2,851 research outputs found
A Simple Mono-Dimensional Approach for Lap Time Optimisation
Lap time minimisation methods have great relevance in the analysis of race tracks, and in the design and optimisation of race vehicles. Several lap time minimisation approaches have been proposed in the literature, which are computationally demanding because they need to either solve differential equations or to implement a forwardâbackward integration based on an apex-finding method. This paper proposes an alternative method, based on a mono-dimensional quasi-steady-state numerical approach. The proposed approach uses a simplified vehicle model accounting for combined tyreâroad interactions, aerodynamic effects, and power limitations. The method exploits the knowledge of the curvature of the trajectory, which is worked out through a rigorous approach that allows for the use trajectories defined with respect to ageneric curve parameter and not necessarily the arc length. An iterative routine is implemented that exploits the vehicle dynamics, without solving differential equations or performing forwardâbackward integrations from the trajectory apexes. Simulations are carried out on three different tracks and are shown to be computationally efficient. Despite being intentionally simple, the proposed method allows to grasp key aspects of the problem, such as the effect of the combined tyreâroad interactions on the acceleration profiles, and the effect of aerodynamic drag and downforce on the position of the braking point on the track and on the speed profile
Intellectual capital and value co-creation: an empirical analysis from a marketing perspective
The aim of this study is to investigate intellectual capital (IC) drivers that may influence Italian consumersâ decision to participate in value co-creation (VCC) activities with firms. Given the exploratory nature of the research, after a review of the relevant literature, we conducted a survey among Italian consumers to see if IC principal sub-dimensions (i.e. Relational Capital, Human Capital and Structural Capital) played a role in triggering VCC processes. Using a Principal Component Analysis (PCA), we analyzed 270 usable questionnaires finding that, in order to decide to co-create value with firms, IC sub-dimensions actually play a critical role. Our findings showed that the motivations (i.e., IC components) that influence Italian consumersâ decision to participate in value co-creation activities with firms are quite homogeneous and similar both for those who already participated in past in these activities as well for those who never participated. The study has several managerial implications as well as limitations. In fact, the survey has been conducted only among Italian consumers and therefore the research should be extended by a geographically standpoint. Moreover, the research analyzed only the demand-side, while it would be certainly useful to know the point of view of companies also adopting other research methods (e.g., in-depth interviews). This study provides to practitioners important suggestions and warnings about the importance of the development of IC sub-dimensions to (co-)create value with external actors and consequently suggests the importance of adopting a âopenâ approach towards consumers to establish an effective and interactive relationship with them. The study fills a gap in the literature, since there are not so many references in literature for a deep understanding of the concrete relationship between IC and VCC. In addition, to our best knowledge this paper is the first that explore IC-related issues from a marketing perspective
Microtesla NMR J-coupling spectroscopy with an unshielded atomic magnetometer
We present experimental data and theoretical interpretation of NMR spectra of
remotely magnetized samples, detected in an unshielded environment by means of
a differential atomic magnetometer. The measurements are performed in an
ultra-low-field at an intermediate regime, where the J-coupling and the Zeeman
energies have comparable values and produce rather complex line sets, which are
satisfactorily interpreted.Comment: 8 pages, 8 figs, appearing in JMR (2016
Simultaneous Detection of H and D NMR Signals in a micro-Tesla Field
We present NMR spectra of remote-magnetized deuterated water, detected in an
unshielded environment by means of a differential atomic magnetometer. The
measurements are performed in a T field, while pulsed techniques are
applied -following the sample displacement- in a 100~T field, to tip both
D and H nuclei by controllable amounts. The broadband nature of the detection
system enables simultaneous detection of the two signals and accurate
evaluation of their decay times. The outcomes of the experiment demonstrate the
potential of ultra-low-field NMR spectroscopy in important applications where
the correlation between proton and deuteron spin-spin relaxation rates as a
function of external parameters contains significant information.Comment: 7 pages (letter, 4 pages) plus supplemental material as an appendix.
This document is the unedited author's version of a Submitted Work that was
subsequently accepted for publication in Journal of Phys. Chem. Lett.,
copyright American Chemical Society after peer review. To access the final
edited and published work see:
pubs.acs.org/doi/abs/10.1021/acs.jpclett.7b0285
Procedures for Damping Properties Determination in Metal Foams to Improve FEM Modeling
The aim of this work is to review the available procedures suitable for the determination of damping parameters in literature and standards for porous and dense materials and to evaluate their applicability to metal foams.
Preliminary experimental setup and characterization data obtained with the selected procedures are presented and compared with representative FEM models. The experimental dynamic measurement on a test structure is compared with the simulated ones in order to validate the chosen procedure
Metabolic syndrome and cardiovascular risk after liver transplantation: a single-center experience.
