Showing papers on "Potassium nitrate published in 1977"
TL;DR: In this paper, the effects of temperature on the kinetics of crystallization of potassium nitrate were investigated in a continuous mixed-suspension, mixed-product-removal (MPM) crystallizer.
Abstract: A laboratory continuous mixed-suspension, mixed-product-removal crystallizer was used to study the effects of temperature on the kinetics of crystallization of potassium nitrate. A differential refractometer was used to continuously monitor the supersaturation permitting the measurement of supersaturation levels of order 10−3Kg solute/Kg water. The nucleation rate exhibited an inverse relationship with temperature.
59 citations
TL;DR: It appears that calcium hydroxide could be used as a desensitizing agent initially following periodontal surgery to reduce pain from hypersensitive roots in order that proper oral hygiene could be reestablished.
Abstract: The purpose of this investigation was to evaluate calcium hydroxide and potassium nitrate individually as densensitizing agents for hypersensitive root surfaces. The apparatus used in the experiment to measure hypersensitivity was (a) a thermo-electric stimulating device to measure hot and cold stimulation quantitatively and (b) a mechanical stimulating device to measure scratch stimulation quantitatively. The conclusions drawn from the study were: 1. Calcium hydroxide was more consistently effective in decreasing sensitivity then was potassium nitrate or the control. 2. Calcium hydroxide as compared to the control was statistically (99% level of significance) more effective in reducing sensitivity to mechanical, hot and cold stimulation immediately and at the conclusion of the experiment (3 months). 3. It appears that calcium hydroxide could be used as a desensitizing agent initially following periodontal surgery to reduce pain from hypersensitive roots in order that proper oral hygiene could be reestablished.
58 citations
TL;DR: In this article, the authors used a recirculating sampling device to test the hypothesis that methaemoglobin was formed as the result of the production of nitrite as an intermediate in the rumen.
Abstract: 2. Three experiments with mature dry Friesian cows lasted for up to 16 days. Nitrate was given as nitrate-rich hay or mixed with concentrates to supply from 2.4 to 16.0 g/100 kg liveweight at each meal. To test the hypothesis that methaemoglobin was formed as the result of the production of nitrite as an intermediate in the rumen, one group was given a daily supplement of KNO2, 2 to 3 g/100 kg liveweight. Blood was sampled at frequent intervals, and ruminal fluid was sampled every 15 min for short periods from cows with a recirculating sampling device. Large intakes of nitrate in either form increased nitrite in the rumen, leading to increase of methaemoglobin in the blood during the first few days, after which the high value was maintained. The high methaemoglobin value was positively correlated with the larger nitrite content in the rumen. Results are discussed in the light of conflicting reports on the tolerance of cattle to large amounts of nitrate and the importance of frequent sampling to obtain a true picture is stressed. Previous inferences regarding the ability of cattle to tolerate nitrate at up to 90 g/100 kg are considered to be mistaken.
ADDITIONAL ABSTRACT: In two experiments groups of 4 cows (415-669 kg body weight) received similar daily amounts of NO3- as either a single oral dose of KNO3 (15 g/100 kg) or a single feed of nitrate rich hay (12.4-15.4 g NO3-/100 kg) for 18 days. In a third experiment 6 cows received 2 or 3 g/100 kg of NO3- as a single oral dose of KNO2 for 6 days. Nitrate, nitrite and ammonia were measured in rumen sample and haemoglobin and methaemoglobin were measured in blood. The daily supply of equal doses of nitrate to cows, as hay with a high nitrate content or as potassium nitrate, induced higher nitrite contents in the rumen fluid and a higher percentage of methaemoglobin in the blood during the first days, after which they remained on this higher level. These increases were probably due to a change in the activity of the reducing micro-organisms in the rumen. The changes also partly explain the controversial data in the literature on the acceptable dosages of nitrate to be supplied to ruminants. This may have led to the mis-interpretation that ruminants should tolerate daily intakes up to 90 g of NO3- per 100 g body weight. (Abstract retrieved from CAB Abstracts by CABI’s permission)
48 citations
TL;DR: Using guppy fry as the test fish the individual and joint toxicities of ammonia and nitrate were estimated in static tests at constant pH and temperature as mentioned in this paper, and the 72-h lc 50 values were 199 and 1.26 mg 1−1 −N for potassium nitrate and free ammonia, respectively.
37 citations
TL;DR: Differences between nitrate uptake in light and dark are explained by the influence of light on nitrate reduction and differences in leaf growth rate have been discussed in relation to root resistance and leaf water content.
