Spectrophotometric study of the compounds obtained with schiff's reagent and acetaldehyde

Five different compounds have been identified spectrophotometrically in the reaction between acetaldehyde and Schiff's reagent.It has been found that, with a small amount of acetaldehyde, a complex with only one molecule of acetaldehyde for every molecule of the reagent is formed. This shows the peak at 545 mμ.With excess of acetaldehyde, the complex contains two molecules of aldehyde per molecule of Schiffs reagent, corresponding to the peak at 555 mμ. After standing for some time, the solution containing this compound, gradually shows the presence of three new compounds, having peaks at 525 mμ, 575 mμ and 615 mμ. The former results from the interaction of two molecules of acetaldehyde and a molecule of fuchsin derived from Schiff's reagent itself. The other two are formed when the former loses one and two water molecules, respectively.     

A search for rare types of fission induced in silver and bromine nuclei

Ternary and quaternary fission produced in silver and bromine nuclei have been studied withK5 nuclear emulsion exposed to 1.8 GeV/cK ⁻ beams. The frequency of the ternary events is found to be ∼0.08 of that of the binary events produced in the same volume of the emulsion. The range ratio and range distribution of the fission fragments are studied and the angles between each pair of the fragments are determined. Ranges are found to vary from 5 to 40μ with a maximum number lying between 5 and 10μ. The angles between the fission fragments are found to form a broad distribution extending from 40° to 180°. A few of the events have also been analysed to give them a possible identity. A possible case of quaternary fission has also been reported. This paper was presented at the Symposium on 3rd High Energy Physics held at Bhubaneswar during November 1976.     

Measurement of plane wave acoustic fields in flow ducts

The response of a fluid loaded plate is derived as function of the incident pressure in the fluid. The results are compared with full scale measurements made in the aft peak tank on a ship. Propeller induced pressure and hull plate velocity were measured with flush-mounted hydrophones and accelerometers. It is found that for a typical aft body construction the boundaries of the plate elements can be assumed to be simply supported. The plate model agrees well with full scale measurements down to 40 Hz. Below this frequency global vibrations determine the response of the hull. Both theoretical and experimental results indicate that the field induced by the vibrating plate elements can be considerable. The response of a plate can be decreased if the width of the plate is decreased or the plate thickness increased.     

Automation in und mit der Analytischen Chemie

Ohne Zusammenfassung

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Automation in and with analytical chemistryV. Classification of working ranges in analytical chemistry with regard to computers

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Teil IV: diese Z. 256, 7 (1971)     

Spectrophotometric study of the formaldehyde-leuco-methylene blue reaction

The sensitivity of the reaction between foimaldchyde and Icuco-mcthyleno blue has been found to be increased in the presence of ethyl alcohol, acetone, dicthyl ketone and methyl ethyl ketone. Acetone has been found to be most effective. Sensitisers increase the absorption maximum and stabilise it, while the rate of development of methylene blue colour is slowed down.Sensitivity also depends upon the content of thiosulphate used to prepare the Icuco-base; a smaller amount of thiosulphate increases greater sensitivity.     

Flow characteristics of primary and digested sewage sludge

Summary Rheological study of sewage sludge is useful for the design, operation and control of sewage treatment plants. The rheology is highly dependent on physical, chemical and biological characteristics of the sludge. A pipeline rheometer is described in this paper for measurement of rheological properties of the sludge. Primary sewage sludge is a complex flocculated suspension having no fixed particle dimension, shape, size distribution or surface characteristics. The information available so far on rheology of sewage sludge is not suitable for application in design because of the lack of data on physico-chemical characteristics of this sludge.Primary and digested sewage sludge are non-Newtonian in character. Both exhibit yield stress and while primary sludge is shear-thinning in nature, digested sludge has been found to be shear-thickening. Parabolic and yield-power law models have been used to express the experimental data obtained for sludges at various concentrations and temperatures. Yield stress of primary sludge varies exponentially with concentration and linearly with temperature within the short temperature range studied. Primary sludge is found to be antithixotropic at low shear stress. Digested sludge does not exhibit time dependency.With 9 figures and 5 tables     

Cataphoretic velocity of colloidal particles of lyophobic sols under constant current. A new setup to measure the boundary movement under constant current

Summary The migration velocities of the boundary of As₂S₃ and Fe(OH)₃ sols have been measured under constant current. A new set up for measuring the movement of the boundary under constant current has been devised. The changes in the boundary movement with time have been observed under constant current condition and it has been discussed and suggested that measurements of cataphoretic velocity of colloidal particles under constant current is theoretically more cogent than the measurements taken under constant voltage, because the changes in the resistance shown by the changes in the potential developed across the different elements in the U-tube at constant current give a more correct picture of what happens in the cataphoretic tube when cataphorisis takes place. A potentio-valve-voltmeter has been employed to measure the instantaneous changes of voltage across the mainU-tube without any time lag. This is a new device which has not been tried before.

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Zusammenfassung Die Wanderungsgeschwindigkeit an der Grenze von As₂S₃ and FeOH₃-Solen wurde gemessen, und zwar bei konstantem Strom. Eine neue Methode zur Messung der Wanderung bei konstantem Strom wird vorgeschlagen. Die Ver?nderungen der Bewegung der Grenze mit der Zeit werden diskutiert, und es wird vermutet, da? Messungen der kataphoretischen Geschwindigkeit von Kolloidpartikeln bei konstantem Strom theoretisch mehr Aussagen geben als Messungen bei konstanter Spannung, weil Widerstands?nderungen in den einzelnen Teilabschnitten des Kataphoreserohres bei konstantem Strom ein korrekteres Bild gibt. Ein Potentialr?hrenvoltmeter wurde für die Messung des Spannungsabfalls angewendet, so da? zeitliche ?nderungen verz?gerungsfrei aufgezeichnet werden konnten.

     

Kinetics and mechanism for the aquation of bismalonatoethylenediaminecobaltate(III) ion in acid perchlorate media

Summary The title complex aquates in acid media, first to [Co(mal)-(H₂O)₂(en)]⁺ (1) (Step 1) and subsequently to [Co(H₂O)₄(en)]³⁺ (2) (Step 2). Complex species (1) has been separated and characterised in solution. While Step 1 involves only a second-order acid catalysed path, Step 2 involves both a first-order acid independent path and a second-order acid catalysed path. The rate constants and activation parameters evaluated for these reaction paths have been compared with those for similar carboxylato-cobalt(III) complexes. This, together with an observed isokinetic relation, indicates that the rate-determining step involves opening of the unprotonated (in the spontaneous acid independent path) or the protonated (for the acid catalysed path) chelate ring of the malonate ligand and insignificant solvation of the central metal ion.