Artículos de revistas: "Viscosimetric properties"

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Schmidt, R., G. Klingenberg y M. Woydt. "Thermophysical and viscosimetric properties of environmentally acceptable lubricants". Industrial Lubrication and Tribology 58, n.º 4 (julio de 2006): 210–24. http://dx.doi.org/10.1108/00368790610670809.

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Tande, Brian M., Norman J. Wagner, Michael E. Mackay, Craig J. Hawker y Miyoun Jeong. "Viscosimetric, Hydrodynamic, and Conformational Properties of Dendrimers and Dendrons". Macromolecules 34, n.º 24 (noviembre de 2001): 8580–85. http://dx.doi.org/10.1021/ma011265g.

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Strelets, L. A., L. V. Gorbunova y A. V. Bogoslovsky. "The Effect of a Hydrocarbon Fragment in a Molecule on Depressant Activity of Resins". Eurasian Chemico-Technological Journal 3, n.º 2 (1 de julio de 2017): 113. http://dx.doi.org/10.18321/ectj553.

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The effect of resins on solidification of paraffin solutions has been studied by vibration viscosimetry. This technique was used for studies of coagulating liquids, since the sample structure is less affected by mechanical oscillations compared to traditional rotary and linear shears. The installation developed for studies of thermo-induced phase transitions and the measurement procedure are described. The viscosimetric technique allows continuous registration of rheological properties with changing temperature, and has proved to be quite sensitive to small amounts of resins in model paraffin solutions. Measurements have been performed for resins extracted from methane-naphtene crudes of various West Siberia oil deposits. Dependencies of viscosity on temperature have been measured and are presented below for various concentrations of resins (up to 3 %) in paraffin solutions. It is demonstrated that increase of resin concentration results in a shift of the inflexion point on the viscosity-temperature curve to lower temperatures. A positive correlation has been found between depressant activity and average dimensions of aliphatic fragments of the resin molecu.

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4

Zec, Nebojša, Marija Bešter-Rogač, Milan Vraneš y Slobodan Gadžurić. "Volumetric and viscosimetric properties of [bmim][DCA] + γ-butyrolactone binary mixtures". Journal of Chemical Thermodynamics 97 (junio de 2016): 307–14. http://dx.doi.org/10.1016/j.jct.2016.02.014.

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5

Cuomo, Francesca, Antonio de Nigris, Lucio Zeppa, Francesco Lopez y Luigi Ambrosone. "Viscosimetric properties of sodium hyaluronate and hypromellose solutions for medical devices". Journal of Molecular Liquids 398 (marzo de 2024): 124182. http://dx.doi.org/10.1016/j.molliq.2024.124182.

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Vraneš, Milan, Teona Teodora Borović, Patrik Drid, Tatjana Trivić, Renato Tomaš y Nenad Janković. "Influence of Sodium Salicylate on Self-Aggregation and Caffeine Solubility in Water—A New Hypothesis from Experimental and Computational Data". Pharmaceutics 14, n.º 11 (26 de octubre de 2022): 2304. http://dx.doi.org/10.3390/pharmaceutics14112304.

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The present study analyzed experimental data from volumetric and viscosimetric measurements and computational simulations to understand caffeine hydration and aggregation properties in 0.1 mol∙kg−1 of sodium salicylate aqueous solution. Sodium salicylate reduces the bitter taste and increases the solubility of caffeine in water, which is the main reason for their combination in food products. The results noted in volumetric and viscosimetric measurements indicate that sodium salicylate promotes the self-aggregation of caffeine in water. After self-aggregation, the hydration number of caffeine significantly increases. Molecular simulations have allowed us to hypothesize how salicylate increases caffeine solubility. At the molecular level, relocating salicylate moiety from the parallel stacking (π–π) aromatic complex with caffeine and its hydration could be the main reason for increasing the solubility of caffeine in water. The presented study provides clear guidelines on the choice of additives to increase caffeine’s solubility in aqueous media. The choice of salicylate as an additive to increase the solubility of caffeine is very important because caffeine and salicylate are found in combination in a large number of formulations.

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Cocchi, Marina, Matteo Manfredini, Daniela Manzini, Andrea Marchetti, Simona Sighinolfi, Lorenzo Tassi, Alessandro Ulrici, Moris Vignali y Paolo Zannini. "Viscosimetric properties and internal structure of N,N-dimethylformamide + 1,2-dimethoxyethane binary mixtures". Journal of Molecular Liquids 102, n.º 1-3 (enero de 2003): 309–45. http://dx.doi.org/10.1016/s0167-7322(02)00071-5.

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Cocca, M., L. D'Arienzo y L. D'Orazio. "Effects of Different Artificial Agings on Structure and Properties of Whatman Paper Samples". ISRN Materials Science 2011 (13 de julio de 2011): 1–7. http://dx.doi.org/10.5402/2011/863083.

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With the aim at controlling cellulose degradation phenomena, the natural aging of Whatman paper samples was simulated through different artificial aging processes: thermal oxidation in air at constant temperature, photo-oxidation under Xenon arc lamp, accelerating ageing in climatic chamber, and chemical oxidation with sodium methaperiodate. The cellulose degradation was studied by means of viscosimetric, Fourier transform infrared spectroscopy (FTIR), and wide angle X-ray scattering (WAXS) techniques together with thermogravimetric (TGA), mechanical, and optical analyses. All the treatments carried out were found to significantly modify paper structure and properties, the extent of the deterioration effects depending upon the aging kind. Direct correlations were, nevertheless, assessed among level of cellulose molecular degradation, formation of carboxyl, and/or carbonyl groups and paper strain at break.

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9

Zeynalova, G. A. "Diagnosis of the rheological properties of oil emulsions considering watercut and temperature factors". Azerbaijan Oil Industry, n.º 6 (15 de junio de 2020): 48–50. http://dx.doi.org/10.37474/0365-8554/2020-6-7-48-50.

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It is well known that one of the factors adversely affecting the operational efficiency of infield technological oil pipelines is persistent oil emulsions formed due to the oils watercut. These hardly demulsifible emulsions with abnormal rheological features show non-Newtonian properties. Depending on the temperature and watercut degree, the viscosity of these emulsions varies widely. The specification of viscosity and other physical-chemical properties in oil-field experience is carried out via laboratory testing of oil samples according to the standards. Based on the roto-viscosimetric studies of oil samples with various temperatures, an empiric formula for the specification of oil emulsions viscosity depending on watercut degree is offered. It was defined that the offered formula enables with permissible error to specify the viscosity of abnormal emulsions considering the changing watercut and temperature aspects.

