Mixture Of Perchlorate Research Articles

The differential precipitation of nucleic acids and proteins from aqueous solutions by ethanol

The addition of an appropriate mixture of ethanol, water and sodium perchlorate to crude extracts of some biological material results in the selective precipitation of nucleic acids. Detergent extracts of tissue-cultured plant cells treated with this reagent yielded as much as 95–100% of the nucleic acid while a similar percentage of the total protein remained in solution.

The mechanism of, and the solvent effects in, the glycosidation of D-glucosyl chlorides having a non-participating group at C-2, using silver perchlorate as catalyst

The mechanism of, and the solvent effects in, the Koenigs—Knorr reaction of D-glucosyl chlorides having a non-participating group at C-2, using silver perchlorate as principal catalyst, were investigated. When a large excess of methanol was used, methyl D-glucopyranosides with inversion of the configuration at C-1 were predominantly obtained, except in one case. When 1 molar equivalent of nucleophile, such as methanol, methyl trityl ether, or 2-propanol, was used, the ratio of α- and β- D-glucopyranosides obtained varied with the solvent used. It is proposed that the reactions proceed via a common intermediate such as a D-glucosyl-perchlorate. The following conclusions are made for the preparation of α- D-glucopyranosides: anhydrous ether is a preferable solvent, silver perchlorate and sym-collidine are superior to a mixture of silver perchlorate and silver carbonate in the presence of Drierite, β- D-glucosyl chloride is preferred to the α- D anomer, and the solvent and reagents should be as dry as possible.

Anomalous pressure dependence of the burning rate for mixtures of ammonium perchlorate and certain organic fuels

Anomalous pressure dependence of the burning rate for mixtures of ammonium perchlorate and certain organic fuels

Mechanism of initiation of an explosion by impact in mixtures of ammonium perchlorate with combustible additives

Mechanism of initiation of an explosion by impact in mixtures of ammonium perchlorate with combustible additives

Effect of aluminum on the burning of ammonium perchloratepolyformaldehyde mixtures

We have investigated the effect of aluminum content and aluminum particle size on the burning of a stoichiometric mixture of ammonium perchlorate and polyformaldehyde. It has been established that:

Microcalorimeter measurements of flame emission

1. A method has been developed for measuring the radiant flux density (q) in the flame of a burning condensed substance using microcalorimeters with low thermal inertia. 2. The effect of aluminum content and aluminum particle size on the radiant flux density has been investigated for a model stoichiometric mixture of ammoninum perchlorate and polyformaldehyde. It has been shown that q increases with increase in pressure and aluminum content. A mechanism is proposed for the increase in q with increase in pressure. 3. The emissivity e of burning particles of aluminum and corundum in the flame of the compositions investigated has been estimated; at 40 at, e=0.13−0.15. 4. Fine thermocouples have been used to study the effect of the radiant flux on measurements of the temperature distribution at the surface of the burning compositions investigated and it is shown that this effect may be neglected.

The cause of the medium effect upon the rate of the electron‐exchange reaction between iron(II) and iron(III)

AbstractThe iron(II)‐ iron(III) electron‐exchange rate has been measured at 0° in aqueous perchloric acid‐sodium perchlorate and perchloric acid‐lithium perchlorate mixtures of varying acid concentration, at three values of the ionic strength.The medium effects upon the rate of this reaction are interpreted as a result of a) the displacement of hydrolysis equilibria with the hydrogen ion concentration, and participation of the hydrolyzed ions in the exchange reaction, and b) the variation of the activity coefficients of the reacting species with the hydrogen ion concentration.

SYNOPTIC: Thermal Decomposition of Ammonium Perchlorate Magnesium Perchlorate Mixtures

SYNOPTIC: Thermal Decomposition of Ammonium Perchlorate Magnesium Perchlorate Mixtures

The variation of the activity coefficients of cations with the hydrogen ion concentration in aqueous perchloric acid‐sodium perchlorate and perchloric acid‐lithium perchlorate mixtures of constant ionic strength

AbstractThe variation of the activity coefficient of some cations and of the ratio of the activity coefficients of the ions of some redox systems with the hydrogen ion concentration has been measured at several (constant) values of ionic strength in perchloric acid‐sodium perchlorate and perchloric acid‐lithium perchlorate mixtures at 25°.These variations differ considerably among different cations or redox systems. They are about the same in perchloric acid‐sodium perchlorate and perchloric acid‐lithium perchlorate mixtures of low ionic strengths but they are much larger in perchloric acid‐sodium perchlorate than in perchloric acid‐lithium perchlorate mixtures at ionic strengths > 3 mole · 1−1.

