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Clay Suspensions (clay + suspension)
Selected AbstractsEgg incubation time and hatching success in tench Tinca tinca (L.) related to the procedure of egg stickiness eliminationJOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2003D. Gela Summary The experiment showed different results after a short (2 min) enzyme alcalase Merck EC 3.4.21.14 (5.0 ml L,1 concentration) treatment of tench eggs in contrast to the traditional methods of eliminating egg stickiness involving milk solution (50 g L,1) treatment for 70 min followed by the addition of a talc suspension (33 g L,1) for 10 min or treatment by fine clay suspension (20 g L,1) for 60 min or talc suspension (33 g L,1) for 80 min. The alcalase enzyme treatment resulted in decreased egg stickiness compared with the conventional milk/clay/talc treatments, indicated by lower duration of egg incubation and higher hatching rates (anova for hatching rate, P < 0.0084). The highest hatching rate (93.2%) was achieved using the enzyme; the lowest (31.3%) was using a talc suspension (control hatching rate was 86.2%). Duration of egg incubation at degree-days (D°) after enzyme treatment (58.6 D°) was about 4,5 h shorter than the classical method using milk solution and talc suspension (63,65 D°). Prolongation in the latter classical method may also be explained by a hardening of the egg envelopes. [source] Ni clay neoformation on montmorillonite surfaceJOURNAL OF SYNCHROTRON RADIATION, Issue 2 2001Rainer Dähn Polarized extended X-ray absorption fine structure spectroscopy (P-EXAFS) was used to study the sorption mechanism of Ni on the aluminous hydrous silicate montmorillonite at high ionic strength (0.3 M NaClO4), pH 8 and a Ni concentration of 0.66 mM. Highly textured self-supporting clay films were obtained by slowly filtrating a clay suspension after a reaction time of 14 days. P-EXAFS results indicate that sorbed Ni has a Ni clay-like structural environment with the same crystallographic orientation as montmorillonite layers. [source] Rheological and electrical properties of bentonite in anionic polystyrene sulfonate and nonionic poly(vinyl alcohol)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2007Bassem A. Mostafa Abstract The flow properties of bentonite were studied with a combination of anionic polystyrene sulfonate (molecular weight = 70,000 g/mol) and nonionic poly(vinyl alcohol) (molecular weight = 50,000 g/mol). This combination had a significant effect on clay suspensions depending on the sequence of the polymer addition. The addition of 50 mg/L anionic polystyrene sulfonate followed by 200 mg/L nonionic poly(vinyl alcohol) improved the rheological properties with a 7% bentonite suspension, especially at 20°C and after 24 h of aging. However, by the reversal of this addition sequence, the rheological properties of bentonite suspensions were reduced. The , potential of bentonite suspensions of the individual polymers at the same concentration was ,42 mV for polystyrene sulfonate and ,63 mV for poly(vinyl alcohol). The combined effect of anionic polystyrene sulfonate followed by nonionic poly(vinyl alcohol) noticeably changed the , potential (,95 mV). With the reversal of the addition sequence, this parameter did not change. Potential energy profiles were constructed to investigate the suspension stability. Potential energy profiles of polystyrene sulfonate added to bentonite suspensions and followed by poly(vinyl alcohol) produced high repulsion potential energy between clay surfaces, reflecting high suspension stability. By the reversal of this sequence, a significant reduction of the energy barrier was observed. On the basis of the rheological and electrical properties of this system, the addition of polystyrene sulfonate followed by poly(vinyl alcohol) provides a promising tendency for a 7% clay concentration to meet desirable drilling mud properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3886,3894, 2007 [source] On the mechanisms of oligopeptide reactions in solution and clay dispersionJOURNAL OF PEPTIDE SCIENCE, Issue 12 2004Dr Juraj Bujdák Abstract Mechanisms of the reactions of representative dipeptides (Gly2, Gly-Ala), oligopeptides (Gly3, Gly4) and the polypeptide (poly-Gly)n) in solution and clay suspensions at 85 °C were investigated. The reaction products and their yields were analysed and determined by means of HPLC. Interestingly, hydrolysis, where water molecules act as the reactant, was not the main reaction, even for oligopeptides. Formation of cyclic dipeptides prevailed in the reactions of dimers as well as oligopeptides. The breakdown of oligopeptide molecules proceeded via an intramolecular cyclization reaction. For example, the reaction of Gly3 led to the formation of equal amounts of cyclic dipeptide, c(Gly)2 and Gly. The presence of clay (montmorillonite) significantly increased yields in the reactions of dipeptides but it did not have much effect on the reactions of oligopeptides. However, an opposite effect of clay, protection of poly(Gly)n against decomposition, was proven. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd. [source] POLYSACCHARIDE RELEASE BY APHANOTHECE HALOPHYTICA INHIBITS CYANOBACTERIA/CLAY FLOCCULATION,JOURNAL OF PHYCOLOGY, Issue 3 2010Li Chen Many microalgae release polysaccharides, but the effects of the polysaccharides on mutual flocculation of microalgae and clay in aquatic environments have not been well studied. Aphanothece halophytica Frémy is a bloom-forming cyanobacterium in salterns and can release large amounts of polysaccharide (AH-RPS). In the present study, we investigated the effect of AH-RPS on mutual flocculation of cyanobacterium and clay and further explored the mechanisms by which AH-RPS affected mutual flocculation. We determined that AH-RPS possessed clay-dispersing activity as defined as the ability to inhibit the flocculation and sedimentation of clay suspensions in water. Supplementation of AH-RPS in cyanobacterial cell suspensions and in the culture media containing the same kaolin clay concentration dose dependently decreased flocculation of cyanobacterial cells and increased clay-dispersing activity. These findings indicate that the clay-dispersing activity of AH-RPS was related to its inhibitory effect on mutual flocculation of cyanobacterial cells and clay particles. Moreover, the clay-dispersing activity of AH-RPS was stable from pH 3 to pH 10 and was increased by adding NaCl, MgCl2, CaCl2, or low concentrations of KCl (up to 0.4 M). Taken together, our data suggest that AH-RPS might maintain its clay-dispersing activity and inhibit mutual flocculation of microalgae and suspended clay in saltern brine. [source] | ||||||||||