Numerical Analysis of a Low NOx Partially Premixed Burner for Industrial Gas Turbine Applications

Abstract A numerical analysis of a low NOx partially premixed burner for industrial gas turbine applications is presented. In the first part the mixing inside a double annular counter-rotating swirl nozzle where the fuel is injected in a transverse jet configuration is studied. Standard k – ∈ model and Two variable Schmidt number models were assessed in order to find a reliable configuration able to fit the available experimental profiles. Resulting profiles are used to perform reactive simulations of the experimental test rig, where NOx, CO measurement were available Results are compared in terms of NOx concentration at the outlet with experimental data

Sleep Apnea Screening by Autoregressive Models From a Single ECG Lead

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Extraction of Pion Transverse Momentum Distributions from Drell-Yan data

We map the distribution of unpolarized quarks inside a unpolarized pion as a function of the quark's transverse momentum, encoded in unpolarized Transverse Momentum Distributions (TMDs). We extract the pion TMDs from available data of unpolarized pion-nucleus Drell-Yan processes, where the cross section is differential in the lepton-pair transverse momentum. In the cross section, pion TMDs are convoluted with nucleon TMDs that we consistently take from our previous studies. We obtain a fairly good agreement with data. We present also predictions for pion-nucleus scattering that is being measured by the COMPASS Collaboration

Recuperare la Dimensione Estetica dell’Educazione alle STEM

L’articolo propone una riflessione metodologica sull’educazione alle STEM che pone l’attenzione su alcuni elementi che possano rappresentare un’innovazione del modo in cui si concepisce l’apprendimento in questo ambito. Lo fa attraverso l’analisi di Future Inventors, un progetto del Museo Nazionale della Scienza e della Tecnologia Leonardo da Vinci, che aspira a creare un nuovo approccio all’educazione alle STEM trasferibile nella pratica scolastica. La riflessione pone attenzione particolare sull’esperienza estetica – qui intesa come una chiave di lettura del mondo che considera come inseparabili l’esperienza cognitiva e quella affettiva; integra la costruzione del sapere con l’apprezzamento della bellezza e della forza delle idee; e attiva un processo trasformativo attraverso cui comprendiamo meglio le cose e noi stessi – in un tentativo di riposizionarla al suo posto primario nel processo di un apprendimento nelle STEM più interdisciplinare ed ecologico

Estimation of Mycobacterium avium subsp. paratuberculosis load in raw bulk tank milk in Emilia-Romagna Region (Italy) by qPCR

Consumption of milk and dairy products is considered one of the main routes of human exposure to Mycobacterium avium subsp. paratuberculosis (MAP). Quantitative data on MAP load in raw cows’ milk are essential starting point for exposure assessment. Our study provides this information on a regional scale, estimating the load of MAP in bulk tank milk (BTM) produced in Emilia‐Romagna region (Italy). The survey was carried out on 2934 BTM samples (88.6% of the farms herein present) using two different target sequences for qPCR (f57 and IS900). Data about the performances of both qPCRs are also reported, highlighting the superior sensitivity of IS900‐qPCR. Seven hundred and eighty‐nine samples tested MAP‐positive (apparent prevalence 26.9%) by IS900 qPCR. However, only 90 of these samples were quantifiable by qPCR. The quantifiable samples contained a median load of 32.4 MAP cells mL (−1) (and maximum load of 1424 MAP cells mL (−1)). This study has shown that a small proportion (3.1%) of BTM samples from Emilia‐Romagna region contained MAP in excess of the limit of detection (1.5 × 10(1) MAP cells mL (−1)), indicating low potential exposure for consumers if the milk subsequently undergoes pasteurization or if it is destined to typical hard cheese production

Strumenti rotanti in lega nichel-titanio per il ritrattamento: un'analisi pre-clinica

