Search results for " PRIN"
showing 10 items of 1809 documents
Politika un tiesības: Tiesību un juridiskās prakses ilgtspējīga attīstība
2012
Izdevumā publicēti Apvienotā Pasaules latviešu zinātnieku 3. kongresa un Letonikas 4. kongresa sekcijā „Tiesību un juridiskās prakses ilgtspējīga attīstība” (LU Juridiskā fakultāte, 2011. gada 25. oktobris, Rīga, Raiņa bulvāris 19) nolasītie referāti.
A Dialysis Photocatalytic Reactor for the Green Production of Vanillin
2020
In the present work, dialysis was used to recover vanillin while being produced by partial photocatalytic oxidation of ferulic acid in an aqueous solution at ambient temperature. The relatively high value of the permeate flux through a dense polyether-block amide membrane allowed continuously extracting vanillin from the reacting solution, thus avoiding its successive oxidation. The rate of vanillin formation was improved, compared to other reactor configurations, because intermediate compounds permeated from the reacting solution and did not hinder the reaction, while ferulic acid permeated in the opposite direction to partially replenish the reactor with the substrate. The photocatalytic …
Heterogeneous Photocatalysis and Photoelectrocatalysis: From Unselective Abatement of Noxious Species to Selective Production of High-Value Chemicals
2015
Heterogeneous photocatalysis and photoelectrocatalysis have been considered as oxidation technologies to abate unselectively noxious species. This article focuses instead on the utilization of these methods for selective syntheses of organic molecules. Some promising reactions have been reported in the presence of various TiO2 samples and the important role played by the amorphous phase has been discussed. The low solubility of most of the organic compounds in water limits the utilization of photocatalysis. Dimethyl carbonate has been proposed as an alternative green organic solvent. The recovery of the products by coupling photocatalysis with pervaporation membrane technology seems to be a…
Il fenomeno della commoditization nel mercato delle conserve ittiche a base di tonno
2017
Nel complesso scenario competitivo dell’odierno mercato globalizzato nasce la minaccia della commoditization: un processo in cui un prodotto (o un servizio) perde la differenziazione significativa rispetto ai concorrenti. Il prezzo risulta così l’unico parametro di scelta per il consumatore e il prodotto si trasforma in una commodity, diviene cioè “banale”. In una prospettiva empirica, si vuole qui studiare la commoditization nell’industria ittico conserviera del tonno descrivendone le dinamiche e le caratteristiche strutturali che presentano chiari segnali della “banalizzazione”. In particolare, attraverso lo strumento della mappa prezzo-benefici saranno indagati il maturo mercato del tonn…
Metafisica come morfologia del principio
2018
The essay analyzes Giuseppe Nicolaci's conception of metaphysic in relation to the Aristotelian determination of prote philosophia and referring to the long exegetical history of metaphysics.
Discrete-lattice theory for Frenkel-defect aggregation in irradiated ionic solids
1998
Institut fu ¨r Physikalische und Theoretische Chemie, Technische Universitat Braunschweig, D-38106 Braunschweig, Germany~Received 11 September 1997; revised manuscript received 6 April 1998!A microscopic theory of diffusion-controlled aggregation of radiation Frenkel defects—called in ionic solidsH and F centers—is presented. This is based on a discrete-lattice formalism for the single defect densities~concentrations! and the coupled joint densities of similar and dissimilar defects treated in terms of a modifiedKirkwood superposition approximation. The kinetics of defect aggregation is studied in detail; the cooperativecharacter of this process for both types of complementary defects is sho…
Il campo della metafisica. Studi in onore di Giuseppe Nicolaci, voll. 2
2018
Mode superposition methods in dynamic analysis of classically and non-classically damped linear systems
1986
Mode-superposition analysis is an efficient tool for the evaluation of the response of linear systems subjected to dynamic agencies. Two well-known mode-superposition methods are available in the literature, the mode-displacement method and the mode-acceleration method. Within this frame a method is proposed called a dynamic correction method which evaluates the structural response as the sum of a pseudostatic response, which is the particular solution of the differential equations, and a dynamic correction evaluated using a reduced number of natural modes. The greater accuracy of the proposed method with respect to the other methods is evidenced through extensive numerical tests, for class…
Computational modeling and experimental characterization of fluid dynamics in micro-CT scanned scaffolds within a multiple-sample airlift perfusion b…
2023
The perfusion of flow during cell culture induces cell proliferation and enhances cellular activity. Perfusion bioreactors offer a controlled dynamic environment for reliable in vitro applications in the tissue engineering field. In this work, to evaluate the effects of the operating parameters of a custom-made bioreactor, numerical simulations were performed to solve the fluid velocity profile inside the bioreactor containing multi-grid support that allows allocating of multiple seeded scaffolds at the same time. The perfusion system exhibited a uniform distribution of liquid velocities within the regions, suitable for cell growth on seeded scaffolds. The effects of the porous microstructu…
Development of a module of stacks of air-breathing microbial fuel cells to light-up a strip of LEDs
2018
Abstract This work focuses on scaling-up of the microbial fuel cells technology according to the principle of miniaturization and multiplication. Seven stacks of 16 mini-MFCs (electrodic area of 0.866 cm2) were built up leading to a big module of 112 MFCs. The electrical connection among the MFCs in the stacks and among the stacks into the modules was optimized in order to implement this technology. Results show that 1 MFC generates 1.22 mW while the optimization of the electric connection in order to achieve the maximum power results in 6.62 mW compared to the theoretical 182 mW, indicating the existence of large energy losses in the system. However, to light a LED there is not a threshold…