The thermal decomposition of magnesium perchlorate and of ammonium perchlorate and magnesium perchlorate mixtures

The thermal decomposition of magnesium perchlorate and of ammonium perchlorate and magnesium perchlorate mixtures

Effect of iron oxide on the combustion of condensed mixtures

We have invest igated the effect of-l% FezO 3 on the burning rate of model mixtures of ammonium perchlorate (AP) + polystyrene (PS) and ammonium perchlorate + po lymethyl methacry la te (PMM) when var i ous physical parameters are varied (pressure, component ra t io a, in i t im temperature T 0, presence of inert diluents--NH4C1 and AlzOa). The effect ive par t ic le sizes were approximate ly 9 p for AP ( technical), 5 g for PS (technical) , 3 g for PMM (technical) , 1 .8 g for Fe203 (ana ly t ica l grade), 12 # for NH4C1 (ana ly t ica l grade), and 8 p for AlzOs (ana ly t ica l grade). The components were mixed on t racing cIoth with a rubber stopper for one hour. From the finished mixture we pressed charges 8 mm in d iameter and 8 -10 mm ta l l with a re la t ive density 6 = P/Pmax = 0 .950.99. The exper iments were conducted in a constant-pressure bomb in nitrogen. The burning t i m e w was measured using a quartz pressure transducer. The average burning rate u = h / r was ca lcula ted . We charac ter ize the effect ol~ the Fe2Os by means of the quant i ty z = u/n0, where u and u0 are the burning rates of the mixture with and without the addit ion of FezOa.

Burning of mixtures of ammonium perchlorate and various organic substances

1. The burning rate of mixtures of ammonium perchlorate and fuels of various chemical structure has been investigated. 2. It has been established that the burning rate of the mixtures depends on the calorific value of fuels of similar structure, or, if the calorific value is the same, on the strength of the chemical bonds and the structure of the molecules.

The cause of the medium effect upon the rate of the electron‐exchange reaction between thallium(I) and thallium(III)

AbstractThe thallium(I)‐thallium(III) electron‐exchange rate has been measured at 25° in aqueous perchloric acid‐lithium perchlorate mixtures of varying acid concentration, at three values of the ionic strength.In these mixtures no detectable medium effect exists, i.e., the specific rate constant is independent of the acid concentration at each value of the ionic strength studied.The medium effect that has been found in aqueous perchloric acid‐sodium perchlorate mixtures must therefore be explained as the result of a variation of the activity coefficients of the reacting species and not, as has been done by the majority of authors, as a result of displacement of hydrolysis equilibria.

Temperature coefficient of burning rate of condensed mixtures at different component ratios

1. The dependence of the burning rate u on the initial temperature T0 has been studied for model mixtures of ammonium perchlorate and polystyrene, polymethyl methacrylate, polyformaldehyde, and bitumen. In all cases, with increase in T0 the burning rate increases monotonically. The relation u(T0) may conveniently be characterized by the temperature coefficient β=(d ln u)/(d T0). 2. The temperature coefficient strongly depends on the fuel-oxidizer ratio α. The curve β(α) has a minimum, whose position coincides with that of the maximum burning rate. 3. For mixtures not too far from stoichiometric the temperature coefficient increases with increase in the oxidizer particle size. 4. The experimental results are in agreement with the notion that the value of β is determined by the temperature Tg in the zone that influences the burning rate; if Tg is large, β is small and, conversely, if Tg is small, β is large.

Upper concentration limit of combustion of condensed mixtures

1. We have determined the position of the upper concentration limit of combustion for mixtures of ammonium perchlorate and polystyrene and polymethyl methacrylate. For the AP+PS mixture the limiting excess of fuel (at which the mixture still burns) is 2\2-3 times greater than for the AP+PMM mixture. In all cases αu is the greater, the higher the pressure and the larger the oxidizer particle size. In these experiments the richest mixture still capable of burning (at p=100 atm and dox=140–320 μ) corresponded to α≃0.055 (about 67% fuel) for polystyrene and to α≃0.12 (∼60% fuel) for polymethyl methacrylate. 2. We have determined the burning rate at the upper limit uu. For the AP+PS mixture uu is almost constant at all p and dox and corresponds to about 1mm/sec. For AP+PMM the value of uu is generally higher than for AP+PS and decreases with increase in p and dox. 3. The results of the experiments can be explained on the basis of the influence (\ldactive combustion\rd) zone concept.

