Studies of phase transformations in nitrates and nitrites I. Changes in ultra-violet absorption spectra on melting

1963 ◽  
Vol 276 (1367) ◽  
pp. 437-452 ◽  
Keyword(s):  
Nitric Acid ◽  
Phase Transformations ◽  
Ammonium Nitrate ◽  
Absorption Spectra ◽  
Ultra Violet ◽  
The Other ◽  
Sodium Potassium ◽  
Nearest Neighbours ◽  
Isopropyl Nitrate ◽  
Sodium And Potassium

Ultra-violet absorption spectra of ions in crystals are sensitive to their environment of neighbouring ions. This fact is utilized to study melting processes in nitrates and nitrites, with particular reference to changes in the average shell of nearest neighbours around any ion, on passing from crystal to melt. For the nitrates of sodium, potassium, rubidium, caesium, thallium and silver, for ammonium nitrate and for the nitrites of sodium and potassium this shell appears to contract on melting, which is attributed to the formation of association complexes in the melt. For the two crystal hydrates HNO 3 . H 2 O and HNO 3 . 3H 2 O, corresponding changes are observed, suggesting that the structure and absorption spectra correspond with the ions (OH 3 )+ and NO - 3 in the crystals, likewise giving rise to tighter association complexes on melting. Pure nitric acid on the other hand behaves in a manner more closely similar to isopropyl nitrate.

Testing your metal: An exhibition of the metals which our body must have

1998 ◽  
Author(s):  
John Emsley
Keyword(s):  
Human Body ◽  
Essential Elements ◽  
The Other ◽  
Healthy Living ◽  
Sodium Potassium ◽  
Metal Elements ◽  
Iron Copper ◽  
Average Person ◽  
Sodium And Potassium ◽  
Average Adult

Ask people which metals are essential for healthy living and I suspect most would say zinc and iron. Some might mention sodium and potassium, although sodium is often regarded as something deleterious to healthy living; and a few people will know that calcium is a metal also, and important. In fact the human body needs fourteen metal elements to function properly. But for every metal that we do need, there is another that our body contains that we could well do without. These metals serve no known purpose, but they come with the food we eat, the water we drink, and the air we breathe and our body absorbs them, mistaking them for more useful elements. As a result we find that the average adult contains measurable amounts of aluminium, barium, cadmium, caesium, lead, silver and strontium. There are also trace amounts of many others, including gold and uranium. Because strontium so closely resembles calcium we absorb a lot of this element, and the average person has about 320 mg in their body, far more than of many of the essential elements. On the other hand the weight of gold in the average person is only 7 mg, worth but a few pence, and the weight of uranium is only 0.07 mg, although turned into pure energy this could drive your car for five kilometres. Our body tends to retain these unwanted intruders either in our skeleton, as in the case of uranium which has a special propensity to bind to phosphate, or in our liver which has proteins that can trap metals like gold. The table below lists the amounts of the essential 14 metals in the average adult—someone who weighs 70 kg (155 pounds). As we would expect, calcium heads the list because, along with phosphate, it is what makes up the bones of our skeleton, which weighs 9 kg on average. Of this, i kg is calcium and 2.5 kg is phosphate. In fact 99% of the body's calcium and 85% of its phosphate is in the skeleton. Bone also contains water and the protein collagen, plus the elements sodium, potassium, iron, copper and chlorine.

COMPARISON OF THE NITROLYSIS OF 1, 3-DICYCLOHEXYLIMIDAZOLIDINE WITH THAT OF HEXAMETHYLENETETRAMINE

1950 ◽  
Vol 28b (5) ◽  
pp. 213-224 ◽  
Author(s):  
J. L. Boivin ◽  
George F Wright
Keyword(s):  
Nitric Acid ◽  
Ammonium Nitrate ◽  
The Other ◽  
Nitrate Salt ◽  
Other Hand ◽  
Dinitro Derivative ◽  
Basic Amine

The nitrolysis of N,N′-dicyclohexylimidazolidine has been effected with formation of the nitrate salt, the nitroso derivative, and the aceto derivative of N,N′-dicyclohexyl-N-nitro-1,2-diaminoethane. The absence of the dinitro derivative suggests that demethylolation is not related to nitramine formation. When formaldehyde splits off to leave a weakly basic amine, as in hexamethylenetetramine nitrolysis, then subsequent nitration will occur; but it will not take place if the resulting amine is strongly basic. Nitrolysis will depend also on reactivity of nitric acid, which can be decreased by addition of ammonium nitrate. This decrease will prevent esterification of intermediate N-methylolamines but not nitrolysis of hexamethylenetetramine types. However both nitrolysis and esterification are thus prevented with dicyclohexylimidazolidine. On the other hand the two nitrolyses are related by the fact that both are accelerated by electropositive chlorine.