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10

Burenin, A. A., L. V. Kovtanyuk y A. S. Ustinova. "Accounting for the elastic properties of a non-Newtonian material under its viscosimetric flow". Journal of Applied Mechanics and Technical Physics 49, n.º 2 (marzo de 2008): 277–84. http://dx.doi.org/10.1007/s10808-008-0038-y.

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11

Bekhta, Atiqa, Rachid Hsissou, Mohamed Berradi, Mehdi El Bouchti y Ahmed Elharfi. "Viscosimetric and rheological properties of epoxy resin TGEUBA and their composite (TGEUBA/MDA/TGEMDA+TSP)". Results in Engineering 4 (diciembre de 2019): 100058. http://dx.doi.org/10.1016/j.rineng.2019.100058.

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12

Vraneš, Milan, Aleksandar Tot, Snežana Papović, Ksenija Pavlović, Pavle Jovanov y Slobodan Gadžurić. "Volumetric and viscosimetric properties of N -methyl-2-pyrrolidone with γ -butyrolactone and propylene carbonate". Journal of Chemical Thermodynamics 91 (diciembre de 2015): 301–12. http://dx.doi.org/10.1016/j.jct.2015.08.013.

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13

Wang, Bao Qin, Ze Ping Xu y Nan Nan Liu. "Study on the Gelation Properties of the Glucan from Sclerotium rolfsii". Advanced Materials Research 581-582 (octubre de 2012): 168–71. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.168.

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Objective: To study the gelation properties of glucan from Sclerotium rolfsii under the different condition. Methods: Using viscosimetric method to determine the influences of the different concentration, shear force, temperature, pH, and metal ions on the viscosity of glucan solution. Results: The viscosity of glucan solution increased with the concentration raised. The viscosity was 350 mPa.s at 0.16% and was 13927 mPa.s at 2.56% concentration, respectively. The viscosity of glucan solution varies inversely as with shear force. When the concentration was at 0.32 and 0.64%, the viscosity of the glucan solution is affected only slightly by temperature variations (8~90 °C), and remains practically constant within the range of pH from 4 to 12. When the concentration was at 0.64%, the viscosity of the glucan was affected by the addition of metallic ion as the extent Fe3+ > Ca2+ > Na+. Conclusion: The glucan from Sclerotium rolfsii will be a kind of gum used with its good processing characteristics in food field for its excellent processing properties.

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14

Shu, Xu-gang, Chun-li Wu, Cui-jin Li, Min Zhang, Ke Wan y Xin Wu. "Synthesis, Crystal Structure, Spectroscopic Properties, and Interaction with Ct-DNA of Zn(II) with 2-Aminoethanethiol Hydrochloride Ligand". Bioinorganic Chemistry and Applications 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/2691253.

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The zinc(II) complex (C2H6NS)2Zn·ZnCl2was synthesized with 2-aminoethanethiol hydrochloride and zinc sulfate heptahydrate as the raw materials in aqueous solution. The composition and structure of the complex were characterized by elemental analysis, infrared spectra, single crystal X-ray diffraction, and thermogravimetry. The crystal structure of the zinc(II) complex belongs to monoclinic system, space groupP 21/n, with cell parameters ofa= 0.84294(4),b= 0.83920(4),c= 1.65787(8) nm,Z=2, andD= 2.041 g/cm3. In this paper, the interaction of complex with Ct-DNA was investigated by UV-visible and viscosimetric techniques. Upon addition of the complex, important changes were observed in the characteristic UV-Vis bands (hyperchromism) of calf thymus DNA and some changes in specific viscosity. The experimental results showed that the complex is bound to DNA intercalative (intercalation binding).

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15

Sacco, Antonio y Enrico Matteoli. "Isotopic substitution effects on the volumetric and viscosimetric properties of water-dimethylsulfoxide mixtures at 25°C". Journal of Solution Chemistry 26, n.º 5 (mayo de 1997): 527–35. http://dx.doi.org/10.1007/bf02767604.

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16

Basilio-Cortés, Ulin, Leopoldo González-Cruz, Gonzalo Velazquez, Gerardo Teniente-Martínez, Carlos Gómez-Aldapa, Javier Castro-Rosas y Aurea Bernardino-Nicanor. "Effect of Dual Modification on the Spectroscopic, Calorimetric, Viscosimetric and Morphological Characteristics of Corn Starch". Polymers 11, n.º 2 (14 de febrero de 2019): 333. http://dx.doi.org/10.3390/polym11020333.

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The effect of dual modification of corn starch, including hydrolysis and succinylation, were evaluated through peak viscosity (PV) analysis, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. This dual modification was shown to increase the reaction efficiency (RE) and degree substitution (DS) compared with starches that were not subjected to acid hydrolysis pretreatment with a 44% and 45% increase respectively. After acid hydrolysis pretreatment, the surface of the corn starch granules exhibited exo-erosion and whitish points due to the accumulation of succinyl groups. The peak viscosity was reduced significantly with the acid hydrolysis pretreatment (between 3 and 3.5-fold decrease), which decreased the pasting temperature and peak time to 20 °C and 100 s respectively. In addition, the dual modification of corn starch altered certain thermal properties, including a reduction in the enthalpy of gelatinization (ΔH) and a higher range of gelatinization (around 6 °C), which may effectively improve industrial applications. Modifications on the FTIR spectra indicated that the dual modification affected the starch crystallinity, while the Raman spectra revealed that the dual modification disrupted the short-range molecular order in the starch. Rearrangement and molecular destabilization of the starch components promoted their granular amphiphilic properties.

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17

Faranda, Silvia, Giorgia Foca, Andrea Marchetti, Lorenzo Tassi, Alessandro Ulrici y Claudia Zucchi. "Analysis of the Temperature and Composition Dependence of Viscosimetric Properties of 2-Butanone + 2-Butanol Solvent Mixtures". Journal of Solution Chemistry 33, n.º 10 (octubre de 2004): 1181–97. http://dx.doi.org/10.1007/s10953-004-7135-1.

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18

Dymond, J. H. y J. Robertson. "Transport properties of nonelectrolyte liquid mixtures?VI. Viscosimetric study of binary mixtures of hexafluorobenzene with aromatic hydrocarbons". International Journal of Thermophysics 6, n.º 1 (enero de 1985): 21–41. http://dx.doi.org/10.1007/bf00505790.

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19

Begum, Syeda K., Ronald J. Clarke, M. Shamsuddin Ahmed, Shahanara Begum y Mohammad A. Saleh. "Volumetric, viscosimetric and surface properties of aqueous solutions of triethylene glycol, tetraethylene glycol, and tetraethylene glycol dimethyl ether". Journal of Molecular Liquids 177 (enero de 2013): 11–18. http://dx.doi.org/10.1016/j.molliq.2012.09.015.

