Microwave-hydrothermal processing of layered anion exchangers

1996 ◽  
Vol 11 (8) ◽  
pp. 1866-1869 ◽  
Author(s):  
Sridhar Komarneni ◽  
Q. H. Li ◽  
Rustum Roy
Keyword(s):  
High Selectivity ◽  
Hydrothermal Processing ◽  
Basic Salt ◽  
Anion Exchangers ◽  
Microwave Hydrothermal ◽  
Order Of Magnitude ◽  
Very High

We have compared the microwave-hydrothermal (M-H) processing with conventional hydrothermal (C-H) processing in the preparation of two layered anion exchangers, i.e., Mg3Al(OH)8NO3 · nH2O and Ni1-xZn2x(OH)2(CH3COO)2x · nH2O. Both these phases can be crystallized more rapidly (an order of magnitude) under M-H processing compared to C-H processing. The above layered mixed basic salt of Ni and Zn was found to exhibit very high selectivity for PO4= (Kd = 15,000). Its order of selectivity for various anions in the presence of 0.1 N̲ NaC1 (ratio of C1- to anion in question is 100) increases as follows: PO4= ≫ SO4= > NO3-.

Microwave-hydrothermal processing of metal powders

1995 ◽  
Vol 10 (7) ◽  
pp. 1687-1692 ◽  
Author(s):  
Sridhar Komarneni ◽  
Rajyalakshmi Pidugu ◽  
Qing Hua Li ◽  
Rustum Roy
Keyword(s):  
Ethylene Glycol ◽  
Metal Powder ◽  
Metal Salts ◽  
Hydrothermal Processing ◽  
Metal Powders ◽  
Ceramic Powders ◽  
Powder Synthesis ◽  
Microwave Hydrothermal ◽  
Order Of Magnitude ◽  
Kinetics Of

Novel microwave-hydrothermal processing has been developed by us recently for the synthesis of a wide variety of ceramic powders. Herein, we report the use of microwave-hydrothermal processing to synthesize several metal powders such as Cu, Ni, Co, and Ag by reducing their corresponding metal salts or hydroxides with ethylene glycol. Metal powders have been produced extremely rapidly a (few minutes) by microwave catalysis. The kinetics of metal powder synthesis have been increased by at least an order of magnitude by microwave-hydrothermal processing compared to the conventional refluxing process in ethylene glycol at about 195 °C.

Selenium oxyanions: Highly selective uptake by a novel anion exchanger

2002 ◽  
Vol 17 (12) ◽  
pp. 2993-2996 ◽  
Author(s):  
Naofumi Kozai ◽  
Toshihiko Ohnuki ◽  
Sridhar Komarneni
Keyword(s):  
Anion Exchanger ◽  
High Selectivity ◽  
Contaminated Water ◽  
Basic Salt ◽  
Selective Uptake ◽  
Very High

We report the extremely high and selective uptake of selenium oxyanions by a novel anion exchanger, Ni1-xZn2x(OH)2(OCOCH3)2xnH2O (0.15<x<0.25). The tested Ni–Zn basic salt (x=0.24) exhibited very high selectivity for Se(IV) [Kd = 9.0 × 104 cm3/g with an initial Se(IV) concentration of 1 × 10-4 M] in the presence of 0.1 M C1− solution. The uptake of Se(IV) on the Ni–Zn basic salt was irreversible when treated with solutions containing 1 N C1− 1N NO3− or 1 N PO43−This novel exchanger also showed high Kd (2.6 × 103 cm3/g) for Se(VI), and therefore it is expected to be useful for decontamination and removal of selenium oxyanions from contaminated water.

scholarly journals Observational manifestations of ‘cosmological dinosaurs’ at redshifts z ∼ 20

2021 ◽  
Vol 503 (2) ◽  
pp. 3081-3088
Author(s):  
V K Dubrovich ◽  
Yu N Eroshenko ◽  
S I Grachev
Keyword(s):  
Black Hole ◽  
Atomic Hydrogen ◽  
Radiation Transfer ◽  
Ring Width ◽  
High Mass ◽  
Primordial Black Hole ◽  
Array Type ◽  
Local Sources ◽  
Order Of Magnitude ◽  
Very High

ABSTRACT We consider a primordial black hole of very high mass, $10^9\!-\!10^{10}\, \mathrm{M}_\odot$, surrounded by the dark matter and bayonic halo at redshifts z ∼ 20 without any local sources of energy release. Such heavy and concentrated objects in the early Universe were previously called ‘cosmological dinosaurs’. Spectral distribution and spatial variation of the brightness in the 21-cm line of atomic hydrogen are calculated with the theory of radiation transfer. It is shown that a narrow and deep absorption arises in the form of the spherical shell around the primordial black hole at the certain radius. The parameters of this shell depend almost exclusively on the mass of the black hole. The angular diameter 18 arcsec of the absorption ring at z ∼ 20 is well within the current technical possibilities of the Square Kilometre Array type telescopes. But the observation of the ring width itself requires an order of magnitude better resolution.

scholarly journals Diffracted Light Contrast: Improving the Resolution of a Basic Light Microscope by an Order of Magnitude

