Showing papers by "National Chemical Laboratory published in 1971"
TL;DR: In this article, a wall jet electrode was presented, in which a jet of solution issued from a circular nozzle was allowed to impinge normally on a disk electrode. And the theoretical predictions for the dependence of the limiting diffusion current upon various experimental variables, i.e., the bulk concentration of depolarizer, the volume flow rate, the radius of the disk electrode, the diameter of the nozzle, etc., were verified experimentally.
227 citations
01 Jan 1971
50 citations
TL;DR: Oleoresin from Dipterocarpus pilosus has been shown to be a complex blend of sesquiterpenes (∼18%) and triterpenoid.
47 citations
TL;DR: In this paper, a novel sequence of reactions, by which 9,19-cyclo-4,4,14α-trimethyl-3β-acetoxy-5α,9β-pregnan-20-one (V) and 9.19-cnn-4.4, 14.1 (VI) can be obtained from cycloartenol (I) in overall yields of over 42% and 38% respectively.
32 citations
TL;DR: In this paper, it was shown that the retreating core model is an adequate representation of the diffusional regime and that the value of the tortuosity parameter (α) can be estimated form an independent set of diffusion experiments and that obtained from kinetic data by using the model represented by the above equation.
26 citations
TL;DR: Besides β-sitosterol and stigmasterol, the major steroids of sugar cane, the following minor triterpenoids and steroids have been isolated and characterized from Indian sugar cane: taraxerol, β-amyrin, betulin, and stigmast-5-en-3β, 7β-diol (epi-ikshusterol).
25 citations
TL;DR: The group screening method has been applied to the selection of the best catalyst for the isomerization of n-butene to isobutene, as the first step in a detailed program of investigations on the mechanism and kinetics of this reaction as discussed by the authors.
24 citations
23 citations
TL;DR: Isolation and characterisation of pure atlantone has been reported for the first time, and has been found to have trans-geometry as discussed by the authors, and a minor constituent of the essential oil from Cedrus deodara is shown to be its cis-isomer.
23 citations
TL;DR: The authors showed that 1-Methyl-1,2-epoxycycloheptane, 2α, 3α-epoxypinane and 3α, 4α-empoxycarane undergo typical carbonium ion rearrangements in contact with active silica gel, while Humulene epoxide-II and caryophyllene oxide did not undergo any transformation under these conditions.
21 citations
TL;DR: In this paper, the authors investigated the topology of the substrate rearrangement of 3β,4β-epoxycarane and the results compared with those obtained earlier with 3α,4α-epoxidecarane.
TL;DR: The triterpene fraction ( ∼ 80%) of the oleoresin from Dipterocarpus pilosus has been found to contain dipterocarolic acid and several known triterpenes related to this as mentioned in this paper.
TL;DR: In this paper, the thermodynamic functions of formation of Cu(II and Ni(II) complexes of some β-diketones have been determined in 75 vol.% dioxane + 25 vol.%.
TL;DR: In this article, a quantitative means of assessing the performance of fixed-, moving-, and fluid-bed reactors under conditions of catalyst fouling is presented, and the role of axial diffusion is examined, and an expression is developed for the effect of catalyst decay on yield in a consecutive reaction.
TL;DR: In this paper, a semi-quantitative method for their estimation, involving short-term hydrolysis, followed by oxidation (CrO3), esterification and GLC estimation of products, has been developed.
TL;DR: The evaluation of ultraviolet light absorbers in PVC is described in this article, including 2-(2'-pentadecyl-4'-hydroxy-phenyl)-benzotriazole, 2.
Abstract: The evaluation of the following ultraviolet light absorbers in PVC is described: 2-(2'-pentadecyl-4'-hydroxy-phenyl)-benzotriazole, 2-(2'-pentadecyl-3'-carboxy-4'-hydroxy-phenyl)-benzotriazole, 2-(2'-hydroxy-4'-pentadecyl-5'-chloro-phenyl)-benzotriazole. 2-hydroxy-4-pentadecyl-benzophenone, nickel complex of di-(4-pentadecyl-6-hydroxy-phenyl)-sulfide, and 3-pentadecyl-phenyl-salicylate.
TL;DR: In this paper, the thermodynamic properties of the bis-histamino Cu(II) and Zn(II)-complexes with histamine were determined in a medium of 0·2M KNO 3.
01 Jan 1971
TL;DR: In this paper, electron diffraction technique has been used to study the growth of CoSe films on different faces of rocksalt and also on glass, showing that depending on substrate temperatures, the deposits not only grew epitaxially but also transformed to two new phases cubic (a 0 = 5.71 A ) and hcp ( a 0 = 4.61 A ).
TL;DR: In this paper, the experimental data on the formation of 137 monocyclic hydrocarbons and 44 polycyclic and cyclophane-type hydro-carbons have been analyzed.
