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41.
A SANS determination of the influence of external conditions on the nanostructure of nafion membrane
Anne‐Laure Rollet Grard Gebel Jean‐Pierre Simonin Pierre Turq 《Journal of Polymer Science.Polymer Physics》2001,39(5):548-558
We have studied the structure of nafion membranes by small‐angle neutron scattering in the q range of 7 10−3 Å−1 to 0.4 Å−1. External conditions were varied: counterions, electrolyte concentration, temperature, and pretreatment of membranes. The nanostructure of Nafion exhibits a sensivity that depends on the parameters considered: changing counterions and concentration leads to a reversible local reorganization of the hydrophilic cavities, whereas changing temperature and pretreament leads to a irreversible reoganization on a larger scale. The mean variation of the radius of the hydrophilic cavities versus these parameters is about 10%. The interface between hydrophobic and hydrophilic phases appears to be sharp except when the temperature exceeds 60 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 548–558, 2001 相似文献
42.
Hebah Muhsien Sabiah AL Ubeed Ronald B. H. Wills Jayani Chandrapala 《Molecules (Basel, Switzerland)》2022,27(5)
The traditional Cannabis plant as a medicinal crop has been explored for many thousands of years. The Cannabis industry is rapidly growing; therefore, optimising drying methods and producing high-quality medical products have been a hot topic in recent years. We systemically analysed the current literature and drew a critical summary of the drying methods implemented thus far to preserve the quality of bioactive compounds from medicinal Cannabis. Different drying techniques have been one of the focal points during the post-harvesting operations, as drying preserves these Cannabis products with increased shelf life. We followed or even highlighted the most popular methods used. Drying methods have advanced from traditional hot air and oven drying methods to microwave-assisted hot air drying or freeze-drying. In this review, traditional and modern drying technologies are reviewed. Each technology will have different pros and cons of its own. Moreover, this review outlines the quality of the Cannabis plant component harvested plays a major role in drying efficiency and preserving the chemical constituents. The emergence of medical Cannabis, and cannabinoid research requires optimal post-harvesting processes for different Cannabis strains. We proposed the most suitable method for drying medicinal Cannabis to produce consistent, reliable and potent medicinal Cannabis. In addition, drying temperature, rate of drying, mode and storage conditions after drying influenced the Cannabis component retention and quality. 相似文献
43.
44.
Imran Ali Zeid A. AL‐Othman Norikaju Nagae Vinay D. Gaitonde Kamlesh K. Dutta 《Journal of separation science》2012,35(23):3235-3249
New generation columns, i.e. packed with superficially porous silica particles are available as trade names with following manufacturers: Halo, Ascentis Express, Proshell 120, Kinetex, Accucore, Sunshell, and Nucleoshell. These provide ultra‐fast HPLC separations for a variety of compounds with moderate sample loading capacity and low back pressure. Chemistries of these columns are C8, C18, RP‐Amide, hydrophilic interaction liquid chromatography, penta fluorophenyl (PFP), F5, and RP‐aqua. Normally, the silica gel particles are of 2.7 and 1.7 μm as total and inner solid core diameters, respectively, with 0.5‐μm‐thick of outer porous layer having 90 Å pore sizes and 150 m2/g surface area. This article describes these new generation columns with special emphasis on their textures and chemistries, separations, optimization, and comparison (inter and intra stationary phases). Besides, future perspectives have also been discussed. 相似文献
45.
Ateyyah M. AL‐Baradi Matthew Mears Richard A. L. Jones Mark Geoghegan 《Journal of Polymer Science.Polymer Physics》2012,50(18):1286-1292
We describe an investigation of fluorescence correlation spectroscopy into the diffusion of fluorescein‐tagged dextran (FDEX) in a poly(methacrylic acid) (PMAA) hydrogel. The temperature dependence of FDEX diffusion is shown to follow Zimm behavior in pure water, and the decrease in the diffusion coefficient when in the PMAA hydrogel has been modeled. The addition of acid and alkali (HCl and NaOH, respectively) not only control the swelling and collapse of the hydrogel but also reveal a strong pH dependence of the dextran diffusion coefficient, which shows a (nonmonatonic) increase with pH. The addition of NaCl and CaCl2 salts similarly showed evidence of network swelling, most notably at low salt concentration, but also that the diffusion coefficient within the gel at these low concentrations is larger than that in the equivalent solution without the hydrogel, indicating that the combination of hydrogel and salt works to increase the diffusion coefficient above that in pure water. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
46.
E. A. Lum J. Moir F. G. Germuth B. S. Evans J. G. Weeldenburg E. H. Hall R. J. Peters St. Soule A. Ledebur A. Eder H. Rubricius G. Ferreri W. J. Agnew M. E. Bertrand L. Malaprade A. Job B. Jones A. P. Rollet G. Schuster Chemikerausschuss des Vereins Deutscher Eisen hüttenleute E. Schiffer S. Glasstone und J. C. Speakman 《Fresenius' Journal of Analytical Chemistry》1931,86(5-6):244-253
Ohne Zusammenfassung 相似文献
47.
The large fluxes of fusion neutrons produced in the Ignitor experiment can cause severe damage to the most exposed components of the tokamak or of the diagnostic system. In a simplified geometry model, the FLUKA and the MCNP-4B Monte Carlo codes are used to evaluate the influence of the neutron source energy and the material composition on the energy deposition in these components. 相似文献
48.
We propose a classification of the solutions K to the semi-dynamical reflection equation with constant rational structure matrices associated to rational scalar Ruijsenaars-Schneider
model. Four sets of solutions are identified and simple analytic transformations generate all solutions from these sets.
Communicated by Petr Kulish
Dedicated to Daniel Arnaudon
Submitted: December 6, 2005; Accepted: December 17, 2005 相似文献
49.
J. Avan T. Fonseca L. Frappat P. P. Kulish E. Ragoucy G. Rollet 《Theoretical and Mathematical Physics》2014,178(2):223-238
We construct new sets of rank n-representations of the Temperley-Lieb algebra TLN(q) that are characterized by two matrices with a generalized complex Hadamard property. We give partial classifications for the two matrices, in particular, in the case where they reduce to Fourier or Butson matrices. 相似文献
50.