ChemInform Abstract: Regioselective Mononitration of Coumarins Using Chromium Nitrate as Nitrating Agent.

Using a new low temperature calorimeter, which is briefly described in the paper, the specific heats have been measured from 65° to 300°K. for the following salts: chromium sulphate (hydrated and anhydrous), chromium nitrate, cobalt nitrate, and nickel nitrate (hydrated). Hydrated chromium sulphate was found to have a transition of the second order at 195°K., while the specific heat of the anhydrous salt was quite regular. The hydrated nitrates all showed second order transitions in the neighborhood of 150°K. The entropy changes associated with these transitions have been estimated approximately, and vary from about 0.4 R for cobalt nitrate to 1.65 R for chromium nitrate, where R is the gas constant. Pending further evidence, it is tentatively suggested that the transitions are due to the onset of partial rotation of the H2O groups in the crystals.

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The Oxidation of Ni and Ni-20Cr Deposited with Chromia Thin Films VIA Combustion CVD

MRS Proceedings ◽

10.1557/proc-555-67 ◽

1998 ◽

Vol 555 ◽

Cited By ~ 2

Author(s):

A. E. Alexiou ◽

M. R. Hendrick ◽

J. M. Hampikian

Keyword(s):

Thin Films ◽

Vapor Deposition ◽

Deposition Temperature ◽

Chemical Vapor ◽

Mass Gain ◽

Chromium Nitrate ◽

Oxidation Protection ◽

Order Of Magnitude ◽

Amorphous Coatings

AbstractChromia thin films were deposited onto substrates of Ni and Ni-20Cr by gaseous fuel combustion chemical vapor deposition. The chemical precursor utilized to achieve chromia films was aqueous 0.27M chromium nitrate, and the depositions took place within the flame at temperatures between 200 and 550°C. Amorphous coatings were deposited between 200 and 375°C, whereas crystalline coatings of chromia (eskolaite) were deposited between 400 and 550°C. The eskolaite deposition rate was approximately five times faster than the amorphous chromia. Chromia coatings containing 2 wt% yttria were also formed. The deposition temperature necessary to form crystalline chromia/yttria coatings was slightly higher (∼50°C) than those containing chromia only. The ability of the various coatings to provide oxidation protection was characterized using thermogravimetric analysis (TGA). The eskolaite coatings that are at least 1 im thick reduce the oxidation mass gain/area of Ni-20Cr by nearly a factor of ten and the parabolic constant by an order of magnitude, whereas the amorphous chromia coatings that are 0.6 μm thick do not demonstrate such an improvement. Yttria-doped chromia coatings further reduce the parabolic constant by two orders of magnitude, consistent with expectation. Characterization of the coatings was accomplished using a variety of techniques, including SEM, TEM, EDS, and XRD.

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On the Action of Metallic (and other) Salts on Carbonate of Lime

Proceedings of the Royal Society of Edinburgh ◽

10.1017/s0370164600007252 ◽

1892 ◽

Vol 18 ◽

pp. 52-54 ◽

Cited By ~ 1

Author(s):

Robert Irvine ◽

W. S. Anderson

Keyword(s):

Copper Nitrate ◽

Cobalt Nitrate ◽

Iron Chloride ◽

Lead Chloride ◽

Mercury Chloride ◽

Chromium Nitrate ◽

Manganese Sulphate ◽

Silver Phosphate ◽

The Past ◽

Marine Station

It is well known that pseudomorphic changes take place with many minerals. These changes may be either by alteration or displacement. In the case of carbonate of lime they are generally of the former order.Among other work conducted at the Marine Station, Granton, during the past year, a number of experiments were instituted with the view of showing how far carbonate of lime was influenced in this direction by metallic and other salts.Corals, preferably the more porous and soft varieties, were selected for this purpose, and these were exposed to the action of solutions of the following salts:–Chloride of manganese, sulphate of iron, chloride of zinc, chloride of chromium, nitrate of nickel, nitrate of cobalt, nitrate of copper, nitrate of lead, chloride of mercury, chloride of tin, nitrate of silver, phosphate of ammonia.

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Restricted Diffusion of Chromium Nitrate Salt Solutions into Porous Sol-Gel-Silica Monoliths

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.1998.tb02422.x ◽

2005 ◽

Vol 81 (4) ◽

pp. 877-884 ◽

Cited By ~ 10

Author(s):

James Kunetz ◽

Larry Hench

Keyword(s):

Sol Gel ◽

Restricted Diffusion ◽

Chromium Nitrate ◽

Nitrate Salt ◽

Salt Solutions ◽

Silica Monoliths

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Determination of lead in serum by graphite furnace atomic absorption spectrometry using chromium nitrate as a matrix modifier.

Eisei kagaku ◽

10.1248/jhs1956.37.22 ◽

1991 ◽

Vol 37 (1) ◽

pp. 22-27 ◽

Cited By ~ 3

Author(s):

SHOJI IMAI ◽

TOSHIYUKI TANAKA ◽

KENGO SAITO ◽

YASUHISA HAYASHI

Keyword(s):

Atomic Absorption Spectrometry ◽

Atomic Absorption ◽

Graphite Furnace ◽

Absorption Spectrometry ◽

Chromium Nitrate ◽

Matrix Modifier ◽

Graphite Furnace Atomic Absorption

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USE OF BRAZILIAN CLAYS FOR THE REMOVAL OF CHROMIUM IONS PRESENT IN INDUSTRIAL EFFLUENTS

Periódico Tchê Química ◽

10.52571/ptq.v6.n11.2009.12_periodico11_pgs_11_16.pdf ◽

2009 ◽

Vol 06 (11) ◽

pp. 11-16

Author(s):

Alexandre Andrade CERQUEIRA ◽

Mônica Regina da Costa MARQUES

Keyword(s):

Batch Reactor ◽

Industrial Effluents ◽

Synthetic Wastewater ◽

Chromium Nitrate ◽

X Ray Diffraction ◽

Experimental Procedure ◽

X Ray ◽

Anion Effect ◽

Chromium Ions ◽

Synthetic Clay

This study aimed to evaluate the ability to remove an ion Cr (III) in synthetic wastewater using a Brazilian clay. We evaluated the influence of the concentration of cation and anion effect on the ability of removal of chromium ions in effluent inorganic synthetic clay for montmorillonite (F-II) Fulmont provided by the industry. The clay was characterized by X-ray diffraction and chemical analysis. The tests were performed by removal of two different methods: in batch reactor and filtration in a column of clay. Tests were conducted at different pH `s (2-10), the mass of clay and solution of chromium nitrate (III) used in each test was 2g and 25 ml respectively. The efficiency of removal was determined by atomic absorption analysis of the supernatants. Preliminary results showed the efficiency of removal of chromium ions by the Brazilian clay. It was observed that the concentration of the solution, the experimental procedure and the presence of anions influenced the process of exchange, with the best results when used dilute solutions in the presence of nitrate ion and technology in filtration column resulting in removal of up to 100% of chromium (III).

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