¿Ante qué se piensa que la razón es “débil”? A nuestro parecer, ante la idea de una razón tan potente como la “razón pura”. En este texto haremos un recorrido crítico por avatares de la razón pura ...yendo desde nuestro presente hacia el pasado para que, una vez ahí, preguntemos si acaso es viable otro camino de la razón, más físicamente responsable. A ese otro camino llamaremos “la vía física”. Entonces haremos el recorrido de vuelta, del pa-sado hasta nuestro presente y veremos cómo por cada “filósofo-lógico” hay al menos un “filósofo-físico” en el contrapunto. Luego del recorrido por los avatares de esta otra vía, lle-garemos al presente señalando que la sistematización contemporánea de la vía física es lo que hoy se está llamando reología.
Induced static-crystallization of grape-molasses (GM) was successfully done via adding crystallized honey (CH) to improve the crystallization rate, crystal size and to obtain a homogeneous ...crystalline structure of the product with the desirable rheological and textural properties. The effect of CH concentration (5, 10, and 15%) as starter and storage time (1st, 7th, 14th, 21st, and 28th day at 14 °C) on the rheological, physicochemical, and crystallization characteristics of GM/CH blends was investigated. Flow behavior of the molasses changed to Ostwalt de Waele model from Newtonian behavior. Apparent viscosity and consistency coefficient values increased and flow behavior index decreased with crystallization. Temperature-dependent apparent viscosity at shear rate 50 s−1 was successfully described by the Arrhenius equation. As storage time increased, activation energy increased from 342.17 to 427.16 (J/mol). All samples showed liquid-like properties because the loss modulus was remarkably higher than the storage modulus. The particle-size ranged between 12.60 and 33.20 μm with the highest value at the 15% sample. Spreadability and firmness values of samples were found to between 0.46 and 5.47 N mm and 0.094–0.195 N, respectively. Spreadability and machinability characteristics of the molasses can be improved by controlled crystallization which can positively affect consumer acceptability of the product.
•GM transformed to spreadable form with CH using different concentration.•The max. spreadability and firmness were observed in the samples seeded with 15% CH.•Crystallization of GM increased the size of crystals and improved spreadability.
Defendemos la postura de la necesidad de un desarrollo y de una lectura de Zubiri en clave metafísica para ello mostramos como se han dado las interpretaciones de zubiri, luego lo que ha sido la ...sedimentación de la interpretación exclusivamente noológica, para en un tercer momento mostrar su carencia y por lo tanto el deber de realizar una reflexión metafísica con las herramientas de la filosofía zubiriana
Three sauces with macauba pulp were formulated: i) without gum (SWG); ii) with xanthan gum (SXG); and iii) with gum arabic (SAG). The sauces were stored in glass and polypropylene (PP) in a ...refrigerator at 5 °C. Macauba pulp has 26.19% lipids, 68.76% oleic acid, 9.03% linoleic acid and 40% dietary fibers. Flavanols such as catechin, epicatechin gallate, epigallocatechin gallate and procyanidin B2 were predominant, which contributes to the antioxidant activity. The sauces had a high fiber content (10%) and low fat content (6%), with an intense yellow color due to the carotenoid content. The sauces showed non-Newtonian behavior with stability influenced by the storage temperature. The SXG stored in PP bottles showed the highest stability (100%) for 28 days of storage at 5 °C. SGA showed lower peroxide value in PP bottles at 5 °C and was preferred by the tasters. Macauba pulp is an alternative base ingredient for formulating sauces.
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•Macauba pulp is a source oleic, linoleic acid and dietary fibers.•Flavanols were predominant phenolic compound in macauba pulp.•Macauba sauce is rich fiber, antioxidants and low fat.•Macauba sauce with xanthan gum showed 100 % stability during 28 days at 5 °C.
