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71.
A closed-loop recycle system using a charged ultrafiltration membrane to decolourise reactive dye effluents from a textile yarn and fabric dyeing process is described. The economics of the process depend on the value of the electrolyte ($5 to $10 per M3). Conventional reactive dyeing technology was examined and modified to facilitate dye liquor reuse. The performance of the membrane was examined in terms of electrolyte rejection, colour rejection and permeate flux under varying conditions of solution pH, ionic strength and operating pressure. 相似文献
72.
Summary The preparation of epoxy fatty acid ester plasticizers has been reviewed. These plasticizers can be prepared by epoxidation
reactions, utilizing a preformed peracid or anin-situ technique. A newin-situ epoxidation process, utilizing hydrogen peroxide and acetic acid in the presence of strong acid catalyst, has been described.
Excellent conversions to epoxide have been achieved with a series of monounsaturated and polyunsaturated esters.
Epoxy fatty acid esters are excellent plasticizers for vinyl resins. Their performance in a series of additional epoxy plasticizers
of vegetable and marine origin is described. Novel epoxy plasticizers based upon mixed acetylated mono- and di-glyceride have
been prepared and are found to have excellent plasticizer performance.
Presented at the 28th fall meeting, American Oil Chemists’ Society, October 1954, Minneapolis, Minn. 相似文献
73.
Recent studies of self-condensation and co-condensation of melamine-formaldehyde resins; cure at low temperatures 总被引:1,自引:0,他引:1
Self-condensation: recent research on the chemical pathways by which alcoholated melamine-formaldehyde (MF) resins react with themselves and on the product structures is summarized. Model compound studies suggest that
bridges are less stable than widely thought unless they are in hexahydro-1,3,5-triazine ring structures. In acyclic structures they are probably less stable than
bridges. Co-condensation: studies of how the composition of MF resins influences the rates of reaction with poly(ol) co-reactant show that MF resins that contain very low levels of
and/or
functionality are quite reactive. Reactivities of a variety of poly(ester) and acrylic coreactants were studied. By combining reactive MF resins with reactive co-reactants one can formulate high solids enamels that cure by co-condensation in 30 min at 50 to 65 °C with 0.5 parts per hundred (phr) of p-toluenesulfonic acid (p-TSA) catalyst. Cure at 25 °C appears feasible with higher catalyst levels. 相似文献
74.
A bivoltine checkerspot butterfly,Poladryas minuta, is aPenstemon specialist, not known to utilize any other plant genus for oviposition and larval feeding. At several intermontane plains sites of central Colorado, the butterfly utilizesPenstemon virgatus as its sole host plant. Analysis of the host plant showed it to contain three cinnamyl-type catalpol esters (scutellarioside-II, globularin, globularicisin) and catalpol. The host plant contained an average of 10% dry weight iridoids, but some variation among individual plants and leaves within plants was noted. Field-collected butterflies contained 2.1–8.7% dry weight catalpol, but no other iridoids. Adults from larvae fedP. virgatus in the lab contained 4.2–9.0% dry weight catalpol and excreted large amounts of catalpol in the meconium. No catalpol was found in the larval frass. Larvae did not consume three alternate iridoid-containing host-plant species, and most eventually died rather than feed on the alternate plants. Larvae did consume small amounts of artificial diets containing the alternate species andP. virgatus, but most went into diapause and some died. Survival was good on artificial diet containing 10% dry weight of the iridoid esters fromP. virgatus. Only catalpol was found in pupae and adults, but it was absent from the larval frass. The cinnamic-type acids expected from larval hydrolysis of the esters were not found in larval frass, pupae, or adults. These results are contrasted with those found for another checkerspot,Euphydryas anicia, which consumes a different host-plant species but was present at one of the same sites withPoladryas minuta.Paper 15 in the series Chemistry of the Scrophulariaceae. Paper 14 Boros, C.M., Stermitz, F.R., and Harris, G.H. 1990.J. Nat. Prod. 5372–80. 相似文献
75.
