Production of aqueous colloidal dispersions of carbon nanotubes.

The Layer Silicates

Preparation and properties of monodispersed colloidal particles of lanthanide compounds: I. Gadolinium, europium, terbium, samarium, and cerium(III)

Properties of Copper Chromite Catalysts in Hydrogenation Reactions

This paper is concerned with the cross-linking of poly(vinyl alcohol) (PVA) using maleic acid as the cross-linker. The curative (maleic acid) dose and the curing temperature and time were varied between 2.5 and 60% (w/w), 120 and 160 °C and 30 and 120 min, respectively. From a thorough swelling study in both hot and cold water (percentage swelling, gel content, swelling ratio, etc-) the optimum curative dose and curing conditions have been evaluated. The molecular weight between the cross-links exhibited a sharp fall up to a maleic acid dose of 20% (w/w). A comparative evaluation of maleic acid cross-linked and heat-treated PVA films has been done. Better heat stability for maleic acid cross-linked PVA was observed from thermogravimetric analysis. A shift in glass transition temperature was observed for both heat-treated and maleic acid treated PVA compared with the virgin one. IR spectroscopic study indicated the presence of an ester linkage and an olefinic double bond in maleic acid treated and heat-treated PVA films, respectively. Maleic acid cross-linked PVA is quite stable in different polar and nonpolar solvents. A definite structural pattern has been observed in maleic acid cross-linked PVA films through scanning electron microscopy.

Studies On The Crosslinking Of Poly (Vinyl Alcohol)

Infrared Absorption Spectroscopy

Analyses of cpDNA using maximum parsimony, maximum likelihood and Bayesian inference reveal that Metastelma is polyphyletic in its present circumscription. Two species are transferred to Tassadia as T. richardiana and T. stricta. One species, M. eggersii, is retrieved as a member of subtribe Gonolobinae rather than Metastelmatinae, and several South American species fall within the “Stelmation” clade together with species of Ditassa. In Metastelma sensu stricto, the South American species are not monophyletic, falling into a M. tubatum Clade and a South American-Caribbean M. parviflorum Clade. Most Caribbean species, except for M. anegadense, M. decipiens, M. lineare, and M. parviflorum, form a clade in which the Cuban species are sister to the remaining taxa. The Central American mainland species show a clear geographical structure with a center of diversity in central Mexico, two radiations along the Occidental portion of Sierra Madre, and one radiation along the Oriental portion of Sierra Madr...

https://bioone.org/journals/systematic-botany/volume-39/issue-2/036364414X680708/Phylogenetics-and-Biogeography-of-the-Genus-Metastelma-Apocynaceae-Asclepiadoideae-Asclepiadeae/10.1600/036364414X680708.pdf

Marc Nikolaus

Papers

Infrared Absorption Spectroscopy

Phylogenetics and Biogeography of the Genus Metastelma (Apocynaceae-Asclepiadoideae-Asclepiadeae: Metastelmatinae)