Showing papers by "National Chemical Laboratory published in 1981"
TL;DR: In this paper, it was shown that CaTiO3 (perovskite), SrTiOO3 and BaTiO 3 are as reactive as some silicate glasses below 100°C, but leach much more slowly than glasses above 100°c.
Abstract: Perovskite, a SYNROC host mineral for nuclear wastes, is thermodynamically unstable in natural waters and in association with common minerals. Leach experiments demonstrate that CaTiO3 (perovskite), SrTiO3 and BaTiO3 are as reactive as some silicate glasses below 100°C, but leach much more slowly than glasses above 100°C.
119 citations
TL;DR: Multiple shoots were obtained from terminal buds of 20-year-old trees of Eucalyptus citriodora Hook on Murashige and Skoog's medium supplemented with calcium pantothenate, biotin, benzylaminopurine and kinetin.
111 citations
TL;DR: In this article, the microwave spectra of four isotopic species of dichlorine monoxide (OCl2) have been observed and the rotational constants have been obtained.
61 citations
TL;DR: In this article, the reaction between Mg2Ni and hydrogen was investigated by volumetric method and the reaction was divided into two stages; the initial stage was a very rapid reaction whose rate could not be measured, the later stage was the slower step whose rate was expressed by the equation ============dn/DT=K′(P−Peq/t/)where k′ is the constant, Peq and P are hydrogen pressures at equilibrium and at time t.
57 citations
Abstract: A comprehensive model for a semibatch ester interchange reactor has been developed with a view to investigate the effect of various process and operational variables on the DMT conversion rate as well as the by-product formation. The influence of important variables such as EG-to-DMT ratio, catalyst concentration, and operational variables such as temperature and pressure has been considered. Definite conclusions concerning the choice of the desirable range of process and operational variables to maximize productivity and minimize by-product formation have been reached.
47 citations
TL;DR: Four β-glucosidase enzymes were extensively purified from the culture filtrates of Sclerotium rolfsii and some of their physicochemical properties studied, showing a single protein band in sodium dodecyl sulfate-gel electrophoresis and in disc gel electrophoreis.
43 citations
TL;DR: In this article, the authors showed that increasing the δp value of the substituent raised the selectivity for 2-arylpropanal and the tendency was the opposite to that found in the absence of phosphines.
38 citations
TL;DR: In this paper, the binding energy shifts are explained on the basis of electronegativity and near-neighbour interactions, and it is found that increased coordination number as well as increased electrone gativity of the neighbouring atoms increases the binding energies of the core electron level.
36 citations
01 Jun 1981
TL;DR: Using a solvent polymeric membrane consisting of polyvinyl chloride, p -nitrophenyl n -heptyl ether, aliphatic dichlorohydrocarbons, and a chelating agent, the transport of zinc, copper, and picrate ions against their concentration gradient was measured as mentioned in this paper.
Abstract: Using a solvent polymeric membrane consisting of polyvinyl chloride, p -nitrophenyl n -heptyl ether, aliphatic dichlorohydrocarbons, and a chelating agent, the transport of zinc, copper, and picrate ions against their concentration gradient was measured. The chelating agents used as carriers of cation transport were bathophenanthroline for zinc, bathocuproine for copper, and dibenzo18-crown-6 for picrate. The transport of the zinc ion against its concentration gradient was observed for systems containing sodium nitrate, chloride, and bromide in the aqueous solution on the donor side of the membrane. The copper ion was transported for a system containing sodium chloride, but no copper transport occurred in the presence of sodium nitrate. The picrate ion moved with the transport of carrier-mediated potassium ions. The total flux of the permeant ions increased linearly with increasing concentration of carriers except at very high concentration ranges.
34 citations
TL;DR: In this paper, the rate constants activation energies for both the steps-non-catalytic and autocatalytic-were obtained, and the effect of various process parameters on the reaction rate was discussed.
31 citations
TL;DR: The lipid productivities of six species (11 strains) of fungi of the order Mucorales in the class Zygomycetes obtained from Institute for Fermentation, Osaka, were investigated and the compositions of both lipid fraction were quantitatively determined by thin layer chromatographic analysis.
Abstract: The lipid productivities of six species (11 strains) of fungi of the order Mucorales in the class Zygomycetes obtained from Institute for Fermentation, Osaka, were investigated. The total lipid extracts of fungus cells grown by stationary culture method were separated to neutral lipid and polar lipid fractions by silicic acid column chromatography, and the amounts of both fractions were determined. Fatty acid compositions of the lipids were analyzed by gas liquid chromatography. Futhermore, the compositions of both lipid fraction were quantitatively determined by thin layer chromatographic analysis. The total lipid amount of Mortierella isabellina IFO No. 7884 was 86.1% of the dry fungus cells cultivated at 20°C.
