Identification of structural parameters from helicopter dynamic test data

A method is presented for obtaining the mass, stiffness, and damping parameters of a linear mathematical model, having fewer degrees of freedom than the structure it represents, directly from dynamic response measurements on the actual helicopter without a priori knowledge of the physical characteristics of the fuselage. The only input information required in the formulation is the approximate natural frequency of each mode and mobility data measured proximate to these frequencies with sinusoidal force excitation applied at only one point on the vehicle. The practicality and numerical soundness of the theoretical development was demonstrated through a computer simulation of an experimental program

Rotor dynamic simulation and system identification methods for application to vacuum whirl data

Methods of using rotor vacuum whirl data to improve the ability to model helicopter rotors were developed. The work consisted of the formulation of the equations of motion of elastic blades on a hub using a Galerkin method; the development of a general computer program for simulation of these equations; the study and implementation of a procedure for determining physical parameters based on measured data; and the application of a method for computing the normal modes and natural frequencies based on test data

Effect of shelf conditions on the phenolic fraction and oxidation indices of monovarietal extra virgin olive oil from cv. ‘Taggiasca’

The quality of monovarietal extra virgin olive oil from cv. ‘Taggiasca’ is influenced by many factors that have impact on shelf-life as well as on sensory and healthy properties of the product. The aim of the work was to recreate the conditions similar to those in consumer sales point (conditions of “shelf”), maintaining the olive oil packaged in dark-green bottles at room temperature (between 18 and 25 °C) under artificial light and away from heat sources, monitoring the oils up to 12 months from bottling with quarterly sampling for the main chemical, physico-chemical, and sensory parameters related to the quality. After one year of storage, an organoleptic alteration with reduction of the attributes ‘fruity’, ‘pungent’, and ‘bitter’, as well as the occurrence of ‘rancid’ defect, was observed. This alteration was found to be accompanied by a decrease in phenolic substances and tocopherols and an increase in primary and secondary oxidation products. The composition of the volatile fraction showed a slight increase of substances related to rancid defect, a constant trend of compounds related to fruitiness, and a slight decrease in alcohols. It can be concluded that the optimum time of storage of the oil under the above-mentioned conditions is approximately 9 months

Influencia de un cosechado nocturno de aceitunas en “Salento” sobre la calidad del aceite de oliva virgen extra

In southern Italy, some olive cultivars such as ‘Ogliarola Salentina’ ripen when the day temperature is still high, at up to 28 to 30 °C. This can affect both the oil quality and the expression of its valuable characteristics. In addition, it increases the risk of undesirable fermentation that can generate off-flavors. In the present study, nocturnal olive harvesting was carried out to determine the influence that temperature can have on the characteristics of the extra virgin olive oil, and particularly on the volatile and oxidative compounds. The data obtained are encouraging: the lower temperatures that occur during the night appear to have a particular and positive impact on the organoleptic characteristics of the extra virgin olive oil produced, with enhanced formation of the volatile compounds that contribute to the ‘green’ notes of the flavor. In areas where daytime temperatures are very high, the nocturnal harvesting of olives at the correct stage of maturity therefore represents a good agronomic practice for the production of oils with high organoleptic and nutritional merit.En el sur de Italia, algunas variedades de olivo maduran cuando la temperatura del día sigue siendo alta, hasta 28 °C a 30 °C. Esto puede perjudicar la calidad del aceite y a la expresión de sus valiosas características, y aumenta el riesgo de fermentación indeseable que puede generar malos sabores. En el presente estudio, la cosecha nocturna de aceitunas se llevó a cabo para determinar la influencia que la temperatura puede tener sobre las características del aceite de oliva virgen extra, y en particular sobre los compuestos volátiles y los compuestos relacionados con la oxidación. Los datos obtenidos son alentadores: las temperaturas más bajas que se producen durante la noche parecen tener un impacto positivo en las características organolépticas del aceite de oliva virgen extra producido, con una mejora de la formación de los compuestos volátiles que contribuyen a las notas “verdes” del sabor. En las zonas donde las temperaturas diurnas son muy altas, la cosecha nocturna de aceitunas, representa, por tanto, una buena práctica agronómica para la producción de aceites con grandes ventajas organoléptica y nutritivas

