Simulants for the Hanford Waste Vitrification Plant feed containing the major non-radioactive components Al, Cd, Fe, Mn, Nd, Ni, Si, Zr, Na, CO{sub 3}{sup 2}-, NO{sub 3}-, and NO{sub 2}- were used to study reactions of formic acid at 90{degrees}C catalyzed by the noble metals Ru, Rh, and/or Pd found in significant quantities in uranium fission products. Such reactions were monitored using gas chromatography to analyze the CO{sub 2}, H{sub 2}, NO, and N{sub 2}O in the gas phase and a microammonia electrode to analyze the NH{sub 4}+/NH{sub 3} in the liquid phase as a function of time. The following reactions have been studied in these systems since they are undesirable side reactions in nuclear waste processing: (1) Decomposition of formic acid to CO{sub 2} + H{sub 2} is undesirable because of the potential fire and explosion hazard of H{sub 2}. Rhodium, which was introduced as soluble RhCl{sub 3}-3H{sub 2}O, was found to be the most active catalyst for H{sub 2} generation from formic acid above {approximately} 80{degrees}C in the presence of nitrite ion. The H{sub 2} production rate has an approximate pseudo first-order dependence on the Rh concentration, (2) Generation of NH{sub 3} from the formic acid reduction of nitrate and/or nitrite is undesirable because of a possible explosion hazard from NH{sub 4}NO{sub 3} accumulation in a waste processing plant off-gas system. The Rh-catalyzed reduction of nitrogen-oxygen compounds to ammonia by formic acid was found to exhibit the following features: (a) Nitrate rather than nitrite is the principal source of NH{sub 3}. (b) Ammonia production occurs at the expense of hydrogen production. (c) Supported rhodium metal catalysts are more active than rhodium in any other form, suggesting that ammonia production involves heterogeneous rather than homogeneous catalysis.
Introduction Secale ccreale L., common rye, has drawn the attention of cytologists for a considerable length of time due to its econonlic importance. This species has been incorporated in a number of breeding programs, both at interspecific and inter~eneric levels. 0 Cytological studies on this species have been mainly concerned with the nature and behaviour of meiotic chron~osomes (Longley and Sando, 1930; Thompson, 193 1 ; Darlington, 193 3 ; Levan, 1942). Detailed study of the meiotic chrornoson~es and chron~omere analysis at pachytene has also been a t tem~ted and on the basis of these data. chron~oson~e maDs of all the seven airs kf chromosomes have been presented (Lima-de-Faria. '1952). Discovery I I , of accessory chronlosomes in this species makes this material very interesting to cytologists and a great deal of worlt has been done on this aspect (Alliintzing, 1949, 1954; Lima-de-Faria, 1948, 1952; Hikansson, 1957). Unfortunately, data on the detailed ltaryotype of this species are very meagre. Some of the cytologists have tried to worlt out the morphology of the somatic chroinosoines (Shmargon, 1938; Levan, 1942; Oinuma, 195 3; Riley and Chapman, 1958). Though the somatic chro~nosomes of rye are quite large in size and possess good stainability, their detailed nlorphology is very difficult to reveal. Except for the one pair of chromosomes with very proilounced secondary constrictions, other chron~osome pairs are rather difficult to distinwish.. With the introduction of addition-and substitution of s~ecif ic rve U I i chromosomes to other cereals, a critical identification of all the seven pairs of cl~rornosoines is an absolute necessity because the phenotypic characters do not always indicate an identifiable effect for each specific chromosome. These considerations led the authors to undertalte a thorougl~ analysis of the ltaryotype of rye. It was thought that if the individual rye chromosomes could be identified from their size. n~or~holocrv and arm index. the data would be of immense value in a DroDer idkntifi;ationu;f addition and sbstitution lines. I I The present report deals with a critical ltaryotype analysis of S. cereale Dakold, a variety used extensively in this laboratory in various breeding projects. Materials and Methods S. ce~eale Dakold, common rye, is a hardy winter type. Seed stoclts utilized in this study came from a foundation stock designated as Daltold 23 which is being maintained bv the Field Husbandry Department, University of Sasltatchewan, Sasltatoon, aska at chew an. Excellent fixation of the somatic chromosomes presented considerable difficulty. Several pre-fixative treatments were tried but it was found that pre-treGment in tap water for 24 hours at 0' to 2OC was most satisfactory.
1. Sphenoclea zeylanica Gaertn. of the family Campanulaceae and Lobelia terminalis Clarke of the related family Lobeliaceae, the two being originally kept under Campanulaceae, have been studied cytologically. Chromosome number observed in them are:i) Sphenoclea zeylanica Gaertn. 2n=42ii) Lobelia terminalis Clarke 2n=142. Their karyotype analysis reveals long metacentric chromosomes in L. terminalis and short chromosomes in S. zeylanica. x=7 has been suggested as the basic number for both the genera. Diminution in chromatin matter along with polyploidy as noticed here has been discussed in the light of recent data.3. A heteromorphic pair of chromosomes has been observed in L. terminalis. Significance of such structural alteration of chromosomes in evolution has been discussed.4. Taxonomic status of Sphenoclea has been discussed. Its relationship with Phytolaccaceae has been criticised on the basis of available cytological data in them. The retention of the genus within the Campanuloid complex has been suggested.5. The relationship of the two families, Campanulaceae and Lobeliaceae as mentioned by taxonomists has been confirmed from cytological studies.
Seeds and seedlings of Cyamopsis psoraloides DC. were treated with different concentrations of colchicine solution for different durations to induce polyploidy. No polyploids could be obtained in seed treatment which can be accounted for the toxic effects of the chemical. Aqueous colchicine solution of two different concentrations viz. 0.25 and 0.5 percent applied on cotton pad around the stem tip at seedling stage responded well. Treatment with 0.25 percent colchicine for 6 hours 2 days treatment gave maximum polyploids.The induced polyploids were either complete tetraploids, or mixoploids with hypotetraploid chromosome numbers. One plant was hexaploid.Typical effect of colchicine, like slow growth of plant during early stages of development, thicker, fleshy and deformed leaves, less number and big size of stomata were observed in treated plants in comparison to diploids. Delayed flowering with lesser number of flowers per inflorescence as well as per plant in the tetraploid plants was significant. Pollen size and sterility in the tetraploids increased considerably. Number of fruits and seeds were few in tetraploids in comparison to those in diploids. On the whole C0 and C1 plants were less vigorous in growth.Detailed cytological studies of the diploid plant have been carried out. Irregularities in chromosome association at metaphase I were prominent in the polyploids. The mean frequency of quadrivalents per cell was 0.89. Unequal separation of chromosomes and laggards were present in the meiosis of the polyploids. The present data have been discussed in relation to the previous reports.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDialkylamino phosphorus metal carbonyls. 9. Acylation rather than Wittig olefination in reactions of the phosphorus-bridging carbonyl derivative (iso-Pr2NP)2COFe2(CO)6 with phosphonium methylidesR. B. King, N. K. Bhattacharyya, and E. M. HoltCite this: Inorg. Chem. 1991, 30, 6, 1174–1178Publication Date (Print):March 1, 1991Publication History Published online1 May 2002Published inissue 1 March 1991https://pubs.acs.org/doi/10.1021/ic00006a005https://doi.org/10.1021/ic00006a005research-articleACS PublicationsRequest reuse permissionsArticle Views60Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
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