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20

Marsili, Lorenzo, Michele Dal Bo, Giorgio Eisele, Ivan Donati, Federico Berti y Giuseppe Toffoli. "Characterization of Thermoresponsive Poly-N-Vinylcaprolactam Polymers for Biological Applications". Polymers 13, n.º 16 (8 de agosto de 2021): 2639. http://dx.doi.org/10.3390/polym13162639.

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Poly-N-Vinylcaprolactam (PNVCL) is a thermoresponsive polymer that exhibits lower critical solution temperature (LCST) between 25 and 50 °C. Due to its alleged biocompatibility, this polymer is becoming popular for biomedical and environmental applications. PNVCL with carboxyl terminations has been widely used for the preparation of thermoresponsive copolymers, micro- and nanogels for drug delivery and oncological therapies. However, the fabrication of such specific targeting devices needs standardized and reproducible preparation methods. This requires a deep understanding of how the miscibility behavior of the polymer is affected by its structural properties and the solution environment. In this work, PNVCL-COOH polymers were prepared via free radical polymerization (FRP) in order to exhibit LCST between 33 and 42 °C. The structural properties were investigated with NMR, FT-IR and conductimetric titration and the LCST was calculated via UV-VIS and DLS. The LCST is influenced by the molecular mass, as shown by both DLS and viscosimetric values. Finally, the behavior of the polymer was described as function of its concentration and in presence of different biologically relevant environments, such as aqueous buffers, NaCl solutions and human plasma.

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Pati, Siddhartha, Anil Chatterji, Bisnu Prasad Dash, Bryan Raveen Nelson, Tanmay Sarkar, Salwa Shahimi, Hisham Atan Edinur et al. "Structural Characterization and Antioxidant Potential of Chitosan by γ-Irradiation from the Carapace of Horseshoe Crab". Polymers 12, n.º 10 (15 de octubre de 2020): 2361. http://dx.doi.org/10.3390/polym12102361.

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Natural product extraction is ingenuity that permits the mass manufacturing of specific products in a cost-effective manner. With the aim of obtaining an alternative chitosan supply, the carapace of dead horseshoe crabs seemed feasible. This sparked an investigation of the structural changes and antioxidant capacity of horseshoe crab chitosan (HCH) by γ-irradiation using 60Co source. Chitosan was extracted from the horseshoe crab (Tachypleus gigas; Müller) carapace using heterogeneous chemical N-deacetylation of chitin, followed by the irradiation of HCH using 60Co at a dose-dependent rate of 10 kGy/hour. The average molecular weight was determined by the viscosimetric method. Regarding the chemical properties, the crystal-like structures obtained from γ-irradiated chitosan powders were determined using Fourier transfer infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses. The change in chitosan structure was evident with dose-dependent rates between 10 and 20 kGy/hour. The antioxidant properties of horseshoe crab-derived chitosan were evaluated in vitro. The 20 kGy γ-irradiation applied to chitosan changed the structure and reduced the molecular weight, providing sufficient degradation for an increase in antioxidant activity. Our findings indicate that horseshoe crab chitosan can be employed for both scald-wound healing and long-term food preservation due to its buffer-like and radical ion scavenging ability.

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Zartdinov, F. F., F. F. Zartdinova, A. L. Khokhlov, A. A. Glushchenko y I. R. Salakhutdinov. "Investigations of the physical properties of camelina oil mixtures for hydraulic systems of agricultural machinery". Traktory i sel hozmashiny 84, n.º 8 (15 de agosto de 2017): 41–46. http://dx.doi.org/10.17816/0321-4443-66340.

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The article considers the use of oils of vegetable origin alternative to mineral and synthetic oil products as a working fluid for hydraulic systems of agricultural machinery. When choosing vegetable oil, the use of camelina oil as a more affordable and economically cheap raw material is most appropriate. The main disadvantages of vegetable oils include low thermal and oxidative stability and unsatisfactory low-temperature properties. Therefore, the use of vegetable oils in hydraulic systems is possible only in the form of mixtures with mineral oil. To study the possibility of using vegetable-mineral oil as a working fluid for hydraulic systems of agricultural machinery, laboratory studies of the physical properties of camelina oil mixtures were carried out. The studies included the determination of the relationship between the kinematic viscosity and the density of the camelina oil mixtures from the temperature and were carried out in various proportions of the mineral hydraulic oil - multigrade oil hydraulic thickened (hydraulic oil - GM) and camelina oil (RyzhM) - 100 % GM, 90 % GM - 10 % RyzhM, 75 % GM - 25 % RyzhM, 50 % GM -50 % RyzhM, 25 % GM - 75 % RyzhM, 10 % GM - 90 % RyzhM, 100 % RyzhM. Determination of the physical properties of the camelina oil mixtures was carried out on a cryo-thermostat with viscosimetric LOIPLT-912, using an ANT-2 hydrometer and capillary viscosimeter VPZh^f, VPZh-2 in accordance with GOST R ISO 3675-2007 and GOST 33-2000 (ISO 3104-94) respectively. Based on the results obtained, it was found that red-and-oil mixtures with a ratio 90 % GM - 10 % RyzhM и 75 % GM - 25 % RyzhM according to viscosity-temperature properties and density can be used as substitutes for merchant mineral hydraulic oil GM. The results of the laboratory tests allow us to display the dynamics of the change in viscosity-temperature and density properties of red-and-oil mixtures of various concentrations.

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Aktar, Jesmin, Zahid Hasan, Tahmina Afroz y Kamruzzaman Pramanik. "Application of gamma radiation and physicochemical treatment to improve the bioactive properties of chitosan extracted from shrimp shell". Nukleonika 62, n.º 4 (1 de diciembre de 2017): 245–51. http://dx.doi.org/10.1515/nuka-2017-0036.

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Abstract The aim of this study is to exploit a suitable chitosan extraction method from the chitin of indigenous shrimp shells by employing different physicochemical treatments and to improve different bioactive properties of this extracted chitosan (CS) by applying gamma radiation. Chitin was prepared from shrimp shell by pretreatment (deproteination, demineralization and oxidation). Chitosan was extracted from chitin by eight different methods varying different physicochemical parameters (reagent concentration, temperature and time) and assessed with respect to the degree of deacetylation, requirement of time and reagents. The method where chitin was repeatedly treated with 121°C for 30 min with 20 M NaOH, produced the highest degree of deacetylation (DD) value (92%) as measured by potentiometric titration, with the least consumption of time and chemicals, and thus, selected as the best suitable extraction method. For further quality improvement, chitosan with highest DD value was irradiated with different doses (i.e., 5, 10, 15, 20 and 50 kGy) of gamma radiation from cobalt-60 gamma irradiator. As the radiation dose was increased, the molecular weight of the wet irradiated chitosan, as measured by the viscosimetric method, decreased from 1.16 × 105 to 1.786 × 103, 1.518 × 103, 1.134 × 103, 1.046 × 103 and 8.23 × 102 dalton, respectively. The radiation treatment of chitosan samples increased the antimicrobial activity significantly in concentration dependent manner on both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, as determined by the well-diffusion method. Four to five percent wet chitosan treated with a radiation dose range of 5.0–10.0 kGy rendered the highest antimicrobial activity with least energy and time consumption. Solubility, water binding capacity (WBC) and fat binding capacity (FBC) also improved due to irradiation of chitosan.

