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101.
Brandaleze Elena Bazán Vanesa Orozco Ivana Valentini Marcelo Gomez Giuliana 《Journal of Thermal Analysis and Calorimetry》2018,133(1):435-441
Journal of Thermal Analysis and Calorimetry - Rhenium production from copper and molybdenum sulphides involves the use of a pyrometallurgical process. In traditional pyrometallurgy processes, gases... 相似文献
102.
Jerry Fields Xiang Ouyang Steven R. Herron Katherine A. Kantardjieff Ali Jabalameli Frank A. Gomez 《Journal of chemical crystallography》2007,37(1):55-62
The synthesis and molecular structure of the novel 1-[ferrocenyl(hydroxy)methyl]-1,7-dicarba-closo-dodecaborane (1) is described. Compound 1 was synthesized from reaction of m-carborane and ferrocene carboxaldehyde using n-butyllithium (n-BuLi) or tetrabutylammonium fluoride (TBAF) in THF in 45% and 36% yield, respectively. Compound 1 consists of a ferrocene molecule tethered to m-carborane through a methylhydroxy bridge. The crystal structure of 1 was determined by single crystal X-ray diffraction analysis. Crystal data: 1 [Fe(C5H5)(C5H4-CH2O-1,7-C2B10H12)], formula weight = 359.17, crystallized in orthorhombic system, space group Pna2
1
with a=19.698(4) ?, b=10.709(2) ?, c=8.520(2) ?, and V=1797.3(7) ?3 and Z=4. Refined to R
1=0.043 for 4124 observed reflections with I/σ>2σ(I). The compound was crystallized as racemic twins in a ratio of 73(2)/27(2). The unsubstituted Cp ring was disordered and
modeled as two conformations in a 53(3)/47(3) ratio. Intermolecular hydrogen bonding was observed from the hydrogen of the
meta-carbon on the carborane cluster towards the hydroxyl oxygen. 相似文献
103.
A critical review of recent developments in the use of chemometric experimental design based optimization techniques in capillary
electrophoresis applications is presented. Current advances have led to enhanced separation capabilities of a wide range of
analytes in such areas as biological, environmental, food technology, pharmaceutical, and medical analysis. Significant developments
in design, detection methodology and applications from the last 5 years (2002–2007) are reported. Furthermore, future perspectives
in the use of chemometric methodology in capillary electrophoresis are considered. 相似文献
104.
Marine derived polysaccharides for biomedical applications: chemical modification approaches 总被引:1,自引:0,他引:1
Polysaccharide-based biomaterials are an emerging class in several biomedical fields such as tissue regeneration, particularly for cartilage, drug delivery devices and gelentrapment systems for the immobilization of cells. Important properties of the polysaccharides include controllable biological activity, biodegradability, and their ability to form hydrogels. Most of the polysaccharides used derive from natural sources; particularly, alginate and chitin, two polysaccharides which have an extensive history of use in medicine, pharmacy and basic sciences, and can be easily extracted from marine plants (algae kelp) and crab shells, respectively. The recent rediscovery of poly-saccharidebased materials is also attributable to new synthetic routes for their chemical modification, with the aim of promoting new biological activities and/or to modify the final properties of the biomaterials for specific purposes. These synthetic strategies also involve the combination of polysaccharides with other polymers. A review of the more recent research in the field of chemical modification of alginate, chitin and its derivative chitosan is presented. Moreover, we report as case studies the results of our recent work concerning various different approaches and applications of polysaccharide-based biomaterials, such as the realization of novel composites based on calcium sulphate blended with alginate and with a chemically modified chitosan, the synthesis of novel alginate-poly(ethylene glycol) copolymers and the development of a family of materials based on alginate and acrylic polymers of potential interest as drug delivery systems. 相似文献
105.
A novel solid-phase synthesis of tetrasubstituted 2-imino-1,3-thiazolines using a functionalizing cleavage strategy is described. The synthetic route utilized the ambident reactivity of a dithiocarbamate functionality to synthesize the key resin-bound electrophilic thiazolium intermediate. The desired products were efficiently obtained in high purity by the reaction of various amines with the thiazolium salt. 相似文献
106.
Griffin TP Diaz JA Arkin CR Soto C Curley CH Gomez O 《Journal of the American Society for Mass Spectrometry》2008,19(10):1411-1418
The visualization of hazardous gaseous emissions at volcanoes using in-situ mass spectrometry (MS) is a key step towards a
better comprehension of the geophysical phenomena surrounding eruptive activity. In-situ data consisting of helium, carbon
dioxide, sulfur dioxide, and other gas species, were acquired with a quadrupole based MS system. Global position systems (GPS)
and MS data were plotted on ground imagery, topography, and remote sensing data collected by a host of instruments during
the second Costa Rica Airborne Research and Technology Applications (CARTA) mission. This combination of gas and imaging data
allowed three-dimensional (3D) visualization of the volcanic plume and the mapping of gas concentration at several volcanic
structures and urban areas. This combined set of data has demonstrated a better tool to assess hazardous conditions by visualizing
and modeling of possible scenarios of volcanic activity. The MS system is used for in-situ measurement of 3D gas concentrations
at different volcanic locations with three different transportation platforms: aircraft, auto, and hand-carried. The demonstration
for urban contamination mapping is also presented as another possible use for the MS system. 相似文献
107.
D. Gomez M. E. Pérez M. Lobo A. V. Podolsky T. A. Shaposhnikova 《Doklady Mathematics》2016,93(2):140-144
We address the homogenization of a variational inequality posed in perforated media issue from a unilateral problem for the p-Laplacian. We consider the n-Laplace operator in a perforated domain of ?n, n ≥ 3, with restrictions for the solution and its flux (the flux associated with the n-Laplacian) on the boundary of the perforations which are assumed to be isoperimetric. The solution is assumed to be positive on the boundary of the holes and the flux is bounded from above by a negative, nonlinear monotone function multiplied by a large parameter. A certain non periodical distribution of the perforations is allowed while the assumption that their size is much smaller than the periodicity scale is performed. We make it clear that in the average constants of the problem, the perimeter of the perforations appears for any shape. 相似文献
108.
Ariana Gonzalez Lissette Estala Michelle Gaines Frank A. Gomez 《Electrophoresis》2016,37(12):1685-1690
A novel microfluidic thread/paper‐based analytical device (μTPAD) to detect glucose through a colorimetric assay is described. The μTPAD was fabricated from nylon thread trifurcated into three channels terminating at analysis sites comprised of circular zones of chromatography paper, which have previously been spotted with glucose of different concentrations. A solution of glucose oxidase (GOx), horseradish peroxidase (HRP), and potassium iodide (KI) is transported via capillary action to the analysis sites where a yellow‐brown color is observed indicating oxidation of iodide to iodine. The device was then dried, scanned, and analyzed yielding a correlation between yellow intensity and glucose concentrations. Both a flat platform constructed mainly of tape, and a cone platform constructed from tape and polyvinyl chloride, are described. Studies to quantitate glucose in artificial urine showed good correlation using the μTPAD. 相似文献
109.
110.