Search results for " norm"

Norm or numerical radius attaining polynomials on C(K)

2004

Abstract Let C(K, C ) be the Banach space of all complex-valued continuous functions on a compact Hausdorff space K. We study when the following statement holds: every norm attaining n-homogeneous complex polynomial on C(K, C ) attains its norm at extreme points. We prove that this property is true whenever K is a compact Hausdorff space of dimension less than or equal to one. In the case of a compact metric space a characterization is obtained. As a consequence we show that, for a scattered compact Hausdorff space K, every continuous n-homogeneous complex polynomial on C(K, C ) can be approximated by norm attaining ones at extreme points and also that the set of all extreme points of the u…

Norm estimates for operators from Hp to ℓq

2008

Abstract We give upper and lower estimates of the norm of a bounded linear operator from the Hardy space H p to l q in terms of the norm of the rows and the columns of its associated matrix in certain vector-valued sequence spaces.

Normal forms of hyperbolic logarithmic transseries

2021

We find the normal forms of hyperbolic logarithmic transseries with respect to parabolic logarithmic normalizing changes of variables. We provide a necessary and sufficient condition on such transseries for the normal form to be linear. The normalizing transformations are obtained via fixed point theorems, and are given algorithmically, as limits of Picard sequences in appropriate topologies.

Gas-liquid chromatographic analyses

1983

Abstract The gas chromatography of mixtures of n -alkyl acetates (CH 3 COOR, R = C 1 —C 8 ) and methyl esters of aliphatic n -carboxylic acids (R′COOCH 3 , R′ = C 1 —C 8 ) and certain of their monochlorinated derivatives has been studied on Carbowax 20M and SE-30 glass capillary columns under the same operating conditions. The separation of the isomeric monochlorinated esters was complete on Carbowax 20M, whereas on SE-30 the peaks of 6- and 7-chlorooctyl acetates and methyl (ω − 1)- and (ω − 2)-chlorooctanoates and -nonanoates partly overlapped. The complete separation of the mixtures could not be achieved, however, on Carbowax 20M, in spite of the use of various operating conditions. The …

Micellar Liquid Chromatography: Fundamentals

2015

The reversed phase liquid chromatography (RPLC) mode with surfactant above the critical micellar concentration (CMC) has been called micellar liquid chromatography (MLC). In pure micellar systems, the retention behavior is explained by considering three phases or environments: surfactant-modified stationary phase, bulk aqueous solvent, and micellar pseudo-phase. Surfactant adsorption on the porous RPLC packing affects chromatographic retention, owing to the change of diverse surface properties of the stationary phase. In pure micellar systems, the retention behavior is explained by considering three phases or environments: surfactant-modified stationary phase, bulk aqueous solvent, and mice…

Pietro Lojacono : restauri in Calabria e Sicilia

2022

The essay investigates the complex personality of the engineer Pietro Lojacono (Palermo 1900 - Rome 1972), who di- stinguished himself throughout his life in the field of conservation of the architectural and landscape heritage, not only in Italy, but also abroad and in particular on the island of Rhodes, in Greece . Lojacono was a man fully inserted into the cultural debate on the Restoration of monuments, able to testify to the principles acquired, but also to suggest new instances, such as maintaining authenticity, against the continuous replacement of degraded stones, up to the complete replacement of the material of the monuments. Among the many researches and restoration interventions…

Mostra per la Candidatura WHL UNESCO dell'itinerario Palermo arabo-normanna e le Cattedrali di Cefalù e Monreale

2012

Vengono presentati i monumenti arabo-normanni presenti, ai fini della candidatura UNESCO, che preservano in modo pressoché integrale le componenti architettoniche e decorative e che, in virtù delle particolari attenzioni rivolte a essi da parte delle istituzioni, si presentano in buono stato di conservazione. Si tratta, infatti, delle opere più rappresentative e artisticamente rilevanti nelle quali è possibile riconoscere inequivocabilmente i tratti salienti dell’arte arabo-normanna in tutte le sue componenti e sfaccettature. L’elenco dei monumenti proposti all’UNESCO per la costituzione dell’itinerario arabo-normanno, comprende: 1. Palazzo Reale 2. Cappella Palatina 3. Chiesa di San Giovan…

Acciones para mejorar la eficiencia energética en los edificios en Europa: estado del arte sobre los standards técnicos

2022

The paper is aimed at reviewing the state of the art of the European technical normative implementation during the last decades concerning the building energy efficiency. Indeed, it is well acknowledged that the present building stock is largely obsolete and inefficient: in the European context alone, around 75% of the buildings is not energy efficient and most are expected to be in use until 2050. Consequently, buildings require not only a general rehabilitation, to extend, or even avoid, its end-of-life time, but also a complete afterthought of their energy performance. That is extremely urgent to improve the overall sustainability of the construction sector that, alone, is one of the mai…

Aspetti giuridici e normativi delle aree naturali protette

2008

Cardinal invariants of cellular Lindelof spaces

2018

A space X is said to be cellular-Lindelof if for every cellular family $$\mathcal {U}$$ there is a Lindelof subspace L of X which meets every element of $$\mathcal {U}$$ . Cellular-Lindelof spaces generalize both Lindelof spaces and spaces with the countable chain condition. Solving questions of Xuan and Song, we prove that every cellular-Lindelof monotonically normal space is Lindelof and that every cellular-Lindelof space with a regular $$G_\delta $$ -diagonal has cardinality at most $$2^\mathfrak {c}$$ . We also prove that every normal cellular-Lindelof first-countable space has cardinality at most continuum under $$2^{<\mathfrak {c}}=\mathfrak {c}$$ and that every normal cellular-Lindel…