2006 ◽  
Vol 14 (6) ◽  
pp. 10-15
Author(s):  
W. Barry Piekos
Keyword(s):  
Epithelial Cells ◽  
Light Microscope ◽  
Depth Of Field ◽  
High Quality ◽  
Surface Lattice ◽  
Buccal Epithelial Cells ◽  
Order Of Magnitude ◽  
Student Laboratory ◽  
Light Contrast ◽  
Very High

The discovery that the diffracted light from a convex edge can be used to form a very high-quality, shadowcast image on any light microscope has led to a device and method, diffracted-light contrast (DLC), which will allow shadowcast imaging to be routinely performed on student/laboratory microscopes (Piekos, 1999, 2003). The surface lattice of Surirella gema was easily resolved, and micrographs comparing the subcellular details of buccal epithelial cells viewed with DLC vs. Nomarski DIC showed that, on the microscopes used, DLC was superior in both the detail it rendered and depth of field. Although the images presented revealed DLC to be an excellent technique, the full capabilities of the technique were not known at the time.

scholarly journals Inexpensive Intelligence Using Procedural Propositional Logic

2009 ◽  
Vol 13 (2) ◽  
Author(s):  
Richard C. Hicks ◽  
Keith Wright
Keyword(s):  
Propositional Logic ◽  
Inference Engine ◽  
External Costs ◽  
High Return ◽  
Order Of Magnitude ◽  
Inference Systems ◽  
The Cost ◽  
Engine Systems ◽  
Logic Rule ◽  
Very High

Implementations of inference engine systems invoke many costs, including the cost of the inference engine itself, the cost of integrating the inference engine, and the cost of specialized personnel needed to create and maintain the system. These costs make a very high return on investment a criterion for incorporating these systems into the corporate portfolio of applications and technologies. Recently, the No Inference Engine Theory (NIET) [8] has been developed for creating procedural propositional logic rule-based systems. The NIET systems are implemented in traditional procedural languages such as C++ and do not need an inference engine or proprietary languages, thus eliminating the cost of the inference engine, the cost of integrating the system, and the cost for knowledge of a proprietary language. In addition, these procedural systems are an order of magnitude faster [8] than inference systems and maintain linear performance. For problems using propositional logic, the procedural systems described in this paper offer dramatically lower costs, higher performance, and ease of integration. Lowering the external costs and eliminating the need for specialized skills should make NIET systems more profitable and lead to the wider use of propositional logic systems in business.

Synthesis of CuxNi(1−x)O coral-like nanostructures and their application in the design of a reusable toxic heavy metal ion sensor based on an adsorption-mediated electrochemical technique

2017 ◽  
Vol 4 (1) ◽  
pp. 191-202 ◽  
Author(s):  
Sayan Dey ◽  
Sumita Santra ◽  
Anupam Midya ◽  
Prasanta Kumar Guha ◽  
Samit Kumar Ray
Keyword(s):  
Heavy Metal ◽  
Detection Limit ◽  
Metal Ion ◽  
High Selectivity ◽  
Heavy Metal Ion ◽  
Electrochemical Technique ◽  
Toxic Heavy Metal ◽  
Ion Sensors ◽  
Metal Ion Sensors ◽  
Very High

Nanostructured, Cu-doped nickel oxides serve as excellent, ultra-fast, re-usable heavy metal ion sensors with an ultra-low detection limit and very high selectivity towards toxic Cr(vi) ions.

ChemInform Abstract: Microwave-Hydrothermal Processing of BiFeO3 and CsAl2PO6.

ChemInform ◽  
2010 ◽  
Vol 27 (40) ◽  
pp. no-no
Author(s):  
S. KOMARNENI ◽  
V. C. MENON ◽  
Q. H. LI ◽  
R. ROY ◽  
F. AINGER
Keyword(s):  
Hydrothermal Processing ◽  
Microwave Hydrothermal

Kinetics of ο-Chloronitrobenzene Hydrogenation on Palladium/Carbon Catalyst

2011 ◽  
Vol 239-242 ◽  
pp. 161-167
Author(s):  
Xiao Zhen Wang ◽  
Yi Feng Zhu ◽  
Xiao Nian Li
Keyword(s):  
High Selectivity ◽  
Total Yield ◽  
Hydrogenation Reaction ◽  
Commercial Application ◽  
Reaction Conditions ◽  
Solvent Free Conditions ◽  
Hydrogenation Kinetics ◽  
Favorable Reaction ◽  
Kinetics Of ◽  
Very High

A 2 wt % Pd/C catalyst has been prepared by chemical impregnation and used to catalyze the hydrogenation of o-chloronitrobenzene (o-CNB) to o-chloroaniline (o-CAN) in solvent-free conditions. The effects of reaction temperature, H2 pressure, and stirring intensity on the hydrogenation kinetics have been investigated. The hydrogenation reaction showed very high selectivity with dehalogenation side products as low as 0.3% of total yield. The favorable reaction conditions were found to be temperature T = 383 K, stirring speed = 900 rpm, and feeding ratio CNB/catalyst = 200/1 (m/m). The recycled Pd/C still retained more than 98% of its original selectivity after 12 repeat used, indicating the catalyst had strong potentials for commercial application at industrial scale.

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