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Raszewski, Zbigniew, Wiktor Piecek, Leszek R. Jaroszewicz, Edward Nowinowski-Kruszelnicki, Paweł Perkowski, Leonid Soms, Roman Dąbrowski et al. "High Birefringence Liquid Crystals Mixtures and their Selected Applications". Advanced Materials Research 909 (marzo de 2014): 12–18. http://dx.doi.org/10.4028/www.scientific.net/amr.909.12.

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High-Birefringence Nematic Liquid Crystals Mixtures (HBNLCM) recently developed in the Military University of Technology (Poland) are presented in this paper. Dielectric, refractometric, viscosimetric and elastomeric characteristic were determined. The properties are discussed in terms of their applicability to electro-optical devices. Applying HBNLCM of LCM to space mission (Phobos Ground) applications for a space-borne laser rangefinder was developed, manufactured and tested under cooperation between Military University of Technology (MUT) in Poland and Vavilov State Optical Institute (Vavilov SOI) in Russia. Transmission T of Liquid Crystal Cell (LCC) at λ=1.064 μm was not smaller than 95% at the aperture diameter not less than 15 mm. Switching on and switching off times in 2.5 μm thick LCC driven by voltage 10 V were not larger than 0.7 ms. Applying HBNLCM of LCM3 to refractive index matched twisted Nematic Liquid Crystal Cell of type LCNP4 for Thomson diagnostics of dense plasma was developed, manufactured and tested under cooperation between MUT in Poland and the National Research University of Information Technologies, Mechanics and Optics in Russia. Transmission T of LCNP4 at λ=1.064 μm was not smaller than 97% at the aperture diameter not less than 30 mm. Switching on time in 2.5 μm thick LCNP4 driven by voltage 200 V was not larger than 3 μs. LCNP4 can easily tolerate 0.42 J/cm2.

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Rivas, Bernabé L. y Kurt E. Geckeler. "Synthesis and properties of hydrophilic polymers, 5. Viscosimetric study on poly(acrylamide-co-4-vinylpyridine) and its interaction with metal ions in aqueous solution". Die Angewandte Makromolekulare Chemie 255, n.º 1 (1 de marzo de 1998): 1–4. http://dx.doi.org/10.1002/(sici)1522-9505(19980301)255:1<1::aid-apmc1>3.0.co;2-a.

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Bozhko, T. V., R. S. Donchevska y R. P. Romanenko. "The rheological properties of cream liqueurs and their changes in the transportation process". Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 21, n.º 91 (23 de abril de 2019): 149–56. http://dx.doi.org/10.32718/nvlvet-f9125.

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In order to determine the stability of colloidal systems of cream liqueurs with cycloractate and egg yolks, their rheological properties after production and during transportation, which was simulated through centrifugation and shaking, study, had been studied. Kinematic viscosity was determined by viscosimetric method using a graduated glass unit and a “Universal Computer Measuring Instrument” manufactured by “ITM Ltd.”, Kharkiv, Ukraine. The coefficient of surface tension was investigated by the method of detachment of the ring from the surface of the test substance, and the density – by the method of hydrostatic weighing. Storage of bottled glass bottles with a capacity of 0.35 l of dessert emulsion cream liqueurs took place in the warehouse at a temperature from +10 to + 250 С and a relative humidity of no more than 85%. Quality indicators in developed beverages were determined at 18, 36, 54, 72, 90 and 108 day. Dynamic viscosity of the sample of dessert emulsion cream liqueur “Healing Source” was 2394.1 MPa · s, cream liqueur “Health” – 2219.7 MPa · s, control sample “Dalkowski Advocaat Starotoruński” – 1949.99 MPa · s. It has been established that the kinematic viscosity and density of developed cream liqueurs are higher by 19.4 ... 21.8% compared with the control sample. For cocktails preparation it is expedient to use a dessert emulsion cream liqueur "Healing Source", the difference of the coefficient of surface tension of which with the control sample lies within the limits of statistical error it is determined. It is noted that in the process of centrifugation, cream liqueurs demonstrate a slight change in rheological properties. The smallest changes in density are noted for emulsion cream liqueur «Healing Source», the largest – for “Health”, due to the peculiarities of their prescription composition. The influence of “shaking effect” on the density of dessert emulsion cream liqueurs was determined. The biggest difference in density after shaking up to 10 s had the cream-liqueur “Health”, after 10s of shaking – the cream-liqueur “Steppe beauty”. The most stable structure of the colloidal system of the cream-liqueur “Healing Source” was the stability difference with the control sample lies within the statistical error.

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Li, Xin-Xue, Gui-Chen Fan, Yan-Wei Wang, Min Zhang y Yi-Qiang Lu. "Volumetric and viscosimetric properties of the binary mixture of triethylene glycol monomethyl ether+water at T=(293.15, 303.15, 313.15, 323.15, 333.15) K under atmospheric pressure". Journal of Molecular Liquids 151, n.º 1 (enero de 2010): 62–66. http://dx.doi.org/10.1016/j.molliq.2009.11.005.

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Dupuis, Guillaume, David Rousseau, René Tabary y Bruno Grassl. "Flow of Hydrophobically Modified Water-Soluble Polymers in Porous Media: Controlled Resistance Factors vs. Flow-Induced Gelation in the Semidilute Regime". SPE Journal 17, n.º 04 (27 de noviembre de 2012): 1196–206. http://dx.doi.org/10.2118/140779-pa.