Excessive weight gain, hypertension, hyperlipidemia, and diabetes are frequently observed among orthotopic liver transplantation (OLT) patients. These alterations, which are probably multifactorial in origin, contribute to posttransplantation metabolic syndrome (PTMS), which increases the risk of cardiovascular events. We assessed the prevalence of PTMS (diagnosed according to modified NCEP Adult Treatment Panel III criteria) in 156 OLT patients undergoing regular follow-up after transplantation (median 68 months; range, 6 to 234 months). Several pre- and post-OLT data were collected to identify the factors associated with the presence of PTMS which was found in 28% of cases. The only independent predictive factors for PTMS were diabetes mellitus and patients who were overweight or obese before-OLT. The prevalence of PTSM was lower among patients on tacrolimus immunosuppression. In our population, 21% of patients showed a high cardiovascular risk score with a 4% incidence of cardiovascular events, which was higher among subjects with PTMS. Close follow-up is mandatory to prevent the development of PTMS mainly among overweight and diabetic patients before transplantation
Verso lo smart retailing. Uno studio esplorativo tra domanda e offerta nel contesto italiano
Il lavoro indaga, adottando una prospettiva esplorativa, il tema dello smart retailing con particolare riferimento al contesto italiano. Lo smart retailing rappresenta oggi per le aziende la modalitĂ principale con cui Ăš possibile rendere le strutture aziendali omnicanali, ossia giungere alla creazione di un sistema di canali e di punti di contatto con i consumatori che siano tra di essi perfettamente integrati. Lo smart retailing consente alle aziende di conseguire questo nuovo obiettivo strategico attraverso lo strumento delle cosiddette in-store technologies, ossia tecnologie âsmartâ applicate nei canali fisici (punti vendita) delle aziende che consentono a queste ultime di poter interagire in maniera costante (seamless) e âubiquaâ (online e offline) con i propri consumatori. Data la novitĂ del tema e la scarsa applicazione, ad oggi, delle in-store technologies nei punti vendita dei retailer italiani, il lavoro Ăš stato volto ad esplorare le opinioni sia della domanda che dellâofferta in merito agli effetti dellâapplicazione di in-store technologies nei punti vendita dei retailer italiani. Nel primo caso, i consumatori intervistati sono stati 46 giovani millennials in merito allâapplicazione delle in-store technologies nei punti vendita monomarca dei retailer di fast fashion. Lo studio, volto a chiarire lâimpatto di questi medium tecnologici sulla in-store experience e sulla store loyalty dei millennials, dimostra che le in-store technologies possono conferire numerosi benefici alle esperienze in store dei millennials, sia da un punto di vista utilitaristico (es. aumentando la facilitĂ di reperire informazioni sui prodotti), che emozionale (es. aumentando il brand engagement) e sociale (es. invogliando i consumatori a recarsi con accompagnatori nel punto vendita per condividere la nuova esperienza di shopping âsmartâ). Le in-store technologies possono altresĂŹ rafforzare la fedeltĂ verso le marche preferite dai millennials, mentre non si rileva un effetto altrettanto forte nel caso in cui ad adottare queste tecnologie fossero retailer di cui i millennials non apprezzino il sistema dâofferta. Infine, con riferimento al lato dellâofferta, sono stati intervistati 13 esperti e consulenti di in-store technologies per il fashion retailing al fine di chiarire: 1) lâatteggiamento complessivo dei retailer di fast fashion italiani verso le in-store technologies; 2) le modifiche che dovrĂ subire il punto vendita in futuro per poter diventare âfattivamenteâ uno smart store; 3) quale possono essere le modalitĂ di creazione di maggiore brand engagement nei millennials qualora un retailer decidesse di adottare queste tecnologie. I risultati mostrano una tendenziale resistenza dei retailer a valutare, oggi, come di valore strategico lâinvestimento in in-store technologies, che viene invece visto dal management in ottica per lo piĂč tattica, di breve periodo e finalizzato al mero aumento del fatturato. In secondo luogo, la struttura organizzativa, assieme alla sua cultura, necessita di profondi ripensamenti a partire dal top management, il quale dovrĂ ripensare alcune figure manageriali (in particolare quelle legate allâIT e alla relazione con il cliente), introdurne di nuove (es. CDO) che consentano allâintera organizzazione di comprendere lâimportanza dellâorientamento allo smart retailing e lâinvestimento in nuove competenze, in particolare nellâassunzione di data scientist. Il punto vendita âdel futuroâ sarĂ sottoposto a significativi cambiamenti che riguarderanno tanto i suoi aspetti strutturali (es. ridimensionamento della superficie calpestabile) quanto strategici (es. rendendolo il principale canale per svolgere comunicazione integrata di marketing). Infine, gli esperti convengono che le tecnologie mostrino un forte potenziale di creazione di maggiore coinvolgimento verso la marca nei millennials grazie alle nuove opportunitĂ di intrattenimento, di personalizzazione dellâesperienza e dellâaccresciuto livello di integrazione online-offline tra i canali e i customer touchpoints
Titanium and Ruthenium Phthalocyanines for NO2 Sensors: A Mini-Review
This review presents studies devoted to the description and comprehension of phenomena connected with the sensing behaviour towards NO2 of films of two phthalocyanines, titanium bis-phthalocyanine and ruthenium phthalocyanine. Spectroscopic, conductometric, and morphological features recorded during exposure to the gas are explained and the mechanisms of gas-molecule interaction are also elucidated. The review also shows how X-ray reflectivity can be a useful tool for monitoring morphological parameters such as thickness and roughness that are demonstrated to be sensitive variables for monitoring the exposure of thin films of sensor materials to NO2 gas
Scaling up Three Dimensional Printing
New processes and machines are proposed in academia and on the market, down to the microscopic range. On a different side, manufacturing complex parts of large size by additive processes has still unexplored potential. This paper describes the patented 3DPrinting D-Shape technology, one of the few available to build parts up to 3 tons. Three sands have been tested, calcareous dolomite, granite and pozzolana (regolith-like) with pulverized MgO, under the action of an aqueous MgCl2 binder, focusing on the optimization of the inkjet parameters
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