Search results for "Function"
showing 10 items of 14432 documents
On some bifurcation analysis techniques for continuous systems
2016
This paper is devoted to techniques in bifurcation analysis for continuous mechanical systems, concentrating on polynomial equations and implicitly given functions. These are often encountered in problems of mechanics and especially in stability analysis. Taking a classical approach, we summarize the relevant features of the cubic polynomial equation, and present some new aspects for asymptotics and parametric representation of the solutions. This is followed by a brief look into the implicit function theorem as a tool for analyzing bifurcations. As an example from mechanics, we consider bifurcations in the transverse free vibration problem of an axially compressed beam. peerReviewed
Effects of electrical stimulation pattern on quadriceps isometric force and fatigue in individuals with spinal cord injury
2015
Introduction Variable frequency trains (VFT) or train combinations have been suggested as useful strategies to offset the rapid fatigue induced by constant frequency trains (CFT) during electrical stimulation. However, most studies have been of short duration with limited functional application in those with spinal cord injury (SCI). We therefore tested force and fatigue in response to VFT, CFT, and combined patterns in strength training-like conditions (6-s contractions). Methods Ten SCI individuals underwent either CFT or VFT patterns until target torque was no longer produced and then switched immediately to the other pattern. Results Target torque was reached more times when VFT was use…
Comparing the Economic Effectiveness of Various Adaptive Schemes for the c Chart
2014
In an attempt to improve the effectiveness of statistical process control (SPC) procedures, a variety of adaptive schemes has been developed in the last decades. However, considering control charts for attributes, relatively few works about adaptive schemes have been proposed, and most of them were proposed only recently. The common characteristic of those schemes is that one or more chart parameters are allowed to adaptively vary during the SPC operations according to the sampling information history, typically the current point plotted on the chart. In this way, the adaptive schemes are smarter than the related static ones, but they are also more complicated in terms of implementation. Th…
Economic design approach for a SPC inspection procedure implementing the adaptive c chart
2014
The present paper proposes a design approach for a statistical process control (SPC) procedure implementing a c control chart for non-conformities, with the aim to minimize the hourly total quality-related costs. The latter take into account the costs arising from the non-conforming products while the process is in-control and out-of-control, for false alarms, for assignable cause locations and system repairs, for sampling and inspection activities and for the system downtime. The proposed economic optimization approach is constrained by the expected hourly false alarms frequency, as well as the available labor resource level. A mixed integer non-linear constrained mathematical model is dev…
Entrepreneurial strategies of Etna wine farms
2014
Viticulture, as well as agriculture in general, performs an environmental and landscaping function and it encourages rural development through the creation of income and job opportunities in the areas where wine is produced. The wine sector, in fact, is of great social and economic importance within the Sicilian agriculture and food industry, because of the job opportunities it provides and due to Sicilian pedoclimatic peculiarities, variety of grape wines cultivars and production process. The present study aims at assessing the competitiveness of small and medium-sized enterprises that cultivate wine grapes in the Etna area. In particular, it has been examined a sample of wine farms that p…
Functionalization of nanoparticles in specific targeting and mechanism release
2017
The development of various nanotechnologies have provided a new field of research, which allows the manipulation of molecular components of matter and covers a vast array of nanodevices. The “smart” multifunctional nanostructures should work as customizable, targeted drug-delivery vehicles capable of carrying large doses of therapeutic agents into malignant cells. Some nanomedical approaches are based on the use of functionalized nanoparticles (NPs), not only to reduce toxicity and side effects of drugs but, also in potential the biological barriers crossing on, such as: the blood–brain barrier, different cellular compartments, including the nucleus. Currently, many materials are used for n…
Towards an efficient meshfree solver
2016
In this paper we focus on the enhancement in accuracy approximating a function and its derivatives via smoothed particle hydrodynamics. We discuss about improvements in the solution by reformulating the original method by means of the Taylor series expansion and by projecting with the kernel function and its derivatives. The accuracy of a function and its derivatives, up to a fixed order, can be simultaneously improved by assuming them as unknowns of a linear system. The improved formulation has been assessed with gridded and scattered data points distribution and the convergence has been analyzed referring to a case study in a 2D domain.
Hybrid magnetic materials based on coordination chemistry: from switching magnetic molecules to 2D coordination polymers
2015
El trabajo descrito en esta tesis se encuadra en el ámbito de los materiales moleculares. Presenta varias estrategias para preparar nuevos materiales híbridos multifuncionales. Los complejos de transición de espín (SCO) constituyen uno de los ejemplos más espectaculares de biestabilidad molecular. En estos sistemas, las transiciones entre los estados de bajo espín (LS) y alto espín (HS) pueden estar inducidos por una variedad de estímulos externos (temperatura, presión o radiación electromagnética). Además de los interesantes aspectos fundamentales, este fenómeno es de interés creciente en el área de los materiales funcionales debido a las posibles aplicaciones en sensores, memorias o dispo…
On the synthesis of functionalized porphyrins and porphyrin conjugates via β-aminoporphyrins
2016
International audience; The synthesis of functionalized porphyrins and their conjugates from meso-tetraarylporphyrins through the acylation and the oxidation of beta-aminoporphyrins was investigated. 2,3-Dioxochlorins were prepared by the oxidation of a variety of beta-aminoporphyrins and subsequently used in a condensation reaction with functionalized aromatic aldehydes and ammonium acetate to form beta-functionalized porphyrins bearing a fused imidazole ring. Under optimized experimental conditions both reactions tolerate various functional groups and afford the products in an appropriate overall yield. The mildness and usefulness of this methodology are illustrated by several examples in…
Regio- and Stereoselective Chloro Sulfoximidations of Terminal Aryl Alkynes Enabled by Copper Catalysis and Visible Light
2021
Advanced synthesis & catalysis 2552-2556 (2021). doi:10.1002/adsc.202100162