Search results for "racket"

The Effect of the Return of Serve on the Server Pair’s Movement Parameters and Rally Outcome in Padel Using Cluster Analysis

2019

Purpose: The pressure exerted on racket sports players by the service has been well documented. Whilst the return of serve has been suggested through qualitative interviews as being of similar importance there is a dearth of quantitative data to support this contention. This study analyzed time, speed, and distance parameters related to the outcome of the return of serve (ROS) in Padel, a sport similar to tennis but played on a court bounded by walls and played in doubles format only. Methods: Matches (n = 18) at two tournaments, sanctioned by the Valencian Federation, in 2012 were recorded and processed using Tracker software. ROS shot type (flat or lob), ball location, players’ positions …

On a possible origin of quantum groups

1991

A Poisson bracket structure having the commutation relations of the quantum group SLq(2) is quantized by means of the Moyal star-product on C∞(ℝ2), showing that quantum groups are not exactly quantizations, but require a quantization (with another parameter) in the background. The resulting associative algebra is a strongly invariant nonlinear star-product realization of the q-algebra Uq(sl(2)). The principle of strong invariance (the requirement that the star-commutator is star-expressed, up to a phase, by the same function as its classical limit) implies essentially the uniqueness of the commutation relations of Uq(sl(2)).

Lotta al racket e all'usura: la stagione della fiducia

2008

Ricerca promossa dalla Camera di Commercio di Palermo, dalla Confesercenti di Palermo, dalla Confcommercio di Palermo, dalla cooperativa sociale Solidaria POR SICILIA 2000/2006 – sottomisura 3.21C

Effect of saliva contamination on cementation of orthodontic brackets using different adhesive systems

2017

Background The enamel condition and the quality of surface are points that need to be considered for achieving optimal efficiency in the treatment with orthodontic brackets. The aim of this study was to assess the immediate bond strength of metallic brackets cemented to dental. Material and Methods Forty human premolars were double-sectioned, placed in PVC matrices and randomly divided into 10 groups (n=8). They received artificial saliva contamination before or after the application of adhesive systems, except for the control groups. The metallic brackets were cemented using two orthodontic cements (Transbond™ Plus Color Change, 3M Unitek e Transbond™ XT Light, 3M Unitek). The specimens we…

Effectivity comparison between three different enamel remineralizing agent postfix orthodontic treatment

2019

Background This study aims to compare the effectiveness of topical fluoride application, a toothpaste containing synthetic hydroxyapatite with one containing calcium sodium phosphosilicate (CSPS) in remineralizing enamel after the debonding process. Material and methods The study constituted experimental laboratory research incorporating posttest-only control group design. A metal bracket was placed on the buccal surface of 40 premolar teeth and immersed in artificial saliva. After 1 month, the bracket was debonded. The teeth were then randomly divided into four groups, namely (n = 6) the control group (C), the 1st treatment group (T1), the 2nd treatment group (T2), and the 3rd treatment gr…

The Influence of Friction on Design of the Type of Bracket and Its Relation to OHRQoL in Patients Who Use Multi-Bracket Appliances: A Randomized Clin…

2021

Background and objectives: The aim of this study was to evaluate the influence of friction on design of the type of bracket, patients’ perception of pain and the impact on their oral health-related quality of life. Materials and Methods: A randomized clinical trial was carried out with 90 patients (62.2% women and 37.8% men) with three kinds of fixed multi-bracket appliances: Conventional (GC), fixed multi-bracket low friction (GS) and self-ligating (GA). The VAS (Visual Analogue Scale) was used to determine pain during the first seven days of treatment at different points in time. The patients were also given the OHIP-14 (Oral Health Impact Profile) questionnaire to analyse their oral heal…

Poisson-Nijenhuis structures and the Vinogradov bracket

1994

We express the compatibility conditions that a Poisson bivector and a Nijenhuis tensor must fulfil in order to be a Poisson-Nijenhuis structure by means of a graded Lie bracket. This bracket is a generalization of Schouten and Frolicher-Nijenhuis graded Lie brackets defined on multivector fields and on vector valued differential forms respectively.

L'analisi dei comportamenti imprenditoriali di fronte al fenomeno delle estorsioni

2010

Sviluppo credibile e sostenibile: esperienze e proposte concrete

2012

La soluzione dei problemi del Mezzogiorno passa attraverso un processo di valorizzazione delle grandi risorse disponibili. Partendo dall'esperienza antiracket di Capo d'Orlando si formulano ipotesi per un modello di sviluppo sostenibile e si presentano i risultati di una esperienza di ricerca e di formazione dell'Università di Palermo sui beni confiscati alla mafia.

Mechanisms of the Embedding of Extortion Racket Systems: The case of Cosa Nostra

2017

The chapter summarises some of the research undertaken in the EU project GLODERS which is directed towards investigating the dynamics of extortion racket systems (ERS) of which the Sicilian Mafia is but one example (http://www.gloders.eu/). Before describing in more detail the principal formal characteristics of the Mafia-type organizations and the ways in which the extortion racket system works in a certain territory it is necessary to briefly outline what is a mafia-type organization and what we mean when we talk about the extortion racket system. The chapter propose an analysis of the mechanisms of the process of extortion in Sicily.