1,721,111 research outputs found
Measuring the Performance of Underplatform Dampers for Turbine Blades by Rotating Laser Doppler Vibrometer
Full text linkUnderplatform friction dampers are commonly used to control the vibration level of turbine blades in order to prevent high-cycle fatigue failures. Experimental validation of highly non-linear response predictions obtained from FEM bladed disk models incorporating underplatform dampers models, has proved to be very difficult so as the assessment of the performance of a chosen design. In this paper, the effect of wedgeshaped underplatform dampers on the dynamics of a simple bladed disk under rotating conditions is measured and the effect of the excitation level on the UPDs performances is investigated at different number of the engine order excitation nearby resonance frequencies of the 1st blade bending modes of the system. The measurements are performed with an improved configuration of a rotating test rig, designed with a noncontact magnetic excitation and a non-contact rotating SLDV measurement syste
Carta Geologica d’Italia alla scala 1:50.000 del Foglio 599 “Patti (settore marino)”. Progetto CARG.
No full textTransculturalità della religione nella letteratura contemporanea
No full textNel quinto numero di «NuBE» lasezione Monografica, curata da Chiara Conterno, Davide Di Maio e Mattia Di Taranto, è dedicata a una esplorazione critica del ruolo che la dimensione religiosa, dopo aver investito l’ambito delle scienze politiche, sociali e storiche, da alcuni decenni sta svolgendo anche nella letteratura. Nei saggi accolti in questa sezione hanno preso corpo prospettive variegate sulla questione religiosa e sul suo rapporto con la secolarizzazione in relazione alle varie espressioni letterarie europee, con una particolare attenzione alle innovazioni apportate dalla critica postsecolare in grado di dar conto della complessità transculturale della contemporaneità. Per una panoramica dei contributi qui raccolti si veda l’introduzione tematica alla sezione intitolata "Transculturalità della religione nella letteratura contemporanea"
Transculturalità della religione nella letteratura contemporanea.
Full text linkIntroduzione alla sezione monografica del 5° numero della rivista NuBE. Tema della rivista: Transculturalità della religione nella letteratura contemporane
Seismostratigraphic and sedimentologic analysis of Late Quaternary deposits in the Gulf of Termini Imerese (offshore Northern Sicily)
No full textCardiocirculatory findings in a group of workers exposed to nitro derivatives. A pathogenetic hypothesis of withdrawal hazard
No full textAfter briefly recalling the professional pathology characteristics of workers exposed to nitro derivatives and the perplexities surrounding the actual pathogenetic mechanism of the "Withdrawal hazard", the AA report the results of an investigation carried out among the workers of a dynamite producing plant. In the study, the NG and EGDN environmental levels were checked and the workers were submitted to ECG tracings, ECG D according to Holter, and monitoring of postural pressure changes both during exposure to the substances and during time-outs. The results obtained showed that the concentrations found in the plant were practically within the recommended TLV values, with no pathological modifications of the parameters examined. The AA put forward a pathogenetic hypothesis based on these findings and analyzing epidemiologic data on coronary sudden death as well as the mechanisms regarded as responsible for the disorders described in the literature in professionally exposed subjects. According to such hypothesis, the "Withdrawal hazard" (if any) would not be due to the cessation of the vasodilation effect of the nitro derivatives but would be a "rebound" phenomenon following the NG - and EGDN - inhalation induced stimulation to the production of endothelial prostaglandins, and of EDRF in particular, in exposed workers. The withdrawal of nitro derivatives inhalation would thus eliminate a vascular and coronary protection mechanism in the case of pathogenetic noxae at cardiovascular level. Such an interpretation would at last account for the time elapsing between cessation of work and occurrence of the disorders, which would not be justified by the cessation of the mere vasodilating action, since this wears out within a few hours.(ABSTRACT TRUNCATED AT 250 WORDS
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