A new approach is presented for the characterization of particle motion in fluid-solid systems based on dynamic imaging with a gamma scintillation camera. A two-dimensional spouted bed of 200-500 micron diameter anion exchange resin beads was used as a test system. One or several beads were radiolabeled with the 140 keV gamma emitting radionuclide 99m-Tc pertechnetate, and particle velocity, panicle path, the spatial distribution of particle residence times, and local bed density were determined from the measured temporal and spatial distributions of particle activity. While care must be exercised in the interpretation of data when the scale for changes in the spatial distribution of activity approaches the limits of camera resolution, the method is quantitative, non-invasive, and well suited to the study of systems having symmetry in one spatial dimension. 相似文献
76.
77.
Phase Stability of Fine-Grained (Mg,Y)-PSZ 总被引:2,自引:0,他引:2
Frank Meschke Nils Claussen Goffredo De Portu Jürgen Rödel 《Journal of the American Ceramic Society》1995,78(7):1997-1999
A fine-grained zirconia, which has been costabilized with yttria and magnesia, has been prepared. Its stability during subeutectoid annealing at 1100deg; C, and its hydrothermal stability during hydrothermal treatment at 180deg; C, have been determined and they are compared to those of Y-TZP and Mg-PSZ materials . 相似文献
78.
Willard A. Cutler Frank W. Zok Fred F. Lange 《Journal of the American Ceramic Society》1996,79(7):1825-1833
Several different hybrid laminated composites comprised of alternating layers of dense ceramic sheets (either SiC or Si3 N4 ) and fiber-reinforced ceramic-matrix-composite (CMC) layers (Nicalon fibers with either glass or glass-ceramic matrices) have been fabricated and characterized. The effects of the reinforcement architecture (unidirectional vs cross-ply) and the relative volume fractions of the phases on the tensile and flexural properties have been examined. Comparisons have been made with the properties of the constituent layers. Rudimentary models have been developed to describe the onset of cracking and for the minimum volume fraction of CMC required to develop multiple cracks and thus obtain a high failure strain. 相似文献
79.
Robert R. Mod Frank C. Magne Evald L. Skau 《Journal of the American Oil Chemists' Society》1959,36(12):616-619
Summary Eighty-eight amine salts of long-chain fatty acids have been prepared, purified by solvent crystallization, and characterized.
Forty-five of these were salts of palmitic acid. The rest included salts of capric, lauric, myristic, stearic, oleic, elaidic,
and 12-hydroxystearic acids. A variety of aliphatic, aromatic, and heterocyclic amines, including primary, secondary, and
tertiary amines, were investigated. The majority of these gave 1∶1 acid-amine compounds on solvent recrystallization of an
equimolar mixture of acid and amine. Some of the amines gave no crystallizable salt, and with others the pure salt could not
be obtained by this procedure. Under the same conditions the symmetrical alkyl, substituted alkyl, and aralkyl secondary amines
investigated gave crystallizable compounds containg two molecules of fatty acid to one of amine. Molecular compounds of 2-aminopyridine
with four molecules of saturated fatty acid were formed by recrystallization starting with a 1 to 4 amine-acid mixture. Surface-tension
measurements were made for aqueous solutions of a few of the amine salts.
One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S.
Department of Agriculture. 相似文献
80.
Frank C. Magne Robert R. Mod Evald L. Skau 《Journal of the American Oil Chemists' Society》1961,38(6):294-296
A systematic investigation has been made of the effect of fatty acid composition on the compatibility of the corresponding
mixed morpholides as plasticizers for vinyl chloride-vinyl acetate copolymer resins. Plasticizer evaluation data were obtained
for the morpholides of lauric, palmitic, elaidic, and epoxyoleic acids and compared with the literature values for other fatty
acid morpholides and morpholide mixtures.
Ternary compatibility-composition diagrams have been constructured for the oleic-linoleic-stearic and the oleic-linoleic-palmitic
morpholide systems. These diagrams make it possible to predict what adjustment, if any, must be made in the composition of
any mixture of these fatty acids so that the corresponding morpholide mixture will be compatible. The diagrams will be useful
in selecting the most appropriate and economical fatty acid sources from which to make compatible morpholide mixtures.
Presented at the 52nd Annual Meeting, American Oil Chemists’ Society, St. Louis, Mo., May 1–3, 1961.
One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U.S.
Department of Agriculture. 相似文献