3D flow around a rectangular cylinder: A computational study

The aim of this paper is to provide a contribution to the analysis of the 3D, high Reynolds number, turbulent, separated and reattached flow around a fixed sharp-edged rectangular cylinder with a chord-to-depth ratio equal to 5. The work is developed in the perspective of the benchmark on the aerodynamics of a rectangular cylinder (BARC), in terms of an exploratory computational study. First, the adopted flow modelling and computational approach are shortly described. Second, the obtained main aerodynamic integral parameters are compared with other results proposed in the literature. Hence, the 3D flow features around the nominally 2D cylinder are investigated by means of both proper orthogonal decomposition and coherence function of the side-surface fluctuating pressure field. Once the main 2D nature of the flow has been pointed out, some of the 2D mechanisms that are responsible for the variation of the fluctuating aerodynamic forces are scrutinised: the computational approach post-processing facilities are employed to look for significant relationships between the flow structures, the pressure field and the aerodynamic force components.     

Metrological characterization of a diagnostic test extending the Receiving Operating Curve analysis using Supplement 2 recommendations

Receiving Operating Curve (ROC) analysis is a powerful and statistical accepted method to assess the performance of a diagnostic test. ROC curve plots true positive rate against false positive rate, evaluated on a certain population. Instrumental and model uncertainty contributions can strongly affect the performance of the ROC analysis especially in the evaluation of performance metrics such as Area Under ROC (AUC) and Optimal Operating Points. Supplement 2 reports detailed instructions to handle and propagate uncertainty through a Multiple Input Multiple Output system, in case of correlate output variables, such as TPR and FPR. After a detailed revision of the existing literature, the present paper describes and applies a novel methodology, totally framed in the GUM and its supplements, to represent and propagate the uncertainty contributions estimated in a medical context, throughout the ROC analysis, providing new concepts such as ROC confidence region and Optimal Operating Region.     

Water‐soluble star polymers with a phthalocyanine as the core and poly(ethylene glycol) chains as branches

Uncharged water‐soluble phthalocyanines (Pc's) and some metallophthalocyanines (Me‐Pc's) were prepared by means of a chemical modification of a commercial Pc or by a cyclic tetramerization reaction starting from 4‐nitrophthalonitrile derivatives. The necessary hydrophilicity for the water solubility of these Pc derivatives was achieved by the binding of eight 9‐methoxytriethyleneoxy branches on peripheral Pc positions or, alternatively, four or eight linear poly(ethylene glycol) methyl ether (PEGME; weight‐average molar mass = 350 or 750 g/mol) units. The chemical structure of these products was characterized by ¹H‐NMR and matrix‐assisted laser desorption/ionization–time ‐of ‐flight mass spectrometric analysis. Finally, their solutions were examined by ultraviolet–visible and luminescence spectroscopy and dynamic light scattering experiments. All of the samples were water soluble, although the formation of small aggregates was ascertained by dynamic light scattering measurements. Furthermore, a lower scattered light intensity was measured for Pc derivatives with longer PEGME branches, which, probably playing a more negative role in the self‐assembly process, hindered the aggregation phenomenon. Preliminary data on their sensing ability are also reported. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mathematical programming representation of pull controlled single-product serial manufacturing systems

Pull policies may perform quite differently depending on the particular manufacturing system they must control. Hence, it is clear the necessity of having efficient performance evaluation models to select the best control policy in a specific context. This paper proposes a mathematical programming representation of the main pull control policies applied to single-product serial manufacturing systems. The proposed models simulate the pull controlled system in the sense that, if instantiated with the same parameter values as in a simulation model, their solution gives the same event sequence of the simulation. The proposed mathematical representation is also used for a formal comparison of the considered pull control policies. The new models presented in this paper can represent a base to build new efficient optimization algorithms for the design of pull controlled production systems.     

