Search results for "44"

Los comuneros ante la hacienda y la deuda del emperador Carlos V: los fundamentos estructurales de la protesta (1516-150)

2018

Una "monstruosidad" particular: los sargentos mayores de los apendicios de Cagliari (1581-1670)

2018

Ciaramitaro, F.y de La Puente Brunke, J. (coord.): Extranjeros, naturales y fronteras en la América Ibérica y Europa (1492-1830)

2018

Turiam, conjetura a Catón (Jordán, 35) y a Livio (XXXIII, 44, 4)

1953

Ultrasound-Assisted Extraction, Centrifugation and Ultrafiltration: Multistage Process for Polyphenol Recovery from Purple Sweet Potatoes

2016

This work provides an evaluation of an ultrasound-assisted, combined extraction, centrifugation and ultrafiltration process for the optimal recovery of polyphenols. A purple sweet potato (PSP) extract has been obtained using ultrasonic circulating extraction equipment at a power of 840 W, a frequency of 59 kHz and using water as solvent. Extract ultrafiltration, using polyethersulfone (PES), was carried out for the recovery of polyphenol, protein and anthocyanin. Pre-treatment, via the centrifugation of purple sweet potato extract at 2500 rpm over 6 min, led to better polyphenol recovery, with satisfactory protein removal (reused for future purposes), than PSP extract filtration without cen…

THE 1-HARMONIC FLOW WITH VALUES IN A HYPEROCTANT OF THE N-SPHERE

2014

We prove the existence of solutions to the 1-harmonic flow — that is, the formal gradient flow of the total variation of a vector field with respect to the [math] -distance — from a domain of [math] into a hyperoctant of the [math] -dimensional unit sphere, [math] , under homogeneous Neumann boundary conditions. In particular, we characterize the lower-order term appearing in the Euler–Lagrange formulation in terms of the “geodesic representative” of a BV-director field on its jump set. Such characterization relies on a lower semicontinuity argument which leads to a nontrivial and nonconvex minimization problem: to find a shortest path between two points on [math] with respect to a metric w…

Lo stress occupazionale. Proposta di un metodo per la valutazione del nesso causale tra esposizione a fattori potenzialmente stressogeni in ambito la…

2011

Preliminary photochemical studies of fluorene in various aqueous media

2014

- The current study investigates the direct photochemical degradation of aqueous fluorene with the aid of a 125W polychromatic medium, pressure Hg lamp. The purpose was to test the effectiveness of the lamp in irradiation using fluorene spiked solution as substrate. A 700 ml volume of fluorene solution of 0.002 mg/l was irradiated batch-wise at 1, 3, 6, 12, 18, 24 and 48 h. The amount of fluorene removal was studied for fluorene solutions prepared from , neutral (distilled water), acidic (by adjusting pH with hydrochloric acid, HCl), basic (by adjusting pH with sodium hydroxide, NaOH) and saline (addition of sodium chloride, NaCl) solutions and there was 95.95, 92.35, 96.65 and 97.15 % remo…

Near infrared spectroscopic characterisation of surface hydroxyl groups on hydrothermally treated silica gel

2011

Published version of an article in the journal International Journal of Chemical and Environmental Engeineering, 2 (1), 27-32. Also available at: http://www.warponline.org/4.%20Near%20infrared%20spectroscopic%20characterisation%20of%20surface%20hydroxyl%20groups%20on%20hydrothermally%20treated%20silica%20gel.pdf OA Surface hydroxyl groups on hydrothermally treated silica gel have been under discussion several decades back with contradictory conclusions. Some authors meant that the hydrothermally treated sila gel increases the concentration of hydrogen bonded silanol groups on the surface and some concluded that the hyrothermal treatment increases the concentration of internal hydrogen bonde…

Near infrared spectroscopic study on the adsorption of methanol on silica gel

2013

Author's version of an article in the journal: Advanced Materials Research. Also available from the publisher at: http://dx.doi.org/10.4028/www.scientific.net/AMR.650.150 The silanol groups on Silica gel surface are sites for adsorption of polar molecules. Alcohols and other polar molecules are easily adsorbed by forming hydrogen bondings with OH groups on silica gel surface. A study on the adsorption of methanol on silica gel was carried out by using NIR spectroscopy in combination with ssecond derivative techniques. Four of the well characterised silica gel samples were used in this study. Each of the silica gel (0.25g) samples with different surface areas and silanol number was pressed i…