lived and died devolves on his first son absolutely; but since the beginning of 20th century litigation as to the real meaning of Igiogbe and who is entitled to inheritance thereof began to increase. Controversies and increase in litigation over Igiogbe has occasioned a shift in the practice, the Bini’s are not conscious of some of these changes, most of them (Bini’s) still claim Igiogbe practices is rigidly adhered to. This study on Igiogbe inheritance in Bini kingdom is therefore carried out with a view to bringing out the changes in Igiogbe cultural practice using legal and anthropological tools to examine the changes. While laying the foundation for the discussion on the main research object the researcher examined the origin and status of customary law in Nigeria. There after I examined Igiogbe inheritance in Bini kingdom. Igiogbe and the issue of first son were critically analyzed with the aid of the research questions bringing out the changes in Igiogbe concept from traditional practice to modern practice. Study shows Igiogbe practice is still relevant in modern Bini kingdom, however, the shift and changes in practice of this cultural milieu has lead me to ask some fundamental questions which I intend to answer in the broader research work in future.