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Summary The associative properties of hydrophobically modified water soluble polymers (HMWSPs) are attractive for improved oil recovery (IOR) because of both their enhanced thickening capability, compared with classical water-soluble polymers (for mobility-control applications), and their permeability-reduction, or plugging, ability (for well-treatment applications). In previous works, we have studied the injectivity of HMWSP made of sulfonated polyacrylamide backbones and alkyl side chains in the dilute regime and have shown, in particular, that it was largely governed by adsorption. In this paper, we report new experimental data on the injectivity of the same class of HMWSP solutions in the semidilute regime. From membrane filtration tests at imposed flow rate, we have first observed the formation of a filter cake made of HMWSP physical gel, which remained largely permeable to polymers. Our observations are compatible with the creation of channels within the gel. This leads to a gel-filtration process, entailing modifications of the solution's viscosimetric properties, which can be explained by a rearrangement of the intra- and interchain hydrophobic bonds in the solution. The second part of our work consisted of injectivity tests in model granular packs. We have performed comparative experiments in porous media with variable permeabilities, but at the same shear rate in the pore throats. Results show that, above a critical permeability kC, or a critical pore-throat radius rpC, HMWSP injection led to stable resistance factors, with values close to the solution's viscosity, and that, at less than kC or rpC the very high resistance factors observed suggest that flow-induced gelation of the HMWSP takes place. Furthermore, resistance factors measured over the core internal sections are compatible with an in-depth formation of the gel. These insights could be of use for designing HMWSP better suited to mobility-control operations and for tuning HMWSP-injection conditions for profile/conformance-control operations.

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Kinart, Cezary M., Magdalena Klimczak y Wojciech Kinart. "Viscosimetric and structural properties of binary mixtures of 2-butoxyethanol with ethylene glycol, diethylene glycol, triethylene glycol and tetraethylene glycol systems atT = 293.15, 298.15 and 303.15 K". Physics and Chemistry of Liquids 49, n.º 2 (marzo de 2011): 181–91. http://dx.doi.org/10.1080/00319100903191405.

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Suwonsichon, T. y M. Peleg. "Imperfect squeezing flow viscosimetry for commercial refried beans / Viscosimetría de extensión biaxial imperfecta de frijoles refritos". Food Science and Technology International 5, n.º 2 (abril de 1999): 159–66. http://dx.doi.org/10.1177/108201329900500205.

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The imperfect squeezing flow patterns of almost intact canned fat free and vegetarian refried beans of two national brands were determined using all Teflon and grooved metal sensors. The force versus height curves were remarkably reproducible and characteristic of the products and brands irrespec tive of the upper plate's diameter and the sensor's finish. Both types of product had a very high degree of plasticity but those of one brand were more sensitive to the deformation rate. The consis tency of the corresponding products of the two brands could be compared in terms of an apparent stress at a predetermined height (1.5 and 2.5 mm), and their yield stress in terms of an apparent residual stress, or percent force drop, after a given time (60 and 120 s). At a deformation rate of 6 mm/min the apparent stress at a height of 1.5 mm was in the order of 9-11 or 15-19 kPa for the fat free products and 14-15 versus 18-20 kPa for the vegetarian products. After 120 s of relaxation, the stress decayed to about 30 to 60% of its initial level depending on the product and brand. The re sidual stress level was generally higher when determined with the grooved metal sensors. The prod ucts with relatively higher stresses at a given height also showed a relatively slower relaxation pat tern suggesting that consistency and apparent yield stress may be related rather than independent properties of refried beans.

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Diamant, Viktor. "MODERN RESEARCH METHODS OF PHYSICOCHEMICAL AND ELECTROCHEMICAL PROPERTIES OF ELECTROLYTES IN FOR Li-ION BATTERIES AND HYBRID SUPERCAPACITIES". Ukrainian Chemistry Journal 87, n.º 6 (26 de julio de 2021): 82–96. http://dx.doi.org/10.33609/2708-129x.87.06.2021.82-96.

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In review examineі base properties of modern non-aqueous electrolytes for li-ion batteries and hybrid supercapacities taking part in the formation of power density, electrochemical and thermal stability. Discussed such aspects as the electrolytes functions in electrochemical power sources, physicochemical and electrochemical properties of electrolytes for supercapacitors, the physicochemical and electrochemical properties of electrolytes for primary and secondary batteries, and methods of electrolytes research. As the base methodі for electrolytes studies considered: electrochemical impedance spectroscopy, voltammetry, amperometry, viscosimetry, and combined Ramman spectroscopy.

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32

Pham, Q. D. y P. V. Surukov. "Rheological properties of dispersed-filled polymer composite materials based on polyethylene containing glass microbeads". Plasticheskie massy, n.º 7-8 (18 de septiembre de 2021): 35–38. http://dx.doi.org/10.35164/0554-2901-2021-7-8-35-38.

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This article presents the results of a study of the effect of the filler content on the rheological properties of polymer composite materials based on high density polyethylene containing glass microbeads. The flow curves of the compositions were obtained by the method of capillary viscosimetry. Simple mathematical models have been constructed that allow estimating the viscosity of the compositions’ melts based on a given filler content.

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33

Barannikov, Mikhail V., Yuri M. Bazarov, Tamara S. Usacheva y Oscar I. Koifman. "CHANGING SOME PA-6 PROPERTIES AT ITS SYNTHESIS BELOW MELTING POINT". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 59, n.º 4 (12 de julio de 2018): 63. http://dx.doi.org/10.6060/tcct.20165904.5309.

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This paper presents the fractionation of PA-6 obtained at temperature below its melting point. Unfractionated samples and polymer fractions were studied by viscosimetry, thermogravimetry (TG, DTG) and differential scanning calorimetry (DTA). It was shown that at the first step of synthesis the polymer is formed with a predominantly linear structure and high parameters of thermal properties. At the second synthesis step the molecular weight of the polymer and its thermal properties increase and subsequent demonomerization-drying is accompanied by a further increase in the polyamide molecular weight.

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34

Nasonov, F. A., V. M. Aleksashin, D. A. Melnikov y S. V. Bukharov. "Zinc-stearate modification of epoxy resins and carbon plastics based on them and its influence on the basic technological properties of the composition". Voprosy Materialovedeniya, n.º 3(95) (10 de enero de 2019): 146–56. http://dx.doi.org/10.22349/1994-6716-2018-95-3-146-156.

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The influence of the special modification of epoxy resins and polymer composites based on them on the basic technological properties of the composition is investigated. Modification is performed in order to reduce the opening damage. The most important technological properties of the initial epoxy composition and modified technological additives are studied and compared by standard methods (viscosimetry, thermoanalytical methods). A kinetic model of the curing process was created, the experimental production of samples from plastics filled with carbon long filler (impregnation under pressure, autoclave molding) and its non-destructive testing were carried out.

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35

Manzhai, V. N., S. G. Kulyshkina, L. V. Chekantseva y I. G. Yashchenko. "COMPOSITION AND STRUCTURE OF HIGH-VISCOSITY OILS FROM VARIOUS DEPOSITS". Oil and Gas Studies, n.º 1 (1 de marzo de 2018): 112–18. http://dx.doi.org/10.31660/0445-0108-2018-1-112-118.

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The article presents the results of investigations of oil samples from various deposits. The samples contain asphaltenes, resins and paraffins in different concentrations. It is established that all oil samples are non-Newtonian fluids and they have pseudoplastic properties. Due to the results of experiments, which were carried out by the method of rotational viscosimetry, size of complex structural units of oils at various sliding velocities was calculated.