Optical method of determining propellant surface temperature

1. An apparatus has been designed for measuring the surface temperature of a burning powder by means of a sapphire light pipe. 2. An optical method of measuring the temperature of the combustion surface (reaction zone) of a powder by extracting the radiation with a sapphire light pipe has been developed. 3. The spectro-optical characteristics of powders have been determined over a broad interval of temperatures and wavelengths. Spectral “windows” that make it possible to use the radiation method of determining surface temperature have been discovered. 4. The surface temperature has been measured in a vacuum and at elevated pressures for the following compositions: N powder (ballistite), model mixture of ammonium perchlorate and fuel. 5. The fraction of radiant energy reaching the reaction zone from the fizz zone has been estimated.

One-Step Release of DNA Rings From Polyoma Virions

A tightly packed regularly coiled DNA ring is assumed to be present inside the polyoma virion. Applying the “one-step” technique of nucleic acid extraction from virions while being adsorbed to a protein monolayer, we studied the configurational changes of the DNA.Intact polyoma virions were mixed with DFP-trypsin (100μg/ml) and spread onto a subphase of a mixture of urea and sodium perchlorate (6M and 2M, or 3M and 1M respectively), at pH 8.2 and room temperature. After spreading the film, aliquots were transferred to grids at different periods of time, and the DNA stained by acetonic uranyl acetate.The length distribution of the DNA molecules measured from electron micrographs is shown in Fig. 1. The number of twists present at different times after spreading were also counted. At 12 minutes, with 3M urea and 1M sodium perchlorate in the subphase, the DNA was found to be 85% supertwisted (Fig. 2); 12% was opened to rings, and 3% existed as linear filaments.

Effect of catalytic additives on the burning of ammonium perchlorate and certain of its mixtures

Potassium bichromate is the most effective catalyst of the burning of ammonium perchlorate and its mixtures with coke. Chromic oxide is less effective as a catalyst and accelerates the burning of the perchlorate only in the pressure range up to 500 atm. The effect of chromic oxide on the burning of a mixture of perchlorate and coke is positive over the enture range of pressures studied.

Kinetics of the reduction of Mn 2+ at the dropping mercury electrode

Theoretical treatments for the kinetic parameters K s and α have been given by Delahay, Koutecky, Randles, Matsuda and Gellings. The analysis of irreversible polarographic waves as proposed by Matsuda and Gellings merits further discussion and application for calculating the kinetic parameters for a quasi-reversible reduction. The reduction of Mn 2+ at the dropping mercury electrode has been studied in perchlorate, chloride, bromide, iodide and mixtures of perchlorate and halides as supporting electrolytes. Both Matsuda's and Gelling's methods have been applied to obtain the kinetic parameters of the electrode reactions at 30 and 40°C. The standard rate constant K s is of the order of 10 −3 cm/s, showing a quasi-reversible reduction. The effect of temperature and halide ions has been investigated. The reversibility of the reduction decreases in the order I − > Br − > Cl − > ClO 4 −. A mechanism of the reduction is proposed.

Experiments relating to the combustion of ammonium perchlorate-based propellants

Experiments designed to examine certain features of the combustion mechanism of ammonium perchlorate-based propellants are briefly discussed in relation to a currently accepted model. New experimental evidence on the gasification process of ammonium perchlorate burning under a very wide variety of conditions shows that the dissociation is generally better represented by a kinetic decomposition law (with an activation energy of about 30 kcal/mole) then by an equilibrium law. During combustion, some exothermic redox reaction in the condensed phase probably accompanies dissociation of the salt. At low pressures, the burning rates of composite mixtures of ammonium perchlorate with organic fuels are little affected by fuel-binder properties, other than heat of combustion, but at high pressures the converse is true. Possible reasons for this have been explored experimentally. At constant final-flame temperature, the volumetric loading of a binder appears to be more important than its thermal stability, and the idea of a fuel “barrier” hindering propagation of the ammonium perchlorate monopropellant flame at high pressures is supported. Rates of flame travel along ammonium perchlorate binder interfaces are not very different from the burning rates of the corresponding composite propellant, and does not now seem to be a rate-controlling feature.