Integrated simulation–optimisation of pull control systems

Pull policies are considered to be among the most efficient control strategy. Setting the correct parameters to maximise their efficiency is, however, not a trivial task. Simulation–optimisation techniques have received particular attention as a means to solve this problem. Nevertheless, they require the iterative solution of an optimisation model to generate the parameter values and a discrete event simulator to evaluate the resulting system performance. In the framework of simulation-optimisation, this paper proposes a combined solution of the optimisation and simulation problems for the optimal operation of pull control systems under several control strategies. Numerical experiments were performed to evaluate the performance of the proposed technique.     

Postharvest stilbenes and flavonoids enrichment of table grape cv Redglobe (Vitis vinifera L.) as affected by interactive UV-C exposure and storage conditions

Flavonoids and stilbenes are secondary metabolites produced in plants that can play an important health-promoting role. The biosynthesis of these compounds generally increases as a response to biotic or abiotic stress; therefore, in order to achieve as high phenolic accumulation as possible, the interactive effects of storage conditions (temperature and time) and UV-C radiation on polyphenols content in postharvest Redglobe table grape variety were investigated. During a storage time longer than 48 h, both cold storage (4 °C) and UV-C exposure of almost 3 min (2.4 kJ m⁻²) positively enhanced the content of cis- and trans-piceid (34 and 90 μg g⁻¹ of skin, respectively) together with quercetin-3-O-galactoside and quercetin-3-O-glucoside (15 and 140 μg g⁻¹ of skin, respectively) up to three fold respect to control grape samples. Conversely, catechin was not significantly affected by irradiation and storage treatments. With regard anthocyanins, the highest concentrations of cyanidin-3-O-glucoside and peonidin-3-Oglucoside were observed in Redglobe, stored at both room temperature and 4 °C, after 5 min (4.1 kJ m⁻²) of UV-C treatment and 24 h of storage. Gathered findings showed that combined postharvest treatments can lead to possible “functional” grapes, within normal conditions of market commercialization, responding to the rising consumers demand to have foods that support and promote health.     

Oleuropein and hydroxytyrosol inhibit MCF‐7 breast cancer cell proliferation interfering with ERK1/2 activation

The growth of many breast tumors is stimulated by estradiol (E2), which activates a classic mechanism of regulation of gene expression and signal transduction pathways inducing cell proliferation. Polyphenols of natural origin with chemical similarity to estrogen have been shown to interfere with tumor cell proliferation. The aim of this study was to investigate whether hydroxytyrosol (HT) and oleuropein (OL), two polyphenols contained in extra‐virgin olive oil, can affect breast cancer cell proliferation interfering with E2‐induced molecular mechanisms. Both HT and OL inhibited proliferation of MCF‐7 breast cancer cells. Luciferase gene reporter experiments, using a construct containing estrogen responsive elements able to bind estrogen receptor alpha (ERα) and the study of the effects of HT or OL on ERα expression, demonstrated that HT and OL are not involved in ERα‐mediated regulation of gene expression. However, further experiments pointed out that both OL and HT determined a clear inhibition of E2‐dependent activation of extracellular regulated kinase1/2 belonging to the mitogen activating protein kinase family. Our study demonstrated that HT and OL can have a chemo‐preventive role in breast cancer cell proliferation through the inhibition of estrogen‐dependent rapid signals involved in uncontrolled tumor cell growth.     

On efficient configurations for Bluetooth scatternets

In this paper we investigate the relationship between capacity and network topology for Bluetooth scatternets. We start by considering the intrinsic capacity limits of a scatternet structure, and we show that capacity may be approached in the presence of very local traffic only and under specific conditions on the scatternet structure. A worst case analysis is presented, addressing the performance of various network configurations in the presence of a uniform end-to-end traffic matrix. In particular, some efficient configurations, based on Platonic solids, are introduced and analyzed. Finally, we focus on the closed loop configuration, for which algorithms able to improve scatternet performance by exploiting traffic locality are presented and discussed.