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36

Van Opdenbosch, Daniel, Martin Kretschmer, Oliver Lieleg y Cordt Zollfrank. "Free volumes in mixed-tacticity poly(3-hydroxybutyrate) determined by viscosimetry and their correlations with structural features and mechanical properties". Applied Rheology 32, n.º 1 (1 de enero de 2022): 56–68. http://dx.doi.org/10.1515/arh-2022-0125.

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Abstract The viscosities of poly(3-hydroxybutyrate) (PHB) with mixed tacticities were determined as functions of temperature and shearing rate via plate–plate viscosimetry, and fitted by a combined Herschel–Bulkley–Cross–Doolittle model while applying Carvalho et al.’s single-point correction. They were compared to values of slit viscosimetry, obtained during processing at a temperature of 428 K. In both cases, measured values and fitted model parameters as a function of tacticity exhibited a discontinuous behaviour at a fraction of meso diads of 0.7. To further investigate, we calculated values of vibrational and excess free volume. We found that these correlate with structural and external properties, some of which were reported in earlier works, namely the paracrystalline contents and specific volumes of the materials at room temperature, as well as their energies of fracture during tensile testing. These, in turn, correlate with the statistical averages of relative lengths of chain segments of similar a- or iso-tacticity. Hence, we found that expressing changing tacticities simply by a continuous progression of the fraction of meso diads is insufficient to trace associated discontinuities of the flow behaviour in mixed-tacticity PHB. We conclude that free volume is generated by polymer chain conformational disorder, which should be treated on the oligomeric chain segment level.

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37

Shinkwin, C. A., G. E. Murty, R. Simo y N. S. Jones. "Per-operative antibiotic/steroid prophylaxis of tympanostomy tube otorrhoea: chemical or mechanical effect?" Journal of Laryngology & Otology 110, n.º 6 (junio de 1996): 531–33. http://dx.doi.org/10.1017/s0022215100134188.

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AbstractThe per-operative instillation of ototopical antibiotic/steroid drops reduces the incidence of early otorrhoea after tympanostomy tube insertion. Whether this is due to the chemical properties of the antibiotic/steroid or simply the mechanical instillation of fluid is unclear. In this paired matched study of 161 subjects Gentisone HC was shown to significantly reduce the otorrhoea rate compared to normal saline (1.24 per cent compared with 9.32 per cent, p<0.005, difference 8.07 per cent, 95 per cent confidence interval for difference 3.21 per cent to 12.93 per cent). Capillary viscosimetry proved Gentisone HC to be more viscous than normal saline. The benefits are due to Gentisone HC's chemical properties, and Gentisone HC rather than normal saline instillation per-operatively is recommended when tympanostomy tubes are inserted.

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38

Wang, Chao, Bi Jun Xie y Bin Li. "Preparation and Characterisation of Konjac Glucomannan (KGM)/SiO₂ Nanoparticles Blend Film". Advanced Materials Research 194-196 (febrero de 2011): 1431–36. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.1431.

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A novel nanocomposite films was prepared by dispersing SiO2 nanoparticles in aqueous konjac glucomanan (KGM) solution. The structure and miscibility of the nanocomposite materials were determined finely by viscosimetry, Fourier transformed infrared spectra (FTIR), micropolariscope (POM), scanning electron microscopy (SEM) and ultraviolet-visible spectrophotometer (UV-Vis). The results indicated that there was a strong interaction between KGM and SiO2 in ethanolamine. The miscibility and ultraviolet-absorption properties of KGM/SiO2 nanoparticles blend film were improved by ball milling treatment. Moreover, the ultraviolet absorption and tensile strength of the nanocomposite films rapidly increase with the increase of SiO2, while breaking elongation of the nanocomposite films slightly decreased.

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39

Osovskaya, Iraida Ivanovna, Anastasia Maksimovna Borodina, Aleksandr Vyacheslavovich Kurzin y Victor Ivanovich Roshchin. "SYNTHESIS AND PROPERTIES OF MODIFIED XANTHAN GUM". chemistry of plant raw material, n.º 4 (14 de diciembre de 2021): 95–104. http://dx.doi.org/10.14258/jcprm.2021049525.

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Xanthan gum is widely used as a stabilizing, emulsifying, thickening agent in pharmacology, medicine, food, oil, paint, textile, perfume, mining and agriculture. For food purposes, potassium, sodium or calcium salts of xanthan formed by carboxyl groups of glucuronic acid and pyruvate group are used. Currently, xanthan gum is not produced on an industrial scale in Russia. There are repeated attempts to create industries in various regions of the country. The paper synthesizes hydrophobized acetylated xanthan gum derivatives with different degrees of substitution. Physical-chemical and colloidal-chemical properties of initial and modified gum are compared by methods of viscosimetry, tensiometry, IR spectroscopy. The point of zero charge of xanthan gum is determined.. Change of macromolecule conformation depending on pH of aqueous solution and preliminary dewatering is shown. Delamination temperatures of initial and modified forms of xanthan gum were determined. The critical micelle formation concentration of the modified gum is 0.2%. At this concentration, the surface activity of the gum is 6.1 and 7.9 mJ m/kg when replacing two and five hydroxo groups, respectively. The possibility of using modified xanthan gum as a binder for obtaining fuel pellets with improved operational properties and calorific value is shown.

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40

Makarewicz, Edwin y Anna Zalewska. "Sedimentation of water dispersed systems of acrylate copolymers in xylene". Polish Journal of Chemical Technology 10, n.º 3 (1 de enero de 2008): 29–34. http://dx.doi.org/10.2478/v10026-008-0032-4.

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Sedimentation of water dispersed systems of acrylate copolymers in xylene Methyl methacrylate - butyl acrylate - methacrylic acid copolymer and butyl methacrylate - methacrylic acid amide copolymer of a different segmental structure were stabilised with non-ionic and anionic surfactants. Gel chromatography, viscosimetry, tensiometry, conductometry and sedimentation methods were applied to define the properties of the synthesized copolymers, surfactants in water solutions and water dispersions. The types and the properties of the phases being in a state of sedimentation balance were also determined. The obtained experimental data were interpreted and justified by using the copolymer and surfactants properties. The existing correlations were pointed out. The obtained results show that the stability of a disperse system considerably depends on the structure of the copolymer. The MMA/BA/MAA copolymer has monomeric units of elastic butyl acrylate. Segments containing these monomeric units adsorb surfactants much better and form more stable water disperse systems. However, the MBA/AMAA copolymer with the polarity of amide group of methacrylamide makes disperse systems less stable.