The Transformation of Thiols Compounded in Raw Rubber

1951 ◽  
Vol 24 (4) ◽  
pp. 914-915
Author(s):  
Jeanle Bras ◽  
Michel Montu
Keyword(s):  
Absorption Spectra ◽  
Analytical Method ◽  
Ultra Violet ◽  
Transformation Products ◽  
Ultraviolet Absorption ◽  
The Other ◽  
Inert Gas ◽  
Rubber Industry ◽  
Acetone Extraction ◽  
The One

Abstract During the last few years the rubber industry has made use of certain thiols, under the technical name of peptizing agents, which have the property of accelerating the plasticization of raw rubber during mastication. It is now known that this process of plasticization involves oxidation of the rubber, and that it does not take place in an atmosphere of an inert gas. Accordingly the present authors were induced, on the one hand, to follow the transformation of thiols during their participation in the mastication of rubber and, on the other hand, to observe their influence on the tendency of rubber to oxidize. In the first of these objectives, the analytical method utilized was ultra- violet absorption spectrography. To avoid pertubations in the spectra caused by the resins present in rubber, crepe rubber purified by acetone extraction was used in the experiments. The rubber was masticated at 100° C, and the thiol was added soon after the beginning of this mastication in the proportion of 5 per cent of the rubber. Samples were withdrawn at successive intervals of time, and the transformation products of the thiol, which were isolated by acetone extraction, were identified by their ultraviolet absorption spectra. In these experiments, chloroform solutions containing 0.5 gram per liter were employed.

SODIUM, POTASSIUM, NITROGEN, PHOSPHORUS, AND LIPID IN MUSCLE MITOCHONDRIA ISOLATED IN SUCROSE MEDIA OF VARYING CONCENTRATIONS

1963 ◽  
Vol 41 (4) ◽  
pp. 831-847 ◽  
Author(s):  
A. R. Craston ◽  
J. F. Manery
Keyword(s):  
Analytical Data ◽  
Dry Weight ◽  
The Other ◽  
High Concentration ◽  
Sodium Potassium ◽  
Excess Sodium ◽  
Sodium And Potassium ◽  
Nitrogen Phosphorus ◽  
Better Than ◽  
Floating Layer

Mitochondrial pellets isolated in 0.25 M sucrose from pigeon breast muscle and washed once contained 77 ± 1.43 g water per 100 g pellet, 7.8 ± 2.0 meq K and 4.29 meq Na per kg dry weight. The Na:K ratio for mitochondria was almost 5 times that of muscle, suggesting that mitochondria might contain some of the "excess" sodium of skeletal muscle. A comparison of mitochondria isolated in three different sucrose media (0.25 M, 0.45 M, 0.88 M) was made with respect to sodium, potassium, and water concentrations of unwashed mitochondria (M1) and those washed once (M2). Washing always resulted in a loss of sodium and potassium but neither repeated washing nor suspension in hypotonic solutions removed all of the cations. These findings and the high concentration ratios observed between mitochondria and the suspension media attested to the presence of "bound" or restricted cations. A few analyses for nitrogen, phosphorus, and lipid made on the various mitochondrial preparations, on microsomal-like material, and on a "floating layer" believed to be washed out of M1 preparations by resuspension, drew attention to the possibility of altering the character of the unit of reference (dry weight, mg N, etc.) used for expressing concentrations of cations. The "floating layer" was unique in being high in lipid and high in sodium. Analytical data and electron micrographs provided evidence that 0.45 M sucrose preserved the chemical and morphological integrity of the mitochondria better than the other concentrations tested.

scholarly journals The absorption spectra of benzene derivatives in the vacuum ultra-violet. II

1947 ◽  
Vol 191 (1024) ◽  
pp. 32-38 ◽  
Keyword(s):  
Absorption Spectra ◽  
Ultra Violet ◽  
Phenyl Isocyanate ◽  
The Other ◽  
Side Chain ◽  
Benzene Derivatives ◽  
Phenyl Acetylene ◽  
Long Wave ◽  
Methyl Styrene ◽  
Vacuum Ultra Violet

The far ultra-violet spectra of styrene, α -methyl styrene, phenyl acetylene, phenyl cyanide and phenyl isocyanate are described. Many of the observed regions of absorption are cor­related with those of the benzene spectrum. The important fact emerges that, with increasing conjugation of the side chain with the ring, the benzene 1980 A absorption moves much farther to long wave-lengths than do the benzene 2600 and 1790 A absorptions. α -Methyl styrene shows a shift to the violet of certain regions of its spectrum relative to styrene. Phenyl isocyanate has a spectrum much closer to that of benzene than have the other molecules discussed.

SODIUM, POTASSIUM, NITROGEN, PHOSPHORUS, AND LIPID IN MUSCLE MITOCHONDRIA ISOLATED IN SUCROSE MEDIA OF VARYING CONCENTRATIONS

1963 ◽  
Vol 41 (1) ◽  
pp. 831-847 ◽  
Author(s):  
A. R. Craston ◽  
J. F. Manery
Keyword(s):  
Analytical Data ◽  
Dry Weight ◽  
The Other ◽  
High Concentration ◽  
Sodium Potassium ◽  
Excess Sodium ◽  
Sodium And Potassium ◽  
Nitrogen Phosphorus ◽  
Better Than ◽  
Floating Layer

