Investigation of crack propagation path in tube gears.

Abstract In this paper, the crack propagation behaviour in tube gears has been investigated. This kind of gear find application in aerospace and in particular in helicopter drivelines. For this reason, an accurate design against catastrophic failure due to particular crack propagation paths, has to be performed. In this work, the effect of tube length and rim thickness and also speed on crack propagation path has been analysed by means of extended finite elements models. In particular, to better understand the effect of speed, the changes in stress intensity factors KI and KII have been considered. Particular crack propagation shapes (wave propagation) have been found in some cases where the length ratio is particularly high

Crack propagation behavior in planet gears

Abstract Aim of this work is to investigate crack propagation paths in planet gears for aerospace applications in order to find how gears parameters may affect the crack path and, consequently, may provide information about gears design to avoid catastrophic failures. The research activity has been carried on by means of extended finite element models (XFEM). In particular, the effect of rim thickness (expressed as backup ratio) and crack initiation point on crack paths has been considered. Obtained results have been compared with those available for standard gears, to highlight the different behavior in crack propagation

Resonating Behaviour of Nanomachined Holed Microcantilevers

The nanofabrication of a nanomachined holed structure localized on the free end of a microcantilever is here presented, as a new tool to design micro-resonators with enhanced mass sensitivity. The proposed method allows both for the reduction of the sensor oscillating mass and the increment of the resonance frequency, without decreasing the active surface of the device. A theoretical analysis based on the Rayleigh method was developed to predict resonance frequency, effective mass, and effective stiffness of nanomachined holed microresonators. Analytical results were checked by Finite Element simulations, confirming an increase of the theoretical mass sensitivity up to 250%, without altering other figures of merit. The nanomachined holed resonators were vibrationally characterized, and their Q-factor resulted comparable with solid microcantilevers with same planar dimensions

Minor mutations in HIV protease at baseline and appearance of primary mutation 90M in patients for whom their first protease-inhibitor ntiretroviral regimens failed

The association between minor mutations in human immunodeficiency virus (HIV) protease at baseline and development of common primary mutation 90M at virological failure (conferring some resistance to all protease inhibitors [PIs]) was evaluated in 93 previously drug-naive patients experiencing failure of their first PI-based antiretroviral regimens. In logistic regression analysis, the probability of accumulating a new 90M mutation at virological failure was associated with the presence at baseline of minor mutation 36I (naturally occurring in ∼25% of HIV clade B and in >80% of HIV non-clade-B viruses) (adjusted odds ratio, 13.5 [95% confidence interval, 1.89–95.6]; P=.009) and, possibly, of 10I/V. This suggests a potential role for the presence of 36I at baseline in predicting the appearance of 90M at virological failure

Response of cactus pear fruit to high temperature conditioning and film wrapping

First crop cactus pear cv "Gialla" fruits harvested the 15th of September were wrapped with a 19 mm thick film or left unwrapped and then divided into two lots, of whom one was immediately stored at 17°C and 60% relative humidity (RH) for 2 or 4 weeks, while the other one before being stored at the same conditions, was conditioned at 36°C and 90% RH for 36 hours. At each inspection time fruit were checked for incidence of decay, overall appearance and presence of dermatosis. High temperature conditioning, although not detrimental, had a negative effect on overall appearance and dermatosis. Dermatosis appeared in the form of brown spots on the peel similar to the symptoms of chilling injury previously described by other authors. The incidence of decay was higher in conditioned fruits than in nonconditioned ones. Plastic film had a positive effect in reducing ageing and dermatosis, while promoted microorganism development. Neither the plastic film nor the curing treatment had important influence on chemical parameters, while significant was the effect of the storage period on pH, which changed from 5.95 of harvest to 6.3 after 4 week's storage, and titratab1e acidity (% citric acid), which decreased from 0.077% of harvest to 0.045% at the end of the storage period. In conclusion, the results show a very positive contribution of the plastic film in maintaining the initial quality of the fruits, in fact at the end of the trial the wrapped fruit appeared as fresh as at harvest, while no positive influence was exerted by the cwing treatment

Edible vegetables as a source of aldose reductase differential inhibitors

The hyperactivity of aldose reductase (AR) on glucose in diabetic conditions or on glutathionyl-hydroxynonenal in oxidative stress conditions, the source of cell damage and inflammation, appear to be balanced by the detoxifying action exerted by the enzyme. This detoxification acts on cytotoxic hydrophobic aldehydes deriving from membrane peroxidative processes. This may contribute to the failure in drug development for humans to favorably intervene in diabetic complications and inflammation, despite the specificity and high efficiency of several available aldose reductase inhibitors. This paper presents additional features to a previously proposed approach, on inhibiting the enzyme through molecules able to preferentially inhibit the enzyme depending on the substrate the enzyme is working on. These differential inhibitors (ARDIs) should act on glucose reduction catalyzed by AR without little or no effect on the reduction of alkenals or alkanals. The reasons why AR may be an eligible enzyme for differential inhibition are considered. These mainly refer to the evidence that, although AR is an unspecific enzyme that recognizes different substrates such as aldoses and hydrophobic aldehydes, it nevertheless displays a certain degree of specificity among substrates of the same class. After screening on edible vegetables, indications of the presence of molecules potentially acting as ARDIs are reported

Sistemazione di piazza Municipio a Pino Torinese

Progetto di concorso per la realizzazione del nuovo municipio e per la sistemazione della piazza antistante. L'intervento non prevede radicali modifiche del contesto - notevolmente disomogeneo - ma tende piuttosto ad una ipotesi di riordino e ricollegamento di spazi e volumi esistenti; il nuovo edificio è visto come elemento di centralità rispetto alla riorganizzazione dello spazio circostante. Il prospetto verso via Molina propone la ricostituzione di un fronte continuo proseguendo l'effetto di chiusura dato dai muri controterra che sorreggono giardini e orti lungo la via - connotazione ambientale specifica legata ai percorsi collinari. Il nuovo fabbricato municipale si articola su tre piani secondo due volumi: uno frontale in cui si collocano attività più legate alla presenza del pubblico e uno arretrato destinato più specificatamente agli uffici comunali, organizzati secondo uno schema distributivo flessibile a manica doppia

Post-graduate medical education in public health: The case of Italy and a call for action

Public health technical expertise is of crucial importance to inform decision makers\u2019 action in the field of health and its broader determinants. Improving education and training of public health professionals for both practice and research is the starting point to strengthen the role of public health so that current health challenges can be efficiently tackled. At the Association of Schools of Public Health in the European Region (ASPHER) Deans\u2019 & Directors\u2019 2017 Annual Retreat, we presented the structure and management of public health training system in Italy, and we reported recent data on Italian public health specialists\u2019 educational experience, employment opportunities and job satisfaction. Public health training in Italy is implemented in the context of the post-graduate medical education residency programme in Hygiene and Preventive Medicine, delivered by 34 University-based Schools of Public Health. We report relatively high employment rates across the county and wide spectrum of career opportunities for young public health specialists. However, job security is low and training expectations only partially met. We call upon other Schools of Public Health to scale up the survey within the broad ASPHER community in a shared and coordinated action of systematically collecting useful data that can inform the development of public health education and training models, their implementation and fruitful interaction with population health, health systems and services