PRRT2 controls neuronal excitability by negatively modulating Na+ channel 1.2/1.6 activity

Proline-rich transmembrane protein 2 (PRRT2) is the causative gene for a heterogeneous group of familial paroxysmal neurological disorders that include seizures with onset in the first year of life (benign familial infantile seizures), paroxysmal kinesigenic dyskinesia or a combination of both. Most of the PRRT2 mutations are loss-of-function leading to haploinsufficiency and 80% of the patients carry the same frameshift mutation (c.649dupC; p.Arg217Profs*8), which leads to a premature stop codon. To model the disease and dissect the physiological role of PRRT2, we studied the phenotype of neurons differentiated from induced pluripotent stem cells from previously described heterozygous and homozygous siblings carrying the c.649dupC mutation. Singlecell patch-clamp experiments on induced pluripotent stem cell-derived neurons from homozygous patients showed increased Na+ currents that were fully rescued by expression of wild-type PRRT2. Closely similar electrophysiological features were observed in primary neurons obtained from the recently characterized PRRT2 knockout mouse. This phenotype was associated with an increased length of the axon initial segment and with markedly augmented spontaneous and evoked firing and bursting activities evaluated, at the network level, by multi-electrode array electrophysiology. Using HEK-293 cells stably expressing Nav channel subtypes, we demonstrated that the expression of PRRT2 decreases the membrane exposure and Na+ current of Nav1.2/Nav1.6, but not Nav1.1, channels. Moreover, PRRT2 directly interacted with Nav1.2/Nav1.6 channels and induced a negative shift in the voltage-dependence of inactivation and a slow-down in the recovery from inactivation. In addition, by co-immunoprecipitation assays, we showed that the PRRT2-Nav interaction also occurs in brain tissue. The study demonstrates that the lack of PRRT2 leads to a hyperactivity of voltage-dependent Na+ channels in homozygous PRRT2 knockout human and mouse neurons and that, in addition to the reported synaptic functions, PRRT2 is an important negative modulator of Nav1.2 and Nav1.6 channels. Given the predominant paroxysmal character of PRRT2-linked diseases, the disturbance in cellular excitability by lack of negative modulation of Na+ channels appears as the key pathogenetic mechanism

Sviluppo di strumenti tecnologici predittivi sanitario/meteo-ambientali per potenziare l’efficienza e la sostenibilità degli impianti di molluschicoltura: avvio del progetto FORESHELL

FORESHELL project is funded by the FLAG Costa Blu trough 2014-20 EMFF program of the Abruzzo Region. It is carrying out a pilot initiative to develop sanitary/weather-environmental predictive technological tools to enhance the efficiency and sustainability of the mussel farm in the Giulianova Maritime District. The hydrographic basins of the rivers close to the farm, Vibrata and Salinello, are constantly monitored trough the hydrological model (CHyM), to forecast occurrences of discharge peaks at the river mouth. Moreover, a specific sampling programme is established before and after severe weather events to determine the concentration of E. coli in freshwater at the river mouths and in mussels/seawater at the farming area. Until September 2021, there were 4 meteorological events that did not cause a peak discharge at the river mouth. Results did not show a significant increase of E. coli in the mussels. At the same time, the environmental parameters such as sea water temperature, salinity, chlorophyll a, sea currents and wave motion are acquired by the satellites and in situ probe. The web application for data visualisation is under construction, as well as the early warning signalling to the farmer. Furthermore, the growth of mussels is constantly monitored with biometric controls. In conclusion, the implementation of all phases of the FORESHELL project are progressing according to the timeline in order to develop innovative tools useful for the management of mussel farming area