Abstract: The experimental data on the heats of formation of 137 monocyclic hydrocarbons and 44 polycyclic and cyclophane-type hydrocarbons have been analyzed, and strain-energy terms and empirical equations for monocyclic hydrocarbons derived to supplement the general bond-energy scheme developed for hydrocarbons. The over-all precision attained in predicting new values of heats of formation is of the order of ±1 kcal/mole, which is slightly poorer than the over-all uncertainty of ±0.8 kcal/mole in the available experimental data. The individual minimum energy conformation assumed by ring compounds is specific and somewhat defies the general additivity principle. This is more so for polycyclic nonaromatic hydrocarbons where deviations to the extent of ±8 to 9 kcal/mole in the strain energy are observed. The various factors responsible for strain in ring compounds sometime either reinforce or reduce the net strain energy. More elaborate procedures of computing the strain energy of a ring structure are nece...
TL;DR: In this article, mass spectral studies on costunolide and lactones derived therefrom, have revealed some general fragmentation modes involving the losses of 44, 55, 57, 59, 71, 73 and 83 mass units from the molecular ion.
Abstract: Mass spectral studies on costunolide and lactones derived therefrom, have revealed some general fragmentation modes involving the losses of 44, 55, 57, 59, 71, 73 and 83 mass units from the molecular ion. The probable genesis of these ions is established by high resolution, metastable transitions and deuterium labelling studies. Comparison has been made with the mass spectra of some C6- desoxy esters.
01 Jan 1971
TL;DR: In this paper, the polymerization of acrylonitrile with the homogeneous catalyst system of VCl4-AlEt3 in acetonitrile at 40°C has been investigated.
Abstract: The polymerization of acrylonitrile with the homogeneous catalyst system of VCl4–AlEt3 in acetonitrile at 40°C has been investigated. The rate of polymerization is found to be first-order with respect to monomer and inversely proportional to the catalyst concentration. The overall activation energy for this catalyst system is 10.97 kcal/mole. The inverse proportionality of rate of polymerization with the catalyst concentration is attributed to the permanent complex formation between the catalyst complex and acrylonitrile, and a reaction scheme is proposed.
TL;DR: Mono-and di-isocyanates have been synthesized from the indigenously available raw material Cashew Nut Shell Liquid (CNSL) and their structures are confirmed on the basis of chemical and spectroscopic methods.
Abstract: Mono- and di-isocyanates have been synthesized from the indigenously available raw material Cashew Nut Shell Liquid (CNSL). These isocyanates have different structural features and hence may have different reactivities. Their structures are confirmed on the basis of chemical and spectroscopic methods. The reactivities of these isocyanates are under study.
Mono- und Diisocyanate wurden aus dem im Lande vorhandenen Rohstoff „Cashew Nut Shell Liquid” (CNSL) synthetisiert. Diese Isocyanate besitzen verschiedene Strukturen und soimit sicherlich auch verschiedene Reaktivitaten. Ihre Struktur wurde durch chemische und spektroskopische Methoden aufgeklart. Reaktivitats-untersuchungen sind im Gange.
TL;DR: In this article, the synthesis of the following ultravilot light absorbers from cashewnutshell liquid are described:============\/\/\/\/\/\/£££ £££€££/$££$££
Abstract: The syntheses of the following ultravilot light absorbers from cashewnutshell liquid are described:
2-(2′-pentadecenyl-4′-hydroxy-phenyl)-benzotriazole, 2-(2′-pentadecyl-4′-hydroxy-phenyl)-benzotriazole, 2-(2′-pentadecyl-3′-carboxy-4′-hydroxy-phenyl)-benzotriazole, 2-(2′hydroxy-4′-pentadecyl-5′-chloro-phenyl)-benzotriazole, 2-(2′-hydroxy-4′-pentadecyl-benzophenone, 3-pentadecyl-phenyl-salicylate and nickel complex of di-(4-pentadecyl-6-hydroxy-phenyl)-sulfide.
Synthesen fur folgende Verbindungen, die als UV-Absorber dienen konnen, werden beschrieben:
2-(2′-Pentadecenyl-4′-hydroxy-phenyl)-benzotriazol, 2-(2′-Pentadecyl-4′-hydroxy-phenyl)-benzotriazol, 2-(2′-Pentadecyl-3′-carboxy-4′-hydroxy-phenyl)-benzotrlazol, 2-(2′Hydroxy-4′-pentadecyl-5′-chlor-phenyl)-benzotriazol, 2-Hydroxy-4-pentadecyl-benzophonon, 3-Pontadecyl-phenyl-salicylat und Nickelkomplex von Di-(4-pentadecyl-6-hydroxy-phenyl)-sulfid.
TL;DR: Some of the fragmentation modes operating in a few furanosesquiterpenes have been established from accurate mass measurements and metastable data as discussed by the authors, but their results are limited to a few species.
Abstract: Some of the fragmentation modes operating in a few furanosesquiterpenes have been established from accurate mass measurements and metastable data.
TL;DR: In this paper, the effects of additives on the formation of syndiotactic structures are discussed on the basis of their electron donating powers, and the configuration of the polymers was affected by the presence of additives.