20 research outputs found
Assessment of the BWB aircraft for military transport
Purpose
The growth in air mobility, rising fuel prices and ambitious targets in emission reduction are some of the driving factors behind research towards more efficient aircraft. The purpose of this paper is to assess the application of a blended wing body (BWB) aircraft configuration with turbo-electric distributed propulsion in the military sector and to highlight the potential benefits that could be achieved for long-range and heavy payload applications.
Design/methodology/approach
Mission performance has been simulated using a point-mass approach and an engine performance code (TURBOMATCH) for the propulsion system. Payload-range charts were created to compare the performance of a BWB aircraft with various different fuels against the existing Boeing 777-200LR as a baseline.
Findings
When using kerosene, an increase in payload of 42 per cent was achieved but the use of liquefied natural gas enabled a 50 per cent payload increase over a design range of 7,500 NM. When liquid hydrogen (LH2) is used, the range may be limited to about 3,000 NM by the volume available for this low-density fuel, but the payload at this range could be increased by 137 per cent to 127,000âkg.
Originality/value
The results presented to estimate the extent to which the efficiency of military operations could be improved by making fewer trips to transport high-density and irregular cargo items and indicate how well the proposed alternatives would compare with present military aircraft. There are no existing NATO aircraft with such extended payload and range capacities. This paper, therefore, explores the potential of BWB aircraft with turbo-electric distributed propulsion as effective military transports
Il valore delle sperimentazioni organizzative: come associarsi diventa innovare. Spunti da unâanalisi delle reti inter-organizzative in unâarea interna del Mezzogiorno
Alcuni studi hanno iniziato a suggerire, dalla metĂ del primo decennio degli anni Duemila, di arricchire il dibattito sul triangolo âimprese, innovazione e policyâ (Edler e Fagerberg 2017) mettendo al centro lo sperimentalismo, sia delle politiche che degli strumenti. In un volume del 2014, lâOECD e la World Bank sostengono che per comprendere e (ri)pensare le politiche di innovazione, occorre âlearning from experimentationâ. Nel libro sono raccolti diversi casi-studio nei quali si analizzano le diverse modalitĂ di âsperimentalismoâ nei diversi contesti territoriali messe in atto da policy makers, stakeholders e imprese, volte a introdurre innovazioni (di prodotto, di processo, organizzative, regolative). Nonostante il numero limitato di casi-studio, la capacitĂ di guardare approfonditamente i vari meccanismi âsperimentaliâ ha aperto la strada a altre ricerche qualitative interessate allâimplementazione situata, al process tracing, a quello che potrebbe essere definito il âvalore dello sperimentalismoâ.
Questo articolo, a partire da quanto detto sin qui, si situa al crocevia tra una riflessione sui meccanismi regolativi e la forma organizzativa, analizzando le strategie di innovazione messe in atto allâinterno di due filiere produttive (agri-food organico e aerospaziale), in un milieux locale di unâarea interna economicamente depressa che comprende le provincie di Benevento e Avellino, attraverso lo strumento del contratto di rete.
Ivi si analizzano sperimentalismi in due âcampiâ:
a) i meccanismi di regolazione âassociativiâ come strumenti per lo sviluppo locale, prendendo come riferimento il modello dellâassociational economy teorizzato dai geografi economici Morgan e Cooke;
b) le relazioni inter-organizzative, motivate e âacceseâ dalla necessitĂ delle aziende di reperire risorse, irreperibili singolarmente, utilizzando il frame organizzativo della resource-based view (Barney 1991)
Validation and implementation of telephone-administered version of the Multidimensional Prognostic Index (TELE-MPI) for remote monitoring of community-dwelling older adults
Background: During the recent lockdown measures adopted by national authorities to contain the COVID-19 pandemic, many vulnerable older patients with chronic conditions, normally followed in ambulatory setting, needed to be monitored and managed in alternative ways, including telemedicine. Aims: In the framework of a telemedicine program, we aimed to validate and implement a telephone-administered version of the Multidimensional Prognostic Index (TELE-MPI) among community-dwelling older outpatients. Method: From March 9 to May 11, 2020, 131 older patients (82.1 years; 74% females) were interviewed using a telephone-based survey to calculate the TELE-MPI. The standard MPI was performed face-to-face three months apart. The BlandâAltman methodology measured the agreement between the two tools. Multivariate logistic regression models were built to ascertain the prognostic value of TELE-MPI and TELE-MPI classes (low, moderate, or severe risk) on negative outcomes occurring during the lockdown period. Results: Mean MPI and TELE-MPI values were 0.523 and 0.522, respectively. Lower and upper 95% limits of agreement were â 0.122 and + 0.124, respectively, with only 4.6% of observations outside the limits. Each 0.1 increase of TELE-MPI score was significantly correlated with higher incidence of psychiatric disorders [odd ratio (OR): 1.57; 95% confidence interval (CI) 1.27, 1.95] and falls (OR: 1.41; 95% CI 1.08, 1.82) in community-dwelling-older adults. Discussion: TELE-MPI showed a strong agreement with the standard MPI and was able to predict psychiatric disorders and falls during lockdown period. Conclusion: TELE-MPI may represent a useful way to follow by remote the health status of older adults