Investigation of upwind, multigrid, multiblock numerical schemes for three dimensional flows. Volume 1: Runge-Kutta methods for a thin layer Navier-Stokes solver

A state-of-the-art computer code has been developed that incorporates a modified Runge-Kutta time integration scheme, upwind numerical techniques, multigrid acceleration, and multi-block capabilities (RUMM). A three-dimensional thin-layer formulation of the Navier-Stokes equations is employed. For turbulent flow cases, the Baldwin-Lomax algebraic turbulence model is used. Two different upwind techniques are available: van Leer's flux-vector splitting and Roe's flux-difference splitting. Full approximation multi-grid plus implicit residual and corrector smoothing were implemented to enhance the rate of convergence. Multi-block capabilities were developed to provide geometric flexibility. This feature allows the developed computer code to accommodate any grid topology or grid configuration with multiple topologies. The results shown in this dissertation were chosen to validate the computer code and display its geometric flexibility, which is provided by the multi-block structure

Runge-Kutta Upwind Multigrid Multi-Block Three-Dimensional Thin Layer Navier-Stokes Solver

A state-of-the-art computer code has been developed that incorporates a modified Runge-Kutta time integration scheme, Upwind numerical techniques, Multigrid acceleration, and Multi-block capabilities (RUMM). A three-dimensional thin-layer formulation of the Navier-Stokes equations is employed. For turbulent flow cases, the Baldwin-Lomax algebraic turbulence model is used. Two different upwind techniques are available, van Leer\u27s flux-vector splitting and Roe\u27s flux-difference splitting. Full approximation multigrid plus implicit residual and corrector smoothing were implemented to enhance the rate of convergence. Multi-block capabilities were developed to provide geometric flexibility. This feature allows the developed computer code to accommodate any grid topology or grid configuration with multiple topologies. The results shown in this dissertation were chosen to validate the computer code and display is geometric flexibility, which is provided by the multi-block structure

Stroke after tadalafil use

No abstract availabl

Reply

We performed a comprehensive literature search in the PubMed and Scopus data bases on blister-like aneurysms

EFFECTS OF SHIFT WORK ON CARDIOVASCULAR ACTIVITY, SERUM CORTISOL AND WHITE BLOOD CELLS COUNT IN A GROUP OF ITALIAN FISHERMEN

We analyzed the effects of working activity and working shifts on the circadian rhythmicity and circadian phase relations of serum cortisol level, white blood cells count, resting heart rate and systolic/diastolic blood pressure in a group of italian fishermen. We observed a shift-induced displacement of cortisol secretion and a modification in leukocyte count. Moreover, systolic/diastolic blood pressure and resting heart rate were markedly influenced by the night shift, whereas no appreciable changes were observed after the morning and afternoon shifts, compared to pre-working values. These data suggest that the human circadian system is greatly influenced by shift work, and serum cortisol level, leukocyte count, systolic and diastolic blood pressure, and resting heart rate are sensitive indicators of the biological responses to a stress workload in shift workers, especially after a night shif

AMOA, Associazione Medici Oculisti per l'Africa, un esempio di solidariet\ue0 istituzionalizzata. La missione Zimbabwe.

AMOA (Associazione Medici Oculisti per l\u2019Africa), \ue8 un\u2019associazione di volontariato legalmente costituita, con sede a Bologna, aconfessionale che non persegue fini di lucro. L\u2019associazione, improntata al volontariato, svolge metodicamente e con continuit\ue0 attivit\ue0 di cooperazione allo sviluppo in favore delle popolazioni del Terzo Mondo ed in particolare di quelle africane. A tale scopo l\u2019associazione stabilisce con le Autorit\ue0 nazionali dei Paesi in cui opera, con le istituzioni nazionali ed internazionali operanti localmente e le organizzazioni sociali, una fattiva collaborazione nel rispetto delle sovranit\ue0 nazionali e secondo i principi della cooperazione internazionale definiti dalla Carta delle Nazioni Unite. Essa opera per mezzo di medici e paramedici volontari che offrono gratuitamente una parte del loro tempo per servire ai bisogni sanitari delle popolazioni di questi Paesi che si trovano in uno stadio di sottosviluppo sanitario in campo oculistico per mancanza di strutture, risorse economiche e umane. Tra le varie missioni effettuate possiamo menzionare quelle in Senegal, Togo, Etiopia, Madagascar, Rwanda, Cameroun, Zimbabwe. L\u2019analisi del presente lavoro verter\ue0 sull\u2019operato della\u2019associazione in Zimbabwe evidenziando: l\u2019epidemiologia delle patologie oculari della zona di intervento; il trattamento delle cause pi\uf9 frequenti di cecit\ue0: cataratta, glaucoma, malposizione palpebrale da tracoma, i traumi del bulbo oculare; lo screening delle deficienze visive nell\u2019et\ue0 scolare: ipermetropia, miopia, astigmatismo, ambliopia; la correzione della presbiopia che riduce la capacit\ue0 lavorativa dopo i 40 anni; la promozione dell\u2019educazione sanitaria nelle scuole e nei dispensari per la prevenzione primaria e secondaria delle carenze visive; l\u2019addestramento del personale scolastico locale a misurare la capacit\ue0 visiva dei bambini a partire dal periodo prescolare; l\u2019aggiornamento del personale medico alla chirurgia mediante soggiorni sia in loco che in Italia ed infine le ricadute sulle condizioni di salute e benessere dei soggetti coinvolti