Mitochondrial pellets isolated in 0.25 M sucrose from pigeon breast muscle and washed once contained 77 ± 1.43 g water per 100 g pellet, 7.8 ± 2.0 meq K and 4.29 meq Na per kg dry weight. The Na:K ratio for mitochondria was almost 5 times that of muscle, suggesting that mitochondria might contain some of the "excess" sodium of skeletal muscle. A comparison of mitochondria isolated in three different sucrose media (0.25 M, 0.45 M, 0.88 M) was made with respect to sodium, potassium, and water concentrations of unwashed mitochondria (M1) and those washed once (M2). Washing always resulted in a loss of sodium and potassium but neither repeated washing nor suspension in hypotonic solutions removed all of the cations. These findings and the high concentration ratios observed between mitochondria and the suspension media attested to the presence of "bound" or restricted cations. A few analyses for nitrogen, phosphorus, and lipid made on the various mitochondrial preparations, on microsomal-like material, and on a "floating layer" believed to be washed out of M1 preparations by resuspension, drew attention to the possibility of altering the character of the unit of reference (dry weight, mg N, etc.) used for expressing concentrations of cations. The "floating layer" was unique in being high in lipid and high in sodium. Analytical data and electron micrographs provided evidence that 0.45 M sucrose preserved the chemical and morphological integrity of the mitochondria better than the other concentrations tested.

scholarly journals The absorption spectra of mixed metallic vapours

1924 ◽  
Vol 105 (730) ◽  
pp. 221-225 ◽  
Keyword(s):  
Absorption Spectra ◽  
Alkali Metals ◽  
Molecular Form ◽  
Band Spectrum ◽  
Absorption Bands ◽  
Metal Vapour ◽  
Sodium Potassium ◽  
Physical Conditions ◽  
Sodium And Potassium ◽  
Great Complexity

It has been known for many years that bands of great complexity occur in the absorption spectra of the alkali metals. The extensive absorption bands of sodium vapour in the green and red portions of the spectrum have, in particular, attracted considerable attention. R. W. Wood has discussed fully the structure of these bands, the manner in which they fluctuate with change in certain physical conditions, and their connection with the fluorescence spectrum. The existence of these bands leads to the conclusion that a certain number of the atoms in an alkali metal vapour are associated, though other considerations have indicated that the proportion present in the molecular form cannot be large. It is reasonable to suppose that, in a mixture of the vapours of two alkali metals, "mixed" molecules containing atoms of both elements will "exist" molecules containing atoms of both elements will exist, in addition to these normally present in the unmixed vapours. These "mixed" molecules if present in sufficient number will exhibit an absorption spectrum, probably similar in character to the bands of the simple alkali metals. In the present communication a new band spectrum is described which is developed only in the vapour of mixtures of sodium and potassium and which, it is suggested, is produced by the sodium-potassium molecules present in the mixed vapour.

Studies of phase transformations in nitrates and nitrites II. Changes in ultra-violet absorption spectra accompanying thermal transformations in the crystals

1963 ◽  
Vol 276 (1367) ◽  
pp. 453-460 ◽  
Keyword(s):  
Phase Transformations ◽  
Absorption Spectra ◽  
Alkali Metals ◽  
Ultra Violet ◽  
Crystal Form ◽  
Potassium Nitrate ◽  
Thermal Transformations ◽  
Absorption Bands ◽  
Potassium Nitrite ◽  
Cyclic Changes

Changes in ultra-violet absorption spectra have been measured for nitrates and nitrites of the alkali metals and for ammonium, silver and thallous nitrates, in relation to thermal transformations in these solids. A gradual shift of absorption bands is found to accompany thermal expansion of all the crystals. More abrupt changes in absorption spectra are observed at transformation points from one crystal structure to another; in many instances these two effects of temperature can be correlated. In cases where crystal structures are known, shifts in absorption maxima due to changes in temperature have been interpreted. in relation to changes in the distances between cations and anions. By means of the techniques described, ultra-violet absorption spectroscopy provides a sensitive means for studying various thermodynamic effects in phase transformations. Thus with ammonium nitrate, hysteresis with both superheating and supercooling is observed for the transitions IV ^ III ( T c ~ 32 °C) and III ^ II ( T c ~ 88 °C), but not II ^ I ( T c ~ 125 °C). With potassium nitrate during cyclic changes of temperature a (metastable) crystal form III appears. With potassium nitrite, a new crystal transformation showing hysteresis ( T c ~ 40 °C) is readily detected by ultra-violet spectroscopy.

TIMETAL 35A

Alloy Digest ◽  
2001 ◽  
Vol 50 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
High Temperature ◽  
Nitric Acid ◽  
Physical Properties ◽  
Chlorine Dioxide ◽  
Heat Treating ◽  
Bend Strength ◽  
Temperature Performance ◽  
Sodium And Potassium

Abstract Titanium shows outstanding resistance to seawater and marine atmospheres. It is also resistant to attack by hot metallic chloride solutions, sodium and potassium hypochlorite, and chlorine dioxide. The metal is resistant to attack by hot nitric acid at concentrations up to 80% and is not attacked by sulfuric acid. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: TI-122. Producer or source: Timet.

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