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41

Vishnevetskii, Dmitry V., Arif R. Mekhtiev, Dmitry V. Averkin y Elizaveta E. Polyakova. "Cysteine–Silver–Polymer Systems for the Preparation of Hydrogels and Films with Potential Applications in Regenerative Medicine". Gels 9, n.º 12 (23 de noviembre de 2023): 924. http://dx.doi.org/10.3390/gels9120924.

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Herein, the problem concerning the poorer mechanical properties of gels based on low molecular weight gelators (LMWGs)—L-cysteine and silver nitrate—was solved by the addition of various polymers—polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG)—to the initial cysteine–silver sol (CSS). The physicochemical methods of analysis—viscosimetry, UV spectroscopy, DLS, and SEM—identified that cysteine–silver hydrogels (CSG) based on PVA possess the best rheological properties and porous microstructure (the average pore size is 2–10 µm) compared to gels without the polymer or with PVP or PEG. Such gels are able to form cysteine–silver cryogels (CSC) and then porous cysteine–silver films (CSF) with an average pore size of 10–20 µm and good mechanical, swelling, and adhesion to skin characteristics as long as the structure of CSS particles remains stable. In vitro experiments have shown that hydrogels are non-toxic to normal human fibroblast cells. The obtained materials could potentially be applied to regenerative medicine.

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42

Águila-Almanza, Eva, René Salgado-Delgado, Zully Vargas-Galarza, Edgar García-Hernández y Heriberto Hernández-Cocoletzi. "Enzymatic Depolimerization of Chitosan for the Preparation of Functional Membranes". Journal of Chemistry 2019 (13 de febrero de 2019): 1–8. http://dx.doi.org/10.1155/2019/5416297.

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This work reports the study of chitosan depolymerization through the synergy of the Celuzyme® XB enzyme complex; it is composed of cellulase, xylanase, andβ-glucanase. The optimal conditions of temperature, pH, and concentration were determined to verify the depolymerization reaction. The specificity of the enzymes at theβ(1-4) glycosidic link site was checked. Low molecular weight chitosan (64 × 103 g·mol−1) with degree of acetylation 15% was obtained. The depolymerized chitosan products were characterized by infrared spectroscopy, the degree of acetylation was obtained by UV-Vis spectroscopy, and the determination of the molecular weight was obtained by capillary viscosimetry. With the depolymerized chitosan, membranes were formed and their antioxidant and antimicrobial functionality was determined; results show that these properties are dependent on the molecular weight and on the acetylation degree of chitosan.

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43

Khokhryakov, A. A., M. A. Samoilova, V. V. Ryabov y L. B. Vedmid’. "EFFECTIVE VISCOSITY AND GLASS TRANSITION TEMPERATURE OF Cs2O–B2O3 MELTS". Расплавы, n.º 6 (1 de noviembre de 2023): 614–23. http://dx.doi.org/10.31857/s0235010623060026.

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Effective viscosity (viscoelasticity) of cesium and boron oxides melts was measured at temperatures 900–1600 K and concentrations 0 ≤ x ≤16 mol % Cs2O by vibration viscosimetry. It was shown that vibration leads to non-Newtonian flow of melts. This means that not only configuration activation energy, the switching energy of bridging oxygen bonds but also the elastic energy of structural units of melts associated with activation energy of viscous flow. Using parameters under conditions of Newtonian and non-Newtonian flow of melts, shear viscosity η', elastic modulus G' and stored viscosity η'' were calculated. It was shown that cesium boron melts in conditions of high shear rates can be considered as liquids with viscous and elastic properties. Glass transition temperature (Tg, K) was measured by DSC, its dependence of content of cesium oxide was plotted and explained.

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44

Frénoy, J. P. "Effect of physical environment on the conformation of ricin Influence of low pH". Biochemical Journal 240, n.º 1 (15 de noviembre de 1986): 221–26. http://dx.doi.org/10.1042/bj2400221.

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The molecular properties of ricin (the toxic lectin from Ricinus communis seeds, RCA II or RCA 60) were evaluated by analytical ultracentrifugation, viscosimetry, c.d., fluorescence and equilibrium dialysis. Measurements of sedimentation (S0(20,W) = 4.60 S) and viscosity (eta = 2.96 × 10(-2) dl/g) indicated that, at neutral pH, the ricin molecule is very compact. Various transitions were explored, and a pH-triggered change in the ricin conformation was observed between pH 7 and 4. In this range, the sedimentation coefficient, far-u.v. c.d. and fluorescence altered simultaneously without unfolding. Below pH 7 the change in the ricin conformation was accompanied by a decrease in the affinity of ricin for galactosides, and at pH 4.0 by an alteration in its binding capacity. These effects of low pH are discussed in relation to the physical conditions encountered by ricin molecules during their entry into living cells.

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45

Soldatova, AE, AY Tsegelskaya, GK Semenova, TS Kurkin, PV Dmitryakov, SI Belousov y AA Kuznetsov. "One-pot synthesis of semicrystalline polyamide imide based on 4,4’-diaminobenzanilide and 2,2-propylidene-bis(1,4-phenyleneoxy)diphthalic anhydride in molten benzoic acid". High Performance Polymers 31, n.º 1 (16 de enero de 2018): 63–71. http://dx.doi.org/10.1177/0954008317750891.

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High-temperature thermoplastic semicrystalline polyamide imide (PAI) with Tg = 250°C, and Tm = 370°C was synthesized from 4,4’-diaminobenzanilide, and 2,2-propylidene-bis (1,4-phenyleneoxy) diphthalic anhydride using three different methods: one-pot high-temperature catalytic polycondensation in molten benzoic acid (BA), low-temperature polycondensation (LTP) in dimethylacetamide (DMAA) followed by chemical imidization, and LTP followed by imidization. The influence of the synthetic route on the crystallinity of PAI was studied by wide-angle X-ray scattering. The PAI synthesized in molten BA comprised a reactive oligomer, which on heating up to 360°C easily transformed into high-molecular-weight PAI. The thermal and rheological properties of the high-molecular-weight PAI thus prepared were studied using differential scanning calorimetry, trimellitic acid, thermogravimetric analysis, and capillary viscosimetry. The rheological characteristics indicate that the obtained PAI can be melt processed by extrusion and hot pressing at 370–380°C.

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46

Surikov, P. V., N. L. Shembel, A. A. Yurkin, A. V. Petrogradsky, V. D. Sevruk y I. D. Simonov-Emelyanov. "PROCESSING ADDITIVES AND RHEOLOGICAL PROPERTIES OF MOLDED PHENOLIC PLASTICS". Fine Chemical Technologies 14, n.º 1 (28 de febrero de 2019): 90–96. http://dx.doi.org/10.32362/2410-6593-2019-14-1-90-96.