Abstract: Using a special apparatus, the uptake of nitrate, potassium, water, and oxygen by a maize plant was recorded at short intervals. After cutting most of the roots, the regrowth of the root system was measured in relation to the increase in nitrate, potassium, and water uptake, oxygen consumption of the root system, and leaf growth rate. It has been suggested that when the root surface is not limiting nitrate reduction is the rate-limiting process for nitrate uptake. Differences between nitrate uptake in light and dark are explained by the influence of light on nitrate reduction. Differences in leaf growth rate have been discussed in relation to root resistance and leaf water content.
33 citations
TL;DR: In this paper, the apparent molar heat capacities at constant pressure of dilute aqueous solutions of HNO 3, NaNO 3, and KNO 3 at 298.15 K were derived.
30 citations
21 citations
TL;DR: The simplicity and ease of this disk test suggest its value as a preliminary screening procedure for nitrate reductase production in anaerobes was investigated and it demonstrated better disk-tube agreement than previously frozen stock strains.
Abstract: The laboratory and clinical evaluation of a potassium nitrate-saturated disk for the rapid detection of nitrate reductase production in anaerobes was investigated. The optimal disk concentration and incubation time were determined by utilizing triplicate sets of quadrant plates prepared with supplemented brucella (Difco) blood agar and swabbed with a 24-h broth (BBL; 135 C thioglycolate) suspension of the test organism. Each set of plates received one control disk and three disks of varying concentrations of potassium nitrate (1 to 8 mg) with 0.1% sodium molybdate. All sets were incubated in GasPak jars for 24, 48, or 72 h, and subsequently sulfanilic acid and 1,6-Cleve's acid were added to each disk. A pink or red color change was indicative of nitrate reductase production. Eighty-eight stock isolates, 23 American Type Culture Collection strains, and 214 fresh clinical isolates were evaluated and compared with results obtained with tubes of preduced indole-nitrite medium (BBL) incubated for 7 to 10 days. The 6-mg disk incubated for 48 h yielded an overall agreement of 89% with the conventional tube technique, and fresh clinical isolates demonstrated better disk-tube agreement (93%) than previously frozen stock strains. The simplicity and ease of this disk test suggest its value as a preliminary screening procedure for nitrate reductase production. There were no false positives. Negative results by disk should be rechecked by tube.
14 citations
TL;DR: In this article, the possibility of determination of copper in natural waters was tested by direct potentiometry with chalcocite copper sensitive ion selective electrode, which can be carried out for the copper concentration down to 6 μg l−1 when the standard additions procedure is used.
11 citations
TL;DR: A sensitive and rapid method was developed for the determination of ruthenium in faces and other products of digestion by ruminants and is suitable for the determined at concentrations between 5 and 50 µg per gram of dry matter.
Abstract: A sensitive and rapid method was developed for the determination of ruthenium in faces and other products of digestion by ruminants. The sample was ashed at 350 °C with a mixture of potassium nitrate and potassium hydroxide, dissolved in dilute nitric acid and analysed by atomic-absorption spectrophotometry using a carbon rod atomiser. The method is particularly free from interferences and is suitable for the determination of ruthenium at concentrations between 5 and 50 µg per gram of dry matter.
9 citations
Patent•
18 Aug 1977
TL;DR: In this article, an electric actuation and a thin film of potassium nitrate is formed and a second electric contact is produced over at least a part of the thin film, and a protective film of silicon dioxide is deposited over the sandwich assembly of the two contacts.
Abstract: Prodn. comprises first forming an electric empact and a solid, thin film of potassium nitrate on at least a part of the contact. The thin film is vapour deposited in vacuum of 10-5 torr. Then a second electric contact is produced over at least a part of the thin film. Subsequently a protective film of silicon dioxide is deposited over the sandwich assembly of the two contacts and the thin potassium nitrate film. Then the assembled laminate is heated for >=15 mins. at 100-300 degrees C. Gold is pref. used for the prodn. of the two contacts.
TL;DR: In this article, the reaction of barium chromate with molten lithium-potassium nitrate eutectic was investigated and the stoichiometry of the reaction established and the results indicated that nitryl ion, NO2+, is possibly an acidic/oxidizing species produced by the autoionization of nitrate ion when a nitrate melt functions as a reactive solvent.
Abstract: The reaction of barium chromate(v) with molten lithium-potassium nitrate eutectic was investigated and the stoichiometry of the reaction established. The results of this study indicate that nitryl ion, NO2+, is possibly an acidic/oxidizing species produced by the autoionization of nitrate ion when a nitrate melt functions as a reactive solvent.
TL;DR: In this paper, Koutecky's method was used to calculate the transfer coefficient, transfer coefficient (α) and formal rate constant (k°f, h) for a single electron transfer process in 0.1M tetramethylammonium bromide.
Abstract: dl Aspartic acid is reduced at the d.m.e. in 0.1M tetramethylammonium bromide, tetraethylammonium bromide, sodium chloride, potassium chloride, potassium nitrate, sodium perchlorate and lithium sulphate; in aqueous media. The waves are irreversible, diffusion controlled involving one electron transfer process determined by millicoulometry. The values of the kinetic parameters, transfer coefficient (α) and formal rate constant (k°
f, h) have been calculated byKoutecky's method and are 0.479 and 15.9×10−16 respectively.