•Gels were prepared by Xanthan and Locust Bean Gum and loaded with niosomes.•Ammonium glycyrrhizinate (AG), a natural compound, was chosen as a model drug.•The niosome-embedded AG formulations ...modulate the diffusion of the drug.•The injectability tests showed that the formulations can be suitable for marketing.•The gels can be considered suitable for topical applications also after 1 year.
In the present paper physical gels, prepared with two polysaccharides, Xanthan and Locust Bean Gum, and loaded with non-ionic surfactant vesicles, are described. The vesicles, composed by Tween20 and cholesterol or by Tween85 and Span20, were loaded with Monoammonium glycyrrhizinate for release experiments. Size and zeta (ζ)-potential of the vesicles were evaluated and the new systems were characterized by rheological and dynamo-mechanical measurements. For an appropriate comparison, a Carbopol gel and a commercial gel for topical applications were also tested. The new formulations showed mechanical properties comparable with those of the commercial product indicating their suitability for topical applications.
In vitro release experiments showed that the polysaccharide network protects the integrity of the vesicles and leads to their slow release without disruption of the aggregated structures. Furthermore, being the vesicles composed of molecules possessing enhancing properties, the permeation of the loaded drugs topically delivered can be improved. Thus, the new systems combine the advantages of matrices for a modified release (polymeric component) and those of an easier permeability across the skin (vesicle components).
Finally, shelf live experiments indicated that the tested gel/vesicle formulations were stable over 1 year with no need of preservatives.
Prunus persica L. is one of the most important fruit crops in European production, after grapes, apples, oranges and watermelons. Most varieties are rich in secondary metabolites, showing antioxidant ...properties for human health. The purpose of this study was to develop a chemical analysis methodology, which involves the use of different analytical-instrumental techniques to deepen the knowledge related to the profile of metabolites present in selected cultivars of peaches and nectarines cultivated in the Mediterranean area (Southern Italy). The comparative study was conducted by choosing yellow-fleshed peaches (RomeStar, ZeeLady) and yellow-fleshed nectarines (Nectaross, Venus) from two geographical areas (Piana di Sibari and Piana di Metaponto), and by determining the chemical parameters for the flesh and skin that allow for identification of any distinctive varietal and/or geographical characteristics. A combined analytical and chemometric approach was used, trough rheological, thermogravimetric (TGA), chromatographic (HPLC-ESI-MS), spectroscopic (UV-Vis, ATR-FTIR, NMR) and spectrometric (ToF-SIMS) analysis. This approach allowed us to identify the characterizing parameters for the analysis of a plant matrix so that the developed methodology could define an easily exportable and extendable model for the characterization of other types of vegetable matrices.
AbstractIn this experimental study, the effect of silica fume on the grouting performance of superfine cement and the engineering properties of grouted sand was examined. The experiments were first ...launched with rheological property determination tests. Bleeding, setting time, and viscosity tests were performed on superfine-cement suspensions with or without silica fume in different water/cement (W/C) ratios. Then, groutability tests were performed on fine to medium sand mixtures prepared in various gradations. Finally, unconfined compression strength (UCS) and falling-head permeability tests were performed on the samples that were successful in the grout test at different time intervals. With the addition of silica fume to superfine cement, the initial and final setting times as well as viscosity values increased, whereas bleeding values decreased. With the addition of silica fume to the superfine cement, the groutability slightly decreased, but the grouting pressure values increased. With the addition of silica fume to superfine cement, UCS values increased, although the permeability values decreased. Sand samples grouted with a superfine-cement suspension with silica fume additive gained strength later than sand samples grouted with superfine-cement suspensions with no additive. Experimental studies have shown that the addition of silica fume to superfine cement improves the engineering properties of the grouted sands.