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By the method of capillary viscosimetry, the melt flow curves of the molded phenolic resin and its compositions with lubricant, plasticizer and their mixture were obtained. It was shown that the size (diameter) of the capillary channel influences the dependence of the effective shear rate on the shear stress (flow curves) of the studied compositions. Such rheological behavior of the compositions during flow is associated with the effect of sliding along the surface of the capillary wall. According to the Mooney method, the dependences of the effective shear rate at given values of shear stress on the reciprocal of the capillary radius are plotted. The function of the slip velocity on the shear stress on the capillary wall is characterized in terms of the slip coefficient, which relates the shear stress on the capillary wall to the velocity of the composition along it. For the studied compositions, the total flow through the capillary was divided into volume fractions, one of which is associated with a shear flow; the other is determined by the slip effect. It has been shown that the introduction of both a lubricant and a plasticizer into the composition leads to an increase in the fluidity of the compositions. At the same time, adding of lubricant increases the volume fraction of the slip flow. The greatest effect of increasing the fluidity of the composition gives the use of complex modifying additives containing both lubricant and plasticizer.

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47

John, A. S., B. Mahanthesh y G. Lorenzini. "Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties". Applied Mathematics and Mechanics 45, n.º 4 (abril de 2024): 677–94. http://dx.doi.org/10.1007/s10483-024-3089-5.

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AbstractCone-disk systems find frequent use such as conical diffusers, medical devices, various rheometric, and viscosimetry applications. In this study, we investigate the three-dimensional flow of a water-based Ag-MgO hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid properties. How the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds’s linearized model for variable viscosity and Chiam’s model for variable thermal conductivity. The single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids, incorporating the experimental data. This model is developed as a coupled system of convective-diffusion equations, encompassing the conservation of momentum and the conservation of thermal energy, in conjunction with an incompressibility condition. A self-similar model is developed by the Lie-group scaling transformations, and the subsequent self-similar equations are then solved numerically. The influence of variable fluid parameters on both swirling and non-swirling flow cases is analyzed. Additionally, the Nusselt number for the disk surface is calculated. It is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system, while the thermal conductivity parameter has the opposite effect.

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48

Chromčíková, Mária y Marek Liška. "Application of Thermophysical Methods for Oxide/Silicate Glasses". Advanced Materials Research 1126 (octubre de 2015): 99–104. http://dx.doi.org/10.4028/www.scientific.net/amr.1126.99.

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An brief overview of the selected thermo-physical measurements realized in the VILA laboratories for the glass industry and for the fundamental research of glass is presented. Among the routine measurements realized for the glass industry the thermodilatometry for measuring the glass transition temperature, and linear thermal expansion coefficients of glass and metastable glassforming melt are described in detail. The fact that the glass transition temperature is not a single valued physical quantity is stressed in connection with the measurement time temperature schedule. The probably most important quantity related to the glass production technology is the viscosity. Its measurement in the range extending ten orders of magnitude is described. The combination of the falling ball method, the rotation viscosimetry and the thermomechanical analysis is needed to cover the above viscosity range. Among the methods used in the fundamental research of glass structure and properties the study of structural relaxation is overviewed. Here the own method of combined viscous flow and structure relaxation TMA measurement is described in detail.

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49

Rodič, Peter, Romana Cerc Korošec, Barbara Kapun, Alenka Mertelj y Ingrid Milošev. "Acrylate-Based Hybrid Sol-Gel Coating for Corrosion Protection of AA7075-T6 in Aircraft Applications: The Effect of Copolymerization Time". Polymers 12, n.º 4 (19 de abril de 2020): 948. http://dx.doi.org/10.3390/polym12040948.

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Pre-hydrolysed/condensed tetraethyl orthosilicate (TEOS) was added to a solution of methyl methacrylate (MMA) and 3-methacryloxypropyltrimethoxysilane (MAPTMS), and then copolymerised for various times to study the influence of the latter on the structure of hybrid sol-gel coatings as corrosion protection of aluminium alloy 7075-T6. The reactions taking place during preparation were characterised using real-time Fourier transform infrared spectroscopy, dynamic light scattering and gel permeation chromatography. The solution characteristics were evaluated, using viscosimetry, followed by measurements of thermal stability determined by thermogravimetric analysis. The optimal temperature for the condensation reaction was determined with the help of high-pressure differential scanning calorimetry. Once deposited on 7075-T6 substrates, the coatings were evaluated using a field emission scanning electron microscope coupled to an energy dispersive spectrometer to determine surface morphology, topography, composition and coating thickness. Corrosion properties were tested in dilute Harrison’s solution (3.5 g/L (NH4)2SO4 and 0.5 g/L NaCl) using electrochemical impedance spectroscopy. The copolymerization of MMA and MAPTMS over 4 h was optimal for obtaining 1.4 µm thick coating with superior barrier protection against corrosion attack (|Z10 mHz| ~ 1 GΩ cm2) during three months of exposure to the corrosive medium.

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50

Loskutova, Juliya V., Natalya V. Yudina y Valeriy A. Daneker. "INFLUENCE OF LOW-FREQUENCY ACOUSTIC FIELD AND POLYMER ADDITIVE ON STRUCTURAL AND MECHANICAL PROPERTIES OF OIL". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, n.º 1 (30 de diciembre de 2018): 70–77. http://dx.doi.org/10.6060/ivkkt.20196201.5766.

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The goal of this work is to study the influence of low-frequency acoustic field and polymer additive on structural and mechanical properties of problematic quick-freezing oil. The results were acquired by methods of rotational viscosimetry and finding phase transition temperatures by using optical density of infrared light as well as optical microscopy method. Highly paraffinic low-resin oil (Tomsk region) was exposed to low-frequency acoustic field (f = 50 Hz, 1 and 3 min of processing at 0 °С), a chemical reagent, the complex-action polymer additive D-210 (0.05% mass concentration in oil) and complex physical-chemical processing This work studies external influence on viscosity, temperature and energy characteristics, phase transition temperature as well as structure of oil residue. It was shown that in the case of problematic oil at a temperature close to freezing point, the acoustic influence leads to increase of viscosity and temperature properties. After adding the additive to processed oil during the complex processing, the thixotropic structure is destroyed, which is followed by a sharp decrease in viscosity, cloud point and freezing point. There is also a decrease in energy parameters, such as activation energy of viscous flow and internal energy of a disperse system. To determine the temperature of spontaneous crystallization we plotted the differential curves of viscosity coefficient dependence on the temperature of the medium. Study of the microstructure of the oil residue had shown that it contains small linear single-crystal and spherical formations prior to acoustic processing. After processing, however, such formations display a significant growth. The structure of the residue after complex processing is represented by many large plate paraffin crystallites.

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