TL;DR: A possibility of the addition-elimination sequence in the formation of nitrodihydrocoumarin from 3-aryl-3-methylbutyric acid was discussed in this paper.
Abstract: Nitration of methyl 3-methyl-3-(3, 4, 5-trimethylphenyl)butyrate with excess of potassium nitrate and sulfuric acid in chloroform gave a new Spiro lactone identified as 4, 4, 7, 8, 9-pentamethyl-6, 8, 10-trinitro-1-oxaspiro[4.5]deca-6, 9-dien-2-one, along with expected 4, 4, 6, 7, 8-pentamethyl-5-nitro-3, 4-dihydrocoumarin and 2, 6-dinitro derivative.A possibility of the addition-elimination sequence in the formation of nitrodihydrocoumarin from 3-aryl-3-methylbutyric acid was discussed.
TL;DR: In this article, the surface tension of molten TlNO/sub 3/ has been measured over the temperature range 220-350 /sup 0/C, using the maximum bubble pressure method.
Abstract: The surface tension of molten TlNO/sub 3/ has been measured over the temperature range 220-350 /sup 0/C, using the maximum bubble pressure method. We have also measured the surface tension of the binary mixtures TlNO/sub 3/-LiNO/sub 3/ and TlNO/sub 3/-KNO/sub 3/ at 350 /sup 0/C over the entire composition range. 3 tables, 2 figures.
TL;DR: Cadmium sulphate reacts at 440 °C in pure lithium nitrate-potassium nitrate eutectic, but at much lower temperatures when Lux-Flood bases (Na2O2, Na2O, and Na[OH]) are present, in accord with the relative availability of oxide ions as discussed by the authors.
Abstract: Cadmium sulphate reacts at 440 °C in pure lithium nitrate–potassium nitrate eutectic, but at much lower temperatures when Lux–Flood bases (Na2O2, Na2O, and Na[OH]) are present, in accord with the relative availability of oxide ions. The product is cadmium oxide, except in the presence of moisture or hydroxide when cadmium hydroxide is formed preferentially. Cadmium oxide does not catalyse decomposition of the melt, and there is no evidence for the formation of anionic cadmate species.
Patent•
26 Sep 1977TL;DR: In this article, the surfaces of a ferrous metal body are coated with a heat-fusible, chemically-oxidizing composition, such as sodium nitrate or potassium nitrate, and the body is heated above the melting temperature of the coating, preferably above 350° C., until the coating melts, spreads over the surfaces, reacts with the material of the surfaces and produces a black oxide coating thereon.
Abstract: The surfaces of a ferrous metal body are coated with a heat-fusible, chemically-oxidizing composition, such as sodium nitrate or potassium nitrate. Then, the coated body is heated above the melting temperature of the coating, preferably above 350° C., until the coating melts, spreads over the surfaces, reacts with the material of the surfaces and produces a black oxide coating thereon.
TL;DR: In this paper, the nitration of 5-formyl- and 5-acetyl-2,2′-dithienyls by the action of potassium nitrate in 60-95% sulfuric acid solutions was studied.
Abstract: The nitration of 5-formyl- and 5-acetyl-2,2′-dithienyls by the action of potassium nitrate in 60–95% sulfuric acid solutions was studied. An increase in the acidity of the medium and a decrease in the reaction temperature from +30°C to −30°C lead to an increase in the percentage of the 5′-nitro isomer in the mixture.
Patent•
05 Jan 1977TL;DR: A glass article or mirrored glass article can be made by combining equal amounts of ammonium hydroxide, acetaldehyde, potassium nitrate, water glass and optionally silver nitrate.
Abstract: This invention involves making a glass article or mirrored glass article by combining equal amounts of ammonium hydroxide, acetaldehyde, potassium nitrate, water glass and optionally silver nitrate, heating the mixture to 1958° C in a mold to expell hydrogen and acetaldehyde and optionally collecting the hydrogen and acetaldehyde in a reservoir
TL;DR: In this article, the reaction of barium chromate with molten lithium-potassium nitrate eutectic was investigated and the stoichiometry of the reaction established and the results indicated that nitryl ion, NO2+, is possibly an acidic/oxidizing species produced by the autoionization of nitrate ion when a nitrate melt functions as a reactive solvent.
Abstract: The reaction of barium chromate(v) with molten lithium-potassium nitrate eutectic was investigated and the stoichiometry of the reaction established. The results of this study indicate that nitryl ion, NO2+, is possibly an acidic/oxidizing species produced by the autoionization of nitrate ion when a nitrate melt functions as a reactive solvent.