TL;DR: In this paper, the OH stretching Raman spectra of aqueous calcium perchlorate solutions were obtained in both liquid state at room temperature and glassy state at liquid nitrogen temperature.
TL;DR: In this article, the appearance energy of NO 2 + from CH 3 NO 2 is close to the thermodynamic onset for CH 3 + NO 2+ while CH 3+ appears 1.2 eV above the onset.
TL;DR: In this paper, the first case of successful carbonylation of organic halides having β-hydrogens was reported, in which α-Pehnylethyl bromide, ethyl α-bromopropionate, and α-phenylpropylbromide were smoothly converted to the corresponding methyl ketones by treatment with carbon monoxide and palladium complex catalysts in the presence of tetramethyltin.
TL;DR: In this article, the inner-outer and outer-outer conformers of 1,2-dimethylhydrazine were assigned and the rotational constants and electron diffraction intensity were used for a joint analysis, from which their CNNC dihedral angles, 88.4 ± 0.7° and 164.2 ± 14°, and abundance ratio at room temperature, 62 ± 8% : 38 ± 8%, respectively, were determined.
TL;DR: Tricontanol, a new plant growth regulator, has been synthesised starting from stearic acid, and by two successive additions of six carbon units through enamine intermediates.
TL;DR: In this paper, the optical and structural properties of copper-black layers prepared by the anodic oxidation of copper in an alkaline medium have been studied, and X-ray diffraction, electron diffraction and ESCA studies indicate that they are mixture of cuprous and cupric oxides.
TL;DR: Among plants, rice is the first genome in which no DNA sequence interspersion is observed, and DNA sequence organization in rice genome has been investigated by studying the extent of DNA reassociation as a function of DNA fragment size.
TL;DR: In this article, a detailed analysis of the Hammill-funabashi (HF) model for electron scavenging in low-temperature glasses is given, and it is concluded that contrary to their assertion, HF model is based upon the tunneling mechanism.
TL;DR: It is proposed that plants with haploid DNA content of more than 2.5 pg exhibit mostly the short period interspersion pattern, while those with haploids content of less than 1.5 PG show diverse patterns of genome organization.
Abstract: Approximately 39 to 49% of the genome of finger millet consists of repetitive DNA sequences which intersperse with 18% of single copy DNA sequences of 1900 nucleotide pairs Agarose gel filtration and electrophoresis experiments have yielded the sizes of interspersed repeated sequences as 4000–4200 nucleotide pairs and 150–200 nucleotide pairs Approximately 20% of the repeated DNA sequences (4000–4200 nucleotide pairs) are involved in long range interspersion pattern, while 60% of the repeated DNA sequences (150–200 nucleotide pairs) are involved in short period interspersion pattern Based on the data available in literature and the results described here on DNA sequence organization in plants, it is proposed that plants with haploid DNA content of more than 25 pg exhibit mostly the short period interspersion pattern, while those with haploid DNA content of less than 25 pg show diverse patterns of genome organization
TL;DR: Oxygen-deficient perovskites of the system (CaxSr1−x)FeO3−y were prepared at high oxygen pressures up to 1900 atm (196 MPa) and measurements were made of their crystallographic and thermodynamic behavior as mentioned in this paper.
TL;DR: The second-order rate constant and activation energy are in good agreement with those reported in the literature as mentioned in this paper, and the relationship between intrinsic viscosity and the extent of reaction is established, using a series of polyacrylamides with known extents of hydrolysis.
Abstract: The alkaline hydrolysis of polyacrylamide in solution is studied viscosimetrically. The viscosity of the solution increases continuously during the course of hydrolysis. The relationship between intrinsic viscosity and the extent of reaction is established, using a series of polyacrylamides with known extents of hydrolysis. The extent of reaction is determined from the observed flowtime, using the relationship between [η] and extent of reaction. The second-order rate constant and the activation energy are in good agreement with those reported in the literature. A four-fold increased reactivity of the amide groups towards hydrolysis is observed at very low extents of hydrolysis.
TL;DR: In this article, a diagnostic method in the context of a modified Maxwell model has been proposed to differentiate between different diffusive phenomena, and the role of co-operative segmental motion for the polymer matrix has been quantitatively examined.
TL;DR: In this article, the coupling between a redox reaction and ion transport in an artificial membrane system was studied and the rate of transference of the lipophilic anion (picrate) was found to be approximately equal to that of the transmembrane reaction.
TL;DR: The Raman spectrum of the phenoxy radical produced duing the course of oxidation of phenol by the Ce(IV) ion was measured by use of a stopped-flow method and a multichannel detection method.