Night-time shift work and related stress responses: A study on security guards

Work-related stress can induce a break in homeostasis by placing demands on the body that are met by the activation of two different systems, the hypothalamic\u2013pituitary\u2013adrenal axis and the sympathetic nervous system. Night-shift work alters the body\u2019s exposure to the natural light\u2013 dark schedule and disrupts circadian (daily) rhythms. The greatest effect of night-shift work is the disruption of circadian rhythms. The impact that these disruptions may have on the pathogenesis of many diseases, including cancer, is unknown. This study aims to discover the relationship among three different job activities of security guards and their stress-related responses by evaluating salivary cortisol levels and blood pressure. Methods: Ninety security guards, including night-time workers and night-time and daily-shift workers, were recruited for this study. Each security guard provided two saliva samples before and after three scheduled time points: (i) at 22:00, (ii) at 06:30, and (iii) at 14:00. Results: The results of the study showed a significant alteration in cortisol levels. Night-time shift cortisol levels significantly increased before and after the work shifts. A physiological prevalence of the vagal tone on the cardiocirculatory activity was found during night-shift work. Conclusions: This study indicates that cortisol levels and blood pressure are sensitive markers of biological responses to severe work stress. Shift-change consequences may occur at the end of the night shift when there is a significant increase in the cortisol level and a significant variation in cardiovascular parameters

A 12-year-old girl with absent radial pulse: arterial thoracic outlet syndrome with subclavian artery aneurysm and thrombosis of the brachial artery

Brachial arterial occlusion is rare in children and adolescents. Once a traumatic cause is excluded, the differential diagnosis consists of a variety of rare conditions. We report the case of a 12-year-old girl whose presenting symptoms—an absent radial pulse and Raynaud's phenomenon of the right hand—could be easily mistaken for a vasculitis. She was found to have arterial thoracic outlet syndrome with right subclavian artery compression and aneurysm formation caused by an anomalous first rib and consecutive thromboembolic occlusion of the brachial artery. The diagnosis and differential diagnosis of this condition are reviewe

Dark photon superradiance quenched by dark matter

Black-hole superradiance has been used to place very strong bounds on avariety of models of ultralight bosons such as axions, new light scalars, anddark photons. It is common lore to believe that superradiance bounds arebroadly model independent and therefore pretty robust. In this work we showhowever that superradiance bounds on dark photons can be challenged by simple,compelling extensions of the minimal model. In particular, if the dark photonpopulates a larger dark sector and couples to dark fermions playing the role ofdark matter, then superradiance bounds can easily be circumvented, depending onthe mass and (dark) charge of the dark matter.<br

Considerations on the Update of the Risk Assessment Document During the Pandemic State by COVID-19 in Italy

Immediately after the outbreak of the SARS-CoV-2 epidemic (which had risen to the level of a pandemic according to the World Health Organization), the question arose whether or not to update the risk assessment, which, as required by Legislative Decree 81/2008, with the consequent updating of the prevention measures. In light of these forecasts, we asked ourselves whether the risk of coronavirus infection should be taken into account by the employer by updating the risk assessment or not. An in-depth analysis of current legislation has led to the conclusion that the biological risk from SARS-CoV-2 is to be considered specific only in health-related activities, in other activities it can be considered exclusively generic or generic aggravated. The Risk Assessment Document can therefore only be integrated