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Abstract

The technique of crystal growth coupled with a stereophotocalorimetric method has been used in a series of supercooling measurements on pure refractory metals. The cooling history of these metals is recorded on photographic films which are calibrated as a function of the temperature. High absolute amounts of supercooling has been observed in W, Ta, Nb and Re liquid droplets. It is noted that the brightness traces of the solidification process for highly supercooled Re droplets evidence of two successive phase transformations (Re cfc to Re hc) shows.

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Abstract  

A mixed crystal of urea–thiourea was grown by slow evaporation of aqueous solution at room temperature. The bright and transparent crystals obtained were characterized by thermogravimetric–differential thermal analysis (TG–DTA), UV and FTIR spectroscopic analyses. A fitting decomposition pattern for the title compound was formulated on the TG curve which shows a two stage weight loss between 200 and 750 °C. In this temperature range DTA curve shows exothermic peaks supporting the formulated decomposition pattern. The UV and FTIR spectra show the characteristic absorption, vibration frequencies due to urea–thiourea mixed crystals. Detailed structural analysis of the compound is under progress.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: R. Jenkins, H. Grubbs, R. Newman, R. Bass, J. Brenizer, D. Jones, T. Williamson, D. Danehower, and R. Long

Abstract  

The use of instrumental neutron activation analysis (INAA) in determining selected elements in biological materials has been reported by numerous authors. Some of these have detailed the use of INAA to determine an elemental analysis in tobaccos of various geographical origins. This paper describes the first use of INAA to measure the distribution of selected inorganic elements within the tobacco leaf at a single plant stalk position for one tobacco curing routine. Three replicate plots of a common bright tobacco cultivar were grown under normal cultural conditions characteristic for the bright variety. The tobacco leaves were sampled at selected positions in the leaf. The brigh tobacco was cured in a conventional flue-curing barn using standard practices. Immediately after collection, each individual sample was freeze-dried, crushed and sampled. The leaf midrib samples were prepared using a similar procedure. A subsample of about 100 mg was taken from each sample, sealed in a polyethylene bag, irradiated in a thermal neutron flux of 2×1017 n·m–2·s–1 in a pneumatic rabbit system, and subsequently counted to obtain the reported data. A standard reference material was used as a comparator to yield relative elemental concentrations for Ca, Mg, Mn, Na, K, Cl and Br. The data show that chlorine, potassium, sodium and calcium have definite concentration trends within the tobacco leaf. The data also show that some elements, e.g. Mn, were more uniformly distributed throughout the leaf.

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Abstract

In the wake of the Cultural Revolution (1966–76) and with China's new “Open Door” policy towards Western culture and Western new music, we have witnessed the exuberant growth of a new generation of Chinese composers. Tan Dun, Chen Yi and Bright Sheng have expressed in various ways their indebtedness to the heritage of Béla Bartók's music. Chen Yi, a fellow student of Tan Dun during her time at Central Conservatory of Music and Columbia University, recalled studying all of Bartók's six string quartets in the composition classes. Bright Sheng also openly admits that his use of the “primitiveness and savageness” of folk elements is directly modelled on the music of Bartók. The dissemination of Bartók's music in China is signified by the extent to which the journals published by China's top two music conservatories — the Central Conservatory of Music and the Shanghai Conservatory of Music — focus on discussion of this repertoire. Frank Kouwenhoven's studies of contemporary Chinese composers also point out that Bartók's influence overshadows most other major composers from the West. In this paper the reception of Bartók's music by Chinese composers in the post-Cultural Revolution era will be explored with reference to the musical as well as socio-cultural factors that fostered the influence.

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Abstract  

Inorganic pigments containing lanthanides based on pseudo cubic structure of SrSnO3 have been prepared by solid state reaction between SrCO3, SnO2 and lanthanide oxides (Tb4O7, Pr6O11, CeO2) in the temperature range 1300–1550°C. The resultant materials were characterised by XRD, TG-DTA and colourimetric techniques were used. The most interesting colour properties were provided by SrTb0.4Sn0.6O3 prepared by firing at temperature 1500°C which has light yellow-green colour hue. The increase of temperature 1300–1500°C caused the creation of pigments with deeper and brighter colour hue. Colour properties of the samples prepared by calcination at 1550°C were of inferior quality due to structural changes from pseudo cubic to orthorhombic system.

