Optimization of Classification Prediction Performances of an Instrumental Odour Monitoring System by Using Temperature Correction Approach

Odour emissions generated by industrial and environmental protection plants are often a cause of nuisances and consequent conflicts in exposed populations. Their control is a key action to avoid complaints. Among the odour measurement techniques, the sensory-instrumental method with the application of Instrumental Odour Monitoring Systems (IOMSs) currently represents an effective solution to allow a continuous classification and quantification of odours in real time, combining the advantages of conventional analytical and sensorial techniques. However, some aspects still need to be improved. The study presents and discusses the investigation and optimization of the operational phases of an advanced IOMS, applied for monitoring of environmental odours, with the aim of increasing their performances and reliability of the measures. Accuracy rates of over 98% were reached in terms of classification performances. The implementation of automatic correction systems for the resistance values of the measurement sensors, by considering the influence of the temperature, has been proven to be a solution to further improve the reliability of IOMS. The proposed approach was based on the application of corrective coefficients experimentally determined by analyzing the correlation between resistance values and operating conditions. The paper provides useful information for the implementation of real-time management activities by using a tailor-made software, able to increase and enlarge the IOMS fields of application

Civiltà della Campania. Anno II, n. 2 (febbraio-marzo 1975)

A. II, n. 2 (febbraio-marzo 1975): M. Parrilli, All’Unesco Ravello e Castellabate, P. 3 ; L’anno santo in Campania, P. 7; B. Gatta, Videre Petrum, P. 8; B. Lucrezi, Gli itinerari sacri, P. 12 ; Il Duomo di Salerno: novecento anni di fede e storia », P. 24 ; R. Causa, Santuari nel Nocerino, P. 26 ; G. Giordano, Pacem in maribus, P. 32 ; R. Virtuoso, L’ambiente e il ruolo del turismo, P. 40 ; S. Pavia, I centri storici, P. 32 ; R. Di Stefano, Villa Campolieto, P. 48 ; R. De Simone, Feste popolari, P. 56 ; E. Corsi, II riassetto di Ischia, P. 60 ; C. Nazzaro, Rosmarino col pomodoro, P. 65 ; G. Doria, Il napoletano che cammina, P. 66 ; M. Stefanile, Raffaele Viviani, P. 68 ; A. Fratta, Amedeo Maiuri: una vita per l’archeologia, P. 80 ; E. Fiore, Gli Incontri del Cinema, P. 86 ; G. Blasi, Petrosino l’antipadrino, P. 90 ; I. Santoro, Il mistero di Velia di, P. 93 ; R. Senatore, La rinascita del Borgo Scacciaventi di, P. 97 ; P. Andria, Salerno: S. Pietro a Corte, P. 100 ; U. Abundo, Amalfi sempre di, P. 102 ; V. Gramignazzi Serrone, S. Agata dei Goti, P. 106 ; Attività congressuali in Campania, P. 108 ; Notiziario, P. 10

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

Genetic algorithm based approach to radial flow impeller design

The authors present a method for fluid-dynamic design of radial flow impellers based on an optimization technique derived from the genetic algorithm theory. The effectiveness of this kind of algorithms is proven by the reduced number of function evaluations which are needed for finding the optimal geometrical features of the impeller. The genetic optimization proceeds with the selection of the impeller parameters without dealing with the typical difficulties which are encountered when employing a numerical optimization technique. The examples presented refer to impellers in centrifugal compressors for aircraft applications, and the authors show the results achieved in terms of both evolution of the optimizing process and of flow and load distribution within the impeller

Genetic algorithm based strategies for radial flow impeller design

A method for radial flow impeller design which pays attention to the set-up of optimal design strategies is presented. The optimal design strategies are based on a genetic algorithm which controls a quasi-three-dimensional flow simulation of a radial flow impeller, with integral boundary calculation. The design procedures are characterized by a progressive reduction in the search interval of each independent variable. A more accurate definition of the blade geometry and flow analysis is obtained through a mesh refinement in the flow model, when the optimization process is close to converge. An optimal choice of the impeller geometrical parameters is achieved by approaching the design data, then by proceeding with a number of fine refinement steps

Optimized design of radial flow compressor rotors

In a recent paper, the authors have analyzed the influence of the blade shape on both flow conditions through centrifugal compressor rotors and overall performance. The method of theoretical investigation was based upon a 'quasi-3D' flow model which accounts for the mutual influence of potential and viscous flow. In this way, both flow distribution and performance were calculated in relation to the boundary layer growth along end-walls and blade surfaces. In the present work, the authors aim to show the possibility of improving the aerodynamic design of compressor rotor, by matching the proposed method with an optimizing technique. Examples are presented as regards the dependence of optimal rotor configuration on the assigned objective (i.e. maximum of efficiency for a given pressure ratio) and on constraints imposed. The latter refer to limits on blade loading, relative and absolute Mach number or peripheral velocity. Of course, minimization of total pressure losses will be achieved also by evaluating the influence of rotor geometry and of the number of blades on boundary layer development and profile losses

Optimum design of radial flow impellers for variable load operation

An improved methodology for optimum design of radial flow impellers is presented. The base methodology consisted of a mathematical optimization technique matched to a flow model base upon an inviscid `quasi 3-D' method linked to a prediction of the boundary layer growth along the blade and end-wall surfaces. The enhanced strategy proposed in the paper utilizes a genetic optimization algorithm and a number of refinement steps. The search of an impeller configuration for satisfactory performance in an assigned field of operation is also addressed