RiassuntoIntroduzioneL'impiego di strumenti in lega nichel-titanio (NiTi) per la rimozione dei materiali da otturazione è stato di recente prospettato con soddisfacenti risultati. Obiettivo di questo lavoro è valutare due sistemi di strumenti meccanici rotanti in lega NiTi per il ritrattamento.Materiali e metodiSono stati selezionati 60 elementi dentali monoradicolati (premolari superiori e inferiori) privi di carie e fratture, estratti per motivi parodontali. Una volta sagomati, detersi e otturati mediante condensazione verticale della guttaperca, gli elementi sono stati suddivisi in due gruppi omogenei denominati rispettivamente R-Endo e D-Endo. Gli strumenti impiegati per eseguire i ritrattamenti nei due gruppi sono stati, rispettivamente, i sistemi R-Endo e D-Endo, impiegati secondo le norme descritte dai produttori; al fine di rendere omogenee le zone apicali di strumentazione in entrambi i gruppi, sono state rifinite, rispettivamente, nel gruppo R-Endo con il file Rs e nel gruppo D-Endo con un Protaper F3 (entrambi ISO 30 in punta). Sono stati valutati i tempi di raggiungimento e di rifinitura del limite apicale di strumentazione, l'estrusione di detriti apicali alla fine della strumentazione per il ritrattamento, il diametro apicale medio al termine della fase di ritrattamento, le fratture di strumenti, i blocchi all'avanzamento degli strumenti in direzione apicale e infine i residui radiograficamente apprezzabili all'interno dei canali radicolari al termine della procedura di ritrattamento. I dati sono stati analizzati statisticamente mediante analisi della varianza (ANOVA) con una significatività posta a p <0,05; i dati qualitativi sono stati analizzati mediante test U di Mann-Whitney con una significatività posta a p <0,05.RisultatiIl tempo medio di sagomatura per la tecnica R-Endo è stato di 6,2 minuti, mentre quello per la metodica D-Endo è stato di 5,1. Tale differenza è risultata significativa (p=0,0003). La quantità di detriti espulsi apicalmente è stata pari a 0,024g nel gruppo R-Endo e di 0,031g nel gruppo D-Endo. Il diametro medio apicale nel gruppo R-Endo è stato di 26,4 ISO, quello nel gruppo D-Endo di 28,1. Questa differenza non è risultata statisticamente significativa. Il numero di fratture di strumenti è stato pari a due nel gruppo D-Endo e a uno nel gruppo R-Endo, mentre abbiamo verificato un'errata progressione nel limite apicale (trasporto o falsa strada) in tre casi nel gruppo R-Endo e in due casi nel gruppo D-Endo. La differenza non è risultata statisticamente significativa. Tutti i campioni hanno dimostrato la presenza di residui di guttaperca all'interno dei canali apprezzabili radiograficamente.ConclusioniI sistemi per ritrattamento presi in esame, pur non essendo, in termini assoluti, altamente efficaci, hanno dimostrato di poter raggiungere il limite apicale di strumentazione in tempi ragionevolmente brevi, di avere pochi effetti collaterali e di produrre una sagomatura del limite apicale rispettosa dell'anatomia. Entrambe le metodiche hanno tuttavia dimostrato, in senso assoluto, un'incompleta rimozione del contenuto intracanalare del materiale da otturazione.SummaryIntroductionEndodontic files made in nickel-titanium (NiTi) alloys have been used not only for shaping procedures, but also for retreatment shaping purposes with satisfactory clinical results. The aim of this paper was to evaluate the efficacy of two NiTi file systems in retreatment.Material and methodsSixty monorooted teeth – upper and lower premolars – caries-free and without any fracture, extracted for periodontal reasons, were carefully selected. After a normal root canal treatment finished by vertical condensation of warm gutta-percha, these teeth were randomly divided into two homogeneous groups, namely R-Endo and D-Endo. The NiTi files for retratment were respectively R-Endo files and D-Endo; the whole shaping procedure during the retreatment phase was accomplished according to the manufacturer's instructions, except at the end of the retreatment. At that point, to make tha final shaping comparable the R-Endo group had an apical finishing with the Rs instrument, while the D-Endo group had the same final instrumentation by Protaper F3 (both ISO 30 at the tip). In the study, the time needed to reach the apical terminus, the weight of debris extruded from the apical foramen, the mean apical size in the two groups, instruments blocks and fractures and finally the presence of residual gutta-percha into the root canals after the whole retreatment procedure were addressed. Data were analyzed by analysis of variance (ANOVA) with a significance level p<0.05 and non-parametric Mann-Whitney U test with the same level of significance.ResultsThe mean shaping time was respectively 6.2minutes in the R-Endo group and 5.1minutes in the D-Endo group (p=0.0003). The amount of debris extruded beyond the apical terminus was 0.024g in the R-Endo group and 0.031g in the D-Endo group; no statistically significance was reported. The mean apical size was 26.4 ISO in the R-Endo group and 28.1 in the D-Endo group; again, no significant difference was shown. In the D-Endo group two instruments fractured, whereas in the R-Endo group only one instrument fractured and three cases were dropped for canal blockage. In these cases as well no statistically significant difference was reported. All the samples in both groups showed a remarkable presence of gutta-percha into the root canals at the end of the retreatment procedure.ConclusionsBoth retreatment system file groups were effective, reaching the apical part of the root canal in relatively short times with a low percentage of instrument breakage or intracanal blocks; the amount of debris was similar and the anatomy of the apical part was carefully preserved. However, the incomplete removal of filling debris was observed in all the samples

Characterization of A phases during the Cyclic Alternating Pattern of sleep

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Sella turcica dimensions between 7 and 13 years: a novel radiographic method for age estimation

Age estimation of the living is becoming a relevant field of application of foren- sic anthropology, where the development of novel methods is urging (1). Several articles highlight the relation with age of different metrical parameters of the sella turcica (2,3), although no study so far has produced regression formulae which may be applicable to the forensic context. The aim of this study was to evaluate the metrical standards of three different measurements of sella turcica (length, depth, diameter) in 177 lateral cephalometric radiograms belonging to male and female individuals aged between 7 and 13 years in order to find standards useful for age estimation. Results were evaluated by two-way ANOVA. Sella diameter was significantly larger in older children (p&lt;0.01), while sella depth was larger in males than in females (p&lt;0.01); there was no significant gender x age interaction in any variable. Principal component analysis (PCA) was conducted to highlight the sources of variability in data. The first principal component accounted for 76% of the overall variance and it was closely correlated with length and diameter (r=0.93 and r=0.92, respectively, p&lt;0.01). The linear regression model fitted on age and diameter measures yielded the following equation: age (years)=3.81*diameter (cm)+6.12. Slope and intercept 95% CI were respectively 4.64 to 7.61 years/cm and 2.34 to 5.28 years. The related coefficient of determination was R2=0.123, while the root mean square error was 1.74 years. The present results provide a novel method useful for age estimation in the living minors: further studies are needed in order to test its applicability to the forensic scenario

Efficient automatic classifiers for the detection of A phases of the cyclic alternating pattern in sleep

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