We use the remarkable similarity between microstructures preserved in naturally and experimentally deformed quartzites as a basis to evaluate quartzite flow laws and their application to natural ...conditions. The precision of this analysis is relatively high because of the well-constrained deformation history of naturally deformed rocks from the Ruby Gap duplex, Central Australia. The external state variables during deformation in the duplex are well constrained by a combination of thermochronological, microstructural and structural observations. Using a flow law with the form ϵ = Af H 2 O m σ n exp ( − Q / RT ) % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfKttLearuavTnhis1MBaeXatLxBI9gBae % rbd9wDYLwzYbItLDharuavP1wzZbItLDhis9wBH5garqqtubsr4rNC % HbGeaGqiVCI8FfYJH8sipiYdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8 % WqFfeaY-biLkVcLq-JHqpepeea0-as0Fb9pgeaYRXxe9vr0-vr0-vq % pWqaaeaabiGaciaacaqabeaadaabauaaaOqaaiqbew7aLzaacaGaey % ypa0JaemyqaeKaemOzay2aa0baaSqaaiabdIeainaaBaaameaacqaI % YaGmaeqaaSGaem4ta8eabaGaemyBa0gaaOGaeq4Wdm3aaWbaaSqabe % aacqWGUbGBaaGccyGGLbqzcqGG4baEcqGGWbaCdaqadaqaaiabgkHi % Tiabdgfarjabc+caViabdkfasjabdsfaubGaayjkaiaawMcaaaaa!4AFA! ϵ = Af H 2 O m σ n exp ( − Q / RT ) , our analysis indicates that values of log (A)=-11.2±0.6 MPa^sup -n^/s and Q=135±15 kJ/mol provide the best description of the combined natural and experimental constraints with values of m=1 and n=4. Motivated by the results of our analysis, we also evaluated the influence of water fugacity on strain rate determined in the laboratory. In this case, we concur with a previously published suggestion that the measured effect of water fugacity ( ϵ f H 2 O 2 % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfKttLearuavTnhis1MBaeXatLxBI9gBae % rbd9wDYLwzYbItLDharuavP1wzZbItLDhis9wBH5garqqtubsr4rNC % HbGeaGqiVCI8FfYJH8sipiYdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8 % WqFfeaY-biLkVcLq-JHqpepeea0-as0Fb9pgeaYRXxe9vr0-vr0-vq % pWqaaeaabiGaciaacaqabeaadaabauaaaOqaaiqbew7aLzaacaGaey % yhIuRaemOzay2aa0baaSqaaiabdIeainaaBaaameaacqaIYaGmaeqa % aSGaem4ta8eabaGaeGOmaidaaaaa!3B76! ϵ f H 2 O 2 ) is likely a manifestation of a change in deformation process with increasing stress. The results of this study provide further support for the application of quartzite flow laws to understand deformation conditions in the Earth, and emphasize the important insights that can be gained by analyzing deformation microstructures in naturally deformed rocks.PUBLICATION ABSTRACT
Rheumatoid arthritis is accompanied by increased parameters of bulk viscosity and relaxation time of the serum to reduce the static background (equilibrium) surface tension and angle of tensiogram, ...which is associated with sex of patients, the activity of the pathological process, the rate of progression, lesions of certain joints, nature of bone-destructive changes, extraarticular (systemic) symptoms of the disease, the degree of immune disorders (including levels of antinuclear and antineutrophil cytoplasmic antibodies), and in the development of oculopathy (uveitis, scleritis, keratitis, conjunctivitis, cataract, glaucoma) violation of the adsorption-rheological properties of blood are involved.
Hydraulic fracturing is one of the most widely stimulation techniques used for increasing well production. The operation depends on the quality of the fracturing fluid. The fracturing fluids are ...varied and their rheological properties are the result of chemical reactions of chemical additives in the fluid. Quality control of fluids is an important tool that should be essential in fracking operations to ensure the quality of the fluids and the success of the operation. Knowing the chemical behavior of fracturing fluids and the parameters affecting it is critical in the quality control for operational decision making in field leading to the use of appropriate fluids. This paper presents the description of the chemical behavior of water-based fracturing fluids and the main physics and chemicals parameters of quality control that can affect their rheological stability. Furthermore, exposes additional fluid control parameters necessary for the success of hydraulic fracturing.
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