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Abstract  

This work is focused on determination of the optimum firing temperature which leads to formation of the compounds LnFeO3 with good pigment-application properties (Ln=Gd, La, Yb, Tm, Lu). Based on results of thermal analysis the compounds were prepared by the solid-state reaction at temperature 900 and 1000°C. Colours of pigments vary depending on type of used lanthanoid (from light sienna to dark brown) and also on the type of precursor. Generally, the compounds prepared from iron oxide have more interesting color properties. Colour of these compounds is brighter and deeper. Increasing of the calcination temperature from 900 to 1000°C causes the darkening of colour. The most problably, the darkening is connected with partial reduction of Fe3+ to Fe2+.

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Abstract  

A complex oxalate precursor, CaCu3(TiO)4(C2O4)8·9H2O, (CCT-OX), was synthesized and the precipitate that obtained was confirmed to be monophasic by the wet chemical analyses, X-ray diffraction, FTIR absorption and TG/DTA analyses. The thermal decomposition of this oxalate precursor led to the formation of phase-pure calcium copper titanate, CaCu3Ti4O12, (CCTO) at ≥680°C. The bright-field TEM micrographs revealed that the size of the as synthesized crystallites to be in the 30–80 nm range. The powders so obtained had excellent sinterability resulting in high density ceramics which exhibited giant dielectric constants upto 40000 (1 kHz) at 25°C, accompanied by low dielectric losses, <0.07.

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A F. oxysporum f. sp. dianthi strain, transformed with genes coding for fluorescent proteins (GFP or DsRedFP) as markers, was used to study the first host/pathogen interaction on carnation roots. The transformants’ mycelium observed under fluorescent light displayed a high expression of GFP and DsRedFP as a bright green or red cytoplasmic fluorescence. The root apparatus of a partially resistant cultivar of carnation was artificially inoculated by stable transformants and local colonization of plant tissues was monitored by means of fluorescence microscopy. A GFP transformed strain of F. oxysporum f. sp. dianthi allowed to follow first colonization steps on and within host root tissues. Implication of this research in studying resistance processes in carnation is discussed.

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Abstract  

Two petroleum-derived aromatic hydrocarbon resins (HRs) were blended (1:1) with expanded polystyrene (EPS) waste and small amounts (up to 10 mass%) of poly(vinyl chloride) (PVC) to increase both the lustrous carbon (LC) yield and softening point of the blends without any deterioration of their rheological characteristics. The blends were prepared and tested for LC content, softening points, shear stress and apparent viscosity to check their applicability as LC precursors under industrial conditions. The properties of polystyrene compositions with bitumen fractions depend primarily on composition and viscosity of oil fraction. Additional modification by poly(vinyl chloride) improves the blends’ properties, like bright coal content, softening point and viscosity, and opens new possibilities of plastics’ wastes utilization.

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Govind Wild Life Sanctuary in the Western Himalayas with its diverse vegetation types provides excellent habitats and microclimates for a lush growth of bryophytes. During investigations on the bryophytes of this region Plagiothecium euryphyllum (Cardot et Thér.) Z. Iwats. and P. cavifolium (Brid.) Z. Iwats. have been identified for the first time from India. P. euryphyllum is characterised by bright green to yellowish green plants, irregularly branched, complanate. Central strand developed. Leaves erectopatent, imbricate, ovate oblong, margin entire, acute to acuminate at apex, costa two forked, decurrent with hyaline, rectangular cells. Seta reddish, capsule erect to inclined, while plants of P. cavifolium are yellowish green, glossy, prostrate, irregularly branched, branches julaceous. Leaves appressed to stem, closely imbricate, erectopatent, ovate lanceolate, symmetrical, margin minutely dentate at apex, cells at alar region rectangular costa two short. Seta reddish brown, capsule erect, pyriform. A morpho-taxonomic account of above two taxa is provided.

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