1,227 research outputs found
Blending Open Source Tools for Rapid Development of Web Data Entry Interfaces
No full textThis paper focuses on our novel web application
aimed to tackle a specific company need. The problem, in our
IOT infrastructure, stems from the complexity of integrating
distinct components along the data ingestion pipeline towards
our BIGDATA infrastructure. The integration requires a massive
manual work in order to classify devices and their data to flow
up into the pipeline. This task is highly time consuming and error
prone. This is why we designed and implemented our in house
application for web data entry. We followed a particular approach
in order to deal with our extremely limited time resources and
a lack of specific knowledge in web related areas. We believe
that our approach and the tool we adopted can be seen as a
development pattern to build any moderately complex web data
entry application
The Role of Part-Load Control Strategies in Optimizing the Efficiency of a Decarbonized Combined Cycle Power Plant in Load-Following Mode
No full textIn pursuit of the goal of decarbonization, postcombustion capture (PCC) by means of mono-ethanolamine (MEA), exhaust gas recirculation (EGR), and hydrogen cofiring were applied to a 2 × 1 combined cycle (CC) under load-following operation in two typical summer/ winter days. Keeping the same electrical demand profiles as in a previous study by the same author, the main novelty is to determine the part-load gas turbine (GT) control strategy that can maximize the CC net electric efficiency (gCC,n) when applying different decarbonization solutions such as: addition of PCC unit and addition of PCC unit with EGR, when the fuel supply is 100% natural gas (NG) or 65% vol hydrogen cofiring. The multivariable optimization problem, with gCC,n as objective function, under the constraint of net power output (PCC,n) equal to electricity demand, has been updated to include the following decision variables: load of each GT; EGR rate, depending on the fuel type, i.e., [0; 0.4] for 100% NG versus [0; 0.55] for hydrogen blending; GT inlet air flow and fuel flow, in a range such that the GT outlet temperature is maintained within the limit of about 50 °C above the nominal value. The main finding is that the operating guidelines depend not only on the load but mainly on the environmental conditions. Under hot weather and part-load conditions, the recommendation is to rely on modulating the air/fuel flow at the GT inlet rather than applying EGR
Evaluation of CFD predictions using thermal field measurements on a simulated film cooled turbine blade leading edge
No full textComputational Fluid Dynamics (CFD) predictions of film cooling performance for gas turbine airfoils are an important part of the design process for turbine cooling. Typically, industry relies on the approach based on Reynolds Averaged Navier Stokes equations, together with a two-equation turbulence model. The Realizable k-ε (RKE) model and the Shear Stress Transport k-ω (SST) model are recognized as the most reliable. Their accuracy is generally assessed by comparing to experimentally measured adiabatic effectiveness. In this study, the performances of the RKE and SST models were evaluated by comparing predicted and measured thermal fields in a turbine blade leading edge with three rows of cooling holes, positioned along the stagnation line and at ±25°. Predictions and measurements were done with high thermal conductivity models which simulated the conjugate heat transfer effects between the coolant flow and the solid. Particular attention was placed on the thermal fields along the stagnation line, and immediately downstream of the off-stagnation line row of holes. Conventional evaluations in terms of adiabatic effectiveness were also carried out. Predictions of coolant flows at the stagnation line were significantly different when using the two different turbulence models. For a blowing ratio of M = 2.0, the predictions with the SST model showed coolant jet separation at the stagnation line, while the RKE predictions showed no separation. Experimental measurements showed that there was coolant jet separation at the stagnation line, but the actual thermal fields obtained from experimental measurements were significantly different from that predicted by either turbulence model. Similar results were seen for predicted and measured thermal fields downstream of the off-stagnation row of holes
PRINCIPIO CONTABILE N. 3 «IL RENDICONTO DEGLI ENTI LOCALI» TESTO DEL DOCUMENTO E COMMENTI - LA CONCLUSIONE DI UN PERCORSO
No full textCon il terzo principio contabile si chiude un percorso nato con la predisposizione dei postulati (il framework), proseguito con la considerazione della gestione e della programmazione, ed ora conclusosi con il rendiconto. Il lavoro compiuto è consistente, di grande rilievo operativo, in grado di conferire effettività all'azione amministrativa per quanto concerne il rispetto dell'ordinamento finanziario e contabile. L'applicazione dei principi contabili dovrà coostituire, nei prossimi mesi ed anni, l'impegno principale di tutti gli operatori, poichè da essi dipenderà l'affermazione della cultura managerile, il buon andamento, la trasparenza e la comprensione dell'attività dell'ente, dunque l'accountability e il controllo sociale e, più in generale, la stessa legalità dell'azione amministrativa
Evaluation of CFD predictions using thermal field measurements on a simulated film cooled turbine blade leading edge
No full textComputational fluid dynamics (CFD) predictions of film cooling performance for gas turbine airfoils are an important part of the design process for turbine cooling. Typically, industry relies on the approach based on Reynolds Averaged Navier Stokes equations, together with a two-equation turbulence model. The realizable k-epsilon (RKE) model and the shear stress transport k-omega (SST) model are recognized as the most reliable. Their accuracy is generally assessed by comparing to experimentally measured adiabatic effectiveness. In this study, the performances of the RKE and SST models were evaluated by comparing predicted and measured thermal fields in a turbine blade leading edge with three rows of cooling holes, positioned along the stagnation line and at +/- 25 deg. Predictions and measurements were done with high thermal conductivity models which simulated the conjugate heat transfer effects between the coolant flow and the solid. Particular attention was placed on the thermal fields along the stagnation line, and immediately downstream of the off-stagnation line row of holes. Conventional evaluations in terms of adiabatic effectiveness were also carried out. Predictions of coolant flows at the stagnation line were significantly different when using the two different turbulence models. For a blowing ratio of M = 2.0, the predictions with the SST model showed coolant jet separation at the stagnation line, while the RKE predictions showed no separation. Experimental measurements showed that there was coolant jet separation at the stagnation line, but the actual thermal fields obtained from experimental measurements were significantly different from that predicted by either turbulence model. Similar results were seen for predicted and measured thermal fields downstream of the off-stagnation row of holes
Intravenous iron therapy for severe anaemia in systemic-onset juvenile chronic arthritis.
No full textThe role of iron supplementation in treating the anaemia of systemic-onset juvenile chronic arthritis is not clear. Eight affected children with severe persistent anaemia unresponsive to oral iron therapy were treated with intravenous iron saccharate. From a median post-oral-iron value of 8.0 g/dL (range 6.5-9.5), haemoglobin rose to 11.0 g/dL (10.1-12.1) (p = 0.01). The concentration of serum transferrin receptor, an indicator of iron deficiency, before intravenous therapy correlated with the increase in haemoglobin (r = 0.88, p < 0.01). Intravenous iron saccharate could be an effective treatment for chronic anaemia in this condition, especially with iron deficiency not responsive to oral iro
Urinary microscopy in the diagnosis of haematuria in Schönlein-Henoch purpura.
No full textA 5.5-year-old boy with Schönlein-Henoch purpura presented flank pain, macroscopic haematuria and voiding of blood clots. Radiologic examination showed a stenosing ureteritis. Treatment with prednisone was accompanied by resolution of the urologic manifestations. Ureteritis is a potentially serious complication of Schönlein-Henoch purpura and its incidence is probably underestimated. Less than half of the reported patients have had symptoms suggesting a urologic complication. Microscopic examination of the urinary sediment can be helpful for the precocious diagnosis of ureteritis in the Schönlein-Henoch purpura
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