Search results for " motore"
showing 10 items of 87 documents
Spray-Drying Performance and Thermal Stability of L-Ascorbic Acid Microencapsulated with Sodium Alginate and Gum Arabic
2019
[EN] The potential of sodium alginate (ALG) and gum arabic (GA) as wall polymers for Lascorbic acid (AA) encapsulation as a tool for their preservation against the thermo-oxidative degradation was investigated. The influence of such polymers used as wall material on the AAcontent, size, encapsulation efficiency, encapsulation yield and thermo-oxidative stability were evaluated. The AA-microparticles were obtained using the spray-drying technique. An experimental Taguchi design was employed to assess the influence of the variables in the encapsulation process. The microparticles morphology and size distribution were characterized by scanning electron microscopy and laser diffraction. The the…
Human platelet-rich plasma improves the nesting and differentiation of human chondrocytes cultured in stabilized porous chitosan scaffolds
2017
[EN] The clinical management of large-size cartilage lesions is difficult due to the limited regenerative ability of the cartilage. Different biomaterials have been used to develop tissue engineering substitutes for cartilage repair, including chitosan alone or in combination with growth factors to improve its chondrogenic properties. The main objective of this investigation was to evaluate the benefits of combining activated platelet-rich plasma with a stabilized porous chitosan scaffold for cartilage regeneration. To achieve this purpose, stabilized porous chitosan scaffolds were prepared using freeze gelation and combined with activated platelet-rich plasma. Human primary articular chond…
Thermal response test analysis for U-pipe vertical borehole heat exchangers under groundwater flow conditions
2021
[EN] Conventional models used in the analysis of thermal response test data only consider conduction as heat transfer mechanism. In cases where presence of groundwater is detected, convection heat transmission plays an important role, so its influence must be determined in the calculation of the effective thermal conductivity, usually overestimated in these situations, increasing its value the higher the power injected and the time elapsed. In this work, based on the data collected in a borehole located at UPV (Valencia) in which have been carried out three thermal response tests with different characteristics, has been implemented a variation of the finite line source model introducing an …
Aprenentatge basat en projectes: aproximació a l'ensenyament de sistemes de potència de gas i vapor
2014
L’objectiu d’aquest treball és presentar l’experiència i els resultats derivats de l’aplicació del mètode d’aprenentatge basat en projectes (PBL) de l’assignatura de Termotècnia de la titulació d’Enginyeria Química de la Universitat del País Basc/Euskal Herriko Unibertsitatea. Després d’un anàlisi crític dels resultats acadèmics dels alumnes que aprenen motors tèrmics, s’observa que l’estratègia d’ensenyament-aprenentatge tradicional, basat en classes magistrals + classes d’aplicació en una llista d’exercicis (totalment acotats i amb una solució única), està fallant. Davant d’aquesta situació, es planteja un enfoc constructivista centrat en l’alumne perquè ell mateix construeixi el seu apre…
Renewable polyol obtained by microwave-assisted alcoholysis of epoxidized soybean oil: Preparation, thermal properties and relaxation process
2019
[EN] The soybean oil polyol (SOP) use as feedstock in the polyurethane industry has been recently emphasized due to its excellent resistance to hydrolysis, which is also applicable in coatings and thermal insulation. In this article, the SOP was obtained by a very fast microwave-assisted alcoholysis of epoxidized soybean oil (ESO). The preparation method, thermal properties, and relaxation process were evaluated. High yields as opening and consumption epoxy group and selectivity of 99.8 mol%, 985 mol%, and 71.2 mol% were obtained. Through titrations, nuclear magnetic resonance and gel permeation chromatography were identified parameters as 0.32 mg KOH.g(-1) acid number, 190 mg KOH.g(-1) hyd…
Aequorin-expressing yeast emits light under electric control
2011
In this study, we show the use of direct external electrical stimulation of a jellyfish luminescent calcium-activated protein, aequorin, expressed in a transgenic yeast strain. Yeast cultures were electrically stimulated through two electrodes coupled to a standard power generator. Even low (1.5. V) electric pulses triggered a rapid light peak and serial light pulses were obtained after electric pulses were applied periodically, suggesting that the system is re-enacted after a short refraction time. These results open up a new scenario, in the very interphase between synthetic biology and cybernetics, in which complex cellular behavior might be subjected to electrical control.
Aristotele. Il movimento degli animali
2014
Nuova traduzione italiana, saggio introduttivo e note al De motu animalium di Aristotele
Microbial Diversity in the Midguts of Field and Lab-Reared Populations of the European Corn Borer Ostrinia nubilalis
2011
Background: Insects are associated with microorganisms that contribute to the digestion and processing of nutrients. The European Corn Borer (ECB) is a moth present world-wide, causing severe economical damage as a pest on corn and other crops. In the present work, we give a detailed view of the complexity of the microorganisms forming the ECB midgut microbiota with the objective of comparing the biodiversity of the midgut-associated microbiota and explore their potential as a source of genes and enzymes with biotechnological applications. Methodological/Principal Findings: A high-throughput sequencing approach has been used to identify bacterial species, genes and metabolic pathways, parti…
Influence of chitin nanocrystals on the dielectric behaviour and conductivity of chitosan-based bionanocomposites
2018
[EN] A series of bionanocomposite films based on chitosan, reinforced with chitin nanocrystals, were developed, and assessed in terms of dielectric behaviour and conductivity by using an experimental methodology that allows avoiding the conductivity contribution and the exclusion of contact and interfacial polarization effects. The dielectric relaxations at low and high frequency and temperatures were modeled by Havriliak-Negami functions. Below the glass transition temperature (Tg), the gamma and beta relaxations were observed, which were related to intramolecular and non-cooperative segmental movements. At higher temperatures, an intermolecular and cooperative macromolecular movement, rel…
Dielectric spectroscopy of novel thiol-ene/epoxy thermosets obtained from allyl-modified hyperbranched poly (ethyleneimine) and diglycidylether of bi…
2019
[EN] Dielectric Thermal Analysis (DETA) of a series of new thermoset obtained by click chemistry was performed. The new thermosets were obtained by a dual-curing process consisting in a first photochemical thiol-ene, followed by a thermal thiol-epoxy starting from an allyl-terminated hyperbranched poly(ethyleneimine) (HBPEI) and different proportions of diglycidylether of bisphenol A (DGEBA) and the corresponding stoichiometric proportions of pentaerythritol tetrakis (3-mercaptopropionate, PETMP). The dielectric behaviour was obtained experimentally supressing the conductive effects. Two sub-Tg intramolecular non-cooperative gamma and beta relaxations and an intermolecular cooperative alpha…